| Literature DB >> 28843817 |
Hong-Yan Luo1, Ma-Feng Liu2, Ming-Shu Wang2, Xin-Xin Zhao2, Ren-Yong Jia1, Shun Chen2, Kun-Feng Sun2, Qiao Yang2, Ying Wu2, Xiao-Yue Chen1, Francis Biville3, Yuan-Feng Zou4, Bo Jing4, An-Chun Cheng5, De-Kang Zhu6.
Abstract
The Gram-negative bacterium Riemerella anatipestifer CH-2 is resistant to lincosamides, having a lincomycin (LCM) minimum inhibitory concentration (MIC) of 128 µg/mL. The G148_1775 gene of R. anatipestifer CH-2, designated lnu(H), encodes a 260-amino acid protein with ≤41% identity to other reported lincosamide nucleotidylyltransferases. Escherichia coli RosettaTM (DE3) containing the pBAD24-lnu(H) plasmid showed four- and two-fold increases in the MICs of LCM and clindamycin (CLI), respectively. A kinetic assay of the purified Lnu(H) enzyme for LCM and CLI showed that the protein could inactive lincosamides. Mass spectrometry analysis demonstrated that the Lnu(H) enzyme catalysed adenylylation of lincosamides. In addition, an lnu(H) gene deletion strain exhibited 512- and 32-fold decreases in LCM and CLI MICs, respectively. The wild-type level of lincosamide resistance could be restored by complementation with a shuttle plasmid carrying the lnu(H) gene. The transformant R. anatipestifer ATCC 11845 [lnu(H)] acquired by natural transformation also exhibited high-level lincosamide resistance. Moreover, among 175 R. anatipestifer field isolates, 56 (32.0%) were positive for the lnu(H) gene by PCR. In conclusion, Lnu(H) is a novel lincosamide nucleotidylyltransferase that inactivates LCM and CLI by nucleotidylylation, thus conferring high-level lincosamide resistance to R. anatipestifer CH-2.Entities:
Keywords: Lincosamide resistance; Nucleotidylyltransferase; Riemerella anatipestifer; lnu(H)
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Year: 2017 PMID： 28843817 DOI： 10.1016/j.ijantimicag.2017.08.022
Source DB: PubMed Journal: Int J Antimicrob Agents ISSN： 0924-8579 Impact factor: 5.283