Distribution of Extended-Spectrum β-Lactamase Genes and Antimicrobial Susceptibility among Residents in Geriatric Long-Term Care Facilities in Japan

Dai Akine,Kazumasa Sasaki,Yumiko Kimura,Longzhu Cui,Ryusuke Ae,Shinya Watanabe,Masanori Ogawa,Yoshinari Kubota,Kotaro Kiga,Teppei Sasahara,Yuji Morisawa,Koki Kosami,Akio Yoshimura

doi:10.3390/antibiotics11010036

Abstract

A high prevalence of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) may call for monitoring in geriatric long-term care facilities (g-LTCFs). We surveyed the distribution of ESBL-causative gene types and antimicrobial susceptibility in ESBL-PE strains from residents in g-LTCFs, and investigated the association between ESBL-causative gene types and antimicrobial susceptibility. First, we analyzed the types of ESBL-causative genes obtained from 141 ESBL-PE strains collected from the feces of residents in four Japanese g-LTCFs. Next, we determined the minimum inhibitory concentration values for alternative antimicrobial agents against ESBL-PE, including β-lactams and non-β-lactams. Escherichia coli accounted for 96% of the total ESBL-PE strains. Most strains (94%) contained blaCTX-M group genes. The genes most commonly underlying resistance were of the blaCTX-M-9 and blaCTX-M-1 groups. Little difference was found in the distribution of ESBL-causative genes among the facilities; however, antimicrobial susceptibility differed widely among the facilities. No specific difference was found between antimicrobial susceptibility and the number of ESBL-causative genes. Our data showed that ESBL-PEs were susceptible to some antimicrobial agents, but the susceptibility largely differed among facilities. These findings suggest that each g-LTCF may require specific treatment strategies based on their own antibiogram. Investigations into drug resistance should be performed in g-LTCFs as well as acute medical facilities.

Highlights

Licensee MDPI, Basel, Switzerland.The importance of health care management in geriatric long-term care facilities is growing worldwide in countries with large aging populations
Investigations into drug resistance should be performed in geriatric long-term care facilities (g-LTCFs) as well as acute medical facilities
No specific association was found between the number of ESBL-causative genes and antimicrobial susceptibility

Summary

Introduction

Licensee MDPI, Basel, Switzerland.The importance of health care management in geriatric long-term care facilities (gLTCFs) is growing worldwide in countries with large aging populations. The prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-PE) has recently been noticeable in g-LTCFs in many countries [7,8,9,10,11,12,13,14,15,16]. Small amounts (0.05–0.10 g) of freshly voided feces from the residents were obtained from paper diapers or papers for self-collection of stool samples (AS ONE Corporation, Osaka, Japan) using stool collection tubes with agar medium Each fecal sample was directly harvested on selective screening agar plates for ESBL-PE

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