Proliferation Of Pathogenic Bacteria Research Articles

Facile biosynthesis of CaO nanoparticles using extract of Tulbaghia violacea and evaluation of their antibacterial and cytotoxicity activity

Inexpensive and environmentally friendly calcium oxide nanoparticles (CaO-NPs) were green synthesized using the aqueous extract of Tulbaghia violacea bulb. Their structural and optical properties were studied using X-ray diffractometer, transmission electron microscopy (TEM), scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and UV–visible spectrophotometer. Also, their antibacterial activity against pathogenic strains (Gram-negative: Escherichia coli and Klebsiella oxytoca, and Gram-positive: Staphylococcus aureus and Bacillus cereus), as well as their anticancer activity in HeLa cells, were evaluated. Results showed that pseudo spherical nanoparticles of about 27.75 nm, with band gap energy of 3.6 eV were obtained. Also, at the highest tested concentration, the nanoparticles exhibited higher antibacterial potency on K. oxytoca with an inhibition zone of 13 mm, compared to other tested bacteria [E. coli (9 mm), S. aureus (9 mm), and B. cereus (11 mm)]. Further, the nanoparticles revealed remarkable anticancer activity in HeLa (IC50: 9.25 µg/mL) and HEK 293 (IC50: 21.1 µg/mL) cells compared to the standard drug (5-Fluorouracil; IC50: 17.5 µg/mL and 6.05 µg/mL, respectively). It was therefore concluded that the green synthesized T. violacea bulb extract-mediated CaO-NPs could potentially be used to inhibit the proliferation of pathogenic bacteria and cancer cells. However, further research to evaluate their pharmacological relevance and cytotoxic effects in normal mammalian cells is required.

Intestinal response of mussels to nano-TiO2 and pentachlorophenol in the presence of predator

With the development of industry, agriculture and intensification of human activities, a large amount of nano-TiO2 dioxide and pentachlorophenol have entered aquatic environment, causing potential impacts on the health of aquatic animals and ecosystems. We investigated the effects of predators, pentachlorophenol (PCP) and nano titanium dioxide (nano-TiO2) on the gut health (microbiota and digestive enzymes) of the thick-shelled mussel Mytilus coruscus. Nano-TiO2, as the photocatalyst for PCP, enhanced to toxic effects of PCP on the intestinal health of mussels, and they made the mussels more vulnerable to the stress from predators. Nano-TiO2 particles with smaller size exerted a larger negative effect on digestive enzymes, whereas the size effect on gut bacteria was insignificant. The presence of every two of the three factors significantly affected the population richness and diversity of gut microbiota. Our findings revealed that the presence of predators, PCP, and nano-TiO2 promoted the proliferation of pathogenic bacteria and inhibited digestive enzyme activity. This research investigated the combined stress on marine mussels caused by nanoparticles and pesticides in the presence of predators and established a theoretical framework for explaining the adaptive mechanisms in gut microbes and the link between digestive enzymes and gut microbiota.

The potential role of alfalfa polysaccharides and their sulphated derivatives in the alleviation of obesity.

Sulfated alfalfa polysaccharides (SAPs) as derivatives of alfalfa polysaccharides (APs) showed better in vitro antioxidant activity and potential obesity inhibition. The purpose of this study was to investigate the effect and mechanisms of APs and SAPs on obesity alleviation. Different concentrations of APs and SAPs were tested for effects on body conditions, gut flora, antioxidant capacity, and immunological factors. The results showed that APs and SAPs improved the physical conditions of obese mice, including organ weight, body weight, intraperitoneal fat ratio, and lipid levels. APs and SAPs increased the antioxidant capacity of the obese mice, enhanced the activity of SOD and CAT, and decreased the activity of MDA in the serum, liver, and colon. APs and SAPs upregulated the mRNA expression of IL-4 and IL-10 and downregulated the mRNA expression of NF-κB, IFN-γ, TNF-α, and IL-6 in the liver and colon. Meanwhile, APs and SAPs improved lipid absorption in the jejunum, upregulated LXR and GLP-2, and down-regulated the mRNA expression of NPC1L1. APs and SAPs also contributed to restoring short-chain fatty acid levels in the colon. APs and SAPs improved the structure of the intestinal flora, promoted the proliferation of bacteria associated with short-chain fatty acid metabolism, and inhibited the proliferation of pathogenic bacteria. At the same concentration, the effect of SAPs on the antioxidant capacity was stronger than that of APs. In the AP group, high concentrations of APs showed the best anti-inflammatory effect, while in the SAP group, medium concentrations of SAPs showed the best inhibition of inflammation. Our results suggest that APs and SAPs alleviate obesity symptoms by relieving inflammation, improving the antioxidant capacity, and regulating intestinal flora and therefore could be used as potential probiotic products to alleviate obesity.

