Objective To explore the distribution of bacteria among community acquired lower respiratory tract infection (LRTI) inpatients with underlying chronic respiratory tract diseases.Methods The clinical data，sputum culture and drug susceptibility results of 212 community acquired LRTI patients who were hospitalized during the period 2001-2005 were retrospectively analyzed.All patients had various underlying chronic respiratory tract diseases.Results A total of 229 strains of pathogens were detected，with the majority being gram negative bacteria.In pathogens of acute exacerbation of chronic obstructive pulmonary disease，gram negative bacteria occupied 73.9%.And Pseudomonas aeruginosa and Klebsiella pneumoniae were the most common pathogens，with each occupying 18.2% and 13.6% respectively.Gram positive bacteria occupied 23.8%，mainly Staphylococcus aureus (10.2%) and Streptococcus pneumoniae (9.1%).In patients with bronchiectasis exacerbated by bacterial infection，86.2% were caused by gram negative bacteria，the top three being，in descending order，Pseudomonas aeruginosa (27.5%)，Haemophilus parainfluenzae (13.7%)，and Haemophilus influenzae (11.8%).Bronchiectasis was the major risk factor of getting Pseudomonas aeruginosa infection (OR=5.590，95%CI 2.792~11.192).The risk factors of getting Acinetobacter baumanii infection were antacid usage within 1 month (OR=9.652，95%CI 2.792~11.192) and hypoalbuminemia (OR=2.679，95%CI 1.108~6.476).For enterobacters infections，including Klebsiella pneumoniae，Enterobacter cloacae and Escherichia coli，the risk factors were antibiotic usage within 1 month (OR=4.236，95%CI 1.982~9.057)，having renal diseases (OR=4.305，95%CI 1.090~17.008) and diabetes mellitus (OR=2.836，95%CI 1.339~6.009).Conclusions Gram negative bacteria were the main pathogens of community acquired LRTI in hospitalized patients with underlying chronic respiratory tract diseases.The pathogens were influenced by underlying diseases，severity of diseases and drug usage history of patients.
Objective To explore the application value of Mycoplasma pneumoniae （MP） rapid culture technique for diagnosis of lower respiratory tract infections （LRTIs ） inpatients. Methods 120 LRTIs inpatients in respiratory ward，Anzhen hospital from January 1，2010 to December 31，2010，were recruited in this study. Their pharynx swabs were obtained for rapid MP culture and the serum antibody detection of MP was performed by Gelatin particle agglutination method. Results There were 33 positive yields in 120 LRTIs patients by rapid culture method and 24 positive yields by serological assay. The positive rates were 27.5% and 20.0% respectively. There was no significant difference in the two detecting methods （Pgt;0.05）. Conclusions MP rapid culture method is a better early diagnostic method at the present. MP rapid culture method combined with serological detection can improve the positive yield and avoid missed diagnosis.
Objective To study the incidence and etiological distribution of lower respiratory tract infection (LRTI) after airway metal stent implantation in patients with malignant central airway obstruction (MCAO). Methods The clinical data of 149 patients with MCAO who underwent airway metal stent implantation in Department of Pulmonary and Critical Care Medicine of Hunan Provincial People's Hospital from April 2014 to April 2021 were selected for a retrospective study. The incidence of LRTI after treatment was counted. According to whether LRTI occurred after operation, they were divided into infected group and uninfected group. The clinical data of the two groups were compared and the influencing factors of LRTI were analyzed. Sputum samples and/or bronchoalveolar lavage fluid samples from patients infected with LRTI were collected for pathogen detection and drug susceptibility test, and the distribution and drug resistance of main pathogens were analyzed. Results A total of 149 patients who met the criteria were included in this study and the incidence of LRTI was 21.48%. People in the infected group was older than that in the uninfected one, and the proportion of people with a history of smoking, chemoradiotherapy, covered metal stents, and stent-related granulation tissue proliferation was higher, and the proportion of people with postoperative standardized aerosol inhalation was lower (P<0.05). Age, smoking history, chemoradiotherapy, covered metal stents, stent-related granulation tissue hyperplasia and postoperative standardized aerosol inhalation were all influencing factors of LRTI in these patients (P<0.05). A total of 38 pathogens were detected in 32 patients with LRTI. Gram negative bacteria, gram positive bacteria and fungi accounted for 68.42% (26/38), 21.05% (8/38) and 10.53% (4/38) respectively. Pseudomonas aeruginosa, the main Gram-negative bacteria, had no resistance to tobramycin, gentamicin and amikacin, but had high resistance to compound sulfamethoxazole, tigecycline and ampicillin; Klebsiella pneumoniae had low resistance to tobramycin, amikacin and tigecycline, and high resistance to cefotaxime, ciprofloxacin and cefepime; the main Gram-positive Staphylococcus aureus had no drug resistance to vancomycin, linezolid, compound sulfamethoxazole and quinuptin/dafuptin, but had high drug resistance to tetracycline, penicillin G, levofloxacin, oxacillin and ciprofloxacin; the main fungi Candida albicans showed no resistance to fluconazole, itraconazole, voriconazole, 5-fluorocytosine and amphotericin B. These results of pathogenic detection and drug susceptibility test contributed to the improvement of the rational application rate of antibiotics. Conclusions LRTI occurs in about a quarter of patients with MCAO after airway metal stent implantation. The pathogens are mainly Pseudomonas aeruginosa and Staphylococcus aureus. Antimicrobial treatment should be based on the results of etiological detection and drug susceptibility test.