Clinical Study On The Pathogenicity Of Non-acinetobacter Baumann Infection

Objective The distribution characteristics and the clinical background of potential pathogenic strains of Acinetobacter exclude Acinetobacter baumann were researched to provide reference for effective clinic prevention and treatment.Methods A total of 394 acinetobacter isolates from hospitalized patients in the same hospital in Shenzhen from 2014 to 2017 were collected,including146 Acinetobacter isolates isolated from sterile sites in 2014 to 2017 and 248 Acinetobacter isolates isolated from non-sterile sites in 2017.Matrixassisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS),PCR amplification of rpoB,gyrB-related gene fragments and sequencing analysis were combined to identify nonBaumann species of Acinetobacter.This article also gave a retrospective review and case analysis on the clinical data of non-acinetobacter baumannii isolated from sterile sites,in which clinical manifestations and laboratory test results met the CDC related infection diagnostic criteria.Results 1.A total of 394 strains of Acinetobacter were identified by MALDITOF-MS method.As a result,339 strains were identified as Acinetobacter baumannii and 55 strains as non-acinetobacter baumann with accuracy of 98.82%(335/339)and 89.09%(49/55)effectively identified to species levels respectively.Furthermore,combined with PCR amplified rpo B,gyrB gene fragments and sequencing analysis it can further improve the non-Acinetobacter baumann species identification accuracy.2.Comparing the clinical isolates of Ab and non-Acinetobacter baumannii in this study,there was no statistical difference in the composition ratio of the bacterial sites to the sterile sites(P = 0.62),and the rate of drug resistance of non-Acinetobacter baumannii was significantly lower(P<0.05).3.In the 22 suspected non-acinetobacter baumann infections,there were 18 from bloodstream specimens,2 from ascites specimens,1 from pleural fluid and 1 from cerebrospinal fluid.To identify the Species,this article used MALDI-TOF MS combined with rpoB and gyrB-related gene detection.And the results showed that in the 22 suspected nonacinetobacter baumann infections,there are 12 strains of Acinetobacter nosocomialis,3 strains of Acinetobacter soli,2 strains of Acinetobacter junii,1 strain of Acinetobacter johnsonii,1 strain of Acinetobacter pitti and 1 strain of Acinetobacter bereziniae.In addition,2 strains could not be identified.4.Eight cases of non-Acinetobacter baumann infections were analyzed finally.The pathogens were identified as 5 cases of A.nosocomialis,2 cases of A.soli,and 1 case of A.pittii.All cases have varying degrees of high-risk infectious factors like serious underlying disease,intervention in invasive procedures or surgical infections.Taking targeted anti-infection treatment measures can effectively alleviate the condition.Conclusions 1.A.nosocomiali,A.pittii and A.soli may be pathogenic strains of Acinetobacter spp.,and clinical measures should be taken to achieve effective prevention and control of them.2.A.johnsonii,A.junii and A.bereziniae may also have potential conditional pathogenicity and deserve further attention.3.MALDI-TOF MS combined with rpoB and gyrB related gene detection technology can effectively improve the identification ability of non-Acinetobacter baumann species.