Indian Journal of Medical Research

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 146  |  Issue : 7  |  Page : 15--22

Investigation into a community outbreak of Salmonella Typhi in Bengaluru, India


Swathi Purighalla1, Saritha Esakimuthu2, Mallika Reddy2, Tara Seth3, Sunita D Patil4, George K Varghese1, Raghunath Dasarathy5, Vijay S Richard1, Vasan K Sambandamurthy6 
1 Department of Hospital Infection Control, Narayana Health City, Bengaluru, India
2 Department of Microbiology, Narayana Health City, Bengaluru, India
3 Department of Microbiology, Narayana Health, Bengaluru, India
4 Department of Pathology & Microbiology, Command Hospital, Bengaluru, India
5 Sir Dorabji Tata Center for Research in Tropical Diseases, Innovation Center, Indian Institute of Science Campus, Bengaluru, India
6 Mazumdar Shaw Centre for Translational Research, Narayana Health City, Bengaluru, India

Correspondence Address:
Vasan K Sambandamurthy
Mazumdar Shaw Centre for Translational Research, Narayana Health City, A-Block, 8th Floor #258/A, Bengaluru 560 099, Karnataka
India

Background & objectives: Outbreaks of infection due to Salmonella enterica servovar Typhi (S. Typhi) are a great threat to public health. A rapid molecular typing method to characterize strains implicated in an outbreak is critical in implementing appropriate control measures. This study was done to demonstrate the power of a PCR-based method to provide rapid insights into the genetic relatedness amongst the Salmonella isolates implicated in a suspected typhoid fever outbreak. Methods: Forty two S. Typhi isolates originating from three geographically distinct areas, with one area suspected to have a single-source outbreak were included in the study. The genetic fingerprint of all isolates was generated using enterobacterial repetitive intergenic consensus sequence based-PCR (ERIC-PCR). The antimicrobial susceptibility profiles were also evaluated. Results: ERIC-PCR was found to be rapid and reproducible with a discriminatory index of 0.766. The dendrogram constructed based on ERIC-PCR fingerprinting revealed the existence of 12 distinct genotypes. The location suspected to have an outbreak displayed two genotypes amongst the 24 isolates. The other two locations (18 isolates) displayed genetic heterogeneity. The clonality of the outbreak isolates from the time-matched control isolates was established. The observed antimicrobial susceptibility profiles did not have any discriminatory power to subtype the isolates compared to the genetic fingerprints. Interpretation & conclusions: Our study demonstrated the discriminatory power and value of ERIC-PCR in the typing of S. Typhi isolates and providing valuable epidemiological insights.


How to cite this article:
Purighalla S, Esakimuthu S, Reddy M, Seth T, Patil SD, Varghese GK, Dasarathy R, Richard VS, Sambandamurthy VK. Investigation into a community outbreak of Salmonella Typhi in Bengaluru, India.Indian J Med Res 2017;146:15-22


How to cite this URL:
Purighalla S, Esakimuthu S, Reddy M, Seth T, Patil SD, Varghese GK, Dasarathy R, Richard VS, Sambandamurthy VK. Investigation into a community outbreak of Salmonella Typhi in Bengaluru, India. Indian J Med Res [serial online] 2017 [cited 2020 Jan 25 ];146:15-22
Available from: http://www.ijmr.org.in/article.asp?issn=0971-5916;year=2017;volume=146;issue=7;spage=15;epage=22;aulast=Purighalla;type=0