Third-generation cephalosporin and carbapenem resistance in Streptococcus mitis/oralis. Results from a nationwide registry in the Netherlands

Abstract

Knowledge of beta-lactam resistance rates in Streptococcus mitis group bacteria is especially important in neutropenic haematological patients as adequate empirical antibiotic treatment (often including agents like meropenem [1]) is paramount. EUCAST guidelines allow one to infer viridans group streptococci (VGS) beta-lactam susceptibility from benzylpenicillin susceptibility; penicillin-resistant isolates should be tested for individual agents. Few studies reported the association between penicillin resistance and broad-spectrum beta-lactam resistance in VGS [2,3], and data from Northern European countries is lacking. Here, we first describe the prevalence of beta-lactam resistance in S. mitis/oralis in The Netherlands. Second, we describe the association between penicillin MIC and broad-spectrum beta-lactam resistance.The Dutch national surveillance system for antimicrobial resistance (ISIS-AR) [4], covering 44 out of 56 Dutch clinical microbiology laboratories in 2017, was searched for susceptibility results of S. mitis/oralis isolates for (benzyl)penicillin, amoxicillin/ampicillin, cefotaxime/ceftriaxone, and meropenem from 2013 through 2017.ISIS-AR collects susceptibility test results of all bacterial isolates of collaborating laboratories. The analysis was limited to the first isolate of each patient. Patients whose first isolate was not tested for penicillin susceptibility were excluded.To avoid bias due to selective testing, for each antibiotic only laboratories testing 50% of isolates were included. Forty-one laboratories were included for analyses on penicillin susceptibility, 24 laboratories for amoxicillin/ampicillin, and 23 for cefotaxime/ceftriaxone. Meropenem was tested in 15 laboratories; here the inclusion rule was not applied, as this resulted in a significant impact on the number of isolates for analysis. All selected laboratories used EUCAST guidelines, except one laboratory in 2013. MIC breakpoint for susceptibility is 0.25 mg/L for penicillin, 0.5 mg/L for amoxicillin/ampicillin and cefotaxime/ceftriaxone, and 2 mg/L for meropenem.Of 4164 S. mitis/oralis isolates tested for penicillin, 3634 were reported susceptible (87.2%), 281 intermediate (6.7%), and 249 resistant (6.0%). Of 2019 isolates with amoxicillin/ampicillin susceptibility reported, 117 isolates were reported resistant (5.8%) to either agent. Of 2079 isolates with cefotaxime/ceftriaxone susceptibility reported, 159 were resistant (7.6%). Of 306 isolates with meropenem susceptibility reported, four were resistant (1.3%). Percentages of broad-spectrum beta-lactam resistance by penicillin susceptibility category is shown in the Table S1.For amoxicillin/ampicillin susceptible isolates, the median penicillin MIC with automated testing was 0.06 mg/L (IQR 0.06e0.12; n ¼ 875), for intermediate isolates 1.0 mg/L (IQR 0.5e2.0; n ¼ 55), and for resistant isolates 2.0 mg/L (IQR 2.0e4.0; n ¼ 51). Results with gradient testing were similar: for susceptible isolates median penicillin MIC was 0.047 mg/L (IQR 0.023e0.094; n ¼ 327), for intermediat...

Antibiotic susceptibility patterns of viridans group streptococci isolates in the United States from 2010 to 2020

“…In a study that included 1152 VGS isolates collected between 1997 and 2000 from around the world, the penicillin susceptibility rate was 68.6%. 7 More recently, a study of 4164 S. mitis and S. oralis isolates collected in the Netherlands between 2013 and 2017 showed that 87.2% of isolates were susceptible to penicillin, 8 which was similar to the susceptibility rate in a smaller study of isolates from the United States and Europe. 10 Herein, the cumulative penicillin susceptibility rate when combining all species was 83.3% among 12 661 isolates (penicillin susceptibility for S. mitis = 71.0%, S. oralis = 80.9%, non-speciated VGS = 86.3%).…”

Metabolic changes associated with adaptive resistance to daptomycin in Streptococcus mitis-oralis

“…Among the viridans group streptococci, the S. mitis-oralis subgroup (i.e., S. mitis, S. oralis, S. gordonii and S. parasanguinis) are the predominant IE etiologies. This sub-group is therapeutically problematic, as between 10 and 40% of strains exhibit resistance to penicillins and/or cephalosporins, including ceftriaxone [3,4]. For this reason, the majority of research into S. mitis-oralis antibiotic resistance todate relates to the genetic determinants of penicillin resistance (e.g., [5]).…”

Clinical and radiological characteristics of brain abscess due to different organisms in hospitalized patients: A 6-year retrospective study from China

“…S. species, including S. milleri group, S. pneumoniae, etc., are the most common bacteria isolated from patients with BAs [ 20 , 21 ]. Third-generation cephalosporin resistance has been reported in less than 8% of Streptococci mitis/oralis isolates in the Netherlands [ 22 ]. According to data from the China Antimicrobial Surveillance Network (CHINET) ( http://www.chinets.com ) in 2021, the resistance rates of Streptococcus viridans to cefotaxime, levofloxacin and clindamycin were 0%, 13.1% and 52.3%, respectively.…”