Am. J. Respir. Crit. Care Med., Vol 155, No. 3, 03 1997, 984-989.
PCR ribotyping and endonuclease subtyping in the epidemiology of Burkholderia cepacia infection
MR Shreve, SJ Johnson, CE Milla, CL Wielinski and WE Regelmann
Department of Pediatrics, University of Minnesota, Minneapolis 55455, USA.
Because of conflicting data about hospital-based transmission of
Burkholderia (Pseudomonas) cepacia, an important respiratory pathogen in
cystic fibrosis (CF), we compared strains found in sputum, lung, or blood
of 29 CF patients in our center from 1988 to 1994, studying the
relationship between strain and hospital exposure of incident and that of
prevalent cases. Exposure was defined as a concurrent hospital stay between
a prevalent and an incident case. B. cepacia strains were determined by
polymerase chain reaction (PCR) ribotyping and endonuclease subtyping. The
16S to 23S spacer regions of the bacterial ribosomal RNA (rRNA) genes were
amplified by PCR, and the product-size patterns used to type each B.
cepacia isolate. Endonuclease digestion of the PCR products provided length
polymorphisms for subtyping. There were 17 incident events during the
period from 1988 to 1994, 16 of which involved a single ribotype. These 16
ribotypes could be divided into five subtypes by endonuclease mapping. Four
patients grew B. cepacia from the blood, with the organism being the same
strain as found in the lung in each case. Case controls were obtained to
evaluate risk factors for B. cepacia acquisition. Concurrent
hospitalization with a prevalent case significantly increased the risk of
acquisition. There was no association between length of hospitalization,
length of exposure, or FEV1 and the risk of B. cepacia acquisition.
