ESBLs and Carbapenemases

Question 1

Beta lactams mechanism of action

Answer 1

-Attack the cell walls

**Bacteria produce beta-lactamases which inactivates the beta lactam ring and prevents it from killing the bacteria

Question 2

Beta lactams importance

Answer 2

-most commonly used in companion animals
-also used in production medicine and human health

Question 3

Beta lactamase diversity

Answer 3

Many different classes of beta-lactamases
-Great diversity of bacteria like Class B, C, D which are not susceptible to beta-lactamase inhibitors

Question 4

ESBLs and Carbapenemases

Answer 4

-more of a gram negative problem
-there is a lack of awareness of these enzymes

Question 5

Beta-lactamase inhibitors

Answer 5

Can be used to prevent beta-lactamase and ensure beta-lactam can still destroy bacterias cell wall

Question 6

Beta-lactamase inhibitor options

Answer 6

**inhibits narrow spectrum of Class A beta-lactamases

1. Clavulanic acid + Amoxicillin or Ticarcillin
2. Sulbactam +Ampicillin
3. Tazobactum + Piperacillin
   *uncommon in vet med

Question 7

Avibactam

Answer 7

-wider spectrum beta lactamase inhibitor including class A, C, D
-but reserved for human med

Question 8

Class A enzymes

Answer 8

Can be inhibited by beta-lactamase inhibitors
-resistance to 3rd generation cephalosporins
**issue with human med

Question 9

Carbapenemases

Answer 9

-Last line of defense
-capable of degrading the vast majority of beta-lactams

Question 10

What enzymes with carbapenem degrading activity?

Answer 10

-KPC type
-Metallo-beta-lactamases
-Oxacillinases

Question 11

Metallo beta lactamase

Answer 11

-2008, patient had UTI with ESBL K. pneumoniae, bed sores, diabetes, stroke. Also found carpabenem resistant e.coli (linked with Indian Hospital)
-found on every continent except Antarctica
-associated with travel to India
-present in Indian water and found in livestock in China

Question 12

Metallo-beta lactamase plasmids

Answer 12

-present on broad host range plasmids
*due to lateral spread not clones

Question 13

Where is metallo beta lactamase found?

Answer 13

-present across Enterobacterales

-e coli, K pseumoniae, S. marcescens, Enterobacter, Citrobacter spp

Question 14

K pseumoniae carbapenemase

Answer 14

-KPC
-Narrow host range plasmid
-first ID in 1990s
-

Question 15

3rd generation cephalosporin resistance

Answer 15

-think broad spectrum beta lactamases
*MAYBE ESBL

Question 16

Carbapenemase resistance

Answer 16

-raise red flags
-likely nothing will work

Question 17

Wild birds resistance

Answer 17

Resistance often linked with urban environments so likely a reverse zoonoses
-Crows were good sentinel for resistance in urban areas

Question 18

How are beta-lactamases often detected?

Answer 18

By PCR

Question 19

Canine UTI resistance

Answer 19

-Low levels of resistance in SK compared to other places
-saw low levels beta-lactamases

Question 20

Food checks

Answer 20

-looking at major food groups and tested for resistance

Unique testing:
-culinary reptiles/amphibians
*often country of origin not on label; others from China and Thailand
-plant based products

Question 21

Culinary reptiles/amphibians

Answer 21

-found resistance to beta lactams including 3rd gen cephalosporins
*found one turtle with last line of defense antimicrobial resistance
*found a Acinetobactor isolate with 4th gen cephalosporins and carbapenems resistance

Question 22

Plant based products

Answer 22

-vegetables, spices, herbs, fruits
-some frozen, some dried
-originated from Asia, Africa, Jamaica
-found various bacteria and resistance