Is Chlamydia pneumoniae infection associated with stroke in children with sickle cell disease?

BACKGROUND: Stroke is often a devastating complication of sickle cell disease (SCD). Most children with SCD-related stroke have stenotic and occlusive disease of cerebral blood vessels due to intimal hyperplasia. This hyperplasia is hypothesized to result from an inflammatory response similar to that in atherosclerosis and has been attributed to infection by Chlamydia pneumoniae. OBJECTIVE: To determine whether C pneumoniae infection is associated with stroke and cerebrovascular disease, including transient ischemic attacks and abnormal transcranial Doppler examinations, in children with SCD. METHODS: Children with SCD on chronic transfusion due to a history of stroke, transient ischemic attack, or abnormal transcranial Doppler; children with SCD without stroke; healthy controls; and children being transfused for other reasons were enrolled. Peripheral blood and nasopharyngeal (NP) swab specimens were collected from all patients. In patients on transfusion, pretransfusion specimens and samples from the unit of packed red blood cells being transfused were obtained. Peripheral blood monocytic cells (PBMCs) and NP swab specimens were cultured for C pneumoniae in HEp-2 cells. C pneumoniae polymerase chain reaction was performed on PBMCs with a nested touch-down method with primers from the omp-1gene (in duplicate) and a second real-time polymerase chain reaction by using 16S ribosomal RNA primers. RESULTS: C pneumoniae DNA was detected in the PBMCs of 1 of 14 (7.1%) children with SCD on chronic transfusion, 1 of 10 (10%) sickle cell controls, 1 of 10 (10%) healthy controls, and none of the 5 children receiving chronic transfusion for other reasons. It was not detected in specimens from transfusion units. One child with SCD and stroke, 1 sickle cell control, and 1 transfusion control had positive NP cultures for C pneumoniae. C pneumoniae DNA was not detected in their PBMCs, and all 3 children were asymptomatic. C pneumoniae was not detected by culture of PBMCs from any of the patients after 7 passages. CONCLUSION: Stroke in children with SCD does not seem to be associated with C pneumoniae infection in our population.

The role of Chlamydia pneumoniae infection in children with chronic sinusitis.

BACKGROUND: Chlamydia pneumoniae infection is a frequent cause of lower respiratory disease in both adults and children. However, its role in upper respiratory disease, including sinusitis, is less clear. OBJECTIVE: To determine the role of infection with C. pneumoniae in chronic sinusitis in children. DESIGN: Prospective collection of specimens. SETTING: Tertiary care academic medical center. PARTICIPANTS: Children with clinical and radiologic evidence of chronic sinusitis unresponsive to medical management undergoing adenoidectomy, maxillary sinus lavage, or endoscopic sinus surgery for treatment. Intervention Nasopharyngeal and middle meatal swabs and portions of surgical specimens were obtained and cultured for C. pneumoniae. RESULTS: Specimens were obtained from 20 children (14 boys and 6 girls) aged 3 through 16 years. Thirteen bilateral endoscopic ethmoidectomies with maxillary antrostomies, 10 adenoidectomies, and 3 bilateral maxillary sinus lavages were performed. Chlamydia pneumoniae was isolated from the nasopharyngeal swab and adenoid tissue of 1 child (aged 6 years); however, his middle meatal swabs and maxillary sinus aspirates were negative. After 10 days of treatment with clarithromycin, repeat nasopharyngeal cultures were negative for C. pneumoniae. CONCLUSIONS: With the use of sensitive culture methods, C. pneumoniae was not isolated from sinus specimens of children enrolled in this study. This preliminary study suggests that C. pneumoniae does not play a significant role in chronic sinusitis in children.

In vitro activity of garenoxacin against recent clinical isolates of Chlamydia pneumoniae.

The in vitro activities of garenoxacin, a novel des-F (6)-quinolone, levofloxacin, moxifloxacin and clarithromycin were tested against 30 recent clinical isolates of Chlamydia pneumoniae. The minimal inhibitory concentration (MIC) at which 90% of the isolates were inhibited and the minimal bactericidal concentration (MBC) at which 90% of the isolates were killed by garenoxacin for C. pneumoniae was 0.03 mg/l (range 0.015-0.03 mg/l).

Microbiological efficacy of ABT-773 (cethromycin) for the treatment of community-acquired pneumonia due to Chlamydia pneumoniae.

Nasopharyngeal specimens for culture of Chlamydia pneumoniae were obtained from patients with community-acquired pneumonia enrolled in a randomized study comparing the novel ketolide antibiotic ABT-773 at a dose of 150 mg once a day to 150 mg twice a day, by mouth for 10 days. C. pneumoniae was eradicated from the nasopharynx of 10 of 10 (100%) microbiologically evaluable patients. MICs and MBCs for 13 isolates of C. pneumoniae from 12 patients obtained before and after therapy were performed against ABT-773. The MIC90 and MBC90 of ABT-773 were 0.015 mg/L.

In vitro activities of rifamycin derivatives ABI-1648 (Rifalazil, KRM-1648), ABI-1657, and ABI-1131 against Chlamydia trachomatis and recent clinical isolates of Chlamydia pneumoniae.

ABI-1648 (rifalazil) is a semisynthetic rifamycin with potent bactericidal activity against intracellular respiratory bacteria, including Mycobacterium tuberculosis, and a long half-life (approximately 60 h) and thus can be administered once weekly. We therefore tested the in vitro activities of ABI-1648, its derivatives ABI-1657 and ABI-1131, azithromycin, and levofloxacin against 10 strains of Chlamydia trachomatis and 10 recent clinical isolates of Chlamydia pneumoniae. The MICs at which 90% of the isolates were inhibited and the minimal bactericidal concentration at which 90% of the isolates were killed for ABI-1648, ABI-1657, and ABI-1131 were 0.0025 micro g/ml for C. trachomatis and 0.00125 to 0.0025 micro g/ml for C. pneumoniae. ABI-1648, ABI-1657, and ABI-1131 were 10- to 1,000-fold more active than azithromycin and levofloxacin.

In vitro activities of BMS-284756 against Chlamydia trachomatis and recent clinical isolates of Chlamydia pneumoniae.

The in vitro activities of BMS-284756 (a novel des-fluoroquinolone), levofloxacin, moxifloxacin, and clarithromycin were tested against 5 strains of Chlamydia trachomatis and 20 isolates of Chlamydia pneumoniae. The MIC at which 90% of the isolates were inhibited and the minimal bactericidal concentration at which 90% of the isolates were killed by BMS-284756 for all isolates of C. pneumoniae and C. trachomatis was 0.015 microg/ml (range, 0.015 to 0.03 microg/ml). BMS-284756 was the most active quinolone tested.