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 clone and secretion express cholera toxin B subunit (CTB) in food-grading Lactococcus lactis expression systems.

METHODSctB fragment that encoding CTB was amplified by polymerase chain reaction (PCR) using the genomic DNA of Vibrio cholera strain 569B as template and was inserted into two secretion expression vector pSQZ and pSQ to construct food-grading expression system L.lactis MBP71/pSQZ-ctB and L.lactis MBP71/pSQ-ctB. The expressed CTB was detected by Western-blot assay.

RESULTSThe ctB fragment was successfully amplified from Vibrio cholera strain 569B and inserted into two secretion expression vectors pSQZ and pSQ to construct food-grading expression system L. lactis MBP71/pSQZ-ctB and L. lactis MBP71/pSQ-ctB. Western-blot assay demonstrated that CTB was secretion and expressed from L.lactis MBP71 harboring vectors pSQZ-ctB and pSQ-ctB, and the quantity of CTB secreted by L. lactis MBP71/pSQ-ctB was about 2 microg/ml, higher than that of L. lactis MBP71/pSQZ-ctB.

CONCLUSIONCTB was successfully secreted and expressed by food-grading L. lactis expression systems.

Cholera Toxin ; biosynthesis ; secretion ; Food Microbiology ; Gene Expression ; Genetic Vectors ; Lactococcus lactis ; metabolism

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

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

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 analysis the etiological and epidemiological characteristics of the reported infectious diarrhea (other than cholera, dysentery, typhoid and paratyphoid) cases in China in 2011.

METHODSA total of 836 591 reported infectious diarrhea cases were collected from "China Information System for Disease Prevention and Control" since first week to fifty-second weeks in 2011, 59 929 out of which were laboratory-confirmed. The information of thirty public health emergencies relevant with infectious diarrhea was collected from "Emergency Public Reporting System" between first week and fifty-second weeks in 2011. The epidemiological characteristics of reported cases, confirmed cases and outbreaks, and the pathogenic spectrum of confirmed cases were then analyzed.

RESULTSIn 2011, 836 591 infectious diarrhea cases (other than cholera, dysentery, typhoid and paratyphoid) were reported, and the incidence rate was 62.39/100 000. More than half patients were children aged under 5 year-old, accounting for 52.13% (436 098/836 591) and the incidence rate was 447.06/100 000 (436 098 cases). Most of the ill children were scattered, accounting for 50.53% (422 752/836 591). Reported cases showed two incidence peaks, with a summer peak from twenty-third weeks to thirty-fifth weeks, accounting for 34.33% (287 231/836 591) and a winter peak from forty-third weeks to fifty-second weeks, accounting for 23.54% (196 939/836 591). Cases distributed all over China, the incidence in Beijing (253.00/100 000 (49 619 cases)), Tianjin (244.34/100 000 (31 614 cases)), Zhejiang (204.42/100 000 (111 257 cases)), Ningxia (132.16/100 000 (9328 cases)) and Guangdong (127.40/100 000 (132 880 cases)) ranked the top five. Among the 30 public health emergencies, 5 outbreaks had lab tested pathogenic results, including 4 were norovirus-induced. Laboratory-confirmed cases accounted for 7.16% (59 929/836 591) of the case reported, including 56 687 viral cases and 3242 bacterial cases. Rotavirus cases took the highest proportion of viral cases, at 97.35% (53 612/55 185); and 97.15% (53 612/55 185) of which were children aged under 5 year-old. 82.42% (45 480/55 185) of the cases distributed in Guangdong and Zhejiang province, with the incidence peak from fiftieth weeks to fifty-first weeks, accounting for 15.42% (8508/55 185) of the whole year cases. The main pathogens of bacterial diarrhea were Salmonella, Vibrio parahaemolyticus and Escherichia coli, accounting for 48.43% (1570/3242), 32.20% (1044/3242) and 8.57% (278/3242) respectively, with the incidence peak from thirty-first weeks to thirty-fifth weeks, accounting for 23.01% (746/3242). Salmonella infection patients were mainly from Shanghai, Guangdong and Zhejiang province (91.59% (1438/1570)), Vibrio parahaemolyticus patients were mainly from Shanghai (80.94% (845/1044)), and Escherichia coli patients were mainly from Guangdong province (84.17% (234/278)). Salmonella patients were concentrated in 0-9 years group, accounting for 42.36% (665/1570), while Vibrio parahaemolyticus patients in 20-39 years group, accounting for 81.99% (856/1044), and Escherichia coli patients in under 1 year old and 20-39 years group, accounting for 63.67% (177/278).

CONCLUSIONIn China, children aged under 5 year-old should be the priority population in surveillance of infectious diarrhea. Rotavirus is the main pathogen causing infectious diarrhea. The lab-testing and case-reporting capabilities differed greatly among areas.

Child, Preschool ; China ; epidemiology ; Cholera ; epidemiology ; Diarrhea ; epidemiology ; microbiology ; virology ; Dysentery ; epidemiology ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Rotavirus Infections ; epidemiology ; Typhoid Fever ; epidemiology

OBJECTIVETo analyze the etiologic characteristics of O1/O139 Vibrio cholerae in Guangdong province in 2009-2013.

METHODSIsolates from cholera cases and from the environment surveillance points were investigated by serological typing, antibiotic susceptibility testings, toxic genes detection and molecular typing to analyze the similarities and differences of the identified species.

RESULTSTotally, 190 isolations of O1/O139 V. cholerae were obtained from cholera cases (16 strains) and environmental samples (174 strains) in Guangdong province in 2009-2013. The sero-types would include Inaba (3 isolates), Ogawa (7 isolates) and O139 (6 isolates) in all the isolates from the cholera cases. Ten strains from the ctxA positive cases were detected by PCR. Two Ogawa strains carried incomplete CTXΦ phage. Results from the antibiotic susceptibility test indicated that 5 strains were absolutely sensitive to 11 antibiotic discs in vitro, while another 3 strains were simultaneously resistant to 4 antibiotic discs. Except for 2 stains, all the O139 strains from the environment were ctxA negative, detected by PCR. Incomplete CTXΦ phage was found in the Inaba (53 isolates), Ogawa (22 isolates) and O139 (2 isolates), respectively. Results from the antibiotic susceptibility test exhibited that 25 strains were resistant simultaneously to 4 and/or more antibiotic discs, especially the Inaba strains from the seafoods(13 isolates). 2 Inaba strains from seafood were simultaneously resistant to 7 antibiotic discs. Results from PFGE molecular typing indicated that the PFGE types digested by Not I expressed significant diversity. Inaba and O139 strains from cases were gathered in the same clusters, while the Ogawa strains from cases scattered in different clusters but no significant correlation among these strains were found. Our results suggested that a distant genetic relationship might exist between these two different sources strains.

CONCLUSIONComplex and diverse as the virulence genes and genetic characteristics and with the grim situation of multi-drug resistant strains, all seemed important to strengthen the surveillance programs on the variation of strain types and antibiotics resistance of O1/O139 V. cholerae in Guangdong province.

Bacterial Typing Techniques ; China ; epidemiology ; Cholera ; epidemiology ; microbiology ; Drug Resistance, Multiple, Bacterial ; Genes, Bacterial ; Humans ; Microbial Sensitivity Tests ; Vibrio cholerae ; classification ; drug effects ; isolation & purification ; Virulence