Population-Level Virulence Factors Amongst Pathogenic Bacteria: Relation to Infection Outcome

Hu, Fang; Ehrlich, Garth D.

doi:10.2217/17460913.3.1.31

Cited by 24 publications

(31 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Ibis T5000 Universal Biosensor has advantages over conventional PCR detection methods because it does not require a presumptive target and detects a broad range of bacteria more rapidly compared to culture methods (17)(18)(19)35), making it a powerful tool for determining the presence of bacteria in a clinical sample. The Ibis approach indicated that multiple aerobic and anaerobic bacteria were present in the adenoids of both the COM and the OSA diagnostic groups (Table 1) with differences between the two groups.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Adenoid Reservoir for Pathogenic Biofilm Bacteria

et al. 2011

View full text Add to dashboard Cite

Biofilms of pathogenic bacteria are present on the middle ear mucosa of children with chronic otitis media (COM) and may contribute to the persistence of pathogens and the recalcitrance of COM to antibiotic treatment. Controlled studies indicate that adenoidectomy is effective in the treatment of COM, suggesting that the adenoids may act as a reservoir for COM pathogens. To investigate the bacterial community in the adenoid, samples were obtained from 35 children undergoing adenoidectomy for chronic OM or obstructive sleep apnea. We used a novel, culture-independent molecular diagnostic methodology, followed by confocal microscopy, to investigate the in situ distribution and organization of pathogens in the adenoids to determine whether pathogenic bacteria exhibited criteria characteristic of biofilms. The Ibis T5000 Universal Biosensor System was used to interrogate the extent of the microbial diversity within adenoid biopsy specimens. Using a suite of 16 broad-range bacterial primers, we demonstrated that adenoids from both diagnostic groups were colonized with polymicrobial biofilms. Haemophilus influenzae was present in more adenoids from the COM group (P ‫؍‬ 0.005), but there was no significant difference between the two patient groups for Streptococcus pneumoniae or Staphylococcus aureus. Fluorescence in situ hybridization, lectin binding, and the use of antibodies specific for host epithelial cells demonstrated that pathogens were aggregated, surrounded by a carbohydrate matrix, and localized on and within the epithelial cell surface, which is consistent with criteria for bacterial biofilms.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Biofilm infections are clinically significant because these three-dimensional (3D), adherent, organized communities of bacteria are far more recalcitrant to antibiotic therapy and killing by host phagocytic cells (27,30,35).…”

mentioning

confidence: 99%

Adenoid Reservoir for Pathogenic Biofilm Bacteria

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The lack of ancient strains without a functional com regulon suggests that there exists selective pressure for the maintenance of transformation-promoting genes (58). Thus, genes involved in DNA uptake can be thought of as "population-level virulence" factors (35,37). This hypothesis helps explain the fact that independent isolates of a bacterial species share a core set of genes but that many of the genes of a species are distributed only in subsets of individual strain genomes (16,17,19,35,70,71).…”

mentioning

confidence: 99%

Comparative Genomic Analyses of 17 Clinical Isolates of Gardnerella vaginalis Provide Evidence of Multiple Genetically Isolated Clades Consistent with Subspeciation into Genovars

et al. 2012

View full text Add to dashboard Cite

Gardnerella vaginalis is associated with a spectrum of clinical conditions, suggesting high degrees of genetic heterogeneity among stains. Seventeen G. vaginalis isolates were subjected to a battery of comparative genomic analyses to determine their level of relatedness. For each measure, the degree of difference among the G. vaginalis strains was the highest observed among 23 pathogenic bacterial species for which at least eight genomes are available. Genome sizes ranged from 1.491 to 1.716 Mb; GC contents ranged from 41.18% to 43.40%; and the core genome, consisting of only 746 genes, makes up only 51.6% of each strain's genome on average and accounts for only 27% of the species supragenome. Neighbor-grouping analyses, using both distributed gene possession data and core gene allelic data, each identified two major sets of strains, each of which is composed of two groups. Each of the four groups has its own characteristic genome size, GC ratio, and greatly expanded core gene content, making the genomic diversity of each group within the range for other bacterial species. To test whether these 4 groups corresponded to genetically isolated clades, we inferred the phylogeny of each distributed gene that was present in at least two strains and absent in at least two strains; this analysis identified frequent homologous recombination within groups but not between groups or sets. G. vaginalis appears to include four nonrecombining groups/clades of organisms with distinct gene pools and genomic properties, which may confer distinct ecological properties. Consequently, it may be appropriate to treat these four groups as separate species.

show abstract

“…Biofilms are composed of microbes embedded in a polymeric matrix that protects them from antimicrobials and allows them to resist host defenses. The study of biofilms has introduced a new paradigm of chronic microbial infections: instead of single free-floating (planktonic) microbes causing disease patterns that can be reproduced by following Koch's postulates, biofilms are metabolically quiescent, sessile, polymicrobial communities in which synergistic relationships between microbes can alter virulence and pathogenicity (2,9,17). Thus, understanding the effect of biofilms on wound healing requires the study of the variation of the polymicrobial communities (microbiome) in relation to wound-healing parameters.…”

mentioning

confidence: 99%

Characterization of Bacterial Communities in Venous Insufficiency Wounds by Use of Conventional Culture and Molecular Diagnostic Methods

et al. 2011

View full text Add to dashboard Cite

Microbial infections delay wound healing, but the effect of the composition of the wound microbiome on healing parameters is unknown. To better understand bacterial communities in chronic wounds, we analyzed debridement samples from lower-extremity venous insufficiency ulcers using the following: conventional anaerobic and aerobic bacterial cultures; the Ibis T5000 universal biosensor (Abbott Molecular); and 16S 454 FLX titanium series pyrosequencing (Roche). Wound debridement samples were obtained from 10 patients monitored clinically for at least 6 months, at which point 5 of the 10 sampled wounds had healed. Pyrosequencing data revealed significantly higher bacterial abundance and diversity in wounds that had not healed at 6 months. Additionally, Actinomycetales was increased in wounds that had not healed, and Pseudomonadaceae was increased in wounds that had healed by the 6-month follow-up. Baseline wound surface area, duration, or analysis by Ibis or conventional culture did not reveal significant differences between wounds that healed after 6 months and those that did not. Thus, pyrosequencing identified distinctive baseline characteristics of wounds that did not heal by the 6-month follow-up, furthering our understanding of potentially unique microbiome characteristics of chronic wounds.

show abstract

Population-Level Virulence Factors Amongst Pathogenic Bacteria: Relation to Infection Outcome

Cited by 24 publications

References 92 publications

Adenoid Reservoir for Pathogenic Biofilm Bacteria

Adenoid Reservoir for Pathogenic Biofilm Bacteria

Comparative Genomic Analyses of 17 Clinical Isolates of Gardnerella vaginalis Provide Evidence of Multiple Genetically Isolated Clades Consistent with Subspeciation into Genovars

Characterization of Bacterial Communities in Venous Insufficiency Wounds by Use of Conventional Culture and Molecular Diagnostic Methods

Contact Info

Product

Resources

About