Update on cholera --- Haiti, Dominican Republic, and Florida, 2010

On October 21, 2010, a cholera outbreak was confirmed by the Haitian National Public Health Laboratory. By November 19, the outbreak had reached every department of the country, and by December 17, a total of 121,518 cases of cholera, resulting in 63,711 hospitalizations and 2,591 deaths, had been reported. By November 16, additional cases of cholera had been confirmed in the neighboring Dominican Republic and in Florida. Several confirmed cases in the Dominican Republic and all confirmed U.S. cases were among travelers from Haiti. This report describes cases of cholera identified in the Dominican Republic and United States and provides recommendations to physicians regarding management of travel-related cases. Travelers who develop watery diarrhea within 5 days after returning from cholera-affected areas should seek health care and report their travel histories. Clinicians should enquire about recent travel when evaluating patients with diarrhea. When cholera is suspected, rehydration should be initiated immediately, a stool specimen should be collected for culture of Vibrio cholerae, and public health authorities should be notified.

Update: cholera outbreak --- Haiti, 2010

On October 19, 2010, the Haitian Ministry of Public Health and Population (MSPP) was notified of unusually high numbers of patients from Artibonite and Centre departments who had acute watery diarrhea and dehydration, in some cases leading to death. Within 4 days, the National Public Health Laboratory (LNSP) in Haiti isolated Vibrio cholerae serogroup O1, serotype Ogawa, from stool specimens obtained from patients in the affected areas by an investigation team from MSPP and CDC Haiti. This report describes the investigation of the initial cases, the ongoing outbreak of cholera in Haiti, and initial control measures. Since the initial identification of cholera, the outbreak has expanded to include cases in seven of Haiti's 10 departments and the capital city of Port-au-Prince. As of November 13, MSPP had reported 16,111 persons hospitalized with acute watery diarrhea and 992 cholera deaths, 620 of which occurred among hospitalized patients. Prevention and control measures implemented by MSPP with assistance from governmental and nongovernmental partners include 1) providing better access to treated drinking water; 2) providing education on improvement of sanitation, hygiene, and food preparation practices; 3) advising ill persons to begin using oral rehydration solution immediately and seek health care at the onset of watery diarrhea; 4) enhancing cholera treatment capacity at existing health-care institutions; and 5) establishing cholera treatment centers.

Cholera outbreak --- Haiti, October 2010

An outbreak of cholera is ongoing in Haiti. On October 21, 2010, toxigenic Vibrio cholerae O1, serotype Ogawa, biotype El Tor was identified by the National Laboratory of Public Health of the Ministry of Public Health and Population in Haiti. Identification of the isolate was confirmed by CDC. Antimicrobial susceptibility testing of selected V. cholerae O1 isolates conducted at the National Laboratory of Public Health and at CDC demonstrated susceptibility to tetracycline (susceptibility to this drug predicts doxycycline susceptibility), ciprofloxacin, and kanamycin; and resistance to trimethoprim-sulfamethoxazole, furazolidone, nalidixic acid, sulfisoxazole, and streptomycin.

[Comparative assessment of dot-immunoassay and immunochromatography methods for detection of 01 serogroup of vibrio cholerae]

AIM

Comparative study of sensitivity and specificity of immunochromatographic (IC) assay kit and dot-immunoanalysis for assessment of feasibility of their use for laboratory diagnostics of cholera.

MATERIALS AND METHODS

Experimental lots of IC assay kit and dot-immunoassay (DIA) for detection of Vibrio cholerae serogroup 01 serovars Ogava and Inaba were constructed on the basis of species-specific monoclonal antibodies (MCA) conjugated with colloid gold (IC) and peroxidase (DIA). Hybridoma-producer of MCAwas obtained and stored in liquid nitrogen in Rostov-on-Don Research Institute for Plague Control. It was deposited in specialized collection of cell cultures of vertebrates in Institute of Cytology (Saint Petersburg).

