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S Rosendal

Publications and source records attributed to S Rosendal.

At least 37 records · Page 2Linked to original sources
PubMed1993

Association of microbiologic flora with clinical, endoscopic, and pulmonary cytologic findings in foals with distal respiratory tract infection.

Undifferentiated distal respiratory tract disease (nasal discharge, cough, pneumonia) in foals (1 to 8 months old) is a burdensome economic problem on breeding farms; yet, the infective agents associated with these episodes have not been well described. Possible causes of these episodes of illness were investigated by culturing specimens of proximal and distal airways of clinically diseased foals (n = 101), prior to any treatment, for aerobic and anaerobic bacteria and viruses (rhinoviruses, equine arteritis virus, equine herpesvirus subtype 1 [EHV-1], influenza virus, and adenovirus). Pairs of sera (n = 47) were examined for antibodies to influenza A virus, equine subtypes 1 and 2, EHV-1, and adenovirus antigens, and sera obtained from foals during acute infection were examined for antibodies (by agar gel immunodiffusion [AGID]) to equi factor antigens of Rhodococcus equi. Viruses were not isolated from the proximal (swab) or distal (bronchial lavage) airway specimens in foals, and only 2 of 47 randomly selected foals seroconverted to EHV-1. Serotiters to the other viruses were low and frequently decreasing between samples, which was compatible with maternally derived antibody. Streptococcus zooepidemicus was the predominant isolate from bronchial lavage specimens (88/101 cases), accompanied by alpha-hemolytic streptococci (8 cases), Bordetella bronchiseptica (13 cases), Staphylococcus epidermidis (9 cases), and other organisms in lesser frequency. Only Str zooepidemicus was recovered significantly (P < 0.05) more often in cases than in controls. The AGID test was found useful to detect foals with presumed exposure to R equi, but positive tests results did not correspond well with bacterial culture results; positive AGID results were recorded in 34% of culture-negative foals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Experimental infection of severe combined immunodeficient beige mice with Mycobacterium paratuberculosis of bovine origin.

Severe combined immunodeficient beige mice were inoculated orally and intraperitoneally with a bovine strain of Mycobacterium paratuberculosis to explore their potential as laboratory animal models in the study of paratuberculosis (Johne's disease). Control animals were similarly inoculated with heat-killed M. paratuberculosis. In the mice inoculated intraperitoneally, focal lesions and acid-fast bacilli were first detected in the livers (4 weeks postinfection) and later in the spleens and intestines of the test but not the control animals. No bacteria were seen in the hearts, kidneys, or lungs. At 12 weeks postinfection, all test mice had significant losses in body weight compared with those in controls (P less than 0.05), a characteristic sign of bovine paratuberculosis. Tumor necrosis factor alpha was not detected in the serum. Histologic lesions were seen in the intestines, livers, and spleens of the animals in the orally inoculated test group after 26 weeks of infection. Our results suggest that the severe combined immunodeficient beige mouse may be a useful model for the investigation of paratuberculosis and cachexia and the evaluation of antimycobacterial drugs.

Animals↗
PubMed1992

Protective local and systemic antibody responses of swine exposed to an aerosol of Actinobacillus pleuropneumoniae serotype 1.

The isotype-specific antibody responses in serum and in nasal and pulmonary lavage fluids of swine following aerosol immunization with an attenuated strain of Actinobacillus pleuropneumoniae serotype 1, strain CM5A, was investigated. The presence of immunoglobulin G (IgG), IgA, and IgM with specificities for capsular polysaccharide, lipopolysaccharide, and hemolysin was determined by enzyme-linked immunosorbent assay by using purified antigens. Strain CM5A induced serum antibodies of each isotype to the three antigens. The serum antibody response was sustained and typical of persistent antigenic stimulation. The specific IgM response decreased and the specific IgG response increased after challenge with strain CM5. IgA specific for the three antigens was detected in nasal secretions from all immune pigs, whereas specific IgG could only be detected in samples contaminated with blood. Both IgA and IgG specific for each of the antigens were detected in pulmonary lavage samples. There was no significant increase in specific IgA in nasal secretions; however, levels of lipopolysaccharide-specific and hemolysin-specific IgG and IgA in pulmonary secretions rose after aerosol challenge with strain CM5. Passive transfer of immune swine serum resulted in protection against pleuropneumonia and in levels of specific serum IgG which were similar to those in actively immunized pigs. It is concluded that specific serum IgG antibodies are important in protection from porcine pleuropneumonia.