Microstructured Electroceutical Fiber‐Device for Inhibition of Bacterial Proliferation in Wounds

AbstractAntibiotic‐resistant infections caused by bacterial pathogens pose a serious threat to public health, hampering wound healing and causing significant morbidities worldwide. A biomedical fiber‐device that functions as a drugless antiseptic is introduced as a solution to this problem. Through stitching, piercing, or topical application to the wound, this fiber slows down the proliferation of pathogenic bacteria, thereby reducing the risks associated with inflammation and inhibiting infections. The fiber's bacterial proliferation inhibition function is based on the galvanic effect, which disturbs bacterial quorum sensing. Detailed herein are the fiber design optimization, scalable fabrication approach, electrical function characterization, and antiseptic function verification in cultures of typical wound pathogens. Such a fiber—mechanically and environmentally resilient, insensitive to harsh storage conditions with nominally infinite shelf‐life, resulting from machining rather than pharmacochemical fabrication— provides a cost‐effective and widely available alternative to current antibiotic treatments of physical injury.

Bacillus subtilis M6 improves intestinal barrier, antioxidant capacity and gut microbial composition in AA broiler.

Bacillus subtilis can secret a variety of substances to improve human and animal gut health via inhibiting the proliferation of pathogenic bacteria. In this study, a fast-growing and stress-resistant strain of Bacillus subtilis M6 (B. subtilis M6) were isolated, which showed a strong antibacterial activity to E. coli K88, S. typhimurium ATCC14028, and S. aureus ATCC25923 in vitro. In vivo studies showed that B. subtilis M6 can significantly improve the average daily gain (ADG) using an AA broiler model. Dietary B. subtilis M6 improved the intestinal morphology. The villus height of jejunum and ileum were significantly increased. The concentration of malondialdehyde (MDA) in the ileal mucosa was significantly reduced in B. subtilis M6 treatment group, which suggested the oxidative stress of the ileum was significantly relieved. Though the β diversity of treatments was not significantly, B. subtilis M6 improved the composition of intestinal microbes, especially at the level of caecum genus, the dominant genus was changed from Ruminococcus to Akkermansia, which indicated the change of intestinal carbohydrate nutrition. In conclusion, these data indicate that the B. subtilis M6 shows a probiotic potential to improve intestinal health via altering gut microbiota.

Raloxifene prevents intracellular invasion of pathogenic bacteria through modulation of cell metabolic pathways.

Pathogenic bacteria can invade and survive inside phagocytic and non-phagocytic cells and use them as a sanctuary against antibiotics. Induction of various host protective mechanisms, including autophagy, can be a novel and effective method to combat intracellular bacteria. Recent studies report that raloxifene, a selective oestrogen receptor modulator, can induce cellular autophagy. To demonstrate the effect of raloxifene on intracellular invasion and proliferation of pathogenic bacteria and investigate raloxifene-induced metabolic changes in host cells. Autophagic induction was determined by the extent of nuclear fragmentation and expression levels of the LC3B protein. Intracellular invasion of MRSA strains into A549 lung epithelial cells and invasion of Mycobacterium abscessus into RAW264.7 macrophages were assessed by invasion and proliferation assays. Changes in host cell metabolism were examined by transcriptomic profiling using RNA sequencing. Our data demonstrate increased autophagy in cells upon raloxifene treatment, which contributed to prevention of bacterial invasion and proliferation. Transcriptomic profiling of host cells revealed changes in cholesterol-related pathways and consequent increases in oxidative stress-related genes and in autophagic induction through the TRIM and GABA pathways. Our results demonstrate raloxifene's potential as a broad-spectrum antibacterial agent through autophagic induction in host cells and prevention of intracellular invasion and proliferation of pathogenic bacteria.

