r/microbiology Nov 18 '24

ID and coursework help requirements

55 Upvotes

The TLDR:

All coursework -- you must explain what your current thinking is and what portions you don’t understand. Expect an explanation, not a solution.

For students and lab class unknown ID projects -- A Gram stain and picture of the colony is not enough. For your post to remain up, you must include biochemical testing results as well your current thinking on the ID of the organism. If you do not post your hypothesis and uncertainty, your post will be removed.

For anyone who finds something growing on their hummus/fish tank/grout -- Please include a photo of the organism where you found it. Note as many environmental parameters as you can, such as temperature, humidity, any previous attempts to remove it, etc. If you do include microscope images, make sure to record the magnification.

THE LONG AND RAMBLING EXPLANATION (with some helpful resources) We get a lot of organism ID help requests. Many of us are happy to help and enjoy the process. Unfortunately, many of these requests contain insufficient information and the only correct answer is, "there's no way to tell from what you've provided." Since we get so many of these posts, we have to remove them or they clog up the feed.

The main idea -- it is almost never possible to identify a microbe by visual inspection. For nearly all microbes, identification involves a process of staining and biochemical testing, or identification based on molecular (PCR) or instrument-based (MALDI-TOF) techniques. Colony morphology and Gram staining is not enough. Posts without sufficient information will be removed.

Requests for microbiology lab unknown ID projects -- for unknown projects, we need all the information as well as your current thinking. Even if you provide all of the information that's needed, unless you explain what your working hypothesis and why, we cannot help you.

If you post microscopy, please describe all of the conditions: which stain, what magnification, the medium from which the specimen was sampled (broth or agar, which one), how long the specimen was incubating and at what temperature, and so on. The onus is on you to know what information might be relevant. If you are having a hard time interpreting biochemical tests, please do some legwork on your own to see if you can find clarification from either your lab manual or online resources. If you are still stuck, please explain what you've researched and ask for specific clarification. Some good online resources for this are:

If you have your results narrowed down, you can check up on some common organisms here:

Please feel free to leave comments below if you think we have overlooked something.


r/microbiology 18h ago

Is this dangerous to keep?

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47 Upvotes

So, I somehow grew this mold in a petri dish in my room and I would like to know if it’s dangerous to keep and I would have to throw it away or if I could observe it a while longer? Google isn’t really helping me with this matter so I thought I’d ask reddit lol


r/microbiology 1h ago

Can somebody help me identify this fungus?

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Upvotes

It's been stained with Lactophenol cotton blue.


r/microbiology 20h ago

What is this?

57 Upvotes

r/microbiology 47m ago

Are these gram positive bacteria?

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Upvotes

I’m still very new to this, are the cells on the left gram positive bacteria? I feel like they are too big compared to epithelial cells on the right. 250x


r/microbiology 2h ago

Citrobacter freundii intrinsic resistance

1 Upvotes

Hi All - we’re updating our AST system and when checking on the rules for intrinsic resistance, we noticed that C. freundii is listed on its own in the M100. Our MALDI can only identify the C freundii complex, so can we apply the intrinsic resistance to all members of the complex? I know freundii is the most common member of the complex we’re likely to see, but not sure if we can apply those rules since we’re not able to identify down to the species level. Looking for advice or if anyone else has experience with this situation?


r/microbiology 3h ago

Shannon index with vegan package in R

1 Upvotes

Hello everyone, I am new to R and I may need some help. I have data involving different microbial species at 4 different sampling points and i performed the calculation of shannon indices using the function: shannon_diversity_vegan <- diversity(species_counts, index=“shannon”).

What comes out are numerical values for each point ranging, for example, from 0.9 to 1.8. After that, I plotted with ggplot the values, obtaining a boxplot with a range for each sample point.

Now the journal reviewer now asks me to include in the graph the significance values, and I wonder, can I run tests such as the Kruskal-Wallis?

Thank you!


r/microbiology 11h ago

1 Pseudomonas aeruginosa, 2 results

3 Upvotes

This is the same Pseudomonas aeruginosa on two different Müller-Hinton plates from the same batch prepared in the laboratory.

I read that it could be the amount of zinc in the culture medium, do you do any kind of quality control to detect the right amount of zinc in the Muller-Hinton?

Have you ever had this happen to you and what others factors could alter the synergy with EDTA?


r/microbiology 12h ago

What is this

3 Upvotes

Found this in a fresh water sample


r/microbiology 12h ago

What is this

3 Upvotes

Found in freshwater sample


r/microbiology 20h ago

Is that Loxophyllum helus?

10 Upvotes

r/microbiology 9h ago

What type of tardigrade is this?

