2e). It has been demonstrated previously that invasin plays a major role in the early invasion of PPs by yersiniae in the mouse infection model (Pepe & Miller, 1993; Pepe et al., 1995; Marra & Isberg, 1996, 1997). PPs were, however, shown to be eventually colonized by yersiniae at later infection stages (Pepe & Miller, 1993). The spread of yersiniae to the spleen and liver as well as LD50 were not dependent on inv. The effect of invasin on the ABT-199 research buy colonization of individual PPs has, however, not been studied. We therefore quantified the colonization of individual PPs using luminescing yersiniae on day 5 p.i. Fourteen mice

were infected with either the Δinv mutant or the wild-type strain. Analysis of PPs with the IVIS camera revealed significantly fewer luminescing PPs after oral infection with the Δinv mutant than wild-type

yersiniae (Fig. 3a). In fact, most PPs did not show any luminescence at all. This was also the case for mice infected for 6 or 7 days (results not shown). Therefore, these experiments show that the inv deletion does VX-809 chemical structure not lead to a delayed invasion phenotype, but rather to invasion and abscessing of fewer PPs. Similarly, the number of abscessed follicles in the cecum (Fig. 3b) as well as the number of mice with abscessed cervical and mesenteric lymph nodes (Fig. 3c and d) were significantly reduced. The spleens and livers of mice infected with the Δinv mutant were, however, more heavily colonized than spleens and livers infected with wild-type yersiniae (Fig. 4). Although this effect was not statistically significant, it was very reproducible in multiple experiments. Interestingly, it was discovered recently that the presence of invasin in Yersinia pseudotuberculosis inhibited colonization of the liver and spleen after intravenous infection (Hudson & Bouton, 2006). In conclusion, these experiments demonstrate Phosphatidylinositol diacylglycerol-lyase the versatility

of the luxCDABE reporter for analyzing and quantifying Yersinia abscessed tissue in mice. Using this method, we could show for the first time that cervical lymph nodes are frequently abscessed by yersiniae and that the absence of inv leads to a reduced number (rather than delayed invasion) of abscessed PPs, cecal lymph follicles, and cervical lymph nodes. Holger Loessner is acknowledged for plasmids pHL289 and pUX-BF13. This work was supported by DFG grant TR 740/2-1. “
“A rapid, high-resolution melting (HRM) analysis protocol was developed to detect sequence variations associated with resistance to the QoIs, benzimidazoles and dicarboximides in Botrytis cinerea airborne inoculum. HRM analysis was applied directly in fungal DNA collected from air samplers with selective medium. Three and five different genotypes were detected and classified according to their melting profiles in BenA and bos1 genes associated with resistance to benzimidazoles and dicarboximides, respectively.