Molecular analyses of Vibrio cholerae O1 clinical strains, including new nontoxigenic variants isolated in Mexico during the Cholera epidemic years between 1991 and 2000.

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Lizárraga-Partida, Marcial Leonardo; Quilici, Marie-Laure

2009-05-01

We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI rRNA analysis revealed that these strains had ribotype profiles, denoted M5 and M6 in our study, that were identical to those previously designated Koblavi B5 or Popovic 5 and Popovic 6a or Tamayo B21a, respectively. Ribotype M5 was isolated between 1991 and 1993. This ribotype had a low level of genetic variation as detected by pulsed-field gel electrophoresis (PFGE). Ribotype M6 persisted from 1991 to 2000. However, PFGE profiles suggested that two epidemiologically unrelated strains coexisted within this single ribotype from 1995 until the end of the epidemic. We identified three new BglI ribotypes, Mx1, Mx2, and Mx3, from nontoxigenic V. cholerae O1 strains isolated between 1998 and 2000; one of them grouped strains positive for the toxin-coregulated pilus island. They differed from nontoxigenic clones isolated in Latin America and on the U.S. Gulf Coast and are probably autochthonous Mexican V. cholerae O1 variants. Most of these new variants were isolated from states surrounding the Gulf of Mexico, where the highest incidence of cholera in the country was recorded. Thus, the Mexican Gulf Coast, like the U.S. Gulf Coast, may act as an environmental reservoir of V. cholerae O1.

Development of an allele-specific PCR assay for simultaneous sero-typing of avian pathogenic Escherichia coli predominant O1, O2, O18 and O78 strains.

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Wang, Shaohui; Meng, Qingmei; Dai, Jianjun; Han, Xiangan; Han, Yue; Ding, Chan; Liu, Haiwen; Yu, Shengqing

2014-01-01

Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR) assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs) bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.

Development of an allele-specific PCR assay for simultaneous sero-typing of avian pathogenic Escherichia coli predominant O1, O2, O18 and O78 strains.

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Shaohui Wang

Full Text Available Systemic infections by avian pathogenic Escherichia coli (APEC are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.

Molecular Analyses of Vibrio cholerae O1 Clinical Strains, Including New Nontoxigenic Variants Isolated in Mexico during the Cholera Epidemic Years between 1991 and 2000

OpenAIRE

Lizárraga-Partida, Leonardo; Quilici, Marie-Laure

2009-01-01

International audience; We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI r...

Whole genome PCR scanning reveals the syntenic genome structure of toxigenic Vibrio cholerae strains in the O1/O139 population.

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Bo Pang

Full Text Available Vibrio cholerae is commonly found in estuarine water systems. Toxigenic O1 and O139 V. cholerae strains have caused cholera epidemics and pandemics, whereas the nontoxigenic strains within these serogroups only occasionally lead to disease. To understand the differences in the genome and clonality between the toxigenic and nontoxigenic strains of V. cholerae serogroups O1 and O139, we employed a whole genome PCR scanning (WGPScanning method, an rrn operon-mediated fragment rearrangement analysis and comparative genomic hybridization (CGH to analyze the genome structure of different strains. WGPScanning in conjunction with CGH revealed that the genomic contents of the toxigenic strains were conservative, except for a few indels located mainly in mobile elements. Minor nucleotide variation in orthologous genes appeared to be the major difference between the toxigenic strains. rrn operon-mediated rearrangements were infrequent in El Tor toxigenic strains tested using I-CeuI digested pulsed-field gel electrophoresis (PFGE analysis and PCR analysis based on flanking sequence of rrn operons. Using these methods, we found that the genomic structures of toxigenic El Tor and O139 strains were syntenic. The nontoxigenic strains exhibited more extensive sequence variations, but toxin coregulated pilus positive (TCP+ strains had a similar structure. TCP+ nontoxigenic strains could be subdivided into multiple lineages according to the TCP type, suggesting the existence of complex intermediates in the evolution of toxigenic strains. The data indicate that toxigenic O1 El Tor and O139 strains were derived from a single lineage of intermediates from complex clones in the environment. The nontoxigenic strains with non-El Tor type TCP may yet evolve into new epidemic clones after attaining toxigenic attributes.

Molecular Analyses of Vibrio cholerae O1 Clinical Strains, Including New Nontoxigenic Variants Isolated in Mexico during the Cholera Epidemic Years between 1991 and 2000▿

Science.gov (United States)

Lizárraga-Partida, Marcial Leonardo; Quilici, Marie-Laure

2009-01-01

We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI rRNA analysis revealed that these strains had ribotype profiles, denoted M5 and M6 in our study, that were identical to those previously designated Koblavi B5 or Popovic 5 and Popovic 6a or Tamayo B21a, respectively. Ribotype M5 was isolated between 1991 and 1993. This ribotype had a low level of genetic variation as detected by pulsed-field gel electrophoresis (PFGE). Ribotype M6 persisted from 1991 to 2000. However, PFGE profiles suggested that two epidemiologically unrelated strains coexisted within this single ribotype from 1995 until the end of the epidemic. We identified three new BglI ribotypes, Mx1, Mx2, and Mx3, from nontoxigenic V. cholerae O1 strains isolated between 1998 and 2000; one of them grouped strains positive for the toxin-coregulated pilus island. They differed from nontoxigenic clones isolated in Latin America and on the U.S. Gulf Coast and are probably autochthonous Mexican V. cholerae O1 variants. Most of these new variants were isolated from states surrounding the Gulf of Mexico, where the highest incidence of cholera in the country was recorded. Thus, the Mexican Gulf Coast, like the U.S. Gulf Coast, may act as an environmental reservoir of V. cholerae O1. PMID:19213700

Occurrence of Vibrio cholerae in fish and water from a reservoir and a neighboring channel in Ouagadougou, Burkina Faso.

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Traoré, Oumar; Martikainen, Outi; Siitonen, Anja; Traoré, Alfred S; Barro, Nicolas; Haukka, Kaisa

2014-10-15

Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. In this study, we surveyed the occurrence of V. cholerae in fish harvested from a reservoir that receives discharges from the population in Ouagadougou through several channels. A total of 238 fish and 80 water samples were analyzed for the presence of V. cholerae. Altogether, 13 V. cholerae strains were isolated. They were all identified as non-O1/non-O139 V. cholerae without the ctxA gene. The strains were mostly susceptible to the antimicrobials tested. Although no strains of epidemic V. cholerae serotypes were encountered, it is important to monitor the microbiological quality of this extensively used water resource and its fish.

Characterization of a clinical Vibrio cholerae O139 isolate from Mexico.

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Parveen, Salina; Farrah, Samuel R; Gonzalez-Bonilla, Celia; Zamudio, Altagracia V; Tamplin, Mark L

2003-01-01

Pathogenic strains of Vibrio cholerae O139 possess the cholera toxin A subunit (ctxA) gene as well as the gene for toxin co-regulated pili (tcpA). We report the isolation of a ctxA-negative, tcpA-negative V. cholerae O139 strain (INDREI) from a patient in Mexico diagnosed with gastrointestinal illness. Certain phenotypic characteristics of this strain were identical to those of V. cholerae O1 biotype El Tor. Unlike ctxA-positive V. cholerae O139 strains, this strain was sensitive to a wide panel of antibiotics, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, furazolidone, nalidixic acid, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin, but was resistant to polymyxin B. Ribotype and pulsed-field gel electrophoresis profiles of INDRE1 differed from those of ctxA-positive V. cholerae O139 and other V. cholerae strains. Phenotypic characteristics of the Mexico strain were similar to those reported for V. cholerae O139 isolates from Argentina and Sri Lanka.

Clonal relationship among Vibrio cholerae O1 El Tor strains isolated in Somalia.

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Scrascia, Maria; Pugliese, Nicola; Maimone, Francesco; Mohamud, Kadigia A; Grimont, Patrick A D; Materu, Sadiki F; Pazzani, Carlo

2009-03-01

One hundred and three Vibrio cholerae O1 strains, selected to represent the cholera outbreaks which occurred in Somalia in 1998-1999, were characterized by random amplified polymorphic DNA patterns, ribotyping, and antimicrobial susceptibility. All strains showed a unique amplified DNA pattern and 2 closely related ribotypes (B5a and B8a), among which B5a was the more frequently identified. Ninety-one strains were resistant to ampicillin, chloramphenicol, spectinomycin, streptomycin, sulfamethoxazole, and trimethoprim, conferred, except for spectinomycin, by a conjugative plasmid IncC. These findings indicated that the group of strains active in Somalia in the late 1990s had a clonal origin.

Determination of tetracycline resistance genes in Vibrio cholerae O1 biotype El Tor serotype Inaba strains isolated from outbreaks occurred in Iran in 2013

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Azin Khany

2016-05-01

Full Text Available V. cholerae is the causative agent of potentially life threatening diarrheal disease named as cholera. Cholera is an endemic disease in Iran. Encountered increasing resistance of V. cholerae to commonly used antibiotics such as tetracycline has led to major challenges in the treatment of this disease .The present study was carried out to determine the prevalence of drug resistance as well as molecular bases of resistant V.cholerae strains which were isolated from patients in cholera outbreaks during summer of 2013 in Iran. Susceptibly testing was performed on V.cholerae strains isolated from stool of patients suffering from cholera in Iranian reference health laboratory by E -test MIC method as recommended by CLSI guideline. Antibiotic strips used included Ampicillin, Ciprofloxacin, Nalidixic acid, Cefixime , Tetracycline, Erythromycin and Trimethoprim-sulfamethoxazole .Regarding observed dominant pattern of tetracycline resistance comparing to results of previous years ,we decided to confirm the resistance by detecting the tetA , tetB and tetC by Polymerase chain reaction method. The results of antibiotic susceptibility testing revealed 100% resistance of isolated strains to tetracycline. Data obtained from PCR reaction on resistant strains for tetA, tetB and tetC showed that 45(44.1%, 37(36.2% and 70(68.6% were containing tetA, tetB and tetC gene respectively. Moreover, the frequency of tetA+tetB, tetA+C, tetB+tetC , tetA+tetB+tetC also were determined as 9(8.8%, 32(31.3%, 19(18.6% and 8(7.8% respectively. This study revealed the pattern of drug resistance distribution of isolates harboring tetA, tetB, tetC genes in relation to sex, age and nationality of patients and the cities where the cases were reported. A significant correlation was obtained between reported geographical incidence and drug resistant strains.

RAPD-PCR typing of Yersinia enterocolitica (Enterobacteriaceae O:3 serotype strains isolated from pigs and humans

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Tereza Cristina A. Leal

1999-09-01

Full Text Available Sixteen strains of Yersinia enterocolitica serotype O:3, isolated from apparently healthy pigs collected in Rio de Janeiro, and four human strains of serotypes O:4, O:5, O:6 and O:13 were analyzed by RAPD-PCR. The strains were grouped into five genotypic profiles according to the amplification patterns obtained with three random primers. Fifteen of the 16 pig strains had identical amplification patterns, which was named genotypic profile 1. The one different profile was named genotypic profile 2. Genotypic profile 1 was also exhibited by the O:6 human serotype strain. The O:4 and O:13 human serotype strains showed similar amplification profiles with two primers. However, the third primer induced a distinct profile in each strain. Therefore, these two strains were placed into genotypic profile 3 and 4, respectively. Each primer produced a completely different amplification profile in the O:5 human serotype strain; therefore, it was named genotypic profile 5. The presence or absence of plasmids in the strains studied did not affect the amplification results. These results show that genetic variations can exist within a serotype, and strains of different serotypes can exhibit the same amplification profile when compared using other primers.Foram utilizados três "primers" aleatórios para caracterizar pela técnica RAPD-PCR 16 cepas de Yersinia enterocolitica do sorotipo O:3, isoladas de suínos sadios do Rio de Janeiro. Pelos resultados dos padrões de amplificação, as 16 cepas dos suínos e as 4 cepas humanas usadas como referência (sorotipos O:4, O:5, O:6 e O:13 foram agrupadas em 5 perfis genotípicos. Quinze cepas de suínos apresentaram um padrão de amplificação idêntico (perfil genotípico 1 e somente uma apresentou um perfil de amplificação diferente (perfil genotípico 2. O mesmo padrão de amplificação do perfil genotípico 1 foi também observado em uma cepa humana do sorotipo O:6. As cepas humanas dos sorotipos O:4 e O:13

Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

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Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

1984-07-01

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to three plasmids. The old and new isolates of classical V. cholerae had two HindIII chromosomal digest fragments containing cholera toxin subunit A genes, whereas the eltor strains from Eastern countries had one fragment. The eltor strains from areas surrounding the Gulf of Mexico also had two subunit A gene fragments, which were smaller and easily distinguished from the classical pattern. All classical strains had 8 to 10 HindIII fragments containing the defective VcA1 prophage genome; none of the Eastern eltor strains had these genes, and the Gulf Coast eltor strains contained a different array of weakly hybridizing genes. These data suggest that the recent isolates of classical cholera in Bangladesh are closely related to the bacterial strain(s) which caused classical cholera during the sixth pandemic. These data do not support hypotheses that either the eltor or the nontoxigenic O1 strains are precursors of the new classical strains.

Anethole inhibits growth of recently emerged multidrug resistant toxigenic Vibrio cholerae O1 El Tor variant strains in vitro.

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Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Hinenoya, Atsushi; Yamasaki, Shinji

2015-05-01

To search natural compounds having inhibitory effect on bacterial growth is important, particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens. Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent of diarrheal disease cholera, is becoming a great concern. As an approach of searching new antimicrobial agents, here, we show that anethole, a well-studied natural component of sweet fennel and star anise seeds, could potentially inhibit the growth of MDR O1 El Tor biotype, the ongoing 7th cholera pandemic variant strains of toxigenic V. cholerae. The minimum inhibitory concentration (MIC) of anethole against diverse O1 El Tor biotype strains is evaluated as 200 µg/ml. Moreover, the effect of anethole is bactericidal and exerts rapid-killing action on V. cholerae cells. This study is the first report which demonstrates that anethole, purified from natural compound, is a potent inhibitor of growth of toxigenic V. cholerae. Our data suggest that anethole could be a potential antimicrobial drug candidate, particularly against MDR V. cholerae mediated infections.

Comparative genome analysis of VSP-II and SNPs reveals heterogenic variation in contemporary strains of Vibrio cholerae O1 isolated from cholera patients in Kolkata, India.

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Imamura, Daisuke; Morita, Masatomo; Sekizuka, Tsuyoshi; Mizuno, Tamaki; Takemura, Taichiro; Yamashiro, Tetsu; Chowdhury, Goutam; Pazhani, Gururaja P; Mukhopadhyay, Asish K; Ramamurthy, Thandavarayan; Miyoshi, Shin-Ichi; Kuroda, Makoto; Shinoda, Sumio; Ohnishi, Makoto

2017-02-01

Cholera is an acute diarrheal disease and a major public health problem in many developing countries in Asia, Africa, and Latin America. Since the Bay of Bengal is considered the epicenter for the seventh cholera pandemic, it is important to understand the genetic dynamism of Vibrio cholerae from Kolkata, as a representative of the Bengal region. We analyzed whole genome sequence data of V. cholerae O1 isolated from cholera patients in Kolkata, India, from 2007 to 2014 and identified the heterogeneous genomic region in these strains. In addition, we carried out a phylogenetic analysis based on the whole genome single nucleotide polymorphisms to determine the genetic lineage of strains in Kolkata. This analysis revealed the heterogeneity of the Vibrio seventh pandemic island (VSP)-II in Kolkata strains. The ctxB genotype was also heterogeneous and was highly related to VSP-II types. In addition, phylogenetic analysis revealed the shifts in predominant strains in Kolkata. Two distinct lineages, 1 and 2, were found between 2007 and 2010. However, the proportion changed markedly in 2010 and lineage 2 strains were predominant thereafter. Lineage 2 can be divided into four sublineages, I, II, III and IV. The results of this study indicate that lineages 1 and 2-I were concurrently prevalent between 2007 and 2009, and lineage 2-III observed in 2010, followed by the predominance of lineage 2-IV in 2011 and continued until 2014. Our findings demonstrate that the epidemic of cholera in Kolkata was caused by several distinct strains that have been constantly changing within the genetic lineages of V. cholerae O1 in recent years.

Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

Energy Technology Data Exchange (ETDEWEB)

Brettin, Thomas S [Los Alamos National Laboratory; Bruce, David C [Los Alamos National Laboratory; Challacombe, Jean F [Los Alamos National Laboratory; Detter, John C [Los Alamos National Laboratory; Han, Cliff S [Los Alamos National Laboratory; Munik, A C [Los Alamos National Laboratory; Chertkov, Olga [Los Alamos National Laboratory; Meincke, Linda [Los Alamos National Laboratory; Saunders, Elizabeth [Los Alamos National Laboratory; Choi, Seon Y [SEOUL NATL. UNIV.; Haley, Bradd J [U. MARYLAND; Taviani, Elisa [U. MARYLAND; Jeon, Yoon - Seong [INTL. VACCINE INST. SEOUL; Kim, Dong Wook [INTL. VACCINE INST. SEOUL; Lee, Jae - Hak [SEOUL NATL. UNIV.; Walters, Ronald A [PNNL; Hug, Anwar [NATL. INST. CHOLERIC ENTERIC DIS.; Colwell, Rita R [U. MARYLAND

2009-01-01

Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the 6th and the current 7th pandemics, respectively. Cholera researchers continually face newly emerging and re-emerging pathogenic clones carrying combinations of new serogroups as well as of phenotypic and genotypic properties. These genotype and phenotype changes have hampered control of the disease. Here we compare the complete genome sequences of 23 strains of V. cholerae isolated from a variety of sources and geographical locations over the past 98 years in an effort to elucidate the evolutionary mechanisms governing genetic diversity and genesis of new pathogenic clones. The genome-based phylogeny revealed 12 distinct V. cholerae phyletic lineages, of which one, designated the V. cholerae core genome (CG), comprises both O1 classical and EI Tor biotypes. All 7th pandemic clones share nearly identical gene content, i.e., the same genome backbone. The transition from 6th to 7th pandemic strains is defined here as a 'shift' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages within the CG clade. In contrast, transition among clones during the present 7th pandemic period can be characterized as a 'drift' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V.cholerae serogroup O139 and V.cholerae O1 El Tor hybrid clones that produce cholera toxin of classical biotype. Based on the comprehensive comparative genomics presented in this study it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to

[The cholera epidemic in Latin America].

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Olsvik, O

1992-05-30

An outbreak of cholera started in Peru in January 1991 and spread through most Latin American countries within a year. This was the first known epidemic of cholera in America for more than a century. In 1991, 321,334 persons were reported to have cholera in Peru, 119,063 were hospitalized, and 2,906 died. Other countries like Ecuador, Colombia, Guatemala, Brazil, Mexico, Bolivia, Chile, El Salvador, Venezuela and Honduras were also affected, but these countries combined accounted for only 20% of the cases registered in Peru. In April 1992, all Latin American countries except Uruguay, Paraguay and French Guyana have reported cholera. The mortality rate for the epidemic in Latin America was only 1%, mainly owing to good oral rehydration treatment provided by Local health services and the Pan American Health Organization. The causative organism was Vibrio cholerae, serogroup O1, serotype Inaba (and Ogawa) of the El Tor biotype. Genetic characterization shows this strain to be unique, and the designation is reserved for the Latin American strain, distinguishing it from the other El Tor isolates from the 7th pandemic.

Pandemic serotypes of Vibrio cholerae isolated from ships' ballast tanks and coastal waters: assessment of antibiotic resistance and virulence genes (tcpA and ctxA).

Science.gov (United States)

Dobbs, Fred C; Goodrich, Amanda L; Thomson, Frank K; Hynes, Wayne

2013-05-01

There is concern that ships' ballasting operations may disseminate Vibrio cholerae to ports throughout the world. Given evidence that the bacterium is indeed transported by ships, we isolated pandemic serotypes O1 and O139 from ballast tanks and characterized them with respect to antibiotic resistance and virulence genes ctxA and tcpA. We carried out concurrent studies with V. cholerae isolated from coastal waters. Of 284 isolates, 30 were serotype O1 and 59 were serotype O139. These serotypes were overrepresented in ballast tanks relative to the coastal waters sampled. All locations, whether coastal waters or ballast tanks, yielded samples from which serotype O1, O139, or both were isolated. There were three groups among the 62 isolates for which antibiotic characterization was conclusive: those exhibiting β-lactamase activity and resistance to at least one of the 12 antibiotics tested; those negative for β-lactamase but having antibiotic resistance; those negative for β-lactamase and registering no antibiotic resistance. When present, antibiotic resistance in nearly all cases was to ampicillin; resistance to multiple antibiotics was uncommon. PCR assays revealed that none of the isolates contained the ctxA gene and only two isolates, one O139 and one O1, contained the tcpA gene; both isolates originated from ballast water. These results support the bacteriological regulations proposed by the International Maritime Association for discharged ballast water.

[Mexican phenotype and genotype Vibrio cholerae 01].

Science.gov (United States)

Giono, S; Gutiérrez Cogno, L; Rodríguez Angeles, G; del Rio Zolezzi, A; Valdespino González, J L; Sepúlveda Amor, J

1995-01-01

This paper presents the phenotypical and genotypical characterization of 26922 Vibrio cholerae 01 strains isolated in Mexico from 1991 to 1993. All strains isolated were El Tor biovar. Strains were sensitive to antibiotics excluding furazolidone, streptomycin and sulfisoxasole to which we found resistance in 97% and we are using this characteristic as epidemiological markers. We detected a marked change in frequency of Inaba serotype from 1991, when it was dominant, with 99.5%, until 1992 when Ogawa serotype turned to be dominant with 95% of isolates. All Vibrio cholerae 01 strains, except one Ogawa strain, were to igenic, and V. choleraeno 01 were not toxigenic by ELISA, PCR and cell culture tests. Dominant ribotype was 5, but we found some strains with 6a pattern and two with ribotype 12. We are searching for ribotype 2 among hemolytic strains in order to learn if there is any relation to Gulf Coast strains prevalent in the USA, but until now we have not found any V. cholerae ribotype 2 in our isolates. Even if rapid tests are recommended for immediate diagnosis of cholera, it is necessary to continue bacterial isolation in order to have strains for phenotyping and genotyping studies that may support epidemiological analysis.

Immunogenicity of a killed bivalent (O1 and O139 whole cell oral cholera vaccine, Shanchol, in Haiti.

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Richelle C Charles

2014-05-01

Full Text Available Studies of the immunogenicity of the killed bivalent whole cell oral cholera vaccine, Shanchol, have been performed in historically cholera-endemic areas of Asia. There is a need to assess the immunogenicity of the vaccine in Haiti and other populations without historical exposure to Vibrio cholerae.We measured immune responses after administration of Shanchol, in 25 adults, 51 older children (6-17 years, and 47 younger children (1-5 years in Haiti, where cholera was introduced in 2010. A≥4-fold increase in vibriocidal antibody titer against V. cholerae O1 Ogawa was observed in 91% of adults, 74% of older children, and 73% of younger children after two doses of Shanchol; similar responses were observed against the Inaba serotype. A≥2-fold increase in serum O-antigen specific polysaccharide IgA antibody levels against V. cholerae O1 Ogawa was observed in 59% of adults, 45% of older children, and 61% of younger children; similar responses were observed against the Inaba serotype. We compared immune responses in Haitian individuals with age- and blood group-matched individuals from Bangladesh, a historically cholera-endemic area. The geometric mean vibriocidal titers after the first dose of vaccine were lower in Haitian than in Bangladeshi vaccinees. However, the mean vibriocidal titers did not differ between the two groups after the second dose of the vaccine.A killed bivalent whole cell oral cholera vaccine, Shanchol, is highly immunogenic in Haitian adults and children. A two-dose regimen may be important in Haiti, and other populations lacking previous repeated exposures to V. cholerae.

Obtaining of a rapid diagnostic test for Cholera, based on latex particles coupled with a monoclonal antibody against Vibrio cholera O1 lipopolysaccharide

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Fátima Reyes-López

2015-08-01

Full Text Available Cholera is an acute contagious intestinal disease caused by ingestion of food or water contaminated with O1 and O139 serotypes of the bacterium Vibrio cholerae. Cholera is characterized by abundant secretory diarrhea leading to dehydration. Death occurs within hours without treatment, so early diagnosis is very important, especially at the beginning of the disease, because it is difficult to differentiate from other acute diarrheal diseases. The diagnostic golden test is the stool culture; however, it does not guarantee a rapid detection of the disease. Rapid tests have been recently developed; they are based on test strips and agglutination with latex particles, which are very effective, but difficult to acquire for their high prices. The objective of this research was to obtain a quick assay based on latex particles coupled with a monoclonal antibody (mAb against V. cholerae O1 lipopolysaccharide obtained in Finlay Institute. Latex particles of 0.8 µm were used in a 10% suspension, and they were coupled to the mAb (0.25 mg/ml for 2 hours at 37°C. The sensitivity, specificity and performance were evaluated in 84 stool samples from patients with presumptive diagnosis of cholera. The diagnostic test obtained showed no cross-reactivity against no-O1 strains and other enteropathogens. Latex diagnostic test showed values of sensitivity, specificity and efficacy of 97.87; 97.29 and 97.6% respectively, very similar to the commercial diagnostic test CTK- Biotech. The latex reagent obtained can be used in the rapid diagnosis of the disease.

Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

OpenAIRE

Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

1984-01-01

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to thr...

High-frequency rugose exopolysaccharide production by Vibrio cholerae strains isolated in Haiti.

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Mustafizur Rahman

Full Text Available In October, 2010, epidemic cholera was reported for the first time in Haiti in over 100 years. Establishment of cholera endemicity in Haiti will be dependent in large part on the continued presence of toxigenic V. cholerae O1 in aquatic reservoirs. The rugose phenotype of V. cholerae, characterized by exopolysaccharide production that confers resistance to environmental stress, is a potential contributor to environmental persistence. Using a microbiologic medium promoting high-frequency conversion of smooth to rugose (S-R phenotype, 80 (46.5% of 172 V. cholerae strains isolated from clinical and environmental sources in Haiti were able to convert to a rugose phenotype. Toxigenic V. cholerae O1 strains isolated at the beginning of the epidemic (2010 were significantly less likely to shift to a rugose phenotype than clinical strains isolated in 2012/2013, or environmental strains. Frequency of rugose conversion was influenced by incubation temperature and time. Appearance of the biofilm produced by a Haitian clinical rugose strain (altered biotype El Tor HC16R differed from that of a typical El Tor rugose strain (N16961R by confocal microscopy. On whole-genome SNP analysis, there was no phylogenetic clustering of strains showing an ability to shift to a rugose phenotype. Our data confirm the ability of Haitian clinical (and environmental strains to shift to a protective rugose phenotype, and suggest that factors such as temperature influence the frequency of transition to this phenotype.

Genetic and antigenic relationship of foot-and-mouth disease virus serotype O isolates with the vaccine strain O1/BFS.

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Xu, Wanhong; Zhang, Zhidong; Nfon, Charles; Yang, Ming

2018-05-15

Foot-and-mouth disease serotype O viruses (FMDV/O) are responsible for the most outbreaks in FMD endemic countries. O1/BFS is one of the recommended FMD/O vaccine strains by World Reference Laboratory for FMD. In the current study, FMDV/O1 BFS vaccine strain and serotype O field isolates (45) were analyzed phylogenetically and antigenically to gain more insight into the genetic and antigenic characteristics of the vaccine strain and field isolates. O1/BFS showed similarity with 89% of the field isolates using a virus neutralization test (VNT). The P1 region encoding the FMDV capsid was sequenced and analysed for 46 strains of FMDV/O. Phylogenetic analysis showed these viruses originated from five continents and covered eight of 11 reported topotypes. Five isolates that demonstrated low antigenic similarities with O1/BFS were analyzed for their antigenic variation at the known neutralizing antigenic sites. Three of the five isolates demonstrated unique amino acid substitutions at various antigenic sites. No unique amino acid substitutions were observed for the other two unmatched isolates. Positively selected residues were identified on the surface of the FMD virus capsid supporting that it is important to continuously monitor field isolates for their antigenic and phenotypic changes. In conclusion, the vaccine strain O1/BFS is likely to confer protection against 89% of the 45 FMDV/O isolates based on VNT. Thus O1/BFS vaccine strain is still suitable for use in global FMD serotype O outbreak control. Combining data from phylogenetic, molecular and antigenic analysis can provide improvements in the process of vaccine selection. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

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Liliana Candida Dengo-Baloi

Full Text Available Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique.The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics.We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09, Memba (01, Tete City (08, Moatize (01, Morrumbala (01 districts, City of Quelimane (01, Lichinga (06 and Nampula (86 districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health.Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53 to Trimethoprim-, being 100% (54/54 for Ampicillin, 99% (72/74 for Nalidixic Acid, 97% (64/66 to Chloramphenicol, 95% (42/44 for Nitrofurantoin and (19/20 Cotrimoxazole, 83% (80

Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

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Dengo-Baloi, Liliana Candida; Semá-Baltazar, Cynthia Amino; Manhique, Lena Vania; Chitio, Jucunu Elias; Inguane, Dorteia Luísa; Langa, José Paulo

2017-01-01

Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique. The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics. We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09), Memba (01), Tete City (08), Moatize (01), Morrumbala (01) districts, City of Quelimane (01), Lichinga (06) and Nampula (86) districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute) 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health. Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53) to Trimethoprim-, being 100% (54/54) for Ampicillin, 99% (72/74) for Nalidixic Acid, 97% (64/66) to Chloramphenicol, 95% (42/44) for Nitrofurantoin and (19/20) Cotrimoxazole, 83% (80

International dissemination of epidemic Vibrio cholerae by cargo ship ballast and other nonpotable waters.

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McCarthy, S A; Khambaty, F M

1994-07-01

In 1991 and 1992, toxigenic Vibrio cholerae O1, serotype Inaba, biotype El Tor, was recovered from nonpotable (ballast, bilge, and sewage) water from five cargo ships docked in ports of the U.S. Gulf of Mexico. Four of these ships had taken on ballast water in cholera-infected countries; the fifth took on ballast in a noninfected country. Isolates examined by pulsed-field gel electrophoresis were indistinguishable from the Latin American epidemic strain, C6707; however, they differed significantly from the endemic Gulf Coast strain (VRL 1984), the sixth-pandemic strain (569-B), and a V. cholerae non-O1 strain isolated from a ship arriving from a foreign port. On the basis of our findings, the Food and Drug Administration recommended that the U.S. Coast Guard issue an advisory to shipping agents and captains requesting that ballast waters be exchanged on the high seas before entry of ships into U.S. ports.

The increased severity in patients presenting to hospital with diarrhea in Dhaka, Bangladesh since the emergence of the hybrid strain of Vibrio cholerae O1 is not unique to cholera patients.

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Chowdhury, Fahima; Kuchta, Alison; Khan, Ashraful Islam; Faruque, A S G; Calderwood, Stephen B; Ryan, Edward T; Qadri, Firdausi

2015-11-01

A hybrid strain of Vibrio cholerae O1 El Tor that expresses a classical cholera toxin (CT) emerged in 2001. This hybrid variant rapidly replaced the previous El Tor strain around the world. The global emergence of this variant coincided with anecdotal reports that cholera patients were presenting with more severe dehydration and disease in many locations. A comparison was made of the severity of disease before and after the emergence of the hybrid strain in cholera patients attending an icddr,b hospital in Dhaka, Bangladesh. It was found that cholera patients presented with more severe dehydration and severe disease in the later period. However, this was also true for all non-cholera patients as well. In addition, in sub-analyses of patients who presented with rotavirus and enterotoxigenic Escherichia coli (ETEC), similar results were found. Comparing the two periods for differences in patient characteristics, nutritional status, vaccination status, and income, no plausible cause for patients presenting with more severe disease was identified in the later period. As a shift in severity for both cholera and non-cholera was observed, these results indicate that the altered El Tor strain cannot fully explain the difference in cholera severity before and after 2001. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Efficacy of Ciprofloxacin for Treatment of Cholera Associated with Diminished Susceptibility to Ciprofloxacin to Vibrio cholerae O1.

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Khan, Wasif Ali; Saha, Debasish; Ahmed, Sabeena; Salam, Mohammed Abdus; Bennish, Michael Louis

2015-01-01

We identified a poor clinical response to treatment of cholera with a single 1 g dose of ciprofloxacin, a standard treatment for cholera. To determine reasons for the poor response and better therapeutic approaches we examined the minimal inhibitor concentration (MIC, n = 275) and disc-diffusion zone sizes (n = 205) for ciprofloxacin and nalidixic acid of V. cholerae O1 strains isolated in Bangladesh from 1994 to 2012, and reexamined data from 161 patients infected with Vibrio cholerae O1 recruited in four clinical trials who received single- or multiple-dose ciprofloxacin for treatment of cholera and compared their clinical response to the V. cholerae O1 susceptibility. Although all 275 isolates of V. cholerae O1 remained susceptible to ciprofloxacin using standard MIC and disc-diffusion thresholds, the MIC90 to ciprofloxacin increased from 0.010 in 1994 to 0.475 μgm/ml in 2012. Isolates became frankly resistant to nalidixic with the MIC90 increasing from 21 μgm/ml in 1994 to >256 μgm/ml and 166 of 205 isolates from 1994 to 2005 being frankly resistant using disc-diffusion testing. Isolates resistant to nalidixic acid by disc-diffusion testing had a median ciprofloxacin MIC of 0.190 μgm/ml (10th-90th centiles 0.022 to 0.380); nalidixic acid-susceptible isolates had a median ciprofloxacin MIC of 0.002 (0.002 to 0.012).The rate of clinical success with single-dose ciprofloxacin treatment for nalidixic acid-susceptible strains was 94% (61 of 65 patients) and bacteriologic success 97% (63/65) compared to 18% (12/67) and 8% (5/67) respectively with nalidixic acid-resistant strains (Ptreatment with ciprofloxacin had 86% and 100% clinical and bacteriologic success rates respectively in patients infected with nalidixic acid-susceptible strains of V. cholerae O1 compared to clinical success 67% and bacteriologic success 60% with nalidixic acid-resistant strains. Single-dose ciprofloxacin is not effective for treating cholera caused by V. cholerae O1 with diminished

Vibrio cholerae classical biotype strains reveal distinct signatures in Mexico.

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Alam, Munirul; Islam, M Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R; Cravioto, Alejandro

2012-07-01

Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 1991 and 1997. In this study, CL biotype strains isolated from areas of cholera endemicity in Mexico between 1983 and 1997 were characterized in terms of major phenotypic and genetic traits and compared with CL biotype strains isolated in Bangladesh between 1962 and 1989. According to sero- and biotyping data, all V. cholerae strains tested had the major phenotypic and genotypic characteristics specific for the CL biotype. Antibiograms revealed the majority of the Bangladeshi strains to be resistant to trimethoprim-sulfamethoxazole, furazolidone, ampicillin, and gentamicin, while the Mexican strains were sensitive to all of these drugs, as well as to ciprofloxacin, erythromycin, and tetracycline. Pulsed-field gel electrophoresis (PFGE) of NotI-digested genomic DNA revealed characteristic banding patterns for all of the CL biotype strains although the Mexican strains differed from the Bangladeshi strains in 1 to 2 DNA bands. The difference was subtle but consistent, as confirmed by the subclustering patterns in the PFGE-based dendrogram, and can serve as a regional signature, suggesting the pre-1991 existence and evolution of the CL biotype strains in the Americas, independent from Asia.

OmpU as a biomarker for rapid discrimination between toxigenic and epidemic Vibrio cholerae O1/O139 and non-epidemic Vibrio cholerae in a modified MALDI-TOF MS assay

NARCIS (Netherlands)

Paauw, A.; Trip, H.; Niemcewicz, M.; Sellek, R.; Heng, J.M.E.; Mars-Groenendijk, R.H.; Jong, A.L. de; Majchrzykiewicz-Koehorst, J.A.; Olsen, J.S.; Tsivtsivadze, E.

2014-01-01

Background Cholera is an acute diarrheal disease caused by Vibrio cholerae. Outbreaks are caused by a genetically homogenous group of strains from serogroup O1 or O139 that are able to produce the cholera toxin. Rapid detection and identification of these epidemic strains is essential for an

Culture supernatants from V. cholerae O1 El Tor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity.

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Vidal, Jorge E; Enríquez-Rincón, Fernando; Giono-Cerezo, Silvia; Ribas-Aparicio, Rosa María; Figueroa-Arredondo, Paula

2009-01-01

To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+) and a non-toxigenic Mexican strain (CM 91-3, ctxAB-). Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.

Vibrio parahaemolyticus Strains of Pandemic Serotypes Identified from Clinical and Environmental Samples from Jiangsu, China

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Jingjiao eLi

2016-05-01

Full Text Available Vibrio parahaemolyticus has emerged as a major foodborne pathogen in China, Japan, Thailand and other Asian countries. In this study, 72 strains of V. parahaemolyticus were isolated from clinical and environmental samples between 2006 and 2014 in Jiangsu, China. The serotypes and six virulence genes including thermostable direct hemolysin (TDR and TDR-related hemolysin (TRH genes were assessed among the isolates. Twenty five serotypes were identified and O3:K6 was one of the dominant serotypes. The genetic diversity was assessed by multilocus sequence typing (MLST analysis, and 48 sequence types (STs were found, suggesting this V. parahaemolyticus group is widely dispersed and undergoing rapid evolution. A total of 25 strains of pandemic serotypes such as O3:K6, O5:K17 and O1:KUT were identified. It is worth noting that the pandemic serotypes were not exclusively identified from clinical samples, rather, nine strains were also isolated from environmental samples; and some of these strains harbored several virulence genes, which may render those strains pathogenicity potential. Therefore, the emergence of these environmental pandemic V. parahaemolyticus strains may poses a new threat to the public health in China. Furthermore, six novel serotypes and 34 novel STs were identified among the 72 isolates, indicating that V. parahaemolyticus were widely distributed and fast evolving in the environment in Jiangsu, China. The findings of this study provide new insight into the phylogenic relationship between V. parahaemolyticus strains of pandemic serotypes from clinical and environmental sources and enhance the MLST database; and our proposed possible O- and K- antigen evolving paths of V. parahaemolyticus may help understand how the serotypes of this dispersed bacterial population evolve.

Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008

OpenAIRE

Choi, Seon Young; Rashed, Shah M.; Hasan, Nur A.; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Ravel, Jacques; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R.

2016-01-01

ABSTRACT An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX?) V.?cholerae El Tor dominated toxigenic (CTX+) strains (2001 to 2003), but V.?cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX? V.?cholerae. Genomes of six Mexican V.?cholerae O1 strains isolated during...

Whole-genome sequence of Escherichia coli serotype O157:H7 strain B6914-ARS

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Escherichia coli serotype O157:H7 strain B6914-MS1 is a Shiga toxin-deficient human fecal isolate obtained by the Centers for Disease Control and Prevention that has been used extensively in applied research studies. Here we report the genome sequence of strain B6914-ARS, a B6914-MS1 clone that has ...

Genetic and antigenic characterization of serotype O FMD viruses from East Africa for the selection of suitable vaccine strain.

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Lloyd-Jones, Katie; Mahapatra, Mana; Upadhyaya, Sasmita; Paton, David J; Babu, Aravindh; Hutchings, Geoff; Parida, Satya

2017-12-14

Foot-and-mouth disease (FMD) is endemic in Eastern Africa with circulation of multiple serotypes of the virus in the region. Most of the outbreaks are caused by serotype O followed by serotype A. The lack of concerted FMD control programmes in Africa has provided little incentive for vaccine producers to select vaccines that are tailored to circulating regional isolates creating further negative feedback to deter the introduction of vaccine-based control schemes. In this study a total of 80 serotype O FMD viruses (FMDV) isolated from 1993 to 2012 from East and North Africa were characterized by virus neutralisation tests using bovine antisera to three existing (O/KEN/77/78, O/Manisa and O/PanAsia-2) and three putative (O/EA/2002, O/EA/2009 and O/EA/2010) vaccine strains and by capsid sequencing. Genetically, these viruses were grouped as either of East African origin with subdivision into four topotypes (EA-1, 2, 3 and 4) or of Middle-East South Asian (ME-SA) topotype. The ME-SA topotype viruses were mainly detected in Egypt and Libya reflecting the trade links with the Middle East countries. There was good serological cross-reactivity between the vaccine strains and most of the field isolates analysed, indicating that vaccine selection should not be a major constraint for control of serotype O FMD by vaccination, and that both local and internationally available commercial vaccines could be used. The O/KEN/77/78 vaccine, commonly used in the region, exhibited comparatively lower percent in vitro match against the predominant topotypes (EA-2 and EA-3) circulating in the region whereas O/PanAsia-2 and O/Manisa vaccines revealed broader protection against East African serotype O viruses, even though they genetically belong to the ME-SA topotype. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

[VNTR-genotyping of Vibrio cholerae strains isolated from objects in the territory of Russian Federation in 2012].

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Vodop'ianov, A S; Mazrukho, A B; Vodop'ianov, S O; Mishan'kin, B N; Kruglikov, V D; Apkhangel'skaia, I V; Oleĭnikov, I P; Zubkova, D A; Monakhova, E V; Grigorenko, L V

2014-01-01

VNTR-typing of Vibrio cholerae strains isolated in the territory of Russian Federation in 2012. 71 Vibrio cholerae O3 and 3 V cholerae O1/O139 strains were used in the study. Genotyping was performed by using PCR for 5 VNTR-loci. Multilocus VNTR-typing allowed to group the strains into 31 VNTR-genotypes. Genotypes were divided among 10 discrete clusters by results of a cluster analysis. The presence of tcpA gene is clearly linked with the presence of VcB locus. Each geographic region was characterized by their own VNTR-genotypes. In the course of the carried out VNTR-genotyping of V. cholerae isolated in 2012, 2 types of vibrio population formation were detected. A geographic attachment to specific regions was characteristic for most of the genotypes.

[Phenotypic diversity of toxigenic Vibrio cholerae O1 El Tor strains identified in China].

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Zhao, Xuan; Zhang, Li; Li, Jie; Kan, Biao; Liang, Weili

2014-05-01

To understand the phenotypic diversity of toxigenic Vibrio cholerae O1 El Tor strains isolated from different provinces in China during the last 50 years. Traditional biotyping testings including susceptibility to polymyxin B, sensitivity to group IV phage, Voges-Proskauer test and haemolysis of sheep erythrocytes were conducted. Data 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. Toxigenic 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.

Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea

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Pacheco, Juan M.; Lee, Kwang-Nyeong; Eschbaumer, Michael; Bishop, Elizabeth A.; Hartwig, Ethan J.; Pauszek, Steven J.; Smoliga, George R.; Kim, Su-Mi; Park, Jong-Hyeon; Ko, Young-Joon; Lee, Hyang-Sim; Tark, Dongseob; Cho, In-Soo; Kim, Byounghan; Rodriguez, Luis L.; Arzt, Jonathan

2016-01-01

Since the early 2000s outbreaks of foot-and-mouth disease (FMD) have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea). One outbreak with FMD virus (FDMV) serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain of serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic. PMID:26735130

[Phylogenetic analysis of genomes of Vibrio cholerae strains isolated on the territory of Rostov region].

