1
Sources of the Environmental Nosocomial Infections and the
2
Bactericidal Efficiency of the Disinfectant Using in Wards at
3
Maharat Nakhon Ratchasima Hospital
4
5
Atchareeya Choungngam1 and Tassanee Saovana2
6
Suranaree University of Technology. 111 Muang District, Nakhon Ratchasima,
7
30000, Thailand. E-Mail: lin_atcha@hotmail.com
8
9
Abstract
10
This study investigated sources of the environmental nosocomial infections (NI)
11
in wards at Maharat Nakhon Ratchasima Hospital. The 415 samples were
12
collected from various environmental sources within common wards. It was
13
found that the important microorganisms were Pseudomonas aeruginosa (Ps.
14
aeruginosa), Stenotrophomonas maltophilia (S. maltophilia), Acinetobacter
15
baumannii (A. baumannii), Klebsiella pneumoniae (K. pneumoniae), Escherichia
16
coli (E. coli) and Enterobacter cloacae (E. cloacae). These microorganisms could
17
associated with human diseases. They were found in most of the environmental
18
sources within wards except in plaster on patient’s skin, 70% alcohol and
19
providine® antiseptic solutions. Therefore, study about bactericidal efficiency of
20
the disinfectants which were commonly used in wards (savlon 1:100, pose-cresol
21
and sodium hypochlorite 1:20) were obtained from Pharmacy Department and
22
unused disinfectants of ward stocks. From this test, Ps. aeruginosa ATCC 15442
23
was killed by sodium hypochlorite (1:20) but not savlon® (1:100) and pose-
24
cresol® . Then, the repeated tests for 2 disinfectants with the low efficiency
25
disinfectants were freshly prepared by Pharmacy Department. It was found that
-1-
1
savlon® (1:100) could kill Ps. aeruginosa ATCC 15442 only within 48 hours while
2
it stated to be expired 7 days after dilution. Pose-cresol® could not kill Ps.
3
aeruginosa ATCC 15442 within 24 hours while it stated to be expired 30 days
4
after dilution. So, the savlon® (1: 100) can be used to be the disinfectant solution
5
within 48 hours, after that it can be used to reduce smell and clean the sexual
6
organ only. In the present, the pose-cresol® is not used for soaking clinical
7
thermometer anymore because it has no bactericidal activities.
8
Keyword: environmental nosocomial sources, Pseudomonas spp., bactericidal
9
efficiency, disinfectant, wards, Maharat Nakhon Ratchasima Hospital
10
11
Introduction
12
Nosocomial infections (NI) are the major health problems in both developed and
13
developing countries. It is associated with a high mortality rate and the cost of
14
treatment is enormous. NI were the significant problems throughout the world and
15
keep increase every year (Alvarado, 2000).
16
In Thailand, the NI surveillance reported that there were 11.7% of incidence
17
rate and 7% of mortality rate or 14000 cases in 1988 which lost about 1000 million
18
bahts per year (Danchaivijitr and Choklolkaew, 1988). Urinary tract infections (UTIs)
19
are the most common type of nosocomial infections since there are 40% of UTIs from
20
all NI in hospitals per year (Burke and Zavasky, 2009). In addition, several studies
21
have reported that about 80% of nosocomial UTIs occur after using instrumentation,
22
especially catheterization (Asher et al., 1988). Because nearly 10% of all hospitalized
23
patients are catheterized, preventing UTIs during catheterization was a major factor to
24
decrease nosocomial infections. Most nosocomial UTIs were caused by gram-
25
negative coliform bacteria, particularly Escherichia coli (E. coli), Pseudomonas spp.
-2-
1
and organisms from the Enterobacter group (Haley et al., 1985). Within the hospital,
2
Pseudomonas aeruginosa (Ps. aeruginosa) was a major cause of urinary tract
3
infection and was commonly found in the environment e.g. soil, water and other moist
4
locations (EHA Consulting Group, Online, 2011). The treatment for Ps. aeruginosa
5
infection is difficult, in part because of this organism’s antibiotic resistance. Therefore
6
it is common and is becoming more widespread (George, 1998).
7
In 2010, Maharat Nakhon Ratchasima Hospital reported that there were 128
8
cases of NI from 1,441 chart reviews. There were 27 cases of the nosocomial UTIs
9
which were the most sites of infections (12 cases were on foley’s catheterization)
10
(Maharat Nakhon Ratchasima Hospital, 2010).
