Bacterial, PCR and clinico-pathological diagnosis of naturally occurring pneumonic pasturellosis (mannheimiosis) during subtropical climate in sheep.

Mannheimia haemolytica is causative agent of pneumonic pasteurellosis (mannheimiosis) that causes huge economic losses to livestock farmers. We investigated the microbial and clinico-pathological patterns associated with ovine pneumonic pasturellosis during an outbreak. Prior to death, infected sheep revealed clinical signs including dyspnoea, salivation, pyrexia and mucopurulent nasal discharge. Mortality was significantly (p < 0.05) high in young sheep as compared to adults. Necropsy findings revealed presence of froth in trachea, congestion and consolidation of lungs, pulmonary edema, severe pleural adhesions, pericarditis, hemorrhages on mucosa of jejunum and kidneys. Histopathological examination revealed circumscribed and centrally calcified necrotic areas punctuated with chronic inflammatory cells and interstitial pneumonia. Moreover, bronchial epithelial hyperplasia, edema, congestion, mononuclear cell infiltration, thick interlobular septae and peri-vascular cuffing were the striking changes in lungs. Furthermore, lungs showed severe fibrin depositions along with abundant amount of fibrin meshwork on pleura infiltrated with chronic inflammatory cells. Histologically, liver, kidneys and lymph nodes showed degenerative changes. Mannheimia haemolytica and Pasteurella multocida were differentially identified on the basis of culture characteristics and biochemical tests. M. haemolytica was further confirmed by using polymerase chain reaction. From the findings of current study, it is concluded that M. haemolytica is a major respiratory threat in small ruminants that causes severe pneumonic changes in infected animals.

Patho-bacteriological investigation of an outbreak of Mycoplasma bovis infection in calves - Emerging stealth assault.

Mycoplasma bovis (M. bovis) is an important bacterium, causing severe respiratory infection, and arthritis in dairy animals worldwide. This study is based on 50 suckling calves among which 15 showed respiratory distress, lameness and swollen joints and died later. M. bovis was isolated and identified from all dead (n = 15) and live (17.14%; 06 out of 35) calves on the basis of bacteriological examination. In morbid calves, the carpus and stifle joints were severely affected, while necropsy revealed multiple well-circumscribed calcified abscesses and caseous exudates in cranio-ventral and diaphragmatic lobes of lungs. Suppurative polyarthritis, fibrino-suppurative, teno-synovitis and otitis media were the common and striking lesion observed at postmortem examination. Histopathological examination revealed broncho-interstitial pneumonia and necrotic fibrino-purulent broncho-pneumonia in lungs. Similarly, synovial membranes and joints revealed presence of multiple foci of liquefactive necrosis surrounded by lymphocytes, plasma cells, macrophages and peripheral fibroplasia. In the bacteriological investigations, the characteristic fried egg colonies of M. bovis further confirmed this infection in all suspected cases. In conclusion, the current clinico-histo-pathological features are the depictive picture, and is the first report of M. bovis infection in calves in Pakistan.

Immuno-pathologic effects of oral administration of chlorpyrifos in broiler chicks.

This study sought to assess if chlorpyrifos (CPF) induced immunotoxic effects in orally-treated day-old broiler chicks. Groups of chicks received per os CPF diluted in xylene at 5, 10, and 20 mg/kg body weight (CPF-5, CPF-10, and CPF-20) orally daily for 15 days. Xylene and control groups received xylene alone (1 ml/kg BW) and physiological saline, respectively. At various times during/after the exposure regimens, different immune end-points were analyzed in the birds. Humoral immunity was examined by assessing antibody responses to sheep red blood cells. Cell-mediated immunity was measured via lymphoproliferative responses to avian tuberculin. Leukocyte phagocytic ability was measured using a carbon clearance assay. Results showed that CPF administered to broiler chicks caused a dose-dependent decrease in humoral immunity, cell-mediated immunity, and phagocytic activity. Dose- and time-related pathological changes were observed in bursa of Fabricius, spleen, and thymus in treated birds. These changes were mild, moderate, and severe, respectively, in the 5, 10, and 20 mg/kg CPF groups. The Bursa of Fabricius in treated birds showed increased inter-follicular connective tissue proliferation, severe moderate cytoplasmic vacuolation, edema, and degenerative changes such as pyknosis and fragmentation of nuclei that depleted the follicles of lymphoid cells. In the spleen, disorganization of follicular patterns, severe congestion, cytoplasmic vacuolation, degenerative changes, and hyperplasia of reticular cells were noted. The thymus in treated birds exhibited congestion, hyper-cellularity, and a presence of immature monocytes in the medullary region, as well as myoid cell necrosis. Taken together, these studies clearly demonstrated that chlorpyrifos could induce immunotoxicities in broiler birds.

