Increase In Antifungal Activity Research Articles

Invitro Antifungal Activity of Ziziphusmauritiana Extraction Against Clinical Isolates of Candida Spp at Khartoum State, 2021

experimental biomedical study was carried out at Omdurman Maternal Hospital, Saudi Maternal Hospital and AlzaiemAlazhari University during the period from September to December 2021. 30 Candida species, of them 17 isolated from urine samples and 13 from vaginal swabs were included in this study. Antifungal activity was performed usingcup plate method using different concentrations of plant extraction (100%, 50% and 25%) and fluconazole(10μg). The statistical analysis was performed using SPSS version 20. Results: the results showed significant increase in antifungal activity with increase in Ziziphusmauritianaconcentration, while fluconazole showed best antifungal activity.However, the fungicidal concentration showed that Ziziphusmauritiana methanol extracts was able to inhibit Candia SPPs rather than C. albicans.

Study of combination of liquid organic waste on antifungal activity Bacillus sp. DB12

This study examines the ability of liquid organic waste carriers to increase the antifungal activity of the active ingredient Bacillus sp DB12, which has been stored for 12 weeks against the pathogen Fusarium oxysporum f.sp. cepae. The research method was carried out in an experimental laboratory using a completely randomized design (CRD) with a single factor in the form of a liquid waste carrier consisting of 9 treatments. The composition of liquid tofu waste (TLW), coconut liquid waste (CLW), and rice washing liquid waste (RLW) was determined as follows: 100% TLW, 75% TLW + 25% CLW, 50% TLW + CLW 50%, TLW 25% + CLW 75%, CLW 100%, TLW 75% + RLW 25%, TLW 50% + RLW 50%, TLW 25% + 75% RLW, and 100% RLW. The results showed that the combination of 75% TLW + 25% CLW carriers increased the antifungal activity of Bacillus sp. DB12 compared to other carrier combinations. An increase in antifungal activity was indicated by an inhibition zone diameter of 13.03 mm during 12 weeks of storage.

Structure modification of an antibiotic: by engineering the fusaricidin bio-synthetase A in Paenibacillus polymyxa.

Fusaricidin, a lipopeptide antibiotic, is specifically produced by Paenibacillus polymyxa strains, which could strongly inhibit Fusarium species fungi. Fusaricidin bio-synthetase A (FusA) is composed of six modules and is essential for synthesizing the peptide moiety of fusaricidin. In this study, we confirmed the FusA of Paenibacillus polymyxa strain WLY78 involved in producing Fusaricidin LI-F07a. We constructed six engineered strains by deletion of each module within FusA from the genome of strain WLY78. One of the engineered strains is able to produce a novel compound that exhibits better antifungal activity than that of fusaricidin LI-F07a. This new compound, known as fusaricidin [ΔAla6] LI-F07a, has a molecular weight of 858. Our findings reveal that it exhibits a remarkable 1-fold increase in antifungal activity compared to previous fusaricidin, and the fermentation yield reaches ~55 mg/L. This research holds promising implications for plant protection against infections caused by Fusarium and Botrytis pathogen infection.

Lactonase-mediated inhibition of quorum sensing largely alters phenotypes, proteome, and antimicrobial activities in Burkholderia thailandensis E264.

Burkholderia thailandensis is a study model for Burkholderia pseudomallei, a highly virulent pathogen, known to be the causative agent of melioidosis and a potential bioterrorism agent. These two bacteria use an (acyl-homoserine lactone) AHL-mediated quorum sensing (QS) system to regulate different behaviors including biofilm formation, secondary metabolite productions, and motility. Using an enzyme-based quorum quenching (QQ) strategy, with the lactonase SsoPox having the best activity on B. thailandensis AHLs, we evaluated the importance of QS in B. thailandensis by combining proteomic and phenotypic analyses. We demonstrated that QS disruption largely affects overall bacterial behavior including motility, proteolytic activity, and antimicrobial molecule production. We further showed that QQ treatment drastically decreases B. thailandensis bactericidal activity against two bacteria (Chromobacterium violaceum and Staphylococcus aureus), while a spectacular increase in antifungal activity was observed against fungi and yeast (Aspergillus niger, Fusarium graminearum and Saccharomyces cerevisiae). This study provides evidence that QS is of prime interest when it comes to understanding the virulence of Burkholderia species and developing alternative treatments.

