Antibacterial Compounds Research Articles

Insights into the Versatility of Using Atomic Absorption Spectrometry in Antibacterial Research.

The ongoing development of bacterial resistance to antibiotics is a global challenge. Research in that field is thus necessary. Analytical techniques are required for such a purpose. From this perspective, the focus was on atomic absorption spectrometry (AAS). Although it is old, AAS often offers unexpected potential. Of course, this should be exploited. The aim was therefore to demonstrate the versatility of the technique in antibacterial research. This is illustrated by various examples of its practical application. AAS can be used, for example, to confirm the identity of antibacterial compounds, for purity controls, or to quantify the antibiotics in pharmaceutical preparations. The latter allowed analysis without laborious sample preparation and without interference from other excipients. In addition, AAS can help elucidate the mode of action or resistance mechanisms. In this context, quantifying the accumulation of the antibiotic drug in the cell of (resistant) bacteria appears to play an important role. The general application of AAS is not limited to metal-containing drugs, but also enables the determination of some organic chemical antibiotics. Altogether, this perspective presents a range of applications for AAS in antibacterial research, intending to raise awareness of the method and may thus contribute to the fight against resistance.

Antimicrobial and Ecological Potential of Chlorellaceae and Scenedesmaceae with a Focus on Wastewater Treatment and Industry

A complex evaluation of antimicrobial activities of microalgae, including those relevant to wastewater treatment (WWT), in light of the integrated biorefinery concept, is performed. An example of this concept is linking a commercial microalgal system to plants, factories, or farms that emit polluted wastewater (WW). The microalgae would not only metabolize the pollutants—such as nitrogen (N) and phosphorus (P)—from the WW, thus fueling their biomass, but they would exert an antibacterial effect against the pathogenic bacteria there. The biomass then could be harvested and used for biofertilizers, biofuels, and bioplastics and might possibly be utilized as animal feed, antimicrobial and other pharmaceutical agents. A large amount of the research on the antimicrobial activity and WWT potential focuses on the families Chlorellaceae and Scenedesmaceae, which are also some of the most commercially used strains of microalgae. For that reason, they are the species chosen for the current review. Furthermore, the increasing antimicrobial resistance necessitates the search for antibiotic alternatives, and the antibacterial and antifungal activity of Chlorellaceae and Scenedesmaceae is very promising. Microalgae are rich in antibacterial compounds like polyunsaturated fatty acids (PUFAs), polysaccharides, carotenoids, proteins, etc., and for that reason, their extracts possess antimicrobial effects. The in vitro antimicrobial activity of Chlorellaceae and Scenedesmaceae families has varied in a broad range from low to strong activity or no effect. Several strains have fulfilled the criteria for outstanding and high activity, especially C. vulgaris and other Chlorellaceae spp., with an effect equal to or better than the control antibiotics. There were several strains with minimum inhibitory concentrations (MIC) below 80 µg/mL and even 10 and 1.5 µg/mL; some species also had inhibition zones (IZ) over 30 mm, even as high as 48 mm. In vivo results are also promising but scarce, and all this warrants further in vivo and in situ studies—from animal models to clinical and environmental trials. Altogether, important data in the light of the circle economy, the urgent necessity to decrease CO2 emissions to fight climate change, and to curb the harmful influence of future pandemics are presented. This review paves the way for further utilizing the total potential of a microalgal system.

