About The Study
This study was conducted at a major university's School of Medicine. The Microbiology Laboratory is a full-service facility capable of providing a wide variety of clinical studies on bacteria, fungi and viruses. The laboratory is accredited by the College of American Pathologists and certified by CLIA. In association with the School of Medicine’s Department of Pathology, the Microbiology Laboratory Conducts numerous studies related to new methods, technology evaluations, and clinical drug studies.
This study was conducted under the direction of a Ph.D. and Chief of Microbiology. They are also a professor of microbiology with the Department of Pathology and Laboratory Medicine, with over 30 years of experience in all areas of clinical microbiology and serves as a consultant to various state and federal agencies.
Method-Minimum Bacterial Concentration (MBC)
MIC panels were prepared by serially diluting the [Microbe Blast] compound with a broth diluent in a 96-well microtiter tray. From an initial dilution of 10:1 doubling dilutions were prepared to a final concentration of 1:5120. The organism suspension was prepared by emulsifying the organism in broth and adjusting the concentration until it was equivalent to a 0.5 McFarland turbidity standard (1 x10 8 Colony Forming Units/mL). This concentration was further diluted by pipetting 100mcl into a 25 ml tube of inoculum water yielding a final concentration of 4 x 105 CFU/ml. The organism suspension was then pipetted 1:1 into each of the microtiter wells containing the [Microbe Blast] dilutions. A positive control well containing the organism suspension without [Microbe Blast] solution and a negative control containing [Microbe Blast] solution without the organism suspension were prepared in the microtiter tray. The tray was then incubated for 24 hours. All wells demonstrating inhibited growth (no visible turbidity when compared to the controls) were subcultured to a TSA w/5% sheep blood agar plate. The plates were inspected after a 24 hour incubation. From these plates a determination was made regarding the lowest concentration of the [Microbe Blast] compound that actually killed the test organism (MBC titer). All tests were performed in triplicate to assure reproducibility.
Method-Kill Curve Generation
TSA w/ 5% SB agar plates were labeled for the test organism with and without the [Microbe Blast] solution for each time interval tested. The organism suspension was prepared by emulsifying the organism in broth and adjusting the concentration until it was equivalent to a 0.5 McFarland turbidity standard (1 x 108 Colony Forming Units/ml). This concentration was further diluted by pipetting 100 mcl into a 25 m; tube of inoculum water yielding a final concentration of 4 x 105 CFU/ml. A test solution was then prepared by diluting the [Microbe Blast] solution in a broth diluent to a concentration equivalent to the MBC of the organism level as determined in the first phase (see above). A negative control was performed using the broth diluent without the [Microbe Blast] solution. An equal volume of the organism suspension was added to both the test solution and the control and a timer was started. The organism/[Microbe Blast] solution and the organism broth solutions were both subcultured quantitatively to the TSA w/ 5% SB agar plates that had been labeled earlier at time zero (T0) and then again every ten minutes for the first hour. After the first hour both solutions were left in ambient air at room temperature. With the exception of Campylobacter jejuni all organisms were then incubated at 35⁰C in ambient air for 24 hours. The Campylobacter jejuni was incubated at 35⁰ under microcropilic conditions (10% CO2, 5% O2,85% N2) for 48 hours. Following incubation the colonies were counted on all plates and final organism concentrations were calculated. The results of the kill curve were graphed using Microsoft Excel. All tests were done in triplicate to assure reproducibility.
Organisms Tested
- Salmonella typhimurium ATCC 14028
- Escherichia coli ATCC 25922
- Chronobacter muytjensiI strain ATCC 51329
- Listeria monocytogenes ATCC 13932
- Campylobacter jejuni ATCC 3g3291
Kill Rate
Salmonella typhimurium
ATCC 14028
Escherichia coli
ATCC 25922
Chronobacter muytjensiI strain
ATCC 51329
Formerly known as Enterobacter sakazakii
Listeria monocytogenes
ATCC 13932
Campylobacter jejuni
ATCC 3g3291
Dilution and Timing
- Lowest killing dilution 1:20
- At 1:20 dilution killing was achieved in 10-20 minutes
- Kill curve never returned indicating a 100% kill
- Lowest killing dilution 1:40
- At 1:40 dilution killing was achieved in 6 hours
- Kill curve never returned indicating 100% kill
Formerly known as Enterobacter sakazakii
- Lowest killing dilution 1:40
- At 1:40 dilution killing was achieved immediately
- Kill curve never returned indicating 100% kill
- Lowest killing dilution 1:80
- At 1:80 dilution killing was achieved in 48 hours
- The Kill Curves were nearly identical for both a 1:40 and 1:80 dilution, indicating
That dosing is not a major factor. - Kill curve never returned indicating 100% kill.
- Unable to determine lowest killing dilution
- Tested at 1:20
- At 1:20 dilution killing was achieved in 10 minutes
- Kill curve never returned indicating 100% kill
Conclusions
Exposure to the [Microbe Blast] compound led to a 100% killing over time, indicating that this substance acts more like a disinfectant than an antibiotic. The mechanism of action is yet to be determined.
Specific details are withheld because "Microbe Blast" was not the original name used in the study. As an exclusive distributor, Microbe Blast LLC has been granted permission by the formula owner to use this study as a reference.