scholarly journals Current Challenges and Perspectives for the Use of Aqueous Plant Extracts in the Management of Bacterial Infections: The Case-Study of Salmonella enterica Serovars

2019 ◽  
Vol 20 (4) ◽  
pp. 940 ◽  
Author(s):  
Sónia Santos ◽  
Cátia Martins ◽  
Carla Pereira ◽  
Armando Silvestre ◽  
Sílvia Rocha
Keyword(s):  
Plant Extracts ◽  
Salmonella Enterica ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Public Health Problem ◽  
Foodborne Diseases ◽  
Salmonella Infection ◽  
Antibiotics Use ◽  
Alternative Approaches

Worldwide, foodborne diseases are a growing public health problem. Among the infectious bacteria, non-typhoidal Salmonella enterica serovars (NTS) are the major cause of hospitalization and death, and the emergence and spread of their antibiotic-resistance is becoming a worldwide health issue. This, coupled with the restrictions of antibiotics use in agriculture and animal production, calls for alternative approaches to solve this problem. Plant-derived aqueous extracts compounds could provide novel straightforward approaches to control pathogenic bacteria. This review discusses the antimicrobial activity of aqueous plant extracts against Salmonella serovars, the possible mechanisms of action involved, which components/structures might be responsible for such activity, and the current challenges for the use of these extracts/components in Salmonella infection management and their application perspectives.

scholarly journals Potentiation of Tobramycin by Silver Nanoparticles against Pseudomonas aeruginosa Biofilms

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marc B. Habash ◽  
Mara C. Goodyear ◽  
Amber J. Park ◽  
Matthew D. Surette ◽  
Emily C. Vis ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Acute Infection ◽  
Public Health Problem ◽  
Chronic Infections ◽  
Content Type

ABSTRACT Increasing antibiotic resistance among pathogenic bacterial species is a serious public health problem and has prompted research examining the antibacterial effects of alternative compounds and novel treatment strategies. Compounding this problem is the ability of many pathogenic bacteria to form biofilms during chronic infections. Importantly, these communities are often recalcitrant to antibiotic treatments that show effectiveness against acute infection. The antimicrobial properties of silver have been known for decades, but recently silver and silver-containing compounds have seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the ability of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the aminoglycoside antibiotic tobramycin, to inhibit established Pseudomonas aeruginosa biofilms. Our results demonstrate that smaller 10-nm and 20-nm AgNPs were more effective at synergistically potentiating the activity of tobramycin. Visualization of biofilms treated with combinations of 10-nm AgNPs and tobramycin reveals that the synergistic bactericidal effect may be caused by disrupting cellular membranes. Minimum biofilm eradication concentration (MBEC) assays using clinical P. aeruginosa isolates shows that small AgNPs are more effective than larger AgNPs at inhibiting biofilms, but that the synergy effect is likely a strain-dependent phenomenon. These data suggest that small AgNPs synergistically potentiate the activity of tobramycin against P. aeruginosa in vitro and may reveal a potential role for AgNP/antibiotic combinations in treating patients with chronic infections in a strain-specific manner.

scholarly journals Borneo herbal plant extracts as a natural medication for prophylaxis and treatment of Aeromonas hydrophila and Pseudomonas fluorescens infection in tilapia (Oreochromis niloticus)

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1847 ◽  
Author(s):  
Esti Handayani Hardi ◽  
Rudy Agung Nugroho ◽  
Irawan Wijaya Kusuma ◽  
Wiwin Suwinarti ◽  
Agung Sudaryono ◽  
...  
Keyword(s):  
Survival Rate ◽  
Pseudomonas Fluorescens ◽  
Plant Extracts ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Prevention Trial ◽  
Phagocytic Index ◽  
Immunological Parameters

