Search PubMed⌕ Search

Biomedical subjects

S Rosendal

Publications and source records attributed to S Rosendal.

At least 91 records · Page 5Linked to original sources
PubMed1984

Acridine orange staining for diagnosis of Mycoplasma bovis infection in cow milk.

Mycoplasma organisms were readily recognized in samples of milk or udder secretions from cows with clinical Mycoplasma bovis mastitis when these samples were stained with 0.01% acridine orange at pH 3.0. Samples could be stored at -4 degrees C for several days or subjected to repeated freezing and thawing without loss of staining or fluorescence properties. Use of this procedure in diagnostic laboratories on suspect samples from cows with clinical mastitis could hasten inauguration of control measures against this highly contagious disease by several days; however, definitive diagnosis still requires standard culture methods.

Acridine Orange↗
PubMed1984

Porcine haemophili and actinobacilli: characterization by means of API test strips and possible taxonomic implications.

Thirty Haemophilus strains and six Actinobacillus strains, all of porcine origin, were examined for their biochemical reactivity on API 20E and API ZYM test strips using dense cell suspensions (supplemented with NAD as appropriate) as strip inocula. When combined with a test for V-factor dependency, the use of both strips allowed adequate differentiation of closely related organisms. Numerical taxonomic analysis of the data demonstrated that the majority of the haemophili and actinobacilli studied could be placed in one of four major clusters; these clusters contained, respectively, the H. pleuropneumoniae--A. pleuropneumoniae strains, the H. parasuis strains, strains belonging to Haemophilus taxon "minor group," and strains belonging to an unusual group of mannitol-positive, urease-negative haemophili. A representative of Haemophilus species taxon C and an unusual Actinobacillus isolate appeared to be comparatively unrelated to organisms in the four major clusters. Although it may, on occasion, be difficult to place an unusual isolate in any one particular group, owing to the uncertain taxonomy of some of these organisms, it is concluded that API test strips can serve as useful tools for the characterization and differentiation of porcine haemophili and actinobacilli.

Actinobacillus↗
PubMed1984

Effect of the caprine variant of Mycoplasma mycoides subsp mycoides on endothelium, monocytes, and complement of guinea pig, calf, sheep, and goat serum.

The caprine variant of Mycoplasma mycoides subsp mycoides causes septicemia with coagulopathy in goats. Pathogenetic mechanisms that might explain the coagulopathy, the ability of the Mycoplasma to persist in the blood, and its specificity for goats were studied. Severe endothelial damage was seen by electron microscopy of goat aorta tissue exposed in vitro to 10(7) colony-forming units of mycoplasmas. The Mycoplasma did not damage 51Cr-labeled adherent cells from peripheral blood of goats. The hemolytic complement titer was reduced by 94%, 50%, 50%, and 25% in guinea pig, calf, sheep, and goat serum, respectively, 30 minutes after treatment with 8 X 10(9) colony-forming units of the Mycoplasma. Freshly prepared serum from these animal species killed the Mycoplasma. Heat-inactivated serum was not mycoplasmacidal. Complement from these 4 animal species was activated by the Mycoplasma through the classical pathway, because ethyleneglycoltetraacetic acid precipitation of serum Ca2+ inhibited activation. Proof that the classical pathway was functional in goats was not conclusive because Ca2+ supplementation of ethyleneglycoltetraacetic acid-treated serum did not restore complement activity. Endothelial damage and complement activation may explain the coagulopathy. The function that complement activation may have in the inflammatory response of this disease is not known. Difference in susceptibility of calves, sheep, and goats to M mycoides septicemia cannot be explained by species variation in complement mycoplasmacidal activity.

Animals↗
PubMed1984

Pathogenetic mechanisms of Mycoplasma mycoides subsp. mycoides septicemia in goats.

The variant best known as the large-colony type of M. mycoides subsp. mycoides is responsible for severe outbreaks of septicemia with coagulopathy in goats. Our objective was to study aspects of the pathogenesis that might explain the coagulopathy, the persistence of mycoplasmas in the blood of septicemic goats, and the host specificity. The endothelial cells of caprine aorta tissue cultured in vitro and exposed to the M. mycoides underwent severe ultrastructural damage. There was no evidence of cytotoxicity to 51Cr-labeled adherent cells from peripheral blood of goats. Complement from goat, sheep, calf and guinea pig was activated by the mycoplasma, resulting in consumption of complement and lysis of mycoplasmas. Goat complement had the poorest mycoplasmacidal effect, whereas guinea pig complement had the highest cidal activity. Complement was activated through the classical pathway, since selective chelation of Ca++ inhibited activation, and serum from C4-deficient guinea pigs was not mycoplasmacidal. Complement activity was restored in chelated serum of sheep, calf and guinea pig after Ca++ supplementation, but not in goat serum, suggesting a difference in the classical pathway activity between these species. Activation of complement may be an important generator of inflammation in this disease. However, species variation in mycoplasmacidal efficiency of complement cannot wholly explain why goats and sheep are susceptible to septicemia and calves and guinea pigs are not. Both endothelial damage and complement activation may be important features of the pathogenesis of tissue damage, and may help explain the coagulopathy in this disease.

