Use of culture and molecular analysis to determine the effect of antibiotic treatment on microbial community diversity and abundance during exacerbation in patients with cystic fibrosis.

BACKGROUND: Anaerobic bacteria are increasingly regarded as important in cystic fibrosis (CF) pulmonary infection. The aim of this study was to determine the effect of antibiotic treatment on aerobic and anaerobic microbial community diversity and abundance during exacerbations in patients with CF. METHODS: Sputum was collected at the start and completion of antibiotic treatment of exacerbations and when clinically stable. Bacteria were quantified and identified following culture, and community composition was also examined using culture-independent methods. RESULTS: Pseudomonas aeruginosa or Burkholderia cepacia complex were detected by culture in 24/26 samples at the start of treatment, 22/26 samples at completion of treatment and 11/13 stable samples. Anaerobic bacteria were detected in all start of treatment and stable samples and in 23/26 completion of treatment samples. Molecular analysis showed greater bacterial diversity within sputum samples than was detected by culture; there was reasonably good agreement between the methods for the presence or absence of aerobic bacteria such as P aeruginosa (κ=0.74) and B cepacia complex (κ=0.92), but agreement was poorer for anaerobes. Both methods showed that the composition of the bacterial community varied between patients but remained relatively stable in most individuals despite treatment. Bacterial abundance decreased transiently following treatment, with this effect more evident for aerobes (median decrease in total viable count 2.3×10(7) cfu/g, p=0.005) than for anaerobes (median decrease in total viable count 3×10(6) cfu/g, p=0.046). CONCLUSION: Antibiotic treatment targeted against aerobes had a minimal effect on abundance of anaerobes and community composition, with both culture and molecular detection methods required for comprehensive characterisation of the microbial community in the CF lung. Further studies are required to determine the clinical significance of and optimal treatment for these newly identified bacteria.

Evidence of persistence of Prevotella spp. in the cystic fibrosis lung.

Purpose. Prevotella spp. represent a diverse genus of bacteria, frequently identified by both culture and molecular methods in the lungs of patients with chronic respiratory infection. However, their role in the pathogenesis of chronic lung infection is unclear; therefore, a more complete understanding of their molecular epidemiology is required.Methodology. Pulsed Field Gel Electrophoresis (PFGE) and Random Amplified Polymorphic DNA (RAPD) assays were developed and used to determine the degree of similarity between sequential isolates (n=42) from cystic fibrosis (CF) patients during periods of clinical stability and exacerbation.Results. A wide diversity of PFGE and RAPD banding patterns were observed, demonstrating considerable within-genus heterogeneity. In 8/12 (66.7 %) cases, where the same species was identified at sequential time points, pre- and post-antibiotic treatment of an exacerbation, PFGE/RAPD profiles were highly similar or identical. Congruence was observed between PFGE and RAPD (adjusted Rand coefficient, 0.200; adjusted Wallace RAPD->PFGE 0.459, PFGE->RAPD 0.128). Furthermore, some isolates could not be adequately assigned a species name on the basis of 16S rRNA analysis: these isolates had identical PFGE/RAPD profiles to Prevotella histicola.Conclusion. The similarity in PFGE and RAPD banding patterns observed in sequential CF Prevotella isolates may be indicative of the persistence of this genus in the CF lung. Further work is required to determine the clinical significance of this finding, and to more accurately distinguish differences in pathogenicity between species.

TeleMedMail: free software to facilitate telemedicine in developing countries.

Telemedicine offers the potential to alleviate the severe shortage of medical specialists in developing countries. However lack of equipment and poor network connections usually rule out video-conferencing systems. This paper describes a software application to facilitate store-and-forward telemedicine by email of images from digital cameras. TeleMedMail is written in Java and allows structured text entry, image processing, image and data compression, and data encryption. The design, implementation, and initial evaluation are described.

An assessment of the fungicidal activity of antimicrobial agents used for hard-surface and skin disinfection.

Trichophyton mentagrophytes and Aspergillus niger conidia and Candida albicans blastospores were employed to assess the fungicidal activity of a range of antimicrobial agents used for hard-surface and skin disinfection in hospitals in the U.K. The antimicrobials were tested at in-use concentrations. The time taken to give greater than 99.99% kill was determined by estimating the number of survivors (cfu/ml) at a variety of time intervals after exposure of washed suspensions of spores to the disinfectants. At equivalent times the recovery in the broth was investigated. An alcoholic solution of chlorhexidine gluconate (0.02%) (Hibitane), iodine in Industrial Methylated Spirit (IMS) and a phenolic (0.36% phenols, Stericol) produced a 99.99% kill of all species within 2 min, alcoholic and aqueous solutions (10%) of povidone-iodine (Betadine) and hypochlorite (0.2%) required 10 min to give a 99.99% kill of all species tested. The preparations which contained cetrimide (Cetavlon), aqueous solutions of chlorhexidine gluconate (Hibitane) and combinations of these (Savloclens and Savlodil) were only slowly fungicidal, particularly against T. mentagrophytes spores, which was the most resistant of the three fungal species to disinfection.

Inhibition of hyphal development in Trichophyton mentagrophytes arthroconidia by ketoconazole and miconazole.

In the presence of 0.5 mg/l ketoconazole and miconazole, arthroconidia from three isolates of Trichophyton mentagrophytes produced germ tubes, which continued to grow for 12 h before further elongation ceased. Lower concentrations reduced the rate of elongation, but did not halt the process. Higher concentrations had no greater effect than 0.5 mg/l. The inhibitory effect of ketoconazole was independent of time of addition of drug during the first six hours of germination. Ketoconazole inhibition was reversible after 12 h contact, whereas miconazole inhibition was not. Morphological effects of drug treatment were investigated by scanning electron microscopy. In the absence of imidazoles, hyphae were straight and regular; ketoconazole treated hyphae were short, irregular and branching; miconazole treatment produced extensive debris and spores forming within the hyphae were visible.

Survival and functional outcome of children with severe cerebral palsy following gastrostomy.

Survival, functional outcome, care setting, early and late complications, and caregiver satisfaction were determined in 61 children with severe cerebral palsy requiring gastrostomies during a six-year period. Fifty-three (87%) of the initial gastrostomies included a Nissen fundoplication. Early and late complications were 32.8% and 39.3%, respectively. Survival after initial surgery was 84.2% at one year, and 67.6% at four years. One child died within one month of surgery. Seventy percent of the children remained totally dependent in self-care, mobility, and communication; an additional 29% had significant limitations in function. Only 4 children (6.5%) ultimately became independent in feeding. Ninety-three percent of the children were cared for at home. Ninety-four percent of the parents/caregivers believed the gastrostomy was beneficial in management of the child. Survival was unexpectedly high compared to studies of adults and mentally retarded children requiring similar surgical procedures.