The Effect of Trichoderma harzianum Hypovirus 1 (ThHV1) and Its Defective RNA ThHV1-S on the Antifungal Activity and Metabolome of Trichoderma koningiopsis T-51

Mycoviruses widely exist in filamentous fungi and sometimes cause phenotypic changes in hosts. Trichoderma harzianum hypovirus 1 (ThHV1) and its defective RNA ThHV1-S were found in T. harzianum and exhibited high transmissibility. In our previous study, ThHV1 and ThHV1-S were transferred to an excellent biological control agent T. koningiopsis T-51 to form a derivative strain 51-13. In this study, we assessed the metabolic changes in strain 51-13 and antifungal activity of its culture filtrate (CF) and volatile organic compounds (VOCs). The antifungal activity of CF and VOCs of T-51 and 51-13 was different. Compared with the CF of T-51, that of 51-13 exhibited high inhibitory activity against B. cinerea, Sclerotinia sclerotiorum, and Stagonosporopsis cucurbitacearum but low inhibitory activity against Leptosphaeria biglobosa and Villosiclava virens. The VOCs of 51-13 exhibited high inhibitory activity against F. oxysporum but low inhibitory activity against B. cinerea. The transcriptomes of T-51 and 51-13 were compared; 5531 differentially expressed genes (DEGs) were identified in 51-13 with 2904 up- and 2627 downregulated genes. In KEGG enrichment analysis, 1127 DEGs related to metabolic pathways (57.53%) and 396 DEGs related to biosynthesis of secondary metabolites (20.21%) were clearly enriched. From the CF of T-51 and 51-13, 134 differential secondary metabolites (DSMs) were detected between T-51 and 51-13 with 39 up- and 95 downregulated metabolites. From these, 13 upregulated metabolites were selected to test their antifungal activity against B. cinerea. Among them, indole-3-lactic acid and p-coumaric acid methyl ester (MeCA) exhibited strong antifungal activity. The IC50 of MeCA was 657.35 μM and four genes possibly related to the synthesis of MeCA exhibited higher expression in 51-13 than in T-51. This study revealed the mechanism underlying the increase in antifungal activity of T-51 because of the mycovirus and provided novel insights in fungal engineering to obtain bioactive metabolites via mycoviruses.

Development and Optimization of Hyaluronic Acid-Poloxamer In-Situ Gel Loaded with Voriconazole Cubosomes for Enhancement of Activity against Ocular Fungal Infection.

Fungal eye infections are largely disseminated, especially in developing countries where they may leave over half a million people blind per year. The current study aims to boost the voriconazole antifungal efficiency via loading it as cubosomes (VZ-Cub) into hyaluronic acid and poloxamer-based ocular in situ gel. VZ-Cub were fabricated applying Box-Behnken design and employing phytantriol, poloxamer F127, and VZ amounts as independent variables. The produced nano vesicles were evaluated for the dependent variables of particle size (PS), entrapment efficiency (EE%), and transcorneal steady-state flux (Jss) of the VZ, and, the obtained optimal VZ-Cub was loaded into an in situ gel base to enhance its ocular residence time. The in situ gel formulation was tested for its gelation temperature, drug release behavior, transcorneal permeation effects, and antifungal activity. The optimized VZ-Cub consisted of 100 mg of phytantriol, 60 mg of poloxamer F127, and 21 mg of VZ. This formulation led to a minimum PS of 71 nm, an EE% of 66%, Jss value of 6.5 µg/(cm2·min), and stability index of 94 ± 2%. The optimized VZ-Cub-loaded in situ gel released 84% VZ after 12 h and yielded a 4.5-fold increase in drug permeation compared with the VZ aqueous dispersion. The antifungal activity, which was obtained by measuring the fungal growth inhibition zones, revealed that the VZ-Cub-loaded in situ gel formulation had a 3.89-fold increase in antifungal activity compared with the VZ dispersion. In summary, an ocular in situ gel loaded with VZ-Cub could be an effective novel nano-paradigm with enhanced transcorneal permeation and antifungal properties.

