Persistence survey of toxic shock syndrome toxin-1 producing Staphylococcus aureus and serum antibodies to this superantigen in five groups of menstruating women.

BACKGROUND: Menstrual Toxic Shock Syndrome (mTSS) is thought to be associated with the vaginal colonization with specific strains of Staphylococcus aureus TSST-1 in women who lack sufficient antibody titers to this toxin. There are no published studies that examine the seroconversion in women with various colonization patterns of this organism. Thus, the aim of this study was to evaluate the persistence of Staphylococcus aureus colonization at three body sites (vagina, nares, and anus) and serum antibody to toxic shock syndrome toxin-producing Staphylococcus aureus among a small group of healthy, menstruating women evaluated previously in a larger study. METHODS: One year after the completion of that study, 311 subjects were recalled into 5 groups. Four samples were obtained from each participant at several visits over an additional 6-11 month period: 1) an anterior nares swab; 2) an anal swab; 3) a vagina swab; and 4) a blood sample. Gram stain, a catalase test, and a rapid S. aureus-specific latex agglutination test were performed to phenotypically identify S. aureus from sample swabs. A competitive ELISA was used to quantify TSST-1 production. Human TSST-1 IgG antibodies were determined from the blood samples using a sandwich ELISA method. RESULTS: We found only 41% of toxigenic S. aureus and 35.5% of non-toxigenic nasal carriage could be classified as persistent. None of the toxigenic S. aureus vaginal or anal carriage could be classified as persistent. Despite the low persistence of S. aureus colonization, subjects colonized with a toxigenic strain were found to display distributions of antibody titers skewed toward higher titers than other subjects. Seven percent (5/75) of subjects became seropositive during recall, but none experienced toxic shock syndrome-like symptoms. CONCLUSIONS: Nasal carriage of S. aureus appears to be persistent and the best predicator of subsequent colonization, whereas vaginal and anal carriage appear to be more transient. From these findings, it appears that antibody titers in women found to be colonized with toxigenic S. aureus remained skewed toward higher titers whether or not the colonies were found to be persistent or transient in nature. This suggests that colonization at some point in time is sufficient to elevate antibody titer levels and those levels appear to be persistent. Results also indicate that women can become seropositive without experiencing signs or symptoms of toxic shock syndrome.

Interval analysis of blood filtration efficacy in novel device for autotransfusion in postpartum hemorrhage.

Postpartum haemorrhage (PPH), the leading cause of maternal mortality, is particularly problematic in low resource settings where access to safe blood supplies and definitive medical treatment is limited. We describe the continued development of an autotransfusion device designed to treat PPH by collection, filtration and infusion of maternal blood. Previous study has demonstrated that the device effectively moves blood through a filtration apparatus and removes up to 97% of aerobic bacteria but had poor anaerobic bacteria reduction. In this study, we investigate the filtration efficacy of the device using configurations comprised of three different leukocyte depletion filter designs: the Pall Leukoguard RS leukocyte reduction filter (PLRF), the Haemonetics BPF4™ (BPF4) leukocyte reduction filter, and the Haemonetics SCRC Leukotrap® (SCRC) filter. All configurations performed well with reductions ranging from 49 to 98%. Configurations containing 2 Haemonetics SCRC Leukotrap®filters (configuration 5 and 6) consistently reduced anaerobic bacteria by at least 73%. These results indicate that utilising a combination of SCRC and PLRF filters confers a high level of microbial filtration with improved removal of anaerobic organisms.

Silver-Coated Endotracheal Tubes Cleaned With a Mechanism for Secretion Removal.

BACKGROUND: Biofilm on the surface of endotracheal tubes (ETTs) is associated with ventilator-associated pneumonia. The use of silver-coated ETTs has been suggested to reduce the occurrence of ventilator-associated pneumonia by preventing biofilm formation. However, mucus accumulation can reduce the antibacterial activity of silver-coated ETTs by isolating bacterial colonies from the silver surface. We hypothesized that, in mechanically ventilated subjects, periodic removal of secretions through the use of a cleaning device would enhance the antimicrobial properties of silver-coated ETTs and thus reduce bacterial colonization. METHODS: Subjects were randomized to either standard suctioning (blind tracheal suctioning, control group) or blind tracheal suctioning plus cleaning maneuver every 8 h (treatment group). Tracheal aspirates were collected immediately before extubation for microbiological culture. After extubation, ETTs were collected for both cultural and non-cultural microbiological analysis and biofilm isolation. RESULTS: 39 subjects expected to be ventilated for > 48 h were enrolled; 36 ETTs (18 control, 18 treatment) and 29 tracheal samples (15 control, 14 treatment) were collected. Among the ETTs positive for bacterial colonization (15 vs 9, P = .18), cleaning maneuvers did not reduce microbial load, shown as the decimal logarithm of colony-forming units (CFU) per mL (1.6 ± 1.2 vs 0.9 ± 1.2 logCFU/mL, P = .15). There was a trend toward decreased biofilm deposition (439.5 ± 29.0 vs 288.9 ± 157.7 mg, P = .09) in the treated ETTs. No significant differences were observed in the number of positive tracheal aspirates (13 vs 10, P = .39) or in the microbial load (4.8 ± 4.0 vs 4.2 ± 3.8 logCFU/mL, P = .70) of tracheal secretions. Finally, no differences in the microbial load of Gram-positive organisms, Gram-negative organisms, or yeasts were found between the ETTs and tracheal aspirates of the 2 groups. CONCLUSIONS: In 39 critically-ill subjects intubated with silver-coated ETTs, periodic cleaning maneuvers did not decrease bacterial colonization of the ETTs and did not lower respiratory tract colonization compared to the standard suctioning. (Clinicaltrials.gov registration NCT02120001.).

