Potential Anti-infective Agents Research Articles

Anticipating Viral Challenges: A Perspective on Phytochemicals Against Existing and Emerging Viruses

Abstract: Viral infections impact millions of individuals annually and in 2018, the WHO called for global preparedness to address potential high-mortality pathogens, referred to as "Pathogen X," which can include fungi, viruses, parasites, or prions. The constant evolution of RNA viruses leads to continually changing variants, challenging the effectiveness of vac-cines and drugs. In underserved healthcare regions, plant-based phytochemicals offer prom-ise in combating viral diseases due to their ready availability, proven effectiveness, and low toxicity. Amidst the evolving virus variants and recurring fatal outbreaks, especially in re-source-constrained regions, phytochemicals hold promise as potential anti-infective agents. This review delves into plant-based antivirals, aiming to update plant-derived antiviral com-pounds' status against existing and emerging viruses from 2019 to 2023. The study aimed to identify active components from medicinal plants with IC50 and EC50 values against human-infecting viruses. It utilized in vitro and in vivo methods to predict phytochemical mechanisms and enhance bioavailability. Among the phytochemicals studied as antivirals, Emodin, Quercetin, Myricetin, Resveratrol, and Silymarin demonstrated efficacy against multiple viruses. Notably, certain plant compounds were effective against multiple viruses and could serve as potential antiviral treatments. Overall, the review illustrates that harness-ing plant-derived compounds shows promise in combating current and evolving infectious threats.

New thiazolyl-isoxazole derivatives as potential anti-infective agents: design, synthesis, in vitro and in silico antimicrobial efficacy

Antimicrobial resistance threatens the efficacious prevention and treatment of infectious diseases caused by microorganisms. To combat microbial infections, the need for new drug candidates is essential. In this context, the design, synthesis, antimicrobial screening, and in silico study of a new series of 5-aryl-3-(2-arylthiazol-4-yl)isoxazole (9a-t) have been reported. The structure of new compounds was confirmed by spectrometric methods. Compounds 9a-t were evaluated for in vitro antitubercular and antimicrobial activity. Against M. tuberculosis H37Rv, fourteen compounds showed good to excellent antitubercular activity with MIC 2.01–9.80 µM. Compounds 9a, 9b, and 9r showed four-fold more activity than the reference drug isoniazid. Nine compounds, 9a, 9b, 9d, 9e, 9i, 9q, 9r, 9s, and 9t, showed good antibacterial activity against E. coli with MIC 7.8–15.62 µg/mL. Against A. niger, four compounds showed good activity with MIC 31.25 µg/mL. Against C. albicans, all twenty compounds reported excellent to good activity with MIC 7.8–31.25 µg/mL. Compounds 9c–e, 9g–j, and 9q–t showed comparable activity concerning the reference drug fluconazole. The compounds 9a-t were screened for cytotoxicity against 3t3l1 cell lines and found to be less or non-cytotoxic. The in silico study exposed that these compounds displayed high affinity towards the M. tuberculosis targets PanK, DprE1, DHFR, PknA, KasA, and Pks13, and C. albicans targets NMT, CYP51, and CS. The compound 9r was evaluated for structural dynamics and molecular dynamics simulations. The potent antitubercular and antimicrobial activity of 5-aryl-3-(2-arylthiazol-4-yl)isoxazole (9a–t) derivatives has recommended that these compounds could assist in treating microbial infections. Communicated by Ramaswamy H. Sarma

Antifungal efficacy of scorpion derived peptide K1K8 against Candida albicans in vitro and in vivo

As an alternative class of antimicrobial agents, antimicrobial peptides (AMPs) have gained significant attention. In this study, K1K8, a scorpion AMP derivative, showed effective activity against Candida albicans including clinically resistant strains. K1K8 killed C. albicans cells mainly by damaging the cell membrane and inducing necrosis via an ROS-related pathway. K1K8 could also interact with DNA after damaging the nuclear envelope. Moreover, K1K8 inhibited hyphal development and biofilm formation of C. albicans in a dose-dependent manner. In the mouse skin infection model, K1K8 significantly decreased the counts of C. albicans cells in the infection area. Overall, K1K8 is a potential anti-infective agent against skin infections caused by C. albicans.

Spotlight on 4-substituted quinolines as potential anti-infective agents: Journey beyond chloroquine.

