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Fernández-García M, Ares-Arroyo M, Wedel E, Montero N, Barbas C, Rey-Stolle MF, González-Zorn B, García A. Multiplatform Metabolomics Characterization Reveals Novel Metabolites and Phospholipid Compositional Rules of Haemophilus influenzae Rd KW20. Int J Mol Sci 2023; 24:11150. [PMID: 37446331 DOI: 10.3390/ijms241311150] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
Haemophilus influenzae is a gram-negative bacterium of relevant clinical interest. H. influenzae Rd KW20 was the first organism to be sequenced and for which a genome-scale metabolic model (GEM) was developed. However, current H. influenzae GEMs are unable to capture several aspects of metabolome nature related to metabolite pools. To directly and comprehensively characterize the endometabolome of H. influenzae Rd KW20, we performed a multiplatform MS-based metabolomics approach combining LC-MS, GC-MS and CE-MS. We obtained direct evidence of 15-20% of the endometabolome present in current H. influenzae GEMs and showed that polar metabolite pools are interconnected through correlating metabolite islands. Notably, we obtained high-quality evidence of 18 metabolites not previously included in H. influenzae GEMs, including the antimicrobial metabolite cyclo(Leu-Pro). Additionally, we comprehensively characterized and evaluated the quantitative composition of the phospholipidome of H. influenzae, revealing that the fatty acyl chain composition is largely independent of the lipid class, as well as that the probability distribution of phospholipids is mostly related to the conditional probability distribution of individual acyl chains. This finding enabled us to provide a rationale for the observed phospholipid profiles and estimate the abundance of low-level species, permitting the expansion of the phospholipidome characterization through predictive probabilistic modelling.
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Affiliation(s)
- Miguel Fernández-García
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
| | - Manuel Ares-Arroyo
- Antimicrobial Resistance Unit (ARU), Departamento de Sanidad Animal and Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Complutense University of Madrid, 28040 Madrid, Spain
| | - Emilia Wedel
- Antimicrobial Resistance Unit (ARU), Departamento de Sanidad Animal and Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Complutense University of Madrid, 28040 Madrid, Spain
| | - Natalia Montero
- Antimicrobial Resistance Unit (ARU), Departamento de Sanidad Animal and Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Complutense University of Madrid, 28040 Madrid, Spain
| | - Coral Barbas
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
| | - Mª Fernanda Rey-Stolle
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
| | - Bruno González-Zorn
- Antimicrobial Resistance Unit (ARU), Departamento de Sanidad Animal and Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Complutense University of Madrid, 28040 Madrid, Spain
| | - Antonia García
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
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Janoušková M, Straw ML, Su YC, Riesbeck K. Gene Expression Regulation in Airway Pathogens: Importance for Otitis Media. Front Cell Infect Microbiol 2022; 12:826018. [PMID: 35252035 PMCID: PMC8895709 DOI: 10.3389/fcimb.2022.826018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Otitis media (OM) is an inflammatory disorder in the middle ear. It is mainly caused by viruses or bacteria associated with the airways. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are the three main pathogens in infection-related OM, especially in younger children. In this review, we will focus upon the multifaceted gene regulation mechanisms that are well-orchestrated in S. pneumoniae, H. influenzae, and M. catarrhalis during the course of infection in the middle ear either in experimental OM or in clinical settings. The sophisticated findings from the past 10 years on how the othopathogens govern their virulence phenotypes for survival and host adaptation via phase variation- and quorum sensing-dependent gene regulation, will be systematically discussed. Comprehensive understanding of gene expression regulation mechanisms employed by pathogens during the onset of OM may provide new insights for the design of a new generation of antimicrobial agents in the fight against bacterial pathogens while combating the serious emergence of antimicrobial resistance.
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Abstract
Nontypeable Haemophilus influenzae (NTHi) is a leading cause of respiratory tract infections worldwide and continues to be a global health burden. Adhesion and colonization of host cells are crucial steps in bacterial pathogenesis, and in many strains of NTHi, the interaction with the host is mediated by the high molecular weight adhesins HMW1A and HMW2A. These adhesins are N-glycoproteins that are modified by cytoplasmic glycosyltransferases HMW1C and HMW2C. Phase variation in the number of short sequence repeats in the promoters of hmw1A and hmw2A directly affects their expression. Here, we report the presence of similar variable repeat elements in the promoters of hmw1C and hmw2C in diverse NTHi isolates. In an ex vivo assay, we systematically altered the substrate and glycosyltransferase expression and showed that both of these factors quantitatively affected the site-specific efficiency of glycosylation on HMW-A. This represents a novel mechanism through which phase variation can generate diversity in the quantitative extent of site-specific post-translational modifications on antigenic surface proteins. Glycosylation occupancy was incomplete at many sites, variable between sites, and generally lower close to the C-terminus of HMW-A. We investigated the causes of this variability. As HMW-C glycosylates HMW-A in the cytoplasm, we tested how secretion affected glycosylation on HMW-A and showed that retaining HMW-A in the cytoplasm indeed increased glycosylation occupancy across the full length of the protein. Site-directed mutagenesis showed that HMW-C had no inherent preference for glycosylating asparagines in NxS or NxT sequons. This work provides key insights into factors contributing to the heterogenous modifications of NTHi HMW-A adhesins, expands knowledge of NTHi population diversity and pathogenic capability, and is relevant to vaccine design for NTHi and related pathogens.
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Aziz A, Sarovich DS, Nosworthy E, Beissbarth J, Chang AB, Smith-Vaughan H, Price EP, Harris TM. Molecular Signatures of Non-typeable Haemophilus influenzae Lung Adaptation in Pediatric Chronic Lung Disease. Front Microbiol 2019; 10:1622. [PMID: 31379777 PMCID: PMC6646836 DOI: 10.3389/fmicb.2019.01622] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/01/2019] [Indexed: 12/03/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi), an opportunistic pathogen of the upper airways of healthy children, can infect the lower airways, driving chronic lung disease. However, the molecular basis underpinning NTHi transition from a commensal to a pathogen is not clearly understood. Here, we performed comparative genomic and transcriptomic analyses of 12 paired, isogenic NTHi strains, isolated from the nasopharynx (NP) and bronchoalveolar lavage (BAL) of 11 children with chronic lung disease, to identify convergent molecular signatures associated with lung adaptation. Comparative genomic analyses of the 12 NP-BAL pairs demonstrated that five were genetically identical, with the remaining seven differing by only 1 to 3 mutations. Within-patient transcriptomic analyses identified between 2 and 58 differentially expressed genes in 8 of the 12 NP-BAL pairs, including pairs with no observable genomic changes. Whilst no convergence was observed at the gene level, functional enrichment analysis revealed significant under-representation of differentially expressed genes belonging to Coenzyme metabolism, Function unknown, Translation, ribosomal structure, and biogenesis Cluster of Orthologous Groups categories. In contrast, Carbohydrate transport and metabolism, Cell motility and secretion, Intracellular trafficking and secretion, and Energy production categories were over-represented. This observed trend amongst genetically unrelated NTHi strains provides evidence of convergent transcriptional adaptation of NTHi to pediatric airways that deserves further exploration. Understanding the pathoadaptative mechanisms that NTHi employs to infect and persist in the lower pediatric airways is essential for devising targeted diagnostics and treatments aimed at minimizing disease severity, and ultimately, preventing NTHi lung infections and subsequent chronic lung disease in children.
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Affiliation(s)
- Ammar Aziz
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Derek S. Sarovich
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Elizabeth Nosworthy
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Jemima Beissbarth
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Anne B. Chang
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- Department of Respiratory and Sleep Medicine, Children’s Health Queensland, Queensland University of Technology, Brisbane, QLD, Australia
| | - Heidi Smith-Vaughan
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Erin P. Price
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Tegan M. Harris
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
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Insights into the population structure and pan-genome of Haemophilus influenzae. INFECTION GENETICS AND EVOLUTION 2018; 67:126-135. [PMID: 30391557 DOI: 10.1016/j.meegid.2018.10.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/20/2018] [Accepted: 10/30/2018] [Indexed: 12/25/2022]
Abstract
The human-restricted bacterium Haemophilus influenzae is responsible for respiratory infections in both children and adults. While colonization begins in the upper airways, it can spread throughout the respiratory tract potentially leading to invasive infections. Although the spread of H. influenzae serotype b (Hib) has been prevented by vaccination, the emergence of infections by other serotypes as well as by non-typeable isolates (NTHi) have been observed, prompting the need for novel prevention strategies. Here, we aimed to study the population structure of H. influenzae and to get some insights into its pan-genome. We studied 305H. influenzae strains, enrolling 217 publicly available genomes, as well as 88 newly sequenced H. influenzae invasive strains isolated in Portugal, spanning a 24-year period. NTHi isolates presented a core-SNP-based genetic diversity about 10-fold higher than the one observed for Hib. The analysis of key factors involved in pathogenesis, such as lipooligosaccharides, hemagglutinating pili and High Molecular Weight-adhesins, suggests that NTHi shape its virulence repertoire, either by acquisition and loss of genes or by SNP-based diversification, likely towards host immune evasion and persistence. Discreet NTHi subpopulations structures are proposed based on core-genome supported with 17 candidate genetic markers identified in the accessory genome. Additionally, this study provides two bioinformatics tools for in silico rapid identification of H. influenzae serotypes and NTHi clades previously proposed, obviating laboratory-based demanding procedures. The present study constitutes an important genomic framework that could lay way for future studies on the genetic determinants underlying invasiveness and disease and population structure of H. influenzae.
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Epigenetic Regulation Alters Biofilm Architecture and Composition in Multiple Clinical Isolates of Nontypeable Haemophilus influenzae. mBio 2018; 9:mBio.01682-18. [PMID: 30228240 PMCID: PMC6143736 DOI: 10.1128/mbio.01682-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Upper respiratory tract infections are the number one reason for a child to visit the emergency department, and otitis media (middle ear infection) ranks third overall. Biofilms contribute significantly to the chronic nature of bacterial respiratory tract infections, including otitis media, and make these diseases particularly difficult to treat. Several mucosa-associated human pathogens utilize a mechanism of rapid adaptation termed the phasevarion, or phasevariable regulon, to resist environmental and host immune pressures. In this study, we assessed the role of the phasevarion in regulation of biofilm formation by nontypeable Haemophilus influenzae (NTHI), which causes numerous respiratory tract diseases. We found that the NTHI phasevarion regulates biofilm structure and critical biofilm matrix components under disease-specific conditions. The findings of this work could be significant in the design of improved strategies against NTHI infections, as well as diseases due to other pathogens that utilize a phasevarion. Biofilms play a critical role in the colonization, persistence, and pathogenesis of many human pathogens. Multiple mucosa-associated pathogens have evolved a mechanism of rapid adaptation, termed the phasevarion, which facilitates a coordinated regulation of numerous genes throughout the bacterial genome. This epigenetic regulation occurs via phase variation of a DNA methyltransferase, Mod. The phasevarion of nontypeable Haemophilus influenzae (NTHI) significantly affects the severity of experimental otitis media and regulates several disease-related processes. However, the role of the NTHI phasevarion in biofilm formation is unclear. The present study shows that the phasevarions of multiple NTHI clinical isolates regulate in vitro biofilm formation under disease-specific microenvironmental conditions. The impact of phasevarion regulation was greatest under alkaline conditions that mimic those known to occur in the middle ear during disease. Under alkaline conditions, NTHI strains that express the ModA2 methyltransferase formed biofilms with significantly greater biomass and less distinct architecture than those formed by a ModA2-deficient population. The biofilms formed by NTHI strains that express ModA2 also contained less extracellular DNA (eDNA) and significantly less extracellular HU, a DNABII DNA-binding protein critical for biofilm structural stability. Stable biofilm structure is critical for bacterial pathogenesis and persistence in multiple experimental models of disease. These results identify a role for the phasevarion in regulation of biofilm formation, a process integral to the chronic nature of many infections. Understanding the role of the phasevarion in biofilm formation is critical to the development of prevention and treatment strategies for these chronic diseases.