Antifungal Activity of Onion and Garlic Extract for The Control of Aspergillus niger Isolated from Ghurki Village

Fungi are cosmopolitan in distribution and have ability to grow in all sort of environmental conditions. They can colonize a wide variety of substrates and as pathogens responsible for various diseases in humans, plants and animals. It was also noticed various plant species has antimicrobial activities and they used to control fungal growth. In the present study samples of agricultural soil were collected from Ghurki village near Lahore and inoculated on Potato dextrose agar. Different Aspergillus species and mucor were observed however, only Aspergillus niger were collected, purified and assessed for inhibitory activity of onion and garlic. Both species belong to genus Allium. 250 grams of each peeled Allium species was taken and plant extracts were prepared in distilled water, ethanol (95.5) and acetone (95.5%) separately. The inhibitory effects of biological extracts were recorded at varying temperature, pH and incubation period. It was noticed inhibitory effect decreased with increase of temperature but no significant results seen for varying pH. Furthermore, an increase in antifungal activity was recorded for garlic extract compared to onion with incubation period (1-7 days). It was also concluded that garlic is best antifungal agent that has capability to reduce growth of Aspergillus niger with all three solutions and produce more pronounced effect with Alcoholic extract.

Amla fruit mediated synthesis of zinc oxide nanoparticles and its antifungal activity

To study the antifungal activity of ZnO nanoparticles synthesised from amla fruit. Nanotechnology has offered great possibilities in various fields of science and technology. It has been playing a crucial role in the development of modern materials in recent years. The antifungal activity of ZnO occurs by the deformation of fungal hyphae leading to the death of fungal hyphae, which may lead to cellular destruction. Preparation of plant extract, Synthesis of nanoparticles, Characteristics of nanoparticles, Preparation of nanoparticles powder, Antifungal activity of nanoparticles against Candida albicans.The peak found in the spectroscopy indicates the formation of ZnO nanoparticle. It is clearly seen from the graph that increase in concentration results in an increase in antifungal activity. The antifungal activity, in this case, was proved with Aspergillus niger and Aspergillus terreus. The results conclude that ZnO nanoparticle can be used to prevent any antifungal diseases.

Isolation of pathogenic Candida species from oral cavity of postpartum females, and its association with obstetric and dental problems

ObjectiveThe aim of the current study was to investigate pathogenic Candida spp. Colonization in oral cavity of postpartum females and its association with adverse pregnancy outcomes (APOs) and dental issues. MethodsSaliva samples and clinico-demographic data were collected from 267 postpartum females along with 54 non-pregnant females (Jan 2016–March 2018). Isolation of Candida was carried out by using standard microbiological methods and different virulence factors (Esterase activity, phospholipase activity and biofilm formation) were evaluated. ResultsCandidacolonization was high in postpartum females (p<0.001, OR = 4.28). This colonization was not significant among females with APOs, however, one to three folds risk was seen with different obstetric and dental factors. High esterase activity was seen among Candida isolates from postpartum females in comparison to control group (p = 0.01). Phospholipase activity of C.albicans isolates from this group was also high (p = 0.001). Majority of the Candida isolates (66.87%) from postpartum females were biofilm formers. Increase in antifungal activity was seen among isolates from postpartum females, with 85% isolates resistant to Fluconazole and Voriconazole (p<0.001) and Amphotericin B resistance was present in 64.38% isolates (p<0.001). ConclusionPostpartum females are more susceptible to oral Candida colonization, which exhibit enhanced virulence characteristics and its carriage are associated with increased risk for development of APOs and dental problems.

Improved smallest peptides based on positive charge increase of the γ-core motif from PνD1 and their mechanism of action against Candida species.

BackgroundPlant defensins have a hallmark γ-core motif (GXCX3-9C) that is related to their antimicrobial properties. The aim of this work was to design synthetic peptides based on the region corresponding to the PvD1 defensin γ-core that are the smallest amino acid sequences that bear the strongest biological activity.MethodsWe made rational substitutions of negatively charged amino acid residues with positively charged ones, and the reduction in length in the selected PvD1 γ-core sequence to verify whether the increased net positive charges and shortened length are related to the increase in antifungal activity. Herein, we opted to evaluate the action mechanism of γ33-41PvD1++ peptide due to its significant inhibitory effect on tested yeasts. In addition, it is the smallest construct comprising only nine amino acid residues, giving it a better possibility to be a prototype for designing a new antifungal drug, with lower costs to the pharmaceutical industry while still maintaining the strongest antimicrobial properties.ResultsThe γ33-41PvD1++ peptide caused the most toxic effects in the yeast Candida buinensis, leading to membrane permeabilization, viability loss, endogenous reactive oxygen species increase, the activation of metacaspase, and the loss of mitochondrial functionality, suggesting that this peptide triggers cell death via apoptosis.ConclusionWe observed that the antifungal activity of PvD1 is not strictly localized in the structural domain, which comprises the γ-core region and that the increase in the net positive charge is directly related to the increase in antifungal activity.