Animals↗
PubMed1984

Antimicrobial susceptibility of 51 strains of Haemophilus pleuropneumoniae.

Fifty-one strains of Haemophilus pleuropneumoniae were tested for susceptibility to 27 antimicrobial agents using agar disc diffusion, broth-tube dilution and microdilution methods. There was generally good agreement between the interpretation of the disc diffusion inhibition zones and the actual minimal inhibitory concentrations obtained with the dilution methods. The agreement between the results obtained with the broth-tube dilution method and the microdilution method was very good. Three strains were resistant to penicillin, ampicillin, carbenicillin, methicillin and tetracycline. One of those was also resistant to chloramphenicol. Forty strains were resistant to streptomycin, 23 strains were resistant to novobiocin and seven were resistant to triple sulfa. It is thus necessary to consider resistance development against antimicrobial agents chosen for the treatment of pleuro-pneumonia in pigs caused by Haemophilus pleuropneumoniae.

Animals↗
PubMed1983

Mycoplasma felis as a cause of pleuritis in horses.

Mycoplasma felis was the only organism recovered from the thoracic cavity of a horse with pleuritis. Large numbers of mildly degenerative neutrophils were in the pleural fluid. The horse developed a serologic response to M felis and recovered during hospitalization. Experimentally, a pony was inoculated in the thoracic cavity with a pure culture of the M felis isolate suspended in the pony's serum. A control pony was inoculated with serum only. Within 48 hours, the principal pony developed fever, increased respiratory rate, pleural effusion, and signs of pain. A highly cellular exudate with nondegenerative neutrophils and large numbers of M felis was recovered from the thoracic cavity. The control pony remained normal. The principal pony developed an antibody response to M felis. The control pony did not. Fourteen days after inoculation, both ponies were euthanatized. Necropsy revealed pleural inflammation in the principal pony. Pleural lesions were not found in the control pony.

Animals↗
PubMed1983

Evaluation of a selective medium for isolation of Haemophilus pleuropneumoniae.

Crystal violet, lincomycin, spectinomycin and bacitracin were evaluated as selective agents in media for isolation of Haemophilus pleuropneumoniae. No single antimicrobial agent or combination of two or more inhibited all non-Haemophilus strains (Escherichia coli, Pasteurella haemolytica, Pasteurella multocida, Streptococcus faecalis, Streptococcus equisimilis and Staphylococcus aureus) without marked suppression of 16 H. pleuropneumoniae strains. A medium containing 1 micrograms/mL of crystal violet, 1 microgram/mL of lincomycin, 8 micrograms/mL of spectinomycin and 128 micrograms/mL of bacitracin inhibited one E. coli strain and the Gram-positive strains while H. pleuropneumoniae strains were suppressed to a minor degree only. Haemophilus pleuropneumoniae was isolated on the selective medium on three occasions from the nose or pharynx of two out of eight experimentally inoculated pigs. Haemophilus pleuropneumoniae was recovered from the nose of only two pigs at necropsy and from tonsil of one, whereas the lower airways in most pigs and the lung lesions in all pigs were positive. There was no advantage to using the selective medium for the recovery of H. pleuropneumoniae at necropsy from these eight experimentally infected pigs, probably because other bacteria were absent or present in very low numbers in the tissues with H. pleuropneumoniae. The isolation rate on selective medium was higher than the rate on non-selective medium (p less than or equal to 0.1; chi 2 test) when the airways of slaughtered pigs were cultured. This was likely due to a high degree of contamination. Dry swabs placed in tryptone yeast extract with nicotinamide-adenine-dinucleotide gave a significantly higher recovery rate than commercial Culturette swabs in modified Stuart's transport medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Agar↗
PubMed1983

Susceptibility of goats and calves after experimental inoculation or contact exposure to a Canadian strain of Mycoplasma mycoides subsp. mycoides isolated from a goat.

