Potent antiplasmodial alkaloids from the rhizobacterium Pantoea agglomerans as hemozoin modulators

Dietary aflatoxin B1 and antimalarial-a lumefantrine/artesunate-therapy perturbs male rat reproductive function via pro-inflammatory and oxidative mechanisms

We investigated the impact of Coartem™ (COA) and aflatoxin B1 (AFB₁) on rats' hypothalamus, epididymis, and testis. Male rats were randomly grouped (n = 5 rats) and treated: control group (corn oil), AFB₁ (70 µg/kg), COA (5 mg/kg), COA + AFB₁ (5 + 0.035 mg/kg) and COA + AFB₁ (5 + 0.07 mg/kg) for 28 days. Blood samples were collected for serum prolactin, testosterone, follicle-stimulating and luteinising hormones (FSH and LH) assay upon sacrifice. The semen, hypothalamus, epididymis, and testes were harvested for morphological, biochemical, and histopathology determination of oxidative, inflammation stress, genomic integrity, and pathological alterations. Exposure to the COA and AFB₁ caused the cauda epididymal spermatozoa to display low motility, viability, and volume, with increased abnormalities. Hormonal disruption ensued in animals exposed to COA and AFB₁ alone or together, exemplified by increased prolactin, and decreased testosterone, FSH and LH levels. Treatment-related reduction in biomarkers of testicular metabolism-acid and alkaline phosphatases, glucose-6-phosphate dehydrogenase, and lactate dehydrogenase-were observed. Also, COA and AFB₁ treatment caused reductions in antioxidant (Glutathione and total thiols) levels and antioxidant enzyme (Catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase) activities in the examined organs. At the same time, treatment-related increases in DNA damage (p53), oxidative stress (xanthine oxidase, reactive oxygen and nitrogen species and lipid peroxidation), inflammation (nitric oxide and tumour necrosis factor-alpha), and apoptosis (caspase-9, and -3) were observed. Chronic exposure to COA and AFB1 led to oxidative stress, inflammation, and DNA damage in male rats' hypothalamic-reproductive axis, which might potentiate infertility if not contained.

Opposite Sides of Pantoea agglomerans and Its Associated Commercial Outlook

Multifaceted microorganisms such as the bacterium Pantoea colonize a wide range of habitats and can exhibit both beneficial and harmful behaviors, which provide new insights into microbial ecology. In the agricultural context, several strains of Pantoea spp. can promote plant growth through direct or indirect mechanisms. Members of this genus contribute to plant growth mainly by increasing the supply of nitrogen, solubilizing ammonia and inorganic phosphate, and producing phytohormones (e.g., auxins). Several other studies have shown the potential of strains of Pantoea spp. to induce systemic resistance and protection against pests and pathogenic microorganisms in cultivated plants. Strains of the species Pantoea agglomerans deserve attention as a pest and phytopathogen control agent. Several of them also possess a biotechnological potential for therapeutic purposes (e.g., immunomodulators) and are implicated in human infections. Thus, the differentiation between the harmful and beneficial strains of P. agglomerans is mandatory to apply this bacterium safely as a biofertilizer or biocontroller. This review specifically evaluates the potential of the strain-associated features of P. agglomerans for bioprospecting and agricultural applications through its biological versatility as well as clarifying its potential animal and human health risks from a genomic point of view.

Loss of Gramicidin Biosynthesis in Gram-Positive Biocontrol Bacterium Aneurinibacillus migulanus (Takagi et al., 1993) Shida et al. 1996 Emend Heyndrickx et al., 1997 Nagano Impairs Its Biological Control Ability of Phytophthora

The soil-borne species Aneurinibacillus migulanus (A. migulanus) strains Nagano and NCTC 7096 were shown to be potent biocontrol agents active against several plant diseases in agricultural and forest ecosystems. Both strains produce the cyclic peptide gramicidin S (GS) that was described as the main weapon inhibiting some gram-negative and gram-positive bacteria and fungus-like organisms along with the production of biosurfactant and hemolysis activities. However, the contribution of the cyclic peptide gramicidin S (GS) to the biocontrol ability of A. migulanus has never been studied experimentally. In this paper, using a mutant of the A. migulanus Nagano strain (E1 mutant) impaired in GS biosynthesis we evaluated the contribution of GS in the biocontrol potential of A. migulanus against Phytophthora spp. The two strains of A. migulanus, Nagano and NCTC 7096, were tested in a pilot study for the inhibition of the growth of 13 Phytophthora species in dual culture assays. A. migulanus Nagano was significantly more inhibitory than NCTC 7096 to all species. Additionally, using apple infection assays, P. rosacearum MKDF-148 and P. cryptogea E2 were shown to be the most aggressive on apple fruits displaying clear infection halos. Therefore, the three A. migulanus strains, Nagano, NCTC 7096, and E1, were used in apple infection experiments to check their effect on infection ability of these two Phytophthora species. Treatment with A. migulanus Nagano significantly reduced the severity of symptoms in apple fruits compared with NCTC 7096. A. migulanus E1 mutant showed total loss of biocontrol ability suggesting that GS is a major actor in the biocontrol ability of A. migulanus Nagano strain.