Vibrio Alginolyticus Research Articles

Synthesis and characterization of silver nanoparticles from Cocos nucifera L. male flowers: An investigation into their potent antibacterial and anticancer efficacy

The current research focused on the production of silver nanoparticles using dichloro methane-mediated Cocos nucifera male flower extract and their minimum inhibitory concentration against ten different bacterial pathogens. C. nucifera male flowers were extracted by 100% DCM, and the phytochemicals present in this extract were studied. These plant phytochemicals act as reducing agents to reduce the silver nitrate (AgNO3) to silver nanoparticles (AgNPs) which was confirmed by UV/Vis spectrophotometer, Fourier transform infra-red spectrum, X-ray diffraction analysis, and scanning electron microscopy. The 15 µL of silver nanoparticles was the minimum inhibitory concentration for Klebsiella pneumonia and Bacillus subtilis. The 20 µL of silver nanoparticles is the MIC for Pseudomonas aeruginosa, Vibrio harveyi, and Plesiomonas shigelloides. 30 µL of plant flower extract concentration highly inhibits the E. coli, Staphylococcus aureus, Salmonella paratyphi, Vibrio mimicus, and Vibrio alginolyticus bacterial pathogens. C. nucifera male flowers extract derived silver nanoparticles are highly stable and have high potential activity against MCF-7 Cell line.
 KEY WORDS: Cocos nucifera, Nanoparticles, Phytochemicals, Antimicrobials, Bacterial pathogens, MCF 7 Cell line
 Bull. Chem. Soc. Ethiop. 2024, 38(3), 715-724. 
 DOI: https://dx.doi.org/10.4314/bcse.v38i3.13

LKB1 regulates autophagy through AMPK/TOR signaling pathway to alleviate the damage caused by Vibrio alginolyticus infection

LKB1 (liver kinase B1) is a key upstream kinase of AMPK and plays an important role in various cellular activities. While the function and mechanism of LKB1 have been widely reported in the study of tumor, there are few reports on its role in bacterial infectious diseases, especially in shrimp. In the present study, molecular characterization revealed that LvLKB1 has an open reading frame (ORF) of 1266 bp encoding 421 amino acids with a molecular weight of about 48 KDa, including the kinase region, N-terminal regulatory domain and C-terminal regulatory domain. LvLKB1 in hepatopancreas and hemocytes was significantly upregulated after infection with Vibrio alginolyticus (V. alginolyticus). After silencing LvLKB1 gene in Litopenaeus vannamei (L. vannamei) and artificially infecting V. alginolyticus, the survival rate of L. vannamei was significantly decreased. Subsequently, it was found that the expression of inflammatory factors in hepatopancreas and hemocytes of shrimp was up-regulated, and the expression of lipid oxidation factors was decreased after silencing LKB1, leading to the phenomenon of lipid accumulation in hepatopancreas. In order to explore the mechanism, autophagy levels of shrimp were detected after silencing LKB1, which showed that autophagy levels in hepatopancreas and hemocytes were significantly reduced. Further studies conclusively showed that silencing LvLKB1 inhibited AMPK phosphorylation induced by V. alginolyticus infection, thereby activating TOR pathway and inhibiting autophagy in shrimp. These results indicate that LvLKB1 regulates autophagy through AMPK/TOR signaling pathway to alleviate the damage caused by V. alginolyticus infection.

