Background/Objective: Bacteriological culture has been a widely used method for the detection of meningococcus, but it has low sensitivity and a long turnaround time. Molecular detection targeting capsule transport A (
ctrA) gene has been used, but over 16% of meningococcal carriage isolates lack
ctrA, resulting in false-negative reports. The Cu-Zn superoxide dismutase gene (
sodC) is specific to
N. meningitidis, and is not found in other
Neisseria species, making it a useful target for improved detection of non-groupable meningococci without intact
ctrA. The primary objective of this study was to evaluate the performance compassion of two in-house PCR methods,
sodC gene- and
ctrA gene-based PCR assays, for detecting
N. meningitidis in asymptomatic carriers. The secondary objective was to assess antimicrobial resistance profiling of
N. meningitidis isolates.
Methods: The performance of
sodC gene-based PCR assay compared to
ctrA gene-based PCR for detection of
N. meningitidis was evaluated using clinical samples (pharyngeal swabs;
n = 137) collected from suspected asymptomatic carriers and culture-confirmed meningococci isolates (
n = 49). Additionally, the antimicrobial sensitivity of the 49 isolates against antimicrobial drugs was determined using a disk diffusion test.
Result: Of 49 DNA samples from culture-positive
N. meningitidis isolates, the
sodC gene-based PCR accurately identified all 49, whereas the
ctrA gene-based PCR identified only 33 out of 49. Of 137 pharyngeal swabs, the
sodC gene-based assay detected
N. meningitidis DNA in 105 (76.6%), while the
ctrA-based assay detected
N. meningitidis DNA in 64 (46.7%). Out of the 49 N. meningitidis isolates, 43 (87.8%) were resistant to amoxicillin, 42 (83.7%) to ampicillin, 32 (65.3%) to trimethoprim–sulfamethoxazole, 22 (44.9%) to ceftazidime, 18 (36.7%) to ceftriaxone, and 7 (15.2%) to meropenem. Additionally, the majority of the isolates, 36 (73.5%), were sensitive to cefepime, 31 (63.3%) to ceftriaxone and meropenem, and 26 (53.1%) to ceftazidime.
Conclusions: The findings of this study highlight the necessity of adopting non-capsular
sodC-based PCR to replace
ctrA in resource-constrained laboratories to improve
N. meningitidis detection, and underscore the importance of periodic antimicrobial resistance surveillance to inform and adapt treatment strategies.
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