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 name:||Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Vienna, Austria, 10 - 13 April 2010|
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