Recently, two successive epidemics of cholera were observed in Korea. The first one started in Suhchun-Goon of Choong-Chung-Namdo in August 1969, and the 2nd in Changyoung-Goon of Kyung Sang-Namdo in August 1970. With stool specimens collected from patients in Suhchun, Ko-Chang, Seoul, Inchun, Youngkwang, Chang-hang and Wooljin were epidemic areas in l969, and from patients in Chang-Young, Pusan, Taegu, and Seoul which were epidemic areas in l970, studies were carried out in 1) the isolation and identification of cholera vibrio strains 2) the differentiation of E1 Tor vibrio from classic cholera strains 3) the liberation test of Kappa-type phages and 4) El Tor phage typing. Five strains, which were isolated in the epidemic area of the Philippines in l969 were included for a comparative study. The results are summarized as follows. 1) The epidemic strains of 1969 were identified as Vibrio cholerae, Celebes type El Tor and those of 1970 epidemic as Vibrio cholerae, biotype El Tor, El Tor phage type IV. 2) Korean strains and Philippine strains of 1969 epidemic appeared to be identical in biochemical and serological tests and phage susceptibility tests.
Cholera/epidemiology ; Cholera/microbiology* ; Human ; Korea ; Philippines ; Vibrio/isolation & purification*

OBJECTIVETo understand the epidemic condition, distribution and biological characteristics of non-O1/non-O139 Vibrio cholerae from 2001 to 2009 in Haizhu District, to provide a scientific basis for the prevention and control of acute diarrhea.

METHODSReferring to the detecting method written in "Cholera control handbook" in the fifth edition, 764 specimens from outside environment (including the water in the Pearl River, drinking water, water for breeding fish, aquatic products and delicatessen foods), 189 specimens of healthy population and 3398 intestinal samples of patients with diarrhea, summing up to 4351 specimens for non-O1/non-O139 Vibrio cholerae test.

RESULTS4,351 specimens were detected of 101 strains of non O1/non O139 Vibrio cholerae, the total detection rate was 2.32%; 66 strains were identified by serotyping and grouped into 26 different serotypes, the typing rate was 65.3%. The strains VBO9, VBO38 and VBO76 were the dominant bacteria.Nine strains of the same type of non-O1/non-O139 Vibrio cholerae were found from external environments also from patients with diarrhea, suggesting that there might be a correlation between the two.

CONCLUSIONNon-O1/non-O139 Vibrio cholerae have diversified serotypes, causing certain infection rate among the population in this region. These bacteria exist extensively in external environment and they are the potential hazard to the citizens.

China ; epidemiology ; Cholera ; epidemiology ; microbiology ; Humans ; Serotyping ; Vibrio cholerae ; classification ; isolation & purification

OBJECTIVETo determine the genetic relationships between different Vibrio cholerae isolates in Shenzhen from 1993 to 2002.

METHODSChromosomal DNA from 60 isolates was digested in seakem gold agrose with restriction enzyme Not I and plugs were then analyzed by pulsed-field gel electrophoresis. Pulsed-field gel electrophoresis (PFGE) patterns of V. cholerae isolates were clustered using BioNumerics software.

RESULTS39 distinctive PFGE patterns were identified with each pattern having 20 to 30 bands. Most PFGE patterns were divided into cluster A or cluster B.

CONCLUSIONThe closely related pandemic clone clusters of V. cholerae strains did exist in Shenzhen. PFGE of V. cholerae could be used for active surveillance and tracking for cholerae.

China ; epidemiology ; Cholera ; epidemiology ; microbiology ; Electrophoresis, Gel, Pulsed-Field ; methods ; Humans ; Phylogeny ; Vibrio cholerae ; classification ; genetics

Vibrio cholerae is an important foodborne pathogen, mainly causes acute intestinal infectious disease. The development of rapid method for detecting Vibrio cholerae is critical for early diagnosis of its infection. In this study, two pairs of specific primers were designed according to housekeeping gene mdh of Vibrio cholerae. Following optimization of the reaction, DNA loop-mediated isothermal amplification (LAMP) for rapidly detecting Vibrio cholerae was successfully established. The optimal reaction for the LAMP assay is 65 degrees C for 60 min, with detection limit for cultivated Vibrio cholerae of 25 CFU/mL and for its contaminated food of 32 CFU/g. The specificity of the assay was determined using thirty-three kinds of same species or closely related bacteria, only Vibrio cholerae strains were specifically amplified. In practice, 85 pieces of positive samples were detected from 1057 pieces of shrimps, crabs, oysters, meat and human diarrhea complex using the LAMP method, which accorded with the detection result by ISO TS 21872-1-2007. Thus, the LAMP assay established in this study is a sensitive, rapid and simple tool for detecting Vibrio cholerae and will facilitate the surveillance for its control.
Cholera ; microbiology ; Food Microbiology ; methods ; Meat ; microbiology ; Nucleic Acid Amplification Techniques ; methods ; Seafood ; microbiology ; Sensitivity and Specificity ; Vibrio cholerae ; genetics ; isolation & purification

