Molecular mechanisms of fluoroquinolone and
expanded-spectrum cephalosporin resistance in
Vibrio parahaemolyticus: abridged secondary
publication
S Chen1,2; EWC Chan1; KHL Po1; L Ye1; R Li1
1 Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
2 Department of Infectious Diseases and Public Health, City University of
Hong Kong, Hong Kong
1. We investigated the molecular mechanisms of
cephalosporin resistance and fluoroquinolone
resistance in Vibrio parahaemolyticus strains
isolated from food and clinical specimens.
2. Cephalosporin resistance in V parahaemolyticus was due to expression of β-lactamase gene, blaPER-1 and blaCMY-2', harboured by various conjugative plasmids.
3. The complete sequence of blaPER-1-bearing plasmid, pVPH1, was depicted and found to belong to the MOB(H12) group of selftransmissible plasmids, which is prevalent in Enterobacteriaceae and Vibrionaceae.
4. Single amino acid substitution Ser83Ile, in GyrA and the Ser85Leu change in ParC, were found to be associated with fluoroquinolone-resistance in V parahaemolyticus.
5. Three novel qnrVC genes, qnrVC5, qnrVC6, and qnrVC7, were detectable in these strains and their structure and functions were characterised.5. Three novel qnrVC genes, qnrVC5, qnrVC6, and qnrVC7, were detectable in these strains and their structure and functions were characterised.
2. Cephalosporin resistance in V parahaemolyticus was due to expression of β-lactamase gene, blaPER-1 and blaCMY-2', harboured by various conjugative plasmids.
3. The complete sequence of blaPER-1-bearing plasmid, pVPH1, was depicted and found to belong to the MOB(H12) group of selftransmissible plasmids, which is prevalent in Enterobacteriaceae and Vibrionaceae.
4. Single amino acid substitution Ser83Ile, in GyrA and the Ser85Leu change in ParC, were found to be associated with fluoroquinolone-resistance in V parahaemolyticus.
5. Three novel qnrVC genes, qnrVC5, qnrVC6, and qnrVC7, were detectable in these strains and their structure and functions were characterised.5. Three novel qnrVC genes, qnrVC5, qnrVC6, and qnrVC7, were detectable in these strains and their structure and functions were characterised.