Transcriptome analysis provides new insights into the immune response of Ruditapes philippinarum infected with Vibrio alginolyticus

Manila clam (Ruditapes philippinarum) is a bivalve species with commercial value, but it is easily infected by pathogenic microorganisms in aquaculture, which restricts the shellfish industry. Notably, the impact of Vibrio alginolyticus on clam culture is obvious. In this study, RNA-seq was performed to analyze clam hepatopancreas tissue in 48 h (challenge group, G48h) and 96 h (challenge group, G96h) after infection with V. alginolyticus and 0 h after injection of PBS (control group, C). The results showed that a total of 1670 differentially expressed genes were detected in the G48h vs C group, and 1427 differentially expressed genes were detected in the G96h vs C group. In addition, KEGG analysis showed that DEGs were significantly enriched in pathways such as Lysosome and Mitophagy. Moreover, 15 immune related DEGs were selected for qRT-PCR analysis to verify the accuracy of RNA-seq, and the results showed that the expression level of DEGs was consistent with that of RNA-seq. Therefore, the results obtained in this study provides a preliminary understanding of the immune defense of R. philippinarum and molecular insights for genetic breeding of V. alginolyticus resistance in Manila clam.

Study of histopathology on Arbacia lixula (Arbaciidae: Arbacioida) and Paracentrotus lividus (Parachinidae: Camarodonta) with bald sea urchin disease symptoms in Gran Canaria Island, Spain

Introduction: Sea urchin diseases have been documented in several locations worldwide, with reported occurrences of bacterial, protozoan, fungal, and algal infections.
 Objective: This study aimed to investigate pathogen agents in populations of Arbacia lixula and Paracentrotus lividus along the coast of Gran Canaria Island (Central-East Atlantic, Spain).
 Methods: Sampling was conducted at San Cristobal beach, on the Northeast side of the island, where sea urchins were manually collected from depths of 1-3 m during June, July, and October 2022. Swab samples were taken from the external and internal areas of the lesions and cultured on various media plates.
 Results: Eight different pathogen agents, including bacteria and fungi, were identified, with Vibrio alginolyticus being the most frequently observed bacteria in all diseased sea urchin samples. Additionally, ciliated protozoans were found within the tests, potentially acting as opportunistic parasites.
 Conclusions: This research provides a unique perspective on bald sea urchin disease by identifying a significant number of associated pathogens, including Candida, previously unreported in diseased organisms. Furthermore, the study highlights the presence of an inflammatory response in tissues with bacterial colonies, offering crucial insights into understanding this sea urchin disease.

Antimicrobial Activity against Antibiotic-resistant Pathogens and Antioxidant Activity and LCMS/MS Phytochemical Content Analysis of Selected Medicinal Plants

Medicinal plants are a major source of numerous therapeutic agents, and the emergence of pathogenic bacteria has rekindled interest in traditional medicine systems as an alternative approach to overcoming resistance. The dried plant material of four medicinal plants, namely Terminalia arjuna (bark), Terminalia bellirica (fruit), Aegle marmelos (leaves), and Bacopa monnieri (leaves), was powdered, and aqueous extracts were prepared. The antimicrobial activity of the extracts was evaluated against three clinically important strains: Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli 385. As E. coli 385 was resistant to the broadest spectrum of antibiotics tested, it was classified as (MDR multi-drug resistant). E. coli, Bacillus subtilis, Mycobacterium smegmatis (MTTC), and Vibrio alginolyticus (ATCC) were also assessed using the agar well diffusion method for zones of inhibition and minimum inhibitory/bactericidal concentration (MIC/MBC). Clinically important strains were found to be sensitive to the aqueous extract of T. bellerica (19.51 ± 0.61 mm) with MICs ranging from 0.31 to 0.62 mg/ml. The MDR strain was also sensitive to Bellirica monnieri (16.10 ± 0.31 mm) aqueous extract. To determine the potential for a wide range of applications, the antioxidant activities of the extracts were evaluated using DPPH, ABTS, and FRAP assays. The T. arjuna plant extract exhibited the highest radical scavenging activity with the lowest EC50 values for DPPH (1.15 ± 0.061 mg/ml) and ABTS (1.02 ± 0.07 mg/ml). The plant extracts were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, and LC-MS/MS.