Continued emerging resistance of pathogens against the clinically approved candidates and their associated limitations continuously demandnewer agents having better potency with a more suited safety profile. Quinoline nuclei containing scaffolds ofnatural and synthetic origin have been documented for diverse types of pharmacological activities, and a number of drugs are clinically approved. In the present review, we unprecedentedly covered the biological potential of 4-substituted quinoline and elaborated a rationale for its special privilege to afford the significant number of approved clinical drugs, particularly against infectious pathogens. Compounds with 4-substituted quinoline are well documented for antimalarial activity, but in the last two decades, they have been extensively explored for activity against cancer, tuberculosis, and several other pathogens including viruses, bacteria, fungi, and other infectious pathogens. In the present study, the anti-infective spectrum of this scaffold is discussed against viruses, mycobacteria, malarial parasites, and fungal and bacterial strains, along with recent updates in this area, with special emphasis on the structure-activity relationship.

Underexplored bacteria as reservoirs of novel antimicrobial lipopeptides.

Natural products derived from microorganisms play a prominent role in drug discovery as potential anti-infective agents. Over the past few decades, lipopeptides produced by particularly Bacillus, Pseudomonas, Streptomyces, Paenibacillus, and cyanobacteria species, have been extensively studied for their antimicrobial potential. Subsequently, daptomycin and polymyxin B were approved by the Food and Drug Administration as lipopeptide antibiotics. Recent studies have however, indicated that Serratia, Brevibacillus, and Burkholderia, as well as predatory bacteria such as Myxococcus, Lysobacter, and Cystobacter, hold promise as relatively underexplored sources of novel classes of lipopeptides. This review will thus highlight the structures and the newly discovered scaffolds of lipopeptide families produced by these bacterial genera, with potential antimicrobial activities. Additionally, insight into the mode of action and biosynthesis of these lipopeptides will be provided and the application of a genome mining approach, to ascertain the biosynthetic gene cluster potential of these bacterial genera (genomes available on the National Center for Biotechnology Information) for their future pharmaceutical exploitation, will be discussed.

Investigating the Antituberculosis Activity of Selected Commercial Essential Oils and Identification of Active Constituents Using a Biochemometrics Approach and In Silico Modeling.

Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis which has become prevalent due to the emergence of resistant M. tuberculosis strains. The use of essential oils (EOs) as potential anti-infective agents to treat microbial infections, including TB, offers promise due to their long historical use and low adverse effects. The current study aimed to investigate the in vitro anti-TB activity of 85 commercial EOs, and identify compounds responsible for the activity, using a biochemometrics approach. A microdilution assay was used to determine the antimycobacterial activity of the EOs towards some non-pathogenic Mycobacterium strains. In parallel, an Alamar blue assay was used to investigate antimycobacterial activity towards the pathogenic M. tuberculosis strain. Chemical profiling of the EOs was performed using gas chromatography-mass spectrometry (GC-MS) analysis. Biochemometrics filtered out putative biomarkers using orthogonal projections to latent structures discriminant analysis (OPLS-DA). In silico modeling was performed to identify potential therapeutic targets of the active biomarkers. Broad-spectrum antimycobacterial activity was observed for Cinnamomum zeylanicum (bark) (MICs = 1.00, 0.50, 0.25 and 0.008 mg/mL) and Levisticum officinale (MICs = 0.50, 0.5, 0.5 and 0.004 mg/mL) towards M. smegmatis, M. fortuitum, M. gordonae and M. tuberculosis, respectively. Biochemometrics predicted cinnamaldehyde, thymol and eugenol as putative biomarkers. Molecular docking demonstrated that cinnamaldehyde could serve as a scaffold for developing a novel class of antimicrobial compounds by targeting FtsZ and PknB from M. tuberculosis.

Detection of Sortase A and Identification of Its Inhibitors by Paramagnetic Nanoparticle-Assisted Nuclear Relaxation.

Sortase A is a virulence factor responsible for the attachment of surface proteins to Staphylococcus aureus and other Gram-positive bacteria. Inhibitors of this enzyme are potential anti-infective agents. Herein, a new highly selective magnetic relaxation-based method for screening potential sortase A inhibitors is described. A 13-amino acid-long peptide substrate of sortase A is conjugated to SiO2-EDTA-Gd NPs. In the presence of sortase A, the LPXTG motif on the peptide strand is cleaved resulting in a shortened peptide as well as a reduced water T2 value whose magnitude is dependent on the concentration of sortase A. The detection limit is determined to be 76 pM. In contrast, the presence of sortase A inhibitors causes the T2 to remain at a higher value. The proposed method is used to characterize inhibition of sortase A by curcumin and 4-(hydroxymercuri)benzoic acid with an IC50 value of 12.9 ± 1.6 μM and 130 ± 1.76 μM, respectively. Furthermore, this method was successfully applied to detect sortase A activity in bacterial suspensions. The feasibility to screen different inhibitors in Escherichia coli and S. aureus suspensions was demonstrated. This method is fast and potentially useful to rapidly screen possible inhibitors of sortase A in bacterial suspensions, thereby aiding in the development of antibacterial agents targeting Gram-positive bacteria.

