[Determination of the sanitary quality and detection of Salmonella spp and Yersinia enterocolitica in ice cream]. / Determinación de la calidad higiénica e investigación de Salmonella spp y Yersinia enterocolítica en helados.

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.

Determinación de la calidad higiénica e investigación de Salmonella spp y Yersinia enterocolítica en helados. / [Determination of the sanitary quality and detection of Salmonella spp and Yersinia enterocolitica in ice cream]

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.