Erythromycin-Susceptible but Clindamycin-Resistant Phenotype of Clinical <i>ermB</i>-PCR-Positive Group B Streptococci Isolates with IS<i>1216E</i>-Inserted <i>ermB</i>

Abstract

Streptococcus agalactiae (Group B Streptococcus, GBS) is a pathogen which causes neonatal sepsis, meningitis, and invasive infections in the elderly and people with medical conditions (1,2). Although β-lactams are prescribed as first line drugs for the treatment and prevention of GBS infections, in case of patients with penicillin-allergies, macrolides and lincosamides are often prescribed for the same (1,2). However, macrolide and lincosamide resistance rates in GBS have been increasing worldwide (3-5). Macrolide resistant Streptococcus spp. has the following 2 major phenotypes: macrolides, lincosamides, streptogramin B (MLSB) and M (6,7). The MLSB phenotype confers a broad resistance to macrolides, lincosamides, and streptogramin B, whereas the M phenotype confers resistance to macrolides, but not to lincosamides and streptogramin B. In addition, an L phenotype also exists, which confers resistance to lincosamides, but not to macrolides (7). A macrolide resistance gene (erm) encoding erythromycin ribosomal methylase, confers typical MLSB phenotype (8). However, in the present study, 3 clinical ermB-PCR-positive isolates of GBS with L phenotype were isolated in Korea and the mechanisms

Whole Genome Analysis of Three Multi-Drug Resistant Listeria innocua and Genomic Insights Into Their Relatedness With Resistant Listeria monocytogenes

“…Sequence comparisons highlighted the mosaic nature of MDR gene islands in both of these plasmids wherein their resistance genes appeared to arise from multiple origins including Staphylococcus aureus, Enterococcus faecium, and Lactococcus lactis, with IS1216E likely to play a decisive role in the recombination steps contributing to their formation. Similar observations have been reported earlier by others (Kang et al, 2019;Moroi et al, 2019;Iimura et al, 2020).…”

Clonal Distribution of Clindamycin-Resistant Erythromycin-Susceptible (CRES) Streptococcus agalactiae in Korea Based on Whole Genome Sequences

“…Another CRES isolate of CPS genotype III was isolated from a patient with bacteremia in Bergen, Norway, in 2010 [23]. Three CRES isolates of serotype III were recovered from clinical specimens in Seoul during 2010-2013 [9,24]. These findings are in line with our observation that all CRES isolates in Gyeongnam Province in the south of Korea were recovered between March 2010 and August 2011.…”

“…Deletion of a segment in erm (B) sequence in CRES suggests loss of function of the erm (B) protein in this isolate, resulting in an erythromycin-susceptible phenotype. Interestingly, three CRES isolates (NUBL-9601, NUBL-9602, and NUBL-9603) isolated at a hospital in Seoul during 2010–2013 had the identical sequences (accession numbers LC430933, LC430934, and LC430935) (3) [ 9 , 10 ]. Furthermore, we observed the IS 1216E insertion in erm (B) (accession numbers LC512881, LC512882, LC512883, LC512885, and LC512886) in five isolates (GCH16, GCH19, GCH38, GCH55, and GCH58, respectively) of this study.…”

“…In addition, an L phenotype exists, which is resistant to lincosamides, but not to macrolides [8]. The clindamycin-resistant erythromycin-susceptible (CRES) phenotype corresponds to the L phenotype [9].…”

Multiplex real-time PCR using SYBR Green: Unspecific intercalating dye to detect antimicrobial resistance genes of Streptococcus pneumoniae in cerebrospinal fluid

“…To the best of our knowledge, there is no documentation about a strain double-positive ( ermB and mef genes) with a phenotype clindamycin-susceptible. It was observed erythromycin susceptibility and clindamycin resistance profile in 3 strains of Streptococcus agalactiae portraying erm and lnuB genes by Moroi et al [ 24 ], and they suggested a loss-of-function of ErmB protein, which could be what happened with our strain, and it keeps the resistance to erythromycin due to the mef gene. Although macrolides and lincosamides are not used to treat meningitis, the genetic characterization of antimicrobial resistance of pneumococcal isolates, which can be performed by different molecular marker methods with the isolated strain, is crucial to monitoring the epidemiology of the pneumococcal disease.…”