Benjamin Obukowho Emikpe

Experimental infection of Peste des Petit Ruminant virus and Mannheimia haemolytica A2 in goats: immunolocalisation of Mannheimia haemolytica antigens

Nigerian strain of Peste des Petit Ruminant (PPR) virus and Mannheimia haemolytica (MH) biotype A serotype 2, was used successfully to reproduce a concurrent disease in West African Dwarf goats. The development of the various pathological features were studied at regular intervals following infection. The acute inflammatory reaction which had developed by day 3 after initial infection was characterised by flooding of the alveoli by neutrophils, oedema, hemorrhage and syncytial cells together with a moderate bronchial and bronchiolar epithelial necrosis. This progressed to a milder acute broncho interstitial pneumonia with giant cells. At this stage, the mucosal immunity were well developed especially the aggregate form of NALT and more of nodular forms of BALT. The organisms were demonstrated with strong immunostaining in the necrotic center, necrotic alveolar wall, fibrin, serous exudate, and degenerated leukocyte in the alveoli and respiratory airways. The bacterial antigens were observed as a strong immunostaining in the blood vessels of the nasal septum, sinusoid in the liver and interstium of the kidney, cytoplasm of alveolar macrophages, pneumocytes, bronchial and bronchiolar epithelium, in the monocytes in the blood vessels. These findings confirmed the enhancement of MH tropism especially in the respiratory tract, liver and kidney. It also showed that West african dwarf goats are highly susceptible to the intratracheal combined infection of PPR virus and MH. The fact that the infection induces strong mucosal responses, this phenomenon can be explored in Africa with the use of combined PPR virus and MH intranasal vaccines to curtail the menace of pneumonia associated with the combined infection on field.

Heavy metal pollutants in selected organs of African giant rats from three agro-ecological zones of Nigeria: evidence for their role as an environmental specimen bank

An assessment of the concentration of heavy metals in the liver, brain, kidney, bone, and lungs of African giant rats (AGRs) from three agro-ecological zones of Nigeria having different industrial activities was carried out using atomic absorption spectrophotometer. Twenty adult AGRs from cities in mangrove/freshwater swamp, rainforest, and woodland/tall grass savanna agro-ecological zones of Nigeria were used for this study. AGRs were euthanized, carefully dissected, and the brains, liver, lungs, bone, and kidneys were harvested, digested, and analyzed for concentrations of vanadium (V), lead (Pb), cadmium (Cd), zinc (Zn), selenium (Se), copper (Cu), and iron (Fe). All data generated were evaluated for statistical significance using one-way ANOVA with Tukey’s multiple post-test comparison. Results showed the major environmental heavy metal pollutants of the mangrove/freshwater swamp to be vanadium and selenium while those of woodland/tall grass savanna agro-ecological zones were lead, selenium, and zinc. The vanadium concentration was more than twofold higher in the observed tissues of AGR from the mangrove/freshwater swamp, and this may be related to increased exploitation of minerals and the activities of militants in pipeline vandalization in this zone. Interestingly, the highest concentration of this metal was seen in the lungs suggestive of a respiratory route of exposure. Among the potential adverse effects derived from exposure to metals, developmental toxicity is a serious risk. This type of investigation can assist in knowing the level of animal and human exposure to environmental pollutants both in highly industrialized and non-industrialized areas and is more ideal in environmental monitoring. This study therefore suggests AGR as model for ecotoxicological research and environmental specimen banks (ESBs) in this part of Africa.

Pattern and associated risk factors of caprine pneumonia complex in Nigeria

Abstract Objective To investigate the pattern of lung consolidation in natural infections and identify the risk factors associated with caprine pneumonia in Nigeria so as to elucidate and aid the understanding of caprine respiratory disease complex in Nigeria. Methods A total of 700 goats were examined before slaughtering between March 2014 and July 2015. Ante mortem evaluation for physical characteristics, body condition, breed and sex, gross morphometry for estimation of the percentage of lung consolidation and histopathology was performed according to standard techniques. Data were presented in percentages, mean ± SEM and subjected to non-parametric analysis. Results The results showed that 30.3% of goats belonged to the breed of West African Dwarf, 55.4% Red Sokoto (RS) and 14.3% Sahelan. As for the age distribution, 3.7% of them were one year old, 30.7% were two years old and 65.6% were above two years old. The overall prevalence of pneumonia was 59.7%. The mean lung consolidation score was 8.1 ± 0.5, consolidation for male was 7.8 ± 0.5 and 21.4 ± 7.7 for female ( P P Conclusions Sex, breed and body scores were observed to be risk factors associated with caprine pneumonia in Nigerian goats. In this study, transport stress may be responsible for the high consolidation in RS. This information will help to increase the knowledge on the pathogenesis and the risk factors that often aggravate the prevalence of pneumonia in goats.

