Discuss the Extended Spectrum Beta-Lactamase producing micro-organisms (ESBL) under thefollowing headings:
a) List six ESBL producing micro-organisms commonly encountered in the ICU.
b) List four risk factors for ESBL producing micro-organism development. (20% marks)
c) Outline infection control measures for ESBL producing micro-organisms. (50% marks)
Aim: To allow the candidate to demonstrate familiarity with multi-resistant organisms.
Key sources include: Papers 2014.1 Q3.3, 2009.1 Q 25.2 CanMEDS Medical Expert.
Discussion: This is a core topic with increasing importance in current ICU practice. The overall standard of response to this question was commendable. Expert answers included a thorough detailing of infection control measures and listing the relevant organisms. Candidates who failed to gain marks did so mainly in part b) with a knowledge deficit in relation to the risks of ESBL development.
Other organisms that can carry ESBL include Chromobacterium violaceum, Enterobacter, E. coli, Hafnia alvei, Lysobacter lactamgenus, Ochrobactrum anthropi, Proteus rettgeri, Pseudomonas aeruginosa, Psychrobacter immobilis, Rhodobacter sphaeroides and Yersinia enterocolitica, as well as potentially Salmonella, Neisseria, Burkholderia and Shigella; but they only asked for six. Every article you google has a list of approximately these dimensions
"risk factors for ESBL producing micro-organism development" could potentially have meant a whole variety of different things, but most probably meant "what are the risk factors for being colonised with an ESBL-producing organism". Otter et al (2019), looking at the data from a universal screening program in London, and Ben-Ami et al (2009) analysing coimmunity patient data identified the following:
This requires a list of standard contact precautions for critically ill patients:
Chaudhary, U., and R. Aggarwal. "Extended spectrum β-lactamases (ESBL)–An emerging threat to clinical therapeutics." Indian journal of medical microbiology 22.2 (2004): 75-80.
Otter, J. A., et al. "Individual-and community-level risk factors for ESBL Enterobacteriaceae colonization identified by universal admission screening in London." Clinical Microbiology and Infection 25.10 (2019): 1259-1265.
Ben-Ami, Ronen, et al. "A multinational survey of risk factors for infection with extended-spectrum β-lactamase-producing Enterobacteriaceae in nonhospitalized patients." Clinical Infectious Diseases 49.5 (2009): 682-690.
Eggimann, Philippe, and Didier Pittet. "Infection control in the ICU." Chest 120.6 (2001): 2059-2093.