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Biomedical subjects

M R Hammerschlag

Publications and source records attributed to M R Hammerschlag.

At least 55 records · Page 3Linked to original sources
PubMed1998

In vitro activity of a new ketolide antibiotic, HMR 3647, against Chlamydia pneumoniae.

The in vitro activities of HMR 3647, roxithromycin, erythromycin, and azithromycin against 19 strains of Chlamydia pneumoniae were tested. The MIC at which 90% of the isolates are inhibited and the minimum bactericidal concentration at which 90% of the isolates are killed of HMR 3647 were 0.25 microgram/ml (range, 0.015 to 2 micrograms/ml). Nine recently obtained clinical isolates from children with pneumonia were more susceptible (MICs, 0.015 to 0.0625 microgram/ml) than older strains that had been passaged more extensively.

Anti-Bacterial Agents↗
PubMed1998

Sexually transmitted diseases in sexually abused children: medical and legal implications.

Sexually transmitted diseases (STDs) may be transmitted during sexual assault. In children, the isolation of a sexually transmitted organism may be the first indication that abuse has occurred. Although the presence of a sexually transmissible agent from a child beyond the neonatal period is suggestive of sexual abuse, exceptions do exist. In this review I discuss the issues of the transmissibility and diagnosis of STDs in the context of child sexual abuse. Rectal or genital infection with Chlamydia trachomatis among young children may be the result of perinatally acquired infection and may persist for as long as 3 years. A major problem with chlamydia testing in the context of suspected sexual abuse in children has been the inappropriate use of non-culture tests. Although the new generation of nucleic acid amplification tests have shown high sensitivity and specificity with genital specimens from adults, data on use of these tests on any site in children are practically non-existent. Bacterial vaginosis (BV) has been identified among children who have been abused and among those who have not been abused. However, many of the methods used to diagnose BV in adults have not been evaluated in children. Recent studies of perinatal infection with human papillomavirus (HPV) have been inconclusive. HPV DNA has been detected at various sites in children who have not been abused. The relation to the development of clinically apparent genital warts is unclear. Although HIV can be acquired through sexual abuse in children, the exact risk to the child and which children should be screened is still controversial.

Child↗
PubMed1997

In-vitro activity of dirithromycin against Chlamydia pneumoniae.

The in-vitro susceptibilities of 12 strains of Chlamydia pneumoniae were determined for dirithromycin, a new macrolide antibiotic, erythromycyclamine, its active metabolite, and erythromycin. Both dirithromycin and erythromycyclamine had an MIC90 of 2 mg/L, as compared with 0.062 mg/L for erythromycin. The combination of dirithromycin and erythromycyclamine appeared to be additive. Determination of the role of dirithromycin for the treatment of C. pneumoniae infection will depend on the results of prospective, controlled studies utilizing culture.

Anti-Bacterial Agents↗
PubMed1997

Use of polymerase chain reaction for the detection of Chlamydia trachomatis in ocular and nasopharyngeal specimens from infants with conjunctivitis.

BACKGROUND: Chlamydia trachomatis is the most common identifiable infectious cause of neonatal conjunctivitis. Nonculture tests including enzyme immunoassays and direct fluorescent antibody tests have been shown to perform well for the diagnosis of chlamydial conjunctivitis with sensitivities and specificities > or = 90%. However, the performance with respiratory specimens has been less than satisfactory. METHODS: We compared a new, commercially available polymerase chain reaction (PCR) assay, Roche AMPLICOR (Roche Diagnostic Systems, Branchburg, NJ) with culture for the detection of C. trachomatis in conjunctival and nasopharyngeal specimens from infants with conjunctivitis. We also evaluated AMPLICOR for the detection of C. trachomatis in the urine of mothers of positive infants. RESULTS: Ocular and nasopharyngeal specimens from 75 infants with conjunctivitis were obtained for culture and PCR. AMPLICOR was equivalent to culture for eye specimens and more sensitive than culture for nasopharyngeal specimens. The sensitivity, specificity and positive and negative predictive values of PCR compared with culture for conjunctival specimens were 92.3, 100, 100 and 98.4%, respectively. The sensitivity, specificity and positive and negative predictive values for nasopharyngeal specimens were 100, 97.2, 60 and 100%, respectively. We also detected C. trachomatis by PCR in the urine of 12 mothers of culture positive infants. CONCLUSIONS: PCR performed comparably to culture for detection of C. trachomatis in conjunctival and nasopharyngeal specimens from infants with conjunctivitis.

Bacteriological Techniques↗
PubMed1997

Chlamydia pneumoniae in acute otitis media.