Background: The combination of some plant extracts to prevent and treat bacterial infections is gaining momentum, because of effectiveness against certain bacteria. This study aims to describe the antibacterial and immunostimulant abilities of Boesenbergia pandurata (BP), Solanum ferox (SF) and Zingiber Zerumbet (ZZ) plant extracts to treat and prevent Aeromonas hydrophila and Pseudomonas fluorescens infection on Tilapia (Oreochromis niloticus). Methods: Tilapia (initial weight 15±2 g) were injected intramuscularly (0.1 ml/fish) with a combination of A. hydrophila and P. fluorescens at a density of 1×10 5 CFU ml -1 of each bacteria. Treatment trials were performed at day 7 post-injection with each combined extract, while the prevention trial was performed by including the combined extract into the commercial diet for six and seven days prior to injection. Various extract combinations were 60 mg SF extract/kg feed with 40 mg ZZ/kg feed (SF60/ZZ40), SF50/ZZ50, BP90/SF10, and BP50/SF50. Haemato-immunological parameters were performed for four weeks. Results: In prevention trials, tilapia fed SF50/ZZ50 showed a significant increase of white and red blood cells. Similarly, significantly increased haematocrit was found in tilapia fed SF50/ZZ50 in the treatment trial but not in the prevention trial. In both trials, haemoglobin of tilapia was not affected by any combined extracts but decreased the number of bacteria. Phagocytic index, respiratory burst, lysozyme activity and survival rate of fish fed combined extracts were found significantly higher than controls. The amount of pathogenic bacteria in fish fed combined extracts was lower than the control at week 4 (P<0.05). In both trials The percentage of survival rate and relative percent survival of tilapia fed SF 50/ZZ 50, showed the optimum results compared to the other combinations. Conclusions: The combined extract in feed, especially SF50/ZZ50 has a positive effect on the tilapia's innate immune system of tilapia to treat and prevent bacterial infections.

scholarly journals Borneo herbal plant extracts as a natural medication for prophylaxis and treatment of Aeromonas hydrophila and Pseudomonas fluorescens infection in tilapia (Oreochromis niloticus)

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1847 ◽  
Author(s):  
Esti Handayani Hardi ◽  
Rudy Agung Nugroho ◽  
Irawan Wijaya Kusuma ◽  
Wiwin Suwinarti ◽  
Agung Sudaryono ◽  
...  
Keyword(s):  
Immune System ◽  
Pseudomonas Fluorescens ◽  
Plant Extracts ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Prevention Trial ◽  
Immunological Parameters ◽  
Prevention Trials

Background: This study aims to describe the antibacterial and immunostimulant abilities of Boesenbergia pandurata (BP), Solanum ferox (SF) and Zingiber Zerumbet (ZZ) plant extracts to treat and prevent Aeromonas hydrophila and Pseudomonas fluorescens infection on Tilapia (Oreochromis niloticus). Methods: Tilapia (initial weight 15±2 g) were injected intramuscularly (0.1 ml/fish) with a combination of A. hydrophila and P. fluorescens at a density of 1×105 CFU ml-1 of each bacteria. Treatment trials were performed at day 7 post-injection with each combined extract, while the prevention trial was performed by including the combined extract into the diet for six and seven days prior to injection. Various combinations of extract—60 ml SF extract/kg feed with 40 ml ZZ/kg feed (SF60/ZZ40), SF50/ZZ50, BP90/SF10, and BP50/SF50—were mixed with a commercial diet and used in both treatment and prevention trials. Haematological and immunological parameters were performed every week for four weeks. Results: In prevention trials, tilapia fed SF50/ZZ50 showed a significant increase of white and red blood cells from weeks 2 to 4. Similarly, significantly increased haematocrit was also found in tilapia fed SF50/ZZ50 in the treatment trial but not in the prevention trial. However, haemoglobin of tilapia in both trials was not affected by any of the various combinations of extract in the diet. Furthermore, phagocytic, respiratory burst, lysozyme activity indexes and survival rate of fish fed with combined extracts were found to be significantly higher than controls. Moreover, the amount of pathogenic bacteria in fish that were fed combined extracts was also lower than the control and was significantly different at week 4. Conclusions: This study indicates that the addition of combined extract into feed has a positive effect on the tilapia's immune system. The SF50/ZZ50 combination appears to improve the innate immune system of tilapia to treat and prevent bacterial infections.

