Analysis Of Distribution And Drug Resistance Of Pathogenic Bacteria Isolated From Patients With Lower Respiratory Tract Infection

Objective: Sputum specimens of the inpatients with lower respiratory tract infection of the respiratory department in our hospital(East Section)were collected to analyze the distribution and drug resistance of pathogenic bacteria isolated from the patients with lower respiratory tract infection,and to provid the scientific basis of choosing antibiotics correctly for the physicians of the respiratory department.The results is important to make empirical anti-infective therapy plan, direct the rational use of antibiotic and improve the curative effect of infective disease.Methods:In the period of January 2014 to December 2014, sputum samples from lower respiratory tract infection inpatients of the respiratory department had been collected in this reseach. And then identified the pathogens and did the drug sensitive test according to the standards of 《National operation regulations of clinical laboratory》and CLSI. Bacterial identification were carried out by VITEK 2 COMPACT automatic bacteria identification system,which was also used to test drug sensitivity with Kirby-Bauer test.Removal of the same patients repeatedly cultured the same stains during the same hospitalization period, and then retrospective analyzed their distributions and drug resistance.To analyze the distribution and drug resistance of pathogenic bacteria,all experiment data using enumeration data were statistically analyzed with screening,summation,rate by excel software establishing a database.Results:In our study,among1150 cases with lower respiratory tract infection in our respiratory department,842 cases were examined by sputum culture.Removal of the same patients repeatedly cultured the same stains during the same hospitalization period,totally307 strains of pathogenic bacteria, examination rate was 73.2% and detection rate was36.5%.307strains of pathogenic bacteria were isolated,242 strains of bacteria(78.8%),65 strains of fungi(21.2%).It found that 213 strains of Gram-negative bacilli(69.4%),and the top five of them were Baumanii(29.1%),Klebsiella pneumoniae(26.8%),Pseudomonas aeruginosa(18.8%), Escherichiacoli(11.3%),Serratia marcescens(5.6%), 29 strains of Gram-positive cocci accounted for 9.4%.The most common species of Gram-positive cocci was Staphylococcus aureus(69.0%).65 strains of fungi,the detection rate is higher, up to 21.2%.Candida albicans(43.1%)was still the majority strains of fungi,followed by aspergillus(30.8%).In our research, Baumanii had a drug resistance to most commonly used antibiotics,but showed lower resistance rate to Tigecycline, Cefoperazone/Sulbactam, 6.8%, 7.8% respectively; the resistance to Amikacin was 45.2%;but to Imipenem,Meropenem was up to 70.1%, 75.8%.Less than 10% of Klebsiella pneumoniae had a resistant to Imipenem,Meropenem,Cefotetan,Cefepime,Amikacin;There is no Klebsiella pneumoniae resistant to Cefoperazone/Sulbactam.To the Pseudomonas aeruginosa, Piperacillin/Tazobactam had the lowest antibiotic resistance,but the resistance to Imipenem reached 12.5%.Less than 10% of Escherichia coli have a resistant to Imipenem,Meropenem, Amikacin and Cefotetan;but more than 70% of them resistant to Levofloxacinand Ciprofloxacin. Serratia marcescens had a low drug resistance to common antibiotics,and the drug sensitive rate to Meropenem,Piperacillin/Tazobactam,Cefoperazone/ Sulbactam was 100%;All Serratia marcescenswere resistant to Cefazolin, Macrodantin,Cefuroxime.There were no gram-positive cocci resistant to Vancomycin?Linezolid and Teicoplanin.Conclusion: Gram-negative bacilli were the most common pathgens of the respiration department,followed by fungi.The proportion of gram-positive cocci was less.Among Gram-negative bacilli,Baumanii had high positive-testing rate, strong drug resistance and wide drug resistance spectrum showed very high resistance rate to carbapenems;Tigecycline, Cefoperazone/Sulbactam had the lowest antibiotic resistance to Baumanii.Therefore,Tigecycline,Cefoperazone/Sulbactam was the first selected drug to treat the Baumanii,avoiding the use of carbapenemes. In addition,The majority of Gram-negative bacilli have higher sensitivity to Imipenem,meropenem,Piperacillin /Tazobactam,Cefoperazone /Sulbactam, Amikacin.However, Ampicillin, Ampicillin/sulbactam, Cefazolin and Cefuroxime have higher resistance rate.There were no Gram-positive cocci resistant to Vancomycin,Linezolid and Teicoplanin. In our research,the detection rate of fungi was high, Candida albicans in the first place,but no resistant to fluconazole.pathgens had relatively strong local features and time differences. Different strains have different resistance to various types of antibiotics. Based on the local distribution and drug resistance of pathogenic bacteria, combining with the characteristics of patients and drug sensitive test,clinicians can choose empiric antibiotic therapy reasonably and adjust the targeted medications in time.This data is important to guide the physicians of the respiration department to promote the rational use ofantibiotics.