A study of pulmonary lesions identified in sheep and goat carcasses in Trinidad and Tobago in 2018

The small ruminant industry has been identified by Caribbean governments as key to agricultural development and food security. • The economic impact of these prolific species is significant to farmers both locally and regionally, given its contribution to foreign exchange, employment generation and poverty alleviation • Recognizing disease is critical for a small ruminant based economy to possess both sustainability and viability. Understanding ways to accurately identify, prevent, cure and control disease is necessary to improve the economic status of this industry. • Post mortem evaluation is a useful diagnostic tool as it can reliably confirm, refute or augment ante-mortem diagnoses. • Respiratory disease is of particular importance as it is commonly encountered in small ruminant flocks, affecting groups or individuals of any breed, age and sex. More often than not, it involves a combination of infectious and non-infectious aetiologies. An interstitial, bronchinterstital or bronchopneumonia may develop which is largely dependent upon the causative agent.

A Case Report of A Urinary Bladder Marsupializatiojm to correct Obstructive Urolithiasis in a 3-Month-Old Boer Goat (Capra hircus)

A 3-month-old intact male Boer caprine kid weighing 22.3Kg. presented to the Large Animal Hospital, School of Veterinary Medicine (SVM), with a primary complaint of stranguria for approximately 8 days. The animal had been treated one week prior to presentation by a private clinician who amputated the vermiform appendage which offered temporary resolution of the clinical signs. Within twodays however, the animal was once again observed with stranguria and the clinician referrred the animal to the SVM for further treatment. On presentation, the patient had multiple anomalies including, paraphimosis. a swelling at the base of the penile shaft and tachycardia. Radiographic examination revealed a distended bladder. No radio-opaque calculi were noted along the urethra. The patient required urgent surgical intervention during which he was maintained under anaesthesia using continuous rate indusion of ketamine and lidocaine to which xylazine was subsequently added after a cystotomy was performed. The patient recovered with minimal post-operative complications. Although not a common procedure in farm animals due to its aftercare, bladder marsupialization was deemed feaseible in this case since the patient was reared with some sentimental value rather than entirely for production. This procedure shpuld thus be considered for pet livestock animals or in salvage situations where a perineal urethrostomy is deemed non-curative,

A Case Report of A Hybrid External Fixator for Fracture Repair in a 3-Month-Old Boer Goat (Capra hircus)

A 3-month-old male intact crossbred Boer Anglo Nubian caprine kid weighing 20.50Kg. presented to the School of Veterinary Medicine (SVM) with a history of acute onset lameness of the left hind limb. Initial examination at a private veterinary clinic revealed a fracture of the left tibia. The patient was referred to the SVM for treatment. Physical and radiographic examination of the animal revealed a closed, complete, short oblique fracture of the distal metaphysis of the left tibia with moderate cranio-proximal displacemnt of the distal segment, The limb was temporarily immobilized using a pre-made bivalve cast until the surgery. Surgical intervention involved using hybrid external fixator best described as a maximal bilateral uniplanar (Type II) fixator frame with a distal fabricated aluminum ring. The post-operative regimen included antibiotics, non-steroidal anti-inflammatories, frequent cleaning of the pin-skin interface and apparatus bandage changes, The animal was also confined to pen rest initially with gradual increase in exercise. Since surgery, the patient has progressively increases weight bearing on the affected limb and was fully weight bearing upon external fixator removal, 6-weeks post operatively. This method of external fixatiojm has not been commonly used foe repair of fractured limbs in goats, however in this scenario it proved ecomonical and highly effectively in provideing the stability required for fracture repair. Veterarians with limited resourcs and financially conservative clients should consider this method for repairing similar type fractures in small ruminant animal species.

Trinidad and Tobago COVID-19 (Novel Coronavirus) Update #137

In its response to safeguard the country in face of the global COVID-19 outbreak, the Trinidad and Tobago, Ministry of Health continues to provide up-to-date information of the country's response to this situation.

