OBJECTIVE To explore the expressions of micro ribonucleic acid (miR)-34a, miR-146a and miR-122-5p in the acute severe craniocerebral injury patients with secondary pulmonary infection and analyze the drug resistance of the major species of pathogens.

METHODS A total of 106 acute severe craniocerebral injury patients with secondary pulmonary infection who were treated in Jinan People′s Hospital from Sep. 2021 to Sep. 2023 were assigned as the infection group and were divided into the mild group with 28 cases, the moderate group with 46 cases and the severe group with 32 cases. Meanwhile, 110 patients who did not have secondary pulmonary infection were chosen as the no infection group. The distribution and drug resistance of pathogens isolated from the infection group were analyzed. The levels of serum miR-34a, miR-146a and miR-122-5p were observed and compared between the infection group and the no infection group and among the patients with different illness condition in the infection group. The predictive values of the above indexes were analyzed.

RESULTS Totally 113 strains of pathogens were isolated from the 106 patients with infection, 78 (69.03%) of which were gram-negative bacteria. The drug resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii strains to cefotaxime and tazobactam were high, while the strains were susceptible to sulbactam. The levels of serum miR-34a and miR-146a of the infection group were higher than those of the no infection group(P < 0.05), while the serum miR-122-5p level of the infection group was lower than that of the no infection group(P < 0.05). The levels of serum miR-34a and miR-146a were elevated with the aggravation of illness condition(P < 0.05), while the serum miR-122-5p level declined(P < 0.05). The area under curve of the joint detection of serum miR-34a, miR-146a and miR-122-5p was higher than that of the single detection in prediction of the secondary pulmonary infection in the acute severe craniocerebral injury patients(P < 0.05).

CONCLUSIONS The gram-negative bacteria are dominant among the pathogens isolated from the acute severe craniocerebral injury patients with secondary pulmonary infection. The pathogens vary in the drug resistance. The patients show the high expressions of serum miR-34a and miR-146a but show the low expression of serum miR-122-5p. The three indexes may get involved in the progression of illness condition, and the predictive value of the joint detection is higher.