Brain monoamine concentrations in turkey poults infected with Bordetella avium

Six hours post-hatch, large white turkey poults were inoculated intranasally with 5 X 10(7) organisms of the "W" isolate of Bordetella avium. Three hours after inoculation and subsequently on days 7, 10, 14, 21, and 28 postinoculation, 30 infected and 30 uninfected control poults were injected intramuscularly with alpha methylparatyrosine (AMPT, 250 mg/kg), and an additional 30 of each group received a saline vehicle. Three hours after AMPT injection, whole brains from treated and untreated poults from both infected and control groups were removed, weighed, and frozen until assayed for norepinephrine (NE), dopamine (DA), and serotonin (5-HT). B. avium-infected poults had a significant reduction in steady-state NE and Da and a greater depletion of NE and DA after AMPT treatment compared with control poults. Infected poults had significantly reduced whole brain 5-HT concentrations, which persisted through 21 days postinoculation. Altered brain NE, DA, and 5-HT concentrations suggest that the B. avium-infected poults may be less able to cope with additional stressors.     

The effects of heat-labile Bordetella avium toxin on turkey poults

Intraperitoneal exposure of turkey poults to various concentrations of Bordetella avium sonicate containing heat-labile toxin indicated a high degree of toxicity: poults died after exposure to sonicate containing as little as 6.32 micrograms of protein. The toxic effects were dose-related: poults that received sonicate containing 158 micrograms of protein died in 4 to 6 1/2 hours, those that received 31.6 and 6.32 micrograms of protein died in 25 to 30 hours, and those that received 1.2 micrograms survived the 6-day course of the study and were apparently unaffected. Histologic examination of poults that received lethal doses of the toxin revealed degeneration and necrosis of parenchymal cells of the liver and pancreas as well as hyperemia, hemorrhage, and necrosis of the mucosa of the small intestine. No lesions were observed in poults that received the sublethal dose of toxin or in unexposed poults. Repeated intranasal exposure of poults to the sonicate did not produce clinical signs of disease or gross lesions.     

Effect of Bordetella avium infection on electrocardiograms in turkey poults.

Electrocardiograms (ECGs) were recorded from turkey poults infected with the W isolate of Bordetella avium. Strip chart data (amplitudes and intervals) were measured at 7, 14, 21, and 28 days postinoculation and compared with data from uninoculated controls. B. avium infection altered P-, RS-, and T-wave amplitudes, as well as P-R and S-T intervals throughout the 4-week experimental period. Heart rates were similar over the 4-week period in control poults, while rates in the infected birds were variable. Alterations in ECGs associated with B. avium infection appeared to be the result of disturbances in the cardiovascular system and may be associated with the pathogenicity of the organism in turkey coryza.     

Protection of turkey poults from Bordetella avium infection and disease by pili and bacterins

The role of pili in protection against Bordetella avium infection in turkey poults was studied. An isolate that produced the largest number of pili under growth conditions developed in our laboratory was used for preparation of pili and bacterin and for challenge. The pili were isolated, purified, examined by electron microscopy, and tested for purity by gel electrophoresis. Poults were vaccinated with oil-adjuvant pili, formaldehyde- or merthiolate-inactivated bacterins, or a commercial bacterin. Poults were vaccinated once or twice subcutaneously at different ages and challenged intranasally with a pathogenic B. avium isolate 5 days following the last vaccination. A few vaccinated birds had very mild clinical signs. B. avium was isolated from the sinuses of a few vaccinated birds, and growth was scanty. The mean colony counts from tracheal sections was significantly higher (P less than 0.1) in unvaccinated challenged poults than in vaccinated challenged poults. It is postulated that B. avium pili are important immunogens in turkey poults.     

Lack of protection against Bordetella avium in turkey poults exposed to B. avium-like bacteria

Six laboratory experiments were designed to determine whether poults infected with the nonpathogenic Bordetella avium-like (BAL) bacteria would develop immunity to B. avium (BA), the causative agent of turkey coryza. The BAL bacteria were isolated from poults given that organism, but few colonies were observed by 3 weeks postexposure. No serum-agglutinating antibody to the BAL bacterium was detected in poults exposed to that organism. Poults exposed to BAL bacteria either once or twice at different ages were not protected from infection or disease following experimental challenge between 1 and 7 weeks of age with pathogenic BA.     

