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Pharmaceuticals and Nutraceuticals from Fish and Their Activities
Published in Ramasamy Santhanam, Santhanam Ramesh, Subramanian Nivedhitha, Subbiah Balasundari, Pharmaceuticals and Nutraceuticals from Fish and Fish Wastes, 2022
Ramasamy Santhanam, Santhanam Ramesh, Subramanian Nivedhitha, Subbiah Balasundari
Antibacterial activity: The skin mucus extracts of both males and females this species showed activity against Streptococcus iniae, Yersinia ruckeri, Staphylococcus aureus, Listeria monocytogenes, Pseudomonas aeruginosa, and Escherichia coli (Adel et al., 2018). The values of inhibition zone diameter and MIC recorded for the different bacterial strains are given in the following table:
The role of apoptosis in non-mammalian host-parasite relationships
Published in G. F. Wiegertjes, G. Flik, Host-Parasite Interactions, 2004
Recent studies have highlighted that the association between apoptosis and the bacterium-host interaction is not limited to higher animals. It is interesting to speculate that studies primarily on human infections but involving bacterial species that have a ubiquitous occurrence may be extrapolated to lower animals. For example Aeromonas hydrophila is associated with gastrointestinal infections in humans and haemorrhagic septicaemia in fish (Hoole et al., 2001; Roberts and Shepherd, 1986). Studies by Falcon et al. (2001) indicate that a cytotoxic entertoxin produced by the bacterial species induces apoptosis in human intestinal cells in culture and Chopra et al. (2000) proposed that an aerolysin-related cytotoxic entertoxin (Act) up-regulated production of Bcl-2 in macrophages. Several studies have been carried out on other bacterial infections in fish. For example, Huang et al. (2000) carried out in vitro and in vivo experiments on the potential of Staphylococcus epidermidis and its secretions produced in culture, to induce apoptosis in tilapia, Oreochromis aureus. Apoptosis was detected in lymphocytes and macrophages of the spleen and kidney and apoptotic figures were occasionally detected in the brain, liver, gonad, mesentery, stomach, intestine and skeletal muscle of infected fish. Other studies on tilapia by Evans and coworkers have concentrated on apoptosis in relationship to non-specific cytotoxic cells and infection with Streptococcus iniae. Flow cytometric analysis by Evans et al. (2000) revealed that non-specific cytotoxic cells from the spleen, pronephros and peripheral blood expressed cytosolic but not membrane Fas ligand. The expression of this and associated proteins, i.e. CAS and FADD were increased in non-specific cytotoxic cells obtained from the peripheral blood and exposed to fish serum, suggesting that cytokine-like factors increased the cytotoxicity of non-specific cytotoxic cells by stimulating proteins associated with apoptosis. Later studies by these workers (Taylor et al., 2001) showed that different isolates of S. iniae regulated the anti-bacterial activity of non-specific cytotoxic cells by affecting levels of apoptosis.
β-Hemolytic Streptococcus anginosus subsp. anginosus causes streptolysin S-dependent cytotoxicity to human cell culture lines in vitro
Published in Journal of Oral Microbiology, 2019
Atsushi Tabata, Takuya Yamada, Hiromi Ohtani, Kazuto Ohkura, Toshifumi Tomoyasu, Hideaki Nagamune
In S. pyogenes, the SLS produced is known to be a virulence factor similar to the pore-forming protein hemolysin streptolysin O, and much research was reported on this topic in the middle of the 1960’s and from the late 1970’s to the early 1980’s. However, possibly due to the questionable molecular properties of SLS (e.g., low or no antigenicity and difficulty in purification), the research on SLS temporarily stagnated in the 1990’s. After the year 2000, the situation improved due to the discovery of the genes for the biosynthesis of SLS and their secretion [15]. As a result, many investigations were conducted and SLS was recognized as the virulence factor of S. pyogenes. For example, the functions of SLS identified include the inhibition of neutrophil recruitment during the early stages of infection [16,17], translocation across the epithelial barrier [18], contribution of GAS evasion from immune cell killing, local tissue damage, and mortality of mouse [19], promotion of programmed cell death and enhancement of inflammatory signaling in epithelial keratinocytes [20], inhibition of neutrophil recruitment and systemic infection [21], and direct activation of nociceptor neurons and production of pain [22]. In addition, by contribution from the dramatic evolution of next-generation sequencing, the presence of the genes encoding SLS-related peptides in the Gram-positive bacteria besides S. pyogenes was also reported. These include the SLS-related peptide hemolysin secreted from Streptococcus iniae [23], perfringolysin S secreted from Clostridium perfringens [24], and listeriolysin S produced from Listeria monocytogenes [25].
Metabolic regulation protects mice against Klebsiella pneumoniae lung infection
Published in Experimental Lung Research, 2018
Sunan Liu, Pan Zhang, Yanan Liu, Xiaoyan Gao, Juan Hua, Wei Li
The meaningful finding of current differential metabolites shows that six metabolites, D-Glucose, Glutamine, L-Serine, Myo-inositol, Ethanedioic acid and Lactic acid, have opposite levels of abundance between Dead and Survival groups. D-Glucose is the key source for glycolysis which is strongly stimulated by bacterial infection.10 The limitation of D-Glucose shortened the life cycle of activated DC and decreased the production of TNF-α, IL-12 and IL-23.30 The supplementation with D-Glucose can relieve the burdens associated with bacteremia in rat model.7 Besides catabolizing in the glycolysis, D-Glucose also enters into the inositol phosphate metabolism to generate Myo-inositol which promotes macrophages to kill bacterial pathogens.13 Although the involved mechanism is unclear, Glutamine is known to support the anti-infective host defense.10,31–33 There is also in vivo evidence that exogenous L-Serine increases the survival of tilapias infected by Streptococcus iniae.26 Given that the higher abundance of D-Glucose, Glutamine, L-Serine, and Myo-inositol are found in Survival group, thus a becoming idea is that accumulations of D-Glucose, Glutamine, L-Serine, and Myo-inositol are vital for survival strategies by pathogen-infected hosts. This hypothesis was further supported by the current study that the addition of L-Serine declines the bacterial load in lung tissue and mouse mortality. The lower level of Lactic acid in Survival group can be explained by the relative slower glycolysis because a part of D-Glucose may afflux into other metabolisms to produce Myo-inositol and L-Serine, which need to be tested in future. Also, the effect of action of Ethanedioic acid on lung infection should be further determined.