The Effect of Giving Probiotic Drinks on Reducing Bad Breath Complaints

Background. Halitosis is a condition in which an unpleasant odor caused by oral microbes comes out of a person's mouth during exhalation, which makes other people feel uncomfortable. Probiotics seek to maintain the homeostasis of bacteria in the gastrointestinal tract to suppress the proliferation of pathogenic bacteria. This study aims to evaluate the potential of probiotics against bad breath as assessed by the levels of volatile sulfur compounds (VSCs).
 Methods. The design of this study is an experimental study with a pre-post test approach. A total of 30 research subjects with criteria aged 20-28 years with complaints of bad breath seek treatment at the dental and oral polyclinic of Siti Hajar Hospital. Research subjects were asked to rinse their mouth with one of the commercial probiotic drinks already circulating in the market, where previously the levels of volatile sulfur compounds (VSCs) and after rinsing the probiotic drink, the levels of VSCs were measured again. Data analysis was carried out with the help of SPSS version 21 software. A univariate data analysis was carried out to obtain an overview of the distribution of degrees and levels of Volatile, Sulfur Compounds (VSCs) before, and after giving drinks probiotics.
 Results. The provision of probiotic drinks is sufficient to provide a significant qualitative change effect where there is a change in the degree of halitosis of the research subjects. After consuming probiotics, there was an improvement in the degree of halitosis of the research subjects, whereas there were no more subjects with severe halitosis.
 Conclusion. Consumption of probiotic drinks can reduce the levels of VSCs in the oral cavity, which indicates the ability of probiotics to reduce bad breath.

Synthesis and characterization of silver nanoparticles using Acremonium borodinense and their anti-bacterial and hemolytic activity

This study explains the mycosynthesis of silver nanoparticles (AgNPs) using Acremonium borodinense by a green route. The synthesized AgNPs were characterized by using UV–vis Spectroscopy , X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM) and fourier transform infra-red (FTIR) spectroscopy. XRD technique revealed that the face centered cubic crystalline structure of AgNPs. FE-SEM and TEM images showed that the synthesized AgNPs having spherical shaped nanostructure with an average size of 0.19 nm. The functional groups present in the synthesized AgNPs were studied by FTIR . Mycosynthesized AgNPs were stable up to 3 months without change in their properties. Pathogenic bacteria proliferation was reduced by modest dosages of AgNPs. The minimum inhibitory concentration and minimum bacterial concentration of AgNPs were determined against both gram-positive and gram-negative bacterial pathogens. Such as Staphylococcus aureus , Proteus vulgaris , Serratia marcescens , Klebsiella pneumonia . Highest Value of MIC (90 μg/mL) 0.098 was found against Proteus vulgaris . Antibacterial activity of AgNPs was investigated at three different concentrations based on MIC (30, 60, and 90 g/mL). The impact of AgNPs on Red Blood Cells from the ‘O' positive blood group was investigated, and it was shown that even at the highest concentrations, AgNPs does not induce higher hemolysis in the cells. Based on these finding, we strongly suggested that the Acremonium borodinense mediated synthesized AgNPs can be used as a potent bio-medical agent. • Mycosynthesized AgNPs were studied and characterized . • Acremonium borodinense fungi produced large quantity of metabolites that containing high medicinal value. • Fungi mediated synthesis of AgNPs contain less toxicity and more beneficial effect of killing pathogenic bacteria.

The effectiveness of exposure to magnetic fields of extremely low frequency 300T and 500T in inhibiting the proliferation of pathogenic bacteria to increase physical resistance of vannamei shrimp

