• Altun, B.
• Gündoğdu, A.
• Gür, D.
• Hazırolan, G.

Abstract

Lactobacilli are part of the microbiota and are also used as probiotics. However, in recent years they have been associated with invasive infections, especially bacteremia. <i>Lactobacillus</i> spp. are usually susceptible to penicillins, macrolides, and carbapenems, but <i>Lactobacillus rhamnosus</i> is intrinsically resistant to glycopeptides. The aim of this study was to determine the antimicrobial susceptibility profile and resistance mechanism of a clinical isolate of <i>L. rhamnosus</i> isolated from 10 sets of blood cultures of the same patient. The isolate was identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (Bruker Daltonics; BD, Bremen, Germany) and 16S rRNA gene sequencing. <i>In vitro</i> susceptibilities to penicillin, ampicillin, imipenem, vancomycin, erythromycin, clindamycin, and linezolid were determined with gradient test strips (bioMérieux, France) on Mueller-Hinton agar plates supplemented with 5% defibrinated horse blood and 20 mg/L β-NAD. The isolate was resistant to vancomycin and imipenem. Polymerase chain reaction test was positive for <i>bla</i>OXA-48 and the presence of this carbapenemase was confirmed by gene sequencing. Although plasmid analysis suggested that the <i>bla</i>OXA-48 is chromosomal in this isolate, it is still an alarming finding for potential transmission of antibiotic resistance genes to other bacteria in the gut. To our knowledge, this is the first report of the presence of <i>bla</i>OXA-48 in a <i>Lactobacillus</i> spp. and has utmost importance as these bacteria are used as probiotics. The isolation of these bacteria from sterile body sites should not go unnoticed.

Topics

• impedance spectroscopy
• susceptibility
• spectrometry
• time-of-flight mass spectrometry