1.
Comparative Efficacy Of Hand Sanitizers And Liquid Soaps Against Commonly Encountered Microbes On The Experimentally Contaminated Palm Surfaces
by Taiba Tahir | Dr.Jawad Nazir | Prof Dr | Prof Dr. Khushi Muhammad.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2013Dissertation note: Hand hygiene plays a key role in the prevention, control and reduction of many communicable infections as contaminated hands are the major source of transmission for microbes. Three categories of hand hygiene products; hand sanitizers (Safeguard, Dettol, and Cool & Cool hand sanitizers), antibacterial soaps (Safeguard, Dettol, and Lifebuoy liquid soaps) and plain soaps (Lux, Capri, and Pears liquid soaps) were evaluated against five bacterial cultures (E. coli, K. pneumonia, Salmonella. spp, S. aureus, P. aeruginosa) for their antibacterial activity through in vivo and in vitro techniques. In vivo testing was performed through palmar surface contamination techniques. Palm surfaces of volunteers' hands were artificially contaminated followed by recovery of the bacteria through glove juice method both before and after the application of product for 30 seconds. Each of the experiment repeated thrice and means log reduction (MLR) in the bacterial count after the application of each product was calculated. In vitro efficacy of hand hygiene products was carried out through calculation of minimum inhibitory concentration (MIC) and phenol coefficient values.
MLR values of the sanitizers were ranged from 2.0 - 5.5 log10 CFU/ml, while that of antibacterial and plain soaps were 3.0 - 4.1 and 3.0 - 4.6 log10 CFU/ml. MIC values for the sanitizers, antibacterial, and plain soaps were ranged from 1:10 - 1:40, 1:6 - 1:20, and 1:2 - 1:8 against all of the 5 bacteria. Hand sanitizers were proved to be superior to medicated and plain soaps during in vivo and in vitro testing. Both of the antibacterial and plain soaps were equally effective in reducing bacterial load on the contaminated hands because during hand washing procedure mechanical removal of contaminants through surfactant activity of soaps is mostly responsible for the removal of bacteria. While a relatively higher MIC values of the antibacterial soaps were attributed to the presence of certain antibacterial agents in them. It was not possible to calculate the phenol coefficient values for any of the hand hygiene product because even least dilutions (1:2) of the products did not stop the bacterial growth. Present study emphasizes the suitability of using hand sanitizers in health care centers as well as in routine life. Because of comparable efficacy of medicated and plain soaps, excessive use of antibacterial soaps should be avoided due to risk of developing antibiotic resistance.
Availability: Items available for loan: UVAS Library [Call number: 1662,T] (1).
3.
Physico-Chemical Factors Affecting In Vitro Stability And Activity Of Phytase From Indigenous Isolate Of Asperillus Therreus
by Safina kouser (2011-VA-422) | Dr. Aftab ahmad anjum | Dr.jawad nazir | Dr.Muhammad Yasir zahoor.
Material type: Publisher: 2017Dissertation note: Phytase is commercially important enzyme. Phytate in food and feed makes it less nutritive as well as acts as anti-nutritional agent. Phytate make complexes with important mineral ions and proteins. Monogastric animals and human are not able to degrade the phytate from plant based food because they lack phytase. This leads to phosphorous deficiency. Addition of phytase into food and feed degrades the phytate. It makes, phosphorous and mineral ions become available for growth and development. There is need to evaluate these factors in vitro which in real affect the stability and activity of enzyme under feed production process and digestive system of monogastric animals.
Indigenous Aspergillus terreus isolate produce stable phytase to be used in poultry feed.Indigenous strains of Aspergillus terreus were identified by macroscopic and microscopic characteristics. These isolates were screened on Phytate Screening Medium (PSM) for phytase production. Phytase producing A. terreus was than analyzed for toxin production through TLC (Thin layer chromatography). Non toxigenic phytase producing A. terreus isolates were inoculated in phytate broth for phytase production through submerged fermentation (SmF) under optimum conditions (28°C for 8-10 days). After centrifugation and filtration supernatants were used as crude enzyme. Phytase enzyme was qualitatively analyzed through phytase assay. Phytases activity units observed for isolate PAST-16 was highest (271.49±8.14 FTU/mL) and lowest (79.00±8.05FTU/mL) of PAST-05. A. terreus phytase (PAST-16) was subjected to temperature, pH and metal ions treatment.
Thermostability of phytases was recorted at 35°C, 55°C, 75 °C and 90°C for 15, 30, 45, and 60 minutes treatments. Enzyme from A. terreus (PAST-16) was observed as thermostable at
Summary
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35°C, 55°C, 75 °C but not much stable at 95°C. Phytases showed 87.23±6.59, 198.34±4.47, 188.59±8.77 and 259.25±0.84 FTU/mL decreased in activity after 60 minutes of treatment at 35°C, 55°C, 75 °C and 95°C temperatures, respectively.
pH stability of phytases was found at pH of 2, 4, 6 and 8 for 15, 30, 45, and 60 minutes treatments. Enzyme from A. terreus (PAST-16) was observed as pH stable at 4, 6 and 8 but not much stable at 2 pH. Phytases showed 206.14±6.37, 169.59±6.37, 110.13±6.75 and 171.54±3.04 FTU/mL decreased in activity after 60 minutes of pH treatments at 2, 4, 6 and 8, respectively.
Metal ions effect on phytase activity was found with Ba2+, Ca2+, Cu2+, Fe3+, K+, Mg2+, Mn2+ and Na+ at the concentration of 1, 5 and 10mM. Enzyme from A. terreus (PAST-16) was observed as shows activity more with K+ less with Na+. Phytases showed 45.32±28.54 and 219.30±11.04 FTU/mL decreased in activity after 1mM conc. of K+ and 10mM conc of Na+, respectively.
Conclusion:
A.terreus isolate (PAST-16) produce stable phytase enzyme used in feed of poultry. In this way it tolerates condition under which feed process at commercial level and under digestive system monogastric animals. Availability: Items available for loan: UVAS Library [Call number: 2825-T] (1).
