In Vitro Efficacy of Flomoxef against Extended-Spectrum Beta-Lactamase-Producing <i>Escherichia coli </i>and <i>Klebsiella pneumoniae </i>Associated with Urinary Tract Infections in Malaysia

• Main Authors: Soo Tein Ngoi, Cindy Shuan Ju Teh, Chun Wie Chong, Kartini Abdul Jabar, Shiang Chiet Tan, Lean Huat Yu, Kin Chong Leong, Loong Hua Tee, Sazaly AbuBakar
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Antibiotics
• Subjects: antimicrobial resistance; β-lactamase inhibitor; broad-spectrum β-lactamase; resistance gene; <i>Enterobacteriaceae</i>
• Online Access: https://www.mdpi.com/2079-6382/10/2/181

The increasing prevalence of extended-spectrum β-lactamase (ESBL)-producing <i>Enterobacteriaceae </i>has greatly affected the clinical efficacy of β-lactam antibiotics in the management of urinary tract infections (UTIs). The limited treatment options have resulted in the increased use of carbapenem. However, flomoxef could be a potential carbapenem-sparing strategy for UTIs caused by ESBL-producers. Here, we compared the in vitro susceptibility of UTI-associated ESBL-producers to flomoxef and established β-lactam antibiotics. Fifty <i>Escherichia coli </i>and <i>Klebsiella pneumoniae </i>strains isolated from urine samples were subjected to broth microdilution assay, and the presence of ESBL genes was detected by polymerase chain reactions. High rates of resistance to amoxicillin-clavulanate (76–80%), ticarcillin-clavulanate (58–76%), and piperacillin-tazobactam (48–50%) were observed, indicated by high minimum inhibitory concentration (MIC) values (32 µg/mL to 128 µg/mL) for both species. The ESBL genes <i>bla</i>_CTX-Mand <i>bla</i>_TEMwere detected in both <i>E. coli </i>(58% and 54%, respectively) and <i>K. pneumoniae </i>(88% and 74%, respectively), whereas <i>bla</i>_SHVwas found only in <i>K. pneumoniae </i>(94%). Carbapenems remained as the most effective antibiotics against ESBL-producing <i>E. coli </i>and <i>K. pneumoniae </i>associated with UTIs, followed by flomoxef and cephamycins. In conclusion, flomoxef may be a potential alternative to carbapenem for UTIs caused by ESBL-producers in Malaysia.