Description of six new capsular types (29-34) of Streptococcus suis.
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Animals↗
Biomedical subjects
M Gottschalk
Publications and source records attributed to M Gottschalk.
[Gallbladder contractility in early stages of lithogenesis in the lithogenic fed guinea pig].
The main aim of our study was the investigation of gallbladder motility prior to gallstone formation in vivo in guinea pigs fed a lithogenic diet. In a first experiment guinea pigs were fed a lithogenic diet for 5, 15, 30 and 45 days. First gallstones (pigment calculi) appeared after 30 days diet application. The in vitro contractility after lithogenic diet remained unchanged. In a second experimental part the in vivo gallbladder contractility was measured in two experimental animal groups (control group and 21 days lithogenic fed guinea pigs). The isovolumetric pressure rise inside the gallbladder following the intravenous injection of 10(-9) mol/kg body weight ceruletid was the essential contractility parameter (intraluminal basal pressure 5 mm hg). Due to lithogenic feeding of 21 days--that means prior to gallstone formation--the isovolumetric pressure rise was significantly elevated (p < 0.01). Moreover we observed passive distensibility changes of gallbladder muscle due to muscular hyperplasia. The main result of this investigation is the fact that gallbladder muscle in guinea pigs fed a lithogenic diet response to ceruletid application with hypercontractility prior to provable pigment gallstone formation. However gallbladder hypomotility--believed to be a causal factor in cholelithogenesis--was not observed in our experimental conditions.
Animals↗
Recovery of long-chain lipopolysaccharides from liquid culture of Actinobacillus pleuropneumoniae (serotype 5) for ELISA serodiagnosis.
Actinobacillus pleuropneumoniae (serotype 5) long-chain lipopolysaccharides (LC-LPS) may be used as the antigen for ELISA serodiagnosis of pig pleuropneumonia. A method was developed in order to augment the recovery of this antigen compared to the previously described method. In liquid culture, A pleuropneumoniae was shown to produce 2.4 times more cells than in solid medium. LC-LPS could be recovered by phenol extraction of the crude extract. Only 1 additional phenol extraction was required to produce LC-LPS of the same quality as the one obtained with solid-medium-grown cells, as revealed by SDS-PAGE and ELISA using reference sera. From the same volume of crude extract, approximately 8 times more antigen was present in the aqueous phase of the phenol extraction.
Actinobacillus pleuropneumoniae↗
Distribution of Streptococcus suis capsular types in 1994.
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Animals↗
Production and characterization of monoclonal antibodies to Actinobacillus pleuropneumoniae serotype 5b.
Monoclonal antibodies specific for capsular polysaccharide (CPS) and lipopolysaccharide (LPS) of A. pleuropneumoniae serotype 5b were generated by hybridoma cells and selected by indirect ELISA of culture supernatants with purified and structurally defined LPS and CPS preparations and their synthetic conjugates. It was shown in this study that at least one monoclonal antibody, 3B4, presented 100% specificity and recognized all A. pleuropneumoniae serotype 5 field strains tested in a dot-ELISA assay.
Actinobacillus pleuropneumoniae↗
A multifactorial intervention to reduce the risk of falling among elderly people living in the community.
