Symbiodiniaceae probiotics for use in bleaching recovery

Coral reefs are currently under threat as a consequence of local and global stressors, in particular, mass coral bleaching induced by climate warming. In conjunction with global cuts to carbon emissions, active restoration interventions are being investigated as an additional option to buy time while these stressors are mitigated. One intervention with the potential to improve recovery during or postbleaching involves the addition of probiotic treatments, that is the addition of microorganisms that provide benefits to the host. Fragments of the branching coral, Acropora millepora, were experimentally exposed to a bleaching event coupled with the inoculation of Symbiodiniaceae probiotics (Durusdinium trenchii and Cladocopium goreaui) to determine if these probiotic treatments could ameliorate bleaching related stress and mortality. Fragments inoculated with C. goreaui and exposed to 32°C for 6 days exhibited significantly less mortality (9.1 ± 5%) compared to corals exposed to 32°C without probiotics (66.7 ± 8%) or with D. trenchii (41.7 ± 9%). Fragments in the C. goreaui probiotic treatment also bleached less and exhibited the highest photosynthetic efficiency compared to fragments inoculated with the D. trenchii at 32°C. Internal transcribed spacer‐2 amplicon sequencing did not detect the inoculated D. trenchii and C. goreaui cells within A. millepora tissues at the end of the experiment, suggesting the corals did not reestablish symbiosis but instead used inoculated cells as a nutritional supplement, although other factors such as shuffling conditions may have had an effect. This study highlights that nutritional supplementation can possibly aid coral resilience to temperature stress, though a far more detailed understanding of the factors that influence host regulation during symbiosis establishment is required.     

The safety of Bacillus subtilis and Bacillus indicus as food probiotics

Aims:  To conduct in vitro and in vivo assessments of the safety of two species of Bacillus , one of which, Bacillus subtilis , is in current use as a food supplement.
Methods and Results:  Cultured cell lines, Caco-2, HEp-2 and the mucus-producing HT29-16E cell line, were used to evaluate adhesion, invasion and cytotoxicity. The Natto strain of B. subtilis was shown to be able to invade and lyse cells. Neither species was able to adhere significantly to any cell line. The Natto strain was also shown to form biofilms. No strain produced any of the known Bacillus enterotoxins. Disc-diffusion assays using a panel of antibiotics listed by the European Food Safety Authority (EFSA) showed that only Bacillus indicus carried resistance to clindamycin at a level above the minimum inhibitory concentration breakpoints set by the EFSA. In vivo assessments of acute and chronic dosing in guinea pigs and rabbits were made. No toxicity was observed in animals under these conditions.
Conclusions:  Bacillus indicus and B. subtilis should be considered safe for oral use although the resistance of B. indicus to clindamycin requires further study.
Significance and Impact of the Study:  The results support the use of B. subtilis and B. indicus strains as food supplements.     

Bacillus probiotics: an alternative to antibiotics for livestock production

The use of probiotics as feed supplements in animal production has increased considerably over the last decade, particularly since the ban on antibiotic growth promoters in the livestock sector. Several Bacillus sp. are attractive for use as probiotic supplements in animal feed due to their ability to produce spores. Their heat stability and ability to survive the low pH of the gastric barrier represent an advantage over other probiotic micro‐organisms. This review discusses important characteristics required for selection of Bacillus probiotic strains and summarizes the beneficial effect of Bacillus‐based feed additives on animal production. Although the mechanism of action of Bacillus probiotics has not been fully elucidated, they are effective in improving the growth, survival and health status of terrestrial and aquatic livestock. Bacillus strains also have utility in bioremediation and can reduce nitrogenous waste, thereby improving environmental conditions and water quality. Finally, recent innovative approaches for using Bacillus spores in various applications are discussed.     

