Prevalence of carbapenem resistance and its potential association with antimicrobial use in humans and animals in rural communities in Vietnam Nguyen Thi Phuong Yen 1 , Nguyen Thi Nhung 1 , Doan Hoang Phu 1,2 , Nguyen Thi Thuy Dung 1 , Nguyen Thi Bich Van 1 , Bach Tuan Kiet 3 , Vo Be Hien 3 , Mattias Larsson 4 , Linus Olson 4 , James Campbell 1,5 , Nguyen Pham Nhu Quynh 1 , Pham Thanh Duy 1 and Juan Carrique-Mas 1,5 * 1 Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam; 2 Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam; 3 Sub-Department of Animal Health and Production, Dong Thap, Vietnam; 4 Department of Global Public Health, Karolinska Institute, Stockholm, Sweden; 5 Centre for Tropical Medicine and Global Health, Oxford University, UK *Corresponding author. E-mail: juanjo_cm@yahoo.com Received 28 December 2021; accepted 13 March 2022 Background: Vietnam and Southeast Asia are hotspots for antimicrobial resistance; however, little is known on the prevalence of carriage of carbapenem resistance in non-hospitalized humans and in animals. Carbapenem- resistant Enterobacteriaceae (CRE), particularly Escherichia coli (CREC) and Klebsiella pneumoniae (CRKP) and also Acinetobacter baumannii (CRAB) are emerging threats worldwide. Methods: We investigated healthy humans (n = 652), chickens (n = 237), ducks (n = 150) and pigs (n = 143) in 400 small-scale farms in the Mekong Delta of Vietnam. Samples (rectal swabs, faecal swabs) were investigated for carriage of CRE/CRAB and were further characterized phenotypically and genotypically. Results: In the Mekong Delta of Vietnam, the prevalence of CRE isolates in human rectal swabs was 0.6%, in- cluding 4 CREC and 1 CRKP. One pig was infected with CREC (prevalence 0.7%). CRAB was isolated from chickens (n = 4) (prevalence 2.1%) and one duck (prevalence 0.7%). CRKP was isolated from a human who was also co- lonized with CREC. The CRKP strain (ST16), from an 80 year-old person with pneumonia under antimicrobial treatment, genetically clustered with clinical strains isolated in a hospital outbreak in southern Vietnam. The prevalence of CRE was higher among humans that had used antimicrobials within 90 days of the sampling date than those had not (4.2% versus 0.2%) (P = 0.005). All CRE/CRAB strains were MDR, although they were sus- ceptible to colistin and neomycin. The carbapenemase genes identified in study strains were bla NDM and bla OXA . Conclusions: The finding of a CRKP strain clustering with previous hospital outbreak raises concerns about po- tential transmission of carbapenem-resistant organisms from hospital to community settings or vice-versa. Introduction Carbapenems are β-lactam antimicrobials used for the treatment of infections caused by MDR Gram-negative bacteria. 1 Currently they are classified by WHO as high priority, critically important antimicrobials; 2 carbapenem-resistant Enterobacteriaceae (CRE) and Acinetobacter baumannii (CRAB) (alongside Pseudomonas aeruginosa) are regarded as ‘critical, high priority pathogens’ by WHO. 3 Globally, the incidence of infections with both types of pathogen has been steadily increasing. 4,5 CRE infections are now being widely reported in Southeast Asian hospital settings. 6,7 Data from Vietnamese hospitals have documented that this leads to increased mortality and asso- ciated health care costs. 8,9 Prevalence of infection with CRE among patients correlates with length of hospitalization (from 13% on admission to 89% at day 15). 9 Laboratory data indicate increased prevalence of carbapenem resistance between 2012 and 2016 among Escherichia coli (CREC) (from 6% to 8%) and Klebsiella pneumoniae (CRKP) (from 17% to 24%). 10 Recently, two nosocomial CRKP outbreaks caused by distinct lineages of se- quence type (ST) 16 have been reported in Vietnam. CRKP strains from Vietnam are typically MDR, and are resistant to colistin. 11,12 Studies in Ho Chi Minh City (southern Vietnam) (2010–12) indi- cated that resistance to carbapenems among Acinetobacter spp. © The Author(s) 2022. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/ by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. 1 of 10 JAC Antimicrob Resist https://doi.org/10.1093/jacamr/dlac038 JAC- Antimicrobial Resistance Downloaded from https://academic.oup.com/jacamr/article/4/2/dlac038/6570901 by guest on 12 April 2024