The efficacy of faropenem for patients with acute cystitis caused by extended spectrum β-lactamase producing Escherichia coli

A systematic scoping review of faropenem and other oral penems: treatment of Enterobacterales infections, development of resistance and cross-resistance to carbapenems

Background

Antimicrobial resistance is an urgent global healthcare concern. Beyond carbapenems as broad-spectrum, often 'last resort' antibiotics, oral penem antibiotics currently are approved only in Japan and India, used for the treatment of indications including urinary tract infections (UTIs). Exploring oral penem use to better understand the impact of antibiotic resistance on public health would help inform the management of infectious diseases, including UTIs.

Scoping Review Methodology

This scoping review investigated the impact of faropenem and other oral penems on Enterobacterales infection treatment and evaluated evidence for faropenem resistance and cross-resistance to carbapenems. PubMed, Embase, J-STAGE and CiNii were searched for relevant English- or Japanese-language articles published between 1 January 1996 and 6 August 2021.

Key Findings

From 705 unique publications, 29 eligible articles were included (16 in vitro studies; 10 clinical trials; 2 in vitro and in vivo studies; and 1 retrospective medical chart review). Limited evidence described faropenem to treat infectious disease; only four randomized clinical trials were identified. Faropenem dosing regimens varied broadly within and between indications. One study indicated potential dependence of penem efficacy on underlying antibiotic resistance mechanisms, while several studies reported UTI persistence or recurrence after faropenem treatment. In vitro MIC data suggested some potential bacterial resistance to faropenem, while limited clinical data showed resistance emergence after faropenem treatment. Preliminary in vitro evidence suggested faropenem resistance might foster cross-resistance to carbapenems. Overall, very limited clinical evidence describes faropenem for treating infectious diseases. Preclinical and clinical research investment and dedicated community surveillance monitoring is crucial for understanding faropenem treatment patterns, resistance and potential cross-resistance to carbapenems.

Nationwide surveillance of bacterial pathogens isolated from patients with acute uncomplicated cystitis in 2018: Conducted by the Japanese Research Group for Urinary Tract Infections (JRGU)

INTRODUCTION

The aim of this study was to monitor the development of drug-resistant bacteria isolated from acute uncomplicated cystitis (AUC) and to evaluate methodology of the survey conducted by collecting only clinical data.

METHODS

We enrolled female patients at least 16 years of age diagnosed with AUC in 2018. Patient information including age, menopausal status, and results of bacteriological examination were collected and analyzed regardless of bacterial identification, antimicrobial susceptibility testing or extended-spectrum β-lactamase (ESBL) detection method.

RESULTS

A total of 847 eligible cases were collected. Escherichia coli (E. coli) was the most frequently isolated bacterial species at about 70%, with proportions of fluoroquinolone-resistant E. coli (QREC) and ESBL-producing E. coli isolates at 15.6% and 9.5% of all E. coli isolates, respectively. The proportion of Staphylococcus saprophyticus (S. saprophyticus) was significantly higher in premenopausal women. Regarding the drug susceptibility of E. coli, isolates from Eastern Japan had significantly higher susceptibility to cefazolin, cefotiam and cefpodoxime and lower susceptibility to levofloxacin in postmenopausal women. ESBL-producing E. coli isolates had a high susceptibility to tazobactam-piperacillin, cefmetazole, carbapenems, aminoglycosides, and fosfomycin. In S. saprophyticus, the susceptibility to β-lactams including carbapenems was 40-60%.

CONCLUSIONS

The proportions of QREC and ESBL-producing E. coli were increasing trends and lower susceptibility to LVFX in postmenopausal women was observed. Such surveillance, consisting of the collecting only clinical data, could be conducted easily and inexpensively. It is expected to be continuously performed as an alternative survey to conventional one collecting bacterial strains.