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Biomedical subjects

I Nachamkin

Publications and source records attributed to I Nachamkin.

At least 73 records · Page 4Linked to original sources
PubMed1988

Evaluation of several commercial biochemical and immunologic methods for rapid identification of gram-positive cocci directly from blood cultures.

To develop laboratory methods for the rapid identification of gram-positive cocci from blood cultures, several commercial immunological and biochemical tests for identifying staphylococci and streptococci from two different blood culture systems (Thiol/TSB, Difco Laboratories; BACTEC, Johnston Laboratories, Inc.) were evaluated and compared with conventional identification methods. A total of 44 cultures contained Staphylococcus aureus as determined by conventional methods. Commercial immunological methods (six tested) ranged in overall sensitivity from 38.6 (Staphyloslide; BBL Microbiology Systems) to 77.3% (Staphaurex; Wellcome Diagnostics). All methods tested had 100% specificity. A total of 30 isolates of group D streptococci were tested with immunological and biochemical identification systems. The overall sensitivity ranged from 14.2% (Phadebact Group D; Pharmacia Diagnostics) to 100% with Streptex (Wellcome; immunological) and Identicult A-E (Scott Laboratories, Inc.; biochemical). The results of this study suggest that some reagents can be used to provide rapid identification of gram-positive cocci from blood cultures 24 h earlier than standard methods.

Catalase↗
PubMed1988

Comparison of three rapid methods for detection of antibodies to streptolysin O and DNase B.

Three commercial systems were compared for ability to detect antibodies to streptolysin O (ASO) and DNase B (ADB). Streptozyme (Wampole Laboratories, Cranbury, N.J.) exhibited high sensitivity (100%) for detecting ASO but low sensitivity for ADB (22.2%). The LeapStrep (Organon Teknika, Malvern, Pa.) and Check-Spectra (Diagnostic Technology, Hauppauge, N.Y.) tests had low sensitivities for detecting ASO (35.3 and 21.4%, respectively) and ADB (22.2 and 33.3%, respectively).

Antibodies, Bacterial↗
PubMed1987

Complement dependent in vitro neutralization of Chlamydia trachomatis by a subspecies-specific monoclonal antibody.

Three murine monoclonal antibodies which combined specifically with Chlamydia trachomatis strain HAR-13 (Serotype A) were characterized. All antibodies cross-reacted with subspecies-specific epitopes in previously undescribed patterns. One of the antibodies showed a complement-dependent partial neutralization of strain HAR-13 in vitro, whereas the remaining two antibodies did not neutralize under any experimental conditions tested. The significance of subspecies-specific antibodies in neutralizing chlamydial infectivity in vivo remains to be determined.

Animals↗
PubMed1987

Prototheca zopfii isolated from a patient with olecranon bursitis.

Prototheca zopfii was isolated from a patient with olecranon bursitis. Olecranon bursitis caused by Prototheca is a distinct clinical entity. Recognition of this infection was made by observing characteristic organisms in tissue and subsequent isolation of the organism.

Aged↗
PubMed1987

Test-of-cure analysis by direct immunofluorescence for Chlamydia trachomatis after antimicrobial therapy.

The direct immunofluorescence assay (DFA) was compared with culture for test-of-cure analysis for Chlamydia trachomatis in patients 7 to 10 days after antimicrobial therapy was given. DFA test-of-cure results correlated with culture results in 79.5% of 39 patients. Of DFA-negative patients, 97% had negative cultures. Six of seven patients with borderline DFA results had negative culture results.

Adolescent↗
PubMed1986

Evaluation of a commercial cytotoxicity assay for detection of Clostridium difficile toxin.

A comparative study was performed to determine the accuracy of Clostridium difficile toxin detection. A commercial cytotoxicity assay (Bartels Immunodiagnostic Supply, Bellevue, Wash.) was compared with conventional microcytotoxicity assays, using Vero and MRC-5 cells. The Bartels system was found to be essentially equivalent to conventional cytotoxicity assays currently being performed for routine C. difficile toxin detection.

Bacterial Toxins↗
PubMed1985

Chlamydial infections.

