Clinical And Causative Pathogens Characteristics Of Pyogenic Liver Abscess And Study Of Virulence Factors For Liver Abscess-Causing Klebsiella Pneumoniae

Clinical and causative pathogens characteristics of pyogenic liver abscessObjective To enhance theoretical support of pyogenic liver abscess(PLA)diagnosis and treatment by analyzing clinical and pathogenic parameters of PLA.Methods In a retrospective study,we analyzed the clinical parameters,features of the causative pathogens,drug susceptibility results,treatments and outcomes for 172 patients in the first affiliated hospital of Soochow university with liver abscesses during 2013-2018.Results 1)The main clinical manifestations were fever(91.9%),followed by abdominal pain(40.1%).2)61.6%of PLA were pyogenic liver abscess of cryptogenic origin(PLAC).The majority of PLA were solitary(83.1%),and localized in right hepatic lobe(82.0%).3)A total of 115 strains of bacteria were isolated,including 71 cases of Klebsiella pneumoniae(61.7%),twenty-one cases of Escherichia coli(E.coli)(18.3%),seventeen cases of Extended Spectrum Beta-lactamases(ESBLs)producing(18.5%),two cases of Carbapenem-Resistant Enterobacteriaceae(CRE)(2.2%).4)There were statistically significant differences in diabetes mellitus(68.9%vs40.4%,P=0.038),biliary diaeases(26.2%vs60.0%,P=0.029),malignant tumors(1.6%vs26.7%,P=0.003)between KP-PLA and EC-PLA.5)After admission,the patients were treated with antibiotics alone or percutaneous drainage,surgical incision and drainage in combination with antibiotics.The survival rate were 97.7%.Conclusions The clinical manifestations of PLA was atypical,and the dominant pathogens were K.pneumoniae and E.coli.The risk factors of KP-PLA and EC-PLA were diabetes mellitus,biliary diseases and malignant tumors,respectively.Individualized precise treatment was selected on the basic of the location,size of abscesses and bacterial drug sensitivity.Study of the virulence factors for Liver Abscess-Causing Klebsiella pneumoniaeObjective The aim of this study was to investigate the virulence factors for Liver Abscess-Causing Klebsiella pneumoniae(LA-KP).Methods The LA-KP-rich strain cohort(n=8)was generated from patients with KP-PLA,and the non-Liver Abscess-Causing Klebsiella pneumoniae(non-LA-KP)-rich cohort(n=13)was generated from patients with Klebsiella pneumoniae bloodstream infections.The hypermucoviscosity phenotype was determined by "the string test." The capsule type was identified by wzi sequencing.PCR amplification can verify the capsule type and rmpA/A2,iutA,iroN.The distribution of virulence factors was compared between the two groups.Results Theprevalences of hypermucoviscosity、K1/K2、rmpA/rmpA2、iutA、iroN in LA-KP-rich cohort were 75.0%,62.5%,100%,75.0%and 50.0%,respectively.The rates in non-LA-KP-rich cohort were 54.0%,0,53.8%,23.1%,30.8%.There were statistically significant differences in K1/K2(P=0.003),rmpA/rmpA2(P=0.032),iutA(P=0.029)between those two groups.Conclusions K1/K2 capsular type,rmpA/rmpA2 and iutA were the key virulence factors for LA-KP.