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xico IntroductionA limiting factor for sustainable development of aquaculture is the presence of bacterial diseases induced principally by associated opportunistic bacterial flora, which become pathogenic when farmed organisms are exposed to stress caused by: poor quality environmental conditions, high stocking densities and inadequate feeding or management techniques . This may lead to physiological and ecological imbalance in the hosted animal, causing massive mortalities (Ruangpan and Kitao 1991;Lightner 1993;Jeney and Jeney 1995). Recently, interest has arisen in preventing bacterial diseases by controlling or eliminating opportunistic pathogens through the use of probiotic bacteria (Moriarty 1997;Gó mez-Gil et al. 2000;Devaraja et al. 2002). The manipulation of bacterial composition in the hosted animals and/or the environment could control the proliferation of bacterial pathogens, through the addition of selected probiotic bacterial species and by the control of AbstractAims: To carry out a rapid and reliable identification of bacterial diversity in the oyster Crassostrea gigas from Todos Santos Bay, México, in the current study we applied the molecular techniques of fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR). In order to reach this goal, genus and group-specific oligonucleotides targeted to 16S rDNA/rRNA were used. Methods and Results: Oysters were collected and different tissues were analysed by means of culture-independent methodologies. In the digestive glands and gonads c-Proteobacteria and Gram-positive bacteria with a low G+C content, were identified as metabolically active by FISH. In the oyster gills a higher active diversity was observed, including Gram-positive bacteria with a low and high G+C content, members of the Cytophaga/Flavobacterium cluster and cProteobacteria. Consistent with FISH analysis, the amplification of 16S rDNA genes fragments with genus and group-specific oligonucleotides confirmed the presence of the same groups, as well as members of the a-and b-Proteobacterias, Pseudomonas spp. and Bacillus spp. Conclusions: The combination of accurate and very easy-to-apply molecular methods allowed us to carry out a rapid screening of high bacterial diversity in oysters. Significance and Impact of the Study: This work is the first report about bacterial diversity in oyster tissues analysed by FISH and PCR, without using culture-dependent methods and allowed us to determine the phylogenetic diversity of the bacterial communities present in oyster cultures, including bacteria with and without metabolic activity, as well as uncultivable cells, which are generally underestimated by traditional identification. Journal of Applied Microbiology

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Bacillus thuringiensis (Bt) is a ubiquitous bacterium in soils, insect cadavers, phylloplane, water, and stored grain, that produces several proteins, each one toxic to different biological targets such as insects, nematodes, mites, protozoa, and mammalian cells. Most Bt toxins identify their particular target through the recognition of specific cell membrane receptors. Cry proteins are the best-known toxins from Bt and a great amount of research has been published. Cry are cytotoxic to insect larvae that affect important crops recognizing specific cell membrane receptors such as cadherin, aminopeptidase-N, and alkaline phosphatase. Furthermore, some Cry toxins such as Cry4A, Cry4B, and Cry11A act synergistically with Cyt toxins against dipteran larvae vectors of human disease. Research developed with Cry proteins revealed that these toxins also could kill human cancer cells through the interaction with specific receptors. Parasporins are a small group of patented toxins that may or may not have insecticidal activity. These proteins could kill a wide variety of mammalian cancer cells by recognizing specific membrane receptors, just like Cry toxins do. Surface layer proteins (SLP), unlike the other proteins produced by Bt, are also produced by most bacteria and archaebacteria. It was recently demonstrated that SLP produced by Bt could interact with membrane receptors of insect and human cancer cells to kill them. Cyt toxins have a structure that is mostly unrelated to Cry toxins; thereby, other mechanisms of action have been reported to them. These toxins affect mainly mosquitoes that are vectors of human diseases like Anopheles spp (malaria), Aedes spp (dengue, zika, and chikungunya), and Culex spp (Nile fever and Rift Valley fever), respectively. In addition to the Cry, Cyt, and parasporins toxins produced during spore formation as inclusion bodies, Bt strains also produce Vip (Vegetative insecticidal toxins) and Sip (Secreted insecticidal proteins) toxins with insecticidal activity during their vegetative growth phase.

Abstract. her-2 gene amplification and its overexpression in breast cancer cells is directly associated with aggressive clinical behavior. The her-2 gene and its Her-2 protein have been utilized for disease diagnosis and as a predictive marker for treatment response to the antibody herceptin. Fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) are the most common FDA-approved methodologies involving gene and protein quantification, respectively. False positive or negative her-2/Her-2 patient results may result in inappropriate treatment administration. To support accurate quantification and interpretation of results, in this study we have standardized qPCR analysis using previously identified IHC samples, obtaining very significant and clinically useful results.