Time to Awaken a Forgotten Antibacterial Agent: A 10-year Nationwide Surveillance of Latamoxef Resistance in China Based on 46,716 Isolates and Establishment of Tentative Epidemiological Cut-Off Values

Pan Chen; Erjia Zhang; Yingying Ma; Luying Xiong; Yunbo Chen; Ping Shen; Jinru Ji; Chaoqun Ying; Zhiying Liu; Yonghong Xiao

doi:10.2147/IDR.S566382

Time to Awaken a Forgotten Antibacterial Agent: A 10-year Nationwide Surveillance of Latamoxef Resistance in China Based on 46,716 Isolates and Establishment of Tentative Epidemiological Cut-Off Values

Infect Drug Resist. 2026 Feb 23:19:566382. doi: 10.2147/IDR.S566382. eCollection 2026.

Authors

Pan Chen^#¹, Erjia Zhang^#^{2

3}, Yingying Ma¹, Luying Xiong³, Yunbo Chen³, Ping Shen³, Jinru Ji³, Chaoqun Ying³, Zhiying Liu³, Yonghong Xiao^{2

3}

Affiliations

¹ Peking Union Medical College & Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Research Units of Infectious Disease and Microecology, Chinese Academy of Medical Sciences, Beijing, People's Republic of China.
² Department of Structure and Morphology, Jinan Microecological Biomedicine Shandong Laboratory, Jinan, People's Republic of China.
³ State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.

^# Contributed equally.

Abstract

Purpose: Latamoxef has been used to treat various bacterial infections. To provide data supporting the rational clinical use of latamoxef, bacterial resistance over 10 years was analyzed at multiple centers throughout China. The results were used to develop tentative epidemiological cut-off values (TECOFFs) for latamoxef.

Methods: A total of 46,716 strains of common Enterobacteriaceae were collected from patients with bloodstream infections at 72 hospitals in 21 provinces of China between 2014 and 2023. The in vitro antimicrobial activities of latamoxef were compared with those of other commonly used cephalosporin and carbapenem. The distribution of minimum inhibitory concentrations was subjected to cumulative log-normal fitting to obtain the TECOFFs of latamoxef for common Enterobacteriaceae.

Results: The sensitivities of Escherichia coli (E. coli), Salmonella species, Serratia marcescens (S. marcescens) and Proteus mirabilis (P. mirabilis) to latamoxef ranged from 94.37% to 98.08%. Klebsiella oxytoca (K. oxytoca) and Enterobacter aerogenes (E. aerogenes) had sensitivities of 89.91% and 87.21%, respectively, whereas Klebsiella pneumoniae (K. pneumoniae) and Enterobacter cloacae (E. cloacae) had lower sensitivities. The in vitro activity of latamoxef against these bacteria, especially extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, was similar to the activities of ertapenem and meropenem and significantly higher than the activities of ceftriaxone, ceftazidime, and cefepime. The sensitivities of ESBL (+) E. coli and ESBL (+) P. mirabilis to latamoxef were similar to their sensitivities to ertapenem and meropenem. ESBL (+) K. pneumoniae and ESBL (+) K. oxytoca exhibited comparable but lower rates of sensitization to latamoxef, ertapenem, and meropenem. Latamoxef had TECOFFs of 2 µg/mL for E. coli, K. pneumoniae, K. oxytoca, P. mirabilis, E. aerogenes, Salmonella, and S. marcescens, and 4 µg/mL for E. cloacae.

Conclusion: Latamoxef has good and stable in vitro antimicrobial activity against Enterobacteriaceae, including ESBL-producing Enterobacteriaceae. The calculated TECOFFs of latamoxef provide an important reference for subsequent use of this antibiotic against Enterobacteriaceae.

Keywords: antimicrobial resistance; epidemiological cut-off values; latamoxef; moxalactam; surveillance.