Airsacculitis in turkeys exposed to Mycoplasma synoviae membranes

In studies to investigate the pathogenesis of mycoplasmal airsacculitis, exudative lesions were produced in turkeys by intra-air-sac inoculation with Mycoplasma synoviae cell membranes and viable organisms. Membrane inocula containing 5 mg of protein produced more severe lesions than inocula containing either 2.5 mg or 1 mg protein. Turkeys exposed to 5 mg of membrane protein developed moderately severe airsacculitis; those exposed to viable organisms developed markedly severe airsacculitis. Microscopic examinations revealed that membrane-induced lesions were generally similar to those resulting from infection but were less severe. At the termination of the study, 8 days after exposure, M. synoviae was isolated from respiratory tract tissues of all turkeys exposed to live organisms, but it was not isolated from any of those exposed to membranes or from unexposed control turkeys. Antibody against M. synoviae was demonstrated with the tube agglutination test in sera from turkeys exposed to membranes and those exposed to live organisms, but it was not demonstrated in sera from unexposed control turkeys.

Pulmonary clearance and lesions of lung and air sac in passively immunized and unimmunized turkeys following exposure to aerosolized Escherichia coli

Two groups of young turkeys, one passively immunized with homologous hyperimmune serum and the other unimmunized but receiving normal turkey serum, were aerosolized with Escherichia coli. Clearance of bacteria from lung and gross and microscopic lung and air-sac lesions were determined after necropsy at timed intervals. The group mean bacterial count in lungs of passively immunized turkeys was significantly less than the mean count in unimmunized turkeys. Lung lesions were generally similar in both groups and were focused in lymphoid nodules, at the junction of primary and secondary bronchi, and at the ostia to the air sacs. Unimmunized birds developed grossly evident purulent airsacculitis by 72 hours after aerosol exposure, whereas passively immunized birds did not.

Tracheal mucus transport rate and bacterial clearance in turkeys exposed by aerosol to La Sota strain of Newcastle disease virus

Tracheal mucus transport rate (TMTR) and quantitative clearance of aerosolized Escherichia coli from the trachea, lung, and air sac were measured in healthy unanesthetized turkeys and in turkeys exposed by aerosol to a La Sota vaccine strain of Newcastle disease virus (NDV). The TMTR of uninfected turkeys was 42.4 +/- 14.7 cm/min. The TMTR of NDV-infected turkeys was depressed on days 3 through 7 postexposure (PE); depression was significant (P less than or equal to 0.05) on day 7 PE. Tracheal E. coli clearance in NDV-infected turkeys was reduced on days 4 through 9 PE, significantly so on day 5 PE (P less than or equal to 0.01). Depression of TMTR and tracheal E. coli clearance were associated histologically with replacement of normal pseudostratified columnar epithelium by 3 to 8 layers of immature nonciliated cells. E. coli clearance by the lung and air sac of NDV-infected turkeys was depressed on days 5 through 9 PE.

Diagnostic cytology in avian medicine

Diagnostic cytology in avian medicine provides a means for better disease definition in the avian patient, which allows for a more specific therapeutic regimen. It is important that cytologic specimens are from fresh sources, since cells degenerate rapidly following the death of the bird or the tissue. Cytologic evaluation is an adjunct to other diagnostic procedures. A definitive diagnosis often requires information from the clinical history, physical examination, evaluation of samples obtained from the bird, radiographs, surgical procedures, necropsy, and histopathology.

Pathogenicity of strains of the IJKNQR group of avian mycoplasmas for turkey embryos and poults

Strains of mycoplasmas isolated from turkey embryos and identified as belonging to the IJKNQR group of avian mycoplasmas were found to produce lethal infections in experimentally exposed turkey embryos. Some strains produced exudative airsacculitis in experimentally exposed poults. Of 4 strains used to inoculate poults, two produced moderate airsacculitis, one produced a slight airsacculitis, and one had little or no effect on turkey poult air sacs. Microscopic examination revealed that the air-sac lesions resulting from infection with these mycoplasmas were similar to those resulting from infections with Mycoplasma gallisepticum, M. meleagridis, and M. synoviae. The results were considered to indicate that some strains of the IJKNQR group of avian mycoplasmas are pathogenic for turkeys.

Turkey airsacculitis: effect of mixed mycoplasmal infections

Turkeys experimentally infected with both Mycoplasma meleagridis and a member of the IJKNQR group of avian mycoplasmas developed more-severe air-sac lesions than did turkeys infected with either of these organisms alone. In addition, exudative air-sac lesions were more widely distributed anatomically in turkeys with mixed infections than in those with single infections. Similar studies with Mycoplasma synoviae and M. meleagridis did not indicate a significant increase in the severity of air-sac lesions. Both M. synoviae alone and M. synoviae and M. meleagridis combined produced severe lesions. Perhaps the severity of lesions produced by M. synoviae alone masked any exacerbating effect caused by the mixed infections.