scholarly journals Harnessing the Intriguing Properties of Magnetic Nanoparticles to Detect and Treat Bacterial Infections

2021 ◽  
Vol 7 (8) ◽  
pp. 112
Author(s):  
Lingchao Xiang ◽  
Ozioma Udochukwu Akakuru ◽  
Chen Xu ◽  
Aiguo Wu
Keyword(s):  
Public Health ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Public Health Problem ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Bacterial Detection ◽  
Prevention And Treatment ◽  
Further Development

Infections caused by pathogenic bacteria, especially multidrug-resistant bacteria, have become a serious worldwide public health problem. Early diagnosis and treatment can effectively prevent the adverse effects of such infections. Therefore, there is an urgent need to develop effective methods for the early detection, prevention, and treatment of diseases that are caused by bacterial infections. So far, magnetic material nanoparticles (MNPs) have been widely used in the detection and treatment of bacterial infections as detection agents and therapeutics. Therefore, this review describes the recent research on MNPs in bacterial detection and treatment. Finally, a brief discussion of challenges and perspectives in this field is provided, which is expected to guide the further development of MNPs for bacterial detection and treatment.

Leishmanicidal Activity of Plant Extracts from Sefrou, a Moroccan Focus of Leishmaniasis, against Various Leishmania Parasites in the Promastigote Stage

2018 ◽  
Vol 17 (2) ◽  
pp. 83-89 ◽  
Author(s):  
I. Zeouk ◽  
A. Et-Touys ◽  
M. Balouiri ◽  
H. Fellah ◽  
A. El Ouali Lalami ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Plant Extracts ◽  
Leishmania Infantum ◽  
Leishmania Major ◽  
Local Population ◽  
Public Health Problem ◽  
World Health ◽  
Total Phenolic ◽  
Leishmania Tropica ◽  
Cistus Salviifolius

According to the World Health Organization, leishmaniasis remains a major worldwide public health problem. The province of Sefrou located in the center of Morocco is a focus of cutaneous leishmaniasis. The present study aims at evaluating the antileishmanial potential of Berberis sp.,Crataegus oxyacantha, Cistus salviifolius, Ephedra altissima and Lavandula dentatafrequently used by the local population. Methanolic extracts were tested against the promastigote form ofLeishmania tropica, Leishmania majorandLeishmania infantumusing tetrazolium-based colorimetric (MTT) assay. The total phenol and flavonoids content of all extracts were determined using the Folin–Ciocalteu reagent, aluminum chloride, and potassium acetate solutions respectively. The plant extracts exhibited antileishmanial activity with variability depending on the tested strain and the plant species compared to Glucantime® used as control (IC50 (the half maximal inhibitory concentration) > 1,000 μg/mL). The best inhibition was observed with Berberis sp., againstLeishmania major(IC50 = 394.40 ± 3.02 μg/ml), andEphedra altissima(reported for the first time) againstLeishmania infantum(IC50 = 490.84 ± 3.15 μg/mL).Leishmania tropicahas shown the same sensitivity behavior toward the five extracts (in average IC50 = 540 ± 11.20 μg/mL). The total phenolic content was higher forCrataegus oxyacanthaandCistus salviifolius(140.67 ± 3.17 μg eq Gallic Acid (GA)/ mg of Extract (E) and 133.83 ± 9.03 μg eq GA/mg of E respectively), while flavonoid was higher forCistus salviifoliusandLavandula dentata(57.92 ± 2.46 μg eq Quercetin (Que)/ mg of Extract (E) and 41.53 ± 1.74 μg eq Que/mg of E). All the tested extracts present some promising aspects that may cure cutaneous leishmaniasis in the center of Morocco; further bioguided assays are needed to isolate the fractions and the bioactive molecule.