Effect of fasting on plasma thyroid and adrenal hormone levels in turkey poults infected with Bordetella avium.

Plasma triiodothyronine (T3), thyroxine (T4), and corticosterone (CS) were measured in fasted and nonfasted control and Bordetella avium-infected poults. The stress of B. avium infection increased plasma CS, and fasting for 24 hours caused a further significant increase in CS levels. Plasma T3 was not affected by the infection, but fasting caused a significant reduction in both control and infected poults. Plasma T4 of fasted poults was increased in both control and infected groups, but infection attenuated the plasma T4 response. Total iodothyronines were increased in the control-fasted poults more than in infected-fasted poults, indicating a reduced responsiveness to stress by the thyroids of infected poults. Changes in plasma thyroid hormones and CS partially explain the decreased body weight gain and decreased body temperature after exposure to B. avium.     

Tracheal cilia response to exogenous niacin in drinking water of turkey poults infected with Bordetella avium.

Niacin was added daily to the drinking water of control and Bordetella avium-infected turkey poults at a dosage of 0, 70, and 280 mg/liter over a 2-week experimental period. Fourteen days postinoculation, tracheal sections were examined by histological and morphometrical analysis of cilia, as well as agar plate isolation for bacteria. Infected poults exhibited a 96-97% loss of cilia along the tracheal epithelial border, compared with only a 4-5% loss in controls. Infected poults receiving niacin in the drinking water exhibited only a 61.0% and 76.0% loss of cilia at doses of 70 mg/liter and 280 mg/liter, respectively. The results indicate that niacin treatment may influence the pathogenicity of B. avium infection.     

Antibiotic aerosolization: tissue and plasma oxytetracycline concentrations in turkey poults

Oxytetracycline hydrochloride (OTC) was delivered by aerosol to healthy 3-week-old turkeys. Trachea, lung, and plasma were evaluated for OTC levels at 1, 4, 8, 12, 24, and 48 hours after aerosol exposure. In Expt. 1, 15 poults in a modified Horsfall unit were exposed to 1 g OTC/m3 of air using a DeVilbiss ultrasonic nebulizer. In Expt. 2, 25,000 poults in a commercial confinement unit were exposed to 0.075 g of OTC/m3 of air using a Fogmaster fogger. In each case, initially high tracheal and lung OTC concentrations were obtained. OTC levels in the trachea fell to less than 1 microgram/g between 4 and 8 hours postexposure. Plasma OTC levels remained low throughout both experiments. Oxytetracycline was still detectable in room air 60 min after aerosol exposure and before ventilation was restored. This method of administration may have promise for use in respiratory infections, but additional studies are needed to further define the use of aerosol therapy in poultry production units.     

Effects of Pasteurella multocida endotoxins on turkey poults

Studies of turkey poult responses to Pasteurella multocida endotoxins indicated that lipopolysaccharide (LPS) preparations from two highly pathogenic strains and free endotoxin from one of these strains were all similar in lethal toxicity. Lethal intravenous doses were generally high, 1 mg or more for 1-week-old poults (13.3 mg/kg). The toxic effects of LPS were not increased by repeated administration of small hourly doses. For both forms of endotoxin, the relationship between dose and response was considered erratic. Attempts to increase the susceptibility of poults to LPS by administering a liver-damaging substance (galactosamine) or a histamine-releasing substance (compound 48/80) or by performing surgical bursectomy were not effective. The LPS did not provoke a dermal Shwartzman reaction, even though doses used were 10 times those that produced a characteristic reaction in a rabbit.     

Histologic evaluation of lung and bronchus-associated lymphoid tissue in young turkeys infected with Bordetella avium

