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Colomba C, Garbo V, Boncori G, Albano C, Bagarello S, Condemi A, Giordano S, Canduscio LA, Gallo C, Parrinello G, Cascio A. Streptococcus mitis as a New Emerging Pathogen in Pediatric Age: Case Report and Systematic Review. Antibiotics (Basel) 2023; 12:1222. [PMID: 37508318 PMCID: PMC10376791 DOI: 10.3390/antibiotics12071222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
Streptococcus mitis, a normal inhabitant of the oral cavity, is a member of Viridans Group Streptococci (VGS). Generally recognized as a causative agent of invasive diseases in immunocompromised patients, S. mitis is considered to have low pathogenic potential in immunocompetent individuals. We present a rare case of sinusitis complicated by meningitis and cerebral sino-venous thrombosis (CSVT) caused by S. mitis in a previously healthy 12-year-old boy with poor oral health status. With the aim of understanding the real pathogenic role of this microorganism, an extensive review of the literature about invasive diseases due to S. mitis in pediatric patients was performed. Our data define the critical role of this microorganism in invasive infections, especially in immunocompetent children and in the presence of apparently harmful conditions such as sinusitis and caries. Attention should be paid to the choice of therapy because of VGS's emerging antimicrobial resistance patterns.
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Affiliation(s)
- Claudia Colomba
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
- Division of Pediatric Infectious Diseases, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Valeria Garbo
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Giovanni Boncori
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Chiara Albano
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Sara Bagarello
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Anna Condemi
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Salvatore Giordano
- Division of Pediatric Infectious Diseases, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Laura A Canduscio
- Division of Pediatric Infectious Diseases, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Cristina Gallo
- Division of Radiology, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Gaspare Parrinello
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Antonio Cascio
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
- Infectious and Tropical Diseases Unit, AOU Policlinico "P. Giaccone", 90100 Palermo, Italy
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Jia J, Shi W, Dong F, Meng Q, Yuan L, Chen C, Yao K. Identification and molecular epidemiology of routinely determined Streptococcus pneumoniae with negative Quellung reaction results. J Clin Lab Anal 2022; 36:e24293. [PMID: 35170080 PMCID: PMC8993597 DOI: 10.1002/jcla.24293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/08/2022] [Accepted: 01/24/2022] [Indexed: 11/16/2022] Open
Abstract
Background Some streptococci strains identified as Streptococcus pneumoniae (S. pneumoniae) by routine clinical methods exhibiting negative Quellung reaction results may belong to other species of viridans group streptococci or non‐typeable S. pneumoniae. The purpose of this study was to investigate the identification and molecular characteristics of S. pneumoniae with negative Quellung reaction results. Methods One hundred and five isolates identified as S. pneumoniae using routine microbiological methods with negative Quellung reaction results were included. Multilocus sequence analysis (MLSA) was used as a gold standard in species identification, and the capacity of matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI‐TOF MS) in identification was evaluated. Capsular genes and sequence types of S. pneumoniae isolates were determined by sequential multiplex PCR and multilocus sequence typing. Antimicrobial susceptibility patterns were determined via broth microdilution with a commercialized 96‐well plate. Results Among the isolates, 81 were identified as S. pneumoniae and 24 were S. pseudopneumoniae by MLSA. MALDI‐TOF MS misidentified six S. pneumoniae isolates as S. pseudopneumoniae and nine S. pseudopneumoniae isolates as S. pneumoniae or S. mitis/S. oralis. Thirty‐one sequence types (STs) were detected for these 81 S. pneumoniae isolates, and the dominant ST was ST‐bj12 (16, 19.8%). The non‐susceptibility rates of S. pseudopneumoniae were comparable to those of NESp strains. Conclusions Some S. pneumoniae isolates identified by routine methods were S. pseudopneumoniae. Most NESp strains have a different genetic background compared with capsulated S. pneumoniae strains. The resistance patterns of S. pseudopneumoniae against common antibiotics were comparable to those of NESp.
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Affiliation(s)
- Ju Jia
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China
| | - Wei Shi
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China
| | - Fang Dong
- Clinical Laboratory, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China
| | - Qingying Meng
- Clinical Laboratory, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China
| | - Lin Yuan
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China
| | - Changhui Chen
- Department of Pediatrics, Youyang County People's Hospital, Chongqing, China
| | - Kaihu Yao
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China
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3
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Sadowy E, Bojarska A, Kuch A, Skoczyńska A, Jolley KA, Maiden MCJ, van Tonder AJ, Hammerschmidt S, Hryniewicz W. Relationships among streptococci from the mitis group, misidentified as Streptococcus pneumoniae. Eur J Clin Microbiol Infect Dis 2020; 39:1865-1878. [PMID: 32409955 PMCID: PMC7497345 DOI: 10.1007/s10096-020-03916-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 04/24/2020] [Indexed: 01/18/2023]
Abstract
The aim of our study was to investigate phenotypic and genotypic features of streptococci misidentified (misID) as Streptococcus pneumoniae, obtained over 20 years from hospital patients in Poland. Sixty-three isolates demonstrating microbiological features typical for pneumococci (optochin susceptibility and/or bile solubility) were investigated by phenotypic tests, lytA and 16S rRNA gene polymorphism and whole-genome sequencing (WGS). All isolates had a 6-bp deletion in the lytA 3' terminus, characteristic for Mitis streptococc and all but two isolates lacked the pneumococcal signature cytosine at nucleotide position 203 in the 16S rRNA genes. The counterparts of psaA and ply were present in 100% and 81.0% of isolates, respectively; the spn9802 and spn9828 loci were characteristic for 49.2% and 38.1% of isolates, respectively. Phylogenetic trees and networks, based on the multilocus sequence analysis (MLSA) scheme, ribosomal multilocus sequence typing (rMLST) scheme and core-genome analysis, clearly separated investigated isolates from S. pneumoniae and demonstrated the polyclonal character of misID streptococci, associated with the Streptococcus pseudopneumoniae and Streptococcus mitis groups. While the S. pseudopneumoniae clade was relatively well defined in all three analyses, only the core-genome analysis revealed the presence of another cluster comprising a fraction of misID streptococci and a strain proposed elsewhere as a representative of a novel species in the Mitis group. Our findings point to complex phylogenetic and taxonomic relationships among S. mitis-like bacteria and support the notion that this group may in fact consist of several distinct species.
