Wide Distribution of Pasteurella haemolytica Type 1 Over the Nasal Mucosa of Cattle

Studies on the site of proliferation of Pasteurella haemolytica in the bovine nasal cavity have been carried out.

P.haemolytica were isolated from 15 selected major anatomical areas of the nasal cavity in calves with high numbers of P.haemolytica following shipment from Western Canada. When the organisms were present in the nasal cavity of live animals in low numbers, they were isolated from many, but not all, areas. P.haemolytica was isolated post mortem from one or more selected areas of several nasal cavities in spite of negative antemortem cultures.

By the direct fluorescent antibody technique, P.haemolytica was demonstrated at the surface of nasal epithelial cells. Organisms were not seen in or between epithelial cells nor in the ducts nor alveoli of glands. The findings were similar when high and low numbers of P.haemolytica were present in the nasal cavity.

     

The Effect of Medicated Feed on the Nasal Microflora and Weight Gain of Pigs

Antimicrobial agents were added to the feed of swine for three weeks to determine the interrelationships of potentially pathogenic agents in the nasal tract, turbinate atrophy and weight gains.

Bordetella bronchiseptica was not isolated from the groups fed the combination of chlortetracycline, penicillin and sulfamethazine. B. bronchiseptica was found in some pigs after the feeding trail, but this organism was not significantly associated with turbinate atrophy at the time of slaughter.

Mycoplasma hyorhinis was not found in the nasal passages of the pigs that received feed containing high concentration chlortetracycline but was found in pigs that received other diets. Hemophilus suis was not significantly reduced by any of the treatments used.

The organisms studied in the pigs were not isolated from the personnel handling the pigs.

     

Pasteurella haemolytica in the Tracheal Air of Calves

Pasteurella haemolytica was shown to be present in the tracheal air of calves and was likely transported in droplet nuclei formed in the nasal passages. The number of colonies of P. haemolytica found in the tracheal air of the calves ranged from 1.9 to 12.5 colonies per cu ft of air. As long as P. haemolytica colonized the nasal passage in numbers detectable in nasal swabs it could be found in the tracheal air but there was no direct correlation between the numbers in the nasal flora and the numbers found in the tracheal air. Of the P. haemolytica which travel via the tracheal air 47.8% were in droplets of the aerodynamic size of from less than one to five microns, the size range which is considered hazardous for lung penetration in man.

The technique used demonstrated the presence of P. haemolytica in the tracheal air of calves and provides a useful tool for monitoring and determining the phase in the colonization of the respiratory tract in which the majority of the potential pathogen P. haemolytica pass from the nose to the tracheal air and presumably to the lung.

     

Epizootiologic Studies of Shipping Fever of Cattle: I. The Microbial Agents Isolated

Nineteen strains of Pasteurella spp., but no viruses cytopathogenic for bovine embryonic kidney cells were isolated from pneumonic lesions present in “normal” veal calves at slaughter.

In studies on two herds of native cattle and six lots of western feeder calves, Pasteurella spp. were isolated from nasal swabs from healthy cattle and those with shipping fever. Viruses of the psittacosis-lymphogranuloma group were isolated from nasal swabs from animals in five groups. Viruses provisionally identified as bovine enteroviruses were isolated from nasal swabs of calves in two lots.

There was serologic evidence of a temporal association of myxovirus para-influenza 3 (PI3) with shipping fever in three lots of calves. From two of these three lots, strains of PI3 were isolated from ten animals, four of which had clinical shipping fever at the time of virus isolation.

     

Experimental Atrophic Rhinitis in Gnotobiotic Pigs

Twenty-nine caesarian derived colostrum deprived germfree pigs were reared in isolators in groups of three to four per isolator. At seven days of age each group was inoculated intranasally with one of four strains of Bordetella bronchiseptica (designated B, J, L and 55B), or Pseudomonas aeruginosa or a mucoid strain of Escherichia coli, all previously isolated from nasal mucus of pigs affected with clinical atrophic rhinitis. Another group was inoculated simultaneously with B. bronchiseptica B and Pasteurella multocida. The animals were observed for clinical signs of atrophic rhinitis and monitored bacteriologically at weekly intervals for seven weeks. Then they were bled for serology and killed and their respiratory organs examined for gross and histopathological lesions.

