- Diet-Dependent Modular Dynamic Interactions of the Equine Cecal Microbiota. [Journal Article]
- MEMicrobes Environ 2016 Oct 21
- Knowledge on dynamic interactions in microbiota is pivotal for understanding the role of bacteria in the gut. We herein present comprehensive dynamic models of the horse cecal microbiota, which inclu...
Knowledge on dynamic interactions in microbiota is pivotal for understanding the role of bacteria in the gut. We herein present comprehensive dynamic models of the horse cecal microbiota, which include short-chained fatty acids, carbohydrate metabolic networks, and taxonomy. Dynamic models were derived from time-series data in a crossover experiment in which four cecum-cannulated horses were fed a starch-rich diet of hay supplemented with barley (starch intake 2 g kg(-1) body weight per day) and a fiber-rich diet of only hay. Cecal contents were sampled via the cannula each h for 24 h for both diets. We observed marked differences in the microbial dynamic interaction patterns for Fibrobacter succinogenes, Lachnospiraceae, Streptococcus, Treponema, Anaerostipes, and Anaerovibrio between the two diet groups. Fluctuations and microbiota interactions were the most pronounced for the starch rich diet, with Streptococcus spp. and Anaerovibrio spp. showing the largest fluctuations. Shotgun metagenome sequencing revealed that diet differences may be explained by modular switches in metabolic cross-feeding between microbial consortia in which fermentation is linked to sugar alcohols and amino sugars for the starch-rich diet and monosaccharides for the fiber-rich diet. In conclusion, diet may not only affect the composition of the cecal microbiota, but also dynamic interactions and metabolic cross-feeding.
- Performance Characteristics of the Reverse Syphilis Screening Algorithm in a Population With a Moderately High Prevalence of Syphilis. [Journal Article]
- AJAm J Clin Pathol 2016 Oct 22
- CONCLUSIONS: Despite a 1.0% false-reactive rate, the reverse syphilis algorithm detected 21 patients with possible latent syphilis that may have gone undetected by traditional syphilis screening.
- Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen. [Journal Article]
- NRNat Rev Microbiol 2016 Oct 10
- The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for ...
The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for early dissemination and immune evasion has earned it the designation 'the stealth pathogen'. Despite the many hurdles to studying syphilis pathogenesis, most notably the inability to culture and to genetically manipulate T. pallidum, in recent years, considerable progress has been made in elucidating the structural, physiological, and regulatory facets of T. pallidum pathogenicity. In this Review, we integrate this eclectic body of information to garner fresh insights into the highly successful parasitic lifestyles of the syphilis spirochete and related pathogenic treponemes.
- The Current Weight of Evidence of the Microbiologic Profile Associated With Peri-Implantitis: A Systematic Review. [Journal Article]
- JPJ Periodontol 2016; 87(11):1295-1304
- CONCLUSIONS: Results of this systematic review suggest moderate evidence supporting association of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia and some evidence supporting association of Prevotella intermedia and Campylobacter rectus with the etiology of peri-implantitis.
- Association of Porphyromonas gingivalis with high levels of stress-induced hormone cortisol in chronic periodontitis patients. [Journal Article]
- JIJ Investig Clin Dent 2016; 7(4):361-367
- CONCLUSIONS: This research offers support for the association between P. gingivalis and higher levels of cortisol in chronic periodontitis patients. These results suggest that high levels of cortisol could increase the occurrence of P. gingivalis in the biofilm.
- Impact of heavy smoking on the clinical, microbiological and immunological parameters of patients with dental implants: a prospective cross-sectional study. [Journal Article]
- JIJ Investig Clin Dent 2016; 7(4):401-409
- CONCLUSIONS: Although smokers presented deeper probing depths, bleeding on probing, and peri-implant microbiota composed of a greater number of periodontal pathogens than in non-smoking patients, these data did not show significant differences. In the present study, and in relation to the samples analyzed, smoking alone did not influence the immunological and microbiological parameters in dental implants with healthy peri-implant tissues. Further studies with larger samples are required to better evaluate the influence of smoking on dental implants.
- Web-Based HIV Testing in Abruzzo, Italy: Analysis of 15-Month Activity Results. [Journal Article]
- APAIDS Patient Care STDS 2016; 30(10):471-475
- Undiagnosed cases of HIV infection in developed countries are estimated at 20-30% of individuals living with HIV. Web-based strategies may represent a new approach to easier, wider, and unrestricted ...