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Affiliation(s)
- Ewa Sadowy
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland.
| | - Agnieszka Bojarska
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Alicja Kuch
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Anna Skoczyńska
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | | | | | | | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Waleria Hryniewicz
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
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4
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Sadowy E, Hryniewicz W. Identification of Streptococcus pneumoniae and other Mitis streptococci: importance of molecular methods. Eur J Clin Microbiol Infect Dis 2020; 39:2247-2256. [PMID: 32710352 PMCID: PMC7669753 DOI: 10.1007/s10096-020-03991-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023]
Abstract
The Mitis group of streptococci includes an important human pathogen, Streptococcus pneumoniae (pneumococcus) and about 20 other related species with much lower pathogenicity. In clinical practice, some representatives of these species, especially Streptococcus pseudopneumoniae and Streptococcus mitis, are sometimes mistaken for S. pneumoniae based on the results of classical microbiological methods, such as optochin susceptibility and bile solubility. Several various molecular approaches that address the issue of correct identification of pneumococci and other Mitis streptococci have been proposed and are discussed in this review, including PCR- and gene sequencing-based tests as well as new developments in the genomic field that represents an important advance in our understanding of relationships within the Mitis group.
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Affiliation(s)
- Ewa Sadowy
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland.
| | - Waleria Hryniewicz
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
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Midouni Ayadi B, Mehiri E, Draoui H, Ghariani A, Essalah L, Raoult D, Fournier PE, Slim-Saidi LN. Phenotypic and molecular characterization of macrolide resistance mechanisms among Streptococcus pneumoniae isolated in Tunisia. J Med Microbiol 2020; 69:505-520. [PMID: 32159507 DOI: 10.1099/jmm.0.001151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Introduction. Streptococcus pneumoniae is responsible for many community infections, with the main ones being pneumonia and meningitis. Pneumococcus has developed increased resistance to multiple classes of antibiotics. The evolution of antibiotic resistance in pneumococcus was influenced by changes in serotype distribution under vaccine selection pressure.Aim. The aim of this study was to determine the genes involved in macrolide resistance, the antimicrobial susceptibility, the serotype distribution and the spread of international antibiotic-resistant clones among clinical isolates of S. pneumoniae.Methodology. We investigated 86 erythromycin-resistant S. pneumoniae strains isolated from respiratory (n=74) or non-respiratory (n=12) samples in Tunisia. Antimicrobial susceptibility was tested using the disk diffusion method. Macrolide-resistant strains were analysed by polymerase chain reaction (PCR) for ermA, ermB, mefA and msrD. We also investigated the macrolide resistance mechanisms in eight isolates (9.3%) by sequencing the L4 and L22 riboprotein-coding genes, plus relevant segments of the three 23S rRNA genes. Capsular serotypes were detected by multiplex PCR. Sequence types (STs) were explored using multilocus sequence typing (MLST).Results. Among the 86 studied strains, 70 (81.4 %) were resistant to penicillin G. The prevalent serotypes were 19F, 14, 19A and 23F. We observed that the cMLSB phenotype (66/86, 76.7%) was the most common in these pneumococci. In addition, ermB was the most frequent resistance gene. No mutation in ribosomal protein L22 or L4 or 23S rRNA was detected. Overall, 44 STs were identified in this study, including 16 that were described for the first time. Resistance to lincomycin, tetracycline and trimethoprim/sulfamethoxazole was observed in 55 (64 %), 34 (39.5 %) and 31 (36 %) isolates, respectively. Furthermore, an increase in fluoroquinolone use in particular may lead to the emergence of levofloxacin-resistant strains. Multidrug resistance was observed in 83 isolates (96.5%). Three global antibiotic-resistant clones were identified: Denmark14 ST230, Portugal19F ST177 and Spain9V ST156.Conclusion. This study shows that macrolide resistance among S. pneumoniae isolated in Tunisia is mainly related to target site modification. Our observations demonstrate a high degree of genetic diversity and capsular types among strains resistant to macrolides.