Uji Daya Hambat Ekstrak Lidah Buaya (Aloe barbadensis miller) terhadap Pertumbuhan Bakteri Propionibacterium Acnes

Aloe vera (Aloe barbadensis miller) contains antibacterial compounds such as tannins and saponins, which have the potential to combat Propionibacterium acnes, the bacteria responsible for acne. This study aims to evaluate the inhibitory effect of aloe vera extract on P. acnes through a laboratory experimental method. The extract was obtained through maceration using various concentrations: 20%, 40%, 60%, 80%, and 100%. Testing was conducted in triplicate, with clindamycin as the positive control and distilled water as the negative control. The well diffusion method was used for testing, followed by analysis with a One-Way ANOVA test. Results showed p = 0.000, indicating that aloe vera extract significantly inhibits P. acnes. Post hoc LSD analysis revealed significant differences between concentrations, except between clindamycin and the 100% concentration (p > 0.05). The highest mean inhibition zone was found at the 100% concentration (16.6 mm) and the lowest at 20% (9.3 mm). This study suggests that aloe vera extract has potential as a natural antibacterial agent for acne treatment, providing an alternative to reduce synthetic antibiotic use and the risk of bacterial resistance.

Current View on Major Natural Compounds Endowed with Antibacterial and Antiviral Effects.

Nowadays, infectious diseases of bacterial and viral origins represent a serious medical problem worldwide. In fact, the development of antibiotic resistance is responsible for the emergence of bacterial strains that are refractory even to new classes of antibiotics. Furthermore, the recent COVID-19 pandemic suggests that new viruses can emerge and spread all over the world. The increase in infectious diseases depends on multiple factors, including malnutrition, massive migration of population from developing to industrialized areas, and alteration of the human microbiota. Alternative treatments to conventional antibiotics and antiviral drugs have intensively been explored. In this regard, plants and marine organisms represent an immense source of products, such as polyphenols, alkaloids, lanthipeptides, and terpenoids, which possess antibacterial and antiviral activities. Their main mechanisms of action involve modifications of bacterial cell membranes, with the formation of pores, the release of cellular content, and the inhibition of bacterial adherence to host cells, as well as of the efflux pump. Natural antivirals can interfere with viral replication and spreading, protecting the host with the enhanced production of interferon. Of note, these antivirals are not free of side effects, and their administration to humans needs more research in terms of safety. Preclinical research with natural antibacterial and antiviral compounds confirms their effects against bacteria and viruses, but there are still only a few clinical trials. Therefore, their full exploitation and more intensive clinical studies represent the next steps to be pursued in this area of medicine.

The Role of Microorganisms and Their Antibacterial Compounds in Food Biopreservation

The increase in the nutritional awareness of consumers has meant that products with high nutritional value, sensory attractiveness, and safety are currently being sought on the market. One of the aspects in which the innovativeness of a food product can be considered is the preservation method. Fermentation is considered one of the oldest methods. In practice, biopreservation is primarily a method of using non-pathogenic microorganisms and/or their metabolites to increase microbiological safety and extend food shelf life. Advances in microbiology and genetic engineering, taking into account various sources of microbiota isolation, have rediscovered the fermentation process and allowed us to obtain innovative functional products. Recently, bacteriocins have gained importance. For many years, they have been applied as biopreservatives in food manufacturing, alone or in combination with other preservatives. The most promising perspective of food preservation seems to be the development of combined systems including natural preservatives (i.e., bacteriocin and lipopeptides), emerging non-thermal technologies, and other methods such as encapsulation nanotechnology and active packaging. In this paper, a narrative review is presented to analyze the most recently published literature regarding the role of microorganisms and microbial produced antibacterial compounds in food biopreservation. New biopreservation technologies as an alternative to artificial preservatives were also discussed.

Antibacterial activity and mechanism of luteolin isolated from Lophatherum gracile Brongn. against multidrug-resistant Escherichia coli.

Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.

Mechanism of antibacterial phytoconstituents: an updated review.

