Objective To analyze the distribution and drug resistance of pathogens from the wounds of thermal burn patients, so as to provide reliable basis for the rational use of antibiotics and the effective control over nosocomial infection.
Methods Wound samples of 1 310 thermal burn patients admitted into our burn wards from January 2012 to December 2017 were collected and retrospectively analyzed. API bacteria identification panels and automatical bacteria identification equipment were used to identify pathogens. E test was conducted to detect drug resistance of pathogens to vancomycin, tigecycline, and oxacillin. Kirby-Bauer paper disk diffusion method was used to detect drug resistance of pathogens to 31 antibiotics including penicillin G, gentamicin and rifampicin, etc., and drug resistance of fungi to 5 antifungal agents (voriconazole, amphotericin B, fluconazole, itraconazole, and ketoconazole). The WHONET 5.6 software was used to analyze the constituent ratios of Gram-negative bacteria, Gram-positive bacteria, and fungi in each year; the distribution of fungi; the distribution of top 10 bacteria with the highest constituent ratios in each year; the constituent ratios of methicillin-resistant
Staphylococcus aureus (MRSA) and methicillin-sensitive
Staphylococcus aureus (MSSA); the drug resistance of top 3 bacteria with the highest constituent ratios to commonly used antibiotics in each year; and the drug resistance of
Candida to commonly used antifungal agents.
Results (1) Totally 2 183 strains of pathogens were isolated for the first time, including Gram-negative bacteria 1 194 (54.70%) strains, Gram-positive bacteria 879 (40.27%) strains, and fungi 110 (5.04%) strains. From 2012 to 2016, the constituent ratio of Gram-negative bacteria showed a decreasing trend, while that of Gram-positive bacteria showed an increasing trend year by year; and the constituent ratio of fungi was with a significantly increasing trend from 2016 to 2017. (2) Among all the fungi, the constituent ratio of
Candida parapsilosis ranked the first,
Aflatoxin ranked the second,
Candida albicans and
Candida tropicalis both ranked the third. (3) From 2012 to 2017, top 10 bacteria with the highest constituent ratios, from high to low, were
Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Staphylococcus haemolyticus, Klebsiella pneumoniae, Enterococcus faecalis, Aeromonas hydrophila, and
Stenotrophomonas maltophilia respectively. The constituent ratio of
Staphylococcus aureus ranked the first in each year. The constituent ratio of
Pseudomonas aeruginosa was fluctuating but showed a rising trend comprehensively. The constituent ratio of
Acinetobacter baumannii went up after decreasing. (4) Among all the
Staphylococcus aureus, constituent ratio of MRSA was above 65.00%, while that of MSSA was below 31.00% in each year. (5) From 2012 to 2017,
Staphylococcus aureus resistant to vancomycin, linezolid, or teicoplanin was not detected; the drug-resistant rates of MRSA to penicillin G, oxacillin, gentamicin, rifampicin, tetracycline, ciprofloxacin, ofloxacin, and levofloxacin were above or equal to 80.0% in each year; the drug-resistant rates of
Staphylococcus aureus to clindamycin and erythrocin showed an obviously increasing trend, the drug-resistant rates of
Staphylococcus aureus to moxifloxacin and queenoputin/daputin in 2017 were higher than those in 2016, while the drug-resistant rates of
Staphylococcus aureus to the other 14 antibiotics showed no significant change in trend. From 2012 to 2017,
Acinetobacter baumannii was sensitive to polymyxin B and tigecycline; the drug-resistant rate of
Acinetobacter baumannii to ceftriaxone was relatively high; the drug-resistant rates of
Acinetobacter baumannii to levofloxacin, minocycline, and tetracycline were decreasing while those to the other 14 antibiotics went up after decreasing. From 2012 to 2017,
Pseudomonas aeruginosa wasn′t resistant to polymyxin B, and its drug-resistant rates to the other 14 antibiotics showed decreasing trends. (6) The drug-resistant rates of
Candida albicans to voriconazole, amphotericin B, fluconazole, itraconazole, and ketoconazole were all zero. The drug-resistant rates of non-
Candida albicans to voriconazole, fluconazole, itraconazole, and ketoconazole were higher than those of
Candida albicans.
Conclusions Among the pathogens from the wounds of thermal burn patients,
Staphylococcus aureus, Pseudomonas aeruginosa, and
Acinetobacter baumannii had the top 3 constituent ratios; the constituent ratio of non-
Candida albicans was obviously higher than that of
Candida albicans. The high drug resistance rates of
Staphylococcus aureus and
Acinetobacter baumanni require more attention from clinicians and the local hospital′s infection control department.
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