Distribution And Antimicrobial Resistance Of Bacterial Isolates From Patients Of Lower Respiratory Tract Infections

Objective To analyze the constitution and antimicrobial resistance pattern of pathogenic bacteria isolates from sputum or bronchoalveolar lavage fluid of lower respiratory tract infections (LRTIs) patients, and to investigate the drug resistance change of common pathogenic bacteria.Methods Collected clinical isolates of bacteria from sputum and bronchoalveolar lavage fluid samples of LRTIs patients since January2011to December2012, contained isolation of bacteria and antimicrobial susceptibility testing of pathogens. Discussed the trend of drug resistance of five common pathogenic bacteria from sputum during2010to2012. The identification of strains was detected by Micro Scan-4from America, and antibiotic resistance test was carried out by Kirby-bauer.Results (1) Out of the1053sputum samples from LRTIs patients,354positive bacterial strains were separated, with Gram-negative bacteria accounting for84.18%of the total strains separated. Klebsiella pneumoniae(23.73%), Acinetobacter baumannii(19.49%) and Pseudomonas aeruginosa(12.15%) were the most common strains of Gram-negative bacteria and were all highly multidrug-resistant. Drug resistance rate of enterobacteriaceae to Ampicillin and Cefazolin were85.18%and50%. Drug resistance rate of nonfermenters to SMZ and Cefotaxime、Ceftriaxone were over55%. Gram-positive bacteria accounted for15.82%of the total strains separated, and the most common strain collected was Staphylococcus aureus(9.89%). Drug resistance rate of Gram-positive bacteria to Erythromyci、Ampicillin Penicillin G and Clindamycin were over88%. The prevalence of ESBLs-producing Klebsiella pneumoniae was22.62%. The prevalence of ESBLs-producing E.Coil was65.22%. The prevalence of MRSA was57.14%.(2) From2010to2012, antibiotic resistance of Gram-negative bacteria had an increasing trend year after year, especially that Acinetobacter baumannii had a high resistant radio to Imipenem.We should be aware of the importance to rational use of antibiotics. While multidrug resistance Gram-positive strains have been decreasing year by year.(3)Out of the134bronchoalveolar lavage fluid from LRTIs patients,74positive pathogenic strains were separated, with Gram-negative bacteria accounting for71.62%of the total strains separated. Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae were the most common strains of Gram-negative bacteria and were all highly multidrug-resistant. Gram-positive bacteria accounted for28.38%of the total strains separated, and the most common strain collected was Staphylococcus aureus.Conclusions The gram-negative bacteria infections account for the majority of lower respiratory tract infections. Situation of antibiotic resistance was rigorous. Frequently used antimicrobial had very low sensitivity against bacteria. According to the antibiotic resistance spectrum of bacteria, we can select antibiotic reasonably. Multidrug resistance strains have been increasing year by year.