ABSTRACT
ABSTRACT The aim of this study was to assess a collection of yeasts to verify the presence of Candida dubliniensis among strains isolated from the oral mucosa of AIDS pediatric patients which were initially characterized as Candida albicans by the traditional phenotypic method, as well as to evaluate the main phenotypic methods used in the discrimination between the two species and confirm the identification through genotypic techniques, i.e., DNA sequencing. Twenty-nine samples of C. albicans isolated from this population and kept in a fungi collection were evaluated and re-characterized. In order to differentiate the two species, phenotypic tests (Thermotolerance tests, Chromogenic medium, Staib agar, Tobacco agar, Hypertonic medium) were performed and genotypic techniques using DNA sequencing were employed for confirmation of isolated species. Susceptibility and specificity were calculated for each test. No phenotypic test alone was sufficient to provide definitive identification of C. dubliniensis or C. albicans, as opposed to results of molecular tests. After amplification and sequencing of specific regions of the 29 studied strains, 93.1% of the isolates were identified as C. albicans and 6.9% as C. dubliniensis. The Staib agar assay showed a higher susceptibility (96.3%) in comparison with other phenotypic techniques. Therefore, genotypic methods are indispensable for the conclusive identification and differentiation between these species.
Subject(s)
Humans , Child , AIDS-Related Opportunistic Infections/microbiology , Candida/genetics , Candidiasis, Oral/microbiology , DNA, Fungal/genetics , Candida albicans/genetics , Candida albicans/isolation & purification , Candida/classification , Candida/isolation & purification , Genotype , Mouth Mucosa/microbiology , Mycological Typing Techniques , Phenotype , Polymerase Chain ReactionABSTRACT
This study discusses isolation and identification new fungal isolate from salinity soil for controlling soil borne diseases. Among sixteen fungal, a potent isolate coded SRBP_ZSHSG1 was isolated from Sugar beet rhizospher samples collected from Al-Hosainia localities-El-Sharkia-Egypt. Traditional methods consistent with phylogenetic analysis of 18S rRNA sequences showed SRBP_ZSHSG1 has 100% similarity with Trichoderma strains and the most closest is Trichoderma asperellum. Thus, it proposed name Trichoderma asperellum SRBP_ZSHSG1 (ID: KP336489). Results proved SRBP_ZSHSG1 followed by T. roseum and Chaetomium globosum were highly inhibitors to the tested pathogens. These results were confirmed by field experiments. SRBP_ZSHSG1 was able to grow on rice straw (biostraw) and produce most active compounds. The biostaw extract was the most effective bioagent and recorded highest reduction in pathogen numbers. GC/MS analysis of ethyl acetate extract revealed the presence of 9 compounds. These compounds were determined 4 volatile alcohols (1-4) and fatty acid esters (5-9).
ABSTRACT
Staphylococcus aureus resistente a meticilina (SARM) está asociado a diversos procesos infecciosos y su creciente resistencia representa un grave problema de salud publica. Los objetivos de este trabajo fueron: detectar fenotípica y genotípicamente la resistencia a meticilina y eritromicina en 60 cepas SARM y confirmar la resistencia a meticilina. Ésta última fue confirmada por concentración inhibitoria mínima (CIM), prueba de descarte, resistencia a cefoxitina (FOX), detección de PBP2a, producción de β-lactamasa y detección del gen mecA (PCR). Para la resistencia a eritromicina se utilizó el método de difusión en disco, CIM, resistencia inducible a clindamicina (D-test) y detección de los genes ermA, ermB, ermC y msrA (PCR). Los métodos de CIM, descarte, FOX y PBP2a, mostraron en cada prueba una sensibilidad y valor predictivo de 100% y 98,3% respectivamente. Una cepa fue mecA negativo, negativa para PBP2a y β-lactamasa positiva y se consideró borderline. Treinta y cinco (58,3%) SARM fueron resistentes a eritromicina y mostraron los fenotipos MS B (6/17,1%), cMLS B (25/71,4%) y iMLS B (4/11,4%), siendo estas últimas D-test positivo. El gen ermA fue el más frecuente. La resistencia a eritromicina encontrada constituye un problema serio, por ser una de las alternativas para su tratamiento.
Methicillin resistant Staphylococcus aureus strains (MRSA) are associated to diverse infectious processes and their growing resistance represents a serious public health problem. The objectives of this study were to detect methicillin and erythromycin resistance of 60 MRSA strains phenotypically and genotypically, and confirm methicillin resistance. This last one was confirmed by the minimal inhibitory concentration (MIC) method, screening test, cefoxitin resistance (FOX), PBP2a detection, β-lactamase production, and mecA gene detection (PCR). For erythromycin resistance, the disk diffusion method, MIC, inducible clindamycin resistance (D-test), and ermA, ermB, ermC, and msrA gene detection (PCR) were used The MIC, discard test, FOX, and PBP2a methods showed in each test a sensitivity and predictive value of 100% and 98% respectively. One strain was mecA negative, PBP2a negative, and β-lactamase positive and it was considered borderline. Thirty five (58.3%) were erythromycin resistant and showed MS B (6/17.1%), eML.S B (25/71.4%) and iML.S B (4/11.4%); these last ones were D-test positive. ermA gene was the most frequent. The erythromycin resistance found contitutes a serious problem since it is one of the treatment alternatives.