The production of colibacillosis in turkeys following sequential exposure to Newcastle disease virus or Bordetella avium, avirulent hemorrhagic enteritis virus, and Escherichia coli.

Female large white turkeys were intranasally inoculated with either Newcastle disease virus (ND) or Bordetella avium (BA) at 4 weeks of age. This was followed by oral inoculation with an avirulent (vaccine) strain of hemorrhagic enteritis virus (HE) at 5 weeks and intravenous inoculation with Escherichia coli (EC) at 6 weeks. Control birds received ND, BA, or HE followed by EC; EC alone; or nothing at all. Turkeys receiving one agent prior to EC challenge did not experience a significant increase in mortality or pericarditis. Those exposed to ND or BA followed by HE and EC experienced a significant elevation in mortality and pericarditis. A highly significant positive correlation between the number of infectious agents encountered during primary exposure and the incidence of colibacillosis after EC challenge was demonstrated.

Increased numbers of duodenal mucosal mast cells in turkeys inoculated with hemorrhagic enteritis virus.

The relation between average duodenal mast cell count, duodenal mucosal mast cell numbers, duodenal connective tissue mast cell numbers, circulating basophil numbers, heterophil-to-lymphocyte ratio, and lesion score were studied to gain an understanding of the events that may lead to intestinal lesion formation associated with hemorrhagic enteritis virus (HEV) infection. Changes in vascular permeability in the duodenum in birds inoculated with HEV were examined, using colloidal carbon and ferritin as vascular markers. Turkeys inoculated with HEV had significantly (P less than 0.05) higher duodenal mast cell counts than did noninfected controls. Birds inoculated with HEV had significantly (P less than 0.05) more mucosal mast cells than did phosphate-buffered saline solution-inoculated birds. Connective tissue mast cell and basophil numbers were unaffected by viral inoculation. Thermal stress did not have significant effect on lesion severity, but did increase number of birds that developed the characteristic intestinal lesions. The heterophil-to-lymphocyte ratio was significantly (P less than 0.05) higher in HEV-inoculated birds, compared with phosphate-buffered saline solution-inoculated controls. Increase in vascular permeability was only detected in HEV-inoculated birds with intestinal lesions. Results indicate that mast cells, and the vasoactive mediators contained within mast cells, may be important in the early manifestation of HEV infection. They also provide a possible mechanism through which biochemical and physiologic changes characteristic of HEV infection can occur.

Optimum conditions for the turkey lymphocyte transformation test.

Optimum conditions for turkey lymphocyte transformation tests were determined. Thrice-washed turkey buffy-coat cells obtained after slow centrifugation (40 x g, 10 minutes) responded well to mitogenic stimulation. Turkey lymphocytes isolated on Ficoll-containing separation media largely lost their ability to respond to mitogens. Maximum responses were obtained with 2 x 10(7) lymphoid cells/ml. Responses to the mitogens were greatest when bovine fetal serum was used at a 2.5% concentration or pooled turkey serum and autologous plasma were used at a 1.25% concentration. Higher concentrations of turkey serum or plasma decreased the responses when sub-optimum doses of concanavalin-A (Con A) or phytohemagglutinin-P (PHA-P) were used. Serum-free cultures gave higher stimulation indices than cultures with serum only when sub-optimum doses of Con A or PHA-P were used. Optimum mitogen concentrations varied with individual birds, timing of the culture, temperature of incubation, and serum concentration in the cultures. Responses were usually greatest with final concentrations of 5 micrograms Con A/ml, 10 micrograms PHA-P/ml, and 20 micrograms pokeweed mitogen (PWM)/ml and when the cultures were incubated in 96-well microplates at 40 C in humidified air with 5% CO2 for 40-42 hours with pulsing with 3H-thymidine during the final 16 hours of incubation.

Factors influencing the severity of Escherichia coli and avian adenovirus group II infections in chickens.