Evaluation of a vaccine against Mycoplasma gallisepticum in commercial broilers

The efficacy of live Mycoplasma gallisepticum (MG) vaccine against respiratory mycoplasmosis was studied in three laboratory trials with commercial broilers. Broiler chickens were infected with the F or R strain of MG by eyedrop at 1 day of age, and challenged by aerosol exposure to the R strain of MG along with eyedrop vaccination against Newcastle disease and infectious bronchitis at 30 or 34 days of age. Observations were made of macroscopic lesions, severity of airsacculitis, isolations of MG, serologic test results, clinical signs, and mortality. In all the vaccinated groups, the air-sac-lesion score was lower after challenge than in unvaccinated control chickens. After challenge the control group also had a higher number of MG isolations from the air sac than did the vaccinated chickens. There were no air-sac lesions observed in broilers before challenge in 2 of 3 trials.

Evaluation of ammonia stress and coccidiosis on broiler performance

Eighty broiler chickens were randomly assigned to each of 12 chambers in a controlled environment poultry facility. Ammonia gas was injected at 0, 50, or 100 ppm from 28 to 53 days of age. All chicks, except the control pens, were innoculated with coccidia at 36 days of age. No significant differences were found in mortality, but weight gains were significantly reduced in chambers that received ammonia gas. This was probably due to the increase in severity of air sac and intestinal lesions in the ammonia pens.

Comparative pathologic findings of Escherichia coli infection in birds

Of the 3 respiratory tract disease syndromes that occur in birds associated with Escherichia coli infection, acute colisepticemia, characterized by hyperemic and swollen viscera, tended to occur in young birds. Subacute fibrinopurulent serositis involving air sacs and pericardium was more common in older birds. Chronic granulomatous pneumonitis was not seen as flock epornitics but as chronic disease in birds dying in small numbers some time after one of the previously mentioned forms of the disease. Serotypes of 100 E coli isolates from turkey colibacillosis revealed most to be O1, O2, O36, or O78. Virulence of the isolates, as conducted by IV inoculation of 6-week-old turkeys, showed O78 strains to be highly virulent and O36 strains to vary in virulence.

Experimental infection of ducklings with Mycoplasma gallisepticum and Mycoplasma anatis

Two groups of day-old ducklings were infected with Mycoplasma gallisepticum and M anatis respectively by air sac inoculation. Clinical disease was not produced but air sacculitis was produced by both infections. M gallisepticum could be recovered readily from respiratory tissue 10 and 30 days after infections but RSA tests were negative. M anatis was not reisolated from these tissues or from the cloaca but a positive RSA test was observed on the serum of a few ducklings.

Pathologic features and mechanisms of hypoxemia in adult respiratory distress syndrome

In 45 consecutive patients referred for severe hypoxemia (Pao2 less than 100 mm Hg on positive end-expiratory pressure of 5 cm H2O and fraction of inspired O2 of 1.0), physiologic studies of gas exchange were correlated with pathologic features from 36 open lung biopsies and 15 autopsies. Three distinct groups were defined. Group 1 included 11 patients with the most severe hypoxia (Pao2, 47 +/- 12 mm Hg), minimal Pao2 response to a 10 cm H2O increase in positive end-expiratory pressure (+2.0 +/- 4.0 mm Hg), and a fixed shunt at all fractions of inspired O2. Pathologic study showed edema, exudation, and hemorrhage to the point of consolidation. In group 2 were 13 patients who had less severe hypoxia (Pao2, 60 +/- 17 mm Hg) and a moderate Pao2 response to a 10 cm H2O increase in positive end-expiratory pressure (+15 +/- 8 mm Hg), but whose maximal response was slowly achieved (30 min to several hours). Pathologic examination showed extensive fibrosis. The 21 patients in group 3 had the least hypoxia (66 +/- 15 mm Hg), and had a rapid and marked improvement in Pao2 with a 10 cm H2O increase in positive end-expiratory pressure (+68 +/- 59 mm Hg). Pathologic features were similar to but less severe than those in group 1. Venous admixture increased with decreasing inspired concentrations of O2, indicating diffusion or ventilation-perfusion abnormalities in groups 2 and 3. Prognosis was best for group 3, with 10 of 21 long-term survivors. Two of 11 group 1 patients survived, but only after prolonged periods of extracorporeal membrane oxygenation. Despite biopsy evidence of extensive fibrosis, 3 of 13 in group 2 survived with moderate to good pulmonary function, including 1 survivor who had had extracorporeal membrane oxygenation. Such combined physiologic and pathologic studies are useful (1) for optimal respiratory care, (2) for prognosis, (3) for development of indications for extracorporeal membrane oxygenation, and (4) for better understanding of the pathophysiology of adult respiratory distress syndrome.

