scholarly journals Seasonal Cholera Caused by Vibrio cholerae Serogroups O1 and O139 in the Coastal Aquatic Environment of Bangladesh

2006 ◽  
Vol 72 (6) ◽  
pp. 4096-4104 ◽  
Author(s):  
Munirul Alam ◽  
Nur A. Hasan ◽  
Abdus Sadique ◽  
N. A. Bhuiyan ◽  
Kabir U. Ahmed ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Ecological Study ◽  
Enrichment Culture ◽  
Fluorescent Antibody ◽  
Blot Hybridization ◽  
Culture Methods ◽  
Lack Of Information ◽  
Direct Fluorescent Antibody ◽  
El Tor

ABSTRACT Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139 was carried out in two coastal areas, Bakerganj and Mathbaria, Bangladesh, where cholera occurs seasonally. The results of a biweekly clinical study (January 2004 to May 2005), employing culture methods, and of an ecological study (monthly in Bakerganj and biweekly in Mathbaria from March 2004 to May 2005), employing direct and enrichment culture, colony blot hybridization, and direct fluorescent-antibody methods, showed that cholera is endemic in both Bakerganj and Mathbaria and that V. cholerae O1, O139, and non-O1/non-O139 are autochthonous to the aquatic environment. Although V. cholerae O1 and O139 were isolated from both areas, most noteworthy was the isolation of V. cholerae O139 in March, July, and September 2004 in Mathbaria, where seasonal cholera was clinically linked only to V. cholerae O1. In Mathbaria, V. cholerae O139 emerged as the sole cause of a significant outbreak of cholera in March 2005. V. cholerae O1 reemerged clinically in April 2005 and established dominance over V. cholerae O139, continuing to cause cholera in Mathbaria. In conclusion, the epidemic potential and coastal aquatic reservoir for V. cholerae O139 have been demonstrated. Based on the results of this study, the coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae.

scholarly journals Toxigenic Vibrio cholerae in the Aquatic Environment of Mathbaria, Bangladesh

2006 ◽  
Vol 72 (4) ◽  
pp. 2849-2855 ◽  
Author(s):  
Munirul Alam ◽  
Marzia Sultana ◽  
G. Balakrish Nair ◽  
R. Bradley Sack ◽  
David A. Sack ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Fluorescent Antibody ◽  
Culture Methods ◽  
Viable But Nonculturable ◽  
Large Numbers ◽  
Direct Fluorescent Antibody ◽  
Nonculturable Cells ◽  
Seasonal Epidemics

ABSTRACT Toxigenic Vibrio cholerae, rarely isolated from the aquatic environment between cholera epidemics, can be detected in what is now understood to be a dormant stage, i.e., viable but nonculturable when standard bacteriological methods are used. In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic periods. Biweekly environmental surveillance for V. cholerae was carried out in Mathbaria, an area of cholera endemicity adjacent to the Bay of Bengal, with the focus on V. cholerae O1 and O139 Bengal. A total of 297 samples of water, phytoplankton, and zooplankton were collected between March and December 2004, yielding eight V. cholerae O1 and four O139 Bengal isolates. A combination of culture methods, multiplex-PCR, and direct fluorescent antibody (DFA) counting revealed the Mathbaria aquatic environment to be a reservoir for V. cholerae O1 and O139 Bengal. DFA results showed significant clumping of the bacteria during the interepidemic period for cholera, and the fluorescent micrographs revealed large numbers of V. cholerae O1 in thin films of exopolysaccharides (biofilm). A similar clumping of V. cholerae O1 was also observed in samples collected from Matlab, Bangladesh, where cholera also is endemic. Thus, the results of the study provided in situ evidence for V. cholerae O1 and O139 in the aquatic environment, predominantly as viable but nonculturable cells and culturable cells in biofilm consortia. The biofilm community is concluded to be an additional reservoir of cholera bacteria in the aquatic environment between seasonal epidemics of cholera in Bangladesh.

