Antimicrobial peptides from amphibians

2011 ◽  
Vol 2 (1-2) ◽  
pp. 27-38 ◽  
Author(s):  
Yao Xiao ◽  
Cunbao Liu ◽  
Ren Lai

AbstractIncreased prevalence of multi-drug resistance in pathogens has encouraged researchers to focus on finding novel forms of anti-infective agents. Antimicrobial peptides (AMPs) found in animal secretions are components of host innate immune response and have survived eons of pathogen evolution. Thus, they are likely to be active against pathogens and even those that are resistant to conventional drugs. Many peptides have been isolated and shown to be effective against multi-drug resistant pathogens. More than 500 AMPs have been identified from amphibians. The abundance of AMPs in frog skin is remarkable and constitutes a rich source for design of novel pharmaceutical molecules. Expression and post-translational modifications, discovery, activities and probable therapeutic application prospects of amphibian AMPs will be discussed in this article.

2019 ◽  
Author(s):  
Serge Ruden ◽  
Annika Rieder ◽  
Thomas Schwartz ◽  
Ralf Mikut ◽  
Kai Hilpert

AbstractWith the rise of various multi-drug resistance pathogenic bacteria, worldwide health care is under pressure to respond. Conventional antibiotics are failing and the development of novel classes or alternative strategies is a major priority. Antimicrobial peptides (AMPs) can not only kill multi-drug resistant bacteria, but also can be used synergistically with conventional antibiotics. We selected 30 short AMPs from different origins and measured their synergy in combination with Polymyxin B, Piperacillin, Ceftazidime, Cefepime, Meropenem, Imipenem, Tetracycline, Erythromycin, Kanamycin, Tobramycin, Amikacin, Gentamycin, and Ciprofloxacin. In total 403 unique combinations were tested against a multi-drug resistant Pseudomonas aeruginosa isolate (PA910). As a measure of the synergistic effects, fractional inhibitory concentrations (FICs) were determined using microdilution assays with FICs ranges between 0.25 and 2. A high number of combinations between peptides and Polymyxin B, Erythromycin and Tetracycline were found to be synergistic. Novel variants of Indolicidin also showed a high frequency in synergist interaction.


2019 ◽  
Author(s):  
Yitagesu Habtu ◽  
Tesema Bereku ◽  
Girma Alemu ◽  
Ermias Abera

BACKGROUND Ethiopia is one of among thirty high burden countries of multi-drug resistant tuberculosis (MDR-TB) in the regions of world health organization. Contextual evidence on the emergence of the disease is limited at a program level. OBJECTIVE The aim of the study is to explore patient-provider factors that may facilitate the emergence of multi-drug resistant tuberculosis. METHODS We used a phenomenological study design of qualitative approach from June to July, 2015. We conducted ten in-depth interviews and 4 focus group discussions with purposely selected patients and providers. We designed and used an interview guide to collect data. Verbatim transcribes were exported to open code 3.4 for emerging thematic analysis. Domain summaries were used to support core interpretation. RESULTS The study explored patient-provider factors facilitating the emergence of multi-drug resistant tuberculosis. These factors as underlying, health system and patient-related factors. Especially, the a shows conflicting finding between having a history of discontinuing drug-susceptible tuberculosis and emergence of multi-drug resistant tuberculosis. CONCLUSIONS The patient-provider factors may result in poor early case identification, adherence to and treatment success in drug sensitive or multi-drug resistant tuberculosis. Our study implies the need for awareness creation about multi-drug resistant tuberculosis for patients and further familiarization for providers. This study also shows that patients developed multi-drug resistant tuberculosis though they had never discontinued their drug-susceptible tuberculosis treatment. Therefore, further studies may require for this discording finding.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marie-Christin Bendix ◽  
Michael Stephan ◽  
Mariel Nöhre ◽  
Wally Wünsch-Leiteritz ◽  
Hagen Schmidt ◽  
...  

