Chance Of Resistance Development Research Articles

Morpho-Molecular Characterization of Trichoderma Isolates from Rhizospheric Soils of Vegetables in Pakistan

Trichoderma, a major fungal genus attaining importance due to its diverse application in biological control programs and is considered a substitute for chemical pesticides. This research was conducted to characterize various Trichoderma species isolated from rhizospheric soil samples morphologically followed by its confirmation using molecular tools. A systematic survey of Trichoderma populations associated with soils of different vegetable hosts would enable a clear picture of the distribution of species in the region. Samples were collected from the rhizospheres of a variety of vegetable hosts and obtained numerous Trichoderma isolates (T. harzianum, T. viride, T. hamatum, T. longibrachiatum, T. asperellum, T. koningii and T. longipile). Morphological characteristics revealed that T. harzianum resembles T. viride but is more pigmented with confined rings than T. viride and other associated species. T. viride sporulation was more rapid than other species, producing a soft mat on PDA media. T. viride produces a sweet smell of coconut; T. asperellum produces a misty odour while T. longibrachiatum produces a yellow pigmentation in the media. Fifty out of 200 morphologically identified species were genetically characterized using universal primers (ITS-1 and ITS-4). ITS-based sequencing resulted in a product of 650 bp in all the isolates. The sequencing of these isolates showed five different species. As per rDNA, the species identified are: T. harzianum, T. hamatum, T. longibrachiatum, T. asperellum and T. viride with 98-100% sequence similarities to other related Trichoderma isolates reported from China, India, Mexico, USA, Portugal, Germany, Spain and Brazil. Bioinformatics analysis was conducted using maximum parsimony (MP) that supports the resemblance of the present study Trichoderma species with species reported from other countries. It is concluded that Trichoderma strains with biocontrol activity are genetically different compared to the pathogenic ones. The findings of this study help in providing an opportunity to test these isolates against different plant pathogens and ultimately leads to the development of bio-pesticides that could be eco-friendly and cost-effective with no chance of resistance development

Molecular Modeling Techniques Applied to the Design of Multitarget Drugs: Methods and Applications

Multifactorial diseases, such as cancer and diabetes present a challenge for the traditional "one-target, one disease" paradigm due to their complex pathogenic mechanisms. Although a combination of drugs can be used, a multitarget drug may be a better choice due to its efficacy, lower adverse effects and lower chance of resistance development. The computer-based design of these multitarget drugs can explore the same techniques used for single-target drug design, but the difficulties associated with the obtention of drugs that are capable of modulating two or more targets with similar efficacy impose new challenges, whose solutions involve the adaptation of known techniques and also to the development of new ones, including machine-learning approaches. In this review, some SBDD and LBDD techniques for the multitarget drug design are discussed, together with some cases where the application of such techniques led to effective multitarget ligands.

Cloning and expression analysis of fused holin-endolysin from RL bacteriophage; Exhibits broad activity against multi drug resistant pathogens

Antibiotic resistance has become a major risk to community health over last few years because of antibiotics overuse around the globe and lack of new antibiotics development. Phages and their lytic enzymes are considered as an effective alternative of antibiotics to control drug resistant bacterial pathogens. Endolysins prove to be a promising class of antibacterials due to their specificity and less chances of resistance development in bacterial pathogens. Though large number of endolysins has been reported against gram positive bacteria, very few reported against gram negative bacteria due to the presence of outer membrane, which acts as physical barrier against endolysin attack to peptidoglycan. In the current study, we have expressed endolysin (RL_Lys) and holin fused at the N terminus of endolysin (RL_Hlys) from RL phage infecting multi drug resistant (MDR) Pseudomonas aeruginosa. Both endolysin variants were found active against wide range of MDR strains P. aeruginosa, Klebsella pneumonia, Salmonella Sp. and Methicillin Resistant Staphylococcus aureus (MRSA). Broth reduction assay showed that RL_Hlys is more active than RL_Lys due to presence of holin, which assist the endolysin access towards cell wall. The protein ligand docking and molecular dynamic simulation results showed that C- terminus region of endolysin play vital role in cell wall binding and even in the absence of holin, hydrolyze a broad range of gram negative bacterial pathogens. The significant activity of RL-Lys and RL_Hlys against a broad range of MDR gram negative and positive bacterial pathogens makes them good candidates for antibiotic alternatives.

