Capsular polysaccharide synthesis regions in Klebsiella pneumoniae serotype K57 and a new capsular serotype.
Community-acquired pyogenic liver abscess caused by Klebsiella pneumoniae is an emerging infectious disease. We explored the capsular polysaccharide synthesis (cps) regions of three non-K1, non-K2 K. pneumoniae strains, A1142, A7754, and A1517, from Taiwanese patients experiencing pyogenic liver abscess. Two of the strains, A1142 and A7754, belonged to capsular serotype K57, while the third belonged to a new capsular serotype, different from the previously reported 77 serotypes. Deletion and complementation experiments suggested that a unique K57 gene, a homologue of wzy, was essential for K57 capsular synthesis and confirmed that this gene cluster was a genetic coding region for K57. Compared to K1 and K2 strains, the three strains were all serum sensitive, suggesting that host factors might also be involved in the three patients. PCR using primers from specific genes for K57 was more sensitive and specific than traditional serotyping. The remaining strain, A1517, did not react to the antisera from any of the 77 serotypes, and none of the 77 reference strains reacted to the serum against this strain. Moreover, PCR analyses using various primer pairs from the serotype-specific open reading frames did not reveal cross-reactivity to any of the 77 reference strains, suggesting that this strain likely represents a new capsular type. We conclude that sequences from these two cps regions are very useful in detecting K57 and the new cps genotype.
Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan.
Yi-Jiun
YJ
Pan
Han-Chi
HC
Fang
Hui-Ching
HC
Yang
Tzu-Lung
TL
Lin
Pei-Fang
PF
Hsieh
Feng-Chiao
FC
Tsai
Yoav
Y
Keynan
Jin-Town
JT
Wang
D016667:Bacterial Capsules / Q000235:genetics*; D017714:Community-Acquired Infections / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D017353:Gene Deletion; D023061:Gene Order; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006801:Humans; D015151:Immunoblotting; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D008100:Liver Abscess / Q000382:microbiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D011135:Polysaccharides, Bacterial / Q000145:classification* / Q000235:genetics*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D012703:Serotyping; D026801:Synteny; D013624:Taiwan
D017931:DNA Primers; D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial