Microbial Contamination of Desktop Computer Keyboards - Research Paper Example

University

Abstract

Most computers both in medical and non-medical institutions tend to harbor different kinds of microorganisms such as Staphylococcus aureus, Enterococcus, and Enterobacter. As such, these computers are known to be associated with hospital-acquired infections. Offices, homes and health centers have taken upon themselves to use surface cleaners and disinfectants to deactivate and kill these microorganisms, hence reducing the chances of nosocomial infections. The research is designed to find out how these microorganisms are transferred to and from computer keyboards and how efficient the disinfectants are against the microbes. Congested areas in the University were used for the study, whereby swabbing procedures were appropriately used to obtain the microorganisms from the computer surfaces. These samples were then inoculated under strict conditions including selective medium, a temperature of 370c for 47 hours after which, the samples were observed to ensure that the medium supported the growth of these microorganisms. Students T-test procedures were then performed on the data with complete comparison to the available literature.

Introduction

Single-celled microorganisms including algae, fungi and bacteria are tiny thus, can only be seen under the microscope. Some of these microorganisms are beneficial to living organisms such as plants and animals while others are harmful. Beneficial microorganisms tend to help in digestion, the disposal of toxins and the breaking down of organic matter. On the other hand, harmful microorganisms bring about harm by the release of toxins that are harmful in one way or another to the host (Dodrill et al., 2011). We tend to interact with the different types of microorganisms in everyday activities since they are present everywhere.

As such, measures such as the use of disinfectants on surfaces have been put in place even though they are not 100% effective in reducing the chances of infections that results by microorganisms’ contamination. Microorganisms can also be transferred from one individual to another through physical contact as well as vectors (World Health Organization, 2001). In a hospital environment, such vectors include skin cells, hair, bedding and clothing while in an office and education setting the vectors include such items as computer keyboards and mice, touch screens, door handles, taps, and telephones. It is, therefore, evident that surfaces are dangerous since they are the main vectors for disease-causing microorganisms (Gillespie et. al., 2012). The objective of this research is to determine the presence of harmful microorganisms in computer keyboards used in the university and to investigate the efficacy of disinfectants against them.

Literature Review

Mirlei et al., 2013; Ashgar and El-Said, 2012 observed that cash dispensers and computer keyboards are the main vectors for spreading diseases in various institutions since they tend to be the most commonly used hence highly contaminated with microorganisms. Cross contamination can, however, be reduced both in public and private places by constantlycarrying out disinfection procedures on the surfaces since disinfectants tend to remove and deactivate the microorganisms (Mirlei et al., 2013; Ashgar and El-Said, 2012).A number of studies have been carried out to determine the efficacy of various disinfectants against microorganisms. For instance, Decker and Slawson (2012) reveal that microorganisms that cause nosocomial diseases can remain on the surfaces that had been disinfected thereby causing continuous infections.

Past studies reveal that the surfaces on which the microbes are present play a crucial role in the chances of cross contamination of microorganisms. In this case, Non-porous surfaces have been found to cause more cross-contamination than the porous surfaces. As such, hydrophobic liquid infused polymers that have the ability to hinder the formation of biofilm are being developed (Li et al., 2013). According to Anderson and Palombo (2009), computer keyboards are a possible source of infection since they are dry and can harbor bacteria. In addition, they are usually shared by many people. In a medical environment, computer keyboards can harbor microorganisms hence, can act as vectors. In learning institutions including universities, computers are in high demand by the students and staff. As such, multiple user computers have been installed to meet the institutions’ demand. With the increase in the multiple user computers comes the increase in the number of people who have access to the same. However, disinfection procedures have not been implemented for these multiple user computers hence they may harbor and transfer microorganisms to and from one computer user to another.

Sharpe and Schmidth (2011) point out that it is mandatory to identify objects that could potentially harbor and eventually act as vectors for cross-infection, including computer keyboards to ensure effective strategies towards prevention of diseases. According to Boa and Rahube, 8% -42% of the computer keyboards in American universities have tested positive for the presence of MRSA, which is a potential health hazard. In addition, commondisinfectant agents used in cleaning computer keyboards were tested for their efficiency and the results proved that these agents were effective against microbes (Rutala et. al., 2006). For the disinfectants to be effective, it was suggested that disinfection on the keyboards is done on a daily basis or when the need arises like blood contamination.