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Clinical and Bacteriologic Analysis of Nontypeable Haemophilus influenzae Strains Isolated from Children with Invasive Diseases in Japan from 2008 to 2015. J Clin Microbiol 2018; 56:JCM.00141-18. [PMID: 29720429 DOI: 10.1128/jcm.00141-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/24/2018] [Indexed: 12/30/2022] Open
Abstract
Haemophilus influenzae type b (Hib) conjugate vaccines have led to dramatic reductions in Hib disease among young children worldwide. Nontypeable H. influenzae (NTHi) is now the major cause of invasive H. influenzae infections. We investigated the clinical characteristics of invasive NTHi diseases among children in Japan, to clarify the pathogenicity of isolated NTHi strains. The mortality rate was 10.7%, with deaths occurring mainly among children with underlying comorbidities. Biotypes II and III were the most common, and most strains (64.3%) had multiple amino acid substitutions at the Asp-350, Ser-357, Ser-385, and/or Met-377 sites of penicillin-binding protein 3. Two strains were β-lactamase positive and ampicillin-clavulanate resistant. Biofilm indices varied widely, and IS1016 was detected in 10.7% of the strains tested. Moreover, there was wide variation in the characteristics of invasive NTHi strains. NTHi strains, showing great genetic diversity, are responsible for most invasive H. influenzae infections in children in the postvaccine era. Continuous monitoring of NTHi strains responsible for invasive diseases in children is important to detect changes in the epidemiology of invasive H. influenzae infections in the postvaccine era.
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Adachi Y, Ando M, Morozumi M, Ubukata K, Iwata S. Genotypic characterization of Haemophilus influenzae isolates from paediatric patients in Japan. J Med Microbiol 2018; 67:695-701. [PMID: 29595417 DOI: 10.1099/jmm.0.000721] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purpose. β-lactamase-negative ampicillin-resistant (BLNAR) Haemophilus influenzae is frequently isolated from respiratory samples and is particularly problematic in Japan. The aim of this study was to characterize circulating isolates of H. influenzae genotypically by BLNAR-PCR and multilocus sequence typing (MLST), and to determine any associations between them.Methods. H. influenzae isolates (n=191) were collected from paediatric patients (1 month to 12 years old) between 2000 and 2011 for three types of infections: pneumonia (n=61), acute otitis media (AOM) (n=68) and meningitis (n=62). All were characterized for capsular type by agglutination tests, and for β-lactam resistance by real-time PCR. The sequence types (STs) determined by MLST were analysed using eburst v3.Results. Eighty-eight out of 191 (46.1 %) H. influenzae isolates were BLNAR by PCR; 37 of 61 (60.7 %) from pneumonia; 33 of 68 (48.5 %) from AOM and 18 of 62 (29.0 %) from meningitis cases. MLST identified 40 and 44 STs among isolates from pneumonia and AOM, respectively. BLNAR were found in singletons such as ST156 in pneumonia, and ST161 and ST396 in AOM. In contrast, eight STs were identified in meningitis, of which seven were genotypically closely related, while ST54 was the most frequent (62.9 %), unlike in the MLST database registrations, where ST6 predominated.Conclusion. Non-typeable H. influenzae (NTHi), mostly derived from pneumonia and AOM, were genetically diverse, in contrast to the predominance of H. influenzae type b (Hib) among meningitis cases. The associations between certain STs and β-lactam resistance among NTHi were confirmed.
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Affiliation(s)
- Yoko Adachi
- Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Mariko Ando
- Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Miyuki Morozumi
- Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kimiko Ubukata
- Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Satoshi Iwata
- Department of Infectious Diseases, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.,Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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Nejati F, Fateh A, Nojoumi SA, Rahbar M, Behrouzi A, Vaziri F, Siadat SD. MLVA typing of Haemophilus influenzae isolated from two Iranian university hospitals. IRANIAN JOURNAL OF MICROBIOLOGY 2018; 10:30-36. [PMID: 29922416 PMCID: PMC6004631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND AND OBJECTIVES Different serotypes of Haemophilus influenzae is now divided into 2 divisions: encapsulated and unencapsulated. Multiple locus variable number tandem repeat analysis (MLVA) includes such specifications as the extra power of separation, ease of data interpretation, and epidemiological data accordance, which have made it an appropriate molecular device for good typing and phylogenetic analysis of bacterial pathogens. MATERIALS AND METHODS In this research, cultured samples were studied and strains identified through biochemical tests were recognized. Moreover, DNA was extracted and studied qualitatively and quantitatively. Four pairs of specialized primers related to H. influenzae variable number tandem repeats (VNTR) and preparation of PCR were designed according to the regulated program. Also, electrophoresis of PCR products was performed. Finally, the interpretation of electrophoresis gel was done with respect to the observable bands showing the presence or absence of the required sequence in the samples related to every primer. RESULTS This study was the first MLVA typing of the unencapsulated H. influenzae in Iran. In this research, the VNTR sequences were tested in 30 strains without the unencapsulated H. influenzae. Among 30 mentioned strains, for which MLVA profile was obtained in this research, 25 different MLVA types were observed. Likewise, there was no repetition in VNTR sequences resulting from PCR in few H. influenzae. In all these cases, the number of repetitions in MLVA profile was determined as 0, except for one of the primers in 4 strains, which was 16%. However, this did not occur for the other VNTRs. CONCLUSION The highest diversity of the repeats was for VNTR5 (7 types), followed by VNTR6 with 6 types of repeats, and VNTR12-1 and VNTR12-2 with 3 different types.
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Affiliation(s)
- Faranak Nejati
- Department of Mycobacteriology & Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Abolfazl Fateh
- Department of Mycobacteriology & Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Ali Nojoumi
- Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Mohammad Rahbar
- Department of Microbiology, Reference Health Laboratories Research Center, Ministry of Health and Medical Education, Tehran, Iran
| | - Ava Behrouzi
- Department of Mycobacteriology & Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Farzam Vaziri
- Department of Mycobacteriology & Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran,Corresponding authors: Farzam Vaziri & Seyed Davar Siadat, PhD, Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran. Tel: +982166968853, Fax: +982166496721
| | - Seyed Davar Siadat
- Department of Mycobacteriology & Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran,Corresponding authors: Farzam Vaziri & Seyed Davar Siadat, PhD, Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran. Tel: +982166968853, Fax: +982166496721
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Kaneko M, Bando Y, Fujita T, Hirose Y, Suganuma E, Ishii M, Takahashi T. Encapsulated pleural effusion due to Haemophilus influenzae biotype II in a child with trisomy 21: A case report and literature review. IDCases 2017; 10:93-96. [PMID: 29062709 PMCID: PMC5645171 DOI: 10.1016/j.idcr.2017.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/23/2017] [Accepted: 09/25/2017] [Indexed: 11/19/2022] Open
Abstract
This is the second case report of pediatric encapsulated pleural effusion (EPE) due to Haemophilus influenzae. We represent typical images of chest X-P, CT, echography to find the EPE. Nontypeable H. influenzae was isolated from the throat after the discharge.
Haemophilus influenzae (Hi) can colonize in the upper respiratory tract and cause severe pulmonary infections, especially among immunocompromised children. Herein, we report a case of left encapsulated pleural effusion (EPE) due to Hi in a 24-month-old girl with trisomy 21. She was already vaccinated against Hi type b. The Hi biotype II was isolated from both the blood and aspirated sputum obtained upon admission. Ampicillin/sulbactam 180 mg/kg/day was administered intravenously for 34 days with oxygen supplementation for 4 days. She clinically recovered without undergoing thoracic drainage. One month after discharge, the girl developed acute otitis media, and the throat swab was cultured. Nontypeable Hi with the same biotype II was isolated, and the infection was controlled by administering antimicrobials. In this report, a literature review regarding the EPE due to Hi in children is also summarized. Pediatric clinicians should be aware of the possibility of Hi-related EPE because of its rapid progression, although it is rare in clinical settings. In addition, they need to consider the possibility of repetitive respiratory infections with Hi in a child with trisomy 21.
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Affiliation(s)
- Masanori Kaneko
- Department of Pediatrics, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama 364-8501, Japan
| | - Yuki Bando
- Department of Pediatrics, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama 364-8501, Japan
- Department of Infection Control and Prevention, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama 364-8501, Japan
- Corresponding author at: Department of Pediatrics, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama 364-8501, Japan.Department of PediatricsKitasato University Medical Center6-100 AraiKitamotoSaitama364-8501Japan
| | - Tomohiro Fujita
- Department of Clinical Laboratory, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama 364-8501, Japan
| | - Yoneji Hirose
- Department of Clinical Laboratory, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama 364-8501, Japan
| | - Eisuke Suganuma
- Division of Infectious Diseases and Immunology, Saitama Children’s Medical Center, 1-2 Shintoshin, Chuuou-ku, Saitama, Saitama 330-8777, Japan
| | - Masahiro Ishii
- Department of Pediatrics, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan
| | - Takashi Takahashi
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences & Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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Ahearn CP, Gallo MC, Murphy TF. Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease. Pathog Dis 2017; 75:3753446. [PMID: 28449098 PMCID: PMC5437125 DOI: 10.1093/femspd/ftx042] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/28/2017] [Indexed: 12/21/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) is the most common bacterial cause of infection of the lower airways in adults with chronic obstructive pulmonary disease (COPD). Infection of the COPD airways causes acute exacerbations, resulting in substantial morbidity and mortality. NTHi has evolved multiple mechanisms to establish infection in the hostile environment of the COPD airways, allowing the pathogen to persist in the airways for months to years. Persistent infection of the COPD airways contributes to chronic airway inflammation that increases symptoms and accelerates the progressive loss of pulmonary function, which is a hallmark of the disease. Persistence mechanisms of NTHi include the expression of multiple redundant adhesins that mediate binding to host cellular and extracellular matrix components. NTHi evades host immune recognition and clearance by invading host epithelial cells, forming biofilms, altering gene expression and displaying surface antigenic variation. NTHi also binds host serum factors that confer serum resistance. Here we discuss the burden of COPD and the role of NTHi infections in the course of the disease. We provide an overview of NTHi mechanisms of persistence that allow the pathogen to establish a niche in the hostile COPD airways.
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Affiliation(s)
- Christian P. Ahearn
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Mary C. Gallo
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Timothy F. Murphy
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Division of Infectious Disease, Department of Medicine, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
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Kappler U, Dhouib R, Nair RP, McEwan AG. Draft Genome Sequences of Three Nontypeable Strains of Haemophilus influenzae, C188, R535, and 1200, Isolated from Different Types of Disease. GENOME ANNOUNCEMENTS 2017; 5:e00035-17. [PMID: 28336588 PMCID: PMC5364213 DOI: 10.1128/genomea.00035-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 01/12/2017] [Indexed: 11/20/2022]
Abstract
Nontypeable Haemophilus influenzae is a persistent human respiratory pathogen known to be involved in a range of acute and chronic respiratory diseases. Here, we report the genome sequences of three H. influenzae strains isolated from sputum, otitis media, and blood. Comparative analyses revealed significant differences in the gene contents including the presence of genes mediating antibiotic resistance.