Prevalence of Methicillin Resistant Staphylococcus aureus(MRSA) in pigs and workers at abattoirs in Trinidad and Tobago

Introduction: Methicillin resistant Staphylococcus aureus (MRSA), a major cause of zoonotic infections, has emerged globally in livestock, particularly pigs. People with occupational contact with food producing animals are at high risk of colonization. The aim of this study was to determine the prevalence of MRSA in pigs and abattoir workers throughout Trinidad and Tobago as well as their resistance to other antimicrobial agents. Methodology: Nasal and skin behind the ear swabs from pigs and nasal swabs from humans were enriched in Mueller Hinton broth with 6.5% sodium chloride, followed by phenol red mannitol broth with 75 mg/L aztreonam and 5 mg/L ceftizoxime. The enriched sample was then plated on both CHROMagar MRSA and Brilliance MRSA. All incubation was at 37ºC for approximately 24 h. Suspect MRSA isolates were confirmed as MRSA using the Penicillin-Binding Protein (PBP2a) test kit and polymerase chain reaction (PCR) to detect the mecA gene. Resistance of the S. aureus and MRSA isolates to 16 antimicrobial agents was determined using the disc diffusion method. Results: Of the 929 pigs and 44 humans sampled, MRSA strains were isolated at a frequency of 0.9% (8/929) and 2.3% (1/44) respectively. All isolates exhibited resistance to one or more of the 16 antimicrobial agents. Conclusions: The study demonstrated that pigs and workers at slaughter houses in Trinidad and Tobago harbour multidrug resistance S. aureus and MRSA. This is of public health significance as occupational exposure of humans can lead to an increased risk of infection and therapeutic failure.

The identification and characterization of high impact avian viruses circulating in wild and domestic birds in Trinidad and Tobago

Objective: To identify the extent of circulation and specific characteristics of various high priority avian viruses in wild and domestic birds in Trinidad and Tobago (T&T). Viruses included Avian Influenza virus (AIV), Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Infectious laryngotracheitis virus (ILTV) Avian metapneumovirus (aMPV), Infectious bursal disease virus (IBDV), Chicken infectious anaemia virus (CIAV), Fowl adenovirus Gp1 (FADV) and Egg drop syndrome virus (EDSV). Design and Methodology: A combination of active and passive surveillance of wild and domestic birds was carried out. Samples were tested for antibodies by enzymelinked immunosorbent assay (ELISA) and for virus by polymerase chain reaction (PCR) / sequencing to identify and characterise the circulating viruses and to determine their serotype and genotype. Results: Antibodies were detected against IBV, NDV, ILTV, APV, IBDV, FADV and EDSV and viral nucleic acid was detected for IBV, APV, CIAV and FADV in domestic poultry in T&T. Further characterisation of FADV revealed that serotypes 8a, 8b, 9, and 11 were circulating in diseased birds, along with CIAV. Phylogenetic analysis of circulating IBV strains identified two lineages, one with high similarity to the vaccine strains and the second being identified as a unique lineage to T&T. AIV antibodies with high neutralising titres against a low pathogenic H5N3 strain were detected in sera from three wild birds, and AIV RNA was detected by PCR in a swab sample taken from another wild bird. Conclusions: This research identified for the first time the presence of various high-impact avian viruses in domestic poultry and wild birds in T&T.

An investigation of the frequency of detection of fluoroquinolone residues in the muscle of broiler chickens sold at supermarkets and pluck shops in Trinidad

Objective: Fluoroquinolones are broad spectrum antimicrobials, used to treat a wide myriad of gastrointestinal, genitourinary and respiratory infections in both humans and animals. They are also used prophylactically in livestock including poultry and fish. this occurrence, coupled with the abuse of the drug due to extra-label and improper use, have led to concerns about both antimicrobial resistance to these drugs and the presence of their residues in veterinary products such as meat. Tremendous human health issues inclusive of antimicrobial resistance, anaphylactic reactions, carcinogenicity, mutagenicity, teratogenicity and the disruption of normal flora can occur due to the use and abuse of these antimicrobials. We hypothesized that fluoroquinolones residues are present in the meat of broiler chickens in Trinidad. Hence, our objectives were to detect the presence and concentrations of fluoroquinolone residues in broiler chickens sold at supermarkets and pluck shops in Trinidad. Design and Methodology: A total of 168 carcasses were sampled from supermarkets and pluck shops across Trinidad and Tobago, during July to August of 2018. The breast muscles were removed and subjected to first the extraction process then to the Ridascreen® Chinolone/Quinolones Enzyme Linked- Immunosorbent Assay (ELISA) to determine the presence and concentrations of fluoroquinolones in these samples. Results: Fluoroquinolone residues were detected at a frequency 14.3% (24/168), with concentrations ranging from 5.53-161.41µg/kg and 2.4% (4/168) of carcasses contained fluoroquinolones at levels higher than (100 µg/kg) that stipulated by the Codex Alimentarius. Conclusion: Fluoroquinolones are present in broiler chickens sold in Trinidad. Its presence, at times higher than the recommended levels, has serious public health implications.

