Contribution to the taxonomy of the turkey coryza agent: cellular fatty acid analysis of the bacterium

Gas-liquid chromatography was used to analyze bacterial cellular fatty acids to elucidate the relatedness of the turkey coryza (TC) bacterium to Alcaligenes spp., Bordetella spp., and other gram-negative bacteria. The results indicated that the TC bacterium is not closely related to Alcaligenes faecalis or any of the reference strains of Alcaligenes and Bordetella studied. Most urease-positive bacterial isolates obtained from the upper respiratory tract of turkeys were identified as Bordetella bronchiseptica. It is suggested that Bordetella avium is a suitable designation for the TC bacterium formally called Bordetella-"like" and A. faecalis type I. It is also suggested that the nonpathogenic bacterium previously identified as type II A. faecalis be designated B. avium-like until further taxonomic studies are available. Furthermore, it is proposed that the term turkey coryza be used to refer to the disease induced by this bacterium.     

Efficacy of a commercial turkey coryza vaccine (Art-Vax) in turkey poults

Four laboratory experiments were designed to study the efficacy of the only available commercial vaccine for turkey coryza, Art-Vax. Poults were vaccinated either once or twice at different ages and challenged with pathogenic Alcaligenes faecalis. In another study, commercial turkeys vaccinated at 1 and 12 days of age on a commercial farm were brought to the laboratory for challenge with pathogenic A. faecalis. Both the laboratory- and field-vaccinated poults were given the manufacturer's recommended dosage of the vaccine strain. Regardless of the vaccine schedule or source of poults, the vaccine was not effective in protecting challenged turkeys from infection. Furthermore, the vaccine was not effective in protecting poults less than 3 weeks of age from disease, but it was effective in protecting poults more than 3 weeks of age from disease. These results indicate that although vaccinated turkeys older than 3 weeks of age were not susceptible to disease, they were susceptible to infection and could act as carriers of field strains of A. faecalis, thus perpetuating the risk of infection to flocks subsequently raised in the same buildings.     

Observations on Alcaligenes faecalis infection in turkeys

Experiments were initiated to study the pathogenicity of 5 Alcaligenes faecalis isolates in specific-pathogen-free poults. The isolates were recovered from commercial flocks suffering from a respiratory disease. There were no differences between cultural or biochemical characteristics of the isolates, but differences in antibiotic sensitivity were detected. All 5 isolates were capable of initiating a respiratory disease in poults similar to that seen in the early stages of turkey coryza. The infection, clinical signs, and lesions were limited to the upper part of the respiratory tract, but there were substantial differences in the severity of disease initiated by different isolates. There were also differences in the persistence of infection in the host. Secondary infections in the tracheas and sinuses were higher in poults infected with A. faecalis. The disease observed in the experimentally infected birds was milder than in 4 naturally infected flocks that also had complicating Escherichia coli infections. There was no evidence of infection with infectious bursal disease virus in 4 naturally occurring outbreaks in Ohio. It is proposed that the term turkey coryza be used to describe the disease initiated by A. faecalis.     

Turkey coryza: toxin production by Bordetella avium

Twelve strains of Bordetella avium representing isolates from turkeys in the United States, the Federal Republic of Germany, and the Republic of South Africa were tested for toxin production. Sterile filtered sonicates from 9 of 12 strains contained a toxin that was lethal for 7-to-10-day-old poults. Mice were also susceptible to the lethal effects of the toxin. No differences in susceptibility to the toxin were found between Beltsville small white and broad-breasted white poults. The toxin was solubilized by sonication and inactivated by heating at 56 C for 30 min. Treatment with formalin or proteolytic enzymes inactivated the toxin, indicating that it is probably a protein. The evidence suggests that the toxin is involved in the pathogenesis of turkey coryza.     

Pathogenicity of Australian isolates of Haemophilus paragallinarum and Haemophilus avium in chickens

Twenty-seven Australian avian Haemophilus isolates were tested for their ability to cause infectious coryza in specific pathogen-free chickens. All 15 isolates, identified as H. paragallinarum, produced infectious coryza, whereas all 12 H. avium isolates were nonpathogenic, but spread to in-contact chickens.     

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.     

Filamentous forms of Bordetella avium: culture conditions and pathogenicity.

Difficulties in preparing suitable antigen for the microagglutination (MA) test led to the discovery of a filamentous form of Bordetella avium. Broth media high in nutrients, vigorous shaking, and incubation at 37 C appeared to promote the development of filamentous forms of the organism. Peptone broth did not induce the development of filamentous forms. Eleven different isolates having both smooth and rough colony types were tested and observed to form filaments of various lengths. Filamentous forms of B. avium hemagglutinated guinea pig erythrocytes were motile, had pili and flagella, and were stable up to the fourth or fifth passage in broth media, at which time a predominance of typical coccobacillus organisms were observed. Filamentous forms of B. avium originating from smooth-colony types were pathogenic in turkey poults, whereas the filamentous forms of B. avium originating from rough-colony types were not pathogenic.     

