- Characterization of Fecal Peritonitis-Induced Sepsis in a Porcine Model. [Journal Article]
- JSJ Surg Res 2019 Jul 19; 244:492-501
- CONCLUSIONS: We implemented a porcine fecal peritonitis-induced sepsis model that demonstrates culture-proven bacteremia and multiple organ failure, particularly cardiovascular system failure. This model could facilitate the development of technologies for the early diagnosis of bacterial pathogens in blood.
- Development of a rapid-viability PCR method for detection of Clostridioides difficile spores from environmental samples. [Journal Article]
- AAnaerobe 2019 Jul 19; :102077
- Clostridioides difficile is a common pathogen that is well known to survive for extended periods of time on environmental healthcare surfaces from fecal contamination. During epidemiological investig…
Clostridioides difficile is a common pathogen that is well known to survive for extended periods of time on environmental healthcare surfaces from fecal contamination. During epidemiological investigations of healthcare-associated infections, it is important to be able to detect whether or not there are viable spores of C. difficile on surfaces. Current methods to detect C. difficile can take up to 7 days for culture and in the case of detection by PCR, viability of the spores cannot be ascertained. Prevention of C. difficile infection in healthcare settings includes adequate cleaning and disinfection of environmental surfaces which increases the likelihood of detecting dead organisms from an environmental sample during an investigation. In this study, we were able to adapt a rapid-viability PCR (RV-PCR) method, first developed for detection of viable Bacillus anthracis spores, for the detection of viable C. difficile spores. RV-PCR uses the change in cycle threshold after incubation to confirm the presence of live organisms. Using this modified method we were able to detect viable C. difficile after 22 h of anaerobic incubation in Cycloserine Cefoxitin Fructose Broth (CCFB). This method also used bead beating combined with the Maxwell 16 Casework kit for DNA extraction and purification and a real-time duplex PCR assay for toxin B and cdd3 genes to confirm the identity of the C. difficile spores. Spiked environmental sponge-wipes with and without added organic load were tested to determine the limit of detection (LOD). The LOD from spiked environmental sponge-wipe samples was 104 spores/mL but after incubation initial spore levels of 101 spores/mL were detected. Use of this method would greatly decrease the amount of time required to detect viable C. difficile spores; incubation of samples is only required for germination (22 h or less) instead of colony formation, which can take up to 7 days. In addition, PCR can then quickly confirm or deny the identity of the organism at the same time it would confirm viability. The presence of viable C. difficile spores could be detected at very low levels within 28 h total compared to the 2 to 10-day process that would be needed for culture, identification and toxin detection.
- Colorectal cancer knowledge and screening adherence among low-income Hispanic employees. [Journal Article]
- HEHealth Educ Res 2019 Apr 28
- Hispanics have the lowest colorectal cancer (CRC) screening rates of all racial/ethnic groups and comprise the largest proportion of low-income manual laborers in the nation. We partnered with busine…
Hispanics have the lowest colorectal cancer (CRC) screening rates of all racial/ethnic groups and comprise the largest proportion of low-income manual laborers in the nation. We partnered with businesses to implement a community health worker (CHW)-led intervention among Hispanic workers in service-related and manual labor occupations, which often pay low wages and do not provide health insurance. CHWs measured knowledge, screening adherence and perceptions of CRC risk before and after educational interventions via interview. CHWs provided fecal immunochemical tests (FITs) to participants aged ≥50 years. Chi-square tests and logistic regression identified pre-intervention predictors of CRC knowledge of all participants and adherence among eligible participants. Adherence among participants increased from 40% (n = 307) pre-intervention to 66% post-intervention. Knowledge about CRC was associated with age ≥50 years (OR = 8.90 [95% CI = 2.61-30.35]; ref = 18-30) and perceived personal risk for CRC (Likely, OR = 3.06 [95% CI = 1.40-6.67]; ref = Not likely). Insurance status was associated with screening adherence pre-intervention (OR = 3.00 [95% CI 1.10-8.12]; ref = No insurance). Improvement in adherence post-intervention was associated with income between $25 000 and ≥$55 000 (OR = 8.49 [95% CI 1.49-48.32]; ref = $5000-<$10 000). Community-based health programs can improve CRC screening adherence among Hispanic workers in service-related and manual labor positions, but lowest-income workers may need additional support.