Science.gov (United States)

Kuleshov, K V; Markelov, M L; Dedkov, V G; Vodop'ianov, A S; Kermanov, A V; Pisanov, R V; Kruglikov, V D; Mazrukho, A B; Maleev, V V; Shipulin, G A

2013-01-01

Determination of origin of 2 Vibrio cholerae strains isolated on the territory of Rostov region by using full genome sequencing data. Toxigenic strain 2011 EL- 301 V. cholerae 01 El Tor Inaba No. 301 (ctxAB+, tcpA+) and nontoxigenic strain V. cholerae O1 Ogawa P- 18785 (ctxAB-, tcpA+) were studied. Sequencing was carried out on the MiSeq platform. Phylogenetic analysis of the genomes obtained was carried out based on comparison of conservative part of the studied and 54 previously sequenced genomes. 2011EL-301 strain genome was presented by 164 contigs with an average coverage of 100, N50 parameter was 132 kb, for strain P- 18785 - 159 contigs with a coverage of69, N50 - 83 kb. The contigs obtained for strain 2011 EL-301 were deposited in DDBJ/EMBL/GenBank databases with access code AJFN02000000, for strain P-18785 - ANHS00000000. 716 protein-coding orthologous genes were detected. Based on phylogenetic analysis strain P- 18785 belongs to PG-1 subgroup (a group of predecessor strains of the 7th pandemic). Strain 2011EL-301 belongs to groups of strains of the 7th pandemic and is included into the cluster with later isolates that are associated with cases of cholera in South Africa and cases of import of cholera to the USA from Pakistan. The data obtained allows to establish phylogenetic connections with V cholerae strains isolated earlier.

Serological characterization of Actinobacillus pleuropneumoniae biotype 1 strains antigenically related to both serotypes 2 and 7

DEFF Research Database (Denmark)

Nielsen, R.; Andresen, Lars Ole; Plambeck, Tamara

1996-01-01

Nine Danish Actinobacillus pleuropneumoniae biotype 1 isolates were shown by latex agglutination and indirect haemagglutination to possess capsular polysaccharide epitopes identical to those of serotype 2 strain 1536 (reference strain of serotype 2) and strain 4226 (Danish serotype 2 strain). Imm...... in the LPS of strains 1536 and 7317 were revealed. Since an antigenic determinant specific for the 9 isolates could not be demonstrated with the methods used, the strains are proposed to be designated K2:O7....

[Antibiotic resistance pattern of 24, 526 strains of Vibrio cholerae O1 isolated in Mexico from 1991 to 1993].

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Giono-Cerezo, S; Zárate, A; Gutiérrez, L; Valdespino, J L

1994-01-01

Profile of antimicrobial resistance by Kirby-Bauer method was performed on 24526 Vibrio cholerae O1 strains isolated in México (1991-1993) from fecal swabs in cholera cases and from asymptomatic carriers. Minimal inhibitory concentration (MIC) tests for tetracycline (Te) and doxycycline (D) were done on selected strains. Single antibiotic discs were used at concentrations of: Te, 30 micrograms; D, 30 micrograms; erythromycin (E), 15 micrograms; chloramphenicol (CM), 30 micrograms; ampicillin (AM), 10 micrograms; trimethoprim-sulfamethoxazole (SXT) 1.25 micrograms/23.75 micrograms. Strains whose halos were of a smaller diameter than the intermediate value were considered resistant. It is important to maintain surveillance on antimicrobial susceptibility as epidemiological marker on geographical selected areas in order to detect changes of resistant patterns.

Prevalence of Vibrio cholerae O1 serogroup in Assam, India: A hospital-based study.

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Sharma, Ajanta; Dutta, Bornali Sarmah; Rasul, Elmy Samsun; Barkataki, Dipa; Saikia, Anjanamoyee; Hazarika, Naba Kumar

2017-09-01

Although cholera remains to be an important public health problem, studies on reliable population-based estimates of laboratory confirmed cholera in endemic areas are limited worldwide. The aim of this hospital-based study was to evaluate the prevalence of Vibrio cholerae serogroup in Assam, India, during 2003-2013. Stool samples/rectal swabs were collected from acute watery diarrhoea (AWD) cases during 2003-2013 and processed by standard microbiological procedures. Antibiotic sensitivity test was done following the Clinical and Laboratory Standards Institute guidelines. Year-wise epidemiological trend of cholera was analyzed. Cholera contributed to 3.93 per cent of AWD cases. In Assam, cholera was found to be more prevalent in the rural areas (6.7%) followed by the tea gardens (5.06%), urban slum (1.9%) and urban areas (1.4%). Highest proportion of cholera (13.7%) was observed in 0-10 yr age group. Of them, 11.5 per cent belonged to 0-5 yr age group. V. cholerae O1 El Tor serotype Ogawa was the predominant isolate. Multiple drug-resistant isolates of V. cholerae O1 Ogawa were reported in the study. Emergence of resistance amongst V. cholerae towards many antibiotics is a matter of concern. Hence, continuous surveillance for diarrhoeal disorders is necessary to control the future outbreaks of cholera in this region.

The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters

DEFF Research Database (Denmark)

Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca

2015-01-01

. aeruginosa O12 OSA gene cluster, an antibiotic resistance determinant (gyrAC248T), and other genes that have been transferred between P. aeruginosa strains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related to P...... in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how the P. aeruginosa OSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83 P....... aeruginosa strains and their serotypes. While most serotypes were closely linked to the core genome phylogeny, we observed horizontal exchange of OSA biosynthesis genes among phylogenetically distinct P. aeruginosa strains. Specifically, we identified a "serotype island" ranging from 62 kb to 185 kb containing the P...

Genetic characterization of ØVC8 lytic phage for Vibrio cholerae O1.

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Solís-Sánchez, Alejandro; Hernández-Chiñas, Ulises; Navarro-Ocaña, Armando; De la Mora, Javier; Xicohtencatl-Cortes, Juan; Eslava-Campos, Carlos

2016-03-22

Epidemics and pandemics of cholera, a diarrheal disease, are attributed to Vibrio cholera serogroups O1 and O139. In recent years, specific lytic phages of V. cholera have been proposed to be important factors in the cyclic occurrence of cholera in endemic areas. However, the role and potential participation of lytic phages during long interepidemic periods of cholera in non-endemic regions have not yet been described. The purpose of this study was to isolate and characterize specific lytic phages of V. cholera O1 strains. Sixteen phages were isolated from wastewater samples collected at the Endhó Dam in Hidalgo State, Mexico, concentrated with PEG/NaCl, and purified by density gradient. The lytic activity of the purified phages was tested using different V. cholerae O1 and O139 strains. Phage morphology was visualized by transmission electron microscopy (TEM), and phage genome sequencing was performed using the Genome Analyzer IIx System. Genome assembly and bioinformatics analysis were performed using a set of high-throughput programs. Phage structural proteins were analyzed by mass spectrometry. Sixteen phages with lytic and lysogenic activity were isolated; only phage ØVC8 showed specific lytic activity against V. cholerae O1 strains. TEM images of ØVC8 revealed a phage with a short tail and an isometric head. The ØVC8 genome comprises linear double-stranded DNA of 39,422 bp with 50.8 % G + C. Of the 48 annotated ORFs, 16 exhibit homology with sequences of known function and several conserved domains. Bioinformatics analysis showed multiple conserved domains, including an Ig domain, suggesting that ØVC8 might adhere to different mucus substrates such as the human intestinal epithelium. The results suggest that ØVC8 genome utilize the "single-stranded cohesive ends" packaging strategy of the lambda-like group. The two structural proteins sequenced and analyzed are proteins of known function. ØVC8 is a lytic phage with specific activity against V. cholerae

Comparative genomic analysis of Vibrio parahaemolyticus: serotype conversion and virulence

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Gil Ana I

2011-06-01

Full Text Available Abstract Background Vibrio parahaemolyticus is a common cause of foodborne disease. Beginning in 1996, a more virulent strain having serotype O3:K6 caused major outbreaks in India and other parts of the world, resulting in the emergence of a pandemic. Other serovariants of this strain emerged during its dissemination and together with the original O3:K6 were termed strains of the pandemic clone. Two genomes, one of this virulent strain and one pre-pandemic strain have been sequenced. We sequenced four additional genomes of V. parahaemolyticus in this study that were isolated from different geographical regions and time points. Comparative genomic analyses of six strains of V. parahaemolyticus isolated from Asia and Peru were performed in order to advance knowledge concerning the evolution of V. parahaemolyticus; specifically, the genetic changes contributing to serotype conversion and virulence. Two pre-pandemic strains and three pandemic strains, isolated from different geographical regions, were serotype O3:K6 and either toxin profiles (tdh+, trh- or (tdh-, trh+. The sixth pandemic strain sequenced in this study was serotype O4:K68. Results Genomic analyses revealed that the trh+ and tdh+ strains had different types of pathogenicity islands and mobile elements as well as major structural differences between the tdh pathogenicity islands of the pre-pandemic and pandemic strains. In addition, the results of single nucleotide polymorphism (SNP analysis showed that 94% of the SNPs between O3:K6 and O4:K68 pandemic isolates were within a 141 kb region surrounding the O- and K-antigen-encoding gene clusters. The "core" genes of V. parahaemolyticus were also compared to those of V. cholerae and V. vulnificus, in order to delineate differences between these three pathogenic species. Approximately one-half (49-59% of each species' core genes were conserved in all three species, and 14-24% of the core genes were species-specific and in different

Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008.

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Choi, Seon Young; Rashed, Shah M; Hasan, Nur A; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Ravel, Jacques; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R

2016-03-15

An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX(-)) V. cholerae El Tor dominated toxigenic (CTX(+)) strains (2001 to 2003), but V. cholerae CTX(+) variant El Tor was isolated during 2004 to 2008, outcompeting CTX(-) V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX(+) El Tor, two were CTX(-) El Tor, and the remaining strain was a CTX(+) classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX(-) isolate is ancestral to the 6th and 7th pandemic CTX(+) V. cholerae isolates. The other CTX(-) isolate joined with CTX(-) non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX(+) isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX(+) El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II) are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX(+) El Tor isolate contained West African-South American (WASA) recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs) and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity. Sequencing of genomes of V. cholerae is critical if genetic changes occurring over time in the circulating population of an area of endemicity are to be understood. Although cholera outbreaks occurred rarely

Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008

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Seon Young Choi

2016-03-01

Full Text Available An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997. Nontoxigenic (CTX− V. cholerae El Tor dominated toxigenic (CTX+ strains (2001 to 2003, but V. cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX−V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX+ El Tor, two were CTX− El Tor, and the remaining strain was a CTX+ classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX− isolate is ancestral to the 6th and 7th pandemic CTX+V. cholerae isolates. The other CTX− isolate joined with CTX− non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX+ isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX+ El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX+ El Tor isolate contained West African-South American (WASA recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity.

O-serotyping of Escherichia coli Strains isolated from Patients With Urinary Tract Infection in Southeast of Iran

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Ahmad Rashki

2014-11-01

Full Text Available Background: Uropathogenic Escherichia coli (UPEC O-serogroups with their phylogenetic background are the most prevalent causes of urinary tract infections (UTIs. Objectives: The association of O types with phylogenetic background was assessed among E. coli isolates collected from patients with UTI. Patients and Methods: In this study, 186 patients with UTI, referred to two hospitals affiliated to Zabol University of Medical Sciences in southeast of Iran, were enrolled during January to July 2013. Phylogenetic groups and serotyping were performed using multiplex-PCR method. Results: A total of 100 E. coli strains were isolated from the urine samples. The most common types of O antigens were O2 (16.43%, O6 (16.43% and O18 (13.69%. The phylogenetic analysis showed that 63 O-antigen-positive isolates were mainly segregated from the phylogenetic group B2 (56% and the substantial prevalence (30% belonged to the phylogenetic group D. Conclusions: This was the first report of E. coli serotyping in patient with UTI from southeast of Iran as well as investigation of their relation with phylogenetic pattern by multiplex-PCR. Further studies from other parts of Iran and on other serotypes are recommended.

Water sources as reservoirs of Vibrio cholerae O1 and non-O1 strains in Bepanda, Douala (Cameroon): relationship between isolation and physico-chemical factors.

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Akoachere, Jane-Francis Tatah Kihla; Mbuntcha, Christelle Kwedjeu Pulcherie

2014-07-30

Cholera has been endemic in Douala since 1971. Most outbreaks start from Bepanda, an overcrowded neighbourhood with poor hygiene and sanitary conditions. We investigated water sources in Bepanda as reservoirs of Vibrio cholerae, the causative agent of cholera, determined its antibiotic susceptibility and some physico-chemical characteristics that could maintain the endemicity of this organism in Bepanda. Three hundred and eighteen water samples collected from 45 wells, 8 taps and 1 stream from February to July 2009 were analyzed for V. cholerae using standard methods. Isolates were characterized morphologically, biochemically and serologically. The disc diffusion technique was employed to investigate antibiotic susceptibility. Differences in prevalence of organism between seasons were analysed. Correlation strength and direction of association between physico-chemical parameters and occurrence of V. cholerae was analyzed using the Kendall tau_b non-parametric correlation. This was further confirmed with the forward-stepwise binary logistic regression. Eighty-seven (27.4%) samples were positive for V. cholerae. Isolation was highest from wells. The organism was isolated in the rainy season and dry season but the frequency of isolation was significantly higher (χ2 = 7.009, df = 1, P = 0.008) in the rainy season. Of the 96 confirmed V. cholerae isolates, 32 (33.3%) belonged to serogroup O1 and 64 (66.6%) were serogroup non-O1/non-O139. Isolates from tap (municipal water) were non-O1/non-O139 strains. Salinity had a significant positive correlation with isolation in the dry season (+0.267, P = 0.015) and rainy season (+0.223, P = 0.028). The forward-stepwise method of binary logistic regression indicated that as pH (Wald = 11.753, df = 1), P = 0.001) increased, odds of isolation of V. cholerae also increased (B = 1.297, S.E = 0.378, Exp(B) = 3.657). All isolates were sensitive to ciprofloxacin and ofloxacin. Multi-drug resistance was predominant among the non-O1/non-O

Avian cholera

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Friend, Milton

1999-01-01

Avian cholera is a contagious disease resulting from infection by the bacterium Pasteurella multocida. Several subspecies of bacteria have been proposed for P. multocida, and at least 16 different P. multocida serotypes or characteristics of antigens in bacterial cells that differentiate bacterial variants from each other have been recognized. The serotypes are further differentiated by other methods, including DNA fingerprinting. These evaluations are useful for studying the ecology of avian cholera (Fig. 7.1), because different serotypes are generally found in poultry and free-ranging migratory birds. These evaluations also show that different P. multocida serotypes are found in wild birds in the eastern United States than those that are found in the birds in the rest of the Nation (Fig. 7.2).

Misidentification of Vibrio cholerae O155 isolated from imported shrimp as O serogroup O139 due to cross-agglutination with commercial O139 antisera

DEFF Research Database (Denmark)

Dalsgaard, A.; Mazur, J.; Dalsgaard, Inger

2002-01-01

. The strain contained two plasmids, in contrast to other O139 strains, which normally do not contain plasmids. The characteristics of the strain led to further agglutination testing with other antisera that are not commercially available, and the strain was found to agglutinate O155 antiserum in repeated...... was isolated from imported raw frozen shrimp. The toxigenicity of the strain was analyzed, and the results of a polymerase chain reaction showed that the V. cholerae strain did not contain the virulence genes ctx, tcp9, and zot, which are normally found in V. cholerae O1 and O139. The strain was resistant...... to colistin and spectinomycin. The high susceptibility of the strain to antimicrobial agents was confirmed by the lack of an SXT element, a self-transmissible, chromosomal genetic element that is normally present in O139 strains and encodes resistance to sulfonamides, trimethoprim, and streptomycin...

Culture supernatants from V. cholerae O1 ElTor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity Cepas de V. cholerae O1 biotipo ElTor aisladas de diferente origen geográfico inducen vacuolización celular y citotoxicidad

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Jorge E Vidal

2009-02-01

Full Text Available OBJECTIVE: To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. MATERIAL AND METHODS: Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. RESULTS: All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+ and a non-toxigenic Mexican strain (CM 91-3, ctxAB-. Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. CONCLUSION: The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.OBJETIVO: Analizar el efecto vacuolizante de cepas de V. cholerae O1 ElTor aisladas de diferente origen geográfico, incluyendo México. MATERIAL Y MÉTODOS: Se realizaron pruebas de hemolisis, vacuolización y citotoxicidad en células Vero, así como PCR, análisis por RFLP y clonación molecular. RESULTADOS: Todas las cepas indujeron el efecto vacuolizante. Las cepas del ribotipo 2, aisladas de las costas del Golfo en Estados Unidos, presentaron títulos altos de vacuolización. El gen hlyA fue amplificado en las nueve cepas mediante PCR, aunque sólo ocho fueron hemolíticas. Se clonó el gen hlyA de una cepa toxigénica (2514-88, ctxAB+ y de una cepa no toxigénica aislada en México (CM 91-3, ctxAB-. El sobrenadante de las clonas recombinantes indujo hemólisis, efecto vacuolizante y citotoxicidad. El RFLP mostró alta similitud del gen hlyA de las cepas estudiadas. CONCLUSIÓN: El efecto vacuolizante es un

Molecular insights into the evolutionary pathway of Vibrio cholerae O1 atypical El Tor variants.

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Kim, Eun Jin; Lee, Dokyung; Moon, Se Hoon; Lee, Chan Hee; Kim, Sang Jun; Lee, Jae Hyun; Kim, Jae Ouk; Song, Manki; Das, Bhabatosh; Clemens, John D; Pape, Jean William; Nair, G Balakrish; Kim, Dong Wook

2014-09-01

Pandemic V. cholerae strains in the O1 serogroup have 2 biotypes: classical and El Tor. The classical biotype strains of the sixth pandemic, which encode the classical type cholera toxin (CT), have been replaced by El Tor biotype strains of the seventh pandemic. The prototype El Tor strains that produce biotype-specific cholera toxin are being replaced by atypical El Tor variants that harbor classical cholera toxin. Atypical El Tor strains are categorized into 2 groups, Wave 2 and Wave 3 strains, based on genomic variations and the CTX phage that they harbor. Whole-genome analysis of V. cholerae strains in the seventh cholera pandemic has demonstrated gradual changes in the genome of prototype and atypical El Tor strains, indicating that atypical strains arose from the prototype strains by replacing the CTX phages. We examined the molecular mechanisms that effected the emergence of El Tor strains with classical cholera toxin-carrying phage. We isolated an intermediary V. cholerae strain that carried two different CTX phages that encode El Tor and classical cholera toxin, respectively. We show here that the intermediary strain can be converted into various Wave 2 strains and can act as the source of the novel mosaic CTX phages. These results imply that the Wave 2 and Wave 3 strains may have been generated from such intermediary strains in nature. Prototype El Tor strains can become Wave 3 strains by excision of CTX-1 and re-equipping with the new CTX phages. Our data suggest that inter-chromosomal recombination between 2 types of CTX phages is possible when a host bacterial cell is infected by multiple CTX phages. Our study also provides molecular insights into population changes in V. cholerae in the absence of significant changes to the genome but by replacement of the CTX prophage that they harbor.

The Mobilome; A Major Contributor to Escherichia coli stx2-Positive O26:H11 Strains Intra-Serotype Diversity

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Sabine Delannoy

2017-09-01

Full Text Available Shiga toxin-producing Escherichia coli of serotype O26:H11/H- constitute a diverse group of strains and several clones with distinct genetic characteristics have been identified and characterized. Whole genome sequencing was performed using Illumina and PacBio technologies on eight stx2-positive O26:H11 strains circulating in France. Comparative analyses of the whole genome of the stx2-positive O26:H11 strains indicate that several clones of EHEC O26:H11 are co-circulating in France. Phylogenetic analysis of the French strains together with stx2-positive and stx-negative E. coli O26:H11 genomes obtained from Genbank indicates the existence of four clonal complexes (SNP-CCs separated in two distinct lineages, one of which comprises the “new French clone” (SNP-CC1 that appears genetically closely related to stx-negative attaching and effacing E. coli (AEEC strains. Interestingly, the whole genome SNP (wgSNP phylogeny is summarized in the cas gene phylogeny, and a simple qPCR assay targeting the CRISPR array specific to SNP-CC1 (SP_O26-E can distinguish between the two main lineages. The PacBio sequencing allowed a detailed analysis of the mobile genetic elements (MGEs of the strains. Numerous MGEs were identified in each strain, including a large number of prophages and up to four large plasmids, representing overall 8.7–19.8% of the total genome size. Analysis of the prophage pool of the strains shows a considerable diversity with a complex history of recombination. Each clonal complex (SNP-CC is characterized by a unique set of plasmids and phages, including stx-prophages, suggesting evolution through separate acquisition events. Overall, the MGEs appear to play a major role in O26:H11 intra-serotype clonal diversification.

The Mobilome; A Major Contributor to Escherichia coli stx2-Positive O26:H11 Strains Intra-Serotype Diversity.

Science.gov (United States)

Delannoy, Sabine; Mariani-Kurkdjian, Patricia; Webb, Hattie E; Bonacorsi, Stephane; Fach, Patrick

2017-01-01

Shiga toxin-producing Escherichia coli of serotype O26:H11/H- constitute a diverse group of strains and several clones with distinct genetic characteristics have been identified and characterized. Whole genome sequencing was performed using Illumina and PacBio technologies on eight stx2 -positive O26:H11 strains circulating in France. Comparative analyses of the whole genome of the stx2 -positive O26:H11 strains indicate that several clones of EHEC O26:H11 are co-circulating in France. Phylogenetic analysis of the French strains together with stx2 -positive and stx -negative E. coli O26:H11 genomes obtained from Genbank indicates the existence of four clonal complexes (SNP-CCs) separated in two distinct lineages, one of which comprises the "new French clone" (SNP-CC1) that appears genetically closely related to stx -negative attaching and effacing E. coli (AEEC) strains. Interestingly, the whole genome SNP (wgSNP) phylogeny is summarized in the cas gene phylogeny, and a simple qPCR assay targeting the CRISPR array specific to SNP-CC1 (SP_O26-E) can distinguish between the two main lineages. The PacBio sequencing allowed a detailed analysis of the mobile genetic elements (MGEs) of the strains. Numerous MGEs were identified in each strain, including a large number of prophages and up to four large plasmids, representing overall 8.7-19.8% of the total genome size. Analysis of the prophage pool of the strains shows a considerable diversity with a complex history of recombination. Each clonal complex (SNP-CC) is characterized by a unique set of plasmids and phages, including stx -prophages, suggesting evolution through separate acquisition events. Overall, the MGEs appear to play a major role in O26:H11 intra-serotype clonal diversification.

Surface antigens contribute differently to the pathophysiological features in serotype K1 and K2 Klebsiella pneumoniae strains isolated from liver abscesses.

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Yeh, Kuo-Ming; Chiu, Sheng-Kung; Lin, Chii-Lan; Huang, Li-Yueh; Tsai, Yu-Kuo; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Siu, Leung-Kei

2016-01-01

The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver. Both of K1 and K2-antigen mutants lost their wildtype resistance to neutrophil phagocytosis and hepatic clearance, and failed to cause abscess formation. K2-antigen mutant became serum susceptible while K1-antigen mutant maintained its resistance to serum killing. The amount of glucuronic acid, indicating the amount of capsular polysaccharide (CPS, K antigen), was inversed proportional to the rate of phagocytosis. O-antigen mutant of serotype K1 strains had significantly more amount of CPS, and more resistant to neutrophil phagocytosis than its wildtype counterpart. O-antigen mutants of serotype K1 and K2 strains lost their wildtype serum resistance, and kept resistant to neutrophil phagocytosis. While both mutants lacked the same O1 antigen, O-antigen mutant of serotype K1 became susceptible to liver clearance and cause mild abscess formation, but its serotype K2 counterpart maintained these wildtype virulence. We conclude that the contribution of surface antigens to virulence of K. pneumoniae strains varies with serotypes.

Isolation of Vibrio cholera El Tor Inaba From Lemna minor and Eichhornia crassipens Roots in Veracruz, Mexico

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Cordoba Aguilar, Edgar; Herrera Rivero, Marisol; Rubi, Alberto; Arroyo-Helguera, Omar; Coutino Rodriguez, Rocio

2014-01-01

Background: During epidemic periods, the strain Vibrio cholera El Tor has been isolated from the aquatic macrophyte roots of Eichhornia crassipens and Lemna minor, suggesting that aquatic plants could be environmental reservoirs through either a non-specific association or a commensalism relationship. Therefore, it is important to understand V. cholera reservoirs in order to establish prevention strategies against this pathogen. Objectives: Our interest was to determine whether V. cholera could be isolated and typified from L. minor and E. crassipens roots. Materials and Methods: From 2004 to 2005, plants were collected from various ecological niches and the roots were used to isolate V. cholera. Standard bacteriological, biochemical and serological tests were used for its typification. Results: In five out of the nine ecological niches explored, we collected either L. minor or E. crassipens, as these specimens cohabited only in two niches. V. cholera was isolated from both L. minor and E. crassipens roots. The isolated V. cholera showed the same biochemical characteristics as the pure V. cholera strain which was used as a control. The isolated V. cholera corresponded to V. cholera O1 El Tor Inaba, which is the same serotype related to the last outbreak in Mexico. Conclusions: For first time V. cholera El Tor Inaba has been isolated several years after the last emergence of cholera in Mexico. A viable and cultivable V. cholera strain, sourced from freshwater niches in E. crassipens and L. minor roots, suggests the importance of these plants as a permanent aquatic reservoir for these organisms. The monitoring of E. crassipens and L. minor is the responsibility of health institutions in order to evaluate the ongoing risks. PMID:25147681

Isolation of Vibrio cholera El Tor Inaba From Lemna minor and Eichhornia crassipens Roots in Veracruz, Mexico.

Science.gov (United States)

Cordoba Aguilar, Edgar; Herrera Rivero, Marisol; Rubi, Alberto; Arroyo-Helguera, Omar; Coutino Rodriguez, Rocio

2014-03-01

During epidemic periods, the strain Vibrio cholera El Tor has been isolated from the aquatic macrophyte roots of Eichhornia crassipens and Lemna minor, suggesting that aquatic plants could be environmental reservoirs through either a non-specific association or a commensalism relationship. Therefore, it is important to understand V. cholera reservoirs in order to establish prevention strategies against this pathogen. Our interest was to determine whether V. cholera could be isolated and typified from L. minor and E. crassipens roots. From 2004 to 2005, plants were collected from various ecological niches and the roots were used to isolate V. cholera. Standard bacteriological, biochemical and serological tests were used for its typification. In five out of the nine ecological niches explored, we collected either L. minor or E. crassipens, as these specimens cohabited only in two niches. V. cholera was isolated from both L. minor and E. crassipens roots. The isolated V. cholera showed the same biochemical characteristics as the pure V. cholera strain which was used as a control. The isolated V. cholera corresponded to V. cholera O1 El Tor Inaba, which is the same serotype related to the last outbreak in Mexico. For first time V. cholera El Tor Inaba has been isolated several years after the last emergence of cholera in Mexico. A viable and cultivable V. cholera strain, sourced from freshwater niches in E. crassipens and L. minor roots, suggests the importance of these plants as a permanent aquatic reservoir for these organisms. The monitoring of E. crassipens and L. minor is the responsibility of health institutions in order to evaluate the ongoing risks.

Distribution and content of class 1 integrons in different Vibrio cholerae O-serotype strains isolated in Thailand

DEFF Research Database (Denmark)

Dalsgaard, Anders; Forslund, Anita; Serichantalergs, Oralak

2000-01-01

only a single antibiotic resistance gene. Although resistance genes in class 1 integrons were found in strains from the same epidemic, as well as in unrelated non-O1, non-O139 strains isolated from children with diarrhea, they were found to encode only some of the antibiotic resistance expressed...

Outbreaks of cholera-like diarrhoea caused by enterotoxigenic Escherichia coli in the Brazilian Amazon Rainforest.

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Vicente, Ana C P; Teixeira, Luiz F M; Iniguez-Rojas, L; Luna, M G; Silva, L; Andrade, J R C; Guth, B E C

2005-09-01

The relationship between enteropathogens and severe diarrhoea in the Brazilian Amazon is poorly understood. In 1998, outbreaks of acute diarrhoea clinically diagnosed as cholera occurred in two small villages localized far from the main cholera route in the Brazilian rainforest. PCR was performed on some enteropathogens and heat-labile (LT) and/or heat-stable (STh) toxin genes, the virulence determinants of enterotoxigenic Escherichia coli (ETEC), were detected. Further characterization of ETEC isolates revealed the presence of two clones, one from each outbreak. One presenting serotype O167:H5 harboured LT-I and STh toxin genes and expressed the CS5CS6 colonization factor. The other, a non-typeable serotype, was positive for the LT-I gene and expressed the CS7 colonization factor. The current study demonstrates the importance of molecular diagnosis in regions such as the Amazon basin, where the enormous distances and local support conditions make standard laboratory diagnosis difficult. Here we also show that the mis-identified cholera cases were in fact associated with ETEC strains. This is the first report of ETEC, molecularly characterized as the aetiological agent of severe diarrhoea in children and adults in the Brazilian Amazon Rainforest.

antimicrobial susceptibility pattern of vibrio cholerae 01 strains

African Journals Online (AJOL)

hi-tech

East African Medical Journal Vol. 77 No. 7 July 2000. ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF VIBRIO CHOLERAE 01 STRAINS DURING TWO CHOLERA OUTBREAKS IN DAR ES SALAAM,. TANZANIA. W.K. Urassa, MD, MSc, MMed, Lecturer, Department of Microbiology and Immunology, Muhimbili University ...

Plasma and Mucosal Immunoglobulin M, Immunoglobulin A, and Immunoglobulin G Responses to the Vibrio cholerae O1 Protein Immunome in Adults With Cholera in Bangladesh.

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Charles, Richelle C; Nakajima, Rie; Liang, Li; Jasinskas, Al; Berger, Amanda; Leung, Daniel T; Kelly, Meagan; Xu, Peng; Kovác, Pavol; Giffen, Samantha R; Harbison, James D; Chowdhury, Fahima; Khan, Ashraful I; Calderwood, Stephen B; Bhuiyan, Taufiqur Rahman; Harris, Jason B; Felgner, Philip L; Qadri, Firdausi; Ryan, Edward T

2017-07-01

Cholera is a severe dehydrating illness of humans caused by toxigenic strains of Vibrio cholerae O1 or O139. Identification of immunogenic V. cholerae antigens could lead to a better understanding of protective immunity in human cholera. We probed microarrays containing 3652 V. cholerae antigens with plasma and antibody-in-lymphocyte supernatant (ALS, a surrogate marker of mucosal immune responses) from patients with severe cholera caused by V. cholerae O1 in Bangladesh and age-, sex-, and ABO-matched Bangladeshi controls. We validated a subset of identified antigens using enzyme-linked immunosorbent assay. Overall, we identified 608 immunoreactive V. cholerae antigens in our screening, 59 of which had higher immunoreactivity in convalescent compared with acute-stage or healthy control samples (34 in plasma, 39 in mucosal ALS; 13 in both sample sets). Identified antigens included cholera toxin B and A subunits, V. cholerae O-specific polysaccharide and lipopolysaccharide, toxin coregulated pilus A, sialidase, hemolysin A, flagellins (FlaB, FlaC, and FlaD), phosphoenolpyruvate-protein phosphotransferase, and diaminobutyrate-2-oxoglutarate aminotransferase. This study is the first antibody profiling of the mucosal and systemic antibody responses to the nearly complete V. cholerae O1 protein immunome; it has identified antigens that may aid in the development of an improved cholera vaccine. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Selection of vaccine strains for serotype O foot-and-mouth disease viruses (2007-2012) circulating in Southeast Asia, East Asia and Far East.

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Mahapatra, Mana; Upadhyaya, Sasmita; Aviso, Sharie; Babu, Aravindh; Hutchings, Geoff; Parida, Satya

2017-12-18

Foot-and-mouth disease (FMD) is endemic in Southeast Asia (SEA) and East Asia with circulation of multiple serotypes and multiple genotypes within each serotype of the virus. Although countries like Japan and South Korea in the Far East were free of FMD, in 2010 FMD serotype O (O/Mya-98) outbreaks were recorded and since then South Korea has experienced several FMD outbreaks despite regular vaccination. In this study a total of 85 serotype O FMD viruses (FMDV) isolated from 2007 to 2012 from SEA, East Asia and Far East were characterized by virus neutralisation tests using antisera to four existing (O/HKN/6/83, O/IND/R2/75, O/SKR/2010 and O/PanAsia-2) and one putative (O/MYA/2009) vaccine strains, and by full capsid sequencing. Serological studies revealed broad cross-reactivity with the vaccine strains; O/PanAsia-2 exhibited a good match with 95.3%, O/HKN/6/83 with 91.8%, O/IND/R2/75 with 80%, and the putative strain O/MYA/2009 with 89.4% isolates employed in this study. Similarly O/PanAsia-2 and O/IND/R2/75 vaccines showed a good match with all eight viruses belonging to O-Ind-2001d sublineage whereas the vaccines of O/Mya-98 lineage, O/MYA/2009 and O/SKR/2010 exhibited the lowest match indicating their unsuitability to protect infections from O-Ind-2001d viruses. A Bayesian analysis of the capsid sequence data indicated these circulating viruses (n = 85) to be of either SEA or Middle East-South Asian (ME-SA) topotype. The ME-SA topotype viruses were mainly detected in Lao PDR, Vietnam, Myanmar and Thailand reflecting the trade links with the Indian subcontinent, and also within the SEA countries. Implications of these results in the context of FMD control in SEA and East Asian countries are discussed. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Vibrio cholerae O1 epidemic variants in Angola: a retrospective study between 1992 and 2006.

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Romy eValia

2013-11-01

Full Text Available Cholera is still a major public health concern in many African countries. In Angola, after a decade of absence, cholera reemerged in 1987, spreading throughout the country until 1996, with outbreaks recurring in a seasonal pattern. In 2006 Angola was hit by one of the most severe outbreaks of the last decade, with ca. 240,000 cases reported.We analyzed 21 clinical strains isolated between 1992 and 2006 from several provinces throughout the country: Benguela, Bengo, Luanda, Cuando Cubango and Cabinda. We used two multiplex PCR assays to investigate discriminatory mobile genetic elements (ICEs, VSP-II, GI12, GI14, GI15, K and TLC phages and we compared the profiles obtained with those of different reference V. cholerae O1 variants (prototypical, altered and hybrid, responsible for the ongoing 7th pandemic. We also tested the strains for the presence of specific VSP-II variants and for the presence of a genomic island (WASA-1, correlated with the transmission of seventh pandemic cholera from Africa to South America. Based on the presence/absence of the analyzed genetic elements, five novel profiles were detected in the epidemic strains circulating in the 1990s. The most frequent profiles, F and G, were characterized by the absence of ICEs and the three GIs tested, and the presence of genomic island WASA-1 and the WASA variant of the VSP-II island. Our results identified unexpected variability within the 1990s epidemic, showing different rearrangements in a dynamic part of the genome not present in the prototypical V. cholerae O1 N16961. Moreover the 2006 strains differed from the current pandemic V. cholerae O1 strain. Taken together, our results highlight the role of horizontal gene transfer in diversifying the genetic background of V. cholerae within a single epidemic.

Vibrio cholerae O1 epidemic variants in Angola: a retrospective study between 1992 and 2006.

Science.gov (United States)

Valia, Romy; Taviani, Elisa; Spagnoletti, Matteo; Ceccarelli, Daniela; Cappuccinelli, Piero; Colombo, Mauro M

2013-01-01

Cholera is still a major public health concern in many African countries. In Angola, after a decade of absence, cholera reemerged in 1987, spreading throughout the country until 1996, with outbreaks recurring in a seasonal pattern. In 2006 Angola was hit by one of the most severe outbreaks of the last decade, with ca. 240,000 cases reported. We analyzed 21 clinical strains isolated between 1992 and 2006 from several provinces throughout the country: Benguela, Bengo, Luanda, Cuando Cubango, and Cabinda. We used two multiplex PCR assays to investigate discriminatory mobile genetic elements (MGE) [Integrative Conjugative Elements (ICEs), VSP-II, GI12, GI14, GI15, K, and TLC phages] and we compared the profiles obtained with those of different reference V. cholerae O1 variants (prototypical, altered, and hybrid), responsible for the ongoing 7th pandemic. We also tested the strains for the presence of specific VSP-II variants and for the presence of a genomic island (GI) (WASA-1), correlated with the transmission of seventh pandemic cholera from Africa to South America. Based on the presence/absence of the analyzed genetic elements, five novel profiles were detected in the epidemic strains circulating in the 1990s. The most frequent profiles, F and G, were characterized by the absence of ICEs and the three GIs tested, and the presence of GI WASA-1 and the WASA variant of the VSP-II island. Our results identified unexpected variability within the 1990s epidemic, showing different rearrangements in a dynamic part of the genome not present in the prototypical V. cholerae O1 N16961. Moreover the 2006 strains differed from the current pandemic V. cholerae O1 strain. Taken together, our results highlight the role of horizontal gene transfer (HGT) in diversifying the genetic background of V. cholerae within a single epidemic.

Comparative Genomics of Vibrio cholerae O1 Isolated from Cholera Patients in Bangladesh

DEFF Research Database (Denmark)

Hossain, Zenat Zebin; Leekitcharoenphon, Pimlapas; Dalsgaard, Anders

patients was co-infected with two V. cholerae strains (VC-1 and VC-3). Major virulence factors, biotype and antimicrobial resistance genes were identified by WGS. A global phylogenetic tree was inferred using genome wide SNPs (Single Nucleotide Polymorphism) analysis. RESULTS: All the V. cholerae strains...

Genomic Evolution Of The Mdr Serotype O12 Pseudomonas Aeruginosa Clone

DEFF Research Database (Denmark)

Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca

2015-01-01

that serotype switching in combination with an antibiotic resistance determinant contributed to the dissemination of the O12 serotype in the clinic. This selective advantage coincides with the introduction of fluoroquinolones in the clinic. With the PAst program isolates can be serotyped using WGS data......Introduction: Since the 1980’s the serotype O12 of Pseudomonas aeruginosa has emerged as the predominant serotype in clinical settings and in epidemic outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics.Methods: In this study, we explore how......).Results: While most serotypes were closely linked to the core genome phylogeny we observed horizontal exchange of LPS genes among distinct P. aeruginosa strains. Specifically, we identified a ‘serotype island’ containing the P. aeruginosa O12 LPS gene cluster and an antibiotic resistance determinant (gyrAC248T...

Detection of Foot-and-mouth Disease Serotype O by ELISA Using a Monoclonal Antibody

OpenAIRE

Chen, Hao-tai; Peng, Yun-hua; Zhang, Yong-guang; Liu, Xiang-tao

2012-01-01

An ELISA assay with monoclonal antibody (MELISA) was used to type serotype O of foot-and-mouth disease virus (FMDV). All FMDV serotype O reference strains were positive by MELISA, while other viruses such as FMDV serotypes Asia 1, C, and A and classical swine fever virus, swine vesicular disease virus, and porcine reproductive and respiratory syndrome virus remained negative. Furthermore, FMDV serotype O positive samples were able to be detected by MELISA. This assay may be particularly suita...

Comparative genomic characterization of a Thailand-Myanmar isolate, MS6, of Vibrio cholerae O1 El Tor, which is phylogenetically related to a "US Gulf Coast" clone.

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Okada, Kazuhisa; Na-Ubol, Mathukorn; Natakuathung, Wirongrong; Roobthaisong, Amonrattana; Maruyama, Fumito; Nakagawa, Ichiro; Chantaroj, Siriporn; Hamada, Shigeyuki

2014-01-01

The cholera outbreaks in Thailand during 2007-2010 were exclusively caused by the Vibrio cholerae O1 El Tor variant carrying the cholera toxin gene of the classical biotype. We previously isolated a V. cholerae O1 El Tor strain from a patient with diarrhea and designated it MS6. Multilocus sequence-typing analysis revealed that MS6 is most closely related to the U. S. Gulf Coast clone with the exception of two novel housekeeping genes. The nucleotide sequence of the genome of MS6 was determined and compared with those of 26 V. cholerae strains isolated from clinical and environmental sources worldwide. We show here that the MS6 isolate is distantly related to the ongoing seventh pandemic V. cholerae O1 El Tor strains. These strains differ with respect to polymorphisms in housekeeping genes, seventh pandemic group-specific markers, CTX phages, two genes encoding predicted transmembrane proteins, the presence of metY (MS6_A0927) or hchA/luxR in a highly conserved region of the V. cholerae O1 serogroup, and a superintegron (SI). We found that V. cholerae species carry either hchA/luxR or metY and that the V. cholerae O1 clade commonly possesses hchA/luxR, except for MS6 and U. S. Gulf Coast strains. These findings illuminate the evolutionary relationships among V. cholerae O1 strains. Moreover, the MS6 SI carries a quinolone-resistance gene cassette, which was closely related with those present in plasmid-borne integrons of other gram-negative bacteria. Phylogenetic analysis reveals that MS6 is most closely related to a U. S. Gulf Coast clone, indicating their divergence before that of the El Tor biotype strains from a common V. cholerae O1 ancestor. We propose that MS6 serves as an environmental aquatic reservoir of V. cholerae O1.

Sequences of a co-existing SXT element, a chromosomal integron (CI) and an IncA/C plasmid and their roles in multidrug resistance in a Vibrio cholerae O1 El Tor strain.

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Wang, Ruibai; Li, Jie; Kan, Biao

2016-09-01

The ongoing seventh cholera pandemic is attributed to Vibrio cholerae O1 El Tor biotype strains. Although antibiotic therapy ameliorates symptoms in patients and reduces pathogen transfer to the environment, multidrug resistance remains a major clinical threat. An O1 El Tor strain isolated from a patient in 1998 was intermediate or resistant to 13 antibiotics and could potentially produce extended-spectrum β-lactamase (ESBL), which is very rare in O1 strains. Using genome sequencing, three relevant genetic elements were identified in this strain: a hybrid SXT element (ICEVchCHN1307); a new IncA/C plasmid (pVC1307); and a chromosomal integron. Twenty antibiotic resistance genes were located on them, including blaTEM-1, blaCTX-M-14 and phenotypically silenced tetRA genes. These data elucidate the role of individual genetic components in antibiotic resistance and the accumulation of drug resistance genes in V. cholerae. Copyright © 2016. Published by Elsevier B.V.

