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da Silva MEP, Gomes MADS, Rodrigues RS, Lima NCDS, Carvalho AG, Taborda RLM, Matos NB. Multidrug-resistant Acinetobacter spp. from hospital intensive care units in Brazilian Amazon. Braz J Infect Dis 2023; 27:103687. [PMID: 37977198 PMCID: PMC10667742 DOI: 10.1016/j.bjid.2023.103687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/19/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023] Open
Abstract
Acinetobacter spp. are one of the main pathogens responsible for healthcare-associated infections and are associated with high rates of morbidity and mortality globally, mainly because of their high capacity to present and develop resistance to antimicrobials. To identify species of the Acinetobacter and their resistance profiles from samples collected from hospitalized patients, health professionals and hospital environmental sources in the intensive care units of different public reference hospitals in Porto Velho City, Rondônia, Western Brazilian Amazon. Isolates were identified using microbiological and molecular techniques. The antimicrobial susceptibility profile was determined by disk diffusion. A total of 201 Acinetobacter spp. isolates were identified, of which 47.3% originated from hospital structures, 46.8% from patients and 6% from healthcare professionals. A. baumannii and A. nosocomialis were the most prevalent, with frequency of 58.7% and 31.8%, respectively. Regarding the susceptibility profile, it was observed that 56.3% were classified as multidrug-resistant and 76.2% of the samples belonging to A. baumannii were resistant to carbapenems. In contrast, 96.9% were susceptible to polymyxin B and 91.3% to doxycycline. The data presented here can be used to guide and strengthen the control of multidrug-resistant infections caused by Acinetobacter spp., in addition to improving providing information from a traditionally unassisted region of Brazil.
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Affiliation(s)
- Marcos Eduardo Passos da Silva
- Fundação Oswaldo Cruz (FIOCRUZ/RO), Laboratório de Microbiologia, Porto Velho, RO, Brazil; Universidade Federal de Rondônia (UNIR), Porto Velho, RO, Brazil; Programa de Pós-Graduação em Biologia Experimental, Porto Velho, RO, Brazil
| | | | - Renata Santos Rodrigues
- Instituto Oswaldo Cruz (IOC), Programa de Pós-graduação em Biologia Celular e Molecular (PGBCM), Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Nucia Cristiane da Silva Lima
- Fundação Oswaldo Cruz (FIOCRUZ/RO), Laboratório de Microbiologia, Porto Velho, RO, Brazil; Centro de Pesquisa em Medicina Tropical de Rondônia (CEPEM), Porto Velho, RO, Brazil
| | - Anjo Gabriel Carvalho
- Fundação Oswaldo Cruz (FIOCRUZ/RO), Laboratório de Microbiologia, Porto Velho, RO, Brazil; Universidade Federal de Rondônia (UNIR), Porto Velho, RO, Brazil; Programa de Pós-Graduação em Biologia Experimental, Porto Velho, RO, Brazil
| | | | - Najla Benevides Matos
- Fundação Oswaldo Cruz (FIOCRUZ/RO), Laboratório de Microbiologia, Porto Velho, RO, Brazil; Universidade Federal de Rondônia (UNIR), Porto Velho, RO, Brazil; Programa de Pós-Graduação em Biologia Experimental, Porto Velho, RO, Brazil; Centro de Pesquisa em Medicina Tropical de Rondônia (CEPEM), Porto Velho, RO, Brazil; Instituto Nacional de Epidemiologia na Amazônia Ocidental (INCT-EPIAMO), Porto Velho, RO, Brazil.
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Gaytán MO, Singh AK, Woodiga SA, Patel SA, An SS, Vera-Ponce de León A, McGrath S, Miller AR, Bush JM, van der Linden M, Magrini V, Wilson RK, Kitten T, King SJ. A novel sialic acid-binding adhesin present in multiple species contributes to the pathogenesis of Infective endocarditis. PLoS Pathog 2021; 17:e1009222. [PMID: 33465168 PMCID: PMC7846122 DOI: 10.1371/journal.ppat.1009222] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 01/29/2021] [Accepted: 11/30/2020] [Indexed: 02/07/2023] Open
Abstract
Bacterial binding to platelets is a key step in the development of infective endocarditis (IE). Sialic acid, a common terminal carbohydrate on host glycans, is the major receptor for streptococci on platelets. So far, all defined interactions between streptococci and sialic acid on platelets are mediated by serine-rich repeat proteins (SRRPs). However, we identified Streptococcus oralis subsp. oralis IE-isolates that bind sialic acid but lack SRRPs. In addition to binding sialic acid, some SRRP- isolates also bind the cryptic receptor β-1,4-linked galactose through a yet unknown mechanism. Using comparative genomics, we identified a novel sialic acid-binding adhesin, here named AsaA (associated with sialic acid adhesion A), present in IE-isolates lacking SRRPs. We demonstrated that S. oralis subsp. oralis AsaA is required for binding to platelets in a sialic acid-dependent manner. AsaA comprises a non-repeat region (NRR), consisting of a FIVAR/CBM and two Siglec-like and Unique domains, followed by 31 DUF1542 domains. When recombinantly expressed, Siglec-like and Unique domains competitively inhibited binding of S. oralis subsp. oralis and directly interacted with sialic acid on platelets. We further demonstrated that AsaA impacts the pathogenesis of S. oralis subsp. oralis in a rabbit model of IE. Additionally, we found AsaA orthologues in other IE-causing species and demonstrated that the NRR of AsaA from Gemella haemolysans blocked binding of S. oralis subsp. oralis, suggesting that AsaA contributes to the pathogenesis of multiple IE-causing species. Finally, our findings provide evidence that sialic acid is a key factor for bacterial-platelets interactions in a broader range of species than previously appreciated, highlighting its potential as a therapeutic target. Infective endocarditis (IE) is typically a bacterial infection of the heart valves that causes high mortality. Infective endocarditis can affect people with preexisting lesions on their heart valves (Subacute IE). These lesions contain platelets and other host factors to which bacteria can bind. Growth of bacteria and accumulation of host factors results in heart failure. Therefore, the ability of bacteria to bind platelets is key to the development of IE. Here, we identified a novel bacterial protein, AsaA, which helps bacteria bind to platelets and contributes to the development of disease. Although this virulence factor was characterized in Streptococcus oralis, a leading cause of IE, we demonstrated that AsaA is also present in several other IE-causing bacterial species and is likely relevant to their ability to cause disease. We showed that AsaA binds to sialic acid, a terminal sugar present on platelets, thereby demonstrating that sialic acid serves as a receptor for a wider range of IE-causing bacteria than previously appreciated, highlighting its potential as a therapeutic target.
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Affiliation(s)
- Meztlli O. Gaytán
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Anirudh K. Singh
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Shireen A. Woodiga
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Surina A. Patel
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Seon-Sook An
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Arturo Vera-Ponce de León
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Sean McGrath
- Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Anthony R. Miller
- Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Jocelyn M. Bush
- Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Mark van der Linden
- Institute of Medical Microbiology, German National Reference Center for Streptococci, University Hospital (RWTH), Aachen, Germany
| | - Vincent Magrini
- Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Richard K. Wilson
- Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Todd Kitten
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Samantha J. King
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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Role of Neuraminidase-Producing Bacteria in Exposing Cryptic Carbohydrate Receptors for Streptococcus gordonii Adherence. Infect Immun 2018; 86:IAI.00068-18. [PMID: 29661931 DOI: 10.1128/iai.00068-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/13/2018] [Indexed: 12/11/2022] Open
Abstract
Streptococcus gordonii is an early colonizer of the oral cavity. Although a variety of S. gordonii adherence mechanisms have been described, current dogma is that the major receptor for S. gordonii is sialic acid. However, as many bacterial species in the oral cavity produce neuraminidase that can cleave terminal sialic acid, it is unclear whether S. gordonii relies on sialic acid for adherence to oral surfaces or if this species has developed alternative binding strategies. Previous studies have examined adherence to immobilized glycoconjugates and identified binding to additional glycans, but no prior studies have defined the contribution of these different glycan structures in adherence to oral epithelial cells. We determined that the majority of S. gordonii strains tested did not rely on sialic acid for efficient adherence. In fact, adherence of some strains was significantly increased following neuraminidase treatment. Further investigation of representative strains that do not rely on sialic acid for adherence revealed binding not only to sialic acid via the serine-rich repeat protein GspB but also to β-1,4-linked galactose. Adherence to this carbohydrate occurs via an unknown adhesin distinct from those utilized by Streptococcus oralis and Streptococcus pneumoniae Demonstrating the potential biological relevance of binding to this cryptic receptor, we established that S. oralis increases S. gordonii adherence in a neuraminidase-dependent manner. These data suggest that S. gordonii has evolved to simultaneously utilize both terminal and cryptic receptors in response to the production of neuraminidase by other species in the oral environment.
