Antifungal activity of mango peel and seed extracts against clinically pathogenic and food spoilage yeasts.

The antioxidant and antifungal (antiyeast) properties of mango (Mangifera indica) peel and seed by-products were investigated. Nine extracts were obtained using three cultivars and two extraction methods. Significant differences between cultivars and extraction methods were detected in their bioactive compounds and antioxidant activity. The antifungal property was determined using agar diffusion and broth micro-dilution assays against 18 yeast species of the genera Candida, Dekkera, Hanseniaspora, Lodderomyces, Metschnikowia, Pichia, Schizosaccharomyces, Saccharomycodes and Zygosaccharomyces. All mango extracts showed antifungal activity. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) values were lower for seed than for peel extracts. MICs and MFCs ranged from values <0.1 to 5 and 5 to >30 mgGAE/mL, respectively. The multivariate analysis showed a relationship between antifungal activity, the capacity to inhibit lipid peroxidation and total phenol content. These properties were associated with high levels of proanthocyanidins, gallates and gallotannins in the extracts.

Fungal Planet description sheets: 320-370.

Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucalyptigena from Eucalyptus brassiana, Myrtapenidiella eucalyptorum from Eucalyptus pellita, Pilidiella eucalyptigena from Eucalyptus brassiana and Strelitziana malaysiana from Acacia mangium. Furthermore, Stachybotrys sansevieriicola is described from Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria trifasciata, Elsinoë othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae fam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia), Hormonema viticola from Vitis vinifera (Canary Islands), Chlorophyllum pseudoglobossum from a grassland (India), Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus (Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora vitícola from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aurantiorugosus from soil (Vietnam), Rhizopogon granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus (Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from Theobroma cacao (Ecuador). Myrmecridium iridis (Myrmecridiales ord. nov., Myrmecridiaceae fam. nov.) is also described from Iris sp. (The Netherlands). Novel genera include (Ascomycetes): Budhanggurabania from Cynodon dactylon (Australia), Soloacrosporiella, Xenocamarosporium, Neostrelitziana and Castanediella from Acacia mangium and Sabahriopsis from Eucalyptus brassiana (Malaysia), Readerielliopsis from basidiomata of Fuscoporia wahlbergii (French Guyana), Neoplatysporoides from Aloe ferox (Tanzania), Wojnowiciella, Chrysofolia and Neoeriomycopsis from Eucalyptus (Colombia), Neophaeomoniella from Eucalyptus globulus (USA), Pseudophaeomoniella from Olea europaea (Italy), Paraphaeomoniella from Encephalartos altensteinii, Aequabiliella, Celerioriella and Minutiella from Prunus (South Africa). Tephrocybella (Basidiomycetes) represents a novel genus from wood (Italy). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

First reported case of catheter-related fungemia due to Candida mengyuniae.

We report a case of intravenous catheter-associated fungemia caused by the recently described species Candida mengyuniae, a yeast not previously associated with human disease. The infection occurred in an 89-year-old woman with pancreatic adenocarcinoma. Yeast isolates recovered from a catheter and blood were identified as C. mengyuniae by sequencing of the 18S, 5.8S internal transcribed spacer, and D1/D2 26S ribosomal DNA domains.

Evaluación del método de difusión en disco de 30 μg de cefoxitina en la detección de resistencia a meticilina en aislamientos seleccionados de Staphylococcus aureus / Evaluation of the cefoxitin 30 μg disk diffusion method for detection of methicillin-resistance in selected Staphylococcus aureus isolates

