Hypervirulent Klebsiella pneumoniae clones causing bacteraemia in adults in a teaching hospital in Barcelona, Spain (2007–2013)

Abstract

Virulent hypermucoviscous Klebsiella pneumoniae strains associated with the magA and rmpA genes have mainly emerged in Asia. We analysed the frequency and the clinical and molecular epidemiology of K. pneumoniae bacteraemia isolates obtained over a 7-year period (2007-2013). Fifty-three of 878 K. pneumoniae invasive isolates (5.4%) showed a hypermucoviscous phenotype (by the string test). Of these, 16 (30.2%) were magA(+)/rmpA(+), 12 (22.6%) were magA(-)/rmpA(+), and the remaining 25 (47.2%) were magA(-)/rmpA(-). After multilocus sequence typing and wzi sequencing, all magA(+)/rmpA(+) isolates were serotype K1 and sequence type (ST)23. Of the 12 magA(-)/rmpA(+) isolates, nine were K2 (ST380, ST86, ST65, ST25 and ST493), and three magA(-)/rmpA(+) isolates had the new wzi allele 122, an unknown serotype, and the new ST1013. The remaining isolates, which were magA(-)/rmpA(-), showed different serotypes and STs. Patients with magA(+)/rmpA(+) or magA(-)/rmpA(+)K. pneumoniae bacteraemia more frequently had pyogenic liver abscesses (PLAs) and pneumonia than patients with magA(-)/rmpA(-)K. pneumoniae bacteraemia (respectively: 21.4% vs. 8%, p 0.26; and 17.9% vs. 0%, p 0.05). In fact, magA(-)/rmpA(-) isolates were similar to the those termed 'classic' K. pneumoniae isolates causing bacteraemia, the urinary and biliary tracts being the main foci of infection. In conclusion, hypervirulent clones (CC23K1, CC86K2, CC65K2, and CC380K2) were infrequent among K. pneumoniae isolates causing bacteraemia in our geographical area. A hypermucoviscous phenotype as determined with the string test is not enough to recognize these clones; additional molecular studies are needed. Patients with magA(+) and/or rmpA(+)K. pneumoniae bacteraemia more frequently had PLAs and pneumonia than patients without hypermucoviscosity genes.

Deciphering Heteroresistance to Colistin in a Klebsiella pneumoniae Isolate from Marseille, France

“…Comparison of the MALDI-TOF MS mass spectra and PFGE gave identical protein profiles (Fig. 2), and the sequence type found by MLST was ST86, which had been reported as a hypermucoviscous (hypervirulent) strain, causing life-threatening infections (14,19). These results confirmed that we had isolated a colistin-heteroresistant Klebsiella pneumoniae isolate, as LB1 and LB2 were isogenic strains.…”

High Prevalence of ESBL-Producing Klebsiella pneumoniae Causing Community-Onset Infections in China

“…CC17 (including ST16, ST17, and ST20) was the most prevalent population accounting for 12.6% (16/127), followed by ST86 ( n = 7), ST107 ( n = 7), ST873 ( n = 7), ST37 ( n = 6), ST776 ( n = 6), ST23 ( n = 5), ST290 ( n = 5). Of note, ST23, ST37, and ST86 account for 14.1% (18/127), and these STs are known frequently associating with hypervirulent K. pneumoniae (hvKP) (Jung et al, 2013; Bialek-Davenet et al, 2014; Cubero et al, 2016). The major carriers of CTX-M-15 were ST86 ( n = 7), ST873 ( n = 6), and ST776 ( n = 6), and those of CTX-M-14 included ST17 ( n = 12) and ST107 ( n = 7).…”

Hypervirulent Klebsiella pneumoniae – clinical and molecular perspectives

“…[119]. Highlighting the diversity amongst isolates, there are examples of rmpAÀ/HMV+ [9,[122][123][124][125], rmpA-/ rmpA2+/HMV+ [10], and rmpA+/HMVÀ [9,118]. Further, in an attempt to identify new biomarkers for clinical testing of hvKp, the string test performed only moderately well as a predictor of cKp versus hvKp [117].…”