Molecular Epidemiology and Genetic Characteristics of Various blaPER Genes in Shanghai, China

We describe the genetic characteristics and possible transmission mechanism of bla(PER) in 25 clinical Gram-negative bacilli in Shanghai. bla(PER), including bla(PER-1), bla(PER-3), and bla(PER-4), was located chromosomally or in different plasmids. Tn1213 harboring blaPER-1 was first identified in two Proteus mirabilis isolates in China. The other bla(PER) variants were preceded by an ISCR1 element inside the complex class 1 integron associated with IS26, Tn21, Tn1696, and a miniature inverted-repeat transposable element.