Low-Dose Nitric Oxide as Targeted Anti-biofilm Adjunctive Therapy to Treat Chronic Pseudomonas aeruginosa Infection in Cystic Fibrosis.

Despite aggressive antibiotic therapy, bronchopulmonary colonization by Pseudomonas aeruginosa causes persistent morbidity and mortality in cystic fibrosis (CF). Chronic P. aeruginosa infection in the CF lung is associated with structured, antibiotic-tolerant bacterial aggregates known as biofilms. We have demonstrated the effects of non-bactericidal, low-dose nitric oxide (NO), a signaling molecule that induces biofilm dispersal, as a novel adjunctive therapy for P. aeruginosa biofilm infection in CF in an ex vivo model and a proof-of-concept double-blind clinical trial. Submicromolar NO concentrations alone caused disruption of biofilms within ex vivo CF sputum and a statistically significant decrease in ex vivo biofilm tolerance to tobramycin and tobramycin combined with ceftazidime. In the 12-patient randomized clinical trial, 10 ppm NO inhalation caused significant reduction in P. aeruginosa biofilm aggregates compared with placebo across 7 days of treatment. Our results suggest a benefit of using low-dose NO as adjunctive therapy to enhance the efficacy of antibiotics used to treat acute P. aeruginosa exacerbations in CF. Strategies to induce the disruption of biofilms have the potential to overcome biofilm-associated antibiotic tolerance in CF and other biofilm-related diseases.

A Systematic Approach for the Evaluation, Validation, and Implementation of Automated Colony Counting Systems.

For several years, automated colony counting systems have been available with varying degrees of automation. Ever more sophisticated instruments are now increasingly used in microbiological laboratories of pharmaceutical quality control. In addition to the colony counting device, the instruments are now also equipped with robotic systems performing the entire handling of the petri dishes, e.g., automated internal transportation of petri dishes from the incubator chamber to the instrument's enumeration device and back. Moreover, the subjective evaluation of microbial enumeration tests by analysts is replaced with a more accurate and precise process. This leads to significant improvements to data integrity compliance. Automated colony counting systems also often enable cost reduction in the microbiological laboratory, e.g., by not requiring a contemporaneous verification by a second analyst. They also enable direct integration of count data into an existing laboratory information management system, reducing the hands-on time, costs per test and also preventing human errors caused by manual transcription. Altogether, these instruments will lead to improved monitoring and assurance of control of biopharmaceutical processes and manufacturing environments, as well as shortened cycle times in the supply chain. Regulators are encouraging the biopharmaceutical industry to adopt these innovative systems. For example, this year a BioPhorum member company received the first health authority approvals from EU, US, CH, Canada, Australia, and China for the use of automated colony counting systems for in-process bioburden testing and the release of drug substance lots, with an incubation time reduced by about 50%. Although these approvals are for release testing of drug substance lots, the instruments can also be used for environmental monitoring, testing of water samples, etc. This article describes a systematic 9-step approach to the evaluation, equipment qualification, and deployment of automated colony counting systems, which can be applied by biopharmaceutical companies wanting to take advantage of their numerous benefits.