BACKGROUND: Since falling is associated with serious morbidity among elderly people, we investigated whether the risk of falling could be reduced by modifying known risk factors. METHODS: We studied 301 men and women living in the community who were at least 70 years of age and who had at least one of the following risk factors for falling: postural hypotension; use of sedatives; use of at least four prescription medications; and impairment in arm or leg strength or range of motion, balance, ability to move safely from bed to chair or to the bathtub or toilet (transfer skills), or gait. These subjects were given either a combination of adjustment in their medications, behavioral instructions, and exercise programs aimed at modifying their risk factors (intervention group, 153 subjects) or usual health care plus social visits (control group, 148 subjects). RESULTS: During one year of follow-up, 35 percent of the intervention group fell, as compared with 47 percent of the control group (P = 0.04). The adjusted incidence-rate ratio for falling in the intervention group as compared with the control group was 0.69 (95 percent confidence interval, 0.52 to 0.90). Among the subjects who had a particular risk factor at base line, a smaller percentage of those in the intervention group than of those in the control group still had the risk factor at the time of reassessment, as follows: at least four prescription medications, 63 percent versus 86 percent, P = 0.009; balance impairment, 21 percent versus 46 percent, P = 0.001; impairment in toilet-transfer skills, 49 percent versus 65 percent, P = 0.05; and gait impairment, 45 percent versus 62 percent, P = 0.07. CONCLUSIONS: The multiple-risk-factor intervention strategy resulted in a significant reduction in the risk of falling among elderly persons in the community. In addition, the proportion of persons who had the targeted risk factors for falling was reduced in the intervention group, as compared with the control group. Thus, risk-factor modification may partially explain the reduction in the risk of falling.
Accidental Falls↗
Evaluation of a saline boiled extract, capsular polysaccharides and long-chain lipopolysaccharides of Actinobacillus pleuropneumoniae serotype 1 as antigens for the serodiagnosis of swine pleuropneumonia.
A saline boiled extract (SBE), capsular polysaccharides (CPS) and long-chain lipopolysaccharides (LC-LPS) of Actinobacillus pleuropneumoniae serotype 1 have been evaluated in ELISA for the serodiagnosis of swine pleuropneumonia caused by this serotype. Mean optical densities (ODs) obtained with the three antigens using sera from negative herds as well as from animals experimentally and naturally exposed to A. pleuropneumoniae serotypes 1, 9 or 11 were not significantly different. The positive ELISA reaction with anti-serotypes 9 and 11 was unexpected with the CPS, which are supposed to be serotype-specific; LPS, and to a lesser extent proteins, were present in the CPS and appeared to be responsible for this reaction. In addition, sera from animals exposed to a field strain of A. pleuropneumoniae serotype 3 and to Actinobacillus suis presented a significantly lower mean OD (P < 0.001) when LC-LPS were used. Cross-reacting antigens consisted mainly of LPS core-lipid A present in the SBE and CPS. The specificity and the sensitivity of the ELISA were evaluated using three different cut-off values (the OD plus two, three and four times the standard deviation or SD) obtained with 667 negative sera. The diagnostic sensitivity was of 81% with the three antigens and the different thresholds. The diagnostic specificity was of 84, 86 and 88% for the mean plus two, three and four times the SD respectively using the SBE and the CPS, while that obtained with the LC-LPS was of 96, 98 and 99% using the same thresholds. In conclusion, LC-LPS make an easily obtainable antigen and seem to retain the best specificity while minimizing losses of sensitivity.
Actinobacillus Infections↗
Evaluation of long chain lipopolysaccharides (LC-LPS) of Actinobacillus pleuropneumoniae serotype 5 for the serodiagnosis of swine pleuropneumonia.
Long chain lipopolysaccharides (LC-LPS) of Actinobacillus pleuropneumoniae serotype 5 have been evaluated and compared with a crude boiled extract (CBE) in ELISA for the serodiagnosis of swine pleuropneumonia caused by this serotype. The mean optical density (OD) obtained with the LC-LPS in ELISA using sera from negative herds as well as from animals experimentally and naturally exposed to A. pleuropneumoniae serotype 5 was not significantly different from that obtained with the CBE. However, sera from animals exposed to serotypes of A. pleuropneumoniae other than serotype 5 presented a significantly lower mean OD (P < 0.05) when the LC-LPS was used. As a consequence, it was demonstrated that a high percentage of non-specific cross-reactions were eliminated, without losing specificity. The specificity and the sensitivity of the LC-LPS- and CBE-ELISA were evaluated using two different cut-off values (the OD plus two and three standard deviations) (SD) obtained from 593 sera from negative herds. The LC-LPS appeared a more suitable antigen than the CBE, since the sensitivity and the specificity (obtained with both thresholds) were statistically improved (P < 0.01). A threshold of 0.244 (mean OD plus three SD) for the LC-LPS-ELISA seemed more suitable, since a sensitivity of 79% and a specificity of 97% was achieved. Nevertheless, it may be advisable to keep a buffer range (OD between 0.194 and 0.243) and to consider sera presenting values within this range as suspicious. In the present study, the complement fixation test presented a high specificity (97%) and a very low sensitivity (47%). A herd with animals presenting ELISA positive and CFT negative results in serology, along with the absence of suggestive lesions should not be considered as a non-infected herd.