All of the pigs inoculated with the Bordetellae had inflammation of the nasal mucosa and developed positive serum antibody titers against all four of the Bordetella strains used in this study. Strain J caused sneezing and turbinate atrophy in three of four pigs. One of the three pigs inoculated with strain L died in ten days from bronchopneumonia and pericarditis and had turbinate atrophy. Strains B and B55 caused no turbinate atrophy, but two out of three pigs inoculated with both B. bronchiseptica B and P. multocida had turbinate atrophy. No nasal lesions were observed in the pigs inoculated with E. coli or P. aeruginosa or in the noninoculated germfree controls.

The results indicate a variation in the ability of different strains of B. bronchiseptica to cause turbinate atrophy in pigs and demonstrate that nasal infections by these organisms stimulate serum antibody response. Presence of P. multocida appears to increase the severity of the lesions. As the E. coli and Pseudomonas failed to produce atrophic rhinitis, they are probably of no significance as primary etiological agents in the atrophic rhinitis syndrome in swine.

     

Comparison of Pathogenicity of Various Isolates of Bordetella Bronchiseptica in Young Pigs

Eight groups of 12-to 24-hour-old pigs were procured from a respiratory disease-free herd of swine and reared in isolation using a box-rearing procedure. They were inoculated intranasally at 3 days of age with different isolates of Bordetella bronchiseptica.

It was found at necropsy 4 weeks post-inoculation that 4 isolates of swine origin, an isolate of rabbit origin and an isolate of cat origin caused mild to moderate turbinate atrophy in 22 of 24 pigs. An isolate of rat origin caused mild turbinate atrophy in 1 of 4 pigs and an isolate of dog origin caused no turbinate atrophy. Pneumonia was present in most of the pigs inoculated with the swine, cat and rabbit isolates.

Bordetella bronchiseptica was recovered in heavy growth from the nasal and tracheal exudate collected at necropsy from pigs inoculated with the 4 isolates of swine origin and the isolate of cat origin. Fewer organisms were isolated from nasal exudate collected from pigs inoculated with the rat, dog and rabbit isolates.

     

The Response of Ponies to Myxovirus influenzae A-equi 2 I. Serum and Antibody Titres Following Exposure

The antibody response in serum and nasal secretions of groups of ponies vaccinated or infected with Myxovirus influenzae A-equi 2 was examined. Following infection by aerosol with live virus, a weak antibody response was recorded in both serum and secretions. Antibody levels were undetectable in secretions at 31 days after infection.

After primary intramuscular vaccination with killed virus, using sodium alginate as an adjuvant, antibody was detected only in the serum. However, following revaccination, a pronounced antibody response was demonstrated in both serum and secretions. Antibody was still detectable in all four ponies when tested 135 days later.

Only a serum antibody response was detected in ponies after primary intramuscular vaccination with a commercial vaccine. Upon revaccination nasal antibody occurred in all ponies but this only persisted for about 30 days.

Neither serum nor nasal antibody response occurred following intranasal vaccination and revaccination with a killed virus vaccine.

     

Pasteurella haemolytica of Cattle: Serotype, Production of Bete-galactosidase and Antibacterial Sensitivity

Two hundred and three isolates of Pasteurella haemolytica from cattle were studied. They originated from the nasal cavity of cattle in housed herds; the nasal cavity and pneumonic lungs of experimental feedlot calves and from pneumonic bovine lungs submitted for bacteriological diagnosis.

To determine whether a single characteristic or combination of characteristics might be a feature of isolates collected from animals with pneumonic pasteurellosis (Shipping Fever), the following tests were made. Cultures were serotyped by indirect haemagglutination; the ability to produce beta-galactosidase was examined in the ortho-nitrophenyl-beta-D-galactopyranoside (ONPG) test and antibacterial sensitivity tests were done. None of these factors could be directly related to the role of P. haemolytica in “Shipping Fever”.

     

Influence of Immunization Procedures on Upper Respiratory Tract Immunity in Cattle

Aspects of respiratory tract immunity have been investigated in the bovine species. Using Past. hemolytica type I as the antigen for this model the relationship of nasal and serum antibody production to the route of vaccination and type of vaccine was investigated in a series of 15 dairy calves from two to four months of age. Experimental results indicated that an aerosol vaccination with live Past. hemolytica resulted in a significant nasal antibody response while parenterally vaccinated gave calves with equivalent serum titers had no significant nasal antibody response.     

