Investigación de Staphylococcus aureus en ensaldas de fruta obtenidas en establecimientos comerciales de la ciudad de San Luis

LUCERO ESTRADA CECILIA STELLA MARYS; VELÁZQUEZ LIDIA DEL CARMEN; STEFANINI DE GUZMÁN ANA MARÍA

Merlo, San Luis

Jornada; XXIII Reunión Científica Anual Sociedad de Biología de Cuyo; 2005

Sociedad de Biología de Cuyo

Staphylococcus aureus is a pathogen bacterium that can cause alimentary intoxication. Fruit juices and their derivates are vehicles of intestinal diseases. The aim of this study was investigate the presence of S. aureus in fruit salads manufactured and sold in San Luis city. Seventy one samples were studied: 25 g of the sample were homogenized in stomacher during 60 s, 0.1 ml of the homogenate were spread onto Bair-Parker agar (BP), incubated at 35ºC 48 h. Characteristic colonies of S. aureus were confirmed by gram coloration, thermonuclease, catalase and coagulase tests. The agar diffusion method of Kirby-Bauer was used to determinate the antibiotic susceptibility. The strains were tested agains: amikacin, ciprofloxacin, fosfomycin, gentamicin, rifampin, sulfamethoxazole-trimethoprim, tetracycline, and vanconycin. Eleven strains (15,49 %) were isolated, the counts varied between 20-300 FCU/g. All the strains gave a 4+ coagulase reaction and were positive to thermonuclease and catalase. Also they were sensitive to every antibiotic tested, showing a similar inhibition halo. It seems that all the strains isolated could come from the same origin. A strict hygienic control during the manufacturing step of this kind of food is suggested.