Histology of air sac lesions induced in chickens by contact exposure to Mycoplasma synoviae

Chickens were housed when 1 day old with chickens experimentally infected with Mycoplasma synoviae. Air sacs from 16 of the 2-week-old and eight of the 3-week-old contact-exposed chickens were given gross lesion scores and embedded in glycol methacrylate for slide preparation. Histologic lesions in air sacs with gross scores of 0-2 were mild edema resulting in a two to eightfold increase in air sac thickness, capillary proliferation, and exudate consisting largely of heterophils and necrotic debris. Histologic lesions in air sacs with gross scores of 3 and 4 were marked hyperplasia of epithelial cells and diffuse infiltration of the air sac connective tissue by mononuclear cells. Nine of 10 air sacs with gross scores of 0 had no histologic evidence of inflammation. The most severe histologic lesions were in those air sacs with gross scores of 4. The glycol methacrylate procedure resulted in 2-mum sections with excellent cellular detail.

Corticosteroids and prevention of pulmonary damage following cardiopulmonary bypass in puppies

A technique of inducing hypothermia using surface cooling and rewarming with a pump oxygenator has been applied clinically in infants with satisfactory results. Respiratory problems postoperatively, however, are reported to be among the complications contributing most to mortality and morbidity. Prednisolone sodium succinate (Solumedrol) has helped to obviate pulmonary damage in hemorrhagic and endotoxic shock and therefore may be effective in preventing pulmonary damage following hypothermia. This hypothesis was investigated in 12 mongrel puppies, 6 that had hypothermic cardiopulmonary bypass and circulatory arrest but were not given Solumedrol, and 6 that were treated preoperatively with Solumedrol. In lung biopsies taken immediately after bypass the pathological changes in both the group treated with steroids and the control group were similar. At six hours, however, lung biopsies from the control group showed further signs of progressive damage, while in the steroid-treated group there was a striking improvement with some lung biopsies showing a normal appearance. Thus, Solumedrol did not prevent initial lung damage, but the progressive and probably permanent changes were reduced.

Effect of route of Newcastle disease vaccination on the incidence of airsacculitis in chickens infected with Mycoplasma synoviae

In two separate experiments, broiler-type chickens were vaccinated at 11 days old with either the B-1 or LaSota strain of Newcastle disease virus (NDV) by aerosol, drinking water, or eyedrop and simultaneously infected with Mycoplasma synoviae (MS). The MS-infected and aerosol-vaccinated chickens had the highest mean lesion scores for airsacculitis. The aerosol-vaccinated groups had the highest hemagglutination-inhibition titers against NDV. Infection with MS had no effect on antibody titers against NDV, and there were no consistent effects on weight gains.

Pathology of velogenic Newcastle Disease virus infection in turkeys

Twenty-four 4-week-old poults, free from Mycoplasma meleagridis and M. gallisepticum, were inoculated with a velogenic viscerotropic strain of Newcastle disease virus. Clinical signs (gasping, coughing, and dyspnea) developed 4-5 days postinoculation, continued until nervous derangement appeared, and then (usually 3 days after initial clinical signs appeared) declined in severity. Prominent nervous signs were paresis and paralysis of the extremities, with pronounced head-shaking. The most constant gross lesions detected involved the airsacs. The abdominal sacs of a few poults contained a large accumulation of yellowish, cheesy exudate and there was cloudiness of the thoracic airsacs of all inoculated poults. A few turkeys had tracheitis with some catarrhal exudates and casts in the lower part of the tracheal lumen. Congestion of lepto-meningeal vessels usually correlated with the severity of the nervous signs. The histologic lesions were characterized by both degenerative and proliferative changes with predominantly mononuclear cell and heterophil infiltrations throughout the body. The obvious lesion seen in the recovery stage of the disease was proliferation of lymphofollicular nodules in the parenchymatous organs.

Candida tropicalis infecting the respiratory tract of turkeys in Israel

A Candida tropicalis epidemic is described that affected the respiratory tract of turkeys receiving antibiotics in their food and drinking water. When the antibiotics were stopped and Io-vine given, the disease was cured.