Characterization of human natural killer cells for therapeutic use

As a part of the innate immune system, natural killer (NK) cells are cytotoxic lymphocytes that can exert cytotoxic activity against infected or transformed cells. Furthermore, due to their expression of a functional Fc receptor, they have also been eluded as a major effector fraction in antibody-dependent cellular cytotoxicity. These characteristics have led to multiple efforts to use them for adoptive immunotherapy against various malignancies.  There are now at least 70 clinical trials testing the safety and efficacy of NK cell products around the world in early-phase clinical trials. NK cells are also being tested in the context of tumor retargeting via chimeric antigen receptors, other genetic modification strategies, as well as tumor-specific activation strategies such as bispecific engagers with or without cytokine stimulations. One advantage of the use of NK cells for adoptive immunotherapy is their potential to overcome HLA barriers. This has led to a plethora of sources, such as cord blood hematopoietic stem cells and induced pluripotent stem cells, which can generate comparatively high cytotoxic NK cells to peripheral blood counterparts. However, the variety of the sources has led to a heterogeneity in the characterization of the final infusion product. Therefore, in this review, we will discuss a comparative assessment strategy, from characterization of NK cells at collection to final product release by various phenotypic and functional assays, in an effort to predict potency of the cellular product.     

The use of probiotics in aquaculture

This study aims to present comprehensive notes for the use of probiotics in aquaculture. Probiotics have been proven to be positive promoters of aquatic animal growth, survival and health. In aquaculture, intestines, gills, the skin mucus of aquatic animals, and habitats or even culture collections and commercial products, can be sources for acquiring appropriate probiotics, which have been identified as bacteria (Gram‐positive and Gram‐negative) and nonbacteria (bacteriophages, microalgae and yeasts). While a bacterium is a pathogen to one aquatic animal, it can bring benefits to another fish species; a screening process plays a significant role in making a probiotic species specific. The administration of probiotics varies from oral/water routine to feed additives, of which the latter is commonly used in aquaculture. Probiotic applications can be either mono or multiple strains, or even in combination with prebiotic, immunostimulants such as synbiotics and synbiotism, and in live or dead forms. Encapsulating probiotics with live feed is a suitable approach to convey probiotics to aquatic animals. Dosage and duration of time are significant factors in providing desired results. Several modes of actions of probiotics are presented, while some others are not fully understood. Suggestions for further studies on the effects of probiotics in aquaculture are proposed.     

Update on field use of the available drugs for the chemotherapy of human African trypanosomiasis

Despite the fact that eflornithine was considered as the safer drug to treat human African trypanosomiasis (HAT) and has been freely available since 2001, the difficulties in logistics and cost burden associated with this drug meant that the toxic melarsoprol remained the drug of choice. The World Health Organization responded to the situation by designing a medical kit containing all the materials needed to use eflornithine, and by implementing a training and drugs distribution programme which has allowed a transition to this much safer treatment. The introduction of the combination of nifurtimox and eflornithine (NECT) has accelerated the shift from melarsoprol to the best treatment available, due to reduced dosage and treatment time for eflornithine that has significantly lessened the cost and improved the burden of logistics encountered during treatment and distribution. The decrease in the use of more dangerous but cheaper melarsoprol has meant a rise in the per patient cost of treating HAT. Although NECT is cheaper than eflornithine monotherapy, an unexpected consequence has been a continuing rise in the per patient cost of treating HAT. The ethical decision of shifting to the best available treatment imposes a financial burden on HAT control programmes that might render long-term application unsustainable. These factors call for continuing research to provide new safer and more effective drugs that are simple to administer and cheaper when compared to current drugs.     

Characterization of the most abundant Lactobacillus species in chicken gastrointestinal tract and potential use as probiotics for genetic engineering

The count and diffusion of Lactobacilli species in the differ ent gastrointestinal tract （GI） regions of broilers were investigated by quantitative realtime polymerase chain reaction, and the probiotic characteristics of six L. reuteri species isolated from broilers＇ GI tract were also investi gated to obtain the potential target for genetic engineering. Lactobacilli had the highest diversity in the crop and the lowest one in the cecum. Compared with the lower GI tract, more LactobaciUi were found in the upper GI tract. Lactobacillus reuteri, johnsonii, L. acidophilus, L. crispatus, L. salivarius, and L. aviarius were the predominant Lactobacillus species and present throughout the GI tract of chickens. Lactobacillus reuteri was the most abundant Lactobacillus species. Lactobacillus reuteri XC1 had good probiotic characteristics that would be a potential and desirable target for genetic engineering.     