Natural and Synthetic Naphthoquinones as Potential Anti-Infective Agents.

Naphthoquinones are a class of aromatic compounds relevant for their chemical characteristics, structural properties, and biological activity. These compounds are found in nature with a wide range of effects, highlighting their antibacterial, antifungal, and antiprotozoal properties. Additionally, naphthoquinones are used as a scaffold to obtain new derivatives with pharmacological potential, mainly compounds against parasitic diseases. The purpose of this work was to carry out a comprehensive review of naphthoquinones and their derivatives obtained from both natural and synthetic sources, also, to analyze their biological activity against Leishmania spp. (Leishmaniasis), Trypanosoma cruzi (Chagas disease), Plasmodium falciparum (Malaria), Toxoplasma gondii (Toxoplasmosis), and Toxocara canis (Toxocariasis). All of these agents are responsible for relevant diseases worldwide. Natural naphthoquinones, such as plumbagin, diospyrin, burmanin, lapachol, lawsone and psychorubrin, show an antiprotozoal activity similar or enhanced antiprotozoal activity to reference drugs. Some naphthoquinones obtained by synthesis or semi-synthesis showed better biological activity or less toxic effects than natural compounds. In this review, natural and synthetic naphthoquinones showed antiparasitic activity, in most cases, with improved results than current drugs currently used in clinical trials. A modification of their structure with different functional groups can enhance their biological effects, improve solubility, and reduce undesirable side effects. Therefore, naphthoquinones are important molecules in the development of new chemotherapeutic agents against parasitic diseases.

Antibacterial Properties of Small-Size Peptide Derived from Penetratin against Oral Streptococci.

Periodontitis, an infectious disease originating from dental biofilms that causes the irreversible loss of alveolar bone, is accompanied by gradual biofilm formation and the continuous progression of inflammation. A small peptide derived from penetratin, Arg-Gln-Ile-Arg-Arg-Trp-Trp-Gln-Arg-NH2 (RR9), appears to have antibacterial properties against selected strains associated with periodontitis. The purpose of this research is to assess the antibacterial activity and mechanism of RR9 against the initial oral colonizers Streptococci oralis, Streptococci gordonii, and Streptococci sanguinis and to investigate the cytotoxicity of RR9 on human gingival fibroblasts in vitro. The effects of RR9 on the initial oral settlers of planktonic and biofilm states were evaluated by measuring the MIC, MBC, bactericidal kinetics, and antibiofilm activity. Visual evidence and antibacterial mechanisms were identified, and the anti-inflammatory activity and cytotoxicity were measured. The results demonstrated that RR9 can inhibit the growth of streptococci in the planktonic state and during biofilm formation in vitro while keeping a low toxicity against eukaryotic cells. The antibacterial mechanism was proven to be related to the lower expression of sspA in streptococci. RR9 may be used as a potential antimicrobial and anti-infective agent for periodontal disease.

2-Aryl-3-(6-trifluoromethoxy)benzo[d]thiazole-based thiazolidinone hybrids as potential anti-infective agents: Synthesis, biological evaluation and molecular docking studies

The search for new antimicrobial agents is greater than ever due to the perpetual threat of multidrug resistance in known pathogens and the relentless emergence of new infections. In this manuscript, ten thiazole-based thiazolidinone hybrids bearing a 6-trifluoromethoxy substituent on the benzothiazole core were synthesized and evaluated against a panel of four bacterial strains Salmonella typhimurium, Staphylococcus aureus, Escherichia coli and Listeria monocytogenes and three resistant strains Pseudomonas aeruginosa, E. coli and MRSA. The evaluation of minimum bactericidal and minimum inhibitory concentrations was accomplished by microdilution assay. As reference compounds ampicillin and streptomycin were employed. All compounds displayed antibacterial efficiencies with MBCs/MICs at 0.25–1 mg/mL and 0.12–1 mg/mL respectively while ampicillin displayed MBCs/MICs at 0.15–0.3 mg/mL and at 0.1–0.2 mg/mL respectively. MICs/MBC of streptomycin varied from 0.05 to 0.15 mg/mL and from 0.1 to 0.3 mg/mL respectively. The best overall effect was observed for compound h4, while compound h1 exhibited the highest effective action against E. coli (MIC/MBC 0.12/0.25 mg/ml) among all tested compounds.

