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G Mumtaz

Publications and source records attributed to G Mumtaz.

11 recordsLinked to original sources

The in-vitro activity of clarithromycin and other macrolides against the type strain of Chlamydia pneumoniae (TWAR).

The activity of oxytetracycline and seven macrolide antibiotics was investigated against a prototype strain of Chlamydia pneumoniae in cell culture. Following incubation, inoculated cell monolayers were fixed in methanol and stained with a genus specific immunofluorescent monoclonal antibody before examination for inhibition of inclusion formation. The most active agent was clarithromycin (MIC 0.007 mg/l), followed by erythromycin (0.06 mg/l). Other macrolides were less active; josamycin and roxithromycin (0.25 mg/l), midecamycin acetate and azithromycin (0.5 mg/l) and spiramycin (4.0 mg/l). The MIC of oxytetracycline was 0.25 mg/l. Clinical evaluation of clarithromycin for C. pneumoniae lower respiratory infection is indicated.

Anti-Bacterial Agents

The in-vitro antibiotic susceptibility of Chlamydia pneumoniae.

A cell culture technique was used to test the in-vitro susceptibility of the type strain of Chlamydia pneumoniae to 23 antibiotics including macrolides, tetracyclines and quinolones. The activity of the antibiotics tested was similar to previous findings with C. trachomatis. Clarythromycin had the lowest MIC overall (0.007 mg/l). Other macrolides were found to have similar MICs to erythromycin (0.06 mg/l). Both the macrolides and the tetracyclines were more active than the quinolones. It is proposed that the tetracyclines and erythromycin should be the drugs of choice for treating infections with C. pneumoniae; however several other antibiotics need to be evaluated.

4-Quinolones

Confirmatory assay increases specificity of the chlamydiazyme test for Chlamydia trachomatis infection of the cervix.

Enzyme immunoassays for the detection of chlamydial antigens are commonly used to diagnose Chlamydia trachomatis infection. As is true for all nonculture methods, the specificities of these tests are a concern. A confirmatory blocking assay (Abbott Laboratories, North Chicago, Ill.) was evaluated at four sexually transmitted disease test sites. This assay is designed to confirm true-positive Chlamydiazyme (CZ) specimens and to identify false-positive CZ reactions caused by cross-reacting bacteria. Cervical specimens were collected from 2,891 women. Chlamydia prevalence by tissue culture (TC) was 9.2% (266 of 2,891 specimens). Compared with TC, the sensitivity and specificity of CZ were 78.9% (210 of 266 specimens) and 98.2% (2,577 of 2,625 specimens), respectively. There were 48 CZ false-positive reactions. The direct fluorescent-antibody test (DFA) was positive for 31 of 48 false-positive reactions, indicating culture misses. Thus, when the standard was both TC and DFA, CZ sensitivity was 81.1% and CZ specificity was 99.3%. Of the 17 CZ-positive patients who were negative by both TC and DFA, 3 were negative on repeat CZ and 11 of 14 were identified as false positive by the confirmatory assay. The confirmatory test was positive for CZ-positive women who were positive by TC or DFA. Use of the confirmatory test, which increased the specificity to 99.9%, would increase confidence in positive CZ results and make the test more useful for screening populations with a low prevalence of C. trachomatis infection.

Adult

Is a test of cure necessary following treatment for cervical infection with Chlamydia trachomatis?

Tests of cure (TOC) were performed on specimens from 106 women following treatment for chlamydial infection of the cervix. 91 women attended for the first TOC with enzyme immunoassay (EIA) within one week of finishing antibiotics. Three were EIA positive, 88 were EIA negative. These three women were subsequently EIA and culture negative although they received no further antibiotics. Ninety women returned for the second TOC with EIA and culture between seven and 27 days after completing treatment. All the results were negative. Routine TOC is unnecessary following appropriate antichlamydial therapy. If TOC is indicated antigen-detection methods should not be used immediately after finishing antibiotics as misleading positive results may be obtained. EIA or culture at one week or later after treatment is reliable.

Chlamydia Infections

Comparison of an enzyme immunoassay (Ortho) with cell culture and immunofluorescence for the detection of genital chlamydial infection.

An enzyme immunoassay (EIA) test (Ortho Diagnostic Systems Ltd) was evaluated against cell culture for the detection of chlamydial genital infection. Specimens were obtained from 409 patients (204 men and 205 women). Sensitivity, specificity, predictive value of a positive result (PVP) and predictive value of a negative result (PVN) for the new test compared to cell culture were respectively 73.1%, 93.8%, 63.3% and 96% for men and 80%, 95.6%, 71.4% and 97.2% for women. Discrepancies were further evaluated by repeating the EIA, and by direct immunofluorescence (IF) on the EIA transport buffer. The sensitivity, specificity, PVP and PVN of the EIA against the combination of cell culture and direct IF were respectively 76.7%, 96%, 76.7% and 96% for men, and unchanged for women. Overall agreement between the EIA and the combination of cell culture and direct IF was 93.4%. The EIA is rapid and simple to perform and does not require elaborate equipment.

Cells, Cultured

Enzyme immunoassay compared with cell culture and immunofluorescence for detecting genital chlamydia.