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Cunha S, Mendes Â, Rego D, Meireles D, Fernandes R, Carvalho A, Costa PMD. Effect of competitive exclusion in rabbits using an autochthonous probiotic. WORLD RABBIT SCIENCE 2017. [DOI: 10.4995/wrs.2017.4533] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
<p>Animal nutrition has been severely challenged by the ban on antimicrobials as growth promoters. This has fostered the study of alternative methods to avoid colonisation by pathogenic bacteria as well as to improve the growth of animals and feed conversion efficiency. These new options should not alter the normal intestinal microbiota, or affect it as little as possible. The use of probiotics, which are live microorganisms that beneficially affect the host by improving its intestinal microbial balance, can be seen as a promising way to achieve that goal. In this study, New Zealand White rabbits were fed diets containing an autochthonous probiotic of Enterococcus spp., with the strains EaI, EfaI and EfaD, and Escherichia coli, with the strains ECI 1, ECI 2 and ECD, during a 25-d trial, to evaluate the impact of the probiotic on the faecal microbiota, including population dynamics and antimicrobial resistance profiles. A control group of rabbits, which was fed a diet containing a commonly used mixture of antimicrobials (colistin, oxytetracycline, and valnemulin), was also studied. To assess the colonisation ability of the mentioned probiotic, the faecal microbiota of the rabbits was characterised up to 10 d after the administration had ended. Isolates of enterococci and E. coli were studied for phylogenetic relationships using enterobacterial repetitive intergenic consensus (ERIC-PCR) and pulse-field gel electrophoresis (PFGE), respectively. Although partially affected by an unexpected clinical impairment suffered by the rabbits in the experimental group, our results showed the following. The difference between the growth rate of the animals treated with antimicrobials and those fed the probiotic was not statistically significant (P> 0.05). The competitive exclusion product was present in the faecal samples in a large proportion, but stopped being recovered by culture as soon as the administration ended and the housing conditions were changed. Multidrug-resistant strains of enterococci and E. coli were more commonly recovered from faecal samples of animals fed diets containing antimicrobials, than from rabbits fed diets with our probiotic formula. The use of E. coli probiotics to prevent infection by enteropathogenic strains must be carefully considered due to the possible occurrence of gastrointestinal signs. On the other hand, enterococci strains may be more effective, but lack the long-term colonisation ability.</p>
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Cui W, Liu J, Su D, Hu D, Hou S, Hu T, Yang J, Luo Y, Xi Q, Chu B, Wang C. Identification of ssDNA aptamers specific to clinical isolates of Streptococcus mutans strains with different cariogenicity. Acta Biochim Biophys Sin (Shanghai) 2016; 48:563-72. [PMID: 27151293 DOI: 10.1093/abbs/gmw034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/29/2016] [Indexed: 11/13/2022] Open
Abstract
Streptococcus mutans, a Gram-positive facultative anaerobic bacterium, is considered to be a major etiological factor for dental caries. In this study, plaques from dental enamel surfaces of caries-active and caries-free individuals were obtained and cultivated for S. mutans isolation. Morphology examination, biochemical characterization, and polymerase chain reaction were performed to identify S. mutans The cariogenicity of S. mutans strains isolated from clinical specimens was evaluated by testing the acidogenicity, aciduricity, extracellular polysaccharide production, and adhesion ability of the bacteria. Finally, subtractive SELEX (systematic evolution of ligands by exponential enrichment) technology targeting whole intact cells was used to screen for ssDNA aptamers specific to the strains with high cariogenicity. After nine rounds of subtractive SELEX, sufficient pool enrichment was achieved as shown by radioactive isotope analysis. The enriched pool was cloned and sequenced randomly, followed by MEME online and RNA structure software analysis of the sequences. Results from the flow cytometry indicated that aptamers H1, H16, H4, L1, L10, and H19 could discriminate highly cariogenic S. mutans strains from poorly cariogenic strains. Among these, Aptamer H19 had the strongest binding capacity with cariogenic S. mutans strains with a dissociation constant of 69.45 ± 38.53 nM. In conclusion, ssDNA aptamers specific to highly cariogenic clinical S. mutans strains were successfully obtained. These ssDNA aptamers might be used for the early diagnosis and treatment of dental caries.
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Affiliation(s)
- Wei Cui
- Department of Stomatology, Chinese PLA General Hospital, Beijing 100853, China Department of Stomatology, Chinese PLA No. 513 Hospital, Lanzhou 732750, China
| | - Jiaojiao Liu
- Department of Stomatology, General Hospital of Shenyang Command, Shenyang 110840, China
| | - Donghua Su
- Department of Special Clinic, School of Stomatology, Fourth Military Medical University, Xi'an 710032, China
| | - Danyang Hu
- Xiaopingdao Division, Dalian Sanatorium of Shenyang Military Region, Dalian 116023, China
| | - Shuai Hou
- Department of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
| | - Tongnan Hu
- Department of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
| | - Jiyong Yang
- Department of Microbiology, Chinese PLA General Hospital, Beijing 100853, China
| | - Yanping Luo
- Xiaopingdao Division, Dalian Sanatorium of Shenyang Military Region, Dalian 116023, China
| | - Qing Xi
- Department of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
| | - Bingfeng Chu
- Department of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
| | - Chenglong Wang
- Department of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
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Streptococcus anginosus Infections; Clinical and Bacteriologic Characteristics. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2016. [DOI: 10.1097/ipc.0000000000000318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tyagi S, Singh DK. Pseudacidovorax austerolens sp. nov., a nifH bacterium isolated from Himalayan valley soil, India. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-014-0852-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Arbefeville S, Levi MH, Ferrieri P. Development of a multiplex real-time PCR assay for the detection of Bordetella pertussis and Bordetella parapertussis in a single tube reaction. J Microbiol Methods 2013; 97:15-9. [PMID: 24333686 DOI: 10.1016/j.mimet.2013.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 12/04/2013] [Accepted: 12/04/2013] [Indexed: 12/01/2022]
Abstract
Pertussis is an infectious respiratory disease caused by the fastidious bacterium Bordetella pertussis, which may infect unvaccinated, previously vaccinated children, and adults in whom immunity has waned. Infants are at a particular risk for severe disease and complications. Bordetella parapertussis may cause a similar illness, however the symptoms are less severe and of shorter duration. Pertussis is a highly contagious disease and early diagnosis is essential. Studies have shown that PCR is 2-4 times more likely than culture to detect Bordetella pertussis. We developed a multiplex, real-time PCR assay using analyte-specific reagent (ASR) primers and probes dispensed in a convenient lyophilized bead format that targeted the multi-copy insertion sequences IS481 and IS1001 of B. pertussis and B. parapertussis, respectively. These specific ASRs were used in conjunction with Cepheid Smartmix. Included in the ASRs is a competitive internal control to evaluate the performance of the PCR reaction. After DNA extraction, amplification and detection were done on the Smart Cycler System, which performs integrated amplification and detection automatically in a single step. Specificity of the assay was confirmed using multiple distinct bacterial strains. Sensitivity of the assay and extraction efficiency were evaluated on DNA isolated from pure bacterial cultures and on spiked respiratory specimens. We also spiked different swab types and transport media to evaluate for interfering substances. To assess accuracy, we studied different patient specimen types received from two outside laboratories that used similar or different methods to detect B. pertussis and B. parapertussis. The sensitivity and the specificity of the assay for B. pertussis were 90% and 96%, respectively, and for B. parapertussis 71% (only 7 positive specimens were available for testing) and 100%, respectively. Our assay was found to be a valid method for the simultaneous detection of B. pertussis and B. parapertussis.
