We analyzed a collection of 97 well-characterized Burkholderia cepacia genomovar III isolates to evaluate multiple genomic typing systems, including pulsed-field gel electrophoresis (PFGE), BOX-PCR fingerprinting and random amplified polymorphic DNA (RAPD) typing. The typeability, reproducibility, and discriminatory power of these techniques were evaluated, and the results were compared to each other and to data obtained in previous studies by using multilocus restriction typing (MLRT). All methods showed excellent typeability. PFGE with SpeI was more reproducible than RAPD and BOX-PCR fingerprinting. The discriminatory power of the methods was variable, with PFGE and RAPD typing having a higher index of discrimination than BOX-PCR fingerprinting. In general, the results obtained by PFGE, BOX-PCR fingerprinting, and MLRT were in good agreement. Our data indicate that different genomic-based methods can be used to type B. cepacia genomovar III isolates depending on the situation and the epidemiologic question being addressed. PFGE and RAPD fingerprinting are best suited to addressing small-scale studies (i.e., local epidemiology), whereas BOX-PCR fingerprinting is more appropriate for large-scale studies (i.e., global epidemiology). In this regard, BOX-PCR fingerprinting can be considered a rapid and easy alternative to MLRT.Cystic fibrosis (CF) is the most common hereditary disease in Caucasian populations. Clinical manifestations of CF result from a disturbance in electrolyte transport that primarily affects the respiratory and digestive systems. The CF lung is particularly susceptible to infection with a variety of opportunistic bacteria (9, 14), and exacerbations of chronic infection cause significant morbidity and mortality (36). Among the bacterial species capable of causing infection in CF are those belonging to the Burkholderia cepacia complex, which is currently comprised of nine closely related genomic species or genomovars (11,21,45). Recent work has demonstrated that the majority of infected CF patients harbor either B. cepacia genomovar III or Burkholderia multivorans (genomovar II) (1,25,38). Furthermore, limited data suggest that B. cepacia genomovar III (or perhaps certain specific strains within genomovar III) may be relatively more virulent than other species in this complex (3,12,19).The broad-spectrum antimicrobial resistance, absence of a vaccine, and virulence of certain strains have made prevention of B. cepacia complex infection an important goal in CF patient care (21, 22). However, much still remains unknown regarding the epidemiology of infection in CF. A number of previous studies have demonstrated transmission of B. cepacia complex strains between persons with CF (for reviews, see references 15, 16, 21, and 22). More recent studies indicate that the natural environment is also a likely reservoir for acquisition of B. cepacia complex strains (4, 24). Better risk assessment of potential sources of infection and the development of optimal infection control policies rely on a more complet...

Previous studies have identified specific Burkholderia cepacia complex strains that are common to multiple persons with cystic fibrosis (CF). Such so-called epidemic strains have an apparent enhanced capacity for inter-patient spread and reside primarily in Burkholderia cenocepacia (formerly B. cepacia complex genomovar III). We sought to identify strains from B. cepacia complex species other than B. cenocepacia that are similarly shared by multiple CF patients. We performed genotype analysis of 360 recent sputum culture isolates from 360 persons residing in 29 cities by using repetitive extragenic palendromic polymerase chain reaction (rep-PCR) and pulsed field gel electrophoresis. The results indicate that sharing of a common Burkholderia multivorans strain occurs relatively infrequently; however, several small clusters of patients infected with the same strain were identified. A cluster of seven patients infected with the same B. cepacia (genomovar I) strain was found. We also identified a large group of 28 patients receiving care in the same treatment center and infected with the same Burkholderia dolosa strain. These observations suggest that B. cepacia complex strains in species other than B. cenocepacia may be spread among CF patients.

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