scholarly journals Lactobacillus johnsonii L531 Alleviates the Damage Caused by Salmonella Typhimurium via Inhibiting TLR4, NF-κB, and NLRP3 Inflammasome Signaling Pathways

2021 ◽  
Vol 9 (9) ◽  
pp. 1983
Author(s):  
Shiyan Chen ◽  
Yanan Li ◽  
Bingxin Chu ◽  
Lanxin Yuan ◽  
Ning Liu ◽  
...  

Salmonella Typhimurium (S. Typhimurium) is an aggressive zoonotic pathogen that causes enteritis and diarrhea. Antibiotic therapy is still the primary method at present. However, the increasing emergence of multi-drug resistant bacteria weakens the therapeutic efficacy of antibiotics. Probiotics have been widely studied as an alternative antibiotic therapy. In this study, we established an IPEC-J2 cell model of S. Typhimurium infection, aiming to determine the protective effect of Lactobacillus johnsonii L531 (L. johnsonii L531) on S. Typhimurium infection. As our data showed, S. Typhimurium infection resulted in a robust inflammatory response demonstrated by promoted protein levels of the inflammatory-related pathway (TLR4, MyD88, p-IκBα, and p-p65), increased cytokine levels of IL-6, IL-1β, IL-18, and TNF-α, and activated the NLRP3 inflammasome via promoting its assembly. However, L. johnsonii L531 pre-incubation inhibited the activation of the above inflammatory signaling pathways and reduced the expression levels of pro-inflammatory cytokines. In addition, L. johnsonii L531 alleviated the damage of S. Typhimurium to tight junctions ZO-1, Occludin, and Claudin-1. In summary, our findings suggested that L. johnsonii L531 alleviated S. Typhimurium-induced tight junction injury by inhibiting the TLR4/NF-κB/NLRP3 inflammasome signaling pathway.

2021 ◽  
Vol 15 (5) ◽  
pp. 1236-1240
Author(s):  
P. Farmehr

Antibiotic resistance has become a significant and growing threat to public and environmental health. The emergence of multiple drug-resistant bacteria has prompted interest in alternatives to conventional antimicrobial. One of the possible replacement options for antibiotics is the use of bacteriophages as antimicrobial. We were forced to look for a new approach in treatment. Phage therapy is an important alternative antibiotic in the current of drug-resistance pathogens. In this way, poisoning bacteria bacteriophage bacteria infect and replicate in bacteria, in this therapy, identify the type of virus per person and can be targeted manipulation of harmful bacteria and then returned the person and invented phage therapy. We discuss the advantages and disadvantages of bacteriophages as therapeutic agents in this regard. And so describe a brief history of bacteriophages and clinical studies on their use in bacterial disease. Much hope is placed in genetic modifications of bacteriophages prevents the development of phage-resistant bacteria. Keywords: antibiotic resistance‚ bacteriophage, phage therapy


2021 ◽  
Author(s):  
Ramasamy Palaniappan ◽  
Govindan Dayanithi

Bacteriophages are bacterial cell-borne viruses that act as natural bacteria killers and they have been identified as therapeutic antibacterial agents. Bacteriophage therapy is a bacterial disease medication that is given to humans after a diagnosis of the disease to prevent and manage a number of bacterial infections. The ability of phage to invade and destroy their target bacterial host cells determines the efficacy of bacteriophage therapy. Bacteriophage therapy, which can be specific or nonspecific and can include a single phage or a cocktail of phages, is a safe treatment choice for antibiotic-resistant and recurrent bacterial infections after antibiotics have failed. A therapy is a cure for health problems, which is administered after the diagnosis of the diseases in the patient. Such non-antibiotic treatment approaches for drug-resistant bacteria are thought to be a promising new alternative to antibiotic therapy and vaccination. The occurrence, biology, morphology, infectivity, lysogenic and lytic behaviours, efficacy, and mechanisms of bacteriophages’ therapeutic potentials for control and treatment of multidrug-resistant/sensitive bacterial infections are discussed. Isolation, long-term storage and recovery of lytic bacteriophages, bioassays, in vivo and in vitro experiments, and bacteriophage therapy validation are all identified. Holins, endolysins, ectolysins, and bacteriocins are bacteriophage antibacterial enzymes that are specific. Endolysins cause the target bacterium to lyse instantly, and hence their therapeutic potential has been explored in “Endolysin therapy.” Endolysins have a high degree of biochemical variability, with certain lysins having a wider bactericidal function than antibiotics, while their bactericidal activities are far narrower. Bacteriophage recombinant lysins (chimeric streptococcal–staphylococcal constructs) have high specificity for a single bacterial species, killing only that species (lysin (CF-301) is focused to kill methicillin resistant Staphylococcus aureus (MRSA)), while other lysins have a broader lytic activity, killing several different bacterial species and hence the range of bactericidal activity. New advances in medicine, food safety, agriculture, and biotechnology demonstrate molecular engineering, such as the optimization of endolysins for particular applications. Small molecule antibiotics are replaced by lysins. The chapter discusses the occurrences of lytic phage in pathogenic bacteria in animals and humans, as well as the possible therapeutic effects of endolysins-bacteriophage therapy in vivo and in vitro, demonstrating the utility and efficacy of the therapy. Further developments in the bacteriophage assay, unique molecular-phage therapy, or a cocktail of phage for the control of a broad range of drug-resistant bacteria-host systems can promote non-antibiotic treatment methods as a viable alternative to conventional antibiotic therapy.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3527-3527
Author(s):  
Hirozumi Sano ◽  
Ryoji Kobayashi ◽  
Daisuke Suzuki ◽  
Daiki Hori ◽  
Kunihiko Kobayashi

