The ox atrioventricular conduction axis compared to human in relation to the original investigation of sunao tawara.

It was Sunao Tawara who, in 1906, established the foundations for knowledge of the arrangement of the atrioventricular conduction axis in man and other mammals. Study of the hearts of ungulates was a central part in his investigation, which assessed other species, including man. He described several subtle differences between the mammals. We have now ourselves studied the cardiac conduction tissue of the ox heart, comparing our findings with our knowledge of the arrangement in man, and providing new insights into the differences illustrated by Tawara. It is, perhaps, surprising that these differences, although subtle, have not attracted more attention. We show that the major difference is the fact that the noncoronary aortic sinus in the ox heart is mainly supported by the myocardium of the ventricular septum, whereas in the human heart the sinus, and its leaflet, are in fibrous contiguity with the aortic leaflet of the mitral valve. It is this feature that determines the difference in the arrangement of the conduction axis between the species. We also show that the emergence of the left bundle branch on the left ventricular aspect of the muscular septum is more variable than previously described. Clin. Anat. 33:383-393, 2020. © 2019 Wiley Periodicals, Inc.

Disseminated Sarcocystis miescheriana infection in a finisher pig in Grenada.

Sarcocystis miescheriana infection is an important cause of carcass condemnation during meat inspection. The infection can cause morbidity and mortality in domestic pigs. In this study, an 8-month-old finisher pig was presented to a local abattoir for slaughter. Multiple white nodular lesions affecting the meat were observed, resulting in the condemnation of the carcass. Consequently, half of the carcass was submitted to the necropsy diagnostic laboratory in the School of Veterinary Medicine for further evaluation. Grossly, all superficial and deep muscle groups had severe multifocal macrocysts (3 mm × 2 mm × 1 mm) on the surface and extending deep into the skeletal musculature. Histopathology revealed moderate multifocal granulomatous and eosinophilic myositis with intralesional degenerated and intact parasites. Sample genomic DNA sequence analysis of the 18S RNA gene showed 100% identity to S. miescheriana in the GenBank. This is the first report of S. miescheriana in Grenada, West Indies.

Retrospective study of Oestrus ovis larvae infestation in small ruminants in Grenada, West Indies.

Oestrosis is a nasal cavity myiasis caused by Oestrus ovis larvae from Oetrus ovis diptera flies in small ruminants. The presence of the larvae in the nasal cavity is known to cause rhinitis and sinusitis which can negatively impact the productivity of small ruminants. The aim of the present study was to estimate the prevalence of Oestrus ovis larvae infestation in sheep and goats presented for necropsy. We reviewed necropsy records of sheep and goats submitted to the Veterinary Pathology diagnostic laboratory at St. George's University from 2001 to 2017. Out of 104 goat necropsy cases, Oestrus ovis larvae were observed in 8 goats giving a prevalence of 7.7% (95% confidence interval (CI):3.38% to 14.6%). Similarly, from the 47 sheep necropsies, Oestus ovis larvae were observed in 4 sheep (8.5%) (95% CI: 2.83% to 20.46%). There was no significant difference in Oestrus ovis larvae infestation rates between sheep and goats (p = 1.000, Fisher's exact test). Oestrosis was an incidental finding in all the small ruminants examined at necropsy. This is the first report on Oestrus ovis larvae infestation in small ruminants in Grenada.

Isolation and RFLP genotyping of Toxoplasma gondii from the mongoose (Herpestes auropunctatus) in Grenada, West Indies.

Little is known of the genetic diversity and epidemiology of Toxoplasma gondii infection in wildlife in Caribbean Islands. The prevalence and genetic diversity of T. gondii in mongooses (Herpestes auropunctatus) was investigated. During 2011 and 2012, 91 mongooses were trapped in different parts of Grenada, bled, euthanized, and examined at necropsy. Antibodies to T. gondii were found in 27 mongooses tested by the modified agglutination test (cut-off titer 25). Muscles (heart, tongue, neck) of 25 of the seropositive mongooses were bioassayed for T. gondii infection in mice. Viable T. gondii was isolated by bioassay in mice from four mongooses with MAT titers of 1:50 in two, 1:200 for one, and 1:400 for one mongoose. The four T. gondii isolates were further propagated in cell culture. Strain typing of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed one isolate belongs to the Type III (ToxoDB #2) lineage, two to ToxoDB#7 lineage, and one to the ToxoDB #216 lineage. This is the first report of T. gondii isolation and genotyping in H. auropunctatus worldwide.