Clinico-hematological and tissue changes induced by butachlor in male Japanese quail (Coturnix japonica).

The present experiment was executed to determine the pathological effects induced by concurrent feeding of butachlor (chloroacetanilide herbicide) in male Japanese quail. For this purpose mature male quail about 4-5weeks of age were procured from the local market and randomly divided into six equal groups (A-F). Butachlor was mixed in corn oil and administered orally for 30days using crop tube. Four birds from each group were killed at day 10, 20 and 30 of the experiment and blood was collected with and without anticoagulant. The birds in groups (A-D) did not reveal any clinical and behavioral alterations. Clinical signs like watery droppings, dullness, ruffled feather, depression, decrease frequency of crowing, mounting with pen mates and foam production were observed. Maximum intensity of these clinical signs and behavioral alterations were observed in group F throughout the experiment. Significant lower values of erythrocytes, hematocrit percent and hemoglobin were recorded. Significantly increased numbers of erythrocytes with micronuclei, lobed and notched nuclei were observed. Histopathologically, enlarged intertubular space, fewer numbers of round spermatids, necrotic spermatids and admixture of dead spermatids were observed in testes. The results revealed significant increase in serum lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT) and urea concentrations. The results of present experimental study indicated that butachlor induces hematobiochemical and testicular changes in birds.

Antioxidant activity via DPPH, gram-positive and gram-negative antimicrobial potential in edible mushrooms.

Edible mushrooms (EMs) are nutritionally rich source of proteins and essential amino acids. In the present study, the antioxidant activity via 1,1-diphenyl-2-picrylhydrazyl (DPPH) and antimicrobial potential in EMs (Pleurotus ostreatus, Morchella esculenta, P. ostreatus (Black), P. ostreatus (Yellow) and Pleurotus sajor-caju) were investigated. The DPPH radical scavenging activity revealed that the significantly higher activity (66.47%) was observed in Morchella esculenta at a maximum concentration. Similarly, the dose-dependent concentrations (200, 400, 600, 800 and 1000 µg) were also used for other four EMs. Pleurotus ostreatus exhibited 36.13% activity, P. ostreatus (Black (B)) exhibited 30.64%, P. ostreatus (Yellow (Y)) exhibited 40.75% and Pleurotus sajor-caju exhibited 47.39% activity at higher concentrations. Furthermore, the antimicrobial potential were investigated for its toxicity against gram-negative bacterial strains (Escherichia coli, Pseudomonas aeroginosa, Salmonella typhi, Klebsiella pneumonia, Erwinia carotovora and Agrobacterium tumifaciens), gram-positive bacterial strains (Bacillus subtilis, Bacillus atrophaeus and Staphylococcus aureus) and a fungal strain (Candida albicans) in comparison with standard antibiotics. Antimicrobial screening revealed that the ethanol extract of P. ostreatus was active against all microorganism tested except E. coli. Maximum zone of inhibition (13 mm) was observed against fungus and A. tumifaciens. P. sajor-caju showed best activities (12.5 mm) against B. subtilis, B. atrophaeus and K. pneumonia. P. ostreatus (Y) showed best activities against P. aeroginosa (21.83 mm), B. atrophaeus (20 mm) and C. albicans (21 mm). P. ostreatus (B) exhibited best activities against C. albicans (16 mm) and slightly lower activities against all other microbes except S. typhi. M. esculenta possess maximum activities in terms of inhibition zone against all microorganisms tested except S. typhi.

Rabies virus glycoprotein is an important determinant for the induction of innate immune responses and the pathogenic mechanisms.

Our previous studies have suggested that street and fixed rabies viruses (RABVs) induce diseases in the mouse model via different mechanisms. In the present study, attempts were made to determine if it is the glycoprotein (G) that is responsible for the observed differences in the pathogenic mechanisms. To this end, an infectious clone from fixed virus B2c was established and used as a backbone for exchange of the G from street viruses. The rate of viral replication, expression of viral proteins, and the induction of innate immune responses were compared in cells or in mice infected with each of the viruses. Furthermore, the infiltration of inflammatory cells into the CNS and the enhancement of blood-brain barrier (BBB) permeability were also compared. It was found that fixed viruses induced stronger innate immune responses (expression of chemokines, infiltration of inflammatory cells, and enhancement of BBB permeability) than street RABV or recombinant viruses expressing the G from street RABVs. Fixed viruses induce disease via an immune-mediated pathogenic mechanism while street viruses or recombinant viruses expressing the G from street RABVs induce diseases via a mechanism other than immune-mediated pathogenesis. Therefore, RABV G is an important determinant for the induction of innate immune responses and consequently the pathogenic mechanisms.

