Evaluation of the shedding routes and serological patterns in experimentally-induced Brucella melitensis infection in dexamethasonetreated and transport-stressed goats

Aim: To identify and evaluate the shedding routes and patterns following experimentally-induced Brucella melitensis infection in dexamethasone-treated and transport-stressed goats. Materials and Methods: Twenty four healthy, adult goats were divided into 4 groups: A, B, C and D respectively. Group A was treated with dexamethasone for 8 days prior to inoculation with 10 (7) Colony Forming Units of B. melitensis via the intraocular route. Group B was transported for 3 hours prior to inoculation with a similar dose. Group C was inoculated with a similar dose without subjecting the animals to any prior treatment, and this group served as our positive control. Group D was not inoculated with the infective dose and served as our negative control. Blood samples along with nasal, ocular, and vaginal swabs were collected on days 0, 3, 7, 10, 14, and weekly thereafter until day 63 post inoculation (pi) and were analyzed by PCR, Rose Bengal Plate Test (RBPT), and indirect ELISAtechniques. Results: The nasal, ocular and vaginal swabs tested positive for Brucellosis with PCR from day 7, with nasal route being the first and most consistent route to reveal the positive results. Group B showed the earliest onset of shedding the bacterium (day 7) followed by group Awhich started from day 10 and shed relatively more positive of the bacterium via the routes examined. Blood samples tested positive with PCR from day 7 through 14 and the results were inconsistent subsequently. Sera samples tested positive with RBPT on day 14 in all the 3 infected groups but more consistent in group C. On the other hand, tests using ELISAshowed positive results from day 7 pi, with group C having a 100% seroconvertion –while groups Aand B showed only 50% seroconvertion. Conclusion: The consistent shedding via the nasal, ocular, and vaginal routes in groups A and B implied possible immunosuppression in the infected animals. We recommend that programs designed to control Brucellosis should consider analyzing a larger number of biological samples to enhance the accuracy of identification of shedders

Changes in haematological parameters and oxidative stress response of goats subjected to road transport stress in a hot humid tropical environment

Even though studies investigating the effect of road transportation on haematological parameters in goats from temperate and hot tropical environments are numerous, few studies have focused on the recovery rate following transportation, especially in the hot, humid tropical environment. This study investigated the haematological parameters and oxidative stress response of goats subjected to 7 h of road transportation in the hot, humid tropical environment and the possible recovery period. Thirty-five healthy Boer goats, aged 2–3, weighing 20–25 kg, were divided into two groups, designated A and B, of 30 and 5 animals, respectively. Group A was transported for 7 h, and blood samples were collected before, 3.5 h on transit, after transport, and on days 3, 7, 16 and 26 post-transport, while five goats served as control. Plasma and haemolysate were prepared and used to assay malondialdehyde, superoxide dismutase and glutathione alongside haematological parameters. The differential leukocyte counts of group A were altered following transportation as neutrophils, monocytes and neutrophil/lymphocyte ratios increased significantly (P < 0.01) during transport compared to group B. Malondialdehyde value increased significantly (P < 0.01) following transportation through day 3 post-transport, while superoxide dismutase and glutathione activities decreased simultaneously following transportation and increased from day 3 through day 7 post-transportation. This study revealed that goats subjected to 7 h of transportation in the hot humid tropical condition experience haematological derangements and oxidative stress which take an average period of 3 to 16 days for recovery

Effects of resveratrol on shedding and pathological dynamics in experimental B. melitensis infection in dexamethasone-treated nonpregnant Boer goats