High-fat diet induced obesity and the effect of fructooligosaccharides on cardiac protein expression

Hypothesis: Obesity alters cardiac protein expression. Fructooligosaccharide modulates this effect. Design and Methodology: Rats fed AIN-93G chow were subsequently fed high-fat AIN-93G. The top 40% weight-gain category were allocated into control (CON), highfat (HF) and high-fat with fructooligosaccharide (HF-FOS) groups; n=10. Body weights were monitored. After 12 weeks, left ventricles were cryopreserved. Serum was stored for glucose and insulin estimations. Tissues were analysed by mass spectrometry using an Orbitrap with a nanospray source and EASY-nLC nano-LC system(ThermoFisher, San Jose, CA). Spectra were analysed with Sequest and fold changes with Scaffold Q+ (Proteome Software Inc., Portland, OR). T-Tests detected differentially expressed proteins (CON vs HF and HF vs HF-FOS) and mean (±SE) differences in body weights, glucose and insulin. The Database for Annotation, Visualization and Integrated Discovery and the Kyoto Encyclopedia of Genes and Genomes revealed pathways containing overrepresented proteins. Hematoxylin and eosin sections were graded for hypertrophy and chi-squared analyses sought differences. A p-value of <0.05 was considered significant with Benjamini­Hochberg corrections where applicable. Results: HF rats (549.4±17.1g) were significantly (p<0.05) heavier than CON (513.6±14.8g). Twenty-three proteins involved in mitochondrial function and lipid metabolism were differentially expressed (p<0.001) between the CON and HF. One hundred and thirty-two proteins involved in contractility, lipid/carbohydrate metabolism and signaling were differentially expressed (p<0.001) between HF and HF-FOS. HF cardiomyocytes were significantly (p<0.001) more hypertrophic than CON. Conclusion: High-fat feeding is associated with subclinical deviations in the cardiac proteome. Coupled to cellular hypertrophy this may influence myocardial compliance. Fructooligosaccharides modulates protein expression.

Efficacy of levofloxacin loaded non-ionic surfactant vesicles (niosomes) in a Pseudomonas aeruginosa infection model in Sprague Dawley rats

Objective: To determine the efficacy of levofloxacin loaded niosomes in treating Sprague Dawley rats infected with Pseudomonas aeruginosa (ATCC 27853). Design and Methodology: Three groups of six (6) animals were infected with a known dose of the pathogen i.e. Pseudomonas aeruginosa via the intraperitoneal (ip) route. At six (6) hours post infection the infected animals were treated with drug free niosomes (control), free levofloxacin (conventional) and levofloxacin trapped in niosomes (ip). Blood was collected via tail snips at days 0,1,3,5,7 and 10 for complete blood counts and viable bacterial counts by colony forming units (CFU/µl). At day 10 the animals were sacrificed and samples from the kidney, liver and spleen were examined for bacterial counts. Results: All animals in the control group succumbed to the infection; one animal from the conventional group died. All niosome treated animals survived. The mean lymphocyte count (X109) was lower for the niosome (7.258±1.773) versus conventional (17.684±10.008) (p<0.03) treated groups at day ten (10). Neutrophil counts (X109) were lower for the niosome (2.563±1.609) versus conventional (6.2±6.548) p<0.02) treated groups. The CFUs in the bloodstream were similar for both treatment groups; the niosome treated group showed greater reduction in liver, kidney and spleen CFUs versus the conventional group (1.33±2.074) vs (5.8± 3.74) (p< 0.043), (1.5±2.35) vs (9.6±8.65) (p< 0.038) and (3.8 4.71) vs (25.6 14.66) (p<0.007) respectively. Conclusions: Further work is recommended on niosomes as a drug delivery system to treat intracellular infections.

