Original Article
Screening of New Delhi metallo-β-lactamase 1 for gram negative bacilli
ZHOU Zhen-wen, XIE Yong-qiang, YANG Yi-yu, YAO Shu-wen, GUAN Rui-li, ZHONG Hua-min, ZHOU Shuai, GONG Si-tang
Published 2013-10-11
Cite as Chin J Lab Med, 2013, 36(10): 916-919. DOI: 10.3760/cma.j.issn.1009-9158.2013.10.014
Abstract
ObjectiveTo screen metallo-β-lactamase (MBL) and New Delhi metallo-β-lactamase 1 (NDM-1) genes among imipenem-resistant gram-negative bacilli,and to provide experimental evidence for the treatment and control of bacteria carrying NDM-1.
MethodsA total of 7 impenem-resistant gram-negative bacilli isolated from 7 patients in Guangzhou Women and Children′s Medical Center during 2010 were screened for NDM-1 gene retrospectively.The MBLs were examined by imipenemethylenediaminetetra acetic acid (EDTA) double-disc synergy test.NDM-1 gene-specific primers were designed for PCR amplification,and the PCR products were cloned into p MD-T plasmid and then transformed to E.coli Dh5a.Recombinant plasmid was identified by EcoRⅠ,XhoⅠ double enzyme and sequencing.
ResultsTwo MBL positive strains (Acinetobacter baumannii 1542,Acinetobacter junii 1454) were identified,and NDM-1 gene was verified in Acinetobacter junii 1454,and showed high concordance with known NDM-1 gene sequences in Genbank (99.9%).Only one nucleotide G-A mutation among 813 nucleotides (G468A) was found,and the amino acid sequences were exactly the same with known NDM-1.The accession number of the sequence of Acinetobacter junii NDM-1 under Genbank is HQ603057.Acinetobacter junii 1454 was resistant to all beta-lactams antibiotics tested except aztreonam and cefoperazone/sulbactam but sensitive to tigecycline,aminoglycosides and quinolones.
ConclusionNDM-1 positive Acinetobacter junii was screened from a hospitalized child,suggesting that clinical microbiology laboratories should strengthen imipenem-resistant NDM-1 gene screening.(Chin J Lab Med,2013,36:916-919)
Key words:
Gram-negative bacteria; beta-Lactamases; Imipenem; Drug resistance,bacterial
Contributor Information
ZHOU Zhen-wen
Clinical Laboratory,Guangzhou Women and Children′s Medical Center,Guangzhou 510120,China
XIE Yong-qiang
YANG Yi-yu
YAO Shu-wen
GUAN Rui-li
ZHONG Hua-min
ZHOU Shuai
GONG Si-tang