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Affiliation(s)
- B Midouni Ayadi
- Aix Marseille University, IRD, SSA, Vitrome, IHU Mediterranee Infection, 19-21 Bd Jean Moulin, 13005 Marseille, France.,Microbiology Laboratory, A. Mami Hospital of Pneumology, UR12/SP18, Ariana, Tunisia.,Faculty of Sciences of Tunis - University of Tunis El Manar, Ariana, Tunisia
| | - E Mehiri
- Microbiology Laboratory, A. Mami Hospital of Pneumology, UR12/SP18, Ariana, Tunisia
| | - H Draoui
- Microbiology Laboratory, A. Mami Hospital of Pneumology, UR12/SP18, Ariana, Tunisia
| | - A Ghariani
- Microbiology Laboratory, A. Mami Hospital of Pneumology, UR12/SP18, Ariana, Tunisia
| | - L Essalah
- Microbiology Laboratory, A. Mami Hospital of Pneumology, UR12/SP18, Ariana, Tunisia
| | - D Raoult
- Aix Marseille University, IRD, Mephi, IHU Mediterranee Infection, 19-21 Bd Jean Moulin, 13005 Marseille, France
| | - P E Fournier
- Aix Marseille University, IRD, SSA, Vitrome, IHU Mediterranee Infection, 19-21 Bd Jean Moulin, 13005 Marseille, France
| | - L N Slim-Saidi
- Microbiology Laboratory, A. Mami Hospital of Pneumology, UR12/SP18, Ariana, Tunisia
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Ercibengoa M, Morales M, Alonso M, Ardanuy C, Marimón JM. Variants of the bile: solubility test to differentiate Streptococcus pneumoniae from other viridans group streptococci. Future Microbiol 2019; 14:949-955. [PMID: 31373220 DOI: 10.2217/fmb-2019-0073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Bile salts promote the specific autolysis of pneumococcal cells, allowing the differentiation between Streptococcus pneumoniae and other viridans group streptococci (VGS). Material & methods: One hundred clinical VGS isolates identified by amplification and sequencing of 16S rRNA, groEL and sodA genes were analyzed with different variants of bile-solubility tests: tube testing read by naked eye; tube testing where the lysis was measured as the decrease of turbidity with a densitometer; and direct testing on blood agar plate. Results: As expected, all S. pneumoniae isolates were fully lysed in the presence of bile salts except for one isolate that partially lysate in tube testing as well as on the blood agar plate. None of the VGS were lysed by bile salts. Conclusion: Bile-solubility testing is an accurate and technically nondemanding method to discriminate between S. pneumoniae and other VGS species.
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Affiliation(s)
- María Ercibengoa
- Biodonostia, Infectious Diseases Area, Respiratory Infection and Antimicrobial Resistance Group; Osakidetza Basque Health Service, Donostialdea Integrated Health Organisation, Microbiology Department, 20014 San Sebastian, Spain
| | - María Morales
- Biodonostia, Infectious Diseases Area, Respiratory Infection and Antimicrobial Resistance Group; Osakidetza Basque Health Service, Donostialdea Integrated Health Organisation, Microbiology Department, 20014 San Sebastian, Spain
| | - Marta Alonso
- Biodonostia, Infectious Diseases Area, Respiratory Infection and Antimicrobial Resistance Group; Osakidetza Basque Health Service, Donostialdea Integrated Health Organisation, Microbiology Department, 20014 San Sebastian, Spain
| | - Carmen Ardanuy
- Network for Respiratory Diseases (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain.,Microbiology Department, Hospital Universitari de Bellvitge, Instituto de Investigación Biomédica de Bellvitge (IDIBELL), University of Barcelona, Spain
| | - José M Marimón
- Biodonostia, Infectious Diseases Area, Respiratory Infection and Antimicrobial Resistance Group; Osakidetza Basque Health Service, Donostialdea Integrated Health Organisation, Microbiology Department, 20014 San Sebastian, Spain
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Raddaoui A, Ben Tanfous F, Achour W, Baaboura R, Ben Hassen A. Description of a novel mutation in the atpC gene in optochin-resistant Streptococcus pneumoniae strains isolates from Tunisia. Int J Antimicrob Agents 2018; 51:803-805. [PMID: 29305958 DOI: 10.1016/j.ijantimicag.2017.12.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 12/19/2017] [Accepted: 12/28/2017] [Indexed: 11/25/2022]
Abstract
Identification of Streptococcus pneumoniae among other α-haemolytic streptococci is based on phenotypic or genotypic characteristics such as colony morphology, bile solubility and optochin susceptibility. This study reports three optochin-resistant S. pneumoniae strains isolated from immunocompromised patients in Tunisia. The three isolates were positive for the bile solubility test. Biochemical identification with API® 20 Strep was not discriminatory for two strains. The three strains had different serotypes (6C, 19F and 23F) and three different sequence types (ST386, ST320 and ST326). Sequencing of the atpA and atpC genes for each strain showed only modification in atpC. The mutations Met13→Val or Val48→Ile were observed in two strains. However, in the third strain a novel type of mutation (Val15→Ile) was identified.
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Affiliation(s)
- Anis Raddaoui
- Université de Carthage, Faculté des Sciences de Bizerte, Jarzouna 7021, Tunisia; Service des Laboratoires, Centre National de Greffe de Moelle Osseuse, Tunis 1006, Tunisia; Université de Tunis El Manar, Faculté de Médecine de Tunis, UR 12ES02, Tunis 1007, Tunisia.