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Affiliation(s)
- Sophie Arbefeville
- Department of Laboratory Medicine and Pathology, U. of Minnesota Medical School, Minneapolis, MN, United States.
| | - Michael H Levi
- Division of Pathology, Montefiore Medical Center and the Albert Einstein College of Medicine, Bronx, NY, United States
| | - Patricia Ferrieri
- Department of Laboratory Medicine and Pathology, U. of Minnesota Medical School, Minneapolis, MN, United States
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Corcuera MT, Gómez-Lus ML, Gómez-Aguado F, Maestre JR, Ramos MDC, Alonso MJ, Prieto J. Morphological plasticity of Streptococcus oralis isolates for biofilm production, invasiveness, and architectural patterns. Arch Oral Biol 2013; 58:1584-93. [PMID: 24112723 DOI: 10.1016/j.archoralbio.2013.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 06/03/2013] [Accepted: 07/23/2013] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Streptococcus oralis is an early coloniser of the oral cavity that contributes to dental plaque formation. Many different genotypes can coexist in the same individual and cause opportunistic infections such as bacterial endocarditis. However, little is known about virulence factors involved in those processes. The aim was to analyze the evolving growth of S. oralis colony/biofilm to find out potentially pathogenic features. DESIGN Thirty-three S. oralis isolates were analyzed for: (1) biofilm production, by spectrophotometric microtiter plate assay; (2) colonial internal architecture, by histological methods and light and electron microscopy; (3) agar invasion, by a new colony-biofilm assay. RESULTS S. oralis colonies showed two different growth patterns: (1) fast growth rate without invasion or minimally invasive; (2) slow growth rate, but high invasion ability. 12.1% of strains were biofilm non-producers and 24.2% not invasive, compared to 51.5% biofilm high-producers and 39.4% very invasive. Both phenotypic characteristics tended to be mutually exclusive. However, a limited number of strains (15%) co-expressed these features at the highest level. CONCLUSIONS Morphological plasticity of S. oralis highlighted in this study may have important ecological and clinical implications. Coexistence of strains with different growth patterns could produce a synergic effect in the formation and development of subgingival dental plaque. Moreover, invasiveness might regulate dissemination and colonisation mechanisms. Simultaneous co-expression of high-invasive and high-biofilm phenotypes gives a fitness advantage during colonisation and may confer higher pathogenic potential.
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Okada T, Fujita K, Suzuki H, Tsuzukibashi O, Umezawa K, Nagahama F, Ikemi T, Takada K. Distribution and sequencing of enterobacterial repetitive intergenic consensus sequence elements in Streptococcus mutans serotype c. J Oral Biosci 2013. [DOI: 10.1016/j.job.2013.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cheon K, Moser SA, Wiener HW, Whiddon J, Momeni SS, Ruby JD, Cutter GR, Childers NK. Characteristics of Streptococcus mutans genotypes and dental caries in children. Eur J Oral Sci 2013; 121:148-55. [PMID: 23659236 DOI: 10.1111/eos.12044] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2013] [Indexed: 11/30/2022]
Abstract
This longitudinal cohort study evaluated the diversity, commonality, and stability of Streptococcus mutans genotypes associated with dental caries history. Sixty-seven 5- and 6-yr-old children, considered as being at high caries risk, had plaque collected from baseline through 36 months for S. mutans isolation and genotyping using repetitive extragenic palindromic-PCR (4,392 total isolates). Decayed, missing, or filled surfaces (dmfs (primary teeth)/DMFS (secondary teeth)) for each child were recorded at baseline. At baseline, 18 distinct genotypes were found among 911 S. mutans isolates from 67 children (diversity), and 13 genotypes were shared by at least two children (commonality). The number of genotypes per individual was positively associated with the proportion of decayed surfaces (p-ds) at baseline. Twenty-four of the 39 children who were available at follow-up visits maintained a predominant genotype for the follow-up periods (stability) and this was negatively associated with the p-ds. The observed diversity, commonality, and stability of S. mutans genotypes represent a pattern of dental caries epidemiology in this high-caries-risk community, which suggests that fewer decayed surfaces are significantly associated with lower diversity and higher stability of S. mutans genotypes.
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Affiliation(s)
- Kyounga Cheon
- Department of Pediatric Dentistry, University of Alabama School of Dentistry, Birmingham, AL 35294, USA
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Thompson CC, Emmel VE, Fonseca EL, Marin MA, Vicente ACP. Streptococcal taxonomy based on genome sequence analyses. F1000Res 2013; 2:67. [PMID: 24358875 PMCID: PMC3799547 DOI: 10.12688/f1000research.2-67.v1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/27/2013] [Indexed: 11/20/2022] Open
Abstract
The identification of the clinically relevant viridans streptococci group, at species level, is still problematic. The aim of this study was to extract taxonomic information from the complete genome sequences of 67 streptococci, comprising 19 species, by means of genomic analyses, multilocus sequence analysis (MLSA), average amino acid identity (AAI), genomic signatures, genome-to-genome distances (GGD) and codon usage bias. We then attempted to determine the usefulness of these genomic tools for species identification in streptococci. Our results showed that MLSA, AAI and GGD analyses are robust markers to identify streptococci at the species level, for instance,
S. pneumoniae,
S. mitis, and
S. oralis. A
Streptococcus species can be defined as a group of strains that share ≥ 95% DNA similarity in MLSA and AAI, and > 70% DNA identity in GGD. This approach allows an advanced understanding of bacterial diversity.
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Affiliation(s)
- Cristiane C Thompson
- Laboratory of Molecular Genetics of Microorganisms, Oswaldo Cruz Institute (IOC - FIOCRUZ) Avenida Brasil 4365, Manguinhos, Rio de Janeiro, P. O. Box 926, Zip Code 21040-360, Brazil
| | - Vanessa E Emmel
- Laboratory of Molecular Genetics of Microorganisms, Oswaldo Cruz Institute (IOC - FIOCRUZ) Avenida Brasil 4365, Manguinhos, Rio de Janeiro, P. O. Box 926, Zip Code 21040-360, Brazil
| | - Erica L Fonseca
- Laboratory of Molecular Genetics of Microorganisms, Oswaldo Cruz Institute (IOC - FIOCRUZ) Avenida Brasil 4365, Manguinhos, Rio de Janeiro, P. O. Box 926, Zip Code 21040-360, Brazil
| | - Michel A Marin
- Laboratory of Molecular Genetics of Microorganisms, Oswaldo Cruz Institute (IOC - FIOCRUZ) Avenida Brasil 4365, Manguinhos, Rio de Janeiro, P. O. Box 926, Zip Code 21040-360, Brazil
| | - Ana Carolina P Vicente
- Laboratory of Molecular Genetics of Microorganisms, Oswaldo Cruz Institute (IOC - FIOCRUZ) Avenida Brasil 4365, Manguinhos, Rio de Janeiro, P. O. Box 926, Zip Code 21040-360, Brazil
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Nyvad B, Crielaard W, Mira A, Takahashi N, Beighton D. Dental Caries from a Molecular Microbiological Perspective. Caries Res 2013. [DOI: 10.1159/000345367] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Amplification of oral streptococcal DNA from human incisors and bite marks. Curr Microbiol 2012; 65:207-11. [PMID: 22638842 DOI: 10.1007/s00284-012-0148-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 05/04/2012] [Indexed: 10/28/2022]
Abstract
Challenges to the evidentiary value of morphometric determinations have led to a requirement for scientifically substantiated approaches to the forensic analysis of bite marks. Human teeth support genotypically distinctive populations of bacteria that could be exploited for forensic purposes. This study explored the feasibility of directly amplifying bacterial DNA from bite marks for comparison with that from teeth. Samples from self-inflicted experimental bite marks (n = 24) and human incisors were amplified by PCR using primers specific for streptococcal 16S ribosomal DNA. Amplicon profiles (resolved by denaturing gradient gel electrophoresis) from bite mark samples aligned significantly more closely with profiles generated from the teeth responsible than with those from other teeth. Streptococcal amplicons were generated from dental samples applied to excised porcine skin for up to 48 h. These findings indicate that streptococcal DNA can be amplified directly from bite marks, and have potential application in bite mark analysis.
