Using gamification to improve engagement and learning outcomes in medical microbiology: the case study of 'BacteriaGame'.

The fight against antibiotic resistance has become a true global public health challenge of gargantuan proportions. Amongst the myriad of approaches being explored to tackle this predicament, one strategy involves enhancing prescriber knowledge and in particular their basic knowledge of medical bacteriology. Yet, as we well know in medical microbiology teachings, traditional lectures can be arduous, attempting to cram in a vast array of information in a limited time.

Co-Lateral Effect of Octenidine, Chlorhexidine and Colistin Selective Pressures on Four Enterobacterial Species: A Comparative Genomic Analysis.

Bacterial adaptation to antiseptic selective pressure might be associated with decreased susceptibility to antibiotics. In Gram-negative bacteria, some correlations between reduced susceptibility to chlorhexidine (CHX) and polymyxins have been recently evidenced in . In the present study, four isolates belonging to distinct enterobacterial species, namely , , and , were submitted to in-vitro selective adaptation to two antiseptics, namely CHX and octenidine (OCT), and to the antibiotic colistin (COL).

Impact of freeze/thaw cycles and single freezing at -80 °C on the viability of aerobic bacteria from rectal swabs performed with the ESwab system.

The testing of bacterial preservation should be included in preliminary studies to epidemiological studies. In the case of multidrug-resistant organism (MDRO) studies, quantifications of the bacteria make it possible to understand their emergence. The purpose of this preliminary study was to evaluate the performance of ESwab on survival of Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis, based on the number of freezing and thawing (F/T) cycles at -80 °C and freezing time.

Long-term evolution of the natural isolate of Escherichia coli 536 in the mouse gut colonized after maternal transmission reveals convergence in the constitutive expression of the lactose operon.

In vitro experimental evolution has taught us many lessons on the molecular bases of adaptation. To move towards more natural settings, evolution in the mice gut has been successfully performed. Yet, these experiments suffered from the use of laboratory strains as well as the use of axenic or streptomycin-treated mice to maintain the inoculated strains.

A Resazurin Reduction-Based Assay for Rapid Detection of Polymyxin Resistance in Acinetobacter baumannii and Pseudomonas aeruginosa.

A rapid test was developed for identification of polymyxin resistance in nonfermenting bacteria. This test detects viable cells after growth in a medium containing a defined concentration of colistin. The principle of this test is based on the visual detection of the reduction of the resazurin reagent, a viability colorant, as observed by its color change (blue to purple or pink).

Performances of the Rapid Polymyxin and Tests for Colistin Susceptibility Testing.

Owing to the emergence of colistin resistance in nonfermenting Gram negative bacteria, reliable and rapid techniques for testing colistin susceptibility are needed. We evaluated the performances of the Rapid Polymyxin and tests using a collection of and clinical isolates. Colistin susceptibility of and isolates (colistin susceptible and colistin resistant) was tested with the Rapid Polymyxin and tests and compared with the broth microdilution method.

Rapid multiplex polymerase chain reaction for detection of mcr-1 to mcr-5 genes.

A rapid (total time <2 h) and reliable multiplex polymerase chain reaction for screening of mcr-1 to mcr-5 genes conferring resistance to colistin has been developed. This technique has been tested on a collection of isolates previously identified as bearing mcr-1, mcr-2, and mcr-like genes and had a sensitivity and a specificity of 100%. Using this method, we were also able to identify a single isolate possessing both mcr-1 and mcr-5 genes.

Evolution of a Dominant Natural Isolate of Escherichia coli in the Human Gut over the Course of a Year Suggests a Neutral Evolution with Reduced Effective Population Size.

and evolution experiments on revealed several principles of bacterial adaptation. However, few data are available in the literature describing the behavior of in its natural environment. We attempted here to study the evolution in the human gut of a commensal dominant clone, ED1a belonging to the B2 phylogroup, through a longitudinal genomic study.

[Molecular epidemiology and kinetics of early Escherichia coli urinary tract infections in kidney transplant recipients].

Background: Escherichia coli strains causing Urinary Tract Infections (UTI) have a fecal origin.

Methods: A fecal sample was collected before Kidney Transplantation (KT) and concomitantly with urine at each of the 15 E. coli UTIs which occurred in 11 KT recipients.

