John G. Routsias

Recurrent vulvovaginal candidiasis (RVVC) affects 5–8% of women of reproductive age. Host genetic factors, particularly single nucleotide polymorphisms (SNPs) in Toll-like receptors (TLRs), may influence RVVC susceptibility by impairing vaginal mucosal antifungal immunity. The aim of this study was to assess the effect of SNPs in genes encoding TLRs on RVVC susceptibility. Τhe distribution of TLR2 Arg753Gln and TLR4 Asp299Gly/Thr399Ile polymorphisms in Greek women, including RVVC (n = 63), first-episode VVC (n = 37), Gardnerella vaginalis vaginitis (GV, n = 36) patients, and healthy controls (n = 61), was investigated using TaqMan SNP genotyping. Genotype and allele frequencies were analyzed under allelic and dominant models, with odds ratios (ORs), 95% confidence intervals (CIs), and linkage disequilibrium assessed. TLR4 Asp299Gly and Thr399Ile heterozygotes were significantly more frequent in RVVC patients compared with controls and affected RVVC susceptibility (OR: 5.57, 95% CI: 1.17–26.56, p: 0.0172; OR: 4.92, 95% CI: 1.02–23.78, p: 0.0306, respectively). No associations were observed for TLR2 Arg753Gln or for any SNP with GV or first-episode VVC. TLR4 variants co-segregated, indicating a haplotype effect. TLR4 haplotypes, rather than TLR2 polymorphism, confer increased RVVC susceptibility, supporting a genetically distinct, mucosal immunity-driven pathogenesis. Larger, ethnically diverse studies with functional assays are warranted to validate these findings and guide personalized prevention and treatment strategies.

Vulvovaginal candidiasis (VVC) is a prevalent vaginal infection predominantly attributed to Candida albicans. A considerable proportion of women experience more than three episodes of VVC annually, a condition referred to as recurrent vulvovaginal candidiasis (RVVC). It is estimated that RVVC affects more than 130 million women globally each year and has a substantial negative impact on their quality of life, resulting in physical discomfort, psychological distress, and social stigma. Nevertheless, not all individuals who develop VVC progress to RVVC, suggesting that genetic variation may play a critical role in host susceptibility. The present review aims to evaluate the associations between genetic predispositions—specifically polymorphisms in Toll-like receptors 2 and 4 (TLR2, TLR4)—and RVVC. TLRs are essential for detecting pathogen-associated molecular patterns (PAMPs) and initiating immune responses. During RVVC episodes, Candida undergoes a reversible transition from the yeast form to the hyphal form, resulting in alterations in surface PAMPs, which are subsequently recognized by innate immune receptors expressed on vaginal epithelial cells. Polymorphisms in these receptors may modulate individual susceptibility to RVVC. This review examines the literature on the impact of specific polymorphisms in TLR2 and TLR4 on fungal recognition and infection. Furthermore, the interactions between TLRs and other elements of the innate immune system have also been explored. A deeper understanding of how genetic variability in immune receptors influences infection susceptibility could pave the way for personalized therapeutic strategies for RVVC, potentially involving immunomodulatory agents or antifungal treatments tailored to an individual’s genetic profile.

Vulvovaginal candidiasis (VVC) is a prevalent vaginal infection predominantly attributed to Candida albicans. A considerable proportion of women experience more than three episodes of VVC annually, a condition referred to as recurrent vulvovaginal candidiasis (RVVC). It is estimated that RVVC affects more than 130 million women globally each year and has a substantial negative impact on their quality of life, resulting in physical discomfort, psychological distress, and social stigma. Nevertheless, not all individuals who develop VVC progress to RVVC, suggesting that genetic variation may play a critical role in host susceptibility. The present review aims to evaluate the associations between genetic predispositions—specifically polymorphisms in Toll-like receptors 2 and 4 (TLR2, TLR4)—and RVVC. TLRs are essential for detecting pathogen-associated molecular patterns (PAMPs) and initiating immune responses. During RVVC episodes, Candida undergoes a reversible transition from the yeast form to the hyphal form, resulting in alterations in surface PAMPs, which are subsequently recognized by innate immune receptors expressed on vaginal epithelial cells. Polymorphisms in these receptors may modulate individual susceptibility to RVVC. This review examines the literature on the impact of specific polymorphisms in TLR2 and TLR4 on fungal recognition and infection. Furthermore, the interactions between TLRs and other elements of the innate immune system have also been explored. A deeper understanding of how genetic variability in immune receptors influences infection susceptibility could pave the way for personalized therapeutic strategies for RVVC, potentially involving immunomodulatory agents or antifungal treatments tailored to an individual’s genetic profile.

Brucellosis remains an important zoonotic disease in several parts of the world; in Greece, although it is declining, it is still endemic, affecting both the financial and public health sectors. The current study was undertaken to investigate the presence and distribution of virulence-associated genes among Brucella spp. clinical strains isolated during 2001–2022. Species identification was performed using conventional methodology and Bruce-ladder PCR. The presence of the virulence genes mviN, manA, wbkA, perA, omp19, ure, cbg and virB was investigated using PCR. During the study period, a total of 334 Brucella isolates were identified, of which 328 (98.2%) were detected from positive blood cultures; 315 (94.3%) of the isolates were identified as B. melitensis, whilst the remaining 16 (4.8%) and 3 (0.9%) were identified as B. abortus and B. suis, respectively. Notably, two of the B. melitensis were assigned to the REV-1 vaccine strain type. The presence of the omp19, manA, mviN and perA genes was confirmed in all 315 B. melitensis isolates, while ure, wbkA, cbg and virB genes were detected in all but 9, 2, 1 and 1 of the isolates, respectively. All eight virulence genes were amplified in all B. abortus and B. suis isolates. The detection rate of virulence genes did not differ significantly among species. In conclusion, brucellosis is still considered a prevailing zoonotic disease in Greece, with the majority of the isolates identified as B. melitensis. The eight pathogenicity-associated genes were present in almost all Brucella isolates, although the ure gene was absent from a limited number of B. melitensis isolates.

