Of onions and men: Report of cavitary community acquired pneumonia due to Burkholderia cepacia complex in an immunocompetent patient and review of the literature.

Burkholderia cepacia complex consists of highly antibiotic resistant gram negative bacilli that are plant symbionts and also potential agents of human infection.  This bacterial family's claim to fame in clinical medicine is as the scourge of cystic fibrosis patients, in whom it is a notorious respiratory pathogen.  Outside of cystic fibrosis, it rarely comes to mind as an etiology of community acquired pneumonia with or without lung cavitation in immunocompetent hosts.  We describe a case of an otherwise healthy, community-dwelling man who presented with subacute cavitary lung disease, the causative organism of which turned out to be Burkholderia cepacia complex.  Our report is accompanied by a review of the literature, which identified an additional eleven cases in the same category.  We analyze all of the available cases for the emergence of any identifiable patterns or peculiarities.

Antimicrobial activity of essential oils against multidrug-resistant clinical isolates of the Burkholderia cepacia complex.

Members of the Burkholderia cepacia complex (Bcc) are an important cause of opportunistic or nosocomial infections that may be hard to treat due to a high incidence of multidrug resistance. We characterised a collection of 51 clinical isolates from this complex, assigning them to 18 sequence types using multi-locus sequence type analysis. Resistance to eight commonly used antibiotics was assessed using by using agar-dilution assays to calculate MICs and widespread and heterogeneous multidrug resistance was confirmed, with eight strains proving resistant to all antibiotics tested. Disc diffusion screening of antimicrobial activity of a range of plant essential oils against these Bcc isolates identified six oils with significant activity (lavender, lemongrass, marjoram, peppermint, tea tree and rosewood) and broth microdilution assays indicated that of these lemongrass and rosewood oils had the highest activity, with MIC50 values of 0.5% and MIC90 values of 1%. Comparison of MIC and MBC values showed that four of these six oils, including lemongrass and rosewood, were bacteriocidal rather than bacteriostatic in their effects. Qualitative analysis of the four bacteriocidal essential oils via GC/MS indicated the presence of 55 different component compounds, mostly monoterpenes. We assessed selected essential oil components as anti-Bcc agents and demonstrated that terpinen-4-ol and geraniol were effective with MICs of 0.125-0.5% (v/v) and 0.125-1% (v/v), respectively. Time-kill studies indicate that these two alcohols are effective against non-growing cells in an efflux-dependent manner. Analysis of bacterial leakage of potassium ions and 260 nm UV-absorbing material on treatment with terpinen-4-ol and geraniol suggested that the observed anti-Bcc activity was a consequence of membrane disruption. This finding was supported by a gas chromatography analysis of bacterial fatty acid methyl esters, which indicated changes in membrane fatty acid composition caused by terpinen-4-ol and geraniol. These essential oils or oil components may ultimately prove useful as therapeutic drugs, for example to treat Bcc infections in CF patients.

Novel antibiotic combinations proposed for treatment of Burkholderia cepacia complex infections.

Effective strategies to manage Burkholderia cepacia complex (Bcc) infections in cystic fibrosis (CF) patients are lacking. We tested combinations of clinically available antibiotics and show that moxifloxacin-ceftazidime could inhibit 16 Bcc clinical isolates at physiologically achievable concentrations. Adding low dose of colistin improved the efficacy of the combo, especially at conditions mimicking CF respiratory secretions.

Clinical and microbiological profile of chronic Burkholderia cepacia complex infections in a cystic fibrosis reference hospital in Brazil.

Burkholderia sp. infections are extremely complex in cystic fibrosis (CF) patients, especially considering the lack of knowledge regarding its behavior, its relationship with prognosis, as well as its transmissibility and multidrug resistance features. This study evaluated the frequency of chronic infection by Burkholderia, using microbiological and clinical data. Ninety-eight patients with CF attended from July 2011 to April 2014 in a Brazilian reference hospital were included. Antimicrobial activity, molecular epidemiology, Shwachman score, body mass index, exacerbations, and lung function were analyzed. Nine patients had chronic colonization, and all of them showed preserved pulmonary function levels, body mass index, and Shwachman score. Meropenem was the most effective antibiotic; however, divergent results were shown by other studies. Cross-contamination may have occurred in only two unrelated patients of different ages, who were colonized by B. vietnamiensis, which does not occur frequently. Twelve new sequence types (STs) were identified and three STs have presented intercontinental distribution. None of the patients presented known epidemic strains. In conclusion, a relatively low number of patients with chronic colonization and suspected cross-infection were identified. Different from other studies that have found CF patients chronically colonized with Burkholderia sp. having a greater deterioration of lung function, more frequent antibiotic therapy, and increased mortality, in the current study, the patients showed good clinical outcomes and favorable options for antibiotics therapy. This study also updated the epidemiological database, which facilitates the multicentric collaborative analysis and assists in the control of global infection by these pathogens.