Escherichia coli contamination of lettuce sold at markets in Trinidad: A preliminary study

Objective: Historically most foodborne disease outbreaks have been attributed to animal products but recently the number of cases associated with vegetable produce has been increasing. Most of these microbial foodborne pathogens are also part of the resident gut flora of many animals and can be shed asymptomatically in the environment. Leafy greens contamination with these pathogens are of particular concern since they are consumed uncooked. Using Escherichia coli (E. coli) as an indicator of faecal contamination, we evaluated lettuce as a potential source of foodborne disease. Design and Methodology: A cross-sectional study was carried out targeting six retail markets in Trinidad. At each market, a total of 15 lettuce samples were purchased from five retailers. The E. coli colony forming units per gram (CFU/g) of lettuce were then assessed using standard laboratory techniques. Results: All farmers surveyed reported using pipe-borne water as their primary source of irrigation water. E. coli was present in all samples. Overall, the E. coli counts ranged from 0.8 to 80,000 CFU/gram. The lettuce E. coli counts varied with location (p=0.01) and was highest in San Fernando (3.4 ± 1.1 Log10CFU/g) and lowest in Marabella (1.5 ± 0.65 Log10 CFU/g). Interestingly, lettuce farms using manure had lower E. coli counts than those not using manure (2.88 ± 1.3 Log10 CFU/g vs 2.27±1.23 Log10 CFU/g; p=0.07.) Conclusion: These high E.coli counts are indicative of either preharvest or post-harvest faecal contamination of lettuce. The high level of E. coli contamination of lettuce being sold at market should be of serious concern since this a potential risk to public health.

Evaluation of pig production practices and constraints faced by smallholder piggeries in Trinidad

Objective: Pork is one of the most consumed sources of animal protein globally. While many countries have recorded an increase in the pig population to satisfy this increasing demand, in Trinidad there has been a drastic decrease in the pig population and consequently a decrease in local pork production. Design and Methodology: A cross-sectional survey to evaluate the production practices and identify farmer constraints was conducted targeting 54 smallholder piggeries. Potential farms were randomly selected from farmer lists obtained from the County Veterinary Offices. Farms were evaluated using a combination of questionnaires and on-site farm observations. Results: The majority of farms were family operated and there were a significantly higher number of male farmers (80%) compared to female farmers (20%) (p = 0.001). The farmers' ages ranged from 24 to 88 years, with 39% of farmers were 50 years or older. Most farmers (87%) lacked any formal agricultural training yet engaged in formulating diets using waste products obtained from other food processing industries. Pigs were primarily reared in either intensive (80%) or semi-intensive production (17%) systems and pigs of all physiological states were reared together. Most farms (89%) used natural service and none had an oestrus synchronisation program. No farmers surveyed were engaged in the production of value added products. The two most common constraints identified by farmers were high feed cost and low revenue obtained for retail pork. Conclusion: Innovative approaches are needed to attract an increased number of younger farmers and encourage the adoption of modern production practices to increase the efficiency of pork production.

Current pig production practices: A potential risk to human and animal health

Objective: Increased awareness of food safety and antimicrobial resistant (AMR) organisms has placed greater emphasis on livestock farmers adopting Good Agricultural Practices. Pork is the most consumed source of animal protein globally, and over 30,000 pigs are reared in Trinidad to meet the local pork demand. While there has been a plethora of studies globally focusing on the role of livestock production practices in the epidemiology of food borne diseases and AMR organisms, there is a dearth of research in Trinidad. Design and Methodology: Using questionnaires and on-site farm evaluations, a cross-sectional study was conducted at 54 randomly selected pig farms to evaluate the risks current production practices may pose to human and animal health. Results: The primary pig herd health issues identified by farmers were outbreaks of diarrhoea and nonspecific infections. Farmers also identified piglet crushing as the leading cause for pre-weaning mortality. 50% of farmers had not had a Veterinarian visit their farm within the last six months and 90% indicated they provided all routine healthcare on their own. Penicillinstreptomycin was the most commonly used antibiotic and none of the farms surveyed had a vaccination programme. All farms evaluated had inadequate biosecurity measures with only 13% screening for diseases prior to adding breeding stock. The majority of farmers (72%) washed their effluent directly into municipal drains without any prior remediation. Conclusion: Greater farmer education as well as increased regulation of pig production practices is required in order to reduce the potential risk of food borne disease as well reducing the risk of propagation of AMR organisms.