Activation of the phenylpropanoid biosynthesis pathway reveals a novel action mechanism of the elicitor effect of chitosan on avocado fruit epicarp

Secondary metabolites play an important role in the avocado fruit defense system. Phenolic compounds are the main biosynthesized metabolites of this system response. Our objective in this investigation was to evaluate the induction of specific metabolic pathways using chitosan as an elicitor. Extracts obtained from avocado in intermediate and consumption maturity stages treated with chitosan exhibited an increase in antifungal activity, which caused inhibition of mycelial growth and a decrease in sporulation as well as spore germination of Colletotrichum gloeosporioides. Additionally, RNA from epicarp of the fruits treated and untreated with chitosan was obtained in order to evaluate the expression of genes related to phenylpropanoids and the antifungal compound 1-acetoxy-2-hydroxy-4-oxo-heneicosa-12,15-diene biosynthesis. An increased in gene expression of genes that participates in the phenylpropanoids route was observed during the stage of physiological fruit maturity, others genes such as Flavonol synthase (Fls), increased only in samples obtained from fruit treated with chitosan at consumption maturity. Our results reveal a new molecular mechanism where chitosan induces a specific accumulation of phenylpropanoids and antifungal diene; this partially explains avocado's resistance against fungal pathogens. Finally, we discuss the molecular connections between chitosan induction and gene expression to explain the biological events that orchestrate the resistance pathways in fruits.

Scarless Genomic Point Mutation to Construct a Bacillus subtilis Strain Displaying Increased Antibiotic Plipastatin Production.

Bacillus strains produce various types of antibiotics, and random mutagenesis has traditionally been used to overproduce these natural metabolites. However, this method leads to the accumulation of unwanted mutations in the genome. Here, we rationally designed a single nucleotide substitution in the degU gene to generate a B. subtilis strain displaying increased plipastatin production in a foreign DNA-free manner. The mutant strain (BS1028u) showed improved antifungal activity against Pythium ultimum. Notably, pps operon deletion in BS1028u resulted in complete loss of antifungal activity, suggesting that the antifungal activity strongly depends on the expression of the pps operon. Quantitative real-time PCR and lacZ assays showed that the point mutation resulted in 2-fold increased pps operon expression, which caused the increase in antifungal activity. Likewise, commercial Bacillus strains can be improved to display higher antifungal activity by rationally designed simple modifications of their genome, rendering them more efficient biocontrol agents.

Increase in antifungal activity by the combination of tolaasin and its analogue peptides

Increase in antifungal activity by the combination of tolaasin and its analogue peptides

Control of Aspergillus flavus growth and aflatoxin production in transgenic maize kernels expressing a tachyplesin-derived synthetic peptide, AGM182

Aspergillus flavus is an opportunistic, saprophytic fungus that infects maize and other fatty acid-rich food and feed crops and produces toxic and carcinogenic secondary metabolites known as aflatoxins. Contamination of maize with aflatoxin poses a serious threat to human health in addition to reducing the crop value leading to a substantial economic loss. Here we report designing a tachyplesin1-derived synthetic peptide AGM182 and testing its antifungal activity both in vitro and in planta. In vitro studies showed a five-fold increase in antifungal activity of AGM182 (vs. tachyplesin1) against A. flavus. Transgenic maize plants expressing AGM182 under maize Ubiquitin-1 promoter were produced through Agrobacterium-mediated transformation. PCR products confirmed integration of the AGM182 gene, while RT-PCR of maize RNA confirmed the presence of AGM182 transcripts. Maize kernel screening assay using a highly aflatoxigenic A. flavus strain (AF70) showed up to 72% reduction in fungal growth in the transgenic AGM182 seeds compared to isogenic negative control seeds. Reduced fungal growth in the AGM182 transgenic seeds resulted in a significant reduction in aflatoxin levels (76–98%). The results presented here show the power of computational and synthetic biology to rationally design and synthesize an antimicrobial peptide against A. flavus that is effective in reducing fungal growth and aflatoxin contamination in an economically important food and feed crop such as maize.