scholarly journals Predictability of Vibrio cholerae in Chesapeake Bay

2003 ◽  
Vol 69 (5) ◽  
pp. 2773-2785 ◽  
Author(s):  
Valérie R. Louis ◽  
Estelle Russek-Cohen ◽  
Nipa Choopun ◽  
Irma N. G. Rivera ◽  
Brian Gangle ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Vibrio Cholerae ◽  
Stream Flow ◽  
Natural Waters ◽  
Global Climate ◽  
Fluorescent Antibody ◽  
Fourfold Increase ◽  
Susquehanna River ◽  
Direct Fluorescent Antibody ◽  
Untreated Water

ABSTRACT Vibrio cholerae is autochthonous to natural waters and can pose a health risk when it is consumed via untreated water or contaminated shellfish. The correlation between the occurrence of V. cholerae in Chesapeake Bay and environmental factors was investigated over a 3-year period. Water and plankton samples were collected monthly from five shore sampling sites in northern Chesapeake Bay (January 1998 to February 2000) and from research cruise stations on a north-south transect (summers of 1999 and 2000). Enrichment was used to detect culturable V. cholerae, and 21.1% (n = 427) of the samples were positive. As determined by serology tests, the isolates, did not belong to serogroup O1 or O139 associated with cholera epidemics. A direct fluorescent-antibody assay was used to detect V. cholerae O1, and 23.8% (n = 412) of the samples were positive. V. cholerae was more frequently detected during the warmer months and in northern Chesapeake Bay, where the salinity is lower. Statistical models successfully predicted the presence of V. cholerae as a function of water temperature and salinity. Temperatures above 19°C and salinities between 2 and 14 ppt yielded at least a fourfold increase in the number of detectable V. cholerae. The results suggest that salinity variation in Chesapeake Bay or other parameters associated with Susquehanna River inflow contribute to the variability in the occurrence of V. cholerae and that salinity is a useful indicator. Under scenarios of global climate change, increased climate variability, accompanied by higher stream flow rates and warmer temperatures, could favor conditions that increase the occurrence of V. cholerae in Chesapeake Bay.

scholarly journals Ecological study of Vibrio cholerae in Vellore

2000 ◽  
Vol 124 (2) ◽  
pp. 201-206 ◽  
Author(s):  
M. V. JESUDASON ◽  
V. BALAJI ◽  
U. MUKUNDAN ◽  
C. J. THOMSON
Keyword(s):  
Vibrio Cholerae ◽  
Ecological Study ◽  
Fluorescent Antibody ◽  
Maximum Temperature ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Environmental Distribution ◽  
Antibody Staining ◽  
The Relationship ◽  
Fluorescent Antibody Staining

Vellore is endemic for cholera due to Vibrio cholerae O1 and O139. In a previous study the prevalence of Vibrio cholerae in drinking water, lakes and sewage outfalls in a single 2-months period in Vellore, India was determined. In addition water samples from three sites were also tested for the presence of V. cholerae O1 and O139 by fluorescent antibody staining. This follow on study has examined how the environmental distribution of V. cholerae at the same sites alters over a 12-month period and the relationship to the clinical pattern of cholera in Vellore. Samples of water were collected from fixed sites at three water bodies each month between April 1997 and March 1998. Bacteria isolated from samples were identified by standard biochemical tests and isolated strains of V. cholerae tested for their ability to agglutinate O1 and O139 antisera. Samples were also tested for the presence of V. cholerae O1 and O139 by fluorescent antibody staining. The clinical isolation rate of V. cholerae in Vellore, maximum temperature and rainfall were also studied. The results demonstrate the presence in the environment of viable but non-cultivable (VNC) V. cholerae in 10 of 12 months of the study year as well as their viability. Their prevalence in the environment also correlated with the isolation of these pathogens from clinical samples over the same study period.

