Genetic diversity and relatedness of uropathogenic Escherichia Coli with non-clinical isolates in Grenada

OBJECTIVE: To compare genetic profiles of uropathogenic E.coli (UPEC) to strains isolated from freshwater, seawater and iguanas in Grenada. DESIGN AND METHODS: Eighty-five E. coli strains were isolated using double streak-plating on eosin methylene blue (EMB) and MacConkey agar from human urine, iguanas, fresh and marine water. Species identification was confirmed using API20E. Genomic DNA was extracted from individual pure cultures of E. coli and amplified using the oligonucleotide (GTG5) and BOX primers. The DNA fingerprints were separated by electrophoresis, normalized using reference American Test Culture collection (ATCC) E.coli and compared using DendroUPGMA, the FigTree™, dominance and co-clustering analyses. RESULTS: Both DNA fingerprinting methods targeted extragenic DNA and demonstrated enormous intra-species diversity within the population of studied 85 E. coli isolated from four major eco-habitats. DNA fingerprinting based on BOX-PCR was less discriminating than the (GTG)5-PCR. The BOX analysis correlated better with the ecotype distribution. The combination of dominance and co-clustering analyses allowed us to trace the relatedness of strains among and between the four different ecotypes. CONCLUSIONS: The (GTG5) PCR based co-clustering analysis indicated that the clinical isolates had a closer relationship to iguana E. coli isolates than to fresh and marine water isolates. However, in accordance with the BOX analysis, clinical isolates were most similar to marine, followed by freshwater and iguanas.

Prevalence, serovars and antimicrobial susceptibility of Salmonella spp. from wild and domestic green iguanas (Iguana iguana) in Grenada, West Indies.

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4-month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty-five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z51 :- (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies.

Prevalence of Salmonella spp. in cane toads (Bufo marinus) from Grenada, West Indies, and their antimicrobial susceptibility.

Cloacal swabs and caecal contents sampled from 58 cane toads (Bufo marinus) in St George's parish, Grenada, during a 7-month period in 2011 were examined by an enrichment and selective culture method for presence of Salmonella spp. Twenty-four (41%) toads were positive for Salmonella spp. of which eight were Salmonella enterica serovar Javiana, and eight were S. enterica serovar Rubislaw. The other serovars were as follows: Montevideo, 6; Arechavaleta, 1; and serovar: IV:43:-:-, 1. The high frequency of isolation of serovar Javiana, an emerging human pathogen associated with several outbreaks in the recent years in the eastern United States, suggests a possible role for cane toads in transmission of this serovar. Although S. Rubislaw has been isolated from lizards, bats and cases of some human infections, there is no report of its carriage by cane toads, and in such high frequency. The rate of carriage of S. Montevideo, a cause for human foodborne outbreaks around the world was also over 10% in the 58 toads sampled in this study. The antimicrobial drug susceptibility tests against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, imipenem, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal and is of little concern. Antimicrobial resistance was limited to ampicillin and amoxicillin-clavulanic acid in one isolate of S. Javiana and one isolate of S. Rubislaw. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars not identified previously in cane toads in Grenada, West Indies.