Detection of virulence factors and antifungal susceptibility of human and avian Aspergillusflavus isolates.

Aspergillusflavus is the second leading cause of invasive and non-invasive aspergillosis. Secretion of hydrolytic enzymes is considered as a virulence factor in this species. Our work aimed to study in vitro production of some virulence factors, to evaluate the biofilm production against human and avian A. flavus isolates and to investigate the antifungal susceptibility agents. Hydrolytic enzymes, biofilm production and molecular typing were studied for 62 human and 36 avian A. flavus isolates by specific solid media and six microsatellite markers. The susceptibility to antifungal agents was evaluated for 37 human isolates. All human and avian A. flavus isolates showed positive activities of extracellular hydrolase: phospholipase, protease and hemolysin. A positive elastase activity was seen in 64.51% of human A. flavus isolates and 86.1% of avian A. flavus isolates. All A. flavus in these two populations formed biofilms. Statistical significant difference was observed for the mean phospholipase activities (P=0.025) and biofilm quantification (P=0.0001) between human and avian A. flavus isolates. The in vitro susceptibility results showed a resistance in 83.7%, 81.08% and 16.21% of A. flavus isolates respectively to amphotericin B, itraconazole and posaconazole. No association was noted between all virulence factors and the genotypes of human and avian isolates. Our study allowed us to show that human strains have a higher production of extracellular hydrolases and biofilm then avian strains. These virulence factors appear to act synergistically to contribute to the virulence of A. flavus strains. Moreover, significant correlation between virulence patterns and antifungal susceptibility profiles was observed.

Environmental and molecular study of fungal flora in asthmatic patients.

The aim of the present study was to investigate the epidemiological and fungal environmental profile in asthmatic patients. We conducted a prospective study involving 49 patients with allergic asthma. One hundred and forty-five clinical samples and 289 environmental samples were performed. Only 30 patients accepted to participate to the environmental study at their home. For specific IgE antibodies, ELISA assay was conducted for 21 patients. Molecular ITS sequencing was performed for 37 isolates. The frequency of attacks was significantly associated with the seasonality, which was closely related to climate (P=0.024), exposure to animals (cats, P=0.025), plants (olive, P=0.018), physical effort (P=0.04) and the number of permanent occupants in house (>6) (P=0.026). Fungal contaminants were detected from 78.6% of biological samples and 97.8% of environmental samples. Antibodies corresponding to the studied allergens were detected in 10 patients (10/21). PCR sequencing allowed as rectified morphological identification for 27.02% (10/37) strains of Aspergillus. The allergy in molds is an indisputable reality that is necessary to look for in front of any severe asthma. So, it is important to establish clearly a relationship between exposure to fungi and health disorders in order to set up specific and effective preventive measures.

Atypical CT and MRI aspects of an epidermoid cyst.

We report a case of an unusual epidermoid cyst (EC) of the cerebellopontine angle that appeared hyperdense on computed tomography (CT) scanning, hyperintense on T1-weighted MR images and hypointense on T2-weighted magnetic resonance (MR) images. Diffusion-weighted imaging showed a hypointense lesion. We discuss imaging characteristics of ECs, explain the atypical findings in our case and confirm that the signal seen on diffusion-weighted images in the EC is related to a T2 effect.

Intramedullary neurenteric cyst without concurrent malformation.

Neurenteric cysts (NECs) are dysraphic lesions. They are usually extramedullary, the intramedullary forms are very rare. To our knowledge, only 10 cases of isolated intramedullary NECs have been reported. We report a case of intramedullary NEC without any associated dysraphic lesion. The clinical findings were: cervical pain and left hemicorporal weakness which predominated at the upper limb. Neuroradiological evaluation was performed by means of MRI which revealed a cystic lesion at C3-C4 level. A partial excision was performed and the diagnosis of NEC was established by histological study.