RESULTS

Strong specificity of IC assay kit and DIA relative to cholera vibrios 01 and absence of crossreactivity with closely related and heterologous microorganisms were shown. Minimal quantity of vibrios, which could be detected using IC assay kit and DIA, was 107 and 105-106 microbial cells respectively.

CONCLUSION

Performance of IC assay takes 5-15 min, DIA--1.5 hour, they allow to visually assess the reaction, do not require instrumentation and in perspective both methods could be used on defined stages of scheme for laboratory analysis of cholera.

Molecular evidence of cholera outbreak caused by a toxigenic Vibrio cholerae O1 El tor variant strain in Kelantan, Malaysia

A total of 20 Vibrio cholerae isolates were recovered for investigation from a cholera outbreak in Kelantan, Malaysia, that occurred between November and December 2009. All isolates were biochemically characterized as V. cholerae serogroup O1 Ogawa of the El Tor biotype. They were found to be resistant to multiple antibiotics, including tetracycline, erythromycin, sulfamethoxazole-trimethoprim, streptomycin, penicillin G, and polymyxin B, with 35% of the isolates being resistant to ampicillin. All isolates were sensitive to ciprofloxacin, norfloxacin, chloramphenicol, gentamicin, and kanamycin. Multiplex PCR analysis confirmed the biochemical identification and revealed the presence of virulence genes, viz., ace, zot, and ctxA, in all of the isolates. Interestingly, the sequencing of the ctxB gene showed that the outbreak strain harbored the classical cholera toxin gene and therefore belongs to the newly assigned El Tor variant biotype. Clonal analysis by pulsed-field gel electrophoresis demonstrated that a single clone of a V. cholerae strain was responsible for this outbreak. Thus, we present the first molecular evidence that the toxigenic V. cholerae O1 El Tor variant has invaded Malaysia, highlighting the need for continuous monitoring to facilitate early interventions against any potential epidemic by this biotype.

Diagnostic limitations to accurate diagnosis of cholera

The treatment regimen for diarrhea depends greatly on correct diagnosis of its etiology. Recent diarrhea outbreaks in Bangladesh showed Vibrio cholerae to be the predominant cause, although more than 40% of the suspected cases failed to show cholera etiology by conventional culture methods (CMs). In the present study, suspected cholera stools collected from every 50th patient during an acute diarrheal outbreak were analyzed extensively using different microbiological and molecular tools to determine their etiology. Of 135 stools tested, 86 (64%) produced V. cholerae O1 by CMs, while 119 (88%) tested positive for V. cholerae O1 by rapid cholera dipstick (DS) assay; all but three samples positive for V. cholerae O1 by CMs were also positive for V. cholerae O1 by DS assay. Of 49 stools that lacked CM-based cholera etiology despite most being positive for V. cholerae O1 by DS assay, 25 (51%) had coccoid V. cholerae O1 cells as confirmed by direct fluorescent antibody (DFA) assay, 36 (73%) amplified primers for the genes wbe O1 and ctxA by multiplex-PCR (M-PCR), and 31 (63%) showed El Tor-specific lytic phage on plaque assay (PA). Each of these methods allowed the cholera etiology to be confirmed for 97% of the stool samples. The results suggest that suspected cholera stools that fail to show etiology by CMs during acute diarrhea outbreaks may be due to the inactivation of V. cholerae by in vivo vibriolytic action of the phage and/or nonculturability induced as a host response.

[Development of multiplex real time PCR methodology for better identification and discrimination of Vibrio cholerae and O139 serotype]

OBJECTIVE

To develop a rapid, sensitive and specific assay method, based on multiplex real time PCR for identifying Vibrio cholerae and distinguishing Vibrio cholerae O139 serotype from Vibrio cholerae.