Machine learning and genetic algorithm-guided directed evolution for the development of antimicrobial peptides

IntroductionAntimicrobial peptides (AMPs) are valuable alternatives to traditional antibiotics, possess a variety of potent biological activities and exhibit immunomodulatory effects that alleviate difficult-to-treat infections. Clarifying the structure-activity relationships of AMPs can direct the synthesis of desirable peptide therapeutics. ObjectivesIn this study, the lipopolysaccharide-binding domain (LBD) was identified through machine learning-guided directed evolution, which acts as a functional domain of the anti-lipopolysaccharide factor family of AMPs identified from Marsupenaeus japonicus. MethodsLBDA-D was identified as an output of this algorithm, in which the original LBDMj sequence was the input, and the three-dimensional solution structure of LBDB was determined using nuclear magnetic resonance. Furthermore, our study involved a comprehensive series of experiments, including morphological studies and in vitro and in vivo antibacterial tests. ResultsThe NMR solution structure showed that LBDB possesses a circular extended structure with a disulfide crosslink at the terminus and two 310-helices and exhibits a broad antimicrobial spectrum. In addition, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that LBDB induced the formation of a cluster of bacteria wrapped in a flexible coating that ruptured and consequently killed the bacteria. Finally, coinjection of LBDB, Vibrio alginolyticus and Staphylococcus aureus in vivo improved the survival of M. japonicus, demonstrating the promising therapeutic role of LBDB for treating infectious disease. ConclusionsThe findings of this study pave the way for the rational drug design of activity-enhanced peptide antibiotics.

Isolation and Identification of Biofilm forming Bacteria from Glass Panels exposed in Sea Waters of South Andaman, India

Marine organisms attach to surfaces that are submerged in seawater in a process known as biofouling. These organisms can colonize on various surfaces such as ship hulls, pillars, jetties, undersea pipelines, oil rigs and buoys. Foulers can include bacteria, algae, barnacles, mussels and other invertebrates. The initial adhesion of fouling bacteria is the first stage of biofouling. The growth and attachment of marine fouling bacteria are influenced by various environmental factors including salinity, temperature and nutrient availability. The bacteria forming marine biofilm were isolated and identified from glass panels. Basic microbiological phenotypic identification methods and genotypic validation using 16s rRNA gene sequencing were used to identify the bacterial strains. The phylogenetic analysis of the 16s rRNA gene sequences confirmed 13 different species (Bacillus aquimaris (2), Vibrio hepatarius (1), Exiguobacterium profundum (3), Exiguobacterium aestuarii (2), Vibrio parahaemolyticus (2), Vibrio alginolyticus (3), Vibrio azureus (2), Vibrio fluvialis (2), Priestia flexa (1), Pseudomonas aeruginosa (2), Bacillus megaterium (2), Lysinibacillus macroides (2) and Bacillus subtilis (1)) of fouling bacteria belonging to six genera.

Anti-vibriosis bioactive molecules from marine-derived variant Streptomyces sp. ZZ741A

The infection of vibrio is an important cause of huge economic losses in aquaculture industry. At present, antibiotics are mainly used to prevent and reduce the infection of the vibrio, which has accelerated the emergence of multi-drug-resistant strains. New generation alternative anti-vibrio drugs were in urgent to solve this problem. In this study, six compounds (1–6) were isolated from the Streptomyces sp. ZZ741A, a marine-derived Streptomyces variant, including one new compound, 2-carbamoylphenyl isobutyrate (1), five known ones, nocardamine (2), dehydroxynocardamine (3), phenylacetic acid (4), thiophenol (5) and 2,3-dihydroxybenzoic acid (6). The anti-vibriosis assay showed that compounds 2 and 3 had specific inhibition activity against Vibrio vulnificus, Vibrio alginolyticus, and Vibrio parahaemolyticus with the MIC values ranging from 8 to 128 μg/mL. The molecular docking study of their possible mechanism of anti-vibriosis activity showed that the activity might come from the inhibition of Outer membrane protein U (OmpU).

Establishment and application of a rapid molecular diagnostic platform for the isothermal visual amplification of group B Streptococcus based on recombinase polymerase.