Los tests de oxacilina habituales pueden fallar en la detección de ciertos casos de Staphylococcus aureus resistente a meticilina. El objetivo del presente trabajo es evaluar la capacidad del método de difusión en disco de cefoxitina (30 μg) para detectar la resistencia a meticilina en aislados de S. aureus con características atípicas de resistencia. Se estudiaron 53 aislados de S. aureus. La sensibilidad de los mismos se estudió mediante el sistema Vitek, y los tests de oxacilina y de cefoxitina mediante difusión en discos (Clinical and Laboratory Standards Institute [CLSI] 2007); la resistencia a oxacilina se confirmó mediante una reacción en cadena de la polimerasa (PCR) múltiple previamente descrita que permite la identificación de S. aureus y la detección simultánea de resistencia a meticilina. Los aislados mecA positivos que presentaban crecimiento en la zona de inhibición al exponerlos a oxacilina se consideraron heterorresistentes; los que eran mecA negativos pero con sensibilidad intermedia o resistencia a oxacilina se consideraron límite (borderline). Todos los aislados se ensayaron frente al disco de 30 μg de cefoxitina según normas CLSI (sensibilidad: > 22 mm; resistencia: < 21 mm). Las cepas de control para todos los ensayos incluyeron S. aureus resistente a meticilina ATCC 43300 y S. aureus sensible a meticilina ATCC 25923. Los aislados formaron cuatro grupos. Grupo I: 20 aislados multirresistentes, sensibles a oxacilina y mecA negativos; grupo II: 16 aislados con resistencia o sensibilidad intermedia a oxacilina y mecA negativos; grupo III: 11 aislados heterorresistentes y mecA positivos; grupo IV: seis aislados mecA positivos con perfiles atípicos de resistencia (penicilina y oxacilina; ciprofloxacino y eritromicina). Treinta y cinco aislados mecA negativos incluidos en los grupos I y II mostraron zonas de inhibición > 22 mm; un aislado del grupo II mostró un halo de 20 mm. Los 17 aislados mecA positivos de los grupos III y IV mostraron resistencia frente al disco de cefoxitina. Podemos concluir que el método de difusión en disco de cefoxitina de 30 μg es eficiente para la detección de resistencia a meticilina y permite una clara definición de aquellos aislados de S. aureus, incluidos aquellos con características atípicas de resistencia (AU)

Oxacillin tests may fail to detect some methicillin- resistant S. aureus populations. The objective of this study is to evaluate the discriminative capacity of the Clinical and Laboratory Standards Institute (CLSI) disk diffusion method with a cefoxitin 30 μg disk on S. aureus isolates with unusual phenotypic characteristics of antimicrobial resistance. We studied 53 clinical S. aureus isolates. The antimicrobial susceptibility of all isolates was routinely studied by the VITEK 2 System (bioMérieux). Methicillin resistance was also studied by CLSI oxacillin method and confirmed by a previously described multiplex polymerase chain reaction (PCR) method which permits S. aureus identification and simultaneous detection of methicillin resistance. MecA positive isolates presenting a diffuse growth within the zone of inhibition when exposed to oxacillin were considered heteroresistant; mecA negative, oxacillin intermediate or resistant isolates were considered borderline. All the isolates were tested with a cefoxitin 30 μg disk, according to the CLSI guidelines (susceptibility: > 22 mm; resistance: < 21 mm). Control strains for all assays included MRSA ATCC 43300 and MSSA ATCC 25923. The isolates formed four groups. Group I: 20 multiresistant, oxacillin susceptible and mecA negative isolates; group II: 16 resistant or with intermediate oxacillin susceptibility and mecA negative isolates; group III: 11 heteroresistant and mecA positive isolates; group IV: six mecA positive isolates with atypical resistance profiles (penicillin and oxacillin, or ciprofloxa- cin and erythromycin resistance). Thirty-five mecA negative isolates included in groups I and II showed inhibition zones > 22 mm; one isolate from group II showed 20 mm. The 17 mecA positive isolates from groups III and IV showed resistance to cefoxitin disk. The 30 μg cefoxitin disk diffusion method is proposed as an efficient method for the detection of methicillin resistance and permits a clear determination set S. aureus isolates, even those with atypical antimicrobial characteristics (AU)

[Evaluation of the cefoxitin 30 microg disk diffusion method for detection of methicillin-resistance in selected Staphylococcus aureus isolates]. / Evaluación del método de difusión en disco de 30 microg de cefoxitina en la detección de resistencia a meticilina en aislamientos seleccionados de Staphylococcus aureus.