Pili of Bordetella avium: expression, characterization, and role in in vitro adherence

Electron microscopy revealed pili on all isolates of Bordetella avium and B. avium-like bacteria examined. Trypticase soy broth (TSB) and 2% peptone agar were the best media for promoting pilus expression. Cultures grown at 37 or 42 C had similar pilus production, whereas cultures grown at 18 C produced few or no pili. Pilus expression of the Art Vax strain was best when that strain was grown in TSB, but the strain yielded fewer pili than B. avium and B. avium-like isolates grown under the same cultural conditions. B. avium pili had a diameter of 2.0 nm, ranged in length from 370 nm to 1500 nm, and had a protein subunit molecular mass of about 13,100 daltons. Purified pili from B. avium did not hemagglutinate guinea pig erythrocytes, and a 1:20 dilution of hyperimmune antisera against B. avium pili did not block the hemagglutinating activity of whole-cell preparations of B. avium. In the indirect immunofluorescence test, B. avium isolates and the Art Vax strain adhered to the tracheal explants of turkeys, but B. avium-like isolates did not. Purified pili from B. avium adhered to the surface of the mucosal lining of the tracheal explants, and hyperimmune antisera against B. avium pili blocked the in vitro adherence of whole-cell preparations of B. avium. It was concluded that pili of B. avium are involved in the in vitro attachment of that bacterium to the mucosal surface of turkey tracheal explants.     

Influence of temperature on the growth of Bordetella avium in turkeys and in vitro

Effects of temperature on growth of three strains of Bordetella avium were determined in young turkeys and in vitro. Colonization of the tracheal mucosa by two virulent strains of B. avium was significantly greater in cold-stressed turkeys than in heat-stressed turkeys. The avirulent vaccine strain, ART-VAX, colonized tracheas of cold-stressed turkeys to a limited extent but failed to colonize heat-stressed turkeys. Growth rates of the three B. avium strains were determined in brain-heart infusion broth at 30, 35, 40, and 45 C. All three strains grew best at 35 C but were killed by 45 C. Compared with virulent strains, ART-VAX grew markedly less at all temperatures, and most cultures of ART-VAX grew at 40 C only after a variable period of declining numbers of viable bacteria. This study indicates that temperature affects growth of B. avium in vivo and in vitro and that growth of the ART-VAX strain is fundamentally different from growth of virulent strains.     

Isolation and characterisation of Bordetella avium and related species and an evaluation of their role in respiratory disease in poultry

A total of 24 Gram negative non fermentative bacteria obtained from poultry were compared with reference strains of Bordetella avium, Alcaligenes faecalis, Bordetella bronchiseptica and a Bordetella avium-like organism. Thirteen isolates were identified as B. avium and 11 were identified as B. avium-like. A commercial microidentification kit (the API2ONE) did not identify the field isolates but did separate them correctly into the 2 groups. A practical identification scheme, suitable for diagnostic laboratories, is proposed for these organisms. The available clinical histories suggest that B. avium is associated with upper respiratory tract disease in turkeys.     

Failure of two serotype II infectious bursal disease viruses to affect the humoral immune response of turkeys

The effect of serotype II infectious bursal disease virus (IBDV) isolates from turkeys on the homoral immune response of turkey poults was determined. Following exposure to the OH IBDV isolate, poults in two experiments were inoculated with sheep red blood cells, which is a T-dependent antigen, and poults in two other experiments were inoculated with Salmonella heidelberg O antigen, which is a T-independent antigen. Prior exposure to serotype II IBDV did not affect serum antibody titers to these antigens. IBDV infection also did not affect the concentrations of serum immunoglobulin M (IgM), IgG, or IgA in these poults. Bursa:body weight ratios of OH IBDV-infected poults were not significantly different from those of uninfected controls. In one experiment, the humoral immune response of poults to the LaSota Newcastle disease vaccine was not affected by infection with the MO IBDV isolate. Although no clinical infectious bursal disease was observed in any poult in these experiments, the serotype II IBDV isolates were infectious and transmissible in poults.     

Isolation and characterization of Bordetella avium plasmids

Experiments were conducted to study the plasmids of Bordetella avium, B. avium-like, and B. bronchiseptica isolates from turkeys and the plasmids of the Art-Vax commercial vaccine strain. Plasmids were observed in 6 of 20 B. avium isolates, in 6 of 20 B. avium-like isolates, in all 5 B. bronchiseptica isolates, and in the Art-Vax strain. Plasmids of B. avium correlated with resistance to antibiotics but not with pathogenicity, hemagglutination of guinea pig erythrocytes, or expression of pili.     

