Biomedical subjects

J C Feeley

Publications and source records attributed to J C Feeley.

At least 55 records · Page 3Linked to original sources

PubMed1982

Evaluation of the microenzyme-linked immunosorbent assay with Treponema pallidum antigen.

Whole-cell sonicates of Treponema pallidum, Nichols strain, were evaluated in an enzyme-linked immunosorbent assay (Elisa) for syphilis, and results were read in a Dynatek Microelisa Reader. The antigen was evaluated with sera from patients with syphilis, persons presumed normal, and biological false-positives. Two hundred and ninety-seven sera were tested by the ELISA with T. pallidum antigens, the Venereal Disease Research Laboratory (VDRL) slide test, the fluorescent treponemal antibody absorption (FTA-Abs) test, and the microhemagglutination assay for T. pallidum antibodies (MHA-TP). The results of all of the tests were compared. The ELISA, with 89.3% sensitivity, was less sensitive than the VDRL (93.3%) and FTA-Abs (100.0%) tests but more sensitive than the MHA-TP (76.0%). THe ELISA was considerably more sensitive in primary syphilis than the MHA-TP. Specificity was as follows: ELISA, 98.5%; FTA-Abs test, 97.8%; MHA-TP, 98.2%; and VDRL test, 92.7%. The ELISA has good potential as a confirmatory test in the serodiagnosis of syphilis.

Antibodies, Bacterial↗

PubMed1982

Sodium desoxycholate-extracted treponemal antigen in an enzyme-linked immunosorbent assay for syphilis.

The extraction of Treponema pallidum antigen with sodium desoxycholate, based on a previously described procedure (J. Portnoy and H.J. Magnuson, J. Immuno. 75:348-355, 1955), was used in an enzyme-linked immunosorbent assay (ELISA) test for syphilis. The antigen was prepared from T. pallidum street strain no. 14, and its overall sensitivity and specificity was compared with those of sonicated antigen preparations made with phosphate-buffered saline. The optimum serum dilution for testing and the significant absorbance reading at 490 nm were selected by examination of quantitative dilutions of 91 sera from presumably normal individuals and 92 sera from syphilitics. The time and temperature of serum and conjugate incubations were also examined. With an absorbance reading of greater than or equal to 0.2 at the 1:80 serum dilution, 88 (95.8%) of 92 sera from syphilitics were reactive in the ELISA test with desoxycholate-extracted antigen, and 82 (89.1%) were reactive with the sonicated antigen. Only one nonsyphilitic serum was reactive with each antigen. Greater sensitivity without loss in specificity was obtained with longer serum and conjugate incubations. We concluded that an ELISA test with sodium desoxycholate-extracted antigen is more sensitive than and equally specific to an ELISA with sonicated treponemal antigen.

Antigens, Bacterial↗

PubMed1982

In-vitro studies of interactions between tampons and Staphylococcus aureus.

In-vitro studies were done to investigate the role of tampons and Staphylococcus aureus in toxic shock syndrome. Tampons did not enhance the growth of S. aureus in nutrient broth or human blood. Intrinsic contamination of tampons with S. aureus was not found among the 504 tampons cultured (95% confidence limits of fraction contaminated; 0 to 0.007). Toxin-producing S. aureus persisted significantly longer on artificially contaminated Rely tampons (Procter & Gamble) than on the other brands tested. The proportion of clinical isolates of S. aureus capable of producing toxin increased from two of 36 in 1960 to eight of 20 in 1979 (p = 0.002, Fisher's exact test). This general increase in the proportion of toxin-producing strains may partially explain the increase in cases of toxic shock syndrome in recent years.

Bacillus↗

PubMed1982

Immunofluorescence and Treponema infection: a method using immunofluorescence to study rabbit testicular tissue infected with T pallidum and T pertenue.

We compared immunofluorescent staining of rabbit testicular tissue infected with Treponema pallidum or T pertenue, and fixed in Bouin's fixative, 95% cold ethyl alcohol with 1% glacial acetic acid, or routine 10% buffered formalin solution. The fixative of choice clearly was Bouin's. Although we studied only rabbit tissue, we assume that these fixatives will work well in human biopsy or autopsy material when identification of pathogenic Treponema is needed.