Oxacillin tests may fail to detect some methicillinresistant S. aureus populations. The objective of this study is to evaluate the discriminative capacity of the Clinical and Laboratory Standards Institute (CLSI) disk diffusion method with a cefoxitin 30 microg disk on S. aureus isolates with unusual phenotypic characteristics of antimicrobial resistance. We studied 53 clinical S. aureus isolates. The antimicrobial susceptibility of all isolates was routinely studied by the VITEK 2 System (bioMérieux). Methicillin resistance was also studied by CLSI oxacillin method and confirmed by a previously described multiplex polymerase chain reaction (PCR) method which permits S. aureus identification and simultaneous detection of methicillin resistance. MecA positive isolates presenting a diffuse growth within the zone of inhibition when exposed to oxacillin were considered heteroresistant; mecA negative, oxacillin intermediate or resistant isolates were considered borderline. All the isolates were tested with a cefoxitin 30 microg disk, according to the CLSI guidelines (susceptibility: > 22 mm; resistance: < 21 mm). Control strains for all assays included MRSA ATCC 43300 and MSSA ATCC 25923. The isolates formed four groups. Group I: 20 multiresistant, oxacillin susceptible and mecA negative isolates; group II: 16 resistant or with intermediate oxacillin susceptibility and mecA negative isolates; group III: 11 heteroresistant and mecA positive isolates; group IV: six mecA positive isolates with atypical resistance profiles (penicillin and oxacillin, or ciprofloxacin and erythromycin resistance). Thirty-five mecA negative isolates included in groups I and II showed inhibition zones > 22 mm; one isolate from group II showed 20 mm. The 17 mecA positive isolates from groups III and IV showed resistance to cefoxitin disk. The 30 microg cefoxitin disk diffusion method is proposed as an efficient method for the detection of methicillin resistance and permits a clear determination set S. aureus isolates, even those with atypical antimicrobial characteristics.

Organization of the gene cluster for biosynthesis of penicillin in Penicillium nalgiovense and antibiotic production in cured dry sausages.

Several fungal isolates obtained from two cured meat products from Spain were identified as Penicillium nalgiovense by their morphological features and by DNA fingerprinting. All P. nalgiovense isolates showed antibiotic activity in agar diffusion assays, and their penicillin production in liquid complex medium ranged from 6 to 38 microgram. ml-1. We constructed a restriction map of the penicillin gene cluster of P. nalgiovense and found that the organization of the penicillin biosynthetic genes (pcbAB, pcbC, and penDE) is the same as in Penicillium chrysogenum and Aspergillus nidulans. The pcbAB gene is located in an orientation opposite that of the pcbC and penDE genes in all three species. Significant amounts of penicillin were found in situ in the casing and the outer layer of salami meat during early stages of the curing process, coinciding with fungal colonization, but no penicillin was detected in the cured salami. The antibiotic produced in situ was sensitive to penicillinase.

[In vitro control of Sclerotinia sclerotiorum and Gaeumannomyces graminis by bacteria of the fluorescent Pseudomonas group]. / Control in vitro de Sclerotinia sclerotiorum y Gaeumannomyces graminis por bacterias del grupo Pseudomonas fluorescentes.