Undiagnosed cases of HIV infection in developed countries are estimated at 20-30% of individuals living with HIV. Web-based strategies may represent a new approach to easier, wider, and unrestricted access to early testing. The Abruzzo Region, Italy, developed a Web-based tool to recruit persons at high risk of HIV and other sexually transmitted infections (STIs). At the Website www.failtestanchetu.it , browsers found information on STIs (HIV, hepatitis B and C, and syphilis), a structured questionnaire called "risk calculator" to assess one's own risk behaviors and direct booking of their test at one of six sites throughout the region. The Website was advertised on local media and in pharmacies, high schools, sports facilities, and factories. Between February 1, 2014, and May 31, 2015, about 6000 users visited the Website; 3046 people attended a visit for counseling on risk behaviors, signs, or symptoms of STIs and accepted blood drawing for HIV, hepatitis B Virus (HBV), hepatitis C Virus (HCV), and syphilis tests. Fifty-eight (1.90%) subjects were positive for HCV, 56 (1.84%) for HBsAg, 90 (2.95%) for Treponema pallidum antibodies, and 28 (0.92%) for HIV. Ninety-two percent of HIV-positive patients were successfully linked to care. Late presenters were less frequent in this sample than in the population diagnosed with HIV in Italy in 2014. An overall 7% proportion of HIV, HBV, HCV, and syphilis-unaware cases were all transferred to care, with the exception of three people. HIV seropositivity among testers was higher than 2/1000, the cost-effectiveness threshold suggested for effective testing. Therefore, our Web-based unrestricted and free access methodology appears worth further and wider evaluation.
- Genome-scale analysis of the non-cultivable Treponema pallidum reveals extensive within-patient genetic variation. [Journal Article]
- NMNat Microbiol 2016 Oct 17; 2:16190
- Insights into the genomic adaptive traits of Treponema pallidum, the causative bacterium of syphilis, have long been hampered due to the absence of in vitro culture models and the constraints associa...
Insights into the genomic adaptive traits of Treponema pallidum, the causative bacterium of syphilis, have long been hampered due to the absence of in vitro culture models and the constraints associated with its propagation in rabbits. Here, we have bypassed the culture bottleneck by means of a targeted strategy never applied to uncultivable bacterial human pathogens to directly capture whole-genome T. pallidum data in the context of human infection. This strategy has unveiled a scenario of discreet T. pallidum interstrain single-nucleotide-polymorphism-based microevolution, contrasting with a rampant within-patient genetic heterogeneity mainly targeting multiple phase-variable loci and a major antigen-coding gene (tprK). TprK demonstrated remarkable variability and redundancy, intra- and interpatient, suggesting ongoing parallel adaptive diversification during human infection. Some bacterial functions (for example, flagella- and chemotaxis-associated) were systematically targeted by both inter- and intrastrain single nucleotide polymorphisms, as well as by ongoing within-patient phase variation events. Finally, patient-derived genomes possess mutations targeting a penicillin-binding protein coding gene (mrcA) that had never been reported, unveiling it as a candidate target to investigate the impact on the susceptibility to penicillin. Our findings decode the major genetic mechanisms by which T. pallidum promotes immune evasion and survival, and demonstrate the exceptional power of characterizing evolving pathogen subpopulations during human infection.
- Bacteria in the apical root canals of teeth with apical periodontitis. [Journal Article]
- JFJ Formos Med Assoc 2016 Oct 10
- CONCLUSIONS: Root canal infections are usually caused by a mixture of two or three species of bacteria. Specific kinds of antibiotic can be selected to control these bacterial infections after antibiotic sensitivity testing.
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- Resistance profiles to antimicrobial agents in bacteria isolated from acute endodontic infections: systematic review and meta-analysis. [Review]
- IJInt J Antimicrob Agents 2016 Sep 30
- Infected root canal or acute apical abscess exudates can harbour several species, including Fusobacterium, Porphyromonas, Prevotella, Parvimonas, Streptococcus, Treponema, Olsenella and not-yet culti...
Infected root canal or acute apical abscess exudates can harbour several species, including Fusobacterium, Porphyromonas, Prevotella, Parvimonas, Streptococcus, Treponema, Olsenella and not-yet cultivable species. A systematic review and meta-analysis was performed to assess resistance rates to antimicrobial agents in clinical studies that isolated bacteria from acute endodontic infections. Electronic databases and the grey literature were searched up to May 2015. Clinical studies in humans evaluating the antimicrobial resistance of primary acute endodontic infection isolates were included. PRISMA guidelines were followed. A random-effect meta-analysis was employed. The outcome was described as the pooled resistance rates for each antimicrobial agent. Heterogeneity and sensitivity analyses were performed. Subgroup analyses were conducted based upon report or not of the use of antibiotics prior to sampling as an exclusion factor (subgroups A and B, respectively). Data from seven studies were extracted. Resistance rates for 15 different antimicrobial agents were evaluated (range, 3.5-40.0%). Lower resistance rates were observed for amoxicillin/clavulanic acid and amoxicillin; higher resistance rates were detected for tetracycline. Resistance rates varied according to previous use of an antimicrobial agent as demonstrated by the subgroup analyses. Heterogeneity was observed for the resistance profiles of penicillin G in subgroup A and for amoxicillin, clindamycin, metronidazole and tetracycline in subgroup B. Sensitivity analyses demonstrated that resistance rates changed for metronidazole, clindamycin, tetracycline and amoxicillin. These findings suggest that clinical isolates had low resistance to β-lactams. Further well-designed studies are needed to clarify whether the differences in susceptibility among the antimicrobial agents may influence clinical responses to treatment.