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M R Hammerschlag

Publications and source records attributed to M R Hammerschlag.

At least 73 records · Page 4Linked to original sources
PubMed1994

Susceptibilities to clarithromycin and erythromycin of isolates of Chlamydia pneumoniae from children with pneumonia.

We tested in vitro 49 isolates of Chlamydia pneumoniae obtained from 35 children with community-acquired pneumonia against clarithromycin and erythromycin. The children were part of a treatment study comparing the two drugs. Clarithromycin was 2- to 10-fold more active than erythromycin, with a MIC for 90% of strains tested and minimal chlamydiacidal concentration for 90% of strains tested of 0.031 microgram/ml compared with 0.125 microgram/ml for erythromycin. Eight of these children, two of whom were treated with erythromycin and six of whom received clarithromycin, remained culture positive after treatment. We were able to test 21 isolates from these children. All were susceptible to both drugs, and the MICs did not change after therapy.

Child↗
PubMed1994

Diagnostic utility of PCR-enzyme immunoassay, culture, and serology for detection of Chlamydia pneumoniae in symptomatic and asymptomatic patients.

To assess the utility of PCR-enzyme immunoassay (EIA) for diagnosis of acute infection with Chlamydia pneumoniae, we compared tissue culture, PCR-EIA, direct fluorescent-antibody (DFA) stain, and serology in studies with 56 patients with respiratory symptoms and 80 asymptomatic persons. Thirty-five patients were positive by either culture or PCR-EIA, and 101 were negative by both assays. Thirty specimens from symptomatic patients and one from an asymptomatic patient were culture positive; 23 of these were also PCR-EIA positive. Of the eight culture-positive, PCR-EIA-negative specimens, five were DFA negative and three were DFA positive. Four additional specimens were culture negative and PCR-EIA positive; of these, three were DFA positive and one was DFA negative. When we used culture- and/or DFA-positive results as a reference or "gold standard," the sensitivity and specificity of PCR were 76.5 and 99.0%, respectively. When we used PCR- and/or DFA-positive results as the reference, the sensitivity of culture was 87.5%. On the basis of single acute serum specimens, only 8 of these 35 patients had diagnostic antibody titers. Of the asymptomatic patients, 75% had immunoglobulin G or immunoglobulin M antibody to C. pneumoniae; 15 (18.8%) of these had antibody levels considered to be diagnostic of acute infection. This multicenter study indicates that culture and/or PCR-EIA is more reliable for prompt diagnosis of C. pneumoniae infection than single-point serology alone.

Adult↗
PubMed1994

Performance of three commercially available monoclonal reagents for confirmation of Chlamydia pneumoniae in cell culture.

We evaluated the performance of three commercially available monoclonal antibodies for confirmation of the presence of Chlamydia pneumoniae in cell culture by examining their abilities to stain inclusions of eight strains of C. pneumoniae. The antibodies tested were two unconjugated C. pneumoniae-specific monoclonal reagents and one conjugated genus-specific reagent. All three produced similar intensities of staining of C. pneumoniae, with some strain-to-strain variation. Methanol appeared to be a better choice of fixative than acetone, which greatly reduced the intensity of fluorescence with one of the species-specific antibodies.

Acetone↗
PubMed1993

Single dose of azithromycin for the treatment of genital chlamydial infections in adolescents.

We compared a single 1 gm dose of azithromycin with the standard 7-day course of doxycycline for the treatment of uncomplicated chlamydial genital infection in sexually active adolescents. Seventy-three adolescents (65 female) with a cervical or urethral culture positive for Chlamydia trachomatis were enrolled in the study; 46 received azithromycin and 27 received doxycycline. Follow-up evaluations were done 1, 2, and 4 weeks after treatment with azithromycin or initiation of treatment with doxycycline. There were four treatment failures (8.7%) among the patients who received azithromycin and four in the doxycycline-treated group (14.8%); all were female. Six of these girls (three treated with azithromycin and three with doxycycline) gave histories of unprotected intercourse with an untreated partner and were probably reinfected. Almost half the patients were clinically symptom free. The clinical response rate for the remaining patients with symptoms was 97.4% at 4 weeks. Nineteen percent of the azithromycin-treated patients and 33.3% of those treated with doxycycline had mild to moderate drug-related side effects, which were predominantly gastrointestinal. We conclude that treatment with a single oral dose of azithromycin appears to be as safe and efficacious as a 7-day course of doxycycline for the treatment of uncomplicated genital chlamydial infection in adolescents.

Administration, Oral↗
PubMed1993

Mycoplasma hominis and Ureaplasma urealyticum in neonates with suspected infection.

The role of genital mycoplasmas in the pathogenesis of neonatal infection is incompletely understood. We performed nasopharyngeal, blood and cerebrospinal fluid (CSF) cultures for Mycoplasma hominis and Ureaplasma urealyticum in 69 neonates who underwent a diagnostic workup for suspected sepsis. The mean gestational age was 35.9 weeks (range, 25 to 42 weeks) with a mean birth weight of 2386 g (range, 652 to 4420 g). Twenty-seven infants (39.1%) had positive nasopharyngeal cultures; 6 were positive for M. hominis, 10 for U. urealyticum and 11 for both organisms. Seven (26%) of these 27 patients developed chronic lung disease compared with 2 (4.7%) infants in the non-colonized group. Nine infants had positive CSF cultures for M. hominis and one infant had a positive CSF culture for U. urealyticum. All blood cultures were sterile. One of the infants with a positive CSF culture for M. hominis had clinical evidence of systemic infection. All of the infants were treated with antibiotic agents that were not active against mycoplasmas. These data indicate that genital mycoplasmas can be found commonly in the CSF and nasopharynx of infants with suspected sepsis. Their etiologic role in the causation of infection and chronic lung disease, however, remains unclear.

