OBJECTIVE: To investigate the distribution of pathogenic bacteria and drug sensitivity results in lower respiratory tract infection in Suzhou First People’s Hospital（ hereinafter referred to as “our hospital”）

so as to guide the rational and effective selection of clinical antibiotics. METHODS: From Jan. 2015 to Jan. 2020

1 636 qualified sputum samples from patients with lower respiratory tract infection in our hospital were examined for etiology.RESULTS: Totally 853 pathogenic bacteria were isolated from 1 636 sputum samples

including 703 Gram-negative bacteria（ 82. 42%）

112 Gram-positive bacteria（ 13. 13%） and 38 fungi（ 4. 45%）. The drug sensitivity results showed that Pseudomonas aeruginosa had the highest resistance rate to cefazolin（ 100. 00%） and the lowest resistance rate to imipenem（ 4. 65%） and meropenem（ 4. 65%）. Klebsiella pneumoniae had the highest resistance rate to ampicillin（ 100. 00%） and the lowest resistance rate to meropenem（ 5. 00%） and imipenem（ 5. 00%）. Escherichia coli had the highest resistance rate to ampicillin（ 57. 30%）

and the lowest resistance rate to meropenem（ 1. 12%） and imipenem（ 1. 12%）. Acinetobacter baumannii had the highest resistance rates to ampicillin（ 100. 00%） and cefazolin（ 100. 00%）

and the lowest resistance rate to meropenem（ 54. 69%）. Staphylococcus aureus had the highest resistance rate to penicillin（ 100. 00%）

and the lowest resistance rate to nitrofurantoin（ 0%）

tigecycline（ 0%）

linezolid（ 0%）

vancomycin（ 0%） and levofloxacin（ 0%）. Streptococcus pneumoniae had the highest resistance rate to erythromycin（ 100. 00%）

clindamycin（ 100. 00%） and tetracycline（ 100. 00%）

and the lowest resistance rate to oxacillin（ 0%）

amoxicillin（ 0%）

cefoxitin（ 0%）

tobramycin（ 0%）

rifampicin（ 0%）

gentamicin（ 0%）

ciprofloxacin（ 0%）

teicoplanin（ 0%）

vancomycin（ 0%）

nitrofurantoin（ 0%）

tigecycline（ 0%）

linezolid（ 0%）and levofloxacin（ 0%）. Candida albicans had the highest resistance rate to fluconazole（ 20. 00%）

and the lowest resistance rate to voriconazole（ 6. 67%）. Candida glabrata had the highest resistance rate to fluconazole（ 60. 00%） and itraconazole（ 60. 00%）

and the lowest resistance rate to amphotericin B（ 0%） and voriconazole（ 0%）. Candida tropicalis had the highest resistance rate to itraconazole（ 66. 67%） and the lowest resistance rate to amphotericin B（ 0%） and voriconazole（ 0%）. CONCLUSIONS: The lower respiratory tract infections in our hospital in the past 5 years were dominated by Gram-negative bacteria with high resistance to broad-spectrum penicillins and low resistance to carbapenems and compound preparations containing β-lactamase inhibitors. Clinical selection of antibiotics should be based on bacterial culture results and resistance rates

and individualized treatment protocols should be developed to improve the efficacy and curb the emergence of multi-drug resistant bacteria.