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1.
Trichosporon species are usually opportunistic pathogens. Here, we present a case of esophagitis caused by T. inkin in a 54-year-old woman with pulmonary cancer and severe neutropenia in whom the susceptibility profile of the isolate against azoles and polyenes was verified. The patient was diagnosed with esophagitis grade I of Wilcox, presenting scattered whitish plaques and exudates in upper two-thirds of the esophageal mucosa. Antifungal therapy involving oral fluconazole (150 mg/day for 14 days) was ineffective. In vitro, the isolate showed no resistance to this azole and sensitivity to amphotericin B. Since T. inkin is of growing importance as an agent of invasive infections in immunocompromised patients, we stress that the diagnosis of esophagitis by this species should be followed by an assessment of the therapeutic sensitivity of the strain involved.  相似文献   

2.
Vibrio vulnificus causes disease in economically important aquaculture raised fish and is an opportunistic human pathogen. This study reports on the isolation of V. vulnificus from diseased hybrid tilapia (Oreochromis niloticus × O. aureus) cultured in a North American water reuse facility. Our objectives were to characterize the isolate using biochemical and molecular methods, develop a disease challenge model, and determine the ability of a formalin inactivated whole-cell vaccine to protect against V. vulnificus. The V. vulnificus isolate recovered was biotype 1, 16S rRNA type B, vcg type C, and vvhA type 2 and caused disease in tilapia held in static salt water (1.5 g/l sea salt). Fish vaccinated with the formalin inactivated whole-cell vaccine responded to vaccination with titers from vaccinated fish ranging from 32 to 64 and titers from non-vaccinated fish ranging from 4 to 8. In two trials, vaccinated tilapia exhibited relative percent survival (RPS) of 73 and 60% following homologous isolate challenge. In two additional trials, vaccinated tilapia exhibited RPS values of up to 88% following challenge with a heterologous isolate; the use of a mineral oil adjuvant enhanced protection. This vaccine may provide an effective means of preventing infections caused by biochemically and genetically diverse V. vulnificus.  相似文献   

3.
Two isolates of Beauveria bassiana, wild type (wt) and its mutant type (mt) were compared in terms of growth patterns on culture plates containing media based on wheat bran, grasshopper exoskeletons, colloidal chitin or Sabouraud-dextrose agar (SDA). Germination for the mt isolate was up to 33% faster in all media. Influence of media on virulence was determined against larvae and adults of Tenebrio molitor. Mortality higher than 90% was reached for adults after 6 days using conidia from all media. For larvae, a mortality of 80% was reached after 11 days with conidia collected from SDA medium and between 15 and 35% with conidia from other media. In SDA medium, conidial yield was almost ten times higher for the mt isolate compared to the wt isolate; however, virulence traits were similar against either larvae or adults. These results may influence commercial preparations of entomopathogenic fungi based on conidia.  相似文献   

4.
Tomato is the most important vegetable crop in Spain. The mirid bug Nesidiocoris tenuis (Reuter) commonly appears in large numbers in protected and open-air tomato crops where little or no broad-spectrum insecticides are used. Nesidiocoris tenuis is known to be a predator of whiteflies, thrips and several other pest species. However, it is also considered a pest because it can feed on tomato plants, causing necrotic rings on stems and flowers and punctures in fruits. Our objectives were to evaluate predation by N. tenuis on sweetpotato whitefly Bemisia tabaci Gennadius under greenhouse conditions and establish its relationship to N. tenuis feeding on tomato. Two different release rates of N. tenuis were compared with an untreated control (0, 1 and 4 N. tenuis plant−1) in cages of 8 m2. Significant reductions of greater than 90% of the whitefly population and correspondingly high numbers of N. tenuis were observed with both release rates. Regression analysis showed that necrotic rings on foliage caused by N. tenuis were best explained by the ratio of B. tabaci nymphs:N. tenuis as predicted by the equation y = 15.086x − 0.6359.
Alberto UrbanejaEmail:
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5.
Methicillin-resistant Staphylococcus aureus (MRSA) colonize most frequently in the anterior nares of the nose and cause serious infections all over the world. The aim of this study was to determine the nasal carriage rate of S. aureus and MRSA strains in Turkish elementary school children. We also analyzed molecular characterizations of MRSA strains by using pulse field gel electrophoresis (PFGE), multi locus sequence typing (MLST), staphylococcal chromosomal cassette mec (SCCmec) typing, and detection of the Panton-valentine leucocidin (PVL) gene. The nasal swabs were obtained from 4,050 children during a 4 month period in Ankara. In vitro antimicrobial susceptibility testing to 1 μg oxacillin and 30 μg cefoxitin was determined by a disk diffusion method. We found that the 1,001 of 4,050 (24.7%) children were colonized with S. aureus. Three S. aureus strains were resistant to oxacillin and cefoxitin. The rate of MRSA among all children was 0.07%. The MRSA strains revealed three different PFGE pattern. All MRSA isolates by harbored the SCCmec type IV element, but not the PVL gene. The two MRSA isolate belonged to sequence type (ST) 30, whereas the other one was a unique type. The results of this study demonstrated that S. aureus nasal carriage rate was consistent with previous studies. However, MRSA carriage rate was low. This study also indicated that the ST30-type IV without PVL gene MRSA clone may be expected to spread in Turkish community.  相似文献   