A novel enzyme immunoassay test (Pharmacia EIA) was evaluated against cell culture for the detection of chlamydial genital infection. Specimens were obtained from 525 patients (257 men and 268 women). Sensitivity, specificity, predictive value of positive (PVP) and predictive value of negative (PVN) for the new test were, respectively, 83.6, 98.5, 94.4 and 95.1% for men and 86, 97.2, 87.8 and 96.8% for women. Discrepancies were further evaluated by repeating the EIA, and by direct immunofluorescence on the EIA transport buffer. The sensitivity, specificity, PVP and PVN of the EIA against the combination of cell culture and direct immunofluorescence were, respectively 85.9, 100, 100, and 95.5% for men, and 90.5, 98.1, 92.3 and 97.7% for women. Overall agreement between the EIA and the combination of cell culture and direct immunofluorescence was 97%. The Pharmacia EIA is rapid and simple to perform and does not require elaborate equipment.

Bacteriological Techniques

Comparative in vitro activity of lomefloxacin, a difluoro-quinolone.

Lomefloxacin is a new difluoro-quinolone. In this study, we have determined the in vitro activity of lomefloxacin against a wide range of clinical bacterial isolates and compared it with that of other fluoro-quinolones and some unrelated antimicrobials. Lomefloxacin was very active against Enterobacteriaceae (MIC90, 0.5 micrograms/ml) with activity comparable to that of ofloxacin (MIC90, 0.25 micrograms/ml). Lomefloxacin was moderately active against isolates of Pseudomonas aeruginosa (MIC90, 4 micrograms/ml), and again the activity was comparable to ofloxacin (MIC90, 4 micrograms/ml) but was eightfold less than ciprofloxacin (MIC90, 0.5 micrograms/ml). Lomefloxacin was also active against isolates of Staphylococcus aureus (MIC90, 1 micrograms/ml), irrespective of methicillin susceptibility, and this activity was most comparable to ofloxacin (MIC90, 0.5 micrograms/ml) and ciprofloxacin (MIC90, 0.5 micrograms/ml). Lomefloxacin was fourfold less active than either ofloxacin or ciprofloxacin against isolates of Enterococcus faecalis (MIC90, 8 micrograms/ml) and Streptococcus pneumoniae (MIC90, 8 micrograms/ml). In common with ofloxacin and ciprofloxacin, lomefloxacin was very active against isolates of Neisseria spp. (MIC90, less than or equal to 0.06 micrograms/ml), Haemophilus spp. (MIC90, less than or equal to 0.06 micrograms/ml), Legionella spp. (MIC90, less than or equal to 0.06 micrograms/ml), Vibrio spp. (MIC90, less than or equal to 0.06 micrograms/ml), and Campylobacter jejuni (MIC90, 1 microgram/ml). Lomefloxacin showed poor activity against isolates of Bacteroides spp. (MIC90, 16 micrograms/ml) or Clostridium difficile MIC90, 32 micrograms/ml) and was only moderately active against isolates of Clostridium perfringens (MIC90, 2 micrograms/ml), Peptostreptococcus spp. (MIC90, 4 micrograms/ml), Chlamydia trachomatis (MIC90, 4 micrograms/ml), Mycoplasma hominis (MIC90, 2 micrograms/ml), and Urea-plasma urealyticum (MIC90, 8 micrograms/ml). Lomefloxacin was found to be bactericidal at concentrations generally close to the MIC with greater than 3 log10 reduction in viability of exponentially dividing cultures of Escherichia coli and S. aureus within 5 hr of exposure to concentrations at eight times the MIC. These results indicate a potential clinical role for lomefloxacin in the treatment of genitourinary tract infections caused by Gram-positive and Gram-negative bacteria, respiratory tract infections caused by susceptible organisms, and soft tissue infections caused by S. aureus.

4-Quinolones

Azithromycin vs doxycycline in the treatment of non-gonococcal urethritis.

Azithromycin is a novel azalide macrolide active against Chlamydia trachomatis and Ureaplasma urealyticum. High persistent tissue concentrations allow short courses or even single doses to be considered. Sixty-two patients were studied, 19 received azithromycin 1 g in a single dose, 22 received azithromycin 500 mg in a single dose on day 1 followed by 250 mg once daily for 2 days and 21 received doxycycline 200 mg in a loading dose followed by 100 mg every 12 h for 7 days. Efficacy of these 3 regimens was compared in the treatment of non-gonococcal urethritis (NGU). Clearance of C. trachomatis from post-treatment cultures was satisfactory with all regimens. Response defined as the absence of symptoms and reduction in polymorphonuclear leucocytes in a Gram stained smear of urethral secretion to less than 5 cells per hpf (x 100 objective) was statistically better for the 3 day regimen of azithromycin than for the other 2 regimens. All treatments were well tolerated. Three days or single doses of azithromycin compared to 7 days of tetracycline (or 10-14 days as is often prescribed) have obvious advantages for patient compliance.

Administration, Oral

Evaluation of an enzyme immunoassay (Chlamydiazyme) with confirmatory test for the detection of chlamydial antigen in urine from men.

First catch urine specimens from 312 male patients were examined for the presence of chlamydial antigen by an enzyme immunoassay (Chlamydiazyme). Positive results were repeated and confirmed using a blocking assay. In addition, urethral swabs were examined by cell culture for Chlamydia trachomatis. Discrepant results were further analysed by direct immunofluorescence (IF) of the spun urine deposit. Paired specimens were positive from 26 subjects, and negative from 276 subjects. Eight paired specimens were urethral culture positive, and urine EIA negative. Two specimens, urine EIA positive but urethral culture negative, were positive on direct IF. The sensitivity, specificity, predictive value of a positive result, and predictive value of a negative result for urine EIA against cell culture and/or direct IF were 77.8%, 100%, 100% and 97.2% respectively.

Chlamydia Infections