Virulence factors of non-O1 non-O139 Vibrio cholerae isolated in Córdoba, Argentina Factores de virulencia de Vibrio cholerae no-O1 no-O139 aislados en Córdoba, Argentina

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C. Bidinost

2004-12-01

Full Text Available V. cholerae non-O1 non-O139 serogroups isolated from clinical and environmental sources in Córdoba, Argentina, were analyzed for the presence and expression of virulence genes. Most of the strains studied contained the genes toxR and hlyA, but lacked ctxA, zot, ace, tcpA and stn. The culture supernatants were tested for hemolytic and cytotoxic activity. The enterotoxic potential of the strains was studied in a rabbit ileal loop assay and their genetic profiles were compared by PFGE. The environmental strains varied in their virulence phenotype and showed no-clonal relationships. The clinical strains were highly enterotoxic, hemolytic, proteolytic and showed indistinguishable PFGE profiles, although they differed in their cytotoxic activity. This is the first description, using cell culture and “in vivo” studies, of the virulence properties of non-O1 non-O139 V. cholerae from Argentina.En este trabajo se analizó la presencia y expresión de genes de virulencia en V. cholerae no-O1 no-O139 de origen clínico y ambiental, aislados en Córdoba, Argentina. La mayoría de las cepas estudiadas contiene los genes toxR y hlyA, pero no ctxA, zot, ace, tcpA y stn. Se analizó la actividad hemolítica y citotóxica de estas cepas en los sobrenadantes de cultivo, así como su potencial enterotóxico en ensayos de asa ileal ligada de conejo. Además, los aislamientos fueron comparados por sus perfiles genéticos en PFGE. Las cepas del medio ambiente mostraron variación en su fenotipo de virulencia y no mostraron relación clonal. Las cepas clínicas fueron muy enterotóxicas, hemolíticas, proteolíticas y mostraron perfiles indistinguibles de PFGE, aunque mostraron diferencias en su actividad citotóxica. En este trabajo se describen por primera vez, utilizando ensayos de cultivo celular e “in vivo”, propiedades de virulencia de V. cholerae no-O1 no-O139 aislados en Argentina.

Antigenic and genetic comparison of foot-and-mouth disease virus serotype O Indian vaccine strain, O/IND/R2/75 against currently circulating viruses.

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Mahapatra, Mana; Yuvaraj, S; Madhanmohan, M; Subramaniam, S; Pattnaik, B; Paton, D J; Srinivasan, V A; Parida, Satya

2015-01-29

Foot-and-mouth disease (FMD) virus serotype O is the most common cause of FMD outbreaks in India and three of the six lineages that have been described are most frequently detected, namely Ind2001, PanAsia and PanAsia 2. We report the full capsid sequence of 21 serotype O viruses isolated from India between 2002 and 2012. All these viruses belong to the Middle East-South Asia (ME-SA) topotype. The serological cross-reactivity of a bovine post-vaccination serum pool raised against the current Indian vaccine strain, O/IND/R2/75,was tested by virus neutralisation test with the 23 Indian field isolates, revealing a good match between the vaccine and the field isolates. The cross reactivity of the O/IND/R2/75 vaccine with 19 field isolates from other countries (mainly from Asia and Africa) revealed a good match to 79% of the viruses indicating that the vaccine strain is broadly cross-reactive and could be used to control FMD in other countries. Comparison of the capsid sequences of the serologically non-matching isolates with the vaccine strain sequence identified substitutions in neutralising antigenic sites 1 and 2, which could explain the observed serological differences. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

A novel plasmid-encoded serotype conversion mechanism through addition of phosphoethanolamine to the O-antigen of Shigella flexneri.

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Qiangzheng Sun

Full Text Available Shigella flexneri is the major pathogen causing bacillary dysentery in developing countries. S. flexneri is divided into at least 16 serotypes based on the combination of antigenic determinants present in the O-antigen. All the serotypes (except for serotype 6 share a basic O-unit containing one N-acetyl-d-glucosamine and three l-rhamnose residues, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation. Serotype Xv is a newly emerged and the most prevalent serotype in China, which can agglutinate with both MASF IV-1 and 7,8 monoclonal antibodies. The factor responsible for the presence of MASF IV-1 (E1037 epitope has not yet been identified. In this study, we analyzed the LPS structure of serotype Xv strains and found that the MASF IV-1 positive phenotype depends on an O-antigen modification with a phosphoethanolamine (PEtN group attached at position 3 of one of the rhamnose residues. A plasmid carried gene, lpt-O (LPS phosphoethanolamine transferase for O-antigen, mediates the addition of PEtN for serotype Xv and other MASF IV-1 positive strains. These findings reveal a novel serotype conversion mechanism in S. flexneri and show the necessity of further extension of the serotype classification scheme recognizing the MASF IV-1 positive strains as distinctive subtypes.

Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

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Afzali H.MD,

2016-03-01

Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.

Viabilidade de Vibrio cholerae O1 em diferentes tipos de águas em condições experimentais Viability of Vibrio cholerae O1 in different types of water under experimental conditions

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Joseli Maria da Rocha Nogueira

2002-10-01

maintained at different temperatures. Survival of the microorganisms in the aquatic environment under these different conditions was then analyzed. Regardless of the serotype, V. cholerae serogroup O1 survived in water with salinity below 0.5‰ and at different temperatures for sufficient periods to spread through "bodies of water", demonstrating the need to constantly monitor areas of possible contamination, especially where the water is used for drinking, thus avoiding spread of the disease to surrounding populations.

Comparison of Growth and the Cytokines Induced by Pathogenic Yersinia enterocolitica Bio-Serotypes 3/O: 3 and 2/O: 9.

Science.gov (United States)

Yang, Haoshu; Gu, Wenpeng; Qiu, Haiyan; Sun, Guixiang; Liang, Junrong; Li, Kewei; Xiao, Yuchun; Duan, Ran; Jing, Huaiqi; Wang, Xin

2017-01-01

Pathogenic Yersinia enterocolitica is widely distributed in China where the primary bio-serotypes are 3/O: 3 and 2/O: 9. Recently, the distribution of 2/O: 9 strains are being gradually replaced by 3/O: 3 strains where presently 3/O: 3 strains are the major pathogenic Y. enterocolitica in China. To identify the growth conditions and cytokines induced by Y. enterocolitica and providing some clues for this shift, we performed competitive growth in vitro and in vivo for these two bio-serotype strains; and we also compared the cytokines induced by them in infected BALB/C mice. We found 2/O: 9 strains grew more in vitro , while 3/O: 3 strains grew more in vivo regardless of using single cultures or mixed cultures. The cytokines induced by the two strains were similar: interleukin-6 (IL-6), IL-9, IL-13, granulocyte colony-stimulating factor (G-CSF), chemokines (KC), monocyte chemotactic protein 1 (MCP-1), macrophage inflammation protein-1α (MIP-1α), tumor necrosis factor-α (TNF-α), and RANTES were statistically up-regulated upon activation of normal T cells compared to the control. The cytokine values were higher in mixed infections than in single infections except for IL-6, G-CSF, and KC. The data illustrated the different growth of pathogenic Y. enterocolitica bio-serotype 3/O: 3 and 2/O: 9 in vitro and in vivo , and the cytokine changes induced by the two strains in infected BALB/C mice. The growth comparisons of two strains maybe reflect the higher pathogenic ability or resistance to host immune response for Y. enterocolitica bio-serotype 3/O: 3 and maybe it as one of the reason for bacteria shift.

Comparison of Growth and the Cytokines Induced by Pathogenic Yersinia enterocolitica Bio-Serotypes 3/O: 3 and 2/O: 9

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Haoshu Yang

2017-05-01

Full Text Available Pathogenic Yersinia enterocolitica is widely distributed in China where the primary bio-serotypes are 3/O: 3 and 2/O: 9. Recently, the distribution of 2/O: 9 strains are being gradually replaced by 3/O: 3 strains where presently 3/O: 3 strains are the major pathogenic Y. enterocolitica in China. To identify the growth conditions and cytokines induced by Y. enterocolitica and providing some clues for this shift, we performed competitive growth in vitro and in vivo for these two bio-serotype strains; and we also compared the cytokines induced by them in infected BALB/C mice. We found 2/O: 9 strains grew more in vitro, while 3/O: 3 strains grew more in vivo regardless of using single cultures or mixed cultures. The cytokines induced by the two strains were similar: interleukin-6 (IL-6, IL-9, IL-13, granulocyte colony-stimulating factor (G-CSF, chemokines (KC, monocyte chemotactic protein 1 (MCP-1, macrophage inflammation protein-1α (MIP-1α, tumor necrosis factor-α (TNF-α, and RANTES were statistically up-regulated upon activation of normal T cells compared to the control. The cytokine values were higher in mixed infections than in single infections except for IL-6, G-CSF, and KC. The data illustrated the different growth of pathogenic Y. enterocolitica bio-serotype 3/O: 3 and 2/O: 9 in vitro and in vivo, and the cytokine changes induced by the two strains in infected BALB/C mice. The growth comparisons of two strains maybe reflect the higher pathogenic ability or resistance to host immune response for Y. enterocolitica bio-serotype 3/O: 3 and maybe it as one of the reason for bacteria shift.

[GM1-dot-EIA for the detection of toxin-producing Vibrio cholerae strains].

Science.gov (United States)

Markina, O V; Alekseeva, L P; Telesmanich, N R; Chemisova, O S; Akulova, M V; Markin, N V

2011-05-01

A new variant of enzyme immunoassay (EIA) has been developed on the basis of GM1 gangliosides to detect the toxin-producing Vibrio cholerae strains--GM1-dot-EIA. Experiments were run using a nitrocellulose membrane to bind GM1 gangliosides and polyclonal antitoxic serum to detect cholerogen. GM1-dot-EIA testing identified cholera toxin in 11 of 13 supernatants of V. cholerae eltor ctx(+) strains isolated from man and in 3 of 7 supernatants of V. cholerae eltor ctx(+) strains isolated from water. These data agree with those obtained in CM1-EIA. There was no reaction with the supernatants of other microorganisms. The sensitivity of the technique was 10 ng/ml. Thus, the simple and specific GM1-dot-EIA may be recommended to detect toxin-producing V cholerae strains isolated from man and water.

Repair of ultraviolet-light-induced DNA damage in Vibrio cholerae

International Nuclear Information System (INIS)

Das, G.; Sil, K.; Das, J.

1981-01-01

Repair of ultraviolet-light-induced DNA damage in a highly pathogenic Gram-negative bacterium, Vibrio cholerae, has been examined. All three strains of V. cholerae belonging to two serotypes, Inaba and Ogawa, are very sensitive to ultraviolet irradiation, having inactivation cross-sections ranging from 0.18 to 0.24 m 2 /J. Although these cells are proficient in repairing the DNA damage by a photoreactivation mechanism, they do not possess efficient dark repair systems. The mild toxinogenic strain 154 of classical Vibrios presumably lacks any excision repair mechanism and studies of irradiated cell DNA indicate that the ultraviolet-induced pyrimidine dimers may not be excised. Ultraviolet-irradiated cells after saturation of dark repair can be further photoreactivated. (Auth.)

Phenotypic and antibiogram pattern of V. cholerae isolates from a tertiary care hospital in Mumbai during 2004-2013: a retrospective cross-sectional study.

Science.gov (United States)

Torane, V; Kuyare, S; Nataraj, G; Mehta, P; Dutta, S; Sarkar, B

2016-11-25

Cholera is a major gastroenteric disease with reports on fluctuation and resistance. Hence, the objective is to determine the trend in seasonality, resistance pattern, prevalent biotypes, serotypes and phage types between 2004 and 2013 among Vibrio cholerae isolates. A retrospective cross-sectional study. A single-centre study was carried out at a tertiary care hospital in a metropolitan city (Mumbai) of a developing country (India). Records of stool specimen cultures of patients with suspected cholera from January 2004 to December 2013 were analysed. The organisms were identified as per standard protocol. Antimicrobial susceptibility testing was performed as per Clinical Laboratory Standard Institute. Biotyping, serotyping and phage typing were carried out. From the confirmed cases of cholera, demographic and laboratory details were noted. Descriptive analysis was used and the data were presented in the form of percentages. Vibrio cholerae was predominant in males and was isolated from 9.41% (439/4664) of stool specimens. Variability was found in terms of the gross appearance of stool specimens, seasonal trend and antibiotic resistance pattern. The antimicrobial susceptibility showed a waxing and waning pattern for most of the antibiotics (ampicillin, cefuroxime, chloramphenicol, tetracycline) tested, while for a few others the strains were either uniformly sensitive (gentamicin, norfloxacin) or resistant (trimethoprim-sulfamethoxazole, nalidixic acid). All isolates belonged to subgroup O1 and biotype El Tor. The most common serotype was Ogawa. The predominant phage type was T2 (old scheme) and T27 (new scheme). The predominant biotype, serotype and phage type were El Tor, Ogawa and T27 phage, respectively. The changing trends in antimicrobial resistance pattern over the years necessitate continued epidemiological and microbiological surveillance of the disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a

Serotype, mating type and ploidy of Cryptococcus neoformans strains isolated from patients in Brazil Sorotipos, "mating type" e ploidia de amostras de C. neoformans isoladas de pacientes no Brasil

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Misako OHKUSU

2002-12-01

Full Text Available Serotype, mating type and ploidy of 84 strains of Cryptococcus neoformans isolated from 61 AIDS and 23 non-AIDS patients admitted in a tertiary teaching hospital in São Paulo, Brazil were examined. Among 61 strains isolated from AIDS patients, 60 strains were var. grubii (serotype A. Only one strain was var. gattii (serotype B. No var. neoformans (serotype D was found. Among 23 strains isolated from non-AIDS patients, 15 were var. grubii (serotype A and the remaining 8 were var. gattii, all of which were serotype B. Seventy-three of the 75 serotype A strains were the heterothallic alpha type (MATalpha and the remaining 2 were untypable (asexual. Most of the MATalpha strains (69/73 were haploid and the remaining 4 strains were diploid. Similarly, both of the 2 asexual strains among the 75 serotype A strains were haploid. There were no alpha-mating type (MATalpha strains among the 84 isolates. All of the 8 var. gattii strains were serotype B and haploid. Among a total of 84 strains tested, neither serotype AD nor serotype D were found. Neither triploid nor tetraploid were found. These results suggest that the serological, sexual and ploidy characteristics in C. neoformans strains isolated from AIDS patients in São Paulo were rather simple, whereas strains isolated from non-AIDS patients presented serotype A and B with predominance of serotype A.Foram estudados os sorotipos, "mating type" e ploidia de 84 amostras de C. neoformans isoladas de 61 pacientes com AIDS e 23 não-AIDS em São Paulo. Das amostras isoladas de pacientes com AIDS, 60 foram identificadas como var. grubii (sorotipo A e 1 como var. gattii (sorotipo B. Não houve isolamento do sorotipo D. Entre as amostras isoladas, de pacientes não-AIDS, 15 foram de var. grubii (sorotipo A e as 8 restantes de var. gattii, todos do sorotipo B. Setenta e três dos 75 sorotipos A foram identificadas como cepas heterotálicas do fenótipo alfa (MATalfa e as 2 remanescentes não

Genome Sequence Analysis of Vibrio cholerae clinical isolates from 2013 in Mexico reveals the presence of the strain responsible for the 2010 Haiti outbreak.

Science.gov (United States)

Díaz-Quiñonez, José Alberto

2017-01-01

La primera semana de septiembre de 2013, el Sistema Nacional de Vigilancia Epidemiológica identificó dos casos de cólera en Ciudad de México. Los cultivos de ambas muestras se confirmaron como Vibrio cholerae serogrupo O1, serotipo Ogawa, biotipo El Tor. Los análisis iniciales por electroforesis por campos pulsados y por reacción en cadena de la polimerasa indicaron que ambas cepas eran similares, pero diferentes de las previamente reportadas en México. La semana siguiente se identificaron cuatro casos más en una comunidad del Estado de Hidalgo, ubicada a 121 kilómetros al noreste de Ciudad de México. Posteriormente se inició un brote de cólera en la región de La Huasteca. Los análisis genómicos de cuatro cepas obtenidas en este estudio confirmaron la presencia de las islas de patogenicidad VPI -1 y VPI-2, VSP-1 y VSP-2, y del elemento integrador SXT. La estructura genómica de los cuatro aislamientos fue similar a la de V. cholerae cepa 2010 EL-1786, identificada durante la epidemia en Haití en 2010. Este estudio pone de manifiesto que la epidemiología molecular es una herramienta muy poderosa para vigilar, prevenir y controlar enfermedades de importancia en salud pública en México. The first week of September 2013, the National Epidemiological Surveillance System identified two cases of cholera in Mexico City. The cultures of both samples were confirmed as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Initial analyses by pulsed-field gel electrophoresis and by polymerase chain reaction-amplification of the virulence genes, suggested that both strains were similar, but different from those previously reported in Mexico. The following week, four more cases were identified in a community in the state of Hidalgo, located 121 km northeast of Mexico City. Thereafter a cholera outbreak started in the region of La Huasteca. Genomic analyses of the strains obtained in this study confirmed the presence of pathogenicity islands VPI-1 and

Distribution ofVibrio cholerae in two Florida estuaries.

Science.gov (United States)

Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

1983-04-01

The distribution ofVibrio cholerae was examined in 2 Florida estuaries, Apalachicola and Tampa Bay.Vibrio cholerae serotype non-01 was the most abundant serotype, being isolated from 45% of the oyster samples, 30% of the sediments, 50% of the waters, and 75% of the blue crabs.Vibrio cholerae serotype 01 was isolated from only one oyster sample. Strong linear correlations betweenV. cholerae and temperature, salinity, or the other physical/chemical parameters measured,Escherichia coli, or fecal coliforms were not observed, but a range of temperatures and salinities appeared relevant to the distribution of the organism. The organism was present in the highest concentrations when salinities were 10‰-25‰ and temperatures were 20‡C-35‡C.In vitro growth curves of 95V. cholerae environmental isolates further supported that 10‰-25‰ was an ideal salinity range for the organisms. The results suggest thatV. cholerae is a widely distributed organism in the nutrient-rich warm waters of the Gulf Coast estuaries.

Comparative genomic analysis of two isolates of Vibrio cholerae O1 Ogawa El Tor isolated during outbreak in Mariupol in 2011.

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Kuleshov, Konstantin V; Kostikova, Anna; Pisarenko, Sergey V; Kovalev, Dmitry A; Tikhonov, Sergey N; Savelievа, Irina V; Saveliev, Vilory N; Vasilieva, Oksana V; Zinich, Liliia S; Pidchenko, Nadiia N; Kulichenko, Alexander N; Shipulin, German A

2016-10-01

Cholera is a water-borne, severe enteric infection essentially caused by toxigenic strains of Vibrio cholera O1 and O139 serogroups. An outbreak of cholera was registered during May-July 2011 in Mariupol, Ukraine, with 33 cholera cases and 25 carriers of cholera. Following this outbreak, the toxigenic strain of V. cholerae 2011EL-301 was isolated from seawater in the recreation area of Taganrog city on the territory of Russia. The aim of our study was to understand genomic features of Mariupol isolates as well as to evaluate hypothesis about possible interconnection between the outbreak of cholera in Mariupol and the single case of isolation of V. cholerae from the Sea of Azov in Russia. Mariupol isolates were phenotypically characterized and subsequently subjected to whole genome sequencing procedure. Phylogenetic analysis based on high-quality SNPs of V. cholera O1 El Tor isolates of the 7th pandemic clade from different regions showed that clinical and environmental isolates from Mariupol outbreak were attributable to a unique phylogenetic clade within wave 3 of V. cholera O1 El Tor isolates and characterized by six clade-specific SNPs. Whereas Taganrog isolate belonged to distantly related clade which allows us to reject the hypothesis of transmission the outbreak strain of V. cholerae O1 from Ukraine to Russia in 2011. Mariupol isolates shared a common ancestor with Haiti\\Nepal-4\\India clade indicating that outbreak progenitor strain most likely originated in the South Asia region and later was introduced to Ukraine. Moreover, genomic data both based on hqSNPs and similarity of virulence-associated mobile genomic elements of Mariupol isolates suggests that environmental and clinical isolates are a part of joint outbreak which confirms the role of contaminated domestic sewage, as an element of the complex chain of infection spread during cholera outbreak. In general, the genome-wide comparative analysis of both genes and genomic regions of epidemiological

The absence of a flagellum leads to altered colony morphology, biofilm development and virulence in Vibrio cholerae O139

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Watnick, Paula I.; Lauriano, Crystal M.; Klose, Karl E.; Croal, Laura; Kolter, Roberto

2010-01-01

Summary Throughout most of history, epidemic and pandemic cholera was caused by Vibrio cholerae of the serogroup O1. In 1992, however, a V. cholerae strain of the serogroup O139 emerged as a new agent of epidemic cholera. Interestingly, V. cholerae O139 forms biofilms on abiotic surfaces more rapidly than V. cholerae O1 biotype El Tor, perhaps because regulation of exopolysaccharide synthesis in V. cholerae O139 differs from that in O1 El Tor. Here, we show that all flagellar mutants of V. cholerae O139 have a rugose colony morphology that is dependent on the vps genes. This suggests that the absence of the flagellar structure constitutes a signal to increase exopolysaccharide synthesis. Furthermore, although exopolysaccharide production is required for the development of a three-dimensional biofilm, inappropriate exopolysaccharide production leads to inefficient colonization of the infant mouse intestinal epithelium by flagellar mutants. Thus, precise regulation of exopolysaccharide synthesis is an important factor in the survival of V. cholerae O139 in both aquatic environments and the mammalian intestine. PMID:11136445

Phenotypic and antibiogram pattern of V. cholerae isolates from a tertiary care hospital in Mumbai during 2004–2013: a retrospective cross-sectional study

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Torane, V; Kuyare, S; Nataraj, G; Mehta, P; Dutta, S; Sarkar, B

2016-01-01

Objectives Cholera is a major gastroenteric disease with reports on fluctuation and resistance. Hence, the objective is to determine the trend in seasonality, resistance pattern, prevalent biotypes, serotypes and phage types between 2004 and 2013 among Vibrio cholerae isolates. Design A retrospective cross-sectional study. Settings A single-centre study was carried out at a tertiary care hospital in a metropolitan city (Mumbai) of a developing country (India). Methods Records of stool specimen cultures of patients with suspected cholera from January 2004 to December 2013 were analysed. The organisms were identified as per standard protocol. Antimicrobial susceptibility testing was performed as per Clinical Laboratory Standard Institute. Biotyping, serotyping and phage typing were carried out. From the confirmed cases of cholera, demographic and laboratory details were noted. Descriptive analysis was used and the data were presented in the form of percentages. Results Vibrio cholerae was predominant in males and was isolated from 9.41% (439/4664) of stool specimens. Variability was found in terms of the gross appearance of stool specimens, seasonal trend and antibiotic resistance pattern. The antimicrobial susceptibility showed a waxing and waning pattern for most of the antibiotics (ampicillin, cefuroxime, chloramphenicol, tetracycline) tested, while for a few others the strains were either uniformly sensitive (gentamicin, norfloxacin) or resistant (trimethoprim-sulfamethoxazole, nalidixic acid). All isolates belonged to subgroup O1 and biotype El Tor. The most common serotype was Ogawa. The predominant phage type was T2 (old scheme) and T27 (new scheme). Conclusions The predominant biotype, serotype and phage type were El Tor, Ogawa and T27 phage, respectively. The changing trends in antimicrobial resistance pattern over the years necessitate continued epidemiological and microbiological surveillance of the disease. PMID:27888174

[Algorithm of toxigenic genetically altered Vibrio cholerae El Tor biovar strain identification].

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Smirnova, N I; Agafonov, D A; Zadnova, S P; Cherkasov, A V; Kutyrev, V V

2014-01-01

Development of an algorithm of genetically altered Vibrio cholerae biovar El Tor strai identification that ensures determination of serogroup, serovar and biovar of the studied isolate based on pheno- and genotypic properties, detection of genetically altered cholera El Tor causative agents, their differentiation by epidemic potential as well as evaluation of variability of key pathogenicity genes. Complex analysis of 28 natural V. cholerae strains was carried out by using traditional microbiological methods, PCR and fragmentary sequencing. An algorithm of toxigenic genetically altered V. cholerae biovar El Tor strain identification was developed that includes 4 stages: determination of serogroup, serovar and biovar based on phenotypic properties, confirmation of serogroup and biovar based on molecular-genetic properties determination of strains as genetically altered, differentiation of genetically altered strains by their epidemic potential and detection of ctxB and tcpA key pathogenicity gene polymorphism. The algorithm is based on the use of traditional microbiological methods, PCR and sequencing of gene fragments. The use of the developed algorithm will increase the effectiveness of detection of genetically altered variants of the cholera El Tor causative agent, their differentiation by epidemic potential and will ensure establishment of polymorphism of genes that code key pathogenicity factors for determination of origins of the strains and possible routes of introduction of the infection.

Cholera after the consumption of raw oysters. A case report.

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Klontz, K C; Tauxe, R V; Cook, W L; Riley, W H; Wachsmuth, I K

1987-12-01

In August 1986, a 76-year-old woman in Miami, Florida, developed profuse watery diarrhea and abdominal cramps. Two and four days before the onset of her illness, she had eaten six raw oysters at each of two restaurants in Miami. A stool specimen yielded toxigenic Vibrio cholerae O1 biotype El Tor, serotype Inaba. The results of toxin gene probing of the organism recovered from the patient differed significantly from those of other V. cholerae O1 isolates from the Gulf Coast and elsewhere in the world. A program of active surveillance identified no other cases of cholera in Miami. The source of the raw oysters eaten by the patient was traced to Louisiana. Her case represents the first reported case of cholera associated with eating raw oysters.

Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

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Daniel Rios Garza

Full Text Available The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics.

EROTYPE IDENTIFICATION OF VIBRIO CHOLERAE BACTERIAWHICH ISOLATED FROM ICE AMONGTUBE AND CUBE ICE TYPE IN FOOD AND BEVERAGES SELLER AT DENPASAR CITY, BALI

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IGP Dhinarananta

2014-01-01

Full Text Available Cholera is a type of watery diarrhea with specific sign stool containing mucus which resembles rice water. Cholera caused by gram negative bacteria Vibrio cholerae (V.Cholerae. The transmissions of bacteria were through a contaminated food or water.Bali is an international tourism destination with tropical weather where ice is widelyused in food and beverage which bring a risk of cholera through a contaminated ice.Iceshave a risk of bacterial contamination whether from the making and the usage process.Type of ice that widely used were cube and tube ice which each of them have a differentin making and usage process. The purpose of this study is to obtain the contamination ofV.cholera in cube and tube ice. The method of this study is descriptive observationalstudy with quota sampling technique. Sample were obtained from a restaurants andstreet vendor which use a block and tube ice with total 10 sample and 5 for each type ofice.Sample then cultured in Alkaline Peptone Water(APW and Thiosulfate Citrate Bilesalt Sucrose(TCBS agar. Bacteriacolony then identified using a gram staining andLatex Serotyping. The result are 3 over 5 (60% sample of cube ice contaminated byV.cholera O1 Inaba serotype and 3 over 5 (60% sample of tube ice contaminated byV.cholera O1 Inaba serotype.

Cholera: an overview with reference to the Yemen epidemic.

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Rabaan, Ali A

2018-06-22

Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

Caracterización de aislamientos de Vibrio cholerae no-O1, no-O139 asociados a cuadros de diarrea Characterization of Vibrio cholerae non-O1 and non-O139 isolates associated with diarrhea

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S. González Fraga

2009-03-01

its virulence factors by PCR, antimicrobial susceptibility patterns and genetic diversity by pulsed-field gel electrophoresis. Eight virulence patterns were obtained although no isolate was positive for the cholera toxin or the thermostable toxin. Four isolates were positive for the type three secretion system. The 17.6% of the isolates were resistant or intermediate to ampicillin and 5.9% were resistant to trimethoprim-sulfamethoxazole. By SfiI-PFGE, all isolates were genetically very diverse, as 27 different patterns were identified in 29 typeable isolates by pulsed-field gel electrophoresis. Although it has a low incidence, V. cholerae continues to be a causative agent of diarrhea in children, who are affected by a variety of circulating strains of V. cholerae non-O1, non-O139.

Evolutionary phylodynamics of foot-and-mouth disease virus serotypes O and A circulating in Vietnam.

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Le, Van Phan; Vu, Thi Thu Hang; Duong, Hong-Quan; Than, Van Thai; Song, Daesub

2016-11-29

Foot-and-mouth disease virus (FMDV) is one of the highest risk factors that affects the animal industry of the country. The virus causes production loss and high ratio mortality in young cloven-hoofed animals in Vietnam. The VP1 coding gene of 80 FMDV samples (66 samples of the serotype O and 14 samples of the serotype A) collected from endemic outbreaks during 2006-2014 were analyzed to investigate their phylogeny and genetic relationship with other available FMDVs globally. Phylogenetic analysis indicated that the serotype O strains were clustered into two distinct viral topotypes (the SEA and ME-SA), while the serotype A strains were all clustered into the genotype IX. Among the study strains, the amino acid sequence identities were shared at a level of 90.1-100, 92.9-100, and 92.8-100% for the topotypes SEA, ME-SA, and genotype IX, respectively. Substitutions leading to changes in the amino acid sequence, which are critical for the VP1 antigenic sites were also identified. Our results showed that the studied strains are most closely related to the recent FMDV isolates from Southeast Asian countries (Myanmar, Thailand, Cambodia, Malaysia, and Laos), but are distinct from the earlier FMDV isolates within the genotypes. This study provides important evidence of recent movement of FMDVs serotype O and A into Vietnam within the last decade and their genetic accumulation to be closely related to strains causing FMD in surrounding countries.

Report of the Working Group on Strengthening the Biosecurity of the United States

Science.gov (United States)

2009-10-01

Typhi (Typhoid) 9 Vibrio cholerae ( Cholera ) (serotypes O1 and O139 only) 10 Yellow fever virus (non-vaccine strains) APPENDIX 4-A 123 Appendix 4-A...is unknown. Scientists at Los Alamos National Laboratory in New Mexico determined the spores were derived from least four different strains of B

Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

NARCIS (Netherlands)

Garza, D.R.; Thompson, C.C.; Loureiro, E.C.; Dutilh, B.E.; Inada, D.T.; Junior, E.C.; Cardoso, J.F.; Nunes, M.R.; Lima, C.P. de; Silvestre, R.V.; Nunes, K.N.; Santos, E.C.; Edwards, R.A.; Vicente, A.C.; Sa Morais, L.L. de

2012-01-01

The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic

Evaluation of Cholera Toxin Expression in Acidic, Alkaline and Neutral Conditions

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Narges Rahimi

2015-02-01

Full Text Available Background: Cholera is a severe disease which is caused by Vibrio cholerae and it is typically transmitted by either contaminated food or water particularly in developing countries. The most important virulence factor of this bacterium is an enterotoxin called cholera toxin which is a protein complex secreted by the Vibrio cholerae. Objectives: In this project, we determined the production of cholera toxin at different pH values. Materials and Methods: Two standard strain of Vibrio cholerae O1 biovar EL Tor N16961 and Vibrio cholerae O1 biovar Classic ATCC 14035 were used. After overnight cultivation of both the strains the total mRNA extracted and converted to total cDNA. Results: By Relative Real-Time PCR analysis the most cholera toxin production in classical and El Tor strains was at pH 8.5 and 8, respectively. Conclusions: Therefore, We may conclude that use of acidic diet will help in reduction of cholera toxin production.

Genomic epidemiology of Vibrio cholerae O1 associated with floods, Pakistan, 2010.

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Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib; Wren, Brendan W

2014-01-01

In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks.

Genomic Epidemiology of Vibrio cholerae O1 Associated with Floods, Pakistan, 2010

Science.gov (United States)

Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib

2014-01-01

In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks. PMID:24378019

Studies on a novel serine protease of a ΔhapAΔprtV Vibrio cholerae O1 strain and its role in hemorrhagic response in the rabbit ileal loop model.

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Aurelia Syngkon

Full Text Available BACKGROUND: Two well-characterized proteases secreted by Vibrio cholerae O1 strains are hemagglutinin protease (HAP and V. cholerae protease (PrtV. The hapA and prtV knock out mutant, V. cholerae O1 strain CHA6.8ΔprtV, still retains residual protease activity. We initiated this study to characterize the protease present in CHA6.8ΔprtV strain and study its role in pathogenesis in rabbit ileal loop model (RIL. METHODOLOGY/PRINCIPAL FINDINGS: We partially purified the residual protease secreted by strain CHA6.8ΔprtV from culture supernatant by anion-exchange chromatography. The major protein band in native PAGE was identified by MS peptide mapping and sequence analysis showed homology with a 59-kDa trypsin-like serine protease encoded by VC1649. The protease activity was partially inhibited by 25 mM PMSF and 10 mM EDTA and completely inhibited by EDTA and PMSF together. RIL assay with culture supernatants of strains C6709 (FA ratio 1.1+/-0.3 n = 3, CHA6.8 (FA ratio 1.08+/-0.2 n = 3, CHA6.8ΔprtV (FA ratio 1.02+/-0.2 n = 3 and partially purified serine protease from CHA6.8ΔprtV (FA ratio 1.2+/-0.3 n = 3 induced fluid accumulation and histopathological studies on rabbit ileum showed destruction of the villus structure with hemorrhage in all layers of the mucosa. RIL assay with culture supernatant of CHA6.8ΔprtVΔVC1649 strain (FA ratio 0.11+/-0.005 n = 3 and with protease incubated with PMSF and EDTA (FA ratio 0.3+/-0.05 n = 3 induced a significantly reduced FA ratio with almost complete normal villus structure. CONCLUSION: Our results show the presence of a novel 59-kDa serine protease in a ΔhapAΔprtV V. cholerae O1 strain and its role in hemorrhagic response in RIL model.

Survival of Vibrio cholerae O1 on fomites

DEFF Research Database (Denmark)

Farhana, Israt; Hossain, Zenat Zebin; Tulsiani, Suhella Mohan

2016-01-01

conditions on fomites, bacteria have been known to assume a viable but non-culturable (VBNC) state after a given period of time. To investigate whether and when V. cholerae O1 assumes such a state, this study investigated the survival and viable quantification on a range of fomites such as paper, wood, glass......, plastic, cloth and several types of metals under laboratory conditions. The fomites were inoculated with an outbreak strain of V. cholerae and its culturability was examined by drop plate count method at 30 min intervals for up to 6 h. For molecular detection, the viable/dead stain ethidium monoazide (EMA......) which inhibits amplification of DNA from dead cells was used in combination with real-time polymerase chain reaction (EMA-qPCR) for direct quantitative analyses of viable V. cholerae at 2, 4, 6, 24 h and 7 day time intervals. Results showed that V. cholerae on glass and aluminum surfaces lost...

Prevailing clone (ST69) of Vibrio cholerae O139 in India over 10 years.

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Anandan, Shalini; Devanga Ragupathi, Naveen Kumar; Muthuirulandi Sethuvel, Dhiviya Prabaa; Thangamani, Suji; Veeraraghavan, Balaji

2017-01-01

Vibrio cholerae is responsible for the cause of severe life-threatening infection known as cholera. The study aimed to analyze the genetic make-up of V. cholerae O139 isolates from India and compare its phylogeny with the global strains. The genome data revealed that all isolates were of same sequence type (ST69) which belongs to seventh pandemic clone, with same virulence gene profile and, antimicrobial resistance gene profile except for two isolates. No known CRISPR repeats were identified in any of these isolates. Three different phages were identified among the isolates. All the isolates were found to harbour int SXT and seventh pandemic-specific gene (VC2346). Results from this study enhance our understanding on the persistence of ST69 V. cholerae O139 over 20 years.

Prevalence and characterization of Vibrio cholerae isolated from shrimp products imported into Denmark

DEFF Research Database (Denmark)

Dalsgaard, A.; Bjergskov, T.; Jeppesen, V.F.

1996-01-01

A total of 3,555 metric tonnes of warm water shrimp were imported into Denmark from December 1994 to July 1995. V. cholerae O1 was not detected in any of the 748 samples analyzed. Non-Ol V. cholerae was found in a single (0.1%) cooked frozen shrimp product and in five (0.7%) raw frozen products......, all originating from shrimp produced in aquaculture. Six isolated strains agglutinated in polyvalent O antisera, but did not agglutinate in Ogawa or Inaba antisera. The six strains were resistant to colistin and sulfisoxazole; three strains also showed resistance to ampicillin. None of the strains...... contained plasmids or genes encoding cholera toxin (CT) or heat-stable enterotoxin (NAG-ST), The absence of V. cholerae O1 and the low number of samples containing CT and NAG-ST negative non-Ol strains in imported shrimp suggest that I! cholerae in such products may not constitute a public health problem....

Diversity and distribution of cholix toxin, a novel ADP-ribosylating factor from Vibrio cholerae.

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Purdy, Alexandra E; Balch, Deborah; Lizárraga-Partida, Marcial Leonardo; Islam, Mohammad Sirajul; Martinez-Urtaza, Jaime; Huq, Anwar; Colwell, Rita R; Bartlett, Douglas H

2010-02-01

Non-toxigenic non-O1, non-O139 Vibrio cholerae strains isolated from both environmental and clinical settings carry a suite of virulence factors aside from cholera toxin. Among V. cholerae strains isolated from coastal waters of southern California, this includes cholix toxin, an ADP-ribosylating factor that is capable of halting protein synthesis in eukaryotic cells. The prevalence of the gene encoding cholix toxin, chxA, was assessed among a collection of 155 diverse V. cholerae strains originating from both clinical and environmental settings in Bangladesh and Mexico and other countries around the globe. The chxA gene was present in 47% of 83 non-O1, non-O139 strains and 16% of 72 O1/O139 strains screened as part of this study. A total of 86 chxA gene sequences were obtained, and phylogenetic analysis revealed that they fall into two distinct clades. These two clades were also observed in the phylogenies of several housekeeping genes, suggesting that the divergence observed in chxA extends to other regions of the V. cholerae genome, and most likely has arisen from vertical descent rather than horizontal transfer. Our results clearly indicate that ChxA is a major toxin of V. cholerae with a worldwide distribution that is preferentially associated with non-pandemic strains. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.

Science.gov (United States)

Chen, Wilbur H; Cohen, Mitchell B; Kirkpatrick, Beth D; Brady, Rebecca C; Galloway, David; Gurwith, Marc; Hall, Robert H; Kessler, Robert A; Lock, Michael; Haney, Douglas; Lyon, Caroline E; Pasetti, Marcela F; Simon, Jakub K; Szabo, Flora; Tennant, Sharon; Levine, Myron M

2016-06-01

No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model. Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration. The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001). The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine. NCT01895855. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

An attenuated Shigella mutant lacking the RNA-binding protein Hfq provides cross-protection against Shigella strains of broad serotype.

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Mitobe, Jiro; Sinha, Ritam; Mitra, Soma; Nag, Dhrubajyoti; Saito, Noriko; Shimuta, Ken; Koizumi, Nobuo; Koley, Hemanta

2017-07-01

Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.

An attenuated Shigella mutant lacking the RNA-binding protein Hfq provides cross-protection against Shigella strains of broad serotype.

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Jiro Mitobe

2017-07-01

Full Text Available Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.

Analysis of invasive pneumonia-causing strains of Streptococcus pneumoniae: serotypes and antimicrobial susceptibility.

Science.gov (United States)

Yoshioka, Cristina R M; Martinez, Marina B; Brandileone, Maria C C; Ragazzi, Selma B; Guerra, Maria L L S; Santos, Silvia R; Shieh, Huei H; Gilio, Alfredo E

2011-01-01

To identify the most common pneumococcal serotypes in children hospitalized with invasive pneumonia, correlate isolated serotypes with those included in conjugate vaccines, and ascertain the sensitivity of the isolated pneumococcal strains to penicillin and other antibiotics. From January 2003 to October 2008, a retrospective study of hospitalized children with a diagnosis of Streptococcus pneumoniae pneumonia was conducted at the university hospital of Universidade de São Paulo. Criteria for inclusion were: age greater than 29 days and less than 15 years, radiological and clinical diagnosis of pneumonia, and isolation of Streptococcus pneumoniae in blood cultures and/or pleural effusion. The study included 107 children. The most common serotypes were 14 (36.5%), 1 (16%), 5 (14.6%), 6B (6.3%) and 3 (4.2%). The proportion of identified serotypes contained in the heptavalent, 10-valent and 13-valent conjugate vaccines was 53.1, 86.5, and 96.9%, respectively. Pneumococcal strains were sensitive to penicillin (minimum inhibitory concentration, MIC ≤ 2 µg/mL) in 100 cases (93.5%) and displayed intermediate resistance (MIC = 4 µg/mL) in 7 cases (6.5%). No strains were penicillin-resistant (MIC ≥ 8 µg/mL) according to the Clinical and Laboratory Standards Institute 2008 standards. Tested isolates were highly sensitive to vancomycin, rifampicin, ceftriaxone, clindamycin, erythromycin, and chloramphenicol. Our results confirm a significant potential impact of conjugate vaccines, mainly 10-valent and 13-valent, on invasive pneumonia. Furthermore, susceptibility testing results show that penicillin is still the treatment of choice for invasive pneumonia in our setting.

Vibrio cholerae Classical Biotype Strains Reveal Distinct Signatures in Mexico

OpenAIRE

Alam, Munirul; Islam, M. Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A.; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R.; Cravioto, Alejandro

2012-01-01

Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 199...

In silico serotyping of E. coli from short read data identifies limited novel O-loci but extensive diversity of O:H serotype combinations within and between pathogenic lineages.

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Ingle, Danielle J; Valcanis, Mary; Kuzevski, Alex; Tauschek, Marija; Inouye, Michael; Stinear, Tim; Levine, Myron M; Robins-Browne, Roy M; Holt, Kathryn E

2016-07-01

The lipopolysaccharide (O) and flagellar (H) surface antigens of Escherichia coli are targets for serotyping that have traditionally been used to identify pathogenic lineages. These surface antigens are important for the survival of E. coli within mammalian hosts. However, traditional serotyping has several limitations, and public health reference laboratories are increasingly moving towards whole genome sequencing (WGS) to characterize bacterial isolates. Here we present a method to rapidly and accurately serotype E. coli isolates from raw, short read WGS data. Our approach bypasses the need for de novo genome assembly by directly screening WGS reads against a curated database of alleles linked to known and novel E. coli O-groups and H-types (the EcOH database) using the software package srst2. We validated the approach by comparing in silico results for 197 enteropathogenic E. coli isolates with those obtained by serological phenotyping in an independent laboratory. We then demonstrated the utility of our method to characterize isolates in public health and clinical settings, and to explore the genetic diversity of >1500 E. coli genomes from multiple sources. Importantly, we showed that transfer of O- and H-antigen loci between E. coli chromosomal backbones is common, with little evidence of constraints by host or pathotype, suggesting that E. coli ' strain space' may be virtually unlimited, even within specific pathotypes. Our findings show that serotyping is most useful when used in combination with strain genotyping to characterize microevolution events within an inferred population structure.

