Coliform bacteria are generally shown as indicators of food hygiene and sanitary conditions; although, their presence does not necessarily imply pathogenicity. The ISO 4832:2006 method is a globally accepted standard used in coliform counting but it is labor-intensive and time-consuming. Faster alternatives, such as chromogenic media and automated MPN systems like TEMPO TC, exist; though, comparative studies across different food matrices are still limited. In this study, ISO 4832, TEMPO TC, and two chromogenic agars (VWR Chromogenic Coliforms Agar and Biokar Compass ECC Agar) were compared for coliform enumeration in milk, chicken, and flour artificially inoculated with E.coli NCTC 12923 at high, moderate, and low contamination levels. Counts were obtained in parallel and analyzed by Pearson correlation and regression analysis. Intralaboratory validation of TEMPO TC was performed in pasteurized milk in accordance with ISO 16140-3:2021. Strong correlations were detected between TEMPO TC and ISO 4832 (R² = 0.83-0.85), TEMPO TC and chromogenic agars (R² = 0.82-0.84), and ISO 4832 and chromogenic agars (R² = 0.85-0.89). Validation of TEMPO TC confirmed reproducibility (SIR = 0.203), satisfying ISO 16140-3 criteria. Our findings demonstrate that chromogenic agars and TEMPO TC can serve as reliable alternative methods to ISO 4832 and TEMPO TC provides additional advantages such as faster processing, automation, and reproducibility.
Hatice Kübra Özer (Sat,) studied this question.