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Antimicrobial‐Resistance Genetic Markers in Potentially Pathogenic Gram Positive Cocci Isolated from Brazilian Soft Cheese
Author(s) -
Resende Juliana Alves,
Fontes Cláudia Oliveira,
FerreiraMachado Alessandra Barbosa,
Nascimento Thiago César,
Silva Vânia Lúcia,
Diniz Cláudio Galuppo
Publication year - 2018
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/1750-3841.14019
Subject(s) - antimicrobial , biology , enterococcus faecium , microbiology and biotechnology , antibiotic resistance , enterococcus faecalis , enterococcus , pathogenic bacteria , staphylococcus haemolyticus , bacteria , staphylococcus epidermidis , enterococcus hirae , staphylococcus aureus , antibiotics , genetics
Although most Brazilian dairy products meet high technological standards, there are quality issues regarding milk production, which may reduce the final product quality. Several microbial species may contaminate milk during manufacture and handling. If antimicrobial usage remains uncontrolled in dairy cattle, the horizontal transfer of antimicrobial resistance genes in foodstuffs may be of particular concern for both food producers and dairy industry. This study focused on the evaluation of putative Gram positive cocci in Minas cheese and of antimicrobial and biocide resistance genes among the isolated bacteria. Representative samples of 7 different industrially trademarked Minas cheeses ( n = 35) were processed for selective culture and isolation of Gram positive cocci. All isolated bacteria were identified by DNA sequencing of the 16S rRNA gene. Antimicrobial resistance genes were screened by PCR. Overall, 208 strains were isolated and identified as follows: Enterococcus faecalis (47.6%), Macrococcus caseolyticus (18.3%), Enterococcus faecium (11.5%), Enterococcus caseliflavus (7.7%), Staphylococcus haemolyticus (7.2%), Staphylococcus aureus (4.3%), Staphylococcus epidermidis (2.9%), and Enterococcus hirae (0.5%). The genetic markers mec A (78.0%) and smr (71.4%) were the most prevalent, but others were also detected, such as bla Z (65.2%), msr A (60.9%), msr B (46.6%), lin A (54.7%), and aac A‐ aph D (47.6%). The occurrence of opportunist pathogenic bacteria harboring antimicrobial resistance markers in the cheese samples are of special concern, since these bacteria are not considered harmful contaminating agents according to the Brazilian sanitary regulations. However, they are potentially pathogenic bacteria and the cheese may be considered a reservoir for antimicrobial resistance genes available for horizontal transfer through the food chain, manufacturing personnel and consumers.