Serotyping and Evaluation of Antimicrobial Resistance of Salmonella Strains Detected in Wildlife and Natural Environments in Southern Italy.

Immacolata La Tela,Francesco Casalinuovo,Maria Francesca Peruzy,Davide Cardinale,Fabio Di Nocera,Daniela Cristiano,Maria Rosaria Carullo,Nicola D’Alessio,Federico Capuano

doi:10.3390/antibiotics10040353

Immacolata La Tela, Francesco Casalinuovo + Show 7 more

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https://doi.org/10.3390/antibiotics10040353

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Abstract

Wild animals are potential vectors of antibiotic-resistant bacteria in the environment. The present study aimed to investigate the occurrence of antimicrobial resistance among Salmonella serovars isolated from wildlife and the environment in Italy. A total of 164 Salmonella isolates were analyzed, and six different subspecies and 64 serovars were detected. High proportions of Salmonella isolates proved resistant to streptomycin (34.1%), followed by trimethoprim-sulfamethoxazole (23.2%), tetracycline (17.7%), ciprofloxacin (14.63%) and ampicillin (11.59%). By source, the lowest level of resistance was observed in Salmonella serovars isolated from a water environment, while antimicrobial resistance was frequent in strains collected from shellfish, reptiles and birds. Multidrug-resistant strains were recovered from seafood (n = 11), mammals (n = 3) and water (n = 1). Three S. Typhimurium monophasic variant strains showed asimultaneous resistance to ampicillin, streptomycin, tetracycline and trimethoprim-sulfamethoxazole, which represents a recognized alert resistance profile for this serovar. These data indicate the environmental dissemination of resistant strains due to anthropogenic activities, which, in southern Italy, probably have a higher impact on marine ecosystems than on terrestrial ones. Moreover, as most of the animals considered in the present study are usually consumed by humans, the presence of resistant bacteria in them is a matter of great concern.

Highlights

IntroductionSalmonella is an enteric pathogen that colonizes the intestinal tract of a wide range of animals, including primates, livestock, birds and pets, and cold-blooded animals and wild fauna [3]
Salmonella are Gram-negative bacteria belonging to the Enterobacteriaceae family.The genus Salmonella includes two species, Salmonella (S.) bongori and S. enterica, and six subspecies: S. enterica subsp. arizonae, S. enterica subsp. diarizonae, S. enterica subsp.enterica, S. enterica subsp. houtenae, S. enterica subsp. indica and S. enterica subsp. salamae [1].the subspecies enterica, according to its surface antigens (O and H), can be divided into over 2600 serovars [2].Salmonella is an enteric pathogen that colonizes the intestinal tract of a wide range of animals, including primates, livestock, birds and pets, and cold-blooded animals and wild fauna [3]
We found resistant and MDR Salmonella strains among the serovars isolated from wild animals and the environment

Summary

Introduction

Salmonella is an enteric pathogen that colonizes the intestinal tract of a wide range of animals, including primates, livestock, birds and pets, and cold-blooded animals and wild fauna [3]. Animals may develop diseases such as enteritis and septicemia, and suffer abortion, Salmonella infections in animals are generally asymptomatic [6]. Infected animals may excrete Salmonella bacteria in large numbers, spreading the pathogen to other habitats, such as water, foodstuffs and the environment, in which it can survive for a long period [7]. The transmission of Salmonella among humans, domestic animals and wildlife mainly occurs through direct contact with live animals or the consumption of contaminated food or water [9]. Salmonella infection in humans is usually associated with raw eggs and inadequately cooked meat

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