937 resultados para Invasive alien species


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Analysis of the 16S rDNA sequence of Conglomeromonas largomobilis subsp. largomobilis supports a phylogenetic relationship with the species of the genus Azospirillum. This confirms results of previous nucleic acid hybridization studies (FALK, E. C., J. L. JOHNSON, V. D. L. BALDANI, J. DOBEREINER, and N. R. KRIEG. 1986. Int. J. Syst. Bacteriol. 36: 80-85). Conglomeromonas largomobilis subsp. largomobilis was most closely related to the species Azospirillim lipoferum and Azospirillum brasilense but sufficiently distant to warrant separate species status. Conglomeromonas largomobilis subsp. parooensis was more distantly related to the existing species of Azospirillum and represents an isolated subline of descent. On the basis of the phylogenetic evidence a prosposal is made to transfer the subspecies Conglom-eromonas largomobilis subsp. largomobilis to the genus Azospirillum as Azospirillum largomobile comb. nov. and to retain the genus Conglomeromonas by elevating the subspecies C. largomobilis subsp. parooensis to the type species of Conglomeromonas as Conglomeromonas parooensis sp. nov.

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The phylogenetic relationships among the species of the genus Pedomicrobium were studied by comparing their 16S rRNA sequences, The Pedomicrobium species form a coherent phylogenetic cluster within the genera of the hyphal budding bacteria in the alpha-Proteobacteria. The sequences of two strains of Pedomicrobium australicum were obtained from DNAs extracted from nonviable freeze-dried cells, which are the only source of material available, and were found to be almost identical (level of similarity, 99.9%), Overall, the Pedomicrobium species are closely related, with sequence similarities ranging from 96.2 to 99.9%, Pedomicrobium manganicum is phylogenetically the most distantly related species and exhibits the lowest similarity (96.2%) with Pedomicrobium americanum, Australian isolate Pedomicrobium sp, strain ACM 3067, P, americanum, and P, australicum are all very highly related, with similarities greater than 99%, Pedomicrobium sp, strain ACM 3067 is most closely related to P, australicum (level of similarity, 99.6%) and P, americanum (99.4%), These manganese-oxidizing species are more closely related to the iron-oxidizing species Pedomicrobium ferrugineum than to the other manganese-oxidizing species, P, manganicum. Taxonomic uncertainties resulting from the loss of the type culture of P, australicum are discussed.

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Six Burkholderia solanacearum (formerly Pseudomonas solanacearum) genomic DNA fragments were isolated, using RAPD techniques and cloning, from the three genetically diverse strains: ACH092 (Biovar 4), ACH0158 (Biovar 2) and ACH0171 (Biovar 3) (1). One of these cloned fragments was selected because it was present constantly in all bacterial strains analysed. The remaining five clones were selected because Southern hybridisation revealed that each showed partial or complete specificity towards the strain of origin. A seventh genomic fragment showing a strain-specific distribution in Southern hybridisations was obtained by differential restriction, hybridisation and cloning of genomic DNA. Each of these clones was sequenced and primers to amplify the insert were designed. When DNA from the strain of origin was used as template, PCR amplification for each of these fragments yielded a single band on gel analysis. One pair of primers amplified the species-constant fragment of 281 bp from DNA of all B. solanacearum strains investigated, from DNA of the closely related bacterium which causes ''blood disease'' of banana (BDB) and in P. syzigii. The sensitivity of detection of B. solanacearum using these ubiquitous primers was between 1.3 and 20 bacterial cells. The feasibility and reliability of a PCR approach to detection and identification of B. solanacearum was tested in diverse strains of the bacterium in several countries and laboratories.

