ABSTRACT
Objective To investigate the genotype of D class of carbapenemase of carbapenem－resistant Acinetobacter baumannii in traumatology department, so as to guide the rational use of antibiotics as well as prevent the nosocomial infection. Methods A total of 96 strains of Acinetobacter baumannii were collected in traumatology department. Patient history were analyzed and genotype of carbapenemases of OXA－51,OXA－23,ISAba1－oxa－51 and ISAba1－oxa－23 were analyzed by PCR.Results 70.84% (68/96) of Acinetobacter baumannii were isolated from wound tissue. 12 antibacterial agents were tested, 96 strains of Acinetobacter baumannii showed the highest resistance rate (78.13%) to imipenem and the lowest resistance rate (43.75%) to levofloxacin. Among 23 strains of imipenem－sensitive Acinetobacter baumannii, OXA－ 51 gene expression was not detected in 4 strains, however, OXA－23 gene expression were observed in 5 strains. The gene expression rates of OXA－51,OXA－23, ISAba1－oxa－51 and ISAba1－oxa－23 genes were 100%, 95.89%, 79.45% and 71.23% respectively in 73 strains of imipenem－insensitive Acinetobacter baumannii. The rate of gene expression profile of OXA－51+ISAba1－oxa－51+OXA－23+ISAba1－oxa－23 was 65.75% .Conclusion The strains of imipenem－sensitive Acinetobacter baumannii may have the gene expression of OXA－23 of D class of carbapenemase. The main pattern of carbapenemase－producing was OXA－51+ISAba1－oxa－51+OXA－23+ISAba1－oxa－23 in traumatology department,which might be regarded as one of the mechanisms that led to the high resistance of the bacterium of acinetobacter baumannii to carbapenem antibiotics.
ABSTRACT
Objective To investigate the distribution and antimicrobial susceptibility of pathogens causing maxillofacial infection in patients,and provide evidence for rational use of antimicrobial agents in clinical practice.Methods Specimens of patients infected with oral and maxillofacial infection in a hospital between January 2012 and December 2016 were performed microbial culture,pathogens were identified and performed antimicrobial susceptibility testing,distribution of pathogens and antimicrobial resistance were analyzed.Results Of 882 patients with maxillofacial infection,male and female accounted for 32.20％ and 67.80％ respectively;35.38％ and 32.65％ of patients aged ～40 years and ～60 years respectively;a total of 145 strains were isolated,88(60.69 ％) of which were gram-negative bacteria,mainly Klebsiella pneumoniae and Pseudomonas aeruginosa;56 (38.62 ％) of which were gram-positive bacteria,mainly Staphylococcus aureus.Resistance rates of Klebsiella pneumoniae to 16 kinds of an timicrobial agents were a11＜50％,resistance rates to imipenem and meropenem were the lowest,both were 3.45％,1 1 strains were extended-spectrum β-lactamases-producing strains;resistance rates of Pseudomonas aeruginosa to 10 kinds of antimicrobial agents were all＜40％.Staphylococcus aureus was susceptible to tigecycline,linezolid,and vancomycin,resistance rate to penicillin was the highest (66.67％),resistance rate to oxacillin was 20.83％.Conclusion The main pathogens causing oral and maxillofacial infection are gram negative bacteria,different pathogens have different antimicrobial resistance,antimicrobial agents should be used rationally during clinical treatment according to antimicrobial susceptibility testing result.