Combining Biocontrol Agents with Chemical Fungicides for Integrated Plant Fungal Disease Control.

Feeding a rising population of currently 7.8 billion people globally requires efficient agriculture, which is preferably sustainable. Today, farmers are largely dependent on synthetic fungicides to avoid food losses caused by fungal diseases. However, the extensive use of these has resulted in the emergence of fungicide-resistant pathogens and concerns have been raised over the residual effects on the environment and human health. In this regard, biocontrol agents (BCAs) have been proposed as an alternative to standard fungicides but their disease management capacity is usually incomplete and heavily relies on uncontrollable environmental conditions. An integrated approach combining BCAs with fungicides, which is the focus of this review, is put forward as a way to reduce the fungicide doses to manage plant diseases and thereby their residue on harvested crops. In addition, such a strategy of combining antifungal treatments with different modes of action reduces the selection pressure on pathogens and thereby the chances of resistance development. However, to allow its large-scale implementation, further knowledge is needed, comprising timing, number and interval of repeated BCA applications and their compatibility with fungicides. The compatibility of BCAs with fungicides might differ when applied in a mixture or when used in alternation.

Effect of the lantibiotic nisin on inhibitory and bactericidal activities of antibiotics used against vancomycin-resistant enterococci

ObjectivesAntibiotic resistance is a serious issue facing clinicians all over the world. Vancomycin-resistant enterococci (VRE) are amongst the most common resistant pathogens that are isolated from patients suffering from infections in our locality. New antimicrobial agents such as the lantibiotic nisin have been previously examined against resistant bacteria as it has strong antibacterial action with no chance of resistance development. This study aimed to explore the effect of nisin in combination with the conventional antibiotics against VRE, with a view to using it as an auxiliary therapy with such antibiotics for combating resistant isolates. MethodsTwenty-three VRE had been examined for the combined effect of nisin with the routine sets of antibiotics using the microplate dilution technique for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) testing. Checkerboard microbroth assay was conducted for inspection of synergism between nisin and either ampicillin or chloramphenicol. ResultsAn obvious improvement of inhibitory and bactericidal activities of the tested antibiotics after addition of lantibiotic nisin was observed, with a remarkable reduction in the MIC values of vancomycin against all of the isolates. Nisin recorded a synergistic outcome when combined with either ampicillin or chloramphenicol using the checkerboard assay. ConclusionNisin could be effectively considered as a supplementary agent to traditional antibiotics in the management of VRE-associated infections, as it had a synergistic outcome with commonly prescribed antibiotics such as ampicillin and chloramphenicol.

Protocols for Studying Inhibition and Eradication of Bacterial Biofilms by Antimicrobial Peptides.

Many pathogenic microorganisms have the ability to form biofilms that are impervious to conventional antibiotics making these pathogens resistant to multiple antibiotics. This necessitates the development of novel antimicrobial compounds with less chance of resistance development and the ability to penetrate the extracellular polymer matrix of bacterial biofilms. In this report, simple assays to test the antibiofilm potential of antimicrobial peptides are described.

Reversal Effect of Doxorubicin on Arteether Resistance in Rodent Malaria Parasite Plasmodium vinckei

Artemisinin based combination therapies may effectively reverse the resistance in malaria parasite by reversal agents. Here, we are first time showing arteether (ART) drug resistance reversal in Plasmodium vinckei by using Doxorubicin (DOXO). We hypothesized that oxidative stress catabolism may interfere with DOXO, resulting increased the efficacy of ART. We show the synergetic effect of DOXO with ART by complete suppression of parasitemia till day 10 post treatment. In addition, results also showed higher Activity Enhancement Index (AEI) of ART. These studies propose the possibility of ART drug combination that may be helpful in reducing the chance of resistance development.