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The fatty acid composition of 11 species of fish caught off the northeast coast of Australia was determined. No fatty acid profiles have been previously published for fish from this area nor for nine of these species. Although the percentage of polyunsaturated fatty acid (PU FA) was the same as the calculated average for Australian fish (42.3%), the percentage of n-3 fatty acids was lower (24.4 +/- 5.4% vs. 30.7 +/- 10.1%) and the n-6 fatty acids higher (16.5 +/- 4.5% vs. 11.2 +/- 5.9%), P < 0.001 in each case. The major n-3 PUFA were docosahexaenoic (15.6 +/- 6.3%) and eicosapentaenoic acid (4.3 +/- 1.1%) while the major n-6 PUFA were arachidonic (8.3 +/- 3.2%) and n-6 docosatetraenoic acid (3.1 +/- 1.3%). The second-most abundant class of fatty acid was the saturates (31.6 +/- 3.5%) while the monounsaturates accounted for 17.4 +/- 4.3% of the total fatty acids. The monounsaturate with the highest concentration was octadecenoic acid (11.8 +/- 2.6%). There was a positive correlation between the total lipid content and saturated and monounsaturated fatty acids (r = 0.675 and 0.567, respectively) and a negative correlation between the total lipid content and PUFA(r = 0.774).

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The following lepocreadiid species are described from Cheilodactylidae from south-western Australia. Cliveus peroni n. g., n. sp, from Nemadactylus valenciennesi is characterised by its attenuated forebody and C. acaenodera n. sp. from Dactylophora nigricans by its attenuated forebody, the pattern of forebody spination and the large cirrus-sac. Jericho chojeri n. g., n. sp. from N. valenciennesi has a large infundibuliform oral sucker and paired ani. Rugocavum n. g. is distinguished by the possession of a blind, wrinkled glandular pit on the postero-ventral surface of the forebody. R. nemadactyli n. sp. from N. valenciennesi has its vitelline field restricted to the hindbody, whereas in R. morwong n. sp, from N. valenciennesi the vitelline field reaches into the forebody. Paraneocreadium australiense Kruse, 1978 from N. valenciennesi is redescribed and its coiled internal seminal vesicle and lobed gonads are considered distinctive features. Scaphatrema nemadactyli (Kurochkin & Korotaeva, 1972) n. g., n. comb. from N. valenciennesi has a wrinkled, boat-shaped body, a 'Lepidapedon-like' cirrus-sac and multiple testes; it was originally placed in the genus Multitestis, but these characters suggest that a new genus should be erected for it within the subfamily Lepidapedinae.

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The tannin-degrading species Streptococcus gallolyticus and Streptococcus caprinus have been shown to be subjective synonyms on the basis of their levels of 16S rRNA sequence similarity (98.3%) and DNA-DNA homology (>70%) and the phenotypes of their type strains. S. gallolyticus has nomenclatural priority according to Rule 24b(2) of the International Code of Nomenclature of Bacteria.

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Candidemia is associated with high morbidity and mortality resulting in significant increases in the length of patients` hospitalization and in healthcare costs. Critically ill patients are at particular risk for candidemia because of their debilitated condition and frequent need for invasive procedures. The aim of this study was to characterize the incidence and epidemiology of candidemia over a seven-year period in intensive care units (ICUs) and the use of fluconazole and caspofungin in a large university-affiliated hospital. All cases of candidemia were identified by surveillance, using the Centers for Diseases Control and Prevention criteria. Demographic variables, use of antifungal (fluconazole and caspofungin) and patient outcomes were evaluated. The 2 test for linear trend was employed to evaluate the distribution of Candida spp. and the use of fluconazole and caspofungin by defined daily dose (DDD) per 1,000 patients-days during the study period. One hundred and eight episodes of candidemia were identified. The overall incidence of candidemia (P=0.20) and incidence of non-Candida albicans Candida infections (P=0.32) remained stable over the study period and ranged from 0.3-0.9 episodes per 1,000 catheter-days and 0.39-0.83 episodes per 1,000 patients-days. However, the use of fluconazole and caspofungin increased significantly (P0.001). While there were no reports of the use of fluconazole for prophylaxis in 1999, its use for this purpose increased from 3% in 2000 to 7.0% (P=0.07) in 2006. C. albicans was the most frequent specie isolated and burns and cancer were the most frequent underlying conditions. The overall mortality was 76%. There was no difference between C. albicans and non-C. albicans Candida infections when the crude and 14-day mortality rates were compared. Our data demonstrated that C. albicans is still the most frequent species causing candidemia in our intensive care units. Our rates of candidemia are lower than those reported from the region and similar to American and European hospitals. Although the incidence of blood stream infections (BSI) and candidemia remained stable, the use of fluconazole and caspofungin increased significantly over the years included in this study but had no impact on the incidence of infections caused by non-C. albicans Candida species.

