Extensively drug-, ciprofloxacin-, cefotaxime-, and azithromycin-resistant Salmonella enterica serovars isolated from camel meat in Egypt

Abstract

Given the great importance of Salmonella as a leading foodborne pathogen of global concern and the few available data regarding its prevalence in camel meat, the present study aimed to determine the prevalence, antimicrobial resistance (AMR) profile, virulence genes, β-lactamase genes of Salmonella enterica serovars isolated from camel meat marketed in Egypt. Forty-five (29.6 %) of the 152 camel meat samples examined were positive for Salmonella spp. Among the 432 Salmonella presumptive colonies isolated, 128 were molecularly verified as Salmonella after confirmation by PCR targeting the Salmonella marker (invA) gene. Virulence genes, encompassing stn, spvC, and hilA genes, were detected in 91.4 % (117/128), 20.3 % (26/128), and 80.5 % (103/128) of the isolates, respectively. S. Enteritidis, S. Typhimurium, S. Cerro, and S. Montevideo were the most prevalent serovars with incidences of 25 % (32/128), 15.6 % (20/128), 15.6 % (20/128), and 12.5 % (16/128), respectively. Interestingly, 56.3 %, 53.1 %, 37.5 %, 28.1 %, 21.9 %, 18.8 %, 12.5 %, and 3.1 % of the isolates tested showed resistance to cefepime, ciprofloxacin, levofloxacin, cefotaxime, gentamicin, colistin, meropenem, and azithromycin, respectively. Salmonella isolates showed resistance to at least one antibiotic, with a mean multiple antibiotic resistance (MAR) index of 0.472. Interestingly, 59.4 %, 15.6 %, and 3.1 % of the isolates were categorized into multidrug-resistant, extensively drug-resistant, and pan-drug-resistant, respectively. Only 23 (25 %) of the 92 ampicillin-resistant isolates were proven to be Extended Spectrum Beta-Lactamase (ESBL)-producing Salmonella, in which β-lactamase (bla) genes were detected. The blaOXA-2 was the most existing gene where it was detected lonely in 10 of the ampicillin-resistant isolates and coexisted with blaCMY-1 in 4 isolates and with blaCMY-2 in a single isolate. The blaCMY-1, however, existed in 11 isolates, whereas the blaCMY-2 gene was only detected in 3 isolates tested. The present findings affirm that camel meat could be a leading reservoir for multi- and extensively-drug-resistance β-lactamase-producing Salmonella, representing a global public health challenge. Therefore, further research is necessary to detect the prevalence and AMR of Salmonella serovars from camel meat in Egypt and other countries to put camel meat as a source of Salmonella in foods of animal origin.