Using long-term experimental evolution to uncover the patterns and determinants of molecular evolution of an Escherichia coli natural isolate in the streptomycin-treated mouse gut.

Although microbial ecology of the gut is now a major focus of interest, little is known about the molecular determinants of microbial adaptation in the gut. Experimental evolution coupled with whole-genome sequencing can provide insights of the adaptive process. In vitro experiments have revealed some conserved patterns: intermediate convergence, and epistatic interactions between beneficial mutations and mutations in global regulators.

Bacterial infection in compensated viral cirrhosis impairs 5-year survival (ANRS CO12 CirVir prospective cohort).

Objective: To assess incidence and prognostic significance of bacterial infections (BIs) occurring in compensated viral cirrhosis.

Design: This prospective study involved 35 French centres. Inclusion criteria were biopsy-proven HCV or HBV cirrhosis, Child-Pugh A and no previous hepatic complications.

The conserved nhaAR operon is drastically divergent between B2 and non-B2 Escherichia coli and is involved in extra-intestinal virulence.

The Escherichia coli species is divided in phylogenetic groups that differ in their virulence and commensal distribution. Strains belonging to the B2 group are involved in extra-intestinal pathologies but also appear to be more prevalent as commensals among human occidental populations. To investigate the genetic specificities of B2 sub-group, we used 128 sequenced genomes and identified genes of the core genome that showed marked difference between B2 and non-B2 genomes.

Carbapenem resistance in a human clinical isolate identified to be closely related to Acinetobacter indicus.

Here we report a case of carbapenem resistance in a human clinical isolate that was found to be closely related to the newly described environmental species Acinetobacter indicus. This strain harboured the blaOXA-23 carbapenemase gene located on a conjugative plasmid. Partial sequencing of 16S rDNA and rpoB genes, together with matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) analysis, showed that this strain was distantly related to the Acinetobacter baumannii-calcoaceticus complex and was closely related to A.

Commensal Escherichia coli strains in Guiana reveal a high genetic diversity with host-dependant population structure.

We undertook a large-scale epidemiological survey of commensal Escherichia coli in Trois-Sauts, an isolated village located in the south of French Guiana where human population exchanges are restricted and source of antibiotics controlled. Stools from 162 Wayampi Amerindians and rectal swabs from 33 human associated and 198 wild animals were collected in the close proximity of the village. The prevalence of E.

Emergence and dissemination of extended-spectrum beta-lactamase-producing Escherichia coli in the community: lessons from the study of a remote and controlled population.

Background: Intestinal carriage is a key factor in extended-spectrum beta-lactamase (ESBL) infection epidemiology but is difficult to study in open communities. To overcome this problem, we studied a highly stable group of Amerindians for whom we reported an ESBL carriage prevalence of 3.2% in 2001.

aes, the gene encoding the esterase B in Escherichia coli, is a powerful phylogenetic marker of the species.

Background: Previous studies have established a correlation between electrophoretic polymorphism of esterase B, and virulence and phylogeny of Escherichia coli. Strains belonging to the phylogenetic group B2 are more frequently implicated in extraintestinal infections and include esterase B2 variants, whereas phylogenetic groups A, B1 and D contain less virulent strains and include esterase B1 variants. We investigated esterase B as a marker of phylogeny and/or virulence, in a thorough analysis of the esterase B-encoding gene.

A module located at a chromosomal integration hot spot is responsible for the multidrug resistance of a reference strain from Escherichia coli clonal group A.

Escherichia coli clonal group A (CGA) commonly exhibits a distinctive multidrug antimicrobial resistance phenotype-i.e., resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, and trimethoprim (ACSSuTTp)-and has accounted for up to 50% of trimethoprim-sulfamethoxazole-resistant E.

Organised genome dynamics in the Escherichia coli species results in highly diverse adaptive paths.

The Escherichia coli species represents one of the best-studied model organisms, but also encompasses a variety of commensal and pathogenic strains that diversify by high rates of genetic change. We uniformly (re-) annotated the genomes of 20 commensal and pathogenic E. coli strains and one strain of E.

Evidence for a human-specific Escherichia coli clone.

Escherichia coli is a widespread commensal of the vertebrate intestinal tract. Until recently, no strong association between a particular clone and a given host species has been found. However, members of the B2 subgroup VIII clone with an O81 serotype appear to be human host specific.