Synthesis, Biological Evaluation and Molecular Docking Studies of Novel 1,8-Naphthyridine-3-carboxylic Acid Derivatives as Potential Antimicrobial Agents (Part-1)

Synthesis and investigation of antimicrobial activity of 6 novel 1,8-naphthyridine-3-carboxylic acid derivatives are presented. Among the derivatives, compounds 4a–5b2 showed a broad-spectrum antimicrobial activity against all reference Gram-positive, Gram-negative bacteria and fungi. These compounds exhibited remarkable bactericidal activity against Staphylococcus and Bacillus sps. The tested substances 4a–5b2 were found also found to be active against E. coli, Salmonella and Shigella sps. The chlorine substituted compounds 4a and 5a2 were found to be the most active towards the tested microorganisms. Compounds 4a–5b2 were found to be fungicidal against Candida sp. with a MIC values in the range of 400-2000 μg/ml. Docking studies of these compounds with Salmonella typhi OmpF complexed with ciprofloxacin using PDB- 4KRA revealed that the compounds acted as covalent crosslinker on the DNA gyrase B of the former and intercalate the latter both with higher C score values. Thus, the antibacterial activity against tested strains suggested 1,8-naphthyridine-3-carboxylic acid derivatives warrant further evaluation as potential novel antiinfective agents. The antifungal activity of thse compounds was comparable to that of griseofulvin. The drug-likeness data of synthesized compounds made them promising leads for the future development as antifungal agents.

Curcumin Encapsulated PEGylated Nanoliposomes: A Potential Anti-Infective Therapeutic Agent.

Exploration of novel bioactive molecules or potentiation of the existing bioactive molecules is necessary to reduce the burden of the infectious diseases for the better human health. Curcumin is a promising molecule with huge therapeutic potential. Despite high bioactivity, its therapeutic suitability is shadowed by poor bioavailability, limited aqueous solubility, and short shelf life. Nanotechnology has generated new avenues to overcome these challenges. In the current study polymer assisted nanoliposomes, PEGylated Curcumin nanoliposomes with good loading efficiency were prepared. These particles have shown 1000 fold enhanced curcumin hydrophilicity and tenfold higher stability. In vitro release kinetic indicates two fold higher curcumin release in the simulated gastric and intestinal environment. Various bioactivity assays have confirmed enhanced bioactivity of nanocurcmin in comparison of the native curcumin. PEGylated Curcumin nanoliposomes could be employed for treating various diseases.

Antisense peptide nucleic acids as a potential anti-infective agent.

Antibiotics have long been used for anti-infective control of bacterial infections, growth promotion in husbandry, and prophylactic protection against plant pathogens. However, their inappropriate use results in the emergence and spread of multiple drug resistance (MDR) especially among various bacterial populations, which limits further administration of conventional antibiotics. Therefore, the demand for novel anti-infective approaches against MDR diseases becomes increasing in recent years. The peptide nucleic acid (PNA)-based technology has been proposed as one of novel anti-infective and/or therapeutic strategies. By definition, PNA is an artificially synthesized nucleic acid mimic structurally similar to DNA or RNA in nature and linked one another via an unnatural pseudo-peptide backbone, rendering to its stability in diverse host conditions. It can bind DNA or RNA strands complimentarily with high affinity and sequence specificity, which induces the target-specific gene silencing by inhibiting transcription and/or translation. Based on these unique properties, PNA has been widely applied for molecular diagnosis as well as considered as a potential anti-infective agent. In this review, we discuss the general features of PNAs and their application to various bacterial pathogens as new anti-infective or antimicrobial agents.

Synthesis, computational studies, antimycobacterial and antibacterial properties of pyrazinoic acid-isoniazid hybrid conjugates.

Benzotriazole and microwave mediated syntheses led to a new set of hybrid conjugates of pyrazinoic acid with isoniazid via amino acid linkers in excellent yields with retention of chirality. Microbiological screening of the synthesized conjugates revealed an exceptionally high activity against some of the pathogenic bacterial strains at low concentrations. Promising antimycobacterial properties were observed against tuberculous and non-tuberculous mycobacteria. Robust molecular models (2D-QSAR and 3D-pharmacophore) support the observed biological properties. Safety profile of the synthesized conjugates against human normal cell (RPE1) was evaluated by MTT technique.