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Affiliation(s)
- Ulrike Kappler
- School of Chemistry & Molecular Biosciences, Australian Infectious Diseases Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Rabeb Dhouib
- School of Chemistry & Molecular Biosciences, Australian Infectious Diseases Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Remya Purushothaman Nair
- School of Chemistry & Molecular Biosciences, Australian Infectious Diseases Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Alastair G McEwan
- School of Chemistry & Molecular Biosciences, Australian Infectious Diseases Centre, The University of Queensland, St. Lucia, Queensland, Australia
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13
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Lichtenegger S, Bina I, Durakovic S, Glaser P, Tutz S, Schild S, Reidl J. Serum resistance and phase variation of a nasopharyngeal non-typeable Haemophilus influenzae isolate. Int J Med Microbiol 2017; 307:139-146. [PMID: 28179078 DOI: 10.1016/j.ijmm.2017.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 11/28/2022] Open
Abstract
Haemophilus influenzae harbours a complex array of factors to resist human complement attack. As non-typeable H. influenzae (NTHi) strains do not possess a capsule, their serum resistance mainly depends on other mechanisms including LOS decoration. In this report, we describe the identification of a highly serum resistant, nasopharyngeal isolate (NTHi23) by screening a collection of 77 clinical isolates. For NTHi23, we defined the MLST sequence type 1133, which matches the profile of a previously published invasive NTHi isolate. A detailed genetic analysis revealed that NTHi23 shares several complement evading mechanisms with invasive disease isolates. These mechanisms include the functional expression of a retrograde phospholipid trafficking system and the presumable decoration of the LOS structure with sialic acid. By screening the NTHi23 population for spontaneous decreased serum resistance, we identified a clone, which was about 103-fold more sensitive to complement-mediated killing. Genome-wide analysis of this isolate revealed a phase variation in the N'-terminal region of lpsA, leading to a truncated version of the glycosyltransferase (LpsA). We further showed that a NTHi23 lpsA mutant exhibits a decreased invasion rate into human alveolar basal epithelial cells. Since only a small proportion of the NTHi23 population expressed the serum sensitive phenotype, resulting from lpsA phase-off, we conclude that the nasopharyngeal environment selected for a population expressing the intact and functional glycosyltransferase.
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Affiliation(s)
- Sabine Lichtenegger
- Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50, 8010 Graz, Austria; Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Neue Stiftingtalstraße 2, 8010 Graz, Austria.
| | - Isabelle Bina
- Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50, 8010 Graz, Austria
| | - Sanel Durakovic
- Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50, 8010 Graz, Austria
| | - Philippe Glaser
- Insitut Pasteur, 25-28 rue du docteur Roux, 75015 Paris, France
| | - Sarah Tutz
- Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50, 8010 Graz, Austria; BioTechMed-Graz, Austria
| | - Joachim Reidl
- Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50, 8010 Graz, Austria; BioTechMed-Graz, Austria.
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14
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Månsson V, Skaare D, Riesbeck K, Resman F. The spread and clinical impact of ST14CC-PBP3 type IIb/A, a clonal group of non-typeable Haemophilus influenzae with chromosomally mediated β-lactam resistance-a prospective observational study. Clin Microbiol Infect 2016; 23:209.e1-209.e7. [PMID: 27852000 DOI: 10.1016/j.cmi.2016.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/02/2016] [Accepted: 11/04/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Increasing incidences of non-typeable Haemophilus influenzae (NTHi) with β-lactam resistance mediated through mutations in penicillin-binding protein 3 (BLNAR or rPBP3) have been observed in the past decades. Recently, an rPBP3 NTHi sequence type (ST) 14 with PBP3 type IIb/A caused a disease outbreak in a nursing home in Sweden with severe outcomes, indicating increased bacterial virulence. In this prospective observational study, the epidemiology and clinical significance of the corresponding clonal group (ST14CC-PBP3IIb/A) in Skåne, Sweden was investigated. METHODS ST14CC-PBP3IIb/A isolates were identified through partial multilocus sequence typing and ftsI(PBP3 gene)-sequencing of prospectively collected H. influenzae from patients with respiratory tract or invasive infections (n=3262) in 2010-2012. Data on type of infection, hospitalization and outcomes were analysed, and the geographical distribution of isolates from different groups was investigated. RESULTS Isolates belonging to ST14CC-PBP3IIb/A constituted 26% (n=94/360) of respiratory tract rPBP3 NTHi. From mapping of patient addresses, a dynamic geographical spread was apparent during the study period. Furthermore, patients with infections by ST14CC-PBP3IIb/A isolates had higher hospitalization rates compared with patients infected with other rPBP3 NTHi (14/83 versus 21/255, p 0.025) and to a group of patients infected with susceptible NTHi (14/83 versus 13/191, p 0.010). ST14CC-PBP3IIb/A isolates constituted 25% (n=2/8) of invasive rPBP3 NTHi during the study period. CONCLUSIONS Our investigation suggests that the ST14CC-PBP3IIb/A clonal group is associated with increased clinical virulence, resistance to several antimicrobial agents, and is persistent over time. We conclude that virulence varies between different NTHi, and that NTHi disease may be more dependent on bacterial factors than previously recognized.
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Affiliation(s)
- V Månsson
- Riesbeck Laboratory, Clinical Microbiology, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - D Skaare
- Department of Microbiology, Vestfold Hospital Trust, Tønsberg, Norway
| | - K Riesbeck
- Riesbeck Laboratory, Clinical Microbiology, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - F Resman
- Riesbeck Laboratory, Clinical Microbiology, Department of Translational Medicine, Lund University, Malmö, Sweden.
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15
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Wong SM, Shaughnessy J, Ram S, Akerley BJ. Defining the Binding Region in Factor H to Develop a Therapeutic Factor H-Fc Fusion Protein against Non-Typeable Haemophilus influenzae. Front Cell Infect Microbiol 2016; 6:40. [PMID: 27148489 PMCID: PMC4829610 DOI: 10.3389/fcimb.2016.00040] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 03/21/2016] [Indexed: 11/13/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) cause a range of illnesses including otitis media, sinusitis, and exacerbation of chronic obstructive pulmonary disease, infections that contribute to the problem of antibiotic resistance and are themselves often intractable to standard antibiotic treatment regimens. We investigated a strategy to exploit binding of the complement inhibitor Factor H (FH) to NTHi as a functional target for an immunotherapeutic containing the NTHi binding domain of FH fused to the Fc domain of IgG1. Chimeric proteins containing the regions that most FH-binding bacteria use to engage human FH, domains 6 and 7 (FH6,7/Fc) and/or 18 through 20 (FH18-20/Fc), were evaluated for binding to NTHi. FH6,7/Fc bound strongly to each of seven NTHi clinical isolates tested and efficiently promoted complement-mediated killing by normal human serum. FH18-20/Fc bound weakly to three of the strains but did not promote complement dependent killing. Outer-membrane protein P5 has been implicated in FH binding by NTHi, and FH6,7/Fc binding was greatly diminished in five of seven P5 deficient isogenic mutant strains tested, implicating an alternative FH binding protein in some strains. Binding of FH18-20/Fc was decreased in the P5 mutant of one strain. A murine model was used to evaluate potential therapeutic application of FH6,7/Fc. FH6,7/Fc efficiently promoted binding of C3 to NTHi exposed to mouse serum, and intranasal delivery of FH6,7/Fc resulted in significantly enhanced clearance of NTHi from the lung. Moreover, a P5 deficient mutant was attenuated for survival in the lung model, suggesting that escape mutants lacking P5 would be less likely to replace strains susceptible to FH6,7/Fc. These results provide evidence for the potential utility of FH6,7/Fc as a therapeutic against NTHi lung infection. FH binding is a common property of many respiratory tract pathogens and FH/Fc chimeras may represent promising alternative or adjunctive therapeutics against such infections, which are often polymicrobial.
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Affiliation(s)
- Sandy M Wong
- Department of Microbiology and Immunology, University of Mississippi Medical Center Jackson, MS, USA
| | - Jutamas Shaughnessy
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School Worcester, MA, USA
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School Worcester, MA, USA
| | - Brian J Akerley
- Department of Microbiology and Immunology, University of Mississippi Medical Center Jackson, MS, USA
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16
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Kress-Bennett JM, Hiller NL, Eutsey RA, Powell E, Longwell MJ, Hillman T, Blackwell T, Byers B, Mell JC, Post JC, Hu FZ, Ehrlich GD, Janto BA. Identification and Characterization of msf, a Novel Virulence Factor in Haemophilus influenzae. PLoS One 2016; 11:e0149891. [PMID: 26977929 PMCID: PMC4792463 DOI: 10.1371/journal.pone.0149891] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 02/05/2016] [Indexed: 12/11/2022] Open
Abstract
Haemophilus influenzae is an opportunistic pathogen. The emergence of virulent, non-typeable strains (NTHi) emphasizes the importance of developing new interventional targets. We screened the NTHi supragenome for genes encoding surface-exposed proteins suggestive of immune evasion, identifying a large family containing Sel1-like repeats (SLRs). Clustering identified ten SLR-containing gene subfamilies, each with various numbers of SLRs per gene. Individual strains also had varying numbers of SLR-containing genes from one or more of the subfamilies. Statistical genetic analyses of gene possession among 210 NTHi strains typed as either disease or carriage found a significant association between possession of the SlrVA subfamily (which we have termed, macrophage survival factor, msf) and the disease isolates. The PittII strain contains four chromosomally contiguous msf genes. Deleting all four of these genes (msfA1-4) (KO) resulted in a highly significant decrease in phagocytosis and survival in macrophages; which was fully complemented by a single copy of the msfA1 gene. Using the chinchilla model of otitis media and invasive disease, the KO strain displayed a significant decrease in fitness compared to the WT in co-infections; and in single infections, the KO lost its ability to invade the brain. The singly complemented strain showed only a partial ability to compete with the WT suggesting gene dosage is important in vivo. The transcriptional profiles of the KO and WT in planktonic growth were compared using the NTHi supragenome array, which revealed highly significant changes in the expression of operons involved in virulence and anaerobiosis. These findings demonstrate that the msfA1-4 genes are virulence factors for phagocytosis, persistence, and trafficking to non-mucosal sites.
