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.

Background/Objectives: Neisseria meningitidis is a human-specific pathogen capable of causing life-threatening illnesses. Occasionally, it is recovered from unusual sites, other than the bloodstream or the central nervous system. Herein, we describe two rare manifestations due to N. meningitidis within a year (2024) in Greece. Methods: Atypical infection due to N. meningitidis was diagnosed in two different patients: Case-1 presented with an inflammatory swelling in the mid-line of the neck, and Case-2 presented with swelling of the left knee. Both patients had high fever and no neurological signs at admission; Case-2 progressed to meningoencephalitis. Phenotypic and genotypic identifications were carried out in both cases. Results: Case-1 and Case-2 isolates were identified as follows: MenX: 18, 25-44, F5-5, ST-823; 198cc and MenB: 7-1, 1, F3-3, ST-7460; 32cc for PorA, FetA and MLST, respectively. MenX was identified for the first time in Greece and finetyping revealed rare genotypic characteristics. Both isolates were susceptible to cefotaxime, ceftriaxone and rifampicin, while Case-2 isolate expressed reduced susceptibility to penicillin and resistance to ciprofloxacin. Both patients recovered fully. Conclusions: Although uncommon, N. meningitidis may be isolated from atypical sites and specimens. Clinicians and microbiologists should remain aware that meningococcus is a potential cause of infections beyond meningitis and septicaemia.

Background/Objectives: Meningitis due to the species Streptococcus is a severe central nervous system infection caused by various microorganisms belonging to Streptococcus spp. Its accurate identification is critical for effective clinical management. This study aimed to identify Streptococcus spp. causing meningitis in Greece over a nine-year period using PCR and sequencing-based methods. Methods: A total of 189 clinical samples, collected between 2015 and 2024 from patients suffering from meningitis and/or septicemia, were analyzed by the use of a combination of multiplex polymerase chain reaction (PCR) assays and tuf gene sequencing for further species identification. Results: Sample analysis identified 70 samples as S. pyogenes (18.52%) (GAS) and S. agalactiae (18.52%) (GBS), while 119 (62.96%) were recorded as non-typable Streptococcus spp. Further analysis using sequencing methods revealed that the most frequent Streptococcus spp. belonged to the mitis group (42.86%) and the pyogenic group (20.17%). A higher prevalence was observed in children aged 0–14 years old and adults over 50 years old. Conclusions: This study highlights the use of molecular diagnostics in identifying other Streptococcus spp., providing insights into age-related susceptibility and epidemiological trends. Future studies are needed to explore the pathogenic role of the identified Lactococcus spp.

Background: The decrease in the rate of meningitis due to Haemophilus influenzae type b after vaccine introduction and a possible change in epidemiology of H. influenzae disease highlights the need for continuous serotype surveillance. Methods: A single-tube multiplex PCR assay for serotyping of H. influenzae was developed and deployed. Results: During 2003–2020, 108 meningitis cases due to H. influenzae were notified; 86 (80%) were confirmed and serotyped by molecular methods. The overall specificity and sensitivity of the assay were estimated (100% PPV and NPV respectively). The overall mean annual reported incidence for H. influenzae was 0.02, while for Hib and non-b meningitis equaled 0.02 and 0.03 per 100 000, respectively. Analysis by age group revealed that H. influenzae peaks in toddlers and children 0–4 years and in adults >45 years old. Among the serotyped cases, 39.8% were identified as Hib, 46.3% as NTHi, and 0.9% and 2.8% as serotypes a (Hia) and f (Hif)) respectively. Conclusions: Low incidence due to Hib was observed while non-typeable H. influenzae (NTHi) and serotypes Hia and Hif seem to emerge. The application of the current assay discloses the ongoing change of invasive H. influenzae disease trends during the Hib post-vaccine era.