11
In Thailand, the environmental NI sources in the hospitals and the
12
disinfectants efficiency were not reported. Therefore, this study investigated the
13
important bacteria from the environments which could be the sources of NI and
14
investigated the bactericidal efficiency of the diluted chemical disinfectants that were
15
commonly used in wards. The results from this study will be the informations to be
16
aware and to develop the preventive measures to reduce the incidence of NI in
17
Maharat Nakhon Ratchasima Hospital and other hospitals.
18
19
Materials and Methods
20
1. The environmental nosocomial infection sources
21
Specimens from the environmental sources were taken from 31 wards of 6
22
departments at Maharat Nakhon Ratchasima Hospital. The specimens were cultured
23
for Pseudomonas spp., Stenotrophomonas maltophilia (S. maltophilia), Acinetobacter
24
baumannii (A. baumannii), Klebsiella pneumoniae (K. pneumonia), E. coli and
-3-
1
Enterobacter cloacae (E. cloacae). Total amount of investigated samples were 415
2
samples.
3
The environmental sampling sources were
4
1. Plaster on patient’s skin
5
2. Hand-wash basins (nursing area)
6
2.1 Sink for hand wash (nursing area)
7
2.2 Faucet aerators for hand wash (nursing area)
8
2.3 Bar soap for hand wash or faucet for hand wash solution (nursing
9
10
area)
3. Equipment wash basin
11
3.1 Sink for equipment wash
12
3.2 Faucet aerators for equipment wash
13
4. Potable water for patients (ward provides)
14
5. Antiseptic solution (during use)
15
5.1 70% alcohol
16
5.2 Providine® antiseptic solution
17
6. 0.9% normal saline solution (during use)
18
7. Patient’s mattress
19
8. Patient’s coat (before use)
20
9. Patient’s coat (after use)
21
10. Air conditioner (air grille)
22
11. Flush toilet
23
The specimens from the environments were kept by cotton swabs moistened
24
with sterile 0.9% normal saline solution and place the swabs in transport medium by
25
steriled technique and transferred to the blood agar plates and Mac Conkey agar
-4-
1
plates. All plates were incubated at 35-37°C for 24 h. Suspected colonies were grown
2
in trypticase soy broth (TSB) at 35-37°C for 5 h. and then identified by biochemical
3
tests (Donna and Grace, 1975).
4
2. The bactericidal efficiency of the chemical disinfectants
5
2.1 The preparations of the chemical disinfectants
6
Nine samples (3 diluted chemical disinfectants x 3 samples) of unused diluted
7
chemical disinfectants from wards’s stock which were supplied by Pharmacy
8
Department at Maharat Nakhon Ratchasima Hospital were determined for the
9
efficiency of disinfectants against Ps. aeruginosa ATCC 15442. The diluted chemical
10
disinfectants which were commonly used were savlon, pose-cresol and sodium
11
hypochlorite.
12
Two chemical disinfectants were prepared by Pharmacy Department as follow
13
Savlon® (1.5% chlorhexidine gluconate: 15% cetrimide) was diluted with
14
steriled water in a ratio 1:100.
15
5 gm. pose-cresol® was diluted with 1,000 ml. steriled water.
16
Another chemical disinfectant was prepared by ward by diluted sodium
17
hypochlorite with water from faucet aerator in a ratio 1:20.
18
19
2.2 The efficiency of disinfectants tested by the AOAC Use-dilution test
(Kenneth and Association of Official Analytical Chemists, 1990).
20
2.2.1 Test organisms preparation
21
The bacteria that used for testing was Ps. aeruginosa ATCC 15442. They
22
were cultured for 48 h. at 37°C in 10 ml. trypticase soy broth (TSB). Bacteria culture
23
were then collected and put into a beaker size 100 ml. Amount for testing was about
24
20 ml.
25
-5-
1
2.2.2 Carriers preparation
2
Cleaned carriers (10 carriers per one bacteria) were put into 1N sodium
3
hydroxide overnight before washing them by distilled water for many times. Let the
4
carriers dried and then put them into 0.1% asparagin solution and sterilized at 121°C
5
for 15 min.
6
2.2.3 Use-Dilution method
7
1. All 10 carriers were transferred into the beaker containing bacteria
8
culture (from 2.2.1). After 10 min., the steriled forceps were then used to remove each
9
carrier, put it on the steriled filter paper that was on the bottom inside the steriled petri
10
dish in vertical position with the same distance between each of them, closed the petri
11
dish and then incubated at 37°C for 60 min.
