title: Occurrence and antibiotic resistance of coliform bacteria and antimicrobial residues in pasteurized cow's milk from Brazil.
abstract: In this study we examined the hygienic and sanitary quality of pasteurized cow's milk in the state of Paraná, Brazil, by determining the presence of coliforms and occurrence of antimicrobial residues. A total of 260 milk samples were collected from commercial establishments in different regions of the state. Coliform populations were estimated by the multiple-tube test, and antimicrobial residues were detected by enzyme-linked immunosorbent assay. Overall, 105 samples (40.4%) were unsuitable for consumption according to Brazilian legal standards. Among the coliforms, Escherichia coli and Klebsiella pneumoniae were respectively identified in 77.05 and 36.07% of the samples. The highest rates of resistance to antimicrobial agents were observed for ampicillin (19.2%), cephalothin (18.9%), and tetracycline (17.1%). Antimicrobial residues were detected in 80 samples (30.8%). Forty-eight samples (18.5%) were positive for tetracycline, 29 (17.4%) for neomycin, 9 (3.5%) for beta-lactams, 6 (2.3%) for gentamicin, 4 (1.5%) for chloramphenicol, and 1 (0.4%) for streptomycin-dihydrostreptomycin. The results demonstrate a high prevalence of coliforms and also a high occurrence of antimicrobial residues in pasteurized cow's milk from Paraná, Brazil.
authors.affiliation: Department of Basic Health Sciences, Toxicology Laboratory, State University of Maringá (UEM), Avenida Colombo 5790, Maringá, Paraná, Brazil.
authors.forename: G N
authors.initials: GN
authors.lastname: Zanella
authors.forename: J M G
authors.initials: JM
authors.lastname: Mikcha
authors.forename: E
authors.initials: E
authors.lastname: Bando
authors.forename: V L D
authors.initials: VL
authors.lastname: Siqueira
authors.forename: M
authors.initials: M
authors.lastname: Machinski
mesh_terms: D000818:Animals; D001938:Brazil; D002417:Cattle; D003257:Consumer Product Safety; D004350:Drug Residues / Q000032:analysis*; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects*; D005506:Food Contamination / Q000032:analysis*; D005519:Food Preservation; D006801:Humans; D006920:Hygiene; D008892:Milk / Q000382:microbiology* / Q000592:standards; D015995:Prevalence