Detection of bacteria in placental tissues obtained from extremely low gestational age neonates.

OBJECTIVE: The objective of the study was to quantify and identify aerobic and anaerobic bacteria as well as Mycoplasma and Ureaplasma in the chorionic parenchyma. STUDY DESIGN: A sample of the chorionic parenchyma from neonates delivered between 23-27 completed weeks was cultured and tested by polymerase chain reaction (PCR) methods using universal bacterial primers for the presence of bacteria and mycoplasmas. RESULTS: The culture positive rate was higher for vaginal deliveries (333/489; 68%) than for cesarean sections (363/876; 41%). Thirty percent of all culture-positive samples had only aerobic bacteria, 21% of the samples had only anaerobic bacteria, and 9% of the samples had only Mycoplasma/Ureaplasma. The mean concentration of Mycoplasma/Ureaplasma (4.00 +/- 1.11 log10 CFU/g) was significantly higher (P < .001) than the total count of either aerobes (3.24 +/- 1.12 log10 CFU/g) or anaerobes (2.89 +/- 0.99 log10 CFU/g). Staphylococcus sp. and Corynebacterium sp. as well as organisms associated with bacterial vaginosis were the most frequently recovered. A PCR product was not detected from either randomly selected or known culture-positive samples. CONCLUSION: Approximately half of second-trimester placentas harbor organisms within the chorionic plate. The chorion parenchyma appears to harbor constituents that prevent the identification of bacterial deoxyribonucleic acid by PCR methods.

Diversity of the gut microbiota and eczema in early life.

BACKGROUND: A modest number of prospective studies of the composition of the intestinal microbiota and eczema in early life have yielded conflicting results. OBJECTIVE: To examine the relationship between the bacterial diversity of the gut and the development of eczema in early life by methods other than stool culture. METHODS: Fecal samples were collected from 21 infants at 1 and 4 months of life. Nine infants were diagnosed with eczema by the age of 6 months (cases) and 12 infants were not (controls). After conducting denaturating gradient gel electrophoresis (DGGE) of stool samples, we compared the microbial diversity of cases and controls using the number of electrophoretic bands and the Shannon index of diversity (H') as indicators. RESULTS: Control subjects had significantly greater fecal microbial diversity than children with eczema at ages 1 (mean H' for controls = 0.75 vs. 0.53 for cases, P = 0.01) and 4 months (mean H' for controls = 0.92 vs. 0.59 for cases, P = 0.02). The increase in diversity from 1 to 4 months of age was significant in controls (P = 0.04) but not in children who developed eczema by 6 months of age (P = 0.32). CONCLUSION: Our findings suggest that reduced microbial diversity is associated with the development of eczema in early life.

Mode of delivery and cord blood cytokines: a birth cohort study.

BACKGROUND: The mechanisms for the association between birth by cesarean section and atopy and asthma are largely unknown. OBJECTIVE: To examine whether cesarean section results in neonatal secretion of cytokines that are associated with increased risk of atopy and/or asthma in childhood. To examine whether the association between mode of delivery and neonatal immune responses is explained by exposure to the maternal gut flora (a marker of the vaginal flora). METHODS: CBMCs were isolated from 37 neonates at delivery, and secretion of IL-13, IFN-gamma, and IL-10 (at baseline and after stimulation with antigens [dust mite and cat dander allergens, phytohemagglutinin, and lipopolysaccharide]) was quantified by ELISA. Total and specific microbes were quantified in maternal stool. The relation between mode of delivery and cord blood cytokines was examined by linear regression. The relation between maternal stool microbes and cord blood cytokines was examined by Spearman's correlation coefficients. RESULTS: Cesarean section was associated with increased levels of IL-13 and IFN-gamma. In multivariate analyses, cesarean section was associated with an increment of 79.4 pg/ml in secretion of IL-13 by CBMCs after stimulation with dust mite allergen (P < 0.001). Among children born by vaginal delivery, gram-positive anaerobes and total anaerobes in maternal stool were positively correlated with levels of IL-10, and gram-negative aerobic bacteria in maternal stool were negatively correlated with levels of IL-13 and IFN-gamma. CONCLUSION: Cesarean section is associated with increased levels of IL-13 and IFN-gamma, perhaps because of lack of labor and/or reduced exposure to specific microbes (e.g., gram-positive anaerobes) at birth.

