RESUMEN
A vancomycin-resistant Gram-positive bacterium of the genus Enterococcus, designated as BT22, was isolated from untreated hospital effluents at Chettia Chlef Hospital. The complete genome of strain BT22 was sequenced using the Illumina MiSeq platform, revealing a total length of 2,577,707 bp, with 2462 coding sequences (CDS) and an average G+C content of 38.00 mol%. Phylogenomic analyses confirmed that strain BT22 belongs to the same species as Enterococcus faecium AVS0243, with a similarity of 99.79 %. The study identified 12 antibiotic resistance genes and one virulence gene in strain BT22. These genes confer resistance to various classes of antibiotics, including aminoglycosides, macrolides, tetracyclines, and vancomycin. However, the virulence gene identified codes for adhesion. Furthermore, mobile genetic elements, such as IS elements carried by a conjugative plasmid, were detected. The genomic sequencing data of E. faecium BT22 will be of great value to the scientific community, enabling comparative genomic analyses and a better understanding of antibiotic resistance mechanisms, particularly towards vancomycin. The genomic information has been deposited in the DDBJ/EMBL/GenBank databases under accession number JASSVD010000000, providing an essential resource in the fight against antibiotic resistance and the spread of resistant bacterial strains.
RESUMEN
The main objective of this work is to investigate the impact of oral administration of ampicillin on the ecological balance of enterococci in the intestinal microbiota of rats during a treatment and a post-treatment. The results have showed that the treated animals excreted significantly higher percentages of resistant enterococci compared to the control group (P ≤ 0.05) during the treatment and after the treatment. The most predominant species selected after the treatment began were Enterococcus faecium. The MICs for ampicillin for all isolates of E. faecium were 32 to 64 µg/mL, with the exception of two strains (TR1LBMB, TR5LBMB), were found to be highly resistant (MICs ≥ 128 µg/mL). Quantification of ampicillin in faeces by the RT-HPLC showed that the significant increase in the number of ampicillin-resistant enterococci was associated with the gradual accumulation of high levels of unabsorbed ampicillin in the faeces. Our results suggest that ampicillin treatment can now be understood as a side effect contributing to the increase in the number of resistant Enterococcus strains, particularly E. faecium strains, recognized as important nosocomial pathogens.