Quantification and distribution of vibrio species in water from an estuary in Ceará-Brazil impacted by shrimp farming

Vibrios were quantified and their distribution determined for the estuary of the Coreaú river, in Northeastern Brazil, based on 24 water samples collected between June and October 2005. The most probable number of vibrios per 100 mL ranged from 230 x 10³ to 240 x 10(11). The pH value was the environmental factor most strongly associated with the abundance of vibrios. Sixty-two vibrio strains were isolated belonging to 15 species (6 of which observed in June-September and 8 in October). The most frequently isolated species were V. parahaemolyticus and V. cholerae.Foram realizadas análises concernentes à quantificação e distribuição de Vibrio em 24 amostras de água do estuário do Rio Coreaú (CE) no período de junho a novembro de 2005. O Número Mais Provável (NMP/100 mL) de Vibrio oscilou de 230 x 10³ a 240 x 10(11). O pH foi o fator ambiental que mais favoreceu ao aumento da microbiota de Vibrio. Foram isoladas 62 cepas de Vibrio, sendo observada uma distribuição de sete espécies nos meses de junho a setembro, e oito espécies no mês de outubro. As espécies mais freqüentes nos isolamentos foram V. parahaemolyticus e V. cholerae

Probiotics mitigate thermal stress- and pathogen-driven impacts on coral skeleton

Threats leading to a reduction in coral populations are apparent worldwide. Several different approaches have been tested to accelerate the adaptation of corals to a changing climate. Here, we evaluated the skeleton structure, crystal habit, and chemical changes of the coral Pocillopora damicornis in response to the pathogen (Vibrio coralliilyticus) and probiotic (Beneficial Microorganisms for Corals, BMCs) inoculation under ambient conditions (26 °C) and thermal stress (30 °C) during a 50-day mesocosm experiment. The skeletons were analyzed using microtomography, energy-dispersive x-ray spectroscopy (EDX/SEM), and densitometry to investigate the skeleto-physico-chemical micro-morphological changes in porosity, median pore-size diameter, crystal habit, Mg/Ca, Sr/Ca, the skeleton mineral density (g/cm2) and skeleton mineral content (g–2). The results indicate considerable changes in the coral skeleton caused by both temperature and microbial inoculation. Most importantly, lower density (to ∼ x̄ 0.5 g/cm2) and higher porosity (up to ∼ x̄ 47%) were correlated with inoculation of V. coralliilyticus and mitigated by probiotics. BMCs also substantially increased calcification, as evidenced by Mg/Ca in the skeleton of thermally stressed corals. At the micron scale, aragonite crystal fibbers precipitated during the experiments showed an acicular habit in thermally stressed and pathogen-inoculated corals kept at 30 °C. In contrast, a spherulitic habit, characteristic of high growth rates, was observed in corals inoculated with both BMCs and V. coralliilyticus. Our findings reveal that pathogen inoculation and thermal stress had notable impacts on coral skeleton properties, including porosity, density, and crystal morphology, in a short period of time, which highlights the potential impacts of shifts in climate warming and environmental quality. Interestingly, BMCs played a role in maintaining the properties of skeleton calcification

Delivering beneficial microorganisms for corals: rotifers as carriers of probiotic bacteria

The use of Beneficial Microorganisms for Corals (BMCs) to increase the resistance of corals to environmental stress has proven to be effective in laboratory trials. Because direct inoculation of BMCs in larger tanks or in the field can be challenging, a delivery mechanism is needed for efficient transmission of the BMC consortium. Packaged delivery mechanisms have been successfully used to transmit probiotics to other organisms, including humans, lobsters, and fish. Here, we tested a method for utilizing rotifers of the species Brachionus plicatilis for delivery of BMCs to corals of the species Pocillopora damicornis. Epifluorescence microscopy combined with a live/dead cell staining assay was used to evaluate the viability of the BMCs and monitor their in vivo uptake by the rotifers. The rotifers efficiently ingested BMCs, which accumulated in the digestive system and on the body surface after 10 min of interaction. Scanning electron microscopy confirmed the adherence of BMCs to the rotifer surfaces. BMC-enriched rotifers were actively ingested by P. damicornis corals, indicating that this is a promising technique for administering coral probiotics in situ. Studies to track the delivery of probiotics through carriers such as B. plicatilis, and the provision or establishment of beneficial traits in corals are the next proof-of-concept research priorities

Genome wide scan for quantitative trait loci affecting tick resistance in cattle (Bos taurus × Bos indicus)

<p><b>Abstract</b></p> <p><b>Background</b></p> <p>In tropical countries, losses caused by bovine tick <it>Rhipicephalus (Boophilus) microplus</it> infestation have a tremendous economic impact on cattle production systems. Genetic variation between <it>Bos taurus</it> and <it>Bos indicus</it> to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (<it>Bos indicus</it>) × Holstein (<it>Bos taurus</it>) cross.</p> <p>Results</p> <p>Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23.</p> <p>Conclusions</p> <p>The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.</p

Horizon scanning the application of probiotics for wildlife

The provision of probiotics benefits the health of a wide range of organisms, from humans to animals and plants. Probiotics can enhance stress resilience of endangered organisms, many of which are critically threatened by anthropogenic impacts. The use of so-called ‘probiotics for wildlife’ is a nascent application, and the field needs to reflect on standards for its development, testing, validation, risk assessment, and deployment. Here, we identify the main challenges of this emerging intervention and provide a roadmap to validate the effectiveness of wildlife probiotics. We cover the essential use of inert negative controls in trials and the investigation of the probiotic mechanisms of action. We also suggest alternative microbial therapies that could be tested in parallel with the probiotic application. Our recommendations align approaches used for humans, aquaculture, and plants to the emerging concept and use of probiotics for wildlife

Marine probiotics: increasing coral resistance to bleaching through microbiome manipulation

Although the early coral reef-bleaching warning system (NOAA/USA) is established, there is no feasible treatment that can minimize temperature bleaching and/or disease impacts on corals in the field. Here, we present the first attempts to extrapolate the widespread and well-established use of bacterial consortia to protect or improve health in other organisms (e.g., humans and plants) to corals. Manipulation of the coral-associated microbiome was facilitated through addition of a consortium of native (isolated from Pocillopora damicornis and surrounding seawater) putatively beneficial microorganisms for corals (pBMCs), including five Pseudoalteromonas sp., a Halomonas taeanensis and a Cobetia marina-related species strains. The results from a controlled aquarium experiment in two temperature regimes (26 °C and 30 °C) and four treatments (pBMC; pBMC with pathogen challenge – Vibrio coralliilyticus, VC; pathogen challenge, VC; and control) revealed the ability of the pBMC consortium to partially mitigate coral bleaching. Significantly reduced coral-bleaching metrics were observed in pBMC-inoculated corals, in contrast to controls without pBMC addition, especially challenged corals, which displayed strong bleaching signs as indicated by significantly lower photopigment contents and Fv/Fm ratios. The structure of the coral microbiome community also differed between treatments and specific bioindicators were correlated with corals inoculated with pBMC (e.g., Cobetia sp.) or VC (e.g., Ruegeria sp.). Our results indicate that the microbiome in corals can be manipulated to lessen the effect of bleaching, thus helping to alleviate pathogen and temperature stresses, with the addition of BMCs representing a promising novel approach for minimizing coral mortality in the face of increasing environmental impacts