Relationships between phagocytosis, mucoid phenotype, and genetic characteristics of Klebsiella pneumoniae clinical isolates

Abstract INTRODUCTION The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated. METHODS Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages. RESULTS Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility. CONCLUSIONS: Several virulence factors act in parallel in K. pneumoniae to impair host defense.

Clinical distribution, virulence factors, and molecular epidemiology of hypervirulent Klebsiella pneumoniae in Hainan Province in 2016 / 中国感染控制杂志

Objective To investigate clinical distribution,capsular serotyping,molecular typing,virulence gene carriage,and antimicrobial susceptibility of hypervirulent Klebsiella pneumoniae (hvKP) strains isolated from a hospital in Hainan Province in 2016.Methods Klebsiella pneumoniae(K.pneumoniae) isolated from the hospital between January and December 2016 were analyzed retrospectively,hvKP strains were selected through string test,antimicrobial susceptibility testing was performed and compared with classic K.pneumoniae(cKP);capsular serotyping,virulence genes,and drug resistance genes of hvKP strains were detected with polymerase chain reaction,molecular typing was performed with pulsed-field gel electrophoresis (PFGE) and multiloeus sequence typing.Results A total of 84 hvKP strains were isolated,the main specimen source was sputum(45 strains);K1 and K2 were the major capsular serotypes of hvKP,while ST23,ST65,and ST86 were the main sequence types of hvKP.The carriage rates of rmpA,aerobatin,allS,kfuBC,and cf29a in hvKP were 90.48％,96.43％,42.86％,66.67％,and 53.57％ respectively,all of them were statistically higher than those of cKP strains,PFGE found that allS was positive only among K1 strains;most antimicrobial resistance rates of hvKP were lower than those of the cKP.Conclusion Sputum is the main specimen source of hvKP,especially K1 serotype;more than 90％ of hvKP strains carry rmpA and aerobatin genes,allS gene only exists in K1 type hvKP.