When cholera was first detected in Papua New Guinea (PNG) in mid-2009, national diagnostic capacity faced many challenges. This was in part due to the non-endemic status of the outbreak, resulting in few local staff experienced in Vibrio cholerae detection and poor access to the required consumables. The PNG Institute of Medical Research conducted culture on specimens from suspected cholera patients in Madang Province, with presumptive V. cholerae isolates sent to Goroka for confirmation. Of 98 samples analysed 15 were culture positive, with V. cholerae detected by polymerase chain reaction (PCR) in an additional 3 samples. Further analyses were conducted to identify other pathogenic bacteria from thiosulphate citrate bile salt sucrose (TCBS) agar. Molecular-based assays detected enteropathogenic (n = 1) and enterotoxigenic (n = 1) strains of Escherichia coli. No other major enteric pathogens were detected. The low detection rate of V. cholerae at the provincial level reflects challenges in the laboratory diagnosis of cholera and in-country challenges in responding to an outbreak of a non-endemic disease, such as lack of in-country diagnostic expertise and available consumables in the early stages. It also suggests that full aetiological investigations are warranted in future outbreaks of acute watery diarrhoea in PNG to fully elucidate the potentially complex aetiology, which could in turn guide diagnostic, treatment and prevention measures.
Cholera/*epidemiology/*microbiology ; *Disease Outbreaks ; Enterobacteriaceae/isolation & purification ; Feces/microbiology ; Humans ; Immunoassay ; Papua New Guinea/epidemiology ; Polymerase Chain Reaction ; Vibrio cholerae/*isolation & purification

OBJECTIVETo study the correlation between Vibrio cholerae strains isolated from natural enviroment and fishery products and the source of infection during V. cholerae outbreaks.

METHODSCholera toxin gene was detected by polymerase chain reaction (PCR) amplification. Pulsed-field gel electrophoresis (PFGE) was used to subtype the isolates. Results of PFGE were analyzed and clustered by BioNumerics software (Version 4.0).

RESULTSDuring the outbreaks, a total number of thirty O139 V. cholerae related serogroups were collected from patients, carriers, sewage and fishery products were identified and proved to be toxigenic. They could be clustered into four PFGE patterns when digested by Not I. These two V. cholerae outbreaks were caused by the same source of infection because of the following reasons: (1) PFGE patterns of the predominant strains isolated from two outbreaks were identical; (2) they were identical to the PFGE patterns of the strains isolated from the green turtle and rana catesbiana which were bought from the same wholesale store.

CONCLUSIONGreen turtle and rana catesbiana that were contaminated by toxigenic O139 V. cholerae strains seemed to be the source of infection causing the O139 V. cholerae outbreaks in Jiangxi province. Rapid laboratory surveillance and epidemiologic investigation were important in identifying the source of infection during the outbreaks of V. cholera.

Animals ; China ; epidemiology ; Cholera ; epidemiology ; Cluster Analysis ; Disease Outbreaks ; Disease Reservoirs ; microbiology ; Electrophoresis, Gel, Pulsed-Field ; methods ; Fisheries ; Humans ; Ranidae ; microbiology ; Sewage ; microbiology ; Turtles ; microbiology ; Vibrio cholerae O139 ; isolation & purification

OBJECTIVETo study the characteristics of molecular typing and phylogenic relationship among the Vibrio cholerae serogroup O139 strains isolated from environment and sea food samples during cholera outbreaks, in Sichuan province in 2004 and to trace the source of infections so as to support the ascertainment of epidemic control strategy.

METHODSCholera toxin gene was detected by polymerase chain reaction amplification. Pulsed-field gel electrophoresis (PFGE) was used for subtyping of isolates and clustering of patterns was analysed with the software BioNumerics.

RESULTSIn all the 72 strains under analysis, 68 appeared to be toxigenic while 4 from river water derived isolates were toxin gene negative. Sixty-seven strains were clustered into 16 PFGE patterns when digested with Not I. The patterns of toxigeinc O139 strains isolated from turtles in the markets were identical with the patterns of strains appeared in the outbreaks respectively. The PFGE patterns of isolates from different outbreaks were inconsistent.

CONCLUSIONThe sources of infection causing these outbreaks were complicated. Contaminated turtles might also be one of the major sources of outbreaks when being served at the dinner parties in Sichuan in 2004.