Genetic variation in response of turkeys to experimental infection with Bordetella avium

One hundred ninety-six male and female turkeys representing two genetic lines were experimentally infected with Bordetella avium. The lines of turkeys included a randombred control line (RBC2) and a subline (F) of RBC2 selected for increased 16-wk body weight. No difference was found between lines RBC2 and F in the number of days to onset of clinical signs, and no mortality due to B. avium infection was observed in either line. Interestingly, however, a significant depression (12%) occurred in body weight of F line poults infected with B. avium, but no significant depression occurred in body weight of RBC2 poults.     

Turkey coryza: selected tests for detection and neutralization of Bordetella avium heat-labile toxin

Bordetella avium heat-labile toxin (HLT) was lethal for poults, mice, and embryonating chicken eggs. It produced hemorrhagic lesions in turkey and guinea pig skin. Antiserum made in turkeys neutralized the lethality of the toxin and its ability to produce hemorrhagic skin lesions. Further, antiserum against HLT of an Ohio strain neutralized lethality of HLT of strains from Iowa, North Carolina, and West Germany. The antiserum did not neutralize lethality of HLT from B. bronchiseptica. Bordetella avium HLT was not ciliostatic for turkey tracheal-ring cultures and did not stimulate adenyl cyclase activity using mouse adrenal cell cultures.     

Prevalence,virulence attributes,and antibiogram of Bordetella avium isolated from turkeys in Egypt

Tropical Animal Health and Production - Turkey coryza is a major respiratory disease caused by Bordetella avium (B. avium). It occurs in all ages of turkeys and is characterized by high morbidity...     

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.     

Observations on the pathogenicity of Alcaligenes faecalis in chickens

A series of trials was conducted in which specific-pathogen-free (SPF) leghorn chicks were exposed to various isolates of Alcaligenes faecalis. Chicks were inoculated with A. faecalis alone or in combination with Newcastle disease/infectious bronchitis (Nc/Br) vaccine, laryngotracheitis vaccine, infectious bursal disease virus, or Mycoplasma gallisepticum. The response was evaluated by morbidity, mortality, airsacculitis, reisolation of A. faecalis, and histopathological lesions of tracheas. Although A. faecalis was recovered up to 42 days postinoculation in some cases, no clinical signs were directly attributed to simple A. faecalis infection. None of the other agents significantly increased the severity of A. faecalis signs or lesions, except that A. faecalis-infected chicks that were given Nc/Br vaccine had prolonged microscopic tracheal lesions. In another trial, the effects of A. faecalis in young SPF leghorns, non-SPF broilers, and turkeys were compared. Broiler-type chicks were more susceptible than leghorns and less susceptible than poults. Consequently, the use of leghorns as a model for studying this infection is questioned.     

Alcaligenes faecalis infection in turkeys: effects on serum corticosterone and serum chemistry

The serum levels of corticosterone, total calcium, inorganic phosphorus, protein, sodium, and potassium were determined for turkey poults from 1 to 42 days of age. Corticosterone levels were higher at days 10, 14, 21, and 28 in Alcaligenes faecalis-infected turkeys than in uninfected poults. The corticosterone responses in this study indicate that A. faecalis infection stimulates adrenal cortical function even in the very young poult, which ordinarily does not show adrenal cortical responsiveness to various environmental and physical stressors. No differences were observed between infected and uninfected turkey poults in other serum chemistries.     

The efficacy of a temperature-sensitive mutant vaccine against Northwest Arkansas isolates of Alcaligenes faecalis

The efficacy of a commercially produced temperature-sensitive mutant Alcaligenes faecalis vaccine was evaluated in turkeys contact-challenged with one of three strains of A. faecalis. In the vaccinated control group, the vaccine strain of A. faecalis colonized the nasal turbinates but not the trachea, caused no clinical signs of turkey coryza, and induced humoral antibodies. In the vaccinated challenged groups, the vaccine reduced both the severity of lesions and the number of birds exhibiting lesions compared with unvaccinated challenged groups, but it did not prevent colonization of challenge strains of A. faecalis.     

Observations on colonial phenotypic variation in Bordetella avium

Two forms of Bordetella avium colonial morphology on artificial media were observed. The smooth colonial morphology is convex, with an entire edge, and has a glistening mucoid appearance when cultured on 5% bovine blood agar or tryptic soy agar. On the same media, the rough morphology has a crenated edge, a flat surface, and sometimes a wrinkled or ground-glass appearance to the surface. Colonial morphology remained stable when cultures were passaged at 37 C every 48 hours. When different salts or crystal violet were added to the media, the colonial morphology of seven different isolates did not change. Following storage at 4 C on agar, B. avium isolates switched between the smooth and rough colonial morphology, indicating that this is a reversible process. Generally, bacteria with the smooth colonial morphology were motile on sulfide indole motility (SIM) media, whereas bacteria with the rough colonial morphology were non-motile. Only the isolates with the smooth colony type colonized the upper respiratory tract of turkeys, caused clinical signs of the disease, and elicited an agglutinating antibody titer by 21 days postexposure.