Detection of Burkholderia pseudomallei O-antigen serotypes in near-neighbor species

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Stone Joshua K

2012-11-01

Full Text Available Abstract Background Burkholderia pseudomallei is the etiological agent of melioidosis and a CDC category B select agent with no available effective vaccine. Previous immunizations in mice have utilized the lipopolysaccharide (LPS as a potential vaccine target because it is known as one of the most important antigenic epitopes in B. pseudomallei. Complicating this strategy are the four different B. pseudomallei LPS O-antigen types: A, B, B2, and rough. Sero-crossreactivity is common among O-antigens of Burkholderia species. Here, we identified the presence of multiple B. pseudomallei O-antigen types and sero-crossreactivity in its near-neighbor species. Results PCR screening of O-antigen biosynthesis genes, phenotypic characterization using SDS-PAGE, and immunoblot analysis showed that majority of B. mallei and B. thailandensis strains contained the typical O-antigen type A. In contrast, most of B. ubonensis and B. thailandensis-like strains expressed the atypical O-antigen types B and B2, respectively. Most B. oklahomensis strains expressed a distinct and non-seroreactive O-antigen type, except strain E0147 which expressed O-antigen type A. O-antigen type B2 was also detected in B. thailandensis 82172, B. ubonensis MSMB108, and Burkholderia sp. MSMB175. Interestingly, B. thailandensis-like MSMB43 contained a novel serotype B positive O-antigen. Conclusions This study expands the number of species which express B. pseudomallei O-antigen types. Further work is required to elucidate the full structures and how closely these are to the B. pseudomallei O-antigens, which will ultimately determine the efficacy of the near-neighbor B serotypes for vaccine development.

Characterization and genetic variation of vibrio cholerae isolated from clinical and environmental sources in Thailand

DEFF Research Database (Denmark)

Siriphap, Achiraya; Leekitcharoenphon, Pimlapas; Kaas, Rolf Sommer

2017-01-01

Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic...... and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using...... online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found...

Anethole inhibits growth of recently emerged multidrug resistant toxigenic Vibrio cholerae O1 El Tor variant strains in vitro

OpenAIRE

ZAHID, M. Shamim Hasan; AWASTHI, Sharda Prasad; HINENOYA, Atsushi; YAMASAKI, Shinji

2015-01-01

To search natural compounds having inhibitory effect on bacterial growth is important, particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens. Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent of diarrheal disease cholera, is becoming a great concern. As an approach of searching new antimicrobial agents, here, we show that anethole, a well-studied natural component of sweet fennel and star anise seeds, could potentially inhibit the grow...

[The development of reagents set in the format of DNA-chip for genetic typing of strains of Vibrio cholerae].

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Pudova, E A; Markelov, M L; Dedkov, V G; Tchekanova, T A; Sadjin, A I; Kirdiyashkina, N P; Bekova, M V; Deviyatkin, A A

2014-05-01

The necessity of development of methods of genic diagnostic of cholera is conditioned by continuation of the Seventh pandemic of cholera, taxonomic variability of strains of Vibrio cholerae involved into pandemic and also permanent danger of delivery of disease to the territory of the Russian Federation. The methods of genic diagnostic of cholera make it possible in a comparatively short time to maximally minutely characterize strains isolated from patients or their environment. The article presents information about working out reagents set for genetic typing of agents of cholera using DNA-chip. The makeup of DNA-chip included oligonucleotide probes making possible to differentiate strains of V. cholerae on serogroups and biovars and to determine their pathogenicity. The single DNA-chip makes it possible to genetically type up to 12 samples concurrently. At that, duration of analysis without accounting stage of DNA separation makes up to 5 hours. In the progress of work, 23 cholera and non-cholera strains were analyzed. The full compliance of DNA-chip typing results to previously known characteristics of strains. Hence, there is a reason to consider availability of further development of reagents set and possibility of its further application in laboratories of regional level and reference centers.

Twee Nederlandse reizigers uit Thailand met cholera

NARCIS (Netherlands)

Smit, A. A.; Kuijper, E. J.; Schultz, M. J.; Wieling, W.; Speelman, P.

1994-01-01

Cholera is a disease rarely imported in the Netherlands. Recently a 34-year-old woman who had returned from a trip through Thailand was admitted to our hospital with complaints of vomiting, watery stools and moderate dehydration. Vibrio cholerae OI serotype Ogawa biotype El Tor was isolated from the

The protective activity of tea against infection by Vibrio cholerae O1.

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Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Shimamura, T

1991-02-01

Extracts of black tea exhibited bactericidal activity against Vibrio cholerae O1. The tea extract inhibited the haemolysin activity of V. cholerae O1, El Tor and the morphological changes of Chinese hamster ovary cells induced by cholera toxin. Tea extract also reduced fluid accumulation induced by cholera toxin in sealed adult mice and by V. cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea has protective activity against V. cholerae O1.

The Pneumococcal Serotype 15C Capsule Is Partially O-Acetylated and Allows for Limited Evasion of 23-Valent Pneumococcal Polysaccharide Vaccine-Elicited Anti-Serotype 15B Antibodies.

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Spencer, Brady L; Shenoy, Anukul T; Orihuela, Carlos J; Nahm, Moon H

2017-08-01

As a species, Streptococcus pneumoniae (the pneumococcus) utilizes a diverse array of capsular polysaccharides to evade the host. In contrast to large variations in sugar composition and linkage formation, O-acetylation is a subtle capsular modification that nonetheless has a large impact on capsular shielding and recognition of the capsule by vaccine-elicited antibodies. Serotype 15B, which is included in the 23-valent pneumococcal polysaccharide vaccine (PPV23), carries the putative O-acetyltransferase gene wciZ The coding sequence of wciZ contains eight consecutive TA repeats [(TA) 8 ]. Replication slippage is thought to result in the addition or loss of TA repeats, subsequently causing frameshift and truncation of WciZ to yield a nonacetylated serotype, 15C. Using sensitive serological tools, we show that serotype 15C isolates whose wciZ contains seven or nine TA repeats retain partial O-acetylation, while serotype 15C isolates whose wciZ contains six TA repeats have barely detectable O-acetylation. We confirmed by inhibition enzyme-linked immunosorbent assay that (TA) 7 serotype 15C is ∼0.1% as acetylated as serotype 15B, while serotype 15X is nonacetylated. To eliminate the impact of genetic background, we created isogenic serotype 15B, (TA) 7 serotype 15C, and 15BΔ wciZ (15X) strains and found that reduction or absence of WciZ-mediated O-acetylation did not affect capsular shielding from phagocytes, biofilm formation, adhesion to nasopharyngeal cells, desiccation tolerance, or murine colonization. Sera from PPV23-immunized persons opsonized serotype 15B significantly but only slightly better than serotypes 15C and 15X; thus, PPV23 may not result in expansion of serotype 15C. Copyright © 2017 American Society for Microbiology.

Improved laboratory capacity is required to respond better to future cholera outbreaks in Papua New Guinea

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Paul Horwood

2012-05-01

Full Text Available Cholera was first detected in Papua New Guinea in July 2009, caused by Vibrio cholerae O1 El Tor serotype Ogawa. By late 2011, 15 500 cases had been reported throughout lowland Papua New Guinea with a case fatality rate of 3.2%. The epidemic has since slowed, with only sporadic cases reported in Western Province and the Autonomous Region of Bougainville (ARB. Accurate and timely diagnosis is a critical element of the public health response to cholera, yet in low-income countries where the burden of cholera is the greatest, diagnostic services are often limited. Here we report on the diagnostic challenges and the logistical factors that impacted on diagnosis during the first reported outbreak of cholera in Papua New Guinea.

Constitutive type VI secretion system expression gives Vibrio cholerae intra- and interspecific competitive advantages.

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Daniel Unterweger

Full Text Available The type VI secretion system (T6SS mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae - the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria and a eukaryote (the social amoeba Dictyostelium discoideum. Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.

Radiation-sensitive mutant of hypertoxinogenic strain 569B of Vibro cholerae

International Nuclear Information System (INIS)

Das, G.; Das, J.

1983-01-01

A radiation-sensitive mutant of the hypertoxinogenic strain 569B of Vibrio cholerae was isolated and characterized. The mutant, designated V. cholerae 569Bsub(s), lacks both excision- and medium-dependent dark-repair mechanisms of UV-induced DNA damage while retaining the wild-type photoreactivating capability. Analysis of the UV-irradiated cell DNA by velocity sedimentation in alkaline sucrose gradient suggests that UV-induced pyrimidine dimers may not be incised in these cells. In contrast to the wild-type cells, the mutant cell DNA was degraded after treatment with nalidixic acid. The mutant cells failed to produce any detectable amount of cholera toxin as measured by ileal-loop assay. (orig.)

Detection of ctx gene positive non-O1/non-O139 V. cholerae in shrimp aquaculture environments.

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Madhusudana, Rao B; Surendran, P K

2013-06-01

Water and post-larvae samples from black tiger (Penaeus monodon) shrimp hatcheries; pond water, pond sediment and shrimp from aquaculture farms were screened for the presence of V. cholerae. A V. cholerae-duplex PCR method was developed by utilizing V. cholerae species specific sodB primers and ctxAB genes specific primers. Incidence of V. cholerae was not observed in shrimp hatchery samples but was noticed in aquaculture samples. The incidence of V. cholerae was higher in pond water (7.6%) than in pond sediment (5.2%). Shrimp head (3.6%) portion had relatively higher incidence than shrimp muscle (1.6%). All the V. cholerae isolates (n = 42) belonged to non-O1/non-O139 serogroup, of which 7% of the V. cholerae isolates were potentially cholera-toxigenic (ctx positive). All the ctx positive V. cholerae (n = 3) were isolated from the pond water. Since, cholera toxin (CT) is the major contributing factor for cholera gravis, it is proposed that the mere presence of non-O1/non-O139 V. cholerae need not be the biohazard criterion in cultured black tiger shrimp but only the presence of ctx carrying non-O1/non-O139 V. cholerae may be considered as potential public health risk.

The aquatic environment as a reservoir of Vibrio cholerae O1 in hydrographic basins of the state of Pernambuco, Brazil.

Science.gov (United States)

Mendes-Marques, Carina Lucena; Silveira Filho, Vladimir da Mota; da Costa, Ana Paula Rocha; Nunes, Mariana de Lira; da Silva Filho, Sandoval Vieira; Figueirôa, Ângela Cristina Torres de Araújo; Hofer, Ernesto; de Almeida, Alzira Maria Paiva; Leal, Nilma Cintra

2013-01-01

After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1) positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR); 2 of these were also ctxA (cholera toxin) positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR), and pulsed field gel electrophoresis (PFGE). The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012) and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

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Carina Lucena Mendes-Marques

2013-01-01

Full Text Available After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1 positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR; 2 of these were also ctxA (cholera toxin positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR, and pulsed field gel electrophoresis (PFGE. The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012 and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

Molecular Analysis and Toxigenic Potential of Vibrio cholerae Isolated from Hilsha fish (Tenualosa ilisha), Bangladesh

DEFF Research Database (Denmark)

Hossain, Zenat Zebin; Farhana, Israt; Tulsiani, Suhella

water fish may serve as a transmission vehicle of potential emerging epidemic causing strains. For this, we studied 9 toxigenic V. cholerae strains isolated from Hilsha fish including 6 V. cholerae O1 and 3 non O1/O139 serogroups for virulence associated genotype and their pathogenic potential on animal......Exposure to contaminated fish may upsurge the virulent strains of Vibrio cholerae, the deadly human pathogen in the households of rural and urban Bangladesh. Since V. cholerae spreading was reported from the Bay of Bengal, this study hypothesized that Hilsha (Tenualosa ilisha), a marine and fresh...

Genetic diversity of clinical and environmental isolates of Vibrio cholerae determined by amplified fragment length polymorphism fingerprinting.

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Jiang, S C; Matte, M; Matte, G; Huq, A; Colwell, R R

2000-01-01

Vibrio cholerae, the causative agent of major epidemics of diarrheal disease in Bangladesh, South America, Southeastern Asia, and Africa, was isolated from clinical samples and from aquatic environments during and between epidemics over the past 20 years. To determine the evolutionary relationships and molecular diversity of these strains, in order to understand sources, origin, and epidemiology, a novel DNA fingerprinting technique, amplified fragment length polymorphism (AFLP), was employed. Two sets of restriction enzyme-primer combinations were tested for fingerprinting of V. cholerae serogroup O1, O139, and non-O1, O139 isolates. Amplification of HindIII- and TaqI-digested genomic DNA produced 30 to 50 bands for each strain. However, this combination, although capable of separating environmental isolates of O1 and non-O1 strains, was unable to distinguish between O1 and O139 clinical strains. This result confirmed that clinical O1 and O139 strains are genetically closely related. On the other hand, AFLP analyses of restriction enzyme ApaI- and TaqI-digested genomic DNA yielded 20 to 30 bands for each strain, but were able to separate O1 from O139 strains. Of the 74 strains examined with the latter combination, 26 serogroup O1 strains showed identical banding patterns and were represented by the O1 El Tor strain of the seventh pandemic. A second group, represented by O139 Bengal, included 12 strains of O139 clinical isolates, with 7 from Thailand, 3 from Bangladesh, and 2 from India. Interestingly, an O1 clinical isolate from Africa also grouped with the O139 clinical isolates. Eight clinical O1 isolates from Mexico grouped separately from the O1 El Tor of the seventh pandemic, suggesting an independent origin of these isolates. Identical fingerprints were observed between an O1 environmental isolate from a river in Chile and an O1 clinical strain from Kenya, both isolated more than 10 years apart. Both strains were distinct from the O1 seventh pandemic strain

Vibrio cholerae Colonization of Soft-Shelled Turtles.

Science.gov (United States)

Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

2017-07-15

Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae -contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N -acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological

A molecular scheme for Yersinia enterocolitica patho-serotyping derived from genome-wide analysis.

Science.gov (United States)

Garzetti, Debora; Susen, Rosa; Fruth, Angelika; Tietze, Erhard; Heesemann, Jürgen; Rakin, Alexander

2014-05-01

Yersinia enterocolitica is a food-borne, gastro-intestinal pathogen with world-wide distribution. Only 11 serotypes have been isolated from patients, with O:3, O:9, O:8 and O:5,27 being the serotypes most commonly associated with human yersiniosis. Serotype is an important characteristic of Y. enterocolitica strains, allowing differentiation for epidemiology, diagnosis and phylogeny studies. Conventional serotyping, performed by slide agglutination, is a tedious and laborious procedure whose interpretation tends to be subjective, leading to poor reproducibility. Here we present a PCR-based typing scheme for molecular identification and patho-serotyping of Y. enterocolitica. Genome-wide comparison of Y. enterocolitica sequences allowed analysis of the O-antigen gene clusters of different serotypes, uncovering their formerly unknown genomic locations, and selection of targets for serotype-specific amplification. Two multiplex PCRs and one additional PCR were designed and tested on various reference strains and isolates from different origins. Our genotypic assay proved to be highly specific for identification of Y. enterocolitica species, discrimination between virulent and non-virulent strains, distinguishing the main human-related serotypes, and typing of conventionally untypeable strains. This genotyping scheme could be applied in microbiology laboratories as an alternative or complementary method to the traditional phenotypic assays, providing data for epidemiological studies. Copyright © 2013 Elsevier GmbH. All rights reserved.

Molecular epidemiology of Vibrio cholerae associated with flood in Brahamputra River valley, Assam, India.

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Bhuyan, Soubhagya K; Vairale, Mohan G; Arya, Neha; Yadav, Priti; Veer, Vijay; Singh, Lokendra; Yadava, Pramod K; Kumar, Pramod

2016-06-01

Cholera is often caused when drinking water is contaminated through environmental sources. In recent years, the drastic cholera epidemics in Odisha (2007) and Haiti (2010) were associated with natural disasters (flood and Earthquake). Almost every year the state of Assam India witnesses flood in Brahamputra River valley during reversal of wind system (monsoon). This is often followed by outbreak of diarrheal diseases including cholera. Beside the incidence of cholera outbreaks, there is lack of experimental evidence for prevalence of the bacterium in aquatic environment and its association with cholera during/after flood in the state. A molecular surveillance during 2012-14 was carried out to study prevalence, strain differentiation, and clonality of Vibrio cholerae in inland aquatic reservoirs flooded by Brahamputra River in Assam. Water samples were collected, filtered, enriched in alkaline peptone water followed by selective culturing on thiosulfate bile salt sucrose agar. Environmental isolates were identified as V. cholerae, based on biochemical assays followed by sero-grouping and detailed molecular characterization. The incidence of the presence of the bacterium in potable water sources was higher after flood. Except one O1 isolate, all of the strains were broadly grouped under non-O1/non-O139 whereas some of them did have cholera toxin (CT). Surprisingly, we have noticed Haitian ctxB in two non-O1/non-O139 strains. MLST analyses based on pyrH, recA and rpoA genes revealed clonality in the environmental strains. The isolates showed varying degree of antimicrobial resistance including tetracycline and ciprofloxacin. The strains harbored the genetic elements SXT constins and integrons responsible for multidrug resistance. Genetic characterization is useful as phenotypic characters alone have proven to be unsatisfactory for strain discrimination. An assurance to safe drinking water, sanitation and monitoring of the aquatic reservoirs is of utmost importance for

Non-01 Vibrio cholerae infections in Cancun, Mexico.

Science.gov (United States)

Finch, M J; Valdespino, J L; Wells, J G; Perez-Perez, G; Arjona, F; Sepulveda, A; Bessudo, D; Blake, P A

1987-03-01

To determine the role of Vibrio cholerae as a cause of diarrheal illness in Cancun, Mexico, an investigation was conducted in July and August 1983. Although toxigenic V. cholerae 01 were not found, non-01 V. cholerae were isolated from 22 (16%) of 134 stools from persons with diarrheal illness and none of 22 stools from well persons; 58 (92%) of 63 sewage samples; 12 (86%) of 14 untreated well water samples; a home storage tank for treated water; and 5 (21%) of 24 samples of raw seafood. None of the V. cholerae isolates from patients were toxigenic. The illness occurred mainly in small children, and were characterized principally by diarrhea and abdominal pain. No patient was seriously ill, and all recovered without sequelae. Seven different serotypes of non-01 V. cholerae were isolated from the stool specimens, and Smith serotype 12 accounted for 10 (46%) of the 22 isolates. A matched-pair case-control study found that cases were more likely than controls to have eaten home prepared gelatin (P = 0.03, OR = 5/0) and seafood (P = 0.06, OR = 4/0).

Development and testing of monoclonal antibody-based rapid immunodiagnostic test kits for direct detection of Vibrio cholerae O139 synonym Bengal.

Science.gov (United States)

Hasan, J A; Huq, A; Nair, G B; Garg, S; Mukhopadhyay, A K; Loomis, L; Bernstein, D; Colwell, R R

1995-11-01

We report on the development and testing of two monoclonal antibody-based rapid immunodiagnostic test kits, BengalScreen, a coagglutination test, and Bengal DFA, a direct fluorescent-antibody test, for direct detection of Vibrio cholerae O139 synonym Bengal in clinical and environmental specimens. The BengalScreen test requires less than 5 min to complete and can be used in the field. Bengal DFA, being more sensitive than BengalScreen, requires only one reagent and less than 20 min for detection and enumeration of V. cholerae O139 synonym Bengal. In tests for specificity, all 40 strains of V. cholerae O139 reacted with both test kits, whereas 157 strains of heterologous species examined did not, yielding 100% specificity in this study. A field trial was conducted in with both BengalScreen and Bengal DFA, and the results were compared with those obtained by conventional culture methods. BengalScreen demonstrated a sensitivity of 95%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 94%. Results obtained by Bengal DFA, on the other hand, were 100% sensitive and 100% specific and yielded 100% positive and negative predictive values compared with culture methods. In a second evaluation, 93 stool specimens from Mexico that were negative for V. cholerae O139 by culture were also tested with both the BengalScreen and Bengal DFA kits. None of the 93 specimens were positive for V. cholerae O139 by both tests. A concentration method was optimized for screening of environmental water samples for V. cholerae O139 synonym Bengal with rapid test kits. BengalScreen results were unequivocally positive when water samples contained at least 2.0 x 10(3) CFU/ml, whereas Bengal DFA demonstrated an unequivocally positive reaction when the water sample contained at least 1.5 x 10(2) CFU/ml. When Bengal DFA was compared with conventional culture methods for enumeration of V. cholerae O139 synonym Bengal organisms, no difference was observed.

IncA/C Conjugative Plasmids Mobilize a New Family of Multidrug Resistance Islands in Clinical Vibrio cholerae Non-O1/Non-O139 Isolates from Haiti.

Science.gov (United States)

Carraro, Nicolas; Rivard, Nicolas; Ceccarelli, Daniela; Colwell, Rita R; Burrus, Vincent

2016-07-19

Mobile genetic elements play a pivotal role in the adaptation of bacterial populations, allowing them to rapidly cope with hostile conditions, including the presence of antimicrobial compounds. IncA/C conjugative plasmids (ACPs) are efficient vehicles for dissemination of multidrug resistance genes in a broad range of pathogenic species of Enterobacteriaceae ACPs have sporadically been reported in Vibrio cholerae, the infectious agent of the diarrheal disease cholera. The regulatory network that controls ACP mobility ultimately depends on the transcriptional activation of multiple ACP-borne operons by the master activator AcaCD. Beyond ACP conjugation, AcaCD has also recently been shown to activate the expression of genes located in the Salmonella genomic island 1 (SGI1). Here, we describe MGIVchHai6, a novel and unrelated mobilizable genomic island (MGI) integrated into the 3' end of trmE in chromosome I of V. cholerae HC-36A1, a non-O1/non-O139 multidrug-resistant clinical isolate recovered from Haiti in 2010. MGIVchHai6 contains a mercury resistance transposon and an integron In104-like multidrug resistance element similar to the one of SGI1. We show that MGIVchHai6 excises from the chromosome in an AcaCD-dependent manner and is mobilized by ACPs. Acquisition of MGIVchHai6 confers resistance to β-lactams, sulfamethoxazole, tetracycline, chloramphenicol, trimethoprim, and streptomycin/spectinomycin. In silico analyses revealed that MGIVchHai6-like elements are carried by several environmental and clinical V. cholerae strains recovered from the Indian subcontinent, as well as from North and South America, including all non-O1/non-O139 clinical isolates from Haiti. Vibrio cholerae, the causative agent of cholera, remains a global public health threat. Seventh-pandemic V. cholerae acquired multidrug resistance genes primarily through circulation of SXT/R391 integrative and conjugative elements. IncA/C conjugative plasmids have sporadically been reported to

Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country.

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Boucher, Yan

2016-05-03

Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15). It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae. Copyright © 2016 Boucher.

Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country

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Yan Boucher

2016-07-01

Full Text Available Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15. It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae.

El Niño, Rainfall, and the Shifting Geography of Cholera in Africa

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Moore, S.; Azman, A. S.; Zaitchik, B. F.; McKay, H.; Lessler, J.

2017-12-01

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between El Niño patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa where many cholera cases and deaths are reported. To understand how ENSO affects the geographic distribution of cholera incidence in Africa, we used a hierarchical Bayesian approach to integrate over 17,000 annual observations of cholera incidence from 2000-2014 in over 3,000 unique locations of varying spatial extent, ranging from entire countries to neighborhoods. The resulting maps reflect modeled cholera incidence at a fine spatial resolution using reported counts of cholera cases, key explanatory variables, and a spatially-dependent covariance term. We then examined the potential mechanistic association between ENSO-related changes in cholera incidence and several environmental variables including rainfall. El Niño profoundly changed the annual geographic distribution of cholera in Africa from 2000-2014, shifting the burden to continental East Africa, where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall suggesting a complex relationship between rainfall and cholera incidence. Here we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño and non-El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with El Niño forecasting could be used to notify countries in Africa when they are likely to see

Cell Vacuolation Caused by Vibrio cholerae Hemolysin

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Figueroa-Arredondo, Paula; Heuser, John E.; Akopyants, Natalia S.; Morisaki, J. Hiroshi; Giono-Cerezo, Silvia; Enríquez-Rincón, Fernando; Berg, Douglas E.

2001-01-01

Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (∼1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (∼16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses. PMID:11179335

Cell vacuolation caused by Vibrio cholerae hemolysin.

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Figueroa-Arredondo, P; Heuser, J E; Akopyants, N S; Morisaki, J H; Giono-Cerezo, S; Enríquez-Rincón, F; Berg, D E

2001-03-01

Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (approximately 1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (approximately 16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses.

Sorotipagem de amostras de Streptococcus suis isoladas de suínos em granjas dos Estados de São Paulo, Minas Gerais e Paraná Serotyping of Streptococcus suis strains isolated from pigs in the States of São Paulo, Minas Gerais e Paraná, Brazil

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Keila J.R. Pagnani

2002-01-01

, para a sorotipagem das amostras de S. suis. A sorotipagem das 51 amostras isoladas mostraram os seguintes resultados: 30 (58,8% foram classificadas como sorotipo 2, 11 (21,6% das amostras como sorotipo 3, sete (13,72% como sorotipo 7, duas (3,92% como sorotipo 1 e uma amostra como pertencente ao sorotipo14 (1,96%. Este é o primeiro relato do isolamento de um grande número de amostras de S. suis no Brasil, de casos típicos de processos infecciosos causados por esta bactéria. Também foi realizada a sorotipagem dos isolados, mostrando uma alta prevalência do sorotipo 2, quando comparada com a dos demais sorotipos encontrados.Streptococcus suis infection in swine is common in all countries where hog production is well developed. This infection has been associated with bronchopneumonia, meningitis, arthritis, pericarditis, myocarditis, endocarditis, fibrinous polyserositis, septicaemia, rhinitis, and abortion. Streptococcus suis has also been described as a pathogen for ruminants and humans. In Brazil there are several clinical evidences about the existence of S. suis disease in pigs affecting more than 50% of farms in States of São Paulo, Minas Gerais and Paraná. In the present research 51 strains of S. suis isolated from piggeries of the States of São Paulo, Minas Gerais and Paraná were collected from different pathologies such as septicaemia, meningitis, arthritis and pneumonia and been recovered either in pure culture or as the predominant organism from porcine tissues. Culture of specimens was carried out on 5% bovine blood agar plates incubated at 37°C for 24 hr. For the biochemical identification the a-hemolytic colonies of all capsulated isolates were submitted to various conventional tests, such as hydrolysis of arginine, Voges-Proskauer Test, and production of acid from various carbohydrates (inulin, salicin, trehalose, lactose, sucrose, sorbitol, mannitol and glycerol. The strains were also tested for their ability to grow in the presence of 6,5% Na

Genetic Diversity of Clinical and Environmental Strains of Salmonella enterica Serotype Weltevreden Isolated in Malaysia

OpenAIRE

Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.

2002-01-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.2...

Phase variable O antigen biosynthetic genes control expression of the major protective antigen and bacteriophage receptor in Vibrio cholerae O1.

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Kimberley D Seed

2012-09-01

Full Text Available The Vibrio cholerae lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system and is of critical importance for vaccine design. We used an O1-specific lytic bacteriophage as a tool to probe the capacity of V. cholerae to alter its O1 antigen and identified a novel mechanism by which this organism can modulate O antigen expression and exhibit intra-strain heterogeneity. We identified two phase variable genes required for O1 antigen biosynthesis, manA and wbeL. manA resides outside of the previously recognized O1 antigen biosynthetic locus, and encodes for a phosphomannose isomerase critical for the initial step in O1 antigen biosynthesis. We determined that manA and wbeL phase variants are attenuated for virulence, providing functional evidence to further support the critical role of the O1 antigen for infectivity. We provide the first report of phase variation modulating O1 antigen expression in V. cholerae, and show that the maintenance of these phase variable loci is an important means by which this facultative pathogen can generate the diverse subpopulations of cells needed for infecting the host intestinal tract and for escaping predation by an O1-specific phage.

Identification of human-pathogenic strains of Shiga toxin-producing Escherichia coli from food by a combination of serotyping and molecular typing of Shiga toxin genes.

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Beutin, Lothar; Miko, Angelika; Krause, Gladys; Pries, Karin; Haby, Sabine; Steege, Katja; Albrecht, Nadine

2007-08-01

We examined 219 Shiga toxin-producing Escherichia coli (STEC) strains from meat, milk, and cheese samples collected in Germany between 2005 and 2006. All strains were investigated for their serotypes and for genetic variants of Shiga toxins 1 and 2 (Stx1 and Stx2). stx(1) or variant genes were detected in 88 (40.2%) strains and stx(2) and variants in 177 (80.8%) strains. Typing of stx genes was performed by stx-specific PCRs and by analysis of restriction fragment length polymorphisms (RFLP) of PCR products. Major genotypes of the Stx1 (stx(1), stx(1c), and stx(1d)) and the Stx2 (stx(2), stx(2d), stx(2-O118), stx(2e), and stx(2g)) families were detected, and multiple types of stx genes coexisted frequently in STEC strains. Only 1.8% of the STEC strains from food belonged to the classical enterohemorrhagic E. coli (EHEC) types O26:H11, O103:H2, and O157:H7, and only 5.0% of the STEC strains from food were positive for the eae gene, which is a virulence trait of classical EHEC. In contrast, 95 (43.4%) of the food-borne STEC strains carried stx(2) and/or mucus-activatable stx(2d) genes, an indicator for potential high virulence of STEC for humans. Most of these strains belonged to serotypes associated with severe illness in humans, such as O22:H8, O91:H21, O113:H21, O174:H2, and O174:H21. stx(2) and stx(2d) STEC strains were found frequently in milk and beef products. Other stx types were associated more frequently with pork (stx(2e)), lamb, and wildlife meat (stx(1c)). The combination of serotyping and stx genotyping was found useful for identification and for assignment of food-borne STEC to groups with potential lower and higher levels of virulence for humans.

Epidemic waves of cholera in the last two decades in Mozambique.

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Langa, José Paulo; Sema, Cynthia; De Deus, Nilsa; Colombo, Mauro Maria; Taviani, Elisa

2015-07-04

Africa is increasingly affected by cholera. In Mozambique, cholera appeared in the early 1970s when the seventh pandemic entered Africa from the Indian subcontinent. In the following decades, several epidemics were registered in the country, the 1997-1999 epidemic being the most extended. Since then, Mozambique has been considered an endemic area for cholera, characterized by yearly outbreaks occurring with a seasonal pattern. At least three pandemic variants are thought to have originated in the Indian subcontinent and spread worldwide at different times. To understand the epidemiology of cholera in Mozambique, whether the disease re-emerges periodically or is imported by different routes of transmission, we investigated clinical V. cholerae O1 isolated during 1997-1999 and 2012-2014 epidemics. By detecting and characterizing seven genetic elements, the mobilome profile of each isolate was obtained. By comparing it to known seventh pandemic reference strains, it was possible to discern among different V. cholerae O1 variants active in the country. During 1997-1999, epidemic strains showed two different genetic profiles, both related to a pandemic clone that originated from India and was reported in other African countries in the 1990s. Isolates from 2012-2014 outbreaks showed a genetic background related to the pandemic strains currently active as the prevalent causative agent of cholera worldwide. Despite cholera being endemic in Mozambique, the epidemiology of the disease in the past 20 years has been strongly influenced by the cholera seventh pandemic waves that originated in the Indian subcontinent.

[Stx2a-producing enteroaggregative Escherichia coli O104:H4-ST678. Microbiological diagnostic already, for this and other STEC/VTEC serotypes!].

Science.gov (United States)

Blanco, Jorge

2012-02-01

A Stx2a-producing Escherichia coli (STEC) strain belonging to serotype O104:H4, with virulence features common to the enteroaggregative E. coli pathotype, was reported as the cause of the recent 2011 outbreak in Germany. In addition, the German outbreak strain was found to possess several virulence factors of extra-intestinal pathogenic E. coli and to have acquired resistance to numerous antibiotics, including third-generation cephalosporins, owing to several plasmid-borne genes encoding TEM-1 and CTX-M-15 β-lactamases. There are only a few reports of serotype O104:H4, which is very rare in humans, and has never been detected in animals or food. Once the serotype of the German outbreak strain became known, specific molecular methods were developed for its detection based on conventional and real-time PCR. Data from Galicia suggest that, per year in Spain, STEC O157:H7 is responsible for more than 500 cases of infection, and non-O157 for more than 2,000. A microbiological diagnosis for O104:H4, O157:H7 and other STEC serotypes is required in Spanish hospitals. Copyright © 2011 Elsevier España, S.L. All rights reserved.

A novel kit for rapid detection of Vibrio cholerae O1.

OpenAIRE

Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

1994-01-01

We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bact...

[Seroepidemiology of cholera in Mexico].

Science.gov (United States)

González-Bonilla, C; Valle-Valdez, J G; Núñez-León, A; Moguel-Pech, L; Villanueva-Zamudio, A

1994-01-01

Antibodies against Vibrio cholerae were determined in 2352 serum samples obtained from patients with clinical diagnosis of cholera. Samples from their contacts and from healthy people living in the same communities were also analyzed. Vibriocidal antibodies with titers 1:160 or higher were observed in 25% of the samples. An increase of vibriocidal and antitoxin antibody titers were observed in 56 to 60% of the patients in which paired samples were available, one obtained in the acute phase of the disease and the other in the convalescence, confirming the diagnosis of cholera. Differences in the antibody titers were noticed when comparing the serotype according to the geographic area and the season of the year.

Phenotypic, Genotypic, and Antibiotic Sensitivity Patterns of Strains Isolated from the Cholera Epidemic in Zimbabwe

NARCIS (Netherlands)

Islam, Mohammad S.; Mahmud, Zahid H.; Ansaruzzaman, Mohammad; Faruque, Shah M.; Talukder, Kaisar A.; Qadri, Firdausi; Alam, Munirul; Islam, Shafiqul; Bardhan, Pradip K.; Mazumder, Ramendra N.; Khan, Azharul I.; Ahmed, Sirajuddin; Iqbal, Anwarul; Chitsatso, Owen; Mudzori, James; Patel, Sheetal; Midzi, Stanley M.; Charimari, Lincoln; Endtz, Hubert P.; Cravioto, Alejandro

This paper details the phenotypic, genotypic, and antibiotic sensitivity patterns of 88 Vibrio cholerae strains from Zimbabwe. Of the 88 strains, 83 were classified as "altered El Tor" and 5 as "hybrid El Tor" strains. All of the strains were susceptible to tetracycline, doxycycline, ciprofloxacin,

Características de la epidemia de cólera de 1998 en Ecuador, durante el fenómeno de "El Niño" Characteristics of the cholera epidemic of 1998 in Ecuador during El Niño

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Jean-Marc Gabastou

2002-09-01

áctica una serie de medidas preventivas en la comunidad y se fortaleció el sistema de vigilancia para reducir el impacto de la enfermedad. Conclusiones. Las medidas preventivas contribuyeron a reducir el impacto de la nueva epidemia de cólera en el Ecuador, tanto en términos de letalidad como de incidencia. En vista de la sensibilidad global de las cepas a los antimicrobianos, no se justifica cambiar los esquemas de tratamiento vigentes en la Región. Teniendo en cuenta la frecuencia de los desastres naturales en este país y su relación con la reaparición del cólera, es recomendable diseñar intervenciones que permitan prevenir y controlar la reaparición de la enfermedad y su extensión hacia las provincias más vulnerables de la Sierra y el Oriente.Objective. To describe the outbreak of cholera that occurred in Ecuador in 1998 during the El Niño weather phenomenon, to present data on the resistance of the circulating strains of Vibrio cholerae to antimicrobial drugs, and to describe the preventive measures taken by health authorities in order to reduce the impact of the disease. Methods. The epidemiological data came from three sources: 1 the registry of the National Bureau of Epidemiology of the Ministry of Public Health of Ecuador, 2 the registry of the National Institute of Hygiene and Tropical Medicine, and 3 the final report of the Training Program for the Fight against Cholera and Diarrheal Diseases. Isolation, identification, and serotyping was done of V. cholerae in the feces samples from 10% of the suspected cholera cases that were identified between 1 January and 31 December 1998. The suspected cases were defined by the sudden appearance of watery diarrhea, with or without dehydration, in epidemic areas. The strains that were isolated were submitted to a standard antibiogram by the diffusion method, in which the following antibiotics were tested: amoxicillin, tetracycline, trimethoprim-sulfamethoxazole, vibriostatic compound O/129, nalidixic acid

Zinc oxide nanoparticles provide anti-cholera activity by disrupting the interaction of cholera toxin with the human GM1 receptor.

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Sarwar, Shamila; Ali, Asif; Pal, Mahadeb; Chakrabarti, Pinak

2017-11-03

Vibrio cholerae causes cholera and is the leading cause of diarrhea in developing countries, highlighting the need for the development of new treatment strategies to combat this disease agent. While exploring the possibility of using zinc oxide (ZnO) nanoparticles (NPs) in cholera treatment, we previously found that ZnO NPs reduce fluid accumulation in mouse ileum induced by the cholera toxin (CT) protein. To uncover the mechanism of action of ZnO NPs on CT activity, here we used classical (O395) and El Tor (C6706) V. cholerae biotypes in growth and biochemical assays. We found that a ZnO NP concentration of 10 μg/ml did not affect the growth rates of these two strains, nor did we observe that ZnO NPs reduce the expression levels of CT mRNA and protein. It was observed that ZnO NPs form a complex with CT, appear to disrupt the CT secondary structure, and block its interaction with the GM1 ganglioside receptor in the outer leaflet of the plasma membrane in intestinal (HT-29) cells and thereby reduce CT uptake into the cells. In the range of 2.5-10 μg/ml, ZnO NPs exhibited no cytotoxicity on kidney (HEK293) and HT-29 cells. We conclude that ZnO NPs prevent the first step in the translocation of cholera toxin into intestinal epithelial cells without exerting measurable toxic effects on HEK293 and HT-29 cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

Science.gov (United States)

Sinyange, Nyambe; Brunkard, Joan M; Kapata, Nathan; Mazaba, Mazyanga Lucy; Musonda, Kunda G; Hamoonga, Raymond; Kapina, Muzala; Kapaya, Fred; Mutale, Lwito; Kateule, Ernest; Nanzaluka, Francis; Zulu, James; Musyani, Chileshe Lukwesa; Winstead, Alison V; Davis, William W; N'cho, Hammad S; Mulambya, Nelia L; Sakubita, Patrick; Chewe, Orbie; Nyimbili, Sulani; Onwuekwe, Ezinne V C; Adrien, Nedghie; Blackstock, Anna J; Brown, Travis W; Derado, Gordana; Garrett, Nancy; Kim, Sunkyung; Hubbard, Sydney; Kahler, Amy M; Malambo, Warren; Mintz, Eric; Murphy, Jennifer; Narra, Rupa; Rao, Gouthami G; Riggs, Margaret A; Weber, Nicole; Yard, Ellen; Zyambo, Khozya D; Bakyaita, Nathan; Monze, Namani; Malama, Kennedy; Mulwanda, Jabbin; Mukonka, Victor M

2018-05-18

On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

Laboratory evaluation of immunochromatographic rapid diagnostic tests for cholera in Haiti.

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Wilfredo R Matias

Full Text Available Rapid diagnostic tests (RDT for cholera are promising tools for detecting cholera in areas with limited laboratory infrastructure. However, evidence on the characteristics of the many available RDTs is scarce, and their use has been limited by suboptimal performance. We evaluated the performance characteristics of three cholera RDTs from Span Diagnostics, Artron Laboratories, and Standard Diagnostics in a regional laboratory in Haiti.We retrospectively reviewed records from May 2014 to October 2015 of a laboratory-based surveillance program for Vibrio cholerae at Hôpital Saint-Nicolas in Saint-Marc, Haiti. We compared the results of 511 Crystal VC, 129 Artron and 451 SD Bioline RDTs to bacterial culture as the gold standard. Of 905 cultures, 477 (52.7% were positive for V. cholerae O1, of which 27.7% were serotype Inaba. No cultures grew V. cholerae O139. Sensitivity and specificity of Crystal VC were 98.6% (95%CI: 96.5%-99.6% and 71.1% (95%CI: 64.7%-76.9%, respectively. Artron demonstrated a sensitivity of 98.6% (95%CI: 92.7%-100% and specificity of 69.1% (95%CI: 55.2%-80.9%. SD Bioline demonstrated a sensitivity of 81.1% (95%CI: 75.6%-85.8% and specificity of 92.8% (95%CI: 88.4%-95.9%. Crystal VC and Artron frequently showed false positive O139 bands, whereas none were seen with SD Bioline.There is significant variation in the performance of different cholera diagnostic RDTs. Artron and Crystal VC RDTs have high sensitivity and low specificity, while SD Bioline RDT has low to moderate sensitivity and high specificity when performed by laboratory technicians in Haiti. Study limitations included its retrospective design. The suboptimal characteristics of these tests limit their use as clinical point-of-care tests; however, they may be useful in outbreak response, surveillance, and research in resource-limited settings.

Phylodynamic analysis of clinical and environmental Vibrio cholerae isolates from Haiti reveals diversification driven by positive selection.

Science.gov (United States)

Azarian, Taj; Ali, Afsar; Johnson, Judith A; Mohr, David; Prosperi, Mattia; Veras, Nazle M; Jubair, Mohammed; Strickland, Samantha L; Rashid, Mohammad H; Alam, Meer T; Weppelmann, Thomas A; Katz, Lee S; Tarr, Cheryl L; Colwell, Rita R; Morris, J Glenn; Salemi, Marco

2014-12-23

Phylodynamic analysis of genome-wide single-nucleotide polymorphism (SNP) data is a powerful tool to investigate underlying evolutionary processes of bacterial epidemics. The method was applied to investigate a collection of 65 clinical and environmental isolates of Vibrio cholerae from Haiti collected between 2010 and 2012. Characterization of isolates recovered from environmental samples identified a total of four toxigenic V. cholerae O1 isolates, four non-O1/O139 isolates, and a novel nontoxigenic V. cholerae O1 isolate with the classical tcpA gene. Phylogenies of strains were inferred from genome-wide SNPs using coalescent-based demographic models within a Bayesian framework. A close phylogenetic relationship between clinical and environmental toxigenic V. cholerae O1 strains was observed. As cholera spread throughout Haiti between October 2010 and August 2012, the population size initially increased and then fluctuated over time. Selection analysis along internal branches of the phylogeny showed a steady accumulation of synonymous substitutions and a progressive increase of nonsynonymous substitutions over time, suggesting diversification likely was driven by positive selection. Short-term accumulation of nonsynonymous substitutions driven by selection may have significant implications for virulence, transmission dynamics, and even vaccine efficacy. Cholera, a dehydrating diarrheal disease caused by toxigenic strains of the bacterium Vibrio cholerae, emerged in 2010 in Haiti, a country where there were no available records on cholera over the past 100 years. While devastating in terms of morbidity and mortality, the outbreak provided a unique opportunity to study the evolutionary dynamics of V. cholerae and its environmental presence. The present study expands on previous work and provides an in-depth phylodynamic analysis inferred from genome-wide single nucleotide polymorphisms of clinical and environmental strains from dispersed geographic settings in

Phylogenetic analyses of the polyprotein coding sequences of serotype O foot-and-mouth disease viruses in East Africa: evidence for interserotypic recombination

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Balinda Sheila N

2010-08-01

Full Text Available Abstract Background Foot-and-mouth disease (FMD is endemic in East Africa with the majority of the reported outbreaks attributed to serotype O virus. In this study, phylogenetic analyses of the polyprotein coding region of serotype O FMD viruses from Kenya and Uganda has been undertaken to infer evolutionary relationships and processes responsible for the generation and maintenance of diversity within this serotype. FMD virus RNA was obtained from six samples following virus isolation in cell culture and in one case by direct extraction from an oropharyngeal sample. Following RT-PCR, the single long open reading frame, encoding the polyprotein, was sequenced. Results Phylogenetic comparisons of the VP1 coding region showed that the recent East African viruses belong to one lineage within the EA-2 topotype while an older Kenyan strain, K/52/1992 is a representative of the topotype EA-1. Evolutionary relationships between the coding regions for the leader protease (L, the capsid region and almost the entire coding region are monophyletic except for the K/52/1992 which is distinct. Furthermore, phylogenetic relationships for the P2 and P3 regions suggest that the K/52/1992 is a probable recombinant between serotypes A and O. A bootscan analysis of K/52/1992 with East African FMD serotype A viruses (A21/KEN/1964 and A23/KEN/1965 and serotype O viral isolate (K/117/1999 revealed that the P2 region is probably derived from a serotype A strain while the P3 region appears to be a mosaic derived from both serotypes A and O. Conclusions Sequences of the VP1 coding region from recent serotype O FMDVs from Kenya and Uganda are all representatives of a specific East African lineage (topotype EA-2, a probable indication that hardly any FMD introductions of this serotype have occurred from outside the region in the recent past. Furthermore, evidence for interserotypic recombination, within the non-structural protein coding regions, between FMDVs of serotypes A

Genetic diversity and population structure of Vibrio cholerae.

