Critical control points (CCPs) associated with Minas Frescal cheese (a Brazilian soft white cheese, eaten fresh) processing in two dairy factories were determined using flow diagrams and microbiological tests for detection of Listeria monocytogenes and other species of Listeria. A total of 218 samples were collected along the production line and environment. The CCPs identified were reception of raw milk, pasteurization, coagulation and storage. Thirteen samples were positive for Listeria; 9 samples were Listeria innocua, 2 were Listeria grayi and 2 were L. monocytogenes. In factory A, Listeria was found in 50% of raw milk samples, 33.3% of curd samples, 16.7% of pasteurized milk samples, 16.7% of cheese samples and 25% of rubber pipes used to transport the whey. The microorganism was not obtained from environmental samples in this plant. In factory B, Listeria was found in one sample of raw milk (16.7%) and in three samples of environment (17.6%) and L. monocytogenes was obtained from raw milk (16.7%) and the floor of the cheese refrigeration room (14.3%). Two serotypes, 4b and 1/2a, were observed among the strains of L. monocytogenes isolated, both which are frequently involved in outbreaks of food-borne listeriosis and sporadic cases of the disease all over the world.

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Microbial enhanced oil recovery (Meor) is an incontestably efficient alternative to improve oil recovery, especially in mature fields and in oil reservoirs with high paraffinic content. This is the case for most oil fields in the Recôncavo basin of Bahia, Brazil. Given the diverse conditions of most oil fields, an approach to apply Meor technology should consider primarily: (i) microbiological studies to select the appropriate microorganisms and (ii) mobilization of oil in laboratory experiments before oil field application. A total of 163 bacterial strains, selectively isolated from various sources, were studied to determine their potential to be used in Meor. A laboratory microbial screening based on physiological and metabolic profiles and growth rates under conditions representative for oil fields and reservoirs revealed that 10 bacterial strains identified as Pseudomonas aeruginosa (2), Bacillus licheniformis (2), Bacillus brevis (1), Bacillus polymyxa (1), Micrococcus varians (1), Micrococcus sp. (1), and two Vibrio species demonstrated potential to be used in oil recovery. Strains of B. licheniformis and B. polymyxa produced the most active surfactants and proved to be the most anaerobic and thermotolerant among the selected bacteria. Micrococcus and B. brevis were the most salt‐tolerant and polymer producing bacteria, respectively, whereas Vibrio sp. and B. polymyxa strains were the most gas‐producing bacteria. Three bacterial consortia were prepared with a mixture of bacteria that showed metabolic and technological complementarity and the ability to grow at a wide range of temperatures and salinity characteristics for the oil fields in Bahia, Brazil. Oil mobilization rates in laboratory column experiments using the three consortia of bacteria varied from 11.2 to 18.3 % [v/v] of the total oil under static conditions. Consortia of B. brevis, B. icheniformis and B. polymyxa exhibited the best oil mobilization rates. Using these consortia under anaerobic conditions could be an interesting alternative for Meor technology because their growth could be easily controlled through the administration of phosphate and inorganic electron acceptors. Bacterial strains selected in this work could be valuable for further application in oil recovery at productive and mature oil well sites as well as for the prevention and control of paraffin deposits.

Microbiological analyses of workers' hands were made for the common indicators, including aerobic mesophilic plate counts (APC), as well as the common food pathogens. Opportunities were observed for cross-contamination of roast beef by workers' hands during slicing operations. Workers' hands showed APC counts of up to 10(7) CFU/hand and the presence of S. aureus and C. perfringens. Salmonella spp were not isolated from hands. These results show that handling of these foods by such workers would be a risk in transmitting pathogenic microorganisms to the foods and is apparent that it is necessary for these workers to take care of personal hygiene. Decimal reductions obtained in the microbiological counts after washing and antisepsis of workers' hands were at 2,6 logs cycles and still demonstrated the importance of this practice in food services by the fact that pathogens such as S. aureus and C. perfringens were inhibited or killed.

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a b s t r a c tSince the 1980s, an increase in outbreaks of human listeriosis linked to contaminated food has been a concern of health authorities. Intensively manipulated foods, such as Brazilian fresh sausage, are frequently responsible for food-borne diseases. In this work the occurrence of Listeria monocytogenes and the efficacy of bacteriophage P100 (LISTEXÔ) to control the microorganism was evaluated in Brazilian fresh sausage. Eighty samples were analyzed, 40 each of swine and chicken Brazilian fresh sausage. Listeria spp. were isolated from 12 samples (15%), of which three (3.75%) were positive for L. monocytogenes. L. monocytogenes strains isolated belonged to serotype 1/2a. L. monocytogenes 1/2a was inoculated in Brazilian fresh sausage (2.1 Â 10 4 cfu/g) with the bacteriophage added thereafter (3.0 Â 10 7 pfu/g). Samples were analysed immediately (day zero) and then stored at 4 C for 10 days. The bacteriophage P100 reduced L. monocytogenes counts by 2.5 log units at both 0 and 10 days compared to controls without bacteriophage. In spite of this, the populations of L. moncytogenes increased over the 10 day storage. Our data demonstrate that in one of the samples the use of the bacteriophage dropped the bacteria count below the level of direct detection. This study demonstrates a new alternative for pathogen control in the food industry, especially in the processes used to produce Brazilian fresh sausage.