Actinobacillus Infections↗
Lipopolysaccharides of Actinobacillus pleuropneumoniae (serotype 1): a readily obtainable antigen for ELISA serodiagnosis of pig pleuropneumonia.
A saline extract of boiled-formalinized whole cells of Actinobacillus pleuropneumoniae serotype 1 reference strain (Shope 4074) has been previously used as the antigen in an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of swine pleuropneumonia. Phenol extraction of this crude extract permitted the recovery of LPS with long O-chains in the aqueous phase. This antigen was shown to be specific for serotypes 1, 9 and 11 as they all possess structurally similar O-chains. Immunoblotting was used to identify the fraction present in the crude extract of strain 4074 responsible for cross-reactions observed in ELISA with a serum raised against a serotype 3 strain of A. pleuropneumoniae. The specific reactions in ELISA were shown to be associated with long O-chain LPS and the cross-reactions to LPS with short O-chains. LPS seem to be an important antigen for A. pleuropneumoniae serotype 1 as all homologous sera tested reacted with it. This antigen is easily recovered from the crude extract and it can be used in minute amounts (1-6 micrograms) for ELISA serodiagnosis of pig pleuropneumonia.
Actinobacillus Infections↗
An impairment and disability assessment and treatment protocol for community-living elderly persons.
BACKGROUND AND PURPOSE: Falls and immobility are common among community-living elderly persons and result from the accumulated effect of multiple impairments and disabilities as well as environmental hazards. We developed and tested a simple assessment and intervention protocol for use in prevention and treatment programs among community-living elderly persons. This article presents the components of the assessment; the criteria for intervening on diagnosed impairments contributing to falls and immobility; and the recommended treatments, environmental adaptations, training, and exercise programs targeting the diagnosed problems. SUBJECTS: A convenience sample of 11 residents of a senior housing complex who were cognitively intact and ambulatory were chosen for reliability testing of the assessment protocol. A random sample of 20 of the 153 elderly subjects involved in a multiple risk factor trial for fall prevention then were chosen to test the reliability of the intervention recommendations. METHODS: The assessment and intervention protocol was developed by a consensus approach among a group consisting of a geriatric physician, two nurses, and three physical therapists. The interrater reliability of both the assessment and the intervention components of the protocol was determined by comparing the results of two of the study physical therapists. RESULTS: There was excellent agreement in assessment and intervention results by the two physical therapists. The assessment required approximately 45 minutes to complete, suggesting it is feasible for use in clinical practice. CONCLUSION AND DISCUSSION: A simple, standardized assessment and intervention protocol, such as the one described, could aid physical therapists in evaluating and treating community-living elderly persons by improving communication among care providers, providing better documentation for reimbursers, and ensuring a direct linkage between assessment and intervention, thus simplifying the development of a treatment plan for elderly persons with complicated or multiple impairments. The ultimate test of this assessment and intervention protocol will be ascertainment of the goal of the protocol, namely a reduction in falls and improvement in mobility among multiply and chronically ill elderly persons.
Accidental Falls↗
High-molecular-mass lipopolysaccharides are involved in Actinobacillus pleuropneumoniae adherence to porcine respiratory tract cells.