Chlamydiae are small bacteria that have a unique life cycle. There are two species, Chlamydia psittaci and C. trachomatis, which cause a wide spectrum of clinical disease, including neonatal conjunctivitis and pneumonia, sexually transmitted disease, psittacosis, and trachoma. The importance of chlamydial disease in public health is being increasingly recognized, and the incidence in developed countries seems to be increasing. An understanding of chlamydial disease, its prevention and treatment, is essential for the infection control practitioner, who can play a significant role in patient education.

Chlamydia↗
PubMed1985

Gonococcal peritonitis in a patient treated with continuous ambulatory peritoneal dialysis (CAPD).

We report a case of gonococcal peritonitis in a sexually active female on continuous ambulatory peritoneal dialysis. The presumed route of entry into the peritoneal cavity was via the Fallopian tube. The episode responded rapidly to a standard antibiotic treatment protocol. Some episodes of culture-negative peritonitis may be caused by genital tract organisms which are not cultured by routine methods.

Adolescent↗
PubMed1985

Western blot analysis of the human antibody response to Campylobacter jejuni cellular antigens during gastrointestinal infection.

Western blot analysis was used to identify antigenic components of Campylobacter jejuni whole cells and outer membranes that elicit antibody responses in patients with campylobacter enteritis. Acute- and convalescent-phase sera from eight patients were analyzed for antibody activity against their homologous infecting strains and heterologous clinical isolates. Whole-cell and Sarkosyl-insoluble membrane components were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred electrophoretically to nitrocellulose paper for immunoblotting experiments. After the separated components were probed with patient sera, antibody binding was detected by autoradiography with 125I-protein A. Using this method, we detected several immunogenic components in whole cells and outer membranes. In the acute-phase response of some patients to infection, two to three components with approximate molecular weights of 66,000 (p66), 43,000 to 46,000 (major outer membrane protein), and 12,000 (p12) were detected in immunoblots. Convalescent-phase sera showed a more broad array of antibody binding to cell components. p66, shown to be campylobacter flagellin, was the major immunodominant component in almost all sera tested, however, p66 was not a major protein in Coomassie blue-stained gels. The major outer-membrane protein also bound to antibody, but with less intensity than p66. In general, the antibody specificity of patient sera was not limited to the homologous infecting strain, and antibodies cross-reacted with most components in heterologous strains. A low-molecular-weight component, identified as lipopolysaccharide with a modified silver stain, showed serological specificity for some patient sera. The results of this study showed that the antibody response of patients with campylobacter enteritis to C. jejuni antigens is variable. Flagellin appeared to be the major immunodominant component during infection.

Adult↗
PubMed1984

Detection of Neisseria gonorrhoeae in cervical swabs using the Gonozyme enzyme immunoassay. Clinical evaluation in a university family planning clinic.

The authors performed a prospective clinical evaluation of the Gonozyme (Abbott Laboratories, Chicago, IL) assay in a family planning clinic population. One thousand five hundred eighty-eight female patients were screened for gonococcal infection using culture and Gonozyme assay. One hundred nine patients were culture positive (6.9% disease prevalence). The sensitivity and specificity of the Gonozyme assay in this setting was 87.2% and 89.1%, respectively. The predictive value of a positive and negative test, given a disease prevalence of 6.9%, was 37.2% and 98.9%, respectively. The false-positive and false-negative rate was 10.9% and 12.8%, respectively. The authors prospectively followed patients with true-positive and false-positive Gonozyme results. The Gonozyme test showed a 83% correlation with test of cure cultures and, thus, should not be used for test cure analysis. False-positive Gonozyme tests could not be explained on the basis of cross-reacting bacteria or detection of vancomycin-sensitive gonococci. The authors' results suggest that the Gonozyme test should not be used in lieu of culture in a clinical setting with a similar population.

Cells, Cultured↗
PubMed1984

Monoclonal antibody that recognizes an outer membrane antigen common to the pathogenic Neisseria species but not to most nonpathogenic Neisseria species.

A hybridoma derived from a mouse immunized with gonococcal outer membranes produced an antibody, designated H.8, that bound to all strains of Neisseria gonorrhoeae and N. meningitidis tested, and to N. lactamica and N. cinerea, but only rarely to other nonpathogenic Neisseria species. Studies with the gonococcal strain used in production of the antibody showed that the antibody bound to a surface-exposed, protease-sensitive, and heat-modifiable outer membrane antigen that we believe is distinct from previously described gonococcal outer membrane proteins.