Transmissibility of Mycoplasma mycoides subsp. mycoides infection from experimentally inoculated goats to other goats and calves was studied. Eight goats and six calves were housed in an 18 m2 room. Six of the goats were inoculated endobronchially with strain D44 isolated from a natural case of polyarthritis in Ontario. These six goats died within a week of Mycoplasma septicemia. The two contact goats or the six calves never showed signs of disease and M. mycoides subsp. mycoides was not recovered from these animals. The contact goats and four calves were killed 25 days after exposure. They were all seronegative, M. mycoides subsp. mycoides was not recovered at necropsy and none had pathomorphological changes attributable to this Mycoplasma. The two remaining calves were inoculated endobronchially with 10(9) CFU of strain D44 and observed for 20 days. They never showed signs of disease and did not have significant lesions at necropsy. Both developed a significant serological response to M. mycoides subsp. mycoides, although this organism was not recovered during the experimental period or at necropsy. This study did not provide evidence for transmission of M. mycoides subsp. mycoides from endobronchially inoculated goats to contact goats or calves and endobronchially inoculated calves did not develop pneumonia. This would suggest that the infection of the goat population in Canada with this pathogen would not be a significant threat to the cattle population.

Animals↗
PubMed1983

Epidemiology of Haemophilus pleuropneumoniae infection in pigs: a survey of Ontario Pork Producers, 1981.

Information about factors associated with the spread and the effect of pleuropneumonia was obtained from 418 pork producers in Ontario, who returned a mailed questionnaire. The overall herd prevalence of pleuropneumonia was 23.2%. The prevalence among herds with feeder pigs only was 34.3% and 16% among sow herds. The chance of pleuropneumonia breaking out in a herd was increased with increased traffic of pigs into the herd. The source of supplementary stock had an important effect on the chance of pleuropneumonia occurring. The highest risk resulted from introducing stock from salesbarns and the lowest from stock of health status known to the purchaser and supplied by one breeder only. Mortality, primarily among feeder pigs, and unthriftiness were the major effects of Haemophilus pleuropneumoniae infection. Stress, such as crowding or inclement climatic conditions, was associated with outbreaks of pleuropneumonia. This would suggest that the infection with H. pleuropneumoniae can be subclinical until stress precipitates the disease.

Animal Husbandry↗
PubMed1982

Haemophilus pleuropneumoniae serotyping.

A total of 126 Haemophilus strains isolated from porcine pneumonia were serotyped, using the indirect fluorescent-antibody technique. Of these, 103 were successfully typed within the recognized scheme of serotypes 1 to 5. Eleven strains were antigenically similar but were different from other strains of H. pleuropneumoniae or H. parasuis. These strains are proposed as serotype 7. Eight strains were not identified as serotype 1 when serum against strain Shope 4074 was used, but their identity as type 1 strains was concluded on the basis of complete cross-titrations, using unabsorbed and absorbed sera and indirect fluorescent-antibody and agglutination tests. The type-specific antigen of these strains may have been masked by an additional antigen. A similar situation was believed to exist for four strains which belonged to serotype 5 but did not react with serum against strain K17 (reference strain) in the indirect fluorescent-antibody test. Strain Femø was antigenically different from other H. pleuropneumoniae or H. parasuis strains and was proposed as serotype 6, thus replacing the "minor group" (represented by strain 202), which is of uncertain taxonomical status within the genus Haemophilus.

Agglutination Tests↗
PubMed1982

Evaluation of the complement fixation test for the diagnosis of pleuropneumonia of swine caused by Haemophilus pleuropneumoniae.

Evaluation of diagnostic sensitivity and specificity was based on test results of 346 sera from pigs known to be infected and 139 sera from pigs known not to be infected. All sera were tested with a monospecific antigen (serotype 1) and a polyspecific antigen (serotypes 1-5). The sensitivity of the polyspecific antigen was approximately 85% at serum dilution 1:2 and was significantly higher than the monospecific antigen at all serum dilution levels. The specificity of the two antigen preparations was not significantly different at any dilution and increased from approximately 78% to 1:2 to 100% at 1:128. When pigs from herds with unknown incidence of infection were studied, it was found that a high proportion seroconverted, presumably as a response to subclinical infection. However, the antibody titres waned rapidly. This indicated that seroreaction expresses current or recent infection. Thus, the complement fixation test provides a reliable means of diagnosing pleuropneumonia of pigs and might be useful as a tool to control this disease.

Animals↗
PubMed1982

Biological effects of sonicated suspension and phenol-water extract of Mycoplasma mycoides subspecies mycoides in goats.

