Autotrophic microbial nitrification is the key process in the removal of ammonia from wastewater. To avoid the limitations of traditional microbiological methods an in situ identification technique for ammonia- and nitrite-oxidizing bacteria was developed. Based on comparative sequence analyses we designed a collection of 16S ribosomal RNA-targeted oligonucleotide probes for all validly described members of the genusNitrobacter . Whole cell hybridizations of target and reference cells with fluorescent probe derivatives were used to determine the optimal hybridization stringency for each of the probes. These probes were applied together with a recently developed probe for important members of the genus Nitrosomonas for simultaneous identification of ammonia- and nitrite-oxidizing bacteria in natural and engineered systems. Ammonia-oxidizing bacteria were identified in situ in river water, epiphytic biofilms from eutrophic wetlands, oligotrophic biofilms, a nitrifying trickling filter biofilm as well as in all analyzed nitrifying activated sludge samples. In none of these samples could Nitrobacter cells be detected in situ. However, all hitherto describedNitrobacter species and a strain of Nitrobacter sp. isolated from one of the analyzed nitrifying activated sludge samples showed bright hybridization signals with all Nitrobacter specific probes. Possible reasons for the absence of in situ detectable Nitrobacter cells are discussed.
Previous in vitro and in vivo animal studies showed that O(2) and CO(2) concentrations can affect virulence of pathogenic bacteria such as Staphylococcus aureus. The objective of this work was to measure O(2) and CO(2) levels in the vaginal environment during tampon wear using newly available sensor technology. Measurements by two vaginal sensors showed a decrease in vaginal O(2) levels after tampon insertion. These decreases were independent of the type of tampons used and the time of measurement (mid-cycle or during menstruation). These results are not in agreement with a previous study that concluded that oxygenation of the vaginal environment during tampon use occurred via delivery of a bolus of O(2) during the insertion process. Our measurements of gas levels in menses showed the presence of both O(2) and CO(2) in menses. The tampons inserted into the vagina contained O(2) and CO(2) levels consistent with atmospheric conditions. Over time during tampon use, levels of O(2) in the tampon decreased and levels of CO(2) increased. Tampon absorbent capacity, menses loading, and wear time influenced the kinetics of these changes. Colonization with S. aureus had no effect on the gas profiles during menstruation. Taken collectively, these findings have important implications on the current understanding of gaseous changes in the vaginal environment during menstruation and the potential role(s) they may play in affecting bacterial virulence factor production.
Culturing has detected vaginal Staphylococcus aureus in 10%-20% of women. Because growth mode can affect virulence expression, this study examined S. aureus-biofilm occurrence in 44 paired-tampon and vaginal-wash-specimens from 18 prescreened women, using fluorescent in situ hybridization (FISH). All 44 specimens were also analyzed for S. aureus by standard culturing on mannitol salt agar, which produced positive results for 15 of the 44 specimens. FISH detected S. aureus cells in all 44 specimens, and S. aureus biofilm was observed in 37 of the 44 specimens. Independent confirmation of the presence of S. aureus in specimens from all 18 women was also obtained by amplification, via polymerase chain reaction, of an S. aureus-specific nuclease gene. The results of this study demonstrate that S. aureus biofilm can form on tampons and menses components in vivo. Additionally, the prevalence of vaginal S. aureus carriage may be more prevalent than what is currently demonstrated by standard culturing techniques.
modification of the Addy 4-day plaque model was used for this evaluation. Plaque was measured at baseline (Day 1) of each treatment period and at Day 4 using the Turesky modification of Quigley-Hein index. During the treatment period, subjects brushed only their lingual surfaces twice daily for up to 60 seconds. Following brushing, subjects used 20 mls of the mouthrinse product for 30 seconds in the morning and evening. Fifty-five subjects completed the study. For non-brushed sites, both the essential oils and CPC rinse exhibited a 25% reduction in plaque vs. placebo after four days of product usage, which was statistically significant (p < 0.0001). Both treatments also exhibited a statistically significant benefit versus placebo (p<0.0001) for brushed sites (>38% plaque reduction). These data support the antibacterial action of the high bioavailable,
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