Antibiotic Resistance in Gram-Negative Bacteria

These flashcards cover vocabulary and key concepts regarding Gram-negative antibiotic resistance, enzyme classifications, and clinical management based on the lecture notes.

Acinetobacter baumanni

A bacterial species categorized under the Critical Priority group for antimicrobial resistance.

Enterobacterales

A group of bacteria listed as a Critical Priority, where enzymes like ESBLs and carbapenemases are the main resistance problem.

Efflux pumps

A resistance mechanism in Gram-negative bacteria that works by pumping antibiotics out of the cell.

Target site alterations

A resistance mechanism involving changes to specific bacterial structures, such as ribosomes in the case of gentamicin resistance.

ESBL

Extended spectrum beta-lactamases; enzymes that confer resistance to penicillins, first-, second-, and third-generation cephalosporins, and aztreonam.

CPE

Carbapenemase-producing enterobacterales, a group where Klebsiella species are the most common producers.

Ambler Classification Class B

A category of beta-lactamases that possess a metal core, including IMP, VIM, and NDM-1.

Ambler Classification (Classes A, C, and D)

Categories of beta-lactamases that possess a serine core.

TEM-1

A beta-lactamase first isolated in Athens, Greece, in December 1964 from an E. coli strain found in a patient named Mrs Temoneira.

TEM-3

A specific mutated enzyme that marked the birth of ESBLs by extending its spectrum of activity through multiple mutations.

Cephalosporins

A class of antibiotics used in the 1980s as a safe alternative to aminoglycosides until ESBL mutations appeared in 1983.

Beta-lactamase inhibitors

Substances such as clavulanate and tazobactam that are capable of inhibiting ESBLs.

SHV-type

A type of ESBL where the acronym stands for sulphydryl variable.

CTX-M

A rapidly expanding type of Extended spectrum beta-lactamase (ESBL).

Double disc testing

A laboratory method used to detect the presence of Extended spectrum beta-lactamases.

Carbapenems

The drugs of choice for treating serious infections caused by ESBL-producing organisms.

CPOs

Carbapenemase-producing organisms, which includes Enterobacterales (CPEs), Pseudomonas sp, and Acinetobacter sp.

OXA-48-like

A carbapenemase family that accounts for $40.7\,\%$ of CPE in E. coli and $37.7\,\%$ in Klebsiella in the UK.

NDM

A carbapenemase family accounting for $38.7\,\%$ of CPE in E. coli and $30.6\,\%$ in Klebsiella in the UK.

KPC

A carbapenemase family accounting for $17.7\,\%$ of CPE in E. coli and $27.5\,\%$ in Klebsiella in the UK.

Pylorus preserving pancreaticoduodenectomy (PPPD)

The surgical procedure performed on the clinical case patient which was complicated by a duodenal stump leak.

Colistin

A polymyxin antibiotic used for serious CPE infections when options are limited, despite its lack of modern standardized dosing trials.

Colistin Toxicity

The side effects of this antibiotic include being neurotoxic, ototoxic, and potentially causing sudden apnoea.

Contact precautions

Infection control measures including strict patient isolation and usage by all health care workers (HCWs) to prevent spread.

AMRHAI Reference Unit

The Public Health England (PHE) unit responsible for confirming CPE isolates.

High Priority Pathogens

A group of bacteria including Salmonella typhi, Shigella sp, Enterococcus faecium, and Pseudomonas aeruginosa.

Medium Priority Pathogens

A group of bacteria including Group A and B streptococci, Streptococcus pneumoniae, and Haemophilus influenzae.

Reduced permeability

A resistance mechanism where the bacterium limits the entry of antibiotics into its cell.

ESBL multi-resistance

Plasmids bearing ESBL genes frequently carry additional genes for resistance to aminoglycosides, quinolones, and trimethoprim/sulfamethoxazole.

Antimicrobial stewardship

One of the two key approaches, along with infection control, for managing the threat of Gram-negative resistance.