| | - Farah Ben Tanfous
- Université de Carthage, Faculté des Sciences de Bizerte, Jarzouna 7021, Tunisia; Service des Laboratoires, Centre National de Greffe de Moelle Osseuse, Tunis 1006, Tunisia; Université de Tunis El Manar, Faculté de Médecine de Tunis, UR 12ES02, Tunis 1007, Tunisia
| | - Wafa Achour
- Service des Laboratoires, Centre National de Greffe de Moelle Osseuse, Tunis 1006, Tunisia; Université de Tunis El Manar, Faculté de Médecine de Tunis, UR 12ES02, Tunis 1007, Tunisia
| | - Rekaya Baaboura
- Service des Laboratoires, Centre National de Greffe de Moelle Osseuse, Tunis 1006, Tunisia; Université de Tunis El Manar, Faculté de Médecine de Tunis, UR 12ES02, Tunis 1007, Tunisia
| | - Assia Ben Hassen
- Service des Laboratoires, Centre National de Greffe de Moelle Osseuse, Tunis 1006, Tunisia; Université de Tunis El Manar, Faculté de Médecine de Tunis, UR 12ES02, Tunis 1007, Tunisia
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Sheppard CL, Kapatai G, Broughton K, Schaefer U, Hannah M, Litt DJ, Fry NK. Clinical streptococcal isolates, distinct from Streptococcus pneumoniae, but containing the β-glucosyltransferase tts gene and expressing serotype 37 capsular polysaccharide. PeerJ 2017; 5:e3571. [PMID: 28729954 PMCID: PMC5518733 DOI: 10.7717/peerj.3571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/22/2017] [Indexed: 01/28/2023] Open
Abstract
The major virulence factor of the pneumococcus, and target for conjugate vaccines, is the polysaccharide capsule, which is usually encoded by the highly variable cps locus. Serotype 37 is an unusual pneumococcal type in which the single β-glucosyltransferase gene responsible for serotype capsule production (tts) is located outside of the capsular operon region. Using a previously described automated whole genome sequence (WGS)-based serotyping bioinformatics tool, PneumoCaT, we identified and investigated seven clinical isolates (three from blood cultures) of non-pneumococcal streptococci containing a highly homologous tts and included them in a study panel of 20 isolates which included a 11 further clinical isolates of S. pneumoniae serotype 37, a reference strain of serotype 37 and the S. pseudopneumoniae type strain BAA 960T. The seven non-pneumococcal isolates generated novel alleles at all pneumococcal MLST loci and gave low percentage similarity (<45%) to S. pneumoniae or S. pseudopneumoniae species by comparison of short sequence patterns in genomic data (k-mer analysis). The S. pseudopneumoniae BAA-960T isolate generated two novel alleles in the MLST and gave a high similarity (>99%) to the reference sequence for BAA-960T. Twelve isolates gave high similarity (>77%) to the Streptococcus pneumoniae 5652-06 serotype 19A reference genome sequence and had previously reported MLST alleles. Each of the seven clinical non-pneumococcal strains and all of the 12 S. pneumoniae possessed a β-glycosyltransferase gene (tts) with >95% similarity to the pneumococcal tts reference DNA sequence with 20–22 non-synonymous SNPs. All but two strains in which the tts gene was detected gave positive reactions for serotype 37 in slide agglutination tests with serotype 37 typing sera. Phylogenetic analysis using both SNP and MLST data showed distinct clades corresponding to strains identified as pneumococcus or non-pneumococcus by kmer WGS analysis. Extended k-mer database analysis and ribosomal MLST placed the non-pneumococcal isolates within the S. mitis group. Biochemical and bile solubility assays showed differences between the unusual isolates and S. pneumoniae. All isolates had detectable pneumolysin (ply) genes, but only those that identified as pneumococcus contained the genes for autolysin (lytA) or the ABC transporter lipoprotein A (piaA) with >80% coverage and >95% similarity. Here we report the existence of a novel group of strains distinct from S. pneumoniae, but which can express a pneumococcal serotype 37 capsular polysaccharide which can be associated with clinical disease.
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Affiliation(s)
- Carmen L Sheppard
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, United Kingdom
| | - Georgia Kapatai
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, United Kingdom
| | - Karen Broughton
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, United Kingdom
| | - Ulf Schaefer
- Infectious Disease Informatics/Bioinformatics, Public Health England, London, United Kingdom
| | - Matthew Hannah
- Virus Reference Department, Public Health England, London, United Kingdom
| | - David J Litt
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, United Kingdom
| | - Norman K Fry
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, United Kingdom
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9
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Simões AS, Tavares DA, Rolo D, Ardanuy C, Goossens H, Henriques-Normark B, Linares J, de Lencastre H, Sá-Leão R. lytA-based identification methods can misidentify Streptococcus pneumoniae. Diagn Microbiol Infect Dis 2016; 85:141-8. [PMID: 27107535 DOI: 10.1016/j.diagmicrobio.2016.03.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/19/2016] [Accepted: 03/20/2016] [Indexed: 02/01/2023]
Abstract
During surveillance studies we detected, among over 1500 presumptive pneumococci, 11 isolates displaying conflicting or novel results when characterized by widely accepted phenotypic (optochin susceptibility and bile solubility) and genotypic (lytA-BsaAI-RFLP and MLST) identification methods. We aimed to determine the genetic basis for the unexpected results given by lytA-BsaAI-RFLP and investigate the accuracy of the WHO recommended lytA real-time PCR assay to classify these 11 isolates. Three novel lytA-BsaAI-RFLP signatures were found (one in pneumococcus and two in S. mitis). In addition, one pneumococcus displayed the atypical lytA-BsaAI-RFLP signature characteristic of non-pneumococci and two S. pseudopneumoniae displayed the typical lytA-BsaAI-RFLP pattern characteristic of pneumococci. lytA real-time PCR misidentified these three isolates. In conclusion, identification of pneumococci by lytA real-time PCR, and other lytA-based methodologies, may lead to false results. This is of particular relevance in the increasingly frequent colonization studies relying solely on culture-independent methods.
