Distribution and antimicrobial resistance profile of the clinical bacterial strains isolated from Beijing Children's Hospital from 2009 to 2015 / 中国感染与化疗杂志

ABSTRACT

Objective To investigate the distribution and antimicrobial resistance profile of the common pathogens isolated during the period from 2009 to 2015.Methods All the bacterial strains isolated from pediatric inpatients in Beijing Children's Hospital during the period from 2009 to 2015 were analyzed. Antimicrobial susceptibility was determined by disk diffusion method and Phoenix 100 Automated Microbiology System. Results were analyzed according to the guidelines of CLSI (2014) using WHONET 5.6 software.Results The total strains were 26630. The most common gram-positive isolates were Streptococcus pneumoniae,Staphylococcusaureusand coagulase-negative Staphylococcus (CNS), while the most frequently isolated gram-negative microorganisms were Klebsiella spp.,Pseudomonas aeruginosa and Escherichia coli. The prevalence of S. pneumoniae was up to 25.7 % (4101/15973) in all respiratory tract specimens. About 50.2 % of the S. pneumoniae isolates were not susceptible to penicillin. The prevalence of methicillin-resistant strains was 20.6 % in S. aureus (MRSA) and 87.8 % in coagulase negative Staphylococcus (MRCNS) on average. The prevalence of MRSA increased from 11.1 % in 2009 to 29.8 % in 2015. No S. pneumoniae or staphylococcal strains were found resistant to vancomycin or linezolid. The Enterococcus strains were still highly susceptible to vancomycin and linezolid. Overall 0.3 % of the Enterococcus faecium isolates were resistant to vancomycin. The extended-spectrum beta-lactamases (ESBLs) producing strains accounted for 71.4 % -78.1 % of E. coli and 65.1 % - 76.9 % of K. pneumoniae isolates. The carbapenem-resistant E. coli and K. pneumoniae were reported for the first time in 2010, but in 2014, the strains resistant to carbapenems had increased to more than 7 % in E. coli, and higher than 20 % in K. pneumoniae. In 2015, up to 27.7 % and 25.7 % of P. aeruginosa isolates were resistant to imipenem and meropenem, respectively, and 59.9 % of the A. baumannii isolates were resistant to imipenem and meropenem. Beta-lactamase was positive in 46.3 % of the H. influenzae isolates. Conclusions MRSA and the carbapenem-resistant strains of E. coli,K. pneumoniae and A. baumannii are still on the rise in pediatric inpatients, which poses a serious threat to clinical practice and implies the importance of strengthening infection control.