Salmonella spp. in Pet Reptiles in Portugal: Prevalence and Chlorhexidine Gluconate Antimicrobial Efficacy

Abstract

A fraction of human Salmonella infections is associated with direct contact with reptiles, yet the number of reptile-associated Salmonellosis cases are believed to be underestimated. Existing data on Salmonella spp. transmission by reptiles in Portugal is extremely scarce. The aim of the present work was to evaluate the prevalence of Salmonella spp. in pet reptiles (snakes, turtles, and lizards), as well as evaluate the isolates’ antimicrobial resistance and virulence profiles, including their ability to form biofilm in the air-liquid interface. Additionally, the antimicrobial effect of chlorhexidine gluconate on the isolates was tested. Salmonella was isolated in 41% of the animals sampled and isolates revealed low levels of antimicrobial resistance. Hemolytic and lypolytic phenotypes were detected in all isolates. The majority (90.63%) of the Salmonella isolates were positive for the formation of pellicle in the air-liquid interface. Results indicate chlorhexidine gluconate is an effective antimicrobial agent, against the isolates in both their planktonic and biofilm forms, demonstrating a bactericidal effect in 84.37% of the Salmonella isolates. This study highlights the possible role of pet reptiles in the transmission of non-typhoidal Salmonella to humans, a serious and increasingly relevant route of exposure in the Salmonella public health framework.

Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections

“…The differences in Salmonella prevalence found in this literature search are similar to those reported previously in a number of individual studies. Specifically, lower detections rates in chelonians in comparison to snakes or lizards have been repeatedly reported ( Geue and Löschner, 2002 ; Scheelings et al, 2011 ; Hydeskov et al, 2013 ; Lukac et al, 2015 ; Corrente et al, 2017 ; Bjelland et al, 2020 ; Cota et al, 2021 ; Zając et al, 2021 ). However, other studies have found a higher prevalence in chelonians ( Ebani et al, 2005 ; Bertelloni et al, 2016 ).…”

“…The differences noted in detection rates between wild reptiles and reptiles in captivity could—as mentioned above—also be due to differences in conditions, with dietary, stress and crowding-related factors likely causing the higher detection rates found in reptiles in captivity. Given the high dependency of ectothermic organisms on their environment, and natural living situations probably reflecting more physiological conditions than those in captivity, this could contribute to a stronger immune system and reduced stress ( DuPonte et al, 1978 ; Geue and Löschner, 2002 ; Dickinson et al, 2005 ; Scheelings et al, 2011 ; Cota et al, 2021 ).…”

“…However, although some of these methods resulted in the reduction of infection and/or shedding rates in hatchling turtles, their excessive use also increased antibiotic resistance ( Mitchell et al, 2007 ). Other substances, such as sodium hypochlorite and polyhexamethylene biguanides ( Mitchell et al, 2007 ) or chlorhexidine gluconate ( Cota et al, 2021 ) also lead to some degree of reduction in Salmonella carriage of hatchlings. However, in general, efforts to eliminate Salmonella spp.…”

Zoonotic potential and prevalence of Salmonella serovars isolated from pets

“…geographic distribution in reptiles, regardless of climate or environment. Including European countries, studies in this area come from Croatia [ 65 ], Italy [ 63 , 66 , 67 ], Spain [ 68 ], Norway [ 31 ], Guadeloupe (French West Indies) [ 59 ], Poland [ 30 , 46 , 69 , 70 ], Portugal [ 71 ] and Slovenia [ 72 ] ( Table 1 ). In Croatia, Salmonella spp.…”

Antimicrobial Resistant Salmonella in Chelonians: Assessing Its Potential Risk in Zoological Institutions in Spain

“…[12,21]. The close contact between chelonians and humans provides favourable conditions for the transmission of zoonotic infections, with reptile-associated salmonellosis being related to more severe clinical scenarios than those caused by other sources of infection [22][23][24].…”