Actinobacillus pleuropneumoniae↗
PubMed1992

Association of the RTX proteins of Actinobacillus pleuropneumoniae with hemolytic, CAMP, and neutrophil-cytotoxic activities.

The immunoglobulin G from a monospecific rabbit antiserum to the 110-kDa RTX hemolysin of Actinobacillus pleuropneumoniae serotype 1 was used to determine that the related RTX proteins in isolates from serotypes 2 to 12 were also responsible for the hemolytic, CAMP, and neutrophil-cytotoxic activities produced by this bacterium. These proteins share common neutralizing epitopes.

Actinobacillus pleuropneumoniae↗
PubMed1992

Changes in the bacterial flora of the upper and lower respiratory tracts and bronchoalveolar lavage differential cell counts in feedlot calves treated for respiratory diseases.

Serial nasopharyngeal swab and bronchoalveolar lavage cultures were used to estimate changes in the bacterial flora of the respiratory tracts of calves during the first month after arrival in the feedlot. Bronchoalveolar lavage (BAL) differential cell counts served to evaluate pulmonary inflammatory changes during this period. Two groups of calves were studied, one consisting of clinically normal controls (n = 60), the other, of cases (n = 59) which received treatment for respiratory disease (penicillin +/- trimethoprimsulfadoxine). A variety of organisms, including Pasteurella multocida, Pasteurella haemolytica, Haemophilus somnus, Mycoplasma bovis and Mycoplasma bovirhinis, were present in the upper and lower airways of both groups during the postarrival period. With the exception of M. bovis, an overall decline in the prevalence of these organisms was observed during the course of the study. In cases, there was a marked decrease in the number of Pasteurella spp. and H. somnus isolates immediately following treatment. For the Pasteurella spp., however, this effect was shortlived as they often appeared to recolonize the respiratory tract within eight days of terminating antimicrobial therapy. Treatment did not appear to affect the frequency of isolating M. bovis. Its prevalence, in both groups of calves, increased to levels approaching 100% during the course of the study. All Pasteurella spp. isolates were tested for susceptibility to several commonly used antimicrobials. Resistance was only evident among P. haemolytica isolated from cases and in every instance this was to a combination of penicillin, ampicillin and tetracycline. Significantly more isolates were resistant after treatment than before. There were BAL differential cell count abnormalities indicative of inflammation in both cases and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Measurement of the cytotoxic effects of different strains of Mycoplasma equigenitalium on the equine uterine tube using a calmodulin assay.

The cytopathic effects induced by five strains of Mycoplasma equigenitalium for cells of equine uterine tube explants were tested by measuring changes in cellular and extracellular concentrations of calmodulin (CaM). Calmodulin concentrations in samples of total homogenate (TH) and total homogenate supernates (THS) of the infected equine uterine tube explants were significantly lower than respective measurements on noninfected controls. In tissue culture medium fractions (TCM) of some infected explants, CaM concentrations were significantly higher than noninfected controls (p > 0.95). The results suggest that M. equigenitalium colonization on ciliated cells of the equine uterine tube can affect the permeability of the cell membrane leading to leakage or release of CaM during cell breakdown. Measurement of CaM concentrations in samples of TH revealed significant differences in the cytotoxic effects induced by different strains of M. equigenitalium on the equine uterine tube (EUT). The data suggests that some strains of M. equigenitalium may have a role in reproductive failure in the mare. In addition comparisons of the means of the concentrations of CaM in samples of TH or THS in EUT explants from four mares in the follicular and four in the luteal phase of the estrous cycle were found to be not significantly different.

Animals↗
PubMed1992

Cytological findings in bronchoalveolar lavage fluid from feedlot calves: associations with pulmonary microbial flora.

Samples obtained by bronchoalveolar lavage (BAL) were used to evaluate pulmonary cytology in 59 feedlot calves with clinical signs of respiratory disease (cases) and 60 clinically normal comparison calves (controls). Many calves in both case and control groups had inflammatory changes in the lower respiratory tract, as determined by changes in proportions in the BAL differential cell count. Approximately 35% of cases and 40% of controls showed a normal differential cell count. It therefore appeared that the criteria used to select cases for treatment, which were similar to those often used in the field, were poor predictors of lower respiratory tract disease. A positive association was found between an increased proportion of neutrophils in BAL fluid and isolations of Pasteurella multocida and Mycoplasma bovis from BAL fluid.

Animals↗
PubMed1992

Mycoplasma felis pleuritis in two show-jumper horses.

