Ekaterina A. Brzhozovskaya, Russian Federation

National Medical Research Center for Children's Health Laboratory of microbiology

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IDENTIFICATION OF FLUOROQUINOLONE-NONSUSCEPTIBLE MULTIPLE DRUG-RESISTANT (MDR) PEDIATRIC NASOPHARYNGEAL STREPTOCOCCUS PNEUMONIAE ISOLATED IN RUSSIA, 2010-2018  (ID 324)

Session Name
Basic Sciences - Conventional and Molecular Microbiology
Presenter
Authors

Abstract

Background

Spread of MDR-S. pneumoniae requires regular monitoring of the resistance level worldwide. Emerging fluoroquinolone resistant pneumococci cause concern.

Methods

MDR-pneumococci (n=478;22%) were collected from nasopharyngeal pediatric pneumococcal collection from Russia, in 2010-2018. Susceptibility testing to ten antimicrobial groups was performed using the broth microdilution method (Sensititre). WGS was performed on the Illumina HiSeq-2500 platform.

Results

The most common resistance (R) profile among MDR-pneumococci was nonsusceptibility to erythromycin/clindamycin/tetracycline/trimethoprim-sulfamethoxazole +/-penicillin, which was determined in 32.4% (n=155) or 23.4% (n=112) isolates, respectively. Moreover, six isolates possessed resistance to fluoroquinolones. A total of 25 different serotypes were identified. One or more isolates of each MDR-serotypes were selected for the WGS.
39 MDR-isolates with levofloxacin MICs<2 mg/L had no mutations in the quinolone-resistance determining regions. Two levofloxacin/moxifloxacin-R 23F/ST81 pneumococci (MIC 8 and 2 mg/L) had mutations in parC(D83N,K137N)/gyrA(S81F)/parE(I460V); susceptible to moxifloxacin 19F/ST8099 and 31/ST2992 (levofloxacin MIC 4 and 8 mg/L) had mutations in parC(D83Y)/parE(I460V). It should be noted, that two levofloxacin/moxifloxacin-R 19F/ST162 and 23F/ST102 isolates (MIC 8 and 1 mg/L) had not typical mutations, and it can be associated with antibiotic efflux. Previously described amino acid substitutions in the gyrB have no been identified.

Conclusions

Genomic surveillance could be a useful tool for monitoring of antibiotic resistance formation.

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Author Of 2 Presentations

 Conference Calendar

IDENTIFICATION OF FLUOROQUINOLONE-NONSUSCEPTIBLE MULTIPLE DRUG-RESISTANT (MDR) PEDIATRIC NASOPHARYNGEAL STREPTOCOCCUS PNEUMONIAE ISOLATED IN RUSSIA, 2010-2018  (ID 324)

Session Name
Basic Sciences - Conventional and Molecular Microbiology
Presenter
Authors

Abstract

Background

Spread of MDR-S. pneumoniae requires regular monitoring of the resistance level worldwide. Emerging fluoroquinolone resistant pneumococci cause concern.

Methods

MDR-pneumococci (n=478;22%) were collected from nasopharyngeal pediatric pneumococcal collection from Russia, in 2010-2018. Susceptibility testing to ten antimicrobial groups was performed using the broth microdilution method (Sensititre). WGS was performed on the Illumina HiSeq-2500 platform.

Results

The most common resistance (R) profile among MDR-pneumococci was nonsusceptibility to erythromycin/clindamycin/tetracycline/trimethoprim-sulfamethoxazole +/-penicillin, which was determined in 32.4% (n=155) or 23.4% (n=112) isolates, respectively. Moreover, six isolates possessed resistance to fluoroquinolones. A total of 25 different serotypes were identified. One or more isolates of each MDR-serotypes were selected for the WGS.
39 MDR-isolates with levofloxacin MICs<2 mg/L had no mutations in the quinolone-resistance determining regions. Two levofloxacin/moxifloxacin-R 23F/ST81 pneumococci (MIC 8 and 2 mg/L) had mutations in parC(D83N,K137N)/gyrA(S81F)/parE(I460V); susceptible to moxifloxacin 19F/ST8099 and 31/ST2992 (levofloxacin MIC 4 and 8 mg/L) had mutations in parC(D83Y)/parE(I460V). It should be noted, that two levofloxacin/moxifloxacin-R 19F/ST162 and 23F/ST102 isolates (MIC 8 and 1 mg/L) had not typical mutations, and it can be associated with antibiotic efflux. Previously described amino acid substitutions in the gyrB have no been identified.

Conclusions

Genomic surveillance could be a useful tool for monitoring of antibiotic resistance formation.

Hide

EMERGENCE OF A COTRIMOXAZOLE RESISTANT SEROTYPE 16F LINEAGE IN AN INTENSIVELY VACCINATED AFRICAN BIRTH COHORT: THE DRAKENSTEIN CHILD HEALTH STUDY (ID 930)

Session Name
Basic Sciences - Conventional and Molecular Microbiology
Presenter
Authors