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Okada T, Takada K, Fujita K, Ikemi T, Osgood RC, Childers NK, Michalek SM. Differentiation of banding patterns between Streptococcus mutans and Streptococcus sobrinus isolates in rep-PCR using ERIC primer. J Oral Microbiol 2011; 3:JOM-3-7190. [PMID: 22145074 PMCID: PMC3230236 DOI: 10.3402/jom.v3i0.7190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 11/09/2011] [Accepted: 11/09/2011] [Indexed: 11/18/2022] Open
Abstract
Background Streptococcus mutans and Streptococcus sobrinus are considered to be important bacterial species in the initiation of human dental caries. Therefore, the establishment of a reliable genotyping method to distinguish S. mutans from S. sobrinus is of central importance. Objective We assessed the usefulness of repetitive extragenic palindromic polymerase chain reaction (rep-PCR) using ERIC primer banding patterns in differentiating S. mutans and S. sobrinus. Design Five S. mutans and two S. sobrinus prototype strains and 50 clinical isolates (38 S. mutans serotype c, 4 S. sobrinus serotype d, and 8 S. sobrinus serotype g) were examined. The banding patterns of amplicons generated were compared among the prototype strains and clinical isolates, to find common bands that distinguish S. mutans and S. sobrinus. Results Multiple banding patterns were seen with all strains tested. The representative strains of S. mutans tested revealed six unique, strong bands at 2,000 bp, 1,700 bp, 1,400 bp, 1,100 bp, 850 bp, and 250 bp, whereas S. sobrinus had seven strong bands at 2,000 bp, 1,800 bp, 1,100 bp, 900 bp, 800 bp, 600 bp, and 550 bp. The band at 1,100 bp was the only band that was observed in both S. mutans and S. sobrinus. Furthermore, most clinical S. mutans isolates revealed identical banding patterns. All S. mutans had amplicons at 1,700 bp, 850 bp, and 250 bp, whereas those of S. sobrinus were at 1,100 bp, 900 bp, and 800 bp. Conclusions These results indicate that using rep-PCR with the ERIC primers can distinguish between S. mutans and S. sobrinus.
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Affiliation(s)
- Tamami Okada
- Department of Operative Dentistry, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
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Abstract
The aim of this paper is to give a brief overview of bite mark analysis: its usefulness and limitations. The study and analysis of such injuries is challenging and complex. The correct protocols for collection, management, preservation, analysis and interpretation of this evidence should be employed if useful information is to be obtained for the courts. It is now possible, with advances in digital technology, to produce more accurate and reproducible comparison techniques which go some way to preventing and reducing problems such as photographic distortions. Research needs to be continued to increase our knowledge of the behaviour of skin when bitten. However, when presented with a high quality bite mark showing good dental detail, and a limited, accessible number of potential biters, it can be extremely useful in establishing a link between the bitten person and the biter or excluding the innocent.
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Cheon K, Moser SA, Whiddon J, Osgood RC, Momeni S, Ruby JD, Cutter GR, Allison DB, Childers NK. Genetic diversity of plaque mutans streptococci with rep-PCR. J Dent Res 2011; 90:331-5. [PMID: 21297016 DOI: 10.1177/0022034510386375] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Mutans streptococci (MS) are key organisms associated with the etiology of dental caries. Using probabilities that were tested by oversampling, we designed this study to determine the minimal number of MS isolates from an individual required to evaluate diversity of genotypes. MS isolates were genotyped by repetitive extragenic palindromic-polymerase chain-reaction (rep-PCR). Analysis of 20 isolates from individuals resulted in a mean of 1.6 and 2.4 genotypes in children (N = 12) and adults (N = 10), respectively. In a follow-up study, reducing the number of isolates to 7-10 resulted in a theoretical probability of up to 78% for detecting up to 4 genotypes. A mean of 1.5 genotypes was found in 35 children and 10 adults. These findings provide evidence for the design of studies of MS genotyping that can serve as a model for the analysis of genotypes within individuals.
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Affiliation(s)
- K Cheon
- Department of Pediatric Dentistry, University of Alabama School of Dentistry, 1919 7th Avenue South, Birmingham, AL 35294, USA
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Teles C, Smith A, Ramage G, Lang S. Identification of clinically relevant viridans group streptococci by phenotypic and genotypic analysis. Eur J Clin Microbiol Infect Dis 2010; 30:243-50. [DOI: 10.1007/s10096-010-1076-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 09/21/2010] [Indexed: 11/24/2022]
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Propionibacterium acnes and Staphylococcus epidermidis isolated from refractory endodontic lesions are opportunistic pathogens. J Clin Microbiol 2010; 48:3859-69. [PMID: 20739494 DOI: 10.1128/jcm.01326-10] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The predominant cultivable microbiota from 20 refractory endodontic lesions (9 with abscesses and 11 without abscesses) were determined, and Propionibacterium acnes and Staphylococcus epidermidis were among the most predominant organisms. The number of species identified from lesions with abscesses (14.1 ± 2.6) was significantly greater (P < 0.001) than the number from lesions without abscesses (7.4 ± 5.9). Comparison of perioral isolates using repetitive extragenic palindromic PCR of the same species from the same subjects demonstrated that the endodontic and skin populations were significantly different. The P. acnes isolates were typed on the basis of recA gene sequence comparison, and only three types (types I, II, and III) were identified among 125 isolates examined. However, we found that type I (type IA and IB) isolates were primarily isolated from the skin, while types II and III were significantly more likely to be isolated from the endodontic lesions (P < 10(-10)). We found that the robustness of the recA phylotypes was not strong by comparing the partial gene sequences of six putative virulence determinants, PAmce, PAp60, PA-25957, PA-5541, PA-21293, and PA-4687. The resulting neighbor-joining trees were incongruent, and significant (phi test; P = 2.2 × 10(-7)) evidence of recombination was demonstrated, with significant phylogenetic heterogeneity being apparent within the clusters. P. acnes and S. epidermidis isolated from refractory endodontic infections, with or without periapical abscesses, are likely to be nosocomial infections.
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Ota-Tsuzuki C, Alves Mayer MP. Collagenase production and hemolytic activity related to 16S rRNA variability among Parvimonas micra oral isolates. Anaerobe 2010; 16:38-42. [DOI: 10.1016/j.anaerobe.2009.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 09/20/2008] [Accepted: 03/25/2009] [Indexed: 10/20/2022]
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21
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Repetitive extragenic palindromic PCR for study of Streptococcus mutans diversity and transmission in human populations. J Clin Microbiol 2009; 48:599-602. [PMID: 20007400 DOI: 10.1128/jcm.01828-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pulsed-field gel electrophoresis (PFGE) is considered the "gold standard" for molecular epidemiological study. Repetitive extragenic palindromic PCR (rep-PCR) is less time-consuming and more suitable for analyzing large numbers of bacterial strains in human populations. PFGE and rep-PCR provide comparable genotyping results for investigating Streptococcus mutans diversity and transmission.
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22
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Do T, Jolley KA, Maiden MCJ, Gilbert SC, Clark D, Wade WG, Beighton D. Population structure of Streptococcus oralis. MICROBIOLOGY-SGM 2009; 155:2593-2602. [PMID: 19423627 PMCID: PMC2885674 DOI: 10.1099/mic.0.027284-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Streptococcus oralis is a member of the normal human oral microbiota, capable of opportunistic pathogenicity; like related oral streptococci, it exhibits appreciable phenotypic and genetic variation. A multilocus sequence typing (MLST) scheme for S. oralis was developed and the resultant data analysed to examine the population structure of the species. Analysis of 113 isolates, confirmed as belonging to the S. oralis/mitis group by 16S rRNA gene sequencing, characterized the population as highly diverse and undergoing inter- and intra-species recombination with a probable clonal complex structure. ClonalFrame analysis of these S. oralis isolates along with examples of Streptococcus pneumoniae, Streptococcus mitis and Streptococcus pseudopneumoniae grouped the named species into distinct, coherent populations and did not support the clustering of S. pseudopneumoniae with S. mitis as reported previously using distance-based methods. Analysis of the individual loci suggested that this discrepancy was due to the possible hybrid nature of S. pseudopneumoniae. The data are available on the public MLST website (http://pubmlst.org/soralis/).
