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H W Wilkinson

Publications and source records attributed to H W Wilkinson.

At least 37 records · Page 2Linked to original sources
PubMed1985

Second serogroup of Legionella hackeliae isolated from a patient with pneumonia.

A Legionella-like organism (strain 798-PA-H, ATCC 35999) isolated from a lung aspirate was shown by DNA hybridization to belong to the species Legionella hackeliae. Growth, gas-liquid chromatographic, and physiologic characteristics were consistent with those of the type strain of L. hackeliae, Lansing 2 (ATCC 35250). However, 798-PA-H was minimally reactive with L. hackeliae direct immunofluorescence assay conjugate or slide agglutination test antiserum. Cross-absorption studies with 798-PA-H and Lansing 2 antisera supported placing 798-PA-H in a second serogroup of L. hackeliae.

Agglutination Tests↗
PubMed1985

Fatal Legionella maceachernii pneumonia.

Legionella maceachernii, previously isolated only from the environment, was shown to be a cause of fatal pneumonia in an immunocompromised patient.

Bacterial Infections↗
PubMed1984

Enzyme-linked immunosorbent assay and indirect immunofluorescence assay for Lyme disease.

The sensitivity and specificity of an indirect immunofluorescence assay (IFA) and ELISA for Lyme disease were estimated. Sera from patients with Lyme disease, patients with other infections, and healthy individuals were examined. Significant cross-reactivity occurred only with sera from patients with syphilis, yaws, and pinta . All tested sera from patients with Lyme disease, however, gave negative results in the rapid reagin screening test and the microhemagglutination assay for antibodies to Treponema pallidum confirmatory for syphilis. When sera from patients with treponemal diseases were excluded from the analysis, the IFA and ELISA were highly specific, having 97% and 100% reliability, respectively. Sensitivity of both tests varied with the stage of disease but was 100% for both tests during complicated Lyme disease. The results indicate that both tests are highly specific and sensitive for complicated Lyme disease but relatively insensitive for patients with erythema chronicum migrans alone.

Antibodies, Bacterial↗
PubMed1984

Legionella pneumophila serogroup 9: a cause of human pneumonia.

A new serogroup of Legionella pneumophila was isolated from bronchoscopic washings and an open-lung biopsy specimen of a patient from California with pneumonia. A serologically identical isolate was obtained from tap water of a hospital ward in the Netherlands, and a fatal case of pneumonia in a patient from Virginia was shown retrospectively to have been caused by this new organism. The type strain of what is now serogroup 9 of L. pneumophila is IN-23-G1-C2 (American Type Culture Collection no. 35289). Disease caused by L. pneumophila serogroup 9 is not apparently different from that caused by other L. pneumophila serogroups.

Agglutination Tests↗
PubMed1983

Reactivity of serum from patients with suspected legionellosis against 29 antigens of legionellaceae and Legionella-like organisms by indirect immunofluorescence assay.

Sets of sera (444) submitted for diagnostic testing for legionellosis were tested against 29 indirect immunofluorescence assay (IFA) antigens prepared from the characterized Legionella species and Legionella-like organisms to determine the prevalence of antibodies to Legionella organisms. Reciprocal titers of 15% of the serum sets rose fourfold or more to greater than or equal to 128 (indicating seroconversion) against one or more Legionella antigens. The specificity of the test was 96% when evaluated in patients with pneumonia due to non-Legionella organisms. Antibodies were of the IgG, IgM, and (infrequently) IgA classes and were either specific for a single species (as defined by a difference in titer of fourfold or more) or reacted with common Legionella antigens (30 [45%] vs. 36 [55%] of 66 seroconversions, respectively). No single antigen detected half of the positive sera. Elevated IFA titers (of greater than or equal to 256) against single or multiple Legionella antigens occurred in 12% of 184 normal control sera. Therefore, only seroconversions to titers of greater than or equal to 128 should be considered indicative of recent Legionella infection.

Antigens, Bacterial↗
PubMed1983

Comparison of slide agglutination test and direct immunofluorescence assay for identification of Legionella isolates.

It is technically impractical for many clinical laboratories to use the direct immunofluorescence assay for identifying and serogrouping clinical isolates of Legionella. We compared the results obtained with the direct immunofluorescence assay with the results of a simple and less-demanding slide agglutination test for identifying 15 serogroups representing seven Legionella species. The slide agglutination test was in complete agreement with the direct immunofluorescence assay, and the serogroup to which 64 clinical isolates of Legionella belonged was correctly identified. With polyvalent, pooled antisera and absorbed, serogroup-specific antisera, the slide agglutination test is a useful alternative to the direct immunofluorescence assay in the diagnosis of Legionella infections and for studying the serological relationships of Legionella-like organisms.

Agglutination Tests↗
PubMed1983

Kinetic-dependent enzyme-linked immunosorbent assay for detection of antibodies to Legionella pneumophila.

A semiautomated, kinetic-dependent, enzyme-linked immunosorbent assay (K-ELISA) was adapted to detect serum antibodies to Legionella pneumophila. In a comparative study, 158 human serum samples (79 pairs) were tested by K-ELISA and the standard indirect immunofluorescence assay for determination of antibody levels to L. pneumophila serogroup 1. K-ELISA determinations were made by using a serogroup-specific antigen or a preparation (unfractionated antigen) which contained both common antigen and serogroup-specific reactivity. There was good correlation between the immunofluorescence assay and the K-ELISA by using either antigen, although greater correlation was achieved with the unfractionated antigen (coefficients of correlation, 0.894 with unfractionated antigen and 0.841 with serogroup-specific antigen). These results indicate that the K-ELISA is a reliable alternative to the immunofluorescence assay for serologically diagnosing legionellosis.

Antibodies, Bacterial↗
PubMed1983

Status of serologic tests for Legionella antigen and antibody at the Centers for Disease Control.

Nine species and 16 serogroups have been defined for the genus Legionella. Direct immunofluorescence assay (DFA) results with 12 conjugates in 3 polyvalent pools showed that L. pneumophila serogroup 1 comprised 63% of the legionellae identified in specimens from patients with legionellosis. Indirect immunofluorescence assay (IFA) titers of paired sera from patients with suspected legionellosis against multiple Legionella antigens showed preferential reactivity for the L. pneumophila antigens. The multiple-antigen IFA was 96% specific when sera from patients with disease due to other etiologic agents were tested. The prevalence of antibody among well individuals is relatively high in some population groups.

Antibodies, Bacterial↗
PubMed1982

Legionella jordanis: a new species of Legionella isolated from water and sewage.

Legionella jordanis sp. nov., as found in two cultures, is described. One isolate was from river water in Indiana and the other isolate was from sewage in DeKalb County, Ga. The former is the type strain of the species, and is designated BL-540 (ATCC 33623). L. jordanis had a partial relationship to L. bozemanii by direct fluorescent-antibody tests but was unrelated to L. pneumophila, L. dumoffii, L. micdadei, L. gormanii, or L. longbeachae. Legionella phenotypic characteristics, including large amounts of branched-chain cellular fatty acids, were shown by the isolates. Studies of DNA relatedness showed that the two cultures of L. jordanis were only slightly related to the six previously described species of Legionella but were more than 90% related to each other. Indirect fluorescent-antibody tests with human sera suggested that unrecognized human infections with L. jordanis may be occurring.

DNA, Bacterial↗
PubMed1982

Evaluation of a solid-phase immunofluorescence assay for detection of antibodies to Legionella pneumophila.

A semiautomated solid-phase immunofluorescence technique (FIAX) was compared with the standard indirect immunofluorescence assay (IFA) for the determination of antibody levels to Legionella pneumophila serogroup 1 in paired human serum samples. The FIAX method was in agreement with the IFA test for 91.8% of the serum pairs but gave evidence of a recent Legionella infection significantly fewer times than did the IFA. These results suggest that the FIAX technique may eventually be a useful alternative test for measuring Legionella antibodies. However, further study will be required to determine its efficacy in providing a serodiagnosis of legionellosis.

Antibodies, Bacterial↗
PubMed1982

Formalin-killed versus heat-killed Legionella pneumophila serogroup 1 antigen in the indirect immunofluorescence assay for legionellosis.

