Validation of the Decontamination of a Specialist Transport System for Patients with High Consequence Infectious Diseases.

When transferring highly infective patients to specialist hospitals, safe systems of work minimise the risk to healthcare staff. The EpiShuttle is a patient transport system that was developed to fit into an air ambulance. A validated decontamination procedure is required before the system can be adopted in the UK. Hydrogen peroxide (H2O2) vapour fumigation may offer better penetration of the inaccessible parts than the liquid disinfectant wiping that is currently suggested. To validate this, an EpiShuttle was fumigated in a sealed test chamber. Commercial bacterial spore indicators (BIs), alongside organic liquid suspensions and dried surface samples of MS2 bacteriophage (a safe virus surrogate), were placed in and around the EpiShuttle, for the purpose of evaluation. The complete kill of all of the BIs in the five test runs demonstrated the efficacy of the fumigation cycle. The log reduction of the MS2 that was dried on the coupons ranged from 2.66 to 4.50, but the log reduction of the MS2 that was in the organic liquids only ranged from 0.07 to 1.90, confirming the results of previous work. Fumigation with H2O2 alone may offer insufficient inactivation of viruses in liquid droplets, therefore a combination of fumigation and disinfectant surface wiping was proposed. Initial fumigation reducing contamination with minimal intervention allows disinfectant wipe cleaning to be completed more safely, with a second fumigation step inactivating the residual pathogens.

Performance Testing of a Venturi-Based Backpack Spray Decontamination System.

Introduction: The performance of 2 disinfectant chemicals, peracetic acid (PAA) and hypochlorous acid (HOCl), was evaluated using a Venturi-nozzle-based light decontamination system (LDS) for delivery. The atomization equipment combined low-pressure air and disinfectant via a handheld lance, producing a fine, dense aerosol. A range of microorganisms, including Bacillus cereus and Bacillus anthracis (Vollum) spores, were used as test challenges to evaluate chemicals and equipment. Methods: The tests undertaken included assessments over fixed and variable exposure times, use of multiple surface materials, and a live agent challenge. Results: Over a fixed-time exposure of 60 minutes, aerosolized PAA gave 7- to 8-log reductions of all test challenges, but HOCl was less effective. Material tests showed extensive kill on most surfaces using PAA (≥6-log kill), but HOCl showed more variation (4- to 6-log). Testing using B. anthracis showed measurable PAA induced spore kill inside 5 minutes and >6-log kill at 5 minutes or over. HOCl was less effective. Discussion: The results demonstrate the importance of testing decontamination systems against a range of relevant microbiological challenges. Disinfectant efficacy may vary depending on product choice, types of challenge microorganisms, and their position in a treated area. The most effective disinfectants demonstrate biocidal efficacy despite these factors. Conclusion: The data confirmed PAA as an effective disinfectant capable of rapidly killing a range of microorganisms, including spores. HOCl was less effective. The LDS system successfully delivered PAA and HOCl over a wide area and could be suitable for a range of frontline biosecurity applications.

Bacterial [Cu,Zn]-cofactored superoxide dismutase protects opsonized, encapsulated Neisseria meningitidis from phagocytosis by human monocytes/macrophages.

Superoxide dismutase cofactored by copper and zinc ([Cu,Zn]-SOD) contributes to the protection of opsonized serogroup B Neisseria meningitidis against phagocytosis by human monocytes/macrophages, with sodC mutant organisms being endocytosed in significantly higher numbers than are wild-type organisms. The influence of [Cu,Zn]-SOD was found to be exerted at the stage of phagocytosis, rather than at earlier (modulating surface association) or later (intracellular killing) stages.

Identification and characterization of genomic loci unique to the Brazilian purpuric fever clonal group of H. influenzae biogroup aegyptius: functionality explored using meningococcal homology.

Brazilian purpuric fever (BPF) is a fulminant septicaemic infection of young children, caused by a clonal group of strains of Haemophilus influenzae biogroup aegyptius (Hae), an organism previously solely associated with conjunctivitis. Their special capacity to invade from the initial site of conjunctival infection is unexplained. A polymerase chain reaction (PCR)-amplified subtractive hybridization technique was used to identify genes specific to the BPF clonal group. A copy of bacteriophage HP1 and 46 further chromosomal loci were identified in the BPF but not in the conjunctivitis strain of Hae. Sixteen were characterized further, and one - encoding an analogue of the Legionella pneumophila epithelial cell entry-enhancing protein EnhC - was investigated in depth. Two genes, bpf001 and bpf002, unique to the BPF clonal group were identified between homologues of HI1276 and HI1277 in a complex locus close to H. influenzae genetic island 1, recently identified in pathogenic H. influenzae type b. Bpf001 encodes a protein homologous to EnhC and to the previously uncharacterized product of the meningococcal gene NMB0419. Functional studies of bpf001 proving intractable, NMB0419 was chosen as a surrogate for investigation and shown to modulate bacterial interaction with monolayers of human respiratory epithelial cells, promoting invasion, the first stage (for Hae) in the pathogenesis of BPF.