6.
This study reports 2 cases in which old grandmothers without dependent offspring provided essential care to their young granddaughters in a free-ranging group of Japanese monkeys (Macaca fuscata). In the first case, a 24-year-old grandmother provided essential care for the survival of her 2-month-old granddaughter for at least 6 days during which the mother had temporarily disappeared from the group for reasons unknown. In the second case, a 14-month-old granddaughter began sucking from her 23-year-old grandmother within 6 weeks after her mother gave birth to a younger sibling. For at least 6 months, the grandmother exhibited various patterns of maternal behavior toward her granddaughter. The behavioral data obtained in this study indicated that old yet healthy females without dependent offspring could contribute to the survival of their young grandchildren.  相似文献   

7.
Two cases are presented of severe pneumococcal infections in infants caused by serotype 14 Streptococcus pneumoniae. The first case — meningitis — caused by S. pneumoniae (pneumococcus) with lowlevel penicillin susceptibility has developed from acute otitis media and resulted in fatal outcome. The second one — an immunocompromised child presenting recurrent otitis and chronic mastoiditis developed into pneumococcal pneumonia. Both cases demonstrate the extreme importance of a relevant initial treatment of localized pneumococcal infections, preventing the development of generalized infection. Amoxicillin (an oral treatment option in both upper and lower respiratory tract infections caused also by Pneumococcus strains with low-level penicillin susceptibility due to its beneficial pharmacokinetics and pharmacodynamics) was not used in either case.  相似文献   

8.
Pseudocercospora griseola is the causal agent of angular leaf spot of common bean (ALS). It has undergone parallel coevolution with its host and two major groups have been defined, “Andean” (P. griseola f. griseola) and “Mesoamerican” (P. griseola f. mesoamericana). The aim of this study was to analyze the nature and the level of the dark pigment synthesized by the representatives of each group. After 21 days of incubation on potato dextrose agar medium, P. griseola f. griseola isolate S3b developed colonies with diameters of 17.5 ± 1.3 mm and concentric rings of pigmentation. Isolate T4 of P. griseola f. mesoamericana presented smaller colonies (9.9 ± 0.3 mm) with a uniform dark-gray color. Both isolates, S3b and T4, produced the same pigment, a 1,8-dihydroxynaphthalene-melanin, although different in quantity and structural features as suggested by the IR spectrum. The P. griseola f. griseola isolate S3b had a higher growth rate and melanin content as well as smaller sensitivity to melanin synthesis inhibitors compared to the isolate T4 of P. griseola f. mesoamericana. These results suggest a possible link between melanin and growth in P. griseola.  相似文献   

9.
Nocardiosis is a rare infection caused by the aerobic actinomycete of the Nocardia genus. In most cases, nocardiosis manifests as a lung infection or a bone lesion. Due to the nonspecific and mild clinical manifestations of nocardiosis, the establishment of definite diagnosis can be difficult. When antibiotic therapy is incorrectly targeted, only the symptoms of the disease are suppressed. The mainstay in the treatment of Nocardia osteomyelitis has so far been the combined surgical debridement with long-term, initially intravenous, antibiotic administration. We present the successful conservative treatment of a nocardiosis osteomyelitis of the tibia caused by the Nocardia cyriacigeorgica species in an 81-year-old female patient that manifested itself as a secondary affection on top of a primary nocardiosis infection of the lung. From microbiological examination, N. cyriacigeorgica was discovered; the identification was made using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) with an identification score of 1.9. The sensitivity was evaluated using E test. Sensitivity to trimethoprim/sulfamethoxazole, amikacin, imipenem, and linezolid was demonstrated. The bacteria were shown to be resistant to ciprofloxacin. For treatment, trimethoprim/sulfamethoxazole was used due to the value of minimum inhibitory concentration, which was 0.25 mg/L. The initial dose of 960 mg of trimethoprim/sulfamethoxazole every 8 h was reduced to 960 mg every 12 h after 3 months. The total duration of treatment was 7.5 months. Under the established treatment, the bone and lung lesions healed. Nocardiosis of the long bone is considered a rare disease and its precise diagnosis has not yet been standardized. We used the MALDI-TOF MS method for the identification of the causal organism which is a fast and reliable method according to current world literature even when compared with the rRNA genetic sequencing reference method. Our case study presents a rare case of osteomyelitis of tibial shaft caused by N. cyriacigeorgica and its successful conservative treatment.  相似文献   

