Prevalence of Chlamydophila pneumoniae among Bangladeshi children under age 5 years with acute respiratory infections.

Despite major improvements in the diagnosis of pathogenic organisms causing acute respiratory infections (ARIs), details of infections caused by atypical pathogens are not well understood, particularly in developing countries. This clinical and epidemiological research was conducted in Bangladesh to explore the prevalence of atypical pathogens in causing childhood pneumonia. Sixty-four children with ARI were studied at the Pediatric Outpatient Department of Dhaka Medical College Hospital, Bangladesh, during September through December 2000. In addition to clinical examination, hematological, radiological, and bacteriological examinations were performed. Antibody titers from paired sera against Mycoplasma pneumoniae and Legionella spp. in the acute and convalescent phases revealed that none of these children were infected with M. pneumoniae, while only one serum sample was positive for L. pneumophila serogroup 4. Antibody titers against Chlamydophila (Chlamydia) pneumoniae, determined by an indirect microimmunofluorescence method, and by an enzyme-linked immunosorbent assay (ELISA) kit (HITAZYME C. pneumoniae kit) indicated that 13 children (20.3%) were infected with C. pneumoniae. Our results indicate a high prevalence rate of C. pneumoniae, suggesting it is as an important causative pathogen of childhood pneumonia in Bangladesh.

Biosynthesized tea polyphenols inactivate Chlamydia trachomatis in vitro.

Biosynthesized tea polyphenols showed antichlamydial activity against Chlamydia trachomatis D/UW-3/Cx and L2/434/Bu using cell culture. The most active compounds were (-)-epigallocatechin gallate and (-)-epicatechin gallate, followed by (-)-epicatechin (EC). (+)-Epicatechin and (-)-epigallocatechin were intermediate. EC was the least toxic. These results warrant evaluation of tea polyphenols as topical antichlamydial agents.

In vitro inhibitory effects of hinokitiol on proliferation of Chlamydia trachomatis.

The inhibitory effects of hinokitiol (beta-thujaplicin) on Chlamydia trachomatis D/UW-3/Cx were shown by MIC, minimum lethal concentration (MLC), and preinoculation minimal microbicidal concentration assays using HeLa 229 cells. The MIC and the MLC were both 32 microg/ml. Further evaluation of hinokitiol as a topical agent against C. trachomatis is warranted.

Prevalence of antibodies against Simkania negevensis in a healthy Japanese population determined by the microimmunofluorescence test.

Simkania negevensis has been associated with bronchiolitis in infants and community-acquired pneumonia in adults. Reports of exposure to this microorganism are only available from Israel, North America and Western Europe. Currently, no standard method for diagnosis of S. negevensis infection has been established nor have prevalence rates been shown in Japan. For the first time we demonstrated the ability of the microimmunofluorescence (MIF) test to detect S. negevensis-specific immunoglobulin G and exposure to S. negevensis in Japan. The positive rate in healthy volunteers was 4.3% (25/588), with rates increasing with age. Results indicate the usefulness of the MIF test as a serological method for detecting S. negevensis-specific antibodies. A standard serological test for infection with S. negevensis is needed.

Severe Chlamydophila psittaci pneumonia rapidly diagnosed by detection of antigen in sputum with an immunochromatography assay.

We report a case of severe Chlamydophila (Chlamydia) psittaci pneumonia rapidly diagnosed by detection of antigen in sputum with an immunochromatography assay. The patient was admitted to our hospital because of shock, disturbance of consciousness, accidental hypothermia, and multiple organ dysfunction syndrome, and he recovered after administration of intravenous erythromycin and high-dose methylpredonisolone therapy. Psittacosis was confirmed by detection of 16S rRNA gene of C. psittasi in sputum with multiplex-polymerase chain reaction analysis. Serological responses to C. psittasi, C. trachomatis, and C. pneumoniae were also evaluated, and serological cross-reactivity was observed between each species. We consider that the commercially available immunochromatography assay for Chlamydia species can be helpful for rapid diagnosis of Chlamydia infection of the respiratory tract. Hereafter, further examination will be necessary regarding pretreatment of specimens or detection sensitivity and specificity.

Factors improving the propagation of Simkania negevensis strain Z in cell culture.

The purpose of the present study was to develop an optimal method for culturing Simkania negevensis. Centrifugation was effective for the propagation of S. negevensis, but sonication was not effective. The addition of cycloheximide to the culture medium significantly decreased the number of inclusions. Pretreatment of host monolayers with diethylaminoethyl-dextran or polyethylene glycol was detrimental. The most optimal conditions were centrifugation of the inocula onto untreated Vero cells, and culture in RPMI 1640 medium containing 10% fetal calf serum without cycloheximide or antimicrobial agents.