Toxoplasma gondii clonal type III is the dominant genotype identified in Grenadian pigs.

BACKGROUND: Toxoplasma gondii is a widespread zoonotic protozoan parasite capable of infecting all warm-blooded animals. Although the genotypes of T. gondii in pigs have been reported worldwide, there is no information on the genotypes and diversity of T. gondii in pigs in Grenada, West Indies. OBJECTIVES: The aims of the present study were to isolate, genotype and determine the diversity of T. gondii genotypes in pigs. METHODS: We carried out a modified agglutination test (MAT) on blood from 149 pig hearts collected from a local meat market. Myocardial tissue homogenate from pigs that tested positive for T. gondii was homogenized and inoculated into mice for isolation of the parasite. We collected mouse tissues and extracted DNA for genotyping based on 11 polymerase chain reaction-restriction fragment length polymorphism markers (SAG1, SAG2, alt. SAG2, SAG 3, BTUB, GRA6, L358, PK1, C22-8, C 29-2 and Apico). RESULTS: Out of the 149 pig hearts, 31 (20.8%) tested positive for T. gondii on MAT. Bioassays in mice yielded 12 isolates designated TgpgGr1 to TgpgGr12. Molecular characterisation of T. gondii revealed four genotypes as follows: ToxoDB #2-clonal type III (seven isolates); ToxoDB #7 (three isolates); ToxoDB #13 (one isolate); ToxoDB #30 (1 isolate). Overall, ToxoDB #2 was the most common (58%). Toxo database (DB) # 13, which causes interstitial pneumonia in affected mice, has also been reported. CONCLUSION: The genetic diversity of T. gondii in pigs in Grenada is lower than that in other surrounding Caribbean areas.

Potential for Scombroid Poisoning from Ingestion of Selar crumenophthalmus Due to Increased Histamine Levels in Grenada, West Indies.

ABSTRACT: In scombroid poisoning, a seafood-associated disease, consumption of fish that contains high levels of histamine results in allergy-like symptoms that range from mild to occasionally severe. To date, there is no published information on scombroid poisoning from Selar crumenophthalmus on the Caribbean island of Grenada, West Indies. S. crumenophthalmus is of particular interest because it is a common and heavily consumed fish that has been implicated in scombroid poisoning in Hawaii. Preliminary data on S. crumenophthalmus in Grenada have demonstrated the presence of Photobacterium damselae, a bacterium associated with scombroid poisoning. The present study further tested S. crumenophthalmus purchased in Grenada for factors that would indicate the potential for scombroid poisoning, including increased histamine levels in fish muscle and DNA evidence of bacteria associated with scombroid poisoning. Histamine levels between 7,160 and 66,688 ppm were found after temperature abuse at 37°C for 19 h; this far exceeds the acceptable limit for the United States (50 ppm) and the European Union (100 to 200 ppm). Even after 4 h of incubation at ambient temperature (28.9°C) during a time-point study, histamine levels exceeded U.S. acceptable limits (>50 ppm), and five samples used for temperature-abuse studies had elevated histamine levels (ranging from 141 to 2,510 ppm) at 0 h. PCR and sequence analysis of bacteria in temperature-abused fish identified P. damselae and Morganella morganii, which are histamine-producing bacteria known to be implicated in scombroid poisoning. These results suggest the potential for scombroid poisoning in Grenada and the need for promoting awareness about this disease.

Giardiasis: Serum antibodies and coproantigens in brown rats (Rattus norvegicus) from Grenada, West Indies.

