Analysis Of Cefotaxime Resistant Bacteria Distribution And Drug Resistance Of Airborne In Some Pet Hospital In Changchun

?-lactam antibiotics are widely used in clinic because of their wide antibacterial spectrum,strong antibacterial activity and low price,however,the abuse of?-lactam antibiotics leads to the increasingly serious problem of drug resistance of major pathogenic bacteria.Relevant studies have shown that aerosol in farms,sewage treatment plants,garbage dumps,hospitals and other places has become the main medium for drug-resistant bacteria and drug-resistant gene transmission,and drug-resistant bacteria carried in PM_2.5(particle diameter between 0.65?m-1.1?m)are more harmful to animals.As a place with intensive contact between human and animals,super drug-resistant bacteria and drug-resistant genes have also been widely spread in pet hospitals,but there is no related report on the research of microbial aerosol drug-resistant bacteria in pet hospitals.For this reason,this study collected aerosol particles with different particle diameters from consulting rooms,inpatient departments and operating rooms of several pet hospitals,isolated and identified cefotaxime-resistant bacteria,and detected the drug resistance level of drug-resistant bacteria in PM_2.5,in order to lay a foundation for the research on the control and transmission mechanism of airborne drug-resistant bacteria in pet hospitals.The relevant research results are as follows.First of all,the pet hospital in Changchun was taken as the research object,and the 8?g/m L cefotaxime resistance medium was used as the sampling medium to collect airborne cefotaxime-resistant bacteria in the pet hospital.The results showed that the length of the pet hospital's operation time was positively correlated with the number or concentration of drug-resistant bacteria,and the longer the operation time,the higher the number of drug-resistant bacteria.Among them,D hospital has been operating for 10 years,and the number of drug-resistant bacteria is the highest(73CFU/m³ in the consulting room,142 CFU/m³ in the inpatient department,and 31CFU/m³ in the operating room);Hospital C has been operating for 3 years,and the content of drug-resistant bacteria is the lowest(11 CFU/m³ in the consulting room,13CFU/m³ in the inpatient department,and 28 CFU/m³ in the operating room);At the same time,the average number of airborne cefotaxime-resistant bacteria in each department was counted.The results showed that there were significant differences in the number of drug-resistant bacteria in different departments.The average number of drug-resistant bacteria in the operating room was the lowest 33 CFU/m³,and the average number of drug-resistant bacteria in the inpatient department was the highest61 CFU/m³;In addition,traditional microbial culture methods were used to analyze the particle diameter distribution characteristics of airborne cefotaxime-resistant bacteria,The results showed that airborne cefotaxime-resistant bacteria were mainly distributed on the aerosol particles of 3.3?m-4.7?m and 1.1?m-2.1?m.The hierarchical distribution of drug-resistant bacteria was different in different departments.The drug-resistant bacteria in the consulting room were mainly 1.1?m-2.1?m,and the drug-resistant bacteria in the inpatient department and the operating room were mainly concentrated in 3.3?m-4.7?m.Secondly,this study analyzed the drug resistance of drug-resistant bacteria in pet hospital PM_2.5,and identified the species of airborne drug-resistant bacteria that can directly enter alveoli(PM_2.5)by 16S r DNA sequencing.The results showed that among the 159 strains,Enterococcus(about 51%),Staphylococcus(about 19%)and Bacillus(about 14%)were the main ones,in addition to Pseudomonas,Lactobacillus,Acinetobacter,Enterobacter and Flavobacterium;On this basis,the micro-broth dilution method was used to identify the drug resistance level of the isolated strains.The results showed that one strain was resistant to 11 commonly used clinical antibiotics,one strain was resistant to 10 commonly used clinical antibiotics,and 57isolates were resistant to 3 or more antibiotics.All isolates had the highest resistance rate to tetracycline(63%);The resistance rate to cefquinoxime was the lowest(27%).It is noteworthy that some isolated strains have developed drug resistance to carbapenem antibiotics,of which imipenem resistance rate reached 53%and meropenem resistance rate reached 43%.The drug resistance of carbapenem-resistant bacteria in pet hospital aerosol is reported for the first time.In a word,the airborne drug-resistant bacteria in pet hospitals have a specific distribution law in particle diameter,among which the drug-resistant bacteria that can enter alveolar aerosol(particle diameter is 0.65?m-1.1?m)are mainly multidrug-resistant enterococcus.In view of this research result,it is urgent to take corresponding measures to control airborne drug-resistant bacteria in pet hospitals.At the same time,the research results also laid a foundation for the study of airborne drug-resistant bacteria and the transmission mechanism of drug-resistant genes.