| Summary: | 碩士 === 慈濟大學 === 公共衛生學系碩士班 === 99 === In recent decades, the increase in antibiotic-resistant bacteria has become one of the
most significant problems in public health. Titanium dioxide (TiO2) has the potential to
inactivate antibiotic-resistant bacteria.
In this study, TiO2 that had been activated by ultraviolet A (UV-A) irradiation was used
to inactivate the following three antibiotic-resistant bacteria in suspension:
methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Acinetobacter
baumannii (MDRAB) and vancomycin-resistant Enterococcus faecalis (VRE). For
comparison, the following antibiotic-sensitive strainswere used as controls: S. aureus
(MSSA), A. baumannii (MDSAB), E. faecalis (VSE), Escherichia coli and the bacteriophage
MS2. Results demonstrated that MSSA and MRSA were equally susceptible to TiO2
photocatalysis, and the susceptibility of MDRAB was double that of MDSAB ( p < 0.05). The
susceptibility of VSE was 2.4 times that of VRE ( p < 0.05).
The results obtained from multiple regression analysis indicated that TiO2 reaction time
had the greatest influence onmicrobial survival following TiO2 exposure in the presence of
UV-A. The development of antibiotic resistance does not appear to be correlated to increased
resistance to TiO2 photocatalysis, but TiO2 in the presence of UV-A still effectively reduces
the number of antibiotic-resistant microbes in suspension by 1–3 logs.
In the second part of the experiment, since the first part of the experiment is extended
out of the aim of Acinetobacter baumannii (17978WTAB) and Colistin-resistant acinetobacter
baumannii (17978CRAB) and the correlation between the photocatalyst. The results showed
that, the susceptibility of 17978WTAB was 2.46 times that of 17978CRAB ( p <0.01). The
results from multiple regression analysis found that, in addition to TiO2 concentrations, the
VI
other variables for the survival rate has significant effects ( p <0.05), which TiO2 reaction
time is the greatest impact on strain survival factor. Additional use of non-culture method -
analysis of sodium dodecyl sulfate Polyacrylamide gelelectrophoresis(SDS-Page) with
silver-stained analysis when the CRAB and WTAB increase reaction time, the decline in the
quality assessment of protein found in the supernatant or pellet only WTAB reduced protein
quality (12-hour and 24 sterilization hours) has reached a statistically significant difference
( p <0.05). In the culture and non-culture on both clearly observed WTAB and CRAB
resistance of the titanium dioxide photocatalyst differences, therefore, further analysis using
two-dimensional gel electrophoresis analysis CRAB and WTAB cell wall and membrane in
the presence of impact sensitivity of photocatalyst differences in protein, indeed, that may be
caused by several more protein let CRAB has strong resistance on the photocatalyst,
respectively: the membrane associated putative ABC1 protein, putative lipoprotein, as well as
antioxidant-related protein alkyl hydroperoxide reductase C22 subunit (AhpC), and
biofilm-related CsuA / B, heat shock protein molecular chaperone DnaK, and cell wall
formation in connection with D-alanine - D-alanine ligase.
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