| Abstract|| |
Background: Cholera is a primordial disease caused by Vibrio cholerae which existed from centuries in different parts of the world and still shows its periodic, endemic and epidemic presence. Thousands of cholera cases are reported from different parts of India and the disease remains endemic throughout the year. At present, we do not have enough knowledge about the phenotypic nature of the circulating V. cholerae strains in this part of the world. Objectives: This study was carried out over a period of 6 years with the aim defer with the changes in the prevalence and distribution of biotypes, serotypes and phage types of V. cholerae clinical isolates from various endemic regions of the country to determine phenotypic characteristics of the circulating strains and also to predict the attributes of cholera strains responsible for causing significant outbreaks in future. Materials and Methods: A total of 1882 V.cholerae O1 isolates from different cholera endemic areas of India were included in this study. V.cholerae strains which were identified as O1 biotype ElTor further analyzed for serotype and phage types using the standard methodologies. Polyvalent O1 and monospecific Inaba and Ogawa antisera were used for serotyping. A panel of five phages of Basu and Mukherjee phage typing scheme and five phages from the new phage typing scheme were used for phage typing analysis following standard methodology. Results: Maximum numbers of strains were isolated from cholera-endemic states like Gujarat and Maharashtra. All the isolates were confirmed as V. cholerae O1 biotype ElTor and majority of them were serotype Ogawa (93.2%). New phage typing scheme resulted in almost 100% typeable V. cholerae O1 strains included in this study and phage type 27 was the predominant type. Although 80% of the strains used in this study were sensitive to all the vibrio phages, S5 phage was found most efficient in lysing cholera strains indicating its broader host range. Conclusion: The current study identified phage type 27 as the most dominant type and serotype Ogawa was found continuous in circulation throughout the year which has caused recent cholera outbreaks in India during the past years. Phage sensitivity data propose an alternative cost-effective approach to prevent cholera outbreak by therapeutic uses of typing phages irrespective of origin or clonality of the strains.
Keywords: ElTor, O1, Ogawa, phage typing, S5 phage, Vibrio cholera
|How to cite this article:|
Chakrabarti AK, Biswas A, Tewari DN, Mondal PP, Dutta S. Phage types of Vibrio cholerae 01 biotype ELtor strains isolated from India during 2012–2017. J Global Infect Dis 2020;12:94-100
|How to cite this URL:|
Chakrabarti AK, Biswas A, Tewari DN, Mondal PP, Dutta S. Phage types of Vibrio cholerae 01 biotype ELtor strains isolated from India during 2012–2017. J Global Infect Dis [serial online] 2020 [cited 2021 Jan 23];12:94-100. Available from: https://www.jgid.org/text.asp?2020/12/2/94/284623
| Introduction|| |
Cholera remains a significant global health burden and is endemic in many parts of the third world countries due to inadequate sanitation and safe drinking water resources mainly during the rainy season.Vibrio cholerae, an extremely motile, halophilic, curved shaped, Gram-negative bacterium is known for causing profound acute secretory diarrhea, cholera. Although V. cholerae is a natural member of aquatic environments, only a small fraction of environmental strains are capable of causing the disease. Among the several known serogroups, only two serogroups, V. cholerae O1 and O139 can produce cholera toxin and V. cholerae O1 often accountable for causing the vast majority of the disease including recent cholera outbreaks throughout the world. Serogroup O1 consists of biotypes ElTor and classical with distinct phenotypes. Both the biotypes carry two serotypes, Inaba and Ogawa with different disease characteristics. Cholera has a long history; in the past 200 years, seven cholera pandemics have killed millions across the globe including the Indian subcontinent (