Characterization of the adherence properties of human Lactobacilli strains to be used as vaginal probiotics

In the present work, the adhesion of 43 human lactobacilli isolates to mucin has been studied. The most adherent strains were selected, and their capacities to adhere to three epithelial cell lines were studied. All intestinal strains and one vaginal isolate adhered to HT-29 cells. The latter was the most adherent to Caco-2 cells, although two of the intestinal isolates were also highly adherent. Moreover, five of the eight strains strongly adhered to HeLa cells. The binding of an Actinomyces neuii clinical isolate to HeLa cells was enhanced by two of the lactobacilli and by their secreted proteins, while those of another two strains almost abolished it. None of the strains were able to interfere with the adhesion of Candida albicans to HeLa cells. The components of the extracellular proteome of all strains were identified by MALDI-TOF/MS. Among them, a collagen-binding A precursor and aggregation-promoting factor-like proteins are suggested to participate on adhesion to Caco-2 and HeLa cells, respectively. In this way, several proteins with LysM domains might explain the ability of some bacterial supernatants to block A.?neuii adhesion to HeLa cell cultures. Finally, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) could explain the good adhesion of some strains to mucin.     

The use of probiotics in shrimp aquaculture

Shrimp aquaculture, as well as other industries, constantly requires new techniques in order to increase production yield. Modern technologies and other sciences such as biotechnology and microbiology are important tools that could lead to a higher quality and greater quantity of products. Feeding and new practices in farming usually play an important role in aquaculture, and the addition of various additives to a balanced feed formula to achieve better growth is a common practice of many fish and shrimp feed manufacturers and farmers. Probiotics, as 'bio-friendly agents' such as lactic acid bacteria and Bacillus spp., can be introduced into the culture environment to control and compete with pathogenic bacteria as well as to promote the growth of the cultured organisms. In addition, probiotics are nonpathogenic and nontoxic microorganisms without undesirable side-effects when administered to aquatic organisms. These strains of bacteria have many other positive effects, which are described in this article.     

Experience of the use of probiotics for Salmonellae control in poultry

The Editors of Letters in Applied Microbiology will, at their discretion, publish invited and submitted 'Opinions' on subjects in the general area of Applied Microbiology. They will not be subjected to the normal refereeing procedures and reprints will not be provided. The 'Opinions' will not necessarily represent the views of the Society of Applied Bacteriology or of the Editors. The Editors may invite or readers may submit 'Responses' to published 'Opinions' , provided that they are not merely polemics, and these will also be published at the discretion of the Editors. 'Responses' will be treated precisely like 'Opinions' . They should clearly indicate, in their first sentence, the 'Opinion' to which they are a response.     

Characterization of Bacillus cereusDissociants

The autoregulation of the phenotypic (populational) variability of the Bacillus cereusstrain 504 was studied. The isolated colonial morphotypes of this bacterium were found to differ in their growth characteristics and the synthesis of extracellular proteases. The phenotypic variabilities of vegetative proliferating cells and those germinated from endospores and cystlike refractory cells were different. Bacterial variants also differed in the production of the d₁and d₂factors (the autoinducers of anabiosis and autolysis, respectively) and sensitivity to them. The possible role of these factors in the dissociation of microorganisms is discussed.     