10.
Groundwater contamination by the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a global problem. Israel’s coastal aquifer was contaminated with RDX. This aquifer is mostly aerobic and we therefore sought aerobic bacteria that might be involved in natural attenuation of the compound in the aquifer. RDX-degrading bacteria were captured by passively sampling the indigenous bacteria onto sterile sediments placed within sampling boreholes. Aerobic RDX biodegradation potential was detected in the sediments sampled from different locations along the plume. RDX degradation with the native sampled consortium was accompanied by 4-nitro-2,4-diazabutanal formation. Two bacterial strains of the genus Rhodococcus were isolated from the sediments and identified as aerobic RDX degraders. The xplA gene encoding the cytochrome P450 enzyme was partially (~500 bp) sequenced from both isolates. The obtained DNA sequences had 99% identity with corresponding gene fragments of previously isolated RDX-degrading Rhodococcus strains. RDX degradation by both strains was prevented by 200 μM of the cytochrome P450 inhibitor metyrapone, suggesting that cytochrome P450 indeed mediates the initial step in RDX degradation. RDX biodegradation activity by the T7 isolate was inhibited in the presence of nitrate or ammonium concentrations above 1.6 and 5.5 mM, respectively (100 mg l−1) while the T9N isolate’s activity was retarded only by ammonium concentrations above 5.5 mM. This study shows that bacteria from the genus Rhodococcus, potentially degrade RDX in the saturated zone as well, following the same aerobic degradation pathway defined for other Rhodococcus species. RDX-degrading activity by the Rhodococcus species isolate T9N may have important implications for the bioremediation of nitrate-rich RDX-contaminated aquifers.  相似文献   

11.
A novel actinomycete, designated KLBMP 1221T, was isolated from the surface-sterilized seeds of an oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China and was characterized taxonomically by using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequence showed that this strain formed a distinct phyletic line within the radiation of the genus Amycolatopsis. The 16S rRNA gene sequence similarity indicated that strain KLBMP 1221T was most closely related to Amycolatopsis eurytherma NT202T (98.9%), Amycolatopsis tucumanensis ABOT (98.8%), Amycolatopsis thermoflava N1165T (98.6%) and Amycolatopsis methanolica IMSNU 20055T (98.5%). Strain KLBMP 1221T had morphological and chemotaxonomic properties that were consistent with its classification in the genus Amycolatopsis. However, DNA–DNA relatedness data and phenotypic differences clearly distinguished the isolate from its closest relatives. Based on the combined genotypic and phenotypic evidence, it is proposed that strain KLBMP 1221T be classified as representative of a novel species for which the name Amycolatopsis endophytica sp. nov. is proposed. The type strain is KLBMP 1221T (= KCTC 19776T = CCTCC AA 2010003T).  相似文献   

12.
A strictly aerobic, gram-negative, non-motile, reddish-pink pigmented, rod-shaped strain designated N5EA6-3A2BT, was isolated from an unidentified marine sponge by use of a bait-streaked agar technique. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate represented a distinct and deep evolutionary lineage of descent in the family Flammeovirgaceae within the phylum Bacteroidetes and clustered with as yet uncultured bacteria. The most closely related established species was Roseivirga spongicola UST030701-084T (89% sequence similarity) in the family of Flammeovirgaceae. The strain could be differentiated phenotypically and physiologically from recognized members of the family Flammeovirgaceae. The G+C content of DNA was 43 mol%, the major respiratory quinone was menaquinone 7 (MK-7) and iso-C15:0, C16:1ω5c and iso-C17:0 3-OH were the major fatty acids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the name Porifericola rhodea gen. nov., sp. nov. is proposed. The type strain of Porifericola rhodea is N5EA6-3A2BT (=MBIC08357T = NBRC 107748T).  相似文献   