A Cyclic Peptide Inhibitor of the iNOS-SPSB Protein-Protein Interaction as a Potential Anti-Infective Agent.

SPRY domain- and SOCS box-containing proteins SPSB1, SPSB2, and SPSB4 interact with inducible nitric oxide synthase (iNOS), causing the iNOS to be polyubiquitinated and targeted for degradation. Inhibition of this interaction increases iNOS levels, and consequently cellular nitric oxide (NO) concentrations, and has been proposed as a potential strategy for killing intracellular pathogens. We previously described two DINNN-containing cyclic peptides (CP1 and CP2) as potent inhibitors of the murine SPSB-iNOS interaction. In this study, we report the crystal structures of human SPSB4 bound to CP1 and CP2 and human SPSB2 bound to CP2. We then used these structures to design a new inhibitor in which an intramolecular hydrogen bond was replaced with a hydrocarbon linkage to form a smaller macrocycle while maintaining the bound geometry of CP2 observed in the crystal structures. This resulting pentapeptide SPSB-iNOS inhibitor (CP3) has a reduced macrocycle ring size, fewer nonbinding residues, and includes additional conformational constraints. CP3 has a greater affinity for SBSB2 ( KD = 7 nM as determined by surface plasmon resonance) and strongly inhibits the SPSB2-iNOS interaction in macrophage cell lysates. We have also determined the crystal structure of CP3 in complex with human SPSB2, which reveals the structural basis for the increased potency of CP3 and validates the original design.

Aspergillus ochraceopetaliformis SSP13 modulates quorum sensing regulated virulence and biofilm formation in Pseudomonas aeruginosa PAO1

Pseudomonas aeruginosa is an opportunistic nosocomial pathogen causing the majority of acute and persistent infections in human beings. The ability to form biofilm adds a new dimension to its resistance to conventional therapeutic agents. In the present study, down-regulation of quorum sensing regulated virulence and biofilm development resulting from exposure to Aspergillus ochraceopetaliformis SSP13 extract was investigated. The in vitro results inferred impairment in the production of LasA protease, LasB elastase, chitinase, pyocyanin, exopolysaccharides and rhamnolipids. In addition, motility and biofilm formation by P. aeruginosa PAO1 was significantly altered. The in vitro results were further supported by molecular docking studies of the metabolites obtained from GC-MS analysis depicting the quorum sensing attenuation by targeting the receptor proteins LasR and RhlR. The in vitro and in silico studies suggested new avenues for the development of bioactive metabolites from A. ochraceopetaliformis SSP13 extract as potential anti-infective agents.

Evaluation of Triazole and Isoxazole Derivatives as Potential Anti-infective Agents.

A series of isoxazole and triazole derivatives, with interesting bioactive scaffolds, were examined for their in vitro antibacterial, antifungal, and antiprotozoal activities. These compounds exhibited antitrypanosomal activity comparable to difluoromethylornithine (DMFO), a drug used in the treatment of human African trypanosomiasis. Isoxazole analogues 1, 3 and 4, and triazole derivatives 16, 17, 28, 37, 40 and 42 showed the highest antitrypanosomal activity with IC50 values of 17.89, 1.82, 10.38, 10.26, 11.77, 9.29, 3.93, 2.11, and 0.93 μM, respectively. Compounds 40 and 42 showed the most potent activity against Leishmania donovani amastigotes with IC50 values of 18.28 and 10.54 μM, respectively. Compound 42 showed the most potent activity against Leishmania donovani macrophage internalized amastigotes with an IC50 value of 8.32 μM. Conjugate triazoles 40-43 displayed potential antimalarial activity against chloroquine-resistant W2 and chloroquine sensitive D6 Plasmodium falciparum strains (IC50 value range from 0.58 to 8.36 μM). Compound 37 showed antibacterial activity against Staphylococcus aureus, MRSA and Mycobacterium intracellulare with IC50 values of 15.53, 14.22 and 47.45 μM, respectively. None of the compounds exhibited antifungal activity.

Antimicrobial inhibitory activity of aqueous, hydroalcoholic and alcoholic extracts of leaves and stem of Daphne mucronata on growth of oral bacteria.