Vannamei shrimp is a type of fish that rots easily, only able to survive about 6 hours at room temperature. This study aims to examine the effectiveness of exposure to an Extremely Low Frequency (ELF) magnetic field with an intensity of 300 T and 500 T in inhibiting the proliferation of pathogenic bacteria to increase the physical resistance of white vaname shrimp. The research design used a completely randomized design and was carried out at the Physics Laboratory of the Faculty of Teacher Training and Education, University of Jember. The Extremely Low Frequency (ELF) magnetic field in this study is a component of the ELF electromagnetic wave generated by the Current Transformer by minimizing the exposure to the ELF electric field to about 30 V/m. The study sample was 210 fresh vaname shrimp and divided into 7 treatment groups, namely the control group (K), the group exposed to the ELF magnetic field intensity of 300 T for 60 minutes (E-300.60’), 90 minutes (E-300.90’), 120 minutes (E-300.120’), and the group exposed to an ELF magnetic field of 500 T intensity for 60 minutes (E-500.60’), 90 minutes (E-500.90’), 120 minutes (E-500,120’). As an indicator of vaname shrimp resistance at room temperature is the population of pathogenic bacteria, color, aroma, texture, mucus, and pH. The research data were analyzed using One Way Anova analysis. The results showed that the population of Salmonella bacteria was significantly lower than the control in the vannamei shrimp sample exposed to an ELF magnetic field of 500 T, but the population of E.Coli bacteria increased significantly in the vannamei shrimp sample exposed to an ELF magnetic field of 300 T and 500 T compared to control. Naturally, vaname shrimp stored at room temperature showed the appearance of the shrimp getting paler, and the texture getting softer, smelling rotten and slimy after the 6th hour. However, the color, smell, and texture of shrimp exposed to an ELF magnetic field of 500 T intensity for 120 minutes were able to survive at a score of 8 at the 5th hour observation and 7th at the 10th hour observation. Conclusion: Exposure to an ELF magnetic field with an intensity of 500 T was effective in suppressing the proliferation of salmonella Sp bacteria but was less effective in suppressing the proliferation of E.Coli bacteria. This condition affects the physical condition of white shrimp until it lasts at the 10th hour. The results of this study serve as the basis for developing food security technology by the ELF magnetic field.

MiR395-regulated sulfate metabolism exploits pathogen sensitivity to sulfate to boost immunity in rice

MicroRNAs (miRNAs) play important roles in plant physiological activities. However, their roles and molecular mechanisms in boosting plant immunity, especially through the modulation of macronutrient metabolism in response to pathogens, are largely unknown. Here, we report that an evolutionarily conserved miRNA, miR395, promotes resistance to Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc), two destructive bacterial pathogens, by regulating sulfate accumulation and distribution in rice. Specifically, miR395 targets and suppresses the expression of the ATP sulfurylase gene OsAPS1, which functions in sulfate assimilation, and two sulfate transporter genes, OsSULTR2;1 and OsSULTR2;2, which function in sulfate translocation, to promote sulfate accumulation, resulting in broad-spectrum resistance to bacterial pathogens in miR395-overexpressing plants. Genetic analysis revealed that miR395-triggered resistance is involved in both pathogen-associated molecular pattern-triggered immunity and R gene-mediated resistance. Moreover, we found that accumulated sulfate but not S-metabolites inhibits proliferation of pathogenic bacteria, revealing a sulfate-mediated antibacterial defense mechanism that differs from sulfur-induced resistance. Furthermore, compared with other bacteria, Xoo and Xoc, which lack the sulfate transporter CysZ, are sensitive to high levels of extracellular sulfate. Accordingly, miR395-regulated sulfate accumulation impaired the virulence of Xoo and Xoc by decreasing extracellular polysaccharide production and biofilm formation. Taken together, these results suggest that rice miR395 modulates sulfate metabolism to exploit pathogen sensitivity to sulfate and thereby promotes broad-spectrum resistance.

Time-Resolved Proteome Analysis of Listeria monocytogenes during Infection Reveals the Role of the AAA+ Chaperone ClpC for Host Cell Adaptation.

ABSTRACTThe cellular proteome comprises all proteins expressed at a given time and defines an organism’s phenotype under specific growth conditions. The proteome is shaped and remodeled by both protein synthesis and protein degradation. Here, we developed a new method which combines metabolic and chemical isobaric peptide labeling to simultaneously determine the time-resolved protein decay and de novo synthesis in an intracellular human pathogen. We showcase this method by investigating the Listeria monocytogenes proteome in the presence and absence of the AAA+ chaperone protein ClpC. ClpC associates with the peptidase ClpP to form an ATP-dependent protease complex and has been shown to play a role in virulence development in L. monocytogenes. However, the mechanism by which ClpC is involved in the survival and proliferation of intracellular L. monocytogenes remains elusive. Employing this new method, we observed extensive proteome remodeling in L. monocytogenes upon interaction with the host, supporting the hypothesis that ClpC-dependent protein degradation is required to initiate bacterial adaptation mechanisms. We identified more than 100 putative ClpC target proteins through their stabilization in a clpC deletion strain. Beyond the identification of direct targets, we also observed indirect effects of the clpC deletion on the protein abundance in diverse cellular and metabolic pathways, such as iron acquisition and flagellar assembly. Overall, our data highlight the crucial role of ClpC for L. monocytogenes adaptation to the host environment through proteome remodeling.IMPORTANCE Survival and proliferation of pathogenic bacteria inside the host depend on their ability to adapt to the changing environment. Profiling the underlying changes on the bacterial proteome level during the infection process is important to gain a better understanding of the pathogenesis and the host-dependent adaptation processes. The cellular protein abundance is governed by the interplay between protein synthesis and decay. The direct readout of these events during infection can be accomplished using pulsed stable-isotope labeling by amino acids in cell culture (SILAC). Combining this approach with tandem-mass-tag (TMT) labeling enabled multiplexed and time-resolved bacterial proteome quantification during infection. Here, we applied this integrated approach to investigate protein turnover during the temporal progression of adaptation of the human pathogen L. monocytogenes to its host on a system-wide scale. Our experimental approach can easily be transferred to probe the proteome remodeling in other bacteria under a variety of perturbations.