Probiotics Slow the Growth of Pathogenic Bacteria

2019 ◽  
Vol 14 (1) ◽  
pp. 28-31 ◽  
Author(s):  
Rowles H. L.
Keyword(s):  
Growth Rate ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Diarrheal Disease ◽  
Growth Curves ◽  
Mortality Rates ◽  
Controlled Delivery ◽  
E Coli ◽  
Multiple Strains ◽  
Commercial Probiotics

Probiotics are live microorganisms, which when ingested in sufficient amounts, confer health benefits to the host by improving the gut microflora balance. The purpose of this research was to determine whether commercial probiotic products containing multitude of commensal bacteria would reduce the growth rate of pathogenic bacteria, specifically Escherichia coli and Salmonella typhimurium. Growth curves were established, and the growth rates were compared for samples of E. coli, S. typhimurium, Nature’s Bounty Controlled Delivery probiotic, Sundown Naturals Probiotic Balance probiotic, and cocultures of the pathogenic bacteria mixed with the probiotics. The findings of this research were that the commercial probiotics significantly reduced the growth rate of E. coli and S. typhimurium when combined in cocultures. Probiotics containing multiple strains may be taken prophylactically to reduce the risk of bacterial infections caused by E. coli and S. typhimurium. Probiotics could be used to reduce the high global morbidity and mortality rates of diarrheal disease.

Scales and Units

2018 ◽  
Author(s):  
Kathryn M. de Luna
Keyword(s):  
Language Change ◽  
Historical Linguistics ◽  
Bantu Languages ◽  
The North ◽  
First Case ◽  
Linguistic Evidence ◽  
River Region ◽  
History Of ◽  
Alternative Approaches

This chapter uses two case studies to explore how historians study language movement and change through comparative historical linguistics. The first case study stands as a short chapter in the larger history of the expansion of Bantu languages across eastern, central, and southern Africa. It focuses on the expansion of proto-Kafue, ca. 950–1250, from a linguistic homeland in the middle Kafue River region to lands beyond the Lukanga swamps to the north and the Zambezi River to the south. This expansion was made possible by a dramatic reconfiguration of ties of kinship. The second case study explores linguistic evidence for ridicule along the Lozi-Botatwe frontier in the mid- to late 19th century. Significantly, the units and scales of language movement and change in precolonial periods rendered visible through comparative historical linguistics bring to our attention alternative approaches to language change and movement in contemporary Africa.

scholarly journals AMPK activates Parkin independent autophagy and improves post sepsis immune defense against secondary bacterial lung infections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathaniel B. Bone ◽  
Eugene J. Becker ◽  
Maroof Husain ◽  
Shaoning Jiang ◽  
Anna A. Zmijewska ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Inflammatory Responses ◽  
Abdominal Sepsis ◽  
Immune Defense ◽  
Bacterial Killing ◽  
Lung Infections ◽  
Sepsis Survivors ◽  
The Impact

AbstractMetabolic and bioenergetic plasticity of immune cells is essential for optimal responses to bacterial infections. AMPK and Parkin ubiquitin ligase are known to regulate mitochondrial quality control mitophagy that prevents unwanted inflammatory responses. However, it is not known if this evolutionarily conserved mechanism has been coopted by the host immune defense to eradicate bacterial pathogens and influence post-sepsis immunosuppression. Parkin, AMPK levels, and the effects of AMPK activators were investigated in human leukocytes from sepsis survivors as well as wild type and Park2−/− murine macrophages. In vivo, the impact of AMPK and Parkin was determined in mice subjected to polymicrobial intra-abdominal sepsis and secondary lung bacterial infections. Mice were treated with metformin during established immunosuppression. We showed that bacteria and mitochondria share mechanisms of autophagic killing/clearance triggered by sentinel events that involve depolarization of mitochondria and recruitment of Parkin in macrophages. Parkin-deficient mice/macrophages fail to form phagolysosomes and kill bacteria. This impairment of host defense is seen in the context of sepsis-induced immunosuppression with decreased levels of Parkin. AMPK activators, including metformin, stimulate Parkin-independent autophagy and bacterial killing in leukocytes from post-shock patients and in lungs of sepsis-immunosuppressed mice. Our results support a dual role of Parkin and AMPK in the clearance of dysfunctional mitochondria and killing of pathogenic bacteria, and explain the immunosuppressive phenotype associated Parkin and AMPK deficiency. AMPK activation appeared to be a crucial therapeutic target for the macrophage immunosuppressive phenotype and to reduce severity of secondary bacterial lung infections and respiratory failure.