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Affiliation(s)
- Thuy Do
- King's College London Dental Institute at Guy's, King's College and St Thomas' Hospitals, Infection Research Group, Guy's Campus, London SE1 9RT, UK
- Biomedical Research Centre, Guy's and St Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK
| | - Keith A. Jolley
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
| | | | - Steven C. Gilbert
- King's College London Dental Institute at Guy's, King's College and St Thomas' Hospitals, Infection Research Group, Guy's Campus, London SE1 9RT, UK
- Biomedical Research Centre, Guy's and St Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK
| | - Douglas Clark
- King's College London Dental Institute at Guy's, King's College and St Thomas' Hospitals, Infection Research Group, Guy's Campus, London SE1 9RT, UK
| | - William G. Wade
- King's College London Dental Institute at Guy's, King's College and St Thomas' Hospitals, Infection Research Group, Guy's Campus, London SE1 9RT, UK
| | - David Beighton
- King's College London Dental Institute at Guy's, King's College and St Thomas' Hospitals, Infection Research Group, Guy's Campus, London SE1 9RT, UK
- Biomedical Research Centre, Guy's and St Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK
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Ota-Tsuzuki C, Brunheira ATP, Mayer MPA. 16S rRNA region based PCR protocol for identification and subtyping of Parvimonas micra. Braz J Microbiol 2008; 39:605-7. [PMID: 24031274 PMCID: PMC3768457 DOI: 10.1590/s1517-83822008000400001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 05/19/2007] [Accepted: 11/02/2008] [Indexed: 11/22/2022] Open
Abstract
The present study established a PCR protocol in order to identify Parvimonas micra and to evaluate the intra-species diversity by PCR-RFLP of 16S rRNA partial sequence. The data indicated that the protocol was able to identify this species which could be clustered in five genotypes.
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Affiliation(s)
- C Ota-Tsuzuki
- Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, SP , Brasil
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Streptococcus intermedius causing infective endocarditis and abscesses: a report of three cases and review of the literature. BMC Infect Dis 2008; 8:154. [PMID: 18992173 PMCID: PMC2600825 DOI: 10.1186/1471-2334-8-154] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 11/10/2008] [Indexed: 11/30/2022] Open
Abstract
Background Streptococcus intermedius is a member of the Streptococcus anginosus group. Clinical disease with S. intermedius is characterized by abscess formation and rarely endocarditis. Identification of Streptococcus intermedius is difficult, leading to the development of molecular methods to more accurately identify and characterize this organism. Case presentation Over a period of 6 months we encountered three cases of invasive Streptococcus intermedius infection presenting as hepatic abscesses, brain abscess, and endocarditis. We confirmed our microbiologic diagnosis through 16S sequencing and found a common virulence gene in each case. Conclusion Our report illustrates three different clinical manifestations due to Streptococcus intermedius infection that can be encountered in healthy individuals in a community hospital setting. To our knowledge, this is the first case of Streptococcus intermedius endocarditis confirmed by 16S sequencing analysis. The use of molecular methods may allow a better understanding of the epidemiology and pathogenesis of this organism.
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Characterization of a Streptococcus sp.-Veillonella sp. community micromanipulated from dental plaque. J Bacteriol 2008; 190:8145-54. [PMID: 18805978 DOI: 10.1128/jb.00983-08] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococci and veillonellae occur in mixed-species colonies during formation of early dental plaque. One factor hypothesized to be important in assembly of these initial communities is coaggregation (cell-cell recognition by genetically distinct bacteria). Intrageneric coaggregation of streptococci occurs when a lectin-like adhesin on one streptococcal species recognizes a receptor polysaccharide (RPS) on the partner species. Veillonellae also coaggregate with streptococci. These genera interact metabolically; lactic acid produced by streptococci is a carbon source for veillonellae. To transpose these interactions from undisturbed dental plaque to an experimentally tractable in vitro biofilm model, a community consisting of RPS-bearing streptococci juxtaposed with veillonellae was targeted by quantum dot-based immunofluorescence and then micromanipulated off the enamel surface and cultured. Besides the expected antibody-reactive cell types, a non-antibody-reactive streptococcus invisible during micromanipulation was obtained. The streptococci were identified as Streptococcus oralis (RPS bearing) and Streptococcus gordonii (adhesin bearing). The veillonellae could not be cultivated; however, a veillonella 16S rRNA gene sequence was amplified from the original isolation mixture, and this sequence was identical to the sequence of the previously studied organism Veillonella sp. strain PK1910, an oral isolate in our culture collection. S. oralis coaggregated with S. gordonii by an RPS-dependent mechanism, and both streptococci coaggregated with PK1910, which was used as a surrogate during in vitro community reconstruction. The streptococci and strain PK1910 formed interdigitated three-species clusters when grown as a biofilm using saliva as the nutritional source. PK1910 grew only when streptococci were present. This study confirms that RPS-mediated intrageneric coaggregation occurs in the earliest stages of plaque formation by bringing bacteria together to create a functional community.
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Evaluation of (GTG)5-PCR for rapid identification of Streptococcus mutans. Antonie van Leeuwenhoek 2008; 94:573-9. [PMID: 18709544 DOI: 10.1007/s10482-008-9275-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Accepted: 08/01/2008] [Indexed: 10/21/2022]
Abstract
Repetitive sequence-based polymerase chain reaction (PCR) fingerprinting using the (GTG)(5) primer was applied for fast screening of bacterial strains isolated from dental plaque of early childhood caries (ECC)-affected children. A group of 29 Gram-positive bacteria was separated into a homogeneous cluster together with Streptococcus mutans reference strains and constituted an aberrant branch after the numerical analysis of (GTG)(5)-PCR fingerprints. Automated ribotyping with EcoRI restriction enzyme (RiboPrinter microbial characterization system) revealed high genetic heterogeneity among the tested group and proved to be a good tool for strain-typing purposes. Further characterization of the studied strains was achieved by extensive phenotyping and whole-cell protein fingerprinting and confirmed all the strains as S. mutans representatives. Obtained results showed rep-PCR fingerprinting with the (GTG)(5) primer to be a fast and reliable method for identification of S. mutans.
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27
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Bishi DK, Verghese S, Verma RS. Molecular typing of colonizing Streptococcus agalactiae strains by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) in a Chennai based hospital. Indian J Microbiol 2008; 48:291-6. [PMID: 23100723 DOI: 10.1007/s12088-008-0017-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 01/15/2008] [Accepted: 01/18/2008] [Indexed: 10/22/2022] Open
Abstract
Streptococcus agalactiae is reported to be an asymptomatic vaginal colonizer in Indian women, although it is considered one of the major causes of neonatal infections in many European countries. DNA based molecular typing methods are more reliable than the conventional serotyping method for identification and typing of this pathogen. In the present study, we have evaluated genetic diversity among colonizing S. agalactiae strains (n=86) by using a PCR-based genotyping method i.e. Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR). With ERIC-PCR fingerprinting at 60% similarity level in a dendrogram generated by UPGMA cluster analysis, 10 different ERIC groups were identified, which were subdivided into 62 distinct genotypes at ≥ 95% similarity level. Based on these findings, we demonstrate that ERIC-PCR is a simple, rapid, and inexpensive tool with sufficient discriminatory power and is applicable for characterization and genotyping of a large number of clinical isolates of S. agalactiae at molecular level.
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Affiliation(s)
- D K Bishi
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, 600 036 India ; Department of Microbiology, Frontier Lifeline Pvt. Ltd., Chennai, 600101 India
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Kumar R, Surendran PK, Thampuran N. Molecular fingerprinting of Salmonella enterica subsp. enterica Typhimurium and Salmonella enterica subsp. enterica derby isolated from tropical seafood in South India. Mol Biotechnol 2008; 40:95-100. [PMID: 18480975 DOI: 10.1007/s12033-008-9067-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 04/23/2008] [Indexed: 10/22/2022]
Abstract
Salmonella enterica subsp. enterica Typhimurium and Salmonella enterica subsp. enterica Derby strains isolated from different seafood were genotyped by PCR-ribotyping and ERIC-PCR assays. This study has ascertained the genetic relatedness among serovars prevalent in tropical seafood. PCR-ribotyping exhibited genetic variation in both Salmonella serovars, and ribotype profile (II) was most predominant, which was observed in 10/18 of Salmonella enterica subsp. enterica Typhimurium and 7/17 Salmonella enterica subsp. enterica Derby isolates. Cluster analysis of ERIC-PCR for Salmonella enterica subsp. enterica Typhimurium strains exhibited nine different banding patterns and four strains showed >95% genetic homology within the cluster pairs. ERIC-PCR produced more genetic variations in Salmonella enterica subsp. enterica Typhimurium; nevertheless, both methods were found to be comparable for Salmonella enterica subsp. enterica Derby isolates. Discrimination index of PCR-ribotyping for Salmonella enterica subsp. enterica Typhimurium isolates was obtained at 0.674 and index value 0.714 was observed for Salmonella enterica subsp. enterica Derby strains. Molecular fingerprinting investigation highlighted the hypothesis of diverse routes of Salmonella contamination in seafood as multiple clones of Salmonella enterica subsp. enterica Typhimurium and Salmonella enterica subsp. enterica Derby were detected in same or different seafood throughout the study period.
