New rapid identification test for Clostridium difficile.
OBJECTIVE
A set of five tests were developed and tested for their ability to confirm the identity of C difficile colonies within 30 minutes.


METHODS
The relevant substrates were incorporated into four filter paper squares attached to a plastic carrier (Diffstrip), five enzymes/products (prolyl aminopeptidase, galactosidase, leucine aminopeptidase, acid phosphatase and indole). The strips were inoculated, incubated for 20 minutes, and reagents added.


RESULTS
96.4% (212 of 220) strains of C difficile were immediately differentiated from 51 other Clostridium spp tested. The remaining 3.6% (eight of 220) of C difficile isolates produced a reaction pattern similar to some of the Clostridium sporogenes tested and required additional tests. None of the other Clostridium spp tested produced reaction patterns similar to C difficile.


CONCLUSIONS
The Diffstrip allowed colonies of C difficile to be confirmed within 30 minutes for 96.4% of isolates, with less than 4% requiring any additional tests. No strains of C difficile were misidentified and no strains of other Clostridium spp tested were misidentified as C difficile.
Aspinall
S T
ST
Public Health Laboratory, Royal Preston Hospital.
Dealler
S F
SF
D015373:Bacterial Typing Techniques; D001431:Bacteriological Techniques; D016360:Clostridioides difficile / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D011934:Reagent Strips; D013045:Species Specificity; D013379:Substrate Specificity; D013997:Time Factors
D011934:Reagent Strips