Science.gov (United States)

Beltrán, P; Delgado, G; Navarro, A; Trujillo, F; Selander, R K; Cravioto, A

1999-03-01

Multilocus enzyme electrophoresis (MLEE) of 397 Vibrio cholerae isolates, including 143 serogroup reference strains and 244 strains from Mexico and Guatemala, identified 279 electrophoretic types (ETs) distributed in two major divisions (I and II). Linkage disequilibrium was demonstrated in both divisions and in subdivision Ic of division I but not in subdivision Ia, which includes 76% of the ETs. Despite this evidence of relatively frequent recombination, clonal lineages may persist for periods of time measured in at least decades. In addition to the pandemic clones of serogroups O1 and O139, which form a tight cluster of four ETs in subdivision Ia, MLEE analysis identified numerous apparent clonal lineages of non-O1 strains with intercontinental distributions. A clone of serogroup O37 that demonstrated epidemic potential in the 1960s is closely related to the pandemic O1/O139 clones, but the nontoxigenic O1 Inaba El Tor reference strain is not. A strain of serogroup O22, which has been identified as the most likely donor of exogenous rfb region DNA to the O1 progenitor of the O139 clone, is distantly related to the O1/O139 clones. The close evolutionary relationships of the O1, O139, and O37 epidemic clones indicates that new cholera clones are likely to arise by the modification of a lineage that is already epidemic or is closely related to such a clone.

Avian cholera in waterfowl: the role of lesser snow and Ross's geese as carriers of avian cholera in the Playa Lakes region

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Samuel, M.D.; Shadduck, D.J.; Goldberg, Diana R.; Johnson, W.P.

2005-01-01

We collected samples from apparently healthy geese in the Playa Lakes Region (USA) during the winters of 2000a??01 and 2001a??02 to determine whether carriers of Pasteurella multocida, the bacterium that causes avian cholera, were present in wild populations. With the use of methods developed in laboratory challenge trials (Samuel et al., 2003a) and a serotype-specific polymerase chain reaction method for identification of P. multocida serotype 1, we found that a small proportion of 322 wild birds (cholera infection. Our results confirm the hypothesis that wild waterfowl are carriers of avian cholera and add support for the hypothesis that wild birds are a reservoir for this disease. In concert with other research, this work indicates that enzootic infection with avian cholera occurs in lesser snow goose (Chen caerulescens caerulescens) populations throughout their annual cycle. Although fewer Rossa??s geese (Chen rossii) were sampled, we also found these birds were carriers of P. multocida. Even in the absence of disease outbreaks, serologic evidence indicates that chronic disease transmission and recent infection are apparently occurring year-round in these highly gregarious birds and that a small portion of these populations are potential carriers with active infection.

Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras Radiosensibility of Vibrio cholerae o1 incorporated in oysters, to 60CO

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Ivany R de Moraes

2000-02-01

Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Canan��ia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.OBJECTIVE: Evaluate the effect of ionizing irradiation by 60Co on Vibrio cholerae O1, El-Tor, Ogawa, non-toxigenic, incorporated in live oysters Crassostrea brasiliana. METHODS: Samples of oysters were selected from Cananéia town in the South coast of S. Paulo state, Brazil, contaminated with Vibrio cholerae and irradiated with 60Co at 0.5 and 1.0 kGy dosages. RESULTS: Showed significant reductions of the initial number of V. cholerae , ranging from 3.4 x10(7 to 10³ and 10², respectively. The D10 values related with the respective doses of irradiation were 0.173 and 0.235. CONCLUSION: Considering a 6 value as safety factor, it is concluded that 1.41 kGy irradiation dosage is necessary to eliminate a high number of V. cholerae viable cells in oysters. Controls were used in the experiment.

Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia.

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Thong, K L; Goh, Y L; Radu, S; Noorzaleha, S; Yasin, R; Koh, Y T; Lim, V K E; Rusul, G; Puthucheary, S D

2002-07-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.

Genetic Diversity of Clinical and Environmental Strains of Salmonella enterica Serotype Weltevreden Isolated in Malaysia

Science.gov (United States)

Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.

2002-01-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia. PMID:12089269

Genetical and functional investigation of fliC genes encoding flagellar serotype H4 in wildtype strains of Escherichia coli and in a laboratory E. coli K-12 strain expressing flagellar antigen type H48

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Schaudinn Christoph

2005-01-01

Full Text Available Abstract Background Serotyping of O-(lipopolysaccharide and H-(flagellar antigens is a wideley used method for identification of pathogenic strains and clones of Escherichia coli. At present, 176 O- and 53 H-antigens are described for E. coli which occur in different combinations in the strains. The flagellar antigen H4 is widely present in E. coli strains of different O-serotypes and pathotypes and we have investigated the genetic relationship between H4 encoding fliC genes by PCR, nucleotide sequencing and expression studies. Results The complete nucleotide sequence of fliC genes present in E. coli reference strains U9-41 (O2:K1:H4 and P12b (O15:H17 was determined and both were found 99.3% (1043 of 1050 nucleotides identical in their coding sequence. A PCR/RFLP protocol was developed for typing of fliC-H4 strains and 88 E. coli strains reacting with H4 antiserum were investigated. Nucleotide sequencing of complete fliC genes of six E. coli strains which were selected based on serum agglutination titers, fliC-PCR genotyping and reference data revealed 96.6 to 100% identity on the amino acid level. The functional expression of flagellin encoded by fliC-H4 from strain U9-41 and from our strain P12b which is an H4 expressing variant type was investigated in the E. coli K-12 strain JM109 which encodes flagellar type H48. The fliC recombinant plasmid carrying JM109 strains reacted with both H4 and H48 specific antisera whereas JM109 reacted only with the H48 antiserum. By immunoelectron microscopy, we could show that the flagella made by the fliC-H4 recombinant plasmid carrying strain are constituted of H48 and H4 flagellins which are co-assembled into functional flagella. Conclusion The flagellar serotype H4 is encoded by closely related fliC genes present in serologically different types of E. coli strainswhich were isolated at different time periods and geographical locations. Our expression studies show for the first time, that flagellins of

Cholera ante portas – The re-emergence of cholera in Kinshasa after a ten-year hiatus

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Bompangue, Didier; Vesenbeckh, Silvan Manuel; Giraudoux, Patrick; Castro, Marcia; Muyembe, Jean-Jacques; Kebela Ilunga, Benoît; Murray, Megan

2012-01-01

Background: Cholera is an endemic disease in certain well-defined areas in the east of the Democratic Republic of Congo (DRC). The west of the country, including the mega-city Kinshasa, has been free of cases since mid 2001 when the last outbreak ended. Methods and Findings: We used routinely collected passive surveillance data to construct epidemic curves of the cholera cases and map the spatio-temporal progress of the disease during the first 47 weeks of 2011. We compared the spatial distribution of disease spread to that which occurred in the last cholera epidemic in Kinshasa between 1996 and 2001. To better understand previous determinants of cholera spread in this region, we conducted a correlation analysis to assess the impact of rainfall on weekly health zone cholera case counts between December 1998 and March 2001 and a Generalized Linear Model (GLM) regression analysis to identify factors that have been associated with the most vulnerable health zones within Kinshasa between October 1998 and June 1999. In February 2011, cholera reemerged in a region surrounding Kisangani and gradually spread westwards following the course of the Congo River to Kinshasa, home to 10 million people. Ten sampled isolates were confirmed to be Vibrio cholerae O1, biotype El Tor, serotype Inaba, resistant to trimethoprim-sulfa, furazolidone, nalidixic acid, sulfisoxaole, and streptomycin, and intermediate resistant to Chloramphenicol. An analysis of a previous outbreak in Kinshasa shows that rainfall was correlated with case counts and that health zone population densities as well as fishing and trade activities were predictors of case counts. Conclusion: Cholera is particularly difficult to tackle in the DRC. Given the duration of the rainy season and increased riverine traffic from the eastern provinces in late 2011, we expect further increases in cholera in the coming months and especially within the mega-city Kinshasa. We urge all partners involved in the response to remain

Genotypic and PFGE/MLVA analyses of Vibrio cholerae O1: geographical spread and temporal changes during the 2007-2010 cholera outbreaks in Thailand.

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Kazuhisa Okada

Full Text Available BACKGROUND: Vibrio cholerae O1 El Tor dominated the seventh cholera pandemic which occurred in the 1960s. For two decades, variants of V. cholerae O1 El Tor that produce classical cholera toxin have emerged and spread globally, replacing the prototypic El Tor biotype. This study aims to characterize V. cholerae O1 isolates from outbreaks in Thailand with special reference to genotypic variations over time. METHODS/FINDINGS: A total of 343 isolates of V. cholerae O1 from cholera outbreaks from 2007 to 2010 were investigated, and 99.4% were found to carry the classical cholera toxin B subunit (ctxB and El Tor rstR genes. Pulsed-field gel electrophoresis (PFGE differentiated the isolates into 10 distinct pulsotypes, clustered into two major groups, A and B, with an overall similarity of 88%. Ribotyping, multiple-locus variable-number tandem-repeat analysis (MLVA, and PCR to detect Vibrio seventh pandemic island II (VSP-II related genes of randomly selected isolates from each pulsotype corresponded to the results obtained by PFGE. Epidemiological investigations revealed that MLVA type 2 was strongly associated with a cholera outbreak in northeastern Thailand in 2007, while MLVA type 7 dominated the outbreaks of the southern Gulf areas in 2009 and MLVA type 4 dominated the outbreaks of the central Gulf areas during 2009-2010. Only MLVA type 16 isolates were found in a Thai-Myanmar border area in 2010, whereas those of MLVA types 26, 39, and 41 predominated this border area in 2008. Type 39 then disappeared 1-2 years later as MLVA type 41 became prevalent. Type 41 was also found to infect an outbreak area. CONCLUSIONS: MLVA provided a high-throughput genetic typing tool for understanding the in-depth epidemiology of cholera outbreaks. Our epidemiological surveys suggest that some clones of V. cholerae O1 with similar but distinctive genetic traits circulate in outbreak sites, while others disappear over time.

Spatiotemporal Variation in Environmental Vibrio cholerae in an Estuary in Southern Coastal Ecuador.

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Ryan, Sadie J; Stewart-Ibarra, Anna M; Ordóñez-Enireb, Eunice; Chu, Winnie; Finkelstein, Julia L; King, Christine A; Escobar, Luis E; Lupone, Christina; Heras, Froilan; Tauzer, Erica; Waggoner, Egan; James, Tyler G; Cárdenas, Washington B; Polhemus, Mark

2018-03-10

Cholera emergence is strongly linked to local environmental and ecological context. The 1991-2004 pandemic emerged in Perú and spread north into Ecuador's El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000 inhabitants, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in five months for pathogenic and non-pathogenic Vibrio cholerae , by polymerase chain reaction (PCR). We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Vibrio cholerae presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera-estuarine system to anticipate potential future cholera outbreaks.

Development of a Novel Protein Microarray Method for Serotyping Salmonella enterica Strains

OpenAIRE

Cai, H. Y.; Lu, L.; Muckle, C. A.; Prescott, J. F.; Chen, S.

2005-01-01

An antibody microarray assay was developed for Salmonella serotyping based on the Kauffmann-White scheme. A model (8 by 15) array was constructed using 35 antibodies for identification of 20 common Salmonella serovars and evaluated using 117 target and 73 nontarget Salmonella strains. The assay allowed complete serovar identification of 86 target strains and partial identification of 30 target strains and allowed exclusion of the 73 nontarget strains from the target serovars.

Characterization of Vibrio cholerae O1 El Tor Biotype Variant Clinical Isolates from Bangladesh and Haiti, Including a Molecular Genetic Analysis of Virulence Genes ▿

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Son, Mike S.; Megli, Christina J.; Kovacikova, Gabriela; Qadri, Firdausi; Taylor, Ronald K.

2011-01-01

Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and a representative strain from the 2010 Haiti cholera outbreak. We observed that all 11 strains produced increased CT (2- to 10-fold) compared to that of wild-type El Tor strains under in vitro inducing conditions, but they possessed various TcpA and ToxT expression profiles. Particularly, El Tor variant MQ1795, which produced the highest level of CT and very high levels of TcpA and ToxT, demonstrated hypervirulence compared to the virulence of El Tor wild-type strains in the infant mouse cholera model. Additional genotypic and phenotypic tests were conducted to characterize the variants, including an assessment of biotype-distinguishing characteristics. Notably, the sequencing of ctxB in some El Tor variants revealed two copies of classical ctxB, one per chromosome, contrary to previous reports that located ctxAB only on the large chromosome of El Tor biotype strains. PMID:21880975

Development of tailored real-time RT-PCR assays for the detection and differentiation of serotype O, A and Asia-1 foot-and-mouth disease virus lineages circulating in the Middle East.

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Reid, Scott M; Mioulet, Valerie; Knowles, Nick J; Shirazi, Nazeem; Belsham, Graham J; King, Donald P

2014-10-01

Rapid and accurate diagnosis is essential for effective control of foot-and-mouth disease (FMD). In countries where FMD is endemic, identification of the serotypes of the causative virus strains is important for vaccine selection and tracing the source of outbreaks. In this study, real-time reverse transcription polymerase chain reaction (rRT-PCR) assays using primer/probe sets designed from the VP1 coding region of the virus genomes were developed for the specific detection of serotype O, A and Asia-1 FMD viruses (FMDVs) circulating in the Middle East. These assays were evaluated using representative field samples of serotype O strains belonging exclusively to the PanAsia-2 lineage, serotype A strains of the Iran-05 lineage and serotype Asia-1 viruses from three relevant sub-groups. When RNA extracted from archival and contemporary field strains was tested using one- or two-step rRT-PCR assays, all three primer/probe sets detected the RNA from homotypic viruses and no cross-reactivity was observed with heterotypic viruses. Similar results were obtained using both single- and multiplex assay formats. Using plasmid standards, the minimum detection level of these tests was found to be lower than two copies. The results illustrate the potential of tailored rRT-PCR tools for the detection and categorization of viruses circulating in the Middle East belonging to distinct subgroups of serotypes O, A and Asia-1. These assays can also overcome the problem of serotyping samples which are found positive by the generic rRT-PCR diagnostic assays but negative by virus isolation and antigen-detection ELISA which would otherwise have to be serotyped by nucleotide sequencing. A similar approach could be used to develop serotyping assays for FMDV strains circulating in other regions of the world. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Avaliação de desinfetantes químicos de uso doméstico contra Vibrio cholerae EL TOR (amostra não toxigênica Evaluation of the effect of chemical domestic disinfectants on Vibrio cholerae EL TOR (non toxigenic strain

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Jorge Timenetsky

1992-10-01

Full Text Available As metodologias de avaliação microbiológica de desinfetantes são permanentemente questionadas porque os protocolos laboratoriais não representam as condições reais de uso desses produtos. Em 1985, adotou-se no Brasil, a metodologia da Diluição-Uso da AOAC, para a qualificação microbiológica de desinfetantes químicos, para fins comerciais. Desta maneira, os desinfetantes domésticos são testados contra amostras padrões de Salmonella choleraesuis e Staphylococcus aureus. Pesquisou-se o emprego de Vibrio cholerae devido a sua atual importância, no Brasil, em termos de Saúde Pública, associada ao estudo da atividade antimicrobiana de desinfetantes. Dezenove produtos desinfetantes de uso doméstico encontrados no comércio foram microbiologicamente avaliados. A metodologia foi a Diluição-Uso com 10 carreadores. Os compostos ativos dos produtos incluíam: formaldeído, fenóis, cresóis, amônio quaternário, cloro e etanol, sendo que sete, eram de composição associada. Conforme as recomendações de uso, dezesseis produtos, devem ser utilizados sem diluição. Nestas condições, 9 desinfetantes foram vibriocidas e sete não revelaram tal atividade antibacteriana. Quatro produtos em diluições não esclarecedoras para a desinfecção também mostraram-se ineficazes. Os produtos vibriocidas que devem ser utilizados sem diluição, foram reavaliados diluídos ao dobro. Estas soluções não inativaram V.cholerae, demonstrando microbiologicamente que os seus compostos ativos estão em concentrações limítrofes. O álcool comercial (95,5° GL a 1:3, a "água sanitária" (2,8% de cloro ativo a 1:200, creolina a 1:10 e o "Lysoform" a 1:20 atingiram os padrões do teste.The methodology of microbiological evaluation of disinfectants is permanently being questioned because the laboratorial protocols do not correspond to the real conditions under which these products are used. In 1985 the Use-Dilution method of AOAC was adopted in

A Cholera Conjugate Vaccine Containing O-specific Polysaccharide (OSP of V. cholerae O1 Inaba and Recombinant Fragment of Tetanus Toxin Heavy Chain (OSP:rTTHc Induces Serum, Memory and Lamina Proprial Responses against OSP and Is Protective in Mice.

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Md Abu Sayeed

Full Text Available Vibrio cholerae is the cause of cholera, a severe watery diarrhea. Protection against cholera is serogroup specific. Serogroup specificity is defined by the O-specific polysaccharide (OSP component of lipopolysaccharide (LPS.Here we describe a conjugate vaccine for cholera prepared via squaric acid chemistry from the OSP of V. cholerae O1 Inaba strain PIC018 and a recombinant heavy chain fragment of tetanus toxin (OSP:rTTHc. We assessed a range of vaccine doses based on the OSP content of the vaccine (10-50 μg, vaccine compositions varying by molar loading ratio of OSP to rTTHc (3:1, 5:1, 10:1, effect of an adjuvant, and route of immunization.Immunized mice developed prominent anti-OSP and anti-TT serum IgG responses, as well as vibriocidal antibody and memory B cell responses following intramuscular or intradermal vaccination. Mice did not develop anti-squarate responses. Intestinal lamina proprial IgA responses targeting OSP occurred following intradermal vaccination. In general, we found comparable immune responses in mice immunized with these variations, although memory B cell and vibriocidal responses were blunted in mice receiving the highest dose of vaccine (50 μg. We found no appreciable change in immune responses when the conjugate vaccine was administered in the presence or absence of immunoadjuvant alum. Administration of OSP:rTTHc resulted in 55% protective efficacy in a mouse survival cholera challenge model.We report development of an Inaba OSP:rTTHc conjugate vaccine that induces memory responses and protection against cholera in mice. Development of an effective cholera conjugate vaccine that induces high level and long-term immune responses against OSP would be beneficial, especially in young children who respond poorly to polysaccharide antigens.

The protective activity of tea catechins against experimental infection by Vibrio cholerae O1.

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Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Hara, Y; Shimamura, T

1992-01-01

Tea catechins inhibited the fluid accumulation induced by cholera toxin in sealed adult mice. The catechins also reduced fluid accumulation by Vibrio cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea catechins may possess protective activity against V. cholerae O1.

El Niño, Climate, and Cholera Associations in Piura, Peru, 1991-2001: A Wavelet Analysis.

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Ramírez, Iván J; Grady, Sue C

2016-03-01

In Peru, it was hypothesized that epidemic cholera in 1991 was linked to El Niño, the warm phase of El Niño-Southern Oscillation. While previous studies demonstrated an association in 1997-1998, using cross-sectional data, they did not assess the consistency of this relationship across the decade. Thus, how strong or variable an El Niño-cholera relationship was in Peru or whether El Niño triggered epidemic cholera early in the decade remains unknown. In this study, wavelet and mediation analyses were used to characterize temporal patterns among El Niño, local climate variables (rainfall, river discharge, and air temperature), and cholera incidence in Piura, Peru from 1991 to 2001 and to estimate the mediating effects of local climate on El Niño-cholera relationships. The study hypothesis is that El Niño-related connections with cholera in Piura were transient and interconnected via local climate pathways. Overall, our findings provide evidence that a strong El Niño-cholera link, mediated by local hydrology, existed in the latter part of the 1990s but found no evidence of an El Niño association in the earlier part of the decade, suggesting that El Niño may not have precipitated cholera emergence in Piura. Further examinations of cholera epicenters in Peru are recommended to support these results in Piura. For public health planning, the results may improve existing efforts that utilize El Niño monitoring for preparedness during future climate-related extremes in the region.

Serotype markers in a Streptococcus agalactiae strain collection from Zimbabwe

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Mavenyengwa R

2010-01-01

Full Text Available Objective: Group B streptococci (GBS from Southern African areas have been less well characterized. Our objective was to study serotype and serovariant distribution of carrier GBS strains as part of a study of the epidemiology of GBS carriage in pregnant women from Zimbabwe. Materials and Methods: We studied GBS isolated from 121 healthy pregnant women living in Harare and surrounding areas, Zimbabwe. Capsular polysaccharide (CPS testing for serotype determination and surface-anchored protein testing for serosubtype determination were done by gene-based serotyping (PCR, except for the proteins R3 and a novel protein called Z, which were detected by antibody-based methods. Results: Strains of the CPS types Ia (15.7%, Ib (11.6%, II (8.3%, III (38.8%, V (24.0% and NT (1.7% were detected along with the strain-variable proteins Cί (15.7% of isolates, Cα (19.8%, Alp1 (epsilon-22.3%, Alp3 (5.0%, R4/Rib (46.3%, R3 (27.3%, Z (27.3%, and SAR5 (28.9%, which encodes the R5 protein. Up to four of the protein genes could be possessed or the gene product expressed by one and the same isolate. A total of 32 serovariants were detected. The findings assessed by us as most important were the very low prevalence of the gene Alp3 (Alp3 - 4.9%, high prevalence of R4 (Rib - 46.2%, the proteins R3 (27.3%, Z (27.3%, and of SAR5 (R5 - 28.9%. The low prevalence of Alp3, notably in GBS type V strains, differed from findings with CPS type V GBS from non-African areas. Bacteria of the various CPS types showed distinct CPS/protein-marker associations. Conclusion: The results are of importance in relation to regional variations of GBS phenotypes and genotypes and thus, of importance in planning and research in the context of future vaccine formulations.

Development of simple and rapid PCR-fingerprinting methods for Vibrio cholerae on the basis of genetic diversity of the superintegron.

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Chowdhury, N; Asakura, M; Neogi, S B; Hinenoya, A; Haldar, S; Ramamurthy, T; Sarkar, B L; Faruque, S M; Yamasaki, S

2010-07-01

To develop simple and rapid PCR-fingerprinting methods for Vibrio cholerae O1 (El Tor and classical biotypes) and O139 serogroup strains which cause major cholera epidemics, on the basis of the diversity of superintegron (SI) carried by these strains. PCR-restriction fragment length polymorphism (PCR-RFLP) assay was developed targeting region between integrase gene in the SI and its nearby ORF, followed by BglI digestion. Besides, a V. cholerae repeat-amplified fragment length polymorphism (VCR-AFLP) assay was also developed. In the PCR-RFLP, 94 El Tor, 29 classical and 54 O139 strains produced nine, three and six different DNA fingerprints, respectively. On the other hand, VCR-AFLP distinguished these El Tor, classical and O139 strains into five, nine and two DNA fingerprints, respectively. Combining both assays the El Tor, classical and O139 strains could be differentiated into 11, 10 and seven different types, respectively. In a comparative study, pulsed-field gel electrophoresis (PFGE) showed similar differentiation for El Tor (11 types), but lower discrimination for O139 (two types) and classical strains (five types). The PCR assays based on SI diversity can be used as a useful typing tool for epidemiological studies of V. cholerae. This newly developed method is more discriminatory, simple, rapid and cost-effective in comparison with PFGE, and thus can be widely applicable. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Vibrio cholerae O1 secretes an extracellular matrix in response to antibody-mediated agglutination.

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Danielle E Baranova

Full Text Available Vibrio cholerae O1 is one of two serogroups responsible for epidemic cholera, a severe watery diarrhea that occurs after the bacterium colonizes the human small intestine and secretes a potent ADP-ribosylating toxin. Immunity to cholera is associated with intestinal anti-lipopolysaccharide (LPS antibodies, which are known to inhibit V. cholerae motility and promote bacterial cell-cell crosslinking and aggregation. Here we report that V. cholerae O1 classical and El Tor biotypes produce an extracellular matrix (ECM when forcibly immobilized and agglutinated by ZAC-3 IgG, an intestinally-derived monoclonal antibody (MAb against the core/lipid A region of LPS. ECM secretion, as demonstrated by crystal violet staining and scanning electron microscopy, occurred within 30 minutes of antibody exposure and peaked by 3 hours. Non-motile mutants of V. cholerae did not secrete ECM following ZAC-3 IgG exposure, even though they were susceptible to agglutination. The ECM was enriched in O-specific polysaccharide (OSP but not Vibrio polysaccharide (VPS. Finally, we demonstrate that ECM production by V. cholerae in response to ZAC-3 IgG was associated with bacterial resistant to a secondary complement-mediated attack. In summary, we propose that V. cholerae O1, upon encountering anti-LPS antibodies in the intestinal lumen, secretes an ECM (or O-antigen capsule possibly as a strategy to shield itself from additional host immune factors and to exit an otherwise inhospitable host environment.

Single Nucleotide Polymorphisms in Regulator-Encoding Genes Have an Additive Effect on Virulence Gene Expression in a Vibrio cholerae Clinical Isolate.

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Carignan, Bailey M; Brumfield, Kyle D; Son, Mike S

2016-01-01

Vibrio cholerae is the etiological agent of the infectious disease cholera, which is characterized by vomiting and severe watery diarrhea. Recently, V. cholerae clinical isolates have demonstrated increased virulence capabilities, causing more severe symptoms with a much higher rate of disease progression than previously observed. We have identified single nucleotide polymorphisms (SNPs) in four virulence-regulatory genes (hapR, hns, luxO, and vieA) of a hypervirulent V. cholerae clinical isolate, MQ1795. Herein, all SNPs and SNP combinations of interest were introduced into the prototypical El Tor reference strain N16961, and the effects on the production of numerous virulence-related factors, including cholera toxin (CT), the toxin-coregulated pilus (TCP), and ToxT, were analyzed. Our data show that triple-SNP (hapR hns luxO and hns luxO vieA) and quadruple-SNP combinations produced the greatest increases in CT, TCP, and ToxT production. The hns and hns luxO SNP combinations were sufficient for increased TCP and ToxT production. Notably, the hns luxO vieA triple-SNP combination strain produced TCP and ToxT levels similar to those of MQ1795. Certain SNP combinations (hapR and hapR vieA) had the opposite effect on CT, TCP, and ToxT expression. Interestingly, the hns vieA double-SNP combination strain increased TCP production while decreasing CT production. Our findings suggest that SNPs identified in the four regulatory genes, in various combinations, are associated with increased virulence capabilities observed in V. cholerae clinical isolates. These studies provide insight into the evolution of highly virulent strains. IMPORTANCE Cholera, an infectious disease of the small intestine caused by the aquatic bacterium Vibrio cholerae, often results in vomiting and acute watery diarrhea. If left untreated or if the response is too slow, the symptoms can quickly lead to extreme dehydration and ultimately death of the patient. Recent anecdotal evidence of cholera

Antimicrobial Susceptibility among Urban Wastewater and Wild Shellfish Isolates of Non-O1/Non-O139 Vibrio cholerae from La Rance Estuary (Brittany, France

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Sandrine Baron

2017-09-01

Full Text Available The early 2000s marked the end of the Golden age of the antibiotics and the beginning of the awareness on the potential threat to human health due to the dissemination of antimicrobial resistance. As a base-line study, we investigated the antimicrobial susceptibility of 99 strains of non-O1/non-O139 Vibrio cholerae isolated from wastewater and shellfish in 2000/2001 within La Rance estuary (Brittany, France. All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, chloramphenicol, nalidixic acid, ciprofloxacin, norfloxacin, amikacin, gentamicin, tetracycline, doxycycline, trimethoprim-sulfamethoxazole, and erythromycin. The only resistances were to streptomycin, sulfonamides and ampicillin: 54.6% of the isolates had acquired resistance to at least one antimicrobial agent among them and only six isolates from cockles were multidrug resistant. On the basis of the distribution of a limited selection of resistance associated genes, our study shows that V. cholerae can constitute an environmental reservoir for these genes. However, none of our isolates harbored integron. This result casts doubt on the capacity of non-O1/non-O139 V. cholerae to acquire resistance-associated genes in such context, and on its potential role of indicator of the dissemination of antimicrobial resistance in the aquatic environment.

Analysis of Recent Serotype O Foot-and-Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages.

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Wekesa, S N; Muwanika, V B; Siegismund, H R; Sangula, A K; Namatovu, A; Dhikusooka, M T; Tjørnehøj, K; Balinda, S N; Wadsworth, J; Knowles, N J; Belsham, G J

2015-06-01

Foot-and-mouth disease (FMD) is endemic in Kenya where four serotypes (O, A, SAT 1 and SAT 2) of the virus are currently in circulation. Within 2010 and 2011, the National Laboratory recorded an increase in the number of FMD outbreaks caused by serotype O virus. The characteristics of these viruses were determined to ascertain whether these were independent outbreaks or one single strain spreading throughout the country. The sequences of the complete VP1-coding region were analysed from viruses sampled within different areas of Kenya during 2010 and 2011. The results indicated that the 2010 to 2011 outbreaks in Kenya were caused by four independent strains. By comparison with earlier type O isolates from Eastern Africa, it was apparent that the outbreaks were caused by viruses from three different lineages of topotype EA-2 and a fourth virus strain belonging to topotype EA-4. The topotypes EA-1 and EA-3 were not detected from these outbreaks. Implications of these results for FMD control in Eastern Africa are discussed. © 2013 Blackwell Verlag GmbH.

[Microbiological characterization of non-O1 Vibrio cholerae isolated in Cuba].

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Bravo Fariñas, Laura; Fernández, Anabel; Ramírez, María M; Llop, Alina; Martínez, Gerardo; Hernández, Raquel I; Cabrera, Luis E; Morier, Luis; Fraga, Jorge; Núñez, Fidel A; Aguila, Adalberto

2007-01-01

The study of 422 non-01 Vibrio cholerae strains from nine provinces, 9 of them isolated from a water-borne disease outbreak, was performed. All the strains exhibited antimicrobial susceptibility and virulence factors. The nine strains from the outbreak were subjected to a DNA macrorestriction study based on the pulsed field electrophoresis technique. For the first time in Cuba and the Caribbean. The circulation of atypical non-01 V cholerae strains (resistent to vibriostatic compound 0129 and trimethoprim/sulfamethoxazole). The behavior of antimicrobial susceptibility evinced for the first time the circulation of two different resistence patterns in Cuba (ampicilline, trimethoprim/ sulfamethoxazole, sulfonamide and tetracycline, trimethoprim/ sulfamethoxazole, sulfonamide). The frequency of trimethoprim/ sulfamethoxazole-resistent strains was similar during the whole period of study. However, resistance to ampicilline decreased whereas resistance to tetracycline increased. The main found virulence factors were gelatinase, hemolysine, elastase and adherence to Hep-2 cells. On the other hand, the outbreak strains showed higher percentages than the others due to the presence of heat-liable toxin and fimbriae. The results of the molecular and epidemiological studies allowed giving a speedy and accurate response that explained the etiology of the first food-borne disease outbreak.

Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries.

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Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

2017-01-01

Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs) in environmental ctx -negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples) collected from ten sites on the river (January and February 2014) were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA) was the most isolated gene. The cholera toxin (ctxAB) and non-O1 heat-stable (stn/sto) genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries

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Akebe Luther King Abia

2017-01-01

Full Text Available Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs in environmental ctx-negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples collected from ten sites on the river (January and February 2014 were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA was the most isolated gene. The cholera toxin (ctxAB and non-O1 heat-stable (stn/sto genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

Comparison and Evaluation of the Molecular Typing Methods for Toxigenic Vibrio cholerae in Southwest China.

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Liao, Feng; Mo, Zhishuo; Chen, Meiling; Pang, Bo; Fu, Xiaoqing; Xu, Wen; Jing, Huaiqi; Kan, Biao; Gu, Wenpeng

2018-01-01

Vibrio cholerae O1 strains taken from the repository of Yunnan province, southwest China, were abundant and special. We selected 70 typical toxigenic V. cholerae (69 O1 and one O139 serogroup strains) isolated from Yunnan province, performed the pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and MLST of virulence gene (V-MLST) methods, and evaluated the resolution abilities for typing methods. The ctxB subunit sequence analysis for all strains have shown that cholera between 1986 and 1995 was associated with mixed infections with El Tor and El Tor variants, while infections after 1996 were all caused by El Tor variant strains. Seventy V. cholerae obtained 50 PFGE patterns, with a high resolution. The strains could be divided into three groups with predominance of strains isolated during 1980s, 1990s, and 2000s, respectively, showing a good consistency with the epidemiological investigation. We also evaluated two MLST method for V. cholerae , one was used seven housekeeping genes ( adk , gyrB , metE , pntA , mdh , purM , and pyrC ), and all the isolates belonged to ST69; another was used nine housekeeping genes ( cat , chi , dnaE , gyrB , lap , pgm , recA , rstA , and gmd ). A total of seven sequence types (STs) were found by using this method for all the strains; among them, rstA gene had five alleles, recA and gmd have two alleles, and others had only one allele. The virulence gene sequence typing method ( ctxAB , tcpA , and toxR ) showed that 70 strains were divided into nine STs; among them, tcpA gene had six alleles, toxR had five alleles, while ctxAB was identical for all the strains. The latter two sequences based typing methods also had consistency with epidemiology of the strains. PFGE had a higher resolution ability compared with the sequence based typing method, and MLST used seven housekeeping genes showed the lower resolution power than nine housekeeping genes and virulence genes methods. These two sequence typing methods

Comparison and Evaluation of the Molecular Typing Methods for Toxigenic Vibrio cholerae in Southwest China

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Feng Liao

2018-05-01

Full Text Available Vibrio cholerae O1 strains taken from the repository of Yunnan province, southwest China, were abundant and special. We selected 70 typical toxigenic V. cholerae (69 O1 and one O139 serogroup strains isolated from Yunnan province, performed the pulsed field gel electrophoresis (PFGE, multilocus sequence typing (MLST, and MLST of virulence gene (V-MLST methods, and evaluated the resolution abilities for typing methods. The ctxB subunit sequence analysis for all strains have shown that cholera between 1986 and 1995 was associated with mixed infections with El Tor and El Tor variants, while infections after 1996 were all caused by El Tor variant strains. Seventy V. cholerae obtained 50 PFGE patterns, with a high resolution. The strains could be divided into three groups with predominance of strains isolated during 1980s, 1990s, and 2000s, respectively, showing a good consistency with the epidemiological investigation. We also evaluated two MLST method for V. cholerae, one was used seven housekeeping genes (adk, gyrB, metE, pntA, mdh, purM, and pyrC, and all the isolates belonged to ST69; another was used nine housekeeping genes (cat, chi, dnaE, gyrB, lap, pgm, recA, rstA, and gmd. A total of seven sequence types (STs were found by using this method for all the strains; among them, rstA gene had five alleles, recA and gmd have two alleles, and others had only one allele. The virulence gene sequence typing method (ctxAB, tcpA, and toxR showed that 70 strains were divided into nine STs; among them, tcpA gene had six alleles, toxR had five alleles, while ctxAB was identical for all the strains. The latter two sequences based typing methods also had consistency with epidemiology of the strains. PFGE had a higher resolution ability compared with the sequence based typing method, and MLST used seven housekeeping genes showed the lower resolution power than nine housekeeping genes and virulence genes methods. These two sequence typing methods could

[An oral chemical vaccine from the hypertoxigenic strains of the causative agent of cholera KM-76 Inaba and KM-68 Ogawa].

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Dzhaparidze, M N; Naumov, A V; Nikitina, G P; Meleshchenko, M V; Dobrova, G V; Zavorotnykh, V I; Gracheva, V P; Zakharova, T L

1991-04-01

The material on the development of chemical vaccine, prepared from two newly formed strains (KM-76 Inaba and KM-68 Ogawa) and intended for oral administration, is presented. The conditions for the submerged cultivation of these strains have been established, which makes it possible to increase the production of choleragen 8- to 10-fold and O-antigen 3- to 4-fold in comparison with V. cholerae natural strain 569B. The maximum accumulation of neuraminidase, protease, phospholipase, along with choleragen, has been registered in the logarithmic phase and that of O-antigen, in the stationary phase of growth. The use of strains KM-76 and KM-68 has led to the fourfold increase of the specific activity of the main immunogens, thus permitting the respective increase of the yield of the oral vaccine without changes in its high capacity for the formation of specific antibodies and its low residual toxigenicity.

Avian cholera causes marine bird mortality in the Bering Sea of Alaska

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Bodenstein, Barbara L.; Kimberlee Beckmen,; Gay Sheffield,; Kathy Kuletz,; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.

2015-01-01

The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).

Occurrence in Mexico, 1998-2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage.

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Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A; Huq, Anwar; Sack, R Bradley; Colwell, Rita R; Cravioto, Alejandro

2014-07-08

The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ(-). Most CTXΦ(-) V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpA(ET) or a variant tcpA with noticeable sequence dissimilarity from tcpA(CL). The tcpA variants were not detected in 2005 after CTXΦ(+) ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005-2008 in Mexico were CTXΦ(+) ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ(-) ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ(+) ET isolated during 2004-2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru.

Spatiotemporal Variation in Environmental Vibrio cholerae in an Estuary in Southern Coastal Ecuador

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Sadie J. Ryan

2018-03-01

Full Text Available Cholera emergence is strongly linked to local environmental and ecological context. The 1991–2004 pandemic emerged in Perú and spread north into Ecuador’s El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000 inhabitants, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in five months for pathogenic and non-pathogenic Vibrio cholerae, by polymerase chain reaction (PCR. We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Vibrio cholerae presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera–estuarine system to anticipate potential future cholera outbreaks.

Acalculous cholecystitis and septicemia caused by non-O1 Vibrio cholerae: first reported case and review of biliary infections with Vibrio cholerae.

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West, B C; Silberman, R; Otterson, W N

1998-03-01

The first case of septicemic acute acalculous cholecystitis caused by non-O1 Vibrio cholerae is described in a healthy traveler, and biliary tract infections from V. cholerae are reviewed. Immediately after a vacation in Cancun, Mexico, a 55-year-old man developed acute cholecystitis. Blood and bile cultures grew non-O1 V. cholerae. At surgery, the gallbladder was acalculous, inflamed, distended, and nearly ruptured. Pathogenetic factors may have included diarrhea prophylaxis with bismuth subsalicylate, distension of the gallbladder from illness-induced fasting, and bacterial toxins in the gallbladder. The patient received i.v. cephapirin, followed by oral cephradine for a total of 10 days, and he made a quick and complete recovery. V. cholerae should be considered in the differential diagnosis of persons from endemic areas who present with cholecystitis or acute jaundice.

Cholera toxin expression by El Tor Vibrio cholerae in shallow culture growth conditions.

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Cobaxin, Mayra; Martínez, Haydee; Ayala, Guadalupe; Holmgren, Jan; Sjöling, Asa; Sánchez, Joaquín

2014-01-01

Vibrio cholerae O1 classical, El Tor and O139 are the primary biotypes that cause epidemic cholera, and they also express cholera toxin (CT). Although classical V. cholerae produces CT in various settings, the El Tor and O139 strains require specific growth conditions for CT induction, such as the so-called AKI conditions, which consist of growth in static conditions followed by growth under aerobic shaking conditions. However, our group has demonstrated that CT production may also take place in shallow static cultures. How these type of cultures induce CT production has been unclear, but we now report that in shallow culture growth conditions, there is virtual depletion of dissolved oxygen after 2.5 h of growth. Concurrently, during the first three to 4 h, endogenous CO2 accumulates in the media and the pH decreases. These findings may explain CT expression at the molecular level because CT production relies on a regulatory cascade, in which the key regulator AphB may be activated by anaerobiosis and by low pH. AphB activation stimulates TcpP synthesis, which induces ToxT production, and ToxT directly stimulates ctxAB expression, which encodes CT. Importantly, ToxT activity is enhanced by bicarbonate. Therefore, we suggest that in shallow cultures, AphB is activated by initial decreases in oxygen and pH, and subsequently, ToxT is activated by intracellular bicarbonate that has been generated from endogenous CO2. This working model would explain CT production in shallow cultures and, possibly, also in other growth conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Detection and transmission of extracellular fac-tor producing Streptococcus suis serotype 2 strains in pigs

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Swildens, B.

2009-01-01

DETECTION AND TRANSMISSION OF EXTRACELLULAR FACTOR PRODUCING STREPTOCOCCUS SUIS SEROTYPE 2 STRAINS IN PIGS INTRODUCTION Streptococcus suis (S.suis) has been implicated in the etiology of many diseases among which meningitis in pigs. The virulent extracellular factor-positive strains of S.suis

Cell envelope proteins of environmental Vibrio cholerae non O1 isolates from Albufera Lake (Valencia, Spain) influence of some factors on OMP expression.

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Amaro, C; Herrero, E; Arnau, A; Garay, E

1989-11-01

The cell envelope proteins of 89 environmental Vibrio cholerae non O1 strains isolated from lake and coastal waters near Valencia, Spain, and six Vibrio cholerae strains from culture collections were analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Considerable heterogeneity was found in the major proteins of the environmental non-O1 strains, but bands between 25,000 and 48,000 daltons were observed in the majority of the strains. Estimated relative mobilities of the total protein profile ranged between 11 and more than 100 Kd. Cluster analysis revealed four groups of strains distinguishable by presence or absence of high and low molecular weight proteins. After treatment with Sarkosyl, the outer membrane proteins (OMPs) were characterized in all strains by densitometric methods. They ranged from 19 to 87 Kilodaltons, and corresponded to the major proteins observed in the total membrane preparations. The major OMP most frequently found had a molecular weight around 37 Kd, similar to that of porins in other Gram-negative bacteria. The OMP composition varied in response to culture medium and growth phase. Generally the OMP expression was affected only in a quantitative way by the growth phase while the growth medium had both a qualitative and a quantitative effect.

Vibrio cholerae Infection of Drosophilamelanogaster Mimics the Human Disease Cholera.