12
13
2. Each sample of diluted chemical disinfectants was prepared and used for
testing. Ten tubes were used per 1 sample and each tube contained 5 ml. of sample.
14
3. The prepared carriers were put into the tube dilution (1 carrier per 1
15
tube). The timer was started when the first carrier was put into the first tube, the next
16
carrier was put into the following tube by 1 minute apart until finished. After 10
17
minutes, each carrier, which was in the diluted disinfectant tube, was transferred into
18
subculture media by steriled technique using holdfast hooked the carrier. The first
19
carrier was transferred first, followed by the rest by 1 minute apart until finished.
20
4. The carriers were cultured in the subculture tubes for 48 h. at 37°C and
21
the turbidity in the subculture tubes were observed and reported as the positive results.
22
5. The efficiency tests were performed by the AOAC Use-dilution test from
23
the first day of preparations until the expired day by 2 days interval (1, 3, 5,…).
24
25
-6-
1
2.2.4 Evaluation
2
The evaluation for the efficiency of disinfectants should have no bacterial
3
growth in any of the ten subculture tubes with diluted disinfectants. If the growth of
4
Ps. aeruginosa ATCC 15442 was found in even one tube, indicating that dilution in
5
the group of samples did not safe enough to use for killing the bacteria.
6
3. The bactericidal efficiency of the low efficient disinfectants before the expired
7
date
8
The efficiency test of the low efficient disinfectants was repeated by 2 days
9
intervals after preparations to prove whether it was efficient or not before the expired
10
date. The low efficiency disinfectants were freshly prepared by Pharmacy
11
Departmentat at Maharat Nakhon Ratchasima Hospital. The efficiency tests were
12
performed by the AOAC Use-dilution test from the first day of preparations until the
13
expired day by 2 days interval (1, 3, 5,…).
14
15
Results
16
Pseudomonas spp., A. baumannii, K. pneumoniae, E. coli and E. cloacae in the
17
environmental NI sources in wards at Maharat Nakhon Ratchasima Hospital were
18
studied. The results were shown in table 1. Bacteria were found in most of the
19
environmental sampling sources within wards except in 70% alcohol and providine®
20
antiseptic solutions. Burkholderia cepacia, Burkholderia mallei and Burkholderia
21
pseudomallei were not found in most of the environmental sampling sources. The
22
microorganisms found in the environments were A. baumannii which was found 13.01%
23
(54 specimens); Ps. aeruginosa which was found 7.22% (30 specimens) and K.
24
pneumoniae which was found 4.57% (19 specimens). The environmental sampling
25
sources which were found the most number of species of screened microorganisms were
-7-
1
the sink for equipment wash (28 specimens), the sink for hand wash (nursing area) (26
2
specimens) and the flush toilet (20 specimens).
3
Table 2 showed that sodium hypochlorite (1:20) was the most effective
4
disinfectant against Ps. aeruginosa ATCC 15442 since
no bacterial growth was
5
occurred in any of the ten subculture tubes with diluted disinfectants. While savlon®
6
(1:100) and pose-cresol® did not pass the criteria because Ps. aeruginosa ATCC 15442
7
was found 3-8 tubes within 48 hours, indicating that both diluted chemical disinfectants
8
could not kill the Ps. aeruginosa ATCC 15442 even before the expired date. To confirm
9
the results, the freshly prepared chemical disinfectants by Pharmacy Department were
10
repeated to check for the really efficiency from the first day of preparations until the
11
expired day by 2 days interval (1, 3, 5,…). The results were shown in table 3. The
12
efficiency tests were shown that savlon® (1:100) could kill Ps. aeruginosa ATCC 15442
13
within 2 days only but pose-cresol® could not possibly kill Ps. aeruginosa ATCC 15442
14
even within the first day of preparation, suggesting that both savlon® (1:100) and pose-
15
cresol® had very poor efficiency, they did not work efficiently as it stated in the
16
manufactory details.
17
18
Discussion
19
The important microorganisms were found in most of the collected environmental
20
sources, except in plaster on patient’s skin, 70% alcohol and providine® antiseptic
21
solutions in common wards at Maharat Nakhon Ratchasima Hospital. The species of
22
Pseudomonas found in the environmental sources were Ps. aeruginosa and S.
23
maltophilia. These two Pseudomonas spp. caused the human diseases.
24
In general, the medical equipments such as the central lines of the ventilators and
25
catheters which make from plastics are steriled by gas sterilization, other equipments
-8-
1
such as scalpels and speculums are steriled by autoclave. But there are some medical
2
equipments that cannot be steriled by autoclave or hot air ovens such as the
3
thermometers, thus pose-cresol® solution is used to soak for reducing the pathogens.