The increase of multiple drug resistance bacteria significantly diminishes the effectiveness of antibiotic armory and subsequently exaggerates the level of therapeutic failure. Phytoconstituents are exceptional substitutes for resistance-modifying vehicles. The plants appear to be a deep well for the discovery of novel antibacterial compounds. This is owing to the numerous enticing characteristics of plants, they are easily accessible and inexpensive, extracts or chemicals derived from plants typically have significant levels of action against infections, and they rarely cause serious adverse effects. The enormous selection of phytochemicals offers very distinct chemical structures that may provide both novel mechanisms of antimicrobial activity and deliver us with different targets in the interior of the bacterial cell. They can directly affect bacteria or act together with the crucial events of pathogenicity, in this manner decreasing the aptitude of bacteria to create resistance. Abundant phytoconstituents demonstrate various mechanisms of action toward multi drug resistance bacteria. Overall, this comprehensive review will provide insights into the potential of phytoconstituents as alternative treatments for bacterial infections, particularly those caused by multi drug resistance strains. By examining the current state of research in this area, the review will shed light on potential future directions for the development of new antimicrobial therapies.

Formulation and Evaluation of Electrospun Nanofiber Mats of Curcumin and Leaf Extract of Tinospora cordifolia: Designed for Accelerating Diabetic Wound Healing

Traditional herbs like Tinospora cordifolia and curcumin have many therapeutic benefits. However, curcumin’s limited bioavailability is a problem. Electrospun nanofibers are an answer because they increase the effective surface area greatly, and make drug delivery better in almost all aspects. The combination in the form of nanofibers can be greatly useful in the treatment of diabetic wound healing, where curcumin, the known antibacterial and anti-inflammatory element, plays an important role. It is observed that when combined with extract of leaves of T. cordifolia, which has known antidiabetic and wound healing actions, blended in the chitosan polymer, which is itself a weak antibacterial compound hence can be one of the solutions to the menace of bacterial resistance which is very common in diabetic wound healing. This research aims to create and test electrospun nanofiber mats of curcumin and T. cordifolia leaves extract blended in chitosan as a base polymer in the treatment of diabetic wound healing. Leaves of the plant T. cordifolia, which were collected from the institute’s botanical garden, were subjected to drying and then prone to solvent extraction using methanol and acetone, resulting in the production of bioactive extracts. The curcumin was obtained as a gift sample from Sanjay Chemicals, Mumbai. Nanofibers were electrospun from chitosan, T. cordifolia leaf extract and curcumin. Characterization included scanning electron microscope (SEM), water contact angle measurement, TGA/DSC analysis, drug release studies, fourier-transform infrared (FTIR) analysis, swelling tests and in-vitro release profiling. The nanofiber mats of curcumin and leaves extract of T. cordifolia using chitosan as a base polymer were prepared and evaluated at various parameters. The results we found are very promising. The nanofibers formed by using electrospinning techniques show good content uniformity as well as good diameter which was checked using SEM. The study confirmed no component interactions using differential scanning calorimetry (DSC). The good hydrophilicity of mats was found to ensure good retention time. The study concluded with the formation of a novel formulation that can fight the menace of bacterial resistance, which is very common in the diabetic wound healing process. The formulation will ensure not only countering bacterial resistance but also the faster healing of diabetic wounds, as T. cordifolia leaves extract is known to improve angiogenesis and tissue remodeling.

Identification, Synthesis, and In Vitro Activities of Antimicrobial Peptide from African Catfish against the Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli.

The global surge in multi-drug resistant bacteria, including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has led to a growing need for new antibacterial compounds. Despite being promising, the potential of fish-derived antimicrobial peptides (AMPs) in combating ESBL-producing E. coli is largely unexplored. In this study, native African catfish antimicrobial peptides (NACAPs) were extracted from the skin mucus of farmed African catfish, Clarias gariepinus, using a combination of 10% acetic acid solvent hydrolysis, 5 kDa ultrafiltration, and C18 hydrophobic interaction chromatography. Peptides were then sequenced using Orbitrap Fusion Lumos Tribrid Mass Spectrometry. The identified peptides were screened for potential antibacterial activity using Random Forest and AdaBoost machine learning algorithms. The most promising peptide was chemically synthesized and evaluated in vitro for safety on rabbit red blood cells and activity against ESBL-producing E. coli (ATCC 35218) utilizing spot-on-lawn and broth dilution methods. Eight peptides ranging from 13 to 22 amino acids with molecular weights between 968.42 and 2434.11 Da were identified. Peptide NACAP-II was non-hemolytic to rabbit erythrocytes (p > 0.05) with a zone of inhibition (ZOI) of 22.7 ± 0.9 mm and a minimum inhibitory concentration (MIC) of 91.3 ± 1.2 μg/mL. The peptide is thus a candidate antibacterial compound with enormous potential applications in the pharmaceutical industry. However, further studies are still required to establish an upscale production strategy and optimize its activity and safety in vivo.