METHODS

Cholera toxin A subunit gene (ctxA) and glycosyltransferase gene (LPSgt) were chosen as targets according to Vibrio cholerae and Vibrio cholerae O139 serotype, and then the primers and TaqMan-MGB probe were designed. The 5'end of probes was labeled with FAM and VIC fluoresceins respectively while the 3'end of probes was labeled with MGB. The PCR reaction was optimized systematically. Then the specificity, sensitivity and reproducibility of multiplex real time PCR were estimated. Finally, multiplex real time PCR was applied to detect the clinical specimens.

RESULTS

Vibrio cholerae was identified by multiplex real time PCR accurately and quickly, which could distinguish Vibrio cholerae O139 serotype from Vibrio cholerae. Vibrio cholerae was identified positive for primer pairs and probes from ctxA gene, and Vibrio cholerae O139 serotype tested was positive for LPSgt gene. Meanwhile, none of other bacteria was identified. Sensitivity of the test was 2 × 10(2) cfu/ml. When this assay was applied directly to identify 45 clinical specimens, results showed that 10 were positive to Vibrio cholerae, in which 4 clinical specimens were positive to Vibrio cholerae O139 serotype. All the results were the same to the one that had been obtained from the conventional assays.

CONCLUSION

Our results showed that the multiplex real time PCR was a reliable, accurate and feasible method for identifying Vibrio cholerae that carrying toxin gene and distinguishing Vibrio cholerae O139 serotype from Vibrio cholerae. This method could be applied to the cholera surveillance, prevention and control system for identifying and distinguishing Vibrio cholerae in the labs.

Evaluation of a rapid immunochromatographic dipstick kit for diagnosis of cholera emphasizes its outbreak utility

We evaluated the Crystal VC, a commercially produced dipstick, for the rapid detection of Vibrio cholerae serotypes O1 and O139 directly from the stool samples of hospitalized diarrheal patients using the conventional bacteriological method as gold standard. The sensitivity and specificity of the dipsticks were about 92 and 73%, respectively. Introduction of the PCR-based method along with the classical bacteriological method as the gold standard for the evaluation of a kit may improve the sensitivity and specificity of the assay. The dipstick method requires minimal technical skill, and the test can be read in about 10 min. This dipstick test has the potential to act as an early warning system for cholera in many developing countries, especially during the start of an outbreak, which would ultimately lead to a decrease in the spread of the disease as well as the case fatality rate. Furthermore, the use of a rapid detection test will improve surveillance and thus reduce the burden of disease estimates, especially in remote settings.

Epidemiological characteristics of cholera in Singapore, 1992-2007

INTRODUCTION

We carried out an epidemiological review of cholera in Singapore to determine its trends and the factors contributing to its occurrence.

MATERIALS AND METHODS

Epidemiological data of all notified cases of cholera maintained by the Communicable Diseases Division, Ministry of Health, for the period 1992 to 2007 were collated and analysed. Case-control studies were carried out in outbreaks to determine the source of infection and mode of transmission. Linear patterns in age and ethnic distribution of cholera cases were assessed using chi2 test for trend.

RESULTS

There were a total of 210 cholera cases reported between 1992 and 2007. The incidence of cholera declined from 17 cases in 1992 to 7 cases in 2007. About a quarter of the cases were imported from endemic countries in the region. Between 76% and 95% of the reported cases were local residents. Four elderly patients with comorbidities and who sought medical treatment late died, giving a case-fatality rate of 1.9%. Vibrio cholerae 01, biotype El Tor, serotype Ogawa, accounted for 83.8% of the cases. The vehicles of transmission identified in outbreaks included raw fi sh, undercooked seafood and iced drinks cross-contaminated with raw seafood.

CONCLUSION

With the high standard of environmental hygiene and sanitation, a comprehensive epidemiological surveillance system and licensing and control of food establishments, cholera could not gain a foothold in Singapore despite it being situated in an endemic region. However, health education of the public on the importance of personal and food hygiene is of paramount importance in preventing foodborne outbreaks. Physicians should also maintain a high level of suspicion of cholera in patients presenting with severe gastroenteritis, especially those with a recent travel history to endemic countries.

