[Bacteria of the genus Bacillus in chicken carcasses and hamburgers]

The incidence of mesophilic aerobic sporulate bacteria in chicken carcasses and hamburgers was studied and the species of isolated sporulate bacteria were identified. Forty seven eviscerated carcasses from a processing plant of Entre Ríos province (Argentina) were analyzed together with fifty samples of hamburgers from two supermarkets of Santa Fe city. All carcasses resulted in contamination with aerobic mesophilic bacteria in the range from 6 x 10(3) to 1.2 x 10(6) CFU/ml liquid washed, and 94% them with sporulate bacteria, the threshold being under 100 CFU/ml (Figure 1). Hamburgers from both places resulted with aerobic mesophilic bacteria in 100% of the cases, in the range of 1 x 10(5)-3.3 x 10(6) CFU/g for supermarket A and 2.2 x 10(5) to 1.7 x 10(7) CFU/g for supermarket B; the incidence of sporulate bacteria was between 4.3 x 10(2) and 1.2 x 10(4) CFU/g for A, while the range for B was 6.2 x 10(2) and 3.8 x 10(4) CFU/g (Figure 2). Two hundred and fourteen Bacillus Genus strains were isolated and purified from the carcasses and five hundred and ninety five from hamburgers. B. subtilis and B. megaterium were most involved in carcasses; while B. licheniformis, B. subtilis and B. pumilus were in hamburgers from supermarket A and B. subtilis and B. pumilus were found in supermarket B (Table 1). The presence of B. cereus was also found, although in low levels, in all the samples (Table 1). Pollution levels with aerobic mesophilic bacteria are high in both kinds of samples.(ABSTRACT TRUNCATED AT 250 WORDS)