ABSTRACT
The detection of methicillin-resistant Staphylococcus aureus (MRSA) and other emerging strains in meat-producing animals and retail meat has increased the risk of contamination of food. The aim of this study was to determine the prevalence and characterize S. aureus strains isolated from the pork chain supply in Chile. A total of 487 samples were collected: 332 samples from pigs at farms and slaughterhouses (nasal, n = 155; skin, n = 177); 85 samples from carcasses at slaughterhouses; and 70 meat samples at supermarkets and retail stores. The isolation of S. aureus was carried out by selective enrichment and culture media. Biochemical testing (API® Staph) and PCR (detection of the nuc and mecA genes) were used to confirm S. aureus and MRSA strains. The agglutination test was used to determine the protein PBP2'. Enterotoxins (SEA, SEB, SEC, SED) were determined by agglutination test and the se genes by PCR method. Oxacillin and cefoxitin susceptibility testing were carried out using the diffusion method. The overall prevalence of S. aureus in the pork meat supply was 33.9%. A higher prevalence was detected on carcasses (56.5%), in pigs sampled at farms (40.6%) than in pigs sampled at slaughterhouses (23.3%) and in nonpackaged retail meat (43.1%) than packaged retail meat (5.3%) (p ≤ 0.05). No significant differences (p > 0.05) were found between the prevalence in pigs (28.3%) and pork meat (32.9%) and between natural pig farming (33.3%) and conventional production (52.8%). The mecA gene and the protein PBP2' were not detected in S. aureus strains. Two S. aureus strains exhibited oxacillin and cefoxitin resistance, and one S. aureus strain was resistant to cefoxitin. One S. aureus strain isolated from a meat sample was positive for enterotoxin SEB. Although the mecA gene was not detected, oxacillin-resistant and seb-producing S. aureus strains were detected, which represent a risk in the pork chain supply.
Subject(s)
Drug Resistance, Multiple, Bacterial , Meat/microbiology , Staphylococcal Infections/epidemiology , Staphylococcus aureus/isolation & purification , Swine/microbiology , Abattoirs , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Cefoxitin/pharmacology , Chile/epidemiology , Enterotoxins/genetics , Food Microbiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Microbial Sensitivity Tests , Oxacillin/pharmacology , Penicillin-Binding Proteins/genetics , Prevalence , Staphylococcal Infections/veterinaryABSTRACT
Se realiza un analisis de los ninos menores de 15 anos de edad con glomerulonefritis aguda, que ingresaron al servicio de Pediatria del Hospital Obrero No 2 de la CNS de Cochabamba, durante el periodo de enero 1981 a diciembre 1990. En este trabajo se realizaron una serie de variables, obteniendose los siguientes resultados: la edad predominante fue de 5 a 12 anos de edad (79
), de estado socioeconomico bajo y medio (97
), con alta incidencia en epoca de invierno y verano (63
), teniendo como antecedente una infeccion previa cutanea y orofaringea (95
), con reporte de laboratorio: hematuria microscopica, anemia, proteinuria y cilindruria importante (92
) y cuyas complicaciones mas importantes fueron insuficiencia cardiaca, insuficiencia renal aguda y la encefalopatia hipertensiva.
), de sexo masculino (55
), de predominancia suburbana (50
), cuyas manifestaciones clinicas mas importantes fueron: hematuria, edema e hipertension arterial (95
), tiempo de hospitalizacion promedio de 10 a 20 dias (71