[2007 cholera epidemic in Comoros islands: a step towards endemisation?]

In 2007, a cholera epidemic occurred on two of the three islands of the Comoros archipelago: Grande Comore and Moheli. This study is based on data from the files of the 1571 patients admitted to five cholera treatment centers (CTC). The outbreak lasted for ten months. A dramatic peak was observed in July and August corresponding to the traditional wedding season during which hundreds of guests including returning diaspora gather to celebrate "Grand Marriages". Initial stool cultures identified Vibrio cholerae O1, Ogawa serotype. The in-center fatality rate was 1.85%. Poor socio-economical conditions combined with a rapid turnover of health personnel and delayed response of the health authorities could lead to endemisation.

A cholera epidemic in Sekong Province, Lao People's Democratic Republic, December 2007-January 2008

Recent large-scale outbreaks in the Lao People's Democratic Republic (Lao PDR) were reported in 1993 and 1994 and from 2000 to 2002. On December 23, 2007, a drastic increase in acute watery diarrhea patients at a health center in Sekong Province was reported to the provincial health office. An outbreak investigation was initiated to understand the magnitude of the outbreak, identify new cases, identify the suspected causal agent, implement control measures, and prevent new cases. Through active village based surveillance, 370 cases and 3 deaths were reported from 31 villages between December 15, 2007 and January 29, 2008. Of these reported cases, 29% were under the age of 5. From 28 fresh stool samples taken, 17 (58.6%) were positive for Vibrio cholerae O1 Ogawa strain. Two water sources close to affected villages were found to be contaminated with the same strain of V. cholerae. Control measures implemented included health education for safe household water consumption and early identification and treatment of suspected cholera patients at village level. The cause of the outbreak was suspected to be a combination of contaminated drinking water and person-to-person transmission.

[Simultaneous detection of Vibrio Cholerae O1 and O139 by real-time quantitative PCR]

OBJECTIVE

Targeting the specific O-antigen gene cluster, a Taq-Man real-time fluorescence PCR assay was developed to detect 01 and O139 Vibrio cholera concurrently and avoid frequently occurred false positives.

METHODS

Two pairs of specific primers and two Taq-Man fluorescent probes respectively targeting rfbM gene of Vibrio cholerae O1 and wbfR of 0139 were designed. After optimization of conditions, the specialty and sensitivity of the detection method were evaluated and ten simulated food samples and 128 clinical samples were tested.

RESULTS

The detection limits of Vibrio cholerae O1 and O139 were 92 CFU/ml and 116 CFU/ml, which were almost the same with the usual PCR method. The developed real-time fluorescence PCR protocol detected only Vibrio cholerae O1 and O139 and it was not affected by many normal food pathogens such as Staphylococcus aureus and Salmonella, especially Vibrio cholerae O141 which contained TCP genes and Vibrio mimicus which contained ZOT gene. The clinical detect results of the developed assay and routine culture method were exactly the same.

CONCLUSION

The developed detection assay could quantitatively detect Vibrio cholerae O1 and O139 concurrently in only 3 hours, and could avoid false positive, and thus was an efficacious method for detecting Vibrio cholerae O1 and O139 and could be used in a wide area such as entry-exit inspection and quarantine, food safety detection and clinical diagnose.

Antimicrobial suceptibility of V. cholerae in north west, Ethiopia

OBJECTIVES

Various Vibrio cholerae serogroups cause cholera, which occurs as major epidemic disease in most developing countries. This study was aimed at determining the antimicrobial susceptibility patterns of V. cholerae and its serotypes from cholera cases.

METHODS

The study was undertaken during cholera epidemics in North West Ethiopia from August 2006 to September 2008. Diarrheic stool samples were processed per the standard microbiology procedures at Bahir Dar Regional Health Research Laboratory. Antimicrobial susceptibility tests were performed using disc diffusion technique per Kirby-Bauer method.

