Clinical Profile Of Clinically Defined Hypervirulent Klebsiella Pneumoniae Infection And Its Capsular Serotypes And Multilocus Sequence Typing

Objective: To describe the clinical profile of hyper-virulent Klebsiella pneumoniae(hv KP)infection as a reference in diagnosing hv KP infection.To provide with antibiotic susceptibility of hv KP useful for empiric antibiotic therapy.To investigate capsule serotype distribution and sequence type(ST)of hv KP and their possible correlation with clinical profilesMethods: We in this study define Hypervirulent Klebsiella pneumonia as bacteria isolated from patient with community-acquired pyogenic liver abscess(CA-PLA)with co-infection sites outside liver or a bloodstream infection in a host without underlying biliary tract diseases.A retrospective analysis was performed in cases of CA-PLA hospitalized in the First Hospital of China Medical University from January 2011 to December 2017.Antibiotic susceptibility was detected by automatic bacterial identification and antibiotic susceptibility analysis system in vitro.Polymerase chain reaction method and gene sequencing were used to detect the main capsule serotype and sequence type(ST)Results: A total of 140 cases with hv KP infection were collected,the co-infections outside liver abscess include 98 cases with bloodstream infection,53 cases with pneumonia,11 cases with perianal abscess,10 cases of urinary system infection,3 cases with subphrenic abscess,3 cases with endophthalmitis,2 cases with spleen abscess,and other miscellaneous infections including 1 case with peritonitis,1 case of skin and soft tissue infection,1 case with myelitis spinal cord abscess,1 case with colitis,1 case with psoas major abscess and 1 case of myocardial abscess.Among the 140 cases,106 cases were associated with a single co-infection site,32 cases with 2 sites,and 2 cases with 3 sites.hv KP manifested high antibiotic susceptibility up to 80% for most commonly used antibiotics.Capsule serotyping of 43 isolates revived indicate that K1 serotype accounted for 53.48%(23/43),K2 for 34.88(15/43),K54 2.33%(1/43),K57 2.33%(1/43),and other serotypes 6.98%(3/43).There was no statistically significant difference between K1,K2,K54 and K57 of hv KP capsule serotypes in patients with or without diabetes mellitus(P > 0.05).Multilocus sequence typing(MLST)indicated that ST23 and ST65 were predominant accounting for 39.53%(17/43)and 25.58%(11/43)respectively.There was no serotype or ST predominance in any of the clinical infections.Conclusion: Hv KP can leads to a wide spectrum of infectious diseases,including multiple extrahepatic sites and bloodstream infection besides CA-PLA,manifested high antibiotic susceptibility.K1 and K2 are the predominant capsule serotypes,and ST 23 and ST65 are the predominant sequence type.