Oxidative stress changes observed in selected organs of African giant rats (Cricetomys gambianus) exposed to sodium metavanadate

Abstract Vanadium is a contaminant of crude oil that released into the atmosphere through burning of fossil fuels. The mechanism by which it exerts toxic influences had not been fully elucidated in African giant rat (AGR). This study investigates the mechanisms of sodium metavanadate (SMV) induced oxidative stress in AGR. A total of 24 adult male AGR weighing 600–850 g were used. Animals were randomly divided into six groups. Groups 1, 3 and 5 served as control while groups 2, 4 and 6 were treated with intraperitoneal 3 mg/kg body weight of SMV for 3, 7 and 14 days, respectively. Serum, brain, liver, testes, kidneys, spleen and lungs were harvested for biochemical assays. SMV induced significant increase in malondialdehyde, hydrogen peroxide, sulfhydryl (total thiol) and protein carbonyl levels but decreased non-protein thiol levels in tissues accessed. A significant decrease was observed in glutathione-S-transferase (GST), superoxide dismutase (SOD), reduced glutathione (GSH) and glutathione peroxidase (GPx) levels in SMV treated rats compared to controls. Serum myeloperoxidase, xanthine oxidase and Advanced Oxidative Protein Products (AOPP) were markedly increased while nitrous oxide levels were significantly decreased in all treated groups. SMV exposure to AGR induced oxidative stress through generation of reactive oxygen species (ROS) and depletion of the antioxidant defence system. These conditions could become severe with prolonged exposure.

Accelerated gastric ulcer healing in thyroxine-treated rats: roles of gastric acid, mucus, and inflammatory response

The roles of gastric acid, mucus, and inflammation on the pro-ulcer-healing effect of thyroid hormone were investigated. Male Wistar rats were randomly divided into four groups: control, thyroidectomised, thyroidectomised with thyroxine treatment (100 μg·kg-1·day-1), and sham-operated animals treated with thyroxine. Thirty-five days after thyroidectomy, sham surgery, or thyroxine treatment, an ulcer was experimentally induced. Healing was assessed 3, 7, and 10 days post-ulceration by measurement of the ulcer area, gastric mucus and acid secretion, and neutrophil lymphocyte ratio (NLR) as an index of inflammation. By day 10, the ulcer area had decreased in all groups. Recovery was significantly greater (P < 0.05) in thyroxine-treated rats (78.5% ± 1.6% reduction in ulcer area) than in controls (72.3% ± 1.2% reduction) or thyroidectomised rats (63.3% ± 1.9% reduction). Thyroxine-treated animals also had the highest reduction in NLR (65.0% ± 2.5%). Mucus secretion was significantly lower (P < 0.05) in thyroidectomised rats by days 3 and 7. Furthermore, by day 10, the concentration of basal acid decreased by 77.4% ± 2.6% in thyroxine-treated, 65.0% ± 0.0% in control, and 51.5% ± 3.3% in thyroidectomised rats. We conclude that thyroxine accelerates gastric ulcer healing by altering mucus and acid secretion and reducing NLR.

First report of immunohistochemical detection of Peste des petit ruminants, parainfluenza 3 and respiratory syncytial viral antigens in lungs of Nigerian goats

ABSTRACT This study determined the of involvement of PPR, PI3, and RS viruses in the pathology of caprine pneumonia across Nigeria. 150 goats were selected randomly. PI3 and RSV monoclonal antibodies and PPR polyclonal antibody were used for the immunolocalization of the antigens. Histologically, 61 of the goats had broncho-interstitial pneumonia, 25 had interstitial pneumonia, 42 had bronchopneumonia, 12 had bronchiolitis, and 10 were normal. PPR, PI3, and RS viral antigens were demonstrated in: intact and desquamated bronchial, bronchiolar epithelial cells, macrophages, leukocytes, pneumocytes, and giant cells. 23% of the caprine lungs had positive immuno-staining to PI3 viral antigen, 10% were positive for RSV antigen while 34% were positive for PPR viral antigen. 8% showed immunostaining for the two and or three respiratory viral antigens in the goats. PI3 and RSV antigens were more in the young goats, red sokoto breed and during the dry season. This is the first report of immunohistochemical detection of PPR, PI3 and RS viral antigens in caprine lungs in Nigeria. These findings underscore the importance of PI3 and RSV viruses in the control of caprine pneumonia in Nigeria.

Development and application of dot-enzyme-linked immunosorbent (dot-ELISA) assay for detection of Brucella melitensis and evaluation of the shedding pattern in infected goats.

ABSTRACT Early and accurate diagnosis of Brucella melitensis is essential for the treatment and control of brucellosis both in animals and humans. The thrust for the development of a rapid diagnostic technique to overcome the limitations of conventional microbiological and serological tests brought about this investigation on the development and application of dot-ELISA for antigen and antibody detection in infected goats. Fifteen apparently healthy Boer aged 2–3 years which tested negative for brucellosis using PCR and ELISA, were grouped into A (10 goats infected intraocularly with 107 CFU of B. melitensis) and B (5 goats) as control. Discharges (ocular, nasal, and vaginal) and blood were collected at days 3, 7, 10, 14, weekly until 42 post-infection (pi) for dot-ELISA, PCR, and RBPT. Dot-ELISA detected B. melitensis antigen and antibody in group A at day 3 and 7 pi, respectively with adequate sensitivity and specificity relative to PCR and RBPT. The bacteria shedding detected from discharges at day 3 pi in the nasal and ocular route with dot-ELISA. Group B were consistently negative. Values such as speed, simplicity, field adaptability, high sensitivity, and specificity make dot-ELISA a rapid and adequate technique for diagnosis of brucellosis in B. melitensis infected goats within few hours.