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Affiliation(s)
- Alexandra S Simões
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier (ITQB), Universidade Nova de Lisboa (UNL), Oeiras, Portugal
| | - Débora A Tavares
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier (ITQB), Universidade Nova de Lisboa (UNL), Oeiras, Portugal
| | - Dora Rolo
- Microbiology Department, Hospital Universitari de Bellvitge, Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; CIBERES (Ciber de Enfermedades Respiratorias), ISCIII, Madrid, Spain
| | - Carmen Ardanuy
- Microbiology Department, Hospital Universitari de Bellvitge, Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; CIBERES (Ciber de Enfermedades Respiratorias), ISCIII, Madrid, Spain
| | - Herman Goossens
- Department of Medical Microbiology, University of Antwerp, Antwerp, Belgium; Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden; Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| | - Josefina Linares
- Microbiology Department, Hospital Universitari de Bellvitge, Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; CIBERES (Ciber de Enfermedades Respiratorias), ISCIII, Madrid, Spain
| | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, ITQB, UNL, Oeiras, Portugal; Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, NY, USA
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier (ITQB), Universidade Nova de Lisboa (UNL), Oeiras, Portugal.
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Ghosh B, Lal H, Srivastava A. Review of bioaerosols in indoor environment with special reference to sampling, analysis and control mechanisms. ENVIRONMENT INTERNATIONAL 2015; 85:254-72. [PMID: 26436919 PMCID: PMC7132379 DOI: 10.1016/j.envint.2015.09.018] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 05/19/2023]
Abstract
Several tiny organisms of various size ranges present in air are called airborne particles or bioaerosol which mainly includes live or dead fungi and bacteria, their secondary metabolites, viruses, pollens, etc. which have been related to health issues of human beings and other life stocks. Bio-terror attacks in 2001 as well as pandemic outbreak of flue due to influenza A H1N1 virus in 2009 have alarmed us about the importance of bioaerosol research. Hence characterization i.e. identification and quantification of different airborne microorganisms in various indoor environments is necessary to identify the associated risks and to establish exposure threshold. Along with the bioaerosol sampling and their analytical techniques, various literatures revealing the concentration levels of bioaerosol have been mentioned in this review thereby contributing to the knowledge of identification and quantification of bioaerosols and their different constituents in various indoor environments (both occupational and non-occupational sections). Apart from recognition of bioaerosol, developments of their control mechanisms also play an important role. Hence several control methods have also been briefly reviewed. However, several individual levels of efforts such as periodic cleaning operations, maintenance activities and proper ventilation system also serve in their best way to improve indoor air quality.
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Affiliation(s)
- Bipasha Ghosh
- School of Environmental Science, Jawaharlal Nehru University, New Delhi, India
| | - Himanshu Lal
- School of Environmental Science, Jawaharlal Nehru University, New Delhi, India
| | - Arun Srivastava
- School of Environmental Science, Jawaharlal Nehru University, New Delhi, India.
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Co-Transcriptomes of Initial Interactions In Vitro between Streptococcus Pneumoniae and Human Pleural Mesothelial Cells. PLoS One 2015; 10:e0142773. [PMID: 26566142 PMCID: PMC4643877 DOI: 10.1371/journal.pone.0142773] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/27/2015] [Indexed: 01/21/2023] Open
Abstract
Streptococcus pneumoniae (Spn) is a major causative organism of empyema, an inflammatory condition occurring in the pleural sac. In this study, we used human and Spn cDNA microarrays to characterize the transcriptional responses occurring during initial contact between Spn and a human pleural mesothelial cell line (PMC) in vitro. Using stringent filtering criteria, 42 and 23 Spn genes were up-and down-regulated respectively. In particular, genes encoding factors potentially involved in metabolic processes and Spn adherence to eukaryotic cells were up-regulated e.g. glnQ, glnA, aliA, psaB, lytB and nox. After Spn initial contact, 870 human genes were differentially regulated and the largest numbers of significant gene expression changes were found in canonical pathways for eukaryotic initiation factor 2 signaling (60 genes out of 171), oxidative phosphorylation (32/103), mitochondrial dysfunction (37/164), eIF4 and p70S6K signaling (28/142), mTOR signaling (27/182), NRF2-mediated oxidative stress response (20/177), epithelial adherens junction remodeling (11/66) and ubiquitination (22/254). The cellular response appeared to be directed towards host cell survival and defense. Spn did not activate NF-kB or phosphorylate p38 MAPK or induce cytokine production from PMC. Moreover, Spn infection of TNF-α pre-stimulated PMC inhibited production of IL-6 and IL-8 secretion by >50% (p<0.01). In summary, this descriptive study provides datasets and a platform for examining further the molecular mechanisms underlying the pathogenesis of empyema.
