In Vitro Antimicrobial Susceptibility Profiles of Gram-Positive Anaerobic Cocci Responsible for Human Invasive Infections

Abstract

The aim of this multicentre study was to determine the in vitro susceptibility to anti-anaerobic antibiotics of Gram-positive anaerobic cocci (GPAC) isolates responsible for invasive infections in humans. A total of 133 GPAC isolates were collected in nine French hospitals from 2016 to 2020. All strains were identified to the species level (MALDI-TOF mass spectrometry, 16S rRNA sequencing). Minimum inhibitory concentrations (MICs) of amoxicillin, piperacillin, cefotaxime, imipenem, clindamycin, vancomycin, linezolid, moxifloxacin, rifampicin, and metronidazole were determined by the reference agar dilution method. Main erm-like genes were detected by PCR. The 133 GPAC isolates were identified as follows: 10 Anaerococcus spp., 49 Finegoldia magna, 33 Parvimonas micra, 30 Peptoniphilus spp., and 11 Peptostreptococcus anaerobius. All isolates were susceptible to imipenem, vancomycin (except 3 P. micra), linezolid and metronidazole. All isolates were susceptible to amoxicillin and piperacillin, except for P. anaerobius (54% and 45% susceptibility only, respectively). MICs of cefotaxime widely varied while activity of rifampicin, and moxifloxacin was also variable. Concerning clindamycin, 31 were categorized as resistant (22 erm(A) subclass erm(TR), 7 erm(B), 1 both genes and 1 negative for tested erm genes) with MICs from 8 to >32 mg/L. Although GPACs are usually susceptible to drugs commonly used for the treatment of anaerobic infections, antimicrobial susceptibility should be evaluated in vitro.

Odontogenic brain abscess due to Anaerococcus prevotii infections: A case report and review article

“…The results of bacterial identification showed that Anaerococcus prevotii was a gram-positive, anaerobic bacteria and was also described as a common resident of the normal flora of the skin, the oral cavity and the gut [15] . Previous studies have shown that Anaerococcus prevotii is sensitive to metronidazole, and AST is used for confirmation before its use [16] , [17] . Usually, “triple high dose” antibiotics are recommended intravenously for 2 weeks, followed by 4 weeks of oral therapy.…”

Antibiotic Resistance and Mechanisms of Pathogenic Bacteria in Tubo-Ovarian Abscess

“…Reduced affinity to target molecule PBP alterations (Gajdacs et al, 2017) b-lactams target site mutation Methylation of the 23S rRNA: ermA, ermB, ermF, and ermTR (Reig et al, 2001;Guerin et al, 2020;Guerin et al, 2021) Nitroimidazole reductase: nimB (Theron et al, 2004) Macrolides Metronidazole…”

“…Overall, 7% of the strains were resistant to penicillin and/or clindamycin ( Brazier et al., 2008 ), even though it is widely accepted that GPAC species retain much greater susceptibility to cephalosporins, carbapenems, chloramphenicol, and β-lactam/β-lactamase inhibitors. Generally speaking, GPAC exhibit varying resistance to penicillins (2–25%), clindamycin (3–24%), and metronidazole (3–15%) while having a much greater susceptibility to β-lactam/β-lactamase inhibitors, cephalosporins, carbapenems, and chloramphenicol ( Hastey et al., 2016 ; Yunoki et al., 2017 ; Byun et al., 2019 ; Cobo et al., 2019 ; Badri et al., 2019 ; Forbes et al., 2021 ; Guerin et al., 2021 ).…”

“…The erm family genes encode adenine-specific N-methyltransferases that methylate the 23S rRNA to prevent antibiotic binding. It is noteworthy that the genetic basis of resistance to macrolides–lincosamides–streptogramins in GPAC is not fully elucidated; only three studies have looked into the molecular basis: ermA , ermTR , ermB , and ermF have been identified in GPAC strains ( Reig et al., 2001 ; Guerin et al., 2020 ; Guerin et al., 2021 ). A β-lactam/β-lactamase inhibitor combination is widely used in the treatment of anaerobic infections.…”

Understanding antimicrobial susceptibility profile of Finegoldia magna: an insight to an untrodden path

“…Antimicrobial resistance among anaerobes is witnessing a significant upsurge in the recent years worldwide [ 5 ]. Though, GPAC are usually susceptible to commonly used anaerobic antimicrobials, increasing resistance trends and significant difference in susceptibility profile among different species of GPAC have been reported in literature [ 5 , 6 ]. Variable resistance to penicillin (7–10%), metronidazole (5–10%) and clindamycin (7–20%) have been reported amongst GPAC [ 1 , 7 ].…”