Single user mice and keyboards are safe in that they have lower transmission rates of microorganisms compared to multiple user mice and keyboards. Hospital keyboards have been shown to be the primary vectors for microbes that transmit MRSA in the US, UK and Canada (Mali and Naeem, 2014). Based on Kramer ET. Al. (2006), the presence of MRSA in learning institutions was recorded at 2%, with high rates presented in primary schools compared to high schools and universities, because older children have increased awareness and a better understanding of hygiene than the younger children (Biddle, 2009). It is crucial that public computer accessories be tested to identify and prevent the outbreak of potential diseases. In addition, strategies should be implemented to prevent the spread of microorganisms like CA-MRSA.

Even with the invention of new keyboard designs that are easier to disinfect, large amounts of microorganisms have still been found on keyboards after testing. According to research carried out in Nigeria by Nwankiti and colleagues (2012), computer keyboards were tested and various microorganisms were found including 84% of B.subtilus, S.epidermidis, S.aureus, S.albus, E.coli, Trichophyton sp., Diptheroids, Aspergillus species and Candida albicans. Some of these bacteria could easily be removed by cleaning since they are linked to skin flora and dust. Recent research concentrates on identifying and isolating microorganisms on keyboards rather that finding out the efficacy of antimicrobial agents (Ruatala, et. al., 2006). It is crucial that the resistance of bacteria to antimicrobial products be tested. This research is aimed at coming up with effective measures for disinfecting computer keyboards.

Materials and Methodology

Methods

Sterile peptone moisten swabs were used to collect samples from various areas in the university including the Learning Resource Centre, one personal keyboard, the Perry Library, the Microbiology Laboratory and the Lecture rooms.

Culture Media Preparation

Selective growth media including Malt agar, Nutrient agar, and Peptone water were used to isolate, identify and characterize the samples that had been collected. Appropriate procedures were used to prepare and weigh the samples, which were then sterilized in an autoclave and stored appropriately.

Inoculation

The pipette and pipette tips were appropriatelysterilized and used to perform serial dilutions and to swirl 1ml of the sample. Each of the inoculation bottles contained 9ml of sterile peptone water before the serial dilutions. The bottles were labeled after carrying put serial dilutions in order ranging from 10-1 to 10-6. 10-1 represented the most concentrated since it contained samples from keyboard surfaces that were cut and dipped in it.

Spread plating

Bacteria Quantification: 100ul pipette was used to transfer 0.1 ml of the sample. Six Petri dishes containing solid nutrient agar, ranging from 10-1 to 10-6 were streaked using sterile pipette after the sample transfer. They were then allowed to grow by being placed in an incubator at 370c for 48 hours, depending on the rate of their growth in each petri dish. There was no control for this experiment since all the samples had previously been sterilized. The colony forming units were the determined using the Gallenkomp Model counter. Given that 10-4 to 10-6 count was too little, serial dilutions were only performed on samples contained on Petri dishes 10-1 to 10-3

Isolation of organisms: nutrient agar plates were used to isolate and identify the microbes morphology and to subculture the pure colonies which had been isolated for 12 hours at 370c.

Identification of Organisms: identification was done using standard procedures of gram staining which were the observed under a ×40 light microscope. The presence of gram-positive colonies was detected and later identified as Bacillus subtillus, Staphylococcus aureus, and some yeast.

Efficacy of disinfectant on known bacteria method: Samples were collected from both personal and lecture room keyboards. They were then swabbed at differing times, disinfected with Dettol and Disifin, and left for 10 minutes to absorb and dry. The swabs were appropriately prepared to carry out serial dilutions, ranging from 10-1 to 10-3, since 10-4 to 10-6 had very few counts on previous dilutions.

