RESUMEN
Numerous sheep with the prion gene (PRNP) that encodes for 171QQ develop scrapie, a neurodegenerative prion disease of sheep. Relatively few cases of scrapie-affected sheep with PRNP genetics that encode for 171RR, however, have been found. Using flow cytometric analysis, statistically fewer PrPc-positive microglia and monocytes were observed from sheep with 171RR PRNP genetics than from sheep with 171QQ PRNP genetics (P<0.05). One possibility for the lack of PrP(Sc) accumulation in brains and lymph nodes of scrapie-exposed sheep with 171RR PRNP genetics is because of fewer PrPc-positive myeloid-derived cells available for conversion of PrPc to PrP(Sc).
Asunto(s)
Células Mieloides/metabolismo , Proteínas PrPC/metabolismo , Priones/genética , Scrapie/metabolismo , Scrapie/patología , Animales , Animales Recién Nacidos , Células Cultivadas , Femenino , Citometría de Flujo/métodos , Genotipo , Proteína Ácida Fibrilar de la Glía/metabolismo , Inmunohistoquímica/métodos , Microglía/patología , Microglía/ultraestructura , Monocitos/metabolismo , Células Mieloides/ultraestructura , Lectinas de Plantas/metabolismo , Proteínas PrPC/patogenicidad , ARN Mensajero/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Scrapie/genética , OvinosRESUMEN
Four-week-old Harlan A/J mice were orally infected with six epidemic and six environmental strains of Listeria monocytogenes. Epidemic strains were significantly more invasive as a group than were environmental strains (P < 0.05), and the intestines of some mice infected with epidemic strains had extensive hemorrhage. Mice inoculated with epidemic strains were significantly more likely to become systemically infected than mice inoculated with environmental strains (P < 0.01).
Asunto(s)
Variación Genética , Listeria monocytogenes/patogenicidad , Listeriosis/inmunología , Animales , Intestinos/microbiología , Intestinos/patología , Listeria monocytogenes/genética , Listeria monocytogenes/inmunología , Listeriosis/patología , RatonesRESUMEN
We developed and tested a glass-based microarray suitable for detecting multiple tetracycline (tet) resistance genes. Microarray probes for 17 tet genes, the beta-lactamase bla(TEM-1) gene, and a 16S ribosomal DNA gene (Escherichia coli) were generated from known controls by PCR. The resulting products (ca. 550 bp) were applied as spots onto epoxy-silane-derivatized, Teflon-masked slides by using a robotic spotter. DNA was extracted from test strains, biotinylated, hybridized overnight to individual microarrays at 65 degrees C, and detected with Tyramide Signal Amplification, Alexa Fluor 546, and a microarray scanner. Using a detection threshold of 3x the standard deviation, we correctly identified tet genes carried by 39 test strains. Nine additional strains were not known to harbor any genes represented on the microarray, and these strains were negative for all 17 tet probes as expected. We verified that R741a, which was originally thought to carry a novel tet gene, tet(I), actually harbored a tet(G) gene. Microarray technology has the potential for screening a large number of different antibiotic resistance genes by the relatively low-cost methods outlined in this paper.