Prevalence and Characteristics of Enteric Pathogens Detected in Diarrhoeic and Non-Diarrhoeic Foals in Trinidad

Abstract

The study determined the relative importance of Escherichia coli, E. coli O157, Salmonella spp., Clostridium spp., rotavirus, Cryptosporidium spp., and Strongyloides westeri in foal (diarrhoeic and non-diarrhoeic) available for sampling during the foaling season of 2010 and determined their sensitivity to antimicrobial agents. A cross-sectional study was conducted on 164 foals (9 diarrhoeic and 155 non-diarrhoeic) from 15 farms in Trinidad. Isolation and detection of enteric pathogens followed standard methods, and the antibiograms of E. coli and Salmonella spp. were determined using the disc diffusion method. All organisms investigated were detected except E. coli O157. A high prevalence of E. coli (85.0%), Cryptosporidium spp. (64.8%), Strongyloides westeri (35.7%) was seen, but the prevalence was comparatively low for Clostridium spp. (12.9%), Salmonella spp. (4.4%) and rotavirus (2.1%). Only Salmonella spp. was isolated at a statistically significantly ( P < 0.05; χ 2 ) higher frequency from diarrhoeic (25.0%) than non-diarrhoeic (4.0%) foals. Amongst E. coli isolates, the frequency of resistance was higher in isolates from diarrhoeic compared with non-diarrhoeic foals but the difference was only statistically significant ( P < 0.05; χ 2 ) for tetracycline. All isolates of Salmonella spp. were sensitive to streptomycin and sulphamethoxazole/trimethoprim, a finding that may have therapeutic significance.

Enteric Pathogens and Coinfections in Foals with and without Diarrhea

“…A total of 18 Salmonella strains were isolated from foals up to 90 days of age in the current study. This result is consistent with those of other studies demonstrating that this pathogen is more prevalent in animals between 1 and 3 months of age [13,52]. In the present study, 25% (14/56) of the Salmonella strains were isolated from diarrheic foals; this is considered a high frequency and is in agreement with the results of similar studies [13,53].…”

“…This result is consistent with those of other studies demonstrating that this pathogen is more prevalent in animals between 1 and 3 months of age [13,52]. In the present study, 25% (14/56) of the Salmonella strains were isolated from diarrheic foals; this is considered a high frequency and is in agreement with the results of similar studies [13,53]. Salmonella Typhimurium appears to be the most commonly reported pathogenic serotype in equines of different ages [46].…”

“…Infectious causes of foal diarrhea predominantly include bacteria, viruses, and parasitic agents [5][6][7]. Some studies of diarrhea in neonatal foals have focused on only one pathogen [2,[8][9][10][11] although it is usually caused by diverse combinations of enteric infections [1,5,7,12,13]. The understanding of the prevalence and complexity of major pathogens associated with enteric infections in neonatal foals is limited [14].…”

“…The understanding of the prevalence and complexity of major pathogens associated with enteric infections in neonatal foals is limited [14]. Comprehensive studies have highlighted the impacts of enteric coinfections in foals with diarrhea and have identified major virulence factors of some pathogens in these infections [1,5,7,13]. However, few studies have evaluated the normal microbial population of the equine intestine, particularly in foals [15][16][17].…”

“…However, few studies have evaluated the normal microbial population of the equine intestine, particularly in foals [15][16][17]. Nondiarrheic foals have been suggested to be potential reservoirs of enteric pathogens, including agents with zoonotic potential [13,18]. The aim of this study was to identify enteric microorganisms involved in monoinfections Table 1: Distribution of total foals per farm; sampled foals with (56) and without diarrhea (60) and coinfections and the associated virulence factors in healthy and diarrheic foals up to three months of age and to identify dehydration, alterations in the complete blood count (CBC), and electrolyte abnormalities.…”