Evaluation of PCR and nested PCR assays currently used for detection of Coxiella burnetii in Japan.

Detection of Coxiella burnetii, the etiologic agent of Q fever, is important for diagnosis of Q fever. PCR-based methods have been widely used for the detection mostly because isolation of C. bumetii is time-consuming. Recent reports showed that PCR-positive rates of Q fever infection widely differed. We have evaluated the PCR and nested PCR assays currently used in Japan. The nested PCR assay detected as few as 6 microorganisms and was 10 times more sensitive than the regular PCR assay. The nested PCR assay did not show any non-specific bands with 12 other bacteria, whereas the PCR assay showed some extra bands for 5 of the 12 bacteria. These results suggest that the nested PCR is more sensitive and specific than the PCR in the detection of C. burnetii. However, nested PCR generally has a risk of cross-contamination during preparation of the 2nd PCR. Using blood specimens serially collected from an acute Q fever patient, the PCR and the nested PCR assays gave very similar results, suggesting that sensitivity of the PCR assay is at an achieved level of the detection for clinical specimens although the nested PCR assay is more sensitive. It is recommended that both the PCR and nested PCR assays should be performed for the detection of C. burnetii to obtain reliable results.

In vitro inhibitory effects of tea polyphenols on the proliferation of Chlamydia trachomatis and Chlamydia pneumoniae.

In vitro inhibitory effects of tea polyphenols on Chlamydia trachomatis and C. pneumoniae were investigated. A product of tea polyphenols, Polyphenon 70S was used. Chlamydial strains used were C. trachomatis D/UW-3/Cx and L(2)/434/Bu, and C. pneumoniae AR-39 and AC-43 strains. HeLa229 cells and HL cells were used for cultivation of C. trachomatis and C. pneumoniae, respectively. In the post-inoculation method, no inclusions of C. trachomatis were observed at 0.5 mg/ml of Polyphenon 70S. However, the toxicity of Polyphenon 70S was noted in HeLa229 cells and HL cells at a concentration of 0.25 mg/ml. In the pre-inoculation method, no toxic effects of Polyphenon 70S on the cells were noted. Complete inhibition of C. trachomatis D and L(2) was noted at concentrations of 1.6 and 0.4 mg/ml, respectively. With C. pneumoniae strains, the end points were 0.8 and 1.6 mg/ml for AR-39 and AC-43, respectively. Our findings encouraged the application of tea polyphenols for topical usage.

[Time course of the levels of antibodies to Coxiella burnetii and detection of C. burnetii-DNA in three imported cases of acute Q fever].

Three patients developed acute Q fever after returning from an inspection tour of farms and abattoirs to Australia. Serum levels of antibodies to Coxiella burnetii and the presence of C. burnetii-DNA in blood samples were examined for more than 100 days. Four-fold raises of IgM and IgG antibodies against C. burnetii phase 2 were observed within the first three weeks in all the three cases. Maximum titers of IgM and IgG antibodies were 1,024-2,048 and 512-4,096, respectively. According to the temporal diagnostic criteria of acute Q fever in the convalescent serum: the IgM titer of > or = 64 and IgG titer of > or = 512 against phase 2, patient A, B and C were determined to be antibody positive for 45, 199 and 122 days, respectively. The result suggests that this standard is practical and reasonable for diagnosis of acute Q fever. C. burnetti-DNA was detected in the sera and buffy coat samples of patient A who developed high fever, severe thrombocytopenia and liver disfunction, but not in those of patient B and C. This study provides useful information for optimization and standardization of Q fever diagnosis in Japan.

Scrub typhus in Japan: epidemiology and clinical features of cases reported in 1998.

Surveillance for scrub typhus was conducted in Japan in 1998 using a questionnaire. A total of 462 cases were reported. Scrub typhus occurred in both the fall and spring in the northern part of Honshu (the main island), and in the fall in the central part of Honshu and on the island of Kyushu. The occurrence of the disease varied with age, gender, and activity. Seventy-six percent of the patients were more than 51 years old, and 36% and 16% of the patients were engaged in farm work and forestry, respectively. Fever, rash, and eschar were detected in 98%, 93%, and 97% of the patients, respectively. Elevated levels of C-reactive protein, aspartate transaminase, and alanine transaminase were detected in 96%, 87%, and 77% of the patients, respectively. Disseminated intravascular coagulation developed in 34 cases and had a unique regional distribution. This study shows the status of scrub typhus in Japan in 1998 and provides important information for diagnosis and prevention.