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Affiliation(s)
- Rakesh Kumar
- Microbiology Fermentation and Biotechnology Division, Central Institute of Fisheries Technology, Cochin, 682 029, India.
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Arif N, Sheehy EC, Do T, Beighton D. Diversity of Veillonella spp. from sound and carious sites in children. J Dent Res 2008; 87:278-82. [PMID: 18296614 DOI: 10.1177/154405910808700308] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Detailed data on the distribution of Veillonella in caries-free and caries-active subjects are scarce. We hypothesized that the diversity of the genus would be lower in caries lesions than in plaque from caries-free individuals. The proportions of Veillonella were not significantly different in the two groups. All isolates (n = 1308) were genotyped by REP-PCR, and different genotypes (n = 170) were identified by 16S rRNA, dnaK, and rpoB sequencing. V. parvula, V. dispar, and V. atypica were in both groups, V. denticariosi only in caries lesions, and V. rogosae only from the caries-free individuals (p < 0.009). Lesions were more likely to harbor a single predominant species (p = 0.0018). The mean number of genotypes in the lesions was less than in the fissure (p < 0.001) or buccal (p = 0.011) sites. The Veillonella from caries-free sites were more diverse than those from caries lesions, and may be related to the acidic environment of caries lesions.
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Affiliation(s)
- N Arif
- King's College London Dental Institute, Infection Research Group, Floor 17, Guy's Tower, Guy's Campus, London SE1 9RT, UK
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30
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Lembo FL, Longo PL, Ota-Tsuzuki C, Rodrigues CRMD, Mayer MPA. Genotypic and phenotypic analysis of Streptococcus mutans from different oral cavity sites of caries-free and caries-active children. ACTA ACUST UNITED AC 2008; 22:313-9. [PMID: 17803628 DOI: 10.1111/j.1399-302x.2007.00361.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Streptococcus mutans exhibits extensive genotypic diversity, but the role of this variation is poorly understood. This study aimed to determine the number and distribution of genotypes of S. mutans isolated from caries-active and caries-free children and to evaluate some of their phenotypic traits. METHODS Stimulated saliva, tongue surface and biofilms over sound and carious teeth surfaces were sampled from 10 caries-free and 11 caries-active children aged 5-8 years. A total of 339 isolates of S. mutans were genotyped by arbitrarily primed polymerase chain reaction using OPA2 primer. One isolate from each genotype was tested for its acid susceptibility and its ability to form a biofilm. RESULTS Fifty-one distinct genotypes were determined, one to three genotypes in each oral sample. A single genotype was detected in seven children, whereas the remaining 14 children exhibited two to seven genotypes. There were no significant differences in the number of genotypes detected in caries-free and caries-active children. No correlation was observed between the number of genotypes and the mutans streptococci salivary levels. Five of the six high biofilm-forming genotypes were obtained from caries-active children, although the differences in biofilm formation between isolates from caries-free and caries-active children were not statistically significant. Genotypes with low susceptibility to acid challenge were statistically more frequent among isolates from caries-active children than among those from caries-free children. CONCLUSION The present data suggested that there were differences in the distribution of genotypes of S. mutans according to the oral site and that S. mutans populations differ in their acid susceptibility and ability to form biofilms, factors allowing their colonization of sucrose-rich environments.
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Affiliation(s)
- F L Lembo
- Department of Microbiology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil
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31
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Montes M, María García-Arenzana J. Género Streptococcus: una revisión práctica para el laboratorio de microbiología. Enferm Infecc Microbiol Clin 2007. [DOI: 10.1157/13111833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Cho HS, Park SY, Ryu CM, Kim JF, Kim JG, Park SH. Interference of quorum sensing and virulence of the rice pathogen Burkholderia glumae by an engineered endophytic bacterium. FEMS Microbiol Ecol 2007; 60:14-23. [PMID: 17313662 DOI: 10.1111/j.1574-6941.2007.00280.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Many bacterial species are known to thrive within plants. Among these bacteria, a group referred to as endophytes provide beneficial effects to the host plants by the promotion of plant growth and the suppression of plant pathogens. Among 44 putative endophytic isolates isolated from surface-sterilized rice roots, Burkholderia sp. KJ006 was selected for further study because of a lack of pathogenicity to rice, a broad spectrum of antifungal properties, and the presence of the nifH gene, which is an indicator for nitrogen fixation. In an attempt to control Burkholderia glumae, a casual pathogen of seedling rot and grain rot of rice, an N-acyl-homoserine lactonase (aiiA) gene from Bacillus thuringiensis was introduced into Burkholderia sp. KJ006 given that the major virulence factor of Burkholderia glumae is controlled in a population-dependent manner (quorum sensing). The engineered strain KJ006 (pKPE-aiiA) inhibited production of quorum-sensing signals by Burkholderia glumae in vitro and reduced the disease incidence of rice seedling rot caused by Burkholderia glumae in situ. Our results indicate the possibility that a bacterial endophyte transformed with the aiiA gene can be used as a novel biological control agent against pathogenic Burkholderia glumae that are known to occupy the same ecological niche.
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Affiliation(s)
- Hyun-Soo Cho
- Laboratory of Microbial Genomics, Systems Microbiology Research Center, KRIBB, Daejeon 305-806, Korea
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Wescombe PA, Burton JP, Cadieux PA, Klesse NA, Hyink O, Heng NCK, Chilcott CN, Reid G, Tagg JR. Megaplasmids encode differing combinations of lantibiotics in Streptococcus salivarius. Antonie van Leeuwenhoek 2006; 90:269-80. [PMID: 16871420 DOI: 10.1007/s10482-006-9081-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 04/27/2006] [Indexed: 01/26/2023]
Abstract
Streptococcus salivarius strains commonly produce bacteriocins as putative anti-competitor or signalling molecules. Here we report that bacteriocin production by the oral probiotic strain S. salivarius K12 is encoded by a large (ca. 190 kb) plasmid. Oral cavity transmission of the plasmid from strain K12 to a plasmid-negative variant of this bacterium was demonstrated in two subjects. Tests of additional S. salivarius strains showed large (up to ca. 220 kb) plasmids present in bacteriocin-producing isolates. Various combinations (up to 3 per plasmid) of loci encoding the known streptococcal lantibiotics salivaricin A, salivaricin B, streptin and SA-FF22 were localised to these plasmids. Since all bacteriocin-producing strains of S. salivarius tested to date appear to harbour plasmids, it appears that they may function as mobile repositories for bacteriocin loci, especially those of the lantibiotic class.
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Affiliation(s)
- Philip A Wescombe
- BLIS Technologies Ltd., Centre for Innovation, University of Otago, PO Box 56, Dunedin, 9001, New Zealand
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Yoshida Y, Palmer RJ, Yang J, Kolenbrander PE, Cisar JO. Streptococcal receptor polysaccharides: recognition molecules for oral biofilm formation. BMC Oral Health 2006; 6 Suppl 1:S12. [PMID: 16934113 PMCID: PMC2147599 DOI: 10.1186/1472-6831-6-s1-s12] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Strains of viridans group streptococci that initiate colonization of the human tooth surface typically coaggregate with each other and with Actinomyces naeslundii, another member of the developing biofilm community. These interactions generally involve adhesin-mediated recognition of streptococcal receptor polysaccharides (RPS). The objective of our studies is to understand the role of these polysaccharides in oral biofilm development. Methods Different structural types of RPS have been characterized by their reactions with specific antibodies and lectin-like adhesins. Streptococcal gene clusters for RPS biosynthesis were identified, sequenced, characterized and compared. RPS-producing bacteria were detected in biofilm samples using specific antibodies and gene probes. Results Six different types of RPS have been identified from representative viridans group streptococci that coaggregate with A. naeslundii. Each type is composed of a different hexa- or heptasaccharide repeating unit, the structures of which contain host-like motifs, either GalNAcβ1-3Gal or Galβ1-3GalNAc. These motifs account for RPS-mediated recognition, whereas other features of these polysaccharides are more closely associated with RPS antigenicity. The RPS-dependent interaction of S. oralis with A. naeslundii promotes growth of these bacteria and biofilm formation in flowing saliva. Type specific differences in RPS production have been noted among the resident streptococcal floras of different individuals, raising the possibility of RPS-based differences in the composition of oral biofilm communities. Conclusion The structural, functional and molecular properties of streptococcal RPS support a recognition role of these cell surface molecules in oral biofilm formation.