RESULTS

Eighty one V. cholerae 01 serotype Inaba were isolated from stools of cholera cases. Antibiograms of V. cholerae 01 Inaba showed that 71.6% of isolates were resistant against two, 18.4% to three and 5% to four antibiotics. All V. cholerae Inaba isolates were resistant to co-trimoxazol 81 (100%). High levels of resistance were also shown to chloramphenicol 76 (94%) and ampicillin 72 (89%) with least resistance to erythromycin 12 (15%), tetracycline 5 (6.2) and ciprofloxacilin 1 (1.2%). However, all isolates remain susceptible to doxycycline 81 (100%).

CONCLUSION

In the study area, doxycycline or ciprofloxacilin could be used for treatment of adult cholera cases whereas erythromycin is alternative for young children. Antimicrobial susceptibility tests are strongly recommended for V. cholerae strains in treatment intervention during epidemics.

Molecular characterisation of Vibrio cholerae O1 strains carrying an SXT/R391-like element from cholera outbreaks in Kenya: 1994-2007

BACKGROUND

Over the last decade, cholera outbreaks in parts of Kenya have become common. Although a number of recent studies describe the epidemiology of cholera in Kenya, there is paucity of information concerning the diversity and occurrence of mobile genetic elements in Vibrio cholerae strains implicated in these outbreaks. A total of 65 Vibrio cholerae O1 El Tor serotype Inaba isolated between 1994 and 2007 from various outbreaks in Kenya were investigated for mobile genetic elements including integrons, transposons, the integrating conjugative elements (ICEs), conjugative plasmids and for their genotypic relatedness.

RESULTS

All the strains were haemolytic on 5% sheep blood and positive for the Vibrio cholerae El Tor-specific haemolysin toxin gene (hylA) by PCR. They all contained strB, sulII, floR and the dfrA1 genes encoding resistance to streptomycin, sulfamethoxazole, chloramphenicol and trimethoprim respectively. These genes, together with an ICE belonging to the SXT/R391 family were transferable to the rifampicin-resistant E. coli C600 en bloc. All the strains were negative for integron class 1, 2 and 3 and for transposase gene of transposon Tn7 but were positive for integron class 4 and the trpM gene of transposon Tn21. No plasmids were isolated from any of the 65 strains. All the strains were also positive for all V. cholera El Tor pathogenic genes except the NAG- specific heat-stable toxin (st) gene. None of the strains were positive for virulence genes associated with the V. cholerae classical biotype. All the strains were positive for El Tor-specific CTXphi bacteriophage rstrR repressor gene (CTXETPhi) but negative for the Classical, Calcutta, and the Environmental repressor types. Pulse Field Gel Electrophoresis (PFGE) showed that regardless of the year of isolation, all the strains bearing the SXT element were clonally related.

CONCLUSIONS

This study demonstrates that the V. cholerae O1 strains carrying an SXT/R391-like element implicated in recent cholera outbreaks in Kenya has not changed significantly between 1994 and 2007 and are clonally related.

[A duplex nested PCR assay detecting of Vibrio cholerae and its application on environmental specimens]

OBJECTIVE

To establish a duplex nested PCR assay system which is capable for detecting O1 and O139 groups of Vibrio cholerae simultaneously, and is applicable to environmental specimens from routine cholera surveillance.

METHODS

Based on nucleic acid sequences available in GenBank, six sets of primers were designed by PrimerSelect program of DNAStar, targeting the rfb gene that encodes the O antigens of O1 and O139 V. cholerae, respectively. The specificity of several primer combinations was tested. A duplex nested PCR assay system for simultaneously detecting O1 and O139 V. cholerae was established, subsequently, its sensitivity, specificity, reproducibility and field evaluation were tested. The sensitivity of this assay was evaluated by comparing detection limits of nested PCR and conventional PCR. Its reproducibility was tested by 32 positive samples (11 samples positive for O1, 21 samples positive for O139) from environmental surveillance. In addition, the selected amplicons from positive samples were sequenced and analyzed with relevant sequences.

