From owner-celegans@net.bio.net Tue Aug 26 23:00:00 1997 Path: biosci!FALCO.GEOBIO.ELTE.HU!fodoran From: fodoran@FALCO.GEOBIO.ELTE.HU Newsgroups: bionet.celegans Subject: Re: Re: OP50.1 Date: 27 Aug 1997 00:29:58 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 70 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <65535.5173037@lamg.com> NNTP-Posting-Host: net.bio.net Dear Bandy, I made a terrible mistake! By written RESISTANT instead of SENSITIVE!!! The OP50 was SENSITIVE not resistant to all antibiotics tested. I may have a starting Alzheimer ... Sorry. Andras On 26 Aug 1997, Tritech Research wrote: > fodoran@FALCO.GEOBIO.ELTE.HU,Internet writes: > ANTIBIOTICS SENSITIVITY OF OP50. > > Csaba Bognar(2), Tibor Vellai(1) and Andras Fodor(1), > 1. Dept. Genetics, Eotvos University, H-1088 Budapest, Muzeum krt. 4/A, > Hungary > 2. Bela Johann National Institute of Public Health in Hungary, Department > of Bacteriology, (OKI), H-1097 Budapest, Gyali ut 2-6, Hungary. > > E. coli OP50 is used practically by everybody in the C. elegans Community > as natural food for C.elegans. Our substrain what we use was kindly > provided by Ian Hope in 1995. We have tested its antibiotics sensitivity, > by the paper disc method routinly used the OKI. We used 30 ug/ml of each > antibiotics tested. The filter paper discs are out on the center of the > NGM plate seeded by OP bacteria. An inhibition zone develops, if the > antibiotics is effective against the baccteria under test. Conventionally, > if the diameter oif the inhibition zone is smaller then 2 cm, we conclude > that the bacteria is resistant to the antibiotics tested. We tested 24 > antibiotics, as follows: > > gentamycin; tobramycin; sumetrolim; chloramphenicol; tetracycline; > ampicyllin; karbenicillin; cefalexine; cefamandol; cefuroxime; amykacin; > netylmycine; azlocilline; mezlocillin; ceftriaxone; cefatoxim; > cefroperazon; ofloxacin; pestloxacin; cyprofloxacim; ceftazidin; cefaclor; > augmentin; and kanamycin. (Some of the names are probably written in very > Hungarian; we promise the correct them in the Newsletter article). > > Well, we found that OP50 was completely resistant to all these > antibiotics. > > I hope these data help Liz and other fellow Colleauges to work with OP50. > > Faithfully yours, > > Andras and his gang. > ------------------ > This sounds very strange to me (?) If true, it would be one of the heartiest > (and most dangerous) strains of bacteria in the world (?) My experience > with OP50 is that it is killed easily by Amp and Str. 2 cm requires a lot > of diffusion. Might this be too much to ask from the filter disks? Is it > possible that doing the test on NGM with a high agar or agarose content is > limiting diffusion? Could this possibly be a contaminating yeast? > > Curious, > Andy Papp > tritech_research@LAMG.COM > ======================================================================== Dr. Andras Fodor e-mail: fodoran@ludens.elte.hu Associate Professor or: fodoran@falco.elte.hu Eotvos University Phone: +36.1.266.1296 Department of Genetics +36.1.267.5444 ext. 2348 Budapest, Muzeum krt. 4/A FAX: +36.1.266.2694 H-1088 HUNGARY ======================================================================== .