From Twinkl10 from aol.com Wed Apr 2 08:59:31 2008 From: Twinkl10 from aol.com (Twinkl10@aol.com) Date: Wed Apr 2 14:39:29 2008 Subject: [Microbiology] A level biology Coursework Message-ID: Hi, I am doing my A level biology coursework. I am struggling to find out why streptomycin is more effective at inhibiting the growth of Gram negative bacteria (E coli) than at inhibiting the growth of gram postive bacteria (B Subtilis). I know about how the antibitoic wokrs, (inhibiting protein synthesis etc) but can not link this to why the effectiveness differs upon the type of bacteria. Any help would eb appreciated and included in my bibiliography. thankyou From limbic_lesion from hotmail.com Thu Apr 3 19:04:04 2008 From: limbic_lesion from hotmail.com (N10) Date: Thu Apr 3 22:17:38 2008 Subject: [Microbiology] Re: A level biology Coursework References: Message-ID: Hi Research and think about what Bob suggests Think about cell wall Structure There is no shortage of information on this topic if you know how to use goggle Twinkl10 sucks as an email identity but then again what do I know.. I wish you the very best with A levels at least you have rare ability to ask when you dont know...thats called collboration well done All the best N10 wrote in message news:mailman.23.1207165251.19248.microbio@net.bio.net... > Hi, I am doing my A level biology coursework. I am struggling to find out > why streptomycin is more effective at inhibiting the growth of Gram > negative > bacteria (E coli) than at inhibiting the growth of gram postive bacteria > (B > Subtilis). I know about how the antibitoic wokrs, (inhibiting protein > synthesis > etc) but can not link this to why the effectiveness differs upon the type > of > bacteria. > Any help would eb appreciated and included in my bibiliography. thankyou > > > > From amurion from gmail.com Wed Apr 9 15:10:17 2008 From: amurion from gmail.com (Nathan Tisdell) Date: Thu Apr 10 09:47:44 2008 Subject: [Microbiology] issues with suspected E. coli Message-ID: <1ec3cad00804091310x42374a4dla30f2f420e21a4d0@mail.gmail.com> I am currently taking an introduction to microbiology class and am having issues with a strain of bacteria. We have run SIM tests, Citrate, MR-VP, TSI and EMB tests. Every test points to it being E. Coli except for the EMB plate, instead of turning purple with a green sheen, it stayed colorless. I did not streak for isolation, just a straight streak across the medium. If someone could let me know about something that I might be missing, I would greatly appreciate it. From kdevik from gmail.com Thu Apr 10 07:21:19 2008 From: kdevik from gmail.com (Kanchanadevi k) Date: Thu Apr 10 09:47:59 2008 Subject: [Microbiology] need help and suggestion Message-ID: <8b3d015d0804100521v18b7ed7el6433222a1c828b0a@mail.gmail.com> Can anyone tell me How to check the bacterial gorwth under anaerobic condition. Actually i am doing bacterial taxonomy. In that this is one of physiological test. Growth under anerobic condition. Is there any special media to be used for doing this test or Is there any separate growth champer. can you please help me for this. waiting for reply thank you so much in advance. kanchana devi From GreenieLeBrun from hotmail.com Thu Apr 10 17:45:10 2008 From: GreenieLeBrun from hotmail.com (GreenieLeBrun) Date: Thu Apr 10 19:07:26 2008 Subject: [Microbiology] Re: need help and suggestion References: Message-ID: Kanchanadevi k wrote: > Can anyone tell me > > How to check the bacterial gorwth under anaerobic condition. > Actually i am doing bacterial taxonomy. > In that this is one of physiological test. > Growth under anerobic condition. > > Is there any special media to be used for doing this test > or > Is there any separate growth champer. > > > > can you please help me for this. > > waiting for reply > > thank you so much in advance. > > > > kanchana devi Use an anaerobic jar From yjgent from nospamcox.net Thu Apr 10 21:23:23 2008 From: yjgent from nospamcox.net (John Gentile) Date: Fri Apr 11 12:52:20 2008 Subject: [Microbiology] Re: issues with suspected E. coli References: Message-ID: <2008041022232316807-yjgent@nospamcoxnet> On 2008-04-09 16:10:17 -0400, "Nathan Tisdell" said: > I am currently taking an introduction to microbiology class and am having > issues with a strain of bacteria. We have run SIM tests, Citrate, MR-VP, > TSI and EMB tests. Every test points to it being E. Coli except for the EMB > plate, instead of turning purple with a green sheen, it stayed colorless. I > did not streak for isolation, just a straight streak across the medium. If > someone could let me know about something that I might be missing, I would > greatly appreciate it. The first thing I teach to anyone in micro is that the bacteria don't read the book. You were probably told that E. coli is lactose postive, indole positive, H2S negative, etc. It all fits in with your nice charts and it looks easy. I have seen too many variations of E. coli including one that was H2S positive - it almost looked like a Salmonella. Look for other tests that ONLY E. coli will be positive for. An obsolete test I liked ( and was a bit dangerous) was growth in NaCn broth, which I had to make fresh, and I mouth pipetted the Na cyanide! Look at the charts some more, you are bound to find something. -- John Gentile MS, M(ASCP) Laboratory Information Mgr. VA Medical Center Providence, RI yjgent@cox.net From mparef from gmail.com Fri Apr 