The Isolation of Trypanosomes from Cattle in Ontario

A method for the recovery by blood culture of a T. theilieri-like flagellate from cattle is described.

In Ontario, 54% of 156 cows in 15 herds were found to have parasitemia.

     

Symptoms and Pathology Produced By Toxic Microcystis Aeruginosa NRC-1 In Laboratory and Domestic Animals

Toxicity tests with lyophilized M. aeruginosa NRC-1 cells have been conducted using mice, guinea pigs, rabbits, chickens, ducks, two calves and one lamb as the test animals.

The symptoms and pathological changes are described. On an equivalent weight basis it required three to five times the oral dosage to kill the large animals and birds as it did to kill the laboratory animals. The symptoms were less pronounced and the survival times were longer in the more resistant animals. Enlargement and congestion of the liver with necrosis of the hepatic cells were constant and pathognomonic. These findings are in general agreement with the observations of other workers who have examined the toxicity of naturally occurring Microcystis waterblooms.

The toxicities and structures of microcystin and of six other biologically active cyclic polypeptides are summarized. The pathological effects produced by microcystin in laboratory and domestic animals resemble those produced in man but differ from those produced in animals by the toxic peptides of Amanita phalloides.

     

Some Effects of the Source of Bovine Milk Leucocytes and Strain of Staphylococcus on their Interaction in Vitro

A method is described for the quantitative study in vitro of the bovine milk leucocyte: staphylococci interaction which is capable of demonstrating differences between groups of leucocytes, and, to some extent, stains of Staph. aureus.

By means of this method it has been possible to show statistically, that significant differences can occur, between quarters of the same udder, in the numbers of leucocytes competent to ingest staphylococci, and also in the numbers of staphylococci ingested.

Between 4 strains of Staph. aureus significant differences were noted in their ability to multiply in the presence of milk leucocytes; in the production of leucocidal factors; and in the reduction of Resazurin in whole, normal milk.

     

Contribution à l'étude quantitative de la flore bactérienne du gros intestin des porcs dysentériques

The bacterial flora and the pH of the large intestine of dysenteric swine during acute subacute and chronic phases have been submitted to quantitative and qualitative studies. The methods used are based on primary isolation and differentiation of the bacteria by the use of selective media and the subsequent differentiation using the replica plating technique. The most characteristic changes are the following:

1. A significant increase of the pH of the chyme in the large intestine during acute dysentery

2. A significant increase of Vibrio, Escherichia coli and Staphylococcus in the colon and cecum during acute dysentery.

3. A significant increase of Shigella in the colon and cecum during subacute dysentery.

4. The almost total disappearance of Aeromonas and of the yeasts in the large intestine during acute, subacute and chronic dysentery.

5. A significant decrease of Klebsiella, in the cecum, during acute dysentery and of the fungi during subacute dysentery.

6. Decrease of Streptococcus in the colon during acute dysentery.

7. The total quantitative flora of the large intestine do not change very much.

     

Preliminary Observations on the Effect of Specific Immunity on Nasal Bacterial Flora

This investigation has shown that Pasteurella hemolytica could actively colonize the nasal cavity of calves in the presence of indirect hemagglutinating IHA antibody against that particular strain. It was not determined if the level of nasal IHA antibody to Past. hemolytica had an effect on colonization of the nasal passage by Past. hemolytica. Specific immunity to Past. hemolytica would appear to be important in respiratory disease induced by this organism.     

A Stable L-form of Haemophilus pleuropneumoniae

A stable L-form of Haemophilus pleuropneumoniae (Shope) was isolated from primary pig kidney cell tissue cultures which had been inoculated 28 days previously with glycine induced spheroplasts of this organism.

H. pleuropneumoniae was definitely cytopathic in primary pig kidney cell cultures, producing cell rounding, cytoplasmic vacuolation and nuclear enlargement with peripheral condensation of nuclear DNA. By contrast, the effect of spheroplasts was much less distinct, producing only loss of cytoplasmic granularity coincident with apparent loss of some cytoplasmic RNA, and slight nuclear enlargement.

