Source Investigation Of Acinetobacter Baumannii Infection In ICU Of Hosoital And Laboratory Study On Disinfection Resistance

Objective:Acinetobacter baumannii is one of the most important conditional pathogens leading to nosocomial infection,especially in the intensive care unit.Acinetobacter baumannii has the ability to accumulate the mechanism of resistanee,which leads to its rapid resistance to the used antimicrobial agents.Acinetobacter baumannii can survive for several months in hospital environment,and it was resistant to the disinfectants used in hospital.For the prevention and control of hospital infection caused by Acinetobacter baumannii,traceability investigation of the Acinetobacter baumannii infection in eight intensive care unit(ICU)of hospitals in Jiangsu province was conducted and the disinfectant resistance of the strains was researched in laboratory in this study.Methods:Environmental samples and air samples of ICU were collected from seven hospitals in southern Jiangsu and northern Jiangsu provinces.Identification,drug sensitivity analysis,homology analysis,qacE△1-sul I gene detection,minimum inhibitory coneentration(MIC)and minimum bactericidal concentration(MBC)of the two kinds of disinfectants(chlorhexidine acetate and benzalkonium bromide)were measured on the the above samples and clinical specimens.Results:Acinetobacter baumannii is widely detected in the ICU environment,the detection rate of Acinetobacter baumannii in the ICU environment was higher in the hospital of southern Jiangsu province than that of northern Jiangsu province(104/417:120/716,P=0.007).Homology analysis clearly showed that the same strain had been detected from nine bed units in a hospital ICU in northern Jiangsu,the same pathogen was still detected in the same medical environment for up to 147 days,eght patients(27 patients In total)were infected lby the Acinetobacter baumannii in the ICU environment.The composition ratio of qacE Δ 1-sul I positive strain was higher in the hospital of northern Jiangsu province than that of southern Jiangsu province(4.5%:42.3%,P<0.001).The determination of MIC and MBC of the two disinfectants(chlorhexidine acetate,benzalkonium bromide)showed no statistical differences between qacE△1-sul I negative bacteria and positive strains,the specific reasons need to be discussed.The resistant strains were multi-resistant(MDRAB)or pan-resistant(PRAB)Acinetobacter baumannii,the percentage of pan-resistant strains accounted for 25.9%of the total.The clinical specimens were at a higher level of drug resistance than the environmental strains,the qacE△1-sul I positive resistance were at a higher level of drug resistance than the qacE Δ 1-sul I negative strain..Conclusion:There are different degrees of spread of Acinetobacter baumannii in the ICU of hospital.The occurrence of nosocomial infection of Acinetobacter baumannii was clearly showed.Not only the cleaning and disinfection of environmental surface and hand of medical staff should be concerned,but also the contamination bring by cleaners and care workers should be pay attention too.In the study of disinfectant resistance,no statistical differences were found in the compare of disinfectant resistance between Acinetobacter baumannii carrying disinfectant resistance gene or not.The dose concentration of the disinfectant is still valid.Subsequent research should focus on how to regulate and optimize the cleaning and disinfection measures.Source investigation and situation of Acinetobacter baumannii infection should be combined for the medium and long-term evaluation of the effect of cleaning and disinfection.