Background: Defensins are natural antimicrobial peptides that the human body secretes to protect itself from an infection. Thus, they are ideal molecules to serve as biomarkers for infection. This study was conducted to evaluate the levels of human β-defensins in patients with inflammation. Methods: CRP, hBD2 and procalcitonin were measured in 423 sera of 114 patients with inflammation and healthy individuals using nephelometry and commercial ELISA assays. Results: Levels of hBD2 in the serum of patients with an infection were markedly elevated compared to those of hBD2 in patients with inflammation of non-infectious etiology (p < 0.0001, t = 10.17) and healthy individuals. ROC analysis demonstrated that hBD2 showed the highest detection performance for infection (AUC 0.897; p < 0.001) followed by PCT (AUC 0.576; p = ns) and CRP (AUC 0.517; p = ns). In addition, analysis of hBD2 and CRP in patients’ sera collected at different time points showed that hBD2 levels could help differentiate inflammation of infectious and non-infectious etiology during the first 5 days of hospitalization, while CRP levels could not. Conclusions: hBD2 has the potential to serve as a diagnostic biomarker for infection. In addition, the levels of hBD2 may reflect the efficacy of antibiotic treatment.

Humoral immunity after SARS-CoV-2 immunization or natural infection is thought to be evanescent. In our study, we aimed to longitudinally characterize the kinetics of antibody titers after dual BNT162b2 immunization or wild-type infection. Vaccinated and recovered individuals displayed distinct antibody kinetics, as convalescents had detectable RBD-, S1-specific, and neutralizing IgG antibody titers two weeks post-infection that gradually increased longitudinally, while RBD-, S1-specific, and neutralizing IgG were detected in vaccinees after the first dose, increased significantly 3 weeks post the second dose and decreased significantly 4–5 months thereafter. Neutralizing IgG was significantly higher initially in convalescent individuals; however, vaccines displayed significantly higher neutralizing antibodies 4–5 months post the second dose. In both groups, there was a strong negative association between elapsed time and antibody levels. The avidity of anti-RBD antibody titers increased significantly in patients longitudinally, while in vaccinees initially increased, with subsequent decrease, remaining however higher than antibody avidity of recovered individuals at all time-points. Anti-RBD antibodies were strongly correlated with neutralizing and anti-S1 antibodies in both groups at all time-points. This study facilitates our further understanding of immune response to SARS-CoV-2 and vaccines.

The most widely used test for the diagnosis of SARS-CoV-2 infection is a PCR test. PCR has very high sensitivity and is able to detect very low amounts of RNA. However, many individuals receiving a positive test result in a context of a PCR-based surveillance might be infected with SARS-CoV-2, but they are not contagious at the time of the test. The question arises regards if the cost effective, portable rapid antigen tests (RATs) have a better performance than PCR in identification of infectious individuals. In this direction, we examined the diagnostic performance of RATs from 14 different manufacturers in 400 clinical samples with known rRT-PCR cycles threshold (cT) and 50 control samples. Substantial variability was observed in the limit of detection (LOD) of different RATs (cT = 26.8–34.7). The fluorescence-based RAT exhibited a LOD of cT = 34.7. The use of the most effective RATs leads to true positive rates (sensitivities) of 99.1% and 90.9% for samples with cT ≤ 30 and cT ≤ 33, respectively, percentages that can guarantee a sensitivity high enough to identify contagious patients. RAT testing may also substantially reduce the quarantine period for infected individuals without compromising personal or public safety.

Prompt COVID-19 diagnosis is urgently required to support infection control measures. Currently available serological tests for measuring SARS-CoV-2 antibodies use different target antigens, although their sensitivity and specificity presents a challenge. We aimed to develop an “in-house” serological ELISA to measure antibodies against SARS-CoV-2 by combining different protein antigens. Sera (n = 44) from COVID-19-confirmed patients were evaluated against different SARS-CoV-2 protein antigens and all potential combinations using ELISA. Patients’ sera were also evaluated against commercially available ELISA diagnostic kits. The mixture containing RBD 2.5 μg/mL, S2 1 μg/mL and N 1.5 μg/mL was found to be the most potent. Plates were incubated with patients’ sera (1:100), and goat anti-human alkaline phosphatase-conjugated IgG, ΙgM and IgA antibody was added. The cut-off value for each assay was determined using the mean optical density plus two standard deviations of pre-pandemic controls. The “in-house” ELISA displayed 91% sensitivity and 97% specificity for IgG antibodies, whereas its sensitivity and specificity for IgM and IgA were 75% and 95% and 73% and 91%, respectively. The “in-house” ELISA developed here combined three SARS-CoV-2 antigens (RBD, S2 and N) as capture antigens and displayed comparable and even higher sensitivity and specificity than otherwise quite reliable commercially available ELISA diagnostic kits.

Full Papers; Authors: D. Marinou, G. Katsifis, G. Barouta, C. Liaskos, L.I. Sakkas, A. Tsakris, J.G. Routsias