Prevalence, distribution and pattern of gastric lesions in slaughtered pigs in south-western Nigeria

Gastric lesions, especially ulceration, cause significant economic losses in the swine industry worldwide. The study was designed to assess its prevalence, distribution and pattern in pigs in south-western Nigeria. Slaughter house surveys were conducted on three government-established abattoirs in Lagos, Ogun and Oyo states. Stomachs from 480 pigs were assessed for gross lesions, which were graded using a modification of a standard technique. Tissues from different regions of the stomach were routinely stained to assess histopathologic changes. Data were presented as frequency counts and analysed using analysis of variance and chi-square technique. Significance was determined at p ≤ 0.05. Gastric lesions were encountered across the four regions of the stomach with a point prevalence of 57.29%. The prevalence of lesions in the non-glandular region was 32.9%, with severe hyperkeratosis (13.13%) being most frequently observed (p < 0.05). Erosions were significantly higher in the cardia (8.54%) (p < 0.05), followed by fundus (8.33%). Gastric ulcers were significantly higher in the fundus (19.58%) (p < 0.05). Scars of healed ulcers and lacerations were also observed in the fundus (5.42%) (p < 0.05). The gastric lesion distribution across the four regions of the stomach and the occurrence of ulceration in the fundus showed an unusual pattern, which is rarely reported in other parts of the world. The reason for these findings in pigs in Nigeria is not fully understood; therefore, further studies are required to identify and manage these factors for increased productivity, improved animal welfare and enhanced food security.

The prevalence of brucellosis in cattle and their handlers in north Tongu District of Volta Region, Ghana

Background: Brucellosis is a zoonotic pathogen responsible for great economic losses in most sub-Saharan nations. Although Ghana has successfully implemented the “One Health” initiative for the control of some emerging infectious zoonotic diseases with pandemic potential like Avian Influenza, there is very limited data available on brucellosis especially human brucellosis prevalence. He objective of his study is to determine the seroprevalence of human and bovine brucellosis as well as the predisposing factors at the community level in the North Tongu District of Ghana. Materials and Methods: Rose Bengal Plate test (RBPT) was used to analyze blood samples from 178 cattle farmers, and 315 cattle. The positive samples were further confirmed with cELISA. Predisposing factors were determined by questionnaires administered to cattle farmers. All sample sites were geo-referenced. Results: Human and bovine brucellosis seroprevalence using RBPT were 10.1% and 22.9% respectively. Eighty six percent (62/72) of bovine cases were confirmed with ELISA. Delivery assistants were more likely to be infected (p=0.043) with odds ratio of 2.7. Out of the human cases (18), males constituted 88.9%. Ages 11-20 years recorded 77.7% seropositivity whilst cattle drovers represented 44.5% (8/18) of positives. Significant risk factors in cattle were herd size (p=0.037), history of retained placenta (0.000) and abortion (0.005). Conclusion: Bovine and human brucellosis is prevalent in North Tongu district, Ghana. Close contact with parturient cows was a major predisposing factor for human infection. Early referral of positive persons to the Hospital for confirmation and treatment is required to comply with the “One Health” initiative on brucellosis and other zoonoses.

Establishment of infestivity model for Sarcoptes scabiei var canis in Nigerian dogs

Experimental transmission patterns involved with the establishment of mange in dogs were studied to ascertain the effective means of infestation model for mange experiments in dogs. A total of eighteen (18) dogs were used out of which three (3) were naturally infested with Sarcoptes scabie var canis. Five (5) healthy dogs were co-mingled with the three (3) donor dogs for direct contact transmission. Another five (5) mange free dogs were aggregated in a kennel recently vacated by mange infested dogs for environmental and formite transmission while the last five (5) healthy dogs had scrapings from a proximate area of mange lesion sites transferred into the pinnae of each dog for experimental and indirect contact transmission. Successful mite transmission with associated clinical features of pruritus, alopecia, erythema, papules and crusts was achieved with co-mingling of mange naïve and mange infested dogs. These clinical features also differed (p < 0.05) from dogs experimentally infested as this method of transmission was largely unsuccessful. Following the success of the direct contact model closely is the environmental and formite transmission model. Here, healthy dogs were housed in recently vacated mange infested kennels. The direct contact model only differed from the environmental model (p < 0.05) in the expression of erythema and papules in dogs. Although comingling infested and mange naïve dogs guarantees successful direct contact transmission, exposure of healthy dogs to infested facility would also lead to infestation. This study showed that comingling remain an effective means of infestation model for mange experiments in dogs.