Nature of TSST-1 Production by Staphylococcus aureus in Aberrant Vaginal Conditions

Menstrual-toxic shock syndrome (TSS) is a serious illness that afflicts women of pre-menopausal age worldwide, and arises from vaginal infection by Staphylococcus aureus and concurrent production of toxic shock syndrome toxin- 1 (TSST-1). The aim of this study was to investigate the influence of aberrant vaginal states and indigenous vaginal bacteria on production of TSST-1 and identify women who are most susceptible to menstrual-TSS. A TSST-1 reporter strain of S. aureus was grown in the presence of vaginal swab contents collected from women in London, Ontario with healthy and aberrant vaginal states. Gene expression assays were also conducted to monitor toxin production in response to indigenous vaginal bacteria. This study found that Streptococcus agalactiae significantly induces TSST-1 production, while resident Lactobacillus spp. suppress production. Results also indicate that women with aerobic vaginitis, but not bacterial vaginosis, may be more susceptible to menstrual-TSS and would benefit most from prophylactic treatment

Exposed aggregate areas and photocatalytic efficiency of photocatalytic aggregate mortar

The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant EP/M003299/1) and the Natural Science Foundation of China (Grant 51461135005) International Joint Research Project (EPSRC-NSFC). Thanks are also given to Mr. Anthon Tacussel Da Silva, Mr. Victor Leger, Mr. Robim Campos and Miss Axelle Airmard for their samples preparation and early exploring studies and to Dr. Laszlo Csetenyi for his help in CT scanning.Peer reviewedPostprin

Photocatalytic Concrete for NOx Abatement: Supported TiO2 efficiencies and impacts

The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant Ref: EP/M003299/1) and the Natural Science Foundation of China (No. 51478370 and 51461135005) International Joint Research Project (EPSRC-NSFC)Peer reviewedPostprin

Microbiome profiling by Illumina sequencing of combinatorial sequence-tagged PCR products

We developed a low-cost, high-throughput microbiome profiling method that uses combinatorial sequence tags attached to PCR primers that amplify the rRNA V6 region. Amplified PCR products are sequenced using an Illumina paired-end protocol to generate millions of overlapping reads. Combinatorial sequence tagging can be used to examine hundreds of samples with far fewer primers than is required when sequence tags are incorporated at only a single end. The number of reads generated permitted saturating or near-saturating analysis of samples of the vaginal microbiome. The large number of reads al- lowed an in-depth analysis of errors, and we found that PCR-induced errors composed the vast majority of non-organism derived species variants, an ob- servation that has significant implications for sequence clustering of similar high-throughput data. We show that the short reads are sufficient to assign organisms to the genus or species level in most cases. We suggest that this method will be useful for the deep sequencing of any short nucleotide region that is taxonomically informative; these include the V3, V5 regions of the bac- terial 16S rRNA genes and the eukaryotic V9 region that is gaining popularity for sampling protist diversity.Comment: 28 pages, 13 figure

Biomaterials used in urology: Current issues of biocompatibility, infection, and encrustation

Importance of the field: Urogenital infections are on average the number-one reason for women to visit the doctor. Yet, treatment and preventive strategies have gone unchanged for close to 50 years. With prevalence rates for bacterial vaginosis at more than 29%, depending on the population, and similarly high incidences of vulvo-vaginal candidiasis and urinary tract infections, plus HIV, new therapies are urgently needed to improve the health of women around the world. Areas covered in the review: This review discusses the vaginal microbiota, our improved understanding of its composition, and its role in health and disease. It also discusses the progress made in the past 10 years or so, with the development and testing of probiotic lactobacilli to improve vaginal health and better manage urogenital infection recurrences. What the reader will gain: The reader will have an understanding of the clinical data obtained so far, and the potential mechanisms of action of probiotics. Despite the need for more clinical studies, the review illustrates a case for inclusion of probiotics as part of the approach to disease prevention, and as an adjunct to antimicrobial treatment. Challenges remain in optimizing clinical benefits, selecting new strains, preparing new products and having them tested in humans then approved with informative claims, and making products readily accessible to women in the developed and developing world. Take home message: The vaginal microbiota is a complex structure that can change quickly and dramatically, and significantly impact a woman\u27s health. New health-maintenance and disease-treatment approaches are badly needed, and probiotics should be considered. © 2010 Informa UK, Ltd

Bioremediation and tolerance of humans to heavy metals through microbial processes: A potential role for probiotics?

We developed a low-cost, high-throughput microbiome profiling method that uses combinatorial sequence tags attached to PCR primers that amplify the rRNA V6 region. Amplified PCR products are sequenced using an Illumina paired-end protocol to generate millions of overlapping reads. Combinatorial sequence tagging can be used to examine hundreds of samples with far fewer primers than is required when sequence tags are incorporated at only a single end. The number of reads generated permitted saturating or near-saturating analysis of samples of the vaginal microbiome. The large number of reads allowed an in-depth analysis of errors, and we found that PCR-induced errors composed the vast majority of non-organism derived species variants, an observation that has significant implications for sequence clustering of similar high-throughput data. We show that the short reads are sufficient to assign organisms to the genus or species level in most cases. We suggest that this method will be useful for the deep sequencing of any short nucleotide region that is taxonomically informative; these include the V3, V5 regions of the bacterial 16S rRNA genes and the eukaryotic V9 region that is gaining popularity for sampling protist diversity. © 2010 Gloor, et al