Mycoplasma felis was identified as the cause of acute pleuritis in 2 show-jumping horses. The pleural exudate was proteinaceous, contained large numbers of neutrophils, and had a markedly increased lactate concentration. M. felis was isolated in pure culture from pleural fluid. Rising serum antibody titers to M. felis as well as a precipitous decline in titers to equine influenza virus were demonstrated in both horses. Pleural effusion in both horses and a pneumothorax detected in one of the horses resolved following a single drainage of pleural fluid and intravenous fluid, antibiotic, and analgesic therapy.

Animals↗
PubMed1991

Endothelial cytotoxicity of Actinobacillus pleuropneumoniae.

The cytotoxicity of Actinobacillus pleuropneumoniae serotype 1 strain CM5 for porcine and bovine endothelial cells in vitro, was dose-dependent. This strain and its attenuated and avirulent substrain CM5A were equally cytotoxic. The cytotoxicity observed during five hours of exposure of endothelial cells to bacterial products was abolished if the bacteria were inactivated by heat or sonication. Exposure of the endothelial cells for five hours to 100 and 200 micrograms of purified lipopolysaccharide resulted in a partial cytotoxicity only, which was not enhanced in the presence of fresh guinea pig serum. The cytotoxicity of viable bacteria could be neutralised by a polyclonal rabbit antiserum to the purified 104kD haemolysin. A bacteria-free supernate of a culture of strain CM5 had both haemolytic and cytotoxic activity. The haemolytic activity could be neutralised completely by the anti-serum to the 104kD haemolysin, whereas the cytotoxic activity was only partially neutralisable. Hence A pleuropneumoniae is cytotoxic for endothelial cells and this cytotoxicity is possibly mediated by the 104kD haemolysin.

Actinobacillus↗
PubMed1991

Immunological characterization of breakdown peptides of the 104 kilodalton hemolysin of Actinobacillus pleuropneumoniae serotype 1.

The 104 kilodalton (kDa) hemolysin of Actinobacillus pleuropneumoniae serotype 1, strain CM-5 was precipitated from RPMI-1640 culture supernatant using ammonium sulfate to 80% saturation. In immunoblots, a rabbit polyclonal antiserum against the 104 kDa hemolysin protein, recognized not only the original 104 kDa monomeric form of the hemolysin but other proteins in the crude antigen mixture ranging in molecular mass from 43 to greater than 125 kDa. The antiserum was able to crosslink these proteins to active hemolysin in RPMI-1640 culture supernatant resulting in bands of hemolysis in blood agar used in a contact assay. Corresponding to these bands of hemolysis, denatured peptides with molecular masses of 51, 85, 104 and greater than 125 kDa were excised and injected into rabbits. In immunoblots, the resultant antibodies recognized the injected peptide and the monomeric 104 kDa protein. However, only the rabbit antisera produced against the 104 and 125 kDa proteins contained antibodies which neutralized the active 104 kDa hemolysin in culture supernatant. These results indicate that (i) the 104 kDa protein hemolysin can exist in a higher molecular weight aggregate (greater than 125 kDa) but can also break down to peptides which have molecular masses smaller than the 104 kDa parent molecule and (ii) while several epitopes are present in the hemolysin molecule, there seems to be a restricted number of antigenic determinants responsible for inducing neutralizing antibodies and these seem to reside only in the 104 kDa parent molecule. This may have consequences, in terms of vaccine development, for the control of pleuropneumonia in swine herds.

Actinobacillus pleuropneumoniae↗
PubMed1991

Serological response to Actinobacillus pleuropneumoniae serovar 7 infection in a commercial pig herd.

Serological responses to Actinobacillus pleuropneumoniae serovar 7 infection were monitored by enzyme-linked immunosorbent assay in a cohort of 66 pigs between weaning and market. Antibody concentrations were high (63/65 seropositive) at 4 weeks of age but declined to low levels from 8 to 12 weeks. Mean antibody concentrations rose significantly (p less than 0.001) between 12 and 23 weeks. Between 8 and 23 weeks of age, 33 (51.5%) of 64 surviving pigs seroconverted to A pleuropneumoniae serovar 7. Peak antibody concentrations in the seroconverting pigs usually (28/33) occurred at 23 weeks. Seroconversion to A pleuropneumoniae during the grower/finisher phase was not significantly associated (p greater than 0.05) with passive antibody concentrations at 4 weeks of age, lack of vaccination against Mycoplasma hyopneumoniae, or weaning weight. Pleuropneumonic lesions were evident at slaughter in 4 (6.3%) of 64 pigs. A pleuropneumoniae serovar 7 was isolated from 2 of 4 lungs with pleuropneumonia and from another lung with lesions considered typical of enzootic pneumonia.