Results

A total of 21 species of bacteria were isolated from the samples collected from the computers in different places of the university. The efficiency of various disinfectants was tested using the bacteria isolated from the computer surfaces. Out of the identified 21 species of bacteria, some were too few to count hence were not included in the report. Based on the study, multiple user keyboards including the ones in the Learning resource center, the Perry Library, and the Microbiology laboratory had a higher count of colonies compared to one personal keyboard. From the multiple user keyboards, 12 species of bacteria were isolated among which were the potentially harmful bacteria like S. aureus and B. subtillis. The different media used to identify the colonies showed the presence of both gram-positive and gram-negative bacteria (Table 1).The total number of colony forming units/ ml of the isolated microorganisms was calculated using the formula (30- 300 CFU/ml) X dilution X volume pipette on plate (0.1 ml X 10), which produced results ranging from 1.2 X 104 to 7.8 x 103cfu/ml, as evident in Table 2.

Table 1: Identification of Isolates

Isolate number

1

2

3

Media used

Nutrient agar

Nutrient agar

Malt agar

media

Staphylococcus

Aureus

Bacillus subtilis

Yeast and mould

Gram strain

Gram positive

Gram positive

Table 1 shows evidence that the sample collected from keyboards in different locations in the University tested positive for pathogenic bacteria although the molds and yeast were minimal. Although S. aureusis known as a disease-causing microorganism, it is known to be present in high concentration in the microbial content of the human skin and nasal passages (Anderson & Palombo, 2009). Given that B.subtilis mostly occurs on soil and vegetation, its presence in the sample collected on the keyboards proves the presence of environmental contamination on the computers (Dijl & Hecker, 2013). Yeast and mould, on the other hand, are airborne fungi hence their presence in the samples indicate the presence of airborne fungi on the environment (Anderson & Palombo, 2009).

Table 2: Microbial load on keyboards in a variety of locations

Location of keyboard

Number of keyboards swabbed

CFU/ml

Learning Resource X 103

1

7.6 x 105

Lecture room E7 X 102

Room FW10 X 101

1

1

6.0 x 104

7.8 x 103

Microbiology Laboratory

X 101

3

1.2 x 104

3.2 x 103

8.2 x 103

LibraryX 101

1

2

3

2.5 x 103

6.2 x 103

6.8 x 104

According to Table 2, the samples collected from multiple user keyboards had a high number of potentially harmful bacteria, with the keyboards in the microbiology laboratory portraying the highest count (8.2 x 103). In addition, the lowest count of bacteria was still found in the microbiology laboratory (1.2 x104), a number that is still higher than the counts from personal keyboards. Table 3 contains the specificmicrobial contaminant present in each location.

Table 3: each of this location

location

Number of swabs

1

Bacillus.s

Media isolated

2

Staph.aureus

3

Mould /yeast

A learning r

3

Positive

Negative

negative

B Lib

3

Positive

Positive

Positive

CFw10

1

Negative

Positive

Negative

DE7

1

Positive

Positive

Negative

E mbl

2

Positive

Positive

Negative

According to the results in Table 3, samples from all the computers contained both B.subtilis and S.aureus apart from the samples from the keyboards in the learning resource center, which were negative for S.aureus. The library computers are the only ones that tested positive for yeasts and mould. The efficiency of disinfectants against microbes was tested by disinfecting the keyboards using two types of disinfectants. After disinfecting the surfaces using Dettol and Disifin, samples were taken from the surfaces and the bacterial count was taken. Dettol and Disifin were appropriated in this research since they are most commonly used and are readily available. Disifin was used to disinfect the computers in the Perry Library while computers from the lecture halls, microbiology laboratory and personal computers were disinfected using Dettol as shown in Table 4.

Table 4: Dettol and Disifin Universal Cleaner

Dettol universal wipes

Microbiology lab

Domestic keyboard

Castle lecture room

disifin universal cleaner

Perry Library

After disinfection, the computers were left for 10 minutes to dry then swabbing and bacteria count was done. The efficiency of the disinfectant against the bacteria on the keyboards has been tabulatedinTable 5. Based on the results, it is evident that disinfection does not totally eliminate the bacteria but rather, it reduces the bacteria count since the levels of B. subtillis and S. aureus significantly dropped the following disinfection.

