Investigation of ERG11 gene expression among fluconazole-resistant Candida albicans: first report from an Iranian referral paediatric hospital.

The multiplicity of mechanisms of resistance to azole antifungal agents has been described. As fluconazole-resistant clinical Candida albicans isolates that constitutively over-express ERG11 have been identified in previous studies, the aim of this study is to investigate this molecular mechanism involved in fluconazole resistance of C. albicans clinical isolates. Fluconazole susceptibility testing was carried out on clinical isolates of Candida spp. obtained from hospitalised children in an Iranian referral children's hospital. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique was used to differentiate Candida spp. The resistant C. albicans isolates were subjected to RT-qPCR using primers that identify ERG11 gene expression. Of the 142 Candida spp. isolates studied, C. albicans was the most predominant isolate, occurring in 68.3% (97/142) of the patients. According to the CLSI method, the majority of the C. albicans isolates (91.7%, 89/97), categorised as susceptible (minimum inhibitory concentration [MIC] ≤8 µg/mL), five isolates were considered resistant (MIC ≤64 µg/mL) and three had dose-dependent susceptibility (MIC = 8.16-32 µg/mL). The ERG11 gene in the five fluconazole-resistant C. albicans isolates was upregulated 4.15-5.84-fold relative to the ATCC 10231 control strain. In this study, the expression of ERG11 was upregulated in all the fluconazole-resistant C. albicans isolates. There are limited data on the antifungal susceptibility of Candida spp. as well as the molecular mechanism of azole resistance in Iran, especially for isolates causing infections in children. Therefore, the surveillance of antifungal resistance patterns and investigation of other mechanisms of azole resistance in all Candida spp. isolates is recommended.

The effect of cytoplasmic crude extracts of Trichophyton verrucosum on cell mediated immunity.

OBJECTIVE: Trichophyton verrucosum is a slow growing dermatophyte responsible for a number of skin diseases such as ringworm, and is characterized by patches of hair loss and thick crusts on the host skin in domestic animals. In this study, we examined the immunomodulatory effects of crude extract of Trichophyton verrucosum (TV)cytoplasm in a mouse model. METHODS: The TV variate was cultured on Sabouraud dextrose agar and the mycelium was grinded by mechanical force. The purified protein was obtained from crude extract of the fungus, and protein concentration was measured by BradFord assay. Six to eight week-female BALB/c mice were divided into three groups: test group, receiving cytoplasmic crude extract plus defibrinated sheep blood; control group, receiving defibrinated sheep blood; and normal group, receiving normal saline. Injections were performed on days 0, 3, 5, 7 and 9 and the mice were sacrificed four days after the last injection. T lymphocyte metabolic activity was examined by methyl thiazol tetrazolium (MTT) assay, and also interleukin-4 (IL-4) and interferon-γ (IFNγ) levels were evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: MTT assay showed that the TV extract stimulated lymphocyte metabolic activity. ELISA results showed that despite increase in the level of IFNγ, no changes were observed in IL-4 level. CONCLUSIONS: Results indicated that crude extract of TV cytoplasm may probably act as an immune modulator, which affects Th1 responses. The TV crude extract may be an appropriate agent to induce cellular immunity for combating dermatophytosis infection in animals; and therefore, TV extract may have some potential applications in vaccine/adjuvant technology.

PCR - RFLP patterns for the differentiation of the Fusarium species in virtue of ITS rDNA.

BACKGROUND AND PURPOSE: The Fusarium species are among the most important fungi in the medical, veterinary and agricultural fields. MATERIALS AND METHODS: In the present study, 172 strains of these fungi have been analyzed. The high molecular weight DNAs were extracted from 23 reference strains as well as from 149 isolated Fusarium species. Using the designed nucleotide primers from rDNA of Fusarium species, PCR analysis was performed for the amplification of ITS regions. Afterwards, the location of the effective endonuclease enzymes has been evaluated within approximately 930 bp of rDNA sequence. RESULTS: Through the selected enzymes including; HhaI, MspI, TaqI and FaqI, the mentioned Fusarium species have been divided into 33 groups. The first three enzymes were able to classify Fusarium species into 23 groups of which 19 groups included one member, one group included two members and three groups included three members of the Fusarium species. This study also revealed the possibility in the identification of F. semitectum, F. solani complex, F. pseudograminearum, F. nisikadoi, F. coeruleum and F. acuminatum species by one unique enzyme. In addition, our study indicated the ability of the differentiation of F. Compactum from F. equiseti. CONCLUSION: As Compared to previous studies with more endonuclease enzymes and with limited in identifications, the ITS-RFLP patterns reported here an attempted to evaluate most of the Fusarium species successfully.