11 10:59:56 2008 From: mparef from gmail.com (mohsen arefnejad) Date: Fri Apr 11 12:52:57 2008 Subject: [Microbiology] To nathan Message-ID: <3be864660804110859w6554caa3n771f87432cfd93a7@mail.gmail.com> It depends on what spiese of E,coli to use , Remember the purpel greenish coloer not fixed identification becuse some citrobacter has purpel greenish and some speies of E,coli are lactose negative ,and can not use the suger so not pruduce Acid to convert colore .ok hope to help you . mohsen PhD student From mparef from gmail.com Fri Apr 11 11:11:37 2008 From: mparef from gmail.com (mohsen arefnejad) Date: Fri Apr 11 12:53:00 2008 Subject: [Microbiology] To kdevik Message-ID: <3be864660804110911r5d25e539o66a54a92cf590509@mail.gmail.com> Try OF test,Thyermartin agar and burocella agar .ok regards mohsen From bactitech from nospamhortonsbay.com Fri Apr 11 21:24:34 2008 From: bactitech from nospamhortonsbay.com (JEDilworth) Date: Sat Apr 12 11:06:25 2008 Subject: [Microbiology] Re: issues with suspected E. coli References: Message-ID: In order to accurately assess colony morphology, you HAVE to streak for isolation. A blob won't tell you much. Touch your loop to just a little of your growth. You do NOT need a huge blob of growth. Take it to a new plate and streak for isolation. It's best to do in four quadrants, flaming after the initial inoculation spread and the first turn. Check your plate after overnight growth if you can. What are your results? EC should be SIM Motile/Indole pos/H2S negative, Citrate negative (very important - if you are getting a positive citrate you do NOT have EC), VP negative, TSI A/A and maybe gas (can't remember), EMB should have metallic sheen. Streak for isolation on non-selective medium to make SURE your isolate is pure. Read all tests after overnight incubation. Don't be lazy and let these sit for a few days before reading. The clinical standard is 18-24 hours. We used traditional media on my very first job in the 70's. Traditional media is still the gold standard. Most clinical labs use automated ID methods now, but the best way to learn is on media where you can see results. Our standard setup for lactose fermenters at my first job was SIM, Citrate, MRVP, Ornithine decarboxylase, Lysine decarboxylase, and control. We had more media for nonlactose fermenters. We used TSI and LIA in combination to screen nonlactose fermenting stool isolates. We also added urea and SIM to this setup also. If you are taking an introductory micro class, chances are you will not be given anything too weird. There are nonlactose fermenting EC's out there clinically. Not sure if they would give a sheen on EMB. Clinical labs usually use MacConkey medium instead of EMB. Micro is not an easy course. I tell our beginning techs fresh out of MT school that it will take them a year to feel comfortable in micro and that's working full time. I've been doing it since 1974 and still see new things all the time. Good luck. Judy Dilworth, M.T. (ASCP) Microbiology "Nathan Tisdell" wrote in message news:mailman.105.1207838929.19248.microbio@net.bio.net... >I am currently taking an introduction to microbiology class and am >having > issues with a strain of bacteria. From bactitech from nospamhortonsbay.com Fri Apr 11 21:39:54 2008 From: bactitech from nospamhortonsbay.com (JEDilworth) Date: Sat Apr 12 11:06:52 2008 Subject: [Microbiology] Re: need help and suggestion References: Message-ID: <3a2dnR_ReuNjvZ3VnZ2dnUVZ_v2pnZ2d@buckeye-express.com> Use an anaerobic jar with the proper gas generating packets. These are available commercially and they're not particularly cheap. If your facility has an anaerobic chamber you can use that also. The chamber is very expensive and you need gas tanks hooked up with special gas for this operation. They are hard to work in. Plates outside are easier but you must work fast. You look at your plates, pick your colonies, restreak, and put them back into anaerobic conditions - usually within 1/2 hour or less or the isolates will die with air exposure. We use BBL anaerobic baggies that come with a dry generator packet that activates upon opening. You have a minute to get the plates in and sealed up once the packet's bag is opened. We put the initial plates from an anaerobic culture in the baggie and incubate for two days before opening. Colony types after two days are subbed for aerotolerance testing. We open the bags, sub suspicious colony types aerobically to chocolate and anaerobically to a new CDC Anaerobic Blood. Each morphology gets their own new plate. The latter plates are reincubated anaerobically. You will probably need an anaerobic jar or anaerobic box to do this if you don't have an anaerobic chamber with gloves. All of this technology is expensive. Anaerobes are not cheap to work with. http://tinyurl.com/3q2pkk - jars http://www.bd.com/ds/productCenter/261215.asp - biobags http://tinyurl.com/3eprrx - links to BD and other anaerobic stuff Good luck. Judy Dilworth, M.T. (ASCP) Microbiology (clinical, not R&D) "Kanchanadevi k" wrote in message news:mailman.106.1207838963.19248.microbio@net.bio.net... > Can anyone tell me > > How to check the bacterial gorwth under anaerobic condition. > Actually i am doing bacterial taxonomy. > In that this is one of physiological test. > Growth under anerobic condition. > > Is there any special media to be used for doing this test > or > Is there any separate growth champer.