Mouse models of otitis media: strengths and limitations.

There has been a rapid rise in the use of the mouse to investigate pathobiology of otitis media. This is for good reason, including easy husbandry, but also capacity for genetic manipulation of the mouse. Insights into human disease have been gleaned from mouse models, but there are limitations of the mouse-to-man approach. First, important differences exist between mouse and man, particularly in immune function. Second, functional equivalence of genes in the 2 species is not ensured. Third, laboratory mice of a uniform genetic background and environment are an inadequate model of the plethora of factors affecting complex disease in humans. Finally, gene function in mouse models is often obliterated using gene knockout technology, but this is a poor mimic of normal gene variation in man. These drawbacks of the mouse may in the future limit its usefulness in otitis media research.

Caprine pleuropneumonia in Beetal goats [corrected].

Seroprevalence, clinical findings, and lesions of contagious caprine pleuropneumonia (CCPP) in Beetal goats were recorded during an outbreak. The overall seroprevalence of CCPP was 32.50%. Confirmation of Mycoplasma mycoides in serum was carried out using counter immunoelectrophoresis (CIE) technique. The highest CIE-positive cases were recorded in the older goats (51.72%) as compared to young ones. Nasal swabs collected from 39 goats showing respiratory signs were found positive for M. mycoides. The most consistent clinical findings were mild to severe cough, purulent nasal secretion, emaciation, dyspnea, increased respiration rate, and pyrexia. Mortality due to CCPP was 9.17%. Consolidation of lungs exhibited the highest frequency (100%), followed by alveolar exudation (90.90%) and pleural adhesion (72.72%). Among the microscopic lesions, septal peribronchiolar fibrosis exhibited the highest frequency (81.81%), followed by fibrinous pleuritis (63.63%) and peribronchiolar cuffing of mononuclear cells (54.54%) in lungs. From these results, it was concluded that CCPP under subtropical conditions has high prevalence in Beetal goats and leads to significant mortality.

Toxicopathological effects of lambda-cyhalothrin in female rabbits (Oryctolagus cuniculus).

The aim of this study was to investigate effects of lambda-cyhalothrin (LCT) on clinical, hematological, biochemical and pathological alterations in rabbits (Oryctolagus cuniculus). New Zealand white female rabbits (n = 24) of 4-5 months age having 997.92 ± 32.83 g weight were divided into four equal groups. Group A (control) received normal saline intraperitoneally (ip). Animals in groups B, C and D were treated with LCT 1.0, 4.0 and 8.0 mg/kg bw ip. Each group received seven consecutive doses at an interval of 48 hours. Blood and serum samples were collected at an interval of 96 hours. Blood analysis revealed a significant (p < 0.05) decrease in red blood cell and white blood cell counts, hemoglobin concentration and lymphocytes, while mean corpuscular hemoglobin concentration, mean corpuscular volume, neutrophils, monocytes and eosinophils were increased. Serum biochemical analysis revealed significant (p < 0.05) decrease in serum total proteins and serum albumin, while an increase was seen in serum alanine aminotransferase and aspartate aminotransferase activities compared with the control group. Serum globulin values varied non-significantly in all treatment groups as compared to control group. A dose-dependent increase in the incidence of micronucleated polychromatic erythrocyte was observed. All gross and histopathological lesions observed in LCT-treated rabbits were dose-dependent. Liver of the treated rabbits exhibited extensive perihepatitis, hyperplasia of bile duct, necrosis, hemorrhages and congestion. In lungs, there were hemorrhages, thickened alveolar walls, congestion, emphysema, collapsed alveoli and accumulation of extensive inflammatory cells. Kidneys were congested and hemorrhagic whereas renal parenchyma and stroma were normal. Microscopically, heart showed congestion of blood vessels and nuclear pyknosis, myodegeneration. It was concluded from the study that LCT produced toxicopathological alterations in rabbits in a dose-dependent manner. On the basis of the results, it can be suggested that overdosing of LCT be avoided while treating animals for ectoparasites.