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Identification of clinical Streptococcus pneumoniae isolates among other alpha and nonhemolytic streptococci by use of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system. J Clin Microbiol 2013; 51:1861-7. [PMID: 23576536 DOI: 10.1128/jcm.03069-12] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Discrimination between Streptococcus pneumoniae and its close relatives of the viridans group is a common difficulty in matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry-based identification. In the present study, the performances of the Vitek MS MALDI-TOF mass spectrometry system were assessed using 334 pneumococci, 166 other S. mitis group streptococci, 184 non-S. mitis group streptococci, and 19 related alpha- and nonhemolytic aerobic Gram-positive catalase-negative coccal isolates. Pneumococci had been identified by means of optochin susceptibility and bile solubility or serotyping, and other isolates mainly by use of RapidID32 Strep strips. In case of discordant or low-discrimination results, genotypic methods were used. The sensitivity of the Vitek MS for the identification of S. pneumoniae was 99.1%, since only three bile-insoluble isolates were misidentified as Streptococcus mitis/Streptococcus oralis. Conversely, two optochin-resistant pneumococci were correctly identified (specificity, 100%). Three Streptococcus pseudopneumoniae isolates were also correctly identified. Among nonpneumococcal isolates, 90.8% (n = 335) were correctly identified to the species or subspecies level and 2.4% (n = 9) at the group level. For the remaining 25 isolates, the Vitek MS proposed a bacterial species included in the list of possible species suggested by genotypic methods, except for 4 isolates which were not identified due to the absence of the species in the database. According to our study, the Vitek MS displays performance similar to that of the optochin susceptibility test for routine identification of pneumococcal isolates. Moreover, the Vitek MS is efficient for the identification of other viridans group streptococci and related isolates, provided that the species are included in the database.
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Rolo D, S. Simões A, Domenech A, Fenoll A, Liñares J, de Lencastre H, Ardanuy C, Sá-Leão R. Disease isolates of Streptococcus pseudopneumoniae and non-typeable S. pneumoniae presumptively identified as atypical S. pneumoniae in Spain. PLoS One 2013; 8:e57047. [PMID: 23437306 PMCID: PMC3578818 DOI: 10.1371/journal.pone.0057047] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 01/16/2013] [Indexed: 11/27/2022] Open
Abstract
We aimed to obtain insights on the nature of a collection of isolates presumptively identified as atypical Streptococcus pneumoniae recovered from invasive and non-invasive infections in Spain. One-hundred and thirty-two isolates were characterized by: optochin susceptibility in ambient and CO2-enriched atmosphere; bile solubility; PCR-based assays targeting pneumococcal genes lytA, ply, pspA, cpsA, Spn9802, aliB-like ORF2, and a specific 16S rRNA region; multilocus sequence analysis; and antimicrobial susceptibility. By multilocus sequence analysis, 61 isolates were S. pseudopneumoniae, 34 were pneumococci, 13 were S. mitis, and 24 remained unclassified as non-pneumococci. Among S. pseudopneumoniae isolates, 51 (83.6%) were collected from respiratory tract samples; eight isolates were obtained from sterile sources. High frequency of non-susceptibility to penicillin (60.7%) and erythromycin (42.6%) was found. Only 50.8% of the S. pseudopneumoniae isolates displayed the typical optochin phenotype originally described for this species. None harbored the cpsA gene or the pneumococcal typical lytA restriction fragment length polymorphism. The Spn9802 and the specific 16S rRNA regions were detected among the majority of the S. pseudopneumoniae isolates (n = 59 and n = 49, respectively). The ply and pspA genes were rarely found. A high genetic diversity was found and 59 profiles were identified. Among the S. pneumoniae, 23 were capsulated and 11 were non-typeable. Three non-typeable isolates, associated to international non-capsulated lineages, were recovered from invasive disease sources. In conclusion, half of the atypical pneumococcal clinical isolates were, in fact, S. pseudopneumoniae and one-fourth were other streptococci. We identified S. pseudopneumoniae and non-typeable pneumococci as cause of disease in Spain including invasive disease.
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Affiliation(s)
- Dora Rolo
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Alexandra S. Simões
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Arnau Domenech
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Asunción Fenoll
- National Center for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Josefina Liñares
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Microbiology, The Rockefeller University, New York, New York, United States of America
| | - Carmen Ardanuy
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Raquel Sá-Leão
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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Sistek V, Boissinot M, Boudreau D, Huletsky A, Picard F, Bergeron M. Development of a real-time PCR assay for the specific detection and identification of Streptococcus pseudopneumoniae using the recA gene. Clin Microbiol Infect 2012; 18:1089-96. [DOI: 10.1111/j.1469-0691.2011.03684.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Characterization of recombinant fluoroquinolone-resistant pneumococcus-like isolates. Antimicrob Agents Chemother 2012; 57:254-60. [PMID: 23114769 DOI: 10.1128/aac.01357-12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fourteen fluoroquinolone-resistant streptococcal isolates with recombinant DNA topoisomerase genes, preliminarily identified as pneumococci, were further characterized using phenotypic and genotypic approaches. Phenotypic tests classified them as atypical pneumococci. Phylogenetic relationships were analyzed by using the sequences of seven housekeeping alleles from these isolates and from isolates of Streptococcus pneumoniae, Streptococcus mitis, Streptococcus oralis, and Streptococcus pseudopneumoniae. Four isolates grouped with S. pneumoniae, seven grouped with S. pseudopneumoniae, and three grouped with S. mitis. These results generally agreed with those obtained with an optochin susceptibility test and with the organization of the atp operon chromosomal region, encoding the F(o)F(1) H(+)-ATPase (the target of optochin). All seven isolates grouping with S. pseudopneumoniae share the same spr1368-atpC-atpA gene order; all four grouping with S. pneumoniae share the spr1368-IS1239-atpC-atpA order, and two out of the three grouping with S. mitis share the spr1284-atpC-atpA order. In addition, evidence for recombination within the seven housekeeping alleles of the S. pseudopneumoniae population was provided by several methods: the index of association (0.4598, P < 0.001), the pairwise homoplasy index, and the split-decomposition method. This study confirms the existence of pneumococci among the alpha-hemolytic streptococci with DNA topoisomerase genes showing a mosaic structure and reveals a close relationship between atypical pneumococci and S. pseudopneumoniae.
