A rare case of gastroenteritis due to salmonella enterica serovar Infantis in South India

Salmonella enterica serovar Infantis is an emerging non-typhoidal Salmonella (NTS) serovar increasingly associated with foodborne gastroenteritis. Human infections caused by this serovar remain underreported in India. We report a case of acute gastroenteritis caused by Salmonella enterica serovar Infantis in a 53-year-old male from South India. The patient presented with acute-onset watery diarrhoea for six days associated with intermittent fever and recent outside food consumption. Stool culture yielded non-lactose fermenting colonies identified by automated identification using the VITEK-2 Compact system as Salmonella group, which was subsequently confirmed as Salmonella enterica serovar Infantis by the National Institute for Research in Bacterial Infections, Kolkata, India. Antimicrobial susceptibility testing revealed susceptibility to ceftriaxone, cefepime, carbapenems, ciprofloxacin, and trimethoprim/sulfamethoxazole, while resistance to aminoglycosides and cefuroxime-axetil was observed. The patient improved clinically with ceftriaxone therapy and supportive management. This case highlights the emerging clinical importance of S. Infantis in India and underscores the necessity of routine serotyping, antimicrobial susceptibility testing, and strengthened surveillance to monitor evolving resistance patterns and public health risks associated with NTS infections.