Background: Plants are a source of potential anti-infective agents. Daphne mucronata is a shrub in the family Thymelaeaceae, which has therapeutic effects. The aim of the present study was to evaluate the antimicrobial activity of aqueous, hydroalcoholic and alcoholic extracts of the leaves and stem of Daphne mucronata on the growth of oral bacteria. Materials and methods: Leaves and stem of Daphne mucronata were collected from the Zagros Mountains, Lorestan, Iran. They were air dried in the shade. Aqueous, hydroalcoholic and alcoholic extracts of Daphne mucronata were made by using classic techniques for solvent extraction of plant material. The antimicrobial effects of the Daphne mucronata extracts were evaluated using the agar disk diffusion method (ADDM) and the minimum inhibitory concentration (MIC). The data were analyzed using Duncan's test and ANOVA. Results: The results showed that the antimicrobial activity depended on the type of extract. The alcoholic extract of Daphne mucronata had the highest antibacterial activity and the highest effect on Streptococcus mutans. The aqueous extract of the plant had no effect on bacterial growth. Conclusion: On the basis of the current results, the alcoholic extract of Daphne mucronata might be promising as a natural antimicrobial agent and as a medicine for the prevention and control of the growth of Streptococcus mutans.

Fruit Fly Maggots as Alternative Feed to Improve Siamese Fighting Fish (Betta splendens) Fecundity, Eggs Hatchability and Fry Survivability

Siamese fighting fish or bettas are highly favoured for their aesthetical value and kept as ornamental fish. They are widely bred to satisfy the market demands. However, large-scale production of bettas is hampered by the relatively high rate of mortality compared to the number of eggs laid. The nutrition intake literally influences the reproductive performance and eggs quality. Therefore, it is plausible to improve the survivability of betta fry through dietary manipulation. Bettas can be fed with a variety of feeds. Bloodworms and commercially available pellets are commonly used. Fruit fly maggots emerged as potential anti-infective agents and have been used as alternative fish feed. Therefore, this study aims to harness the beneficial properties of maggots to enhance reproductive performance and increase the survivability of the bettas. The effects on fecundity, eggs hatchability and fry survivability of maggot feed were compared with the other common feed, namely bloodworms and commercial pellet. The results showed that maggots can serve as an alternative feed for bettas whereby it gave an average hatchability rate of 65% and survivability rate of 69%. Although the mean hatchability and survivability rate did not differ significantly from the other two feeds, this study suggests the attainable yet economic feeding material, has the potential to inaugurate further studies to enhance the production of bettas on large scale.

Effective antimicrobial activity of a peptide mutant Cbf-14-2 against penicillin-resistant bacteria based on its unnatural amino acids

Broad spectrum activities, a unique mode of actions and rare resistant variants make antimicrobial peptide (AMP) a potential alternative to antibiotics. However, AMPs still have limitations in clinical development due to their physiological stability, toxicity and manufacturing costs. Cbf-14, derived from cathelicidin-BF has been proven to be effective against drug-resistant bacteria. Herein, a series of Cbf-14 mutants were designed to overcome these limitations. Design strategies included substitutions of lysine (Lys) or leucine (Leu) with similar residues such as ornithine (Orn) and norleucine (Ile), which are unnatural amino acids, to generate AMPs with enhanced therapeutic potential. Antimicrobial activity, hemolytic activity and cytotoxicity against mouse spleen cells of the peptide mutants were investigated. Among all of the mutants, Cbf-14-2 was regarded as the most potent candidate with the amino acid sequence of RLLR-Orn-FFR-Orn-LKKSV-NH2, which exhibited a superior antimicrobial activity with a minimum inhibitory concentration (MIC) of 4–32μg/ml. Meanwhile, Cbf-14-2 displayed low levels of hemolysis in sheep red blood cells (sRBCs) and negligible cytotoxicity against mouse spleen cells, suggesting low toxicity against mammalian cells. A circular dichroism (CD) study indicated that Cbf-14-2 has a higher alpha-helix content than Cbf-14 (68.3% vs 35.1%) in SDS, which may contribute to its superior activity. Time-killing curves showed Cbf-14-2 can eliminate all tested bacteria within 240min, suggesting its rapid bactericidal effect. Transmission electron microscopy (TEM), flow cytometry and calcein release assays revealed its excellent antimicrobial potency by inducing membrane permeation and disruption. In addition, Cbf-14-2 (10mg/kg) could significantly elevate the survival rate of clinical strain infected mice, with a survival rate of 70.0%. Taken together, the data suggest that Cbf-14-2 possesses effective antimicrobial activity against penicillin-resistant bacteria in vitro and in vitro, thus rendering it as a potential anti-infective agent in clinical settings.