BACKGROUND: Aerobic bacterial pathogens are recovered from 65 to 85% of patients with acute otitis media (AOM). Although Chlamydia pneumoniae is a common pathogen of pediatric pneumonia, it has rarely been cultured from children with chronic otitis media and its role in AOM is unknown. METHODS: We cultured for C. pneumoniae in tympanocentesis aspirates and nasopharyngeal swabs from 101 consecutive, otherwise healthy children with AOM or refractory AOM. A control group of 50 similarly aged, healthy children was evaluated for nasopharyngeal carriage of C. pneumoniae. Specimens were also evaluated by PCR for C. pneumoniae. RESULTS: C. pneumoniae was recovered by tympanocentesis in 8 (8%) of 101 children with AOM. Among the 8 children with C. pneumoniae-positive-AOM, 5 had C. pneumoniae detected by PCR in middle ear fluid, none had C. pneumoniae recovered by nasopharyngeal culture or PCR and 5 were younger than 16 months. C. pneumoniae was the sole pathogen isolated in 2 patients. Copathogens included beta-lactamase-positive positive Haemophilus influenzae (2), beta-lactamase positive Moraxella catarrhalis (1), penicillin-resistant Streptococcus pneumoniae (2) and penicillin-susceptible S. pneumoniae (1). C. pneumoniae was recovered from nasopharyngeal culture in 2 additional patients with C. pneumoniae-negative AOM and in none of 50 healthy control children, although 2 controls were positive by PCR from the nasopharynx. CONCLUSIONS: This is the first study to report the isolation of C. pneumoniae in middle ear fluid of children with AOM.

Acute Disease↗
PubMed1997

In vitro activity of trovafloxacin against Chlamydia pneumoniae.

The in vitro susceptibilities of 12 strains of Chlamydia pneumoniae to a new quinolone, trovafloxacin, and ofloxacin, doxycycline, erythromycin, and azithromycin were determined. The activity of trovafloxacin was similar to that of ofloxacin, with a MIC at which 90% of the isolates are inhibited and a minimal concentration at which 90% of the isolates are killed of 1.0 microg/ml, but trovafloxacin was less active than doxycycline, erythromycin, and azithromycin.

Anti-Bacterial Agents↗
PubMed1997

Evaluation of Chlamydia immunoglobulin M (IgM), IgG, and IgA rELISAs Medac for diagnosis of Chlamydia pneumoniae infection.

Chlamydia pneumoniae is an important pathogen responsible for a variety of respiratory diseases in humans. Cell culture remains the most specific method for C. pneumoniae diagnosis, but it is labor-intensive and time-consuming. Thus, serology, particularly microimmunofluorescence (MIF) testing, is frequently utilized. However, the MIF test has a significant subjective component. We evaluated a new serological test: Chlamydia Immunoglobulin M (IgG, IgA, and IgM rELISAs Medac, based on a recombinant Chlamydia-specific lipopolysaccharide (LPS) fragment, for the diagnosis of C. pneumoniae infection. The results of this study demonstrated that the use of rELISAs Medac with single sera does not appear to be sensitive or specific for diagnosis of C. pneumoniae infection compared to culture. In children, sensitivities of the rELISAs compared to culture did not exceed 34.2%, and the specificities ranged from 68.4% (IgG) to 91.2% (IgA). In adults, the sensitivities of the rELISAs were slightly higher, up to 77.8% (IgA or IgG), but the specificities ranged from a very low 20.8% for IgA or IgG to 81.1% for IgM. When multiple sera were tested, the results of the rELISAs Medac correlated with culture results in five of eight (62.5%) patients. However, this offers only a retrospective diagnosis, which makes it difficult to manage these patients prospectively.

Adolescent↗
PubMed1997

Evaluation of a new optical immunoassay for diagnosis of neonatal chlamydial conjunctivitis.

The BioStar OIA Chlamydia test (BioStar, Inc., Boulder, Colo.) is a novel immunoassay system that uses changes in reflection of light to directly detect chlamydial antigen in clinical specimens. We compared the optical immunoassay (OIA) with culture for detecting Chlamydia trachomatis in ocular specimens from infants with suspected chlamydial conjunctivitis. We initially performed a retrospective evaluation, testing 152 ocular specimens previously collected for culture with the OIA. The sensitivity and specificity were 94.2 and 97%, respectively. A subsequent prospective study evaluating 37 ocular specimens from infants with suspected C. trachomatis conjunctivitis revealed a sensitivity and specificity of 100 and 92.6%, respectively.

Antigens, Bacterial↗
PubMed1996

Chlamydia pneumoniae infection in patients with cystic fibrosis.

