Cefsulodin and Vancomycin: A Supplement for Chromogenic Coliform Agar for Detection of Escherichia coli and Coliform Bacteria from Different Water Sources

• Published in: Microorganisms (Basel) Vol. 10; no. 12; p. 2499
• Main Authors: Schalli, Michael, Inwinkl, Sarah Maria, Platzer, Sabine, Baumert, Rita, Reinthaler, Franz F, Ofner-Kopeinig, Petra, Haas, Doris
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 16.12.2022; MDPI
• Subjects: Agar; Antibiotics; Bacteria; bathing water; Cefsulodin; coliform bacteria; Coliforms; Drinking water; E coli; Enumeration; Enzymes; Escherichia coli; Gram-positive bacteria; Microorganisms; mineral water; Pseudomonas aeruginosa; Reproducibility; Selectivity; Surface water; Vancomycin; Water analysis; Water sampling; Austria; Escherichia coli; mineral water; coliform bacteria; Cefsulodin; Vancomycin; drinking water; bathing water
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms10122499

Background microorganism growth on Chromogenic Coliform Agar (CCA) can be challenging. For this reason, a new alternative method with a Cefsulodin/Vancomycin (CV)-supplemented CCA should be developed in this study. CCA supplemented with CV was validated according to ÖNORM EN ISO 16140-4:2021 using water from natural sources in Styria, Austria. Results show that the alternative method using the supplemented CCA has similar values in relation to sensitivity (82.2%), specificity (98.6%) and higher selectivity (59%) compared to the reference method. Repeatability and reproducibility were acceptable for the alternative method and showed similar results with the reference method. The alternative method shows a very low false positive rate and a low false negative rate paired with good performance regarding the inclusion study. The exclusion study shows the advantage of our method by suppressing background microorganisms and facilitating the process of enumeration of and other coliform bacteria on CCA plates. and growth was inhibited using the supplement. To conclude, the coliform CV selective supplement combined with CCA is an appropriate tool for coliform bacteria detection in water samples.