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2005-09-01

Full Text Available Cholera, the pandemic diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, continues to be a major public health challenge in the developing world. Cholera toxin, which is responsible for the voluminous stools of cholera, causes constitutive activation of adenylyl cyclase, resulting in the export of ions into the intestinal lumen. Environmental studies have demonstrated a close association between V. cholerae and many species of arthropods including insects. Here we report the susceptibility of the fruit fly, Drosophila melanogaster, to oral V. cholerae infection through a process that exhibits many of the hallmarks of human disease: (i death of the fly is dependent on the presence of cholera toxin and is preceded by rapid weight loss; (ii flies harboring mutant alleles of either adenylyl cyclase, Gsalpha, or the Gardos K channel homolog SK are resistant to V. cholerae infection; and (iii ingestion of a K channel blocker along with V. cholerae protects wild-type flies against death. In mammals, ingestion of as little as 25 mug of cholera toxin results in massive diarrhea. In contrast, we found that ingestion of cholera toxin was not lethal to the fly. However, when cholera toxin was co-administered with a pathogenic strain of V. cholerae carrying a chromosomal deletion of the genes encoding cholera toxin, death of the fly ensued. These findings suggest that additional virulence factors are required for intoxication of the fly that may not be essential for intoxication of mammals. Furthermore, we demonstrate for the first time the mechanism of action of cholera toxin in a whole organism and the utility of D. melanogaster as an accurate, inexpensive model for elucidation of host susceptibility to cholera.

Update on: Shigella new serogroups/serotypes and their antimicrobial resistance.

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Muthuirulandi Sethuvel, D P; Devanga Ragupathi, N K; Anandan, S; Veeraraghavan, B

2017-01-01

Shigellosis represents a major burden of disease in developing countries. A low infectious dose allows the disease to be spread effectively. Although shigellosis is mostly a self-limiting disease, antibiotics are recommended to reduce deaths, disease symptoms and organism-shedding time. However, in India, antimicrobial resistance among the genus Shigella is more common than among any other enteric bacteria. Notably, new serotypes or subserotypes in Shigella are reported from various parts of the world. Identification of new subserotypes of Shigella spp. is becoming a major issue as these strains are nontypeable by conventional serotyping. The commercially available antisera may not cover all possible epitopes of the O lipopolysaccharide antigen of Shigella serotypes. Therefore, molecular methods which most closely approach the resolution of full serotyping are necessary to identify such strains. In addition, the knowledge of a prevalent serotype in various geographic regions may assist in formulating strategies such as the development of a vaccine to prevent infection especially when the immunity to disease is serotype specific, and to understand the disease burden caused by new Shigella serotypes. © 2016 The Society for Applied Microbiology.

The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010.

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Rolf S Kaas

Full Text Available The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE elements were identified and annotated. A global phylogeny (378 genomes was inferred using a single nucleotide polymorphism (SNP analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains.

Survival of Vibrio cholerae in industrially polluted water, with ...

African Journals Online (AJOL)

containing industrial effluents. The effect of iron as well as pH on the survival of Vibrio cholerae (non-O1, El Tor and classical strains) in water samples from 12 points, where selected industrial effluents were discharged into rivers, was studied.

Occurrence in Mexico, 1998–2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage

Science.gov (United States)

Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A.; Huq, Anwar; Sack, R. Bradley; Colwell, Rita R.; Cravioto, Alejandro

2014-01-01

The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ−. Most CTXΦ− V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpAET or a variant tcpA with noticeable sequence dissimilarity from tcpACL. The tcpA variants were not detected in 2005 after CTXΦ+ ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005–2008 in Mexico were CTXΦ+ ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ− ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ+ ET isolated during 2004–2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru. PMID:24958870

Surface and virulence properties of environmental Vibrio cholerae non-O1 from Albufera Lake (Valencia, Spain).

Science.gov (United States)

Amaro, C; Toranzo, A E; González, E A; Blanco, J; Pujalte, M J; Aznar, R; Garay, E

1990-04-01

A total of 140 environmental Vibrio cholerae non-O1 isolates, together with several culture collection strains from both environmental and clinical sources, were studied in relation to hemagglutination, surface hydrophobicity, and the enzymatic, hemolytic, cytotoxic, and enterotoxic activities of their extracellular products. A total of 78 and 62% of the strains produced hemagglutinins and exohemagglutinins, respectively. Four different hemagglutinating and two exohemagglutinating activities were found by using eight sugars in the inhibition assays. Cell-bound mannose-sensitive hemagglutination was detected mainly in chicken blood, whereas fucose-sensitive hemagglutination was recorded only in human blood. Cell-bound hemagglutinin resistant to all sugars tested was the only one related to surface hydrophobicity. The surface properties varied along the growth curves. The non-O1 strains displayed strong enzymatic and hemolytic activities, except for esculin hydrolysis. Of 26 non-O1 isolates selected for cytotoxin and enterotoxin production, 23 showed a wide spectrum of cytotoxic effects on cell lines of poikilothermic and homoiothermic species, but they were weakly enterotoxigenic in the infant mouse test. All extracellular products of cytotoxic strains were proteolytic, lipolytic, and hemolytic, and a high percentage produced hemagglutination of chicken blood. The cytotoxic factors in the non-O1 strains analyzed were not R plasmid mediated.

Genesis of a novel Shigella flexneri serotype by sequential infection of serotype-converting bacteriophages SfX and SfI

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Sun Qiangzheng

2011-12-01

Full Text Available Abstract Background Shigella flexneri is the major pathogen causing bacillary dysentery. Fifteen serotypes have been recognized up to now. The genesis of new S. flexneri serotypes is commonly mediated by serotype-converting bacteriophages. Untypeable or novel serotypes from natural infections had been reported worldwide but have not been generated in laboratory. Results A new S. flexneri serotype-serotype 1 d was generated when a S. flexneri serotype Y strain (native LPS was sequentially infected with 2 serotype-converting bacteriophages, SfX first and then SfI. The new serotype 1 d strain agglutinated with both serotype X-specific anti-7;8 grouping serum and serotype 1a-specific anti- I typing serum, and differed from subserotypes 1a, 1b and 1c. Twenty four S. flexneri clinical isolates of serotype X were all converted to serotype 1 d by infection with phage SfI. PCR and sequencing revealed that SfI and SfX were integrated in tandem into the proA-yaiC region of the host chromosome. Conclusions These findings suggest a new S. flexneri serotype could be created in nature. Such a conversion may be constrained by susceptibility of a strain to infection by a given serotype-converting bacteriophage. This finding has significant implications in the emergence of new S. flexneri serotypes in nature.

An outbreak of El Tor cholera in an institution for the mentally retarded in Nonthaburi, June-July 1987.

Science.gov (United States)

Swaddiwudhipong, W; Limpakarnjanarat, K

1991-06-01

In June and July 1987, an outbreak of cholera caused by V.cholerae O1, biotype El Tor, serotype Inaba, occurred in an institution for the mentally retarded in Nonthaburi. Of the 447 retarded inmates, 74 were found to be infected and one died. Epidemiological investigation revealed that the inmates with severe mental retardation who ate food in their own sleeping-room were significantly (p less than 0.001) more likely to be infected than those taking food in the dining-room. We hypothesize that the liquid diet commonly served to the more severely mentally retarded may have increased the risk of infection by more rapid gastric emptying. The long average period of time for meal consumption among these individuals may have allowed the organisms to multiply to a level capable of causing disease. Contamination of food with cholera might have occurred during food handling in the kitchen or within the sleeping-room where overcrowded conditions and poor personal hygiene facilitated person-to-person spread of infection. Prompt implementation of control measures effectively terminated cholera transmission in the outbreak.

Critical Analysis of Compositions and Protective Efficacies of Oral Killed Cholera Vaccines

Science.gov (United States)

2014-01-01

Two cholera vaccines, sold as Shanchol and Dukoral, are currently available. This review presents a critical analysis of the protective efficacies of these vaccines. Children under 5 years of age are very vulnerable to cholera and account for the highest incidence of cholera cases and more than half of the resulting deaths. Both Shanchol and Dukoral are two-spaced-dose oral vaccines comprising large numbers of killed cholera bacteria. The former contains Vibrio cholerae O1 and O139 cells, and the latter contains V. cholerae O1 cells with the recombinant B subunit of cholera toxin. In a field trial in Kolkata (India), Shanchol, the preferred vaccine, protected 45% of the test subjects in all of the age groups and only 17% of the children under 5 years of age during the first year of surveillance. In a field trial in Peru, two spaced doses of Dukoral offered negative protection in children under 5 years of age and little protection (15%) in vaccinees over 6 years of age during the first year of surveillance. Little is known about Dukoral's long-term protective efficacy. Both of these vaccines have questionable compositions, using V. cholerae O1 strains isolated in 1947 that have been inactivated by heat and formalin treatments that may denature protein. Immunological studies revealed Dukoral's reduced and short-lived efficacy, as measured by several immunological endpoints. Various factors, such as the necessity for multiple doses, poor protection of children under 5 years of age, the requirement of a cold supply chain, production costs, and complex logistics of vaccine delivery, greatly reduce the suitability of either of these vaccines for endemic or epidemic cholera control in resource-poor settings. PMID:25056361

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013

OpenAIRE

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-01-01

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ.

Characterization of virulence of the Streptococcus suis serotype 2 reference strain Henrichsen S 735 in newborn gnotobiotic pigs

NARCIS (Netherlands)

Vecht, U.; Wisselink, H.J.; Stockhofe-Zurwieden, N.; Smith, H.E.

1996-01-01

Strain Henrichsen S 735 (NCTC 10234) of Streptococcus suis serotype 2 reference and three other such strains (strains S 4005, S 3921 and T 141) were tested for virulence by inoculating pigs intranasally and intravenously. The taxonomical properties of each strain were determined. Phenotypes were

Impact of solar irradiation on cholera toxin secretion by different strains of Vibrio cholerae

CSIR Research Space (South Africa)

Ssemakalu, CC

2013-09-01

Full Text Available , Salomon RN, Garrity K, Reveillaud I, Kopin A, Jackson FR, et al. Vibrio cholerae infection of Drosophila melanogaster mimics the human disease cholera. PLoS Pathog. 2005;1(1):e8. http://dx.doi.org/10.1371/ journal.ppat.0010008 2. World Health...

Molecular Characterization of Vibrio cholerae Isolated From Clinical Samples in Kurdistan Province, Iran.

Science.gov (United States)

Ramazanzadeh, Rashid; Rouhi, Samaneh; Shakib, Pegah; Shahbazi, Babak; Bidarpour, Farzam; Karimi, Mohammad

2015-05-01

Vibrio cholerae causes diarrhoeal disease that afflicts thousands of people annually. V. cholerae is classified on the basis of somatic antigens into serovars or serogroups and there are at least 200 known serogroup. Two serogroups, O1 and O139 have been associated with epidemic diseases. Virulence genes of these bacteria are OmpW, ctxA and tcpA. Due to the importance of V. cholerae infection and developing molecular diagnostics of this organism in medical and microbiology sciences, this study aimed to describe molecular characterization of V. cholerae isolated from clinical samples using a molecular method. In this study, 48 samples were provided during summer 2013 (late August and early September) by reference laboratory. Samples were assessed using biochemical tests initially. The primer of OmpW, ctxA and tcpA genes was used in Polymerase Chain Reaction (PCR) protocols. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR and Repetitive Extragenic Palindromic (REP)-PCR methods were used to subtype V. cholerae. In this study, from a total of 48 clinical stool samples 39 (81.2 %) were positive for V. cholerae in biochemical tests and bacteria culture tests. The PCR results showed that of 39 positive isolates 35 (89.7%), 34 (87.1%) and 37 (94.8%) were positive for ctxA, tcpA and OmpW gene, respectively. Also, in the REP-PCR method with ERIC primer strains were divided into 10 groups. In the REP-PCR method with REP primer, strains were divided into 13 groups. Polymerase chain reaction has specificity and accuracy for identification of the organism and is able to differentiate biotypes. Enterobacterial repetitive intergenic consensus sequence is one of the informative and discriminative methods for the analysis of V. cholerae diversity. The REP-PCR is a less informative and discriminative method compared to other methods for the analysis of V. cholerae diversity.

Vibrio Cholerae 01 Infections In Jos, Nigeria | Opajobi | African ...

African Journals Online (AJOL)

A study to determine the prevalence of Vibrio cholerae 01 in stool sample submitted for routine examination of enteric pathogens, as well as identify the serotypes and antibiogram of the isolates to commonly used antibiotics was undertaken. The survey involved the examination of 774 (763 stool and 11 rectal swabs) ...

Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania

DEFF Research Database (Denmark)

Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V

2016-01-01

gene (tcpA) and the haemolysin gene (hlyA). RESULTS: The prevalence of V. cholerae in wastewater, vegetables and fish was 36.7, 21.7 and 23.3 %, respectively. Two isolates from fish gills were V. cholerae O1 and tested positive for ctx and tcpA. One of these contained in addition the hlyA gene while......BACKGROUND: Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non......-outbreak period in Morogoro, Tanzania. METHODS: From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological...

Genome sequences of Mannheimia haemolytica serotype A1 strains D153 and D193 from bovine pneumonia

Science.gov (United States)

Here we report two genomes, one complete and one draft, from virulent bovine strains of Mannheimia haemolytica(strains D171 and D35)serotype A2 recovered prior to the field usage of modern antimicrobial drugs....

Genotypic and serotypic stability of Campylobacter jejuni strains during in vitro and in vivo passage

DEFF Research Database (Denmark)

Nielsen, Eva M.; Engberg, J.; Fussing, V.

2001-01-01

The stability of four typing methods and the sero- and genotypic stability of three Campylobacter jejuni strains were evaluated after subculturing 50 times in triplicate and after colonising mice for up to 26 days. The employed methods were Penner heat-stable serotyping; automated ribotyping (Ribo......Printing) using HaeIII restriction enzyme; pulsed-field gel electrophoresis (PFGE) using SmaI, SalI and KpnI; and random amplified polymorphic DNA analysis (RAPD) using primers 1254, 1281 and HLWL85. No changes in any of the DNA profiles or in the reactions to heat-stable antigens were identified among...... these strains after the in vitro and in vivo passages. However, one isolate became untypeable with RAPD after passage in one of the mice. In addition, eleven other C. jejuni strains of four different serotypes were subcultured ten times to screen for instability. Neither of these showed instability using PFGE...

Cholera in Azov area

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O. N. Domashenko

2015-01-01

Full Text Available The purpose of research is analysis of clinical course and treatment results of patients with cholera in the Azov area. Materials and methods. During the period from 29.05.2011 to 19.08.2011 33 cases of cholera (32 adults and 1 child and 25 vibrio carriers (22 adults and 3 children, which were caused by toxigenic strains of Vibrio cholera El Tor serogroup O1 Ogawa. Results. Likely factors of disease transmission in Mariupol are sea and river water, and the fish that were caught in the waters of the city. Typical and watery diarrhoea, vomiting, abdominal pain and lack of normal body temperature, dehydration syndrome, characterized clinical cholera for adults in most cases. The mean duration of diarrhoea was 6,6 days. At 46.9% observed atypical symptoms in 10 (31,3% – abdominal pain (1 patient cramping in 7 cases, localized in the epigastria region, at 2-over stomach. In 5 patients (15,6% had an increase in body temperature to 37,2–37,7 degrees Celsius. In 15 (46,9% patients had severe nausea accompanied by vomiting. Easy for cholera was observed in 1 (3.1%, moderate – in 14 (43,8%, heavy – in 17 (53,1% patients. Dehydration I level is set at 4 (12,5%, II – from 6 (18,7%, III – in 18 (56,3%, IV – 4 (12,5% patients. Cholera outbreak was characterized by a predominance of severe disease and severe dehydration (III and IV, which was observed in 68.8% of patients. The decisive factor in the treatment of cholera patients was initiated in a timely manner rehydration therapy, in particular the introduction of the solution «Trisol». Against the background of rehydration therapy hyperkalaemia was observed in 9,4% of cases, vascular rehydration at 9,4%, the cell rehydration in 3,1% of patients. Fatal accidents cholera outbreaks have not been observed. Conclusion. Clinical diagnosis of cholera and the provision of medical care in the prehospital phase were poor, indicating the need for systematic conducting training seminars among experts

Revealing the glycation sites in synthetic neoglycoconjugates formed by conjugation of the antigenic monosaccharide hapten of Vibrio cholerae O1, serotype Ogawa with the BSA protein carrier using LC-ESI-QqTOF-MS/MS

Science.gov (United States)

Jahouh, Farid; Saksena, Rina; Kováč, Pavol; Banoub, Joseph

2012-01-01

In this manuscript, we present the determination of glycation sites in synthetic neoglycoconjugates formed by conjugation of the antigenic monosaccharide hapten of Vibrio cholerae O1 serotype Ogawa to BSA using nano- liquid chromatography electrospray ionization quadrupole time-of-flight tandem mass spectroscopy (LC-ESI-QqTOF-MS/MS). The matrix-assisted laser desorption/ionization-TOF/TOF-MS/MS analyses of the tryptic digests of the glycoconjugates having a hapten:BSA ratio of 4.3:1, 6.6:1 and 13.2:1 revealed only three glycation sites, on the following lysine residues: Lys 235, Lys 437 and Lys 455. Digestion of the neoglycoconjugates with the proteases trypsin and GluC V8 gave complementary structural information and was shown to maximize the number of recognized glycation sites. Here, we report identification of 20, 27 and 33 glycation sites using LC-ESI-QqTOF-MS/MS analysis of a series of synthetic neoglycoconjugates with a hapten:BSA ratio of, respectively, 4.3:1, 6.6:1 and 13.2:1. We also tentatively propose that all the glycated lysine residues are located mainly near the outer surface of the protein. PMID:22791257

Meningococcal Disease Caused by Neisseria meningitidis Serogroup B Serotype 4 in São Paulo, Brazil, 1990 to 1996

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Sacchi Claudio Tavares

1998-01-01

Full Text Available A large epidemic of serogroup B meningococcal disease (MD, has been occurring in greater São Paulo, Brazil, since 1988.21 A Cuban-produced vaccine, based on outer-membrane-protein (OMP from serogroup B: serotype 4: serosubtype P1.15 (B:4:P1.15 Neisseria meningitidis, was given to about 2.4 million children aged from 3 months to 6 years during 1989 and 1990. The administration of vaccine had little or no measurable effects on this outbreak. In order to detect clonal changes that could explain the continued increase in the incidence of disease after the vaccination, we serotyped isolates recovered between 1990 and 1996 from 834 patients with systemic disease. Strains B:4:P1.15, which was detected in the area as early as 1977, has been the most prevalent phenotype since 1988. These strains are still prevalent in the area and were responsible for about 68% of 834 serogroup B cases in the last 7 years. We analyzed 438 (52% of these strains by restriction fragment length polymorphism (RFLPs of rRNA genes (ribotyping. The most frequent pattern obtained was referred to as Rb1 (68%. We concluded that the same clone of B:4:P1.15-Rb1 strains was the most prevalent strain and responsible for the continued increase of incidence of serogroup B MD cases in greater São Paulo during the last 7 years in spite of the vaccination trial.

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013.

Science.gov (United States)

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-10-30

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. Copyright © 2014 Díaz-Quiñonez et al.

Comparative genomic analysis shows that avian pathogenic Escherichia coli isolate IMT5155 (O2:K1:H5; ST complex 95, ST140 shares close relationship with ST95 APEC O1:K1 and human ExPEC O18:K1 strains.

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Xiangkai Zhu Ge

Full Text Available Avian pathogenic E. coli and human extraintestinal pathogenic E. coli serotypes O1, O2 and O18 strains isolated from different hosts are generally located in phylogroup B2 and ST complex 95, and they share similar genetic characteristics and pathogenicity, with no or minimal host specificity. They are popular objects for the study of ExPEC genetic characteristics and pathogenesis in recent years. Here, we investigated the evolution and genetic blueprint of APEC pathotype by performing phylogenetic and comparative genome analysis of avian pathogenic E. coli strain IMT5155 (O2:K1:H5; ST complex 95, ST140 with other E. coli pathotypes. Phylogeny analyses indicated that IMT5155 has closest evolutionary relationship with APEC O1, IHE3034, and UTI89. Comparative genomic analysis showed that IMT5155 and APEC O1 shared significant genetic overlap/similarities with human ExPEC dominant O18:K1 strains (IHE3034 and UTI89. Furthermore, the unique PAI I5155 (GI-12 was identified and found to be conserved in APEC O2 serotype isolates. GI-7 and GI-16 encoding two typical T6SSs in IMT5155 might be useful markers for the identification of ExPEC dominant serotypes (O1, O2, and O18 strains. IMT5155 contained a ColV plasmid p1ColV5155, which defined the APEC pathotype. The distribution analysis of 10 sequenced ExPEC pan-genome virulence factors among 47 sequenced E. coli strains provided meaningful information for B2 APEC/ExPEC-specific virulence factors, including several adhesins, invasins, toxins, iron acquisition systems, and so on. The pathogenicity tests of IMT5155 and other APEC O1:K1 and O2:K1 serotypes strains (isolated in China through four animal models showed that they were highly virulent for avian colisepticemia and able to cause septicemia and meningitis in neonatal rats, suggesting zoonotic potential of these APEC O1:K1 and O2:K1 isolates.

Vibrio cholerae infection, novel drug targets and phage therapy.

Science.gov (United States)

Fazil, Mobashar Hussain Urf Turabe; Singh, Durg V

2011-10-01

Vibrio cholerae is the causative agent of the diarrheal disease cholera. Although antibiotic therapy shortens the duration of diarrhea, excessive use has contributed to the emergence of antibiotic resistance in V. cholerae. Mobile genetic elements have been shown to be largely responsible for the shift of drug resistance genes in bacteria, including some V. cholerae strains. Quorum sensing communication systems are used for interaction among bacteria and for sensing environmental signals. Sequence analysis of the ctxB gene of toxigenic V. cholerae strains demonstrated its presence in multiple cholera toxin genotypes. Moreover, bacteriophage that lyse the bacterium have been reported to modulate epidemics by decreasing the required infectious dose of the bacterium. In this article, we will briefly discuss the disease, its clinical manifestation, antimicrobial resistance and the novel approaches to locate drug targets to treat cholera.

Virulence, serotype and phylogenetic groups of diarrhoeagenic ...

African Journals Online (AJOL)

Dr DADIE Thomas

2014-02-17

Feb 17, 2014 ... The virulence, serotype and phylogenetic traits of diarrhoeagenic Escherichia coli were detected in 502 strains isolated during digestive infections. Molecular detection of the target virulence genes, rfb gene of operon O and phylogenetic grouping genes Chua, yjaA and TSPE4.C2 was performed.

Bacteriemia por Vibrio cholerae no-O1, no-O139 en un paciente en hemodiálisis crónica Non-O1, non-O139 Vibrio cholerae bacteremia in a chronic hemodialysis patient

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Mariela S. Zárate

2011-06-01

Full Text Available Vibrio cholerae no-O1, no-O139 es un agente poco frecuente como causal de bacteriemias y no hay informes que documenten su presencia en pacientes en hemodiálisis crónica. Se describe el caso de una paciente en hemodiálisis crónica que presentó un cuadro de sepsis, por lo cual inició un tratamiento con vancomicina y ceftacidima. Al cabo de seis horas y media de incubación en el sistema BACT/ALERT de hemocultivo, se evidenció la presencia de bacilos curvos gram negativos, posteriormente identificados como Vibrio cholerae mediante pruebas bioquímicas convencionales y el uso de los kits API 20 NE y VITEK 2. La evaluación del serogrupo y de la presencia de factores de patogenicidad, realizada en el laboratorio de referencia, determinó que el microorganismo hallado pertenecía al serogrupo no-O1, no-O139. No se detectó la toxina de cólera, tampoco el factor de colonización ni la toxina termoestable. El aislamiento presentó sensibilidad frente a ampicilina, trimetoprima-sulfametoxazol, ciprofloxacina, tetraciclina, ceftacidima y cefotaxima por el método de difusión con discos y por VITEK 2. La paciente cumplió 14 días de tratamiento con ceftacidima endovenosa, con evolución favorable.Non-O1, and non-O139 Vibrio cholerae is an infrequent cause of bacteremia. There are no reports of such bacteremia in chronic hemodialysis patients. This work describes the case of a chronic hemodialysis patient that had an episode of septicemia associated with dialysis. Blood cultures were obtained and treatment was begun with vancomycin and ceftazidime. After 6.5 hours of incubation in the Bact/Alert system there is evidence of gram-negative curved bacilli that were identified as Vibrio cholerae by conventional biochemical tests, API 20 NE and the VITEK 2 system. This microorganism was sent to the reference laboratory for evaluation of serogroup and virulence factors and was identified as belonging to the non-O1 and non-O139 serogroup. The cholera

Survivability of Vibrio cholerae O1 in Cooked Rice, Coffee, and Tea

Science.gov (United States)

Tang, John Yew Huat; Izenty, Bariah Ibrahim; Nur' Izzati, Ahmad Juanda; Masran, Siti Rahmah; Yeo, Chew Chieng; Roslan, Arshad; Abu Bakar, Che Abdullah

2013-01-01

This study aimed to investigate the survival of Vibrio cholerae O1 in 3 types of preparation for cooked rice, Oryza sativa L., (plain rice, rice with coconut milk, and rice with ginger); coffee, Coffea canephora, (plain coffee, coffee with sugar, and coffee with sweetened condensed milk); and tea, Camellia sinensis, (plain tea, tea with sugar, and tea with sweetened condensed milk) held at room temperature (27°C). The survival of V. cholerae O1 was determined by spread plate method on TCBS agar. Initial cultures of 8.00 log CFU/mL were inoculated into each food sample. After 6 h incubation, significant growth was only detected in rice with coconut milk (9.67 log CFU/mL; P < 0.05). However, all 3 types of rice preparation showed significant growth of V. cholerae after 24 h (P < 0.05). For coffee and tea preparations, V. cholerae survived up to 6 h in tea with condensed milk (4.72 log CFU/mL) but not in similar preparation of coffee. This study showed evidence for the survivability of V. cholerae in rice, coffee, and tea. Thus, holding these food and beverages for an extended period of time at room temperature should be avoided. PMID:26904604

Survivability of Vibrio cholerae O1 in Cooked Rice, Coffee, and Tea

Directory of Open Access Journals (Sweden)

John Yew Huat Tang

2013-01-01

Full Text Available This study aimed to investigate the survival of Vibrio cholerae O1 in 3 types of preparation for cooked rice, Oryza sativa L., (plain rice, rice with coconut milk, and rice with ginger; coffee, Coffea canephora, (plain coffee, coffee with sugar, and coffee with sweetened condensed milk; and tea, Camellia sinensis, (plain tea, tea with sugar, and tea with sweetened condensed milk held at room temperature (27°C. The survival of V. cholerae O1 was determined by spread plate method on TCBS agar. Initial cultures of 8.00 log CFU/mL were inoculated into each food sample. After 6 h incubation, significant growth was only detected in rice with coconut milk (9.67 log CFU/mL; P<0.05. However, all 3 types of rice preparation showed significant growth of V. cholerae after 24 h (P<0.05. For coffee and tea preparations, V. cholerae survived up to 6 h in tea with condensed milk (4.72 log CFU/mL but not in similar preparation of coffee. This study showed evidence for the survivability of V. cholerae in rice, coffee, and tea. Thus, holding these food and beverages for an extended period of time at room temperature should be avoided.

Serotype and genetic diversity of human rhinovirus strains that circulated in Kenya in 2008.

Science.gov (United States)

Milanoi, Sylvia; Ongus, Juliette R; Gachara, George; Coldren, Rodney; Bulimo, Wallace

2016-05-01

Human rhinoviruses (HRVs) are a well-established cause of the common cold and recent studies indicated that they may be associated with severe acute respiratory illnesses (SARIs) like pneumonia, asthma, and bronchiolitis. Despite global studies on the genetic diversity of the virus, the serotype diversity of these viruses across diverse geographic regions in Kenya has not been characterized. This study sought to characterize the serotype diversity of HRV strains that circulated in Kenya in 2008. A total of 517 archived nasopharyngeal samples collected in a previous respiratory virus surveillance program across Kenya in 2008 were selected. Participants enrolled were outpatients who presented with influenza-like (ILI) symptoms. Real-time RT-PCR was employed for preliminary HRV detection. HRV-positive samples were amplified using RT-PCR and thereafter the nucleotide sequences of the amplicons were determined followed by phylogenetic analysis. Twenty-five percent of the samples tested positive for HRV. Phylogenetic analysis revealed that the Kenyan HRVs clustered into three main species comprising HRV-A (54%), HRV-B (12%), and HRV-C (35%). Overall, 20 different serotypes were identified. Intrastrain sequence homology among the Kenyan strains ranged from 58% to 100% at the nucleotide level and 55% to 100% at the amino acid level. These results show that a wide range of HRV serotypes with different levels of nucleotide variation were present in Kenya. Furthermore, our data show that HRVs contributed substantially to influenza-like illness in Kenya in 2008. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Viability of Vibrio cholerae 01 on frog legs under frozen and refrigerated conditions and low dose radiation treatment

International Nuclear Information System (INIS)

Sang, F.C.; Hugh-Jones, M.E.; Hagstad, H.V.

1987-01-01

Frog legs were contaminated with Vibrio cholerae 01, Inaba serotype, EITor biotype. The organism remained viable for more than 28 and 2 d when stored at -20°C and 4°C, respectively. Exposure to a multicuries 60 Cobalt source of 50 and 100 kilorads eliminated V. cholerae from both the frozen and fresh frog legs

Successful small intestine colonization of adult mice by Vibrio cholerae requires ketamine anesthesia and accessory toxins.

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Verena Olivier

2009-10-01

Full Text Available Vibrio cholerae colonizes the small intestine of adult C57BL/6 mice. In this study, the physical and genetic parameters that facilitate this colonization were investigated. Successful colonization was found to depend upon anesthesia with ketamine-xylazine and neutralization of stomach acid with sodium bicarbonate, but not streptomycin treatment. A variety of common mouse strains were colonized by O1, O139, and non-O1/non-O139 strains. All combinations of mutants in the genes for hemolysin, the multifunctional, autoprocessing RTX toxin (MARTX, and hemagglutinin/protease were assessed, and it was found that hemolysin and MARTX are each sufficient for colonization after a low dose infection. Overall, this study suggests that, after intragastric inoculation, V. cholerae encounters barriers to infection including an acidic environment and an immediate immune response that is circumvented by sodium bicarbonate and the anti-inflammatory effects of ketamine-xylazine. After initial adherence in the small intestine, the bacteria are subjected to additional clearance mechanisms that are evaded by the independent toxic action of hemolysin or MARTX. Once colonization is established, it is suggested that, in humans, these now persisting bacteria initiate synthesis of the major virulence factors to cause cholera disease. This adult mouse model of intestinal V. cholerae infection, now well-characterized and fully optimized, should serve as a valuable tool for studies of pathogenesis and testing vaccine efficacy.

Human and Animal Isolates of Yersinia enterocolitica Show Significant Serotype-Specific Colonization and Host-Specific Immune Defense Properties

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Schaake, Julia; Kronshage, Malte; Uliczka, Frank; Rohde, Manfred; Knuuti, Tobias; Strauch, Eckhard; Fruth, Angelika; Wos-Oxley, Melissa

2013-01-01

Yersinia enterocolitica is a human pathogen that is ubiquitous in livestock, especially pigs. The bacteria are able to colonize the intestinal tract of a variety of mammalian hosts, but the severity of induced gut-associated diseases (yersiniosis) differs significantly between hosts. To gain more information about the individual virulence determinants that contribute to colonization and induction of immune responses in different hosts, we analyzed and compared the interactions of different human- and animal-derived isolates of serotypes O:3, O:5,27, O:8, and O:9 with murine, porcine, and human intestinal cells and macrophages. The examined strains exhibited significant serotype-specific cell binding and entry characteristics, but adhesion and uptake into different host cells were not host specific and were independent of the source of the isolate. In contrast, survival and replication within macrophages and the induced proinflammatory response differed between murine, porcine, and human macrophages, suggesting a host-specific immune response. In fact, similar levels of the proinflammatory cytokine macrophage inflammatory protein 2 (MIP-2) were secreted by murine bone marrow-derived macrophages with all tested isolates, but the equivalent interleukin-8 (IL-8) response of porcine bone marrow-derived macrophages was strongly serotype specific and considerably lower in O:3 than in O:8 strains. In addition, all tested Y. enterocolitica strains caused a considerably higher level of secretion of the anti-inflammatory cytokine IL-10 by porcine than by murine macrophages. This could contribute to limiting the severity of the infection (in particular of serotype O:3 strains) in pigs, which are the primary reservoir of Y. enterocolitica strains pathogenic to humans. PMID:23959720

A simple filtration method to remove plankton-associated Vibrio cholerae in raw water supplies in developing countries.

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Huq, A; Xu, B; Chowdhury, M A; Islam, M S; Montilla, R; Colwell, R R

1996-07-01

Plankton to which cells of Vibrio cholerae O1 and/or O139 were attached was introduced into 0.5% Instant Ocean microcosms maintained at 25 degrees C. The bulk of the plankton and associated particulates was removed with a filter constructed from either nylon net and one of several different types of sari material, the latter being very inexpensive and readily available in villages in Bangladesh, where V. cholerae is endemic. V. cholerae was enumerated before and after filtration to evaluate the efficiency of the filtration procedure. The results obtained indicate that 99% of V. cholerae, i.e., those cells attached to plankton, were removed from the water samples. Epidemic strains of V. cholerae O1 and O139 from various geographical sources, including Bangladesh, Brazil, India, and Mexico, were included in the experiments. Removal of vibrios from water by this simple filtration method was found to yield consistent results with all strains examined in this study. Thus, it is concluded that a simple filtration procedure involving the use of domestic sari material can reduce the number of cholera vibrios attached to plankton in raw water from ponds and rivers commonly used for drinking. Since untreated water from such sources serves as drinking water for millions of people living in developing countries (e.g., Bangladesh), filtration should prove effective at reducing the incidence and severity of outbreaks, especially in places that lack fuel wood for boiling water and/or municipal water treatment plants. The results of this study provide the basis for determining such reductions, which are to be carried out in the near future.

Proteins involved in difference of sorbitol fermentation rates of the toxigenic and nontoxigenic Vibrio cholerae El Tor strains revealed by comparative proteome analysis

Science.gov (United States)

2009-01-01

Background The nontoxigenic V. cholerae El Tor strains ferment sorbitol faster than the toxigenic strains, hence fast-fermenting and slow-fermenting strains are defined by sorbitol fermentation test. This test has been used for more than 40 years in cholera surveillance and strain analysis in China. Understanding of the mechanisms of sorbitol metabolism of the toxigenic and nontoxigenic strains may help to explore the genome and metabolism divergence in these strains. Here we used comparative proteomic analysis to find the proteins which may be involved in such metabolic difference. Results We found the production of formate and lactic acid in the sorbitol fermentation medium of the nontoxigenic strain was earlier than of the toxigenic strain. We compared the protein expression profiles of the toxigenic strain N16961 and nontoxigenic strain JS32 cultured in sorbitol fermentation medium, by using fructose fermentation medium as the control. Seventy-three differential protein spots were found and further identified by MALDI-MS. The difference of product of fructose-specific IIA/FPR component gene and mannitol-1-P dehydrogenase, may be involved in the difference of sorbitol transportation and dehydrogenation in the sorbitol fast- and slow-fermenting strains. The difference of the relative transcription levels of pyruvate formate-lyase to pyruvate dehydrogenase between the toxigenic and nontoxigenic strains may be also responsible for the time and ability difference of formate production between these strains. Conclusion Multiple factors involved in different metabolism steps may affect the sorbitol fermentation in the toxigenic and nontoxigenic strains of V. cholerae El Tor. PMID:19589152

Exoproteome and Secretome Derived Broad Spectrum Novel Drug and Vaccine Candidates in Vibrio cholerae Targeted by Piper betel Derived Compounds

Science.gov (United States)

Barh, Debmalya; Barve, Neha; Gupta, Krishnakant; Chandra, Sudha; Jain, Neha; Tiwari, Sandeep; Leon-Sicairos, Nidia; Canizalez-Roman, Adrian; Rodrigues dos Santos, Anderson; Hassan, Syed Shah; Almeida, Síntia; Thiago Jucá Ramos, Rommel; Augusto Carvalho de Abreu, Vinicius; Ribeiro Carneiro, Adriana; de Castro Soares, Siomar; Luiz de Paula Castro, Thiago; Miyoshi, Anderson; Silva, Artur; Kumar, Anil; Narayan Misra, Amarendra; Blum, Kenneth; Braverman, Eric R.; Azevedo, Vasco

2013-01-01

Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC) for most of the pathogenic Vibrio strains. Two targets (uppP and yajC) are novel to Vibrio, and two targets (uppP and ompU) can be used to develop both drugs and vaccines (dual targets) against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species. PMID:23382822

Exoproteome and secretome derived broad spectrum novel drug and vaccine candidates in Vibrio cholerae targeted by Piper betel derived compounds.

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Debmalya Barh

Full Text Available Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC for most of the pathogenic Vibrio strains. Two targets (uppP and yajC are novel to Vibrio, and two targets (uppP and ompU can be used to develop both drugs and vaccines (dual targets against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

An Explosive Cholera Outbreak In A Rural Community of Gujarat State

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Sengupta P.G

1994-01-01

Full Text Available Research Question : What are the epidemiological features of an el Tor biotype of V. cholerae outbreak? Objective : To describe the epidemiological features of a cholera outbreak. Design: Epidemic investigation. Setting : Rural area near Baroda city. Participants : Residents of the village hamlet. Results : The overall attack rate among 248 people was 13.3% and was highest (26.9% in the 0-4 years age group. All the patients, except one who died at home, had to be hospitalized for treatment . V. Cholerae biotype el Tor serotype Inaba and phage type IV could be isolated from 62.5% of the cases. Some pathogens could be isolated in pure culture from the open well water which was the only source of drinking water for the hamlet.

Transplacental Transmission of Bluetongue Virus Serotype 1 and Serotype 8 in Sheep: Virological and Pathological Findings

NARCIS (Netherlands)

Sluijs, van der M.T.W.; Schroer-Joosten, D.P.H.; Fid-Fourkour, A.; Vrijenhoek, M.P.; Debyser, I.; Moulin, V.; Moormann, R.J.M.; Smit, de A.J.

2013-01-01

The Bluetongue virus serotype 8 (BTV-8) strain, which emerged in Europe in 2006, had an unusually high ability to cause foetal infection in pregnant ruminants. Other serotypes of BTV had already been present in Europe for more than a decade, but transplacental transmission of these strains had never

Label-free electrochemical immunosensor based on cerium oxide nanowires for Vibrio cholerae O1 detection

International Nuclear Information System (INIS)

Tam, Phuong Dinh; Thang, Cao Xuan

2016-01-01

This paper developed a label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application. The CeO 2 nanowires were synthesized by hydrothermal reaction. The immobilization of Anti-V. cholerae O1 onto CeO 2 nanowire-deposited sensor was performed via an amino ester, which was created by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and sulfo-N-hydroxysuccinimide. The electrochemical responses of the immunosensor were studied by electrochemical impedance spectroscopy with [Fe (CN) 6 ] 3−/4− as redox probe. A linear response in electron transfer resistance for cell of V. cholerae O1 concentration was found in the range of 1.0 × 10 2 CFU/mL to 1.0 × 10 4 CFU/mL. The detection limit of the immunosensor was 1.0 × 10 2 CFU/mL. The immunosensor sensitivity was 56.82 Ω/CFU·mL −1 . Furthermore, the parameters affecting immunosensor response were also investigated, as follows: pH value, immunoreaction time, incubation temperature, and anti-V. cholerae O1 concentration. - Highlights: • A label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application was developed. • A linear response was found in the range of 1.0 × 10 2 CFU/mL to 1.0 × 10 4 CFU/mL. • The detection limit of the immunosensor was 1.0 × 10 2 CFU/mL. • The immunosensor sensitivity was 56.82 Ω/CFU.mL −1 .

Sialic Acid Catabolism Confers a Competitive Advantage to Pathogenic Vibrio cholerae in the Mouse Intestine▿

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Almagro-Moreno, Salvador; Boyd, E. Fidelma

2009-01-01

Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae ΔnanA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment. PMID:19564383

Sialic acid catabolism confers a competitive advantage to pathogenic vibrio cholerae in the mouse intestine.

Science.gov (United States)

Almagro-Moreno, Salvador; Boyd, E Fidelma

2009-09-01

Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae DeltananA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment.

Characterization of Foot-And-Mouth Disease Viruses (FMDVs) from Ugandan Cattle Outbreaks during 2012-2013: Evidence for Circulation of Multiple Serotypes

Science.gov (United States)

Namatovu, Alice; Tjørnehøj, Kirsten; Belsham, Graham J.; Dhikusooka, Moses T.; Wekesa, Sabenzia N.; Muwanika, Vincent B.; Siegismund, Hans R.; Ayebazibwe, Chrisostom

2015-01-01

To investigate the foot-and-mouth disease virus (FMDV) serotypes circulating in Uganda’s cattle population, both serological and virological analyses of samples from outbreaks that occurred during 2012–2013 were performed. Altogether, 79 sera and 60 oropharyngeal fluid (OP)/tissue/oral swab samples were collected from herds with reported FMD outbreaks in seven different Ugandan districts. Overall, 61/79 (77%) of the cattle sera were positive for antibodies against FMDV by PrioCHECK FMDV NS ELISA and solid phase blocking ELISA detected titres ≥ 80 for serotypes O, SAT 1, SAT 2 and SAT 3 in 41, 45, 30 and 45 of these 61 seropositive samples, respectively. Virus neutralisation tests detected the highest levels of neutralising antibodies (titres ≥ 45) against serotype O in the herds from Kween and Rakai districts, against SAT 1 in the herd from Nwoya district and against SAT 2 in the herds from Kiruhura, Isingiro and Ntungamo districts. The isolation of a SAT 2 FMDV from Isingiro was consistent with the detection of high levels of neutralising antibodies against SAT 2; sequencing (for the VP1 coding region) indicated that this virus belonged to lineage I within this serotype, like the currently used vaccine strain. From the Wakiso district 11 tissue/swab samples were collected; serotype A FMDV, genotype Africa (G-I), was isolated from the epithelial samples. This study shows that within a period of less than one year, FMD outbreaks in Uganda were caused by four different serotypes namely O, A, SAT 1 and SAT 2. Therefore, to enhance the control of FMD in Uganda, there is need for efficient and timely determination of outbreak virus strains/serotypes and vaccine matching. The value of incorporating serotype A antigen into the imported vaccines along with the current serotype O, SAT 1 and SAT 2 strains should be considered. PMID:25664876

A recent outbreak of cholera due to Vibrio cholerae O1 Ogawa in & around Chandigarh, North India.

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Taneja, Neelam; Kaur, Jasjit; Sharma, Kusum; Singh, Malkit; Kalra, J K; Sharma, N M; Sharma, Meera

2003-06-01

An outbreak of cholera caused by Vibrio cholerae O1 Ogawa occurred in and around Chandigarh during July 22-31, 2002. Of the 303 patients admitted to two hospitals, 82 were confirmed by culture. Two rehabilitation colonies located at the periphery of Chandigarh were mainly affected. The isolates were biotyped as Eltor and were susceptible to many antibiotics. Thirty one (35.2%) of 88 water samples showed evidence of faecal contamination. The survey of the area revealed sewage contamination of the drinking water supply. The outbreak was controlled by providing safe drinking water to the people and correcting the defects in the sewage and water pipelines.