Phytochemical Screening & Antibacterial Activity of Clitoria ternatea L Extract against Staphylococcus epidermidis Bacteria

Telang flowers contain secondary metabolite compounds that have benefits as antibacterial or antiseptic compounds including flavonoids, tannins, alkaloids and saponins. This research was an experimental research. Telang flower extract was obtained using 70% ethanol solvent by remaceration method then it tested like phytochemical content. Antibacterial activity testing with variaty concentrations media MHA (Mueller Hinton Agar) 15, 30, 45, 60, and 75% against Staphylococcus epidermidis. The positive control was Klindamycin. The obtained data were analyzed by Statistical Package for the Social Sciences (SPSS). The results shown that telang flower extract with concentrations 15, 30, 45, 60 and 75% had an average inhibition zone activity against Staphylococcus epidermidis were respectively 4.45 (15%); 4.63 (30%); 4.35 (45%); 5.47 (65%); and 7.02 mm (75%). The SPSS results show that the p value is <0.05 at the 95% confidence level, which indicates that there is a significant difference in antibacterial activity between butterfly pea flower extracts between concentrations of 15, 30, 45, 60, and 75%. Post hoc tests using LSD showed that there was a difference in antibacterial activity between concentrations of 75% and concentrations of 15, 30, 45, and 60%, but there was no difference in antibacterial activity between concentrations of 15, 30, 45, and 60%.Minimal inhibitor concentration of telang flower extract was obtained at 15%

The Effect of Bay Leaf (Syzygium Polyanthum) Extract Hand Washing Liquid Soap Preparation on The Growth of Escherichia Coli Bacteria in Vitro

Bay leaf (Syzygium polyanthum) is known as a complement to cooking spices, also used by the community for treatment. The content of antibacterial compounds from bay leaves such as alkaloids, flavonoids, saponins and tannins which can inhibit bacterial growth. This study aims to determine the effect of hand washing liquid soap with bay leaf extract on the growth of Escherichia coli bacteria. This study uses a Quasi Experiment research design. The population in this study is located on Jalan Atot Ahmad, West Pontianak District. The sample used was liquid hand washing soap with bay leaf extract at a concentration of 3, 6, and 9%, 9 repetitions with a total of 27 samples, using the disc diffusion method. The results of the antibacterial study showed that the average diameter of the inhibition zone at 3% concentration was 8.27 mm, 6% concentration was 10.55 mm and 9% concentration was 11.16. The results of the Linear Regression test using the Anova test obtained pvalue = 0.000, which is pvalue < α, with α = 0.05, so that it was stated that H1 was accepted so that there was an effect on the preparation of liquid hand washing soap (Syzygium polyanthum) extract on the growth of Escherichia coli bacteria in vitro.

CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY TEST OF HONEY, LEMON, GINGER FERMENTATION AGAINST BACTERIA CAUSING ACUTE RESPIRATORY INFECTIONS (ARI)