scholarly journals Performance of the Syva Direct Fluorescent Antibody Assay for Chlamydia in a Low-Prevalence Population

1993 ◽  
Vol 1 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Mark B. Reedy ◽  
Patricia J. Sulak ◽  
William B. McCombs III ◽  
Thomas J. Kuehl
Keyword(s):  
Tissue Culture ◽  
Fluorescent Antibody ◽  
Transmitted Disease ◽  
The United States ◽  
Current Data ◽  
Chlamydia Infection ◽  
Culture Methods ◽  
Predictive Values ◽  
Direct Fluorescent Antibody ◽  
Low Prevalence

Chlamydia trachomatisis the most common reportable sexually transmitted disease (STD) in the United States. In the 1980s, rapid diagnostic tests for chlamydia began to replace more cumbersome tissue culture methods. Current data on rapid antigen detection assays demonstrate acceptable sensitivity, specificity, and predictive values in populations with a high prevalence of chlamydia. Few studies report the performance of these assays in a low-prevalence obstetric and gynecologic (Ob/Gyn) population, This study compares the most commonly used direct fluorescent antibody (DFA) assay (Syva Microtrak) with tissue culture (TC) in a low-prevalence population. Endocervical specimens (775) were tested from women at risk for chlamydia infection, and the prevalence was found to be 7.7%. The DFA assay demonstrated a sensitivity of 80% and a specificity of 97% compared with TC. The positive and negative predictive values were 72% and 98%, respectively. The results of this study indicate that the Syva DFA assay lacks the sensitivity and positive predictive value for routine use in Ob/Gyn populations with a lowprevalence ofC. trachomatis.

scholarly journals Association of Vibrio cholerae O1 El Tor and O139 Bengal with the Copepods Acartia tonsa and Eurytemora affinis

2007 ◽  
Vol 73 (24) ◽  
pp. 7926-7933 ◽  
Author(s):  
Tonya K. Rawlings ◽  
Gregory M. Ruiz ◽  
Rita R. Colwell
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Acartia Tonsa ◽  
Copepod Species ◽  
Life Stages ◽  
Eurytemora Affinis ◽  
Rural Bangladesh ◽  
Laboratory Microcosm ◽  
Vibrio Cholerae O1 ◽  
El Tor

ABSTRACT The association of Vibrio cholerae with zooplankton has been suggested as an important factor in transmission of human epidemic cholera, and the ability to colonize zooplankton surfaces may play a role in the temporal variation and predominance of the two different serogroups (V. cholerae O1 El Tor and O139) in the aquatic environment. To date, interactions between specific serogroups and species of plankton remain poorly understood. Laboratory microcosm experiments were carried out to compare quantitatively the colonization of two copepod species, Acartia tonsa and Eurytemora affinis, by each of the epidemic serogroups. V. cholerae O1 consistently achieved higher abundances than V. cholerae O139 in colonizing adults of each copepod species as well as the multiple life stages of E. affinis. This difference in colonization may be significant in the general predominance of V. cholerae O1 in cholera epidemics in rural Bangladesh where water supplies are taken directly from the environment.

scholarly journals Genotypes Associated with Virulence in Environmental Isolates of Vibrio cholerae

2001 ◽  
Vol 67 (6) ◽  
pp. 2421-2429 ◽  
Author(s):  
Irma N. G. Rivera ◽  
Jongsik Chun ◽  
Anwar Huq ◽  
R. Brad Sack ◽  
Rita R. Colwell
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Vibrio Cholerae ◽  
High Frequency ◽  
Aquatic Environment ◽  
Human Health Risk ◽  
The Other ◽  
Genetic Element ◽  
Environmental Isolates ◽  
El Tor