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Affiliation(s)
- Jennifer M. Kress-Bennett
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - N. Luisa Hiller
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Rory A. Eutsey
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Evan Powell
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Mark J. Longwell
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Todd Hillman
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Tenisha Blackwell
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Barbara Byers
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Joshua C. Mell
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - J. Christopher Post
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Otolaryngology, Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, Pennsylvania, United States of America
| | - Fen Z. Hu
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Otolaryngology, Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, Pennsylvania, United States of America
| | - Garth D. Ehrlich
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Otolaryngology, Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, Pennsylvania, United States of America
| | - Benjamin A. Janto
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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17
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Tikhomirova A, Jiang D, Kidd SP. A new insight into the role of intracellular nickel levels for the stress response, surface properties and twitching motility by Haemophilus influenzae. Metallomics 2016; 7:650-61. [PMID: 25350148 DOI: 10.1039/c4mt00245h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nickel acts as a co-factor for a small number of enzymes in bacteria. Urease is one of the two nickel-dependent enzymes that have been identified in Haemophilus influenzae; glyoxalase I is the other. However, nickel has been suggested to have roles in H. influenzae that can not attributed to the function of these enzymes. We have previously shown that in the H. influenzae strain Rd KW20 the inability to acquire nickel led to alterations to the cell-type; an increased biofilm formation and changes in cell surface properties. Here we report the differences in the genome wide gene expression between Rd KW20 and a strain incapable of importing nickel (nikQ); revealing a link between intracellular nickel levels and genes involved in metabolic pathways, stress responses and genes associated with surface factors such as type IV pili. We have then taken a strain previously shown to use type IV pili both in biofilm formation and for twitching motility (86-028NP) and have shown its homologous genes (NTHI1417-1422; annotated as cobalt transporter, cbiKLMOQ) did import nickel and mutations in this locus had pleiotropic effects correlating to stress response and motility. Compared to wild type cells, the nickel depleted cells were more electronegativity charged, they aggregated and formed a biofilm. Correct intracellular nickel levels were also important for resistance to oxidative stress; the nickel depleted cells were more sensitive to oxidative stress. The nickel depleted cells were also non-motile, but the addition specifically of nickel returned these cells to a wild type motility state. We have also analysed the role of nickel uptake in a naturally, urease negative strain (the blood isolate R2866) and depleting intracellular nickel (a nikQ mutant) in this strain effected a similar range of cell functions. These data reveal a role for the capacity to acquire nickel from the environment and for the correct intracellular nickel levels as part of H. influenzae stress response and in signalling for a switch to a sessile bacterial lifestyle.
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Affiliation(s)
- Alexandra Tikhomirova
- Research Centre for Infectious Disease, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, 5005, Australia.
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18
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VanWagoner TM, Atack JM, Nelson KL, Smith HK, Fox KL, Jennings MP, Stull TL, Smith AL. The modA10 phasevarion of nontypeable Haemophilus influenzae R2866 regulates multiple virulence-associated traits. Microb Pathog 2015; 92:60-67. [PMID: 26718097 DOI: 10.1016/j.micpath.2015.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/10/2015] [Accepted: 12/18/2015] [Indexed: 12/28/2022]
Abstract
Non-typeable Haemophilus influenzae (NTHi) is a human restricted commensal and pathogen that elicits inflammation by adhering to and invading airway epithelia cells: transcytosis across these cells can result in systemic infection. NTHi strain R2866 was isolated from the blood of a normal 30-month old infant with meningitis, and is unusual for NTHi in that it is able to cause systemic infection. Strain R2866 is able to replicate in normal human serum due to expression of lgtC which mimics human blood group p(k). R2866 contains a phase-variable DNA methyltransferase, modA10 which switches ON and OFF randomly and reversibly due to polymerase slippage over a long tetrameric repeat tract located in its open reading frame. Random gain or loss of repeats during replication can results in expressed (ON), or not expressed (OFF) states, the latter due to a frameshift or transcriptional termination at a premature stop codon. We sought to determine if the unusual virulence of R2866 was modified by modA10 phase-variation. A modA10 knockout mutant was found to have increased adherence to, and invasion of, human ear and airway monolayers in culture, and increased invasion and transcytosis of polarized human bronchial epithelial cells. Intriguingly, the rate of bacteremia was lower in the infant rat model of infection than a wild-type R2866 strain, but the fatality rate was greater. Transcriptional analysis comparing the modA10 knockout to the R2866 wild-type parent strain showed increased expression of genes in the modA10 knockout whose products mediate cellular adherence. We conclude that loss of ModA10 function in strain R2866 enhances colonization and invasion by increasing expression of genes that allow for increased adherence, which can contribute to the increased virulence of this strain.
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Affiliation(s)
- Timothy M VanWagoner
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, 73104, OK, USA
| | - John M Atack
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Kevin L Nelson
- Center for Global Infectious Disease Research, Seattle Children's Hospital, Seattle, WA, 98105, USA
| | - Hannah K Smith
- Center for Global Infectious Disease Research, Seattle Children's Hospital, Seattle, WA, 98105, USA
| | - Kate L Fox
- School of Chemical and Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland, 4072, Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Terrence L Stull
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, 73104, OK, USA
| | - Arnold L Smith
- Center for Global Infectious Disease Research, Seattle Children's Hospital, Seattle, WA, 98105, USA.
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19
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Jiang D, Tikhomirova A, Bent SJ, Kidd SP. A discrete role for FNR in the transcriptional response to moderate changes in oxygen by Haemophilus influenzae Rd KW20. Res Microbiol 2015; 167:103-13. [PMID: 26499095 DOI: 10.1016/j.resmic.2015.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/21/2015] [Accepted: 09/29/2015] [Indexed: 11/28/2022]
Abstract
The survival by pathogenic bacteria within the specific conditions of an anatomical niche is critical for their persistence. These conditions include the combination of toxic chemicals, such as reactive oxygen (ROS) and reactive nitrogen species (RNS), with factors relevant to cell growth, such as oxygen. Haemophilus influenzae senses oxygen levels largely through the redox state of the intracellular fumarate-nitrate global regulator (FNR). H. influenzae certainly encounters oxygen levels that fluctuate, but in reality, these would rarely reach a state that results in FNR being fully reduced or oxidized. We were therefore interested in the response of H. influenzae to ROS and RNS at moderately high or low oxygen levels and the corresponding role of FNR. At these levels of oxygen, even though the growth rate of an H. influenzae fnr mutant was similar to wild type, its ROS and RNS tolerance was significantly different. Additionally, the subtle changes in oxygen did alter the whole cell transcriptional profile and this was different between the wild type and fnr mutant strains. It was the changed whole cell profile that impacted on ROS/RNS defence, but surprisingly, the FNR-regulated, anaerobic nitrite reductase (NrfA) continued to be expressed and had a role in this phenotype.
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Affiliation(s)
- Donald Jiang
- Research Centre for Infectious Disease, The University of Adelaide, Adelaide, Australia; School of Biological Science, The University of Adelaide, Adelaide, Australia; Agri-Food and Veterinary Authority of Singapore, Singapore.
| | - Alexandra Tikhomirova
- Research Centre for Infectious Disease, The University of Adelaide, Adelaide, Australia; School of Biological Science, The University of Adelaide, Adelaide, Australia.
| | - Stephen J Bent
- School of Biological Science, The University of Adelaide, Adelaide, Australia; Robinson Research Institute, The University of Adelaide, Adelaide, Australia.
| | - Stephen P Kidd
- Research Centre for Infectious Disease, The University of Adelaide, Adelaide, Australia; School of Biological Science, The University of Adelaide, Adelaide, Australia.
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20
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Development and validation of an Haemophilus influenzae supragenome hybridization (SGH) array for transcriptomic analyses. PLoS One 2014; 9:e105493. [PMID: 25290153 PMCID: PMC4188559 DOI: 10.1371/journal.pone.0105493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 07/23/2014] [Indexed: 01/04/2023] Open
Abstract
We previously carried out the design and testing of a custom-built Haemophilus influenzae supragenome hybridization (SGH) array that contains probe sequences to 2,890 gene clusters identified by whole genome sequencing of 24 strains of H. influenzae. The array was originally designed as a tool to interrogate the gene content of large numbers of clinical isolates without the need for sequencing, however, the data obtained is quantitative and is thus suitable for transcriptomic analyses. In the current study RNA was extracted from H. influenzae strain CZ4126/02 (which was not included in the design of the array) converted to cDNA, and labelled and hybridized to the SGH arrays to assess the quality and reproducibility of data obtained from these custom-designed chips to serve as a tool for transcriptomics. Three types of experimental replicates were analyzed with all showing very high degrees of correlation, thus validating both the array and the methods used for RNA profiling. A custom filtering pipeline for two-condition unpaired data using five metrics was developed to minimize variability within replicates and to maximize the identification of the most significant true transcriptional differences between two samples. These methods can be extended to transcriptional analysis of other bacterial species utilizing supragenome-based arrays.
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21
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Davis GS, Patel M, Hammond J, Zhang L, Dawid S, Marrs CF, Gilsdorf JR. Prevalence, distribution, and sequence diversity of hmwA among commensal and otitis media non-typeable Haemophilus influenzae. INFECTION GENETICS AND EVOLUTION 2014; 28:223-32. [PMID: 25290952 DOI: 10.1016/j.meegid.2014.09.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 09/25/2014] [Accepted: 09/27/2014] [Indexed: 12/18/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) are Gram-negative coccobacilli that colonize the human pharynx, their only known natural reservoir. Adherence to the host epithelium facilitates NTHi colonization and marks one of the first steps in NTHi pathogenesis. Epithelial cell attachment is mediated, in part, by a pair of high molecular weight (HMW) adhesins that are highly immunogenic, antigenically diverse, and display a wide range of amino acid diversity both within and between isolates. In this study, the prevalence of hmwA, which encodes the HMW adhesin, was determined for a collection of 170 NTHi isolates recovered from the middle ears of children with otitis media (OM isolates) or throats or nasopharynges of healthy children (commensal isolates) from Finland, Israel, and the U.S. Overall, hmwA was detected in 61% of NTHi isolates and was significantly more prevalent (P=0.004) among OM isolates than among commensal isolates; the prevalence ratio comparing hmwA prevalence among ear isolates with that of commensal isolates was 1.47 (95% CI (1.12, 1.92)). Ninety-five percent (98/103) of the hmwA-positive NTHi isolates possessed two hmw loci. To advance our understanding of hmwA binding sequence diversity, we determined the DNA sequence of the hmwA binding region of 33 isolates from this collection. The average amino acid identity across all hmwA sequences was 62%. Phylogenetic analyses of the hmwA binding revealed four distinct sequence clusters, and the majority of hmwA sequences (83%) belonged to one of two dominant sequence clusters. hmwA sequences did not cluster by chromosomal location, geographic region, or disease status.
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Affiliation(s)
- Gregg S Davis
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - May Patel
- Department of Pediatrics, University of Michigan Medical School, D5101 Medical Professional Building, Ann Arbor, MI 48109-5718, USA.
| | - James Hammond
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - Lixin Zhang
- Department of Epidemiology and Biostatistics, Michigan State University, 909 Fee Road Room B601, East Lansing, MI 48824, USA..
| | - Suzanne Dawid
- Department of Pediatrics, University of Michigan Medical School, D5101 Medical Professional Building, Ann Arbor, MI 48109-5718, USA; Department of Microbiology and Immunology, University of Michigan Medical School, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Carl F Marrs
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - Janet R Gilsdorf
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA; Department of Pediatrics, University of Michigan Medical School, D5101 Medical Professional Building, Ann Arbor, MI 48109-5718, USA.
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22
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Ishiwada N, Hishiki H, Nagasawa K, Naito S, Sato Y, Chang B, Sasaki Y, Kimura K, Ohnishi M, Shibayama K. The incidence of pediatric invasive Haemophilus influenzae and pneumococcal disease in Chiba prefecture, Japan before and after the introduction of conjugate vaccines. Vaccine 2014; 32:5425-31. [PMID: 25131741 DOI: 10.1016/j.vaccine.2014.07.100] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/18/2014] [Accepted: 07/30/2014] [Indexed: 10/24/2022]
Abstract
The Haemophilus influenzae type b (Hib) vaccine and the heptavalent pneumococcal conjugate vaccine (PCV7) were introduced in Japan in 2008 and 2010, respectively. In 2011, immunization with these two vaccines was encouraged throughout Japan through a governmental program. Children treated in Chiba prefecture for culture-proven invasive H. influenzae disease (IHiD) and invasive Streptococcus pneumoniae disease (IPD) were identified in a prefectural surveillance study from 2008 to 2013. The incidence rate ratio (IRR) and its confidence interval (CI) were calculated to compare the 3 years before and after governmental financial support for vaccination. The average number of IHiD and IPD cases among children <5 years of age in 2011-2013 decreased 84% (IRR: 0.16, 95% CI: 0.09-0.26, p<0.0001) and 51% (IRR: 0.49, 95% CI: 0.37-0.63, p<0.0001) compared with those occurring in 2008-2010. The most common non-PCV7 serotype encountered in 2011 and 2013 was 19A. After governmental subsidization of Hib and PCV7 vaccination, IHiD and IPD decreased in Chiba prefecture, Japan. Continuous surveillance is necessary to determine the effectiveness of these two vaccines and for detection of emerging invasive serotypes.
