Salmonella enterica in Invasive Lizard from Fernando de Noronha Archipelago: Serotyping, Antimicrobial Resistance and Molecular Epidemiology

Abstract

Salmonella infection can pose serious health issues, especially to children, elders or immunosuppressed humans. Wild populations of reptiles can reach Salmonella prevalence of up to 100% and the direct or indirect transmission from reptiles to humans have been extensively reported. Fernando de Noronha (FN) is an inhabited oceanic archipelago in the northeast coast of Brazil, with an economy based on tourism. The tegu (Salvator merianae) is the largest lizard native to South America and was introduced to the archipelago in the early 20th century. This study determines the prevalence, serotypes, antimicrobial resistance, and molecular epidemiology of Salmonella enterica in the tegu population from FN archipelago. Results show that S. enterica is widely distributed in the FN tegu population, with 43.8% prevalence. The bacteria were isolated from 70.5% of the sampled sites and a total of 15 serotypes were detected in 98 S. enterica isolates. Strains were further classified into 31 genotypes. Recaptured animals presented distinct genotypes in each season, demonstrating a seasonal strain turnover. Most S. enterica isolates from FN tegus presented low antimicrobial resistance. This is possibly due to geographical isolation of the island population, hampering contact with strains from livestock from the continent, where antimicrobial resistance is common.

Occurrence, Antimicrobial Resistance, and Virulence Profiles of Salmonella Serovars Isolated from Wild Reptiles in South Africa

“…In contrast to our results, Abrahão et al [37] have reported 13.3% of isolates from lizard resistant to colistin in Brazil. Given this growing evidence for antibiotic resistance, the importance of reptile-associated Salmonella spp.…”

“…Higher (76.9%) prevalences of Salmonella spp. were recorded in pet snakes, lizards, and tortoises from Poland [5], 64.5% in snakes and lizards from Norwegian zoos [1], and 32.6% in domestic snakes, chameleons, and lizards from central Europe [35], 43.28% of the pet reptiles carried from Western Romania [36], and 50.0% of the lizard from Fernando de Noronha Archipelago (Brazil) [37]. Te current study is one of the few studies to isolate Salmonella serovars from wild reptiles.…”

Zoonotic potential and prevalence of Salmonella serovars isolated from pets

“…In another study, after examination of faeces from 426 reptiles (322 anoles, 69 iguanas and 35 geckos) caught in Guadeloupe National Park, the frequency of S. enterica carriage was 15% (64/426, 15%) [59%]. In Slovenia, Romero et al [72] examined the presence of [73] China [74], Malaysia [75], Brazil [76,77], the US [52,78] Australia [79,80], New Zealand [81], Grenada [82], Canada [83] and Japan [12,64,84]. Relatively low Salmonella-prevalence was reported in 2020 in Japan.…”

“…Taking into account non-European countries and the period 2015–2021, Salmonella -prevalence in reptiles was reported in Costa Rica [ 73 ] China [ 74 ], Malaysia [ 75 ], Brazil [ 76 , 77 ], the US [ 52 , 78 ] Australia [ 79 , 80 ], New Zealand [ 81 ], Grenada [ 82 ], Canada [ 83 ] and Japan [ 12 , 64 , 84 ]. Relatively low Salmonella -prevalence was reported in 2020 in Japan.…”

“…were isolated from 26 reptiles (26/76; 34.2%) [ 77 ]. Other Brazilian study has shown high prevalence of S. enterica serovars in black and white tegu lizard ( Salvator merianae ) which is an invasive species on the sampled area [ 76 ]. Increased Salmonella -prevalence was observed in Australia, where 52 from a total of 130 wild-caught reptiles were Salmonella spp.…”