Sub-lethal doses of widespread nanoparticles promote antifungal activity in Pseudomonas protegens CHA0

Nanoparticles are widely used as antimicrobial compounds. At sub-lethal concentrations, they may also stress microbes, potentially inducing antibiosis. Here we assess whether nanoparticles can serve as an enhancer of antibiosis in beneficial microbes. Several host-associated bacteria can suppress pathogens, providing therefore a first line of defense against diseases. In the present study, we assessed whether nanoparticles stimulate the antifungal activity of Pseudomonas protegens CHA0, a model plant-associated bacterium, against the ascomycete yeast Candida albicans. We synthesized and characterized four of the most common nanoparticles, namely Ag, SiO2, TiO2, and ZnO, with an average size of 25, 11, 25 and 35 nm, respectively. The dose-dependent effect of these nanoparticles on the growth of Pseudomonas protegens CHA0 was assessed. Ag, SiO2, TiO2, and ZnO nanoparticles inhibited the growth of Pseudomonas protegens by 100, 22, 15 and 15%, respectively at a concentration of 250 μg/mL. We then selected sub-lethal dose (500 ng/mL) and assessed whether the same nanoparticles stimulated the production of antifungal compounds inhibiting C. albicans. Incubating the bacteria in the presence of nanoparticles led to a four-fold increase in antifungal activity. We finally show that nanoparticles induce the expression of the prn operon, responsible for the production of antifungal compound pyrrolnitrin, within hours after nanoparticle exposure. This study shows that nanoparticle application may be a valuable tool to stimulate the antifungal activity of fluorescent pseudomonads, potentially assisting the development of future sustainable disease control strategies.

Synthesis, characterization and antifungal activity of coumarin-functionalized chitosan derivatives

Four novel coumarin-functionalized chitosan derivatives 4a–4d were synthesized via condensation reactions of thiosemicarbazide chitosan with coumarin derivatives. Their structures were confirmed by FT-IR, 13C NMR, XRD and elemental analysis. Their antifungal activities against three kinds of phytopathogens, Alternaria solani sorauer (A. solani), Fusarium oxysporum f.sp. vasinfectum (F. oxysporum) and Fusarium moniliforme (F. moniliforme), were tested using the mycelial growth rate in vitro at 0.1, 0.5, and 1.0mg/mL. The degree of substitution for 4a–4d ranged from 40 to 60%. At 1mg/mL, 4a inhibited F. moniliforme growth by 58.1%, and had an inhibitory index against F. Moniliforme of 77.2%. Derivative 4a was more effective than unmodified chitosan whose antifungal index was 9.7%. The fungicidal tests showed that the synthesized chitosan derivatives have higher activity against the tested fungi compared to unmodified chitosan. Moreover, the introduction of halogen atoms into the chitosan derivatives causes an increase in antifungal activity.

English

Silver nanoparticles (AgNPs) are nanoforms that express higher antimicrobial potential due to their shape and reduced size. The use of fungi to mediate the synthesis of AgNPs has increased the interest of scientists because of their rapid growth, large-scale cultivation and secretion of non-toxic molecules. The aim of this study was to synthesize AgNPs mediated by Aspergillus oryzae DPUA 1624 and evaluate the antimicrobial activity of these molecules incorporated in cellulose acetate nanomembranes (NanoMAC). The synthesis of AgNPs was confirmed by UV-visible spectroscopy and the characterization was performed by dynamic light scattering, transmission electron microscopy, X-ray diffraction, X-ray dispersive energy and advanced spectroscopy and spectroscopy methods. The synthesis of the membrane was done by electro-spinning and its thickness was analyzed in scanning electron microscope. The AgNPs were added to NanoMAC and the antimicrobial effect was evaluated by agar diffusion method against Staphylococcus aureus, Escherichia coli and Candida albicans. The aqueous extract of A. oryzae mediated the synthesis of AgNPs with rounded and some triangular shapes. The diameter and zeta potential of these particles were 61.15&plusmn;11.45 nm and -28.7 mv, respectively. The NanoMAC with AgNPs showed an increase in antifungal activity of 24.22% when tested against C. albicans. This study demonstrated that A. oryzae is able to mediate AgNP synthesis with anti-yeast action and the impregnation of AgNPs in acetate cellulose nanomembranes resulted in the development of a more efficient antimicrobial nanocomposite. &nbsp; Key words: Silver nanoparticles, Aspergillus oryzae, cellulose nanofibers, anti-yeast.

