de Centorbi O P, de Guzmán A C, de Cuadrado A A, Laciar A L, Alcaraz L E, de Milán M C, de Pederiva N B
Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Argentina.
Rev Argent Microbiol. 1989 Apr-Jun;21(2):63-9.
In order to determine the sanitary quality of ice-creams and the presence of pathogenic or potentially pathogenic species of Salmonella and Yersinia enterocolitica, 50 samples from 5 different industrial and semi-industrial producers in San Luis (Argentine) were examined. The enumeration of coliforms was positive for all the samples with values less than or equal to 20/g. Fourteen per cent of the samples were positive for the investigation of Staphylococcus aureus in 1 g. For the plates enumeration 12.0% of the samples gave less than 10 u.f.c./g, 4.0% between 101 and 1000 and 4.0% between 1001 and 10,000. Fifteen strains were isolated, 26.6% biotype A (human ecovar) and the others biotype C (bovine ecovar). All of them were susceptible to chloramphenicol, cephalosporin and erythromycin; 46.6% to penicillin G and ampicillin; 93.3% to kanamycin (6.6% intermediate ones = I); 73.3% to methicillin (26.6% I); 86.6% to tetracycline (13.3% I). Six per cent of the samples over came the acceptability limit for S. aureus. Salmonella spp was not isolated. In 4.0% of the samples Y. enterocolitica were isolated, one of them typified as B1; 0:3, 50, 51, Lis Xz. The latter, isolated in samples with values of coliforms inferior to the limit fixed by some legislations, suggests a post elaboration contamination.