A comparison of the efficacy of two commercial acaricides (fipronil and amitraz) with Azadirachta indica (neem) on the brown dog tick (Rhipicephalus sanguineus) from canines in Trinidad

Objective: Rhipicephalus sanguineus, the most common species of tick found on canines in Trinidad. It is a potential vector for potentially fatal zoonotic diseases such as borreliosis (Lyme disease), babesiosis, anaplasmosis and human granulocytic ehrlichiosis. Common acaricides used by pet owners such as fipronil and amitraz are often misused and abused as owners may fail to follow the manufacturers' instructions. The objectives of this study were to compare the efficacies of the commercial acaricides (fipronil and amitraz) to the herbal alternative, neem on brown dog ticks in Trinidad. Design and Methodology: The Larval Packet Test (LPT) was conducted in triplicate for each of three concentrations (high, recommended and low concentrations) of fipronil, amitraz, neem oil and neem leaf extract. STATA version 15 was used to perform a mixed effects Poisson regression analysis. Results: Both the commercial and herbal acaricides were effective in causing death of the larvae. Larvae were susceptible to amitraz and fipronil at all concentrations used, however they displayed variable resistance to the neem oil and neem leaf extract. Conclusions: The commercial preparations (amitraz and fipronil) proved to be more effective than neem oil and neem leaf extract, however the latter can be used as a herbal alternative to control R. sanguineus in Trinidad.

Estrus synchronization and expression of estrus behaviors during periovulatory period in doublesynch treated buffalypso (Bubalus bubalis) in Trinidad

Objectives: Experiment was conducted to investigate (a) the effect of the doublesynch protocol on pregnancy rate in buffalypso (b) the effectiveness of the doublesynch protocol for estrous synchronization and (c) to observe and record signs of estrous in buffalypso. Design and Methodology: In this study, eleven buffalypsoes (n=11) were administered Prostaglandin (PGF2α)on day 0, Gonadotropin-releasing hormone (GnRH) on day 2, a second PGF2α injection on day 9, and a second GnRH injection on day 11. Timed artificial insemination (TAI) was performed 16 and 24 hours after the second GnRH injection. Eleven buffalypso females (n=11) were bred after spontaneous estrus was detected (control group). Oestrous behaviour and intensity were recorded in all the experimental animals, transrectal palpation and ultrasound was performed 60 days postinsemination to determine conception rate. Results: All buffalypsoes treated with the doublesynch protocol elicited signs of swollen vulva and frequent urination which are classical signs of behavioural estrus. The pregnancy rates were 54.5% using TAI in all the treated buffalypsoes and 45.5% for the control group buffalypsoes. The conception rate between doublesynch treatment and Aripo farm herd were also compared and it was found that doublesynch treated buffalypsoes had higher conception rate (54.5%) compared to the overall Aripo farm herd (24.0%) by artificial insemination. Conclusion: The doublesynch protocol effectively synchronized the estrus in buffalypsoes. The study also demonstrated that this protocol followed by TAI enhanced the pregnancy rate with classical signs of estrus in the buffalypsoes.

Molecular analysis of Salmonella isolates from poultry by pulsed-field gel electrophoresis

Objective: The study was conducted to determine geneticrelatedness of Salmonella serotypes by pulsed field gel electrophoresis (PFGE). Design and Methodology: A total of 1503 caecal samples of freshly slaughtered poultry were randomly collected from 'pluck shops' across the country. The samples were screened for Salmonella by biochemical, serological and molecular methods. The Salmonella serotypes were analyzed for genetic relatedness for phenotypic antimicrobial resistance, resistance and virulence gene profiles by PFGE generated by digestion with XbaI. Results: Ten different serotypes were detected from all 91 Salmonella isolates. PFGE fingerprinting profiles showed that the Salmonella serotypes in general, were genetically diverse with the detection of a total of 20 PFGE groups. The antibiograms of the isolates were also clearly very variable, which suggest that genotypic antimicrobial resistance may not relate to the phenotypic antibiograms in dendrograms, except for qnrB gene. Results demonstrated a varied spectrum of antimicrobial resistance and PFGE patterns among Salmonella isolates and signify the importance of sustained surveillance of foodborne pathogens in retail poultry pluck shops. Conclusions: The findings provide evidence that poultry from pluck shops are colonized by pathogenic Salmonella harboring antimicrobial resistance genes. The study also reported for the first time in Trinidad, molecular characterization of Salmonella isolates from poultry regarding the relatedness of antibiograms, possession of resistance and virulence genes using their PFGE profiles. The epidemiological surveillance of these serotypes would be necessary to evaluate their possible impact on human health in the country and possibly in the Caribbean region.

