Chlamydia pneumoniae TWAR has been associated with coronary heart disease by seroepidemiologic studies and direct detection of the organism in atheromatous lesions of coronary arteries and aorta. In this study, 38 fresh tissue specimens from patients with coronary artery lesions that were treated by directional coronary atherectomy were tested for C. pneumoniae. Twenty-three specimens were from patients with primary lesions and 15 were from patients with restenoses. C. pneumoniae was detected by polymerase chain reaction (PCR), immunocytochemical stain (ICC), or both in 20 of 38 specimens. Using cell identity markers, the organism was localized to macrophages. Ultrastructural evidence of the organism was found in the 2 specimens examined by transmission electron microscopy, which were also positive by both ICC and PCR. C. pneumoniae was found more frequently in tissues from restenoses than in primary lesions (P = .17). There was no relation between the frequency of detection of the organism and C. pneumoniae-specific antibody titers.

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.

Mycoplasma genitalium is a sexually transmitted pathogen associated with several acute and chronic reproductive tract disease syndromes in men and women. To evaluate the suitability of a pig-tailed macaque model of M. genitalium infection, we inoculated a pilot animal with M. genitalium strain G37 in the uterine cervix and in salpingeal pockets generated by transplanting autologous Fallopian tube tissue subcutaneously. Viable organisms were recovered throughout the 8-week experiment in cervicovaginal specimens and up to 2 weeks postinfection in salpingeal pockets. Humoral and cervicovaginal antibodies reacting to MgpB were induced postinoculation and persisted throughout the infection. The immunodominance of the MgpB adhesin and the accumulation of mgpB sequence diversity previously observed in persistent human infections prompted us to evaluate sequence variation in this animal model. We found that after 8 weeks of infection, sequences within mgpB variable region B were replaced by novel sequences generated by reciprocal recombination with an archived variant sequence located elsewhere on the chromosome. In contrast, mgpB region B of the same inoculum propagated for 8 weeks in vitro remained unchanged. Notably, serum IgG reacted strongly with a recombinant protein spanning MgpB region B of the inoculum, while reactivity to a recombinant protein representing the week 8 variant was reduced, suggesting that antibodies were involved in the clearance of bacteria expressing the original infecting sequence. Together these results suggest that the pig-tailed macaque is a suitable model to study M. genitalium pathogenesis, antibody-mediated selection of antigenic variants in vivo, and immune escape. Mycoplasma genitalium is a recently recognized sexually transmitted pathogen associated with reproductive tract disease in men and women (reviewed in references 1 to 3). Infection with this organism has been associated with urethritis in men (4-6) and cervicitis (7-9), urethritis (10, 11), acute endometritis (12), chronic pelvic inflammatory disease (13), tubal factor infertility (14, 15), and preterm birth (16, 17) in women. When untreated or inappropriately treated, M. genitalium infection can persist for months to years (18-21), suggesting that this organism avoids elimination by the host immune response. Recent studies assessing M. genitalium treatment regimens have found that standard antibiotic therapy fails to cure a significant proportion of infections (reviewed in reference 1), highlighting the importance of a better understanding of M. genitalium pathogenesis so that effective treatment and prevention methods can be devised.The distinct flask-shaped morphology of M. genitalium cells can be attributed to its complex tip organelle involved in gliding motility (22-25) and adherence to host cells and inanimate surfaces (26-30). Included among the tip organelle-associated proteins are the major adhesin, MgpB (also known as MgPa or P140), and its accessory protein, MgpC (also known as P110), which is required for the sta...

The ultrastructural lung pathology of Swiss Webster mice on days 2, 4, 7, 11, 15, and 21 after intranasal inoculation of Chlamydia pneumoniae AR-39 is described. The inflammatory infiltrate was predominantly polymorphonuclear leukocytes on day 2. By day 7, mononuclear cells were most prominent in the infiltrate. On day 2, chlamydial inclusions were found frequently in the bronchial ciliated epithelial cells and less frequently in the interstitial cells that appeared to be macrophages. Free particles of all developmental forms of the chlamydial microorganism were found in the bronchial lumen and alveolar space. These particles were likely organisms released from infected cells. Inclusions as well as free particles were difficult to find after day 4. These ultrastructural observations suggest an immunopathologic basis for the acute phase of the disease process.

BufferGel has an acceptable safety profile after repeated vaginal and rectal use, but does not prevent chlamydial infection in the macaque models.