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Affiliation(s)
- Yasuo Yoshida
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA
| | - Robert J Palmer
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA
| | - Jinghua Yang
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA
| | - Paul E Kolenbrander
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA
| | - John O Cisar
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA
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Rahimi M, Heng NCK, Kieser JA, Tompkins GR. Genotypic comparison of bacteria recovered from human bite marks and teeth using arbitrarily primed PCR. J Appl Microbiol 2006; 99:1265-70. [PMID: 16238758 DOI: 10.1111/j.1365-2672.2005.02703.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS This study assessed, for forensic purposes, the feasibility of genotypically matching oral streptococci recovered from recent human bite marks with those from the teeth of the biter. METHODS AND RESULTS Streptococci were isolated from the incisors of eight volunteers. Arbitrarily primed PCR (AP-PCR) distinguished 106 streptococcal genotypes among the participants, each harbouring at least eight distinct strains. In a crime simulation, a sample from an experimental bite mark was analysed by an experimenter unaware of its origin. The bacteria were unambiguously matched to the biter by comparing the amplicon profiles with those from the eight participants. In contrast, bacteria from an additional bite mark (not generated by one of the original participants) could not be matched to any of the eight participants. Between 20 and 78% of catalogued bacterial genotypes were recovered 12 months later from each participant. Throughout the study period, none of the bacterial genotypes were shared between participants. CONCLUSIONS Streptococci isolated from recent bite marks can be catalogued by AP-PCR and matched to the teeth responsible for the bite. SIGNIFICANCE AND IMPACT OF THE STUDY The study provides 'proof of concept' that genotypic analysis of streptococci from bite marks may provide valuable forensic evidence in situations where the perpetrator's DNA cannot be recovered.
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Affiliation(s)
- M Rahimi
- Department of Oral Sciences, University of Otago School of Dentistry, Dunedin, New Zealand
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Kignel S, de Almeida Pina F, André EA, Alves Mayer MP, Birman EG. Occurrence of Helicobacter pylori in dental plaque and saliva of dyspeptic patients. Oral Dis 2005; 11:17-21. [PMID: 15641962 DOI: 10.1111/j.1601-0825.2004.01043.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Helicobacter pylori infection in the stomach is associated with gastric and duodenal ulcers, gastric cancers and gastric lymphoma. The organism is transmitted by ingestion, but the oral-oral route and the fecal-oral route are also suggested. The prevalence of infection with H. pylori in developing countries, including Brazil, is higher than in developed countries. PURPOSE This study aimed to evaluate the role of the oral cavity as a reservoir of this species, by evaluating the occurrence of H. pylori in supragingival dental plaque and in saliva of Brazilian dyspeptic patients, whether harboring the organism or not in the stomach. MATERIAL AND METHODS Forty-nine patients reporting dyspeptic symptoms were subjected to oral clinical examination and collection of saliva and supragingival dental plaque samples prior to the endoscopic examination. The detection of H. pylori in oral samples was performed by PCR using 16S rRNA primers. The bacteria were detected in stomach by means of the rapid urease test. RESULTS Helicobacter pylori was detected in the stomach of 20 of 49 subjects reporting dyspeptic symptoms. The organism was detected in only one supragingival plaque sample, obtained from a patient positive for the urease test in the stomach and in none of the salivary samples. CONCLUSION Supragingival dental plaque and saliva may not be relevant reservoirs of H. pylori.
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Affiliation(s)
- S Kignel
- Department of Stomatology, School of Dentistry, Universidade de São Paulo, São Paulo, Brazil
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Paddick JS, Brailsford SR, Kidd EAM, Gilbert SC, Clark DT, Alam S, Killick ZJ, Beighton D. Effect of the environment on genotypic diversity of Actinomyces naeslundii and Streptococcus oralis in the oral biofilm. Appl Environ Microbiol 2004; 69:6475-80. [PMID: 14602602 PMCID: PMC262309 DOI: 10.1128/aem.69.11.6475-6480.2003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genotypic diversity of Actinomyces naeslundii genospecies 2 (424 isolates) and Streptococcus oralis (446 isolates) strains isolated from two sound approximal sites in all subjects who were either caries active (seven subjects) or caries free (seven subjects) was investigated by using the repetitive extragenic palindromic PCR. The plaque from the caries-active subjects harbored significantly greater proportions of mutans streptococci and lactobacilli and a smaller proportion of A. naeslundii organisms than the plaque sampled from the caries-free subjects. These data confirmed that the sites of the two groups of subjects were subjected to different environmental stresses, probably determined by the prevailing or fluctuating acidic pH values. We tested the hypothesis that the microfloras of the sites subjected to greater stresses (the plaque samples from the caries-active subjects) would exhibit reduced genotypic diversity since the sites would be less favorable. We found that the diversity of A. naeslundii strains did not change (chi2 = 0.68; P = 0.41) although the proportional representation of A. naeslundii was significantly reduced (P < 0.05). Conversely, the diversity of the S. oralis strains increased (chi2 = 11.71; P = 0.0006) and the proportional representation of S. oralis did not change. We propose that under these environmental conditions the diversity and number of niches within the oral biofilm that could be exploited by S. oralis increased, resulting in the increased genotypic diversity of this species. Apparently, A. naeslundii was not able to exploit the new niches since the prevailing conditions within the niches may have been deleterious and not supportive of its proliferation. These results suggest that environmental stress may modify a biofilm such that the diversity of the niches is increased and that these niches may be successfully exploited by some, but not necessarily all, members of the microbial community.
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Affiliation(s)
- James S Paddick
- Department of Microbiology, Guy's, King's, and St. Thomas' Dental Institute, King's College London, London, United Kingdom
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Li Y, Pan Y, Qi F, Caufield PW. Identification of Streptococcus sanguinis with a PCR-generated species-specific DNA probe. J Clin Microbiol 2003; 41:3481-6. [PMID: 12904342 PMCID: PMC179791 DOI: 10.1128/jcm.41.8.3481-3486.2003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The objective of the present study was to design a PCR-generated DNA probe and determine the specificity of the probe for the identification of clinical isolates of Streptococcus sanguinis. To do this, we examined over 200 arbitrarily primed PCR (AP-PCR) amplicon patterns obtained with DNA from clinical isolates of S. sanguinis. A 1.6-kb DNA amplicon that was common to all AP-PCR profiles was extracted from agarose gels and then cloned and sequenced. A search for a similar sequence in the GenBank database with the BLASTN program revealed that the 1.6-kb DNA fragment comprised an intergenic region between two housekeeping genes, uncC (proton-translocating ATPase) and murA (UDP-N-acetylglucosamine enolpyruvyl transferase). Three digoxigenin-labeled DNA probes were synthesized on the basis of the sequence of the 1.6-kb fragment: the sequence of probe SSA-1 contained the proton-translocating ATPase (uncC) and the entire intergenic region, the sequence of probe SSA-2 contained only the intergenic region, and the sequence of probe SSA-3 contained an internal region of the murA gene. Dot blot hybridization showed that the three probes displayed signals for hybridization to both S. sanguinis strain ATCC 10556 and the S. sanguinis clinical isolates. Probe SSA-1, however, hybridized to DNA from S. oralis and S. mitis. Probe SSA-3 hybridized to DNA from S. gordonii, S. mitis, S. oralis, S. parasanguinis, and S. vestibularis. The probe SSA-2-specific intergenic region appeared to be specific for S. sanguinis. The results from this study suggest that probe SSA-2 may serve as a species-specific DNA probe for the identification of clinical isolates of S. sanguinis.
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Affiliation(s)
- Yihong Li
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York 10010, USA.
