Bacteriological Examination of Computer Keyboards and Mouse Devices and their Susceptibility Patterns to Disinfectants
Anyim Chukwudi,
Ilang Donatus C,
Okonkwo Eucharia C.
Issue:
Volume 1, Issue 3, June 2013
Pages:
36-43
Received:
15 June 2013
Published:
30 June 2013
Abstract: Computers are ubiquitous and have been shown to be contaminated with potentially pathogenic bacteria in some communities. There is no economical way to test all the keyboards and mouse out there, but there are common-sense ways to prevent bacterial contamination or eliminate it if it exists. In this study, swabs specimens were collected from surfaces of 250 computer keyboards and mouse and plated on different bacteriological media. Organisms growing on the media were purified and identified using microbiological standards. It was found that all the tested computer keyboards and mouse devices, were positive for microbial contamination. The percentages of isolated bacteria (Staphylococcus spp., Escherichia spp., Pseudomonas spp. and Bacillus spp.) were 43.3%, 40.9%, 30.7%, 34.1%, 18.3%, 18.2%, 7.7% and 6.8% for computer keyboards and mouse respectively. The isolated bacteria were tested against the 6 different disinfectants (Dettol, Isol, Izal, JIK, Purit and Septol®). Antibacterial effects of the disinfectants were also concentration dependent. The agar well diffusion technique for determining Minimum Inhibitory Concentration (MIC) was employed. The Killing rate (K) and Decimal Reduction Time (DRT) of the disinfectants on the organism were also determined. The overall result of this study showed that Dettol®, followed by JIK® was highly effective against all the bacterial isolates tested while Septol and Izal® were least effective. Isol and Purit® showed moderate antibacterial effects. Keyboards and mouse should be disinfected daily. However, it is recommended that heightened surveillance of the microbial examination of computer keyboards should be undertaken at predetermiant intervals.
Abstract: Computers are ubiquitous and have been shown to be contaminated with potentially pathogenic bacteria in some communities. There is no economical way to test all the keyboards and mouse out there, but there are common-sense ways to prevent bacterial contamination or eliminate it if it exists. In this study, swabs specimens were collected from surfac...
Show More
Advances on Using a Bioluminescent Microbial Biosensor to Detect Bioavailable Hg (II) In Real Samples
G. S. Costa,
A. M. Salgado,
P. R. G. Barrocas
Issue:
Volume 1, Issue 3, June 2013
Pages:
44-48
Received:
15 May 2013
Published:
10 July 2013
Abstract: Technology has improved human quality of life but it caused several impacts also, due to the various contaminants released in the environment. Among these contaminants, mercury is a major concern because of its high toxicity and ubiquity in the biosphere, being classified as a global pollutant. It can occur in different forms (i.e. soluble, gaseous or solid) and chemical species (e.g. Methylmercury, elemental mercury, Hg (II), etc.), which have very different physico-chemical characteristics that, in turn, determine its cycling and bioavailability. Thus, to assess mercury potential impacts, it is necessary to go beyond the total quantitative determination, developing methods that can measure the toxicity of individual Hg species. In this context, we used a novel technique, a bioluminescent microbial biosensor, which detect only bioavailable mercury species, since bacterial Hg bioavailability is critical to define their risks. Biosensors have large applicabilities in different scientific domains such as environmental biomonitoring, medicine, and food analysis. The chosen biological receptor for the biosensor was the bacteria Escherichia coli MC1061, which is a genetic engineered organism capable of emitting light proportional to amount of Hg that enters its cell. Therefore it is a true mercury bioavailability measurement. In the present study the biosensor was used to detect bioavailable mercury from environmental samples collected at three different locations (open dump, semi-controlled landfill and controlled landfill).The biosensor showed high specificity for Hg (II) and good repeatability. Among the tested samples, collected between September and October 2009, the open dump samples had the highest bioavailable mercury levels compared to other samples from semi-controlled and controlled landfill. Thus, the bioluminescent microbial biosensor technique were sensitive enough to measure bioavailable Hg in landfill samples, and probably in other environmental samples, showing a high potential as an environmental monitoring method.
Abstract: Technology has improved human quality of life but it caused several impacts also, due to the various contaminants released in the environment. Among these contaminants, mercury is a major concern because of its high toxicity and ubiquity in the biosphere, being classified as a global pollutant. It can occur in different forms (i.e. soluble, gaseous...
Show More