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Affiliation(s)
- Naruhiko Ishiwada
- Division of Control and Treatment of Infectious Diseases, Chiba University Hospital, Chiba, Japan.
| | - Haruka Hishiki
- Department of Pediatrics, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Koo Nagasawa
- Department of Pediatrics, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Sachiko Naito
- Department of Pediatrics, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yasunori Sato
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Bin Chang
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yuko Sasaki
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kouji Kimura
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Keigo Shibayama
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
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Davis GS, Marino S, Marrs CF, Gilsdorf JR, Dawid S, Kirschner DE. Phase variation and host immunity against high molecular weight (HMW) adhesins shape population dynamics of nontypeable Haemophilus influenzae within human hosts. J Theor Biol 2014; 355:208-18. [PMID: 24747580 DOI: 10.1016/j.jtbi.2014.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 03/21/2014] [Accepted: 04/04/2014] [Indexed: 12/16/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a bacterium that resides within the human pharynx. Because NTHi is human-restricted, its long-term survival is dependent upon its ability to successfully colonize new hosts. Adherence to host epithelium, mediated by bacterial adhesins, is one of the first steps in NTHi colonization. NTHi express several adhesins, including the high molecular weight (HMW) adhesins that mediate attachment to the respiratory epithelium where they interact with the host immune system to elicit a strong humoral response. hmwA, which encodes the HMW adhesin, undergoes phase variation mediated by 7-base pair tandem repeats located within its promoter region. Repeat number affects both hmwA transcription and HMW-adhesin production such that as the number of repeats increases, adhesin production decreases. Cells expressing large amounts of HMW adhesins may be critical for the establishment and maintenance of NTHi colonization, but they might also incur greater fitness costs when faced with an adhesin-specific antibody-mediated immune response. We hypothesized that the occurrence of large deletion events within the hmwA repeat region allows NTHi cells to maintain adherence in the presence of antibody-mediated immunity. To study this, we developed a mathematical model, incorporating hmwA phase variation and antibody-mediated immunity, to explore the trade-off between bacterial adherence and immune evasion. The model predicts that antibody levels and avidity, catastrophic loss rates, and population carrying capacity all significantly affected numbers of adherent NTHi cells within a host. These results suggest that the occurrence of large, yet rare, deletion events allows for stable maintenance of a small population of adherent cells in spite of HMW adhesin specific antibody-mediated immunity. These adherent subpopulations may be important for sustaining colonization and/or maintaining transmission.
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Affiliation(s)
- Gregg S Davis
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - Simeone Marino
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Med Sci II SPC 5620, Ann Arbor, MI 48109, USA.
| | - Carl F Marrs
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - Janet R Gilsdorf
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA; Department of Pediatrics, University of Michigan Medical School, L2225 Women׳s Hospital, Ann Arbor, MI 48109, USA.
| | - Suzanne Dawid
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Med Sci II SPC 5620, Ann Arbor, MI 48109, USA; UMHS Pediatric Infectious Diseases, University of Michigan Health System, D5101 MPB, Ann Arbor, MI 48109, USA.
| | - Denise E Kirschner
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Med Sci II SPC 5620, Ann Arbor, MI 48109, USA.
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Ishak N, Tikhomirova A, Bent SJ, Ehrlich GD, Hu FZ, Kidd SP. There is a specific response to pH by isolates of Haemophilus influenzae and this has a direct influence on biofilm formation. BMC Microbiol 2014; 14:47. [PMID: 24555828 PMCID: PMC3938079 DOI: 10.1186/1471-2180-14-47] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 02/19/2014] [Indexed: 12/22/2022] Open
Abstract
Background Haemophilus influenzae colonizes the nasopharynx as a commensal. Strain-specific factors allow some strains to migrate to particular anatomical niches, such as the middle ear, bronchi or blood, and induce disease by surviving within the conditions present at these sites in the body. It is established that H. influenzae colonization and in some cases survival is highly dependent on their ability to form a biofilm. Biofilm formation is a key trait in the development of chronic infection by certain isolates. This is exemplified by the contrast between the biofilm-forming strains found in middle ear infections and those isolates that survive within the blood and are rarely associated with biofilm development. Results Screening a group of H. influenzae strains revealed only slight variations in their growth across a range of pH conditions. However, some isolates responded to a pH of 8.0 by the formation of a biofilm. While the type b capsular blood isolate Eagan did not form a biofilm and grew at the same rate regardless of pH 6.8-8.0, transcriptomic analyses demonstrated that at pH 8.0 it uniquely induced a gluconate-uptake and metabolism pathway, which concurrently imports H+. A non-typeable H. influenzae, isolated from the middle ear, induced biofilm formation at pH 8.0, and at this pH it induced a series of iron acquisition genes, consistent with previous studies linking iron homeostasis to biofilm lifestyle. Conclusions Different strains of H. influenzae cope with changes in environmental factors using strain-specific mechanisms. These pathways define the scope and mode of niche-survival for an isolate. The pH is a property that is different from the middle ear (at least pH 8.0) compared to other sites that H. influenzae can colonize and infect. The transcriptional response to increasing pH by H. influenzae varies between strains, and pH is linked to pathways that allow strains to either continue free-living growth or induction of a biofilm. We showed that a biofilm-forming isolate induced iron metabolism pathways, whereas a strain that does not form biofilm at increasing pH induced mechanisms for growth and pH homeostasis based on sugar acid transport.
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Affiliation(s)
| | | | | | | | | | - Stephen P Kidd
- Research Centre for Infectious Diseases, The University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia.
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A PCR-high-resolution melt assay for rapid differentiation of nontypeable Haemophilus influenzae and Haemophilus haemolyticus. J Clin Microbiol 2013; 52:663-7. [PMID: 24478508 DOI: 10.1128/jcm.02191-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have developed a PCR-high-resolution melt (PCR-HRM) assay to discriminate nontypeable Haemophilus influenzae (NTHi) colonies from Haemophilus haemolyticus. This method is rapid and robust, with 96% sensitivity and 92% specificity compared to the hpd#3 assay. PCR-HRM is ideal for high-throughput screening for NTHi surveillance and clinical trials.
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26
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Eutsey RA, Hiller NL, Earl JP, Janto BA, Dahlgren ME, Ahmed A, Powell E, Schultz MP, Gilsdorf JR, Zhang L, Smith A, Murphy TF, Sethi S, Shen K, Post JC, Hu FZ, Ehrlich GD. Design and validation of a supragenome array for determination of the genomic content of Haemophilus influenzae isolates. BMC Genomics 2013; 14:484. [PMID: 23865594 PMCID: PMC3723446 DOI: 10.1186/1471-2164-14-484] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 07/10/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Haemophilus influenzae colonizes the human nasopharynx as a commensal, and is etiologically associated with numerous opportunistic infections of the airway; it is also less commonly associated with invasive disease. Clinical isolates of H. influenzae display extensive genomic diversity and plasticity. The development of strategies to successfully prevent, diagnose and treat H. influenzae infections depends on tools to ascertain the gene content of individual isolates. RESULTS We describe and validate a Haemophilus influenzae supragenome hybridization (SGH) array that can be used to characterize the full genic complement of any strain within the species, as well as strains from several highly related species. The array contains 31,307 probes that collectively cover essentially all alleles of the 2890 gene clusters identified from the whole genome sequencing of 24 clinical H. influenzae strains. The finite supragenome model predicts that these data include greater than 85% of all non-rare genes (where rare genes are defined as those present in less than 10% of sequenced strains). The veracity of the array was tested by comparing the whole genome sequences of eight strains with their hybridization data obtained using the supragenome array. The array predictions were correct and reproducible for ~ 98% of the gene content of all of the sequenced strains. This technology was then applied to an investigation of the gene content of 193 geographically and clinically diverse H. influenzae clinical strains. These strains came from multiple locations from five different continents and Papua New Guinea and include isolates from: the middle ears of persons with otitis media and otorrhea; lung aspirates and sputum samples from pneumonia and COPD patients, blood specimens from patients with sepsis; cerebrospinal fluid from patients with meningitis, as well as from pharyngeal specimens from healthy persons. CONCLUSIONS These analyses provided the most comprehensive and detailed genomic/phylogenetic look at this species to date, and identified a subset of highly divergent strains that form a separate lineage within the species. This array provides a cost-effective and high-throughput tool to determine the gene content of any H. influenzae isolate or lineage. Furthermore, the method for probe selection can be applied to any species, given a group of available whole genome sequences.
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Affiliation(s)
- Rory A Eutsey
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
| | - N Luisa Hiller
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Joshua P Earl
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
| | - Benjamin A Janto
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
| | - Margaret E Dahlgren
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
| | - Azad Ahmed
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
| | - Evan Powell
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
| | - Matthew P Schultz
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
| | - Janet R Gilsdorf
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MC, USA
- Department of Pediatrics and Communicable Diseases, University of Michigan School of Public Health, Ann Arbor, MC, USA
| | - Lixin Zhang
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MC, USA
| | - Arnold Smith
- Center for Childhood Infections, Seattle Children’s Hospital Research Institute, Seattle, WA, USA
| | - Timothy F Murphy
- Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Sanjay Sethi
- Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Kai Shen
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
- Department of Otolaryngology Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
| | - J Christopher Post
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
- Department of Otolaryngology Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
| | - Fen Z Hu
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
- Department of Otolaryngology Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
| | - Garth D Ehrlich
- Center for Genomic Sciences, Allegheny Singer Research Institute, Allegheny General Hospital, 320 East North Avenue, 11th Floor, South Tower, Pittsburgh, PA 15212, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
- Department of Otolaryngology Head and Neck Surgery, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA, USA
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Ng J, Kidd SP. The concentration of intracellular nickel in Haemophilus influenzae is linked to its surface properties and cell–cell aggregation and biofilm formation. Int J Med Microbiol 2013; 303:150-7. [DOI: 10.1016/j.ijmm.2013.02.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 12/17/2012] [Accepted: 02/03/2013] [Indexed: 10/27/2022] Open
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LaCross NC, Marrs CF, Gilsdorf JR. Population structure in nontypeable Haemophilus influenzae. INFECTION GENETICS AND EVOLUTION 2012; 14:125-36. [PMID: 23266487 DOI: 10.1016/j.meegid.2012.11.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 11/28/2012] [Accepted: 11/30/2012] [Indexed: 01/28/2023]
Abstract
Nontypeable Haemophilus influenzae (NTHi) frequently colonize the human pharynx asymptomatically, and are an important cause of otitis media in children. Past studies have identified typeable H. influenzae as being clonal, but the population structure of NTHi has not been extensively characterized. The research presented here investigated the diversity and population structure in a well-characterized collection of NTHi isolated from the middle ears of children with otitis media or the pharynges of healthy children in three disparate geographic regions. Multilocus sequence typing identified 109 unique sequence types among 170 commensal and otitis media-associated NTHi isolates from Finland, Israel, and the US. The largest clonal complex contained only five sequence types, indicating a high level of genetic diversity. The eBURST v3, ClonalFrame 1.1, and structure 2.3.3 programs were used to further characterize diversity and population structure from the sequence typing data. Little clustering was apparent by either disease state (otitis media or commensalism) or geography in the ClonalFrame phylogeny. Population structure was clearly evident, with support for eight populations when all 170 isolates were analyzed. Interestingly, one population contained only commensal isolates, while two others consisted solely of otitis media isolates, suggesting associations between population structure and disease.