Characterization of Bacillus anthracis strains used for vaccination

Three Bacillus anthracis strains, formerly used as anti-anthrax vaccine strains in Argentina, were characterized from genetic and pathogenic perspectives. Southern blotting and PCR with pXO1 and pXO2 probes and primers, as well as pathogenicity and protection tests in guinea pigs and mice, were performed. Two of the B. anthracis strains contained both pXO1 and pXO2 plasmids, as did the fully virulent strains, while the third was a Sterne-type strain (pXO1+, pXO2-). The three strains were, however, markedly less pathogenic than a wild-type virulent strain. The methodology applied here may be used to characterize other B. anthracis strains.     

Characterization of Bacillus Probiotics Available for Human Use

Bacillus species (Bacillus cereus, Bacillus clausii, Bacillus pumilus) carried in five commercial probiotic products consisting of bacterial spores were characterized for potential attributes (colonization, immunostimulation, and antimicrobial activity) that could account for their claimed probiotic properties. Three B. cereus strains were shown to persist in the mouse gastrointestinal tract for up to 18 days postadministration, demonstrating that these organisms have some ability to colonize. Spores of one B. cereus strain were extremely sensitive to simulated gastric conditions and simulated intestinal fluids. Spores of all strains were immunogenic when they were given orally to mice, but the B. pumilus strain was found to generate particularly high anti-spore immunoglobulin G titers. Spores of B. pumilus and of a laboratory strain of B. subtilis were found to induce the proinflammatory cytokine interleukin-6 in a cultured macrophage cell line, and in vivo, spores of B. pumilus and B. subtilis induced the proinflammatory cytokine tumor necrosis factor alpha and the Th1 cytokine gamma interferon. The B. pumilus strain and one B. cereus strain (B. cereus var. vietnami) were found to produce a bacteriocin-like activity against other Bacillus species. The results that provided evidence of colonization, immunostimulation, and antimicrobial activity support the hypothesis that the organisms have a potential probiotic effect. However, the three B. cereus strains were also found to produce the Hbl and Nhe enterotoxins, which makes them unsafe for human use.     

The use of bacterial spore formers as probiotics

The field of probiosis has emerged as a new science with applications in farming and aqaculture as alternatives to antibiotics as well as prophylactics in humans. Probiotics are being developed commercially for both human use, primarily as novel foods or dietary supplements, and in animal feeds for the prevention of gastrointestinal infections, with extensive use in the poultry and aquaculture industries. The impending ban of antibiotics in animal feed, the current concern over the spread of antibiotic resistance genes, the failure to identify new antibiotics and the inherent problems with developing new vaccines make a compelling case for developing alternative prophylactics. Among the large number of probiotic products in use today are bacterial spore formers, mostly of the genus Bacillus. Used primarily in their spore form, these products have been shown to prevent gastrointestinal disorders and the diversity of species used and their applications are astonishing. Understanding the nature of this probiotic effect is complicated, not only because of the complexities of understanding the microbial interactions that occur within the gastrointestinal tract (GIT), but also because Bacillus species are considered allochthonous microorganisms. This review summarizes the commercial applications of Bacillus probiotics. A case will be made that many Bacillus species should not be considered allochthonous microorganisms but, instead, ones that have a bimodal life cycle of growth and sporulation in the environment as well as within the GIT. Specific mechanisms for how Bacillus species can inhibit gastrointestinal infections will be covered, including immunomodulation and the synthesis of antimicrobials. Finally, the safety and licensing issues that affect the use of Bacillus species for commercial development will be summarized, together with evidence showing the growing need to evaluate the safety of individual Bacillus strains as well as species on a case by case by basis.     

Characterization of sulfhydryl heterogeneity in human serum albumin and recombinant human serum albumin for clinical use

Since human serum albumin has one sulfhydryl group and 17 disulfides, reactive sulfhydryl groups give rise to heterogeneity. The present paper presents a comparison of sulfhydryl heterogeneity in human serum albumin and recombinant human serum albumin for clinical use. Low molecular weight sulfhydryl compounds were identified from both sources. The recombinant albumin had a much higher sulfhydryl content than plasma serum albumin.