A case report of albendazole toxicity mimicking tetanus in an Anglo-Nubian ­ Alpine cross goat (Capra hircus)

An unvaccinated pregnant two-year-old Anglo- Nubian ­ Alpine crossed doe presented to The University of the West Indies School of Veterinary Medicine in lateral recumbency with bilaterally stiff hind limbs. The owner indicated that he had dewormed the animal three days prior with 380mg of Albendazole per os and that the doe started experiencing seizures two days later. On clinical physical examination, the animal was bloated and had severe ocular lesions to the right eye including corneal oedema and ulceration and a miotic and non-responsive pupil. Abdominal ultrasound suggested the presence of two foetuses but their viability could not be confirmed as only one heartbeat was detected. The doe was initially treated with tetanus antitoxin, parenteral antibiotics, non-steroidal anti-inflammatory medication, intravenous fluids and anticonvulsants. Two days later, she aborted two foetuses. Once the doe was stabilized, physiotherapy and hydrotherapy were performed. Within two weeks of initial presentation, she had regained a healthy appetite and was able to stand and walk unassisted. Despite the similarities between the initial clinical signs to that of tetanus, the abortion, subsequent case progression and eventual resolution of clinical signs are more consistent with the final diagnosis of albendazole toxicity. This case is important as it demonstrates how the indiscriminate use of anthelmintics and the lack of proper deworming strategies can potentially result in animal fatalities. Appropriate anthelmintic use is essential for both animal health and continued drug efficacy. Veterinarians should also be aware of the striking similarities in clinical signs of albendazole toxicity with those of tetanus.

A study of the histological classification and grading of canine malignant mammary tumours in Trinidad

Objective: Mammary gland tumors are a common occurrence in dogs, cats and humans but a rarity in other species. Histologically, grading these tumors evaluates the relevant prognostic variables which may be useful in treatment. The objective of this study was to classify canine malignant mammary tumours according to their morphological and staining characteristics using a standardized histologic classification scheme. Design and Methodology: A total of n = 78 canine mammary gland tumours (CMTs) were diagnosed during the period March 2013 to April 2017. CMTs were evaluated subsequent to routine tissue processing for microscopic evaluation followed by statistical analyses. Results: The two main tumour groups examined were malignant epithelial neoplasms and malignant epithelial neoplasms ­ special types, n= 69 (88.5%) and n= 9 (11.5%) respectively. The majority, n= 62 (79.5%) of tumours were classified as low grade or well differentiated (grade 1), n= 14 (17.9%) of tumours were intermediate grade or moderately differentiated (grade 2) and n= 2 (2.6%) of tumours were classified as high grade or poorly differentiated (grade 3). The significance of age or breed predilection could not fully be determined with this small sample size n = 78, however, all the dogs in this study were female. Conclusion: This study is the first of its kind to be conducted in Trinidad, which fully applies a standardized classification scheme as an independent prognostic indicator of CMTs.

Prevalence of Salmonella species in broilers during slaughtering by processing plants in Trinidad using three isolation methods