Chickens from lines selectively bred for either a high (HH) or low (LL) antibody response to sheep erythrocytes were challenged intravenously with avian adenovirus group II (AA). Spleen size was determined 6 days later. In some experiments the responses of chickens to AA and Escherichia coli infections were compared. The level of corticosterone in the feed (15 mg/kg) which resulted in the lowest incidence of pericarditis in response to E. coli resulted in the greatest incidence of large spleens in response to AA infection. Incidence of enlarged spleens in response to AA infection was increased in fasted chickens and reduced in socialized LL-line chickens. Among ignored chickens harshly treated for 2 weeks before challenge, LL-line chickens had a higher incidence of enlarged spleens than HH-line chickens. Socialized HH-line chickens subjected to social stress 1 day before challenge had more severely affected spleens than socialized LL-line chickens. The HL cross was more severely affected by AA than the LH cross but was less severely affected by E. coli. Antibody responsiveness to sheep erythrocytes did not affect the severity of AA infection. Factors that increased the severity of AA infection seemed to result in a decreased severity of E. coli infection.

Effect of oral Escherichia coli inoculation on performance of young turkeys.

A strain of Escherichia coli isolated from the yolk sac of stunted turkey poults was administered orally to day-old large white poults. Poults were inoculated with either 0.1 ml of sterile broth or 0.1 ml of a 10(-2) dilution of a 24-hr E. coli culture containing 3.4 x 10(8) viable bacteria per ml. Two levels of dietary protein (28 or 22%) were fed from 1 day to 3 weeks of age. Following E. coli inoculation of 3.4 x 10(5) viable bacteria at day one, body weight gain and feed consumption from 0 to 3 weeks of age were numerically increased 4.5 and 2.1%, respectively, and feed efficiency was significantly increased 2.4%. E. coli had a greater effect on performance of poults fed the 28% protein diet than on poults fed the 22% protein diet. Metabolism studies, conducted from 7 to 10 and from 17 to 20 days postinoculation, showed no significant changes in the measurements of nutrient utilization due to E. coli other than a 17% increase in nitrogen retention from 17 to 20 days by those poults fed the 28% protein diet.

Genetic and environmental effects on the response of chickens to avian adenovirus group II infection.

The effects of husbandry procedures on an intravenous challenge with avian adenovirus group II were studied in lines of White Leghorns selected for high (HH) and low (LL) antibody response to sheep erythrocytes and their reciprocal crosses (HL and LH). Husbandry procedures were deprivation or no deprivation of water during the first week after hatching (ES), habituation or no habituation to humans throughout life, and flock stability or instability (LS) 24 hours prior to an intravenous challenge with avian adenovirus group II. Spleens of chickens were weighed 6 days after challenge. HL chicks were most susceptible and LH chicks were most resistant to avian adenovirus group II. Chicks subjected only to ES or no stress responded similarly and were less affected than those subjected to LS or to both ES and LS. There were major genetic-environment interactions which affected spleen size.

Effect of oxytetracycline-hydrochloric acid on reproduction of female turkeys.

Effects of oxytetracycline-HCl on reproductive performance of turkey breeder hens from the 13 to 24-wk production period were evaluated. During the 13th wk of production, females were grouped into low, medium, and high fertility subclasses. Females within each fertility subclass were randomly reassigned to treatments. The antibiotic was administered via the drinking water (T-2) or via the drinking water plus an intravaginal lavage (T-3). Hens receiving T-2 treatment showed significantly higher fertility than untreated controls (T-1) but also showed significantly higher early embryonic mortality than those receiving the T-3 treatment. Hatchability of all egg set was significantly higher in both antibiotic-treated groups than in controls. Females in the fertility subclasses remained significantly different from each other throughout the experiment. To determine the duration of the effect of antibiotic treatment, eggs were collected in a treatment and posttreatment periods. Fertility (P less than .05), and hatchability (P less than .10) were improved during the treatment period compared with results of the posttreatment period. The T-3 treatment had a long-term effect: it maintained early embryonic mortality at 10% and hatchability at the same level during both treatment periods. A short-term effect was observed in the T-2 group; early embryonic mortality increased (P less than .05) and hatchability decreased (P less than .10) during the posttreatment period. No correlations were found between mycoplasmal or bacterial populations and fertility subclass or antibiotic treatment. Egg production, body weight, feed consumption, feed consumed per egg, egg weight, and egg specific gravity were unaffected by antibiotic treatment.

Dietary protein and yolk sac inoculation with Escherichia coli in young turkeys.

