ABSTRACT
Objective To study Aeromonas hydrophila infection and the clinical status of the major causative factor Aerolysin gene.Methods Clinical isolates of Aeromonas hydrophila was collected from 2012 to 2013 year in People’s Hospital of Shenzhen Longhua Branch.Its identification and antibiotic susceptibility testing was analyzed by VITEK 2 compact.Clinical resistance rates and distribution was analyzed by WHONET5.6 software.Polymerase chain reaction (PCR)was used to de-tect the Aerolysin gene form in chromosomes and plasmids extracted genome.Results The clinical total of 48 isolated Aero-monas hydrophila ,distributed in 16 clinical samples of sputum,blood 11,10 secretions,urine 7 and stool 4.Distribution in ward decentralized,the central tendency was not detected.Drug resistance rates to ampicillin,ampicillin/sulbactam and ce-fazolin reached more than 80%,while amikacin,cefepime,levofloxacin,piperacillin/tazobactam and imipenem was low 10%or less.43.7% strains carried the Aerolysin gene.39.5% of Aerolysin gene was found on chromosome genome.Conclusion Aeromonas hydrophila clinical infection existed in dispersed form,most of which carried Aerolysin gene in chromosome ge-nome.Aeromonas hydrophila had serious resistance to penicillins and first generation cephalosporin,but to broad-spectrum drugs maintaining high sensitivity.Precaution of Aeromonas hydrophila ,as an important condition pathogenic bacteria,is some significant for preventing it’s proliferation of drug-resistant strains.
ABSTRACT
The aerolysin genes (aerA) of BZ and NK isolates were cloned and sequenced. The sequence analysis showed that the partial aerA of BZ and NK isolates consisted of 1393 bp, encoding a protein of 464 amino acids. The similarity of nucleotide and amino acid sequences of aerA between BZ and NK isolates was 97.6% and 98.3% respectively. The nucleotide sequence of aerA of BZ strain exhibited 71.6% to 97.5% homology with other Aeromonas isolates, and the amino acid sequence exhibited 68.0% to 98.9% homology. The phylogenetic tree based on aerA nucleotide sequences from Aeromonas isolates was constructed with neighbor-joining method. It showed that there were three branches of aerolysin genes, and a close relation- ship among Aeromonas hydrophila isolates which were clustered into the same branch.