With growing concerns about Group B streptococcal (GBS) infections and their adverse effects on perinatal pregnancies, including infection, premature delivery, neonatal septicemia, and meningitis, it is urgent to promote GBS screening at all pregnancy stages. The purpose of this study is to establish a device-independent, fast, sensitive, and visual GBS detection method. Taking advantage of the characteristics of the recombinase polymerase isothermal amplification (RPA), the activity of the nfo nuclease cleavage base analog (tetrahydrofuran, THF) site, and the advantages of visual reading of the lateral flow chromatography strip (LFS), a GBS detection method was developed. This method focused on the conservative region of the Christie-Atkins-Munch-Petersen factor encoded by the cfb gene, a virulence gene specific to GBS. Two forward primers, two biotin-labeled reverse primers, and one fluorescein isothiocyanate (FITC)-labeled and C3spacer-blocked probe were designed. The study involved optimizing the primer pair and probe combination, determining the optimal reaction temperature and time, evaluating specificity, analyzing detection limits, and testing the method on 87 vaginal swabs from perinatal pregnant women. The results showed that the visual detection method of GBS-RPA-LFS, using the cfb-F1/R2/P1 primer probe, could detect GBS within 15 min at the temperature ranging from 39°C to 42°C. Furthermore, the method specifically amplified only GBS, without cross-reacting with pathogens like Lactobacillus iners, Lactobacillus crispatus, Candida albicans, Listeria monocytogenes, Yersinia enterocolitica, Klebsiella Pneumoniae, Enterobacter cloacae, Citrobacter freundii, Vibrio alginolyticus, Vibrio parahaemolyticus, Salmonella typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa, or Trichomonas vaginalis. It could detect a minimum of 100 copies per reaction. In clinical 98 samples of vaginal swabs from pregnant women, the agreement rate between the GBS-RPA-LFS method and TaqMan real-time fluorescence quantification method was 95.92%. In conclusion, this study successfully established a combined RPA and LFS GBS in situ detection platform, with short reaction time, high sensitivity, high specificity, portability, and device independence, providing a feasible strategy for clinical GBS screening.

The Mediterranean Zoanthid Parazoanthus axinellae as a Novel Source of Antimicrobial Compounds

Marine bioprospecting is a dynamic research field that explores the oceans and their biodiversity as noteworthy sources of new bioactive compounds. Anthozoans are marine animals belonging to the Cnidaria phylum characterized by highly specialized mechanosensory cells used both for defence against predators and prey capture. Here, high concentration of cnidocysts have been isolated from the Mediterranean zoanthid coral Parazoanthus axinellae (Schmidt, 1862) and their antimicrobial potential has been investigated. The cnidocyst extract exerted significant antibacterial activity against some human pathogens capable of developing resistance to conventional antibiotics such as Streptococcus agalactiae and Coccus sp., and against several Vibrio species, including some microbial strains for humans and farmed fish, such as Vibrio alginolyticus, Vibrio anguillarum, Vibrio fischeri, Vibrio harveyi, and Vibrio vulnificus. Results have been discussed in light of both the ecological aspects and biotechnological value of the cnidocyst extract in the nutritional, nutraceutical, and pharmaceutical fields.

The pathogen Vibrio alginolyticus H1 and its antagonist Pseudoalteromonas piscicida H2 associated with the health status of cuttlefish Sepia pharaonis