An experiment was conducted to examine the effect of pathogenic Escherichia coli inoculated into the yolk sac of day-old turkeys. Escherichia coli was isolated from the yolk sac of stunted poults and inoculated directly into the yolk sac of day-old birds. Poults were administered either .1 ml of uninoculated sterile Todd-Hewitt broth or .1 ml of a 10(-3) or 10(-2) dilution of a 24-hr E. coli culture containing 3.4 X 10(8) viable bacteria/ml. In addition, poults were fed either 28 or 22% protein diets from 0 to 21 days of age to form a 3 X 2 factorial arrangement. Body weight gain and feed consumption were measured weekly, and dry matter and protein retention and nitrogen-corrected metabolizable energy were measured from 7 to 10 and 17 to 20 days postinoculation. Intestinal mucosal dipeptidase and maltase activities were determined at 21 days of age. Average mortality by 7 days of age was increased from 1 to 36% from the E. coli inoculation of the yolk sac. Escherichia coli significantly depressed body weight gain and feed consumption 27 and 30, 13 and 16, and 6 and 8%, respectively, during the first, second, and third weeks of the experiment but failed to affect feed efficiency. Feeding a 28% protein diet alleviated the depression in feed consumption and body weight gain to some extent compared with a substantial depression at 22% protein. Nitrogen content and gross energy of the excreta were increased by both dilutions of E. coli for the 7 to 10-day period; this was indicative of a malabsorption of nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)

Colibacillosis of turkeys exacerbated by hemorrhagic enteritis virus. Laboratory studies.

Lesions typical of colibacillosis disease were reproduced in laboratory experiments. Mortality resulting from experimentally produced colibacillosis was significantly increased when Escherichia coli O1:K1 was presented to poults that had been orally inoculated with hemorrhagic enteritis virus (HEV) 1 week earlier. These and previous data suggest that HEV infection can exacerbate colibacillosis of older poults. HEV infection apparently damages the poults' defense system enough to account for the observed increase in susceptibility to E. coli.

Field outbreaks of colibacillosis of turkeys associated with hemorrhagic enteritis virus.

In a study of field material and a survey conducted by the authors, typical signs of colibacillosis of 6-to-12-week-old poults included sudden onset, listlessness, rales, and high mortality. Signs persisted for about 2 weeks and were often followed by a low incidence of lameness caused by Escherichia coli. Gross lesions included enlarged and congested spleens and livers, and dilated discolored black or purple duodenal loops. Microscopic lesions included splenic and hepatic congestion. In some birds (freshly killed and fixed immediately), the epithelium at the tips of the duodenal villi was sloughing, but in other birds the villi were intact and normal in appearance. Splenic enlargement, the presence of intranuclear splenic inclusions similar to those found in hemorrhagic enteritis (HE), and the isolation of HE virus from some of the field spleens all indicated that inapparent HE infection often occurs at approximately the same time as this type of colibacillosis. It is therefore believed that HE infection often exacerbates colibacillosis of older poults.

Encephalomalacia associated with hypovitaminosis E in turkey poults.

Four-to-five-week-old turkey poults fed a diet markedly deficient in vitamin E (alpha-tocopherol) abruptly developed neurologic signs such as tremor, incoordination, and recumbency shortly after being moved to new quarters. Serum concentrations of alpha-tocopherol in birds on this diet were significantly lower than control values. Associated lesions included recent ischemic necrosis of the cerebellum and spinal cord. The condition closely resembled nutritional encephalomalacia of chicks. This report represents the initial published description of that entity in turkeys.

Hemorrhagic enteritis in captive American kestrels (Falco sparverius).

Hemorrhagic enteritis and hepatitis of suspected adenovirus etiology were the apparent cause of death of nine captive American kestrels. Cloacal hemorrhage was the only prominent gross lesion: disseminated hepatocellular necrosis, and intranuclear inclusion bodies were evident microscopically. Electron microscopy revealed numerous adenovirus-like particles associated with the hepatic lesions. Attempts to serologically identify the agent were unsuccessful.

Pulmonary congestion and edema (marble spleen disease) of chickens produced by group II avian adenovirus.