Table 5: Disinfectant effect on microbial growth

Location

Before disinfecting

1 2

After disinfecting

1 2

Castle Lecture

Staph present

Reduced

Microbiology Laboratory

Both 1 and 2staphy and bacillus

Reduced to staph. Aureus

Domestic keyboard

Bacillus

Few

Discussion

Computers are crucial in every aspect of our lives ranging from their use at home, workplaces, learning institutions and research activities. In the past, it was believed that disease-causing microorganisms were only present in clinics, hospitals, and unhygienic places, a belief that has highlybeen contradicted by recent researches carried out on personal and multiuser computers. Education need to be passed to the populationon thepresence of microbes everywhere and not just in specific places to reduce the occurrence of health complications that result from the lack of knowledge on the occurrence of microorganisms (Ali et. al., 2013, Tagoe & Ansah, 2010).

Previous studies indicate that there exist various vectors for the transfer of microorganisms among people including door handles, computers, money, and phones. These objects tend to provide breeding grounds where bacteria can grow and form colonies and the same objects end up acting as vectors for their transmission to other surfaces or people (Olduro et. al., 2011). In university, everyone has access to computersoccasionally, with 92% of these constantly using computers (Ali et. al., 2013). Due to the high demand, multiuser computers have been put in place; therefore, a lot of people tend to have access to them on a daily basis. However, routine disinfection procedures have not been implemented, as such making these multi-user computers be the main route of transmission of the potentially harmful microorganisms (Enemuor, et. al., 2013).

This is evident from past studies, which reveal that multi-user computer keyboards are highly contaminated with microbes since there is no restriction on their access. As such, these people carry specific bacteria to the keyboards, and since they are many, the keyboards end up being congested by different microbes (Enemuor et. al., 2013). In this study, the main bacterial strains found on the computer keyboards were B. subtilis and S. aureus, which is a clear reflection of the bacteria found in other past studies (Ali et. al., 2013, Anderson & Palombo, 2009, Alemu et. Al., 2015, Enemuor, et. al., 2013, Olduro et. al., 2013).The Bacillus species have been seen to be abundant since they have developed some survival tactics such as the ability to withstand dry heat, resistance to chemical disinfectants, and they have also developed resistance to environmental changes (Ali et. al., 2013).S. aureus is mostly found on the nostrils and the skin as a contaminant and can be transferred to the environment through skin contact and sneezing or coughing. This bacteria is a causative agent for various diseases including infections that involve the formation of pus (Enemuor, et. al., 2013).

Multiple user computers have been shown to have a higher bacterial load compared to single user computers (Anderson & Palombo, 2009). For instance, and people who are quite unhygienic and may be carriers of different types of pathogenic microorganisms may use the computers located in the library and the laboratory. Given that these two areas have high traffic all the time, some of the people may be sick and as such deposit some of those pathogens on the keyboards through physical contact or by air (Ali et. al., 2013). Single user computers, on the other hand, pose minimal risk of microbial presence since they are only accessed by one person. In addition, it is possible for an individual to maintain contamination procedures on single user computers compared to multi-user computers hence single user computers have a lower count of bacteria.

This study did not focus on the sterilization technique used by the university staff but based on the bacteria count of the samples collected from the University, it was evident that the sterilization procedure used were either ineffective or no sterilization procedures were used at all. When Disifil and Dettol were used they proved to be highly effective in reducing the load of the microbes. However, it is recommended that these disinfectants be regularly used or when there is a need to for them to be effective against microbes on the keyboards (Anderson & Palombo, 2009). Given that the gaps between the keyboard buttons and the corners are hard to access when cleaning the computers, they are the ideal breeding grounds for such microorganisms. In addition, the continuous use of computers causes them to heat up thereby providing appropriate temperatures for the growth of bacteria. Since multi-usercomputers are rarely cleaned and highly used, the chances of cross infection among the users is very high. Therefore, various strategies have been implemented to ensure there is low bacterial count in multi-user computers. For instance, the implementation of flexible keyboard covers made from polyutherane to protect the keyboard from dirt, dust, and liquids while allowing the user use the keyboard.

When it is placed on the keyboard, it gives a smooth surface with no corners that are easier to clean and does not allow the microbes to build up and multiply in the keyboard. The keyboard cover makes cleaning easy, and should be incorporated in a multi-userkeyboard environment. In addition, hand hygiene procedures may be implemented whereby a computer user washes his hands before and after using the computer for the purpose of reducing cross contamination and to increase the efficacy of flexible keyboard covers (Ali et. al., 2013, Saleh, 2015). These techniques, together with others including no eating and drinking near keyboards are crucial in reducing microbial contamination in multi-user computers. A constant disinfection procedure should also be implemented and strictly followed. In addition, computers should be covered and disinfected weekly to reduce the bacterial load (Enemuor, et. al., 2013).