The balance in bacterial community is very important for the maintenance of the health status in the hosts. During the occurrence of a pervasive skin ulcer disease in Sepia pharaonis, bacterial isolate H1 and its antagonist bacterial isolate H2 were simultaneously isolated from the healthy cuttlefish, but only bacterial isolate H1 was isolated from the diseased cuttlefish. In the present study, the genetic and biochemical analysis showed that isolate H1 was identified as Vibrio alginolyticus, and isolate H2 was identified as Pseudoalteromonas piscicida, respectively. The antibiotic susceptibility test using CLSI M45–2015 method showed that the antibiotic resistance of V. alginolyticus H1 and P. piscicida H2 was different, and V. alginolyticus H1 showed strongly resistance to ampicillin. LD50 was calculated based the infection using immerse infection experiment. The result showed that the LD50 for 7 d of V. alginolyticus H1 was 1.58 × 106 CFU/mL, while the no death was observed during the infection of P. piscicida H2. Since the virulence related factors were significantly influenced by host immunity, the virulence factors of pathogen V. alginolyticus H1 was assessed under the stressors of H2O2 and 2,2′-dipyridyl. The results showed that the pathogenicity of V. alginolyticus H1 was associated with the haemolytic activity and bacterial motility. Different components of the P. piscicida H2 were collected and were tested for the antagonistic activity. It was unexpected that no antagonistic substance was detected, while V. alginolyticus H1 showed obvious phobotaxis to P. piscicida H2. It could be concluded that V. alginolyticus H1 was a pathogen of S. pharaonis, and P. piscicida H2 was a potential antagonistic bacteria to inhibit V. alginolyticus H1 via chemotaxis instead of producing antagonistic substance.

Characterization and function analysis of cathepsin C in Marsupenaeusjaponicus

Cathepsin C is a cysteine protease widely found in invertebrates and vertebrates, and has the important physiological role participating in proteolysis in vivo and activating various functional proteases in immune/inflammatory cells in the animals. In order to study the role of cathepsin C in the disease resistance of shrimp, we cloned cathepsin C gene (MjcathC) from Marsupenaeus japonicus, analyzed its expression patterns in various tissues, performed MjcathC-knockdown, and finally challenged experimental shrimps with Vibrio alginolyticus and WSSV. The results have shown the full length of MjcathC is 1782 bp, containing an open reading frame of 1350 bp encoding 449 amino acids. Homology analysis revealed that the predicted amino acid sequence of MjcathC shared respectively 88.42 %, 87.36 % and 87.58 % similarity with Penaeus monodon, Fenneropenaeus penicillatus and Litopenaeus vannamei. The expression levels of MjcathC in various tissues of healthy M. japonicus are the highest in the liver, followed by the gills and heart, and the lowest in the stomach. The expression levels of MjcathC were significantly up-regulated in all examined tissues of shrimp challenged with WSSV or V. alginolyticus. After knockdown-MjcathC using RNAi technology in M. japonicus, the expression levels of lectin and heat shock protein 70 in MjcathC-knockdown shrimp were significantly down-regulated, and the mortality of MjcathC-knockdown shrimp challenged by WSSV and V. alginolyticus significantly increased. Knockdown of the MjcathC reduced the resistance of M. japonicus to WSSV and V. alginolyticus. The above results have indicated that cathepsin C may play an important role in the antibacterial and antiviral innate immunity of M. japonicus.

TURMERIC EXTRACT EFFECTIVENESS WHITE (CURCUMA DOMESTICA .VALL ) FOR TREATMENT OF BACTERIAL INFECTIONS IN VIBRIO ALGINOLYTICUS MOUSE GROUPER (CROMILEPTES ALTIVELIS)

This study were aimed to (1) To study the effectiveness of white turmeric extract Curcuma domestica .Vall in treating a mouse Cromileptes altivelis from the attack of Vibrio alginolyticus., (2) To study the dose of the best white turmeric extract in treating a Cromileptes altivelis from attacks by bacteria Vibrio alginolyticus. (3) To study the effect of white turmeric extract against the survival rate Mouse grouper (Cromileptes altivelis), which in the infection of Vibrio alginolyticus. The experiment was arranged with a Completely Randomized Design (CRD). Preliminary research conducted LD50 test to determine the pathogenic bacterium V. alginolyticus which caused the death of test fish as much as 50%. In vitro test was done to see anti-bacterial activity of white turmeric extract against V. alginolyticus. From this test, the optimum concentration of white turmeric extract the effective tackling of V. Alginolyticus was obtained was obtained Test in vivo was carried out to determine the effect of the bacteria V. alginolyticus against Cromileptes altivelis healing response in Cromileptes altivelis after giving white turmeric extract. Results showed that (1) MIC and MBC values obtained by concentration of 0.25% and 0.75%, where the concentration of 0.75% was the effective dose of white turmeric extract in tackling the V. alginolyticus (2) The best treatment dose of the best survival rate of Cromileptes altivelis was 1% of white turmeric extract (3) the Survival Rate of mouse grouper wasn’t effected by white turmeric extract treatment significantly