4
Normally, the antiseptic solutions (70% alcohol, providine®) and isotonic solution
5
(0.9% normal saline) are used for wound dressing on the skin. For urogenital tract
6
which has the sensitive soft tissue cannot use 70% alcohol or providine to be the
7
antiseptic solutions because it will irritate the soft tissue. In the past, external genital
8
wash before pervagina (PV) examination or washing when the genital organ had the
9
infection, every hospital used savlon® (1:100) to clean the external genital organ, but
10
later, it was found that savlon was out of standard and used savlon ® or not were not
11
different. After that, some hospitals changed to use 0.9% normal saline solution to clean
12
the urogenital tract. Thus, many hospitals change the solutions used for cleaning the
13
organisms or wounds of the patients. The 0.9% normal saline solution or savlon® 1:100
14
are used for flush vulva before insert the urinary catheters, during on catheterizations
15
and before cervical examinations. For the patients with cervical cancer, the savlon®
16
1:100 was used only to reduce smell.
17
Some wards at Maharat Nakhon Ratchasima Hospital usually used savlon®
18
1:100 to clean the sexual organ (flush vulva before insert urinary catheters, during on
19
catheterizations, before cervical examinations, and reduce smell for the patients with
20
cervical cancer) which different from Siriraj Hospital and Songklanagarind Hospital
21
that used 0.9% normal saline solution for clean the sexual organ, while used savlon ®
22
1:100 for reduce smell from cervical cancer patients only.
23
Normally, the disinfectant solutions using in the hospitals must not have the
24
bacteria. Surprisingly, in this study, bacteria (Ps. aeruginosa and A. baumannii) were
25
found in 0.9% normal saline solution (during used). This solution is usually used for
-9-
1
wound dressing and locking the blood vessel to give the medicine through the vessel.
2
By observing and interviewing the nurses, it was found that sometimes they used
3
0.9% normal saline solution for over than 24 h. after opening the bottles without
4
specify the opened time. Moreover, the researcher discovered that the 0.9% normal
5
saline solution bottle had been punctured by the syringe and it was still remaining on
6
the rubber cork which might be contaminated by the bacteria that passed into the
7
bottle. When the contaminated solution was used with the patients, it would cause the
8
wound and the blood vessels to be infected in the other way (Pattarachai, 2006).
9
From the bactericidal efficiency test of disinfectants used in wards at Maharat
10
Nakhon Ratchasima Hospital, the only chemical disinfectant that passed the criterion
11
which was able to kill the Ps. aeruginosa ATCC 15442 was sodium hypochlorite
12
(1:20) while savlon® (1:100) and pose-cresol® did not pass the criteria. Therefore, the
13
researchers were interested in savlon® (1:100) and pose-cresol® because they were out
14
of use before the expired day. Then, the repeated tests for these two disinfectants with
15
the low efficiency disinfection were freshly diluted by Pharmacy Department at
16
Maharat Nakhon Ratchasima Hospital and tested for bactericidal efficiency from the
17
first day that were diluted until the expired day (tested 2 days interval). The efficiency
18
disinfected results showed that savlon® (1:100) was able to pass the criteria (no
19
bacterial growth in any of the ten subculture tubes) within 48 h. after dilution.
20
However, its bactericidal effect on Ps. aeruginosa ATCC 15442 did not pass the
21
criteria after 48 h, indicating that this diluted disinfectant did not work efficiently as it
22
stated in the manufactory efficiency rate of 7 days. Furthermore, Maharat Nakhon
23
Ratchasima Hospital had ever used pose-cresol® for soaking clinical thermometers,
24
but the bactericidal efficiency test of pose-cresol® had produced a very poor result
25
indeed. It was not able to kill Ps. aeruginosa ATCC 15442 within 24 h. even the time
- 10 -
1
that it had stated to expire was 30 days. In the present, the pose-cresol® is not used for
2
soaking the clinical thermometers anymore because it has no bactericidal activity.
3
The results came to the conclusion of these tests that both savlon® (1:100) and
4
pose-cresol® had very poor efficiency, they did not work efficiently as they were
5
stated in the manufactory details. If they continued to be used at the same
6
concentrations in the hospitals, it would be danger to risk for spreading the bacteria
7
from one patient to another.