Strain Y3343 isolated from a goat with septicemia and polyarthritis was studied. The strain was virulent and induced septicemia, polyarthritis and coagulopathy in two goats. Limulus amebocyte lysate active material was present in plasma, but not in higher titre in inoculated goats. Sonicated mycoplasma material induced a dramatic somatic cell response in the mammary gland of cows and goats and marked clotting of the cows' milk, but it did not clot limulus amebocyte lysate or kill chick embryos. Phenol-water extract clotted limulus amebocyte lysate and induced somatic cell response in cows but not in goats. The phenol-water extract did not kill chick embryos, was not pyrogenic in rabbits or goats, and did not induce generalized Shwartzman reaction or change the leukocyte kinetics in rabbits. It therfore appears that the virulence mechanisms of strain Y3343 can not be explained on the basis of factors with strong endotoxin activity.

Animals↗
PubMed1982

Attempts to produce granulomatous colitis in Boxer dogs with a mycoplasma.

Four of six Boxer dogs with granulomatous colitis had mycoplasmas in the colon and three in the draining lymph node as well. One isolate identical with Mycoplasma strain HRC-689 was inoculated into the colon of five Boxer dogs at eight weeks of age; four controls were inoculated with medium. Animals were killed at two week intervals and examined. The mycoplasma strain produced changes of the colon characterized by lymphocytic infiltration of mucosa, lymphocytic submucosal perivasculitis, and enlargement of colonic lymphoid nodules but granulomatous colitis did not occur. The experimental dogs developed antibodies, and dogs from a kennel with a high prevalence of colitis cases had high antibody titers against strain HRC-689.

Animals↗
PubMed1981

Enumeration of mycoplasmas after acridine orange staining.

Samples of liquid mycoplasma cultures were mixed with equal part of a 0.01% solution of acridine orange and placed on agar plates. The number of fluorescing organisms per field was counted in an epifluorescence microscope at an X 1,000 magnification. When the number of fluorescing organisms per field was related to the number of colony-forming units per milliliter during the growth cycle, highly significant correlation was found in cultures with greater than or equal to 10(6) colony-forming units per ml during the exponential growth phase. The counts were weakly correlated during the stationary phase and not correlated during the death phase. This technique provides a mean to enumerate mycoplasmas in liquid cultures.

Acridine Orange↗
PubMed1981

Toxicity of Haemophilus pleuropneumoniae for porcine lung macrophages, peripheral blood monocytes, and testicular cells.

Strain CM5 of Haemophilus pleuropneumoniae was toxic for porcine lung macrophages in minimum doses of 10(6) colony-forming units per ml and for peripheral blood monocytes at 10(7) colony-forming units per ml. The organism was not toxic for porcine testicular cells in a concentration of 10(8) colony-forming units per ml. Filtered sterile culture supernatant diluted 10(0), 10(-1), and 10(-2) was toxic for porcine pulmonary lavage cells. In dilutions of 10(0) and 10(-1), culture supernatant was toxic for peripheral blood monocytes, and at 10(0) it was toxic for testicular cells. Toxicity associated with bacterial cells was sensitive to heating (60 degrees, 60 min), whereas that of the culture supernatant was heat stable (100 degrees C, 15 min). Swine convalescent serum neutralized supernatant toxicity in dilutions of greater than or equal to 1:320. The findings promote the understanding of the pathogenesis of pleuropneumonia in swine caused by H. pleuropneumoniae.

Animals↗
PubMed1981

Experimental infection of goats, sheep and calves with the large colony type of Mycoplasma mycoides subsp. mycoides.

Goats, sheep and calves were inoculated intravenously with strain Y3343 of the large colony type of Mycoplasma mycoides subsp. mycoides isolated from a goat with polyarthritis. The goats and sheep died of septicemia (one was killed in extremis) within eight days. The goats had leukopenia and granulocytopenia. Coagulopathy was indicated in some goats; the fibrinogen titer, prothrombin and partial thromboplastin times increased with the progress of disease and the number of platelets decreased dramatically in one goat. Goats and sheep had cellulitis at the site of inoculation, pleural hemorrhages, pneumonia, myocarditis, renal infarcts, glomerulitis, adrenal cortical necrosis, enteritis, focal splenic necrosis, polyarthritis and lymphadenitis. Vasculitis and thrombi were seen occasionally, suggesting that vascular changes, perhaps together with coagulopathy, had a role in pathogenesis. One of two experimental calves developed a slight fever, arthritis and minor inflammation of adrenal tissue. Calves seen less susceptible to the mycoplasma organism given intravenously than do goats or sheep.

Animals↗