Two case reports of the successful eradication of new isolates of Burkholderia cepacia complex in children with cystic fibrosis.

BACKGROUND: Chronic infection with Burkholderia cepacia complex (BCC) has a detrimental effect on morbidity and mortality for patients with cystic fibrosis (CF). It is therefore logical to attempt to eradicate new isolates however there is a paucity of information to guide treatment. We report the successful eradication of new isolates of BCC in two children with CF. CASE PRESENTATION: Burkholderia cepacia was successfully eradicated in a 14 year old boy with CF and Burkholderia gladioli was successfully eradicated in a six year old girl with CF. In both children two weeks of intravenous (IV) tobramycin, ceftazidime and temocillin were used followed by three months of inhaled tobramycin. Bronchoalveolar lavage samples taken during flexible bronchoscopy were used prior to treatment to exclude spontaneous clearance as well as after treatment to confirm eradication. CONCLUSIONS: New isolates of BCC can be successfully eradicated in children with CF. More research is urgently required in this area to identify the best treatment regimen for BCC eradication.

Activity of the siderophore monobactam BAL30072 against multiresistant non-fermenters.

BACKGROUND: We tested the activity of BAL30072, a novel siderophore monobactam, against multiresistant clinical isolates of Pseudomonas aeruginosa, Burkholderia cepacia group and Acinetobacter spp. and against laboratory P. aeruginosa strains with defined resistance mechanisms. METHODS: MICs were determined on Mueller-Hinton agar supplemented with 2,2' bipyridyl to induce iron transport; comparators were aztreonam, imipenem, meropenem and piperacillin/tazobactam. RESULTS: BAL30072 was strikingly active against Acinetobacter baumannii, with 73% of 200 carbapenemase-producing isolates, most of them belonging to the UK-dominant OXA-23 clone 1 and SE clone lineages, susceptible at 1 mg/L and 89% at 8 mg/L. Resistance nevertheless was seen in a few representatives of these clones and appeared commoner among isolates representing other A. baumannii clones. Sixty-eight per cent of 50 B. cepacia complex isolates from cystic fibrosis (CF) were susceptible to BAL30072 at 1 mg/L and 78% at 8 mg/L, compared with only 22% susceptible to aztreonam at 8 mg/L. Activity against P. aeruginosa was good, though less dramatic, with 36% of 50 (mostly multiresistant) CF isolates susceptible at 8 mg/L, compared with 12% susceptible to aztreonam at 8 mg/L. BAL30072 was active against 11/19 metallo-beta-lactamase-producing P. aeruginosa at 8 mg/L compared with 3/19 for aztreonam (12/19 versus 8/19 at 16 mg/L). Studies on P. aeruginosa mutants, isolates and transconjugants showed that BAL30072 was affected by efflux, AmpC and by a few uncommon acquired beta-lactamases, including some extended-spectrum OXA types and PER-1. CONCLUSIONS: BAL30072 displayed impressive activity against many carbapenemase-producing A. baumannii, particularly against the two clones most prevalent in the UK, and also against B. cepacia complex isolates from CF; it was more active than aztreonam against P. aeruginosa.

Variation of the antimicrobial susceptibility profiles of Burkholderia cepacia complex clonal isolates obtained from chronically infected cystic fibrosis patients: a five-year survey in the major Portuguese treatment center.