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Affiliation(s)
- Nathan C LaCross
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
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Watson ME, Nelson KL, Nguyen V, Burnham CAD, Clarridge JE, Qin X, Smith AL. Adhesin genes and serum resistance in Haemophilus influenzae type f isolates. J Med Microbiol 2012; 62:514-524. [PMID: 23242639 DOI: 10.1099/jmm.0.052175-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The incidence of invasive infections due to Haemophilus influenzae has decreased significantly in developed countries with high rates of vaccination against H. influenzae serotype b (Hib). This vaccine provides no protection against H. influenzae serotype f (Hif), typically associated with invasive infections in adults with chronic disease and/or immunodeficiency, and rarely in otherwise healthy adults and children. The specific properties of Hif associated with virulence remain largely uncharacterized. A panel of 26 Hif strains consisting of both invasive disease-associated and mucosal surface non-invasive disease-associated isolates was surveyed by DNA fingerprinting, biotyping and PCR detection of hmw1, hmw2, hsf, the hif fimbrial locus and the lipo-oligosaccharide (LOS) biosynthetic island, and assessment of β-lactamase expression and determination of resistance to the bactericidal activity of normal adult human serum. Repetitive sequence-based PCR fingerprinting differentiated the 26 strains into three clusters, with the majority of isolates (22/26, 84.6 %) clustered into a single indistinguishable group. Most isolates (24/26, 92.3 %) were of biotype I and two isolates produced β-lactamase with detection of a conjugative plasmid, and the isolates displayed a range of resistances to the bactericidal activity of human serum. All 26 isolates carried the adhesin hsf, 21 carried a partial hif fimbrial operon and 4 had the adhesin genes hmw1/2. A LOS biosynthetic island was detected in 20 isolates consisting of the genes lic2BC. It was concluded that Hif has many recognized virulence properties and comprises a relatively homogeneous group independent of the anatomical source from which it was isolated.
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Affiliation(s)
- Michael E Watson
- Divison of Pediatric Infectious Diseases, Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Kevin L Nelson
- Center for Childhood Infections, Seattle Children's Hospital Research Institute, Seattle, Washington, USA
| | - Victoria Nguyen
- Center for Childhood Infections, Seattle Children's Hospital Research Institute, Seattle, Washington, USA
| | - Carey-Ann D Burnham
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri, USA
| | - Jill E Clarridge
- Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Xuan Qin
- Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Arnold L Smith
- Center for Childhood Infections, Seattle Children's Hospital Research Institute, Seattle, Washington, USA
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Haemophilus parainfluenzae has a limited core lipopolysaccharide repertoire with no phase variation. Glycoconj J 2012; 30:561-76. [PMID: 23093380 DOI: 10.1007/s10719-012-9455-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 10/14/2012] [Accepted: 10/15/2012] [Indexed: 10/27/2022]
Abstract
Cell surface lipopolysaccharide (LPS) is a well characterized virulence determinant for the human pathogen Haemophilus influenzae, so an investigation of LPS in the less pathogenic Haemophilus parainfluenzae could yield important insights. Using a panel of 18 commensal H. parainfluenzae isolates we demonstrate that the set of genes for inner core LPS biosynthesis largely resembles that of H. influenzae, with an additional heptosyltransferase I gene similar to waaC from Pasteurella multocida. Inner core LPS structure is therefore likely to be largely conserved across the two Haemophilus species. Outer core LPS biosynthetic genes are much less prevalent in H. parainfluenzae, although homologues of the H. influenzae LPS genes lpsB, non-phase variable lic2A and lgtC, and losA1, losB1 and lic2C are found in certain isolates. Immunoblotting using antibodies directed against selected LPS epitopes was consistent with these data. We found no evidence for tetranucleotide repeat-mediated phase variation in H. parainfluenzae. Phosphocholine, a phase variable H. influenzae LPS epitope that has been implicated in disease, was absent in H. parainfluenzae LPS as were the respective (lic1) biosynthetic genes. The introduction of the lic1 genes into H. parainfluenzae led to the phase variable incorporation of phosphocholine into its LPS. Differences in LPS structure between Haemophilus species could affect interactions at the bacterial-host interface and therefore the pathogenic potential of these bacteria.
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Livorsi DJ, Macneil JR, Cohn AC, Bareta J, Zansky S, Petit S, Gershman K, Harrison LH, Lynfield R, Reingold A, Schaffner W, Thomas A, Farley MM. Invasive Haemophilus influenzae in the United States, 1999-2008: epidemiology and outcomes. J Infect 2012; 65:496-504. [PMID: 22902945 DOI: 10.1016/j.jinf.2012.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/06/2012] [Accepted: 08/07/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Introduction of the Haemophilus influenzae type b (Hib) conjugate vaccine has resulted in a dramatic reduction of Hib disease in the U.S. and an increase in the relative importance of infections caused by nontypeable strains. The current project describes the characteristics and clinical outcomes of pediatric and adult patients with invasive H. influenzae (HI) and, through multivariable analysis, identifies risk factors for in-hospital mortality. METHODS HI cases were identified during 1999-2008 through active surveillance as part of active bacterial core surveillance (ABCs). Multivariable analysis was performed with logistic regression to identify factors predictive of in-hospital death. RESULTS 4839 cases of HI were identified from 1999-2008. Children accounted for 17.1% of cases and adults 82.9%. Underlying conditions were present in 20.7% of children and 74.8% of adults. In-hospital mortality was highest in cases ≥65 years (21.9%) and <3 months (16.2%). The risk of in-hospital death in children <1 year was higher among those who were prematurely-born (<28 weeks, OR 7.1, 95% CI 3.2-15.6; 28-36 weeks OR 2.1, 95% CI 0.9-4.8) and, among children aged 1-17 years, higher in those with healthcare-associated onset and dialysis (OR 5.66, 95% CI 1.84-17.39; OR 18.11, 95% CI 2.77-118.65). In adults, age ≥40 was associated with death in nontypeable, but not encapsulated, infections. Infections with nontypeable strains increased the risk of death in cases ≥65 years (OR 1.81, 95% CI 1.31-2.52). Healthcare-associated HI, bacteremia without identifiable focus, bacteremic pneumonia, associated cirrhosis, cerebrovascular accident, dialysis, heart failure, and non-hematologic malignancy also increased the risk of death in adults. CONCLUSION Prematurity in infants, advanced age and certain chronic diseases in adults were associated with an increased risk of in-hospital death. Nontypeable HI was associated with higher mortality in the elderly.
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Affiliation(s)
- Daniel J Livorsi
- Department of Medicine, Emory University School of Medicine, The Atlanta VA Medical Center, 1670 Clairmont Road, Mail Code 151-ID, Atlanta, GA 30333, USA.
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Rubach MP, Bender JM, Mottice S, Hanson K, Weng HYC, Korgenski K, Daly JA, Pavia AT. Increasing incidence of invasive Haemophilus influenzae disease in adults, Utah, USA. Emerg Infect Dis 2012; 17:1645-50. [PMID: 21888789 PMCID: PMC3322072 DOI: 10.3201/eid1709.101991] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
TOC Summary: The infection disproportionately affected patients >65 years of age. Since the introduction of the Haemophilus influenzae type b vaccine, the incidence of invasive H. influenzae type b disease among children has fallen dramatically, but the effect on invasive H. influenzae disease among adults may be more complex. In this population-based study we examined the epidemiology and outcomes of invasive disease caused by typeable and nontypeable H. influenzae among Utah adults during 1998–2008. The overall incidence increased over the study period from 0.14/100,000 person-years in 1998 to 1.61/100,000 person-years in 2008. The average incidence in persons >65 years old was 2.74/100,000 person-years, accounting for 51% of cases and 67% of deaths. The incidence was highest for nontypeable H. influenzae (0.23/100,000 person-years), followed by H. influenzae type f (0.14/100,000 person-years). The case-fatality rate was 22%. The incidence of invasive H. influenzae in Utah adults appears to be increasing. Invasive H. influenzae infection disproportionately affected the elderly and was associated with a high mortality rate.
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Invasive polyarticular septic arthritis caused by nontypeable haemophilus influenzae in a young adult: a case report and literature review. J Clin Rheumatol 2012; 17:380-2. [PMID: 21946466 DOI: 10.1097/rhu.0b013e318236e499] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nontypeable Haemophilus influenzae is a rare cause of septic arthritis in adults and has been reported to be associated with underlying medical conditions. We present a case of nontypeable H. influenzae-infected severe invasive polyarticular septic arthritis in a young adult without any underlying predisposing medical conditions. Diagnosis was made from both positive blood culture and joint aspiration culture. The patient was successfully treated with employment of aggressive surgical debridement of multiple affected septic joints as well as prolonged antibiotic treatment. Further laboratory testing did not reveal significant underlying medical conditions including negative HIV, normal levels of complement and IgG subclasses, and normal-appearing spleen on computed tomography. This case illustrates that nontypeable H. influenzae can cause serious invasive septic arthritis infection in both patients with and without predisposing underlying medical conditions and that prompt diagnosis with aggressive treatment of combined surgical and medical treatment can result in optimal recovery.
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Abstract
OBJECTIVE The spectrum of diseases caused by Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) represents a large burden on healthcare systems around the world. Meningitis, bacteraemia, community-acquired pneumonia (CAP), and acute otitis media (AOM) are vaccine-preventable infectious diseases that can have severe consequences. The health economic model presented here is intended to estimate the clinical and economic impact of vaccinating birth cohorts in Canada and the UK with the 10-valent, pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) compared with the newly licensed 13-valent pneumococcal conjugate vaccine (PCV-13). METHODS The model described herein is a Markov cohort model built to simulate the epidemiological burden of pneumococcal- and NTHi-related diseases within birth cohorts in the UK and Canada. Base-case assumptions include estimates of vaccine efficacy and NTHi infection rates that are based on published literature. RESULTS The model predicts that the two vaccines will provide a broadly similar impact on all-cause invasive disease and CAP under base-case assumptions. However, PHiD-CV is expected to provide a substantially greater reduction in AOM compared with PCV-13, offering additional savings of Canadian $9.0 million and £4.9 million in discounted direct medical costs in Canada and the UK, respectively. LIMITATIONS The main limitations of the study are the difficulties in modelling indirect vaccine effects (herd effect and serotype replacement), the absence of PHiD-CV- and PCV-13-specific efficacy data and a lack of comprehensive NTHi surveillance data. Additional limitations relate to the fact that the transmission dynamics of pneumococcal serotypes have not been modelled, nor has antibiotic resistance been accounted for in this paper. CONCLUSION This cost-effectiveness analysis suggests that, in Canada and the UK, PHiD-CV's potential to protect against NTHi infections could provide a greater impact on overall disease burden than the additional serotypes contained in PCV-13.