AIM: Giardia is a serious zoonotic parasite, which causes diarrheal disease in humans and animals including rodents. The purpose of this study was to estimate the prevalence of Giardia spp. in brown rats (Rattus norvegicus) in Grenada. MATERIALS AND METHODS: Intestinal contents from 99 and serum samples from 169 brown rats (R. norvegicus) from Grenada were collected. These samples were examined for the Giardia coproantigens using Cryptosporidium/Giardia Quik Chek assay (Tech lab® Inc., USA), and the serum was screened through an enzyme-linked immunosorbent assay (ELISA) test kit for Giardia antibody (anti-GD) ELISA kit (MyBioSource, San Diego, CA, USA). RESULT: Giardia coproantigens were positive in 17.17% (95% confidence interval [CI]; 10.33-26.06%) rats, whereas 55% (95% CI: 47.20-62.68) were positive with serum antibodies (anti-GD) to Giardia. CONCLUSION: The prevalence of Giardia spp. in brown rats in Grenada was moderate based on the presence of coproantigens in the intestinal contents and antibody in serum. The findings of Giardia infections and prevalence in brown rats will help veterinarians and physicians to better plan diagnostic and preventative strategies. This is the first report of prevalence of Giardia in brown rats in Grenada.

Gastrointestinal parasites in small ruminants from Grenada, West Indies: A coprological survey and a review of necropsy cases.

Gastrointestinal parasites are important in small ruminant farming because they can impact negatively on the productivity of animals. The objectives of the present study were to estimate the prevalence of gastrointestinal parasites and to assess mortality attributable to gastrointestinal parasite infection in sheep and goats. We collected fecal samples from 114 sheep and 292 goats from 34 farms for coprological examination. In addition, we evaluated necropsy records for sheep and goats that were submitted from 2002 to 2016 to the pathology diagnostic laboratory in the School of Veterinary Medicine at St. George's University, Grenada. Out of 406 small ruminant (292 goat and 114 sheep) fecal samples examined, 385 were positive for gastrointestinal parasites, giving an overall prevalence of 95% (95% confidence interval (CI) 92% to 97%). All the 34 farms visited were found to have positive animals to at least one type of gastrointestinal parasite; 100% herd prevalence (95% CI: 88% to 100%). Among the 292 goat fecal samples examined, 285 were positive for gastrointestinal parasites (98%; 95% CI: 95% to 99%) whereas the proportion of positive fecal samples in sheep was 88% (95% CI: 80% to 93%). There was a significant difference in prevalence of gastrointestinal parasites between sheep and goats (p = .0002). The proportion of infection with coccidia in goats and sheep was 76% and 75%, respectively. For helminthes, the proportions were as follows: Moniezia spp., 14% in goats and 4% in sheep; Strongyloides spp., 36% in goats and 21% in sheep; strongyle type eggs 89% in goats and 66% in sheep. Mixed infections in both sheep and goats were more common (92%) than single ones (8%). Out of 220 necropsy records evaluated, 29% of mortality was due to Haemonchus contortus infection. Moniezia spp and Oesophagostomum spp. were also commonly found.

Isolation and RFLP Genotyping of Toxoplasma gondii in Free-Range Chickens (Gallus domesticus) in Grenada, West Indies, Revealed Widespread and Dominance of Clonal Type III Parasites.

The objectives of the present cross-sectional study were to isolate and genotype Toxoplasma gondii in free-range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with titers of 25 in 7 chickens, 50 in 6 chickens, 100 in 2 chickens, and 200 or higher in 24 chickens. The hearts of the 39 seropositive chickens were bioassayed in mice; viable T. gondii was isolated from 20 and further propagated in cell culture. Genotyping of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed 4 genotypes, including ToxoDB PCR-RFLP no. 2 (Type III), no. 7, no. 13, and no. 259 (new). These results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent (15/20 = 75%) compared to other genotypes in Grenada.

Genotypes, Antibiotic Resistance, and ST-8 Genetic Clone in Campylobacter Isolates from Sheep and Goats in Grenada.

