Antibiotic resistance patterns of Gram-negative and Gram-positive strains isolated from inpatients with nosocomial infections in a tertiary hospital in Beijing, China from 2011 to 2014.

This study was to evaluate the resistance of antimicrobial agents against pathogens from inpatients with nosocomial infection collected in Beijing, China, during 2011-2014. Measurement of minimum inhibitory concentrations (MICs) was carried out using the broth microdilution method with the Clinical and Laboratory Standards Institute (CLSI) guidelines as the indicator. A total of 5442 Gram-negative and 806 Gram-positive isolates were collected in this study in 2011-2014. Two carbapenem-resistant strains appeared among Escherichia coli (E. coli), while imipenem-resistant isolates increased in proportion from 0% to 8.2% among Klebsiella pneumonia (K. pneumonia) during 4 year. Acinetobacter baumannii (A. baumannii) revealed severe antibacterial resistance to most antimicrobial agents. In contrast, a decreasing trend on resistance had been observed among Pseudomonas aeruginosa (P. aeruginosa) especially after 2012, range from 1.8% for co-trimoxazole to 13.5% for piperacillin. The resistance of Staphylococcus aureus (S. aureus) also had the lowest resistant to linezolid and vancomycin (0.1%). In summary, antimicrobial-resistant nosocomial pathogens have gradually increased from 2011 to 2014, so improved surveillance of hospital-acquired infections and effective infection-control measures may be the best way to solve the present problem.