Faecal carriage of multidrug-resistant Gram-negative bacilli during a non-outbreak situation in a French university hospital

Objectives: To determine the prevalence of multidrug-resistant (MDR) Gram-negative bacilli and extended spectrum beta-lactamase (ESBL)-producing isolates in stool specimens obtained from patients hospitalized for acute diarrhoea in a French university hospital. Methods: Bacteria in stool specimens were screened for ESBL production on Drigalski agar supplemented with ceftazidime, ESBL CHROMagar (R) and CTX CHROMagar (R) media and confirmed by the double-disc synergy test. Genetic detection was performed by PCR and sequencing with bacterial DNA extracted from isolates. Results: The presence of MDR bacteria was markedly high (96 of 303 patients, 31.7%). The majority of MDR bacteria were Enterobacter cloacae (44, 38%) and Escherichia coli (32, 28%). Moreover, the prevalence of ESBL and CTX-M producers among all included patients was 15.8% and 5.9%, respectively. The clone E. coli O25b:H4-ST131 was detected in 63% of CTX-M strains. Surprisingly, 16 carbapenemases (5.3% of patients) were isolated. Conclusions: The study revealed the wide dissemination of MDR bacteria, including carbapenemase producers, in a French hospital during a non-outbreak situation. Public health efforts to combat emergence and dissemination of MDR organisms need to be developed.