Chlamydia pneumoniae is a widespread pathogen of humans causing pneumonia and bronchitis. There are many reports of an association between C.PNEUMONIAE: infection and atherosclerosis. We determined the whole genome sequence of C.PNEUMONIAE: strain J138 isolated in Japan in 1994 and compared it with the sequence of strain CWL029 isolated in the USA before 1987. The J138 circular chromosome consists of 1 226 565 nt (40.7% G+C) with 1072 likely protein-coding genes that is 3665 nt shorter than the CWL029 genome. Plasmids, phage- or transposon-like sequences were not identified. The overall genomic organization, gene order and predicted proteomes of the two strains are very similar, suggesting a high level of structural and functional conservation between the two unrelated isolates. The most conspicuous differences in the J138 genome relative to the CWL029 genome are the absence of five DNA segments, ranging in size from 89 to 1649 nt, and the presence of three DNA segments, ranging from 27 to 84 nt. The complex organization of these 'different zones' may be attributable to a unique system of recombination.

Abstract:In Once considered as a phytopathogen, Burkholderia cepacia, a multi-drug-resistant bacteria, is now recognized as an important pathogen in the lung of patients with cystic fibrosis (CF) and can lead to severe pneumonia and death (15). B. cepacia strain KF1 isolated from a non-CF patient with pneumonia, produces extracellular metalloprotease in large quantities (37), and causes lung infections in mice on intratracheal inoculation (42). We have been analyzing the mechanism of protease production to explore its involvement in the pathogenesis.In a previous study, we showed that the protease-negative, lipase-positive mutant KFT1007, a Tn5-Tp insertion mutant of B. cepacia KF1, was impaired in the dsbB gene which encodes a membranebound disulfide bond oxidoreductase, DsbB, resulting in secretion of a premature and catalytically inactive form of protease (1). In Escherichia coli, DsbB couples with DsbA, a periplasmic disulfide bond oxidoreductase that directly makes S-S bonds on target molecules (26). Thus, the reduced-DsbA is reoxidized by oxidized-DsbB that is recycled with the aid of a respiratory electron transfer chain (14). The DsbA-DsbB circuit in E. coli is involved in flagellar basal body assembly (9), type IV pilin biogenesis (44), and the maturation of heat-stable enterotoxin (22) and alkaline phosphatase (10). In some Gram-negative bacteria, homologs of E. coli DsbA and their target proteins are found in Vibrio cholerae TcpG for enterotoxin (23)

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Chlamydia pneumoniae is a widespread pathogen of the respiratory tract that is also associated with atherosclerosis. The whole genome sequence was determined for a Japanese isolate, C. pneumoniae strain J138. The sequence predicted a variety of genes encoding outer membrane proteins (OMPs) including ompA and porB, another 10 predicted omp genes, and 27 pmp genes. All were detected in the whole genome sequence of strain CWL029, a strain isolated and sequenced in the United States. A comparative study of the OMPs of the two strains revealed a nucleotide sequence identity of 89.6%-100% (deduced amino acid sequence identity, 71.1%-100%). The overall genomic organization and location of genes are identical in both strains. Thus, a few unique sequences of the OMPs may be essential for specific attributes that define the differential biology of two C. pneumoniae strains.