Objective To investigate the pathogen distribution and drug resistance in ICU patients, provide reference for prevention of severe infection and empirical antibacterial treatment. Methods The patients admitted in ICU between January 2013 and December 2014 were retrospectively analyzed. The pathogenic data were collected including bacterial and fungal culture results, the flora distribution and drug resistance of pathogenic bacteria. Results A total of 2088 non-repeated strains were isolated, including 1403 (67.2%) strains of Gram-positive bacteria, 496 (23.8%) strains of Gram-negative bacteria, and 189 (9.0%) strains of fungus. There were 1324 (63.42%) strains isolated from sputum or other respiratory specimens, 487 (23.33%) strains from blood specimens, 277 (13.27%) strains from other specimens. The bacteria included Acinetobacter baumannii (17.2%), Klebsiella pneumoniae (14.8%), Pseudomonas aeruginosa (9.9%), C. albicans (6.3%), E. coli (5.6%), E. cloacae (5.4%), Epidermis staphylococcus (5.0%) and Staphylococcus aureus (4.7%). There were 15 strains of penicillium carbon resistant enterobacteriaceae bacteria (CRE) accounting for 2.3%, including 5 strains of Pneumonia klebsiella, 4 strains of E. cloacae. In 117 strains of E. coli, drug-resistant strains accounted for 86.4% including 85.5% of multiple drug-resistant strains (MDR) and 0.9% of extremely-drug resistant (XDR) strains. In 359 strains of Acinetobacter baumannii, drug-resistant strains accounted for 75.2% including 72.1% of XDR strains and 3.1% of MDR strains. MDR strains accounted for 10.6% in Pseudomonas aeruginosa. Detection rate of methicillin resistant Staphylococcus aureus (MRSA) and methicillin resistant coagulase-negative Staphylococci (MRCNS) was 49.0% and 95.5%, respectively. There were 4 strains of vancomycin resistant Enterococcus faecalis. There were 131 (69.3%) strains of C. albicans, 23 (12.2%) strains of smooth candida. C. albicans was sensitive to amphotericin and 5-fluorine cytosine, and the resistance rate was less than 1% to other antifungle agents. The resistance rate of smooth ball candida was higher than C. albicans and nearly smooth candida, but still less than 15%. Conclusions The predominant pathogens in ICU was gram-negative bacteria. The top eight pathogenic bacteria were Acinetobacter baumanni, Klebsiella pneumoniae, Pseudomonas aeruginosa, C. albicans, E. coli, E. cloacae, Epidermis staphylococcus and S. aureus. Sputum and blood are common specimens. CRE accounts for 2.3%. Drug-resistant strains are most common in E. coli mainly by MDR, followed by Acinetobacter baumannii mainly by XDR, and least in Pseudomonas aeruginosa. C. albicans is the most common fungus with low drug resitance.
ObjectiveTo detect the in vitro susceptibility of common clinical multidrug-resistant bacteria to tigecycline by disk diffusion (KB), minimum inhibitory concentrations (MIC) test strip (MTS) and Vitek 2 Compact methods, in order to evaluate the accuracy of the three different susceptibility testing methods. MethodsA total of 140 multidrug-resistant isolates (excluding Pseudomonas aeruginosa) were collected retrospectively from West China Hospital between January 2014 and March 2015. The inhibitory zone diameters and MIC of tigecycline were determined by KB, Vitek 2 Compact system and MTS respectively. The results of Vitek 2 Compact system and KB method were compared with that of MTS. ResultsAmong the 140 multidrug-resistant isolates, 119 were Acinetobacter baumannii, and 21 were Enterobacteriaceae. According to the US Food and Drug Administration standards, the sensitivity rates of 119 Acinetobacter baumannii isolates to tigecycline were 88.2%, 85.7%, and 90.8% respectively for KB method, Vitek 2 Compact system and MTS, and those of 21 Enterobacteriaceae were 76.2%, 81.0%, and 81.0%, respectively. ConclusionsTigecycline displays effective in vitro antibacterial activity to clinical common multidrug-resistant bacteria (excluding Pseudomonas aeruginosa), but different susceptibility testing methods have shown different susceptibility rates. For Acinetobacter baumannii, KB method is superior to Vitek 2 Compact system, and for Enterobacteriaceae, Vitek 2 Compact system is superior to KB method.
Inappropriate and irrational prescription of antimicrobial agents has led to increasing bacterial resistance, which has become a major concern around the world. Clinical microbiology service provides a basis and guarantee for the rational application of antimicrobial agents and an important technical support for antimicrobial stewardship, and plays an important role in promoting the rational use of antimicrobial agents. This paper summarizes and evaluates the specific role and technical requirements of clinical microbiology service in the diagnosis of infectious diseases, rational application of antimicrobial agents, hospital infection control and training of medical staff, so as to provide a technical guidance for clinical microbiology service in the antimicrobial stewardship.