AbstractClinical observations show that patients with anorexia nervosa (AN) are surprisingly free from infectious diseases. There is evidence from studies in Drosophila melanogaster that starvation leads to an increased expression of antimicrobial peptides (AMPs). AMPs are part of the innate immune system and protect human surfaces from colonization with pathogenic bacteria, viruses and fungi. We compared the expression of AMPs between patients with AN and healthy controls (HC) and investigated the influence of weight gain. Using a standardized skin rinsing method, quantitative determination of the AMPs psoriasin and RNase 7 was carried out by ELISA. Even though non-significant, effect sizes revealed slightly higher AMP concentrations in HC. After a mean weight gain of 2.0 body mass index points, the concentration of psoriasin on the forehead of patients with AN increased significantly. We could not confirm our hypotheses of higher AMP concentrations in patients with AN that decrease after weight gain. On the contrary, weight gain seems to be associated with increasing AMP concentrations.


2018 ◽  
Vol 8 (12) ◽  
pp. 2627
Author(s):  
Hui Xie ◽  
Yonghua Zhan ◽  
Xueli Chen ◽  
Qi Zeng ◽  
Dan Chen ◽  
...  

The issue of Staphylococcus aureus (MRSA) developing a resistance to drugs such as methicillin has long been the focus for new drug development. In recent years, antimicrobial peptides, such as small molecular peptides with broad-spectrum antibacterial activity and special antibacterial mechanism, have shown a strong medicinal potential. In particular, the Brevinin-2 family has been shown to have a significant inhibitory effect against gram-positive bacteria (G+). In this study, we researched the influence of MRSA on the behavior and survival rate of nematodes. We established an assay of Caenorhabditis elegans–MRSA antimicrobial peptides to screen for new potent anti-infective peptides against MRSA. From the Brevinin-2 family, 13 peptides that had shown strong effects on G+ were screened for their ability to prolong the lifespan of infected worms. Real-time Polymerase Chain Reaction (PCR) tests were used to evaluate the effect on the innate immune pathway dauer formation defective (DAF)-2/DAF-16 of C. elegans. The assay successfully screened and filtered out four of the 13 peptides that significantly improved the survival rate of MRSA-infected worms. The result of real-time PCR indicated that the mRNA and protein expression levels of lys-7 were consistently upregulated by being treated with four of the Brevinin-2 family. The Brevinin-2 family peptides, including Brevinin-2, Brevinin-2-OA3, Brevinin-2ISb, and Brevinin-2TSa, also played an active role in the DAF-2/DAF-16 pathway in C. elegans. We successfully demonstrated the utility of anti-infective peptides that prolong the survival rate of the MRSA-infected host and discovered the relationship between antibacterial peptides and the innate immune system of C. elegans. We demonstrated the antimicrobial effects of Brevinin-2 family peptides, indicating their potential for use as new drug candidates against MRSA infections.


Parasitology ◽  
2018 ◽  
Vol 146 (6) ◽  
pp. 774-780 ◽  
Author(s):  
Ibrahim I. Wangwe ◽  
Sarah A. Wamwenje ◽  
Caroline Mirieri ◽  
Nicodemus M. Masila ◽  
Lillian Wambua ◽  
...  

AbstractTrypanocide resistance remains a huge challenge in the management of animal African trypanosomiasis. Paucity of data on the prevalence of multi-drug resistant trypanosomes has greatly hindered optimal veterinary management practices. We use mathematical model predictions to highlight appropriate drug regimens that impede trypanocide resistance development in cattle. We demonstrate that using drugs in decreasing resistance order results in a negligible increase in number of cattle with resistant infection, in contrast to a more pronounced increase from trypanocide use in increasing resistance order. We demonstrate that the lowest levels of trypanocide resistance are achieved with combination therapy. We also show that increasing the number of cattle treated leads to a progressive reduction in the number of cattle with drug resistant infections for treatments of up to 80% of the cattle population for the combination treatment strategy. Our findings provide an initial evidence-based framework on some essential practices that promote optimal use of the handful of trypanocides. We anticipate that our modest forecasts will improve therapeutic outcomes by appropriately informing on the best choice, and combination of drugs that minimize treatment failure rates.


2012 ◽  
Vol 4 ◽  
pp. 405-409 ◽  
Author(s):  
Adrianna Pawlik ◽  
Grażyna Sender ◽  
Rafał Starzyński ◽  
Agnieszka Korwin-Kossakowska

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