Resuscitation of viable but non-culturable Vibrio parahaemolyticus in a minimum salt medium

Vibrio parahaemolyticus is food-borne pathogen prevalent in Asian countries. This work analyzes factors that influence the resuscitation of the viable but nonculturable (VBNC) state in this bacterium. The MMS-0.5% NaCl medium alone limited cell multiplication, and in this medium, resuscitation was successful when the temperature was upshifted to 25 degrees C but not 37 degrees C. Chloramphenicol inhibition experiments revealed that protein synthesis in the first 24 h of temperature upshift was critical in determining the success of the three-day resuscitation period. The VBNC state induction period and the age of the VBNC cells for successful resuscitation were strain-dependent. Results of this work facilitate further physiological and pathological study of the VBNC state in this pathogen.     

Resuscitation of viable but nonculturable cells of Vibrio parahaemolyticus induced at low temperature under starvation

Vibrio parahaemolyticus is known to exist in a viable but nonculturable state when incubated at low temperature under starvation. It has long been debated whether the culturable cells which appear after temperature upshift are the result of true resuscitation or regrowth of a few residual culturable cells. Starved V. parahaemolyticus cells at 4 degrees C reached the nonculturable stage in about 12 days. The true resuscitation of nonculturable cells of V. parahaemolyticus occurred after spreading them onto an agar medium supplemented with H(2)O(2)-degrading compounds such as catalase or sodium pyruvate. The proposed method may be applicable to detecting the enteropathogen from environmental samples.     

Serovars of Vibrio parahaemolyticus

Seashore water samples collected along the coastline in Bulgaria and Rumania contained in large numbers OK serovars of V. parahaemolyticus; some of these had been isolated repeatedly over an extended time period: 01 K32, 03 K30, 03 K48, 04 K37, 04 K53, 05 K17, 05 K30. The serovar 05 K17 was virtually present in all water samples and was also isolated from a case of purulent ear infection in a child from Burgas. In contrast, strains recovered from Asian and African coastal water had different K antigens and were never identified in Europe. Two strains of V. parahaemolyticus (serovars 05 K15 and 07 K10) had positive swarming growth resembling that of V. alginolyticus. The first of these was Kanagawa-positive and was isolated from a case of severe diarrhea in Brazzaville. Vibrio parahaemolyticus isolates came from marine or brackish water specimens collected on sand banks, 3 strains were recovered from marine or brackish water in Africa. Vibrio harveyi, a sucrose-negative species important from differential diagnostic aspects, has been isolated from seashore water samples collected on coarse-sand or pebbly beaches.     

副溶血弧菌的致病机制

副溶血性弧菌是引发微生物食源性疾病的首要病原菌,其在临床上主要引起3种疾病,即胃肠炎、伤口感染和败血症。经过多年的研究,人们对副溶血性弧菌的致病机制有了一定的认识。我们着重介绍副溶血性弧菌的主要毒力因子、毒力基因表达调控及常用的毒力表型研究方法。     

Survival of Vibrio parahaemolyticus After Chilling in Transport Media: an Explanation for Divergent Findings

Differing incidences of Vibrio parahaemolyticus reported by separate government agencies are attributable to sample handling and subsequent isolation techniques.     

Medium for Isolation and Differentiation of Vibrio parahaemolyticus and Vibrio alginolyticus

Trypticase soy agar supplemented with sucrose, sodium chloride, bile salts, and triphenyltetrazolium chloride is an improved plating medium for the isolation of Vibrio parahaemolyticus from samples of seawater, permitting better differentiation of this organism from Vibrio alginolyticus and other bacteria.     

Medium for isolation and differentiation of Vibrio parahaemolyticus and Vibrio alginolyticus

Trypticase soy agar supplemented with sucrose, sodium chloride, bile salts, and triphenyltetrazolium chloride is an improved plating medium for the isolation of Vibrio parahaemolyticus from samples of seawater, permitting better differentiation of this organism from Vibrio alginolyticus and other bacteria.     

A novel multiplex PCR for the identification of Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus

AIM: To establish a simple multiplex polymerase chain reaction (PCR) that will identify Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus. METHODS AND RESULTS: A total of 429 Vibrio spp. from various origins were tested with the novel primers targeting toxR. The reverse primers were all designed to be species specific, while the forward primer was universal. The primers correctly identified all the V. parahaemolyticus, V. cholerae and V. vulnificus isolates tested. CONCLUSIONS: The toxR multiplex PCR works well when the initial colony morphology is known. If not, Vibrio alginolyticus might represent a diagnostic obstacle. SIGNIFICANCE AND IMPACT OF THE STUDY: The method provides a fast and reliable way of identifying the main Vibrio spp. involved in food-borne disease. The method could prove very useful for laboratories working with identification of these Vibrio spp.     

Method for the Detection of Injured Vibrio parahaemolyticus in Seafoods

The sensitivity of Vibrio parahaemolyticus cells to refrigeration and frozen storage and the development of a method for detecting injured and uninjured V. parahaemolyticus cells were studied. Cell suspensions in different kinds of seafood homogenates were either regrigerated (4°C) or frozen (−20°C), stored, and examined for cell survival during storage. V. parahaemolyticus cells were sensitive to both storage temperatures. Many cells died, and many survivors were sublethally injured. In general, refrigeration storage appeared to be more injurious than frozen storage. The initial recovery of the sublethally injured cells was highest in a nutritionally rich, nonselective liquid medium such as Trypticase soy broth, whereas maximum cell multiplication was observed in Trypticase soy broth containing 3% NaCl. The sublethally injured V. parahaemolyticus cells demonstrated sensitivity to the selective enrichment medium, glucose salt teepol broth. From these findings, a new method (designated as the “repair-detection” method) was developed for the isolation and enumeration of V. parahaemolyticus. Comparative studies between the recommended and the repair-detection methods showed that injured V. parahaemolyticus cells were present in commercial seafoods and that the repair-detection method was definitely more effective for the detection of total numbers of V. parahaemolyticus cells.     

Production of pili on Vibrio parahaemolyticus

Electron microscopic examination showed that all strains of Vibrio parahaemolyticus examined had pili on their surface when the organism was grown on marine agar at 28 degrees C for 6-12 h. The pili were morphologically stable on heat treatment at 60 degrees C for 10 min, but both the lateral and polar flagella possessed by this organism were labile. No immunological cross-reactivity between pili of enterotoxigenic Escherichia coli and Vibrio cholerae non-01 and those of V. parahaemolyticus was observed.