Abstract Background Febrile neutropenia (FN) remains an important cause of morbidity and mortality in pediatric cancer patients. Although monotherapy using broad spectrum antibiotics is now a standard of care, there is currently no consensus on optimal agents. Carbapenems are effective and widely used in the treatment of FN; however, they have several disadvantages such as the risk of the emergence of drug-resistant bacteria. The usefulness of intravenous immunoglobulin (IVIG) for FN remains unclear. This randomized crossover study was designed to assess whether piperacillin/tazobactam (PIPC/TAZ) is as effective as meropenem (MEPM). We also evaluated the effectiveness of IVIG in combination with switched antibiotics as a second-line therapy. METHODS Febrile and neutropenic patients treated with conventional or high-dose chemotherapy at the Department of Pediatrics, Sapporo Hokuyu Hospital between April 2012 and March 2016 were included. As a first-line treatment, FN cases were randomized for treatment with either PIPC/TAZ (337.5 mg/kg/day in 3 portions, 1-hour DIV, maximum 13.5 g/day; arm PM) or MEPM (120 mg/kg/day in 3 portions, 1-hour DIV maximum 3 g/day, arm MP). Success was defined as (1) fever and clinical signs of infection resolving within 120 hours of the initiation of antibiotic therapy; and (2) no recurrence of infection/fever after the end of the treatment. Failure was defined as the persistence of fever and infectious signs more than 120 hours after the initiation of antibiotic therapy, a required change in the initial antibiotic therapy, or deterioration/death due to infection. FN cases judged as failures were registered for a second-line treatment, in which antibiotics were switched to another antibiotic (MEPM (arm PM) or PIPC/TAZ (arm MP)), and further randomized to be treated with or without IVIG at 100 mg/kg/day (maximum 5 g/day) for 3 consecutive days. The effects of the second-line therapy were evaluated 72 hours after its initiation. The Institutional Review Board of the hospital approved our project, and written informed consent was obtained from all patients or their parents. RESULTS A total of 434 febrile episodes in 105 patients (42 females and 63 males) with a median age of 8 years (range, 0-25) were enrolled for the first-line therapy. During the study period, 26 patients underwent hematopoietic stem cell transplantation (HSCT). Blood cultures were positive in 47 out of 434 episodes (10.8%) and the leading cause of bacteremia was a-streptococcus (25.5%). Regarding responses to the first-line treatment, success rates between the PIPC/TAZ and MEPM groups were similar (62.4% vs 65.9%, P=0.484), even if patients were restricted to those with bacteremia (26.1% vs 37.5%, P=0.534). Mortality rates did not significantly differ between the two groups (0.8% vs 0%, P=0.500). A total of 144 febrile episodes in 71 patients (29 females and 42 males) with a median age of 11 years (range, 0-25) were enrolled for the second-line therapy. During the study period, 20 patients underwent HSCT. Success rates did not significantly differ between cases treated with PIPC/TAZ (switched from MEPM, with and without IVIG; arm MP) and with MEPM (switched from PIPC/TAZ, with and without IVIG; arm PM) (55.3% vs 44.3%, P=0.936). Cases treated with IVIG had slightly better success rates than those without IVIG (58.7% vs 41.9%, P= 0.064). When cases were restricted to those with IgG <500 mg/dl at the beginning of the second-line therapy, success rates were significantly better in cases with IVIG than in those without (81.8% vs 38.5%, P=0.047). No significant differences were observed in total success rates between arm PM (PIPC/TAZ followed by MEPM) and arm MP (MEPM followed by PIPC/TAZ) (57.7% vs 63.4%, P=0.174). The rates of adverse events in the first- and second-line therapies were not significantly different between the two groups. DISCUSSION This study demonstrated that PIPC/TAZ and MEPM were effective and safe as empirical therapies for FN. Therefore, we concluded that these agents are equally effective. Large numbers of cases with treatment failure after MEPM may be rescued by PIPC/TAZ and vice versa. Carbapenems are now more widely used in the treatment of FN; however, this may increase the prevalence of drug-resistant bacteria, and, thus, the use of PIPC/TAZ for neutropenic children is favorable. In addition, the concomitant use of IVIG needs to be considered for patients with low serum IgG values. Disclosures No relevant conflicts of interest to declare.


