Burkholderia cepacia Complex
المؤلف:
Stefan Riedel, Jeffery A. Hobden, Steve Miller, Stephen A. Morse, Timothy A. Mietzner, Barbara Detrick, Thomas G. Mitchell, Judy A. Sakanari, Peter Hotez, Rojelio Mejia
المصدر:
Jawetz, Melnick, & Adelberg’s Medical Microbiology
الجزء والصفحة:
28e , p257-258
2025-09-03
401
Burkholderia cepacia and 17 other genomospecies comprise the B. cepacia complex. The classification of these bacteria is complex; their specific identification is difficult. These are environmental organisms able to grow in water, soil, plants, animals, and decaying vegetable materials. In hospitals, members of the B. cepacia complex have been isolated from a variety of water and environmental sources from which they can be transmitted to patients. People with CF and those patients with chronic granulomatous disease are particularly vulnerable to infection with bacteria in the B. cepacia com plex. It is likely that B. cepacia can be transmitted from one CF patient to another by close contact. They may have asymptomatic carriage, progressive deterioration over a period of months, or rapidly progressive deterioration with necrotizing pneumonia and bacteremia. Although a relatively small per centage of CF patients become infected, the association with progressive disease makes B. cepacia complex a major concern for these patients. A diagnosis of B. cepacia infection in a CF patient may significantly alter the patient’s life because he or she may not be allowed association with other CF patients and may be removed from eligibility for lung transplantation. B. gladioli, while primarily a plant pathogen, is known to cause infections in CF patients and people with chronic granulomatous diseases and/or other immunosuppression.
B. cepacia grows on most media used in culturing specimens for Gram-negative bacteria. Selective media containing colistin (eg, B. cepacia selective agar) can be used and is recommended when culturing the sputum of patients with CF. B. cepacia grows more slowly than enteric Gram-negative rods, and it may take 3 days before colonies are visible. B. cepacia are oxidase positive and lysine decarboxylase positive and produce acid from glucose, but differentiating B. cepacia from other pseudomonads, including S. maltophilia, requires a battery of biochemical tests and can be difficult. Submission of isolates to reference laboratories is recommended because of the prognostic implications of colonization in CF patients. In the United States, the Cystic Fibrosis Foundation (http://www.cff.org) supports a reference laboratory that uses phenotypic and genotypic methods to confirm the identity of organisms within the B. cepacia complex. Antimicrobial susceptibility testing should be performed on B. cepacia complex isolates, although slow growth may make routine testing somewhat difficult. B. cepacia complex isolates recovered in clinical laboratories frequently express one or more antibiotic resistances; isolates recovered from CF patients often are multidrug- or pan-resistant. Antimicrobial resistance is typically mediated by efflux pumps, antimicrobial degradation or modifying enzymes, and/or altered membrane functions. Carbapenems (eg, meropenem), TMP-SMX, chloramphenicol, and minocycline are effective treatments. Ceftazidime and ciprofloxacin have demonstrated good activity against B. cepacia, especially in its planktonic form or when embedded in a biofilm.
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