hydrophila, but the strain NJ-4 did not (unpublished data). Some investigations showed that in the presence of Tetrahymena sp., bacterial exotoxins augment the fitness of bacterial populations that carry them (Steinberg & Levin, 2007; Lainhart et al., 2009). The coordinated release of exotoxins, at either the pre- or the postingestional state, could comprise one of the bacterium’s major antipredator defense strategies (Matz & Kjelleberg, 2005). We hypothesize that the extracellular products encoded by

the virulence genes (not present in the avirulent A. hydrophila NJ-4 strain) likely contributed to the death of T. thermophila. Reverse transcription-PCR Afatinib mouse analysis further demonstrated that the virulence genes (aerA and ahe2) of the strain J-1 were upregulated 4 h after co-culture with T. thermophila, which might partly explain the powerful cytotoxic effects of the virulent strain J-1 compared with the avirulent strain NJ-4. This finding is consistent with the opinion that

protozoa seem to be evolutionary incubators of bacterial virulence (Mahajan-Miklos et al., 2000). In conclusion, the work presented here suggests that T. thermophila represents a permissive host for A. hydrophila infections and can be used as a simple host model to assess the virulence of A. hydrophila strains. Cabozantinib This system could allow, in the future, high-throughput screening for the identification of bacterial virulence factors, and with the publication of the T. thermophila macronuclear genome sequence (Eisen et al., 2006), and establishments of the T. thermophila Genome Database (http://www.ciliate.org) and the platform for genome-wide microarray analysis of gene expression in T. thermophila (Miao et al., 2009), new opportunities have opened up to help us examine host–pathogen interactions at the cellular and genetic levels in order to decipher the function of bacterial virulence factors as well as host responses against them. This research

was supported by the Program for New Century Excellent Talents in University (NCET-07-0440), Pyruvate dehydrogenase lipoamide kinase isozyme 1 National Nature Science Foundation (31072151), Special Funding of Public Sector Agricultural Research Project from the Chinese Ministry of Agriculture (200803013) and the State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences (SKLVEB2010KFKT006). “
“Vanillin dehydrogenases (VDHs) were purified and characterized from two bacterial strains that have different pH dependencies for growth. The alkaliphile Micrococcus sp. TA1, isolated from an alkaline spa, can grow on several aromatic compounds such as ferulic acid, vanillin, vanillic acid, and protocatechuic acid under alkaline conditions.