2020-2024年某三甲医院重症监护病房革兰氏阳性菌分布特征及耐药性分析OA

Objective To analyze the composition and antimicrobial resistance trends of Gram-positive bacteria in the intensive care unit(ICU)of a grade A tertiary hospital from 2020 to 2024,so as to provide evidence for antimicrobial stew-ardship and healthcare-associated infection prevention and control.Methods Gram-positive bacteria isolated from various clinical specimens in the ICU and their antimicrobial susceptibility results from 2020 to 2024 were retrospectively collected.Differences in bacterial constituent ratios and resistance rates of major bacteria among years were compared,respectively,and trend tests were conducted.Results A total of 2227 strains of Gram-positive bacteria were isolated during the five-year period,accounting for 21.41％of all isolates.Among them,Staphylococcus aureus accounted for 42.43％of all Gram-posi-tive bacteria,and Streptococcus pneumoniae accounted for 15.27％.Trend analysis showed that Staphylococcus pneumoniae and Staphylococcus haemolyticus exhibited an overall downward trend(P<0.05),while Enterococcus faecium and Enterococ-cus faecalis showed an overall upward trend(P<0.05).Staphylococcus aureus,Staphylococcus epidermidis,and Staphylococ-cus hominis remained generally stable in overall trend(P>0.05).Regarding drug resistance,the resistance rate of Staphylo-coccus aureus to oxacillin,clindamycin,and erythromycin were 48.04％,36.61％,and 51.11％,respectively,all showing an overall decreasing trend(P<0.05).No resistance to linezolid or vancomycin was detected.Classification data showed that both methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-susceptible Staphylococcus aureus(MSSA)maintained extremely high resistance rates to penicillin(>90％),with MRSA showing an overall upward trend in resistance to penicillin(P<0.05),while MSSA showed no significant trend.MRSA had a high five-year average resistance rate to erythromycin(74.26％),but the trend was not obvious,while MSSA showed an overall upward trend in erythromycin resist-ance.The resistance rates of Streptococcus pneumoniae to erythromycin(96.18％)and tetracycline(91.47％)were relatively high and remained generally stable,and the resistance rate to compound sulfamethoxazole maintained at a high level(67.65％)with a year-by-year increasing trend(P<0.05).The resistance rates of Streptococcus pneumoniae to meropenem and ceftriaxone/cefotaxime were extremely low,and no resistance to moxifloxacin,ertapenem,or levofloxacin was detected.No resistance to vancomycin was detected in Enterococcus;only one linezolid-resistant strain was identified among enterococ-cus-like organisms in 2024,and no linezolid resistance was detected in other years;Enterococcus showed high resistance rates to tetracycline and erythromycin.Conclusion Gram-positive bacteria in the ICU are primarily Staphylococcus aureus and Streptococcus pneumoniae,and the microbial community structure and drug resistance spectrum show dynamic changes.Sig-nificant differences exist in the drug resistance characteristics of MRSA and MSSA among Staphylococcus aureus,with MRSA remaining a key target for control.Streptococcus pneumoniae exhibits persistently high resistance to macrolides,tetracyclines,and trimethoprim-sulfamethoxazole,requiring careful selection in empirical treatment.Enterococcus showed a continuous upward trend,suggesting that enhanced surveillance for vancomycin-resistant Enterococcus(VRE)-related risks is warranted.It is recommended to continue pathogen surveillance,optimize empirical treatment pathways,strengthen contact isolation and hand hygiene in the ICU,and dynamically adjust antimicrobial stewardship programs and formularies in accordance with resistance trends.