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J D Klinger

Publications and source records attributed to J D Klinger.

46 records · Page 3Linked to original sources
PubMed1983

Protective immunization against chronic Pseudomonas aeruginosa pulmonary infection in rats.

Rats were immunized systemically with various doses of the polyvalent Pseudomonas aeruginosa vaccine PEV-01. After a series of two or three doses (25 to 50 micrograms each) at 8- to 11-day intervals, animals were challenged intratracheally by the agarose bead technique with a serotype 5 P. aeruginosa strain at periods of 9 to 42 days. Immunized animals developed circulating antibodies (primarily immunoglobulin M) against vaccine components at levels significantly higher than challenged, nonimmunized controls (P less than 0.005). Eight to ten days postinfection, histological sections of lungs from immunized animals showed only minimal inflammation associated with infectious foci (agarose beads) as compared with the extensive pathological changes of airways and parenchyma seen in infected nonimmunized control animals. However, no significant reduction in bacterial numbers was observed. Such protection lasted at least 6 weeks after the final immunization. It is speculated that the vaccine may contain components of cell surface proteins and virulence exoproducts.

Animals↗
PubMed1983

In vitro inhibition of lymphocyte proliferation by Pseudomonas aeruginosa phenazine pigments.

Human lymphocyte proliferation is inhibited in vitro in the presence of killed Pseudomonas aeruginosa or cell-free P. aeruginosa culture supernatants. A comparison of culture supernatants obtained under similar conditions from Staphylococcus aureus, Escherichia coli, P. aeruginosa, and Pseudomonas cepacia strains demonstrated that all P. aeruginosa supernatants were strongly inhibitory, whereas supernatants from other bacteria were mildly inhibitory or not inhibitory at all. These P. aeruginosa inhibitors prevent proliferative responses of resting cells upon mitogen activation and decrease [3H]thymidine uptake when added to human lymphocytes undergoing active proliferation in culture. The inhibitory effect is reversible and not due to cytotoxicity. Most of the inhibitory activity present in crude supernatants was detected in ultrafiltrates of molecular weights below 2,000. Purified P. aeruginosa pyocyanine, a low-molecular-weight phenazine pigment present in culture supernatant, was strongly inhibitory for lymphocyte proliferation. Extraction of pyocyanine and phenazine pigments from inhibitory P. aeruginosa supernatants eliminated their inhibitory activity. Inhibitors were recovered from reverse-phase chromatographic cartridges by both chloroform and methanol elution, indicating that pyocyanine and other phenazine pigments present in P. aeruginosa supernatants are responsible for the inhibition of lymphocyte proliferation. In addition to the identification of phenazine pigments as lymphocyte proliferation inhibitors, several criteria ruled out major contributions of P. aeruginosa polysaccharide, exotoxin A, and proteases to this phenomenon. P. aeruginosa strains selected for very low protease production or for very low exotoxin A production produced supernatants as inhibitory for lymphocyte proliferation as supernatants obtained from clinical P. aeruginosa isolates. Purified P. aeruginosa lipopolysaccharide and protease preparations failed to induce reversible lymphocyte proliferation inhibition. Finally, heat inactivation of P. aeruginosa supernatants at 100 degrees C for 60 min inactivates exotoxin A and proteases but produced only a moderate decrease of the inhibitory activity for lymphocyte proliferation.

Cell Division↗
PubMed1982

Induction of phagocytic inhibitory activity in cats with chronic Pseudomonas aeruginosa pulmonary infection.

