The study used PCR to determine the molecular basis of the antibiotic resistance and virulence profiles of isolates of Salmonella by targeting genes encoding for carriage and persistence in the poultry.  A total of 1503 cecal samples from poultry were collected, 91 (6.1%) were positive for Salmonella spp. Ten different serotypes were detected from Salmonella isolates.  The study was also conducted to determine the occurrence of 13 virulence and 12 resistance genes in isolates of Salmonella spp. All  46 isolates of Salmonella spp. tested were positive to one or more of the 12 virulence genes detected, ranging from 0.0% (viaB) to 100.0% (invA, mgtB, pipA and spi4D) (P<0.05).  Occurrence of virulence genes varied significantly (P<0.05) by serotype but not by animal species.  Of the 12 resistance genes assayed, only 4 (33.3%), strA, ampC, cmy2 and qnrB were detected. Overall, the occurrence of detection resistance genes was 71.7% (33/46), with 87.1% and 40.0% of the isolates from chickens and ducks, respectively positive (p=0.0009). The occurrence of resistance gene ranged from 2.2% (cmy2) to 50.0% (qnrB) in resistance gene positive isolates.  The findings provide evidence that poultry from pluck shops are colonized by pathogenic Salmonella harboring virulence and antimicrobial resistance genes which may have clinical and therapeutic consequences, if the genes detected are expressed. Although there is a need for prudent use of antimicrobial agents in poultry production systems which should be constant monitoring for the prevalence of resistance in Salmonella isolates using phenotypic methods, the importance and knowledge of the occurrence of resistance genes in the pathogen in Trinidad cannot be ignored.

The aim of the study was to determine the prevalence and zonal distribution of Salmonella serotypes in poultry and to determine the antimicrobial resistance profile of Salmonella isolates. A total of 1,503 cecal samples of poultry were randomly collected from 33 pluck shops across Trinidad. Isolation and identification of Salmonella followed standard methods, and the disk diffusion method was used to determine resistance of isolates to 14 antimicrobial agents. Ninety-one (6.1%) of the 1,503 samples collected from four zones were positive for Salmonella. The frequency of isolation of Salmonella from chicken ceca (6.5%) was higher than that detected in duck ceca (5.1%), but the difference was not statistically significant (P > 0.05). Ten serotypes were detected, with Salmonella Molade, Salmonella enterica subsp. enterica I, and Salmonella Typhimurium the most prevalent at 56.0, 11.0, and 8.8%, respectively. The highest frequency of isolation of Salmonella was recorded in the northeast zone (59.3%). All 91 isolates exhibited resistance to at least 1 of the 14 antimicrobial agents. The highest frequency of resistance was exhibited to ampicillin (51.0%), kanamycin (49.5%), and streptomycin (37.4%). A total of 22 resistance patterns were exhibited by the 91 isolates of Salmonella, and 13 isolates (14.3%) exhibited multiple drug resistance. The results emphasize the need to implement hygienic practices to reduce the levels of contamination at poultry pluck shops and the need for prudent use of antimicrobial agents in the poultry production system in Trinidad.

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Salmonella spp. are the most relevant foodborne pathogens globally including Trinidad and Tobago. Salmonella infections in human are usually associated, not only with the consumption of contaminated animal food sources, but also with pet animals, reptiles, fruits, vegetables, drinking water, and other human. Poultry products, such as eggs and poultry meat, are involved in the outbreaks of human salmonellosis, posing an important threat to

Determination of hydrological properties of the aquifer is of fundamental importance in hydro-geological and geoelectrical studies. An attempt has been made to review briefly the fundamental equations that form the basis of electrical prospecting and relationship with the aquifer parameters in terms of hydrogeologic and electrical soundings. The empirical relationship between hydrogeologic and Dar Zarrouk parameters will also need to review the concepts of anisotropy, equivalence, and suppression for characterization of the water quality through the electrical resistivity.