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A study was undertaken to compare a commercialized needle filter with a 0.2-μm filtered epidural set and a non-filtered standard needle. No culturable bacteria were detected following filtration through the 0.2-μm filter. Bacterial breakthrough was observed with the filtered needle (pore size 5 μm) and the non-filtered needle. Filtered systems (0.2 μm) should be employed to achieve total bacterial retention. This highlights that filtration systems with different pore sizes will have varying ability to retain bacteria. Healthcare professionals need to know what type/capability of filter is implied on labels used by manufacturers, and to assess whether the specification has the desired functionality to prevent bacterial translocation through needles., (Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Current autoclaving practices are designed to kill bacteria. Little is known about the effect of autoclaving on the integrity of bacterial genomic DNA. An experiment was performed to examine the effect of standard autoclaving on the integrity of bacterial DNA, employing polymerase chain reaction (PCR) as an indicator of DNA integrity. Amplifiable PCR signal was observed at t = 10, 20 and 30 min autoclaving time for Pseudomonas aeruginosa NCTC 10662; at t = 10, 20, 30 and 40 min for Salmonella Nottingham NCTC 7832; and at t = 10 and 20 min for Escherichia coli NCTC 9001. Careful consideration should therefore be given to residual molecular artefacts in future risk and environmental impact assessments, where the legacy of residual genomic DNA from dead bacterial and higher organisms may act as a potential reservoir, thereby feeding horizontal gene transfer scenarios in viable cells with potential hazardous genes of virulence, persistence or antibiotic resistance characteristics., (Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Universal or 'broad-range' eubacterial polymerase chain reaction (PCR) was performed on 53 isolates from environmental water-associated sites in a haematology unit (N = 22) and the outer surfaces of cleaning lotion containers sited throughout a tertiary referral hospital (N = 31) 16 S rDNA PCR was performed using two sets of universal primers, including the novel reverse primer, XB4, to generate a composite amplicon of 1068 bp, which was sequenced to obtain each isolate's identity. Sequence analysis was able to identify 51 isolates. Most (75% from the haematology unit and 81% from cleaner containers) were Gram-positive. Nine different genera were identified from the haematology unit and 13 from the cleaning lotion containers. This study provides the first reports of Terrabacter spp. and Brachybacterium paraconglomeratum isolated from a hospital environment. As unusual and difficult-to-identify environmental organisms are unlikely to be clinically significant, and molecular identification is costly and labour-intensive, we recommend that molecular methods are only used as an adjunct to first-line phenotypic identification schemes where a definitive identification is required. Where molecular identification methods are justified, partial 16 S rDNA PCR and sequencing employing the novel universal primer XB4, is a valuable and reliable technique.