Animals ; Bacterial Typing Techniques ; methods ; China ; epidemiology ; Cholera ; epidemiology ; microbiology ; transmission ; Cholera Toxin ; genetics ; Cluster Analysis ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Food Microbiology ; Humans ; Phylogeny ; Polymerase Chain Reaction ; Population Surveillance ; Software ; Turtles ; microbiology ; Vibrio cholerae O139 ; classification ; genetics ; isolation & purification ; Water Microbiology

OBJECTIVETo establish a loop-mediated isothermal amplification (LAMP) method for rapid diagnosis of Vibrio cholerae.

METHODSBased on the ompW nucleic sequence of Vibrio cholerae, a pair of primers was designed for LAMP. The reaction conditions were optimized, and the specificity, sensitivity, and practicability of LAMP were tested using 47 bacterial strains and simulated contaminated sites.

RESULTSThe results of viable bacterium count showed that LAMP was capable of detecting Vibrio cholerae at a level as low as 1.6x10(2) cfu/ml. The minimal detectable concentration was 1.6+10(3) cfu/ml for simulated contaminated samples such as feces and seawater, and 1.6+10(4) cfu/ml for contaminated milk. All the 21 strains of Vibrio cholerae yielded positive results in LAMP, and the 26 strains of other bacteria all showed negative results, with a detection specificity of 100%.

CONCLUSIONThe established LAMP method has high specificity and sensitivity for detecting Vibrio cholerae and is applicable in field monitoring and epidemiological study of Vibrio cholerae.

Bacterial Proteins ; genetics ; Cholera ; diagnosis ; microbiology ; Clinical Laboratory Techniques ; methods ; Humans ; Nucleic Acid Amplification Techniques ; methods ; Sensitivity and Specificity ; Vibrio cholerae ; genetics ; isolation & purification

OBJECTIVETo analyze the molecular characteristics and genetic correlations of Vibrio cholerae isolates in Hainan in 2008, so as to provide pathogenic proof to diagnose the plague.

METHODSSeventy six cholera strains were isolated from this cholera epidemic.69 strains were obtained from patients, 7 were isolated from external environment, among which, one was from patient's toilet, one from water sample, three were isolated from fish pond near patient's home, one came from swab of the patient vomit on the ground of health center and one from swab of kitchen knife from Hainan University canteen respectively. With conventional aetiological methods, pulse-field gel electrophoresis was conducted and the patterns of the 76 isolates were analyzed. The PFGE image was analyzed using BioNumerics (Version4.0, Applied Maths BVBA, Belium). Image bands were identified and similarity coefficient was automatically generated.

RESULTSSeventy six strains were isolated from Vibrio cholerae outbreaks in Hainan in 2008.5 PFGE patterns of patient's isolates in June were the same, sharing a similarity coefficient of 100%. 70 PFGE patterns of patients and water in October and November were completely same, the similarity coefficient being 100%. But they were not same as that of June. 1 PFGE pattern of isolate from the sample in Hainan University was different, only sharing a similarity coefficient of 79.7%, which showed no correlation with the outbreak.

CONCLUSIONDifferent outbreaks of Vibrio cholera occurred in Hainan in 2008. The epidemic in October and November at different counties was one outbreak. The pollution of water in environment was an important factor for outbreak.

Bacterial Typing Techniques ; methods ; China ; epidemiology ; Cholera ; epidemiology ; microbiology ; DNA, Bacterial ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; methods ; Humans ; Vibrio cholerae ; classification ; isolation & purification

OBJECTIVETo investigate the molecular characteristics of phage-type 6b isolates emerging in 1998-2001 cholera epidemics in Sichuan province.

METHODSIsolates were analyzed by phage-typing, pulsed field gel electrophoresis (PFGE) and ompW gene sequencing.

RESULTSAll phage-type 1b and 6b isolates in Sichuan province from 1998 to 2001 were toxigenic. A total of 24 patterns were identified after PFGE analysis, and one predominant pattern consisted of 13 isolates. Several 1b and 6b isolates from Sichuan and isolates of the 1b from other provinces showed the same PFGE pattern. Mutation in ompW gene was found in 6b isolates.

CONCLUSIONV.cholerae O1 6b isolates in Sichuan province from 1998 to 2001 have special genetic markers, and might genetically correlate with contemporaneous 1b isolates.

Bacterial Typing Techniques ; Bacteriophage Typing ; China ; epidemiology ; Cholera ; epidemiology ; microbiology ; DNA, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; Genes, Bacterial ; Genotype ; Vibrio cholerae ; classification ; genetics ; isolation & purification