There are some articles that consider only Klibsella pneumoniae, K. oxytoca, E. coli, Proteus mirabillus and Proteus volgaris as ESBL in reporting for clinical patients, but should we not consider all the Enterobacteriaciea genera as ESBL when they are positive or just these five?
Not only these five species could be ESBL positive (further Enterobacter sp., Seratia sp. ant other species and generas) but not whole group of Enterobacteriaceae. It depends on harbouring of genes encoding ESBL production and nowadays not in every species of Enterobacteriaceae were these genes detected.
According to CLSI, it stated only K.pneumoniae, K.oxytoca, E.coli and P.mirabilis should look for ESBL. However, please bear in mind that ESBLs gene are usually located in the plasmid and this plasmid is highly mobile and can be transferred to other bacteria via conjugation (acquired gene)...Thus it is dangerous to assume ESBLs only can be detected among these four bacteria but not to the other Enterobacteriaceae...Detection of ESBLs among other Enterobacteriaceae is a bit difficult especially among AmpC beta lactamase producer bacteria due to obscure detection of ESBLs by presence of AmpC,however ESBLs can be detected by putting antibiotic disc FEP-30ug side by side with antibiotic disc AMC-30ug (20mm apart) then observe clavulanic effect in between FEP-AMC...when both ESBL and AmpC beta lactamase detected, ESBLs reporting rules should be followed...
Thank you very much for responding, we can detect the ESBL features by testing the disc diffusion sens, we use ceftazidim disc and ceftazidim with calvionelic acid if the variation between two discs more than 5 mm so it will be considered as ESBL. So if this is enough so we can consider every Enterobacteriacea spp. is ESBL if the test is positive, or we must stuck to the CLSI recomendation to test for the four spps only???
ESBL are detected in diverse Enterobacteria spp. Beyond the species referred we have in our hospitals ESBL in Enterobacter sp., Citrobacter sp, M. morgannii. The problem in detecting ESBL in these because they produce AmpC b-lactamase.
Dear Ola: In my lab we used CAZ-30ug and CTX-30ug then arrange side by side (15-20mm apart) with AMC-30ug, then observe 'clavulanic effect' in between CAZ-AMC or CTX-AMC and on the same plate we test FOX-30ug and FEP-30ug...ESBLs enzyme characteristic is FOX-S, FEP-R...if you just depend CAZ-30 alone you may missed detect ESBL CTX-M type coz this ESBL type confer hydrolyze CTX rather than CAZ (will be sensitive),mean there is no clavulanic effect in between CAZ-AMC and ESBL phenotypic confirmatory (CAZ/CLA - CAZ) wil be negative...
Dear Shyam Mishra: Agreed...even ESBL has been reported among E.cloacae, the well known AmpC beta lactamase producer...
Dear Gabriela: Agreed with you...however, for your information ESBL detection among AmpC beta lactamase producer can be done...how? by putting FEP-30ug side by side (20mm) with AMC-30 or CAZ/CLA or CTX/CLA then look 'clavulanic effect' or zone of enhancement in between FEP-AMC or FEP-CAZ/CLA or FEP-CTX/CLA...
Here, I enclosed picture of K.pneumoniae and E.cloacae harbor both ESBL and AmpC beta lactamase
E. coli, K. pneumoniae, K. oxytoca, P. mirabilis, Enterobacter,Salmonella
Not only these species could be ESBL positive (further Enterobacter sp., Serratia sp. and other s) but not whole group of Enterobacteriaceae.
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology