Distribution And Transmission Analysis Of Hospital Environmental Flora Based On 16S RDNA

Objective: To understand the distribution characteristics of surface microbiota in the environment of general wards and ICU wards in hospitals,analyze the relationship between environmental resistant bacteria and drug-resistant bacteria isolated from patients,explore the role of patient side contamination in hospital transmission and clinical infections,and provide scientific basis for guiding hospitals in formulating disinfection measures and for hospital infection prevention and control.Research method: The surface of objects in the general ward and ICU of a tertiary hospital in Beijing was taken as the research object.From June to December 2021,samples were taken every 15 days for six consecutive months.Five antibiotic culture media were used to screen the collected samples for drug-resistant strains,and 16 S r DNA full-length amplification and first-generation sequencing were used for species identification.Perform whole genome sequencing of Klebsiella pneumoniae isolated from patients and environment during the sampling period,to explore the transmission relationship of Klebsiella pneumoniae strains between patients and the environment.SPSS 22.0 was used for statistical analysis,and the counting data was analyzed using case numbers and percentages.The differences in constituent ratios were compared using chi-square test.and P<0.05 was considered statistically significant.Result: A total of 55 sampling points in the general ward and ICU were selected,and660 environmental swabs were collected in 12 batches,as well as clinical samples from46 patients collected at the same time.1.Detection of drug-resistant bacteria in the environment: 442 environmental samples were cultured positive,with a total positive rate of 66.97%,mainly including Staphylococcus,Acinetobacter,Klebsiella,Pseudomonas,Bacillus,Enterobacteriaceae,Enterococcus,etc.1424 strains of drugresistant bacteria were finally isolated,and the detection rate of human staphylococcus(135 strains,9.48%)was the highest,Next were Staphylococcus hemolyticus(109strains,7.65%)and Acinetobacter baumannii(102 strains,7.16%);2.Overall distribution of drug-resistant bacteria: The majority of drug-resistant bacteria are Gram negative bacilli(756 strains,53.09%),mainly including Acinetobacter baumannii,Klebsiella pneumoniae,and Acinetobacter pettii.Among the gram-positive cocci(668strains,46.91%),Staphylococcus hominis was the highest,followed by Staphylococcus haemolyticus,among which Acinetobacter baumannii,Staphylococcus hominis,Staphylococcus haemolyticus,Acinetobacter pettii,Klebsiella pneumoniae,Pseudomonas aeruginosa,Staphylococcus epidermidis,and Enterococcus were all resistant to five antibiotics;3.Distribution of drug-resistant bacteria in different wards:A total of 757 strains of drug-resistant bacteria were isolated in the general ward,with Staphylococcus aureus(66 strains,8.72%),Staphylococcus hemolyticus(64 strains,8.45%),and Staphylococcus epidermidis(55 strains,7.27%)as the main strains.A total of 667 strains of drug-resistant bacteria were isolated in the ICU,with Staphylococcus aureus(69 strains,10.34%),Acinetobacter baumannii(69 strains,10.34%),and Klebsiella pneumoniae(53 strains,7.95%)as the main strains.There was a statistical difference in the distribution of Gram negative bacteria and Gram positive cocci between the two wards(X2=398.115,P<0.05);4.Distribution of sampling locations for drug resistant bacteria: Drug resistant bacteria detected in general wards are mainly concentrated in 612 faucets(61 strains,8.06%),B-medical faucets(57 strains,7.53%),34 bedside tables(51 strains,6.74%),etc.In ICU wards,they are mainly distributed in1 A sink traps(53 strains,7.95%),2A sink traps(52 strains,7.80%),and 2A faucets(47strains,7.05%);5.Transmission of drug-resistant bacteria: The genome of Klebsiella pneumoniae isolated from ICU patients is closest to that of Klebsiella pneumoniae detected from ICU sink traps and vents,indicating a possible exchange of drug-resistant bacteria between the hospital ICU environment and patients.Conclusion: By analyzing the distribution characteristics of drug-resistant bacteria on the surface of objects in general wards and ICUs of hospitals,it was found that there were differences in the distribution of drug-resistant bacteria on different surfaces of objects at different times.A large number of drug-resistant bacteria were isolated from the surfaces of sinks,faucets,bedside tables,and bed railings in the two wards.It was found that Klebsiella pneumoniae was transmitted in the hospital environment and between patients,indicating that hospitals need to strengthen environmental monitoring of drug-resistant bacteria and strengthen hospital cleaning and disinfection measures,To effectively control the infection and transmission of potential hospital resistant bacteria.