- BarrettNET-a prospective registry for risk estimation of patients with Barrett's esophagus to progress to adenocarcinoma. [Journal Article]
- DEDis Esophagus 2019 Apr 24
- Risk stratification in patients with Barrett's esophagus (BE) to prevent the development of esophageal adenocarcinoma (EAC) is an unsolved task. The incidence of EAC and BE is increasing and patients…
Risk stratification in patients with Barrett's esophagus (BE) to prevent the development of esophageal adenocarcinoma (EAC) is an unsolved task. The incidence of EAC and BE is increasing and patients are still at unknown risk. BarrettNET is an ongoing multicenter prospective cohort study initiated to identify and validate molecular and clinical biomarkers that allow a more personalized surveillance strategy for patients with BE. For BarrettNET participants are recruited in 20 study centers throughout Germany, to be followed for progression to dysplasia (low-grade dysplasia or high-grade dysplasia) or EAC for >10 years. The study instruments comprise self-administered epidemiological information (containing data on demographics, lifestyle factors, and health), as well as biological specimens, i.e., blood-based samples, esophageal tissue biopsies, and feces and saliva samples. In follow-up visits according to the individual surveillance plan of the participants, sample collection is repeated. The standardized collection and processing of the specimen guarantee the highest sample quality. Via a mobile accessible database, the documentation of inclusion, epidemiological data, and pathological disease status are recorded subsequently. Currently the BarrettNET registry includes 560 participants (23.1% women and 76.9% men, aged 22-92 years) with a median follow-up of 951 days. Both the design and the size of BarrettNET offer the advantage of answering research questions regarding potential causes of disease progression from BE to EAC. Here all the integrated methods and materials of BarrettNET are presented and reviewed to introduce this valuable German registry.
- Effects of two-dose ceftiofur treatment for metritis on the temporal dynamics of antimicrobial resistance among fecal Escherichia coli in Holstein-Friesian dairy cows. [Journal Article]
- PlosPLoS One 2019; 14(7):e0220068
- A pair-matched longitudinal study conducted on three dairy farms in the U.S. High-Plains explored the temporal effects of two-dose ceftiofur crystalline-free acid (CCFA) treatment for metritis on thi…
A pair-matched longitudinal study conducted on three dairy farms in the U.S. High-Plains explored the temporal effects of two-dose ceftiofur crystalline-free acid (CCFA) treatment for metritis on third-generation cephalosporin (3GC) resistance among enteric E. coli in Holstein-Friesian cows. The current 13-day slaughter withholding period does not account for rising populations of third-generation cephalosporin (3GC) resistant bacteria in feces of animals following CCFA treatment. A total of 124 matched-pairs of cows were enrolled in the study. Cows diagnosed with postpartum metritis received the product twice at the labeled dose of 6.6 mg/kg subcutaneously at the base of alternating ears. Untreated cows-absent clinical metritis-were matched on lactation number and calving date. Feces were collected per rectum on days 0 (baseline), 6, 16, 28, and 56. Environmental samples, from watering troughs as well as surface manure from fresh-cow, hospital, maternity, and milking pens, and from the compost pile were collected prior to the animal sample collection period. Historical data on metritis rates and CCFA use were compiled from herd records. On day 0, cows exhibited an overall mean difference of over 4 log10 colony forming units (CFU) comparing 3GC resistant E. coli to the general E. coli population. At the first eligible slaughter date, the difference declined to 3.31 log10 CFU among cows in the CCFA group (P<0.01 compared to control cows). Such differences were no longer observed between the treated and control groups by day 28. Results suggest a 13-day withholding period following the final treatment is insufficient to allow levels of 3GC resistant E. coli to return to baseline. This effect varied by farm and was dependent upon the starting level of resistance. A farm-specific extended slaughter-withholding period could reduce the microbial risk to food products at slaughter.
- Caspase-mediated cleavage of murine norovirus NS1/2 potentiates apoptosis and is required for persistent infection of intestinal epithelial cells. [Journal Article]
- PPPLoS Pathog 2019 Jul 22; 15(7):e1007940
- Human norovirus (HNoV) is the leading cause of acute gastroenteritis and is spread by fecal shedding that can often persist for weeks to months after the resolution of symptoms. Elimination of persis…
Human norovirus (HNoV) is the leading cause of acute gastroenteritis and is spread by fecal shedding that can often persist for weeks to months after the resolution of symptoms. Elimination of persistent viral reservoirs has the potential to prevent outbreaks. Similar to HNoV, murine norovirus (MNV) is spread by persistent shedding in the feces and provides a tractable model to study molecular mechanisms of enteric persistence. Previous studies have identified non-structural protein 1 (NS1) from the persistent MNV strain CR6 as critical for persistent infection in intestinal epithelial cells (IECs), but its mechanism of action remains unclear. We now find that the function of CR6 NS1 is regulated by apoptotic caspase cleavage. Following induction of apoptosis in infected cells, caspases cleave the precursor NS1/2 protein, and this cleavage is prevented by mutation of caspase target motifs. These mutations profoundly compromise CR6 infection of IECs and persistence in the intestine. Conversely, NS1/2 cleavage is not strictly required for acute replication in extra-intestinal tissues or in cultured myeloid cells, suggesting an IEC-centric role. Intriguingly, we find that caspase cleavage of CR6 NS1/2 reciprocally promotes caspase activity, potentiates cell death, and amplifies spread among cultured IEC monolayers. Together, these data indicate that the function of CR6 NS1 is regulated by apoptotic caspases, and suggest that apoptotic cell death enables epithelial spread and persistent shedding.