Brucellosis constitutes an infectious re-emerging zoonosis. Spread of diseases could be exacerbated by stress-induced immunosuppression. This study evaluated relationship between Brucella melitensis infection, shedding dynamics, dexamethasone-induced stress, pathological alterations and resveratrol ameliorative effects in goats. Twelve nonpregnant goats were divided into four groups A, B, C, and D of three animals each. Groups A and B were administered 107 CFU/mL of B. melitensis ocularly, 21 days prior to 7 days consecutive administration of dexamethasone (2 mg/kg). Group A was further administered resveratrol (5 mg/kg) intravenously for 5 consecutive days from day 31 post B. melitensis inoculation. Group C was administered similar dose of B. melitensis while group D was inoculated normal saline. Blood, nasal, ocular, and vaginal swabs were collected at intervals for analysis. The does were sacrificed at day 42 post inoculation (pi). Tissues were collected for tissue bacterial load determination, histopathology, and immunohistochemistry. Dexamethasone administration from day 21 pi increased the frequency in the shedding dynamics, tissue bacterial load, pathological alterations (frequency of microgranuloma and intensity of immunostaining) in group B while 5 days treatment with resveratrol following dexamethasone administration significantly reduced tissue bacterial load, decline in shedding dynamics, and ameliorate damage by dexamethasone administration/B. melitensis infection

Dexamethasone-induced stress exacerbates shedding, tissue antigen distribution, and pathology of caprine Brucellosis

This study investigated dexamethasone-treatment, shedding routes, tissue antigen distribution, and pathology of caprine Brucellosis. Eighteen non-pregnant goats were randomly grouped into A, B, and C. Group A was administered dexamethasone for 7 days at 2 mg/kg before inoculating 0.5 mL B. melitensis at 107 CFU ocularly while group B was inoculated 0.5 mL B. melitensis only, and C as control negative. Blood samples, ocular, nasal, and vaginal swabs were obtained for evaluation. Three goats were sacrificed from each group at days 21 and 42 post-inoculation (pi) and selected tissues collected for PCR, histopathology, and immunohistochemistry. Brucella melitensis was detected in the ocular swabs of group A significantly higher than group B. Shedding was prolonged in group A compared to B. The overall shedding was 22.2% in group A and 9.4% in group B. The uterus of both groups A and B revealed mild inflammation and microgranuloma, extensive necrotic lesions in lymph nodes. Liver showed multifocal necrosis predominantly in group A. Lesion scoring showed significantly higher scores in A compared to B. Strong immunostaining was observed in the liver, lungs, and spleen, predominantly at day 21 pi. This study demonstrated dexamethasone prolonged shedding, tissue antigen distribution, and pathology in dexamethasone-treated goats

Resveratrol ameliorates pathophysiological changes associated with Brucella melitensis infection in dexamethasone-treated does

Brucellosis has been regarded as the most widespread zoonotic disease. Infected animals have always been the source of human infection. Studies on the influence of stress on the pathological dynamics of this zoonotic disease are uncommon. This study aimed at evaluating serological responses, oxidative status, and pathological derangements associated with Brucella melitensis infection in does treated with dexamethasone. Twelve does were divided into 4 groups designated A, B, C, and D with 3 animals each. Groups A and B were ocularly inoculated with 107 CFU of B. melitensis. From day 21 postinoculation (pi), dexamethasone was administered for 7 days at 2 mg/kg intramuscularly. Group A was further treated with resveratrol for 5 days from day 31 post-B. melitensis inoculation. Group C was inoculated with similar dose of B. melitensis ocularly while group D was inoculated normal saline. Blood samples were collected at regular intervals for PCR, serology, and oxidative stress analysis. The does were sacrificed at day 42 pi. Selected tissues were collected for immunohistochemistry and histopathological examination. Dexamethasone administration induced increase in molondialdehyde level, intensity of immunostaining, and pathological alterations while decreasing superoxide dismutase, and glutathione levels in group A compared to group B. Five-day treatment with resveratrol following dexamethasone administration was observed to significantly ameliorate pathological derangements compared to group A. While stress could exacerbate pathological alterations associated with B. melitensis infection, antioxidants are capable of mitigating the impact of stress associated diseases

