Introduction
One of the major causes of HAIs that is associated with patient morbidity and mortality is fomites.1, 2 In hospitals, fomites can serve as a reservoir of pathogens being spread from the inanimate environment to an animate (patient) environment via the hands of health care workers (HCW).3, 4, 5 To reduce morbidity and mortality in hospitals, identification of common fomites associated pathogens in any hospital settings is important. Because, the most important factor in prevention of a disease is to simply identify what has been transferring the disease.
Among the vast range of fomites, door handles is one of the most common one, which serves as route for contamination. Hard and nonporous surface allows more adhesion of bacteria to it. Due to having such a surface, door handles provide the highest rate of bacterial transfer to the hands.6
Bacterial pathogens that have been isolated from door handles in previous studies includes S. aureus, K.pneumonia, E. coli, Enterobacter spp, Citrobacter spp, P. aeruginosa, Proteus spp, Streptococcus spp, Salmonella spp, Shigella spp, Campylobacter spp.7, 8 These organisms have been known to cause one or more diseases that are mild and could be sometimes serious. The examples of such diseases range from simple skin diseases like pimple, impetigo, scalded skin syndrome to respiratory diseases like, pneumonia to even severe meningitis, osteomyelitis, rhinoscleroma, kidney failure, septicemia and so on.9
Toilets act as a vehicle for the transmission of pathogens from gut, respiratory tract and skin via hands and surfaces from one person to another. Later, when another person holds that door handle, the bacteria can pass on. In adverse situation, such a transfer may even bring about outbreaks of infection.10
The hands serve as a medium for the propagation of microorganisms from place to place and from person to person. Although, it is nearly impossible for the hand to be free of microorganisms, the presence of pathogenic bacteria may lead to chronic or acute illness. Human hands usually harbor microorganisms both as part of the body normal flora as well as transient microbes collected from the environment.11
The occurrence of this may be attributed to the unhygienic use of the toilet facilities, which results to the filthy contamination of the place including door-handle, which individuals are less likely to see as contaminated.12 Improper use of the toilets, inadequate cleanliness of the toilets facilitates transmission of bacteria from the toilets to even household living rooms. Contaminated hands of toilet users can transmit the bacteria from their hands to the flushing handles, door handles and faucets of the toilets as well as household door handles and equipment. Toilet flushing results in a large quantity of flush aerosols, which can reach the seats and leads, surrounding floors and nearby surfaces. The ability of the pathogen deposited to survive on the different surfaces in the toilets poses a great risk of infection to the toilet users. 13 The time of survival depends on the type of pathogen, majority including Shigella species, Escherichia species, Clostridium species, severe acute respiratory syndrome (SARS) coronavirus, and norovirus which can survive on surfaces for weeks or even months. 5
Aims and Objectives
The aim of identify and evaluate the occurrence of bacterial contaminations form the door handles of washrooms of a hospital and their harmful consequence to public health.
Overall the main objectives were: To determine the presence of bacterial contamination, to isolate and identify both Gram-positive and Gram-negative bacteria, to determine the prevalence and antibiotic susceptibility pattern of bacteria isolated from washroom door handles of hospital.
Materials and methods
Study area
The study was carried out in the, Laboratory of the Department of Medical Lab Technology (Microbiology) of Rajeev Gandhi College and General Hospital, Bhopal.
Sample size
A total of 16 door handles of washrooms of Rajeev Gandhi College and General Hospital, Bhopal were included in this study.
Sample collection
The samples were collected from toilet door handles using the swab-rinse method. Door knobs/ handles were swabbed with sterile cotton swabs moistened with sterile normal saline. The swab was wiped firmly on the entire surface of the door handles/ knobs. It was then introduced into a test-tube containing sterile nutrient broth. Then it was immediately transported to the Microbiology Research Laboratory of Rajeev Gandhi College & General Hospital Bhopal for further processing and analysis. The test tube containing the sample incubated at 37ºC overnight.
Technique
After 24 hours, each sample was streaked onto Nutrient agar, MacConkey agar, Mannitol salt agar and Membrane fecal coliform agar plates. Four-quadrant streak plate technique was performed. All the plates were incubated for 24 hours at 37ºC. After the overnight incubation, the plates were observed for colony characteristics. Isolated colonies were then sub-cultured onto fresh nutrient agar. Single isolated colonies from nutrient agar plates were subjected to Gram staining, Spore staining and Standard Biochemical tests to identify the organism. Media used for biochemical tests are: Indole broth, Methyl Red (MR) broth, Voges-Proskauer (VP) broth, Simmons citrate agar, Triple Sugar Iron (TSI) agar, Motility Indole Urease (MIU) agar Nitrate reduction broth.
Plasmid extraction of the isolates were done according to the modified hot alkaline method by Kado and Liu.Modified hot alkaline method by Kado and Liu (Kado and Liu, 1981), Agarose gel electrophoresis.