Objective: To determine the prevalence of Salmonella species during slaughtering and dressing of broiler chickens at four poultry processing plants in Trinidad using three isolation methods. Design and Methodology: In this cross-sectional study, a total of 396 samples were collected from all four commercial poultry processing plants in Trinidad. Samples collected comprised swabs of cloacae pre-slaughter, pre evisceration and post evisceration carcasses; immersion chiller water, neck skins, whole carcasses and chicken parts (final product). Isolation and identification of Salmonella spp. were performed using standard bacteriological techniques (whole carcass enrichment, whole carcass rinse and neck skin methods). Results: The overall prevalence of Salmonella spp. was 27.5% (109/396). The prevalence of Salmonella spp. was 2.2% (2/90), 55.6% (25/45), 37.8% (17/45), 27.8% (25/90), 5.6% (2/36), 44.4% (20/45) and 40.0% (18/45) for cloacal swabs, preevisceration carcasses, post evisceration carcass swabs, neck skins, immersion chiller water, whole carcass and chicken parts respectively (p<0.001). Salmonella was isolated from 52.3% (46/88), 19.3% (34/176), 11.4% (5/44) and 27.3% (24/88) of the samples from Plant A, B, C and D respectively (p<0.001). Overall, Salmonella was detected in 27.2% (49/180), 27.8% (25/90) and 39.4% (71/180) carcasses by whole carcass rinse, neck skin method and whole carcass enrichment method respectively (p= 0.028). Conclusion: Data from the study indicate the extent of contamination by Salmonella spp. throughout the various stages of broiler processing at the four plants studied and, of significance is the risk of salmonellosis posed to consumers of contaminated, undercooked chicken sold to retail outlets by these processing plants in the country.

Angiostrongylus cantonensis and the giant African snail ­ threat or not?

Objective: Angiostrongylus cantonensis or the rat lungworm can cause eosinophilic meningitis in humans. The Giant African snail has been reported to be a suitable intermediate host for this parasite. As the population of Giant African snails has recently exploded, there is an increased risk of transmission of this helminths to humans residing in this country. Therefore the objective of this study is to detect the presence of the rat lungworm in the Giant African Snails in Trinidad by conventional polymerase chain reaction (PCR). Design and Methodology: A total of 178 Giant African snails were collected from ten different locations throughout Trinidad. DNA was extracted from 25 mg of the mantle of each Giant African snail using the DNeasy® PoweSoil® Kit. Conventional PCR was performed using the primers AngioF1 and AngioR1 to amplify a 1,134bp fragment of the 18S rRNA gene of Angiostrongylus spp. The PCR reactions and conditions were are adapted from Qvarnstrom et al in 2007(1). Results: Six of the DNA extracted samples were positive for Angiostrongylus spp. by conventional PCR. Conclusion: Giant African snails in Trinidad are a suitable intermediate host for the rat lungworm and can increase transmission of these helminths to humans. Therefore Angiostrongylus cantonensis infection should be considered to be a differential for eosinophilic meningitis in humans.

Cytokines changes in beagle dogs vaccinated and challenged with virulent Leptospira strains

Objective: To determine the immune response of dogs by measuring the levels of cytokines tumour necrosis factor (TNF) α, interleukin (IL)-4 and interferon (IFN) γ pre- and post-vaccination with a locally produced killed whole-celled Leptospira vaccine. Design and Methodology: Three separate vaccine-challenge experiments involving 21 beagle dogs were conducted. Study 1 (duration of immunity), used 6 vaccinated and 3 non-vaccinated (control) dogs. Vaccination was done at 12 and 16 weeks of age and challenged at 12 months of age with 1-2.5 x 108 live Leptospira. Study 2 (onset of immunity) also contained the same number of dogs as study 1. Vaccination was done at 12 and 16 weeks of age and challenged at 18 weeks of age. Study 3 (onset of immunity study), as study 2, used 4 vaccinated and two control dogs but challenged with 1-2.5 X 109 live Leptospira. Blood samples were collected to measure the levels of TNF α, IL-4 and IFN γ in dogs 2 days pre-challenge and daily thereafter until day 7 post-challenge. Results: For cytokine TNF α, pre-challenge levels for Study 1, 2 and 3 were 0.0000, 0.0755 and 0.0705 pg/ml which increased to a maximum post-challenge level of 49.05 pg/ml, 0.47 pg/ml and 1.667pg/ml respectively. For cytokine IL-4 and IFN γ the level increased from 0.00 pg/ml to a maximum post-challenge level of 52.67 pg/ml, 243.34 pg/ml and 989.14 pg/ml; and 281.91 pg/ml, 1223.85 pg/ ml and 1778.95 pg/ml respectively. Conclusion: The locally produced Leptospira vaccine induced immune response post-challenge with live Leptospira.