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Walker RL, Runyan CA. Identification of variations in SzP proteins of Streptococcus equi subspecies zooepidemicus and the relationship between protein variants and clinical signs of infection in horses. Am J Vet Res 2003; 64:976-81. [PMID: 12926588 DOI: 10.2460/ajvr.2003.64.976] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether previously unidentified variations of the SzP protein of Streptococcus equi subsp zooepidemicus were present in horses with various clinical signs of infection and whether any relationship could be identified between SzP protein variants and naturally occurring clinical conditions. SAMPLE POPULATION 23 isolates of S equi subsp zooepidemicus were recovered from specimens of horses with various clinical conditions and used as a representative population of isolates for evaluation of different SzP protein variants. PROCEDURE Genetic heterogeneity of the isolates was demonstrated by repetitive extragenic palindromic-polymerase chain reaction analysis. The SzP gene was sequenced and the presumed protein sequence determined for each isolate. Characteristics of the SzP proteins were compared among the isolates and in relation to the clinical conditions of horses from which they were recovered. RESULTS The signal peptide types, number of proline-glutamic acid-proline-lysine repeats, and anchor sequences were consistent with those previously described for the SzP protein. Many of the isolates clustered with 5 previously described types on the basis of the hypervariable region of the SzP protein. One additional variant, which represented 8 of the isolates, was identified. Particular motifs in the hypervariable region accounted for many of the differences among hypervariable types. CONCLUSIONS AND CLINICAL RELEVANCE The SzP protein appears to be limited to a selected number of types. Variations in the SzP protein are frequently determined on the basis of different motifs rather than random amino acid substitutions. There does not appear to be any association of SzP protein variations and clinical manifestations of infection in horses.
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Affiliation(s)
- Richard L Walker
- California Animal Health and Food Safety Laboratory School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Barsotti O, Décoret D, Renaud FNR. Identification of streptococcus mitis group species by RFLP of the PCR-amplified 16S-23S rDNA intergenic spacer. Res Microbiol 2002; 153:687-91. [PMID: 12558188 DOI: 10.1016/s0923-2508(02)01382-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mitis group streptococci are pioneer colonizers of tooth surfaces and are implicated in various pathologies. Thus, accurate identification of oral mitis group strains would be valuable for studies of plaque ecology and dental caries and for diagnostic use in endocarditis or sepsis patients. The aim of this study was to evaluate the usefulness of PCR-RFLP analysis of the 16S-23S intergenic spacer for differentiating and identifying streptococcus mitis group species. The 16S-23S rDNA spacer regions of 27 type and reference Streptococcus strains, representing 8 species, were studied by PCR-mediated amplification by using oligonucleotide primers FGPS 1490-72 and FGPL 132'-38. PCR products were digested, independently, with 14 restriction enzymes. Only AluI, MboI, CfoI, HinfI and MaeII distinguished some species, particularly AluI and CfoI, but not all the species. Eight clusters were clearly generated, corresponding to currently recognized species, but only with the addition of five ITS restriction patterns, generated by AluI + MboI + CfoI + HinfI + MaeII, then clustered by UPGMA, on a distance consensus matrix. The combination of these five ITS RFLP tests allowed a relatively conclusive genomic group differentiation of mitis group species. Despite this observation, more strains of each species will need to be analyzed, particularly clinical isolates, before arriving at general conclusions about the utility of ITS restrictions for identification of strains at the species level. An ITS PCR-RFLP-based identifying method for streptococcus mitis group species would provide significant advantages over other molecular taxonomic methods which require DNA extraction and DNA-DNA hybridization.
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Affiliation(s)
- Odile Barsotti
- Laboratoire d'Etude des Interfaces et des Biofilms en Odontologie, UFR d'Odontologie, rue Guillaume Paradin, 69372 Lyon cedex 08, France.
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Abstract
Since the division of the Streptococcus genus into enterococci, lactococci, and streptococci in 1984, many changes in the nomenclature and taxonomy of the Streptococcus genus have taken place. The application of genetic comparisons has improved the proper classification of the different species. The Lancefield system of serogrouping the streptococci by the expression of beta-hemolysis on blood agar plates is still very useful for the identification of streptococci for patient management. The Lancefield grouping system cannot be used in itself for accurate identification of specific beta-hemolytic species, but it can be a useful part of the identification procedure. Except for identification of the "Streptococcus bovis group" of species and Streptococcus suis, Lancefield grouping is of little value in identification of the non-beta-hemolytic streptococci and related genera. In fact, identification of the non-beta-hemolytic species is problematic for conventional as well as commercially available identification procedures. A combination of conventional tests and specific chromogenic tests suggested by several investigators is presented and discussed. Tables are included that suggest tests and procedures to guide investigators attempting to identify all the species.
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Affiliation(s)
- Richard Facklam
- Streptococcus Laboratory, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Lopes VC, Back A, Shin HJ, Halvorson DA, Nagaraja KV. Development, characterization, and preliminary evaluation of a temperature-sensitive mutant of Ornithobacterium rhinotracheale for potential use as a live vaccine in turkeys. Avian Dis 2002; 46:162-8. [PMID: 11922328 DOI: 10.1637/0005-2086(2002)046[0162:dcapeo]2.0.co;2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A temperature-sensitive (Ts) mutant strain of Ornithobacterium rhinotracheale (ORT) was developed after exposure of the wild-type organism to N-methyl-N'-nitro-N-nitrosoguanidine. The Ts mutant strain grew at 31 C but had its growth inhibited at 41 C unlike wild-type parent strain. The Ts mutant and parent strains were characterized. Morphologic and biochemical properties of wild-type and mutant strains did not show any differences. The strains were also characterized by polymerase chain reaction (PCR)-based fingerprinting methods. Results showed similar patterns in repetitive sequences by repetitive PCR (enterobacterial repetitive intergenic consensus, highly conserved repeated DNA elements present in Streptococcus pneumoniae (BOX), repetitive extragenic palindromic, and Salmonella enteritidis repetitive element primers); however, random amplified polymorphic DNA fingerprinting was able to differentiate mutant and parent strains showing a unique pattern for each of the ORT strains. The rationale for the use of a Ts strain as a vaccine is based on the ability of the mutant to colonize the upper respiratory tract but not the lower respiratory tract and systemic system of the birds, where the wild-type strain causes severe lesions. In a preliminary evaluation, Ts strain of ORT was recovered from tracheas and choanae of Ts-treated turkeys for 13 days postadministration of the strain either in drinking water or by oculonasal instillation. Humoral immune response was detected in Ts-vaccinated but not in control group birds after 3 wk postadministration. Results suggest that Ts strain of ORT has promising potential use as a live vaccine for ORT.
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Affiliation(s)
- V C Lopes
- Department of Veterinary PathoBiology, College of Veterinary Medicine, University of Minnesota, Saint Paul 55108, USA
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Donnelly JP. Infection in the neutropenic and haematopoietic stem cell transplant recipient. Curr Opin Infect Dis 2000; 13:337-342. [PMID: 11964799 DOI: 10.1097/00001432-200008000-00002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Patterns of bacterial infection have remained fairly static with Gram-positive bacteria predominating, although this varies between institutions and between patient populations. Similarly, antimicrobial resistance rates differ widely and reflect antibiotic use and exposure. Hence, each institution should devote microbiological resources to maintain surveillance and employ vigilance so that antimicrobial treatment protocols can be adapted to meet any new challenges. Most changes are being seen in the diagnosis of fungal infections, particularly aspergillosis, and the way in which it is being incorporated into treatment strategies.
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Affiliation(s)
- J. Peter Donnelly
- Department of Haematology, University Medical Center, St Radboud, Nijmegen, The Netherlands
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Alam S, Brailsford SR, Adams S, Allison C, Sheehy E, Zoitopoulos L, Kidd EA, Beighton D. Genotypic heterogeneity of Streptococcus oralis and distinct aciduric subpopulations in human dental plaque. Appl Environ Microbiol 2000; 66:3330-6. [PMID: 10919787 PMCID: PMC92151 DOI: 10.1128/aem.66.8.3330-3336.2000] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (chi(2) = 13.09; P = 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.
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Affiliation(s)
- S Alam
- Dental Caries Research Group, Guy's, King's, and St. Thomas' Dental Institute, London, England
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