ABSTRACT Vibrio cholerae is an autochthonous inhabitant of riverine and estuarine environments and also is a facultative pathogen for humans. Genotyping can be useful in assessing the risk of contracting cholera, intestinal, or extraintestinal infections via drinking water and/or seafood. In this study, environmental isolates ofV. cholerae were examined for the presence of ctxA, hlyA, ompU, stn/sto, tcpA, tcpI, toxR, and zot genes, using multiplex PCR. Based on tcpA and hlyAgene comparisons, the strains could be grouped into Classical and El Tor biotypes. The toxR, hlyA, and ompU genes were present in 100, 98.6, and 87.0% of the V. choleraeisolates, respectively. The CTX genetic element and toxin-coregulated pilus El Tor (tcpA ET) gene were present in all toxigenicV. cholerae O1 and V. cholerae O139 strains examined in this study. Three of four nontoxigenic V. cholerae O1 strains contained tcpA ET. Interestingly, among the isolates of V. cholerae non-O1/non-O139, two hadtcpA Classical, nine contained tcpA El Tor, three showed homology with both biotype genes, and four carried thectxA gene. The stn/sto genes were present in 28.2% of the non-O1/non-O139 strains, in 10.5% of the toxigenicV. cholerae O1, and in 14.3% of the O139 serogroups. Except for stn/sto genes, all of the other genes studied occurred with high frequency in toxigenic V. cholerae O1 and O139 strains. Based on results of this study, surveillance of non-O1/non-O139 V. cholerae in the aquatic environment, combined with genotype monitoring using ctxA, stn/sto, andtcpA ET genes, could be valuable in human health risk assessment.

scholarly journals Role of Chitin for Harbouring of Toxigenic Vibrio cholerae O1 El Tor in Aquatic Environment

1970 ◽  
Vol 25 (1) ◽  
pp. 26-30 ◽  
Author(s):  
M Mahmud Hasan ◽  
Sucharit Basu Neogi ◽  
Iqbal Kabir Jahid ◽  
M Sirajul Islam ◽  
Anwara Begum
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Genotypic Variation ◽  
Aquatic Organisms ◽  
Crustacean Zooplankton ◽  
Term Survival ◽  
Cellular Density ◽  
Main Component ◽  
El Tor

Vibrio cholerae, the etiological agent of cholera is an autochthonous bacterium of aquatic environment, often found attached to crustacean zooplankton. Chitin is the main component of crustacean exoskeleton, an insoluble polysaccharide. V. cholerae can secrete chitinase enzymes, which can facilitate the bacterium's association with chitinous aquatic organisms to utilize it as a potential nutrient source. In the present study, we checked the role of chitin for long term survival of V. cholerae. Laboratory based microcosms were prepared with purified artificial chitin chips and a toxigenic strain of V. cholerae O1 El Tor. In the presence of chitin, V. cholerae was found in a higher cellular density for >61 days in culturable condition than control water. We observed that the older chitin chips gradually thinner which indicated that V. cholerae utilized chitin. PCR experiment confirmed the presence of the bacterium's cholera toxin coding gene (ctxA) and membrane associated virulent gene ompU remained unaltered. Finally, from randomly amplified polymorphic DNA (RAPD) analysis no significant genotypic variation was detected in the bacterium's genome after its long time association with chitin. Keywords: Vibrio cholerae; Chitin; Polymerase chain reaction (PCR); MicrocosmDOI: http://dx.doi.org/10.3329/bjm.v25i1.4851 Bangladesh J Microbiol, Volume 25, Number 1, June 2008, pp 26-30

Temperature affects Vibrio cholerae O1 El Tor persistence in the aquatic environment via an enhanced expression of GbpA and MSHA adhesins

2010 ◽  
Vol 2 (1) ◽  
pp. 140-144 ◽  
Author(s):  
Monica Stauder ◽  
Luigi Vezzulli ◽  
Elisabetta Pezzati ◽  
Barbara Repetto ◽  
Carla Pruzzo
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Enhanced Expression ◽  
Vibrio Cholerae O1 ◽  
El Tor
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