Association of clustered regularly interspaced short palindromic repeat (CRISPR) elements with specific serotypes and virulence potential of shiga toxin-producing Escherichia coli.

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Toro, Magaly; Cao, Guojie; Ju, Wenting; Allard, Marc; Barrangou, Rodolphe; Zhao, Shaohua; Brown, Eric; Meng, Jianghong

2014-02-01

Shiga toxin-producing Escherichia coli (STEC) strains (n = 194) representing 43 serotypes and E. coli K-12 were examined for clustered regularly interspaced short palindromic repeat (CRISPR) arrays to study genetic relatedness among STEC serotypes. A subset of the strains (n = 81) was further analyzed for subtype I-E cas and virulence genes to determine a possible association of CRISPR elements with potential virulence. Four types of CRISPR arrays were identified. CRISPR1 and CRISPR2 were present in all strains tested; 1 strain also had both CRISPR3 and CRISPR4, whereas 193 strains displayed a short, combined array, CRISPR3-4. A total of 3,353 spacers were identified, representing 528 distinct spacers. The average length of a spacer was 32 bp. Approximately one-half of the spacers (54%) were unique and found mostly in strains of less common serotypes. Overall, CRISPR spacer contents correlated well with STEC serotypes, and identical arrays were shared between strains with the same H type (O26:H11, O103:H11, and O111:H11). There was no association identified between the presence of subtype I-E cas and virulence genes, but the total number of spacers had a negative correlation with potential pathogenicity (P CRISPR-cas system and potential virulence needs to be determined on a broader scale, and the biological link will need to be established.

Incidence of Vibrio cholerae and related vibrios in a coastal lagoon and seawater influenced by lake discharges along an annual cycle.

Science.gov (United States)

Garay, E; Arnau, A; Amaro, C

1985-08-01

Most probable numbers of Vibrio cholerae and related vibrios were determined in Albufera Lake, Valencia, Spain, and in coastal waters under the influence of the lake discharges over the course of an annual cycle. The influence of temperature, kind of water, and characteristics of the different sampling sites on the numbers of vibrios recovered was evaluated. Maximum recovery of vibrios reached 10(3)/ml in both types of waters analyzed. V. cholerae numbers reached 10(3)/ml in the lake and 10(2) in one of the coastal sites. Frequently during the warm season, all vibrios isolated were identified as V. cholerae. Occasionally, no V. cholerae was recovered. The recovery of vibrios was significantly influenced by the temperature of the water and the type of water analyzed. Most of the V. cholerae isolates were included in Heiberg groups I and II, and nearly 50% of the strains used chitin as sole carbon source. Indole was not produced by 100% of the strains. All strains tested were non-O1 serovars.

Label-free electrochemical immunosensor based on cerium oxide nanowires for Vibrio cholerae O1 detection

Energy Technology Data Exchange (ETDEWEB)

Tam, Phuong Dinh, E-mail: phuongdinhtam@gmail.com; Thang, Cao Xuan, E-mail: thang.caoxuan@hust.edu.vn

2016-01-01

This paper developed a label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application. The CeO{sub 2} nanowires were synthesized by hydrothermal reaction. The immobilization of Anti-V. cholerae O1 onto CeO{sub 2} nanowire-deposited sensor was performed via an amino ester, which was created by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and sulfo-N-hydroxysuccinimide. The electrochemical responses of the immunosensor were studied by electrochemical impedance spectroscopy with [Fe (CN) {sub 6}] {sup 3−/4−} as redox probe. A linear response in electron transfer resistance for cell of V. cholerae O1 concentration was found in the range of 1.0 × 10{sup 2} CFU/mL to 1.0 × 10{sup 4} CFU/mL. The detection limit of the immunosensor was 1.0 × 10{sup 2} CFU/mL. The immunosensor sensitivity was 56.82 Ω/CFU·mL{sup −1}. Furthermore, the parameters affecting immunosensor response were also investigated, as follows: pH value, immunoreaction time, incubation temperature, and anti-V. cholerae O1 concentration. - Highlights: • A label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application was developed. • A linear response was found in the range of 1.0 × 10{sup 2} CFU/mL to 1.0 × 10{sup 4} CFU/mL. • The detection limit of the immunosensor was 1.0 × 10{sup 2} CFU/mL. • The immunosensor sensitivity was 56.82 Ω/CFU.mL{sup −1}.

Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras

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Ivany R de Moraes

2000-02-01

Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Cananéia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.

Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras

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Moraes Ivany R de

2000-01-01

Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Cananéia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.

Draft Genome Sequences of Two Salmonella enterica Serotype Infantis Strains Isolated from a Captive Western Lowland Gorilla (Gorilla gorilla gorilla) and a Cohabitant Black and White Tegu (Tupinambis merianae) in Brazil.

Science.gov (United States)

Paixão, Tatiane A; Coura, Fernanda M; Malta, Marcelo C C; Tinoco, Herlandes P; Pessanha, Angela T; Pereira, Felipe L; Leal, Carlos A G; Heinemann, Marcos B; Figueiredo, Henrique C P; Santos, Renato L

2016-01-21

The draft genome sequences of two Salmonella enterica serotype Infantis isolates are reported here. One of the strains was isolated from a western lowland gorilla (Gorilla gorilla gorilla) with colitis. The second strain was isolated from a reptile that inhabited the same premises. Whole-genome sequencing demonstrated that these isolates were not clonal. Copyright © 2016 Paixão et al.

Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation

International Nuclear Information System (INIS)

Moraes, Ivany Rodrigues de

1998-01-01

The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of 60 Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

A prolonged, community-wide cholera outbreak associated with drinking water contaminated by sewage in Kasese District, western Uganda.

Science.gov (United States)

Kwesiga, Benon; Pande, Gerald; Ario, Alex Riolexus; Tumwesigye, Nazarius Mbona; Matovu, Joseph K B; Zhu, Bao-Ping

2017-07-18

In May 2015, a cholera outbreak that had lasted 3 months and infected over 100 people was reported in Kasese District, Uganda, where multiple cholera outbreaks had occurred previously. We conducted an investigation to identify the mode of transmission to guide control measures. We defined a suspected case as onset of acute watery diarrhoea from 1 February 2015 onwards in a Kasese resident. A confirmed case was a suspected case with Vibrio cholerae O1 El Tor, serotype Inaba cultured from a stool sample. We reviewed medical records to find cases. We conducted a case-control study to compare exposures among confirmed case-persons and asymptomatic controls, matched by village and age-group. We conducted environmental assessments. We tested water samples from the most affected area for total coliforms using the Most Probable Number (MPN) method. We identified 183 suspected cases including 61 confirmed cases of Vibrio cholerae 01; serotype Inaba, with onset between February and July 2015. 2 case-persons died of cholera. The outbreak occurred in 80 villages and affected all age groups; the highest attack rate occurred in the 5-14 year age group (4.1/10,000). The outbreak started in Bwera Sub-County bordering the Democratic Republic of Congo and spread eastward through sustained community transmission. The first case-persons were involved in cross-border trading. The case-control study, which involved 49 confirmed cases and 201 controls, showed that 94% (46/49) of case-persons compared with 79% (160/201) of control-persons drank water without boiling or treatment (OR M-H =4.8, 95% CI: 1.3-18). Water collected from the two main sources, i.e., public pipes (consumed by 39% of case-persons and 38% of control-persons) or streams (consumed by 29% of case-persons and 24% control-persons) had high coliform counts, a marker of faecal contamination. Environmental assessment revealed evidence of open defecation along the streams. No food items were significantly associated with

The burden of diarrhoea, shigellosis, and cholera in North Jakarta, Indonesia: findings from 24 months surveillance

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Lee Hyejon

2005-10-01

Full Text Available Abstract Background In preparation of vaccines trials to estimate protection against shigellosis and cholera we conducted a two-year community-based surveillance study in an impoverished area of North Jakarta which provided updated information on the disease burden in the area. Methods We conducted a two-year community-based surveillance study from August 2001 to July 2003 in an impoverished area of North Jakarta to assess the burden of diarrhoea, shigellosis, and cholera. At participating health care providers, a case report form was completed and stool sample collected from cases presenting with diarrhoea. Results Infants had the highest incidences of diarrhoea (759/1 000/year and cholera (4/1 000/year. Diarrhea incidence was significantly higher in boys under 5 years (387/1 000/year than girls under 5 years (309/1 000/year; p Shigella flexneri was the most common Shigella species isolated and 73% to 95% of these isolates were resistant to ampicillin, trimethoprim-sulfamethoxazole, chloramphenicol and tetracycline but remain susceptible to nalidixic acid, ciprofloxacin, and ceftriaxone. We found an overall incidence of cholera of 0.5/1 000/year. Cholera was most common in children, with the highest incidence at 4/1 000/year in those less than 1 year of age. Of the 154 V. cholerae O1 isolates, 89 (58% were of the El Tor Ogawa serotype and 65 (42% were El Tor Inaba. Thirty-four percent of patients with cholera were intravenously rehydrated and 22% required hospitalization. V. parahaemolyticus infections were detected sporadically but increased from July 2002 onwards. Conclusion Diarrhoea causes a heavy public health burden in Jakarta particularly in young children. The impact of shigellosis is exacerbated by the threat of antimicrobial resistance, whereas that of cholera is aggravated by its severe manifestations.

Comparison of multiplex RT-PCR and real-time HybProbe assay for serotyping of dengue virus using reference strains and clinical samples from India

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Anita Chakravarti

2016-01-01

Full Text Available Background: Dengue virus serotyping is crucial from clinical management and epidemiological point of view. Aims: To compare efficacy of two molecular detection and typing methods, namely, multiplex reverse transcription polymerase chain reaction (RT-PCR and real-time Hybprobe assay using a panel of known dilution of four reference Dengue virus strains and a panel of sera collected from clinically suspected dengue patients. Settings: This study was conducted at a tertiary-care teaching hospital in Delhi, India. Materials and Methods: Dengue serotype specific virus strains were used as prototypes for serotyping assays. Viral load was quantified by quantitative real time reverse transcription polymerase chain reaction (qRT-PCR. Acute phase serum samples were collected from 79 patients with clinically suspected Dengue fever on their first day of presentation during September-October 2012. Viral RNA from serum and cell culture supernatant was extracted. Reverse transcription was carried out. Quantitative detection of DENV RNA from reference strain culture supernatants and each of the 79 patient samples by real-time PCR was performed using light cycler Taqman master mix kit. Serotyping was done by multiplex RT-PCR assay and Hybprobe assay. Results: The multiplex RT-PCR assay, though found to be 100% specific, couldn't serotype either patient or reference strains with viral load less than 1000 RNA copies/ml. The Hybprobe assay was found to have 100% specificity and had a lower limit of serotype detection of merely 3.54 RNA copies/ml. Conclusions: HybProbe assay has an important role especially in situations where serotyping is to be performed in clinical samples with low viral load.

Comparison of genotypes and serotypes of Campylobacter jejuni isolated from Danish wild mammals and birds and from broiler flocks and humans

DEFF Research Database (Denmark)

Petersen, L.; Nielsen, E.M.; Engberg, J.

2001-01-01

(MRPs) of C. jejuni isolates from different sources. The serotype distribution in wildlife was significantly different from the known distributions in broilers and humans. Considerable sero- and genotype diversity was found within the wildlife collection, although two major groups of isolates within...... serotype O:12 and the O:4 complex were found. Common clonal lines among wildlife, chicken, and/or human isolates were identified within serotype O:12 and the O:4 complex. However, MRPs of O:12 and O:38 strains isolated from wildlife and other sources indicated that some clonal lines propagated in a wide...

EVALUASI MEDIUM PENGAYAAN Vibrio cholerae UNTUK DIAGNOSIS KOLERA MENGGUNAKAN IMMUNOCHROMATOGRAPHIC STRIP TEST

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Kambang Sariadji

2013-05-01

Full Text Available Abstract. Vibrio cholerae strains are capable of causing  outbreak cholera in developing country with poor sanitation and hygiene .Conventional culture methods currently available for detection of V. cholerae 01 takes 3 – 5 days. Other diagnostic tools are by using rapid immunochromatographic strip test for controlling and preventing the spreading of cholera outbreak. This method has limitation in detection of V.cholerae O1, especially under 105 cfu/mL. Furthermore rapid method can be improved by  enrichment media and incubation in 37° C for 6 – 8 hours. The aims of research are to analyse enrichments media in increasingl V.cholerae O1, and it’s to improve the finding of the laboratory diagnosis of cholera cases. The research was conducted at the Laboratory of Bacteriology, Center of Biomedical and Basic Technology of Health National Institute of Health Research and Development (NIHRD from January - July 2011. Medium evaluation was done by making serial dilutions of Vibrio cholerae O1 from 107-101 cfu / ml  inoculated into three mediums: alkaline peptone water, bismuth sulfite, and gelatin phosphate salt broth medium. Then were incubated 37°C for 8 hours and every two hours was tested by immunochromatographic strip test. The data analysis to determine treatment and individual differences  each group was done by one way ANOVA test. The results showed that alkali peptone water are better than gelatine phosphate salt broth and bismuth sulfite in increasing V.cholerae O1, p.value 0.000 means significant different. Meanwhile from 24 samples dilutions which were inoculated in three enrichment media, and detected by rapid immunochromatographic in every 2 hours for 8 hours showed positive result in enrichments media are 17 samples for alkali peptone water, 13 samples for gelatine phosphate salt broth  and 8 samples for bismuth sulfite. Key Words : V.Cholerae, Enrichment Media, Immunochromatographic strip test   Abstrak. Vibrio cholerae O1

gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples.

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Luigi Vezzulli

Full Text Available The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA is a chitin-binding protein involved in V. cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V. cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V. cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR samples. Overall, the method is sensitive (50 gene copies, highly specific for V. cholerae and failed to amplify strains of the closely-related species Vibrio mimicus. The sensitivity of the assay applied to environmental and stool samples spiked with V. cholerae ATCC 39315 was comparable to that of pure cultures and was of 102 genomic units/l for drinking and seawater samples, 101 genomic units/g for sediment and 102 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V. cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V. cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies.

Vibrio cholerae interactions with Mytilus galloprovincialis hemocytes mediated by serum components.

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Laura eCanesi

2013-12-01

Full Text Available Edible bivalves (e.g., mussels, oysters can accumulate large amount of bacteria in their tissues and act as passive carriers of pathogens to humans. Bacterial persistence inside bivalves depends, at least in part, on hemolymph anti-bacterial activity that is exerted by both serum soluble factors and phagocytic cells (i.e., the hemocytes. It was previously shown that Mytilus galloprovincialis hemolymph serum contains opsonins that mediate D-mannose-sensitive interactions between hemocytes and V. cholerae O1 El Tor bacteria that carry the Mannose–Sensitive Hemagglutinin (MSHA. These opsonins enhance phagocytosis and killing of vibrios by facilitating their binding to hemocytes. Since V. cholerae strains not carrying the MSHA ligand (O1 classical, non O1/O139 are present in coastal water and can be entrapped by mussels, we studied whether in mussel serum, in addition to opsonins directed towards MSHA, other components can mediate opsonization of these bacteria. By comparing interactions of O1 classical and non O1/O139 strains with hemocytes in ASW and serum, it was found that M. galloprovincialis serum contains components that increase by at approximately two fold their adhesion to, association with and killing by hemocytes. Experiments conducted with high and low molecular mass fractions obtained by serum ultrafiltration indicated that these compounds have molecular mass higher than 5000 Da. Serum exposure to high temperature (80°C abolished its opsonizing capability suggesting that the involved serum active components are of protein nature. Further studies are needed to define the chemical properties and specificity of both the involved bacterial ligands and hemolymph opsonins. This information will be central not only to better understand V. cholerae ecology, but also to improve current bivalve depuration practices and properly protect human health.

Antibiotic Susceptibilities and Serotyping of Clinical Streptococcus Agalactiae Isolates

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Altay Atalay

2011-11-01

Full Text Available Objective: Streptococcus agalactiae (Group B streptococci, GBS are frequently responsible for sepsis and meningitis seen in the early weeks of life. GBS may cause perinatal infection and premature birth in pregnant women. The aim of this study was to serotype GBS strains isolated from clinical samples and evaluate their serotype distribution according to their susceptibilities to antibiotics and isolation sites. Material and Methods: One hundred thirty one S. agalactiae strains isolated from the clinical samples were included in the study. Of the strains, 99 were isolated from urine, 20 from soft tissue, 10 from blood and 2 from vaginal swab. Penicillin G and ceftriaxone susceptibilities of GBS were determined by the agar dilution method. Susceptibilities to erythromycin, clindamycin, vancomycin and tetracycline were determined by the Kirby-Bauer method according to CLSI criteria. Serotyping was performed using the latex aglutination method using specific antisera (Ia, Ib, II-VIII. Results: While in 131 GBS strains, serotypes VII and VIII were not detected, the most frequently isolated serotypes were types Ia (36%, III (30.5% and II (13% respectively. Serotype Ia was the most frequently seen serotype in all samples. All GBS isolates were susceptible to penicilin G, ceftriaxone and vancomycin. Among the strains, tetracycline, erythromycin and clindamycin resistance rates were determined as 90%, 14.5%, and 13% respectively. Conclusion: Penicillin is still the first choice of treatment for the infections with all serotypes of S. agalactiae in Turkey.

The prevalence of O serogroups of Escherichia coli strains causing acute urinary tract infection in children in Iran

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Fatemeh Emamghorashi

2011-01-01

Full Text Available The aim of present study was to determine the prevalence of O serogroups of Escherichia coli (E. coli strains that cause community-acquired urinary tract infections (UTI in children. In this study, 96 children with UTI referred to two Jahrom University-affiliated Hospitals in Iran were enrolled, during the period from August 2005 to August 2006. Drug sensitivity was tested by disk diffusion method and serotyping done by slide agglutination method. A total of 96 E. coli strains were isolated from urine samples of the study children whose age ranged from one month to 14 years. Cystitis was diagnosed in 49.2% and pyelonephritis in 50.8% of the study patients. Maximum drug resistance was seen with ampicilin (80.2% and the least with imipenem (1.1%. The most common type of O antigen was O1 (12.2%. There was significant correlation between the presence of O antigens and sensitivity to nalidixic acid and gentamicin (P < 0.05. This is the first report of E. coli serotyping in children with UTI from the south of Iran and their relation to antibiotic resistance and clinical presentation. Further studies from other parts of Iran and on other serotypes are recommended.

QA prime-boost vaccination strategy in prevent serotype O FMDV infection using a "single-cycle" alphavirus vector and empty capsid particles

DEFF Research Database (Denmark)

Gullberg, Maria; Lohse, Louise; Bøtner, Anette

Introduction Foot-and-mouth disease (FMD) remains one of the most economically important infectious diseases of production animals globally. Vaccination can help to control this disease, however, current vaccines based on chemically inactivated FMDV, are imperfect and there is a need for new, safe...... and effective vaccines to control FMD. There is no cross protection between the 7 serotypes but serotype O is the most abundant globally. Material and methods The FMDV capsid protein precursor (P1-2A) of strain O1 Manisa has been expressed with the FMDV 3C protease (3Cpro) using a “single cycle” packaged...... alphavirus self-replicating RNA based on Semliki Forest virus (SFV). Purified O1 Manisa empty capsid particles (ECs) have been prepared using a recombinant vaccinia virus expression system. Cattle have been vaccinated with the SFV-FMDV vectors and boosted subsequently with the ECs and then challenged...

Diversity and transboundary mobility of serotype O foot-and-mouth disease virus in East Africa: Implications for vaccination policies

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Balinda, Sheila; Sangula, Abraham; Heller, Rasmus

2010-01-01

Foot-and-mouth disease (FMD) virus serotype O has been responsible for most reported outbreaks of the disease in East Africa. A sustained campaign for the past 40 years to control FMD mainly by vaccination, combined with quarantine and zoosanitary measures has been undertaken with limited success....... We investigated the genetic relationships among serotype O strains in eastern Africa using complete VP1 coding region sequences obtained from 46 FMD virus isolates collected in Kenya in the years 1964–2008 and 8 Ugandan isolates collected between 1999 and 2006. In addition, 21 selected FMDV sequences...... the dominant evolutionary force. Cross-border disease transmission within the region has been suggested with probable incursions of topotypes EA-3 and EA-4 into Kenya and Uganda from neighboring Ethiopia and Sudan. We conclude that the vaccines have probably been effective in controlling EA-1, but less so...

Clinical isolates of Vibrio cholerae O1 El Tor Ogawa of 2009 from Kolkata, India: preponderance of SXT element and presence of Haitian ctxB variant.

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Braj M R N S Kutar

Full Text Available BACKGROUND: Increase in the number of multidrug resistant pathogens and the accompanied rise in case fatality rates has hampered the treatment of many infectious diseases including cholera. Unraveling the mechanisms responsible for multidrug resistance in the clinical isolates of Vibrio cholerae would help in understanding evolution of these pathogenic bacteria and their epidemic potential. This study was carried out to identify genetic factors responsible for multiple drug resistance in clinical isolates of Vibrio cholerae O1, serotype Ogawa, biotype El Tor isolated from the patients admitted to the Infectious Diseases Hospital, Kolkata, India, in 2009. METHODOLOGY/PRINCIPAL FINDINGS: One hundred and nineteen clinical isolates of V. cholerae were analysed for their antibiotic resistance phenotypes. Antibiogram analysis revealed that majority of the isolates showed resistance to co-trimoxazole, nalidixic acid, polymixin B and streptomycin. In PCR, SXT integrase was detected in 117 isolates and its sequence showed 99% identity notably to ICEVchInd5 from Sevagram, India, ICEVchBan5 from Bangladesh and VC1786ICE sequence from Haiti outbreak among others. Antibiotic resistance traits corresponding to SXT element were transferred from the parent Vibrio isolate to the recipient E. coli XL-1 Blue cells during conjugation. Double-mismatch-amplification mutation assay (DMAMA revealed the presence of Haitian type ctxB allele of genotype 7 in 55 isolates and the classical ctxB allele of genotype 1 in 59 isolates. Analysis of topoisomerase sequences revealed the presence of mutation Ser83 → Ile in gyrA and Ser85→ Leu in parC. This clearly showed the circulation of SXT-containing V. cholerae as causative agent for cholera in Kolkata. CONCLUSIONS: There was predominance of SXT element in these clinical isolates from Kolkata region which also accounted for their antibiotic resistance phenotype typical of this element. DMAMA PCR showed them to be a mixture

Genomic relationships of Actinobacillus pleuropneumoniae serotype 2 strains evaluated by ribotyping, sequence analysis of ribosomal intergenic regions, and pulsed-field gel electrophoresis

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Fussing, V.

1998-01-01

The aim of the present study was to examine the genomic relationship among 112 Actinobacillus pleuropneumoniae serotype 2 strains obtained throughout Europe and North America. HindIII ribotyping of the strains resulted in five ribotypes of high similarity (87-98%). Sequence analysis of the riboso......The aim of the present study was to examine the genomic relationship among 112 Actinobacillus pleuropneumoniae serotype 2 strains obtained throughout Europe and North America. HindIII ribotyping of the strains resulted in five ribotypes of high similarity (87-98%). Sequence analysis...... of the ribosomal intergenic region of strains representing each ribotype and each country showed no differences. A common ribotype was further characterized by PFGE of 12 strains representing all countries. The resultant five PFGE patterns of European strains showed a similarity of more than 91%, to which the two...

Novel chimeric foot-and-mouth disease virus-like particles harboring serotype O VP1 protect guinea pigs against challenge.

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Li, Haitao; Li, Zhiyong; Xie, Yinli; Qin, Xiaodong; Qi, Xingcai; Sun, Peng; Bai, Xingwen; Ma, Youji; Zhang, Zhidong

2016-02-01

Foot-and-mouth disease is a highly contagious, acute viral disease of cloven-hoofed animal species causing severe economic losses worldwide. Among the seven serotypes of foot-and-mouth disease virus (FMDV), serotype O is predominant, but its viral capsid is more acid sensitive than other serotypes, making it more difficult to produce empty serotype O VLPs in the low pH insect hemolymph. Therefore, a novel chimeric virus-like particle (VLP)-based candidate vaccine for serotype O FMDV was developed and characterized in the present study. The chimeric VLPs were composed of antigenic VP1 from serotype O and segments of viral capsid proteins from serotype Asia1. These VLPs elicited significantly higher FMDV-specific antibody levels in immunized mice than did the inactivated vaccine. Furthermore, the chimeric VLPs protected guinea pigs from FMDV challenge with an efficacy similar to that of the inactivated vaccine. These results suggest that chimeric VLPs have the potential for use in vaccines against serotype O FMDV infection. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification and differentiation of the twenty six bluetongue virus serotypes by RT-PCR amplification of the serotype-specific genome segment 2.

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Narender S Maan

Full Text Available Bluetongue (BT is an arthropod-borne viral disease, which primarily affects ruminants in tropical and temperate regions of the world. Twenty six bluetongue virus (BTV serotypes have been recognised worldwide, including nine from Europe and fifteen in the United States. Identification of BTV serotype is important for vaccination programmes and for BTV epidemiology studies. Traditional typing methods (virus isolation and serum or virus neutralisation tests (SNT or VNT are slow (taking weeks, depend on availability of reference virus-strains or antisera and can be inconclusive. Nucleotide sequence analyses and phylogenetic comparisons of genome segment 2 (Seg-2 encoding BTV outer-capsid protein VP2 (the primary determinant of virus serotype were completed for reference strains of BTV-1 to 26, as well as multiple additional isolates from different geographic and temporal origins. The resulting Seg-2 database has been used to develop rapid (within 24 h and reliable RT-PCR-based typing assays for each BTV type. Multiple primer-pairs (at least three designed for each serotype were widely tested, providing an initial identification of serotype by amplification of a cDNA product of the expected size. Serotype was confirmed by sequencing of the cDNA amplicons and phylogenetic comparisons to previously characterised reference strains. The results from RT-PCR and sequencing were in perfect agreement with VNT for reference strains of all 26 BTV serotypes, as well as the field isolates tested. The serotype-specific primers showed no cross-amplification with reference strains of the remaining 25 serotypes, or multiple other isolates of the more closely related heterologous BTV types. The primers and RT-PCR assays developed in this study provide a rapid, sensitive and reliable method for the identification and differentiation of the twenty-six BTV serotypes, and will be updated periodically to maintain their relevance to current BTV distribution and

[Isolation and identification of the temperate bacteriophage from isolated strains of Streptococcus suis serotype 2].

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Ma, Yuling; Lu, Chengping; Fan, Hongjie

2008-04-01

A PCR assay was developed to study the distributional characteristics of phage integrase gene in Streptococcus suis serotype 2 (SS2). A 323bp distinct DNA target can be amplified in 25 strains of virulent SS2, while can not be amplified in avirulent strain T15, 5 strains of other serotypes (SS1, SS7, SS9) and strains of group C Streptococcus strains from pigs, which suggested that the phage integrase gene may be related to the pathogenicity of SS2 and can be consider as a detection factor of the virulent gene of SS2. The sequencing and restriction endonuclease analysis of the PCR products were also done. Comparisons between the sequences of phage integrase gene with that of SS2 strain, showed a high homology with SS2 China strains 98HAH33, 05ZYH33 and North American strain 89-1591. Complete cell lysis was observed with SS2 virulent strains but not with avirulent strain T15 after the induction by mitomycin C. Electron microscopy analysis of the lysate from SS2 virulent strains HA9801 and ZY05719 revealed the presence of phage particles. The induced phage, named SS2-HA and SS2-ZY, both have a small isometric nucleocapsid approximately 50 nm in diameter and have no tail and is therefore a member of the Tectiviridae family. The phage integrase gene sequence of phage SS2-HA and SS2-ZY shared high homologue identities with virulent SS2 strains, which suggested that the phage integrase gene of SS2 has high specify. The temperate phage and phage integrase gene can only detected from SS2 virulent strains but not from avirulent strain, and the detection of phage integrase gene was related to the virulence-associate factors of SS2, such as the muramidase-released protein gene (mrp), which suggested that the temperate phage of SS2 may be related to the pathogenicity of SS2.

Epidemiological characteristics of an institutional outbreak of cholera.

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Goh, K T; Lam, S; Ling, M K

1987-01-01

An outbreak of cholera caused by Vibrio cholerae 01, biotype El Tor, serotype Inaba, phage type 4, occurred in an institution for the aged in Singapore in August and September 1984. 96 inmates were infected (21 symptomatic and 75 asymptomatic) and 5 died. The index case was a 72-year-old male inmate who continued to assist in food preparation in the kitchen from the time of onset of diarrhoea until he was seriously ill and hospitalized 4 days later. Another kitchen helper was found to have asymptomatic V. cholerae 01 infection. The infection rate for males was significantly higher than that for females (P less than 0.025), associated with the use of unsanitary toilets. The main mode of transmission was through food contaminated by the 2 kitchen helpers who probably accounted for most of the infections, while poor personal hygiene of the inmates helped to sustain person-to-person spread. The outbreak was confined within the institution as the result of the prompt and effective implementation of control measures.

Removal of Cholera Toxin from Aqueous Solution by Probiotic Bacteria

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Jussi A. O. Meriluoto

2012-06-01

Full Text Available Cholera remains a serious health problem, especially in developing countries where basic hygiene standards are not met. The symptoms of cholera are caused by cholera toxin, an enterotoxin, which is produced by the bacterium Vibrio cholerae. We have recently shown that human probiotic bacteria are capable of removing cyanobacterial toxins from aqueous solutions. In the present study we investigate the ability of the human probiotic bacteria, Lactobacillus rhamnosus strain GG (ATCC 53103 and Bifidobacterium longum 46 (DSM 14583, to remove cholera toxin from solution in vitro. Lactobacillus rhamnosus strain GG and Bifidobacterium longum 46 were able to remove 68% and 59% of cholera toxin from aqueous solutions during 18 h of incubation at 37 °C, respectively. The effect was dependent on bacterial concentration and L. rhamnosus GG was more effective at lower bacterial concentrations. No significant effect on cholera toxin concentration was observed when nonviable bacteria or bacterial supernatant was used.

Genetic Variability of the Heme Uptake System among Different Strains of the Fish Pathogen Vibrio anguillarum: Identification of a New Heme Receptor

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Mouriño, Susana; Rodríguez-Ares, Isabel; Osorio, Carlos R.; Lemos, Manuel L.

2005-01-01

The ability to utilize heme compounds as iron sources was investigated in Vibrio anguillarum strains belonging to serotypes O1 to O10. All strains, regardless of their serotype or isolation origin could utilize hemin and hemoglobin as sole iron sources. Similarly, all of the isolates could bind hemin and Congo red, and this binding was mediated by cell envelope proteins. PCR and Southern hybridization were used to assay the occurrence of heme transport genes huvABCD, which have been previously described in serotype O1. Of 23 strains studied, two serotype O3 isolates proved negative for all huvABCD genes, whereas nine strains included in serotypes O2, O3, O4, O6, O7, and O10 tested negative for the outer membrane heme receptor gene huvA. A gene coding for a novel outer membrane heme receptor was cloned and characterized in a V. anguillarum serotype O3 strain lacking huvA. The new heme receptor, named HuvS, showed significant similarity to other outer membrane heme receptors described in Vibrionaceae, but little homology (39%) to HuvA. This heme receptor was present in 9 out of 11 of the V. anguillarum strains that tested negative for HuvA. Furthermore, complementation experiments demonstrated that HuvS could substitute for the HuvA function in Escherichia coli and V. anguillarum mutants. The huvS and huvA sequences alignment, as well as the analysis of their respective upstream and downstream DNA sequences, suggest that horizontal transfer and recombination might be responsible for generating this genetic diversity. PMID:16332832

Deciphering the Origin of the 2012 Cholera Epidemic in Guinea by Integrating Epidemiological and Molecular Analyses

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Rebaudet, Stanislas; Mengel, Martin A.; Koivogui, Lamine; Moore, Sandra; Mutreja, Ankur; Kande, Yacouba; Yattara, Ousmane; Sarr Keita, Véronique; Njanpop-Lafourcade, Berthe-Marie; Fournier, Pierre-Edouard; Garnotel, Eric; Keita, Sakoba; Piarroux, Renaud

2014-01-01

Cholera is typically considered endemic in West Africa, especially in the Republic of Guinea. However, a three-year lull period was observed from 2009 to 2011, before a new epidemic struck the country in 2012, which was officially responsible for 7,350 suspected cases and 133 deaths. To determine whether cholera re-emerged from the aquatic environment or was rather imported due to human migration, a comprehensive epidemiological and molecular survey was conducted. A spatiotemporal analysis of the national case databases established Kaback Island, located off the southern coast of Guinea, as the initial focus of the epidemic in early February. According to the field investigations, the index case was found to be a fisherman who had recently arrived from a coastal district of neighboring Sierra Leone, where a cholera outbreak had recently occurred. MLVA-based genotype mapping of 38 clinical Vibrio cholerae O1 El Tor isolates sampled throughout the epidemic demonstrated a progressive genetic diversification of the strains from a single genotype isolated on Kaback Island in February, which correlated with spatial epidemic spread. Whole-genome sequencing characterized this strain as an “atypical” El Tor variant. Furthermore, genome-wide SNP-based phylogeny analysis grouped the Guinean strain into a new clade of the third wave of the seventh pandemic, distinct from previously analyzed African strains and directly related to a Bangladeshi isolate. Overall, these results highly suggest that the Guinean 2012 epidemic was caused by a V. cholerae clone that was likely imported from Sierra Leone by an infected individual. These results indicate the importance of promoting the cross-border identification and surveillance of mobile and vulnerable populations, including fishermen, to prevent, detect and control future epidemics in the region. Comprehensive epidemiological investigations should be expanded to better understand cholera dynamics and improve disease control

Genetic mapping of the regulator gene determining enterotoxin synthesis in Vibrio cholerae

International Nuclear Information System (INIS)

Smirnova, N.I.; Livanova, L.F.; Shaginyan, I.A.; Motin, V.L.

1986-01-01

Data on the genetic mapping of mutation tox-7 (the mutation affecting the synthesis of the cholera toxin) were obtained by conjugation crosses between the atoxigenic donor strain Vibrio cholerae Eltor and the toxigenic recipient strain V. cholera classica. The molecular and genetic analysis of the Tox - recombinants indicated that, when the synthesis of the cholera toxin is disrupted in these strains, the tox-7 mutation (which impairs the regulator gene tox) is gained. Close linkage between the tox-7 and pur-63 mutations was established (during the selection procedure there was 81.1% combined transfer with respect to marker pur-63 situated in the donor strain chromosome more proximal than mutation tox-7). The markers were localized in the following order in the region under investigation: asp-cys-nal-pur-61-trp-his-pur-63-tox-7-ile

An atypical biotype I Actinobacillus pleuropneumoniae serotype 13 is present in North America

DEFF Research Database (Denmark)

Perry, Malcolm B.; Angen, Øystein; MacLean, Leann L.

2012-01-01

Atypical Actinobacillus pleuropneumoniae serotype 13 strains present in North America are described here for the first time. Different from serotype 13 strains described in Europe, North America strains are biotype I and antigenically related to both, serotypes 13 and 10. Chemical and structural...

Investigation of carbon storage regulation network (csr genes) and phenotypic differences between acid sensitive and resistant Escherichia coli O157:H7 strains

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Background: Escherichia coli O157:H7 and related serotype strains have previously been shown to vary in acid resistance, however, little is known about strain specific mechanisms of acid resistance. We examined sensitive and resistant E. coli strains to determine the effects of growth in minimal and...

Molecular characterization of Orientia tsutsugamushi serotypes causing scrub typhus outbreak in southern region of Andhra Pradesh, India.

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Usha, K; Kumar, E; Kalawat, Usha; Kumar, B Siddhartha; Chaudhury, A; Gopal, D V R Sai

2016-10-01

Scrub typhus is a vector-borne zoonotic infection caused by Orientiatsutsugamushi. Local epidemiology of the circulating serotypes of scrub typhus is not available from most parts of India. We conducted this study for the diagnosis of scrub typhus using IgM ELISA and to detect O. tsutsugamushi serotypes circulating in southern Andhra Pradesh, India. Samples were collected from patients clinically suspected to have scrub typhus and were subjected to IgM ELISA to measure IgM antibodies against O. tsutsugamushi. Nested polymerase chain reaction (PCR) was performed targeting strain-specific regions in ELISA-positive samples. Of a total of 663 samples, 258 (38.91%) were found to be positive by IgM ELISA. Serotypes could be detected in 230 (34.69%) samples only. Only two serotypes, Karp and Kawasaki, were found in the serum samples, with the former being predominant. The dual infection of Karp and Kawasaki serotypes was found in seven patients. Other serotypes such as Gilliam, Kuroki and Kato were not detected in the samples. The nested PCR products proved useful in presumptively identifying the endemic O. tsutsugamushi serotypes. The present study could be significant in understanding scrub typhus epidemiology in this region.

Cholera Epidemiology in Nigeria: an overview | Adagbada | Pan ...

African Journals Online (AJOL)

Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium, Vibrio cholera. Choleragenic V. cholera O1 and O139 are the only causative agents of the disease. The two most distinguishing epidemiologic features of the disease are its tendency to appear in explosive ...

Determination of Serotypes and Antibiotic Resistance in Streptococcus Pneumoniae

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Deniz Akgun Karapinar

2016-01-01

Full Text Available Aim: In this study, the distribution of serogroup/serotype and antibiotic susceptibility testing of Streptococcus pneumoniae strains, recovered from pediatric and adult patients were evaluated. Material and Method: A total of 80 clinical isolates recovered from 19 pediatric and 61 adult patients were performed by latex aglutination method and antibiotic susceptibility tests in Istanbul University, Istanbul Faculty of Medicine, Medical Microbiology Laboratories. Results: Sixty-two strains (76 %, were serogroup/serotyped and 18 (23 % strains couldn%u2019t serogroup/serotyped. The most frequent identified serogroups were 19, 14, 23, 6, 4 in pediatrics, and 3, 19, 23 and 9 in adults. In adults, serogroups 3, 9, 5, 8, 18, 1, 15 were determined, but these serogroups weren%u2019t found in pediatrics. Vaccine serotypes rates were found as 53 % in pediatric and as 85 % in adults. The serogroups 2, 7, 10, 11, 12, 17, 20, 22, 33 were not detected, which are available in vaccine serotypes. Only 1 (1 % strain was found to exhibit low level resistance to penicillin and high level resistance wasn%u2019t found in any strain. Resistant results for trimethoprim-sulfamethoxazole, erythromycin, chloramphenicol and ofloxacin were found as 45 (56 %, 22 (27.5 %, 7 (9 %, 2 (2.5 %, respectively. All strains were found susceptible to vancomycin, linezolid and levofloxacin. The most resistant serogroups were 19, 23, 9 and 14 in the tested antibiotics. Multidrug resistance was found in 9 (11 % strains and these strains were found as serogroups 19, 23, 9, 6 and 14. Discussion: The epidemiological studies are important that the distribution of serotype and antibiotic resistance vary depending on many factors like age, and geographic region.

Cholera forecast for Dhaka, Bangladesh, with the 2015-2016 El Niño: Lessons learned

Science.gov (United States)

Martinez, Pamela P.; Reiner, Robert C.; Cash, Benjamin A.; Rodó, Xavier; Shahjahan Mondal, Mohammad; Roy, Manojit; Yunus, Mohammad; Faruque, A. S. G.; Huq, Sayeeda; King, Aaron A.; Pascual, Mercedes

2017-01-01

A substantial body of work supports a teleconnection between the El Niño-Southern Oscillation (ENSO) and cholera incidence in Bangladesh. In particular, high positive anomalies during the winter (Dec-Feb) in sea surface temperatures (SST) in the tropical Pacific have been shown to exacerbate the seasonal outbreak of cholera following the monsoons from August to November. Climate studies have indicated a role of regional precipitation over Bangladesh in mediating this long-distance effect. Motivated by this previous evidence, we took advantage of the strong 2015–2016 El Niño event to evaluate the predictability of cholera dynamics for the city in recent times based on two transmission models that incorporate SST anomalies and are fitted to the earlier surveillance records starting in 1995. We implemented a mechanistic temporal model that incorporates both epidemiological processes and the effect of ENSO, as well as a previously published statistical model that resolves space at the level of districts (thanas). Prediction accuracy was evaluated with “out-of-fit” data from the same surveillance efforts (post 2008 and 2010 for the two models respectively), by comparing the total number of cholera cases observed for the season to those predicted by model simulations eight to twelve months ahead, starting in January each year. Although forecasts were accurate for the low cholera risk observed for the years preceding the 2015–2016 El Niño, the models also predicted a high probability of observing a large outbreak in fall 2016. Observed cholera cases up to Oct 2016 did not show evidence of an anomalous season. We discuss these predictions in the context of regional and local climate conditions, which show that despite positive regional rainfall anomalies, rainfall and inundation in Dhaka remained low. Possible explanations for these patterns are given together with future implications for cholera dynamics and directions to improve their prediction for the city

Cholera forecast for Dhaka, Bangladesh, with the 2015-2016 El Niño: Lessons learned.

Science.gov (United States)

Martinez, Pamela P; Reiner, Robert C; Cash, Benjamin A; Rodó, Xavier; Shahjahan Mondal, Mohammad; Roy, Manojit; Yunus, Mohammad; Faruque, A S G; Huq, Sayeeda; King, Aaron A; Pascual, Mercedes

2017-01-01

A substantial body of work supports a teleconnection between the El Niño-Southern Oscillation (ENSO) and cholera incidence in Bangladesh. In particular, high positive anomalies during the winter (Dec-Feb) in sea surface temperatures (SST) in the tropical Pacific have been shown to exacerbate the seasonal outbreak of cholera following the monsoons from August to November. Climate studies have indicated a role of regional precipitation over Bangladesh in mediating this long-distance effect. Motivated by this previous evidence, we took advantage of the strong 2015-2016 El Niño event to evaluate the predictability of cholera dynamics for the city in recent times based on two transmission models that incorporate SST anomalies and are fitted to the earlier surveillance records starting in 1995. We implemented a mechanistic temporal model that incorporates both epidemiological processes and the effect of ENSO, as well as a previously published statistical model that resolves space at the level of districts (thanas). Prediction accuracy was evaluated with "out-of-fit" data from the same surveillance efforts (post 2008 and 2010 for the two models respectively), by comparing the total number of cholera cases observed for the season to those predicted by model simulations eight to twelve months ahead, starting in January each year. Although forecasts were accurate for the low cholera risk observed for the years preceding the 2015-2016 El Niño, the models also predicted a high probability of observing a large outbreak in fall 2016. Observed cholera cases up to Oct 2016 did not show evidence of an anomalous season. We discuss these predictions in the context of regional and local climate conditions, which show that despite positive regional rainfall anomalies, rainfall and inundation in Dhaka remained low. Possible explanations for these patterns are given together with future implications for cholera dynamics and directions to improve their prediction for the city.

