Video abstract of original research paper “Occurrence of extended-spectrum and AmpC beta-lactamases in multiple drug resistant Salmonella isolates from clinical samples in Lagos, Nigeria” published in the open access journal Infection and Drug Resistance by authors Akinyemi, Iwalokun, Oyefolu, et al.
Purpose: Salmonella spp. are important foodborne pathogens exhibiting increasing resistance
to antimicrobial drugs. Resistance to broad-spectrum β-lactams, mediated by extended-spectrum
β-lactamase (ESBL) and AmpC β-lactamase enzymes is fast spreading and has had negative impacts
on the clinical outcomes, particularly on third-generation cephalosporins. This study investigated
the carriage of AmpC gene among multidrug-resistant Salmonella spp. from Lagos, Nigeria.
Methods: Forty Salmonella spp. from clinical samples (S. typhi = 13; S. typhimurium = 10; S.
enteritidis = 8; S. choleraesuis = 5; S. paratyphi = 4) were subjected to in vitro susceptibility test
by disk diffusion methods. Isolates that were resistant to cefoxitin and third-generation cephalosporins
were screened for ESBL (Double Disk Synergy Test Method) and AmpC enzyme (AmpC
disk test) production. Detection of AmpC fox gene was carried out by polymerase chain reaction.
Results: Thirty-two (80%) of the Salmonella isolates were cefoxitin resistant. Plasmid-mediated
AmpC β-lactamase and ESBL enzymes were recorded in 10/40 (25%) and 16/40 (40%) of the
Salmonella isolates, respectively. Specifically, 16/40 (40%) of the Salmonella isolates possessed
380 bp AmpC fox gene, with the highest occurrence found in S. typhi strains (43.8%) followed
by S. typhimurium (25%). There was no AmpC fox gene detected in S. paratyphi strains. Interestingly,
coproduction of enzymes occurred in some of the isolates, raising fears of resistance
to a multitude of antibiotics in the treatment of bacterial infections.
Conclusion: Emergence of AmpC b-lactamase–producing Salmonella isolates in our environment
was recorded for the first time, raising concern on increased antibiotic resistance among
strains of Salmonella serovars in Lagos. Further genotypic study of the isolates could answer
the questions on strain sources, clonal relatedness, and mechanism of spread.
Read the Original Research paper here: [ Ссылка ]