The presence of bacterial colonies on the University keyboards proves the lack of knowledge on the importance of hygiene among the university population. the university should ensure that there is a safe environment for everyone thereby providing education on matters such as microbial contamination and hygiene (Alemu et. al., 2015).Community education concerning the risks posed by computer keyboards on microbial infection and the control measures to be talked need to be put in place to ensure that the population is able to deal with such risks. Following the awareness project, a responsible health, and hygienic procedure should be implemented on every publicly accessed keyboards (Kassem et. al., 2007). The health procedures should focus on increasing awareness of bacteria containing vectors including the skin and nasal passages which will be mandatory in reducing incidences that would otherwise increase the chances of microbial transfer and cross contamination through the keyboards (Kassem et. al., 2007). High traffic areas that require the use of computers including lecture halls, library, and the laboratory should have hand washes and sanitizers to ensure their use before and after using computers. This is crucial in preventing the spread of infectious diseases among the users through cross contamination. In addition, all the computers within the university need to be regularly cleaned and disinfected. These measures are crucial to both the staff and the student body of the university since the spread of diseases would lower the students’ performance thereby reducing productivity among the staff and at large lowering the university standards.

Limitations of the study

The study has a number of limitations. The first limitationis seen on the techniques used in swabbing the keyboards. Based on the location, the keyboards were swabbed on different areas. For instance, the keyboards in the resource center computers were swabbed from the Ctrl keys while the keyboards in the library were swabbed on the top keys. Past studies on the swabbing techniques are limited and the techniques used may have had an influence on the results of this study. In addition, computer mice have not been included in the study yet they are mostly used just like keyboards and therefore contain microbes. However, their role in bacterial cross contamination has not been left out (Awe et. al., 2013, Engelhert et. al., 2008, Hamzeh & Nawas, 2015, Hartmann et. al., 2004). As such, the exemption of mice in the study may have limited the scope of the research.

Secondly, the study is limited since it mainly concentrated on multi-user computers and touched less on single user computers. A comparison between the bacteria counts in multi-usercomputers and single user computers would have been crucial in providing more insight into the discussion part and recommendations. In addition, the fact that only three computers in each location were picked for the study limits the results since they are of a smaller number compared to the numbers used by previous researchers. For instance, Eltablawy & Elhifnawi (2009) used 24 computers for their studies and some other researchers used, even more, computers. This limited the study in that it may have affected the range of the microorganisms that were present.

In addition, the study was limited since it did not use the protocol for investigation that had been implemented by the University. If the protocol were followed, the bacteria count would have been done when their levels were expected to be highest and when they were expected to be lowest and this would otherwise provide conclusive results and fair conclusion on the same. Furthermore, the physical characteristics of the computer keyboards limit the study since they were not mentioned or observed in swabbing. The samples were collected from some older keyboards and some newer keyboards, rough and smooth keyboards among other variations without mentioning or specifying. This might have affected the type of bacteria found on the keyboards and their count as well.

Conclusion and Recommendations

Computer surfaces especially the keyboard and the mouse have been seen to play a crucial role in transmitting pathogenic microorganisms. Various strategies have been recommended for use in reducing the bacterial counts. Such strategies include hand washing and use of hand sanitizers, cleaning and disinfection procedures for the keyboard surfaces (Ali et. al., 2013, Saleh, 2015). It is, however, difficult for the university to enforce such strategies and ensure everyone follows them. It is, therefore,personal responsibility to ensure you follow the strategies for ones’ safety (Anderson & Palombo, 2009). Disinfectants have proved to be effective towards reducing the microbial count on keyboard surfaces rather than removing them completely. These disinfectants have been recommended for use regularly as well as when the need arises for them to be effective (Ali et. al., 2013, Enemuor, et. al., 2013; Messina et. al., 2013).In addition, some practices including eating and drinking on keyboards should be stopped to reduce the chances of cross-contamination.