Sequence analysis of pKF3-70 in Klebsiella pneumoniae: probable origin from R100-like plasmid of Escherichia coli.
BACKGROUND
Klebsiella pneumoniae is a clinically significant species of bacterium which causes a variety of diseases. Clinical treatment of this bacterial infection is greatly hindered by the emergence of multidrug-resistant strains. The resistance is largely due to the acquisition of plasmids carrying drug-resistant as well as pathogenic genes, and its conjugal transfer facilitates the spread of resistant phenotypes.


RESULTS
The 70,057 bp plasmid pKF3-70, commonly found in Klebsiella pneumoniae, is composed of five main functional modules, including regions involved in replication, partition, conjugation, transfer leading, and variable regions. This plasmid is more similar to several Escherichia coli plasmids than any previously reported K. pneumoniae plasmids and pKF3-70 like plasmids share a common and conserved backbone sequence. The replication system of the pKF3-70 is 100% identical to that of RepFII plasmid R100 from E. coli. A beta-lactamase gene ctx-m-14 with its surrounding insertion elements (ISEcp1, truncated IS903 and a 20 bp inverted repeat sequence) may compose an active transposon which is directly bordered by two putative target repeats "ATTAC."


CONCLUSIONS
The K. pneumoniae plasmid pKF3-70 carries an extended-spectrum beta-lactamase gene, ctx-m-14. The conjugative characteristic makes it a widespread plasmid among genetically relevant genera which poses significant threat to public health.
Yi
Huiguang
H
Institute of Biomedical Informatics/Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, China.
Xi
Yali
Y
Liu
Jing
J
Wang
Junrong
J
Wu
Jinyu
J
Xu
Teng
T
Chen
Wei
W
Chen
Biaobang
B
Lin
Meili
M
Wang
Huan
H
Zhou
Mingming
M
Li
Jinsong
J
Xu
Zuyuan
Z
Jin
Shouguang
S
Bao
Qiyu
Q
D001483:Base Sequence; D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000235:genetics*; D007711:Klebsiella pneumoniae / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D012689:Sequence Homology, Nucleic Acid