Tag: BD-BBL Crystal Rapid ID
When Angelo Falcon chose his water source for the first project in BIOL 3410 Microbiology lab, he had little idea that it would bring to light an issue being discussed in Abilene City Hall. The class was charged with finding various sources of ground water and surface water to test for the numbers and types of bacteria present. Angelo sampled water from a man-made waterfall downtown, while others in the class tested streams and lakes and ponds and wells in and around Abilene. Testing included a standard MPN (most probable number) assay, followed by isolation and purification of a Gram negative bacterium, characterization of its colony morphology and staining characteristics, and biochemical testing to provide hints at its identity. The project culminated in confirming the identifications of isolates using BD-BBL Crystal(R) E/NF panels for rapid identification of enteric and non-fermenting Gram negative rods. Angelo’s isolate came back as Enterobacter cloacae, and a little snooping revealed this to be a microbe frequently associated with sewage and soil. A conversation with people associated with the waterfall revealed the water source to be a shallow well tapping into an aquifer found under much of northern Abilene.
And that is things began to add up. In early September, Abilene’s City Council dealt with the issue of shallow ground water in northern Abilene and its unsanitary condition by issuing a warning to residents with wells into this water source – do not drink the water, do not use the water for irrigating vegetables, do not allow pets or livestock to drink the water. Angelo can testify to the presence of nasty bacteria in the water. Add to Angelo’s work confirming evidence from Amanda Carter, a classmate who tested water from her father’s north-side well, and you have every reason to believe City Council made the right decision.
Its nice when what you are doing in the lab to develop basic skills has a purpose and relevance to society.
We had another BUSY week in Biomedical Science courses.
- Freshman-level BIMS 1300 Intro to Scientific Research students learned how to use their Tablet PCs to gather data from a “Brain Test” all students took (determined analytical vs. creative, auditory vs. visual) and calculate standard error of the mean, as well as linear regression analysis of data sets. In the lab, students finished up their observation projects that will be presented in the coming week.
- The new microbiology course for allied health majors, BIOL 3403 Fundamentals of Microbiology participated in a webinar hosted by McMurry alumna Mary Lynn Smith (’83) on biofilms in healthcare. This was an example of how experts and professionals a thousand miles away can contribute to our students’ education.
- In BIOL 3410 Microbiology, students finished the identification of Gram positive bacteria found in their cars. They are working on research posters describing their studies and will turn those in next week. In short, they took samples from the HVAC and interior surfaces of their cars, isolated and purified bacteria, and pursued identifications of the Gram positive cocci found using conventional tests and the BD-BBL Crystal(TM) Rapid ID panels. Follow-up tests included testing for oxacillin-resistance, an indicator of community-borne MRSA.
- In BIMS 4391 Advanced Microbiology, students moved forward in their development of antibiotic-producing bacteria. They completed the identification of their endospore-formers using microscopy, conventional tests, and BD-BBL Crystal(TM) Rapid ID panels. Then, they grew their bacterium in batch culture, removed the cells and spores by centrifugation and filtration, and challenged six microbes (two Gram negative rods, two Gram positive cocci, two yeasts) with the filtrate in disk diffusion tests. Those antibiotic producers with the most promise will be grown in our new benchtop fermenters and their products characterized by chemical, physical, and physiological means to learn more.
- In our BIMS 4201 Capstone Research class, senior students began cultivating the Saccharomyces cerevisiae strain genetically-modified with human estrogen receptor as a prelude to the use of the YES assay for monitoring the presence of estrogen-mimics in the environment.
All this may sound way beyond the reach of normal college students in normal college classes. Not so! We find that students are more engaged in learning techniques and information when there’s a reason or goal – a pot of gold at the end of the rainbow! It is at the heart of the skills-laden, research-rich approach taken in teaching BIMS courses.
When the CSI television show kicks off each episode with The Who singing “Who are you? Who-ooh Who-ooh?”, I’m often reminded that some of the most satisfying moments in science come when a mystery is solved and we come to understand something that was beyond our knowing. In the TV show, the discovery is often the identity of a killer. In the microbiology lab, it is often the identity of a microbe. Sometimes, that microbe can also be a killer!
The traditional way for identifying bacteria is through completion of a series of biochemical tests conducted using tubes and plates of special growth media. That was one of the things that drew me to microbiology – instead of trying to provide names to structures penetrated by pins stuck through cat muscles or plant leaves, test results in the micro lab were unambiguously black and white, or at least red and yellow. I may nothave been sure whether the pin was in the semimembranosus or the pectineus, but I sure could tell the difference between red and yellow!
Today microbiologists still conduct the tests using tubes and plates, especially in the typical college teaching lab. But the BIMS program is committed to exposing students to the tools that are used in hospitals and research labs to do things more quickly and accurately. So, once students believe they know the identity of the bacteria they have isolated from nature, we follow up to confirm identity using a rapid ID system like those used in clinical labs. This approach comes at a cost, but the experience is worth every penny.
There are many to choose from, and those schools exposing students to rapid ID systems typically choose to use either Enterotubes or API strips, which are on the “lower-tech” end of the spectrum. We have decided to go a bit more high-tech and use the BD-BBL Crystal Rapid ID system. Students place a colony or two of their purified unknown into the dilution broth and fill all 30 wells with inoculum. A panel of 30 dehydrated media is snapped into place, enabling the inoculum to rehydrate the media, and the panels are tossed into an incubator overnight. Ten-digit numerical codes are derived from the results and fed into a computer that spits out an identity. Most recently, my students have used the panels for identifying bacteria contaminating foods – meats, fresh fruits and vegetables.
Who are you? When our students look at their plates of unknown bacteria and ask that question, they will find the answer is easy to determine using Crystal panels. We fully believe by the time they graduate, BIMS students will be capable of answering the same question for CSI. All it takes is the right tools, methods, and skills – something we are committed to providing.