Epidemiology of CTX-M-type extended-spectrum beta-lactamase (ESBL)-producing nosocomial -Escherichia coli infection in China

Abstract

Background: Escherichia coli is one of the most common clinical pathogens causing nosocomial infection. The widespread cefotaxime-beta lactamases (CTX) has increased the multidrug resistance (MDR) of E. coli and has brought great trouble to the doctor treating the infection. Methods: ESBL-positive E. coli isolates were collected from different hospitals in different areas and the minimal inhibitory concentration (MIC) was analyzed by the agar dilution method. The resistance gene types were detected using polymerase chain reaction (PCR) and the sequence types were determined by multilocus sequence typing (MLST). Results: We found that the blaCTX-M-1 group and the blaCTX-M-9 group were the main CTX-M gene types, with many kinds of MLST gene types. Except for TEM with high isolate, SHV, OXA and VEB were relatively rare, while no PER and GES was detected. Most strains may have other resistance mechanisms, and the ESBL positive strains have high resistance not only to cephalosporins but also to other kinds of antibiotics. Conclusion: The study provides wide epidemiological data and enables more effective infection control and treatment plans.