One-day-old turkeys were inoculated intranasally with Bordetella avium. Noninoculated hatchmates were housed separately. At postinoculation weeks 1, 2, 3, 4, and 5, B avium-infected (BA+) and B avium-free (BA-) turkeys were necropsied; specimens of tracheas, intrapulmonary primary bronchi, and lung adjacent to primary bronchi were bacteriologically cultured. Lung tissue was collected for histologic examination. Lungs perfused with acetic acid were collected for evaluation to determine the size, number, and distribution of lymphoid nodules associated with primary bronchi. Bordetella avium was isolated from trachea and primary bronchi of all BA+ turkeys, but was never isolated from lung parenchyma. Acute purulent bronchitis was associated with colonization of the primary bronchi by B avium from postinoculation weeks 1 to 3. Macrophages and lymphocytes persisted in the peribronchial connective tissue for 5 weeks after inoculation. Bronchus-associated lymphoid tissue consisted of discrete lymphoid nodules protruding into the lumens of primary bronchi. Lymphoid nodules, morphologically similar in BA+ and BA- turkeys, were composed of nonciliated, cuboidal epithelium covering a zone of loosely arranged lymphocytes and macrophages and a deeper, sharply demarcated lymphoid follicle. Compared with bronchus-associated lymphoid tissue of BA- turkeys, lymphoid nodules of bronchus-associated lymphoid tissue in BA+ turkeys were more numerous and widely distributed along primary bronchi. In both BA- and BA+ turkeys, the mean diameter of lymphoid nodules doubled between 1 and 5 weeks of age.     

Clinical outbreak of Bordetella avium infection in two turkey breeder flocks

An acute upper respiratory disease was observed in two broad-breasted white (BBW) turkey primary breeder flocks. Associated clinical signs included sneezing, depression, and a deep dry cough originating from large conducting airways. Morbidity reached approximately 15-20% of the hens in an affected house. None of the turkeys died, and total feed consumption was not affected. A minimal effect upon egg production was noticed. Sera from an acutely affected flock exhibited a marked rise in titer to Bordetella avium compared with preinfection sera samples. In Case 1, B. avium was isolated in pure culture from affected birds. In Case 2, B. avium was diagnosed by serological results and clinical signs; bacteriological examination was not attempted. The findings presented here are consistent with an acute clinical outbreak of B. avium-induced turkey rhinotracheitis (turkey coryza) in BBW turkey breeder hens.     

Rickets in turkey poults

Fifteen outbreaks of rickets were diagnosed in turkey poults in Saskatchewan between 1978 and 1981. No relationship to farm, source of poults, or source of feed was apparent. Most outbreaks started when the poults were between 10 and 14 days of age, and they had recovered by 28 days of age. Losses varied from 1% to 14% of poults started. Skeletal lesions were characteristic of a vitamin D or calcium deficiency. On the basis of chemical analyses, adequate levels of calcium and phosphorus and proper amounts of vitamin premixes were present in the feed, but in five outbreaks biological feed tests implicated feed as a causative factor. The severity of rickets in poults fed defective feeds was markedly reduced by providing the poults with extra vitamin D in the drinking water or by injection. Two premixes used in different feeds contained adequate available vitamin D on the basis of biological testing. In some of the outbreaks, the rickets may have resulted from inadequate distribution of vitamin D in the feed, destruction of vitamin D during feed processing, or some unknown factor in the feed interfering with vitamin D utilization.     

Effects of Bordetella avium toxin on turkey tracheal organ cultures as measured with a tetrazolium-reduction assay

Turkey tracheal organ cultures (TOCs) were exposed to one of the following Bordetella avium fractions or controls: live B. avium, formalin-killed B. avium, B. avium sonicate, heat-inactivated sonicate, culture supernatant, heat-inactivated culture supernatant, phosphate-buffered saline, or brain-heart infusion broth. After the TOCs were incubated for 2 hours with the bacterial fractions, the cellular metabolism of each TOC was evaluated using a tetrazolium chloride reduction assay, and cellular morphology was determined by light microscopy. Additionally, bacterial fractions and controls were injected into turkeys to test lethality. Although the bacterial sonicate was lethal for turkeys, neither the sonicate nor any other B. avium fraction significantly affected the metabolism or morphology of turkey TOCs.     

Effects of poults on plasma concentrations of prolactin in turkey hens incubating without eggs or a nest

1. Plasma prolactin (PRL) concentrations, total daylight sitting time and extent of brood patch development were compared in singly caged hens incubating without a nest or eggs and in penned hens incubating eggs in nest boxes. No significant differences were found in any of the three measures of incubation intensity. 2. When 10 newly-hatched poults were placed in the cages of incubating hens their plasma PRL concentrations fell rapidly. No fall in plasma PRL was observed in hens that could see and hear, but not touch the poults. 3. When physical contact between hens and poults was maintained, visual isolation of hens from poults, surgical devocalisation of poults, or the combination of visual isolation and devocalisation of poults had no effect on the poult-stimulated decline in plasma PRL concentrations. 4. Sensory cues from poults that evoke the PRL response in incubating hens are primarily tactile.     