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Infant rat infection modifies phenotypic properties of an invasive nontypeable Haemophilus influenzae. Microbes Infect 2011; 14:509-16. [PMID: 22222846 DOI: 10.1016/j.micinf.2011.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 12/16/2011] [Accepted: 12/21/2011] [Indexed: 11/21/2022]
Abstract
Enhancing the virulence trait of a specific bacterium in an animal model is often performed prior to the use of the strain for ex vivo human studies, such as reactivity with complement and antibody, or with phagocytic cells. For example, in Streptococcus pneumoniae mouse passage is used to enhance capsule production. While investigating an unusual serum-resistant unencapsulated Haemophilus influenzae (R2866), we found that animal passage yielded an isolate (R3392) which had decreased resistance to human serum, but increased virulence in Chang conjunctival cell monolayers, but with less invasion and transcytosis of polar H292 cells. We examined 90 colonies recovered from three infant rats for phase variants of LPS biosynthetic genes. In 88 colonies lgtC was OFF due to tetrameric repeat mediated slipped-strand mispairing at the time of DNA replication, while there was no variation in lic1A, lic2A, lic3A, lexA and oaf A. With lgtC OFF the LPS lacks Galα1-4βGal, an epitope mimicking the human p(k) blood group, and molecular mimicry is lost. Selection for strain susceptible to NHS in the infant rat was not antibody mediated. We conclude that the passage of pathogens virulent in humans and animals may select for phenotypes only relevant for the animal species used.
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MacNeil JR, Cohn AC, Farley M, Mair R, Baumbach J, Bennett N, Gershman K, Harrison LH, Lynfield R, Petit S, Reingold A, Schaffner W, Thomas A, Coronado F, Zell ER, Mayer LW, Clark TA, Messonnier NE. Current Epidemiology and Trends in Invasive Haemophilus influenzae Disease--United States, 1989-2008. Clin Infect Dis 2011; 53:1230-6. [DOI: 10.1093/cid/cir735] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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A clonal group of nontypeable Haemophilus influenzae with two IgA proteases is adapted to infection in chronic obstructive pulmonary disease. PLoS One 2011; 6:e25923. [PMID: 21998721 PMCID: PMC3187821 DOI: 10.1371/journal.pone.0025923] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 09/13/2011] [Indexed: 11/19/2022] Open
Abstract
Strains of nontypeable Haemophilus influenzae show enormous genetic heterogeneity and display differential virulence potential in different clinical settings. The igaB gene, which encodes a newly identified IgA protease, is more likely to be present in the genome of COPD strains of H. influenzae than in otitis media strains. Analysis of igaB and surrounding sequences in the present study showed that H. influenzae likely acquired igaB from Neisseria meningitidis and that the acquisition was accompanied by a ~20 kb genomic inversion that is present only in strains that have igaB. As part of a long running prospective study of COPD, molecular typing of H. influenzae strains identified a clonally related group of strains, a surprising observation given the genetic heterogeneity that characterizes strains of nontypeable H. influenzae. Analysis of strains by 5 independent methods (polyacrylamide gel electrophoresis, multilocus sequence typing, igaB gene sequences, P2 gene sequences, pulsed field gel electrophoresis) established the clonal relationship among the strains. Analysis of 134 independent strains collected prospectively from a cohort of adults with COPD demonstrated that ~10% belonged to the clonal group. We conclude that a clonally related group of strains of nontypeable H. influenzae that has two IgA1 protease genes (iga and igaB) is adapted for colonization and infection in COPD. This observation has important implications in understanding population dynamics of H. influenzae in human infection and in understanding virulence mechanisms specifically in the setting of COPD.
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Murphy TF, Brauer AL. Expression of urease by Haemophilus influenzae during human respiratory tract infection and role in survival in an acid environment. BMC Microbiol 2011; 11:183. [PMID: 21843372 PMCID: PMC3166929 DOI: 10.1186/1471-2180-11-183] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2011] [Accepted: 08/16/2011] [Indexed: 12/21/2022] Open
Abstract
Background Nontypeable Haemophilus influenzae is a common cause of otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Prior studies have shown that H. influenzae expresses abundant urease during growth in the middle ear of the chinchilla and in pooled human sputum, suggesting that expression of urease is important for colonization and infection in the hostile environments of the middle ear and in the airways in adults. Virtually nothing else is known about the urease of H. influenzae, which was characterized in the present study. Results Analysis by reverse transcriptase PCR revealed that the ure gene cluster is expressed as a single transcript. Knockout mutants of a urease structural gene (ureC) and of the entire ure operon demonstrated no detectable urease activity indicating that this operon is the only one encoding an active urease. The ure operon is present in all strains tested, including clinical isolates from otitis media and COPD. Urease activity decreased as nitrogen availability increased. To test the hypothesis that urease is expressed during human infection, purified recombinant urease C was used in ELISA with pre acquisition and post infection serum from adults with COPD who experienced infections caused by H. influenzae. A total of 28% of patients developed new antibodies following infection indicating that H. influenzae expresses urease during airway infection. Bacterial viability assays performed at varying pH indicate that urease mediates survival of H. influenzae in an acid environment. Conclusions The H. influenzae genome contains a single urease operon that mediates urease expression and that is present in all clinical isolates tested. Nitrogen availability is a determinant of urease expression. H. influenzae expresses urease during human respiratory tract infection and urease is a target of the human antibody response. Expression of urease enhances viability in an acid environment. Taken together, these observations suggest that urease is important for survival and replication of H. influenzae in the human respiratory tract.
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Affiliation(s)
- Timothy F Murphy
- Division of Infectious Diseases, Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY 14203, USA.
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Martí-Lliteras P, López-Gómez A, Mauro S, Hood DW, Viadas C, Calatayud L, Morey P, Servin A, Liñares J, Oliver A, Bengoechea JA, Garmendia J. Nontypable Haemophilus influenzae displays a prevalent surface structure molecular pattern in clinical isolates. PLoS One 2011; 6:e21133. [PMID: 21698169 PMCID: PMC3116884 DOI: 10.1371/journal.pone.0021133] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 05/20/2011] [Indexed: 11/22/2022] Open
Abstract
Non-typable Haemophilus influenzae (NTHi) is a Gram negative pathogen that causes acute respiratory infections and is associated with the progression of chronic respiratory diseases. Previous studies have established the existence of a remarkable genetic variability among NTHi strains. In this study we show that, in spite of a high level of genetic heterogeneity, NTHi clinical isolates display a prevalent molecular feature, which could confer fitness during infectious processes. A total of 111 non-isogenic NTHi strains from an identical number of patients, isolated in two distinct geographical locations in the same period of time, were used to analyse nine genes encoding bacterial surface molecules, and revealed the existence of one highly prevalent molecular pattern (lgtF+, lic2A+, lic1D+, lic3A+, lic3B+, siaA−, lic2C+, ompP5+, oapA+) displayed by 94.6% of isolates. Such a genetic profile was associated with a higher bacterial resistance to serum mediated killing and enhanced adherence to human respiratory epithelial cells.
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Affiliation(s)
- Pau Martí-Lliteras
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
| | - Antonio López-Gómez
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
| | - Silvia Mauro
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
| | - Derek W. Hood
- Molecular Infectious Diseases Group, Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Headington, Oxford, United Kingdom
| | - Cristina Viadas
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
| | - Laura Calatayud
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
- Servicio de Microbiología, Hospital Universitario Bellvitge, Barcelona, Spain
- Instituto de Investigación Biomédica de Bellvitge (IDIBELL), Barcelona, Spain
- Universidad de Barcelona, Barcelona, Spain
| | - Pau Morey
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
| | - Alain Servin
- INSERM, UMR 756, Signalisation and Physiopathology of Epithelial cells, Paris, France
| | - Josefina Liñares
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
- Servicio de Microbiología, Hospital Universitario Bellvitge, Barcelona, Spain
- Instituto de Investigación Biomédica de Bellvitge (IDIBELL), Barcelona, Spain
- Universidad de Barcelona, Barcelona, Spain
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases, Palma Mallorca, Spain
| | - José Antonio Bengoechea
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
- Consejo Superior de Investigaciones Científicas-CSIC, Madrid, Spain
| | - Junkal Garmendia
- Programa de Infección e Inmunidad, Fundación Caubet-CIMERA, Bunyola, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias-CIBERES, Vitoria, Spain
- Instituto de Agrobiotecnología, CSIC-Universidad Pública de Navarra-Gobierno de Navarra, Mutilva, Spain
- * E-mail:
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ArcA-regulated glycosyltransferase lic2B promotes complement evasion and pathogenesis of nontypeable Haemophilus influenzae. Infect Immun 2011; 79:1971-83. [PMID: 21357723 DOI: 10.1128/iai.01269-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Signaling mechanisms used by Haemophilus influenzae to adapt to conditions it encounters during stages of infection and pathogenesis are not well understood. The ArcAB two-component signal transduction system controls gene expression in response to respiratory conditions of growth and contributes to resistance to bactericidal effects of serum and to bloodstream infection by H. influenzae. We show that ArcA of nontypeable H. influenzae (NTHI) activates expression of a glycosyltransferase gene, lic2B. Structural comparison of the lipooligosaccharide (LOS) of a lic2B mutant to that of the wild-type strain NT127 revealed that lic2B is required for addition of a galactose residue to the LOS outer core. The lic2B gene was crucial for optimal survival of NTHI in a mouse model of bacteremia and for evasion of serum complement. The results demonstrate that ArcA, which controls cellular metabolism in response to environmental reduction and oxidation (redox) conditions, also coordinately controls genes that are critical for immune evasion, providing evidence that NTHI integrates redox signals to regulate specific countermeasures against host defense.
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Olvera A, Pina S, Macedo N, Oliveira S, Aragon V, Bensaid A. Identification of potentially virulent strains of Haemophilus parasuis using a multiplex PCR for virulence-associated autotransporters (vtaA). Vet J 2011; 191:213-8. [PMID: 21247786 DOI: 10.1016/j.tvjl.2010.12.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 11/19/2010] [Accepted: 12/11/2010] [Indexed: 10/18/2022]
Abstract
Haemophilus parasuis is the aetiological agent of Glässer's disease and is also a commensal of the upper respiratory tract of pigs. Trimeric autotransporter (vtaA) genes have been identified in H. parasuis and divided into three groups on the basis of the translocator domain sequence. In this study, group 3 vtaA genes were demonstrated by PCR in all 157 H. parasuis isolates tested. Group 1 vtaA genes were associated with virulent strains; 52/54 (96%) group 1 vtaA negative field isolates were isolated from the nasal passages of healthy animals, whereas no group 1 vtaA negative field isolates were isolated from cases of Glässer's disease. There was an association between absence of group 1 vtaA, sensitivity to phagocytosis and serum and classification of isolates into nasal cluster C by multilocus sequence typing. A multiplex PCR was developed for diagnosis of H. parasuis at the species level (group 3 vtaA positive) and to differentiate putative non-virulent strains (group 1 vtaA negative). When applied to field samples, the PCR confirmed a high prevalence of H. parasuis in conventionally farmed pigs and demonstrated that almost half of the animals carried potentially virulent strains.