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16
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Novel molecular method for identification of Streptococcus pneumoniae applicable to clinical microbiology and 16S rRNA sequence-based microbiome studies. J Clin Microbiol 2012; 50:1968-73. [PMID: 22442329 DOI: 10.1128/jcm.00365-12] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The close phylogenetic relationship of the important pathogen Streptococcus pneumoniae and several species of commensal streptococci, particularly Streptococcus mitis and Streptococcus pseudopneumoniae, and the recently demonstrated sharing of genes and phenotypic traits previously considered specific for S. pneumoniae hamper the exact identification of S. pneumoniae. Based on sequence analysis of 16S rRNA genes of a collection of 634 streptococcal strains, identified by multilocus sequence analysis, we detected a cytosine at position 203 present in all 440 strains of S. pneumoniae but replaced by an adenosine residue in all strains representing other species of mitis group streptococci. The S. pneumoniae-specific sequence signature could be demonstrated by sequence analysis or indirectly by restriction endonuclease digestion of a PCR amplicon covering the site. The S. pneumoniae-specific signature offers an inexpensive means for validation of the identity of clinical isolates and should be used as an integrated marker in the annotation procedure employed in 16S rRNA-based molecular studies of complex human microbiotas. This may avoid frequent misidentifications such as those we demonstrate to have occurred in previous reports and in reference sequence databases.
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Streptococcus pseudopneumoniae identification by pherotype: a method to assist understanding of a potentially emerging or overlooked pathogen. J Clin Microbiol 2012; 50:1684-90. [PMID: 22378913 DOI: 10.1128/jcm.00131-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The recent identification of Streptococcus pseudopneumoniae (pseudopneumococcus) has complicated classification schemes within members of the "mitis" streptococcal group. Accurate differentiation of this species is necessary for understanding its disease potential and identification in clinical settings. This work described the use of the competence-stimulatory peptide ComC sequence for identification of S. pseudopneumoniae. ComC sequences from clinical sources were determined for 17 strains of S. pseudopneumoniae, Streptococcus pneumoniae, and Streptococcus oralis. An additional 58 ComC sequences from a range of sources were included to understand the diversity and suitability of this protein as a diagnostic marker for species identification. We identified three pherotypes for this species, delineated CSP6.1 (10/14, 79%), CSP6.3 (3/14, 21%), and SK674 (1/14, 7%). Pseudopneumococcal ComC sequences formed a discrete cluster within those of other oral streptococci. This suggests that the comC sequence could be used to identify S. pseudopneumoniae, thus simplifying the study of the pathogenic potential of this organism. To avoid confusion between pneumococcal and pseudopneumococcal pherotypes, we have renamed the competence pherotype CSP6.1, formerly reported as an "atypical" pneumococcus, CSPps1 to reflect its occurrence in S. pseudopneumoniae.
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18
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New species genetic approach to identify strains of mitis group streptococci that are donors of rifampin resistance to Streptococcus pneumoniae. Antimicrob Agents Chemother 2010; 55:368-72. [PMID: 21041504 DOI: 10.1128/aac.00856-10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eight rifampin-resistant streptococci of the mitis group were identified at the species level by using a concatenated 16S rRNA gene-sodA-rpoB-hlpA sequence. Characterization of their rpoB alleles showed single amino acid changes involved in rifampin resistance. Comparison of RpoB sequences from pneumococcal recombinant isolates, viridans isolates, and type strains revealed a species-specific amino acid signature, which allowed it to be ascertained that recombinant RpoBs were originated in genetic interchanges with Streptococcus mitis and Streptococcus oralis.
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Mittman SA, Huard RC, Della-Latta P, Whittier S. Comparison of the automated Phoenix with the Vitek 2 for the identification of Streptococcus pneumoniae. Can J Microbiol 2010; 56:326-32. [PMID: 20453899 DOI: 10.1139/w10-016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rapid and accurate identification of Streptococcus pneumoniae is a critical component in the optimal management of infected patients. The performance of the BD Phoenix Automated Microbiology System (BD Diagnostic Systems, Sparks, Md.) was evaluated for identification of S. pneumoniae (n = 311) and was compared to the Vitek 2 (bioMérieux, Marcy l'Etoile, France). Strains with discordant identification between methods were resolved with 16S rRNA gene sequencing as the gold standard. The Phoenix and the Vitek 2 correctly identified 96.8% (n = 301) and 95.2% (n = 296) of S. pneumoniae strains, respectively. Overall, there was no statistically significant difference in the performance of the 2 automated systems for the identification of S. pneumoniae in this study. The Vitek 2 mean time-to-results for all streptococcal identification was 1.5 h faster than that for the Phoenix. We conclude that the automated Phoenix and the Vitek 2 systems are comparable in their ability to identify S. pneumoniae and are preferable to the use of routine biochemical assays, which have delayed time-to-results and are not dependably accurate.
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Affiliation(s)
- Scott A Mittman
- Clinical Microbiology Service, NewYork-Presbyterian Hospital, Columbia University Medical Center, New York, NY 10032, USA
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20
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Das A, Behera B, Madan M, Mathur P, Pandey A. Empyema caused by optochin sensitive Streptococcus mitis in the course of varicella. Indian J Pediatr 2010; 77:464. [PMID: 20140766 DOI: 10.1007/s12098-010-0024-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Evidence of localized prophage-host recombination in the lytA gene, encoding the major pneumococcal autolysin. J Bacteriol 2010; 192:2624-32. [PMID: 20304992 DOI: 10.1128/jb.01501-09] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
According to a highly polymorphic region in the lytA gene, encoding the major autolysin of Streptococcus pneumoniae, two different families of alleles can be differentiated by PCR and restriction digestion. Here, we provide evidence that this polymorphic region arose from recombination events with homologous genes of pneumococcal temperate phages.