Author(s):  
E.A. Martis ◽  
G M Doshi ◽  
G V Aggarwal ◽  
P P Shanbhag

With the emergence of newer diseases, resistant forms of infectious diseases and multi-drug resistant bacteria, it has become essential to develop novel and more effective antibiotics. Current antibiotics are obtained from terrestrial life or made synthetically from intermediates. The ocean represents virtually untapped resource from which novel antibiotic compounds can be discovered. It is the marine world that will provide the pharmaceutical industry with the next generation of antibiotics. Marine antibiotics are antibiotics obtained from marine organisms. Scientists have reported the discovery of various antibiotics from marine bacteria (aplasmomycin, himalomycins, and pelagiomycins), sponges (Ara C, variabillin, strobilin, ircinin-1, aeroplysin, 3,5-dibromo-4-hydroxyphenylacetamide), coelenterates (asperidol and eunicin), mollusks (laurinterol and pachydictyol), tunicates (geranylhydroquinone and cystadytins), algae (cycloeudesmol, aeroplysinin-1(+), prepacifenol and tetrabromoheptanone), worms (tholepin and 3,5-dibromo-4-hydroxybezaldehyde), and actinomycetes (marinomycins C and D). This indicates that the marine environment, representing approximately half of the global diversity, is an enormous resource for new antibiotics and this source needs to be explored for the discovery of new generation antibiotics. The present article provides an overview of various antibiotics obtained from marine sources.


Author(s):  
Daniel Berman

How can we prevent the rise of resistance to antibiotics? In this video, Daniel Berman,  Nesta Challenges, discusses the global threat of AMR and how prizes like the Longitude Prize can foster the development of rapid diagnostic tests for bacterial infections, helping to contribute towards reducing the global threat of drug resistant bacteria. Daniel outlines how accelerating the development of rapid point-of-care tests will ensure that bacterial infections are treated with the most appropriate antibiotic, at the right time and in the right healthcare setting.


2020 ◽  
pp. 607-619
Author(s):  
Ya’nan Qi ◽  
◽  
Zhibao Guo ◽  
Huijun Hu ◽  
Xiang’en Meng ◽  
...  

Neuroinflammation plays an important role in brain damage after acute carbon monoxide poisoning (ACOP). The nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing (NLRP) 3 inflammasome triggers the activation of inflammatory caspases and maturation of interleukin (IL)-1β and -18, and has been linked to various human autoinflammatory and autoimmune diseases. In this study we investigated the effects of hyperbaric oxygen (HBO2) on NLRP3 inflammasome activation after ACOP. Mice were randomly divided into four groups: sham group (exposure to normobaric air – i.e., 21% O2 at 1 atmosphere absolute); HBO2-only group; CO + normobaric air group; and CO + HBO2 group. Cognitive function was evaluated with the Morris water maze; myelin injury was assessed by Fluoro-Myelin GreenTM fluorescent myelin staining and myelin basic protein (MBP) immunostaining; and mRNA and protein levels of NLRP3 inflammasome complex proteins were measured by quantitative real-time PCR and Western blot, respectively. Additionally, serum and brain levels of IL-1β and -18 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were determined by enzyme-linked immunosorbent assay. It was found that HBO2 improved learning and memory, and alleviated myelin injury in mice subjected to acute CO exposure. Furthermore, HBO2 decreased NLRP3, absent in melanoma 2 (AIM2), caspase-1, and apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain mRNA and protein levels, and reduced brain and serum concentrations of IL-1β and -18 and NADPH oxidase. These results indicate that HBO2 suppresses the inflammatory response after ACOP by blocking NLRP3 inflammasome activation, thereby alleviating cognitive deficits.


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