Multidrug-Resistant Methicillin-Resistant Coagulase-Negative Staphylococci in Healthy Poultry Slaughtered for Human Consumption.

Vanessa Silva,Madalena Vieira-Pinto,José Luis Capelo,Cândido Saraiva,Manuela Caniça,Gilberto Igrejas,Eugénia Ferreira,José Eduardo Pereira,Patrícia Poeta

doi:10.3390/antibiotics11030365

Abstract

Coagulase-negative staphylococci are commensals that are known to be prevalent in most environments, and they are also an important reservoir of antimicrobial-resistant genes. Staphylococcal infections in animal husbandry are a high economic burden. Thus, we aimed to determine the prevalence and species diversity of methicillin-resistant coagulase-negative staphylococci (MRCoNS) in poultry slaughtered for human consumption and to study the antimicrobial resistance of the isolates. Swab samples were recovered from 220 commercial chickens, homebred chickens and quails. Species identification was performed using MALDI-TOF. Antimicrobial susceptibility testing was performed by the disc diffusion method against 14 antimicrobials. The presence of antimicrobial-resistant genes was investigated by polymerase chain reaction. Totals of 11 (19.6%), 13 (20.3%), and 51 (51%) MRCoNS were isolated from commercial chickens, homebred chickens and quails, respectively. S. lentus was isolated from all homebred chickens, whereas 11 S. lentus and 2 S. urealyticus were isolated from commercial chickens. As for quails, the most prevalent MRCoNS were S. urealyticus. Almost all isolates had a multidrug-resistant profile and carried the mecA gene. Most isolates showed resistance to erythromycin, clindamycin, penicillin, tetracycline, ciprofloxacin and fusidic acid and harbored the ermA, ermB, ermC, mphC tetK, tetL, tetM and tetO genes. This study showed a frequent occurrence of multidrug resistance in MRCoNS isolated from healthy poultry in Portugal.

Highlights

Staphylococci colonize the skin and mucous membranes of humans and are considered commensals or opportunistic pathogens [1]
methicillin-resistant coagulase-negative staphylococci (MRCoNS) are common bacteria found in healthy poultry in Portugal
The high frequency of MRCoNS isolates in this study may be due to the fact that these bacteria are colonizers of the normal skin flora of animals

Summary

Introduction

Staphylococci colonize the skin and mucous membranes of humans and are considered commensals or opportunistic pathogens [1]. By 2018, 45 species and 24 subspecies of Staphylococcus had been described [2]. Staphylococci are divided into two groups, coagulasepositive (CoPS) and coagulase-negative staphylococci (CoNS), according to their ability to coagulate plasma. CoPS are pathogenic species which have the coagulase enzyme that converts plasma fibrinogen into fibrin [3]. CoNS lack this enzyme and were considered, until recently, to be minor pathogens or apathogenic [4]. CoNS possess fewer virulence factors that participate in the pathogenesis of infection when compared to CoPS, such as

Objectives

Methods

Results

Discussion

Conclusion