Actinobacillus Infections↗
PubMed1991

Calcium binds to and is required for biological activity of the 104-kilodalton hemolysin produced by Actinobacillus pleuropneumoniae serotype 1.

Actinobacillus pleuropneumoniae serotype 1, strain Shope 4074, was grown on agar medium containing 10 mM Ca2+ and under Ca2+ limiting conditions by addition of 2 and 5 mM EGTA to the growth medium. Hemolysis of washed bovine erythrocytes was observed from the culture grown in Ca2+ excess but not from the two cultures where Ca2+ was chelated from the growth medium by using EGTA. However, the hemolytic activity of these latter two cultures could be restored if 10 mM Ca2+ was added to the dilution buffer. This restored hemolytic activity could be neutralized with a rabbit homologous polyclonal antiserum specific for the 104-kDa hemolysin of serotype 1 but not with preimmune serum from the same rabbit. Stained SDS-PAGE gels and immunoblots showed the 104-kDa protein hemolysin in fractions from each of the three growth conditions. Thus, the restored hemolytic activity was associated with the 104-kDa protein in the three cultures. In addition, the 104-kDa protein, when electroblotted onto nylon membranes, bound 45Ca, indicating that the molecule has binding sites for Ca2+. The results indicate that Ca2+ is required for the biological activity of the 104-kDa hemolysin of A. pleuropneumoniae serotype 1.

Actinobacillus↗
PubMed1991

Binding of tumor necrosis factor alpha to activated forms of human plasma alpha 2 macroglobulin.

We tested the hypothesis that human plasma alpha 2 macroglobulin (alpha 2M) is a latent binding glycoprotein for human tumor necrosis factor alpha (TNF-alpha). Human recombinant 125I-TNF-alpha was incubated for 2 hours (37 degrees C) with purified native alpha 2M and with alpha 2M that was modified by reaction with methylamine or various proteinases. 125I-TNF-alpha/alpha 2M complexes were detected by nondenaturing polyacrylamide gel electrophoresis after autoradiography or by liquid chromatography on Superose-6. 125I-TNF-alpha bound strongly but noncovalently to alpha 2M-plasmin and alpha 2M-methylamine. There was minimal binding of 125I-TNF-alpha to native alpha 2M, alpha 2M-trypsin, or alpha 2M-thrombin. A 10(6) molar excess of porcine heparin did not reduce the binding of 125I-TNF-alpha to alpha 2M-methylamine or alpha 2M-plasmin. alpha 2M-plasmin or alpha 2M-methylamine added to human plasma or serum preferentially bound 125I-TNF-alpha in the presence of native alpha 2M. 125I-TNF-alpha also bound to 'fast' alpha-macroglobulins in methylamine-reacted human, rat, mouse, swine, equine, and bovine plasma. However, TNF-alpha, preincubated with either alpha 2M-plasmin or alpha 2M-methylamine, remained a potent necrogen for cultured L929 cells. Purified 125I-TNF-alpha/alpha 2M-plasmin complex injected intravenously in CD-1 mice rapidly cleared from the circulation, unless the alpha 2M-receptor pathway was blocked by coinjection of excess alpha 2M-trypsin. These findings demonstrate that alpha 2M is a latent plasmin-activated binding glycoprotein for TNF-alpha and that TNF-alpha/alpha 2M-plasmin complexes can be removed from the circulation by the alpha 2M-receptor pathway. This suggests that alpha 2M may be an important regulator of the activity and distribution of TNF-alpha in vivo.

Animals↗
PubMed1991

The microbial flora of the respiratory tract in feedlot calves: associations between nasopharyngeal and bronchoalveolar lavage cultures.

The upper and lower respiratory tracts of 59 feedlot calves with clinical signs of naturally occurring respiratory disease (cases) and 60 comparison (control) animals were cultured before treatment, using nasopharyngeal swabs (NPS) and bronchoalveolar lavage (BAL). The most prevalent organisms were Pasteurella multocida and Mycoplasma bovis. Isolations of P. multocida from NPS and BAL fluid were found to be significantly associated with morbidity (p less than or equal to 0.05), but the frequency with which other organisms were isolated from the nasopharynx and lungs was similar in cases and controls. There was evidence of moderate agreement between NPS and BAL isolates at the individual calf level using the kappa statistic, (range of kappa values = 0.47-0.61) but the variability of the kappa statistics was large. Therefore, in an individual calf NPS cultures did not accurately predict BAL cultures. The NPS and BAL culture results were quite similar at the group level, however.