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The major adhesin of A. pleuropneumoniae has been identified as the lipopolysaccharides (LPSs) (M. Bélanger, D. Dubreuil, J. Harel, C. Girard, and M. Jacques, Infect. Immun. 58:3523-3530, 1990). Using immunoelectron microscopy and flow cytometry, we showed in the present study that LPSs were well exposed at the surface of this encapsulated microorganism. Immunolocalization with porcine lung and tracheal frozen sections showed that extracted LPS bound to the lung mesenchyme and vascular endothelium and to the tracheal epithelium, respectively. Inhibition of adherence of A. pleuropneumoniae with extracted LPS was also performed with lung and tracheal frozen sections. Acid hydrolysis of LPS revealed that the active component of LPS was not lipid A but the polysaccharides. LPSs from A. pleuropneumoniae serotypes 1 and 2 were separated by chromatography on Sephacryl S-300 SF, in the presence of sodium deoxycholate, according to their molecular masses. The adherence-inhibitory activity was found in the high-molecular-mass fractions. These high-molecular-mass fractions contained 2-keto-3-deoxyoctulosonic acid and neutral sugars, and they were recognized by a monoclonal antibody directed against A. pleuropneumoniae O antigen but not recognized by a monoclonal antibody against capsular antigen.
Actinobacillus pleuropneumoniae↗
Genomic relatedness among reference strains of different Streptococcus suis serotypes.
Hybridization studies using genomic DNA and a rDNA probe revealed genetic relatedness among reference strains of different Streptococcus suis serotypes. Although most serotype 22 isolates are biochemically atypical, the reference strain of capsular type 22 is genetically related to other S. suis serotypes, but not to Streptococcus pneumoniae. Using DNA digested with BamHI and BglII for ribotyping, some S. suis reference strains had common patterns, but this analysis mainly revealed variations in patterns of S. suis strains of different serotypes.
Blotting, Southern↗
Distribution of Streptococcus suis capsular types in 1993.
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Animals↗
Evaluation of the antibody response in pigs vaccinated against Streptococcus suis capsular type 2 using a double-antibody sandwich enzyme-linked immunosorbent assay.
A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was standardized for the detection of specific antibodies following vaccination with Streptococcus suis capsular type 2 bacterins. No statistically significant increase of antibody titers was detected in vaccinated piglets compared to the nonvaccinated control group, even if a minority of piglets demonstrated an important postvaccinal response. Three of four vaccinated sows showed a low antibody response to vaccine and specific immunity was detected in piglets of only one litter of these three sows. Passive protection studies showed that none of the sera from vaccinated piglets were protective for mice whereas serum obtained from hyperimmunized pigs gave protection.
Animals↗
Yale FICSIT: risk factor abatement strategy for fall prevention.
Based on finding a strong association between number of impairments and risk of falling in earlier studies, Yale FICSIT investigators are conducting an intervention trial comparing the effectiveness of usual care plus social visits (SV) and a targeted risk abatement intervention (TI) strategy in reducing falls among at risk community elderly persons. Subjects include members of a participating HMO who are > or = 70 years of age, cognitively intact, not terminally ill, not too physically active, and possess at least one fall risk factor. The targeted risk factors include postural hypotension; sedative use; at least four targeted medications; upper and lower extremity strength and range of motion impairments; foot problems; and balance, gait, and transfer dysfunctions. The interventions include medication adjustments, behavioral change recommendations, education and training, and home-based exercise regimens targeting the identified risk factors. The interventions are carried out by the study nurse practitioner and physical therapist in TI subjects' homes. The SV subjects receive a comparable number of home visits as the TI subjects during which a structured life review is performed by social work students. The primary outcome is occurrence of falls during the 12-month followup. Secondary outcomes include change in mobility performance and fall-related efficacy.
Accidental Falls↗
Use of polyvalent coagglutination reagents for serotyping of Streptococcus suis.
