MICRO BIOLOGY
5PY017 Pharmaceutical Microbiology
Evaluation of antimicrobial effectiveness of disinfectants
Abstract
A control experiment was performed to rule out the effects of the medium and neutralizer to allow us to see the effect of the disinfectant on the four organisms within a 5 minute range. The bacterial suspension used for paired at different concentration data was Staphylococcus Aureus for which gave good results when the reduction factor value of 1.20x106 ml-1 was obtained for the organism as it was above the value 105 which was used a guideline for effectiveness of the test.
For class data there was four organisms investigated which were: Staphylococcus Aureus, Enterococcus hirae, Pseudomonas aeruginosa and Escherichia coli. In general the disinfectant didn’t work as class data shows some organism values weren’t above the benchmark value of 105.
Intro
Disinfectants are agents that destroy many of the components of the micro-organism at once. These disinfectant agents are composed of many different ingredients such as sterile water and surfactants. The disinfectants will be used against both gram negative and gram positive bacteria. And data will be collected as to how much the disinfectant can reduce the count of the bacterial organism with a contact time of five minutes. We will judge whether this specific disinfectant can prevent bacteria from spreading.
Method
Refer to practical booklet
Pair Results
Count the cfu/plate and record in the tables below.
Bacterial Culture: Staphylococcus Aureus
Table 1 – This shows the results of the duplicates at the concentration of the 10-6 and the 10-7 along with the mean values
10-6
10-7
Duplicate 1
118
7
Duplicate 2
121
3
Mean cfu ml-1
119.5
5
Mean cfu ml-1 in undiluted* N
119.5x106 = 1.195x108
We used the dilution of 10-6 in the calculation to achieve the mean value against concentration as it was the most appropriate dilution
Evaluation of antimicrobial effectiveness of disinfectants
Abstract
A control experiment was performed to rule out the effects of the medium and neutralizer to allow us to see the effect of the disinfectant on the four organisms within a 5 minute range. The bacterial suspension used for paired at different concentration data was Staphylococcus Aureus for which gave good results when the reduction factor value of 1.20x106 ml-1 was obtained for the organism as it was above the value 105 which was used a guideline for effectiveness of the test.
For class data there was four organisms investigated which were: Staphylococcus Aureus, Enterococcus hirae, Pseudomonas aeruginosa and Escherichia coli. In general the disinfectant didn’t work as class data shows some organism values weren’t above the benchmark value of 105.
Intro
Disinfectants are agents that destroy many of the components of the micro-organism at once. These disinfectant agents are composed of many different ingredients such as sterile water and surfactants. The disinfectants will be used against both gram negative and gram positive bacteria. And data will be collected as to how much the disinfectant can reduce the count of the bacterial organism with a contact time of five minutes. We will judge whether this specific disinfectant can prevent bacteria from spreading.
Method
Refer to practical booklet
Pair Results
Count the cfu/plate and record in the tables below.
Bacterial Culture: Staphylococcus Aureus
Table 1 – This shows the results of the duplicates at the concentration of the 10-6 and the 10-7 along with the mean values
10-6
10-7
Duplicate 1
118
7
Duplicate 2
121
3
Mean cfu ml-1
119.5
5
Mean cfu ml-1 in undiluted* N
119.5x106 = 1.195x108
We used the dilution of 10-6 in the calculation to achieve the mean value against concentration as it was the most appropriate dilution