Optimization of Nutrient and Fermentation Parameters for Antifungal Activity byStreptomyces lavendulaeXjy and Its Biocontrol Efficacies againstFulvia fulvaandBotryosphaeria dothidea

AbstractThis study has been proved that statistical experimental designs offer efficient and feasible approaches for determination of culture medium and fermentation conditions ofStreptomyces lavendulaeXjy. Nutrition and cultural conditions have high influence on the antibiotic production ofS. lavendulaeXjy. Soya bean meal, NaCl and (NH4)2SO4were identified as the best ingredients for high antifungal activity of Xjy based on single variable experiments. Using response surface methodology, the best concentrations of medium ingredients were 1.46% soya bean meal, 2.25% NaCl and 1.26% (NH4)2SO4. The potential components were reduced from seven to three, and the antibiotic activity was increased by 10%. The optimized conditions for Xjy in a 250‐ml Erlenmeyer flask were initialpH5, medium volume 25 ml/250 ml and inoculation volume 10% at 30°C with 200 rpm by response surface methodology. Validation experiments carried out to check the accuracy of the models indicated that the predicted values agreed with the experimental values. The extension of necrosis lesion ofBotryosphaeria dothideawas impeded by the application of Xjy in apple fruit. In tomato plants, Xjy showed the 43.7–51.7% curative and protective effects againstFulvia fulva. The optimal medium not only gave a 20% increase in antifungal activity, but it provided a simpler formulation. The results will set a basis for further study on large‐scale fermentation volumes usingS. lavendulaeXjy and be useful for the development of more advanced control strategies on plant diseases.

Engineered biosynthesis of pimaricin derivatives with improved antifungal activity and reduced cytotoxicity.

Pimaricin is an important antifungal antibiotic for antifungal therapy and prevention of mould contamination in the food industry. In this study, three new pimaricin derivatives, 12-decarboxy-12-methyl pimaricin (1), 4,5-desepoxy-12-decarboxy-12-methyl pimaricin (2), and 2-hydro-3-hydroxy-4,5-desepoxy-12-decarboxy-12-methyl pimaricin (3), were generated through the inactivation of P450 monooxygenase gene scnG in Streptomyces chattanoogensis L10. Compared with pimaricin, 1 displayed a twofold increase in antifungal activity against Candida albicans ATCC 14053 and a 4.5-fold decrease in cytotoxicity with erythrocytes, and 2 had comparable antifungal activity and reduced cytotoxicity, whereas 3 showed nearly no antifungal and hemolytic activities. Genetic and biochemical analyses proved that 1 is converted from 2 by P450 monooxygenase ScnD. Therefore, the overexpression of scnD in scnG-null strain eliminated the accumulation of 2 and improved the yield of 1 by 20 %. Conversely, scnG/scnD double mutation abolished the production of 1 and improved the yield of 2 to 2.3-fold. These results indicate that the pimaricin derivatives with improved pharmacological properties obtained by genetic engineering can be further developed into antifungal agents for potential clinical application.

Evaluation of in vitro cytotoxic activity of mono-PEGylated StAP3 (Solanum tuberosum aspartic protease 3) forms

StAP3 is a plant aspartic protease with cytotoxic activity toward a broad spectrum of pathogens, including potato and human pathogen microorganisms, and cancer cells, but not against human T cells, human red blood cells or plant cells. For this reason, StAP3 could be a promising and potential drug candidate for future therapies. In this work, the improvement of the performance of StAP3 was achieved by means of a modification with PEG. The separation of a mono-PEGylated StAP3 fraction was easily performed by gel filtration chromatography. The mono-PEGylated StAP3 fraction was studied in terms of in vitro antimicrobial activity, exhibiting higher antimicrobial activity against Fusarium solani spores and Bacillus cereus, but slightly lower activity against Escherichia coli than native protein. Such increase in antifungal activity has not been reported previously for a PEGylated plant protein. In addition, PEGylation did not affect the selective cytotoxicity of StAP3, since no hemolytic activity was observed.