Acute respiratory infection (ARI) is a disease that attacks one or more parts of the airway, from the nose to the alveoli. The most common bacteria found in the samples of patients with ARI were Streptococcus pneumonia, Staphylococcus aureus, and Klebisilia pneumonia. Honey contains flavonoids, amino acids and potassium as antibiotics that are bactericidal (kill bacteria) and bacteriostatic (inhibit bacterial growth). Gingerol in ginger (Zingiber officinale) and lemon (Citrus limon) has antibacterial activity. Honey fermentation is believed to have great potential as an antibacterial compound. This study aimed to determine the inhibitory activity and physical characteristics of fermented honey, lemons, and ginger against ARI bacteria. The test bacteria used were Streptococus pneumonia, Stahpylococcus aureus, and Klebsilia pneumonia. Fermentation of honey, lemon, and ginger was performed with variations in fermentation time (days 1, 3, 5, and 7) and honey without fermentation to determine the effect of fermentation time on inhibitory activity. The inhibition activity was tested using the agar diffusion method. Measurement of inhibition diameter using a caliper. Determination of ginger lemon fermented honey characteristics, including water content, sucrose content, and total sugar content, using gravimetric and titrimetric methods. Based on the activity test, honey fermented for 1 day had the greatest inhibitory activity of 9.71 mm; 9.20 mm; and 9.86 mm against Stahpylococcus aureus, Staphylococcus pneumonia, Klebsilia pneumonia compared to honey fermented for 3 days, 5 days, 7 days and honey without fermentation. ...

Triclosan inhibits testosterone biosynthesis in adult rats via inducing m6A methylation-mediated autophagy

Triclosan is a potent antibacterial compound widely used in everyday products. Whether triclosan affects Leydig cell function in adult male rats remains unknown. In this study, 0, 50, 100, or 200 mg/kg/day triclosan was gavaged to Sprague-Dawley male rats from 56 to 63 days postpartum. Triclosan significantly reduced serum testosterone levels at ≥ 50 mg/kg/day via downregulating the expression of Leydig cell gene Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3 and regulatory transcription factor Nr3c2 at 100–200 mg/kg. Further analysis showed that triclosan markedly increased autophagy as shown by increasing LC3II and BECN1 and decreasing SQSTM1. The mRNA m6A modification analysis revealed that triclosan significantly downregulated Fto expression at 200 mg/kg while upregulating Ythdf1 expression at 100 and 200 mg/kg, leading to methylation of Becn1 mRNA as shown by MeRIP assay. Triclosan significantly inhibited testosterone output in rat R2C Leydig cells at ≥ 5 μM via downregulating Fto and upregulating Ythdf1. SiRNA Ythdf1 knockdown can reverse triclosan-mediated mitophagy in R2C cells, thereby reversing the reduction of testosterone output. In summary, triclosan caused Becn1 m6A methylation by downregulating Fto and upregulating Ythdf1, which accelerated Becn1 translation, thus leading to the occurrence of autophagy and the decrease of testosterone biosynthesis.

Triazole-benzenesulfonamide hybrids: Synthesis, biological evaluation, and molecular docking study as non-toxic antimicrobial and antioxidant agents

We have synthesized a library of twenty novel heterocyclic compounds having benzenesulfonamide and triazole moieties in their skeleton. Synthesized target compounds were tested for their inhibition potential against the growth of seven bacterial and one fungal pathogens. Free radical scavenging activities were also determined for the synthesized series of compounds using DPPH method. Furthermore, cytotoxicity studies of the target compounds were performed against mouse fibroblast animal cell lines and plant seed germination cell lines. To identify the binding modes, molecular docking of the most active antibacterial compound 3e and the most active antifungal compound 3g was performed in the active sites of target enzymes. All the tested compounds were found to be good antibacterial (MIC values = 4.9 – 37.8 µM) and antifungal (MIC values = 5.4 – 37.8 µM) agents. Results of antioxidant study showed that all the tested compounds are moderate to excellent free radical scavengers (% RSA values = 75.45 – 95.34). Furthermore, all were found safe against both the tested cell lines during cytotoxicity studies.