Both the organism and its L-form were shown to be related by cultural methods, antibiotic sensitivity tests, immunofluorescence and immunodiffusion.

The L-form remained stable after 90 serial passages on agar and 45 in broth, each medium being capable of supporting the growth of both forms of the organism.

     

Prevalence and Species Distribution of Yeast in Mammary Glands of Dairy Cows in Minnesota

A study of the prevalence of yeast-like fungi in the mammary glands of dairy cattle was conducted in Minnesota. Quarter samples from 6,020 cows were cultured for yeast. Growth of organisms was obtained from 3.2% of the quarter milk samples. The rate of yeast infection for Minnesota dairy cattle in this study was 2.0%.

The majority of the yeast isolated belonged to one of four species of the Candida genus. Candida krusei, Candida parakrusei, Candida guilliermundi, and Candida tropicalis, comprised 89% of the yeasts isolated. All of these species have been reported to cause clinical mastitis (1, 7, 9, 10, 12, 13, 15, 16).

It would appear that yeast-like fungi are of sufficient prevalence in mammary glands that yeast infection would be considered in the differential diagnosis in cases of clinical mastitis.

     

Une étude expérimentale sur la variation du taux d'anticorps sériques suivant le cycle évolutif des oestres du cheval

The changes of antibody titers in the sera of colts infested naturally or artificially with Gasterophilus have been determined in relation to the life cycle of this arthropod using passive hemagglutination, complement fixation, double diffusion techniques and saline extracts of antigens from the third larval stages of Gasterophilus intestinalis and G. nasalis.

In the sera of the infected animals the hemagglutinating antibodies were present at low titers at the third week post-infestation by using somatic extract of G. intestinalis and at the seventh week in case of G. nasalis. At eight weeks post-infestation the antibody titers reached their maximum 1:8192 (G. intestinalis) and 1:4096 (G. nasalis), then dropped at 12 weeks post-infestation.

The complement fixing antibodies were present occasionally between the seventh and 11th weeks after infestation. Precipitating antibodies were absent in all sera.

     

A Mycoplasma Isolated from Cattle with Infectious Bovine Keratoconjunctivitis

A mycoplasma has been recovered from the eyes of calves in two naturally-occurring outbreaks of infectious bovine keratoconjunctivitis; also from a third group of calves accidentally exposed to an animal which had ocular exudates from one of the outbreaks instilled into its eyes.

The severity of the ocular lesions in infectious bovine keratoconjunctivis outbreaks may be related to a mixed infection with the mycoplasma and Moraxella bovis.

Preliminary typing studies indicate the mycoplasma is not serologically related to any known bovine mycoplasma.

     

The Detection of Specific Complement-Fixing Antibodies in Serum of White-Tailed Deer (Odocqileus Virginianus) with Theileria Infection

A complement-fixation (CF) antigen which has been prepared from Theileria infected erythrocytes is capable of reacting to specific serum antibodies of deer acutely infected with Theileria.

No sera from 17 deer known to be free of Theileria infection reacted positively to the CF test. Of 35 tests on sera from 12 infected deer having a parasitemia of 2% or less and no accompanying anemia, only 10 (29%) were positive, 2 (6%) were suspicious, and 23 (66%) were negative. Of 65 tests on 8 acutely infected deer, 49 (75%) were positive, 4 (6%) were suspicious and 12 (18%) were negative. Of the 8 deer in which acute theileriasis occurred all reacted to Theileria antigen at one time or another.

A significant correlation was found between CF titers and the degree of parasitemia in acute infections.

Rabbits were hyperimmunized using erythrocytes from either normal or Theileria infected deer. Reciprocal absorption of the hyperimmune sera with Theileria and normal erythrocytic antigens demonstrated the presence of antibodies specific for Theileria.

     

Toxicité et effet immunosuppresseur de la sulfaquinoxaline chez la poule

Secondary effects of sulfaquinoxaline have been studied by comparing specific antibody titres of treated birds with the titres of those birds which were not treated.

Previously these birds had been immunized by intramuscular injections of a killed antigen of S. pullorum, standard strain, and S. pullorum, variant strain. This experiment demonstrated that this drug possesses an immuno-suppressing action. This secondary effect was confirmed by an experimental infection with the GB strain of Newcastle disease virus.