Survival After Lung Transplantation of Cystic Fibrosis Patients Infected with Burkholderia cepacia Complex

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71603/1/j.1600-6143.2008.02186.x.pd

Burkholderia cenocepacia Vaginal Infection in Patient with Smoldering Myeloma and Chronic Hepatitis C

We report a case of a vaginal infection caused by a strain of Burkholderia cenocepacia. The strain was isolated from vaginal swab specimens from a 68-year-old woman with smoldering myeloma and chronic hepatitis C virus infection who was hospitalized for abdominal abscess. Treatment with piperacillin/tazobactam eliminated B. cenocepacia infection and vaginal symptoms

Impact of Enhanced Staphylococcus DNA Extraction on Microbial Community Measures in Cystic Fibrosis Sputum

Staphylococcus aureus is a common constituent of the bacterial community inhabiting the airways of persons with cystic fibrosis (CF). Culture-independent studies have shown that this species is often present in relatively high abundance and would therefore be expected to exert a pronounced effect on measures of CF airway bacterial community structure. We investigated the impact of DNA extraction method on pyrosequencing-based measures of Staphylococcus abundance and bacterial community structure in 17 sputum samples from five CF patients. Staphylococcus was detected in fewer samples when DNA was extracted using a standard bacterial lysis method compared to when DNA was extracted using a lysis buffer amended with lysostaphin and lysozyme. The standard lysis method resulted in significantly lower measures of Staphylococcus relative abundance and higher levels of community diversity, richness, and evenness compared to the lysostaphin-lysozyme modified method. Measures of community dynamics in serial sputum samples from the same individual were nevertheless highly concordant between the two DNA extraction methods. These results illustrate the impact of DNA preparation method on measures of Staphylococcus abundance and bacterial community structures in studies of the airways microbiota in CF

Bacterial activity in cystic fibrosis lung infections

BACKGROUND: Chronic lung infections are the primary cause of morbidity and mortality in Cystic Fibrosis (CF) patients. Recent molecular biological based studies have identified a surprisingly wide range of hitherto unreported bacterial species in the lungs of CF patients. The aim of this study was to determine whether the species present were active and, as such, worthy of further investigation as potential pathogens. METHODS: Terminal Restriction Fragment Length Polymorphism (T-RFLP) profiles were generated from PCR products amplified from 16S rDNA and Reverse Transcription Terminal Restriction Fragment Length Polymorphism (RT-T-RFLP) profiles, a marker of metabolic activity, were generated from PCR products amplified from 16S rRNA, both extracted from the same CF sputum sample. To test the level of activity of these bacteria, T-RFLP profiles were compared to RT-T-RFLP profiles. RESULTS: Samples from 17 individuals were studied. Parallel analyses identified a total of 706 individual T-RF and RT-T-RF bands in this sample set. 323 bands were detected by T-RFLP and 383 bands were detected by RT-T-RFLP (statistically significant; P ≤ 0.001). For the group as a whole, 145 bands were detected in a T-RFLP profile alone, suggesting metabolically inactive bacteria. 205 bands were detected in an RT-T-RFLP profile alone and 178 bands were detected in both, suggesting a significant degree of metabolic activity. Although Pseudomonas aeruginosa was present and active in many patients, a low occurrence of other species traditionally considered to be key CF pathogens was detected. T-RFLP profiles obtained for induced sputum samples provided by healthy individuals without CF formed a separate cluster indicating a low level of similarity to those from CF patients. CONCLUSION: These results indicate that a high proportion of the bacterial species detected in the sputum from all of the CF patients in the study are active. The widespread activity of bacterial species in these samples emphasizes the potential importance of these previously unrecognized species within the CF lung