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This is a retrospective observational study of clinical and epidemiologic data from bloodstream yeast infections over 5 years (2004-2008) in a tertiary-care hospital. During this period, there were 52 such infections, at a rate of 2.4 per 1,000 hospital admissions. Non-C. albicans Candida species and other genera were responsible for 82% of infections, with C. tropicalis and C. parapsilosis being the most common. In 2008 no C. albicans infections occurred. Several uncommon fungal pathogens were observed, including Trichosporon asahii, Rhodotorula spp. and Candida zeylanoides. Of 16 isolates tested, 3 (19%) were resistant to fluconazole, including one C. zeylanoides (MIC 8 mu g/ml) and one C. tropicalis (MIC 16 mu g/ml) isolate, as well as intrinsically resistant C. krusei. All isolates tested were susceptible to itraconazole (n = 7) and amphotericin B (n = 8). Yeast infections were associated with severe underlying diseases, mainly hematological/solid cancers (71%), hospitalization in the ICU (41%), central venous catheters (80%), and use of antimicrobials (94%). The overall mortality rate was 50%. Our finding of a predominance of non-C. albicans Candida species infection with uncommon yeasts, and fluconazole resistance, suggests the need for continuous surveillance of fungemia and of antibiotic susceptibility trends, in order to adopt treatment strategies applicable to particular healthcare institutions.

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Introduction: Current advances in frame modeling and computer software allow stereotactic procedures to be performed with great accuracy and minimal risk of neural tissue or vascular injury. Case Report: In this report we associate a previously described minimally invasive stereotactic technique with state-of-the-art 3D computer guidance technology to successfully treat a 55-year-old patient with an arachnoidal cyst obstructing the aqueduct of Sylvius. We provide 1 detailed technical information and discuss how this technique deals with previous limitations for stereotactic manipulation of the aqueductal region. We further discuss current advances in neuroendoscopy for treating obstructive hydrocephalus and make comparisons with our proposed technique. Conclusion: We advocate that this technique is not only capable of treating this pathology but it also has the advantages to enable reestablishment of physiological CSF flow thus preventing future brainstem compression by cyst enlargement.

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Objective: Our aim was to evaluate the challenges in obtaining a successful restoration of the rotation center as well as a good positioning of the acetabular component when using the minimally-invasive posterior approach for uncemented total hip replacement. Methods: In a comparative non-random prospective study, 64 adult patients underwent elective total hip arthroplasty using the minimally-invasive posterior approach performed by one single surgeon, All patients included in this study had a superior and lateral migration of the rotation center of the hip in comparison to the normal contralateral hip. Patients were excluded from the study if they presented the following: diagnosis of femoral neck fracture, displasic hip types 2, 3 and 4 (Crowe`s classification), osteoarthritis of the contralateral hip. Of the 64 patients in the study, 39 had a radiographic pre-op acetabular size planning equal or less than 50 mm and 25 patients had a radiographic pre-op acetabular size planning equal or more than 52 mm. We considered a good result the following goals: acetabular bend between 35 and 50 degrees, acetabular size according to the pre-op estimative with full contact in the three zones of DeLee-Charnley, a lower medial and vertical positioning of the rotation center in comparison with the pre-op values and a final limb discrepancy lower than 10 mm. Results: A better restoration of the rotation center, as well as, excellent acetabular positioning was found in patients with smaller acetabular size (equal or less than 50), p=0, 04. We must draw attention to two risks when using the minimally-invasive posterior approach: a vertical acetabular position and a lateral position of the acetabular component increasing the risk of a poor contact in the zone 1 due to an insufficient reaming of the medial acetabular host bone. Conclusion: We propose standard surgical approaches in patients with larger anatomical measurements (acetabular planning size more than 50).