Chronic pulmonary infection has been established in cats by repeated intrapulmonary inoculation of viable Pseudomonas aeruginosa enmeshed in agarose beads. In the serum of all chronically infected animals, a substance(s) developed which inhibited phagocytosis of P. aeruginosa by normal cat alveolar macrophages. Phagocytosis was measured by incubating macrophage monolayers (5 X 10(5) alveolar macrophages) for 20 min in the presence of 3H-labeled bacteria and 5% serum from control or infected animals. Inhibitory activity developed 4 to 16 weeks after initial infection, and inhibition of phagocytosis of P. aeruginosa in the presence of infected cat serum ranged from 30 to 79%. After inhibitory activity developed, it persisted throughout the remainder of the experiment in each animal. The activity was specific for P. aeruginosa of the infecting serotype and did not affect phagocytosis of gram-positive organisms. Inhibitory activity was unchanged by heating serum at 56 degrees C for 30 min. We have previously described a P. aeruginosa-specific, heat-stable, phagocytosis-inhibitory activity in the serum of patients with cystic fibrosis. Since inhibitory activity also develops in cats with chronic P. aeruginosa pulmonary infection, such activity may not be a primary intrinsic abnormality in patients with cystic fibrosis. The animal model described here offers a system for following the development of and for characterization of the P. aeruginosa-specific phagocytosis-inhibitory activity.

Animals↗
PubMed1978

Antibodies to proteases and exotoxin A of Pseudomonas aeruginosa in patients with cystic fibrosis: Demonstration by radioimmunoassay.

Sera from 33 patients with cystic fibrosis and two pediatric patients being treated for chronic pulmonary infections not related to cystic fibrosis and six sera or serum pools from uninfected individuals were tested with a microtiter radioimmunoassay for reactivity against exotoxin A and two proteases from Pseudomonas aeruginosa. Exotoxin A was purified from a low-protease strain of P. aeruginosa and shown to have adenosine diphosphate-ribose transferase activity and mouse lethality. Proteases were purified from an isolate of P. aeruginosa from a patient with cystic fibrosis and had proteolytic activity against elastin and collagen in an assay employing dimethylated protein substrates. The antibody responses of the patients detected using 125I-labeled antibody to human immunoglobulin were correlated with clinical evaluations expressed as a composite score based on pulmonary findings, case histories, growth and nutrition, and chest X rays. Values in the radioimmunoassay for patients' sera were compared with those of a control serum pool and expressed as the ratio of counts per minute (cpm) in patient serum to the cpm in the control pool. Inverse correlations were found between these ratios for each of the pseudomonas exoproducts and clinical scores; highest ratios occurred in patients showing the lowest clinical scores. These results confirm that proteases and exotoxin A of P. aeruginosa are produced in cystic fibrosis pulmonary infections due to P. aeruginosa and suggest that they may serve as significant virulence factors in these chronic infectious states.

Adolescent↗
PubMed1976

Isolation and characterization of mutants of Escherichia coli K12 resistant to the new aminoglycoside antibiotic, amikacin.

Spontaneous mutants of Escherichia coli K12 that are resistant to the new aminoglycoside antibiotic, amikacin, were isolated. These mutants have simultaneously acquired cross-resistance to kanamycin, gentamicin and neomycin but not to streptomycin or spectinomycin. Sensitivity of the mutant strains to the non-aminoglycoside antibiotics, ampicillin, tetracycline and polymyxin, was unaffected. The mutation responsible for amikacin resistance was mapped by PI transduction and found to be tightly linked to strA, distal with respect to spcA and aroE.

Amikacin↗
PubMedDate not supplied

Therapeutic evaluation of piperacillin for acute pulmonary exacerbations in cystic fibrosis.