RETROSPECTIVE ANALYSIS OF BLOOD CULTURES AND THEIR ASSOCIATION WITH CLINICAL FINDINGS AND OUTCOME IN GREEN SEA TURTLES (CHELONIA MYDAS) AT A FLORIDA SEA TURTLE REHABILITATION FACILITY, 2017-2020.

Septicemia is commonly suspected of sea turtles entering rehabilitation. However, blood culture results of green sea turtles (Chelonia mydas) are infrequently reported in the literature. Aerobic blood cultures were performed for intake examinations of 167 green sea turtles undergoing rehabilitation at Brevard Zoo's Sea Turtle Healing Center, Melbourne, Florida, USA from 2017 to 2020. The incidence of positive cultures during intake examinations was 24% (40/167). The most common bacterial isolates identified were Vibrio alginolyticus, Shewanella algae, Achromobacter xylosoxidans, Photobacterium damselae, Sphingomonas paucimobilis, and Vibrio parahaemolyticus. There was a statistically significant association (P < 0.05) between culture status and evidence of external injury. There was no significant association between culture status and Caryospora-like coccidia infection, or fibropapillomatosis. Culture-positive turtles had significantly lower (P < 0.05) total white blood cell, lymphocyte, monocyte, total protein, albumin, and calculated globulin values compared to turtles with negative blood cultures. Significantly more culture-positive turtles died in rehabilitation compared to culture-negative (P = 0.042). Positive blood cultures suggestive of septicemia are commonly found during intake examinations at a Florida sea turtle rehabilitation facility.

Inhibitory effect and mechanism of algicidal bacteria on Chaetomorpha valida

Chaetomorpha valida, filamentous green tide algae, poses a significant threat to both aquatic ecosystems and aquaculture. Vibrio alginolyticus Y20 is a new algicidal bacterium with an algicidal effect on C. valida. This study aimed to investigate the physiological and molecular responses of C. valida to exposure to V. alginolyticus Y20. The inhibitory effect of V. alginolyticus Y20 on C. valida was content dependent, with the lowest inhibitory content being 3 × 105 CFU mL−1. The microscopic results revealed that C. valida experienced severe morphological damage under the influence of V. alginolyticus Y20, with a dispersion of intracellular pigments. V. alginolyticus Y20 caused the decrease in chlorophyll-a content and Fv/Fm in C. valida. At the molecular level, V. alginolyticus Y20 downregulated the expression of genes related to photosynthetic pigment synthesis, light capture, and electron transport. Furthermore, V. alginolyticus Y20 induced oxidative damage to algal cells. The production of reactive oxygen species significantly increased after 11 days of exposure. Malondialdehyde content significantly increased, and the cell membranes were severely damaged by lipid peroxidation. The content of superoxide dismutase and peroxidase also markedly increased, whereas catalase content decreased significantly. Additionally, peroxisomes were inhibited due to the downregulation of PEX expression, leading to irreversible oxidative damage to algal cells. Our findings provided a new theoretical basis for exploring the interaction between algicidal bacteria and green tide algae at the molecular level.

