Objective: To analyze the etiological and epidemiological characteristics of Vibrio cholerae in Beijing during 2015-2021 and provide evidence for the prevention and control of cholera. Methods: The V. cholerae strains isolated in Beijing during 2015-2021 were analyzed by serotyping and virulence genes detection. Pulsed field gel electrophoresis (PFGE) was performed for the molecular typing of the strains. Based on the collected epidemiological and clinical data of cholera cases,the epidemiological characteristics of cholera were analyzed by descriptive epidemiology method. Results: A total of 76 Vibrio cholerae O1 strains were isolated in Beijing during 2015-2021, including 61 strains from human, 10 strains from environment and 5 strains from seafood. The 76 strains consisted of 68 Ogawa strains and 8 Inaba strains. Six Ogawa strains isolated from sporadic cases carried ctxAB. After NotⅠ digestion, 76 strains were divided into 33 PFGE patterns. From 2015 to 2021, a total of 38 cholera epidemics were reported in Beijing, most of them were sporadic ones, accounting for 92.11% (35/38). A total of 45 cases were reported, and the cases occurred during June-September accounted for 97.78% (44/45). Cholera cases occurred in 9 districts of Beijing, and the cases reported in Chaoyang district accounted for 42.22% (19/45) and in Changping district accounted for 31.11% (14/45). The age of the cholera cases ranged from 19 to 63 years. Except for one case with unknown clinical symptoms, 44 cases had diarrhea symptoms with 84.09% (37/44) of the cases reporting diarrhea (3-9 times/day), followed by yellow watery stool (95.45%, 42/44), abdominal pain (68.18%, 30/44), nausea and vomiting (40.91%, 18/44) and fever (36.36%, 16/44). Conclusion: Vibrio cholerae strains isolated in Beijing during 2015-2021 were mainly O1 serotype Ogawa,most of which were non-toxigenic. The PFGE of the strains varied. Cholera epidemics occurred in 9 districts of Beijing, but most were sporadic ones with incidence peak during June-September.
Adult ; Beijing/epidemiology* ; Cholera/epidemiology* ; Diarrhea/epidemiology* ; Electrophoresis, Gel, Pulsed-Field ; Humans ; Middle Aged ; Vibrio cholerae O1/genetics* ; Young Adult

PURPOSE: An oral cholera vaccine (OCV), Euvichol, with thimerosal (TM) as preservative, was prequalified by the World Health Organization (WHO) in 2015. In recent years, public health services and regulatory bodies recommended to eliminate TM in vaccines due to theoretical safety concerns. In this study, we examined whether TM-free Euvichol induces comparable immunogenicity to its TM-containing formulation in animal model. MATERIALS AND METHODS: To evaluate and compare the immunogenicity of the two variations of OCV, mice were immunized with TM-free or TM-containing Euvichol twice at 2-week interval by intranasal or oral route. One week after the last immunization, mice were challenged with Vibrio cholerae O1 and daily monitored to examine the protective immunity against cholera infection. In addition, serum samples were obtained from mice to measure vibriocidal activity and vaccine-specific IgG, IgM, and IgA antibodies using vibriocidal assay and enzyme-linked immunosorbent assay, respectively. RESULTS: No significant difference in immunogenicity, including vibriocidal activity and vaccine-specific IgG, IgM, and IgA in serum, was observed between mice groups administered with TM-free and -containing Euvichol, regardless of immunization route. However, intranasally immunized mice elicited higher levels of serum antibodies than those immunized via oral route. Moreover, intranasal immunization completely protected mice against V. cholerae challenge but not oral immunization. There was no significant difference in protection between two Euvichol variations. CONCLUSION: These results suggested that TM-free Euvichol could provide comparable immunogenicity to the WHO prequalified Euvichol containing TM as it was later confirmed in a clinical study. The pulmonary mouse cholera model can be considered useful to examine in vivo the potency of OCVs.
Animals* ; Antibodies ; Cholera Vaccines ; Cholera* ; Clinical Study ; Enzyme-Linked Immunosorbent Assay ; Immunization ; Immunoglobulin A ; Immunoglobulin G ; Immunoglobulin M ; Mice ; Models, Animal* ; Public Health ; Thimerosal ; Vaccines ; Vibrio cholerae O1 ; World Health Organization

OBJECTIVETo assess the antibiotic resistance and molecular characterization of cholera strains and to provide basis for clinical treatment and prevention of cholera.

