Molecular markers for differentiation of multiresistant Klebsiella pneumoniae isolates in a pediatric hospital.
OBJECTIVE
To study the spread of extended-spectrum beta-lactamase-producing, but aminoglycoside-susceptible, Klebsiella pneumoniae strains in our hospital over an 8-month period, by using two genotypic markers.


METHODS
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.


METHODS
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 Debré Hospital of Paris, France.


RESULTS
Ribotyping of the 20 clinical isolates, the type strain of the species, and two epidemiologically unrelated isolates with EcoRI and HindIII 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 genotypic results showed that 11 patients from wards S1, S2, and GE harbored genotypically related strains, suggesting nosocomial transmission and cross-colonization between and within the three wards.


CONCLUSIONS
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.
Lhopital
S
S
Service of Microbiology, Intensive-Care Surgery, and Gastroenterology, Hôpital Robert Debré, Paris, France.
Bonacorsi
S
S
Meis
D
D
Brahimi
N
N
Mathy
S
S
Navarro
J
J
Aigrain
Y
Y
Bingen
E
E
D003428:Cross Infection / Q000382:microbiology* / Q000635:transmission; D016172:DNA Fingerprinting; D018432:Drug Resistance, Multiple; D005260:Female; D005838:Genotype; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007362:Intensive Care Units; D007710:Klebsiella Infections / Q000382:microbiology* / Q000635:transmission; D007711:Klebsiella pneumoniae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D019105:Random Amplified Polymorphic DNA Technique