Published online by Cambridge University Press: 02 January 2015
To study the spread of extended spectrum ß-lactamase-producing, but aminoglycoside-susceptible, Klebsiella pneumoniae strains in our hospital over an 8-month period, by using two genotypic markers.
Ribotyping (using two endonucleases) and randomly amplified polymorphic DNA analysis (RAPD; using two different 10-mer primers) were applied to the epidemiological typing of clinical K pneumoniae isolates from stools, ileal fluid, or urine of hospitalized children.
The surgical intensive care ward (S1: 9 patients, 17 isolates), surgical unit (S2: 2 patients, 2 isolates), and gastroenterology ward (GE: 1 patient, 1 isolate) of the Robert Debre Hospital of Paris, France.
Ribotyping of the 20 clinical isolates, the type strain of the species, and two epidemiologically unrelated isolates with EcoRI and HindlII revealed 6 and 5 different patterns, respectively. Six ribotypes were identified by using these two enzymes. RAPD generated 6 distinct patterns, in complete agreement with ribotyping. Our geno-typic results showed that 11 patients from wards Sl, S2, and GE harbored genotypically related strains, suggesting nosocomial transmission and cross-colonization between and within the three wards.
Ribotyping and RAPD appear to be reliable methods for distinguishing K pneumoniae strains. The spread of one strain of K pneumoniae in different units of our hospital was demonstrated by both methods. However, RAPD has the advantage of simplicity and rapidity conferred by polymerase chain reaction.