Protocol Online logo
Top : New Forum Archives (2009-): : Microbiology

Ways to Quickly Identify Antibiotic Resistance in Bacterial Cells (Non-tradition - (Jan/25/2014 )

Pages: 1 2 Next

Hello All,

Does anyone know of (a) good and sensetive molecular method(s) to identify the antibiotic resistence or sensetivity in bacterial cells directly from microlitter amount of sample without going throuhg 24-48 hours of work to grow the bacterial culture or plates in the begining?

I would be very thankful if you could help me on this. 

Thanks much in advance!

FL.

-Fluoresce-

no

 

You could run a PCR to look for the presence of genes encoding resistence, but thats pretty much it.

-pito-

As ;oito said, you could find the genetic signal but that wouldn't confirm expression and effective resistance.

-Phil Geis-

Thanks guys, that's what I was suspecting.

 

Now I am trying to figure out a few things:

 

How do Vitek2 and Phoenix phenotypically identify the bacterial suscep. in a short time?  Still need to read more on this but can anyone help here?

 

Any info on  16S rRNA is also being studied to identify the suscep/resist. of the bacterial strains? 

-Fluoresce-

16S rRNA is just to determine bacteria, not to figure out if they are suscep or res.

Dont forget that many of the resistance comes from plasmid DNA rather than genomic.

 

 

The Phoenix and Vitek2 just use standard tests (Bergeys) to identify bacteria, its actually just an "improved" way of the API strips.

For the suscep/resis : its just the same as doing it manually, but its just more automated and I guess a bit faster...

But it will still take time: you will still need to grow the bacteria etc....

 

 

Thanks guys, that's what I was suspecting.

 

Now I am trying to figure out a few things:

 

How do Vitek2 and Phoenix phenotypically identify the bacterial suscep. in a short time?  Still need to read more on this but can anyone help here?

 

Any info on  16S rRNA is also being studied to identify the suscep/resist. of the bacterial strains? 

-pito-

For Vitek2 and Phoenix you still need to grow and isolate the bugs. It is only fast if you have them isolated and because you don't have to do the profiling manually nor prepare all the media. if you wanted to do something like a molecular method for that, you would need to integrate all the known potential elements that may indicate resistance, either DNA/RNA sequences or proteins (through specific antibodies), into a microarray... not easy stuff... and you will not cover sequences that are not discovered or divergent mutations, while in the present methods you only need the antibiotics, which in comparison are very limited in number

-El Crazy Xabi-

Thank you both for the useful info.  Meanwhile I also read the documents provided by Biomerieux and BD.  Yes as Pito said they are still going through traditional methods and they need you to isoalte a single colony which is time consuming.  I need to cut this time down. 

So, El Crazy Xabi, do you know of good papers on the microarray format for bacterial ID/AST? 

Thanks for your help guys!

-Fluoresce-

You want micro-arrays to identify bacteria?

 

If so: they are out there, but most of them (if not all) are designed for specific bacteria: fish pathogens, plant pathogans, human pathogens......

SO it all depends on what you want ......

 

If you are speaking about the antibiotic resistance: it would not be that hard to design micro-arrays yourself based on resistance genes, but I doubt this really would work for what you want...

I mean: the gene can be present, but not active, plasmid vs genomic DNA, you would not know the levels it can tolerate....

Pretty much what EL Crazy Xabi also told: mutations in the genes, proteins to detect... it would be very complicated.

-pito-

Thanks Pito...I need to read a little more in this then...

-Fluoresce-

i did some research on this topic last year. You can get some information from these two studies and search more from related articles
Development of a DNA Microarray to Detect Antimicrobial Resistance Genes Identifiedin the National Center for Biotechnology Information Database(JG Frye,2010)
Analysis of Antimicrobial Resistance Genes Detected In Multidrug-Resistant Salmonella enterica Serovar Typhimurium Isolated from Food Animals(LSM Glenn, 2011)

-squint-
Pages: 1 2 Next