Hepcidin Protects Yellow Catfish (Pelteobagrus fulvidraco) against Aeromonas veronii-Induced Ascites Disease by Regulating Iron Metabolism.

Aeromonas veronii (A. veronii) is one of the main pathogens causing bacterial diseases in aquaculture. Although previous studies have shown that hepcidin as an antimicrobial peptide can promote fish resistance to pathogenic bacterial infections, but the mechanisms remain unclear. Here, we expressed and purified recombinant yellow catfish (Pelteobagrus fulvidraco) hepcidin protein (rPfHep). rPfHep can up-regulate the expression of ferritin and enhance the antibacterial activity in primary hepatocytes of yellow catfish. We employed berberine hydrochloride (BBR) and Fursultiamine (FSL) as agonists and antagonists for hepcidin, respectively. The results indicated that agonist BBR can inhibit the proliferation of pathogenic bacteria, and the antagonist FSL shows the opposite effect. After gavage administration, rPfHep and the agonist BBR can enhance the accumulation of iron in liver, which may hinder the iron transport and limit the amount of iron available to pathogenic bacteria. Moreover, rPfHep and the agonist BBR can also reduce the mortality rate, bacterial load and histological lesions in yellow catfish infected with A. veronii. Therefore, hepcidin is an important mediator of iron metabolism, and it can be used as a candidate target for prevent bacterial infections in yellow catfish. Hepcidin and BBR have potential application value in preventing anti-bacterial infection.

Phycoremediation of wastewater by microalgae: a review

Wastewater treatment requires the removal of contaminants, solids, nutrients, coliforms, and pathogenic bacteria. Classical treatments require high energy and induce secondary pollution by disinfectants. Alternatively, phycoremediation, which involves the use of algae to clean water, appears smarter and more sustainable because compounds such as nitrogen, phosphorus, sulfur, and minerals appear as ‘nutrients’ to feed algae rather than ‘contaminants’. Phycoremediation thus allows to remove phosphates, nitrates, heavy metals, pesticides, hydrocarbons, nitrogen, and phosphorus. Moreover, the conditions favoring algal growth are disfavoring bacterial growth, which prevents the proliferation of pathogenic bacteria and improves water disinfection. Open pond systems have low maintenance, simple design, and reduce carbon footprint. Here we review factors controlling wastewater phycoremediation, and the most common systems. Microalgae are the main species used for phycoremediation. Efficiency is controlled by biotic factors, abiotic factors and algal strains. Photobioreactors appear unsuitable for large-scale applications due to cost, complicated operational procedures and scaling-up difficulties. Open pond systems are ideal for providing clean water in developing countries.

Cross-kingdom inhibition of bacterial virulence and communication by probiotic yeast metabolites

