API Listeria, a new and promising one-day system to identify Listeria isolates

Abstract

API Listeria is a new 10-test strip for 24-h biochemical identification ofListeria isolates. With this commercial system, 85% of 646 Listeria strains, including atypical isolates selected for this study, were recognized at the species and subspecies level without a complementary test. A new test differentiates Listeria monocytogenes from L. innocua on the basis of the absence of arylamidase from the former. With this system, 97.7% (252 of 258) of the L. monocytogenes strains tested were correctly identified and differentiated from 99.4% (175 of 176) of the L. innocua strains also tested. Gram-positive bacteria other than Listeria spp. gave quite different biochemical patterns. This system considerably reduced the time needed for conventional identification, since results were available within 18 to 24 h.

Confirmation and identification of Listeria spp.

“…Carbohydrate tests (mainly xylose in the API, and all fermentation tests in the Micro-ID strip) were occasionally difficult to interpret. This phenomenon was also reported byBannerman et al (1992) andBille et al (1992). By repeated testing with the same system, or with conventional fermentation tests, correct results were obtained.…”

“…Bannerman et al 1992;Bille et al 1992;Higgins and Robison 1993 ; Fusijawa and Mori 1994). Carbohydrate tests (mainly xylose in the API, and all fermentation tests in the Micro-ID strip) were occasionally difficult to interpret.…”

Development of a real-time loop-mediated isothermal amplification assay for the sensitive and rapid detection of Listeria monocytogenes

“…Routine culture methods for L. monocytogenes detection require at least 6-7 days (Curtis et al 1989;Eld et al 1993). The commercial API Listeria assay used for the differentiation of Listeria species, which is based mainly on the differential fermentation of various sugars (Bubert et al 1997) and haemolytic reactions (McLauchlin 1997) generally works well; however, the API Listeria test kit has been reported to produce occasional discrepant results (Bille et al 1992).…”

MALDI-TOF mass spectrometry-based identification of Listeria species in surveillance: A prospective study

“…Conventional identification was carried out by API-Listeria (bioMérieux) combined with hemolysis test on horse blood agar according to manufacturer's instructions (Bille et al, 1992).…”