tive vibrio samples are non-motile under dark field microscope supporting the role bacteriophages in controlling and spread of an outbreak.
Bacteriophages are a cost effective alternative to antibiotics and sometimes may be used for therapeutic purposes to treat multi drug resistance (MDR) bacteria with limited success.,,,, In India, the history of phage therapy dates back to 1930s when vibriophages had been successfully used to treat cholera infection in the pre-antibiotic era.,,
Phage therapy remained a standard part of the healthcare systems in Eastern Europe and the USSR since the second half of the 20th century. However, it was largely neglected in the other part of the world due to easy availability of antibiotics for treatment. Widespread use of antibiotics resulted in the development of MDR bacteria which is a major problem in healthcare units today. Increase in multidrug resistance phenotype of V. cholerae O1 biotype ElTor makes the population vulnerable to a new pandemic., To overcome the problem of MDR phenotypes of V. cholerae, phage therapy may be a better option. Earlier studies have shown that cocktail of the five bacteriophages reduced the V. cholerae load in a rabbit model of infection when administered 6 or 12 h after the pathogen challenge. In other similar studies virulent vibriophages were used to control diseases in the animal model., We found that typing phages are highly reactive to circulating ElTor strains [Table 2]. Our analysis revealed that the ability of the phages to cause lysis of V.cholerae strains ranges between 80%–94%, signifying their probable usages as candidate for phage cocktail for therapeutic uses. Moreover, as 94% of the circulating strains are susceptible to S5 phage, vibriophage S5 alone may also be used as an ideal candidate for phage therapy. Therefore a cocktail of these vibriophages or vibriophage S5 in combination with lytic phages of other diarrhea causing organisms may be considered as an universal cocktail for the prophylaxis of diarrheal diseases.,,, Hopefully future studies will be helpful to ascertain the decisive use of phages to treat diarrheal diseases. Cholera typing phages used in this study were found nonreactive (inability to cause bacterial lysis) to other commensals which makes them more suitable than antibiotics to manage cholera outbreak.
| Conclusion|| |
We have demonstrated that phage typing is still an internationally recognized method of choice for characterizing circulating strains. The present study has identified and characterized dominant cholera strains circulating in India throughout the year. This knowledge will be helpful to design a novel strategy to manage cholera outbreak in different parts of the country. Moreover, this study indirectly supports the use of phages as a cost-effective alternative to control the disease and antibiotic resistance burden of V. cholerae strains. We also advocate the use of these typing phages by directly applying them to water bodies and drinking water supply systems to reduce the burden of cholera incidence in the cholera hot spot region in India or anywhere in the world.
We would like to thank Dr. B. L Sarkar for his enthusiastic support, guidance and helpful advice in preparation of this manuscript. We are thankful to Mr. Motilal Gupta for technical support. This study was supported by the Indian Council of Medical Research as an Institutional service project.
Financial support and sponsorship
This study was funded by ICMR-NICED institutional grant.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Sack DA, Sack RB, Nair GB, Siddique AK. Cholera. Lancet 2004;363:223-33.
Clemens JD, Nair GB, Ahmed T, Qadri F, Holmgren J. Cholera. Lancet 2017;390:1539-49.
Mandal S, Mandal MD, Pal NK. Cholera: A great global concern. Asian Pac J Trop Med 2011;4:573-80.
Sur D, Dutta P, Nair GB, Bhattacharya SK. Severe cholera outbreak following floods in a northern district of West Bengal. Indian J Med Res 2000;112:178-82.
Feng L, Reeves PR, Lan R, Ren Y, Gao C, Zhou Z, et al
. A recalibrated molecular cl