Comparative analysis of Nigella sativa L. oil extraction processes: impacts on chemical composition, antioxidant and antimicrobial properties

ABSTRACT This work intended to study differences in oil yield and co-extraction of antioxidant and antibacterial compounds of Nigella sativa L. seed oil as a function of two main extraction processes: mechanical pressing and solvent extraction, including hexane and chloroform. Next, we studied such oils’ chemical composition and antioxidant and antibacterial activities. Notably, the chemical cartelization was conducted by use of HPLC. The antioxidant activity of the oils was assessed using DPPH, TAC, and FRAP assays. Antimicrobial activity was investigated against bacteria and fungi with clinical importanceT. HPLC-DAD analysis identified some bioactive compounds in the oils, including thymoquinone, carvacrol, and gallic acid. Results showed that oils extracted by different methods exhibit varying levels of antioxidant activity, with a higher concentration of antioxidant compounds in chloroform-extracted oils. Antimicrobial tests revealed significant inhibitory effects of the studied oils on the growth of bacteria and fungi. In conclusion, this research has made it possible to characterize the oils extracted from Nigella sativa L. Seeds by determining their chemical composition and biological properties, notably their antioxidant, antibacterial, and antifungal activity. These results contribute to a better understanding of the potential benefits of these oils for human health and open up exciting prospects for their use in various fields, notably as food additives and therapeutic agents.

Effect of gallium nitrate on the antibacterial activity of vancomycin in methicillin-sensitive and resistant Staphylococcus aureus.

The extension of multidrug-resistant strains of Staphylococcus aureus (S. aureus) is one of the main health challenges in the world, which requires serious solutions to deal with it. Combination therapies using conventional antibiotics and new antibacterial compounds that target different bacterial pathways are effective methods against resistant bacterial infections. Gallium is an iron-like metal that competes with iron for uptake into bacteria and has the potential to disrupt iron-dependent vital processes in bacteria. In this study, we explored the antibacterial effects of gallium nitrate (Ga(NO3)3) and vancomycin alone and in combination with each other on methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) using microdilution assay and checkerboard test, respectively. Then, their effect on the formation and destruction of biofilms was investigated. Finally, the amount of ROS production in the presence of these two compounds in bacteria was evaluated. The results indicated that the vancomycin/ Ga(NO3)3 combination reduced the MIC of vancomycin in the MRSA strain and had an additive effect on it. Vancomycin plus Ga(NO3)3 reduced the formation of biofilms and increased the destruction of biofilms formed in both strains, especially in the MRSA strain. ROS production was also higher in the combination of vancomycin with Ga(NO3)3 compared to vancomycin alone, especially in MRSA. Therefore, our results showed that Ga(NO3)3 enhances the antibacterial activity of vancomycin and this combination therapy can be considered as a new strategy for the treatment of MRSA infections.

Initial analysis of profiles from Pseudovibrio denitrificans and Vibrio parahaemolyticus antagonism by LC-MS-based metabolomics

Research on bioprospecting bioactive secondary metabolites from marine bacteria has rapidly expanded in the past few decades. The complexity of the environment in which bacterial communities live involves complex interactions with other communities competing for resources for survival. Previously, the ability of Pseudovibrio denitrificans has been demonstrated to inhibit the growth and virulence of different patho-gens such as Vibrio parahaemolyticus. The antagonism of these bacteria has been studied, considering the latter's importance in producing farmed shrimp. The molecules produced by P. denitrificans may be fun-damental for its antibacterial effect. In the present work, we examine LC/MS profiles of the interaction under two different circumstances: direct and delayed antagonism. The results show marked differences in the chemical composition between both interactions and the tentative identification of antibacterial and antibiofilm compounds. The observed profile could be part of P. denitrificans chemical arsenal to halt V. parahaemolyticus growing. The presented data is relevant to designing future studies on bacterial antago-nism with relevant implications for the aquaculture industry. Keywords: vibriosis, probiotics, chemometrics, white shrimp.

