ABSTRACT
Fresh aquacultured catfish fillets were obtained from three processors using different processing protocols in summer, autumn, winter, and spring and evaluated for microbial quality. Twenty freshly processed fillets were randomly selected and each fillet was placed in a sterile polyethylene bag. The fillets were transported on ice-pack overnight by air immediately after processing. Five fillets were randomly selected for microbial assays. Each fillet was weighed and an equal volume of sterile 0.1 % peptone water at 0 to 1°C was added aseptically. The fillet was massaged (or rinsed) for 120 s and the rinse was used to determine microbial quality. Aerobes (incubation at 35°C for 48 h) and psychrotrophs (incubation at 20°C for 96 h) were enumerated using 3M Petrifilm™ Aerobic Count plates. Escherichia coli (incubation at 35°C for 24 to 48 h) and total coliforms (incubation at 35°C for 24 to 48 h) were enumerated on 3M Petrifilm™ E. coli Count plates. Staphylococcus aureus counts were determined on Baird-Parker agar (incubation at 35°C for 48 h). Significant differences (P ≤ 0.05) in aerobic, psychrotrophic, total coliform, E. coli , and S. aureus counts due to temperature effects during production and variations in processing protocols were observed. E. coli and S. aureus counts were significantly different during the four seasons. E. coli and S. aureus counts were high during summer and low during winter weather. There was a significant difference (P ≤ 0.05) in aerobic, psychrotrophic, and total coliform counts among the three processors during warm weather; however, these differences were significantly (P≤ 0.05) reduced in cold weather.
ABSTRACT
Aquacultured channel catfish ( Ictalurus punctatus ) were evaluated for the presence of human pathogenic bacteria. Fresh catfish fillets procured from three catfish processors in the southeastern United States during the four annual seasons (e.g., summer, fall, winter, and fall) were screened for selected human pathogens. At each sampling time point, 20 freshly processed catfish fillets were randomly selected from each processor during each season. Five catfish fillets were randomly selected for aerobic plate counts and all 20 fillets were screened for five pathogenic bacteria viz. Campylobacter jejuni/coli , Escherichia coli O157:H7, Klebsiella pneumoniae subsp. pneumoniae , Plesiomonas shigelloides , and Vibrio cholerae . There was a significant difference (P < 0.05) in the aerobic plate counts due to differences in unit processing operations and processing season. C. jejuni/coli , E. coli O157:H7 and K. pneumoniae subsp. pneumoniae were not isolated. Only P. shigelloides and V. cholerae were isolated during the warm weather.
ABSTRACT
This study was conducted to determine the levels of Campylobacter jejuni , Campylobacter coli , Salmonella , Klebsiella pneumoniae , and Escherichia coli O157:H7 in fresh hand-picked blue crab ( Callinectes sapidus ) meat. An attempt was made to correlate these selected pathogens and general microbial quality to processors' sanitation practices and facility size. Hand-picked crabmeat samples from 12 blue-crab-processing facilities in the Chesapeake Bay region were collected and analyzed. Twenty samples from each of the different facilities were collected on different processing days. Facilities were chosen on the basis of production levels and Virginia Department of Health inspection scores as an indicator of sanitation practices (excellent, ≥94.5, acceptable, <94.5). All samples were tested between 16 h and 36 h after collection. Campylobacter jejuni was isolated from 36 (15%) of the 240 samples and Campylobacter coli was isolated from 14 (5.8%). Quantitative levels in all case were below limits of detection (<0.30 MPN/g). Klebsiella pneumoniae was isolated from a total of 51 (21%) samples. Counts ranged from less than 0.30 to 4.3 MPN/g. Aerobic plate counts ranged from 7.4 × 103 to 4.6 × 108 CFU/g with coliform counts ranging from <0.3 to 32.8 MPN/g. Fecal coliform levels were <0.3 to 2.26 MPN/g and Escherichia coli from <0.3 to 0.77 MPN/g. Salmonella spp. and Escherichia coli O157:H7 were not detected in any of the 240 samples analyzed. No significant differences (P < 0.05) between size and inspection scores were observed for general microbial quality or the presence of Klebsiella pneumoniae or Campylobacter species.
ABSTRACT
Consumption of Lactobacillus products and supplements containing viable lactic acid bacteria results in their establishment in the gastrointestinal tract. Their presence in the intestinal tract has been suggested to be prophylactic. They may reduce risk associated with dietary onset of carcinogenesis directly due to the reduction of procarcinogenic substances or indirectly due to the reduction in the level of enzymes that convert procarcinogens to carcinogens. In short-term studies, feeding as well as intraperitoneal administration of lactic acid bacteria suppress tumors implanted in rodents. The suppression is probably mediated by lactic acid bacteria through activation of host defense system. The activation of host defense system has been hypothesized to augment the immune system. Transient increase in the host immune defense system has been observed following feeding of cultured dairy products, but the biological significance of these changes has not yet been elucidated.