"Marble spleen disease" of chickens was diagnosed in 22-week-old chickens. Total mortality was 8.9%. Deaths occurred over a period of 2 months. Gross lesions included pulmonary congestion, splenomegaly, hepatomegaly, and congestion of egg follicles. Microscopic lesions included pulmonary congestion and edema, and reticuloendothelial cell hyperplasia of the spleen with concurrent white-pulp necrosis and lymphocyte depletion. The pulmonary lesions were of sufficient intensity to have caused the death of fatally affected birds. Many of the hyperplastic reticuloendothelial cells contained basophilic intranuclear inclusions similar to those that characterize hemorrhagic enteritis of turkeys, marble spleen disease of pheasants, and adenovirus group II splenomegaly of chickens. These characteristic lesions, plus serologic identification of the causal virus, indicate that "marble spleen disease" caused by avian group II adenovirus was affecting the flock under study. This appears to be the first report of death of chickens due to pulmonary congestion and edema caused by spontaneous infection with avian group II adenovirus.

Histopathology of avian adenovirus group II splenomegaly of chickens.

Chickens were infected with an avian adenovirus group II isolate previously obtained from chickens exhibiting splenomegaly in commercial broiler flocks. The isolate was inoculated orally in 6-week-old experimental chickens, which were euthanatized and necropsied 6 days postinoculation. The primary gross lesions found were splenomegaly and splenic mottling. Numerous tissues from 12 chickens were taken for histologic evaluation. Histologic lesions included splenic reticuloendothelial cell hyperplasia with intranuclear inclusions. Lymphocytic degeneration was seen in the lungs of most chickens examined. Lung hemorrhage and edema with endothelial disruption and congestion of pulmonary arterioles were found less frequently. The splenic lesions in the chickens were similar to those seen in turkeys naturally infected with hemorrhagic enteritis, and the lung lesions resembled those seen in pheasants naturally infected with marble spleen disease.

Incidence and distribution of "avian adenovirus group II splenomegaly of chickens".

Forty-six percent of 3,585 serum samples from 174 broiler-breeder chicken flocks in 9 states were positive for the precipitating antibody of hemorrhagic enteritis (HE) of turkeys/marble spleen disease (MSD) of pheasants. Seroconversion was detected only in flocks 19 weeks of age and older. The percent of individual serum samples positive within a flock increased with the age of the flock.

Production and persistence of antibodies in chickens to sheep erythrocytes. 2. Resistance to infectious diseases.

A line of chickens selected for ability to product high antibody titers to sheep red blood cells exhibited stronger antibody to Newcastle disease, was more resistant to Mycoplasma gallisepticum, Eimeria necatrix, a splenomeglia virus, and feather mites and less resistant to Escherichia coli and Staphylococcus aureus infection than a line selected for a lack of ability to produce antibody titers. A line of chickens selected for a nonpersistance of antibody titers to sheep red blood cells was relatively more susceptible to all infectious agents tested than a line selected for a persistence of atibody titers.

Vaccination of ring-necked pheasant for marble spleen disease.

Laboratory evidence indicates that a safe and effective procedure was developed for vaccinating pheasants against marble spleen disease. Field trials confirm the safety of the vaccine and suggest that vaccination will prevent marble spleen disease. Vaccination is by drinking-water administration of turkey-spleen-propagated turkey-origin live avirulent virus to pheasants 4 1/2 weeks old or older. The effect of field vaccination was studied in 39,000 pheasants in pens where recurrent annual mortality had been 5-15%.

Vaccination for hemorrhagic enteritis of turkeys.

Laboratory and field evidence indicates that a safe and effective procedure has been developed for vaccinating turkey poults against hemorrhagic enteritis of turkeys. Vaccination is by drinking-water administration of turkey-spleen-propagated pheasant-origin live avirulent virus to 4 1/2-week-old-poults. The effect of vaccination was studied in a field location having recurrent 10-15% mortality and in a second location having recurrent mortality of 0.1-0.2%. The poults involved totaled 214,554.

Hemorrhagic enteritis in two-and-one-half-week-old turkey poults.

A field outbreak of hemorrhagic enteritis was observed in 2 1/2-week-old poults. Similar poults from the same parent flock were susceptible to laboratory-induced infection at 2 weeks old.

Serologic examination of wild birds for hemorrhagic enteritis of Turkey and marble spleen disease of pheasants.

Precipitin antibody which reacted with the hemorrhagic enteritis (HE) of turkeys/marble spleen disease (MSD) of pheasants group of avian adenoviruses, was not detected in serum samples of 618 wild birds (42 species) from Florida, Texas and Virginia. HE/MSD precipitin antibody was detected in serum samples of pen-reared ring-necked pheasants ( Phasianus colchicus ) which had experienced MSD, but not in serum samples of similar MSD unaffected birds.