Hypervirulent Clostridium difficile PCR-Ribotypes Exhibit Resistance to Widely Used Disinfectants

The increased prevalence of Clostridium difficile infection (CDI) has coincided with enhanced transmissibility and severity of disease, which is often linked to two distinct clonal lineages designated PCR-ribotype 027 and 017 responsible for CDI outbreaks in the USA, Europe and Asia. We assessed sporulation and susceptibility of three PCR-ribotypes; 012, 017 and 027 to four classes of disinfectants; chlorine releasing agents (CRAs), peroxygens, quaternary ammonium compounds (QAC) and biguanides. The 017 PCR-ribotype, showed the highest sporulation frequency under these test conditions. The oxidizing biocides and CRAs were the most efficacious in decontamination of C. difficile vegetative cells and spores, the efficacy of the CRAs were concentration dependent irrespective of PCR-ribotype. However, there were differences observed in the susceptibility of the PCR-ribotypes, independent of the concentrations tested for Virkon®, Newgenn®, Proceine 40® and Hibiscrub®. Whereas, for Steri7® and Biocleanse® the difference observed between the disinfectants were dependent on both PCR-ribotype and concentration. The oxidizing agent Perasafe® was consistently efficacious across all three PCR ribotypes at varying concentrations; with a consistent five Log10 reduction in spore titre. The PCR-ribotype and concentration dependent differences in the efficacy of the disinfectants in this study indicate that disinfectant choice is a factor for llimiting the survival and transmission of C. difficile spores in healthcare settings

The development of digital field data collection systems to fulfil the British Geological Survey mapping requirements

Geological mapping with pen and paper is proving inefficient in many respects in the digital age. With this in mind, the British Geological Survey (BGS) instigated the System for Integrated Geospatial MApping programme (SIGMA) to improve the mapping workflow by evaluating and implementing effective digital procedures for baseline data review, geological data acquisition, and geological mapping and modelling. The project has developed digital field data capture systems to collect information for output to a Geographical Information System (GIS) and digital geological maps. BGS first explored the concept of digital field data collection in the early 1990’s with the conclusion that the mobile computing hardware available at the time was not suitable. An effective digital field data capture system will have a number of advantages over the conventional analogue recording systems. The first is to increase the efficiency of data collection and its subsequent manipulation, predominantly by reducing the time spent copying analogue field data to databases/GIS. The system design will ensure that all field geologists record the same range of structured data and also that mandatory or important information is not omitted. Drop-down menus and approved dictionaries are incorporated to standardise nomenclature. An additional advantage of a digital field system is that a GIS of baseline data (e.g. a series of historic topographic maps) can be uploaded onto the mobile PC, ensuring that new data are collected in the context of prior geological knowledge and with a wide range of other geographic and environmental datasets. It should be noted that while we strive to guarantee corporate consistency and common standards by structuring our data collection, there must also be a degree of flexibility so that geologists are not unduly constrained. Moreover, when we replicate functions that are ideally suited to pencil and paper, such as drawing sketches, we must ensure that the digital solutions are fit for purpose and do not leave field geologists yearning for ‘the old days’

Meiotic interstrand DNA damage escapes paternal repair and causes chromosomal aberrations in the zygote by maternal misrepair

De novo point mutations and chromosomal structural aberrations (CSA) detected in offspring of unaffected parents show a preferential paternal origin with higher risk for older fathers. Studies in rodents suggest that heritable mutations transmitted from the father can arise from either paternal or maternal misrepair of damaged paternal DNA, and that the entire spermatogenic cycle can be at risk after mutagenic exposure. Understanding the susceptibility and mechanisms of transmission of paternal mutations is important in family planning after chemotherapy and donor selection for assisted reproduction. We report that treatment of male mice with melphalan (MLP), a bifunctional alkylating agent widely used in chemotherapy, induces DNA lesions during male mouse meiosis that persist unrepaired as germ cells progress through DNA repair-competent phases of spermatogenic development. After fertilization, unrepaired sperm DNA lesions are mis-repaired into CSA by the egg's DNA repair machinery producing chromosomally abnormal offspring. These findings highlight the importance of both pre- and post-fertilization DNA repair in assuring the genomic integrity of the conceptus