title: Antibiotic resistance and molecular analysis of Staphylococcus aureus isolated from cow's milk and dairy products in northeast Brazil.
abstract: This work aimed to assess the clonal distribution among 94 strains of Staphylococcus aureus isolated from cow's milk, raw cheese, and a milking machine in 12 dairy farms in northeast Brazil, by analyzing different typing methods and detecting resistance and toxigenic profiles. For the first time, isolates of this region were assessed simultaneously by the polymorphism of the 3'-end coa gene and 16S-23S rDNA, pulsed-field gel electrophoresis, antibiotic resistance phenotyping, and toxigenic arsenal. Although pulsed-field gel electrophoresis patterns showed a wider variation (discriminatory index 0.83) than the PCR-based methods, the internal transcribed spacer-PCR proved to be a useful and inexpensive procedure for conducting epidemiological surveys of S. aureus on a regional scale. Each dairy farm had its own resistance profile, and in two herds, 63% of the strains were multiresistant, probably due to the indiscriminate use of antibiotics in bovine mastitis treatment. No methicillin-resistant S. aureus strains were detected in this study; however, 93.6% of S. aureus strains harbored variable profiles of staphylococcal enterotoxin genes seg, seh, sei, and sej. Transcriptional analysis revealed that 53.3% of staphylococcal enterotoxin genes actually transcribed, pointing out the food poisoning risk of these dairy products to consumers in the region. Based on the detection of the most prevalent clones in a herd or region, appropriate antibiotic therapy and specific immunization can be used for the treatment and control of staphylococcal mastitis.
authors.affiliation: Universidade de Pernambuco (UPE), Garanhuns, Pernambuco 55295-110, Brazil.
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Silveira-Filho
authors.affiliation: Universidade Federal de Pernambuco (UFPE), Recife, Pernambuco 50670-901, Brazil.
authors.forename: Isabelle S
authors.initials: IS
authors.lastname: Luz
authors.affiliation: Centro de Pesquisas Aggeu Magalhães (CPqAM/Fiocruz), Recife, Pernambuco 50670-420, Brazil.
authors.forename: Ana Paula F
authors.initials: AP
authors.lastname: Campos
authors.affiliation: Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco 52171-900, Brazil.
authors.forename: Wellington M
authors.initials: WM
authors.lastname: Silva
authors.affiliation: Centro de Pesquisas Aggeu Magalhães (CPqAM/Fiocruz), Recife, Pernambuco 50670-420, Brazil.
authors.forename: Maria Paloma S
authors.initials: MP
authors.lastname: Barros
authors.affiliation: Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco 52171-900, Brazil.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Medeiros
authors.affiliation: Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco 52171-900, Brazil.
authors.forename: Manuela F L
authors.initials: MF
authors.lastname: Freitas
authors.affiliation: Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco 52171-900, Brazil.
authors.forename: Rinaldo A
authors.initials: RA
authors.lastname: Mota
authors.affiliation: Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco 52171-900, Brazil.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Sena
authors.affiliation: Universidade Federal de Pernambuco (UFPE), Recife, Pernambuco 50670-901, Brazil. cristina@cpqam.fiocruz.br.
authors.forename: Tereza C
authors.initials: TC
authors.lastname: Leal-Balbino
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001938:Brazil; D002417:Cattle; D015169:Colony Count, Microbial; D003611:Dairy Products / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005506:Food Contamination / Q000032:analysis; D059022:Food Safety; D006801:Humans; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000188:drug therapy / Q000517:prevention & control; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents