Association between rmpA and magA genes and clinical syndromes caused by Klebsiella pneumoniae in Taiwan.
BACKGROUND
The association of the magA gene with the hypermucoviscosity phenotype relevant to the pathogenesis of Klebsiella pneumoniae liver abscess has been reported in Taiwan. Similarly, the rmpA gene, known as a positive regulator of extracapsular polysaccharide synthesis that confers a mucoid phenotype, may be another candidate gene causing hypermucoviscosity. However, the association of rmpA with K. pneumoniae clinical syndromes is unreported. We aimed to investigate the clinical correlation between rmpA and primary Klebsiella abscess, focusing on sites other than the liver.


METHODS
From July 2003 through December 2004, a total of 151 K. pneumoniae isolates recovered from 151 patients with bacteremia were collected from 2 large medical centers in southern Taiwan. Clinical data were collected from medical records. The genes rmpA and magA were amplified by polymerase chain reaction using specific primers.


RESULTS
The prevalences of hypermucoviscosity, rmpA, and magA were 38%, 48%, and 17%, respectively. As determined by statistical multivariate analysis, strains carrying rmpA were significantly associated with the hypermucoviscosity phenotype, and there was a significant correlation with purulent tissue infections, such as liver abscess and lung, neck, psoas muscle, or other focal abscess.


CONCLUSIONS
Our data support a statistical correlation between the rmpA gene and virulence in terms of abscess formation for these hypermucoviscous K. pneumoniae strains. Hypermucoviscosity associated with rmpA, together with a thorough physical examination, may be helpful as a guide to carry out appropriate diagnostic tests on patients with an initially unknown source of K. pneumoniae bacteremia, particularly when looking for the occurrence of an underlying abscess.
Yu
Wen-Liang
WL
Department of Intensive Care Medicine, Chi-Mei Medical Center, Yungkang City, Tainan, Taiwan.
Ko
Wen-Chien
WC
Cheng
Kuo-Chen
KC
Lee
Hsin-Chun
HC
Ke
Der-Shin
DS
Lee
Ching-Chien
CC
Fung
Chang-Phone
CP
Chuang
Yin-Ching
YC
D016470:Bacteremia / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D046290:Liver Abscess, Pyogenic / Q000382:microbiology; D009092:Mucous Membrane / Q000382:microbiology; D010641:Phenotype; D013577:Syndrome; D013624:Taiwan; D014157:Transcription Factors / Q000235:genetics*; D014774:Virulence; D014783:Viscosity
D001426:Bacterial Proteins; D017931:DNA Primers; C501254:MagA protein, Klebsiella pneumoniae; C512267:RmpA protein, Klebsiella pneumoniae; D014157:Transcription Factors