Indirect immunofluorescence assay titers of human sera obtained against the Legionella pneumophila serogroup 1 antigen (Philadelphia 1 strain) killed with 10% Formalin showed a tendency to be lower than those obtained against the reference heat-killed antigen (geometric mean titer of 194 and 370, respectively) when all other variables in the test were held constant. Test results were interpreted the same for 96% of 60 paired sera if the cutoff level used to interpret a positive test result for the formalinized antigen was lowered by one twofold dilution factor.

Antigens, Bacterial↗
PubMed1981

Validation of Legionella pneumophila indirect immunofluorescence assay with epidemic sera.

Sera from six outbreaks of legionellosis and four outbreaks of pneumonia of other etiologies were tested with the indirect immunofluorescence assay (IFA) as currently performed. The current IFA is at least as sensitive as the original test in detecting cases of Legionnaires disease (78 to 91%). By using Center for Disease Control criteria for a positive (fourfold increase in titer during convalescence to greater than or equal to 128) or presumptive (single titer greater than or equal to 256) serological test, the specificity exceeded 99%. No cross-reactions against Legionella pneumophila antigens were observed among sera from epidemic cases of Q fever, tularemia, and psittacosis; the only positive L. pneumophila IFA titer among the epidemic Mycoplasma pneumonia sera was reduced to a negative titer with an immunosorbent extracted from Escherichia coli strain O13:K92:H4. The slight increase in specificity (to 100%), however, was offset by a slight decrease in sensitivity. The sensitivity of the IFA was maximal when a conjugate that detected immunoglobulins G, M, and A was used. IFA titers were not significantly altered by replacing the monovalent serogroup 1 antigen with a polyvalent antigen (serogroups 1 through 4) nor by the presence of rheumatoid factor or heat-labile serum factors.

Antibodies, Bacterial↗
PubMed1981

Detection of cell-associated or soluble antigens of Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and Legionella micdadei by staphylococcal coagglutination tests.

Current methods used for the detection of whole-cell isolates of Legionella or for the detection of Legionella soluble antigens are technically impractical for many clinical laboratories. The purpose of this study was to explore practical alternatives. The results showed that whole cell isolates of Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and Legionella micdadei were identified specifically by a simple slide agglutination test or slide coagglutination test in which the reagent antisera are first bound to staphylococcal protein A. Soluble antigens were also identified specifically by the slide coagglutination test and by a sandwich immunofluorescence assay. The latter test may be useful in detecting antigen in body fluids of patients with legionellosis or in environmental samples.

Agglutination Tests↗
PubMed1981

Legionnaires' disease imported to Denmark from Italy.

Three cases of imported Legionnaires' disease are reported. All 3 patients became ill after their return to Denmark from a holiday tour in northern Italy. High titers of antibodies to Legionella pneumophila in the indirect immunofluorescence (IF) test confirmed the diagnosis. The fact that the onset of illness was within 10 days of the last day the patients spent in Italy strongly suggests that the disease was imported to Denmark from Italy. 10 of the 77 tourists who participated in the study had IF titers of at least 256. Of these 6 had clinical signs of Legionnaires' disease. An additional case of legionella infection occurred months after the case described in this report and was probably contracted in Italy.

Antibodies, Bacterial↗
PubMed1981

Pediatric Legionnaires' disease: diagnosis by direct immunofluorescent staining of sputum.

Legionnaires' disease occurred in a 3-year-old boy with Down's syndrome. His illness was characterized by bilateral pneumonia, high fever, and response to erythromycin. The diagnosis was made by demonstrating Legionella pneumophila, serogroup 1, in sputum with a direct fluorescent antibody stain. L pneumophila antigen was detected in urine by an enzyme-linked immunospecific assay. The diagnosis was confirmed by a more than fourfold rise in serum antibody titer. Although Legionnaires' disease appears to be uncommon in children, it should be included in the differential diagnosis of pneumonia in the immunocompromised child.

Antibodies, Bacterial↗
PubMed1981

Legionellosis.

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Agglutination Tests↗