scholarly journals Enacting alternatives to nationalist essentialising in language learning: Students’ voices

2021 ◽  
pp. 001458582098650
Author(s):  
Gloria De Vincenti ◽  
Angela Giovanangeli
Keyword(s):  
Language Learning ◽  
Critical Discourse Analysis ◽  
Teaching And Learning ◽  
Social Contexts ◽  
Critical Discourse ◽  
Innovative Teaching ◽  
Language And Culture ◽  
Theoretical Approaches ◽  
Alternative Approaches

Researchers examining nationalistic conceptions of language learning argue that nationalist essentialism often shapes the way languages are taught by educators and understood by learners. While numerous studies focus on how frameworks informed by Critical Discourse Analysis (CDA) and intercultural education offer alternative approaches to national stereotyping, these studies tend to focus on theoretical approaches, teacher perspectives or innovative teaching and learning resources. The literature to date, however, does not provide case studies on student responses to activities designed by the teacher to open up the classroom with opportunities that move beyond essentialist representations. This article responds to the need for such scholarship and presents a case study involving a focus group with tertiary students in an Italian language and culture subject. It reveals some of the ways in which students enacted and reflected upon alternatives to nationalist essentialising as a result of language learning activities that had been informed by the discursive processes of CDA. The findings suggest that students demonstrated skills and attitudes such as curiosity, subjectivities and connections with broader social contexts. Some of the data also indicates student engagement in critical inquiry and their potential for social agency.

scholarly journals Sorting out the Superbugs: Potential of Sortase A Inhibitors among Other Antimicrobial Strategies to Tackle the Problem of Antibiotic Resistance

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 164 ◽  
Author(s):  
Nikita Zrelovs ◽  
Viktorija Kurbatska ◽  
Zhanna Rudevica ◽  
Ainars Leonchiks ◽  
Davids Fridmanis
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Resistance Mechanisms ◽  
Surface Proteins ◽  
Sortase A ◽  
Inhibitory Compounds ◽  
Alternative Means ◽  
Alternative Approaches ◽  
Conventional Antibiotics

Rapid spread of antibiotic resistance throughout the kingdom bacteria is inevitably bringing humanity towards the “post-antibiotic” era. The emergence of so-called “superbugs”—pathogen strains that develop resistance to multiple conventional antibiotics—is urging researchers around the globe to work on the development or perfecting of alternative means of tackling the pathogenic bacteria infections. Although various conceptually different approaches are being considered, each comes with its advantages and drawbacks. While drug-resistant pathogens are undoubtedly represented by both Gram(+) and Gram(−) bacteria, possible target spectrum across the proposed alternative approaches of tackling them is variable. Numerous anti-virulence strategies aimed at reducing the pathogenicity of target bacteria rather than eliminating them are being considered among such alternative approaches. Sortase A (SrtA) is a membrane-associated cysteine protease that catalyzes a cell wall sorting reaction by which surface proteins, including virulence factors, are anchored to the bacterial cell wall of Gram(+) bacteria. Although SrtA inhibition seems perspective among the Gram-positive pathogen-targeted antivirulence strategies, it still remains less popular than other alternatives. A decrease in virulence due to inactivation of SrtA activity has been extensively studied in Staphylococcus aureus, but it has also been demonstrated in other Gram(+) species. In this manuscript, results of past studies on the discovery of novel SrtA inhibitory compounds and evaluation of their potency were summarized and commented on. Here, we discussed the rationale behind the inhibition of SrtA, raised some concerns on the comparability of the results from different studies, and touched upon the possible resistance mechanisms as a response to implementation of such therapy in practice. The goal of this article is to encourage further studies of SrtA inhibitory compounds.

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