Cho-Chou Kuo

Current knowledge on Chlamydia pneumoniae, strain TWAR, an important cause of pneumonia and other acute respiratory diseases

This article reviews current knowledge ofChlamydia pneumoniae strain TWAR, a newly recognizedChlamydia organism that causes acute respiratory infection, especially atypical pneumonia. Information is included on the microbiology, classification and laboratory diagnosis of the organism. Details of a series of studies of both endemic and epidemic respiratory infections are reviewed to present information on both the clinical and epidemiological characteristics of infection with strain TWAR. Laboratory studies of antibiotic sensitivity and recommendations for treatment are presented.

Respiratory infection with Chlamydia pneumoniae in middle-aged and older adult outpatients.

This study was undertaken to characterize the epidemiology and clinical presentation of infection withChlamydia pneumoniae in a population composed primarily of middle-aged and older adults. Pharyngeal swabs and acute and convalescent phase sera were obtained from outpatients presenting with signs and symptoms of an acute respiratory infection. Sera were examined using the micro-immunofluorescence (MIF) test to detect antibody toChlamydia pneumoniae and complement fixation tests to detectMycoplasma pneumoniae, influenza A virus, influenza B virus, respiratory syncytial virus and adenovirus. Pharyngeal swab specimens were cultured forChlamydia pneumoniae and tested forChlamydia pneumoniae by the polymerase chain reaction (PCR). A total of 743 patients with a mean age of 40.5 ± 16.1 years were enrolled in the study. Twenty-one patients were serologically positive for acuteChlamydia pneumoniae infection in the MIF test. PCR was positive in 15 of the 20 serologically positive patients tested. AcuteChlamydia pneumoniae infection was identified in 3 % (2/76) of subjects with pneumonia, 5 % (12/247) of those with bronchitis, 5 % (3/61) of those with sinusitis only and 2 % (2/103) of those with pharyngitis only. Of the 21 patients withChlamydia pneumoniae infection, seven (mean age of 33 years) had an antibody pattern suggesting a primary infection while 14 (mean age of 54 years) had a reinfection pattern. Patients with reinfection had milder disease than those with primary infection. PCR testing in the current study confirms the previously proposed serologic criteria of acuteChlamydia pneumoniae infection.

Serological response to Chlamydia pneumoniae in patients with sarcoidosis

The antigen-specific serological response to Chlamydia pneumoniae was studied in 24 patients with sarcoidosis and compared to that seen in acute C. pneumoniae respiratory infection. By the micro-immunofluorescence test, five sarcoidosis patients had acute antibody, 15 had chronic antibody and four had no antibody against C. pneumoniae. By enzyme immunoassay, 20 sarcoidosis patients had antibody against ReLPS but that cross-reacts with chlamydial LPS. Immunoblot analysis of sera using purified C. pneumoniae elementary bodies showed that recognition of the 40 kDa C. pneumoniae major outer membrane protein was rare (20%). Reactivities with proteins with Mw of 42 K (70%), 60 K (65%), 98 K (55%) and 52 K (50%) were often noted. To study reactivity of chlamydial HSP 60 in sarcoidosis sera, sarkosyl-soluble (contains the 60 kDa HSP) and sarkosyl-insoluble (contains the 60 kDa structural protein) fractions of C. pneumoniae elementary bodies were prepared. The 60 kDa structural protein was recognized with equal frequency by sera from patients with sarcoidosis and acute respiratory infection, while the HSP 60 was more frequently recognized by sera with acute respiratory infection than sarcoidosis. Recombinant fusion proteins expressed from pGEX-2T containing overlapping DNA fragments of the C. pneumoniae 60 kDa HSP gene were purified. Different recognition patterns were identified for sera from sarcoidosis patients and from patients with acute C. pneumoniae respiratory infection.

Seroprevalence of Chlamydia pneumoniae infection in Taiwan.

OBJECTIVES To survey the seroprevalence of Chlamydia pneumoniae (C. pneumoniae) infection in healthy subjects in Taiwan. MATERIALS AND METHODS We used microimmunofluorescence antibody assay to survey the prevalence of antibodies to C. pneumoniae in 620 serum samples from healthy subjects aged 6 months to 86 years in Taiwan. RESULTS The mean prevalence (+/-SD) of IgG antibodies against C. pneumoniae at titer greater than or equal 1:16 was 55.8% (range 7.8-81.8%). The antibody prevalence was low in children under the age of 10 years (7.8%), and increased rapidly with age. Most individual acquired infection during the second and third decades of life with highest antibody prevalence reached up to 81.8% at fifth decade of life and remained high (70%) thereafter. CONCLUSIONS Chlamydia pneumoniae infection is highly endemic in Taiwan. These data contribute to the understanding of asymptomatic infections with C. pneumoniae in general population and should serve as a basis for studies on the role of C. pneumoniae infections and their related diseases.

Current Knowledge of Chlamydia TWAR, an Important Cause of Pneumonia and Other Acute Respiratory Diseases

This article reviews current knowledge of the TWAR strain, a newly recognized chlamydia organism that causes acute respiratory infection, especially atypical pneumonia. Information is presented under the following topics: introduction and history of the organism; microbiology and classification, including the proposal for a new chlamydia species, Chlamydia pneumoniae; laboratory diagnosis by isolation and serology; endemic TWAR disease and evidence for etiology, including studies in university students, in hospitalized pneumonia patients in three cities, and in a health maintenance organization from 1963 to 1974 and from 1985 to 1987; epidemic TWAR disease both country-wide in Denmark, Norway and Sweden 1981–1983, and localized in Finland and other countries; treatment including laboratory determination of antibiotic and sulfa drug sensitivity of the TWAR organism; population TWAR antibody prevalence; and studies by other investigators.