13.
Pinus taeda is one of the main timber trees in Brazil, occupying 1.8 million ha with an annual productivity of 25–30 m3 ha−1. Another important species is Araucaria angustifolia, belonging to the fragile Rainforest biome, which for decades has been a major source of timber in Brazil. Some diseases that affect the roots and/or the stem of these trees and cause “damping-off” of the seedlings, with economic and environmental losses for the forest sector, are caused by the plant pathogenic fungi Fusarium sp. or Armillaria sp. This research project intended to isolate actinobacteria from the Araucaria rhizosphere, which present an antagonistic effect against these fungi. After the selection of the best pathogen inhibitors, morphologic characteristics, enzyme production, and their effect on the growth of Pinus taeda were studied. The actinobacteria were tested for their antagonistic capacity against Fusarium sp. in Petri plates with PDA as substrate. The inhibition zone was measured after 3, 5, 7, and 10 days. Of all the isolates tested, only two of them maintained inhibition zones up to 4 mm for 10 days. The inhibition of Armillaria sp. was tested in liquid medium and also in Petri dishes through the evaluation of the number of the fungal rhizomorphs in dual culture with the actinobacteria. It was found that all five isolates were able to inhibit the rhizomorph production, with the best performance of the isolate A43, which was capable of inhibiting both fungi, Fusarium and Armillaria. In a greenhouse experiment, the effect of five isolates on the growth of Pinus taeda seedlings was tested. Plant height, stem diameter, root and shoot dry matter were determined. The Streptomyces isolate A43 doubled plant growth. These results may lead to the development of new technologies in the identification of still unknown bacterial metabolites and new management techniques to control forest plant diseases.  相似文献   

14.
Calpain-3 is a skeletal muscle-specific protease and participates in the regulation of myogenesis. In this study, we quantified the expression of calpain-3 (CAPN3) mRNA in a Chinese local chicken breed (Sichuan Mountainous Black-boned chicken [MB]), to discern the tissue and ontogenic expression pattern. Meanwhile, we compared the CAPN3 mRNA expression pattern in MB chicken at 10 weeks with a commercial meat type chicken line (S01) of the same age to identify the unique expression pattern under different genetic background. A real time quantitative PCR (qRT-PCR) assay was developed for an accurate measurement of its expression in various tissues from chickens at different ages (0, 2, 4, 6, 8, 10, and 12 weeks). Expression of the CAPN3 mRNA was detected in the selected tissues, regardless of age. The breast muscle and leg muscle tissues had a significantly higher expression than the other tissues from the same individual (P < 0.01). Overall, the CAPN3 mRNA level exhibited a “rise-decline” developmental change in detected tissues except for brain. The S01 chicken had a higher expression of the CAPN3 mRNA in detected tissues than the MB chicken at 10 weeks. The present expression data of chicken CAPN3 gene may provide some information to shed light on the tissue and ontogenic expression pattern during chicken development.  相似文献   

15.
In a survey performed in Chania and Aetoloacarnania, Greece in years 2013–2014, fungal isolates causing twig and shoot blight and branch canker of citrus trees were morphologically characterized and identified by multiple gene sequence analysis. By sequencing the ITS‐5.8S rRNA, the elongation factor 1‐α (EF1‐α), the β‐tubulin and the RNA polymerase II subunit (Rpb2) genes, the isolates examined were associated with Diaporthe foeniculina (six isolates) and Neofusicoccum parvum (one isolate). All six D. foeniculina isolates showed slow colony growth rates (7.4 ± 3.2 mm/day), while the N. parvum isolate exhibited fast growth (41.6 mm/day). Koch's criteria were met after re‐isolation of D. foeniculina isolates from all inoculated Citrus spp. and N. parvum from inoculated C. reticulata “Ortanique” and after having developed symptoms similar to those detected on shoots and branches collected from citrus fields. Based on lesion length on detached C. medica “Lia Kritis” shoots, N. parvum caused long necrotic lesions (58 mm in length) in comparison with a length of 12–21 mm lesions caused by D. foeniculina isolates. Pathogenicity trials on nine Citrus spp., which had been inoculated with D. foeniculina and N. parvum, revealed different levels of susceptibility, indicating a host‐dependent infection effect, with Poncirus trifoliate × C. paradisi (“Citrumelo Swingle”) being the most resistant citrus genotype. Lack of host specificity suggests that their pathogen–host association could be attributed to ecological rather to co‐evolutionary factors. This work represents the first report, accompanied with pathogenicity tests, on botryosphaeriaceous and diaporthaceous pathogens associated with twig and shoot blight and branch canker of citrus in Greece.  相似文献   

