ABSTRACT
Objective To investigate the status of genotype of the KPC(Klebsiella pneumoniae carbapenemase)-encoding genes in Pan-resistant K. Pneumoniae, isolated from the 98th Hospital of People' s Liberation Army, Huzhou district, Zhejiang province, China. Methods 19 strains of Pan-resistant K. Pneumoniae were isolated from the inpatients between November, 2008 and July,2009. Phenotypic confirmatory test for suspected carbapenemases production were carried out by Modified Hodge test. Carbapenemase gene of blaKPC was analyzed by PCR and verified by DNA sequencing. Results In 19 strains of K. Pneumoniae, the positive rates of Modified Hodge test and gene of blaKPC were both 100.0%. These genes all belonged to blaKPC-2 subtype confirmed by nucleotide sequence analysis. Among them, the blaKPC-2 gene sequence of the HZ001 strain (its original serial number was HZ9871 ) had been registered in GenBank (GenBank Accession Number: GU086225).Conclusion All of the Pan-resistant K. Pneumoniae isolated from the inpatients harbored blaKPC-2 type carbapenemases gene and causing an outbreak in a hospital. Carbapenemases that producing type KPC-2 might be the major reason which causing the resistance to Carbapenems antibiotics.
ABSTRACT
Objective To investigate the 16S rRNA methylase genes and Aminoglycoside modifying enzymes(AMEs)genes in Enterobacter cloacae isolated from the People's Liberation Army 98th Hospital,Huzhou district,Zhejiang province,China.Methods 40 strains of Enterobacter cloacae were isolated from the inpatients between September,2003 and November,2004.5 kinds of 16S rRNA methylase gene (including armA,rmtA,rmtB,rmtC and rmtD)and 9 kinds of AMEs gene[including aac(3)-Ⅰ,aac(3)-Ⅱ,aac(3)-Ⅲ,aac(3)-Ⅳ,aac(6')-Ⅰ b,aac(6')-Ⅱ,ant(3'')-Ⅰ,ant(2'')-Ⅰ and aph(3')-Ⅵ]were analyzed by PCR and verificated by DNA sequencing.Results In 40 strains of Enterobacter cloacae,the positive rates of genes of rmtB,aac(3)-Ⅱ,aac(6')-Ⅰ b,ant(3'')-Ⅰ,ant(2'')-Ⅰ and aph(3')-Ⅵ were 12.5%(5/40),27.5%(11/40),72.5%(29/40),32.5%(13/40),5.0%(2/40)and 5.0%(2/40),respectively.8 kinds of the rest of genes were all tested negative.The total positive rate of AMEs gene was 85.0%(34/40).Among 29 strains of Enterobacter cloacae that the aac(6')-Ⅰ b gene was positive,through PCR and verification by DNA sequencing,7 strains(24.1%)were confirmed to take the aac(6')-Ⅰ b-cr(the GenBank register number:EF375620,EU159121)alone,18 strains(62.1%)were confirmed to take the aac(6')-Ⅰ b-Suzhou(EU085533)alone,3 strains(10.3%)were confirmed to take both aac (6')-Ⅰ b-Suzhou and aac(6')-Ⅰ b-cr while only 1(3.4%)was aac(6')-Ⅰ b(the classical type).Conclusion There was lower positive rate of 16S rRNA methylase gene but very high AMEs genotypes in Enterobacter cloacae isolated from inpatients and the finding of rmtB gene was reported for the first time in the world.At least 5 kinds of AMEs gene existed in Enterobacter cloacae were isolated and they were the new host of both gene of aac(6')-Ⅰ b-cr and aac(6')-Ⅰ b-Suzhou,with aac(6')-Ⅰ b-Suzhou gene was the predominance subtype in aac(6')-Ⅰ b.
ABSTRACT
Objective To investigate the presence and genetic background of 16S rRNA methylase gene and Aminoglycoside modifying enzymes(AMEs) genes in Klebsiella pneumoniae isolated from the People's Liberation Army 98th HospitaI,Huzhou district,Zhejiang province,China.Methods 25 strains of Klebsiella pneumoniae were isolated from the inpatienta between September,2005 and April,2006.6 kinds of 16S rRNA methylase gene (including armA,rmtA,rmtB,rmtC,rmtD and npmA ),6 kinds of AMEs genes [ including aac (3)-Ⅰ,sac (3)-Ⅱ,sac (6')-Ⅰ,aac (6')-Ⅱ,ant (3")-Ⅰand ant(2")-Ⅰ],intI1,intI2,intI3,mercuric reductase gene merA (merA gene were the collective genetic markers of transposona of Tn21 and Tn501 ) and tnpA ( tnpA gene were the collective genetic markers of transposons of Tn1,Tn2,Tn3 and Tn1000) were analyzed by PCR and verificated by DNA sequencing.Results In 25 strains of Klebsiella pneumoniae,the positive rate of genes of rmtB,sac (3)-Ⅱ,sac (6')-Ⅰ,ant(3")-Ⅰ and intI1 were 60.0%(15/25),4.0%(1/25),48.0%(12/25),60.0%(15/25) and 96.0%(24/25),respectively.The rest 12 kinds of genes were all tested negative.The total positive rate of 6 kinds of AMEs gene was 84.0%(21/25).Conclusion There were very high positive rate on both genes of rmtB and AMEs genotypes in Klebsiella pneumoniae isolated from inpatients,and this was the first report of the emergence of 16S rRNA methylase gene rmtB in Klebsiella pneumoniae identified in Zhejiang province,China.