The alarming association between antibiotic resistance and reduced susceptibility to biocides in nosocomial MRSA isolates from two regional hospitals in Egypt

Methicillin-resistant Staphylococcus aureus is one of the major clinical problems in hospitals because of its resistance to many antimicrobials. Biocides are used in hospitals to control nosocomial infections. This work aimed to investigate the relationship between the presence of integrons and reduced susceptibility to both biocides and antimicrobials in nosocomial multidrug-resistant (MDR)-MRSA isolates. A total of 114 clinical and eight environmental MRSA isolates were collected from Zagazig University Hospitals and El-Ahrar Educational Hospital, Egypt. These isolates were identified as MRSA by disk diffusion method (DDM) and confirmed by PCR. Susceptibility profile against 12 antibiotics and five biocides was determined by DDM and agar dilution method, respectively. Presence of integrons was investigated by PCR in MDR isolates. Seventy-five clinical and six environmental isolates were MDR and had reduced susceptibility to biocides. Class I integron was detected in plasmid DNA of 34 isolates and genomic DNA of 14 isolates. Meanwhile, class II integron was only detected in plasmid DNA of 10 clinical isolates. This study revealed a high prevalence of MDR-MRSA clinical and environmental isolates, both had reduced susceptibility to investigated biocides. Class I integron was more predominant in plasmid DNA of isolates, indicating that plasmid is a major carrier for integrons that transfer resistance genes. In conclusion, the association between antibiotic resistance and biocides reduced susceptibility is alarming. The selection of curative antibiotic should depend on the antimicrobial susceptibility profile. Furthermore, biocides should always be used at appropriate concentrations to prevent the evolution of resistance and to control the hospital-transmission of MRSA.

Epidemiology and prevalence of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae in humans, animals and the environment in West and Central Africa

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) are widespread. Here we used the 'One Health' approach to determine knowledge gaps on ESBL-E and CPE in West and Central Africa. We searched all articles on ESBL-E and CPE in these African regions published in PubMed, African Journals Online and Google Scholar from 2000 onwards. Among the 1201 articles retrieved, we selected 165 studies (West Africa, 118; Central Africa, 47) with data from 22 of the 26 West and Central Africa countries. Regarding the settings, 136 articles focused only on humans (carriage and/or infection), 6 articles on humans and animals, 13 on animals, 1 on humans and the environment, 8 on the environment and 1 on humans, animals and environments. ESBL-E prevalence ranged from 11-72% in humans and 7-79% in aquatic environments (wastewater). In animals, ESBL-E prevalence hugely varied: 0% in cattle, 11-36% in chickens, 20% in rats, 21-71% in pigs and 32-75% in dogs. The bla_CTX-M-15 gene was the predominant ESBL-encoding gene and was associated with plasmids of incompatibility groups F, H, K, Y, N, I1 and R. CPE were studied only in humans. Class B metallo-β-lactamases (NDM) and class D oxacillinases (OXA-48 and OXA-181) were the most common carbapenemases. Our results show major knowledge gaps, particularly on ESBL and CPE in animals and the environment, that might limit antimicrobial resistance management in these regions. The results also emphasise the urgent need to improve active surveillance programmes in each country and to support antimicrobial stewardship.