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BackgroundExtracellular hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm production are considered as major virulence factors of the opportunistic pathogenic fungus Candida albicans. However, the impact of antifungal therapy on such virulence attributes is not well investigated. The common antifungal agents may disturb the production of secreted hydrolases as well as biofilm formation. Accordingly, this study addressed the effect of subinhibitory concentrations (sub-MICs) of selected antifungal agents on some virulence factors of C. albicans clinical isolates.MethodsC. albicans isolates (n = 32) were recovered from different clinical samples and their identification was confirmed to the species level. Antifungal susceptibility profiles of isolates were determined against (nystatin, fluconazole and micafungin) and minimum inhibitory concentrations (MICs) were interpreted according to Clinical and Laboratory Standards Institute guidelines. Virulence determinants comprising secreted hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm formation were investigated in the presence of the sub-MICs of the tested antifungal agents.ResultsTreatment of clinical C. albicans isolates with subinhibitory nystatin, fluconazole and micafungin concentrations significantly decreased production of extracellular hydrolases. Nystatin had the greatest inhibitory effect on phospholipase and aspartyl protease production. However, micafungin showed the highest reducing effect on the hemolytic activity of the treated clinical isolates. Moreover, nystatin and micafungin, but not fluconazole, had a noticeable significant impact on inhibiting biofilm formation of C. albicans clinical isolates.ConclusionOur findings highlighted the significant influences of commonly prescribed antifungal agents on some virulence factors of C. albicans. Accordingly, antifungal therapy may modulate key virulence attributes of C. albicans.Electronic supplementary materialThe online version of this article (10.1186/s12879-019-3685-0) contains supplementary material, which is available to authorized users.

Candida albicans remains the most common cause of hospital-acquired fungal infections due to its virulence determinants. Resistance to antifungal therapy has increased dramatically, narrowing the few available therapeutic options due to their potential toxicity. However, the association between C. albicans virulence determinants and resistance profiles needs further investigation. C. albicans (n=25) isolated from various clinical samples were identified. Antibiogram analysis of the tested isolates against different antifungal agents was performed and their minimum inhibitory concentrations (MICs) were verified. Virulence determinants including extracellular hydrolytic enzymes, biofilm formation, and cell surface hydrophobicity (CSH) were investigated. Correlations between virulence determinants and resistance profiles of the experimented isolates, in addition to their potential association with the source of clinical specimens, were analyzed. All isolates were amphotericin B, nystatin and micafungin sensitive, while 100% were clotrimazole, fluconazole and voriconazole resistant. Extracellular hydrolytic activities were detected in 52, 68 and 100% of the tested isolates for phospholipase, protease, and hemolysin, respectively, while CSH and biofilm production was shown in 24 and 20% of isolates, respectively. CSH had significant (P<0.05) positive as well as negative associations with amphotericin B and fluconazole MICs, respectively. Source of clinical isolates showed significant (P<0.05) influence on some resistance and virulence patterns.

Background and study aim: Epidemiological data reported lower death rates of COVID-19 cases in countries with higher & recent coverage by measles containing vaccines. In this study we aim to identify measles IgG titer in COVID-19 patients & correlate it with disease severity. Patients and Method: This is a Crosssectional study where 78 patients admitted to Ain Shams University Quarantine hospitals with positive PCR for SARS-CoV-2 were enrolled. All patients underwent quantification of serum measles IgG titer. Then classified according to the COVID-19 severity into mild, moderate and severe.Results: Measles IgG was positive in 53 patients (68%) with median of 1600 (IQR 1000-or3100), borderline in 18 patients (23%) with median 250 and negative in seven patients (9%) with median 100 (IQR 80-120). Patients with positive measles IgG were significantly older (56±16 years) than those with negative measles IgG ( 48±15 years) (P=0.03).No significant difference was found in measles IgG titer between mild , moderate and severe COVID19 cases. Intensity of pulmonary involvement by CT chest was not correlated with measles IgG titer. The median of measles IgG titer of the ICU admitted patients and those who were not, was 1150 (IQR=600-3500) and 1050 (IQR=200-1800) respectively (p=0.46). No difference in measles IgG titer between patients who recovered or died. Conclusion:Severity of COVID-19 disease and its outcome seem to be unaffected by measles IgG titer.

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