Pathological and genotoxic effects of atrazine in male Japanese quail (Coturnix japonica).

The objective of the present study was to determine the pathological and genotoxic effects of atrazine (ATZ) in male Japanese quail. Adult male Japanese quail were administered ATZ daily at 0-500 mg/kg bw (A-H groups) orally for 45 days. The blood and morbid tissues were collected at day 15, 30, and 45 of the treatment. A significant decrease in feed intake, body weight, erythrocyte counts, hemoglobin and hematocrit values were observed at high ATZ dose compared to control. Leukocyte counts decreased significantly throughout the experiment in groups E-H (50-500 mg/kg bw). Grossly, testes from ATZ treated birds were comparatively smaller in size. Histologically, seminiferous tubules of testes in group H (500 mg/kg bw) exhibited decreased number of spermatocytes, necrotic nuclei of spermatids, and lesser number or absence of spermatozoa. Biliary hyperplasia and vacuolar degeneration in liver and mild renal tubular necrosis was observed in birds higher doses. Significantly longer comet tails of DNA damage in leukocytes and isolated hepatocytes were recorded with 500 mg/kg bw ATZ.

Clinico-hematological and micronuclear changes induced by cypermethrin in broiler chicks: Their attenuation with vitamin E and selenium.

This study was carried out on 90 one-day-old broiler chicks to know clinico-hematological alterations, DNA damage caused by cypermethrin (CY), and attenuation of toxic effects by vitamin E (Vit E) and selenium (Se). Birds were randomly divided into five equal groups. Groups 1-4 received CY (600mlkg(-1)b.wt) daily for 30 days by crop tubing. In addition to CY, groups 2, 3 and 4 received Vit E (150mgkg(-1)b.wt), Se (0.25mgkg(-1)b.wt), and Vit E (150mgkg(-1)b.wt)+Se (0.25mgkg(-1)b.wt), respectively. Group 5 served as control. Birds were monitored twice daily for clinical signs. They were weighed and blood samples were collected at experimental days 10, 20 and 30 for hematological studies. CY-treated birds showed more prominent signs of toxicity compared to CY+Vit E, CY+Se and CY+Vit E+Se birds. Body weight in groups 1-3 was significantly (P<0.05) smaller at days 20 and 30 when compared with the control group. Significantly (P<0.001) higher numbers of micronuclei appeared in chicks treated with CY compared to CY+Vit E- and CY+Se-treated birds. Significantly decreased total erythrocyte counts (TEC), hemoglobin (Hb) concentration and packed cell volume (PCV) in all treated groups were recorded. Treated birds suffered from macrocytic hypochromic anemia. Leukocytosis in early stage and later leucopenia was seen in treated birds. It can be concluded that CY induces toxic effects in broilers chicks; however, these toxic effects can be ameliorated by Vit E or Se. Combination of Vit E and Se was more effective to ameliorate toxic effects of cypermethrin.

Cutaneous form of pox infection among captive peafowl (Pavo cristatus) chicks.

The present study was carried out to investigate the epidemiology and lesions of avian pox in captive peafowl chicks. Overall values of morbidity, mortality and case fatality were 45.2%, 27.1% and 60.0%, respectively. The chicks of 9 to 12 weeks of age showed a significantly (P<0.001) higher prevalence rate than other age groups. The morbidity and mortality due to avian pox in peafowl chicks was significantly (P<0.001) reduced when kept in mosquito-proof cages and hatched under broody chicken hens. Morbidity due to poxvirus infection on the peafowl farm was 82%, 26% and 12% in successive years. This reduction might have been the result of the introduction of mosquito-proof nets after year 1, although this was not the subject of a controlled experiment. All of the peafowl chicks suffering from dry pox showed pustular and nodular lesions on eye lids, beak, legs and toes. Distribution of lesions in different body parts varied significantly (P<0.023). Lesion diameters were less than 1 cm (59.73%), 1 to 2 cm (23.75%) and more than 2 cm (16.87%). Histopathological studies revealed extensive proliferation of subdermal connective tissue and infiltration of heterophils and macrophages. The keratinocytes showed degenerative changes in the form of cytoplasmic vacuolation, ballooning and hyper-chromatic nuclei. Eosinophilic intracytoplasmic inclusions (Bollinger bodies) in keratinocytes were consistently present. It was concluded that avian pox rendered high morbidity, mortality and case fatality in peafowl chicks.