METHODS4 stains isolated from an outbreak of cholera epidemic in Huai'an City in Jiangsu province in September 2010 were characterized using antibiotic susceptibility, biotype analysis, virluence genes detection, ctxB gene sequencing, and PFGE analysis.

RESULTSThe 4 strains were all resistant to sulphamethoxazole/trimethoprim, erythromycin, streptomycin. High drug susceptibility of the samples was found to 6 kinds of antibiotics such as amikacin, norfloxacin, ciprofloxacin, gentamicin, chloramphenicol, ampicillin. The isolates expressed phenotypic traits of both serogroup O1 ogawa and El Tor and carried 9 kinds of virulence genes, ctxA, ace, zot, toxR, tcpI, ompU, rtxC, tcpA, and hlyA gene. They were also identified as harboring the classical ctxB genotype based on amino acid residue substitutions. The PFGE profiles of NotI showed a single banding pattern, while SfiI's was 2 banding patterns.

CONCLUSIONThe bacterium type of Vibrio cholerae causing the epidemic outbreak of cholera belonged to the atypical EL Tor variant which was also identified as toxicogenic strain. The mapping of the strains prompted that there should be the common contamination source. Drug sensitivity test can guide the clinical drug use, in order to reduce the emergence of resistant strains.

Anti-Bacterial Agents ; Cholera ; Cholera Toxin ; Disease Outbreaks ; Drug Resistance, Bacterial ; Drug Resistance, Microbial ; Epidemics ; Genotype ; Humans ; Vibrio cholerae ; Vibrio cholerae O1 ; Virulence

OBJECTIVETo understand the ctxB and rstR variations of toxigenic Vibrio cholerae (V.cholerae) O1 El Tor strains isolated from different provinces in China from 1961 to 2010.

METHODSAll 385 toxigenic V.cholerae O1 El Tor strains were selected, which were isolated in China between year 1961 and 2010. ctxB gene was amplified by PCR method and sequenced for further analysis. rstR was detected with PCR by using the genotype specific primers.

RESULTSctxB sequence analysis revealed that 52.5% (202/385) isolates carried ctxB(ET) and 47.5% (183/385) carried ctxB(class), namely Y(39) to H and I(68) to T substitutions which were specific to the classical biotype CT-B sequence. From 1961 to 1992, strains carrying ctxB(ET) were predominant and the proportion was as high as 98.4% (182/185). After 1993, strains carrying ctxB(class) were sharply increased. Especially during year 1993 to year 2005, 97.2% (174/179) of the isolated strains carried ctxB(class). Since 2006, resurgence of dominant strains carrying ctxB(ET) or co-existing of strains with ctxB(ET) or ctxB(class) was noticed. rstR genotype detection showed that 62.9% (242/385)of the tested strains carried the rstR(ET), while 6.8% (26/385) with rstR(class), and the remainings contained at least two types of rstR in different combination forms, among which rstR(ET)+rstR(class) combination were the most, accounting for 75.7% (75/99) . Similar to the ctxB, the distribution of rstR genotypes showed time specificity. From 1961 to 1992, strains carrying rstR(ET) predominated (87.0%, 161/185). After 1993, the diversity of rstR genotypes was observed accompanying by a sharp increase of strains containing other rstR genotype, such as rstR(class), rstR(env) and different combinations. There were separately 96% (25/26), 84% (63/75) and 18/18 strains containing rstR(class), rstR(ET)+rstR(class) and rstR(ET)+rstR(class)+rstR(env) isolated after 1993.

CONCLUSIONThe distribution of different genotypes of ctxB and rstR showed obvious time-specificity, and there were various combining forms of rstR, reflecting the diversity of the genetic and evolutionary characteristics of Chinese V.cholerae isolates.

