Qualified presumption of safety (QPS) was developed to provide a generic safety evaluation for biological agents to support EFSA's Scientific Panels. The taxonomic identity, body of knowledge, safety concerns and antimicrobial resistance are assessed. Safety concerns identified for a taxonomic unit (TU) are where possible to be confirmed at strain or product level, reflected by 'qualifications'. No new information was found that would change the previously recommended QPS TUs and their qualifications. The list of microorganisms notified to EFSA was updated with 54 biological agents, received between April and September 2019; 23 already had QPS status, 14 were excluded from the QPS exercise (7 filamentous fungi, 6 Escherichia coli, Sphingomonas paucimobilis which was already evaluated). Seventeen, corresponding to 16 TUs, were evaluated for possible QPS status, fourteen of these for the first time, and Protaminobacter rubrum, evaluated previously, was excluded because it is not a valid species. Eight TUs are recommended for QPS status. Lactobacillus parafarraginis and Zygosaccharomyces rouxii are recommended to be included in the QPS list. Parageobacillus thermoglucosidasius and Paenibacillus illinoisensis can be recommended for the QPS list with the qualification 'for production purposes only' and absence of toxigenic potential. Bacillus velezensis can be recommended for the QPS list with the qualification 'absence of toxigenic potential and the absence of aminoglycoside production ability'. Cupriavidus necator, Aurantiochytrium limacinum and Tetraselmis chuii can be recommended for the QPS list with the qualification 'production purposes only'. Pantoea ananatis is not recommended for the QPS list due to lack of body of knowledge in relation to its pathogenicity potential for plants. Corynebacterium stationis, Hamamotoa singularis, Rhodococcus aetherivorans and Rhodococcus ruber cannot be recommended for the QPS list due to lack of body of knowledge. Kodamaea ohmeri cannot be recommended for the QPS list due to safety concerns.

https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2020.5965

Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 13: suitability of taxonomic units notified to EFSA until September 2020.

Toxic effects of lead exposure on bioaccumulation, oxidative stress, neurotoxicity, and immune responses in fish: A review

The use of Bacillus species in maintenance of water quality in aquaculture: A review

In our daily life, we are surrounded by harmful pollutants, including heavy metals that are not visible in the macroscopic view easily. Heavy metals can disrupt different aspects of human health, such as the immune system which has gained a lot of attention in recent decades. This had led to its rapid progression and new insights into its alterations in different diseases especially cancer. Heavy metals are non-biodegradable materials that exist in different parts of the food cycle, such as fruits and vegetables as commonly consumed foods and also unexpected sources such as street dust, that exists in the streets that we pass every day, soil, air, and water. These heavy metals can enter the human body through respiratory, cutaneous, and gastrointestinal pathways and then accumulate in different organs, leading to their encountering with various parts of the body. These sources and natural characteristics of heavy metals facilitate their interaction with the immune system. In this review, we investigated the effect of lead and cadmium, as pollutants that exist in many different parts of the human environment, on the immune system which is known to have a key role in the pathophysiology of cancer.

Effects of lead and cadmium on the immune system and cancer progression.

Thiamethoxam (TMX) is a widely used neonicotinoid insecticide for its effective potential for controlling insects from the agricultural field, which might induce toxicity to the aquatic biota. In this study, the role of the probiotic Bacillus subtilis (BS) and a phytogenic oil extract of Thymus vulgaris essential oil (TVEO) in the modulation of thiamethoxam (TMX)-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus) has been evaluated. Fish were subjected to TMX (5 mg L−1) and fed with a diet either supplemented with BS (1000 ppm) or TVEO (500 ppm). The experiment lasted for 1 month. By the end of the experiment, blood was sampled for biochemical analysis and fish organs and tissues were collected for histopathological and immunohistochemical examinations. Results showed a substantial increase of serum markers of hepatorenal damage such as the activities of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) and levels of blood urea nitrogen (BUN) and creatinine with an obvious decrease of serum protein levels in the TMX-intoxicated group. Also, there was a considerable increase in malondialdehyde (MDA) levels and glutathione-S-transferase (GST) activity. TMX remarkably suppressed serum lysozyme activity, respiratory burst activity, and phagocytosis with a conspicuous elevation of the levels of interleukins (interleukin-1 beta (IL-1β) and interleukin-6 IL-6). The histopathological findings showed that TMX induced degenerative changes and necrosis in the gills, liver, head kidneys, and spleen of the intoxicated fish. Significant alterations of frequency, size, and area percentage of melanomacrophage centers (MMCs), decreased splenocyte proliferation, and increased number of caspase-3 immunopositive cells were also observed. Contrariwise, the concurrent supplementation of either BS or TVEO in the diets of catfish partially mitigated both the histopathological and histomorphometric lesions of the examined tissues. Correspondingly, they improved the counts of proliferating cell nuclear antigen (PCNA) and caspase-3 immunopositive splenocytes. In conclusion, the co-administration of either BS or TVEO in catfish diets partially diminished the toxic impacts of TMX. Nonetheless, the inclusion of TVEO in the diets of catfish elicited better protection than BS against TMX-induced toxicity in response to its potential anti-inflammatory, antioxidant, anti-apoptotic, and immune-stimulant effects.

