1.3 E. coli resistant to meropenem‐Antibiotic Susceptibility Test (AST) Browser

Background

Here, using the Antibiotic Susceptibility Test (AST) Browser we will look for Escherichia coli that have an MIC >= 2 versus the antibiotic meropenem. These are isolates that either have a resistant or intermediate susceptibility phenotype.

Exercises

Go the AST Browser: https://www.ncbi.nlm.nih.gov/pathogens/ast/#:

1. In Filters, select "Organism group", and then select "E. coli and Shigella"
2. In Filters, select "Antibiotic", and then select "meropenem"
3. In Filters, select "MIC", and then toggle the range pulldown menu to ">=", then enter "2" in the adjacent cell. Then click the checkmark.

• line command:

taxgroup_name:("E.coli and Shigella") AND ANTIBIOTICS:("meropenem") AND (measurement_sign:(">=" "==") AND mic:[2 TO *])

• Link: https://www.ncbi.nlm.nih.gov/pathogens/ast/#taxgroup_name:(%22E.coli%20and%20Shigella%22)%20AND%20ANTIBIOTICS:(%22meropenem%22)%20AND%20(measurement_sign:(%22%3E=%22%20%22==%22)%20AND%20mic:[2%20TO%20*])

Using Cross Browser selection, go to MicroBIGG-E.

• We can examine the meropenem (carbapenem) resistance mechanisms that have been identified by AMRFinderPlus:
• • In Filters, select "Subclass" and choose "CARBAPENEM"
• • Note that there are far fewer isolates with resistance mechanisms than with resistant phenotypes (17 vs. 43).
• • Also note there is a point mutation mutation mechanism too (ompC).

One could investigate the isolates lacking resistance mechanisms further.