Transmission of Burkholderia cepacia Complex: Evidence for New Epidemic Clones Infecting Cystic Fibrosis Patients in Italy

Abstract

To analyze national prevalence, genomovar distribution, and epidemiology of the Burkholderia cepacia complex in Italy, 225 putative B. cepacia complex isolates were obtained from 225 cystic fibrosis (CF) patients attending 18 CF centers. The genomovar status of these isolates was determined by a polyphasic approach, which included whole-cell protein electrophoresis and recA restriction fragment length polymorphism (RFLP) analysis. Two approaches were used to genotype B. cepacia complex isolates: BOX-PCR fingerprinting and pulsedfield gel electrophoresis (PFGE) of genomic macrorestriction fragments. A total of 208 (92%) of 225 isolates belonged to the B. cepacia complex, with Burkholderia cenocepacia as the most prevalent species (61.1%). Clones delineated by PFGE were predominantly linked to a single center; in contrast, BOX-PCR clones were composed of isolates collected either from the same center or from different CF centers and comprised multiple PFGE clusters. Three BOX-PCR clones appeared of special interest. One clone was composed of 17 B. cenocepacia isolates belonging to recA RFLP type H. These isolates were collected from six centers and represented three PFGE clusters. The presence of insertion sequence IS1363 in all isolates and the comparison with PHDC reference isolates identified this clone as PHDC, an epidemic clone prominent in North American CF patients. The second clone included 22 isolates from eight centers and belonged to recA RFLP type AT. The genomovar status of strains with the latter RFLP type is not known. Most of these isolates belonged to four different PFGE clusters. Finally, a third clone comprised nine B. pyrrocinia isolates belonging to recA RFLP type Se13. They represented three PFGE clusters and were collected in three CF centers.In the late 1970s and 1980s, reports on the recovery of Burkholderia cepacia from cystic fibrosis (CF) specimens began to appear (29), and the emergence of this pathogen was subsequently reviewed (25,35,36). Polyphasic taxonomic studies identified bacteria tentatively classified as B. cepacia as a complex of at least nine closely related species (genomovars). This B. cepacia complex consists of B. cepacia,

Infection Prevention and Control Guideline for Cystic Fibrosis: 2013 Update

“…Strain PHDC has been recovered from agricultural soil in the United States, including onion fields, and from people with CF in diverse locations in the United States and Europe, suggesting that this strain is widely distributed in the natural environment, which serves as a source of ongoing acquisition. 161,[298][299][300] Strains identical to those found in people with CF have also been isolated from onions and onion rot. 301,302 Furthermore, MLST analysis demonstrated that more than 20% of 381 CF isolates of Burkholderia were indistinguishable from strains recovered from the natural environment.…”

“…Shared strains from other species in the B. cepacia complex have been reported and generally involved smaller numbers of patients. 133,161,163,164 A notable exception is B. dolosa strain SLC6, which was identified in an outbreak in a US CF center and associated with deterioration in lung function and increased mortality. 25,133 The Glasgow strain of B. multivorans was identified in an outbreak among people with CF in the city in the early 1990s.…”

“…For ex-ample, there is a separate clinic for people infected with MRSA or a separate clinic for people infected with an epidemic strain of P. aeruginosa. 1,161,185,374,375,[444][445][446] While cohort segregation has been associated with a reduced incidence of LES of P. aeruginosa 185,373,375,444 and a decrease in the incidence and prevalence of Burkholderia spp. in the United States, 44 additional IP&C practices were also implemented at the same time.…”

“…[158][159][160] Other B. cenocepacia strains have been shared among multiple individuals with CF in various Italian CF centers. 161,162 Other species of B. cepacia complex. Shared strains from other species in the B. cepacia complex have been reported and generally involved smaller numbers of patients.…”

Structure of Burkholderia cepacia UDP-Glucose Dehydrogenase (UGD) BceC and Role of Tyr10 in Final Hydrolysis of UGD Thioester Intermediate

“…In general, B. cenocepacia predominates, followed by Burkholderia multivorans (2,4,5,31,33,44). However, the species B. cepacia, found infrequently in CF patients worldwide, has an exceptionally high representation among the BCC isolates in Portugal, accounting for one-half of the number of the isolates retrieved from 1995 to 2006 (12).…”