Animals↗
PubMed1991

Cross protection among Haemophilus parasuis strains in immunized gnotobiotic pigs.

In an attempt to establish if cross protection can be induced by different strains of Haemophilus parasuis, three groups of 12 gnotobiotic pigs were immunized each with an aluminum hydroxide adsorbed whole cell bacterin of one of three H. parasuis strains. Two weeks later, four pigs within each vaccinated group were challenged with aerosols of live cultures of each of the three test strains and observed for response. Two virulent strains V1 and V2 protected all the vaccinated pigs, while all nonvaccinated controls succumbed to Glasser's disease when challenged with these strains. Vaccination with strain LV (of low virulence) protected the pigs against challenge with strain V2, but not against strain V1. Strain LV did not cause disease in the immunized animals and only in one of ten nonimmunized pigs upon second challenge. The results suggest that strains may differ in antigenicity and that virulence and immunoprotection are positively related. Strains to be used in commercial vaccines should therefore be selected carefully. Antibodies detected in the sera of vaccinated pigs were to outer membrane proteins of the bacteria, but not to lipopolysaccharides or capsular polysaccharides. This would suggest that for gnotobiotic pigs outer membrane proteins are more immunogenic than lipopolysaccharide or capsular antigens. Further work is needed to determine if outer membrane proteins also contribute protective immunogens.

Animals↗
PubMed1990

Phenotypical and genotypical characteristics of paired isolates of Pasteurella multocida from the lungs and kidneys of slaughtered pigs.

Twenty-eight strains of Pasteurella multocida were isolated from 12 Danish and two Canadian abattoir pigs. Fourteen strains were isolated from pulmonary inflammatory lesions, and 14 strains were isolated from kidneys of the same animals. Phenotypical and genotypical characteristics of the strains were evaluated with a view to determine if P. multocida isolated from kidneys might have been disseminated from the lungs. All field strains were capsular type A. The biochemical reactivity in the API-20E and API-ZYM commercial test-kits was uniform with the exception of alpha-glucosidase activity which was present at low levels in only ten of the strains. One strain was markedly serum sensitive, six strains slightly sensitive and the remaining were serum resistant. The peptide patterns obtained by polyacrylamide gel electrophoresis of whole cell proteins of the strains were very uniform with the exception of differences in intensity of bands in the 38 and 34 kD regions. The pattern of oligonucleotides obtained after electrophoresis of total genomic DNA digested with BamHI showed that the paired isolates had identical patterns in eight of the 14 animals. It is therefore likely that isolates from kidney lesions represent blood borne dissemination from primary pulmonary lesions.

Abattoirs↗
PubMed1990

Humoral antibody response and protective immunity in swine following immunization with the 104-kilodalton hemolysin of Actinobacillus pleuropneumoniae.

Five cesarean-derived, colostrum-deprived pigs were given three adjuvant-supplemented subcutaneous and one intravenous injection of the purified 104-kDa hemolysin from serotype 1 Actinobacillus pleuropneumoniae CM-5. Six control animals received phosphate-buffered saline only. Five of six control pigs died within 24 h after challenge. The sixth control pig was moribund and euthanized after 48 h. All six pigs had pleuropneumonia, and A. pleuropneumoniae was isolated from all six lungs. None of the vaccinated pigs died as a result of challenge. After being euthanized, two pigs in this group had no lung lesions but three had chronic pleuropneumonia involving 10, 20, and 40% of the lung tissue. A. pleuropneumoniae was isolated from lung lesions of these three animals but not from the two pigs without lesions. The prechallenge hemolysin-neutralizing antibody titers in the vaccinated pigs were 1:10,900, 1:10,600, 1:4,800, 1:3,900, and 1:3,000, in order of increasing lung involvement. None of the control pigs had neutralizing antibodies. Enzyme-linked immunosorbent assay (ELISA) antibodies to capsule, lipopolysaccharide, and hemolysin were not detected in serum samples collected from the control pigs. In the vaccinated group, prechallenge sera did not contain ELISA antibodies to capsule or lipopolysaccharide. ELISA antibodies to the hemolysin were detected only in the prechallenge and postchallenge serum samples. These results indicate that pigs immunized with the 104-kDa hemolysin of serotype 1 A. pleuropneumoniae are protected against challenge with virulent bacteria. The association between neutralizing antibodies and protection indicates indirectly that the hemolysin is an important virulence factor.

Actinobacillus↗