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.
ABSTRACT
Since its original description from the Amazonian region, the tick species Amblyomma goeldii Neumann, 1899 has been misidentified with Amblyomma rotundatum Koch, 1844 in different countries of the Neotropical region. Because of this, some authors have considered that the only confirmed records of A. goeldii were from French Guyana. Herein, we reviewed all specimens of A. goeldii that have been deposited at two tick collections in Brazil. In addition, we describe the nymphal stage of A. goeldii for the first time. A total of 10 unpublished records of the adult stage of A. goeldii are recorded from the Amazonian region of Brazil, confirming the occurrence of A. goeldii in this country. Except for one record on the snake Boa constrictor Linnaeus, all records of A. goeldii reported in the present study were from anteaters (Pilosa: Myrmecophagidae). Our results, in conjunction with previous literature records, indicate that anteaters and large snakes are important hosts for the adult stage of A. goeldii. The nymph of A. goeldii is morphologically similar to the nymphs of Amblyomma romitii Tonelli-Rondelli, 1939, Amblyomma dissimile Koch, 1844, and A. rotundatum. We present a modification of a previously published taxonomic key of Amblyomma nymphs from Brazil, in order to perform taxonomic identification of the nymph of A. goeldii based on external morphology. The geographical distribution of A. goeldii appears to be restricted to the Amazonian region. There were no previous host records for the immature stages of A. goeldii, thus it is expected that the present nymphal description will facilitate further works on the ecology of this poorly studied tick species.