China ; Cholera ; Genotype ; Molecular Epidemiology ; Polymerase Chain Reaction ; Vibrio cholerae ; Vibrio cholerae O1

The safety, tolerability and immunogenicity of an oral cholera vaccine (OCV) was assessed in adult Korean male through an open-label, non-comparative clinical study. Two doses of vaccine with an interval of 2 weeks were given to 20 healthy subjects. A total of 7 adverse events occurred in 6 subjects. However, no clinically significant change was observed in electrocardiograms, vital signs, physical examinations, and clinical laboratory tests. The immunogenicity of OCV was evaluated by serum vibriocidal assay where anti-Vibrio cholerae O1 and O139 antibodies were measured at day 0, 14, and 28 of vaccine administration. The antibody titers ranged from < 2.5-5,120 for V. cholerae O1 Inaba, < 2.5-10,240 for V. cholerae O1 Ogawa and < 2.5-480 for V. cholerae O139. In addition, the fold increase in antibody titers ranged from 1-4,096 for O1 Inaba, 1-8,192 for O1 Ogawa, and 1-384 for O139. The seroconversion rate was 95% and 45% for O1 and O139 antibodies, respectively. Our study clearly shows that administration of two doses of OCV at a 2 week-interval increases an appropriate level of antibody titer in the serum of healthy Korean adult males (Clinical Trial Number, NCT01707537).
Administration, Oral ; Adult ; Antibodies, Bacterial/*blood/immunology ; Antibody Formation ; Cholera/*prevention & control ; Cholera Vaccines/adverse effects/*immunology ; Creatine Kinase/blood ; Humans ; Male ; Republic of Korea ; Toothache/etiology ; Vibrio cholerae O1/immunology

OBJECTIVETo understand the phenotypic diversity of toxigenic Vibrio cholerae O1 El Tor strains isolated from different provinces in China during the last 50 years.

METHODSTraditional biotyping testings including susceptibility to polymyxin B, sensitivity to group IV phage, Voges-Proskauer test and haemolysis of sheep erythrocytes were conducted.

RESULTSData from Biotype-specific phenotype analysis revealed that only 133 isolates carried the typical El Tor phenotypes while the other 251 isolates displayed atypical El Tor phenotypes. Combined with ctxB, rstR genotypes and phenotypic characteristics, 64 isolates were identified as typical El Tor biotype, 21 were El Tor variants that showing the typical El Tor biotype-specific phenotype but with ctxB(class). 280 isolates were defined as the hybrid groups with traits of both classical and El Tor biotypes that could be further classified into 45 groups, based on the combination of genotypes of ctxB, rstR and phenotypic characteristics.

CONCLUSIONToxigenic Vibrio cholerae O1 El Tor strains that isolated from different provinces in China displayed high phenotypic diversity. The traditional biotype traits could not be used to correctly distinguish the two different biotypes.

China ; Genotype ; Phenotype ; Polymorphism, Genetic ; Vibrio cholerae O1 ; genetics

BACKGROUND: Cholera is a representative water-borne disease that is caused by V. cholera ctx (+). V. cholera El Tor was previously the primary pathogen, but after the seventh pandemic outbreak, it was replaced by a V. cholera El Tor variant with a classical phenotype and genotype. In this study, we investigated the genotypic and phenotypic characteristics of imported V. cholerae El Tor in Korea. METHODS: Forty-nine V. cholerae O1 El Tor strains isolated from 2004 to 2011 were used in this study. Polymerase chain reaction amplification of the ctxB and rstR genes was used for biotype determination. An antimicrobial susceptibility test was performed for phenotypic analysis, and pulse field gel electrophoresis (PFGE) was used for analysis of genetic relatedness. RESULTS: Classical ctxB genes were found in all of the isolates, while classical, El Tor, and combined rstR genes were found. Twenty strains showed antimicrobial resistance against streptomycin, sulfamethoxazole/trimethoprim, nalidixic acid, and ciprofloxacin. Based on PFGE, all isolates were grouped as cluster B. The country of origin and resistance pattern were highly related, although the time of influx and serogroup were not. CONCLUSION: Isolates of V. cholera El Tor imported since 2004 were hybrids of V. cholera El Tor, which has the classical ctxB gene and is considered to be a CTX prophage. The SXT element plays an important role in antimicrobial resistance. PFGE patterns, which can be used for analysis of imported V. cholera, revealed the relatedness of the resistant isolates.
Chimera ; Cholera ; Ciprofloxacin ; Electrophoresis ; Genotype ; Korea ; Nalidixic Acid ; Pandemics ; Phenotype ; Polymerase Chain Reaction ; Prophages ; Streptomycin ; Vibrio ; Vibrio cholerae ; Vibrio cholerae O1

OBJECTIVETo study the molecular characteristics and antibiotic resistances of Vibrio cholerae (V. cholerae) O1 isolates in Hangzhou in 2009.

