Problems associated with traditional hygiene swabbing: the need for in-house standardization
Griffith, Chris J.
Wiley-Blackwell Publishing Ltd.
MetadataDangos cofnod eitem llawn
Aims: To investigate factors influencing the recovery of micro-organisms from surfaces using traditional swabbing techniques. Methods and Results: Stainless steel squares were inoculated with known levels (approx. 2·7 x 102-2·7 x 104) of either Escherichia coli or Staphylococcus aureus and sampled using different swab/solution combinations. Overlaying the coupons with agar allowed colonies remaining on the surface to be enumerated. Conventional cultivation was used to determine the ease with which the bacteria were released from the swabs and the viability of the organisms within the solutions over a 24-h period. Minimal bacterial growth occurred when the samples were stored at 4°C. At room temperature, whilst the presence of nutrients significantly increased bacterial numbers over time, the addition of Tween 80 to nutrient depleted environments significantly reduced the viability of Staph. aureus. The percentage of bacteria released from directly inoculated swabs was significantly higher than that recovered from surface swabs, highlighting the importance of effectively removing bacterial contaminants from a surface. Increasing the level of mechanical energy generated during swabbing increased the number of bacteria removed from a wet surface. However, it is hypothesized that cellular damage, perhaps caused by the swabbing action itself, may have reduced recoverability from a dry surface. Nonetheless, an increased ability to effectively remove bacteria from a surface did not necessarily correlate with higher bacterial recovery, implying that an equally important factor in terms of swabbing efficiency is the ability of a swab to effectively release bacteria into a diluent. Conclusions: Both swab and wetting solution can influence the number of bacteria recovered. Under the experimental conditions described here, the use of swabs coated with a brush-textured nylon flock in combination with a non-growth-enhancing wetting solution appeared the best system to use when sampling a wet surface. However, this combination may not always be ideal and proper consideration must be given to how the sample is to be taken, transported and, if necessary, stored prior to analysis. Significance and Impact of the Study: Careful selection of swabbing materials can increase the sensitivity of traditional microbiological analysis. However, any improvements made are likely to be insignificant in relation to the overall poor performance of the swabbing technique.
Journal of Applied Microbiology
Journal of Applied Microbiology, 103 (0), pp.1090-1103
Dynodwr Gwrthrych Digidol (DOI)http://dx.doi.org/10.1111/j.1365-2672.2007.03330.x
Yn dangos eitemau sy’n perthyn drwy deitl, awdur, pwnc a chrynodeb.
Hospital surfaces and their importance in cross contamination and the spread and transmission of bacteria Obee, Peter (University of WalesCardiff School of Health Sciences, 2009)Healthcare associated infections (HCAI) place an economic burden on health services, and cause distress to patients and relatives. The recent rise in HCAI rates has been linked to poor standards of environmental hygiene, ...
The effect of the flavanol morin on biofilm formation, expression of fibronectin-binding proteins and aggregation properties of streptococcus pyogenes. Green, Angharad Ellen (Cardiff Metropolitan University, 2011)The aim of this study was to establish the impact of the flavanol Morin on S.pyogenes biofilm formation and expression of streptococcal fibronectin binding proteins. Whilst also investigating if the flavanol affects the ...
Henriques, Ana (University of Wales, 2006)Honey is an old remedy recently rediscovered as a possible alternative to modern antibiotics in wound management but its mode of action is not fully understood. The antibacterial activity of honey can be divided into ...