Cerebrospinal Fluid↗
PubMed1992

Persistent infection with Chlamydia pneumoniae following acute respiratory illness.

Chlamydia pneumoniae is emerging as a significant cause of respiratory disease, including pneumonia and bronchitis, in humans. In this recently completed study of infection due to C. pneumoniae in patients presenting with pneumonia to SUNY Health Science Center at Brooklyn, we identified two individuals for whom cultures were positive on multiple occasions over a 1-year period. To determine the frequency of persistent respiratory infection with C. pneumoniae, follow-up specimens were obtained from nine individuals with culture-documented C. pneumoniae infection. Five of these individuals had persistent infection: four had a flulike illness characterized by pharyngitis, and one had bronchitis with prominent bronchospasm. All five individuals appeared to have acute C. pneumoniae infection as determined by results of serologic tests (titers of IgM antibody for all individuals were greater than or equal to 1:16). For three patients, cultures remained positive for 11 months despite therapy with 10- to 21-day courses of tetracycline or doxycycline. These observations suggest that persistent infection with C. pneumoniae may follow acute infection and may persist for many months. Infection with C. pneumoniae may be very difficult to eradicate with use of currently available antibiotics even if there is a clinical response to therapy.

Acute Disease↗
PubMed1992

In vitro activities of five quinolones against Chlamydia pneumoniae.

The in vitro susceptibilities of 10 strains of Chlamydia pneumoniae were determined for five quinolones, including ciprofloxacin, ofloxacin, fleroxacin, temafloxacin, and sparfloxacin. Sparfloxacin was the most active compound tested, followed by ofloxacin and temafloxacin. Ciprofloxacin and fleroxacin were the least active. The use of HEp-2 cells for testing C. pneumoniae resulted in larger inclusions but essentially the same endpoints as were seen with use of HeLa 229 cells.

Anti-Infective Agents↗
PubMed1992

In vitro activities of azithromycin, clarithromycin, L-ofloxacin, and other antibiotics against Chlamydia pneumoniae.

The in vitro susceptibilities of 11 strains of Chlamydia pneumoniae to azithromycin, clarithromycin, erythromycin, L-oflaxacin, and doxycycline were determined. Clarithromycin was the most active agent tested, with an MIC for 90% of strains and minimal chlamydiacidal concentration for 90% of strains of 0.03 microns/ml. The activity of azithromycin was similar to those of erythromycin and doxycycline, with MICs for 90% of strains of 0.125 to 0.25 microns/ml. However, the prolonged half-life and enhanced tissue penetration of azithromycin should allow for less frequent dosing and shorter duration of therapy than with erythromycin or clarithromycin. L-Ofloxacin had activity similar to that of ofloxacin, with MICs of 0.125 to 0.5 micron/ml. From the results of this in vitro study, azithromycin and clarithromycin appear to be effective antibiotics that may have a role in the treatment of infections due to C. pneumoniae.

Anti-Bacterial Agents↗
PubMed1992

Comparison of a chemiluminometric immunoassay with culture for diagnosis of chlamydial infections in infants.

The performance of Magic Lite (CIBA-Corning), a chemiluminescent immunoassay (CIA), was compared with that of culture for the diagnosis of neonatal chlamydial conjunctivitis and respiratory infection. We performed a retrospective evaluation of 51 ocular and 96 nasopharyngeal specimens previously collected for culture testing with the CIA. The sensitivities for the ocular and the nasopharyngeal specimens were 91 and 91.7%, respectively. The specificities for both sites were 100%. A subsequent prospective study evaluating 71 ocular and 38 nasopharyngeal specimens revealed sensitivities of 83.3 and 20%, respectively. The specificities for both sites were 100%. The CIA performed favorably, compared with culture, for the diagnosis of chlamydial conjunctivitis; however, the CIA appeared less sensitive for the diagnosis of respiratory infection, including pneumonia.

Antigens, Bacterial↗
PubMed1992

Use of HEp-2 cells for improved isolation and passage of Chlamydia pneumoniae.

Chlamydia pneumoniae has proved to be difficult to isolate and propagate in cell culture. We compared the growth of three strains of C. pneumoniae, TW-183 and two clinical isolates from Brooklyn, N.Y., in five cell lines, including HeLa 229, McCoy, HL, HEp-2, and HTED, an immortalized human tracheal cell line. HEp-2 was the most sensitive cell line tested. When 10-fold dilutions of three C. pneumoniae strains at known titers were inoculated into the different cell lines, the mean number of inclusion-forming units per milliliter was 1 to 2 log units higher in the HEp-2 than in the other cell lines. This difference was statistically significant. Omission of pretreatment with DEAE-dextran resulted in larger inclusions than those seen in pretreated cells, with the exception of McCoy and HTED cells. Retrieval of clinical specimens previously cultured on HeLa 229 cells and comparison of mean inclusion counts in fresh clinical specimens simultaneously inoculated on HeLa 229 and HEp-2 cells suggested that culture in HEp-2 cells may require only the initial inoculation and one passage, compared with three to four passages, as required by culture in HeLa 229 cells.

Bacteriological Techniques↗