In Vitro and In Silico Antifouling Activity Analysis of Secondary Metabolites Extracted from the Marine Bacterium Vibrio alginolyticus

In Vitro and In Silico Antifouling Activity Analysis of Secondary Metabolites Extracted from the Marine Bacterium Vibrio alginolyticus

Effect of fermented lemon peel as a functional feed additive on growth, non-specific immune responses, and Vibrio alginolyticus resistance in whiteleg shrimp, Litopenaeus vannamei

The study evaluated the impact of lemon peel fermented with Lactobacillus plantarum (FLP) being a practical feed additive, and its effects on growth performance, non-specific immune indicators, and disease resistance for whiteleg shrimp (Litopenaeus vannamei). The FLP was incorporated into the control diet at a graded level of 0%, 1%, 2%, and 3%. Four experimental feeds were randomly assigned to 4 replicates of L. vannamei with average weight of 2.37 g in a recirculation system for 56 days. Shrimp fed the four diets revealed similar (p > 0.05) weight gain percentage (489.01%−520.25%), feed conversion rate (2.46–2.70), protein efficiency ratio (1.05–1.14), and survival (78.75%−90.00%) after the feeding trial. Total hemocyte count (THC) was higher in shrimp delivered feeds containing 1% and 2% FLP whereas the phenoloxidase (PO) activity was advanced in shrimp fed the feed containing 2% FLP comparing with the FLP-free control group. In the V. alginolyticus challenge test, final survival after 72 h injection was higher in shrimp delivered feeds containing 2% and 3% FLP (66.67%−70.00%) than that in the control group (43.33%). The findings emphasize that fermented lemon peel is a potential functional feed additive on improving immunity and disease resistance for whiteleg shrimp, and showing no negative effects on growth and hepatopancreas morphology. An inclusion rate of 2% FLP is suggested for whiteleg shrimp to maximize the THC and PO activity and resistance ability to V. alginolyticus.

The new collagenase from Vibrio alginolyticus in the treatment of Dupuytren's disease

The new collagenase from Vibrio alginolyticus in the treatment of Dupuytren's disease

Efficacy of vaccine from whole killed Vibrio alginolyticus cells on the immune response of white shrimp (Litopenaeus vannamei)

Efficacy of vaccine from whole killed Vibrio alginolyticus cells on the immune response of white shrimp (Litopenaeus vannamei)

Correlation between Total Phenolic Content and Antibacterial Activities of Some Selected Traditional Plants against Some Species of Pathogenic Bacteria

Plants produce non-nutritive compounds known as secondary metabolites. These compounds can be found in several parts of the plants. Emphases have been placed on these compounds as curative agents in treating different types of diseases. Total phenolic contents of the plant extracts (leaf extract of Anacardium occidentalle, bulb extract of Allium sativum, bark extract of Casaurina equisetifolia, leaf extract of Dysophylla auriculata and bark extract of Mimusops elengi) were determined by using Folin-Ciocalteu method, and the values were expressed in microgram (µg) gallic acid equivalent (GAE) to 1 milligram (mg) of extract. The antibacterial activities of the 80% methanolic extracts of the plants were determined against nine species of pathogenic bacteria; that were Escherichia coli 0157:H7, Vibrio alginolyticus (ATCC 17749), Vibrio parahaemolyticus (ATCC 17082), Salmonella paratyphi (ATCC 9150), Yersiniae enterocolitica (ATCC 23715), Listeria monocytogenes (ATCC 19115), Salmonella typhi (ATCC 14028), Escherichia coli (ATCC 0157) and Staphylococcus aureus (ATCC 700699). Out of the five selected samples, the highest phenolic content was recorded with the bark extract of Mimusops elengi (442.59 ± 2.09). From the antibacterial screening, the most potent extract was observed with the bark extract of Mimusops elengi against L. monocytogenes (ATCC 19115), with a minimum inhibitory concentration value of 15.63 µg/mL, then followed by Allium sativum with 62.5 µg/mL. The correlation determined in this study between the total phenolic content and the antibacterial activity of the bark extract of Mimusops elengi confirmed its effectiveness against the screened species of bacteria. This work may be useful for the pharmaceutical industry in developing new natural product-based therapy for pathogenic bacteria.