- Std fimbriae-fucose interaction increases Salmonella-induced intestinal inflammation and prolongs colonization. [Journal Article]
- PPPLoS Pathog 2019 Jul 22; 15(7):e1007915
- Expression of ABO and Lewis histo-blood group antigens by the gastrointestinal epithelium is governed by an α-1,2-fucosyltransferase enzyme encoded by the Fut2 gene. Alterations in mucin glycosylatio…
Expression of ABO and Lewis histo-blood group antigens by the gastrointestinal epithelium is governed by an α-1,2-fucosyltransferase enzyme encoded by the Fut2 gene. Alterations in mucin glycosylation have been associated with susceptibility to various bacterial and viral infections. Salmonella enterica serovar Typhimurium is a food-borne pathogen and a major cause of gastroenteritis. In order to determine the role of Fut2-dependent glycans in Salmonella-triggered intestinal inflammation, Fut2+/+ and Fut2-/- mice were orally infected with S. Typhimurium and bacterial colonization and intestinal inflammation were analyzed. Bacterial load in the intestine of Fut2-/- mice was significantly lower compared to Fut2+/+ mice. Analysis of histopathological changes revealed significantly lower levels of intestinal inflammation in Fut2-/- mice compared to Fut2+/+ mice and measurement of lipocalin-2 level in feces corroborated histopathological findings. Salmonella express fimbriae that assist in adherence of bacteria to host cells thereby facilitating their invasion. The std fimbrial operon of S. Typhimurium encodes the π-class Std fimbriae which bind terminal α(1,2)-fucose residues. An isogenic mutant of S. Typhimurium lacking Std fimbriae colonized Fut2+/+ and Fut2-/- mice to similar levels and resulted in similar intestinal inflammation. In vitro adhesion assays revealed that bacteria possessing Std fimbriae adhered significantly more to fucosylated cell lines or primary epithelial cells in comparison to cells lacking α(1,2)-fucose. Overall, these results indicate that Salmonella-triggered intestinal inflammation and colonization are dependent on Std-fucose interaction.
- Development of a humanized murine model for the study of Oxalobacter formigenes intestinal colonization. [Journal Article]
- JIJ Infect Dis 2019 Jul 22
- CONCLUSIONS: Transplanting mice with human feces and O. formigenes introduced new microbial populations resembling the human microbiome, with stable O. formigenes colonization; such models can define optimal O. formigenes strains to facilitate clinical trials.
- Storage procedures and time influence the detectability of Clostridium difficile toxin A but not toxin B in porcine fecal specimens. [Journal Article]
- JVJ Vet Diagn Invest 2019 Jul 22; :1040638719864383
- Storage procedures are known to affect the detectability of Clostridium difficile toxins in equine and human feces. We assessed the impact of different storage conditions on the detectability of C. d…
Storage procedures are known to affect the detectability of Clostridium difficile toxins in equine and human feces. We assessed the impact of different storage conditions on the detectability of C. difficile toxins in swine feces. Specimens were inoculated with toxins, 112 ng/g of toxin A (TcdA) and 16 ng/g of toxin B (TcdB) and subjected to the following 3 storage treatments: 4°C, -30°C, repetitive freezing at -30°C and thawing. Toxin determination was assessed at 1, 2, 7, 14, and 21 d with ELISA. A decrease in concentrations of TcdA with time was observed for samples stored at 4°C and repetitive freezing-thawing (p ≤0.05). On day 14, storage at 4°C resulted in decreased TcdA concentration as opposed to storage at -30°C and repetitive freezing-thawing (p ≤0.05). On day 21, storage at 4°C resulted in decreased TcdA detectability compared with storage at -30°C (p ≤0.05). The TcdB concentration was unaffected. These results on toxin detectability in swine feces should be carefully considered in in vitro studies on toxigenic C. difficile. Our results also offer valuable information for microbiologists and veterinarians monitoring the presence of virulent C. difficile in pigs.
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- Selected commensal bacteria change profiles of Helicobacter pylori-induced T cells via dendritic cell modulation. [Journal Article]
- HHelicobacter 2019 Jul 21; :e12614
- CONCLUSIONS: In contrast to Lp, Lr probiotic strain overcomes Hp-mediated immune profile in the DC/T-cell co-cultures toward Th1 pattern and limited generation of Tregs in vitro. Lr may therefore be used as a component of anti-Hp treatment.