Non-typhoidal salmonellosis: Detection of genes responsible for virulence: A hospital-based study from Manipal, India.

Abstract

Background: Non-typhoidal Salmonella (NTS) is one of the four critical worldwide reasons for diarrhoeal infections and causes a noted zoonotic infection termed non-typhoidal salmonellosis. Non-typhoidal salmonellosis generally causes self-limited gastroenteritis, whereas in immunocompromised conditions can result in invasive infections. Aim and Objectives: To detect the likely NTS serovars causing non-typhoidal Salmonellosis and their virulence genes. Material and Methods: This is a prospective cross-sectional research work carried out at the Enteric Diseases Division, Central Research Lab, Kasturba Medical College, Manipal from January 2016 - June 2018. Stool samples were collected from patients with diarrhoea admitted to the tertiary care centre in Udupi district, India. Stool samples were processed according to the World Health Organisation laboratory protocol. Non-typhoidal Salmonella isolated were subjected to PCR for the detection of virulence genes. Results: Of the 1599 diarrheal samples processed, 55 NTS were isolated with a prevalence of 3.43 %. invA gene was existent in 83.6% of the isolates, spvC gene in 61.8%, stn in 100% sopB in 96.4% and sefA in 5.45%. Conclusion: The presence of virulence genes among NTS increases the complications of non-typhoidal salmonellosis. Routine antimicrobial susceptibility tests for salmonellae should be carried out and then reported to prevent the associated morbidity and mortality.

Keywords

• non-typhoidal salmonella
• salmonellosis
• invasiveness
• virulence genes