Evaluation of the shedding routes and serological patterns in experimentally-induced Brucella melitensis in dexamethasone-treated and transport-stressed goats

Aim: To identify and evaluate the shedding routes and patterns following experimentally-induced Brucella melitensis infection in dexamethasone-treated and transport-stressed goats. Materials and Methods: Twenty four healthy, adult goats were divided into 4 groups: A, B, C and D respectively. Group A was treated with dexamethasone for 8 days prior to inoculation with 107 Colony Forming Units of B. melitensis via the intraocular route. Group B was transported for 3 hours prior to inoculation with a similar dose. Group C was inoculated with a similar dose without subjecting the animals to any prior treatment, and this group served as our positive control. Group D was not inoculated with the infective dose and served as our negative control. Blood samples along with nasal, ocular, and vaginal swabs were collected on days 0, 3, 7, 10, 14, and weekly thereafter until day 63 post inoculation (pi) and were analyzed by PCR, Rose Bengal Plate Test (RBPT), and indirect ELISA techniques. Results: The nasal, ocular and vaginal swabs tested positive for Brucellosis with PCR from day 7, with nasal route being the first and most consistent route to reveal the positive results. Group B showed the earliest onset of shedding the bacterium (day 7) followed by group A which started from day 10 and shed relatively more positive of the bacterium via the routes examined. Blood samples tested positive with PCR from day 7 through 14 and the results were inconsistent subsequently. Sera samples tested positive with RBPT on day 14 in all the 3 infected groups but more consistent in group C. On the other hand, tests using ELISA showed positive results from day 7 pi, with group C having a 100% seroconvertion –while groups A and B showed only 50% seroconvertion. Conclusion: The consistent shedding via the nasal, ocular, and vaginal routes in groups A and B implied possible immunosuppression in the infected animals. We recommend that programs designed to control Brucellosis should consider analyzing a larger number of biological samples to enhance the accuracy of identification of shedders

Immunohistochemical detection of Brucella mellitensis and Coxiella burnetii antigens in formalin-fixed tissues of West African Dwarf goats

Immunohistochemical detection of Brucella mellitensis and Coxiella burnetii antigens in formalin-fixed tissues of West African Dwarf goats. The information on the evidence of Brucella mellitensi and Coxiella burnetti infections or co-infection in goats had been scanty, This investigation reports the immuno-histochemical evidence of Brucella mellitensi and Coxiella burnetti infections in West African dwarf goats. Goats presented for post mortem in the Department of Veterinary Pathology, University of Ibadan were used for this investigation. By simple randomisation, lung, kidney, liver and spleen of fifteen goats were used for this immunohistochemical evaluation using stardard technique. 60% of the goats examined were positive for Brucella mellitensis, 33% were positive for Coxiella burnetti while 7% were positive for both infection. The spleen liver, kidney and lungs were positive for Brucella mellitensis while only the spleen and lungs were positive for Coxiella burnetti. Coxiella burnetti antigens were located in the cytoplasm of macrophages of alveoli of the lung and in the red splenic pulp while Brucella melitensis antigens were located in the cytoplasm of macrophages in the lung, in the red splenic pulp, Kupffer cells of the liver, macrophages in the glomeruli and epithelial cells of cortical tubules. This appears to be the first report of immunohistochemical detection of Brucella and Coxiella antigens in tissues of West African dwarf goats. The presence of these antigens in apparently healthy and pneumonic goats showed the level of risk posed by goats’ meat and meat products in the spread of these zoonotic diseases hence the need for facilities for rapid detection of these diseases

The influence of dexamethasone treatment and successive road transport stress on the occurrence of caprine pneumonia in a hot humid tropical environment