Influence of Bordetella avium infection on association of Escherichia coli with turkey trachea

Four-week-old Bordetella avium-infected and B avium-free turkeys were inoculated intratracheally with a suspension of fimbriated or nonfimbriated Escherichia coli. Numbers of E coli associated with tracheal sections were determined at postinoculation hour (PIH) 1 or 6. Significantly (P less than 0.05) greater numbers of E coli were isolated from the tracheas of B avium-infected turkeys compared with numbers in B avium-free turkeys. In B avium-free turkeys, tracheal associated E coli were 90% less at PIH 6 compared with that at PIH 1. However, in B avium-infected turkeys, numbers of E coli were not affected by postinoculation time. Seemingly, B avium-infected turkeys had reduced capacity to clear E coli from the trachea.     

Salt poisoning in turkey poults

A 4% mortality in 5-to-11-day-old turkey poults was attributed to 1.85% sodium chloride in the feed. The syndrome included peracute respiratory distress, ascites, and sudden death that resembled peracute heart failure. Clinical signs were observed only in the final phase of the toxicity, but progressive histologic lesions were found. Live, apparently unaffected poults showed increases in intracellular glycogen and cytoplasmic granularity, loss of striation, and early mild intercellular myocardial edema; similar but more severe histologic lesions were seen in live, ascites-affected poults. The ascites-affected poults had hydropericardium and hydrothorax which seemed to develop just minutes before death. Ultrastructurally, focal areas of myocardial cells exhibited myofibrillar disarray, lysis of myofilaments, widened Z-bands, and dilation of sarcoplasmic reticulum.     

A heat-stable toxin isolated from the turkey coryza agent, Bordetella avium

A toxin was isolated from Bordetella avium grown in a defined medium. The toxin was active for mice but not for turkey poults or Japanese quail. The extraction procedure is described. The toxin was trypsin-sensitive and heat-stable (85 C for 30 min), and its activity was blocked by B. avium hyperimmune serum.     

Furazolidone toxicity in neomycin-treated turkey poults

Furazolidone (FZ) toxicity was evaluated in turkey poults treated with neomycin at a dose of 20 mg/kg body weight for 5, 10, or 26 days. Neomycin treatment had no effect on FZ-induced anorexia, delayed the onset of altered electrocardiographic patterns by approximately 1 week, and did not significantly affect the development of FZ-induced cardiomyopathy. Data indicated that FZ toxicity is not significantly altered by the gut microflora.     

Enteric viruses in diarrheic turkey poults

Thirty-three intestinal samples from 10-to-21-day-old diarrheic turkey poults were examined for the presence of enteric viruses by electron microscopy. Samples originated from 32 flocks in six commercial operations located in six states. Mortality in these flocks ranged from 3 to 15%, and birds from recovered flocks varied greatly in size. Rotavirus-like agents (RVLA) were the most common viruses associated with diarrhea outbreaks in the flocks examined, occurring in five out of six operations. Other viruses detected either singly or in combination, in order of prevalence, were astroviruses, reoviruses, rotaviruses, enteroviruses, and adenoviruses. With the exception of RVLA and rotaviruses, the other viruses were identified solely on the basis of morphology. Salmonellae were isolated from only one of the intestinal samples. By electron microscopy, RVLA were morphologically indistinguishable from rotaviruses, occurring as both 55-nm single-shelled and 70-nm double-shelled particles. However, immune electron microscopy was useful for antigenic differentiation of these two viruses. Turkey rotaviruses reacted with antisera to porcine and bovine rotaviruses, whereas turkey RVLA did not. Neither turkey rotaviruses nor RVLA reacted with antisera to porcine para-rotavirus or an antigenically distinct bovine rotavirus (bovine rotavirus-like agent). Similarly, convalescent anti-turkey RVLA serum (from recovered specific-pathogen-free poults) reacted with homologous virus but did not react with mammalian or avian rotaviruses or reoviruses. Further, RVLA were found to possess RNA electrophoretic migration patterns unlike those of conventional rotaviruses or reoviruses. This trait was used as an additional means of differentiating these viruses.