Rectal swabs from 155 sheep and 252 goats from Grenada were evaluated to determine the prevalence of Campylobacter spp., antibiotic resistance, and multilocus sequence types. Fifteen Campylobacter isolates were obtained (14 C. jejuni and 1 C. coli). The prevalence (3.7%) did not differ significantly between sheep (4.5%) and goats (3.2%). Among the seven antimicrobials tested, resistance was only detected for tetracycline (30.8%) and metronidazole (38.5%). Campylobacter isolates showed no significant difference between sheep and goats for type of antimicrobial resistance or percent of resistant isolates. Twelve of the isolates were successfully genotyped consisting of four recognized clonal complexes and three novel sequence types. Importantly, one isolate from one goat was identified as the C. jejuni sequence type-8, a zoonotic and tetracycline-resistant clone reported to be a highly virulent clone associated with ovine abortion in the USA. Although most samples were from comingled sheep and goat production units, there were no shared sequence types between these two host species. None of the sequence types identified in this study have previously been reported in poultry in Grenada, suggesting sheep- and goat-specific Campylobacter clones in Grenada. This is the first report of genotyping of Campylobacter isolates from sheep and goats in the Eastern Caribbean.

The phylogeography of rabies in Grenada, West Indies, and implications for control.

In Grenada, West Indies, rabies is endemic, and is thought to be maintained in a wildlife host, the small Indian mongoose (Herpestes auropunctatus) with occasional spillover into other hosts. Therefore, the present study was undertaken to improve understanding of rabies epidemiology in Grenada and to inform rabies control policy. Mongooses were trapped island-wide between April 2011 and March 2013 and examined for the presence of Rabies virus (RABV) antigen using the direct fluorescent antibody test (dFAT) and PCR, and for serum neutralizing antibodies (SNA) using the fluorescent antibody virus neutralization test (FAVN). An additional cohort of brain samples from clinical rabies suspects submitted between April 2011 and March 2014 were also investigated for the presence of virus. Two of the 171 (1.7%) live-trapped mongooses were RABV positive by FAT and PCR, and 20 (11.7%) had SNAs. Rabies was diagnosed in 31 of the submitted animals with suspicious clinical signs: 16 mongooses, 12 dogs, 2 cats and 1 goat. Our investigation has revealed that rabies infection spread from the northeast to the southwest of Grenada within the study period. Phylogenetic analysis revealed that the viruses from Grenada formed a monophyletic clade within the cosmopolitan lineage with a common ancestor predicted to have occurred recently (6-23 years ago), and are distinct from those found in Cuba and Puerto Rico, where mongoose rabies is also endemic. These data suggest that it is likely that this specific strain of RABV was imported from European regions rather than the Americas. These data contribute essential information for any potential rabies control program in Grenada and demonstrate the importance of a sound evidence base for planning interventions.

Antimicrobial drug resistance as determined by the E-test in Campylobacter jejuni, C. coli, and C. lari isolates from the ceca of broiler and layer chickens in Grenada.

One hundred and twenty five chickens from Grenada, consisting of 77 broilers and 48 layers were examined for carriage of thermophilic campylobacters in their ceca by culture. Seventy nine percent of chickens were positive for campylobacters, with an isolation rate of 93.5% for broilers and 56.3% for layers, the difference being significant. Sixty-four pure cultures comprising 39 Campylobacter coli, 21 Campylobacter jejuni, and 4 Campyilobacter lari isolates were tested for their resistance against 7 antibiotics using the E-test. None of the isolates were resistant to chloramphenicol and gentamicin. Resistance rates to other drugs were: ampicillin, 9.4%; ciprofloxacin, 12.5%; erythromycin, 3.1%; metronidazole, 9.4%, and tetracycline, 50% with MICs of >or=256 microg/mL for tetracycline. There were no significant differences in resistance rates between C. coli and C. jejuni. Multiple resistance to >or=2 drugs was seen in 15.6% of total isolates. All C. lari isolates were resistant to ciprofloxacin, and 3 of 4 isolates had multiple drug resistance. Overall, erythromycin, which is the drug of choice for treatment of Campylobacter infections in humans, is effective in vitro against 97% of chicken isolates in Grenada.