Animals↗

PubMed1982

Duration of maternally derived immunity to tetanus and response in newborn foals given tetanus antitoxin.

Serum tetanus antitoxin (TAT) concentrations were measured in a group of 30 foals from birth to 4 months of age. Five of 30 foals (16.6%) had serum titers less than 0.01 IU of TAT/ml by 1 month of age. At 2 months of age, 17 of 28 foals (60.7%) had titers less than 0.01 IU/ml. By 3 months of age, 22 of 29 (75.5%) foals tested had titers of less than 0.01 IU/ml. At the age of 4 months, 24 of 29 foals (82.1%) had titers of less than 0.01 IU/ml. The TAT given to foals at birth resulted in an immediate increase in titer when circulating antitoxin was absent or minimal. Titers considered protective against tetanus resulting from an IM injection of exogenous TAT at birth were maintained for at least 3 months after the injection.

Animals↗

PubMed1981

Vi serology in the detection of typhoid carriers.

A new haemagglutination assay for Vi antibodies was evaluated in searches for symptom-free carriers of Salmonella typhi associated with sporadic cases of typhoid fever. The assay differs from previous ones in that a purified (instead of crude) Vi antigen from Citrobacter was used to sensitise the red blood cells. In ten sporadic outbreaks of typhoid stool culture identified seven enteric carriers of S. typhi among the patients' families or other close contacts. All seven carriers had Vi antibodies in titres ranging from 1:40 to 1:2560. Moreover, among thirty-seven stool-culture-negative contacts of patients, only one had Vi antibodies, in a titre of 1:10. Thus, the new assay for Vi antibodies was as sensitive and as specific as faecal culture in detecting symptom-free typhoid carriers. It could become a convenient screening test.

Adolescent↗

PubMed1981

Serologic studies of naturally acquired infection with Vibrio cholerae serogroup O1 in the United States.

The discovery of 11 persons infected with Vibrio cholerae serogroup O1 (biotype El Tor, serotype Inaba) in southwestern Louisiana in 1978 provided an opportunity to evaluate the serologic response to this agent in North Americans with naturally acquired infection. One antibacterial assay (vibriocidal assay) and two antitoxin assays (enzyme linked immunosorbent assays [ELISA] and rabbit skin permeability factor assay) were used. Antitoxin levels were elevated longer than vibriocidal antibody levels, and asymptomatic infected persons had levels of antitoxin and vibriocidal antibody levels, and asymptomatic infected persons had levels of antitoxin and vibriocidal antibody as high as those of persons with clinical cholera. With use of serologic criteria derived from these studies, one additional person infected with V. cholerae O1 was discovered, and a relatively low (4%-7%) prevalence rate of elevated levels of vibriocidal antibody and antitoxin was found in a serum survey of a community with several known cases. Comparison of the results from the ELISA and the rabbit skin permeability factor assay demonstrated similar rates of elevated levels of antitoxin, but the ELISA required less time and less serum per sample analyzed.

Animals↗

PubMed1981

Pontiac fever: isolation of the etiologic agent (Legionella pneumophilia) and demonstration of its mode of transmission.

Pontiac fever, a unique epidemiologic form of legionellosis, is characterized by a short (one- to two-day) incubation period and a self-limited grippe-like illness without pneumonia. In 1968, the first documented outbreak of this syndrome affected persons who had entered a health department building in Pontiac, Michigan. Epidemiologic analyses clearly implicated as airborne agent and suggested that evaporative condenser water aerosols being disseminated by a defective air conditioning system played a key role in the outbreak. Guinea pigs that were exposed in the building and to laboratory aerosols of evaporative condenser water developed bronchopneumonia. Legionella pneumophilia (serogroup 1) was isolated from the exposed guinea pigs' lungs. Paired acute and convalescent serum specimens from 37 patients were tested by the indirect fluorescent antibody technique using L. pneumophila serogroup 1 antigen, and 31 (84%) had rises in titer from less than 32 to greater than or equal to 64.

Air Conditioning↗

PubMed1981

Susceptibility of Pittsburgh pneumonia agent (Legionella micdadei) and other newly recognized members of the genus Legionella to nineteen antimicrobial agents.

The susceptibilities of 11 strains representing the five recognized species of Legionella were determined by agar dilution testing on buffered charcoal-yeast extract agar. All of the legionellae tested were susceptible to rifampin, erythromycin, rosaramycin, chloramphenicol, and the aminoglycosides and were resistant to clindamycin and vancomycin. Susceptibilities to penicillins and cephalosporins were variable. Legionella micdadei, Legionella bozemanii, and Legionella gormanii were susceptible to these agents, but minimal inhibitory concentrations for each species were different. Legionella dumoffii resembled Legionella pneumophila in being resistant to penicillin, cephalothin, and cephamandole and susceptible to moxalactam and cefoxitin. All species except L. micdadei produced beta-lactamase.

Anti-Bacterial Agents↗

PubMed1981

Fluorescent treponemal antibody-absorption double-staining procedure.

The fluorescent treponemal antibody-absorption double-staining step-by-step procedure and proposed reference reagents for the test are described. The test and reagents were evaluated in two separate laboratories on 265 fresh sera, and test results were compared with the reference fluorescent treponemal antibody-absorption test results performed in a third laboratory. The data indicate that the tests are comparable in the areas where the test is recommended for use. Problems with inadequate light filtration occurred, but these could be resolved. This test is recommended for use with microscopes equipped with incident illumination.

Antibodies, Anti-Idiotypic↗

PubMed1981

Legionellosis.

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Agglutination Tests↗

PubMed1980

Cholera--a possible endemic focus in the United States.

In September and October 1978, after a case of cholera had been discovered in southwestern Louisiana, 10 more Vibrio cholerae O-Group 1 infections were detected in four additional clusters. All 11 infected persons had recently eaten cooked crabs from five widely separated sites in the coastal marsh, and a matched-triplet case-control study showed a significant relation between cholera and eating such crabs (P = 0.007). V. cholerae O1 was isolated from estuarine water, from fresh shrimp, from a leftover cooked crab from a patient's refrigerator, and from sewage in six towns, including three without identified cases. All isolates in Louisiana and an isolate from a single unexplained case in Texas in 1973 were biotype El Tor and serotype inaba; they were hemolytic and of a phage type unique to the United States--suggesting that the organism persisted undetected along the Gulf Coast for at least five years.

Adolescent↗

PubMed1980

Plasmid-mediated tissue invasiveness in Yersinia enterocolitica.

Plasmids have an important role in the pathogenicity of certain bacterial species, and Escherichia coli provides the most complete example of the relationship involved. Enterotoxigenic strains of E. coli, in addition to producing heat-stable and/or heat-labile enterotoxins, may also produce a haemolysin and fimbriate cell surface antigens which facilitate the adherence of the bacterial cell to the mucosa of the small bowel. Numerous studies have shown that these properties are plasmid-mediated and that the plasmids act in concert to confer on the host bacterium the ability to produce enteric disease in man and in animals. Moreover, studies with invasive strains of E. coli have shown that the Col V plasmid, which codes for the synthesis of colicin V, significantly enhances the pathogenicity of its host bacterium. Although the relationship between Col V plasmids and virulence is unclear, reports indicate that Col V-containing strains of E. coli are better able to survive in the alimentary tract and that colicine V itself inhibits macrophage function. It is probable that bacterial virulence is a complex phenomenon involving both chromosomal and plasmid genes. We describe here a virulence plasmid which mediates tissue invasiveness in human pathogenic strains of Yersinia enterocolitica.

Bacterial Toxins↗

PubMed1980

Pittsburgh pneumonia agent: direct isolation from human lung tissue.

Pittsburgh pneumonia agent (PPA) was recently cultivated from infected egg yold on charcoal yeast extract agar. PPA has now been isolated both from infected egg yolk and human lung tissue on charcoal yeast extract agar and on a new medium, buffered charcoal yeast extract agar. PPA resembles Legionella pneumophila and other Legionella-like organisms in requirements for growth and composition of fatty acids. It differs in genetic relatedness, antigenic composition, and colonial morphology and has distinctive characteristics that allow it to be identified. The name Legionella pittsburgensis species nova is proposed for this organism.

Animals↗

PubMed1980

Evaluation of a new assay for Vi antibody in chronic carriers of Salmonella typhi.

