Clinical Outcomes and Bacterial Characteristics of Carbapenem-resistant Acinetobacter baumannii Among Patients From Different Global Regions
Authors: Wang Minggui , Ge Lizhao , Chen Liang , Komarow Lauren , Hanson Blake , Reyes Jinnethe , Cober Eric , Alenazi Thamer , Zong Zhiyong , Xie Qing , Liu Zhengyin , Li Lanjuan , Yu Yunsong , Gao Hainv , Kanj Souha S , Figueroa Jairo , Herc Erica , Cordova Ezequiel , Weston Gregory , Ananth Tambyah Paul , Garcia-Diaz Julia , Kaye Keith S , Dhar Sorabh , Munita Jose M , Salata Robert A , Vilchez Samuel , Stryjewski Martin E , Villegas Botero Maria Virginia , Iovleva Alina , Evans Scott R , Baum Keri , Hill Carol , Kreiswirth Barry N , Patel Robin , Paterson David L , Arias Cesar A , Bonomo Robert A , Chambers Henry F , Fowler Vance G , Satlin Michael J , van Duin David , Doi Yohei ,   Multi-Drug Resistant Organism Network Investigators, Kanj Souha S , Zhang Fujie , Lok Judith J , Salata Robert A , Stryjewski Martin , Di Castelnuovo Valentina , Gutierrez Jose Millan Oñate , Cober Eric , Richter Susan , Anderson Deverick J , Evans Beth , Hill Carol , Cross Heather R , Baum Keri , Arias Rebekka , Fowler Vance G , Ordoñez Karen , Jacob Jesse T , Li Linghua , Kreiswirth Barry N , Manca Claudia , Chen Liang , Desai Samit , Herc Erica , Cordova Ezequiel , Rioseco Maria , Vilchez Samuel , Sanchez Marisa L , Valderrama Sandra , Figueroa Jairo , Arias Cesar A , Dinh An Q , Panesso Diane , Rydell Kirsten , Tran Truc T , Hu Fupin , Su Jiachun , Jiang Jianping , Wang Minggui , Xu Xiaogang , Yang Yang , Munita Jose M , Spencer Maria , Alenazi Thamer , Bonomo Robert A , Marshall Steven H , Rudin Susan D , Huskins Charles , Greenwood-Quaintance Kerry , Patel Robin , Schmidt-Malan Suzannah , Revolinski Sara , Wortmann Glenn , Kalayjian Robert C , Weston Gregory , Ostrowsky Belinda , Patel Gopi , Eiras Daniel , Kim Angela , Garcia-Diaz Julia , Salcedo Soraya , Farrell John J , Liu Zhengyin , Henderson Andrew , Paterson David L , Xie Qing , Kaye Keith S , Gao Hainv , Yu Yunsong , Waters Mary , Fries Bettina C , Eilertson Brandon , Marimuthu Kalisvar , Ng Oon Tek , De Partha Pratim , Chew Kean Lee , Smitasin Nares , Tambyah Paul Ananth , Gallagher Jason C , Peleg Anton , Leroi Marcel , Li Lanjuan , Xiao Yonghong , Komarow Lauren , Ge Lizhao , Evans Scott , McCarty Todd , Chambers Henry F , Garner Omai B , Abbo Lilian M , van Duin David , Lautenbach Ebbing , Han Jennifer H , Doi Yohei , Wong Darren , Hanson Blake , Reyes Jinnethe , Botero Maria Virginia Villegas , Diaz Lorena , Perez Federico , Banerjee Ritu , Dhar Sorabh , Satlin Michael J , Westblade Lars F , Zong Zhiyong 
Published: September 2023

Abstract

Background
Carbapenem-resistant Acinetobacter baumannii (CRAb) is 1 of the most problematic antimicrobial-resistant bacteria. We sought to elucidate the international epidemiology and clinical impact of CRAb.

Methods
In a prospective observational cohort study, 842 hospitalized patients with a clinical CRAb culture were enrolled at 46 hospitals in five global regions between 2017 and 2019. The primary outcome was all-cause mortality at 30 days from the index culture. The strains underwent whole-genome analysis.

Results
Of 842 cases, 536 (64%) represented infection. By 30 days, 128 (24%) of the infected patients died, ranging from 1 (6%) of 18 in Australia-Singapore to 54 (25%) of 216 in the United States and 24 (49%) of 49 in South-Central America, whereas 42 (14%) of non-infected patients died. Bacteremia was associated with a higher risk of death compared with other types of infection (40 [42%] of 96 vs 88 [20%] of 440). In a multivariable logistic regression analysis, bloodstream infection and higher age-adjusted Charlson comorbidity index were independently associated with 30-day mortality. Clonal group 2 (CG2) strains predominated except in South-Central America, ranging from 216 (59%) of 369 in the United States to 282 (97%) of 291 in China. Acquired carbapenemase genes were carried by 769 (91%) of the 842 isolates. CG2 strains were significantly associated with higher levels of meropenem resistance, yet non-CG2 cases were over-represented among the deaths compared with CG2 cases.

Conclusions
CRAb infection types and clinical outcomes differed significantly across regions. Although CG2 strains remained predominant, non-CG2 strains were associated with higher mortality.
Clinical Trials Registration. NCT03646227.