8
The causes of errors in such standard dilution of the chemical disinfectants that
9
were used in the hospitals could be possibly due to their low quality, low constant or
10
efficiency over dilution for saving the cost. Out of standard disinfectant solutions
11
which were produced by the companies could also be the important parts in the
12
quality of the chemical disinfectants which were diluted and used in the hospitals.
13
Other factors, the mixing containers and the environments around the mixing areas
14
were also important. By using the low quality chemical disinfectants, there was a high
15
risk rate because it was not only harmful to the patients directly but it also caused
16
nosocomial infections and it could spread outside the hospitals later on. The
17
effectiveness of the chemical disinfectants used in the hospitals has been concerned
18
for many years. One hundred and two samples of the chemical disinfectants from 32
19
hospitals throughout the country were tested for their disinfectants qualities. The
20
results showed that 43.1% samples were out of standard (Department of Medical
21
Sciences Center of Thailand, 1993). Thus, the chemical disinfectants which were out
22
of standard, they were one of the harmful reasons for nosocomial infections.
23
Therefore, the determinate expired day of savlon which is diluted with steriled water
24
in a ratio 1:100 bases on the stability factors (physical stability and chemical stability)
25
of the productions in each hospital. Moreover it depends on the preparation of steriled
- 11 -
1
water for dilution, the packaging size and the method for cleaning the package before
2
pouring to the chemical disinfectants (Wallaporn Theanthong, Online, 2011).
3
The informations about sources of the microorganisms found in wards were
4
reported to the head of Infection Control at Maharat Nakhon Ratchasima Hospital for
5
control and prevention management and reported to the head of Pharmacy Department
6
at Maharat Nakhon Ratchasima Hospital about the efficiency of the diluted chemical
7
disinfectants which were out of standard. It is very important to control the quality of
8
the chemical disinfectants which were diluted and used in the hospitals.
9
Today, Maharat Nakhon Ratchasima Hospital and many hospitals do not use
10
pose-cresol® anymore because it is not difference between using it or not since it was
11
confirmed by the very poor bactericidal efficiency results.
12
13
Acknowledgements
14
I am deeply indebted to Assistant Professor Dr. Benjamart Chitsomboon, Assistant
15
Professor Dr. Griangsak Eumkeb, Assistant Professor Dr. Rungrudee Srisawatt, Dr.
16
Pongrit Krubphachaya, the School of Biology, Suranaree University of Technology
17
and Dr. Pramote Suginpram for their kindly assistances and suggestions.
18
19
References
20
Alvarado, C.J. (2000). The Science of Hand Hygiene: A self-study monograph.
21
University of Wisconsin Medical School and Social-Health Communications. (n.p.).
22
Danchaivijitr, S. and Chokloikaew, S. (1989). A nation prevalence study on
23
nosocomial infection 1988. Journal of Medical Association of Thailand, 72(2):
24
13.
25
George, A.W. (1988). Bacteriology. 5th ed. Prentice Hall, America. 424p.
- 12 -
1
Kenneth, H. and Association of Official Analytical Chemists. (1990). Official
2
Methods of Analysis of the Association of Official Analytical Chemists.
3
Arlington, VA: The Association of Official Analytical Chemists, 684p.
4
Maharat Nakhon Ratchasima Hospital. (2010). A Point Prevalence Survey on
5
Nocosomial Infections in Maharat Nakhon Ratchasima Hospital. Nakhon
6
Ratchasima. (n.p.).
7
8
9
10
Theanthong, W. (2010). Drug Pharmacy. Songklanagarind Hospital. Available from:
www.drug. pharmacy. psu.ac.th. Accessed date: Feb 12, 2011.
EHA Consulting Group. (2012). What is Pseudomonas aeruginosa? Available from:
www.ehagroup.com. Accessed date: May 14, 2012.
11
Haley, R.W., Culver, D.H. and White, J.W. (1985). The efficacy of infection
12
surveillance and control programs in preventing nosocomial infections in
13
USA hospitals. American Journal of Epidemiology. 121(1): 182-250.
14
Lim, V. K. E. and Path, F.R.C. (1995). Disinfection and the Control of Nosocomial
15
Infection. Available from: www. e-mjm.org. Accessed date: May 16, 2012.
16
17
18
Donna, J.B. and Grace, M.E. (1975). Principles of Biochemical Test in Diagnostic
Microbiology. Wiley, NY, 135p.
Burke, J.P. and Zavasky, D.M. (2009). Epidemiology of hospital acquired urinary
19
tract infections in a medical college hospital in Goa Indian. Journal of the
20
Urological Society of India. 25(1): 76-80.