RESULTS

This newly-established duplex nested PCR assay might distinguish O1 V. cholerae from O139 V. cholerae, based on fragment lengths of amplicons, with reliable reproducibility, and no specific amplification was observed as compared with other vibrio species. The sensitivity of this nested PCR was (15 000) higher than conventional PCR, and there was no interference observed with multiple primers and complicated templates in the same vial. In its field evaluation, 32 positive DNA samples were detected and be further confirmed with double or triple tests, implying reliable reproducibility and consistency of this system. These results indicated that this assay had reliable reproducibility. No amplification was observed in all negative specimens and also suggested the acceptable specificity of this assay. Sequence analysis of the selected amplification products revealed 100% homogeneous with relevant genes from V.cholerae, indicating that these amplicons were originated from V. cholerae.

CONCLUSION

This duplex nested PCR assay system should be rapid, sensitive and especially applicable to small laboratories, and be suitable for dynamic environmental surveillance.

Antibacterial activity of ciprofloxacin and trimethoprim, alone and in combinittion, against Vibrio cholerae O1 biotype El Tor serotype Ogawa isolates

In this communication, the ciprofloxacin-trimethoprim (Cp-Tm) combination showed synergistic (Fractional Inhibitory Concentration, FIC index 0.399) and additive (FIC index 0.665-0.83) effects against Vibrio cholerae O1 biotype El Tor serotype Ogawa isolates having Cp MICs 10 microg/ml and Cp 0.66 microg/ml, respectively, following agar dilution checkerboard method. The time-kill study results demonstrated synergy between Cp and Tm against both groups of isolates providing 2.04 log10 (for strain with Cp MIC 0.66 microg/ml) and 3.12 log10 (for strain with Cp MIC 10 microg/ml) decreases in CFU/ml between the combination and its most active compound. Thus, the findings of the present study suggest an introduction of Cp-Tm combination treatment regimen against drug resistant cholera and this in turn will help in combating the drug resistance of V. cholerae O1 biotype El Tor serotype Ogawa.

Changing characteristics of Vibrio cholerae: emergence of multidrug resistance and non-O1, non-O139 serogroups

The serogroups and antimicrobial susceptibility patterns of V. cholerae isolated in Hubli, India during the years 2000 to 2004 were monitored. A total of 256 V. cholerae isolates were obtained during the study period, of which 129 (50.4%) belonged to serogroup O1 while the O139 and non-O1, non-O139 serogroups constituted 61 (23.8%) and 66 (25.8%) isolates, respectively. V. cholerae O1 Ogawa was the predominant isolate during the first 2 years of the study. However, this was replaced by V. cholerae non-O1, non-O139 serogroups in the following years. The V. cholerae, which was susceptible to most enteric antimicrobials in 2000, was found to be multidrug resistant in subsequent years, with the development of fluroquinolone resistance since 2002. Surveillance of the epidemiological and microbiological characteristics of V. cholerae provides useful information for managing cholera cases. The V. cholerae non-O1, non-O139 serogroups coupled with multiple antimicrobial resistance may form a group of emerging diarrheal pathogens in the tropics.

A comparison of clinical and immunologic features in children and older patients hospitalized with severe cholera in Bangladesh

BACKGROUND

: Infection with Vibrio cholerae induces protection from subsequent severe disease, suggesting that an effective vaccine could be an important preventive strategy. Available vaccines provide less protection against cholera than natural infection, particularly in children.

METHODS

: We examined a cohort of 121 children (2 years-12 years of age) and 276 older patients (>12 years of age) hospitalized with cholera in Dhaka, Bangladesh over a 4-year period, to compare clinical features in older patients and children and immune responses to key antigens.

