title: Prevalence, antimicrobial resistance, and virulence characteristics of mecA-encoding coagulase-negative staphylococci isolated from soft cheese in Brazil.
abstract: Coagulase-negative staphylococci (CoNS), which are generally neglected as foodborne bacteria, are emerging as significant opportunistic pathogens that may be highly resistant to available antimicrobial drugs. In this study, antimicrobial susceptibility patterns, mecA gene occurrence, and virulence-associated characteristics were evaluated in CoNS isolated from soft cheese in Brazil. A total of 227 bacterial isolates were recovered from 35 cheese samples belonging to 5 batches with 7 different trademarks. The CoNS counts ranged from 10(6) to 10(7) CFU/g. High antimicrobial resistance percentages were observed for oxacillin (76.2%), penicillin (78.5%), erythromycin (67.8%), gentamicin (47.2%), clindamycin (35.7%), rifampicin (26.8%), azithromycin (14.7%), tetracycline (14.7%), levofloxacin (14.2%), and sulfamethoxazole-trimethoprim (11.9%). A low antimicrobial resistance percentage was observed for chloramphenicol (2.3%), and all of the tested bacteria were susceptible to vancomycin and linezolid. In total, a multiple antibiotic resistance (MAR) index of >0.2 was observed for 80.6% of the isolated CoNS. However, the MAR index ranged from 50% to 92.6% when only bacterial cheese isolates belonging to the same trademark were considered. Regarding to the prevalence of CoNS carrying mecA gene, 81.5% of the isolated strains were mecA(+) , and 76.2% of these were phenotypically resistant to oxacillin. Three isolates carried the enterotoxin A gene (sea), 29.5% produced biofilm in a laboratory test, and α- or ß-hemolysis were observed for 3% and 5.2%, respectively. This study highlights the extent of the antimicrobial resistance phenomenon in neglected foodborne microorganisms and the potential public health risks that are related to the consumption of CoNS-contaminated soft cheese.
authors.affiliation: Department of Parasitology, Microbiology and Immunology, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
authors.forename: Cláudia Oliveira
authors.initials: CO
authors.lastname: Fontes
authors.forename: Vânia Lúcia
authors.initials: VL
authors.lastname: Silva
authors.forename: Mayara Rodrigues Brandão
authors.initials: MR
authors.lastname: de Paiva
authors.forename: Rafaela Alvim
authors.initials: RA
authors.lastname: Garcia
authors.forename: Juliana Alves
authors.initials: JA
authors.lastname: Resende
authors.forename: Alessandra Barbosa
authors.initials: AB
authors.lastname: Ferreira-Machado
authors.forename: Cláudio Galuppo
authors.initials: CG
authors.lastname: Diniz
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001938:Brazil; D002611:Cheese / Q000382:microbiology*; D003030:Coagulase / Q000378:metabolism; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial; D005506:Food Contamination; D005516:Food Microbiology; D017422:Sequence Analysis, DNA; D013210:Staphylococcus / Q000187:drug effects / Q000302:isolation & purification* / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003030:Coagulase; D004269:DNA, Bacterial