Pathogenic bacterial profile and drug resistance analysis of community-acquired pneumonia in older outpatients with fever

Objectives To study the pathogenic bacterial profile and drug resistance in older patients with community-acquired pneumonia (CAP) in outpatients with fever, and provide evidence to diagnose and treat CAP timely and accurately. Methods We studied older (>60 years) patients with CAP in Beijing Shijitan Hospital from 2016 to 2017. Pathogenic bacteria from sputum of patients were isolated and identified and their resistance to antibiotics was tested. Risk factors for multidrug-resistant CAP (MDR-CAP) and clinical outcomes were analyzed. Results A total of 5563 outpatients with fever were recruited and 391 had CAP. A total of 117 isolates of pathogenic bacteria were obtained from 176 CAP cases. The main pathogenic bacteria were Klebsiella pneumoniae (27.4%), Escherichia coli (17.9%), Staphylococcus aureus (12.0%), Pseudomonas aeruginosa (10.3%), and Streptococcus pneumoniae (9.4%). A drug sensitivity test (DST) showed that K. pneumoniae, E. coli, and P. aeruginosa had good sensitivity to imipenem, cefoperazone/sulbactam, piperacillin/tazobactam, and amikacin. Staphylococcus aureus and Streptococcus pneumoniae had strong sensitivity to vancomycin, linezolid, and levofloxacin. Previous multiple antibiotic treatment was an independent risk factor for MDR-CAP. Conclusions Gram-negative bacteria are the main pathogenic bacteria in older patients with CAP. Identification and DSTs of pathogens could enable accurate diagnosis and treatment of CAP.