Aim: The information on the effect of multiple stress and caprine pneumonia especially in a hot humid environment is limited in literature. Materials and Methods: Sixteen goats were divided into 4 groups. Group A were subjected to 8 hours and 3 hours transportation, group B to 8 hours transport stress once and dexamethasone injection, group C to 8 hours transport only while group D was the control. All goats were observed for respiratory signs while temperature was monitored daily. Dead ones were necropsied while the survivors and the goats in group D were sacrificed on day 21. The clinical, gross, histopathological, immunohistochemical scores were according to standard methods. Results: The mean total clinical score was higher in group B than group A, C and D. Two goats of the groups A, B and C goats died 21, 14 and 7 days post treatment. The dead goats in groups A, B, C had lung lesions typical of pneumonic pasteurellosis. An average of the lung consolidation of dead animals in group A was 15%, in group B, 8.5% and group C, 6.5% mostly involving the anterior and ventral part of the lung. The immunostaining results was also similar with all the lung samples positive for both Pasteurella multocida and Mannheimia haemolytica especially in the groups A, B, C with enhanced severity in A > B > C. Conclusion: This further buttress the need to reduce stress in farm animals and the emergence of P. multocida over M. haemolytica in the epidemiology of bacterial caprine pneumonia in stressed goats in Malaysia

Clinicopathological features and immunohistochemical detection of antigens in acute experimental Streptococcus agalactiae infection in red tilapia (Oreochromis spp.)

This study investigates the clinicopathological features of acute experimental streptococcosis in red tilapia using various routes of infection; intraperitoneal (IP), immersion (IM) and immersion cut (IC). Twenty four red tilapia in duplicates were inoculated intraperitoneally with 109 CFU/ml of S. agalactiae while another sets: intact, one with sharp cut at the tail end were exposed to bacterial inoculums 109 CFU/ml diluted in water while two groups of control fish were similarly manipulated. Clinical signs were recorded; samples from the gills, brain, eyes and kidneys were also taken for bacterial isolation and histopathology. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) were employed to detect the antigen. The diseased fish showed skin, fin haemorrhages and exophthalmia with obvious signs in IP at 2 hpc followed by IC and IM at 4 hpc. The lesions were noticed earlier in the kidney and most severe in IP. IHC detected antigen as early as PCR and isolation with intense staining in blood vessel lumen and wall, macrophages in choroid, focal haemorrhage in the renal interstitium and meninges especially in IP followed by IC and IM. The immunolocalisation of the antigen described for the first time further explain the pathogenesis of streptococcosis in red tilapia

The effect of heat stress on clinicopathological changes and immunolocalization of antigens in experimental Streptococcus agalactiae infection in Red hybrid tilapia (Oreochromis spp.)

Aim: To understand the influence of environmental temperature on streptococcosis, heat stress associated pathological changes in acute streptococcosis in red tilapia using various routes of infection was investigated. Materials and Methods: Red hybrid tilapia were inoculated with 109 CFU/ml of agalactiae using intraperitoneal (IP), immersion (IM), and immersion cut (IC) which were maintained at 34C for 24 hours while the positive control groups were infected using similar routes but maintained at 28C and the negative control was at 34C without infection. Samples from the gills, brain, eyes and kidney were taken for bacterial isolation, polymerase chain reaction (PCR), histopathology and immunohistochemistry (IHC). Results: Diseased fish showed skin haemorrhage, fin haemorrhage and exophthalmia with more signs in IP route of infection followed by IC and lastly IM at 34C. The bacteria were isolated and detected with PCR in all the organs of fish from 4 hour post-challenge (hpc). The lesions were noticed earlier and severe in heat stressed groups from 4 hpc with 50% mortality in IP group while for all, the bacterium was isolated from 4 hpc in the brain. IHC test also detected the antigen in the tissues as early as 4 hpc with intense staining in the heat stressed group, IP followed by IC and IM routes. Positive immunostaining were observed in the thrombi, meningeal vessels, choroid and interstitial haemorrhagic areas. Conclusion: The severe lesions observed in the brain, eye and kidney under heat stress reveals its contributory role to the mortality pattern and severe pathological changes associated with streptococcosis in fish