21
22
23
24
Asher, E.F., Oliver, B.G. and Fry, D.E. (1988). Urinary tract infections in the surgical
patient. Journal of the American Surgery. 54(1): 466–469.
Pattarachai, G. (2006). Textbook of Medical Bacteriology. Bangkok: V.J. Printing.
730p.
25
- 13 -
1
Table 1. Type of the microorganisms which were isolated from the
2
environmental sources in wards at Maharat Nakhon Ratchasima
3
Hospital (415 samples)
Micoorganisms
Ps.aeruginosa
S.
A.
K.
E.coli
maltophilia
baumannii
pneumoniae
E.
Total
cloacae
+ ve
The environmental
sources
1. Sink for hand
9
3
8
2
2
2
26
3
3
10
1
1
0
18
3
0
1
2
0
3
9
4
1
12
8
2
1
28
4
1
9
2
0
0
16
0
0
2
0
0
0
2
1
0
1
0
0
0
2
8. Patient’s mattress.
0
0
3
1
0
0
4
9. Patient’s coat
0
0
1
0
0
0
1
wash
(nursing area)
2. Faucet aerators
for hand wash
(nursing area)
3. Bar soap for hand
wash or faucet
for hand wash
solution
(nursing area)
4. Sink for equipment
wash
5. Faucet aerators for
equipment
6. Potable water for
patients
(ward provides)
7. 0.9% normal
saline solution
(during use)
(before use)
- 14 -
Table 1. (Continued)
Micoorganisms
Ps.aeruginosa
S.
A.
K.
E.coli
maltophilia
baumannii
pneumoniae
E.
Total
cloacae
The environmental
sources
10. Patient’s coat
1
0
0
0
2
0
3
1
0
0
0
0
0
1
12. Flush toilet
4
0
7
3
5
1
20
Total
30
8
54
19
12
7
130
7.23
1.93
13.01
4.58
2.90
1.69
31.34
(after use)
11. Air conditioner
(air grille)
Percentage from
415 samples
1
2
Notes
3
Ps. aeruginosa = Pseudomonas aeruginosa
4
S. maltophilia = Stenotrophomonas maltophilia
5
A. baumannii = Acinetobacter baumannii
6
K. pneumoniae = Klebsiella pneumoniae
7
E. coli = Escherichia coli
8
E. cloacae = Enterobacter cloacae
9
10
11
12
- 15 -
1
Table 2. The bactericidal efficiency of diluted chemical disinfectants used in
2
wards at Maharat Nakhon Ratchasima Hospital
Diluted chemical disinfectants
Lab Results
Date
positive samples/ total samples
Diluted
Expired
day1*
day 3*
date
date**
Sample 1
3/10
4/10
10/10
Sample 2
6/10
6/10
10/10
28/9/2008
5/10/2008
Sample 3
8/10
8/10
10/10
25/9/2008
2/10/2008
Sample 1
8/10
8/10
10/10
18/9/2008
18/10/2008
Sample 2
0/10
6/10
10/10
22/9/2008
22/10/2008
Sample 3
0/10
6/10
10/10
22/9/2008
22/10/2008
Sample 1
0/10
0/10
0/10
1/10/2008
29/10/2008
Sample 2
0/10
0/10
0/10
1/10/2008
29/10/2008
Sample 3
0/10
0/10
0/10
1/10/2008
29/10/2008
day 5*
Savlon® 1:100
25/9/2008
2/10/2008
Pose-cresol®
Sodium hypochlorite 1:20
3
4
Notes
5
* collected samples on 1/ 10/ 2008 and 2 days interval
6
** Expired date that was stated in the manufactory details
7
8
- 16 -
1
Table 3. The repeated bactericidal efficiency of diluted chemical disinfectants
2
with low efficiency from freshly prepared by Pharmacy Department at
3
Maharat Nakhon Ratchasima Hospital
Diluted chemical disinfectants
Lab Results
positive samples/ total samples
day1*
day 3*
day 5*
Savlon® 1:100
Sample 1
0/ 10
7/ 10
10/ 10
Sample 2
0/ 10
6/ 10
10/ 10
Sample 3
0/ 10
6/ 10
10/ 10
pose-cresol®
Sample 1
10/ 10
-
-
Sample 2
10/ 10
-
-
Sample 3
10/ 10
-
-
4
5
6
Notes
* collected samples on 30/ 10/ 2008 and 2 days interval
7
- 17 -