The prevalence of atypical community-acquired infections as acute pulmonary exacerbations in patients with cystic fibrosis was prospectively studied. Thirty-two patients admitted to the hospital because of acute pulmonary exacerbations and 24 clinically stable patients seen for their routine visits were examined. The prevalence of infection with Chlamydia pneumoniae was assessed by culture and serology, and the presence of IgE to C. pneumoniae was studied by immunoblotting. A subgroup of patients was also examined for the presence of Mycoplasma pneumoniae infection. C. pneumoniae was isolated from four patients presenting with acute pulmonary exacerbations (12.5%) and from none of the stable patients; all patients for whom cultures were positive also had IgE to C. pneumoniae. Polymerase chain reaction analysis for M. pneumoniae was not positive for any patient, and only one patient with an acute exacerbation had an antibody titer compatible with a recent infection. We conclude that infection with C. pneumoniae is associated with acute pulmonary exacerbations in some patients with cystic fibrosis and that it may trigger the production of IgE specific to C. pneumoniae, thus leading to bronchial reactivity in these patients.

Adolescent↗
PubMed1996

Failure to detect Chlamydia pneumoniae in coronary atheromas of patients undergoing atherectomy.

To further investigate a proposed relationship between Chlamydia pneumoniae and coronary heart disease, coronary atheromas were collected from patients undergoing percutaneous atherectomy. Fifty-eight atheroma specimens were examined by culture and polymerase chain reaction (PCR) and 22 by electron microscopy. All were negative for C. pneumoniae, except a single specimen that was PCR-positive. These results differ from studies in other populations, in which this organism was identified by nonculture methods within coronary atheromas obtained at autopsy. Anti-C. pneumoniae antibody titers from 65 of the patients were compared with those of 28 asymptomatic controls. IgG titers were higher in controls than in patients. There is no evidence that C. pneumoniae exists within atheromas in this study population, nor does seroprevalence correlate with the presence of coronary disease in these patients.

Adult↗
PubMed1996

Effect of hydrocortisone succinate on growth of Chlamydia pneumoniae in vitro.

We examined the effect of hydrocortisone succinate on the growth of three isolates of Chlamydia pneumoniae in vitro. There was a significant increase in the number of inclusions seen in two of the C. pneumoniae strains in the presence of hydrocortisone. There was no significant increase in the number of inclusions with various concentrations of hydrocortisone over time. The addition of hydrocortisone did not affect the in vitro activities of azithromycin, erythromycin, and doxycycline against C. pneumoniae.

Chlamydophila pneumoniae↗
PubMed1995

Prevalence of asymptomatic nasopharyngeal carriage of Chlamydia pneumoniae in subjectively healthy adults: assessment by polymerase chain reaction-enzyme immunoassay and culture.

Although Chlamydia pneumoniae is a well-described and common respiratory tract pathogen, up to 90% of infections with this organism are thought to be asymptomatic. Because asymptomatic infection with C. pneumoniae has not been studied in a systematic manner, we conducted a prospective study of healthy adults to establish the prevalence of asymptomatic infection. Nasopharyngeal swab specimens were obtained from 104 subjectively healthy people and evaluated by culture and polymerase chain reaction-enzyme immunoassay (PCR-EIA) for the presence of the organism. Serum obtained from 103 of these individuals was tested by microimmunofluorescence for the titer of specific antibody to C. pneumoniae. For two individuals, C. pneumoniae was identified in nasopharyngeal specimens by culture and/or PCR-EIA; one of these individuals had an IgG titer of 1:256, whereas the other had no detectable antibody. Of the remaining 101 individuals with negative culture and PCR-EIA results, 19 fulfilled presently accepted serological criteria for acute infection; i.e., the IgM titer was > or = 1:16, the IgG titer was > or = 1:512, or both. On the basis of our findings, we conclude that asymptomatic upper airway infection and carriage with C. pneumoniae occur among subjectively healthy persons; we also propose that such individuals may represent a reservoir for this organism in the community. Further, this study demonstrates that currently available diagnostic tests for C. pneumoniae may be unable to accurately distinguish between infection responsible for respiratory tract disease and that representing carriage.

Adult↗
PubMed1995

Detection of anti-Chlamydia pneumoniae IgE in children with reactive airway disease.

An association of Chlamydia pneumoniae infection and reactive airway disease has been demonstrated in children. To determine if C. pneumoniae infection triggers production of C. pneumoniae-specific IgE, sera were examined from 45 children with and without C. pneumoniae infection. Anti-C. pneumoniae IgE was demonstrated by immunoblotting in 12 (85.7%) of 14 culture-positive asthmatic patients with wheezing compared with only 1 (9.1%) of 11 culture-positive patients with pneumonia, 2 (18.2%) of 11 culture-negative asthmatic children with wheezing, and 2 (22.2%) of 9 culture-negative asymptomatic patients. The most commonly recognized proteins were at 98 (82.4%), 78 (58.8%), 58-60 (70.6%), and 36 kDa (64.7%). The presence of anti-C. pneumoniae IgE by immunoblotting was not associated with the presence of anti-C. pneumoniae IgG and IgM by microimmunofluorescence. These results suggest that production of specific IgE may be an underlying mechanism leading to reactive airway disease in some patients with C. pneumoniae infection.

