Capsular Polysaccharide Synthesis Regions in Klebsiella pneumoniae Serotype K57 and a New Capsular Serotype

Abstract

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.

Effects of an immunomodulatory feed additive on the development of mastitis in a mouse infection model using four bovine-origin isolates

“…It is possible that the introduction of a lactose-fermenting, rapidly growing bacterium (Walia et al, 1987) overwhelmed the natural and augmented aspects of mammary gland immunity. Second, K. pneumoniae is surrounded by a large bio-protective mucoid polysaccharide (Pan et al, 2008) capsule that protects it from phagocytosis. This capsule may have protected the organism from neutrophil-mediated killing by the host's natural and augmented immune systems.…”

Identification of Klebsiella pneumoniae K1 and K2 Capsular Types by PCR and Quellung Test

“…For the PCR assay, we selected wzc gene, encoding tyrosine-protein kinase and open reading frame 10 (orf-10) encoding putative inner membrane proteins for K1 and K2 serotypes, respectively. There have been many reports linking magA, rmpA and wcaG with virulence, also wzc and orf-10 have been studied (16).…”

“…Since these are considered as important virulence factors, it could be suggested that reversible protein phosphorylation on tyrosine may be part of the cascade of reactions that determine the pathogenicity of bacteria (17). The open reading frames (ORFs) of the complete cps regions suggested that this region was responsible for capsular polysaccharide synthesis (16).…”

Assessment the Effects of Low Power Laser Light on Some Virulent Factors of Klebsiella pneumoniae Isolated from Respiratory Tract Infections

“…Its colonization can be further found in the urinary tract, respiratory tract, gastrointestinal tract and blood. At least 78 capsular (K antigen) serotypes have been recognized for K. pneumoniae (Pan et al, 2008;Hsu et al, 2013).…”