The assay for serum antibody to the Salmonella typhi capsular polysaccharide (Vi) antigen has recently been revised because of the availability of a purified, highly polymerized Vi antigen. We compared this revised Vi antibody assay to the traditional one for potential usefulness in the surveillance of chronic enteric carriers of S. typhi. The purified Vi antigen of Citrobacter freundii was incorporated into a passive hemagglutination assay for serum Vi antibody; the standard Vi antibody assay was also a hemagglutination assay that employed as the Vi antigen a crude extract of Citrobacter (Ballerup O group 29). As determined by the revised assay, Vi antibody was found in the sera of 22 (71%) of 31 current typhoid carriers, none of 6 resolved carriers, and none of 22 control subjects. According to the traditional assay, Vi antibody was present in 23 of those current carriers (74%), 1 of the resolved carriers (17%), and 4 of the control subjects (18%). The rate of false-positive Vi antibody tests among resolved carriers and control subjects was less with the revised assay (P < 0.05). Successful antimicrobial therapy resulted in a reversion to seronegativity within 1 year in 8 of 10 Vipositive carriers according to the revised assay, but in only 3 of 11 according to the standard assay (P < 0.05). During a 2-year period of observation, 15 (94%) of 16 current typhoid carriers had at least one positive purified Vi antibody test; among 12 of those patients with Vi titers of 1:40 or greater, 9 (75%) were continuously Vi positive. Thus, the revised Vi antibody assay is more specific and no less sensitive than the standard assay for the condition of current enteric carriage of S. typhi. This serological test could be of value in the surveillance of typhoid carriers by public health agencies.

Aged↗

PubMed1980

Further studies with the fluorescent treponemal antibody-absorption double-staining procedure.

A double-staining procedure for the fluorescent treponemal antibody-absorption test, using fluorescein isothiocyanate as a label for the class-specific anti-human globulin and tetramethylrhodamine isothiocyanate as a label for a counterstain reagent, has been described. This method requires the addition of a KP560 barrier filter, with a microscope equipped with vertical illumination, to exclude the rhodamine emission in reading the fluorescein fluorescence. The present study evaluated reversing the dye label for each conjugate in the double-staining procedure, thus eliminating the need for the KP560 filter. It also considered the possibility of shortening the counterstaining time and compared various methods for preparing antigen slides in an attempt to establish a method that increases the number of treponemes per microscopic field. The results indicate that a rhodamine-labeled class-specific anti-human globulin as a primary stain, and a fluorescein-labeled anti-treponemal globulin as a counterstain, provide an acceptable method for performing the fluorescent treponemal antibody-absorption double-staining procedure. Nonfixed antigen slides were held for 16 days in a desiccator or stored in plastic bags with silica gel for 3 weeks; then, with methanol fixation, they were used satisfactorily in the double-staining procedure. A shortened incubation time for the counterstain allowed more rapid slide processing.

Antigens, Bacterial↗

PubMed1980

Legionella gormanii sp. nov.

A new species of Legionella was isolated from soil collected from a creek bank. The name Legionella gormanii sp. nov. is proposed.

DNA, Bacterial↗

PubMed1980

Antibody response to serogroup A and C meningococcal polysaccharide vaccines in infants born of mothers vaccinated during pregnancy.

During the large epidemic of serogroups A and C meningococcal disease in Brazil, we studied the immunologic response to meningococcal polysaccharide vaccine in infants born to women vaccinated during pregnancy. Radioimmunoassay serum levels against serogroups A and C polysaccharide were more than threefold higher in vaccinated than in unvaccinated women at delivery. Cord blood levels were also threefold or higher in infants whose mothers were vaccinated while pregnant compared to infants born of unvaccinated mothers. Within 3 mo, the infants' A and C serum antibody levels declined by approximately 80%. When vaccinated at about 6 mo of age, infants born of vaccinated mothers had antibody responses to A and C polysaccharide vaccines indistinguishable from those born of unvaccinated mothers. The response did not vary with the trimester of vaccination. We conclude that the vaccination of pregnant women with groups A and C meningococcal polysaccharide vaccine does not produce immune tolerance in the subsequently born infants.

Antibodies, Bacterial↗