Disregard the comments stating MR and VP test cannot both be positive. The fact of the matter is that they absolutely can both be positive. There are a number of organisms positive for both including: Proteus myxofaciens, Enterobacter intermedium, Klebsiella planticola and Serratia liquefaciens. Those stating otherwise please review the literature before commenting. Reply
Same thing to point out – MR and VP test both can never be positive. Please provide the correction. Reply
pls how can i identified E.coli strain in a culture madia ReplyDepends on the culture – Like if u use EMB media it will give a metallic sheen and if u use MLA it will give pink coloured colonies because of Lactose fermentation. Reply
Hüseyin Sait Öztürkif you use TSA its appeared white regular colonies
if you use ENDO agar is seems metalic sheen
if you use MCA you can see pink colonies whit zones Reply
how can MR test and VP test both be positive. if one is positive ,other has to be
negative and vice versa . both can be negative, but both tests can never be positive. Reply
Sagar sir, I am Amit khanal from B.Sc. Microbiology 4th year, St.Xavier’s college. I happened to be doing a practical homework on Enzymatic Activities of bacteria- one of which included COAGULASE TEST. After going through some of the literatures, including the (prescribed)college book itself; I found the lines:
1. Coagulase reacting factor—abbreviated as CRF—which in your site has been abbreviated as CRP
2. Tube test for coagulase tests both BOUND AND FREE COAGULASE.. mentioned only free coagulase on this site. Could you shed some light in this ? Thanks a lot Reply
Hi, may i know what are the possible reasons as to why does s. aureus gives of positive result in Ornithine decarboxylase? thank you! Reply
if the xylose broth was first yellow and it turned red, would it be a + or – reaction Reply abhinab mudaican use PDA(potato dextrose agar) to identify or detect the growth? and what about the result outcome? Reply
S. aureus is historically regarded as a non-motile organism. More recently it has been shown that S. aureus can passively move across agar surfaces in a process called spreading. Discovered that S. aureus can spread across the surface of media in structures that we term ‘comets’. Reply
leedia amira Thermonuclease -positive ReplyDear Sagar,
Can I have a question?
How can I do Bacitracin Susceptibility test for Staphylococci identification?
Thank you for your help.
Best regards. Reply
Use Bacitracin Taxo A (0.04IU) as we did to identify S.pyogenes.
Diameter zone: S>=10mm, R Staphylococcus/Macrococcus: Bacitracin resistant
Micrococcus: Bacitracin sensitive To differentiate between Staphylococcus/Macrococcus, we can do glucose fermentation under anaerobic condition whereas Staphylococcus able to ferment glucose anaerobically (positive) whiles Macrococcus not able to ferment glucose anaerobically (negative). Micrococcus also not able to ferment glucose anaerobically (negative) Reply
Hi sir, why Macrococcus and Micrococcus will not ferment anaerobically . can you explain please . Reply
