how to do 20x20 Matrix in Biology/Microbilogy

For this course our lecturer asked us to make or draft a 20x20 matrix based on our field of study and am studying microbiology even though it is a statistics course

[the cyclist]

I don't know what "draft a matrix" means. Do you? Can you explain it here? We'll need a bit more detail to help you.

You might want to read this guide on how to ask a good question here.

Answer 1

[Star Strider]

One thought that would combine microbiology and statistics would be for you to look up 20 different bacteria (from E. coli to M. tuberculosis), assign each of them to a row, consider each column as a specific time, and using Gompertz kinetics, calculate the number of each species that would exist at each time. E. coli would increase rapidly, and M. tuberculosis likely very little. (Assume each is grown on its usual medium.) Use your imagination for the others: Y. pestis, B. burgdorferi, Clostridium perfringens, Campylobacter jejuni, Helicobacter pylori, ...

From a statistics perspective, you could see if there is a significant difference in the growth rates.

Another more morbid option is to take data from 20 mice, each injected with an increasingly concentrated inoculum of perhaps S. aureus and again using the columns as time, compare the mortality over time. The mice with the lowest inoculum might all survive, while those with the highest might all die quickly.

The statistical approach here would be survival analysis.

I’m sure you can think of others. You can synthesise the Gompertz growth curves from published data. Ask your microbiology faculty for data for the mouse study, since we did this sort of study in Medical Microbiology in medical school ’way back when.

[Deborah Opadiran]

Thank you for the answer but I don't understand how I should use Gompertz kinetics for it, please can you enlighten me on that or can I use any random number; For example Microorganism and the food they contaminate and I will use any random number inside the box...

[Star Strider]

My pleasure.

I was under the impression that the Gompertz function describes bacterial growth. Use another function if that is more accurate. Ask one of your microbiology professors for that information. You will need to look up the parameters for each species.

The idea is to model bacterial growth on the typical medium and under the specific conditions used to grow them. Each species is a row of the matrix, and the growth over time is in the columns, with each column denoting the same specific time increment (hours, days, weeks, or whatever you want, but the same for all species). So the first column would be time t=0, the second column would be t=1, and so forth, with you defining the time unit. The calculations should not be that difficult.

I would not use random numbers, except to add small amounts of measurement or other noise to your calculated values (and use the randn function for that). If this is for a statistics course, you want to provide data you can actually analyse.

Any microorganism can contaminate any food if given the opportunity, so I do not suggest that you proceed in that direction.