Comparison of the phylogenetic analysis of PFGE profiles and the characteristic of virulence genes in clinical and reptile associated Salmonella strains

Abstract

Background Salmonella is generally considered as a human pathogen causing typhoid fever and gastrointestinal infections called salmonellosis, with S. Enteritidis and S. Typhimurium strains as the main causative agents. Salmonella enterica strains have a wide host array including humans, birds, pigs, horses, dogs, cats, reptiles, amphibians and insects. Up to 90% of reptiles are the carriers of one or more serovars of Salmonella. Extraintestinal bacterial infections associated with reptiles pose serious health threat to humans. The import of exotic species of reptiles as pet animals to Europe correlates with the emergence of Salmonella serotypes, which not found previously in European countries. The presented study is a new report about Salmonella serotypes associated with exotic reptiles in Poland. The goal of this research was to examine the zoonotic potential of Salmonella strains isolated from reptiles by comparative analysis with S. Enteritidis strains occurring in human population and causing salmonellosis. Results The main findings of our work show that exotic reptiles are asymptomatic carriers of Salmonella serovars other than correlated with salmonellosis in humans ( S . Enteritidis, S . Typhimurium). Among the isolated Salmonella strains we identified serovars that have not been reported earlier in Poland, for example belonging to subspecies diarizonae and salamae . Restriction analysis with Pulsed-field Gel Electrophoresis ( PFGE), showed a great diversity among Salmonella strains isolated from reptiles. Almost all tested strains had distinct restriction patterns. While S . Enteritidis strains were quite homogeneous in term of phylogenetic relations. Most of the tested VGs were common for the two tested groups of Salmonella strains. Conclusions The obtained results show that Salmonella strains isolated from reptiles share most of virulence genes with the S. Enteritidis strains and exhibit a greater phylogenetic diversity than the tested S. Enteritidis population. Electronic supplementary material The online version of this article (10.1186/s12917-019-2019-1) contains supplementary material, which is available to authorized users.

Pet Reptiles: A Potential Source of Transmission of Multidrug-Resistant Salmonella

“…The close contact between reptiles and their owners provides favourable conditions for the transmission of zoonotic pathogens infections, constituting a public health concern, as these pets have been considered as potential Salmonella carriers (7)(8)(9)(10)(11). Reptiles are natural reservoirs of Salmonella, which can hold a wide variety of serovars simultaneously without symptoms (12)(13)(14). However, reptile-associated salmonellosis seems to be responsible for more serious complications, with invasive disease and hospitalisation, especially in children (14,15).…”

“…Reptiles are natural reservoirs of Salmonella, which can hold a wide variety of serovars simultaneously without symptoms (12)(13)(14). However, reptile-associated salmonellosis seems to be responsible for more serious complications, with invasive disease and hospitalisation, especially in children (14,15). From a public health standpoint, pet reptiles represent a persistent source of salmonellosis in households (16)(17)(18)(19).…”

Salmonella in Captive Reptiles and Their Environment—Can We Tame the Dragon?

“…The issue of microbiological hazards associated with reptiles kept in houses or zoos is rarely investigated in Poland, but a few reports are available [ 7 , 8 , 9 , 10 ]. The aim of this study was to further investigate the occurrence of Salmonella in exotic reptiles, including the serovar distribution and antimicrobial resistance of the strains, in the context of an improved detection procedure and public health concerns.…”

Zoonotic potential and prevalence of Salmonella serovars isolated from pets

“…Those changes can lead to resistance of Salmonella spp. to human serum, especially the complement system which is part of the innate immune response [43][44][45][46]. Salmonella serovars isolated from reptiles are often resistant to human serum, which enables them to cause disease in humans.…”

“…Since 2015, only a few reports determined amphibians as a source of human salmonellosis [46,[60][61][62].…”