Presence and characterization of Klebsiella pneumoniae from the intestinal tract of diarrhoea patients.

The objective of this study was to investigate the presence and characterization of Klebsiella pneumoniae (KP) from the intestinal tract. Forty-three KP strains were isolated from 551 stool specimens from diarrhoea patients from 2013 to 2016, with a carriage rate of 7·80%. All isolates were hypervirulent KP strains with hypermucoviscosity phenotype. The virulence factors and antibiotic resistance exhibited diverse distribution. 2·33% (1/43), 2·33% (1/43), 6·98% (3/43), 6·98% (3/43), 4·65% (2/43), 11·63% (5/43) and 18·60% (8/43) were identified as serotypes of K1, K2, K3, K5, K20, K54 and K57 respectively. K54 and K57 were relatively predominant. Virulence genes distribution differed with serotypes. fimH, ureA and wabG had the highest detection rates while iroNB the lowest. With the highest resistance rates to azithromycin and sulfamethoxazole of 97·67%, and the lowest to imipenem of 0%, 31 isolates (79·02%) were detected to be multidrug resistant. A significant negative correlation existed between multidrug resistance and number of virulence genes (R2  = -0·78). Forty one PFGE types had been identified among the 43 isolates and the diversity banding pattern had no relation with the drug-resistance and virulence factors.

SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to comprehensively report the presence, distribution of serotypes and virulence genes, antimicrobial susceptibility and DNA fingerprints of Klebsiella pneumoniae (KP) from intestinal tract of diarrhoea patients of China. Distribution of virulence genes, antimicrobial resistance spectrum, and relationship between virulence genes and antimicrobial resistance are clarified. It will be of great public health significance to estimate the prevalence of KP in faeces of diarrhoea patients, and to provide a theoretical foundation for the traceability, prevention and control, and reasonable treatment of infections caused by this bacterium.