Chlamydophila (Chlamydia) pneumoniae as a cause of community-acquired pneumonia in Thailand.

Chlamydophila (Chlamydia) pneumoniae infection is increasingly reported worldwide nowadays. We studied twelve Thai adults presenting with the clinical symptoms and signs of community-acquired pneumonia (CAP) due to C. pneumoniae (TWAR) at Pramongkutklao Hospital in Bangkok, Thailand. Their mean age was 38 (range 21-73) years. Six patients lived in Bangkok. Seven patients had comorbid diseases (four cases with allergic asthma, one each with diabetes mellitus, chronic obstructive pulmonary disease and coronary artery disease). C. pneumoniae pneumonia presented as subacute pneumonia in 6 patients. The clinical manifestations were mild (IDSA risk class I-III) except in 4 patients who had preexisting allergic asthma, COPD and coronary heart disease. The diagnosis of C. pneumoniae pneumonia was based on microimmunofluorescence (MIF) antibody technique (IgM titer > or = 1:16, IgG > or = 1:512, IgA > or = 1:256 with or without fourfold rises). The clinical conditions were consistent with the primary infection (IgM titer of 1:16 or higher) in 6 patients and reinfection (IgG titer of 1:512, IgA titer of 1:256 or higher without rises of IgM titer) in the other 6 patients. Minimal bilateral pleural effusion was detected in only one patient. Coinfection was demonstrated in 2 patients (one each with S. pneumoniae and K. pneumoniae). All patients markedly improved after a 2-week course of macrolide, doxycycline or newest fluoroquinolone therapy. All patients had done well at one year of follow-up. C. pneumoniae infection has been recently recognized and a high seroprevalence (37%) in Thai school children and 100 per cent in young male Thai military conscripts has been reported. This report suggests that this infection, C. pneumoniae, may be a common pathogen of CAP in Thailand.

Evolution of cell-surface acid phosphatase of Burkholderia pseudomallei.

Acid phosphatase active fractions were obtained from cell-free extract, outermembrane fraction and culture filtrate of Burkholderia pseudomallei by column chromatography with sepharose 6B and DEAE cellulose. The comparison of the elution patterns of protein, sugar and enzymatic activity among these three components suggested that the enzyme is a glycoprotein evolving from premature proteins through glycosylation and that the enzyme is translocated during glycosylation from the cytoplasm to the outer membrane and finally excreted into the environment. When tunicamycin, a glycosylation inhibitor, was added to the culture, the peaks of sugar and enzymatic activity were lowered concomitantly leaving the protein peak unchanged in the elution pattern of the culture filtrate. The affinity of the bacterial surface to antienzyme sera was demonstrated by immuno-fluorescence microscopy.

Separation of antigenic glycoprotein fractions from cell-free homogenate of Pseudomonas pseudomallei and characterization as tyrosine phosphatase.

Cell-free extracts were prepared from Pseudomonas pseudomallei cells by freezing-thawing, sonication, and differential ultracentrifugation. The extracts were subjected to column chromatography with DEAE-sepharose to obtain glycoprotein fractions. The fractions showed acid phosphatase activity to p-nitrophenyl phosphate, tyrosine phosphate, serine phosphate, but not to threonine phosphate. They were highly antigenic when tested by immunofluorescence assay with the sera of melioidosis patients.

Application of indirect immunofluorescence microscopy to colony identification of Pseudomonas pseudomallei.

Indirect immunofluorescence microscopy was used as a colony identification method of Pseudomonas pseudomallei isolates. The antisera against lipopolysaccharide and protein fractions of P. pseudomallei were prepared in guinea pigs and rabbits. With these antisera and fluorescence-labelled anti-guinea pig IgG and anti-rabbit IgG prepared in sheep (goat), indirect immunofluorescence microscopy was conducted on the colonies of P. pseudomallei and other species of bacteria. The overall results indicated that this method is efficient, rapid and specific for identification of P. pseudomallei colonies from clinical specimens.

Use of endotoxin antigens in enzyme-linked immunosorbent assay for the diagnosis of P. pseudomallei infections (melioidosis).

An enzyme-linked immunosorbent assay (ELISA) with endotoxin preparations of P. pseudomallei as antigen was developed for detection of IgG antibodies specific to melioidosis. Forty-seven sera of bacteriologically confirmed melioidosis patients, 55 non-melioidosis sera and 50 sera of healthy blood donors from non-endemic areas were subjected to this assay in comparison with indirect hemagglutination assay (IHA). The data were treated by receiver operating characteristics analysis. The sensitivity, specificity and accuracy in this ELISA were 95.7%, 94.2%, and 94.7%, respectively, with cut-off value of OD = 0.312 at 490 nm. Meanwhile, those in IHA were 81.0%, 91.4%, and 88.1%, respectively, with a cut-off value of > or = 1:160. From these results, the ELISA was judged to be more reliable than IHA as the seroassay for diagnosis of melioidosis.