Cholera Outbreaks in Nigeria Are Associated with Multidrug Resistant Atypical El Tor and Non-O1/Non-O139 Vibrio cholerae

Abstract

BackgroundThe current millennium has seen a steep rise in the number, size and case-fatalities of cholera outbreaks in many African countries. Over 40,000 cases of cholera were reported from Nigeria in 2010. Variants of Vibrio cholerae O1 El Tor biotype have emerged but very little is known about strains causing cholera outbreaks in West Africa, which is crucial for the implementation of interventions to control epidemic cholera.Methodology/Principal Findings V. cholerae isolates from outbreaks of acute watery diarrhea in Nigeria from December, 2009 to October, 2010 were identified by standard culture methods. Fifteen O1 and five non-O1/non-O139 strains were analyzed; PCR and sequencing targeted regions associated with virulence, resistance and biotype were performed. We also studied genetic interrelatedness among the strains by multilocus sequence analysis and pulsed-field gel electrophoresis. The antibiotic susceptibility was tested by the disk diffusion method and E-test. We found that multidrug resistant atypical El Tor strains, with reduced susceptibility to ciprofloxacin and chloramphenicol, characterized by the presence of the SXT element, and gyrA Ser83Ile/parC Ser85Leu alleles as well CTX phage and TCP cluster characterized by rstR ElTor, ctxB-7 and tcpA CIRS alleles, respectively, were largely responsible for cholera outbreaks in 2009 and 2010. We also identified and characterized a V. cholerae non-O1/non-O139 lineage from cholera-like diarrhea cases in Nigeria.Conclusions/SignificanceThe recent Nigeria outbreaks have been determined by multidrug resistant atypical El Tor and non-O1/non-O139 V. cholerae strains, and it seems that the typical El Tor, from the beginning of seventh cholera pandemic, is no longer epidemic/endemic in this country. This scenario is similar to the East Africa, Asia and Caribbean countries. The detection of a highly virulent, antimicrobial resistant lineage in Nigeria is worrisome and points to a need for vaccine-based control of the disease. This study has also revealed the putative importance of non-O1/non-O139 V. cholerae in diarrheal disease in Nigeria.

Multi-drug resistant Vibrio species isolated from abattoir effluents in Nigeria

“…Vibrio strains in this study were also considerably sensitive to nalidixic acid, ofloxacin, ciprofloxacin, chloramphenicol, and rifampicin (Table 2), contrary to the observation of Ottaviani et al [22], who reported resistance against rifampicin. Marin et al [16] also reported an intermediate/reduced sensitivity to chloramphenicol and ciprofloxacin, and resistance against nalidixic acid, contrary to the observation of this study. However, consistent with the observation of this study, Li et al [21] reported sensitivity of Vibrio strains isolated from cultured silver sea bream to rifampicin, while Opajobi et al [19] observed sensitivity of epidemic strains of V. cholerae to ofloxacin.…”

“…However, contrary to the report of Chiang and Chuang [20], V. vulnificus and V. cholerae in this study exhibited reduced sensitivity and resistance to ceftazidime (29%) and cefixime (17%), respectively ( Table 2). Li et al [21] reported remarkable sensitivity to the aminoglycosides (streptomycin and kanamycin), in agreement with the observation of this study; however, other reports [16,21] suggested otherwise. Vibrio strains in this study were also considerably sensitive to nalidixic acid, ofloxacin, ciprofloxacin, chloramphenicol, and rifampicin (Table 2), contrary to the observation of Ottaviani et al [22], who reported resistance against rifampicin.…”

“…Hence, increased attention is being focused on nucleic acid-based characterization of bacterial isolates due to the relative sensitivity and specificity of such techniques. Consistent with the observation of this study, Igbinosa et al [10] reported considerable resistance of Vibrio isolates from municipal wastewater against ampicillin, trimethoprim, and trimethoprim/sulphamethoxazole in South Africa, while Marin et al [16] documented resistance against trimethoprim and trimethoprim/sulphamethoxazole among clinical Vibrio strains isolated from different parts of Nigeria. The observation of resistance against trimethoprim is worrisome, as the antibiotic was previously reported to be the drug of choice for the treatment of cholera in children and pregnant women [17].…”

Antimicrobial Resistance Risks of Cholera Prophylaxis for United Nations Peacekeepers

“…Although surveillance systems to monitor DR cholera are poor, resistance to first-line therapies such as tetracycline derivatives, ciprofloxacin, and chloramphenicol is prevalent in some geographical regions (12)(13)(14). Lower rates of resistance to azithromycin, potentially contributing to the drug's superior efficacy against cholera diarrhea in clinical trials, have been reported (15,16).…”

Intestinal ameliorative effects of traditional Ogi-tutu, Vernonia amygdalina and Psidium guajava in mice infected with Vibrio cholera

“…Vibrio cholerae is a human pathogen that causes a severe acute watery diarrhea called cholera, a waterborne disease characterized by severe dehydration 1,2 . Vibrio cholerae is a major public health problem because of its epidemic potential 3 .…”