Modulatory role of dietary Thymus vulgaris essential oil and Bacillus subtilis against thiamethoxam-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus)

Effect of sub-chronic exposure to lead (Pb) and Bacillus subtilis on Carassius auratus gibelio: Bioaccumulation, antioxidant responses and immune responses.

The aim of this study was to explore the effects of lead exposure on the antioxidant and immune responses of Crucian carp. Three hundred sixty healthy Crucian carp were randomly grouped into four groups and exposed to different doses of lead (0, 0.05, 0.5, and 1 mg/L). Fish were sampled at 30 and 60 days, respectively, and antioxidant capability, immune parameters, ALAD activity, and immune-related genes were assessed. The results showed that T-AOC and GSH activities of the liver were significantly increased in 60 days (P < 0.05); the activities of SOD, CAT, T-AOC, and GSH were significantly increased (P < 0.05) compared to the control in the kidney in 60 days. With an increase in Pb dose, the activity and expression of lysozyme and the content of immunoglobulin M were significantly decreased compared to the control. Compared with the control group, the activity of ALAD in the lead-exposed group decreased significantly (P < 0.05). The expression of the HSP70, tumor necrosis factor-α (TNF-α), interleukins (IL-10), and immunoglobulin M genes was all enhanced in lead-exposed group, whereas lysozyme gene expression was decreased. The results indicated that lead induced oxidative stress and had immunotoxic effects on Crucian carp.

Effect of Lead on Antioxidant Ability and Immune Responses of Crucian Carp.

Lead (Pb) is one of the most ubiquitous and toxic elements in the aquatic environment. Bacillus subtilis (B. subtilis) is a widely used probiotic in aquaculture. The aim of this study was to explore the toxic effects on bioaccumulation, hematological parameters, and antioxidant responses of Carassius auratus gibelio (C. gibelio) exposed to dietary lead at 0, 120, and 240 mg/kg and/or B. subtilis at 109 cfu/g. At 15 and 30 days, the fish were sampled and bioaccumulation, hematological parameters, and antioxidant responses were assessed. The result showed that B. subtilis administration can provide a significant protection against lead toxicity by reducing lead bioaccumulation in tissues, increasing the antioxidant enzymes activity, recovering δ-aminolevulinic acid dehydratase activity and optimizing the hematological parameters. Our results suggested that administration of B. subtilis (109 cfu/g) has the potential to combat dietary lead toxicity in C. gibelio.

Study of Bioaccumulation, Hematological Parameters, and Antioxidant Responses of Carassius auratus gibelio Exposed to Dietary Lead and Bacillus subtilis.

Cadmium (Cd) is the most common heavy metal and is easily detected in aquatic environments on a global scale. Vitamin C was a widely used vitamin in aquaculture. The aim of this study was to explore the potential of vitamin C in ameliorating Cd-induced toxicity in grass carp kidney (CIK) cells. Cell viability, oxidative response, metallothionein (MT), and immune-related gene expression was analyzed in the present study. The results show that cell viability was significantly reduced following Cd exposure, but the vitamin C supplementation attenuated the increased in cell viability. In addition, vitamin C supplementation can increase the antioxidation response and MT and immune-related gene expression. These results indicate that vitamin C has the potential to alleviate the effects of Cd toxicity in CIK cells.

Peijun Zhang

Papers

Effect of sub-chronic exposure to lead (Pb) and Bacillus subtilis on Carassius auratus gibelio: Bioaccumulation, antioxidant responses and immune responses.

Effect of Lead on Antioxidant Ability and Immune Responses of Crucian Carp.

Study of Bioaccumulation, Hematological Parameters, and Antioxidant Responses of Carassius auratus gibelio Exposed to Dietary Lead and Bacillus subtilis.

Amelioration of Cd-Induced Oxidative Stress, MT Gene Expression, and Immune Damage by Vitamin C in Grass Carp Kidney Cells

Ginsenoside Rg3 inhibits grass carp reovirus replication in grass carp ovarian epithelial cells.