Polyvalent coagglutination reagents (PRs) have been evaluated for the serotyping of Streptococcus suis. Monovalent antisera produced against 28 S. suis reference strains have been grouped to obtain five different pools. A total of 249 field isolates previously identified and belonging to different serotypes were tested with PRs prepared by two different procedures: (i) monovalent coagglutination reagents were individually prepared and mixed in equal proportions, and (ii) antisera were mixed in equal proportions before the addition of the Staphylococcus aureus suspension. Only antisera tested by a tube agglutination test with 2-mercaptoethanol and presenting titers of 1:32 or higher were used. Results obtained with PRs prepared by both procedures were similar, and there was a very good correlation between the capsular type of the isolate and the reaction obtained with PRs. Thus, from a practical viewpoint, it is suggested that PRs be prepared by the first procedure. To isolates, were tested in parallel with both the PRs and the monovalent coagglutination reagents over a 1-year period. Ninety-nine percent of the typeable and all of the untypeable isolates were correctly identified. Serotyping with PRs is suggested to be a very useful and reliable screening procedure, particularly when a large number of S. suis isolates have to be serotyped. In addition, the choice of antisera to be included in a given pool is facultative and should be oriented to the needs of a region or a country.
Agglutination Tests↗
Detection of Actinobacillus pleuropneumoniae in the porcine upper respiratory tract as a complement to serological tests.
Attempts were made to isolate Actinobacillus pleuropneumoniae from the nasal cavities and tonsils of 442 healthy pigs from 15 herds. Samples were streaked onto different media formulations. Serum samples were assayed for antibodies to A. pleuropneumoniae by enzyme-linked immunosorbent assay and complement fixation test. Actinobacillus pleuropneumoniae was isolated from the nasal cavities only in 24 pigs, from tonsils only in 90 pigs, and from both the nasal cavities and the tonsils in 11 pigs. A PPLO medium supplemented with lincomycin, bacitracin and crystal violet allowed recovery of A. pleuropneumoniae from more animals than a tryptic soy agar medium from both sites. Incubation of plates in an enriched CO2 atmosphere did not affect the recovery rate. Actinobacillus pleuropneumoniae belonging to serotypes 1, 2, 3, 5a, 5b, 7, 8, 10 and 12 were isolated, and, in several herds, more than one serotype were recovered. Serotypes of A. pleuropneumoniae were isolated from nine herds which were found seronegative to these. The isolation of A. pleuropneumoniae from the upper respiratory tract can be useful for detection of carrier pigs and complements serological screening.
Actinobacillus Infections↗
A sandwich enzyme-linked immunosorbent assay for the detection of Streptococcus suis.
A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection and the identification of Streptococcus suis capsular types 1, 2, 1/2, 3 and 22. The specificity of this test was first evaluated using reference strains of S. suis capsular types 1 to 28 and 1/2 as well as 15 different bacterial species susceptible to be isolated from swine. The ELISA developed was very specific for capsular types 1, 3 and 22 but it could not discriminate between capsular types 2 and 1/2. In a second study, S. suis isolates from 328, 493, 368 and 76 diseased pigs were used to detect capsular types 1, 2 or 1/2, 3 and 22 respectively. The relative specificity and sensitivity varied between 98% and 100%. The ELISA results were in excellent agreement with the standard techniques (biochemical tests, coagglutination and capsular reaction tests) in detecting both positive and negative strains. Kappa values were 0.80, 0.99, 0.97 and 1.00 for detecting S. suis capsular types 1, 2 or 1/2, 3, and 22 respectively. To evaluate the relative-sensitivity of the test, primary cultures from 73 diseased pigs and tissue samples from 67 diseased pigs were used directly for detecting these capsular types. With primary cultures, the relative specificity and sensitivity (95.9% and 91.6% respectively) remained high and the test was very suitable (Kappa = 0.87). The ELISA using tissue samples gave a good specificity (97.6%), a moderate sensitivity (62.5%) and a low agreement with standard tests (Kappa = 0.64).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