Occurrence and Phenotypic and Molecular Characterization of Antimicrobial Resistance of Salmonella Isolates from Food in Tunisia

Abstract

Salmonella is a leading cause of foodborne diseases worldwide. The use of antibiotics in food-producing animals may contribute to the development of antimicrobial resistance in nontyphoidal Salmonella. The development of resistance to potent antimicrobials such as fluoroquinolones and extended-spectrum β-lactamases is a significant public health problem. The present study was conducted to examine the occurrence and antimicrobial resistance of Salmonella isolates obtained from food samples. Salmonella was cultured according to ISO 6579:2002 method, and antimicrobial resistance was evaluated with the Kirby-Bauer disk diffusion method. Forty-five Salmonella isolates were recovered, and a high Salmonella prevalence was detected in clams (7 of 20 samples, 35%), chicken (28 of 97 samples, 28.9%) and cow's milk (10 of 80 samples, 12.5%). Salmonella Enteritidis (n = 19) and Salmonella Kentucky (n = 18) were the most prevalent isolates. Multidrug resistance was found in 31.1% of the isolates (14 of 45); 84, 46, 28, and 17% of the isolates were resistant to nalidixic acid, ciprofloxacin, amoxicillin–clavulanic acid, and both ofloxacin and cefotaxime, respectively. The isolates resistant to cefotaxime were screened by PCR for the genes for TEM β-lactamase, extended-spectrum β-lactamases (CTX and OXA), and AmpC β-lactamases (FOX, MOX, DHA, ACC, CIT, and EBC). One Salmonella Kentucky isolate from milk harbored an AmpC gene (FOX), and the same serotype isolated from chicken carried the EBC AmpC determinant. The blaTEM gene was detected in all nonsusceptible isolates. We also screened isolates with reduced fluoroquinolone susceptibility for the presence of transferable plasmid-mediated quinolone resistance determinants. Three qnr genes (qnrB, qnrD, and qnrS) were detected in four isolates (two from milk and two from chicken). To our knowledge, this is the first report of the AmpC FOX and EBC gene families and the qnrD gene within a foodborne pathogen in Tunisia. These findings highlight the emergence of multidrug-resistant Salmonella isolates with decreased susceptibility to fluoroquinolones and third-generation cephalosporins, which are drugs commonly used for the treatment of Salmonella infections. HIGHLIGHTS

Prevalence, Risk Factors, Antimicrobial Resistance and Molecular Characterization of Salmonella in Northeast Tunisia Broiler Flocks

“…Carbapenem resistance, mainly among Gram-negative pathogens, is an ongoing public health problem of global dimensions. This type of antimicrobial resistance, especially when mediated by transferable carbapenemase-encoding genes, is spreading rapidly, causing serious outbreaks and dramatically limiting treatment options [55].In addition, the results of our study corroborate those of Ben Hassena et al (2019) [56], who reported the emergence of multidrug-resistant Salmonella strains isolated from food with decreased susceptibility to fluoroquinolones and third-generation cephalosporin in Tunisia. Then, our findings show the importance of embracing the "One Health" approach that was promulgated by the World Health Organization in its action plan against antimicrobial resistance, which mobilizes various actors in three main sectors: animal husbandry, environment, and human health.…”

Antimicrobial Resistance in Salmonella Serovars Isolated From an Egg-Producing Region in Brazil

“…The resistance of Salmonella spp. to critically important antimicrobials, such as fluoroquinolones and extendedspectrum cephalosporins, is a significant public health concern, threatening the efficiency of antimicrobial agents (Campos et al, 2018;Hassena et al, 2019). High rates of Salmonella spp.…”

Prevalence and antimicrobial resistance profiles of <i>Salmonella</i> spp. in poultry meat

“…Salmonella spp. is among the most frequent causes of foodborne illnesses and the growing presence of MDR strains is a further cause of concern (Franco et al ., 2015 ; Hassena et al ., 2019 ; Parvin et al ., 2020 ; Proietti et al ., 2020 ; Peruzy et al ., 2020 ; Gargano et al ., 2021 ; Lauteri et al ., 2022 ). Between 2019 and 2021, 40 strains of Salmonella spp.…”