In a recent lab exercise, we performed the Kirby-Bauer test and determined that for…

1. Streptomycin: E.coli was susceptible(S), S. aureus was susceptible (S), M. luteus was resistant (R)

2. Tetracycline: E.coli was intermediate (I), S. aureus was susceptible (S), M. luteus was susceptible (S)

3. Neomycin: E.coli was intermediate (I), S. aureus was susceptible (S), M. luteus was susceptible (S)

Originally, I thought that tetracycline and neomycin were the most effective because all of the bacteria we tested against were affected whether they were (S) or (I). Now, I’m wondering if it should be streptomycin because E.coli (gram -) and S. aureus (gram +) are both (S)

2 (S) gram+ bacteria & 1 (I) gram- bacteria vs 1 (S) gram+ & 1(S) gram-

For my microbio last test i am given an unknown. My gram stain is positive and rosales in long chains. I already ran a SIM test did a streak plate and made broth n slants for descriptions. i will see the results tmrw. tmrw im doing catalase and oxidase test on my streak plate. I’m not allowed to do any biochemical test. I’m only allowed to do presumptive identification. What test should i do tmrw.

i’m not very interested with doing research as a career but i want to work within healthcare. i was on a biochemistry track so i have a bunch of bio, chem, and calc/math credits done and don’t want to go to waste.

I have some question regarding this type of bacteria: are they capable of using aerobic, anaerobic respiration and fermentation?

If there is no oxygen, doesn’t anaerobic generate more ATP than fermentation? Maybe it depends if the media contains elements used as electron acceptors?

Why can’t we use oxidase test if they utilize aerobic respiration?

I'm a male and my regular urine tests are negative.

But after prostate massage my urine showed up WBC (6-12 hpf), RBC (>30), Protein (Trace), and Bacteria (moderate). Unfortunately, urine culture didn't grow/identify what bacteria they were. This test was done at my doctor's on-site lab.

Is it possible that till regular labs like Labcorp/Quest get our urine samples (24-48 hours), WBC won't show up anymore? WBC can be seen if only urine is tested immediately?

If I have an overnight culture of bacteria cell and another overnight culture of bacteria cells (two overnight culture), I mix a small amount together and incubate them, will the bacteria be in the stationary phase again, considering that nothing else was added to the mixture?

I’ve just finished reading I Contain Multitudes by Ed Yong. Do you have any other microbio based books similar to it that you recommend?

Many thanks

I have a question regarding an issue observed in an experiment performed: when performing conjugation between cells ( E.Coli that were incubated overnight), is there difference in conjugation efficiency in relation to time? If we have overnight culture of two bacteria types (one with plasmide and one without), and I mix the solutions together and after 1 hour, 2 hours and 3 hours incubation I take samples and plate them.

My initial thoughts were that the more time the bacteria come to contact, the higher the chance that conjugation will occur. However, the experiment showed that in the first hour, the frequency/ success was the highest. Is there a reason for that?

Does a repository of information like this exist? Here’s an example of what I’m looking for:

Data List

Organism: Yeast

Produces: Ethanol, etc

Substrate: Glucose, etc

Metabolic process: fermentation, etc

Basically something like this, but for as many different microorganisms as possible.

Thank you for any help you may provide, and thanks for reading! :)

i'm a microbiologist in my 3rd year. If i want to move my lab equipments and work to my living room to have my own space. On a scale 1-10 how dangerous is it? and do yall recommend it or should i stay on the lab cuz my friends always warned me about this idea

hello, im studying chemistry and yesterday i have a microbiology exam about gram stain, and i didnt pass...

i knew the step by step and did everything, i was in the microscope in the x100 when i lost it, every zoom that i did, i was able to find it but not in the last one, i got scared and start looking everywhere moving the microscope slide to see if could find it, and i was zooming in and zooming out until my teacher comes up to me and says "your never gonna find it" and just turns off my microscope and tell me that i have another chance next Monday, im bit scared cuz now im doubting myself even though i´ve done it before, is there any advice your could give me? thanks for reading

p.d sorry if my grammar isnt very good, im not a native speaker

Much preferred if it’s not too common like the Dead Sea :)

Hi everyone, I’m having some trouble understanding the difference between actinomyces, actinomycetes, actinomycetales, and actinobacteria.

Any help would be much appreciated!

If I have a broth with a bacteria suspension, and I decide to pipette a volume of specific concentration of an antibiotic in the broth. Will the antibiotic concentrations decrease over time? right?

Is S. Aureus positive for Urease or no? While doing my unknown project it came back as negative but sources online says it is. Thank you!!!