| Abstrakt: |
Arcobacterspecies are gram-negative rods that have been implicated in food- and waterborne illness. Although various cultural isolation methods have been proposed, the current procedures are unable to fully suppress the growth of background microbiota present in food samples, which inhibits Arcobacterisolation. The purpose of this study was to develop a selective enrichment broth and chromogenic plating medium to detect three Arcobacterspecies that have been recognized as emerging foodborne pathogens: Arcobacter butzleri, Arcobacter cryaerophilus,and Arcobacter skirrowii. The developed Nguyen-Restaino-Juárez (NRJ) Arcobacterdetection system consists of a selective enrichment broth (NRJ-B) and a selective-differential plating medium (NRJ-M). The protocol of the detection method was determined by evaluating the growth of A. butzleri, A. cryaerophilus,and A. skirrowiiunder various temperatures (30, 35, and 42°C) and incubation (aerobic, microaerophilic, and anaerobic) conditions. Additionally, 47 Arcobacterstrains and 39 non-Arcobacterstrains were tested in inclusivity and exclusivity evaluations of NRJ-B and NRJ-M. Overall, the study determined that the optimal growth conditions of Arcobacterspecies using the NRJ Arcobacterdetection system were aerobic incubation at 30°C. NRJ-B supported good growth of A. butzleri, A. cryaerophilus,and A. skirrowiiwhile effectively suppressing the growth of non-Arcobacterstrains after 48 h. Furthermore, NRJ-M yielded 97.8% inclusivity and 100.0% exclusivity using the tested strains and resulted in salmon-pigmented Arcobactercolonies (1.0 to 1.5mm in diameter) after 72 h. The novel protocol is the first to develop a chromogenic plating medium for the isolation of Arcobacterspecies. This simple and accurate test method would greatly contribute to understanding the distribution of pathogenic Arcobacterspecies in food samples. |
