Trends in Antibiotic-Resistant Bacteria Isolated from Screening Clinical Samples in a Tertiary Care Hospital over the 2018-2022 Period.

To assess the putative impact of the COVID-19 pandemic on multidrug-resistant (MDR) bacteria recovered from routine screening samples and, more globally, the trends in time to first positive screening sample and carriage duration of those bacteria in patients admitted to a tertiary hospital, data from laboratory results were retrospectively mined over the 2018-2022 period. No significant differences could be found in the number of positive patients or MDR isolates per year, time to positive screening, or carriage duration. Extended-spectrum beta-lactamase producers were dominant throughout the studied period but their relative proportion decreased over time as well as that of meticillin-resistant Staphylococcus aureus. Meanwhile, carbapenemase-producing enterobacteria (CPE) proportion increased. Among the 212 CPE isolates, Klebsiella pneumoniae and Escherichia coli were the more frequent species but, beginning in 2020, a significant rise in Enterobacter cloacae complex and Citrobacter freundii occurred. OXA48 was identified as the leading carbapenemase and, in 2020, a peak in VIM-producing enterobacteria linked to an outbreak of E. cloacae complex during the COVID-19 pandemic was singled out. Finally, a worrisome rise in isolates producing multiple carbapenemases (NDM/VIM and mostly NDM/OXA48) was highlighted, especially in 2022, which could lead to therapeutic dead-ends if their dissemination is not controlled.

Bacillus cereus strains from donor human milk and hospital environment: uncovering a putative common origin using comparative analysis of toxin and infra-red spectroscopy profiles.

Bacillus cereus is reported as a common cause of toxin-induced food poisoning and of contamination in pasteurized human milk donations. As various toxins can be produced by B. cereus, the aim of this work was first to investigate the toxigenic potential and profiles of 63 B. cereus isolates from Amiens Picardie human milk bank. A comparison to the toxigenic profiles of 27 environmental B. cereus isolates harvested in the hospital in which this human milk bank is situated was performed. Toxin gene prevalences were the highest for nhe (ABC) and entFM followed by cytK and hbl(ACD). A 27% prevalence was found for ces human milk isolates, which is higher than previous works reporting on pasteurized milk and dairy products. No significant differences could be found between human milk and environmental isolates regarding toxin gene prevalences and/or toxin gene profiles. The second aim was to establish whether a B. cereus cross-contamination between human milk and the environment could occur. This was achieved with the help of Fourrier-transform infra-red spectroscopy which enabled the discrimination of 2 main clusters of 11 and 8 isolates, each containing human milk and Amiens Picardie human milk bank environmental isolates. For these two clusters, the time sequence showed that human milk isolates were the first to occur and might have contaminated the milk bank environment as well as other human milk donations. Routinely used on B. cereus isolates, Fourrier-transform infra-red spectroscopy could help in rapidly detecting such clusters and in limiting the spread of a B. cereus strain that might generate rejection of pasteurized donation by the human milk bank.

Bacillus cereus contamination of pasteurized human milk donations: frequency, origin, seasonal distribution, molecular typing of strains and proposed corrective/preventive actions.

OBJECTIVES: An increase in pasteurized human milk contamination with Bacillus cereus was witnessed in milk donated to the Amiens-Picardie Human Milk Bank over the 2017-2018 period. To better understand the origin of such an increase, this study aimed to describe the frequency of Bacillus cereus contamination in anonymous and personalized human milk donations of Amiens Human Milk Bank in 2018, compare the genetic profiles of Bacillus cereus strains found in pasteurized human milk and set up corrective/preventive actions to reduce Bacillus cereus contamination. STUDY DESIGN: A retrospective cohort study of human milk donated from January to December 2018 was set. Data on the microbiological quality of donated human milk and genetic profiles of Bacillus cereus strains isolated from pasteurized donated human milk and the environment were collected. RESULTS: The overall noncompliance rate related to the microbiological quality in the 1585 batches of analyzed human milk donations was of 27.3%. Post-Holder pasteurization, rejection rates were significantly higher for anonymous donations as compared to personalized ones. Bacillus cereus was the main cause of noncompliance. Bacillus cereus contaminations could not be attributed to a single strain spreading through Amiens human milk bank and Amiens hospital environment as the genetic profiles of the collected strains were different. Corrective actions led to a decrease in the noncompliance rate due to Bacillus cereus (37.7-9.7%) post-Holder pasteurization. CONCLUSION: Bacillus cereus was the primary cause of rejection for pasteurized human milk donations over the investigated period. These contaminations did not originate from the spread of a single strain. A first round of corrective actions enabled a fair decrease in Bacillus cereus contaminations.

Validation of a Worst-Case Scenario Method Adapted to the Healthcare Environment for Testing the Antibacterial Effect of Brass Surfaces and Implementation on Hospital Antibiotic-Resistant Strains.

The evaluation of antibacterial activity of metal surfaces can be carried out using various published guidelines which do not always agree with each other on technical conditions and result interpretation. Moreover, these technical conditions are sometimes remote from real-life ones, especially those found in health-care facilities, and do not include a variety of antibiotic-resistant strains. A worst-case scenario protocol adapted from published guidelines was validated on two reference strains (Staphylococcus aureus ATCC 6538 and Enterobacter aerogenes ATCC 13048). This protocol was designed to be as close as possible to a healthcare facility environment, including a much shorter exposure-time than the one recommended in guidelines, and evaluated the impact of parameters such as the method used to prepare inocula, seed on the surface, and recover bacteria following exposure. It was applied to a panel of 12 antibiotic-resistant strains (methicillin resistant, vancomycin-resistant, beta-lactamase, and carbapenemase producing strains as well as efflux pump-overexpressing ones) chosen as representative of the main bacteria causing hospital acquired infections. Within a 5-min exposure time, the tested brass surface displayed an antibacterial effect meeting a reduction cut-off of 99% compared to stainless steel, whatever the resistance mechanism harbored by the bacteria.

Factors influencing field testing of alcohol-based hand rubs.

BACKGROUND: According to the World Health Organization guidelines, field tests, in the context of a bid for the supply of alcohol-based hand rubs, should take into account climatic region, test period, products already in use, and type of use (hygienic or surgical) when assessing tolerance. This laborious method is often contested. OBJECTIVE: To conduct a post hoc analysis of the data of a large bid, including 5 factors, to validate the relevance of their inclusion. METHODS: For the purposes of the bid, products were compared in terms of the 4 World Health Organization tolerance criteria (appearance, intactness, moisture content, sensation) during product testing and were separated into groups on the basis of the studied factors. The post hoc analysis method included (1) comparison of the mean before-and-after difference based on the self-evaluation of the skin with the 4 World Health Organization tolerance criteria, between climatic regions, periods, products in use, test product, and the type of use; (2) generalized linear models, taking into account all studied factors. RESULTS: The analysis included data for 1,925 pairs of professionals. The means of the differences observed were independently and significantly associated with the test period (P<.001), the hygienic or surgical use (P=.010 to .041, not significant for appearance), the product already in use (significant for appearance P=.021), and the test product (P<.001). The association with climatic region was found to be significant only in the nonadjusted analysis. CONCLUSION: The type of use, the test period, and the product in use should be taken into account when designing field tests of alcohol-based hand rubs.