Detection of KPC-2 and qnrS1 in clinical isolates of Morganella morganii from China

Abstract

Seven carbapenem-nonsusceptible Morganella morganii isolates, which have similar antibiotic susceptibility profiles, were isolated over a 5-month period. MICs of imipenem, meropenem, and ertapenem were 8, 1, and 0.25 to 0.5 μg/mL, respectively. Pulsed-field gel electrophoresis indicated that 6 isolates were indistinguishable or closely related. Carbapenem resistance can be transferred from M. morganii to Escherichia coli by conjugation. All M. morganii isolates and E. coli transconjugants produced KPC-2 and carried the qnrS1 gene. Production of KPC-2 mainly contributed to the carbapenem resistance in M. morganii. KPC-2-producing M. morganii clonally spread in a hospital in China.