Recently, a K-value-kit was developed for simple and rapid determination of freshness of fishes, shellfish and chicken meat. We examined the kit for usefullness for quality control of chicken meat at slaughterhouses and during the distribution. The results obtained were as follows: (1) The K-value of the broiler carcass were differed depending on the muscle. The K-value of the breast muscle except for the red part (the inside upper part) was lower than that of the thigh muscle. It was concluded that the breast muscle is suitable for measuring the K-value in chicken meat. (2) All K-values of the breast and thigh muscles were lower than 15%. The K-value of the meat did not increase during processing the chicken carcass at the slaughterhouse. (3) The K-value of the breast muscles increased during distribution of the chicken meat from the slaughterhouse to meat shops on the market after dressing and freezing (-5°C, 2 days). (4) The K-value of the chicken meat (the breast muscle) increased when in parallel with the increase in the viable count of the meat during the storage at 10°C or 25°C. The viable count hardly increased during the storage at -2°C or -20°C and the K-value of the meat increased slowly. From these results, it was considerd that the K-value-kit is applicable for quality control (test of freashness) of the chicken meat from the slaughterhouse to the meat shops.
An outbreak of food poisoning caused by heat-stable enterotoxin (ST) -producing Escherichia coli occurred at a school for physiologically-handicapped children in Saitama Prefecture during the period from Sept. 27 to Oct. 2, 1991. It was recognized that 51 of 219 students and 78 of 119 staff members had enteritis. The main symptoms observed in the 78 diseased staff members were diarrhea (87.2%), abdominal pain (67.9%) and fever (21.8%). In bacteriological examinations, E. coli O169: H41 was isolated from the feces of 35 diseased staff members, two nonpatients and four asymptomatic cooks. School lunch was suspected to be the source of this outbreak, but E. coli or any other pathogen was not isolated from any food, water or the swabs of cook's hands or utensils. It was demonstrated that E. coli O169: H41 strains isolated from 39 of 41 persons produced ST. The virulence of isolates was confirmed by enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR) and the suckling mouse test. The ST-producing strains were carrying about 88 Md and 49 Md plasmid, however the non-toxigenic strains were carrying only the 49 Md plasmid. All of the strains from the 41 persons have the same phenotypical characteristics and antimicrobial susceptibility patterns. This report may be the first one of an outbreak caused by E. coli O169: H41 in Japan.
A total of 180 meat samples, consisting of 60 beef, 60 pork and 60 chicken obtained at three butchers in Shimane prefecture, were examined for the presence of Salmonella during the period from June, 1991 to March, 1992. The results were as follows. 1) Salmonella were found in 1 (1.7%) of 60 beef, 4 (6.7%) of 60 pork and 24 (40.0%) of 60 chicken. The rates of detectiòn was highest for chicken. 2) The population of Salmonella varied under 10 cfu/100 g in beef and pork, under 102 cfu/100 g in chicken. Chicken tended to be somewhat more heavily contaminated with Salmonella than beef and pork. 3) Thirteen-six strains isolated from these meat were classified into 11 serotypes. Main detected serotype was S. Haifa (9 strains: 25.0%), S. Typhimurium (7 strains: 19.4%) and S. Virchow (5 strains: 13.9%). 4) The plasmid profile of S. Haifa from 14 strains (from 9 strains of chicken, 1 strain of food poisoning and 4 strains of salmonellosis) showed 6 groups. First group, having 4.2 Md and 2.6 Md of plasmid DNA, was isolated from 3 strains of chicken, 1 strain of food poisoning and 1 strain of salmonellosis. Second group, having 4.8 Md and 2.9 Md of plasmid DNA, was done from 1 strain of chicken 2 strains of salmonellosis. Third group having 9.2 Md, 4.2 Md, 3.7 Md, 2.9 Md and 2.6 Md of plasmid DNA, was done from 2 strains of chicken and 1 strain of salmonellosis. This is suggested that food poisoning happens from chicken meat polluted with S. Haifa in Shimane prefecture and the plasmid profile is valuable for the epidemiological examination as a maker.
The LUMAC PATH-STIK Rapid Salmonella Test is based on a dip stick enzyme immunoassay for detection of Salmonella antigens in food. The dip stick is composed of a membrane fitted on a plastic strip. On the bottom part of the membrane, a small line is coated with highly specific anti-Salmonella antibodies. Two colored lines develop when Salmonella is present in the enrichment culture and only one line in the absence of the organism. The PATH-STIK was tested for the detection limit of Salmonella and compared with the culture procedure for detection of Salmonella in commercial raw chicken. The detection limit of the assay is 104cfu/ml in pure culture and the assay of the preenrichment with EEM broth and enrichment with selenite broth detected Salmonella at a low concentration (under 10cfu/25g) in raw meat. In 98 specimens of commercial raw chicken including the viscera, the correlation between this assay and the traditional culture method was 87.8%, with a false positive rate of 6.0%, and false negative rate of 6.0%. The correlation was not high for the positive specimens, but the dip-stick was a rapid screening test not requiring a pipette or washing step that are necessary in traditional ELISA's. The protocol took only 20 minutes until the end results were available. The assay was found to be a rapid screening method for detection of Salmonella in food.