The treatment of cystic fibrosis (CF) patients chronically infected with Burkholderia cepacia complex (Bcc) bacteria requires extensive and aggressive antibiotics therapy, exposing these bacteria to prolonged antibiotics-selective pressure. In the present study, we have compared the susceptibility patterns to 13 antimicrobials of 94 Bcc isolates obtained from 15 Portuguese CF patients in the course of chronic infection during a five-year survey. These isolates were previously genotyped and represent 11 different strains of the species B. cenocepacia (subgroups A and B), B. cepacia, B. multivorans, and B. stabilis. The results are consistent with the notion that CF Bcc isolates are resistant to the most clinically relevant antimicrobials and suggest an uneven distribution of resistance rates among the different species, with B. cenocepacia subgroup A isolates being the most resistant. Phenotypic variants exhibiting differences in the antimicrobial susceptibility patterns were obtained from the sputum samples of clinically deteriorated CF patients during chronic lung infection. The isolation of resistant variants coincided with periods of pulmonary exacerbation and antibiotics therapy.

Identification and onion pathogenicity of Burkholderia cepacia complex isolates from the onion rhizosphere and onion field soil.

Burkholderia cepacia complex strains are genetically related but phenotypically diverse organisms that are important opportunistic pathogens in patients with cystic fibrosis (CF,) as well as pathogens of onion and banana, colonizers of the rhizospheres of many plant species, and common inhabitants of bulk soil. Genotypic identification and pathogenicity characterization were performed on B. cepacia complex isolates from the rhizosphere of onion and organic soils in Michigan. A total of 3,798 putative B. cepacia complex isolates were recovered on Pseudomonas cepacia azelaic acid tryptamine and trypan blue tetracycline semiselective media during the 2004 growing season from six commercial onion fields located in two counties in Michigan. Putative B. cepacia complex isolates were identified by hybridization to a 16S rRNA gene probe, followed by duplex PCR using primers targeted to the 16S rRNA gene and recA sequences and restriction fragment length polymorphism analysis of the recA sequence. A total of 1,290 isolates, 980 rhizosphere and 310 soil isolates, were assigned to the species B. cepacia (160), B. cenocepacia (480), B. ambifaria (623), and B. pyrrocinia (27). The majority of isolates identified as B. cepacia (85%), B. cenocepacia (90%), and B. ambifaria (76%) were pathogenic in a detached onion bulb scale assay and caused symptoms of water soaking, maceration, and/or necrosis. A phylogenetic analysis of recA sequences from representative B. cepacia complex type and panel strains, along with isolates collected in this study, revealed that the B. cenocepacia isolates associated with onion grouped within the III-B lineage and that some strains were closely related to strain AU1054, which was isolated from a CF patient. This study revealed that multiple B. cepacia complex species colonize the onion rhizosphere and have the potential to cause sour skin rot disease of onion. In addition, the onion rhizosphere is a natural habitat and a potential environmental source of B. cenocepacia.

A biosurfactant from Burkholderia cenocepacia BSP3 and its enhancement of pesticide solubilization.

AIMS: To isolate a biosurfactant (BS)-producing bacterium, to characterize the BS properties and to evaluate its ability to enhance pesticide solubilization for further application in environmental remediation. METHODS AND RESULTS: Five BS-producing bacteria were isolated from fuel oil-contaminated soil. Among them, Burkholderia cenocepacia BSP3 exhibited the highest emulsification index and was chosen for further study. Glucose-containing medium supplemented with nitrate or sunflower seed oil provided suitable conditions for growth and BS production. The BS was identified as a glucolipid, having a critical micelle concentration (CMC) of 316 mg l(-1). It could lower the surface tension of deionized water to 25 +/- 0.2 mN m(-1) and exhibited good emulsion stability. Finally, the application of the BS to facilitate pesticide solubilization demonstrated that this BS at the concentration below and above its CMC could enhance the apparent water solubility of three pesticides, i.e. methyl parathion, ethyl parathion and trifluralin. CONCLUSIONS: Burkholderia cenocepacia BSP3 is a BS-producing bacterium isolated from oil-contaminated soil. The BS was identified as a glucolipid having a molecular mass of 550.4 g mol(-1). An apparent yield of the BS was 6.5 +/- 0.7 g l(-1). This glucolipid-type BS noticeably enhanced pesticide solubilization suggesting its role in environmental remediation. SIGNIFICANCE AND IMPACT OF THE STUDY: A glucolipid type BS normally found in marine micro-organisms was isolated from a soil-bacterium. Due to its surface active properties and good performance in enhancement of pesticide solubilization, it could be used as a solubilizing agent for environmental remediation and synergistic treatment with bioremediation of pesticide-contaminated soil.