Occurrence of carbapenemase producing NAG Vibrio cholerae (NAG-CPV.c) in aquatic environment before the recommendation of carbapenem antibiotics

Abstract

Abstract Recent research updates and advances have shown an upsurge of antibiotic resistance reports amongst bacterial species with increasing spread/distribution especially in the water nexus. Such has been the trend among Vibrio cholerae strain as it is observed to be emerging with diverse resistant determinants. The current study presents the occurrence of carbapenemase producing NAG Vibrio cholerae (NAG-CPV.c) in aquatic environment before the recommendation of Carbapenem antibiotics. It focused on carbapenem resistant phenotype/genotype among environmental and somatic antigen nonagglutinating V. cholerae (SANAG-Vc) strains recovered from water sources, applying standard microbiological, serological and molecular biology techniques. Domestic water samples were collected for isolation of V. cholerae strains in Eastern Cape Province, South Africa. Carbapenem and specific β-lactamase inhibitors were employed for antibiotic susceptibility testing using K-B disc diffusion technique in addition to the Modified-Hodge-Test (MHT). Our results revealed 61 strains of environmental and SANAG-Vc serogroups. Amongst these confirmed SANAG-Vc strains recovered, 25 possess carbapenemase phenotype or NDM-1 phenotype (40.89%), whereas 24 (39.34%) were MHT positive phenotype. Further gene-based detection revealed 20 (32.79%) PCR confirmed as NDM-1 resistant gene positive strains. It is important to note that the carbapenem members of antibiotics are not readily employed in the therapeutic control of cholera cases as recommended by CLSI. Observing such resistant phenotypes/genotypes indicates a possible transfer/dissemination and emergence of such resistant determinants in the environment as the coastal water serves as a potential breeding hub for such resistant genes among potential pathogens. This is a serious threat to environmental wellness/public health especially those in the sub-urban and poor living localities, who source the analyzed water as their major source of water for domestic activities. The need for adroit and continuous monitoring of released water effluents of domestic and clinical sources remains a control strategy for environmental wellness and water bodies safety.

Keywords

• Antibiotic susceptibility testing
• Carbapenem antibiotics
• SANAG-Vibrio cholerae
• Water nexus
• Resistance phenotype
• Resistance genotype