Table 2.

Summary of Key Features and Findings of the Multi-Drug Resistant Organism (MDRO) Network Studies

Study	Isolates	Setting and Years	No. of Patients	Carbapenemase Prevalence	30-d Mortality Rate in Infected Patients	Summary of Key Findings
CRACKLE- 2 [4–6]	CRE (all body sites)	49 US hospitals; 2016–2017	1040	59% (92% of CP-CRE had KPC)	Overall: 24% (107/449)	Clinical outcomes not significantly different between CP-CRE, non-CP-CRE and isolates not confirmed to be carbapenem-resistant; CG 258 K. pneumoniae is the most common CP-CRE, but CG 307 K. pneumoniae is emerging
	CRKP (all body sites)	71 Hospitals in South America, Australia, China, Lebanon, Singapore, and the US; 2017–2018	991	90% (91% of CP-CRE had KPC); Australia, Lebanon, and Singapore: 75%; China: 98%; South America: 75%; US: 88%	Overall: 19% (93/502); BSI: 34% (44/130)	The 30-d mortality rate is lower in China (12%) than in South America (28%) or the US (23%), but adjusted DOOR outcomes are similar; O2 variant 2 O genetic locus is associated with survival
	CP Escherichia coli (all body sites)	26 Hospitals in Australia, China, Colombia, Lebanon, Singapore, and the US; 2017–2018	114	57% Serine carbapenemase, 43% MBLs (96% of MBLs had NDM)	Overall: 16% (18/114)	MBL-producing E. coli is most common in China; 30-d mortality rate is lower with MBL-producing E. coli (6%) vs other CP E. coli (23%)
POP [8]	CRPA (bloodstream, respiratory, urine, and wound isolates)	44 Hospitals in South/Central America, Australia, China, Lebanon, Saudi Arabia, Singapore, and the US; 2018–2019	972	22% (49% of CP-CRPA had KPC-2% and 36% had VIM-2); Australia and Singapore: 57%; China: 32%; Middle East: 30%; South/Central America: 69%; US: 2%	Overall: 18% (105/581); BSI: 30% (21/69); pneumonia: 19% (69/358)	CP-CRPA is rare in the US (2% of isolates) but common elsewhere (30%–69% of isolates); CP-CRPA infections: increased 30-d mortality rate compared with non-CP-CRPA infections (22% vs 12%)
SNAP	CRAB (all sites)	46 Hospitals in South/Central America, Australia, China, Lebanon, Saudi Arabia, Singapore, and the US; 2017–2019	842	91% (88% of CP-CRAB had OXA-23); Australia and Singapore: 100%; China: 99%; Middle East: 100%; South/Central America: 92%; US: 83%	Overall: 24% (128/536); BSI: 42%	Infection types and mortality rates varied substantially across regions; CG2 was the most common CRAB lineage except in South/Central America
SHREC [10]	E. coli (bloodstream isolates)	14 US hospitals; 2020–2021	300	NA (150 CRO-resistant, 150 CRO-susceptible)	CRO-resistant: 13% (20/150); CRO-susceptible: 8% (12/150)	Patients with CRO-resistant E. coli BSI had increased mortality rates and worse outcomes in unadjusted but not adjusted analyses

Abbreviations: BSI, bloodstream infection; CG, clonal group; CP, carbapenemase-producing; CRAB, carbapenem-resistant Acinetobacter baumannii; CRACKLE-2, Consortium on Resistance Against Carbapenems in Klebsiella and Other Enterobacterales; CRE, carbapenem-resistant Enterobacterales; CRKP, carbapenem-resistant Klebsiella pneumoniae; CRO, ceftriaxone; CRPA, carbapenem-resistant Pseudomonas aeruginosa; DOOR, desirability of outcome ranking; KPC, Klebsiella pneumoniae carbapenemase; MBL, metallo-β-lactamase; NA, not applicable; NDM, New Delhi metallo-β-lactamase; POP, Prospective Observational Pseudomonas Study; SHREC, Study of Highly Resistant Escherichia coli; SNAP, Study Network of Acinetobacter as a Carbapenem-Resistant Pathogen; VIM-2, Verona integron-encoded metallo-β-lactamase 2.