Maternal microbe-specific modulation of inflammatory response in extremely low-gestational-age newborns.

The fetal response to intrauterine inflammatory stimuli appears to contribute to the onset of preterm labor as well as fetal injury, especially affecting newborns of extremely low gestational age. To investigate the role of placental colonization by specific groups of microorganisms in the development of inflammatory responses present at birth, we analyzed 25 protein biomarkers in dry blood spots obtained from 527 newborns delivered by Caesarean section in the 23rd to 27th gestation weeks. Bacteria were detected in placentas and characterized by culture techniques. Odds ratios for having protein concentrations in the top quartile for gestation age for individual and groups of microorganisms were calculated. Mixed bacterial vaginosis (BV) organisms were associated with a proinflammatory pattern similar to those of infectious facultative anaerobes. Prevotella and Gardnerella species, anaerobic streptococci, peptostreptococci, and genital mycoplasmas each appeared to be associated with a different pattern of elevated blood levels of inflammation-related proteins. Lactobacillus was associated with low odds of an inflammatory response. This study provides evidence that microorganisms colonizing the placenta provoke distinctive newborn inflammatory responses and that Lactobacillus may suppress these responses.

Active Video/Arcade Games (Exergaming) and Energy Expenditure in College Students.

Video games have become increasingly popular among young adults. The purpose of this pilot study was to determine if interactive video/arcade games, requiring physical activity to play, increase the energy expenditure (EE) and heart rate (HR) of young adults enough to elicit a training response. Thirteen male and female participants 26.6 ± 5.7 years of age were in the study. Participants were familiarized with equipment and allowed to practice with three games: (1) moving and striking lighted pads, (2) riding a bike to increase the pace of a race car, and (3) boxing against a video simulated opponent. A portable metabolic cart and HR monitor were attached to participants to measure baseline and exercise values. Participants could play any of the three games for 30 minutes while metabolic and HR data were collected. Exercise data were compared to baseline measures, and the 3 games were compared for EE. Paired sample t-tests showed baseline and exercise values differed for HR (t(12) = -18.91, p < 0.01), and EE (t(12) = -15.62, p < 0.01). The boxing game provided the highest VO2 (17.47 ± 4.79 ml·kg(·-1)min(-1)). Participants achieved 60% or better of their HR reserve (162.82 ± 10.78 beats·min(-1),) well within the ACSM guidelines for a training HR. Caloric expenditure during the 30-minute exercise session (226. 07 ± 48.68) is also within the ACSM recommendations for daily physical activity. Thus, interactive video/arcade games that require physical activity to play can be utilized as part of an overall aerobic exercise program.

Prevalence of toxic shock syndrome toxin 1-producing Staphylococcus aureus and the presence of antibodies to this superantigen in menstruating women.

Menstrual toxic shock syndrome (mTSS) is thought to be associated with colonization with toxic shock syndrome toxin 1 (TSST-1)-producing Staphylococcus aureus in women with insufficient antibody titers. mTSS has been associated with menstruation and tampon use, and although it is rare, the effects can be life threatening. It remains of interest because of the widespread use of tampons, reported to be about 70% of women in the United States, Canada, and much of Western Europe. This comprehensive study was designed to determine S. aureus colonization and TSST-1 serum antibody titers in 3,012 menstruating women in North America between the ages of 13 and 40, particularly among age and racial groups that could not be assessed reliably in previous small studies. One out of every four subjects was found to be colonized with S. aureus in at least one of three body sites (nose, vagina, or anus), with approximately 9% colonized vaginally. Eighty-five percent of subjects had antibody titers (> or =1:32) to TSST-1, and the vast majority (81%) of teenaged subjects (13 to 18 years) had already developed antibody titers. Among carriers of toxigenic S. aureus, a significantly lower percentage of black women than of white or Hispanic women were found to have antibody titers (> or =1:32) to TSST-1 (89% versus 98% and 100%). These findings demonstrate that the majority of teenagers have antibody titers (> or =1:32) to TSST-1 and are presumed to be protected from mTSS. These findings also suggest that black women may be more susceptible to mTSS than previously thought.