Stiliani Demeridou

Background: Streptococcus agalactiae (group B Streptococcus, GBS) remains a leading cause of invasive infections in pregnant women, fetuses, and neonates. Universal screening at 36–37 weeks of gestation and intrapartum antimicrobial prophylaxis are essential to prevent adverse outcomes. This study aimed to determine the prevalence, serotype distribution, and antimicrobial susceptibility of GBS isolates among pregnant women in Greece. Methods: Vaginal and rectal swabs were collected from pregnant women undergoing GBS screening between January 2021 and December 2025. Samples were processed using Todd-Hewitt broth with colistin and nalidixic acid, and cultured on blood agar and chromogenic media. The VITEK2 system was used for GBS identification and antimicrobial susceptibility testing against penicillin, erythromycin, clindamycin, tetracycline, levofloxacin, and vancomycin, according to EUCAST guidelines. The double-disk diffusion test was used for macrolide-lincosamide-streptogramin B (MLS_B) phenotyping. Serotyping for all ten serotypes was conducted using a commercial latex agglutination assay. Results: Among 941 women screened, 118 (12.5%) were colonized with GBS. The most prevalent serotypes were III (29.7%), V (18.6%), Ib (14.4%), IX (10.2%), Ia (9.3%), and II (9.3%). All isolates were susceptible to penicillin. Resistance to erythromycin and/or clindamycin was detected in 37 isolates. In these isolates, the predominant MLS_B phenotype was constitutive (cMLS_B, 78.4%), followed by inducible (iMLS_B, 13.5%), L (5.4%), and M (2.7%) phenotypes. Conclusions: GBS colonization was detected in 12.5% of pregnant women, with serotype III predominating, underscoring its clinical relevance due to its association with invasive neonatal disease. Although penicillin remains fully effective, the observed resistance to macrolides and lincosamides, primarily mediated by the cMLS_B phenotype, raises concerns regarding alternative therapies.

Background: Aerobic vaginitis (AV) is characterized by dysbiotic vaginal microflora with overgrowth of aerobic pathogens of enteric origin, presence of vaginal inflammation and immature epithelial cells. This study aimed to evaluate, over a period of 10 years, women of reproductive age (non-pregnant and pregnant) as well as menopausal women affected by AV. Methods: We included non-pregnant, pregnant and menopausal women diagnosed with AV over a period of 10 years. Diagnosis of AV was determined according to the criteria proposed by Donders in 2002. The isolated pathogens were identified with the rapid identification system I-dOne (Alifax S.r.l, Polverara, Italy) and the automated system VITEK2 (Biomerieux, Marcy l’Etoile, France), which was used for antimicrobial susceptibility testing. Results: The overall aerobic vaginitis prevalence rate during the studied period was 9.5%. The most common isolated pathogens were Escherichia coli 27.3%, Enterococcus faecalis 25.0%, Streptococcus agalactiae 22.2%, Klebsiella pneumoniae 8.9%, Proteus spp 4.7%, and Staphylococcus aureus 3.5%. E. coli infection significantly increased the odds of mild AV by 1.65 times (p = 0.002) and Proteus species infection was over 6 times more likely to progress to severe disease (p < 0.001). Furthermore, pregnant women were more likely to be infected with E. faecalis (p < 0.001) while menopausal women were diagnosed significantly more with severe AV (p < 0.001) compared to the other groups. Conclusions: The prevalence of aerobic vaginitis in the population studied was in concordance with global rates. Menopausal women displayed increased severe AV cases while, in contrast, mild cases were recorded during pregnancy. The most commonly isolated pathogens were of enteric origin.

Background: Aerobic vaginitis (AV) is characterized by dysbiotic vaginal microflora with overgrowth of aerobic pathogens of enteric origin, presence of vaginal inflammation and immature epithelial cells. This study aimed to evaluate, over a period of 10 years, women of reproductive age (non-pregnant and pregnant) as well as menopausal women affected by AV. Methods: We included non-pregnant, pregnant and menopausal women diagnosed with AV over a period of 10 years. Diagnosis of AV was determined according to the criteria proposed by Donders in 2002. The isolated pathogens were identified with the rapid identification system I-dOne (Alifax S.r.l, Polverara, Italy) and the automated system VITEK2 (Biomerieux, Marcy l’Etoile, France), which was used for antimicrobial susceptibility testing. Results: The overall aerobic vaginitis prevalence rate during the studied period was 9.5%. The most common isolated pathogens were Escherichia coli 27.3%, Enterococcus faecalis 25.0%, Streptococcus agalactiae 22.2%, Klebsiella pneumoniae 8.9%, Proteus spp 4.7%, Staphylococcus aureus 3.5%. E. coli infection significantly increased the odds of mild AV by 1.65 times (p=0.002) and Proteus species infection was over 6 times more likely to progress to severe disease (p=0.000). Furthermore, pregnant women were more likely to be infected with E. faecalis (p=0.000) while menopausal women were diagnosed significantly more with severe AV (p=0.000) compared to the other groups. Conclusions: The prevalence of aerobic vaginitis in the population studied was in concordance to global rates. Menopausal women displayed significantly more severe AV cases while, in contrast, mild cases were recorded during pregnancy. The most commonly isolated pathogens were of enteric origin.

Background: Streptococcus agalactiae (group B Streptococcus, GBS) remains a leading cause of invasive infections in pregnant women, fetuses, and neonates. Universal screening at 36-37 weeks of gestation followed by intrapartum antibiotic prophylaxis is essential to prevent adverse outcomes. However, data on GBS serotype distribution are limited in several regions, including Greece. This study aimed to determine the prevalence, serotype distribution, and antimicrobial susceptibility of GBS isolates among pregnant women in Greece. Methods: Vaginal and rectal swabs were collected from pregnant women undergoing routine GBS screening between January 2021 and December 2025. Samples were processed using selective enrichment broth and cultured on blood agar and chromogenic media. Identification was based on standard microbiological methods, CAMP test, and VITEK2 system. Antimicrobial susceptibility testing and macrolide-lincosamide-streptogramin B (MLS_B) phenotyping were performed. Serotyping was conducted using a commercial latex agglutination assay. Results: Among 941 women screened, 118 (12.5%) were colonized with GBS. The most prevalent serotypes were III (29.7%), V (18.6%), Ib (14.4%), IX (10.2%), Ia (9.3%), and II (9.3%). All isolates were susceptible to penicillin. Resistance to erythromycin and clindamycin was observed in 29.7% and 22.9% of isolates, respectively. The predominant MLSB phenotype was constitutive (cMLSB, 78.4%), followed by inducible (iMLSB, 13.5%), L (5.4%), and M (2.7%) phenotypes. Conclusions: GBS colonization was detected in 12.5% of pregnant women, with serotype III predominating, underscoring its clinical relevance due to its association with invasive neonatal disease. Although penicillin remains fully effective, the observed resistance to macrolides and lincosamides, primarily mediated by the cMLS_B phenotype, raises concerns regarding alternative therapies.