Adolescent↗
PubMed1995

Mycoplasma pneumoniae and Chlamydia pneumoniae in pediatric community-acquired pneumonia: comparative efficacy and safety of clarithromycin vs. erythromycin ethylsuccinate.

We evaluated 260 previously healthy children ages 3 through 12 years who had clinical signs and symptoms of pneumonia, radiographically confirmed. Patients were randomized 1:1 to a 10-day course of either clarithromycin suspension 15 mg/kg/day divided twice a day or erythromycin suspension 40 mg/kg/day divided twice a day or three times a day. Evidence of infection with Chlamydia pneumoniae was detected in 28% (74) of patients: 13% (34) by nasopharyngeal culture and 18% (48) by serology with the microimmunofluorescence assay. Evidence of infection with Mycoplasma pneumoniae was detected in 27% (69) of patients: 20% (53) by nasopharyngeal culture or polymerase chain reaction and 17% (44) by serology with the use of enzyme-linked immunosorbent assay. Serologic confirmation of infection was observed in 23% (8) and 53% (28) of patients with bacteriologically detected C. pneumoniae and M. pneumoniae, respectively. Treatment with clarithromycin vs. erythromycin, respectively, yielded the following outcomes: clinical success 98% (121 of 124) vs. 95% (105 of 110); radiologic success 98% (109 of 111) vs. 94% (92 of 110); and eradication by pathogen, C. pneumoniae 79% (15 of 19) vs. 86% (12 of 14) and M. pneumoniae 100% (9 of 9) vs. 100% (4 of 4). Adverse events were primarily gastrointestinal occurring in almost one-fourth of patients in both groups, and were mild to moderate in severity. Clarithromycin and erythromycin were similarly effective and safe for the treatment of radiographically proved, community-acquired pneumonia in children older than 2 years old.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1995

Atypical pneumonias in children.

The major agents responsible for atypical pneumonia in children include a wide variety of organisms, one Mycoplasma species, two Chlamydia species, a rickettsia, and one fastidious bacterium. Mycoplasma pneumoniae and C. pneumoniae together may be responsible for over 40% of these infections. Recognition of the role that these agents play in pneumonia is important since many of the diagnostic methods used to detect these organisms are not available in most hospital microbiology laboratories. If you don't look, you won't find. Epidemiologic factors can provide valuable clues, especially with the less frequently encountered infections, since it is almost impossible to make a clinical diagnosis on which to base treatment. A reliable history of avian exposure should suggest psittacosis, exposure to sheep or pregnant cats suggests Q fever, and children with underlying malignancy or immunodeficiency or those receiving systemic steroids may have legionnaires' disease. None of these organisms are susceptible to beta-lactam antibiotics. Sometimes the diagnosis is not considered until after the child has failed to respond to a penicillin or a cephalosporin and routine bacteriology is negative. In view of the role played by M. pneumoniae and C. pneumoniae, a macrolide may be the first-line antibiotic for atypical pneumonia in children.

Child↗
PubMed1994

The association of Chlamydia pneumoniae infection and reactive airway disease in children.

OBJECTIVE: To determine the possible association of Chlamydia pneumoniae infection and reactive airway disease in children. DESIGN: Prospective observational study. SETTING: Pediatric emergency department in Children's Medical Center of Brooklyn (NY), Kings County Hospital Center. PARTICIPANTS: One hundred eighteen children with acute episodes of wheezing and 41 age- and sex-matched healthy controls, aged 5 to 16 years. INTERVENTIONS: Children with cultures positive for C pneumoniae were treated with antibiotics. MEASUREMENTS/MAIN RESULTS: Cultures for C pneumoniae and serum samples for antibody testing were obtained from subjects and healthy controls. We isolated C pneumoniae from 13 (11%) children with wheezing and from two (4.9%) controls. Seven (58.3%) of 12 children with positive cultures had no detectable antibody to C pneumoniae and only three (25%) children had serologic evidence of acute infection. Six children had positive cultures on multiple occasions, ranging from 1 to 5 months. The children with wheezing were treated with erythromycin or clarithromycin, a new macrolide antibiotic approved for use in adults; all eventually had a negative culture. Nine (75%) of these children demonstrated clinical and laboratory improvement of the reactive airway disease after the eradication of chlamydial infection. CONCLUSIONS: Infection with C pneumoniae can trigger acute episodes of wheezing in children with asthma. Treatment of C pneumoniae infection may improve the course of reactive airway disease in these patients.

Adolescent↗