Animals↗
PubMed1984

Characterization of Neisseria gonorrhoeae protein II phase variation by use of monoclonal antibodies.

The protein II (P.II) outer membrane proteins of Neisseria gonorrhoeae, which have been implicated in gonococcal pathogenesis, have been previously shown to undergo a type of phase variation in which expression of any of several different forms of the proteins may be switched on or off. We identified six electrophoretically distinct forms of P.II proteins (designated P.IIa through P.IIf) within strain FA1090, and we isolated colonial variants of FA1090 that expressed only one of the six different P.II protein forms. Two monoclonal antibodies that bound specifically and differentially to P.II proteins were produced. One antibody bound to proteins P.IIb and P.IId and was bactericidal for all colonial variants expressing P.IIb. The second antibody bound to P.IIa and was bactericidal for colonial variants expressing P.IIa. P.II protein profiles of survivors of antibody killing indicated that multiple P.II protein species may be expressed on a single bacterium and that P.II protein switching in the gonococcus is nonrandom.

Antibodies, Monoclonal↗
PubMed1984

Campylobacter laridis causing bacteremia in an immunosuppressed patient.

An unusual species, Campylobacter laridis , belonging to the group of nalidixic acid resistant thermophilic Campylobacter species, was isolated from the blood of a 71-year-old man with multiple myeloma, hyperviscosity syndrome, and renal failure. The organism was first recognized in the laboratory by gram-stain reaction and resistance to nalidixic acid. The organism differs from C. jejuni and C. coli by its resistance to nalidixic acid, whereas anaerobic growth in the presence of trimethylamine N-oxide hydrochloride differentiates this organism from other Campylobacter species. Biochemical characterization and DNA homology studies confirmed the identity of this species as being C. laridis . To our knowledge, this is the first recorded case of bacteremia due to C. laridis in humans.

Aged↗
PubMed1983

The clinical significance of streptococcal species isolated from cerebrospinal fluid.

Alpha-hemolytic (viridans) streptococci are often isolated from cerebrospinal fluid (CSF); however, the significance of such isolates is poorly understood. In order to clarify the clinical significance of isolating these organisms from CSF, we did a retrospective analysis of 43 patients, from whom eight different species of alpha-hemolytic streptococci were recovered. Eight patients (19%) had significant infections based on bacteriologic, laboratory, and clinical findings. Significant infections were associated with S. sanguis, S. salivarius, S. intermedius, S. faecalis, and S. bovis. Thirty-five patient isolates (81%) from CSF were considered as contaminants, with S. mitis being the most frequently isolated organism (49%). Direct gram stain of CSF sediment, CSF glucose concentration, and CSF cell differential were clearly abnormal in most patients with significant infections, in contrast to patients with streptococci isolated as contaminants. Cultures of the lumbar puncture skin site yielded streptococci and other bacteria, suggesting a possible reservoir for contaminants.

Cerebrospinal Fluid↗
PubMed1983

Inhibition of Neisseria gonorrhoeae attachment to HeLa cells with monoclonal antibody directed against a protein II.

This study showed that a protein II (PII) of Neisseria gonorrhoeae FA1090 appeared to act as a mediator of attachment to HeLa cells. Two colony variants of FA1090 were selected. Both gonococcal variants were nonpiliated, but one contained a PII and the other did not. A monoclonal antibody (1090-10.1), which was directed against the PII, inhibited the apparent PII-mediated attachment to HeLa cells. Antibodies produced from clone 1035-4, which had no PII specificity, did not inhibit the attachment and were used as controls. Inhibition of gonococcal attachment by the 1090-10.1 monoclonal antibodies was demonstrated by fluorescent microscopy analysis. Monoclonal antibody 1090-10.1 appeared to cause agglutination of the PII-containing organism. To block the clumping caused by the PII-specific monoclonal antibodies, Fab fragments of goat anti-mouse IgG were incubated with gonococci and the 1090-10.1 monoclonal antibodies. The results showed that the goat anti-mouse IgG Fab fragments partially blocked the agglutination caused by the PII-specific monoclonal antibody. The effect of the 1090-10.1 antibodies on attachment was also determined by monitoring the HeLa cells with attached iodinated gonococci. The monoclonal antibody appeared to inhibit the PII-mediated attachment.

Animals↗