Prevalence and molecular characterisation of extended-spectrum β-lactamases genes in Escherichia coli and Salmonella spp. isolated from fish samples in Chhattisgarh, India

Abstract

In this study, fish samples were examined for the presence of extended spectrum β-lactamases (ESBL) producing Escherichia coli and Salmonella spp. Out of 200 samples collected from retail markets of Durg, Raipur, Rajnandgaon and Balod districts of Chhattisgarh State, 76 (38) and 46 (23%) samples were found contaminated with E. coli and Salmonella spp., respectively. Multiple antibiotic resistant (MAR) index varied between 0.00 to 0.88 and 0.11 to 0.88 for E. coli and Salmonella isolates, respectively. The isolates were screened phenotypically for ESBL production and multiplex PCR targeting bla TEM , bla SHV , andbla CTX-M genes, was carried out followed by sequencing. Prevalence of bla TEM , bla SHV and bla CTX-M genes in E. coli and Salmonella isolates were found to be 13.2, 1.3, 0 and 6.5, 0, 4.4%, respectively. Higher percentage of resistant genes was detected in plasmid DNA in comparison to genomic DNA. Sequencing of PCR amplicons of bla TEM and bla CTX-M genes revealed the presence of bla TEM-116 and bla CTX-M-15 variants, respectively. The study indicates the presence of multidrug resistant ESBL producing E. coli and Salmonella in fish samples, which may pose threat to the fish consumers.

ERIC-PCR-based molecular typing of multidrug-resistant Escherichia coli isolated from houseflies (Musca domestica) in the environment of milk and meat shops

“…Genomic DNA was extracted from pure cultures of E. coli isolates using the snap chill method (Khan et al . 2021). The extracted DNA was stored at −20°C until further analysis.…”

“…The colonies exhibiting Indole, methyl-red as positive Voges-Proskauer and Citrate utilization tests as negative were confirmed as E. coli isolates. Genomic DNA was extracted from pure cultures of E. coli isolates using the snap chill method (Khan et al 2021). The extracted DNA was stored at À20°C until further analysis.…”

Antibiotic Resistance Pattern and Distribution of Resistance Genes in Salmonella Isolated from Chicken and Duck Eggs in Chhattisgarh, India

“…Isolation and identification of Salmonella spp. from egg samples was carried out according to the method described by Khan et al (2021) with some modifications. For investigation of Salmonella contamination over the egg surface, the entire surface of the egg shell was swabbed with sterile cotton swabs soaked in buffered peptone water (BPW) (HiMedia, India).…”

“…In addition to conventional methods, Salmonella isolates were confirmed by the genus-specific polymerase chain reaction (PCR) method described by Rahn et al (1992) for the detection of invA gene (Table 1). Template DNA of Salmonella isolates for PCR was prepared by the boiling and snap chill method (Khan et al, 2021). Salmonella genomic DNA (MBT 103, MolBio TM , HiMedia, India) and Escherichia coli isolate maintained in the departmental laboratory were used as positive and negative controls, respectively.…”