Virulence factors and antibiotic resistance in uropathogenic Klebsiella pneumoniae isolates from paediatric units at a Portuguese hospital

Abstract number: P1484

Arriaga Cerqueira S., Machado P., Marto J., Silva A., Lito L., Melo Cristino J., Duarte A.

Objectives: The aim of this study was to verify the relationship of Klebsiella pneumoniae isolates, as well as investigate their extended-spectrum b-lactamases (ESBLs) and virulence factors.

Methods: This study included thirty-nine Klebsiella pneumoniae isolates identified from urine culture collected from eight paediatric patients at Santa Maria Hospital, Lisbon, throughout 2008. Antibiograms were determined by disk diffusion method on Mueller-Hinton agar plates. Molecular typing was performed by M13-Polymerase Chain Reaction (PCR) fingerprinting and in representative strains by Multilocus Sequence Typing (MLST) to confirm the genotype. Genetic environment of blaCTX-M-type and virulence factors (iucC, magA, rmpA, khe, fimH, mrkD, capsular gene k2) were screened by PCR and the products were sequenced.

Results: M13-PCR fingerprinting identified two predominant clones among the isolates, which we designated M1 and M2. MLST confirmed this result, showing different sequence types (STs): M1 profile matched ST15 and ST326, which differed only in tonB allele sequence (98.1% of similarity); M2 corresponded to ST20. 40% of M1 isolates showed antibiotic resistance profile R1 (resistance to cefotaxime, CTX, ceftazidime, CAZ, gentamicin, GM, and ciprofloxacin, CIP) and 60% showed profile R2 (resistance to CTX, GM and CIP). 14.3% of M2 isolates exhibited profile R1, 71.4% was profile R3 (resistance to CTX, CAZ and GM) and 14.3% was profile R4 (resistance to CTX and CAZ). All the isolates of both M13-PCR fingerprinting profiles were imipenem-susceptible. We could also detect the gene for CTX-M-15 in 43.6% of all the isolates included in the study. None of the clones showed iucC, magA, rmpA or capsular gene k2, but they were positive for khe (50% in M1 isolates; 85.7% in M2), fimH (100% in M1; 92.9% in M2) and mrkD (80% in M1; 100% in M2).

Conclusion: The isolates included in this study have a high incidence of fimH and mrkD, which reinforces the fact that they are uropathogenic and might explain their persistence in some patients for periods as long as four months.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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