Evaluation of Antimicrobial Resistance in Salmonella Strains Isolated from Food, Animal and Human Samples between 2017 and 2021 in Southern Italy

Abstract

Salmonella enterica is one of the most common causes of foodborne infection in the world, and the most common one in Italy. Italy collaborates with the other EU member states to survey the antimicrobial resistance of Salmonella on a large scale. This study on the situation in Apulia and Basilicata provides a more focused point of view on the territory, and anticipates the data reported in future Italian reports. Antimicrobial resistance was detected using the MIC detection method, with EUVSEC® plates, on the strains collected between 2017 and 2021. The results of serotyping showed that Salmonella Infantis is the serovar that has increased the most over time in veterinary samples, while Salmonella Tyhimurium and its monophasic variant are the most isolated in human samples. The results of the antimicrobial resistance study comply with European data, showing high resistance to quinolones, tetracyclines, ampicillin and trimethoprim, and low resistance to colistin and cephems. The significant exception was that all strains were resistant to sulphametoxazole. The presence of MDRs, which was 85% in veterinary and 77.4% in human strains, often included critically important antibiotics, which is a sign that more study and action is needed to manage the use of antibiotics.

Antimicrobial resistance and genetic relatedness of Salmonella serotypes isolated from food, asymptomatic carriers, and clinical cases in Shiyan, China

“…Moreover, historically, tetracycline and streptomycin have been widely employed as growth promoters in animal husbandry [ 37 , 38 ]. Meropenem was the only antibiotic observed to be sensitive to all Salmonella isolates in our study, consistent with reports from Nantong, China, and Southern Italy [ 25 , 39 ]. Third-generation cephalosporins and fluoroquinolones are the highest priority antibiotics for the treatment of human invasive salmonellosis [ 29 ].…”

Salmonella Shedding in Slaughter Pigs and the Use of Esterified Formic Acid in the Drinking Water as a Potential Abattoir-Based Mitigation Measure

“…In general, the observed levels of resistance against the antimicrobials tested in this group of isolates was similar to that described in the last report from EFSA and ECDC regarding antimicrobial resistance in zoonotic and indicator bacteria from humans, animals, and food in 2018-19 [51], with the exception of two antibiotics, namely, ciprofloxacin and tigecycline. Resistance to ciprofloxacin, a first-line antimicrobial agent for the treatment of non-typhoidal Salmonella in humans, was observed at lower levels (1.2%) than those noticed in pigs in the EU (10.3%; [46]), and at much lower levels than those recently observed in Italy (60.7%; [53]). This type of resistance in Salmonella has been related to fluoroquinolone consumption in food-producing animals [54,55]; thus this reduction may be related to a decreasing trend in its use, as the last European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) report on sales of veterinary antimicrobial agents suggests [56].…”

Systematic Survey of Vibrio spp. and Salmonella spp. in Bivalve Shellfish in Apulia Region (Italy): Prevalence and Antimicrobial Resistance

“…in the current study and only one S. Typhimurium strain showed multidrug resistance. Despite the low prevalence of Salmonella , the detection of pathogenic serovars raises concerns about consumer health, especially given the recent finding of S. Typhimurium strains of human origin, collected from the same region and resistant mainly to ampicillin, tetracycline, azithromycin, and sulfamethoxazole [ 17 ], which are the same antimicrobials depicted in our multidrug-resistant strain, except for azithromycin replaced with gentamicin. Giacometti et al [ 36 ] carried out a similar investigation on 102 Salmonella isolates from bivalve molluscs and water samples collected during the official monitoring programme in the area of the province of Ferrara (northwestern area of the Adriatic Sea) between 2001 and 2017.…”

“…Salmonella spp. is another important zoonotic pathogen frequently found in bivalve molluscs and for which the occurrence of multidrug resistance is widely reported also in the areas investigated in the present work [ 17 ]. Moreover, Salmonella spp.…”