BackgroundProbiotic milk-fermented microorganism mixtures (e.g., yogurt, kefir) are perceived as contributing to human health, and possibly capable of protecting against bacterial infections. Co-existence of probiotic microorganisms are likely maintained via complex biomolecular mechanisms, secreted metabolites mediating cell-cell communication, and other yet-unknown biochemical pathways. In particular, deciphering molecular mechanisms by which probiotic microorganisms inhibit proliferation of pathogenic bacteria would be highly important for understanding both the potential benefits of probiotic foods as well as maintenance of healthy gut microbiome.ResultsThe microbiome of a unique milk-fermented microorganism mixture was determined, revealing a predominance of the fungus Kluyveromyces marxianus. We further identified a new fungus-secreted metabolite—tryptophol acetate—which inhibits bacterial communication and virulence. We discovered that tryptophol acetate blocks quorum sensing (QS) of several Gram-negative bacteria, particularly Vibrio cholerae, a prominent gut pathogen. Notably, this is the first report of tryptophol acetate production by a yeast and role of the molecule as a signaling agent. Furthermore, mechanisms underscoring the anti-QS and anti-virulence activities of tryptophol acetate were elucidated, specifically down- or upregulation of distinct genes associated with V. cholerae QS and virulence pathways.ConclusionsThis study illuminates a yet-unrecognized mechanism for cross-kingdom inhibition of pathogenic bacteria cell-cell communication in a probiotic microorganism mixture. A newly identified fungus-secreted molecule—tryptophol acetate—was shown to disrupt quorum sensing pathways of the human gut pathogen V. cholerae. Cross-kingdom interference in quorum sensing may play important roles in enabling microorganism co-existence in multi-population environments, such as probiotic foods and the gut microbiome. This discovery may account for anti-virulence properties of the human microbiome and could aid elucidating health benefits of probiotic products against bacterially associated diseases.2QFco5PMZ3Qz7tD11LACHhVideo

Development of chitosan/agar-silver nanoparticles-coated paper for antibacterial application

AbstractThe radical proliferation of pathogenic bacteria and their infections causes significant issues for human health and the environment. Today, biopolymers are used to produce different nanoparticles. In the present investigation, the fabricated chitosan/agar-silver nanoparticles (Cht/Ar-AgNPs)-coated papers were tested for antibacterial applications. Agar was used as a reducing agent for the synthesis of AgNPs. Synthesized Ar-AgNPs were examined through optical, phase crystallinity and topological analysis. Cht and Ar-AgNPs solution was mixed with various ratios of 9:1, 8:2, 7:3, 6:4, and 5:5 by weight. In addition to that, the conformity of Cht/Ar-AgNPs-coated papers was characterized by structural, spectral, and morphological analysis. However, Cht/Ar-AgNPs-coated papers were subjected to antibacterial properties. The ratio of (6:4) Cht/Ar-AgNPs-coated paper showed excellent antibacterial agent, and it can be used as extending the food product shelf life.

Mannose-Binding Lectin Possesses Agglutination Activity and Promotes Opsonophagocytosis of Macrophages with Calreticulin Interaction in an Early Vertebrate.

The innate immune system is an ancient defense system in the process of biological evolution, which can quickly and efficiently resist pathogen infection. In mammals, mannose-binding lectin (MBL) is a key molecule in the innate immune and plays an essential role in the first line of host defense against pathogenic bacteria. However, the evolutionary origins and ancient roles of immune defense of MBL and its mechanism in clearance of microbial pathogens are still unclear, especially in early vertebrates. In this study, Oreochromis niloticus MBL (OnMBL) was successfully isolated and purified from the serum of Nile tilapia (O. niloticus). The OnMBL was able to bind and agglutinate with two important pathogens of tilapia, Streptococcus agalactiae and Aeromonas hydrophila Interestingly, the OnMBL was able to significantly inhibit the proliferation of pathogenic bacteria and reduce the inflammatory response. Upon bacterial challenge, the downregulation of OnMBL expression by RNA interference could lead to rapid proliferation of the pathogenic bacteria, ultimately resulting in tilapia death. However, the phenotype was rescued by reinjection of the OnMBL, which restored the healthy status of the knockdown tilapia. Moreover, a mechanistic analysis revealed that the OnMBL could clear pathogenic bacteria by collaborating with cell-surface calreticulin to facilitate phagocytosis in a complement activation-independent manner. To our knowledge, these results provide the first evidence on the antibacterial response mechanism of MBL performing evolutionary conserved function to promote opsonophagocytosis of macrophages in early vertebrates and reveals new insights into the understanding of the evolutionary origins and ancient roles basis of the C-type lectins in the innate immune defense.

Kinetics of Adhesion Staphylococcus aureus on Glass in the Presence of Sodium Lauryl Sulfate

