[Serotypes of urease producing Vibrio parahaemolyticus and their relation to possession of tdh and trh genes].

We analysed 467 isolates of Vibrio parahaemolyticus for possession of tdh/trh gene in comparison with urease production and serotypes. Strains possessing tdh+/trh-, tdh+/trh+, tdh-/trh-, and tdh-/trh- show positive urease production 2.1, 100, 65.7, 100%, respectively. Serotypes of O1:K69, O3:K6, O3:K72, O6:K18, O6:K46 and O1:KUT were frequently positive (100% except 91.7% of the latest one) in urease production. All isolates of O3:K6 prossessed trh, whereas all isolates of certain serotypes including O1:K69 and O3:K72 possessed both trh and trh and tdh genes. Among these, most of O1:K69 and O3:K72 were urease producer. From these results, we speculate that urease production is closely related to the presence of the trh gene or/and lesser production of TDH. We also found the new combination of serovar, O3:K25, O4:K37 and O13:K72 in Kanagawa phenomenon-positive strains.

[Bacteriological studies of travellar's diarrhoea. 5) Analysis of enteropathogenic bacteria at Osaka Airport Quarantine Station from January 1992 through September 3rd, 1994].

During the last 2 years and 8 months before the closure of Osaka Airport Quarantine Station (from Jan. 1992 to Sep. 3, 1994), a total of 7,421,909 overseas travellers were quarantined. 15,919 reported themselves of suffering from diarrhoea. Bacteriological examination of a total of 6,031 individuals' stools were performed. 1) Various enteropathogenic bacteria were isolated from 31.2% of the stools examined. Isolated species were as follows: Plesiomonas shigelloides, 1,127 cases (59.9%); Vibrio parahaemolyticus, 293 cases (15.6%); Salmonella spp., 262 cases (13.9%); Shigella spp., 235 cases (12.5%); Aeromonas sobria, 93 cases (4.9%); V. cholerae non-O1, 69 cases (3.7%). 2) The enteropathogenic bacteria were isolated through out the year without any seasonal variation. 3) The major regions where the travellers were infected with the pathogens are as follows: V. cholerae non-O1 (NAG Vibrio) and enteropathogenic Escherichia coli, South-East and South-West Asia; Vibrio other than NAG, South-East and East Asia; Shigella, widely distributed but especially in India; P. shigelloides and Salmonella, widely distributed. 4) 2 strains of toxigenic (cholera toxin-producing) V. cholerae O139 were isolated from patients who had visited Indonesia and Thailand, respectively. 5) In 320 cases (17%), plural enteropathogenic bacteria were isolated from single patients, suggesting a high frequency of the mixed infections. 6) Among Shigella strains, S. sonnei were isolated the most, followed by S. flexneri (24.7%), S. boydii (8.8%) and S. dysenteriae (2.9%). 7) Among Salmonella serovers, Salmonella Enteritidis was isolated the most frequently (39 cases, 14.1%). 8) 218 (91.6%) of 238 Shigella strains and 103 (37.6%) of 276 Salmonella strains were resistant to one or more drugs tested (SM.CP.TC.KM.ABPC.NA.OFLX). 9) All of the 22 V. cholerae O1 strains were Ogawa, E1 Tor. Among them, 19 were toxigenic strains and 3 were non-toxigenic. 10) O4:K8 was the most frequently isolated serover of V. paraemolyticus. 87.4% of all V. parahaemolyticus strains were positive with thermostable direct hemolysin (TDH) gene, and 12.6% of them were positive with TDH-related hemolysin (TRH) gene by DNA-probe methods.