Distribution and antimicrobial resistance pattern of bacteria isolated from alveolar lavage fluid in pediatric patients with lower respiratory tract infection / 中华传染病杂志

ABSTRACT

Objective:To analyze the distribution and antimicrobial resistance pattern of bacteria isolated from alveolar lavage fluid in pediatric patients with lower respiratory tract infection from 2016 to 2018.Methods:The alveolar lavage fluid of pediatric patients aged <18 years old with lower respiratory tract infection in ten hospitals from January 2016 to December 2018 were collected, and the pathogenic bacteria were cultured and isolated. The paper diffusion method or minimum inhibitory concentration method was used to conduct drug susceptibility tests for the isolated strains.The distribution of pathogenic bacteria and the source department of the strains were analyzed.Chi-sqare test was used for statistical analysis.Results:Of 1 271 isolates, 606 strains (47.7%) were gram-negative bacteria, 628 strains (49.4%) were gram-positive bacteria, and 37 strains (2.9%) were fungi. The common pathogens were Streptococcus pneumoniae (36.7%, 466/1 271), Acinetobacter baumannii (16.8%, 214/1 271), Staphylococcus aureus (12.7%, 162/1 271), Klebsiella pneumoniae (8.3%, 105/1 271), Haemophilus influenzae (7.4%, 94/1 271), Pseudomonas aeruginosa (6.2%, 79/1 271), Burkholderia cepacia (5.3%, 67/1 271) and Escherichia coli (3.7%, 47/1 271). The main pathogens in the intensive care unit (ICU) were gram-negative bacteria (80.1%, 428/534), among which Acinetobacter baumannii was the most common (3.7%, 199/534). The main pathogens in the non-ICU were gram-positive bacteria (70.8%, 522/737). The detection rates of methicillin-resistant Staphylococcus aureus (MRSA) were 45.1%(23/51) in the ICU and 43.2% (48/111) in the non-ICU, respectively. The detection rates of penicillin-resistant Streptococcus pneumoniae (PRSP) were 10.9%(6/55) in the ICU and 18.5% (76/411) in the non-ICU, respectively. The detection rates of carbapenem-resistant Klebsiella pneumoniae (CRKP) were 57.3%(43/75) in the ICU and 33.3%(10/30) in the non-ICU, respectively. The detection rate of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in the ICU was higher than that in the non-ICU (49.1%(27/55) vs 25.0%(6/24)), and the difference was statistically significant ( χ2=3.98, P=0.046). Eight strains (17.0%) of carbapenem-resistant Escherichia coli were detected, and 164 strains(76.6%) of carbapenem-resistant Acinetobacter baumannii were detected. Seventy-eight Haemophilus influenzae isolates were isolated from non-ICU, and the resistance rate to ampicillin was 57.4%(54/94). Burkholderia cepacia isolates were all isolated from ICU, and the resistance rates to piperacillin-tazobactam, levofloxacin, ciprofloxacin and compound sulfamethoxazole were 13.4%(9/67), 3.0%(2/67), 0(0/67) and 9.0%(6/67), respectively. Conclusions:Streptococcus pneumoniae is still the most common pathogen in pediatric patients with lower respiratory tract infection. Gram-negative bacilli are the main pathogens in pediatric patients with lower respiratory tract infection in the ICU. The dection rates of MRSA, PRSP and carbopenem-resistant gram-negative bacilli are high. And the resistance rate of Haemophilus influenzae to ampicillin is also high. The clinical empirical treatment should be determined according to different clinical background.