Results
After performing the biochemical tests and observing cultural and morphological characteristics 43 isolates were identified from 16 different samples collected from hospital toilet doorknobs. The isolates include Staphylococcus spp., (found in 16 samples), Bacillus spp., (found in 8 samples), E.coli (found in 7 samples), Fecal coliform (found in 6 samples), Micrococcus spp., (found in 3 samples), Pseudomonas spp, (found in 2 samples), Klebsiella spp. (found in 1 sample).
Table 1
Prevalence of bacteria isolated from door handles of washrooms of a hospital
Table 2
Distribution of the isolates according to Gram’s Reaction
|
Isolates |
Number of isolates |
Percentage (%) |
|
Gram Positive |
27 (out of 43) |
62.8% |
|
Gram Negative |
16 (out of 43) |
37.2% |
Table 3
Percentage of isolates resistant to antibiotics
The most resistance was seen against penicillin G, with a number of 41(95.35%) isolates being resistant against it. Next to penicillin G, 32 isolates were resistant to SXT, giving a percentage of 65.12. The third highest resistance was seen against, amoxicillin where 32 (65.12) isolates were resistant to it. Whereas, the isolates were most sensitive toward gentamicin (2.33%) followed by resistance to chloramphenicol (4.65%) and streptomycin (6.98%).
Discussion
The result obtained from this study was that out of 16 samples 16 of them showed bacterial contamination. After conducting the biochemical tests, the isolates were confirmed as the following organisms: E. coli, Klebsiella spp., Micrococcus spp., Staphylococcus spp., Bacillus spp., Pseudomonas spp., and some other fecal organisms.
In this study, among the isolates, the most predominant bacteria were Staphylococcus spp., with a percentage of 37. This is anticipated as it is a major component of the normal flora of the skin and nostrils. The findings of other researchers. 13, 11, 8 is in accordance with this finding.
Staphylococcus species (54.7%) was the most frequent bacteria isolated in hospital environment. In contrast, the result of this study did not agree with the work of Orskov et al (2005) which showed that Staphylococcus aureus was the least isolated bacteria. 14
As mentioned before, Gram-positive bacteria are found more in the hospital fomites than Gram Negative one. This can become dangerous as Gram positive bacteria are causing more infections than ever before in surgical patients, who are increasingly aged, ill and debilitated. 15
Isolation of more Gram positive bacteria than Gram negative canbe explained, as they are members of the body flora of both asymptomatic carriers and sick persons. These organisms can be spread by the hand, expelled from the respiratory tract or transmitted by animate or inanimate objects. 16 Their main source(s) of colonization on the fomites might likely be nasal carriage by hospital personnel, 17 likely facilitated by hand-to-mouth or hand-to-nose contact while using these fomites, and/or by improper hand washing. Isolation of Staphylococcus aureus from almost all the fomites indicates their ubiquitous nature. Additionally, they can be sources of infection to patients as previously noted. 18, 4, 19
A high percentage of Bacillus spp. was isolated from hospital washroom door handles. This is also in agreement with the research carried out by Brooks et al., (2007) who reported that Bacillus spp. was found to be the predominant organism among all the organisms that were isolated from door handles.
Bacillus spp., the only Gram positive bacilli encountered in this study, has been isolated with the highest frequency in some studies in Nigeria. 4, 2 This organism forms endospores, which, allows them to settle well on the surface from fomites from air.
Although, Gram positive organisms were more frequently isolated in this study, the Gram negative bacterium E. coli was also isolated from toilet doorknobs. This indicates improper hand washing after the use of toilet.
Pseudomonas spp., and Klebsiella spp., and some fecal coliform bacteria were also isolated which are Gram negative. Micrococcus spp., which is Gram positive bacteria, was also isolated from hospital toilet door knobs.
From the findings in this study, it was observed that most of the isolates obtained were resistant to most commonly used antibiotics. These antibiotics are Amoxicillin, SXT and Penicillin G. The resistance to these antibiotics that antibiotic resistant microorganism contaminates environmental surfaces such as toilet. Moreover, reported that most of the isolates obtained in their study were resistant to commonly used antibiotics such as Amoxicillin and Ampicillin.
The plasmid profile showed the absence of plasmids for maximum isolates. The occurrence of plasmids in Gram negative bacteria was found. Eleven isolates including E.coli, Klebsiella spp., and fecal coliforms contained plasmid. Findings also indicated that isolates that were resistant to more than two antibiotics may harbor plasmid. Isolation of plasmids using agarose gel electrophoresis and observation under UV trans-illuminator showed the bands for the E.coli, Klebsiella spp., and other fecal coliforms with the molecular weights of plasmids ranging from approximately 8 to 85 MDal.
Conclusion
The causes of these infections in hospitals can be connected to increased microbial load of fomites of these places. The data from this study indicates that there is a high level of bacterial contamination on door handles of hospital washrooms. In this study most of the isolates were resistant to more than two antibiotics and plasmids were found in some multi-drug resistant organisms. Further study can be done to find out any correlation between multidrug resistance of bacteria and presence of plasmids. So, further research upon plasmid will also be very significant.
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