Hello,
The first file shows the bacteria growing on LB with ampicillin and the second picture depicts the same bacteria on BCY agar with chloamphenicol. The bacteria were isolated as a contamination on a BHI erythromycin agar plate. They grow very slowly, the first colonies were visible after 3 days at room temperature. They are resistent to kanamycin, ampicillin, chloramphenicol and erythromycin. We did not test other antibiotics. They seem to be chitinase negativ.
hi,
It is very difficult, if not impossible, to identify bacteria on phenotypic criteria. You must perform 16S rRNA sequencing and compare the sequence to NCBI database.
You are certainly right. Since we were merely curious what kind of bacteria this might be and as it has nothing to do with our project we didn't want to invest into further analysis. Thanks for your input though.
im not sure but i can guess this one might be mycobacterium, so as Mr Yoann Perrin sayed You should realise 16S rRNA sequencing and compare the sequence to NCBI database to identify it. i see a great pigmentation in all these colony , so may be you can see what kind of pigmentation ( like lycopene ), and if you can exploit it in industrial applications.
Are the colonies dry or creamy ?
Given the time of incubation, and the look of the colonies, it could (although Obviously I completely agree with Yoann in that sequencing would be mandatory to ensure a correct identification) be an Actinobacteria such as Nocardia. I doubt Mycobacteria produce colonies with this kind of pigmentation (usually white, yellow or orange but no red). However, I remember growing strains of Nocardia having the same kind of pigmentation...
Might just be a wild guess... Anyway, it would be nice to know the id of this isolate!
Best,
Vincent
Did you try gram staining? You can get a lot of information from this simple test, also catalase and oxidase test. Perhaps you could do an API gallery, and obtain a presumptive identification.
The best will be to do 16S rRNA sequencing but you also could realize some API galleries or MALDI-TOF analysis.
It's difficult just with pictures to help you because colonies morphology also depend of the growth conditions (time, medium, temperature, ...).
Dear Sangeeta
I think that the kind of bacteria is difficult to be depicted morphologically. You need more informations including biochemical or molecular informations. Please add PCR test.
Thank
Marius
It's so difficult to identify bacteria clone from colonies and you should first realize Gram staining to determine the kind and form and then realize some biochemical key tests depend on the staining result and the most important test is to extract DNA and 16SDNA sequencing to confirm the affiliation of the two kinds of clones. Good Luck
The colonies does not usually look like the regular seen in clinical setting ,but a few feature showed that the colonies produces pigment , secondly what sample was the taken from before culture , a simple gram stain would determine is staph or strep specie or bacilli, the followed by other test especially xylose,peroxidase ,de-oxygenated jar test .you would get close ,the finally a PCR gene test.
It is very difficult to predict bacterial colonies. Hence, identifying them with polyphasic approach (morphological, biochemical and molecular) will be fruitful.
An alternative to 16s sequencing is for you to use an API strip (a panel of biochemical tests on one easy to use tab) if you can borrow one from a colleague it would be a very simple and straightforward test. It's a fairly common piece of kit in many Microbiology labs.
The color of the colony may not ensure that it is a bacterial culture only. Some yeast cultures are also colored. It requires more morphological and microscopic studies to reach to a conclusion.
What was the source of your sample?
I have isolated marine Mycobacterium spp. with a similar dark orange to almost red pigment. Such pigmentation and colony morphology can possibly be attributed to some soil organisms as well such as Bacillus and Rhodococcus spp.
If this were my isolate, I would work it up as a mycolic acid containing gram-positive species or fungus. You should at least perform a gram stain and acid fast stain.
Gram staining followed by isolation and molecular sequencing would be better for proper identification.
Since they are groeing in media containing antibiotics, most probably yeast , and as said by Nicholas, most probably Rhodotorula .
Please do a gram stain and ZN stain
Staining gramma will give you answer if this bacteria or rather some yeast. The colonies look like pseudomons stutzeri, while the color of Rhodotorula rubra. If you can please upload a photo from microscope.
After gram stain, do catalase and oxidase test. Could be Micrococcus roseus.
Actinomycetes
https://www.researchgate.net/publication/232758410_Taxonomic_and_ecological_studies_of_actinomycetes_from_Vietnam_Isolation_and_genus-level_diversity/figures?lo=1
Article Taxonomic and ecological studies of actinomycetes from Vietn...
Thanks everyone for your great suggestions. After reading the suggestions from Tandon and Sharma that it might be yeast I took a microscopic picture and it seems indeed to look like yeast. I have attached the pictures: the first two depict the unkown microorganism and the third one is a picture of E. coli for comparison; 100x magnification. So it might indeed be Rhodotorula.
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