ISSN 1673-6184 CN 31-1966/R
Objective To identify the antibiotic sensitivity of multi-drug resistant Salmonella typhi and detect its resistant genes. Methods 5 resistant Salmonella typhi strains and 1 sensitive strain was selected randomly, then antibiotic susceptibility to 12 different antibiotics were tested by K-B method. Reserpine inhibition test was also performed to find the drug excretion system. TEM type of β-lactamase gene, aminoglycosides modifying enzyme gene aac(6′)-Ⅰb, aac3-Ⅱ, qacEΔ1-sul1 gene, catA, catB gene, and cmlA gene were detected by PCR process. Results 5 multi-drug resistant strains were resistant to ampicillin, piperacillin, cefuroxime, ceftazidime, kanamycin, gentamycin, trimesulf and chloramphenicol, and they were all sensitive to meropenem, cefoperazone and cefepime; they showed an intermediate sensitivity to cafalotin. The strain which doesn’t carry pRST98 was sensitive to all of the antibiotics. All strains were negative in reserpine inhibition test. 5 drug-resistant strains carried aac3-Ⅱ、qacEΔ1-sul1 and catA gene, 4 of them harbored TEM type of β-lactamase gene, but none of the 5 strains carried aac(6′)-Ⅰb, catB or cmlA. Conclusion The multi-drug resistant Salmonella typhi strains carrying pRST98 contained an array of drug resistant genes, which lead to the resistance to different antibiotics.