AbstractBacterial contamination of surfaces is a natural and spontaneous process that often results in the formation of biofilms. The extracellular matrix of biofilm is mostly composed of proteins, polysaccharides, and extracellular DNA and is responsible for the strong persistent ability of biofilm in the food industry. Despite cleaning and disinfection processes, persistent bacteria cause a major problem in food processing environments. Synthetic surfactants, mainly anionic surface‐active agent, are commonly used as detergents, foaming agents, wetting agents, emulsifiers, and dispersants. Their tendency to adsorb to surfaces and interfaces and modify their surface tension, is considered among their main properties. They also have the ability to attach to bioactive macromolecules such as proteins, peptides, and DNA causing cell membrane damage. In order to estimate the adhesion kinetic and proliferation of pathogenic bacteria Staphylococcus aureus, the surface of glass was coated with anionic surfactant Sodium Lauryl Sulfate (SLS). Moreover, SLS was added in suspension with the culture medium. The physicochemical properties of the material were calculated using the contact angle measurement method and bacterial hydrophobicity using the microbial adhesion to hydrocarbons (MATH) test. The obtained results showed that the number of adhering cells increased gradually as a function of time. However, changing the surface properties of the glass and S. aureus has affected the rate of adherent cells with time as well as their organization. SLS inhibited the attachment of cells, whether it is added with the microbial suspension or at the surface of the support. Generally, the present article points to a relationship between the microbial adhesion, the surface chemistry of the solid material and the bacteria, and the suspension properties.

13 Opportunities for using low-protein diets for weanling pigs to improve intestinal health

Abstract Dietary manipulation with respect to crude protein (CP) content has been suggested as part of the overall strategy for the nutritional management of weanling pigs to improve intestinal health. This has focused on the use of low CP diets that are appropriately fortified with crystalline amino acids (AA). Use of low CP diets minimizes the amount of undigested dietary protein entering the large intestine and being subjected to bacterial fermentation. This is important because protein fermentation leads to the production of toxic metabolites and encourages the proliferation of pathogenic bacteria, thus causing enteric problems such as post-weaning diarrhea. There have been considerable efforts to elucidate the mechanisms underlying the potential benefits of feeding low CP diets to piglets. In addition to impacting the intestinal microbiome and its associated activities, it is clear that feeding a low CP diets interferes with the attachment of enterotoxigenic E. coli to the intestinal mucosa, thus minimizing its ability to cause disease. Another area of interest has been how use low CP diets in combination with other dietary manipulations to further enhance intestinal health in piglets. In this regards, existing evidence suggests that a low CP diet may be used in combination with other dietary interventions, such as probiotics and dietary fiber, to further enhance gut health outcomes in piglets. Also, addressing the potential reduction in piglet performance when feeding low CP diets by looking more into diet formulation to avoid deficiencies of essential AA or even some of non-essential AA, is critical for successful use low CP diets. Based on the available information, a reduction of dietary protein by four percentage units coupled with appropriate AA supplementation can be a useful dietary strategy to improve intestinal health.

A global analysis on the systemic effects of antibiotics in cultured fish and their potential human health risk: a review

AbstractThe rearing of fish in intensive systems reduces their immunity leading to eruption of diseases, consequently prompting the use of antibiotics. Antibiotics are currently used in cultured fish globally to treat/prevent diseases. On the one hand, antibiotics used in aquaculture help to improve fish health by killing or inhibiting pathogenic bacteria proliferation. However, on the other hand, they cause multiple side effects. To date, information on systemic effects of antibiotics in cultured fish is scattered and their potential human health risk remains elusive. This review critically analyses and discusses the available information in the literature on the positive and negative effects of antibiotics in cultured fish and their potential human health risk via fish consumption. The review found 44 different antibiotics dominated by oxytetracycline were studied in various fish species worldwide. Antibiotics used in global aquaculture either decrease or increase fish growth and survival rates. They induce oxidative stress, which affect antioxidant and detoxification responses and cause host–microbiota dysbiosis. These changes compromise the fish immunity system, which ultimately lead to cellular damage. The toxicities generated inhibit the fish aerobic glycolysis, suppress lipogenesis and fatty acid β‐oxidation while increase energy demand by initiating gluconeogenesis and anaerobic glycolysis. Consumption of fish treated with antibiotics causes human health risk. Future studies are required on agents to restore dysfunctions induced by antibiotics in cultured fish, while attempts to limit their utilisation in aquaculture production are underway. [Correction added on 21 November 2020, after first online publication: The abstract has been amended to clarify the scope of the review.]

Potential Application of Bacteriocin Produced from Lactic Acid Bacteria

Kaoutar El Issaoui, Nadia Skali Senhaji, Sanae Zinebi, Rajae Zahli, Imane Haoujar, Nadia Amajoud, Jamal Abrini and El Ouardy Khay. Microbiol. Biotechnol. Lett. 2020;48:237-51. https://doi.org/10.4014/mbl.2001.01004