A multicentre study to determine the in vitro efficacy of flomoxef against extended-spectrum beta-lactamase producing Escherichia coli in Malaysia.

Background: The high burden of extended-spectrum beta-lactamase-producing (ESBL)-producing Enterobacterales worldwide, especially in the densely populated South East Asia poses a significant threat to the global transmission of antibiotic resistance. Molecular surveillance of ESBL-producing pathogens in this region is vital for understanding the local epidemiology, informing treatment choices, and addressing the regional and global implications of antibiotic resistance.
Methods: Therefore, an inventory surveillance of the ESBL- Escherichia coli (ESBL-EC) isolates responsible for infections in Malaysian hospitals was conducted. Additionally, the in vitro efficacy of flomoxef and other established antibiotics against ESBL-EC was evaluated.
Results: A total of 127 non-repetitive ESBL-EC strains isolated from clinical samples were collected during a multicentre study performed in five representative Malaysian hospitals. Of all the isolates, 33.9% were isolated from surgical site infections and 85.8% were hospital-acquired infections. High rates of resistance to cefotaxime (100%), cefepime (100%), aztreonam (100%) and trimethoprim-sulfamethoxazole (100%) were observed based on the broth microdilution test. Carbapenems remained the most effective antibiotics against the ESBL-EC, followed by flomoxef. Antibiotic resistance genes were identified by PCR. The bla _CTX-M-1 was the most prevalent ESBL gene, with 28 isolates (22%) harbouring bla _CTX-M-1 only, 27 isolates (21.3%) co-harbouring bla _CTX-M-1 and bla _TEM , and ten isolates (7.9%) co-harbouring bla _CTX-M-1, bla _TEM and bla _SHV . A generalised linear model showed significant antibacterial activity of imipenem against different types of infection. Besides carbapenems, this study also demonstrated a satisfactory antibacterial activity of flomoxef (81.9%) on ESBL-EC, regardless of the types of ESBL genes.
Competing Interests: Cindy Shuan Ju Teh is an Academic Editor for PeerJ. Loong Hua Tee and Kin Chong Leong were employed by Shionogi Singapore Pte Ltd at the time of the study.
(© 2023 Yap et al.)