Unique Clones of Vibrio cholerae O1 El Tor with Haitian Type ctxB Allele Implicated in the Recent Cholera Epidemics from Nigeria, Africa.

Akinsinde Kehinde Adewale,Asish K Mukhopadhyay,Gururaja Perumal Pazhani,Iwalokun Bamidele Abiodun,Thanadarayan Ramamurthy,Oluwadun Afolabi,Olukoya Daniel Kolawole,Martyn Kirk

doi:10.1371/journal.pone.0159794

Akinsinde Kehinde Adewale, Asish K Mukhopadhyay + Show 6 more

Open Access

https://doi.org/10.1371/journal.pone.0159794

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Abstract

Background and ObjectivesThe antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. In this study, we screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality.ResultsAll the V. cholerae O1 biotype El Tor isolates isolated during 2007–2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria. Emergence of CT genotype 7 (Haitian type of ctxB allele) was predominantly seen among Ogawa serotype and the CT genotype 1 (classical ctxB allele) was mostly found in Inaba serotype. Overall, V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis. V. cholerae isolates from Abia, Kano and Bauchi were found to be genetically distinct from the other states of Nigeria.ConclusionFecal contamination of the water sources may be the possible source of the cholera infection. Combined prevalence of Haitian and classical ctxB alleles were detected in Ogawa and Inaba serotypes, respectively. This study further demonstrated that V. cholerae O1 with the ctxB has been emerged similar to the isolates reported in Haiti. Our findings suggest that the use of fluoroquinolones or tetracycline/doxycycline may help in the effective management of acute cholera in the affected Nigerian states. In addition, strengthening the existing surveillance in the hospitals of all the states and supply of clean drinking water may control cholera outbreaks in the future.

Highlights

Despite several efforts, cholera continues to occur as a major public health problem in African countries with high rates of morbidity and mortality
All the V. cholerae O1 biotype El Tor isolates isolated during 2007–2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria
V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis

Summary

Introduction

Cholera continues to occur as a major public health problem in African countries with high rates of morbidity and mortality. In 2013 alone, 22 countries from the African continent have reported 56,329 cholera cases, including 1366 deaths with case fatality rate (CFR) of 2.43% [1]. The intermittent large cholera outbreaks such as the one observed in 2010 with 41,787 cases and 1,716 deaths has increased the CFR to 4.1% [6]. The antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. We screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality

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Conclusion