RESULTS

: Older patients had more severe disease. Children with cholera were more commonly retinol deficient, while zinc deficiency was equally prevalent in both groups. Children developed higher vibriocidal and serum immune responses to the B subunit of cholera toxin (CTB). In contrast, older patients mounted higher immune responses to 2 other key V. cholerae antigens, the lipopolysaccharide (LPS) and toxin coregulated pilus antigens (TcpA). We compared immune responses following infection with those occurring after receipt of a live, oral vaccine in both children and older patients in Bangladesh, during a similar time period. The response rates for vibriocidal and LPS antibodies were higher after infection than after vaccination. Both vaccinated older patients and children responded poorly to CTB and TcpA.

CONCLUSIONS

: Although children developed vigorous vibriocidal and CTB-specific responses following infection, they had lessened responses to LPS and TcpA compared with older patients, as well as lessened responses to vaccination. More studies need to be carried out to determine factors, including micronutrient interventions that can improve responses in children to both natural infection and vaccination.

Incidence of bacterial enteropathogens among hospitalized diarrhea patients from Orissa, India

Bacteriological analysis of 1,551 stool/rectal swabs from all age groups of diarrhea patients of different hospitals of Orissa from January 2004 to December 2006 was carried out using standard procedures. Among all enteropathogens isolated in 886 culture-positive samples, Escherichia coli constituted 75.5%, including 13.2% pathogenic E. coli; Vibrio cholerae O1 constituted 17.3%; V. cholerae O139, 1%; Shigella spp., 4.5% (Shigella flexneri type 6, 2.9%, S. dysenteriae type I, 0.7%, S. sonnei, 0.6%, and S. boydii, 0.3%); Salmonella spp., 0.7%; and Aeromonas spp., only 2.0%. The isolation of bacterial enteropathogens was highest during July, 2005, followed by September, 2006. The prevalence of shigellosis in this region was relatively low. Cholera cases were more frequent during the rainy seasons. The dominance of V. cholerae O1 Inaba over Ogawa serotypes was observed in 2005, whereas this trend was reversed in 2006. The resistance profile of V. cholerae O1 was co-trimoxazole (Co), furazolidone (Fr), and nalidixic acid (Na); for Aeromonas spp., it was ampicillin (A), Fr, ciprofloxacin (Cf), Na, norfloxacin (Nx), and Co. Pathogenic E. coli strains were resistant to A, Fr, Co, streptomycin (S), Cf, Na, Nx, and neomycin (N); Shigella spp. were resistant to Fr, Na, Co, and S; and Salmonella spp. were resistant to A and Fr. Active surveillance should be continued among diarrhea patients to look for different enteropathogens and to define the shifting antibiogram patterns in this region.

Association of ompU gene in Vibrio cholerae from patients and environment with bile resistance

The objective of this study was to determine whether Vibrio cholerae, possessing ompU isolated from patients and the environment, conferred bile resistance and whether other virulence genes were also related to bile resistance. Fifty-two V cholerae O1 and non-O1 isolates were examined by PCR for the presence of the virulence-associated and regulatory genes, ctxA, tcpA, zot, ace, ompU, toxR, hlyA and stn/sto. V. cholerae possessing ompU resistant to equal or greater than 10% sodium deoxycholate were found in 93% of isolates but only in 9% of V. cholerae isolates not possessing ompU. The effects of other virulence genes on bile resistance could not be ascertained in this study. Thus V cholerae non-O1 with ompU and possibly other virulence genes isolated from the environment have the potential of affecting public health.

[Vibrio cholerae serogroups O1 and O139: susceptibility to antibiotics during 7th cholera pandemic]

The review presents data on circulation of antibiotic resistant and susceptible strains of Vibrio cholerae serogroups O1 and O139 isolated from cholera patients and healthy persons as well as from the environment, in Asia, Africa, Australia, and Europe (including New Independent States) during 7th cholera pandemic.