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Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
Published on: May 2, 2018
Association between Type A blaZ Gene Polymorphism and Cefazolin Inoculum Effect in Methicillin-Susceptible
Sun Hee Lee1, Wan Beom Park2, Shinwon Lee3
1Department of Internal Medicine, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Hospital, Busan, Republic of Korea.
Abstract:
Some proportion of type A blaZ gene-positive methicillin-susceptible Staphylococcus aureus strains exhibit the cefazolin inoculum effect (CIE). The type A blaZ gene was divided into two groups by single nucleotide polymorphisms (SNPs) at Ser226Pro and Cys229Tyr. The median cefazolin MICs at a high inoculum concentration were 5.69 μg/ml for the Ser-Cys group and 40.32 μg/ml for the Pro-Tyr group (P = 0.01). The SNPs at codons 226 and 229 in the amino acid sequence encoded by the blaZ gene were closely associated with the CIE.
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