Skip to main content
Fig. 2 | BMC Microbiology

Fig. 2

From: Prevalence and mechanisms of antibiotic resistance in Escherichia coli isolated from mastitic dairy cattle in Canada

Fig. 2

Response pattern of 113 E. coli isolates toward metal salts. Serial dilutions of metal salts added to MH broth were prepared in 96 well plates and each well was innoculated with live bacteria. After overnight incubation, bacterial viability was assessed using the Resazurin assay. E. coli ATCC 25922 was used as a QC strain. The IC50 values of each metal salt against every E. coli isolate was calculated using GraphPad Prism 7 software. The IC50 value of each metal salt against the QC strain was considered as the cut-off concentration. E. coli isolates with IC50 values less or equal or non-significant (p>0.05) to the cut-off were considered as susceptible whereas, statistically significant (p≤0.05) non-susceptible isolates were categorized into weakly resistant isolate(WRI) (QCIC50cut-off < WRI ≤ 1.5 folds of QCIC50cut-off ), moderately resistant isolate (MRI) (1.5 folds of QCIC50cut-off < MRI ≤ 2 folds of QCIC50cut-off) and strongly resistant isolate (SRI) (SRI > 2 folds of QCIC50cut-off)

Back to article page

BMC Microbiology

ISSN: 1471-2180

Contact us