Microbiology of airway disease in a cohort of patients with Cystic Fibrosis

BACKGROUND: Recent reports document an increasing incidence of new Gram-negative pathogens such as Stenotrophomonas maltophilia and Alcaligenes xylosoxidans isolated from patients with Cystic Fibrosis, along with an increase in common Gram-negative pathogens such as Pseudomonas aeruginosa and Burkholderia cepacia complex. Furthermore, the increase in multidrug-resistance of such organisms makes the therapeutic management of these patients more problematic. Therefore, careful isolation and identification, and accurate studies of susceptibility to antibiotics are critical for predicting the spread of strains, improving therapeutic measures and facilitating our understanding of the epidemiology of emerging pathogens. The first aim of this study was to determine the incidence and the prevalence of colonization by Gram-negative organisms isolated from respiratory samples of Cystic Fibrosis patients in the Regional Referral Cystic Fibrosis Centre of Naples; the second was to evaluate the spectrum of multidrug-resistance of these organisms. METHODS: Patients (n = 300) attending the Regional Cystic Fibrosis Unit were enrolled in this study over 3 years. Sputum was processed for microscopic tests and culture. An automated system, Phoenix (Becton Dickinson, Sparks, Maryland, USA), was used for phenotypic identification of all strains; the API 20 NE identification system (bioMérieux, Marcy l'Etoile, France) was used when the identification with the Phoenix system was inaccurate. A PCR-RFLP method was used to characterize the organisms in the Burkholderia cepacia complex. A chemosusceptibility test on microbroth dilutions (Phoenix) was used. Primary outcomes such as FEV1 were correlate with different pathogens. RESULTS: During the period of study, 40% of patients was infected by Pseudomonas aeruginosa, 7% by Burkholderia cepacia complex, 11% by Stenotrophomonas maltophilia and 7% by Alcaligenes xylosoxidans. Of the strains isolated, 460 were multidrug-resistant. Multiresistant were Pseudomonas aeruginosa and Burkholderia cepacia complex. CONCLUSION: The results confirm previously reported data; in particular, they show an increase the isolation of non-fermentative Gram-negative bacteria in Cystic Fibrosis patients. They also demonstrate increased resistance to antibiotics. Beta-lactams are rarely effective, with exception of ceftazidime, which is the most efficacious agent against multiresistant strains. Aminoglycosides and quinolones are poorly efficacious

Binding of protegrin-1 to Pseudomonas aeruginosa and Burkholderia cepacia

BACKGROUND: Pseudomonas aeruginosa and Burkholderia cepacia infections of cystic fibrosis patients' lungs are often resistant to conventional antibiotic therapy. Protegrins are antimicrobial peptides with potent activity against many bacteria, including P. aeruginosa. The present study evaluates the correlation between protegrin-1 (PG-1) sensitivity/resistance and protegrin binding in P. aeruginosa and B. cepacia. METHODS: The PG-1 sensitivity/resistance and PG-1 binding properties of P. aeruginosa and B. cepacia were assessed using radial diffusion assays, radioiodinated PG-1, and surface plasmon resonance (BiaCore). RESULTS: The six P. aeruginosa strains examined were very sensitive to PG-1, exhibiting minimal active concentrations from 0.0625–0.5 μg/ml in radial diffusion assays. In contrast, all five B. cepacia strains examined were greater than 10-fold to 100-fold more resistant, with minimal active concentrations ranging from 6–10 μg/ml. When incubated with a radioiodinated variant of PG-1, a sensitive P. aeruginosa strain bound considerably more protegrin molecules per cell than a resistant B. cepacia strain. Binding/diffusion and surface plasmon resonance assays revealed that isolated lipopolysaccharide (LPS) and lipid A from the sensitive P. aeruginosa strains bound PG-1 more effectively than LPS and lipid A from resistant B. cepacia strains. CONCLUSION: These findings support the hypothesis that the relative resistance of B. cepacia to protegrin is due to a reduced number of PG-1 binding sites on the lipid A moiety of its LPS

A Novel Inactivated Intranasal Respiratory Syncytial Virus Vaccine Promotes Viral Clearance without Th2 Associated Vaccine-Enhanced Disease

Respiratory syncytial virus (RSV) is a leading cause of bronchiolitis and pneumonia in young children worldwide, and no vaccine is currently available. Inactivated RSV vaccines tested in the 1960's led to vaccine-enhanced disease upon viral challenge, which has undermined RSV vaccine development. RSV infection is increasingly being recognized as an important pathogen in the elderly, as well as other individuals with compromised pulmonary immunity. A safe and effective inactivated RSV vaccine would be of tremendous therapeutic benefit to many of these populations.In these preclinical studies, a mouse model was utilized to assess the efficacy of a novel, nanoemulsion-adjuvanted, inactivated mucosal RSV vaccine. Our results demonstrate that NE-RSV immunization induced durable, RSV-specific humoral responses, both systemically and in the lungs. Vaccinated mice exhibited increased protection against subsequent live viral challenge, which was associated with an enhanced Th1/Th17 response. In these studies, NE-RSV vaccinated mice displayed no evidence of Th2 mediated immunopotentiation, as has been previously described for other inactivated RSV vaccines.These studies indicate that nanoemulsion-based inactivated RSV vaccination can augment viral-specific immunity, decrease mucus production and increase viral clearance, without evidence of Th2 immune mediated pathology