Detection of Salmonella enterica Serovar Montevideo and Newport in Free‐ranging Sea Turtles and Beach Sand in the Caribbean and Persistence in Sand and Seawater Microcosms

Abstract

Salmonellae are Gram-negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non-typhoidal Salmonella enterica in the nesting and foraging populations of sea turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting leatherback sea turtles compared with foraging green and hawksbill sea turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 leatherback sea turtle samples. Salmonella DNA was detected in one hawksbill turtle, but viable isolates were not recovered from any hawksbill sea turtles. No Salmonella was detected in green sea turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive-element palindromic PCR (rep-PCR) fingerprint analysis and pulsed-field gel electrophoresis of the 2014 isolates from turtles and sand as well as archived Salmonella isolates recovered from leatherback sea turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory-controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32 days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free-ranging marine reptiles and the potential public health risks associated with human interactions with these animals in the Caribbean.

Identification and Characterization ofEscherichia coli,SalmonellaSpp.,Clostridium perfringens, andC. difficileIsolates from Reptiles in Brazil

“…The reptiles were selected from the following habitats: private owners volunteers ( n = 23), free-living from metropolitan area of Belo Horizonte captured for monitoring ( n = 37), and captivity ( n = 16) randomly selected from the Wildlife Screening Center (CETAS) and Ezequiel Dias Foundation (FUNED). For sampling procedures, a sterile swab (BactiSwab; Remel, Lenexa, KA, USA) was introduced 5–6 cm into the cloaca and rotated five times, as described by Ives et al [14]. The swab was vigorously agitated in 500 μ L of phosphate-buffered saline (PBS), stored in a transport box with ice packs and transported to the Bacterial and Research Laboratory of Veterinary School of Federal University of Minas Gerais for immediate processing.…”

A Review of the Public Health Challenges of Salmonella and Turtles

“…Salmonella enterica was detected in the tested cloacal swabs taken from the leatherback sea turtles [33]. Another investigation conducted several years later in this country compared the prevalence of Salmonella in leatherback sea turtles with that of green and hawksbill sea turtles [30]. The results indicated a higher prevalence of Salmonella in nesting leatherback sea turtles compared to hawksbill sea turtles, while no Salmonella was detected in green sea turtles.…”

“…Considering the significance of turtle-associated salmonellosis in human health several studies have been conducted in different parts of the world in order to improve the knowledge about the rate of Salmonella contamination in turtles. In Saint Kitts, three different sea turtle species can be found year round, including marine environment turtle species (hawksbill, Eretmochelys imbricata, and green turtles, Chelonia mydas), and seasonal nester species (leatherback, Dermochelys coriacea) [30]. Little is known about the risk of Salmonella transmission from wild sea turtles to humans, and it has only been investigated in a few studies [31,32].…”

“…The results indicated a higher prevalence of Salmonella in nesting leatherback sea turtles compared to hawksbill sea turtles, while no Salmonella was detected in green sea turtles. S. enterica serovar Montevideo and S. enterica serovar Newport were the only ones detected in this study [ 30 ]. The reason for the higher prevalence of Salmonella in leatherback sea turtles in this study compared to the previous investigation conducted by Dutton et al (2013) [ 33 ] might be due to sampling from different geographical locations in Saint Kitts, human interaction with animals and environment, the age of the animals, and other possible unknown reasons [ 30 ] ( Table 3 ).…”

Multiple Food-Animal-Borne Route in Transmission of Antibiotic-Resistant Salmonella Newport to Humans

“…Additional functional experiments in our group, and genomic analysis suggested that S. Newport of different lineages carried distinct genetic signatures and behaved with dramatically different pathogenic features ( Yue et al, 2012 , 2015 ; Yue and Schifferli, 2014 ; De Masi et al, 2017 ; Zheng et al, 2017 ), further supporting the distinct populations in S. Newport. Additional large-scale population analysis of S. Newport with a focus on other sources such as many sea animals and various of wild-caught or farm-reared amphibians ( Deekshit et al, 2012 , 2015 ; Goupil et al, 2012 ; Sylvester et al, 2014 ; Nowakiewicz et al, 2015 ; Ives et al, 2016 ; Nguyen et al, 2016 ; Ribas and Poonlaphdecha, 2017 ) needs further investigations.…”