An outbreak of gastroenteritis by Salmonella enterica subspecies diarizonae

Gastroenteritis in human by Salmonella enterica subspecies diarizonae is rare and usually observed in neonates and children with history of contact with reptiles. Salmonella enterica subspecies diarizonae were isolated from two young adult male patients with symptoms of acute gastroenteritis. The isolates were identifi ed by Vitek 2 compact system and agglutination by specifi c antisera. The isolates were susceptible to Amikacin, Imipenam, Cefazolin and Ceftazidime. Patient rapidly responded to Amikacin and Ceftazidime therapy. Arizona group Salmonella should be looked in cases of gastroenteritis whenever there is history of proximity with reptiles. Case Study An outbreak of gastroenteritis by Salmonella enterica subspecies diarizonae RS Parihar, Archana Bora, Prabhat Kiran Khatri and Vikrant Negi* Assistant Professor, Department of Microbiology, GMC Haldwani, India Received: 10 February, 2020 Accepted: 26 March, 2020 Published: 27 March, 2020 *Corresponding author: Vikrant Negi, M. Sc Medical Microbiology, Assistant Professor, Department of Microbiology, GMC Haldwani, India, E-mail:


Introduction
Food borne diseases including, food borne intoxication and infections, are terms applied to illness acquired through the consumption of contaminated food; they are frequently and inaccurately referred to as food poisoning. The incidence becomes an outbreak only if the illness occurs within a short but variable period of time after a meal during which individuals have consumed foods in common [1]. Acute gastroenteritis caused by non-typhoidal Salmonella continues to be an important public health problem worldwide. Consumption of raw and undercooked meat, poultry eggs, and dairy products are the most common reasons for its transmission [2]. Reptileassociated salmonellosis is an emerging zoonosis in humans who handle reptiles directly or indirectly, causing mainly enteric illness. Rare cases of gastroenteritis in humans with Salmonella enterica subspecies arizonae [3] and Salmonella enterica subspecies diarizonae [4] are reported. Here we describe two cases of Salmonella enterica subspecies diarizonae gastroenteritis during a clinically suspected outbreak of gastroenteritis which occurred in a camp at Barmer district of Thar desert.

Cases
Four patients from a camp located in Gadra (Barmer) were in monotremes, turkeys, chickens, goats, and rarely in humans [6]. Salmonella enterica ssp diarizonae and arizonae are the major reptile-associated pathogens in humans [7] and are highly prevalent in free-living and captive reptiles, particularly in snakes [8,9] S. enterica ssp. diarizonae enteritis or systemic infections have been well described in patients residing in the southern states of the USA and Europe. It is much rare, with only a few cases reported in the literature [10][11][12][13]. It can be diffi cult to identify S. enterica ssp. diarizonae due to their distinguishing biochemical features such as the ability to utilize malonate, liquefy gelatin and the inability to grow in the presence of KCN (potassium cyanide), which are generally not looked into for routine identifi cation of bacterial isolates. Isolation of S. enterica ssp. diarizonae from the stools is diffi cult as some strains ferment lactose within 48 hours (approximately 15%) and they may be routinely discarded as non-pathogens. However, the presence of hydrogen sulfi de is an important diagnostic clue during routine screening [14].
Most cases of invasive S. enterica ssp. diarizonae infection have been either in younger patients specially neonates or those with underlying diseases including collagen vascular diseases, malignancy, organ transplantation and HIV infection [4,5,15,16]. However, in this case both the patients were adults with no underlying diseases. The stool specimens were sent to Microbiology two days after the onset of symptoms which may be reason for pathogens not growing in most of the specimens.
The leftover food was also not available to trace the source of infection. The camp is present in Thar Desert region which is largely inhabited by reptiles such as lizards and snakes. Snakes and lizards frequently break into the compound area of the camp. Only the history of snakes and lizards contaminating that region can be associated with the isolated pathogens.

Conclusion
Incidences of Arizona group of Salmonella are rare but exist in India. S. enterica ssp. diarizonae can cause gastroenteritis in healthy adults. The laboratory should also attempt to detect Arizona group in patients with gastroenteritis and have history with proximity to reptiles.