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Affiliation(s)
- Alex Olvera
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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SUNAKAWA K, TAKEUCHI Y, IWATA S. Nontypeable Haemophilus influenzae (NTHi) Epidemiology. ACTA ACUST UNITED AC 2011; 85:227-37. [DOI: 10.11150/kansenshogakuzasshi.85.227] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | | | - Satoshi IWATA
- Center for Infectious Diseases and Infection Control, Keio University School of Medicine
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Hallström T, Riesbeck K. Haemophilus influenzae and the complement system. Trends Microbiol 2010; 18:258-65. [PMID: 20399102 DOI: 10.1016/j.tim.2010.03.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/10/2010] [Accepted: 03/17/2010] [Indexed: 02/04/2023]
Abstract
The respiratory tract pathogen Haemophilus influenzae is responsible for a variety of infections in humans including septicemia, bronchitis, pneumonia, and acute otitis media. The pathogenesis of H. influenzae relies on its capacity to resist human host defenses including the complement system, and thus H. influenzae has developed several efficient strategies to circumvent complement attack. In addition to attracting specific host complement regulators directly to the bacterial surface, the capsule, lipooligosaccharides, and several outer membrane proteins contribute to resistance against complement-mediated attacks and hence increased bacterial survival. Insights into the mechanisms of complement evasion by H. influenzae are important for understanding pathogenesis and for developing vaccines and new therapies aimed at patients with, for example, chronic obstructive pulmonary disease. Here we overview current knowledge on the different mechanisms by which H. influenzae evades attack by the host complement system.
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Affiliation(s)
- Teresia Hallström
- Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden
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Hood DW, Deadman ME, Engskog MKR, Vitiazeva V, Makepeace K, Schweda EKH, Moxon R. Genes required for the synthesis of heptose-containing oligosaccharide outer core extensions in Haemophilus influenzae lipopolysaccharide. MICROBIOLOGY-SGM 2010; 156:3421-3431. [PMID: 20688825 DOI: 10.1099/mic.0.041780-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Heptose-containing oligosaccharides (OSs) are found in the outer core of the lipopolysaccharide (LPS) of a subset of non-typable Haemophilus influenzae (NTHi) strains. Candidate genes for the addition of either l-glycero-d-manno-heptose (ld-Hep) or d-glycero-d-manno-heptose (dd-Hep) and subsequent hexose sugars to these OSs have been identified from the recently completed genome sequences available for NTHi strains. losA1/losB1 and losA2/losB2 are two sets of related genes in which losA has homology to genes encoding glycosyltransferases and losB to genes encoding heptosyltransferases. Each set of genes is variably present across NTHi strains and is located in a region of the genome with an alternative gene organization between strains that contributes to LPS heterogeneity. Dependent upon the strain background, the LPS phenotype, structure and serum resistance of strains mutated in these genes were altered when compared with the relevant parent strain. Our studies confirm that losB1 and losB2 usually encode dd-heptosyl- and ld-heptosyl transferases, respectively, and that losA1 and losA2 encode glycosyltransferases that play a role in OS extensions of NTHi LPS.
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Affiliation(s)
- Derek W Hood
- Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Mary E Deadman
- Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Mikael K R Engskog
- Clinical Research Centre, Karolinska Institutet and University College of South Stockholm, Huddinge, Sweden
| | - Varvara Vitiazeva
- Clinical Research Centre, Karolinska Institutet and University College of South Stockholm, Huddinge, Sweden
| | - Katherine Makepeace
- Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Elke K H Schweda
- Clinical Research Centre, Karolinska Institutet and University College of South Stockholm, Huddinge, Sweden
| | - Richard Moxon
- Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
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Tracing phylogenomic events leading to diversity of Haemophilus influenzae and the emergence of Brazilian Purpuric Fever (BPF)-associated clones. Genomics 2010; 96:290-302. [PMID: 20654709 DOI: 10.1016/j.ygeno.2010.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 07/12/2010] [Accepted: 07/14/2010] [Indexed: 11/22/2022]
Abstract
Here we report the use of a multi-genome DNA microarray to elucidate the genomic events associated with the emergence of the clonal variants of Haemophilus influenzae biogroup aegyptius causing Brazilian Purpuric Fever (BPF), an important pediatric disease with a high mortality rate. We performed directed genome sequencing of strain HK1212 unique loci to construct a species DNA microarray. Comparative genome hybridization using this microarray enabled us to determine and compare gene complements, and infer reliable phylogenomic relationships among members of the species. The higher genomic variability observed in the genomes of BPF-related strains (clones) and their close relatives may be characterized by significant gene flux related to a subset of functional role categories. We found that the acquisition of a large number of virulence determinants featuring numerous cell membrane proteins coupled to the loss of genes involved in transport, central biosynthetic pathways and in particular, energy production pathways to be characteristics of the BPF genomic variants.
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Antibodies specific for the Hia adhesion proteins of nontypeable Haemophilus influenzae mediate opsonophagocytic activity. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:1040-6. [PMID: 19474261 DOI: 10.1128/cvi.00090-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Hia autotransporter proteins are highly immunogenic surface adhesins expressed by nontypeable Haemophilus influenzae (NTHI). The objective of our study was to assess the opsonophagocytic activity of anti-Hia antibodies against homologous and heterologous NTHI. A segment of the hia gene that encodes a surface-exposed portion of the H. influenzae strain 11 Hia protein was cloned into a pGEMEX-2 expression vector. Escherichia coli JM101 was transformed with the resulting pGEMEX-Hia BstEII del recombinant plasmid, and recombinant fusion protein was recovered. An immune serum against recombinant GEMEX-Hia (rGEMEX-Hia)-mediated killing of the homologous NTHI strain 11 at a 1:160 titer and five heterologous Hia-expressing strains at titers of > or =1:40. Immune serum did not mediate killing of two Hia-knockout strains whose hia genes were inactivated but did mediate killing of one knockout strain at a high titer after the strain was transformed with a plasmid containing the hia gene. Immune serum did not mediate killing of HMW1/HMW2-expressing NTHI strains, which do not express the Hia adhesin. However, when two representative HMW1/HMW2-expressing strains were transformed with the plasmid containing the hia gene, they expressed abundant Hia and were susceptible to killing by the immune serum. Immune serum did not mediate killing of HMW1/HMW2-expressing strains transformed with the plasmid without the hia gene. Our results demonstrate that the Hia proteins of NTHI are targets of opsonophagocytic antibodies and that shared epitopes recognized by such antibodies are present on the Hia proteins of unrelated NTHI strains. These data argue for the continued investigation of the Hia proteins as vaccine candidates for the prevention of NTHI disease.
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Schweda EKH, Twelkmeyer B, Li J. Profiling structural elements of short-chain lipopolysaccharide of non-typeable Haemophilus influenzae. Innate Immun 2009; 14:199-211. [PMID: 18669606 DOI: 10.1177/1753425908095958] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Lipopolysaccharide (LPS) is a major virulence determinant of the human bacterial pathogen Haemophilus influenzae. A characteristic feature of H. influenzae LPS is the extensive intra- and inter-strain heterogeneity of glycoform structure which is key to the role of the molecule in both commensal and disease-causing behaviour of the bacterium. The chemical composition of non-typeable Haemophilus influenzae (NTHi) LPS is highly diverse. It contains a number of different monosaccharides (Neu5Ac, L-glycero-D-manno heptose, D-glycero-D-manno heptose, Kdo, D-Glc, D-Gal, D-GlcNAc, D-GalNAc) and non-carbohydrate substituents. Prominent non-carbohydrate components are O-acetyl groups, glycine and phosphates. We now know that sialic acid (N-acetylneuraminic acid or Neu5Ac) and certain oligosaccharide extensions are important in the pathogenesis of NTHi; however, the biological implications for many of the various features are still unknown. Electrospray ionization mass spectrometry in combination with separation techniques like CE and HPLC is an indispensable tool in profiling glycoform populations in heterogeneous LPS samples. Mass spectrometry is characterized by its extreme sensitivity. Trace amounts of glycoforms expressing important virulence determinants can be detected and characterized on minute amounts of material. The present review focuses on LPS structures and mass spectrometric methods which enable us to profile these in complex mixtures.
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Affiliation(s)
- Elke K H Schweda
- Clinical Research Centre, Karolinska Institutet and University College of South Stockholm, NOVUM, Huddinge, Sweden.
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Abstract
Nontypeable Haemophilus influenzae is a significant pathogen in children, causing otitis media, sinusitis, conjunctivitis, pneumonia, and occasionally invasive infections. H. influenzae type b conjugate vaccines have no effect on infections caused by nontypeable strains because nontypeable strains are nonencapsulated. Approximately, one-third of episodes of otitis media are caused by nontypeable H. influenzae and the bacterium is the most common cause of recurrent otitis media. Recent progress in elucidating molecular mechanisms of pathogenesis, understanding the role of biofilms in otitis media and an increasing understanding of immune responses have potential for development of novel strategies to improve prevention and treatment of otitis media caused by nontypeable H. influenzae. Feasibility of vaccination for prevention of otitis media due to nontypeable H. influenzae was recently demonstrated in a clinical trial with a vaccine that included the surface virulence factor, protein D.
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High genetic diversity of nontypeable Haemophilus influenzae isolates from two children attending a day care center. J Clin Microbiol 2008; 46:3817-21. [PMID: 18845825 DOI: 10.1128/jcm.00940-08] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Twenty-one nontypeable Haemophilus influenzae (NTHi) isolates from the throats of two healthy children were genotyped by multilocus sequence typing. Nine unique sequence types (STs) were identified. These STs were scattered throughout the phylogenetic tree of reported NTHi STs, demonstrating the high level of NTHi diversity found in colonized children.
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Association of IS1016 with the hia adhesin gene and biotypes V and I in invasive nontypeable Haemophilus influenzae. Infect Immun 2008; 76:5221-7. [PMID: 18794287 DOI: 10.1128/iai.00672-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A subset of invasive nontypeable Haemophilus influenzae (NTHI) strains has evidence of IS1016, an insertion element associated with division I H. influenzae capsule serotypes. We examined IS1016-positive invasive NTHI isolates collected as part of Active Bacterial Core Surveillance within the Georgia Emerging Infections Program for the presence or absence of hmw1 and hmw2 (two related adhesin genes that are common in NTHI but absent in encapsulated H. influenzae) and hia (homologue of hsf, an encapsulated H. influenzae adhesin gene). Isolates were serotyped using slide agglutination, confirmed as NTHI strains using PCR capsule typing, and biotyped. Two hundred twenty-nine invasive NTHI isolates collected between August 1998 and December 2006 were screened for IS1016; 22/229 (9.6%) were positive. Nineteen of 201 previously identified IS1016-positive invasive NTHI isolates collected between January 1989 and July 1998 were also examined. Forty-one IS1016-positive and 56 randomly selected IS1016-negative invasive NTHI strains were examined. The hia adhesin was present in 39 of 41 (95%) IS1016-positive NTHI strains and 1 of 56 (1.8%) IS1016-negative NTHI strains tested; hmw (hmw1, hmw2, or both) was present in 50 of 56 (89%) IS1016-negative NTHI isolates but in only 5 of 41 (12%; all hmw2) IS1016-positive NTHI isolates. IS1016-positive NTHI strains were more often biotype V (P < 0.001) or biotype I (P = 0.04) than IS1016-negative NTHI strains, which were most often biotype II. Pulsed-field gel electrophoresis revealed the expected genetic diversity of NTHI with some clustering based on IS1016, hmw or hia, and biotypes. A significant association of IS1016 with biotypes V and I and the presence of hia adhesins was found among invasive NTHI. IS1016-positive NTHI strains may represent a unique subset of NTHI strains, with characteristics more closely resembling those of encapsulated H. influenzae.
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