16.
A hyperthermophilic heterotrophic archaeon (strain WB1) was isolated from a thermal pool in the Washburn hot spring group of Yellowstone National Park, USA. WB1 is a coccus, 0.6–1.2 μm in diameter, with a tetragonal S-layer, vacuoles, and occasional stalk-like protrusions. Growth is optimal at 84°C (range 64–93°C), pH 5–6 (range 3.5–8.5), and <1 g/l NaCl (range 0–4.6 g/l NaCl). Tests of metabolic properties show the isolate to be a strict anaerobe that ferments complex organic substrates. Phylogenetic analysis of the 16S rRNA gene sequence places WB1 in a clade of previously uncultured Desulfurococcaceae and shows it to have ≤96% 16S rRNA sequence identity to Desulfurococcus mobilis, Staphylothermus marinus, Staphylothermus hellenicus, and Sulfophobococcus zilligii. The 16S rRNA gene contains a large insertion similar to homing endonuclease introns reported in Thermoproteus and Pyrobaculum species. Growth is unaffected by the presence of S0 or SO4 2−, thereby differentiating the isolate from its closest relatives. Based on phylogenetic and physiological differences, it is proposed that isolate WB1 represents the type strain of a novel genus and species within the Desulfurococcaceae, Thermogladius shockii gen. nov., sp. nov. (RIKEN = JCM-16579, ATCC = BAA-1607, Genbank 16S rRNA gene = EU183120).  相似文献   

17.
Holm oak (Quercus ilex ssp. ballota [Desf.] Samp) is one of the most important species in forest communities of the western Mediterranean Basin, but is very vulnerable to environmental stress during the first years of its life. In particular, summer drought and winter frosts limit the distribution, survival, and growth of Holm oak. These two stress factors can lead to plasmolysis and/or oxidative stress. We hypothesized that autumn fertilization with nitrogen (N) can improve plant tolerance to these abiotic stress factors and improve plant quality and therefore reforestation success. A 12-week autumn application of 30 or 60 mg N (plus 70 mg N applied to both treatments during the previous 28 weeks in the nursery, i.e. 100 and 130 mg N in total, respectively) improved overall growth, root growth capacity, frost tolerance, and nutritional status of plants relative to plants given 0.0 and 1.5 mg autumnal N, and had no negative effect on seedling response to water stress. A very small increment in N doses during the autumn (1.5 vs. 0.0 mg N) improved some morphological parameters, such as stem diameter (D) and shoot dry weight, and physiological parameters, such as total antioxidant activity. The highest autumnal N dose (60 mg) increased leaf nutrient content without decreasing the concentration, but had a tendency to reduce frost tolerance relative to seedlings given a lower autumnal N dose (30 mg).  相似文献   

18.

Background  

Members of the genus Nocardia are ubiquitous environmental saprophytes capable to cause human pulmonary, disseminated and cutaneous nocardiosis or bovine mastitis. Innate immunity appears to play an important role in early defense against Nocardia species. To elucidate the contribution of antimicrobial peptides (AMPs) in innate defense against Nocardia, the activity of human α-defensins human neutrophil peptides (HNPs) 1-3, human β-defensin (hBD)-3 and cathelicidin LL-37 as well as bovine β-defensins lingual and tracheal antimicrobial peptides (LAP, TAP) and bovine neutrophil-derived indolicidin against four important Nocardia species was investigated.  相似文献   

19.
Four gram-negative, aerobic, motile, non-spore, forming rods with a wide pH and temperature range for growth (pH 7.0–11.0, optimum pH 8.0; 20–45°C, optimum 28°C) strains were isolated from root nodules of Sphaerophysa salsula and characterized by means of a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the four strains formed a new lineage related to the genus Rhizobium and the sequence similarities between the isolate and the most related type strain Rhizobium giardinii was 96.5%. These strains also formed a distinctive group from the reference strains for defined Rhizobium species based on housekeeping gene sequences (atpD and recA), BOX-PCR fingerprinting, phenotypic features and symbiotic properties. The representative strain CCNWGS0238T has DNA-DNA relatedness of less than 33.4% with the most closely related species R. giardinii. It is therefore proposed as a new species, Rhizobium sphaerophysae sp. nov., with isolate CCNWGS0238T (=ACCC17498T = HAMBI3074T) as the type strain.  相似文献   

20.
Zhao L  Zhao C  Han D  Yang S  Chen S  Yu CP 《Biotechnology letters》2011,33(11):2135-2140
A phenanthrene-utilizing bacterium was anaerobically isolated and identified as Rhodopseudomonas palustris. It tolerated up to 100 mg phenanthrene l−1 and degraded 50% of 50 mg phenanthrene l−1 over 10 days. The presence of phenanthrene caused a prolonged lag phase (2–3 days) in cell growth and affected the photopigments biosynthesis, while DMSO (the solvent for phenanthrene) had no impact on cell growth. The cell surface hydrophobicity of the isolate was also increased.  相似文献   

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