| ObjectiveTo investigate the factors affecting the infection and prognosis of patients with liver failure,and on this basis,to screen carbapenem-resistant enterobacteriae(CRE)in patients with liver failure,and to study the molecular epidemiology of CRE positive strains.Methods1.Clinical data of patients with liver failure in two non-intensive care wards of Infection Department of the First Affiliated Hospital of Nanchang University from July 2022 to December 2022 were collected by retrospective analysis.T-test,Mann Whitney U test and Chi-square test were used to analyze the influence of infection on patients with liver failure.2.Fecal samples of patients admitted to two non-intensive care wards of the infection department of our hospital from July 2022 to December 2022 and diagnosed with liver failure on day 1,day 7,day 14 and day 28 were collected.After culture,strains were identified by time-of-flight mass spectrometer and whether the strains were resistant to carbon penem was determined by disk diffusion method.3.The modified carbapenemase inactivation assay(m CIM)and the combined carbapenemase inactivation assay(e CIM)were used to detect the phenotype of the screened positive strains,and the polymerase chain reaction(PCR)was used to detect the carbapenemase gene of the screened positive strains.The homology analysis of the screened strains was carried out by enterobacter intergene repeated sequence polymerase chain reaction(ERIC-PCR),MLST typing and pulsed field gel electrophoresis(PFGE).The conjugation experiment was conducted to determine whether the carbapenase gene could be passed horizontally.Results1.A total of 216 patients with liver failure were included in this study,including57 patients in the non-infected group and 159 patients in the infected group.The length of hospital stay and poor prognosis rate were statistically significant(P < 0.05).In the infection group,only 111 patients were tested by bacterial culture(69.8%),among which 18 patients were positive(15.3%),and abdominal infection was the main site of infection.According to the prognosis groups(79 patients in remission group and 80 patients in poor prognosis group),the nosocomial infection rate was statistically significant(P < 0.01).2.A total of 294 fecal cultures were collected from 100 hospitalized patients with liver failure from July 2022 to December 2022 on day 1,day 7,day 14 and day28 of admission.287 were positive,with a positive rate of 97.6%,among which 8were CRE(7 Escherichia coli and 1 Citrobacter freaudiensis).According to the results of CRE screening,100 patients with liver failure were divided into the colonized group and the non-colonized group.The comparison between the groups suggested that the length of hospital stay(P=0.002)and the prognosis(P=0.044)were statistically significant.The isolation time nodes of 8 CRE positive strains were all on the 14 th and 28 th day of hospitalization,suggesting that intestinal CRE may have originated from hospital transmission.3.Carbapenase phenotype and gene detection showed that all 8 strains of CRE produced NDM-5 carbapenase,and MLST typing results showed that 7 strains of NDM-5 producing Eschericcoli had a total of 6 ST types(the ST type of strain 5 and strain 75 was ST1236.The other strains were ST5454,ST2852,ST2973,ST683,ST156).PFGE and ERIC-PCR results also showed that all intestinal CRE showed epidemic polymorphism,and other non-CRE intestinal strains had strong clonal transmission,mainly ERIC type A.Conjugation test showed that all 8 intestinal colonized CRE strains could transfer NDM-5 carbapenase gene through conjugation.Conclusion1.Hepatic failure combined with infection is closely related to length of hospital stay and poor prognosis.Because of the low positive rate of liver failure combined with infection,the pathogen can not be identified,which seriously affects the clinical diagnosis and treatment effect.2.With the extension of hospital stay in patients with liver failure,the possibility of intestinal flora disturbance is gradually increased,and the detection rate of CRE is also increased.3.The intestinal CRE of patients with liver failure in the Department of Infectious Diseases of the First Affiliated Hospital of Nanchang University is dominated by Eschericheria coli,which mainly carries the gene encoding NDM-5carbapenemase,and is mostly transmitted horizontally through plasmid binding.Therefore,it is necessary to carry out regular intestinal CRE screening of patients with liver failure,and establish comprehensive prevention and control measures for intestinal colonization of CRE.Avoid outbreaks of CRE in hospitals. |