Adhesion of two uropathogens to silicone and lubricious catheters: influence of pH, urea and creatinine

Menstrual toxic shock syndrome (TSS) is a serious illness that afflicts women of premenopausal age worldwide and arises from vaginal infection by Staphylococcus aureus and concurrent production of toxic shock syndrome toxin-1 (TSST-1). Studies have illustrated the capacity of lactobacilli to reduce S. aureus virulence, including the capacity to suppress TSST-1. We hypothesized that an aberrant microbiota characteristic of pathogenic bacteria would induce the increased production of TSST-1 and that this might represent a risk factor for the development of TSS. A S. aureus TSST-1 reporter strain was grown in the presence of vaginal swab contents collected from women with a clinically healthy vaginal status, women with an intermediate status, and those diagnosed with bacterial vaginosis (BV). Bacterial supernatant challenge assays were also performed to test the effects of aerobic vaginitis (AV)-associated pathogens toward TSST-1 production. While clinical samples from healthy and BV women suppressed toxin production, in vitro studies demonstrated that Streptococcus agalactiae and Enterococcus spp. significantly induced TSST-1 production, while some Lactobacillus spp. suppressed it. The findings suggest that women colonized by S. aureus and with AV, but not BV, may be more susceptible to menstrual TSS and would most benefit from prophylactic treatment. © 2013, American Society for Microbiology

Application of novel 3,4-dihydroxyphenylalanine-containing antimicrobial polymers for the prevention of uropathogen attachment to urinary biomaterials

Introduction and Objective: Urinary catheters and stents are frequently prone to catheter-associated urinary tract infections (CAUTI) through biofilm formation. Several strategies have been evaluated in search of a stent coating to reliably prevent adherence of bacteria and biofilm. Previous in vivo and in vitro research with methoxylated polyethylene glycol 3,4-dihydroxyphenylalanine (DOPA) copolymer as a candidate coating showed promising results to reduce the bacterial attachment. We aimed to further enhance this antimicrobial activity by adding antimicrobial agents to newly synthesized DOPA-based copolymers. Materials and Methods: Building on our previous experience, novel copolymers were engineered based on DOPA. Quaternary ammonium groups and silver particles were added by cross-linking to increase the antimicrobial activity through both kill-by-contact and planktonic killing. After coating polyurethane sheets and measuring contact angles, all candidate coatings were challenged in vitro with an Escherichia coli culture. The most promising coatings were then further evaluated against a panel of seven clinically relevant uropathogens and planktonic killing, and microbial attachment was determined. Results: Initially, seven coatings were developed, referred to as Surphys 093-099. The most significant increase in contact angle was identified in Surphys-095 and -098. Surphys coatings S-094, S-095, and S-098 were cross-linked with silver and exhibited profound antimicrobial properties when challenged with E. coli. Further testing demonstrated S-095 to have antimicrobial efficacy against gram-positive and gram-negative bacteria at different silver-loading concentrations. The final coating, consisting of a 2 mg/mL solution of S-095 cross-linked with 0.25 mg/mL AgNO3, appeared to be highly bactericidal showing a >= 99.9% bacterial killing effect while remaining below cytotoxicity levels. Conclusions: We were able to engineer DOPA-based copolymers and add quaternary ammonium and silver particles, thus increasing the bactericidal properties of the coating. These coatings have exhibited a biologically significant ability to prevent uropathogens from attaching to biomaterials and represent a realistic opportunity to combat CAUTI

Subinhibitory antibiotic therapy alters recurrent urinary tract infection pathogenesis through modulation of bacterial virulence and host immunity

The capacity of subinhibitory levels of antibiotics to modulate bacterial virulence in vitro has recently been brought to light, raising concerns over the appropriateness of low-dose therapies, including antibiotic prophylaxis for recurrent urinary tract infection management. However, the mechanisms involved and their relevance in influencing pathogenesis have not been investigated. We characterized the ability of antibiotics to modulate virulence in the uropathogens Staphylococcus saprophyticus and Escherichia coli. Several antibiotics were able to induce the expression of adhesins critical to urothelial colonization, resulting in increased biofilm formation, colonization of murine bladders and kidneys, and promotion of intracellular niche formation. Mice receiving subinhibitory ciprofloxacin treatment were also more susceptible to severe infections and frequent recurrences. A ciprofloxacin prophylaxis model revealed this strategy to be ineffective in reducing recurrences and worsened infection by creating larger intracellular reservoirs at higher frequencies. Our study indicates that certain agents used for antibiotic prophylaxis have the potential to complicate infections. IMPORTANCE Antibiotics are the mainstay treatment for bacterial infections; however, evidence is emerging that argues these agents may have off-target effects if sublethal concentrations are present. Most studies have focused on changes occurring in vitro, leaving questions regarding the clinical relevance in vivo. We utilized a murine urinary tract infection model to explore the potential impact of low-dose antibiotics on pathogenesis. Using this model, we showed that subinhibitory antibiotics prime uropathogens for adherence and invasion of murine urothelial tissues. These changes in initial colonization promoted the establishment of chronic infection. Furthermore, treatment of chronically infected mice with subtherapeutic ciprofloxacin served to exacerbate infection. A part of these changes was thought to be due to suppression of mucosal immunity, as demonstrated through reductions in cytokine secretion and migration of leukocytes into the urinary tract. This work identifies novel risk factors associated with antibiotic therapy when dosing strategies fall below subtherapeutic levels