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Accuracy of phenotypic methods for identification of Streptococcus pneumoniae isolates included in surveillance programs. J Clin Microbiol 2008; 46:2184-8. [PMID: 18495854 DOI: 10.1128/jcm.00461-08] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Similarities between Streptococcus pneumoniae and viridans group streptococci may result in misidentification of these organisms. In surveillance programs which assess antimicrobial resistance rates among respiratory tract pathogens, such identification errors could lead to overestimates of pneumococcal resistance rates. DNA probe analysis (Gen-Probe, San Diego, CA), the bile solubility test, optochin susceptibility, colony morphology, and the capsular swelling reaction with Omni serum (Staten Serum Institut, Copenhagen, Denmark) were used to characterize 1,733 organisms provisionally identified as S. pneumoniae in a 2004 to 2005 antimicrobial resistance surveillance program. These organisms were obtained in 41 U.S. medical centers. Among these, 1,647 (95%) were determined to be S. pneumoniae by DNA probe. Elimination of those isolates found not to be S. pneumoniae resulted in 1 to 2% decreases in resistance rate estimates with penicillin, erythromycin, tetracycline, and trimethoprim-sulfamethoxazole. With AccuProbe as a reference standard, the sensitivities and specificities of each phenotypic method for the identification of S. pneumoniae were, respectively, 98.8% and 82.6% for bile solubility, 99.3% and 74.4% for the capsular swelling reaction with Omni serum, and 87.9% and 59.3% for optochin susceptibility. Colony morphology was of limited value, as 391 (23.7%) isolates lacked the typical button or mucoid colony appearance of S. pneumoniae.
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Savini V, Favaro M, Fontana C, Consilvio NP, Manna A, Talia M, Catavitello C, Balbinot A, Febbo F, Di Bonaventura G, Di Giuseppe N, D'Antonio D. A case of pharyngitis caused by Streptococcus pneumoniae. J Med Microbiol 2008; 57:674-675. [PMID: 18436606 DOI: 10.1099/jmm.0.47641-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Throat cultures from an adult pharyngitis patient yielded Streptococcus pneumoniae as a single organism, with a very high bacterial count. The isolate was found to be macrolide and fluoroquinolone resistant, and the same strain was cultured from the patient's denture washing solution. Ceftriaxone therapy, a gradual reduction in the bacterial count and progressive clinical improvement proceeded at the same pace, so we labelled this clinical case as a pneumococcal pharyngitis.
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Affiliation(s)
- Vincenzo Savini
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Marco Favaro
- Dipartimento di Microbiologia Clinica, Policlinico Torvergata, Roma, Italy
| | - Carla Fontana
- Dipartimento di Microbiologia Clinica, Policlinico Torvergata, Roma, Italy
| | | | - Assunta Manna
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Marzia Talia
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Chiara Catavitello
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Andrea Balbinot
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Fabio Febbo
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Giovanni Di Bonaventura
- Laboratorio di Microbiologia Clinica, Centro Studi Invecchiamento (Ce.S.I.), Università Degli Studi Gabriele D'Annunzio, Chieti, Italy
| | - Nicola Di Giuseppe
- Dipartimento di Otorinolaringoiatria e Chirurgia Cervico-Facciale, Ospedale Civile Spirito Santo, Pescara, Italy
| | - Domenico D'Antonio
- Unità Operativa Complessa di Microbiologia e Virologia Clinica, Dipartimento di Medicina Trasfusionale, Ospedale Civile Spirito Santo, Pescara, Italy
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Polymenakou PN, Mandalakis M, Stephanou EG, Tselepides A. Particle size distribution of airborne microorganisms and pathogens during an Intense African dust event in the eastern Mediterranean. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:292-6. [PMID: 18335093 PMCID: PMC2265054 DOI: 10.1289/ehp.10684] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Accepted: 12/07/2007] [Indexed: 05/21/2023]
Abstract
BACKGROUND The distribution of microorganisms, and especially pathogens, over airborne particles of different sizes has been ignored to a large extent, but it could have significant implications regarding the dispersion of these microorganisms across the planet, thus affecting human health. OBJECTIVES We examined the microbial quality of the aerosols over the eastern Mediterranean region during an African storm to determine the size distribution of microorganisms in the air. METHODS We used a five-stage cascade impactor for bioaerosol collection in a coastal city on the eastern Mediterranean Sea during a north African dust storm. Bacterial communities associated with aerosol particles of six different size ranges were characterized following molecular culture-independent methods, regardless of the cell culturability (analysis of 16S rRNA genes). RESULTS All 16S rDNA clone libraries were diverse, including sequences commonly found in soil and marine ecosystems. Spore-forming bacteria such as Firmicutes dominated large particle sizes (> 3.3 microm), whereas clones affiliated with Actinobacteria (found commonly in soil) and Bacteroidetes (widely distributed in the environment) gradually increased their abundance in aerosol particles of reduced size (< 3.3 microm). A large portion of the clones detected at respiratory particle sizes (< 3.3 microm) were phylogenetic neighbors to human pathogens that have been linked to several diseases. CONCLUSIONS The presence of aerosolized bacteria in small size particles may have significant implications to human health via intercontinental transportation of pathogens.
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