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401.
Reliability of hsp65-RFLP analysis for identification of Mycobacterium species in cultured strains and clinical specimens 总被引:2,自引:0,他引:2
de Magalhães VD de Melo Azevedo Fda P Pasternak J Valle Martino MD 《Journal of microbiological methods》2002,49(3):295-300
The purpose of this study was to evaluate the reliability of an amplification restriction analysis based method (hsp65-RFLP) to detect and identify mycobacterial species in clinical samples and cultures with low number of bacilli. We examined 247 clinical specimens and 88 culture vials, comparing hsp65-RFLP results with conventional culture/biochemical tests. The analytical sensitivity of the method was assessed with cerebrospinal fluid (CSF), broncho-alveolar lavage (BAL), sputum, water, and 12B medium containing defined amounts of mycobacterial chromosome. We detected the equivalent of 10(3) cells per ml in all samples, except sputum, the most common source of clinical sample for mycobacterial testing, which presented inhibition throughout. We investigated two purification procedures to overcome inhibition of DNA amplification: DNAzol and phenol/chloroform. The former was superior, eliminating inhibition in 93.7% of the clinical samples. The technique was effective for bacterial cultures, including those with very low growth indices (GIs), substantially abbreviating time for diagnosis, but showed low sensitivity (25%) when applied to clinical samples, an issue that has never been extensively assessed by other researchers. 相似文献
402.
Antisense (AS) oligodeoxynucleotides targeting G-protein alpha-subunits distinguish feeding responses of morphine and its metabolite, as well as nocturnal and deprivation-induced feeding. The present study examined whether feeding elicited by beta-endorphin (betaEND) or dynorphin A(1-17) was altered by ventricularly-applied G(i)alpha(1), G(i)alpha(2), G(i)alpha(3), G(s)alpha, G(o)alpha, G(q)alpha or G(x/z)alpha AS probes, or a nonsense (NS) control. The betaEND-induced feeding was reduced by the G(i)alpha(1) and G(x/z)alpha AS probes, and increased by G(i)alpha(2) or G(i)alpha(3) AS treatment. Dynorphin-induced feeding was attenuated by G(i)alpha(1) and G(o)alpha AS treatment. Yet, G(s)alpha or G(q)alpha AS and NS treatments failed to alter opioid agonist-induced feeding. These data provide initial characterization of potential effector signaling pathways mediating betaEND and dynorphin-induced feeding. 相似文献
403.
The obligate fish ectoparasite Argulus coregoni is strictly specific to salmonids and is very rarely found on other fish species. The ability of the parasite to grow and complete its life cycle on a cyprinid host, Rutilus rutilus, was compared with that on a typical salmonid host, Oncorhynchus mykiss. Rearing experiments were run for 42 d with newly hatched metanauplii in flow-through tanks. Body length and sex of the parasites were recorded every 5 d. Growth rates on O. mykiss exceeded those on R. rutilus from the age of 2 wk, at which time the parasites reached a length of about 3.5 mm. Males grew faster than females at the beginning of the experiment up to a length of 2.5 to 3.0 mm; thereafter, a faster growth rate was observed in females. In another experiment, association of parasites with the hosts was monitored and residence time defined as the period between attachment and first detachment from the host. Longer residence time was observed on O. mykiss than on R. rutilus; female parasites stayed on both fish species longer than did males. Faster growth of parasites could be associated with longer uninterrupted periods of attachment to hosts, since frequent detachment means higher energy losses and less time available for feeding. Despite its slower growth on R. rutilus, A. coregoni matured and laid egg clutches, but took 5 d longer than on O. mykiss. The potential of A. coregoni to complete its life cycle on cyprinids could have important ecological consequences, creating an infection reservoir when the main salmonid hosts are rare or temporarily missing. 相似文献
404.
Publication of the complete diploid genome sequence of the yeast Candida albicans will accelerate research into the pathogenesis of Candida infections. Comparative genomic analysis highlights genes that may contribute to C. albicans survival and its fitness as a human commensal and pathogen. 相似文献
405.
406.
Analysis of original and published data on predator avoidance by marine and freshwater plankton copepods, a major diet of many young fishes, suggests that individual defense mechanisms play a minor role in copepod anti-predator behavior. Capture success by planktivorous fish depends largely on prey visibility and the ability of the prey to escape. Copepods have almost no chance to avoid relatively large fish when encountered, but they can be ranked according to their ability to escape from larvae and fries. In contrast to small pelagic fish, which are also under heavy predation pressure, copepods rely more on prevention of the threat of predation than on active attempts to escape. Seeking a refuge in habitats non-accessible to predators would be more effective for these small and rather slow animals. Retreat into such refuges is accomplished by vertical and horizontal migrations, either diel, seasonal or ontogenetic. A decrease in activity (feeding, metabolism, reproduction, movement), resulting in diapause in deep water layers in its most pronounced version, is the ultimate attempt by copepods to separate from their predators, both in time and in space. 相似文献
407.
Tao Che Susruta Majumdar Saheem A. Zaidi Pauline Ondachi John D. McCorvy Sheng Wang Philip D. Mosier Rajendra Uprety Eyal Vardy Brian E. Krumm Gye Won Han Ming-Yue Lee Els Pardon Jan Steyaert Xi-Ping Huang Ryan T. Strachan Alexandra R. Tribo Gavril W. Pasternak Bryan L. Roth 《Cell》2018,172(1-2):55-67.e15
408.
Ricardo Andreotti Siqueira Andre Mario Doi Paulo Petrus de Petrus Crossara Paula Celia Mariko Koga Alexandre Gimenes Marques Fabiane Gomes Nunes Jacyr Pasternak Marines Dalla Valle Martino 《Revista iberoamericana de micología》2018,35(2):83-87
Background
An increased incidence of fungal infections caused by Candida species, especially Candida glabrata and Candida krusei, which are less susceptible to azoles, has been observed. Standardized susceptibility testing is essential for clinical management and for monitoring the epidemiology of resistance.Aims
We evaluated the performance of two different susceptibility testing commercial methods, Vitek 2® and Sensititre YeastOne®, and compared them with the standard broth microdilution method (CLSI).Methods
A total of 80 isolates of several Candida species (Candida albicans, Candida parapsilosis complex, Candida tropicalis, C. glabrata and C. krusei) were selected for this study.Results
We analyzed the categorical agreement (CA) between the methods, stratifying the disagreements. The average CA between the methods was 96.3% for Vitek 2® and 84% for Sensititre YeastOne®. No very major errors were observed. Major errors and minor errors were found for all the isolates tested. With the azoles, both Vitek 2® and Sensititre YeastOne® had good and similar performance levels, except for C. tropicalis and C. krusei (Sensititre YeastOne® showed low CA, 56.2%). With the echinocandins, both methods showed good performance for C. albicans, C. parapsilosis and C. tropicalis. However, we observed important discrepancies for C. krusei with caspofungin: Vitek 2® had 100% CA while Sensititre YeastOne® had only 25%. With amphotericin B, both Vitek 2® and Sensititre YeastOne® had good performance with high CA.Conclusions
Despite the limited isolates tested, we concluded that both methods have good performance and are reliable for antifungal susceptibility testing. However, caspofungin activity against C. krusei and C. glabrata should be interpreted carefully when using Sensititre YeastOne® because we observed a low CA. 相似文献409.