Initial analysis of profiles from Pseudovibrio denitrificans and Vibrio parahaemolyticus antagonism by LC-MS-based metabolomics

Research on bioprospecting bioactive secondary metabolites from marine bacteria has rapidly expanded in the past few decades. The complexity of the environment in which bacterial communities live involves complex interactions with other communities competing for resources for survival. Previously, the ability of Pseudovibrio denitrificans has been demonstrated to inhibit the growth and virulence of different pathogens such as Vibrio parahaemolyticus. The antagonism of these bacteria has been studied, considering the latter's importance in producing farmed shrimp. The molecules produced by P. denitrificans may be fundamental for its antibacterial effect. In the present work, we examine LC/MS profiles of the interaction under two different circumstances: direct and delayed antagonism. The results show marked differences in the chemical composition between both interactions and the tentative identification of antibacterial and antibiofilm compounds. The observed profile could be part of P. denitrificans chemical arsenal to halt V. parahaemolyticus growing. The presented data is relevant to designing future studies on bacterial antagonism with relevant implications for the aquaculture industry. Keywords: vibriosis, probiotics, chemometrics, white shrimp.

Antibacterial Activity of Lactuca virosa with an In silico Approach

The current work aims to screen the phytoconstitutes of the Lactuca virosa leaves ethanolic extract by using GC-MS analysis and investigate its antibacterial activity. GC-MS analysis was conducted to identify the various phytochemical constituents within the ethanolic extracts of Lactuca virosa. Subsequently, protein-ligand docking was performed using proteins PDBID: 6AHT and 5C5H, revealing a strong affinity between the bioactive compounds and the proteins, indicating potent inhibitory action. Furthermore, each concentration of Lactuca virosa was assessed for antibacterial activity using Minimum Inhibitory Concentration (MIC) against bacterial strains including Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Streptococcus mutans. Preliminary phytochemical testing revealed the presence of alkaloids, coumarins, flavonoids, glycosides, phenols, terpenoids, oils, and resins. GC-MS showed the presence of many bioactive compounds in extract. Docking results highlighted that two compounds exhibited the most favourable binding energies of approximately -8.1 kcal/mol and -8.5 kcal/mol with 6AHT, and -8.8 kcal/mol with 5C5H. The ethanolic extract of 0.4mg concentration has shown good antibacterial activity against gram positive bacteria. The study identifies a new source of antibacterial compounds, which could lead to the development of new drugs, particularly effective against gram positive strains like Bacillus cereus and Streptococcus mutans. Keywords: Lactuca virosa, GC-MS, Docking, ADMET, Antibacterial Activity

Identifying Novel Therapeutics for the Resistant Mutant "F533L" in PBP3 of Pseudomonas aeruginosa Using ML Techniques.

Pseudomonas aeruginosa (P. aeruginosa) is a highly infectious and antibiotic-resistant bacterium, which causes acute and chronic nosocomial infections. P. aeruginosa exhibits multidrug resistance due to the emergence of resistant mutants. The bacterium takes advantage of intrinsic and acquired resistance mechanisms to resist almost every antibiotic. To overcome the drug-resistance problem, there is a need to develop effective drugs against antibiotic-resistant mutants. Therefore, in this study, we selected the F533L mutation in PBP3 (penicillin-binding protein 3) because of its important role in β-lactam recognition. To target this mutation, we screened 147 antibacterial compounds from PubChem through a machine-learning model developed based on the decision stump algorithm with 75.75% accuracy and filtered out 55 compounds. Subsequently, out of 55 compounds, 47 compounds were filtered based on their drug-like activity. These 47 compounds were subjected to virtual screening to obtain binding affinity compounds. The binding affinity range of all 47 compounds was -11.3 to -4.6 kcal mol-1. The top 10 compounds were examined according to their binding with the mutation point. A molecular dynamic simulation of the top 8 compounds was conducted to understand the stability of the compounds containing the mutated PBP3. Out of 8 compounds, 3 compounds, namely, macozinone, antibacterial agent 71, and antibacterial agent 123, showed good stability and were validated by RMSD, RMSF, and binding-free analysis. The findings of this study revealed promising antibacterial compounds against the F533L mutant PBP3. Furthermore, developments in these compounds may pave the way for novel therapeutic interventions.