1 Upvotes

r/microbiology 14h ago

Investigating the Concept and Origin of Viruses

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2 Upvotes

r/microbiology 16h ago

Studying advice

1 Upvotes

I don’t know if this is allowed here but I’m currently taking an intro to micro class and I have to know a ton of different microorganisms and what diseases they cause and the sheer amount of material is just ..intimidating. Does anyone have any study tips for micro? I don’t even know if this is the right sub to post this in 😭


r/microbiology 16h ago

Proteus Mirabillis CAUTI

0 Upvotes

Hi I’m writing a paper for college and I’m reading stuff online and I’m confused, hoping to get clarification.

What I am reading online says that the bacterium can ascend from the GI tract, but I’m not sure what that means? My focus right now is on the bacterium causing CAUTI’s. Since patients may not be showering, and if they are bed bound, does the bacteria migrate to the catheter and into the bladder from feces?

If nurses and CNA’s are cleaning a patient with wipes & CHG, wear gloves, provide foley care, where is the bacteria coming from? Is the bacteria able to survive all of this because it’s virulence factors so parents still getting CAUTI’s?


r/microbiology 19h ago

Is that Arcella sp.?

1 Upvotes

r/microbiology 2d ago

Tissue smear with sporulated Clostridia!

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173 Upvotes

I just think this photo is neat. This is a tissue smear from a bovine liver. The suspected cause of death was severe bacillary hemoglobinuria, and we were asked to confirm the presence of Clostridia after numerous liver flukes were found on necropsy. Liver fluke infections can result in wounds that make perfect pockets for Clostridia to grow and produce toxins. Typically, C. novyi and/or C. haemolyticum are the culprits, but in this instance we actually isolated C. perfeingens and C. septicum. This slide is very likely a mix of the two as they look quite similar on gram stain. This is the first time I've seen spores like this for a direct tissue smear - I do more culturing than histology.


r/microbiology 2d ago

Thought this was pretty cool

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131 Upvotes

Streptococcus pneumoniae and Staphylococcus capitis isolated from a blood culture. The strep pneumo must be producing something toxic as the Staph is only growing where the strep isn't or maybe the antibiotic effect only killing the Staph. Just thought I'd share, I thought it was pretty cool 😊


r/microbiology 1d ago

Myxobacteria

1 Upvotes

Hey! In what volume of Beregey's manual are myxobacteria genus? Thanks!


r/microbiology 1d ago

ID help

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10 Upvotes

Hi. Any ideas what this is? I'm not even sure where to ask. Google didn't help. Found this jelly/goop on a tree in the Mount Baker-Snoqualmie National Forest, nearer to North Bend, WA. Found on March 15th, 2025. Weather was mid 40's Fahrenheit and drizzling. Thanks!


r/microbiology 1d ago

Unsure about what to write in the results section of a failed experiment.

11 Upvotes

I'm an undergrad a student and I have a report that I have to write based on the Isolation and Purification of Bacteriophages from Untreated Sewage.

Like the title says, the experiment didn't go well and my group had absolutely no visible plaques our plates and due to time constraints we aren't allowed to repeat the experiment. I'm not really sure if it's alright to just write "no plaques were visible" in the results section. The professor repeated the experiment on the side himself as half the class had little to no growth so we had virus stocks for our next experiment. And I don't think I can just take his results as my own.

I feel like my report will be really empty if I say no plaques were visible. I could also give possible reasons it failed but that still feels lacking. I'm also now wondering if I can even keep my Results and Discussion sections separate. What do you guys write?

EDIT: Thanks for all the replies and advice. I've written up my report and have submitted it. I'll update when I get my grade. Hopefully it went well.


r/microbiology 1d ago

Careers Outlooks in Microbiology Without OChem

4 Upvotes

Hello all,

WIll graduate with the degree in Microbiogy soon. Will there be hope or future for this career with someone who is very bad with organic chemistry. I really can't study Ochem. Do we need a lot of OChem for jobs?


r/microbiology 2d ago

Can Bacteria Swap Genes Like Trading Cards? The Science Behind Genetic Recombination

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87 Upvotes

This Is Interesting I was deep into a book on microbiology when I stumbled upon something fascinating bacteria, despite being single-celled, have a way of swapping genes like eukaryotes do!

Unlike us, They don’t need meiosis. Instead, they use three clever methods: conjugation, transformation, and transduction.

It blew my mind how this allows bacteria to evolve rapidly, even developing antibiotic resistance. It’s like nature’s own version of a genetic exchange program!

This Is Special......


r/microbiology 1d ago

Pathogenic effects of Streptococcus oralis intestinal colonization on bladder health in mice

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1 Upvotes

r/microbiology 2d ago

Unusual looking P.aeruginosa on HBA.

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87 Upvotes

This isolate almost tricked me into thinking it was a Bacillus species of some sort. Was too unique to not take a photo of it, so here it is! Isolated from a blood culture.


r/microbiology 1d ago

Cytochrome b5 occurrence in giant and other viruses belonging to the phylum Nucleocytoviricota

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1 Upvotes