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Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Meningococcal Antibiotic Resistance: Molecular Characterization of Isolates from Patients with Invasive Meningococcal
Ioanna Spiliopoulou1,2,3, Athanasia Xirogianni1, Stelmos Simantirakis1
1National Meningitis Reference Laboratory, Department of Public Health Policy, School of Public Health, University of West Attica, 11521 Athens, Greece.
Abstract:
For effective case management and chemoprophylaxis of Invasive Meningococcal Disease (IMD), prompt antibiotic treatment is required. N. meningitidis is usually susceptible to antibiotics, but reduced susceptibility to penicillin, ciprofloxacin, and rifampicin is increasing worldwide, jeopardizing patients' outcome. We assessed, phenotypically and genotypically, the antimicrobial resistance patterns of 192 strains isolated from IMD cases from all over Greece during 2010-2021. Antimicrobial susceptibility to penicillin, rifampicin, and ciprofloxacin was determined using the E-test. All isolates were genotyped by Multilocus Sequence Typing (MLST). penA, rpoB, and gyrA genes were amplified by PCR and sequenced. Of the 192 isolates, 37% (72/192) were penicillin-susceptible/had increased exposure, and 11% (21/192) were penicillin-resistant. Among those, 40 penA alleles were identified; penA1, penA27, and penA3 were highly associated with susceptibility to penicillin; penA14, penA25, and penA22 related to reduced susceptibility to penicillin, while penA9, penA910, and penA295 had resistance to penicillin. Two ciprofloxacin-resistant isolates harbored the gyrA346 allele, while one rifampicin-resistant isolate harbored the rpoB5 allele. Resistance to ciprofloxacin and rifampicin remains rare. As Greece is one of the countries with high antimicrobial resistance, continued monitoring of antibiotic resistance is important to ensure timely detection of emerging resistance for treatment and prevention guidelines.
Insights
Antimicrobial resistance in Invasive Meningococcal Disease (IMD) is rising globally. This study found specific penA gene alleles linked to penicillin resistance in Greek IMD strains, highlighting the need for ongoing surveillance.
Area of Science:
- Microbiology
- Infectious Diseases
- Genetics
Background:
- Prompt antibiotic treatment is crucial for managing Invasive Meningococcal Disease (IMD).
- Increasing global antibiotic resistance to common treatments like penicillin, ciprofloxacin, and rifampicin poses a significant threat to patient outcomes.
- Monitoring antimicrobial resistance patterns is essential for effective public health strategies.
Purpose of the Study:
- To assess the antimicrobial resistance patterns of Neisseria meningitidis strains isolated from IMD cases in Greece.
- To identify specific genetic markers associated with resistance to penicillin, ciprofloxacin, and rifampicin.
- To inform treatment and prevention guidelines in a region with high antimicrobial resistance.
Main Methods:
- Phenotypic antimicrobial susceptibility testing (E-test) for penicillin, rifampicin, and ciprofloxacin.
- Genotypic characterization using Multilocus Sequence Typing (MLST).
- PCR amplification and sequencing of penA, rpoB, and gyrA genes.
Main Results:
- Of 192 isolates, 11% were penicillin-resistant, and 37% showed reduced susceptibility.
- Forty penA alleles were identified, with specific alleles (e.g., penA9, penA910) strongly associated with penicillin resistance.
- Resistance to ciprofloxacin and rifampicin was rare, with only a few isolates harboring specific resistance-associated alleles (gyrA346, rpoB5).
Conclusions:
- Specific penA gene alleles are key indicators of penicillin resistance in N. meningitidis.
- While ciprofloxacin and rifampicin resistance remain uncommon, continued monitoring is vital.
- Ongoing surveillance of antibiotic resistance in Greece is critical for adapting treatment and prevention strategies against IMD.
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