Thirty six fluorescent Pseudomonas isolates were obtained from the rhizosphere of sunflower plants. By antibiosis tests, the six more efficient strains in Sclerotinia sclerotiorum growth inhibition, were selected. Simultaneously, twenty three fluorescent Pseudomonas isolates were recuperated from the rhizosphere of wheat plants and the five most efficient strains in growth inhibition of the fungi Gaeumannomyces graminis were selected. The strains selected from the rhizosphere of sunflower plants had no antagonistic effect on G. graminis and the bacteria isolated from the wheat rhizosphere showed no fungistatic activity on S. sclerotiorum. These results suggest the existence of a certain degree of plant bacteria pathogenic specificity. Among the selected bacteria, the strain FF5 of P. fluorescens originated the major inhibiting halo in vitro against S. sclerotiorum (Figure 1). In liquid culture medium this bacterium produces an antifungal substance that promotes lysis of fungi mycelium (Figure 2) and inhibition of ascospore germination and is not inhibited by the presence of Fe+3 in the culture medium (Table 1). Its synthesis is not associated with the production of fluorescein. Its action is not enzymatic because it is a substance of low molecular weight (< 2000), resistant to autoclave sterilization and photo-stable. The amount of NH4+ and the high pH values produced by the FF5 strain in the liquid culture medium (Table 2) are not responsible for the antifungalal action.

Control in vitro de Sclerotinia sclerotiorum y Gaeumannomyces graminis por bacterias del grupo Pseudomonas fluorescentes / [In vitro control of Sclerotinia sclerotiorum and Gaeumannomyces graminis by bacteria of the fluorescent Pseudomonas group]

Thirty six fluorescent Pseudomonas isolates were obtained from the rhizosphere of sunflower plants. By antibiosis tests, the six more efficient strains in Sclerotinia sclerotiorum growth inhibition, were selected. Simultaneously, twenty three fluorescent Pseudomonas isolates were recuperated from the rhizosphere of wheat plants and the five most efficient strains in growth inhibition of the fungi Gaeumannomyces graminis were selected. The strains selected from the rhizosphere of sunflower plants had no antagonistic effect on G. graminis and the bacteria isolated from the wheat rhizosphere showed no fungistatic activity on S. sclerotiorum. These results suggest the existence of a certain degree of plant bacteria pathogenic specificity. Among the selected bacteria, the strain FF5 of P. fluorescens originated the major inhibiting halo in vitro against S. sclerotiorum (Figure 1). In liquid culture medium this bacterium produces an antifungal substance that promotes lysis of fungi mycelium (Figure 2) and inhibition of ascospore germination and is not inhibited by the presence of Fe+3 in the culture medium (Table 1). Its synthesis is not associated with the production of fluorescein. Its action is not enzymatic because it is a substance of low molecular weight (< 2000), resistant to autoclave sterilization and photo-stable. The amount of NH4+ and the high pH values produced by the FF5 strain in the liquid culture medium (Table 2) are not responsible for the antifungalal action.

Control in vitro de Sclerotinia sclerotiorum y Gaeumannomyces graminis por bacterias del grupo Pseudomonas fluorescentes. / [In vitro control of Sclerotinia sclerotiorum and Gaeumannomyces graminis by bacteria of the fluorescent Pseudomonas group]

Thirty six fluorescent Pseudomonas isolates were obtained from the rhizosphere of sunflower plants. By antibiosis tests, the six more efficient strains in Sclerotinia sclerotiorum growth inhibition, were selected. Simultaneously, twenty three fluorescent Pseudomonas isolates were recuperated from the rhizosphere of wheat plants and the five most efficient strains in growth inhibition of the fungi Gaeumannomyces graminis were selected. The strains selected from the rhizosphere of sunflower plants had no antagonistic effect on G. graminis and the bacteria isolated from the wheat rhizosphere showed no fungistatic activity on S. sclerotiorum. These results suggest the existence of a certain degree of plant bacteria pathogenic specificity. Among the selected bacteria, the strain FF5 of P. fluorescens originated the major inhibiting halo in vitro against S. sclerotiorum (Figure 1). In liquid culture medium this bacterium produces an antifungal substance that promotes lysis of fungi mycelium (Figure 2) and inhibition of ascospore germination and is not inhibited by the presence of Fe+3 in the culture medium (Table 1). Its synthesis is not associated with the production of fluorescein. Its action is not enzymatic because it is a substance of low molecular weight (< 2000), resistant to autoclave sterilization and photo-stable. The amount of NH4+ and the high pH values produced by the FF5 strain in the liquid culture medium (Table 2) are not responsible for the antifungalal action.