Turkey syndrome 65, oedema syndrome and Mycoplasma meleagridis

Comparisons of liver histology and serum protein characteristics from cases of oedema syndrome and from poults with Mycoplasma meleagridis induced ascites revealed that the two conditions, though presenting grossly similar post mortem appearances, are different entities. Serum albumin concentrations, but not total serum protein levels, were markedly reduced in poults with M meleagridis induced ascites and in those with turkey syndrome 65. Poults which were infected with M meleagridis but which failed to develop either of these conditions had more normal serum protein characteristics. It is argued that M meleagridis induced ascites may be an acute manifestation of a pathological process of which TS65 is the chronic form. It is also suggested that low serum albumin concentrations may play a primary role in the pathogenesis of TS65.

A field trial, using killed-Mycoplasma gallisepticum vaccine to protect against chicken respiratory mycoplasmosis

In a field trial with chickens, the efficacy of killed Mycoplasma gallisepticum vaccine against respiratory mycoplasmosis was determined. Broiler chickens were vaccinated by aerosol administration at 3, 14, and 25 days of age, and observations were made of survival rate, body weight gain ratio, macroscopic lesion grade of airsacculitis, isolation of organisms, serologic test results, histopathologic changes, and clinical signs. Inhalation of the vaccinal aerosol did not influence livability and body weight gain ratios. In the control group, M gallisepticum, M synoviae, or both, wereisolated in 6 of 10 chickens at age 84 days and in 1 of 10 chickens at age 134 days. In all of the vaccinated groups (10 broilers each), however, results of bacteriologic cultural examination during the observation period were negative. The killed M gallisepticum vaccine also suppressed increase of antibody titers in the tube agglutination and the hemagglutination-inhibition tests at different intervals. Both the histopathologic changes and the clinical signs appeared minimal in the vaccinated group.

An epornitic of fatal chlamydiosis (ornithosis) in South Carolina turkeys

An unusual epornitic of fatal chlamydiosis occurred in a flock of 10,283 domestic turkeys in South Carolina. Total mortality over a 2-week period was 483 birds (4.7% of the flock). The principal gross lesion was severe pericarditis, but there was little or no airsacculitis, an observation at variance with many previous reports of chlamydiosis. Furthermore, an unusually heavy infestation of the turkeys with sanguivorous black flies (Simulium slossonae and S congareenarum) was observed at the time of the epornitic, an occurrence that may have permitted rapid transmission of chlamydiae between turkeys in the affected flock. The strains of Chlamydia psittaci isolated from naturally infected turkeys caused pericarditis and heptopathy as well as occasional airsacculitis, with a 41% mortality in intravenously (IV) inoculated turkeys. Turkeys inoculated intramuscularly (IM) or intraperitoneally (IP) did not die; however, airsacculitis was observed in more than 85% of turkeys inoculated intraperitoneally or exposed to infection by pen contact with inoculated turkeys. The strain was highly infectious but not lethal by the latter method of transmission. The strain was similar to other virulent chlamydiae isolated from turkeys, in that small numbers of the organism caused fatal infection in guinea pigs when inoculated IP.

Plastic embedding of avian tissues for diagnostic histopathology

A series of photomicrographs show the histologic features of avian tissues embedded in plastic and sectioned on glass knives. The techniques described gave superior resolution, less cell shrinkage, and fewer sectioning artifacts than sections prepared with conventional paraffin methods.

Influence of strain of Mycoplasma synoviae and route of infection on development of synovitis or airsacculitis in broilers

Two strains of Mycoplasma synoviae (WVU 1853 and F10-2AS) were compared for their relative pathogenicity in terms of airsacculitis and synovitis. Both strains produced air-sac lesions after aerosol exposure of chickens vaccinated against Newcastle disease and infectious bronchitis; both produced synovitis when inoculated into the foot pad. The WVU 1853 strain was more likely to result in synovitis, whereas the F10-2AS strain was more apt to produce air-sac lesions.

Infectious bronchitis and mixed infections of Mycoplasma synoviae and Escherichia coli in gnotobiotic chickens. I. Synergistic role in the airsacculitis syndrome

The synergistic role of infectious bronchitis virus (IBV) and mixed infections of Mycoplasma synoviae (MS) and Escherichia coli (EC) in the airsacculitis syndrome was evaluated in gnotobiotic chickens. Relative air sac lesion score indexes, in descending order of severity, from various combinations of organisms were: 9.5-IBV, MS, EC; 6.8-IBV, EC; 4.5-IBV, MS; 2.7-IBV; and 0.5-MS, EC. Infectious bronchitis virus caused a mild fibrinous inflammation. M. synoviae combined with IBV increased heterophilic and follicular lymphoid infiltration and mortality. E. coli combined with IBV increased exudation and prolonged airsacculitis. Concentrations of fibrinogen, gamma globulin, and total plasma proteins were elevated significantly by combined infections of IBV, MS, and EC (P < 0.01).