Why are some of my zones of inhibition larger for a deep agar than shallow agar in disc diffusion for antibiotic sensitivity testing?
This illustrates why it’s important, when you test sensitivity to antibiotics or anti-microbial compounds, to always use consistent agar plates - it is worth using a sterile pipet, or a sterile Falcon tube, to make sure that you pour your plates always consistently at the same depth (if you want to compare data across different plates, or different strains tested on different plates, or something of the sort.) It can also be useful, if you have enough of your compound of interest, to repeat the test several times, measure the zone of inhibition, and look at the average.There are a few reasons why you may be seeing different results from plate to plate. If the “thin” plates are old (thin because they have dried out a bit), the concentration of all of the nutrients is different and there is less water left in the plate. If the plates are the same age, we are still talking about differences, from thick plate to thin plate, in the amount of nutrients present and the growth rate of your microorganism of choice, which can affect susceptibility to antimicrobials. If your microbe is not growing very fast (fewer nutrients), it may be less susceptible to killing/growth inhibition by your test compound.
Why is Brain Heart Infusion agar (BHI) used for testing for antibiotic resistance instead or regular agar?
I'm not sure what "regular agar" is, but BHI is not the most-widely used agar for disc diffusion testing - Mueller-Hinton agar is.For appropriate materials and methods for AST testing, you should refer to the CLSI standards described in publications M07 and M100M07-A10 and M100-S25 Package of 2 Docs
During an IV drip, I have seen many small air bubbles draining inside the blood vessel. Is it dangerous if these air bubbles reach (and block) the brain's blood vessels?
A bit odd, since all i.v.'s have a bubble trap, that's the plastic container with a fluid level in it hung underneath the i.v. fluid bag, it will trap any bubbles, and if an infusion pump was used, there would be an alarm underneath this bubble trap that on detection of an air bubble would shut the infusion pump down.Are you sure the small bubbles you saw were not in the tubing from the i.v. fluid bag to this bubble trap?A few small air bubbles wouldn't cause any problem.A big air bubble (but that is not so in your case) would make you very sick, since it will block the blood flow to your lungs, and if a connection from the right heart to the left heart was open (patent foramen ovale) your brain causing a stroke.There supposedly are reports from Nazi experiments conducted on prisoners of war during WW II (the results of which because these experiments are far from being ethical are suppressed) that >50 ml of air injected into a vein in one go is fatal (from Page on www.ajol.info).I used to be an intensive care physician, and have performed a lot of i.v. injections/infusions.If you feel bad after reading our replies that is not because of maybe small air bubbles in your i.v. lines, but because of the worries it caused you, otherwise you would be very short of breath, or would have developed a stroke.
How safe are blood agar plates?
So I had to do a throat test today with a blood agar plate and I stuck the qtip down my throat and put the saliva on the agar and my lab partner didn't think it was enough so I told her I'd redo it. I took the qtip I previously used after touching the agar and stuck it down my throat again. I was thinking ahh **** I touched the agar and touched my throat and it bothered me so I asked my lab instructer if the agar would harm me and she said it's sterilized and it's nothing to worry about. I'm still wondering how safe they are what what they're made from. I even heard that the bacteria is safe (which we didn't use in this experiment.).
Do MBBS students have to study all the time? I have heard that medical college students have a lot of pressure, they barely complete their sleep.
Its a real misconception that MBBS people have to study all the time.I am a final year exam going student in KMC,Mangalore.I had one of my best days while in MBBS.I go to the gym regularly (Fitness is important!)This is me in final year MBBS.I went to the Netherlands from my college to present a paper recently and ended up going to Paris,Switzerland,Leiden and Germany all in final year.Last month we had a huge party in our college called 'Socials' although it was only 2 days we were planning it since 1 month.These are few pics of SOCIALSAfter this we went to Goa and Munnar too.And Diwali party afer that.Our usual Saturday night preparationsBTW I'm writing this sitting in the library which is underground so I won't be seeing today's sunset. ( Exams are up next week)My 1st 1k upvotes. Thank you :)EDIT 1: Many people are saying that I'm from a rich background so I have all these perks.Yes maybe my college fees is high but the quality of the education that I get is outstanding! Trust me when I say this!And I didn't pay a single penny to get admitted here (Through merit only).Furthermore,to get in here I left AIIMS (7 others),A college in UP (State Quota) and also another one in Maharashtra (NEET-UG) a copy of my Rank card :And I can sponsor my own needs as I run a business in Mangalore (Where my college is)So instead of complaining that people who aren't rich can't afford all the leisures life will give you,there are many opportunities,one should start recognising them.“To be able to sacrifice for what you are for what you'll become" -Eric ThomasAlso,start investing on your health rather than terrorising it with junk food and laziness,trust me it makes a huge difference.
What is the time taken to die if injected by an empty syringe?
I would strongly advise against trying, but unless it was a huge syringe, you'd probably survive. In most cases, as long as it's not one giant bubble of air that fills up a chamber of the heart enough to prevent it from pumping *any* blood, the air will just end up being dissipated in the pulmonary vessels of the lung. This is assuming the air goes into a vein (so it only has to pass the right heart before reaching the lungs) - if you injected air into an artery, all bets are off - even a small temporary disruption of a crucial artery could cause a stroke (if it was in the brain), or trigger an arrhythmia (disrupting the coronary arteries feeding the heart). Of course, you could also get unlucky even if it went into a vein - a bubble could escape the lungs and end up in the arterial circulation anyway. With water, nothing would happen, unless it was contaminated water (possible infection/toxins) or enough water given fast enough to mess up the concentration of ions in the body. Otherwise, you can give sterile water by IV, if you want to or if it is necessary - the body will just absorb it (like it would if you drank it) and get rid of the excess as urine.READ MORE HERE
Is injecting an empty syringe dangerous?
Short answer: No If you have accidentally injected empty syringe nothing would happen so relax, there's nothing to worry about. However its not advisable to do so :p.Air is only dangerous when it enters the vein. When empty syringe is injected,air enters the circulatory system and causes a condition called as "air embolism".When reasonably high amount of air enters the blood stream fast,the bubbles(Embolism) can block major vessels.If it occur in brain,leads to stroke;in heart,causes heart attack.But usually,such air reaches lung ,and get cleared.Problem arises when lung is bypassed somehow. So, yes you can die if air gets in your blood stream BUT you would need more than a full syringe of nothing but air.