METHODSThe virulence genes ctxA and tcpA of the thirty V. cholerae O1 isolates from 7 counties and districts of Hangzhou were detected by PCR. Pulsed-field gel electrophoresis (PFGE) was performed for molecular typing and similarity analysis. Antibiotic resistances of these isolates were measured by the Kirby-Bauer method.

RESULTSVirulence gene analysis showed that 80.00% (24/30) of the genotype in V. cholerae isolates was ctxA- and tcpA+, 13.33% (4/30) was ctxA- and tcpA-, and 6.67% (2/30) was ctxA+ and tcpA+. Twenty-seven isolates tested were typed into 11 PFGE patterns (P1-P11). Twenty-three isolates with genotype ctxA- and tcpA+ were clustered into 7 PFGE patterns (P1-P7, termed P1-like cluster) with the similarity to be equal or greater than 91.4%, and 56.52%(13/23) of them belong to P1. 7 isolates with very high similarity (97.6%), belonging to P1 (6 isolates), and P2 (1 isolate), respectively, were collected from one foodborne disease outbreak. The resistant rates of the 24 isolates with genotype ctxA- and tcpA+ to ampicillin, tobramycin and amikacin were 20.83% (5/24), 4.17% (1/24) and 4.17% (1/24), respectively.

CONCLUSIONThe genotype of the epidemic strains of V. cholerae O1 isolates in Hangzhou in 2009 with high similarity was ctxA- and tcpA+; The level of drug resistances of this kind of V. cholerae O1 isolates were not high.

China ; Cholera Toxin ; genetics ; Drug Resistance, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; Genes, Bacterial ; Genotype ; Humans ; Molecular Typing ; Vibrio cholerae O1 ; drug effects ; genetics ; isolation & purification

Vibrio cholerae non-O1 have caused several well-studied food-borne outbreaks of gastroenteritis and also have been responsible for sporadic cases of otitis media, wound infection, and bacteremia. Few cases of liver abscess caused by Vibrio cholerae non-O1 have been reported. A 73-year-old man with underlying diabetes mellitus was admitted with nausea, vomiting, dyspepsia and febrile sensation. We identified Vibrio cholerae non-O1 in his blood cultures and multiple hepatic microabscess on abdominal computed tomography. He was treated with systemic antibiotics and fluid therapy, but died due to septic shock on sixth day. We report here, a case of liver abscess with bacteremia due to Vibrio cholerae non-O1 in a patient with diabetes mellitus.
Aged ; Anti-Bacterial Agents/therapeutic use ; Bacteremia/drug therapy/*microbiology ; Ceftriaxone/therapeutic use ; Humans ; Liver Abscess/*diagnosis/drug therapy/microbiology ; Male ; Metronidazole/therapeutic use ; Shock, Septic/diagnosis ; Tomography, X-Ray Computed ; Vibrio Infections/drug therapy/*microbiology ; Vibrio cholerae non-O1/*isolation & purification

A 63-year-old man with underlying liver cirrhosis was admitted with painful swelling of the right thigh. We identified a non-O1 Vibrio cholerae strain in blood cultures and multiple pyomyositis in the lower limbs. Non-O1 V. cholerae strains have caused several well-studied food-borne outbreaks of gastroenteritis and have been responsible for sporadic cases of otitis media, skin and soft tissue infection, and bacteremia. Skin and soft tissue infection due to non-O1 V. cholerae is rare and is commonly associated with the presence of chronic underlying disease, such as liver cirrhosis, diabetes mellitus, an immunocompromised state, or a hematological malignancy. We report the first case of pyomyositis caused by non-O1 V. cholerae in Korea. Physicians should consider non-O1 V. cholerae strains as a pathogen that can cause pyomyositis.
Bacteremia ; Cholera ; Diabetes Mellitus ; Disease Outbreaks ; Gastroenteritis ; Hematologic Neoplasms ; Humans ; Korea ; Liver ; Liver Cirrhosis ; Lower Extremity ; Middle Aged ; Otitis Media ; Pyomyositis ; Skin ; Soft Tissue Infections ; Sprains and Strains ; Thigh ; Vibrio ; Vibrio cholerae ; Vibrio cholerae non-O1