Effect of Serotype on Pneumococcal Competition in a Mouse Colonization Model.

Science.gov (United States)

Trzciński, Krzysztof; Li, Yuan; Weinberger, Daniel M; Thompson, Claudette M; Cordy, Derrick; Bessolo, Andrew; Malley, Richard; Lipsitch, Marc

2015-09-15

Competitive interactions between Streptococcus pneumoniae strains during host colonization could influence the serotype distribution in nasopharyngeal carriage and pneumococcal disease. We evaluated the competitive fitness of strains of serotypes 6B, 14, 19A, 19F, 23F, and 35B in a mouse model of multiserotype carriage. Isogenic variants were constructed using clinical strains as the capsule gene donors. Animals were intranasally inoculated with a mixture of up to six pneumococcal strains of different serotypes, with separate experiments involving either clinical isolates or isogenic capsule-switch variants of clinical strain TIGR4. Upper-respiratory-tract samples were repeatedly collected from animals in order to monitor changes in the serotype ratios using quantitative PCR. A reproducible hierarchy of capsular types developed in the airways of mice inoculated with multiple strains. Serotype ranks in this hierarchy were similar among pneumococcal strains of different genetic backgrounds in different strains of mice and were not altered when tested under a range of host conditions. This rank correlated with the measure of the metabolic cost of capsule synthesis and in vitro measure of pneumococcal cell surface charge, both parameters considered to be predictors of serotype-specific fitness in carriage. This study demonstrates the presence of a robust competitive hierarchy of pneumococcal serotypes in vivo that is driven mainly, but not exclusively, by the capsule itself. Streptococcus pneumoniae (pneumococcus) is the leading cause of death due to respiratory bacterial infections but also a commensal frequently carried in upper airways. Available vaccines induce immune responses against polysaccharides coating pneumococcal cells, but with over 90 different capsular types (serotypes) identified, they can only target strains of the selected few serotypes most prevalent in disease. Vaccines not only protect vaccinated individuals against disease but also protect by

Viabilidade de Vibrio cholerae O1 em diferentes tipos de águas em condições experimentais

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Nogueira Joseli Maria da Rocha

2002-01-01

Full Text Available A natureza endêmica e sazonal da cólera depende da sobrevivência de Vibrio cholerae O1 em estado viável, mas não necessariamente cultivável em nichos ambientais aquáticos durante períodos interepidêmicos, sendo de suma importância o estudo da sobrevivência deste microrganismo nesses locais. Para tal, foram coletadas, semanalmente, alíquotas de água pertencentes a duas lagoas e dois rios do Estado do Rio de Janeiro. Esses volumes foram divididos em duas porções idênticas, uma das quais foi autoclavada. Uma diluição padronizada de V. cholerae O1 Inaba e de V. cholerae O1 Ogawa, foi inoculada em três alíquotas de 100ml dessas diferentes águas e mantidas em diferentes temperaturas. A sobrevivência desses microorganismos no âmbito aquático sob esses diferentes fatores foi então analisada. Os resultados demonstraram que o V. cholerae sorogrupo O1, independente do sorotipo, é capaz de se manter em água com salinidade abaixo de 0,5? e em diferentes temperaturas, por períodos suficientes para sua disseminação através de "corpos d'água", demonstrando a necessidade de monitoramento constante em áreas de possível contaminação, principalmente onde a água é utilizada para o consumo, evitando assim, a disseminação da doença para as populações próximas a esses ambientes.

Ultraviolet inactivation and photoreactivation of the cholera phage 'Kappa'

International Nuclear Information System (INIS)

Samad, S.A.; Bhattacharyya, S.C.; Chatterjee, S.N.

1987-01-01

The lysogenic cholera phage, 'Kappa' is some ten to twenty folds more resistant to UV (254 nm) than are most of the T. phages of E. coli, or the cholera phage PL 163/10, or the host V. cholerae strain H218 Sm r , the 37% (D 37 ) and 10% (D 10 ) survival doses being 255.8 J/m 2 and 633.6 J/m 2 respectively. The UV-irradiated 'Kappa' phages could be photoreactivated in the host V. cholerae strain H218 Sm r to a maximum extent of 40%. The removal of the number of lethal hits per phage by the survival-enhancement treatment (photoreactivation) with time followed an exponential relation, the constant probability of removal of lethal hit per unit time being 2.8x10 -2 min -1 . The UV-irradiated phages could also be Weigle reactivated in the host strain of H218 Sm r by a small degree, the maximum reactivation factor (ratio of survivals in UV-irradiated and non-irradiated hosts) being 1.50. (orig.)

Tiempo de excreción de Vibrio cholerae O1 en pacientes con tratamiento

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Elizabeth Castañeda

1992-12-01

Full Text Available El tiempo de excreción del Vibrio cholerae O1 en pacientes con cólera está influenciado por el tratamiento antimicrobiano. Se determinó en un grupo de pacientes con diagnóstico bacteriológico de cólera, que empezaron a recibir tratamiento con antibióticos una vez establecido el diagnóstico clínico, el tiempo de excreción del V. cholerae O1 empleando muestras de materia fecal obtenidas dentro de los cinco días siguientes al diagnóstico clínico inicial. En las 32 muestras obtenidas en ese período de cinco días el porcentaje de negativos fue del 81,2% (26/ 32; en 21 muestras obtenidas 24 horas después de haberse establecido el diagnóstico, se observó negativización en el 81% (17/21. Con nuestros datos podemos confirmar, al compararlos con los datos de la literatura en pacientes no tratados, que el tratamiento acorta el periodo de excreción del V. cholerae O1.

Complete Genome Sequence of an Escherichia coli O121:H19 Strain from an Outbreak in Canada Associated with Flour

Science.gov (United States)

Robertson, James; Lin, Janet; Levett, Paul N.; Nadon, Celine; Nash, John

2018-01-01

ABSTRACT Here, we present the first complete genome sequence of an Escherichia coli non-O157 Shiga-toxin producing isolate, 16-9255, from serotype O121:H19. This strain is notable as a clinical case recovered from a recent Canadian flour-associated outbreak event. PMID:29371368

Serotype diversity of astroviruses in Rawalpindi, Pakistan during 2009-2010.

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Muhammad Masroor Alam

Full Text Available Astroviruses are globally known enteropathogens causing gastroenteritis and diarrhea, with eight well defined serotypes. Epidemiological studies have recognized serotype-1 as the most common subtype but no such data is available in Pakistan. During 2009-2010, we found astroviruses in 41 out of 535 (7% samples collected from hospitalized children. Thirty one strains belonged to serotype-1 and clustered into two distinct lineages. Serotype-3, -4 and -6 were detected with 97-98% genetic homology to Indian and Chinese strains.

A prolonged, community-wide cholera outbreak associated with drinking water contaminated by sewage in Kasese District, western Uganda

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Benon Kwesiga

2017-07-01

Full Text Available Abstract Background In May 2015, a cholera outbreak that had lasted 3 months and infected over 100 people was reported in Kasese District, Uganda, where multiple cholera outbreaks had occurred previously. We conducted an investigation to identify the mode of transmission to guide control measures. Methods We defined a suspected case as onset of acute watery diarrhoea from 1 February 2015 onwards in a Kasese resident. A confirmed case was a suspected case with Vibrio cholerae O1 El Tor, serotype Inaba cultured from a stool sample. We reviewed medical records to find cases. We conducted a case-control study to compare exposures among confirmed case-persons and asymptomatic controls, matched by village and age-group. We conducted environmental assessments. We tested water samples from the most affected area for total coliforms using the Most Probable Number (MPN method. Results We identified 183 suspected cases including 61 confirmed cases of Vibrio cholerae 01; serotype Inaba, with onset between February and July 2015. 2 case-persons died of cholera. The outbreak occurred in 80 villages and affected all age groups; the highest attack rate occurred in the 5–14 year age group (4.1/10,000. The outbreak started in Bwera Sub-County bordering the Democratic Republic of Congo and spread eastward through sustained community transmission. The first case-persons were involved in cross-border trading. The case-control study, which involved 49 confirmed cases and 201 controls, showed that 94% (46/49 of case-persons compared with 79% (160/201 of control-persons drank water without boiling or treatment (ORM-H=4.8, 95% CI: 1.3–18. Water collected from the two main sources, i.e., public pipes (consumed by 39% of case-persons and 38% of control-persons or streams (consumed by 29% of case-persons and 24% control-persons had high coliform counts, a marker of faecal contamination. Environmental assessment revealed evidence of open defecation along the streams. No

Surface reaction of Leishmania. III. Ulex europaeus II lectin affinity for excreted factor (EF) serotype A strains.

Science.gov (United States)

Greenblatt, C L; Meline, D; Slutzky, G M; Schnur, L F; Levene, C

1984-04-01

Eukaryotic parasites, including species of Leishmania, acquire or synthesize carbohydrate moieties similar to human blood group antigens. Leishmanial strains separate into three serotypes: A, B and AB. All strains containing the A component are agglutinated by Ulex europaeus lectin. Inhibition by haptene sugar suggests that a Ulex II-like receptor is involved. Organic solvents, but not protease treatment, remove its reactivity, suggesting that the receptor is a glycolipid.

Identification of critical residues of the serotype modifying O-acetyltransferase of Shigella flexneri

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Thanweer Farzaana

2012-07-01

Full Text Available Abstract Background Thirteen serotypes of Shigella flexneri (S. flexneri have been recognised, all of which are capable of causing bacillary dysentery or shigellosis. With the emergence of the newer S. flexneri serotypes, the development of an effective vaccine has only become more challenging. One of the factors responsible for the generation of serotype diversity is an LPS O-antigen modifying, integral membrane protein known as O-acetyltransferase or Oac. Oac functions by adding an acetyl group to a specific O-antigen sugar, thus changing the antigenic signature of the parent S. flexneri strain. Oac is a membrane protein, consisting of hydrophobic and hydrophilic components. Oac bears homology to several known and predicted acetyltransferases with most homology existing in the N-terminal transmembrane (TM regions. Results In this study, the conserved motifs in the TM regions and in hydrophilic loops of S. flexneri Oac were targeted for mutagenesis with the aim of identifying the amino acid residues essential for the function of Oac. We previously identified three critical arginines–R73, R75 and R76 in the cytoplasmic loop 3 of Oac. Re-establishing that these arginines are critical, in this study we suggest a catalytic role for R73 and a structural role for R75 and R76 in O-acetylation. Serine-glycine motifs (SG 52–53, GS 138–139 and SYG 274–276, phenylalanine-proline motifs (FP 78–79 and FPV 282–84 and a tryptophan-threonine motif (WT141-142 found in TM segments and residues RK 110–111, GR 269–270 and D333 found in hydrophilic loops were also found to be critical to Oac function. Conclusions By studying the effect of the mutations on Oac’s function and assembly, an insight into the possible roles played by the chosen amino acids in Oac was gained. The transmembrane serine-glycine motifs and hydrophilic residues (RK 110–111, GR 269–270 and D333 were shown to have an affect on Oac assembly which suggests a structural role

The molecular epidemiology of cholera in Latin America.

Science.gov (United States)

Wachsmuth, I K; Evins, G M; Fields, P I; Olsvik, O; Popovic, T; Bopp, C A; Wells, J G; Carrillo, C; Blake, P A

1993-03-01

To explain the sudden appearance and rapid spread of cholera in Latin America in January 1991, molecular techniques were used to define Vibrio cholerae O1 isolates from around the world. Restriction fragment length polymorphisms of rRNA and ctxA genes, DNA sequence of cholera toxin B subunit gene ctxB, and multilocus enzyme electrophoresis data were used to characterize 197 isolates. Worldwide, there are at least four distinct toxigenic El Tor V. cholerae O1 clones: the seventh pandemic (Eastern Hemisphere), US Gulf Coast, Australian, and Latin American. Nontoxigenic V. cholerae O1 previously isolated in Brazil, Mexico, and Peru are unlike current toxigenic isolates. The Latin American clone probably represents an extension of the seventh pandemic into the Western Hemisphere, while the US Gulf Coast clone most likely evolved separately. These data will be useful in monitoring the spread of cholera, determining the origin of outbreaks in both hemispheres, and implicating specific vehicles of transmission.

Development of tailored real-time RT-PCR assays for the detection and differentiation of serotype O, A and Asia-1 foot-and-mouth disease virus lineages circulating in the Middle East

DEFF Research Database (Denmark)

Reid, Scott M.; Mioulet, Valerie; Knowles, Nick J.

2014-01-01

transcription polymerase chain reaction (rRT-PCR) assays using primer/probe sets designed from the VP1 coding region of the virus genomes were developed for the specific detection of serotype O, A and Asia-1 FMD viruses (FMDVs) circulating in the Middle East. These assays were evaluated using representative...... by the generic rRT-PCR diagnostic assays but negative by virus isolation and antigen-detection ELISA which would otherwise have to be serotyped by nucleotide sequencing. A similar approach could be used to develop serotyping assays for FMDV strains circulating in other regions of the world....

Application of photostable quantum dots for indirect immunofluorescent detection of specific bacterial serotypes on small marine animals

International Nuclear Information System (INIS)

Decho, Alan W; Beckman, Erin M; Chandler, G Thomas; Kawaguchi, Tomohiro

2008-01-01

An indirect immunofluorescence approach was developed using semiconductor quantum dot nanocrystals to label and detect a specific bacterial serotype of the bacterial human pathogen Vibrio parahaemolyticus, attached to small marine animals (i.e. benthic harpacticoid copepods), which are suspected pathogen carriers. This photostable labeling method using nanotechnology will potentially allow specific serotypes of other bacterial pathogens to be detected with high sensitivity in a range of systems, and can be easily applied for sensitive detection to other Vibrio species such as Vibrio cholerae

Chromosome sizes and phylogenetic relationships between serotypes of Actinobacillus pleuropneumoniae

OpenAIRE

Chevallier, Bruno; Dugourd, Dominique; Tarasiuk, Kazimirez; Harel, Josée; Gottschalk, Marcelo; Kobisch, Marylène; Frey, Joachim

2017-01-01

The genome size of Actinobacillus pleuropneumoniae was determined by pulsed field gel electrophoresis of AscI and ApaI digested chromosomal DNA. The genome size of the type strain 4074T (serotype 1) was determined to be 2404±40 kb. The chromosome sizes for the reference strains of the other serotypes range between 2.3 and 2.4 Mb. The restriction pattern profiles of AscI, ApaI and NheI digested chromosomes showed a high degree of polymorphism among the different serotype reference strains and ...

Microbial glycolipoprotein-capped silver nanoparticles as emerging antibacterial agents against cholera.

Science.gov (United States)

Gahlawat, Geeta; Shikha, Sristy; Chaddha, Baldev Singh; Chaudhuri, Saumya Ray; Mayilraj, Shanmugam; Choudhury, Anirban Roy

2016-02-01

With the increased number of cholera outbreaks and emergence of multidrug resistance in Vibrio cholerae strains it has become necessary for the scientific community to devise and develop novel therapeutic approaches against cholera. Recent studies have indicated plausibility of therapeutic application of metal nano-materials. Among these, silver nanoparticles (AgNPs) have emerged as a potential antimicrobial agent to combat infectious diseases. At present nanoparticles are mostly produced using physical or chemical techniques which are toxic and hazardous. Thus exploitation of microbial systems could be a green eco-friendly approach for the synthesis of nanoparticles having similar or even better antimicrobial activity and biocompatibility. Hence, it would be worth to explore the possibility of utilization of microbial silver nanoparticles and their conjugates as potential novel therapeutic agent against infectious diseases like cholera. The present study attempted utilization of Ochrobactrum rhizosphaerae for the production of AgNPs and focused on investigating their role as antimicrobial agents against cholera. Later the exopolymer, purified from the culture supernatant, was used for the synthesis of spherical shaped AgNPs of around 10 nm size. Further the exopolymer was characterized as glycolipoprotein (GLP). Antibacterial activity of the novel GLP-AgNPs conjugate was evaluated by minimum inhibitory concentration, XTT reduction assay, scanning electron microscopy (SEM) and growth curve analysis. SEM studies revealed that AgNPs treatment resulted in intracellular contents leakage and cell lysis. The potential of microbially synthesized nanoparticles, as novel therapeutic agents, is still relatively less explored. In fact, the present study first time demonstrated that a glycolipoprotein secreted by the O. rhizosphaerae strain can be exploited for production of AgNPs which can further be employed to treat infectious diseases. Although this type of polymer has

Household Transmission of Vibrio cholerae in Bangladesh.

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Jonathan D Sugimoto

2014-11-01

Full Text Available Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures.Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001-2006. We estimated the probabilities of cholera transmission through 1 direct exposure within the household and 2 contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-value<0.0001 occurred among 1414 members of 364 households. Fecal shedding of O1 El Tor Ogawa was associated with a 4.9% (95% confidence interval: 0.9%-22.8% risk of infection among household contacts through direct exposure during an 11-day infectious period (mean length. The estimated 11-day risk of O1 El Tor Ogawa infection through exposure to community-based sources was 2.5% (0.8%-8.0%. The corresponding estimated risks for O1 El Tor Inaba and O139 infection were 3.7% (0.7%-16.6% and 8.2% (2.1%-27.1% through direct exposure, and 3.4% (1.7%-6.7% and 2.0% (0.5%-7.3% through community-based exposure. Children under 5 years-old were at elevated risk of infection. Limitations of the study may have led to an underestimation of the true risk of cholera infection. For instance, available covariate data may have incompletely characterized levels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered.Direct exposure contributes substantially to endemic transmission of symptomatic cholera in an urban setting. We provide the first estimate of

The global establishment of a highly-fluoroquinolone resistant Salmonella enterica serotype Kentucky ST198 strain

DEFF Research Database (Denmark)

Le Hello, Simon; Bekhit, Amany; Granier, Sophie A.

2013-01-01

While the spread of Salmonella enterica serotype Kentucky resistant to ciprofloxacin across Africa and the Middle-East has been described recently, the presence of this strain in humans, food, various animal species (livestock, pets, and wildlife) and in environment is suspected in other countrie...

Cholera between 1991 and 1997 in Mexico was associated with infection by classical, El Tor, and El Tor variants of Vibrio cholerae.

Science.gov (United States)

Alam, Munirul; Nusrin, Suraia; Islam, Atiqul; Bhuiyan, Nurul A; Rahim, Niaz; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Gil, Ana I; Watanabe, Haruo; Morita, Masatomo; Nair, G Balakrish; Cravioto, Alejandro

2010-10-01

Vibrio cholerae O1 biotype El Tor (ET), the cause of the current 7th pandemic, has recently been replaced in Asia and Africa by an altered ET biotype possessing cholera toxin (CTX) of the classical (CL) biotype that originally caused the first six pandemics before becoming extinct in the 1980s. Until recently, the ET prototype was the biotype circulating in Peru; a detailed understanding of the evolutionary trend of V. cholerae causing endemic cholera in Latin America is lacking. The present retrospective microbiological, molecular, and phylogenetic study of V. cholerae isolates recovered in Mexico (n = 91; 1983 to 1997) shows the existence of the pre-1991 CL biotype and the ET and CL biotypes together with the altered ET biotype in both epidemic and endemic cholera between 1991 and 1997. According to sero- and biotyping data, the altered ET, which has shown predominance in Mexico since 1991, emerged locally from ET and CL progenitors that were found coexisting until 1997. In Latin America, ET and CL variants shared a variable number of phenotypic markers, while the altered ET strains had genes encoding the CL CTX (CTX(CL)) prophage, ctxB(CL) and rstR(CL), in addition to resident rstR(ET), as the underlying regional signature. The distinct regional fingerprints for ET in Mexico and Peru and their divergence from ET in Asia and Africa, as confirmed by subclustering patterns in a pulsed-field gel electrophoresis (NotI)-based dendrogram, suggest that the Mexico epidemic in 1991 may have been a local event and not an extension of the epidemics occurring in Asia and South America. Finally, the CL biotype reservoir in Mexico is unprecedented and must have contributed to the changing epidemiology of global cholera in ways that need to be understood.

Structural organization of the transfer RNA operon I of Vibrio cholerae

Indian Academy of Sciences (India)

Nine major transfer RNA (tRNA) gene clusters were analysed in various Vibrio cholerae strains. Of these, only the tRNA operon I was found to differ significantly in V. cholerae classical (sixth pandemic) and El Tor (seventh pandemic) strains. Amongst the sixteen tRNA genes contained in this operon, genes for tRNA Gln3 ...

PCR deduction of invasive and colonizing pneumococcal serotypes from Venezuela: a critical appraisal.

Science.gov (United States)

Bello Gonzalez, Teresita; Rivera-Olivero, Ismar Alejandra; Sisco, María Carolina; Spadola, Enza; Hermans, Peter W; de Waard, Jacobus H

2014-04-15

Serotype surveillance of Streptococcus pneumoniae is indispensable for evaluating the potential impact of pneumococcal conjugate vaccines. Serotyping by the standard Quellung reaction is technically demanding, time consuming, and expensive. A simple and economical strategy is multiplex PCR-based serotyping. We evaluated the cost effectiveness of a modified serial multiplex PCR (mPCR), resolving 24 serotypes in four PCR reactions and optimally targeting the most prevalent invasive and colonizing pneumococcal serotypes found in Venezuela. A total of 223 pneumococcal isolates, 140 invasive and 83 carriage isolates, previously serotyped by the Quellung reaction and representing the 18 most common serotypes/groups identified in Venezuela, were serotyped with the adapted mPCR. The mPCR serotyped 76% of all the strains in the first two PCR reactions and 91% after four reactions, correctly identifying 17 serotypes/groups. An isolate could be serotyped with mPCR in less than 2 minutes versus 15 minutes for the Quellung reaction, considerably lowering labor costs. A restrictive weakness of mPCR was found for the detection of 19F strains. Most Venezuelan 19F strains were not typeable using the mPCR, and two 19F cps serotype variants were identified. The mPCR assay is an accurate, rapid, and economical method for the identification of the vast majority of the serotypes from Venezuela and can be used in place of the standard Quellung reaction. An exception is the identification of serotype 19F. In this setting, most 19F strains were not detectable with mPCR, demonstrating a need of serology-based quality control for PCR-based serotyping.

Association of Heavy Rainfall on Genotypic Diversity in V. cholerae Isolates from an Outbreak in India

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A. K. Goel

2011-01-01

Full Text Available The outbreak of waterborne disease cholera has been associated with rainfall and flooding events by contamination of potable water with environmental Vibrio cholerae. The continuation of the epidemic in a region, however, is often due to secondary transmission of the initial outbreak strain through human waste. This paper reports, on the contrary, a rapid shift of genotype from one V. cholerae strain to another one in an epidemic region. V. cholerae isolated from patients during 2005 cholera epidemic in Chennai, India were characterized using PCR identification of toxin genes, antibiogram, and genomic fingerprinting analysis. The results showed that in spite of the similarity of toxin genes and antibiogram, the Vibrio isolates grouped into two different clusters based on the ERIC-PCR fingerprinting. Each cluster corresponded to a distinct peak of cholera outbreak, which occurred after separate heavy rainfall. The results suggest that the rainfall event can bring various genotypes of V. cholerae strains causing multiple outbreaks.

Re-emergence of dengue virus serotype 2 strains in the 2013 outbreak in Nepal

Science.gov (United States)

Gupta, Birendra Prasad; Singh, Sneha; Kurmi, Roshan; Malla, Rajani; Sreekumar, Easwaran; Manandhar, Krishna Das

2015-01-01

Background & objectives: Epidemiological interventions and mosquito control are the available measures for dengue control. The former approach uses serotype and genetic information on the circulating virus strains. Dengue has been frequently reported from Nepal, but this information is mostly lacking. The present study was done to generate a comprehensive clinical and virological picture of a dengue outbreak in Nepal during 2013. Methods: A hospital-based study involving patients from five districts of Nepal was carried out. Demographic information, clinical details and dengue serological status were obtained. Viral RNA was characterized at the molecular level by reverse-transcription polymerase chain reaction (RT-PCR), nucleotide sequencing and phylogenetic analysis. Results: From among the 2340 laboratory-confirmed dengue cases during the study period, 198 patients consented for the study. Clinically they had fever (100%), headache (59.1%), rashes (18.2%), retro-orbital pain (30.3%), vomiting (15.1%), joint pain (28.8%) and thrombocytopenia (74.3%). Fifteen (7.5%) of them had mucosal bleeding manifestations, and the rest were uncomplicated dengue fever. The patients were mostly adults with a mean age of 45.75 ± 38.61 yr. Of the 52 acute serum samples tested, 15 were positive in RT-PCR. The causative virus was identified as DENV serotype 2 belonging to the Cosmopolitan genotype. Interpretations & conclusions: We report here the involvement of DENV serotype 2 in an outbreak in Nepal in 2013. Earlier outbreaks in the region in 2010 were attributed to serotype 1 virus. As serotype shifts are frequently associated with secondary infections and severe disease, there is a need for enhancing surveillance especially in the monsoon and post-monsoon periods to prevent large-scale, severe dengue outbreaks in the region. PMID:26905233

Sensitivity of Vibrio cholerae cells to lethal and mutagenic effect of UV-irradiation mediated by plasmids

International Nuclear Information System (INIS)

Tiganova, I.G.; Evdokimova, N.M.; Aleshkin, G.I.

1988-01-01

The effect of UV-irradiation on Vibrio cholerae cells and its changes mediated by the plasmid R245 have been studied. Vibrio cholerae strains 569B and RV31 have been shown to be considerably more sensitive to lethal effect of UV-irradiation as compared with Escherichia coli and Salmonella typhimurium cells. Highly toxigenic strain 569B and practically atoxigenic strain RV31 have the same UV-sensitivity. Lethla effect of UV-irradiation on Vibrio cholerae cells is incresed when the irradiated cells are plated on enriched media. UV-induction of mutations was not registered in plasmidless strains of Vibrio cholerae. Plasmid R245 increase UV-resistance of vibrio cells and makes them UV-mutable

Sorotipos de Salmonella isolados de processos entéricos humanos em Recife-Pernambuco, durante o triênio 1978-1980 Salmonella serotypes isolated from enteric human cases in Recife, Pernambuco State, Brazil, during 1978-1980

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Nilma Cintra Leal

1987-03-01

Full Text Available De 13.196 coproculturas realizadas durante o triênio 1978-1980 em Recife, Pernambuco, foram isoladas 1.720 salmonelas, das quais 1.387 foram caracterizadas sorologicamente. O estudo global possibilitou o reconhecimento de 63 sorotipos concentrados em primeiro plano no grupo sorológico B (73,18% e identificando-se como tipos mais incidentes: S. typhimurium, S. saint-paul, S. poona, S. derby, S. agona, S. newport, S. oranienburg, S. infantis, S. tshiongwe e S. ndolo, que representaram 1.231 amostras ou 88,75% do total de isolamentos. Algumas considerações de ordem epidemiológica e bacteriológica são discutidas em relação aos quatros sorotipos mais freqüentes.From 13,196 faecal cultures made in Recife-Pernambuco during the period form 1978 to 1980, 1,720 strains of Salmonella were isolated. Serological typing on 1,387 of the isolates recognized 63 serotypes, 73,18% of which belonged to group B. The prevalent serotypes adding up to 1,231 strains (88,75% of the total of the isolats were: S. typhimurium, S. saint-paul, S. poona, S. derby, S. agona, S. newport, S. oraniengurg, S. infantis, S. tshiongwe and S. ndolo. Some epidemiological and bacteriological aspects are discussed regarding the four commonest serotypes.

[The role of food in cholera transmission].

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Dobosch, D; Gomez Zavaglia, A; Kuljich, A

1995-01-01

The spreading of cholera, from Peru to other Latinoamerican countries in 1991, raised questions regarding food safety, food transportation and handling. Control, prevention and risks implied in food import-export were also matters of concern. We deemed it interesting to determine the viability of Vibrio cholerae in wide consumption food locally. Selected food had different intrinsic characteristics such as: acidity (pH), water activity (aw), chemical composition, indigenous flora and other biologic and physic parameters. Twenty food products were contaminated with V. cholerae O1, Ogawa, toxigenic and not toxigenic strains: yoghurt, cream cheese, apricot marmelade, hip rose marmelade, mayonnaise, italian pasta for "empanadas", "dulce de leche", meat sausage, meat and spinach ravioli, margarine, milk dessert (made with cocoa, milk confiture, starch and additives), lettuce, tuna fish, ricotta and sterilized milk. Table I shows the viability of V. cholerae in tested foods, its pH and the reasons why the experiments were ended: 75% of the products studied could tolerate the development of the microorganism for a period ranging from one day (pasta for "empanadas") to ninety days (sterilized milk). Foods with acredity higher than pH 5.5 did not favor the growth of Vibrio. When pH was neutral or slightly acid, viability persisted independently from aw, microbial antagonisms and other physic, chemical or biologic parameters. Nevertheless, other factors such as: surface adherence, amino acids, magnesium and environmental influences not yet well determined, could eventually modify the persistence of V. cholerae in food. According to this study, most food products could tolerate growth and persistence of the infectant agent, up for three months in some cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Household and Individual Risk Factors for Cholera among Cholera Vaccine Recipients in Rural Haiti.

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Matias, Wilfredo R; Teng, Jessica E; Hilaire, Isabelle J; Harris, Jason B; Franke, Molly F; Ivers, Louise C

2017-08-01

Oral cholera vaccination was used as part of cholera control in Haiti, but the vaccine does not provide complete protection. We conducted secondary data analyses of a vaccine effectiveness study in Haiti to evaluate risk factors for cholera among cholera vaccine recipients. Individuals vaccinated against cholera that presented with acute watery diarrhea and had a stool sample positive for Vibrio cholerae O1 were included as cases. Up to four vaccinated individuals who did not present for treatment of diarrhea were included as controls for each case, and matched by location of residence, enrollment time, and age. We evaluated sociodemographic characteristics and risk factors for cholera. Univariable and multivariable logistic regression were performed to identify risk factors for cholera among vaccinees. Thirty-three vaccine recipients with culture-confirmed cholera were included as cases. One-hundred-and-seventeen of their matched controls reported receiving vaccine and were included as controls. In a multivariable analysis, self-reporting use of branded household water disinfection products as a means of treating water (adjusted relative risk [aRR] = 44.3, 95% confidence interval [CI] = 4.19-468.05, P = 0.002), and reporting having a latrine as the main household toilet (aRR = 4.22, 95% CI = 1.23-14.43, P = 0.02), were independent risk factors for cholera. Self-reporting always treating water (aRR = 0.09, 95% CI = 0.01-0.57, P = 0.01) was associated with protection against cholera. The field effectiveness of water, sanitation, and hygiene interventions used in combination with cholera vaccination in cholera control should be measured and monitored over time to identify and remediate shortcomings, and ensure successful impact on disease control.

Vaxchora: A Single-Dose Oral Cholera Vaccine.

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Cabrera, Adriana; Lepage, Jayne E; Sullivan, Karyn M; Seed, Sheila M

2017-07-01

To review trials evaluating the efficacy and safety of Vaxchora, a reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine for the prevention of travel-related cholera caused by V cholerae serogroup O1. A literature search was conducted using MEDLINE (1946 to January week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical trials published in English since 2010. ClinicalTrials.gov was used as a source for unpublished data. Additional data sources were obtained through bibliographic review of selected articles. Studies that addressed the safety and efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera vaccine, were selected for analysis. Approval of Vaxchora, was based on efficacy of the vaccine in human trials demonstrating 90.3% protection among those challenged with V cholerae 10 days after vaccination and in immunogenicity studies with 90% systemic vibriocidal antibody conversion at 6 months after a single-dose of vaccine. Tolerability was acceptable, with the most common adverse effects reported to be fatigue, headache, and abdominal pain. Vaxchora is the only FDA-approved, single-dose oral vaccine for the prevention of cholera caused by V cholerae serogroup O1 in adult travelers from the United States going to cholera-affected areas. Safety and efficacy has not been established in children, immunocompromised persons, and pregnant or breastfeeding women or those living in cholera-endemic areas.

Investigation of household contamination of Vibrio cholerae in Bangladesh

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Hossain, Zenat Zebin; Farhana, Israt; Mohan Tulsiani, Suhella

. cholerae El Tor strain N16961, showed hemolysis and proteolysis activity but none of them exhibited any hemagglutinin activity on human erythrocytes. The study findings indicate that V. cholerae contamination is mostly originated in and around kitchen area rather than latrine area. Contaminated food...... and water supply may be the reason behind this relatively high presence of virulence factors in food plates and water pots. Direct exposure routes of disease transmission should be a major consideration in cholera prevention policies. Investigation of household contamination of Vibrio cholerae in Bangladesh......The role of in-house transmission on the incidence of Vibrio cholerae, the deadly waterborne pathogen, is still not developed. The aim of the current study was to investigate possible contamination routes in household domain for effective cholera control in Bangladesh. To examine the prevalence...

Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation; Estudo da sensibilidade in vitro de diferentes cepas de Vibio cholerae 01 a radiacao gama de 60Co

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Moraes, Ivany Rodrigues de [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Servicos de Saude; Gelli, Dilma Scala; Jakabi, Miyoko [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Microbiologia; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@net.ipen.br

1998-07-01

The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of {sup 60} Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

Molecular serotyping and antimicrobial resistance profiles of Actinobacillus pleuropneumoniae isolated from pigs in South Korea.

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Kim, Boram; Hur, Jin; Lee, Ji Yeong; Choi, Yoonyoung; Lee, John Hwa

2016-09-01

Actinobacillus pleuropneumoniae (APP) causes porcine pleuropneumonia (PP). Serotypes and antimicrobial resistance patterns in APP isolates from pigs in Korea were examined. Sixty-five APP isolates were genetically serotyped using standard and multiplex PCR (polymerase chain reaction). Antimicrobial susceptibilities were tested using the standardized disk-agar method. PCR was used to detect β-lactam, gentamicin and tetracycline-resistance genes. The random amplified polymorphic DNA (RAPD) patterns were determined by PCR. Korean pigs predominantly carried APP serotypes 1 and 5. Among 65 isolates, one isolate was sensitive to all 12 antimicrobials tested in this study. Sixty-two isolates was resistant to tetracycline and 53 isolates carried one or five genes including tet(B), tet(A), tet(H), tet(M)/tet(O), tet(C), tet(G) and/or tet(L)-1 markers. Among 64 strains, 9% and 26.6% were resistance to 10 and three or more antimicrobials, respectively. Thirteen different antimicrobial resistance patterns were observed and RAPD analysis revealed a separation of the isolates into two clusters: cluster II (6 strains resistant to 10 antimicrobials) and cluster I (the other 59 strains). Results show that APP serotypes 1 and 5 are the most common in Korea, and multi-drug resistant strains are prevalent. RAPD analysis demonstrated that six isolates resistant to 10 antimicrobials belonged to the same cluster.

Detection of viable and viable nonculturable Vibrio cholerae O1 through cultures and immunofluorescence in the Tucumán rivers, Argentina Detecção de Vibrio cholerae O1 viável e viável não cultivável, através de técnicas de cultivo e imunofluorescência nos rios de Tucumán, Argentina

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Olga Aulet

2007-08-01

Full Text Available Vibrio cholerae has been sporadically isolated from rivers in Tucumán, Argentina, since the outbreak in 1991. The aim of this study was to determine the environmental reservoir of the bacterium in these rivers, assessing the presence of Vibrio cholerae non-O1 and O1 (the latter both in its viable culturable and non culturable state and its relationship to environmental physicochemical variables. 18 water samplings were collected in the Salí River (in Canal Norte and Banda and the Lules River between 2003 and 2005. Physical-chemical measurements (pH, water temperature, electrical conductivity and dissolved oxygen were examined. Vibrio cholerae was investigated with conventional culture methods and with Direct Immunofluorescence (DFA-VNC in order to detect viable non culturable organisms. All isolated microorganisms corresponded to Vibrio cholerae non-O1 and non-O139 (Lules 26%, Canal Norte 33% and Banda 41%. The majority was found during spring and summer and correlated with temperature and pH. Non culturable Vibrio cholerae O1 was detected year round in 38 of the 54 water samples analyzed. Application of the Pearson correlation coefficient revealed that there was no relationship between positive immunofluorescence results and environmental physicochemical parameters. Genes coding for somatic antigen O1 were confirmed in all DFA-VNC-positive samples, whereas the virulence-associated ctxA and tcpA genes were confirmed in 24 samples.Vibrio cholerae tem sido isolado esporadicamente nos rios da Província de Tucumán, Argentina, desde outubro de 1991. O objetivo deste estudo foi localizar os reservatórios nestes rios, identificar a presença de Vibrio cholerae O1 (em estado cultivável e não cultivável e relacionar a presença desta bactéria com as variações físico-químicos da água. Foram coletadas dezoito amostras de água do rio Salí (nas localidades de Canal Norte e Banda e do rio Lules, entre 2003 e 2005. Estas foram submetidas a an

Characterization and biological role of the O-polysaccharide gene cluster of Yersinia enterocolitica serotype O : 9

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Skurnik, Mikael; Biedzka-Sarek, Marta; Lubeck, Peter S.

2007-01-01

Yersinia enterocolitica serotype O:9 is a gram-negative enteropathogen that infects animals and humans. The role of lipopolysaccharide (LPS) in Y. enterocolitica O:9 pathogenesis, however, remains unclear. The O:9 LPS consists of lipid A to which is linked the inner core oligosaccharide, serving...

Progress toward characterization of the group A Streptococcus metagenome: complete genome sequence of a macrolide-resistant serotype M6 strain.

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Banks, David J; Porcella, Stephen F; Barbian, Kent D; Beres, Stephen B; Philips, Lauren E; Voyich, Jovanka M; DeLeo, Frank R; Martin, Judith M; Somerville, Greg A; Musser, James M

2004-08-15

We describe the genome sequence of a macrolide-resistant strain (MGAS10394) of serotype M6 group A Streptococcus (GAS). The genome is 1,900,156 bp in length, and 8 prophage-like elements or remnants compose 12.4% of the chromosome. A 8.3-kb prophage remnant encodes the SpeA4 variant of streptococcal pyrogenic exotoxin A. The genome of strain MGAS10394 contains a chimeric genetic element composed of prophage genes and a transposon encoding the mefA gene conferring macrolide resistance. This chimeric element also has a gene encoding a novel surface-exposed protein (designated "R6 protein"), with an LPKTG cell-anchor motif located at the carboxyterminus. Surface expression of this protein was confirmed by flow cytometry. Humans with GAS pharyngitis caused by serotype M6 strains had antibody against the R6 protein present in convalescent, but not acute, serum samples. Our studies add to the theme that GAS prophage-encoded extracellular proteins contribute to host-pathogen interactions in a strain-specific fashion.

Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscesses.

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Dahlén, G; Gmür, R; Yoshino, T

2007-04-01

This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas-liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and alpha-fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS-PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses.

Enteroaggregative Shiga toxin-producing Escherichia coli of serotype O104:H4 in Belgium and Luxembourg

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K. De Rauw

2014-09-01

Full Text Available In 2011, a large outbreak of infections caused by Shiga toxin-producing Escherichia coli (STEC O104:H4 occurred in Germany. This exceptionally virulent strain combined virulence factors of enteroaggregative E. coli (EAggEC and STEC. After the outbreak only a few sporadic cases of infection with this rare serotype were reported, most of which were related to travel to the Middle East or North Africa. Here we describe two cases of enteroaggregative STEC (Agg-STEC O104:H4 infection that occurred in Belgium in 2012 and 2013 respectively. In both cases travel in a Mediterranean country preceded the infection. The first strain was isolated from the stool of a 42-year-old woman presenting bloody diarrhoea, who had travelled to Tunisia the week before. The second case involves a 14-year-old girl who, upon her return from Turkey to Belgium, suffered from an episode of bloody diarrhoea and haemolytic uraemic syndrome. Extended typing of the isolates with pulsed field gel electrophoresis revealed that the strains were closely related, though not exactly the same as the 2011 outbreak strain. This report supports the previously made hypothesis that Agg-STEC has a human reservoir and might be imported by travellers coming from an area where the pathogen is endemic. Furthermore, it emphasizes the concern that these bacteria may cause future outbreaks as evenly virulent O104:H4 isolates seem to be widespread.

Towards the development of a DNA-sequence based approach to serotyping of Salmonella enterica

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Logan Julie MJ

2004-08-01

Full Text Available Abstract Background The fliC and fljB genes in Salmonella code for the phase 1 (H1 and phase 2 (H2 flagellin respectively, the rfb cluster encodes the majority of enzymes for polysaccharide (O antigen biosynthesis, together they determine the antigenic profile by which Salmonella are identified. Sequencing and characterisation of fliC was performed in the development of a molecular serotyping technique. Results FliC sequencing of 106 strains revealed two groups; the g-complex included those exhibiting "g" or "m,t" antigenic factors, and the non-g strains which formed a second more diverse group. Variation in fliC was characterised and sero-specific motifs identified. Furthermore, it was possible to identify differences in certain H antigens that are not detected by traditional serotyping. A rapid short sequencing assay was developed to target serotype-specific sequence motifs in fliC. The assay was evaluated for identification of H1 antigens with a panel of 55 strains. Conclusion FliC sequences were obtained for more than 100 strains comprising 29 different H1 alleles. Unique pyrosequencing profiles corresponding to the H1 component of the serotype were generated reproducibly for the 23 alleles represented in the evaluation panel. Short read sequence assays can now be used to identify fliC alleles in approximately 97% of the 50 medically most important Salmonella in England and Wales. Capability for high throughput testing and automation give these assays considerable advantages over traditional methods.

Two-step processing for activation of the cytolysin/hemolysin of Vibrio cholerae O1 biotype El Tor: nucleotide sequence of the structural gene (hlyA) and characterization of the processed products.

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Yamamoto, K; Ichinose, Y; Shinagawa, H; Makino, K; Nakata, A; Iwanaga, M; Honda, T; Miwatani, T

1990-12-01

Vibrio cholerae O1 biotype El Tor produces and secretes a 65-kDa cytolysin/hemolysin into the culture medium. We cloned the structural gene (hlyA) for the cytolysin from the total DNA of a V. cholerae O1 El Tor strain, N86. Nucleotide sequence analysis of hlyA revealed an open reading frame consisting of 2,223 bp which can code for a protein of 741 amino acids with a molecular weight of 81,961. Consistent with this, a 79-kDa protein was identified as the product of hlyA by maxicell analysis in Escherichia coli. N-terminal amino acids of this 79-kDa HlyA protein and those of a 65-kDa El Tor cytolysin purified from V. cholerae were Asn-26 and Asn-158, respectively. The 82- and 79-kDa precursors of the 65-kDa mature cytolysin were found in V. cholerae by pulse-chase labeling and Western blot (immunoblot) analysis of hlyA products. Hemolytic activity of the 79-kDa HlyA protein from E. coli was less than 5% that for the 65-kDa cytolysin from V. cholerae. Our results suggest that in V. cholerae, the 82-kDa preprotoxin synthesized in the cytoplasm is secreted through the membranes into the culture medium as the 79-kDa inactive protoxin after cleavage of the signal peptide and is then further processed into the 65-kDa active cytolysin by release of the N-terminal 15-kDa fragment.

Characterisation of foot-and-mouth disease virus strains circulating in Turkey during 1996-2004

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