The efficacy and pharmacokinetics of piperacillin monotherapy were studied in 46 patients with cystic fibrosis. Two patients were dropped from the study within 24 hr of enrollment because of drug-associated nausea and vomiting. Initially fourteen older patients (greater than 12 years) receiving piperacillin 450 mg/kg/day underwent a preliminary evaluation. Based on the results, 30 younger patients (less than or equal to 12 years) randomized in a double-blind fashion received either 600 or 900 mg/kg/day of piperacillin in six divided doses. Pharmacokinetic parameter estimates for t1/2 Vdss, and Cl were similar for first dose and steady-state evaluations. In 27 patients, approximately 43% of the administered dose was recovered in the urine after 4 hr. Piperacillin CiR averaged 49% of the total Cl. No difference in overall clinical efficacy could be identified between 600 and 900 mg/kg/day of piperacillin using two different objective scoring systems. Although a reduction in sputum Pseudomonas colony counts was greater following the 900 mg/kg/day regimen, this appeared to be independent of clinical effect. In 14 patients (32%), a distinct adverse serum-sicknesslike reaction was observed. The incidence of this reaction appeared to increase as the dose of piperacillin increased. All signs and symptoms of this reaction resolved within 36 hr of discontinuing piperacillin administration but recurred immediately on rechallenge in four patients. All patients with the adverse reaction were subsequently treated with beta-lactam antibodies without ill effect. Overall, clinical improvement appeared to be independent of the piperacillin dose. Our data support the use of total daily piperacillin dosages not exceeding 600 mg/kg.

Adolescent↗
PubMedDate not supplied

Cystic fibrosis. Infection and immunity to Pseudomonas.

Chronic pulmonary infection with P. aeruginosa in CF may result from: 1. An initial failure of clearance mechanisms (increased adherence) leading to the development of a highly compartmentalized inflammatory reaction; 2. Inhibition of clearing mechanisms for bacteria present in the bronchial lumen; and 3. A largely ineffective, and possibly damaging, hyperactivity of inflammatory cells in the lumen and bronchial wall. The special relationship between the CF host and P. aeruginos, always long-term, and frequently subtle in its complexity, needs further understanding in order to develop new strategies for the treatment of chronic lung infections with this organism.

Cystic Fibrosis↗
PubMedDate not supplied

Comparative studies of nucleic acid hybridization assay for Listeria in foods.

A nucleic acid hybridization assay has been developed for Listeria spp. in dairy foods and environmental samples. The assay is based on detection of unique Listeria 16S rRNA sequences by using a 32P-labeled synthetic DNA probe. Inclusivity and exclusivity of the probe were confirmed with 139 Listeria isolates representing all known species, and 73 non-Listeria bacterial strains. In this paper, we present results from our preliminary studies comparing the hybridization assay with conventional culture on a total of 575 specimens that represent a variety of inoculated and uninoculated foods and environmental samples. The assay, which is done in a filter manifold format after 2 days of cultural enrichment, requires a total assay time of less than 2.5 days. The false-negative rate for all sample groups tested using the GENE-TRAK hybridization assay was less than the rate for culture. Thus, the new assay allows rapid screening of the indicated product groups and provides reliable numerical results.

Dairy Products↗
PubMedDate not supplied

Identification of Salmonella enteritidis from experimentally infected hens using a colorimetric DNA hybridization method.

Identification of Salmonella enteritidis from cloacally challenged commercial laying hens was studied by comparing bacterial isolations using conventional methods with detection by the use of the GENE-TRAK colorimetric DNA probe assay. More positive test results were obtained using the latter on days 14, 28, and 42 postchallenge, but the difference between the two methods was not statistically significant. Over the duration of the experiment, positive cloacal samples were statistically more frequent from a commercial strain of white leghorn hens when compared with a commercial brown egg-producing strain (28/60 vs. 9/57; chi-square 1 df = 12.9, P < 0.001). Eggs having various shell defects were produced by the infected hens only after Salmonella challenge. These defects included, in order of frequency, elongated shape, thin shells, off-white color (tints), small size, wrinkles, and pimples. No Salmonella could be recovered from 193 defective eggs, nor were positive isolates made from additional tests performed on 50 normal eggs. Proteus sp. was isolated from 10 eggs, however. Our observations demonstrate that the GENE-TRAK colorimetric method is comparable with conventional bacteriology for the identification of Salmonella in cloacal samples taken from laying hens. Moreover, the two methods demonstrate the existence of breed differences in susceptibility to S. enteritidis challenge.

Analysis of Variance↗