BACKGROUND: Bersama abyssinica Fresen is a plant that is used in folk medicine for the treatment of mastitis and other infectious diseases.
OBJECTIVE: The antibacterial activity of methanol crude extract of plant was evaluated against three common bacterial pathogens, including Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli and Pseudomonas aeruginosa).
METHODS: The antibacterial activities and minimum inhibitory concentration of B. abyssinica crude extracts were evaluated using agar-well diffusion and broth dilution methods according to the National Committee for Clinical Laboratory Standards (NCCLS).
RESULTS: A significant difference in the antibacterial activity of crude extracts was observed among different levels of concentration against tested isolates. A higher mean inhibition zone diameter was recorded in E. coli (29.2 ± 1.5 mm), followed by S. aureus (27.8 ± 1.1 mm) and P. aeruginosa (18.0 ± 0.7 mm) at a concentration of 100 mg/mL. The antibacterial activity of crude plant extract at 100 mg/mL was comparable with that of a standard antibiotic (27.6 ± 2.6) against S. aureus and E. coli isolates. The findings indicated that bacterial growth inhibition increased as the concentration of the crude extracts increased. E. coli and S. aureus isolates showed significantly higher susceptibilities to crude extracts than P. aeruginosa at all concentrations. The minimum inhibitory concentrations of extracts against S. aureus, E. coli and P. aeruginosa isolates were 0.78 mg/mL, 1.56 mg/mL and 1.56 mg/mL, respectively.
CONCLUSIONS: All tested pathogenic bacterial species were susceptible to plant leaf extract and broad-spectrum activity against Gram-positive and Gram-negative bacteria. The study recommends further fractionation of the B. abyssinica plant that contributes to its antibacterial activity and understands the mode of action of this plant against bacteria and other microbes.

Aedes mosquitoes are the major cause of several vector-borne diseases in tropical and subtropical regions. Synthetic pesticides against these mosquitoes have certain limitations; hence, natural, eco-friendly, and safe larvicides obtained from plant resources are used to overcome these. In the present study, the larvicidal efficiency of Commiphora wightii against the fourth instar stage of the dengue fever mosquito Aedes aegypti (Linnaeus, 1762) was studied. The gum resin of C. wightii was collected using the borehole tapping method, and hexane extracts in different concentrations were prepared. The fourth-instar larvae were exposed to the extracts, and percent mortality, as well as LC20, LC50, and LC90, was calculated. Volatile compounds of the hexane gum extract were analyzed by Headspace GC/MS, and the sequence of the acetylcholine, Gamma-aminobutyric acid (GABA) receptor, and octopamine receptor subunit of A. aegypti was obtained. It was found that the hexane gum extract was toxic and lethal for larvae at different concentrations. Minimum mortality was observed at 164 µg mL-1 (10%/h), while maximum mortality was at 276 µg mL-1 (50%/h). The lethal concentrations LC20, LC50, and LC90 were 197.38 µg mL-1, 294.13 µg mL-1, and 540.15 µg mL-1, respectively. The GC/MS analysis confirmed the presence of diterpenes, monoterpenes, monoterpene alcohol, and sesquiterpenes in the gum samples, which are lethal for larvae due to their inhibitory activity on the acetylcholinesterase enzyme, GABA receptor, and octopamine receptor subunit. The use of commonly occurring plant gum for the control of mosquitoes was explored, and it was found that the gum of C. wightii had larvicidal activities and could be potentially insecticidal.

Lettuce crop is an important horticultural crop of several Mediterranean countries, including Italy. The Italian region which is a major producer of lettuce crops is Apulia, where this crop is cultivated in open fields an in greenhouses. Since several microbial pathogens are responsible for important diseases found on lettuce produced in greenhouses, in this study, the experimental activities focused on the most severe fungal soilborne pathogens, i.e., Sclerotinia sclerotiorum and Athelia rolfsii. Their control is often performed with fungicides which cause public concern over the environment and human health. The main aims of this study were to determine the biocontrol efficacy of a Streptomyces strain in vitro and in vivo conditions on lettuce seedlings against Athelia rolfsii and Sclerotinia sclerotiorum as severe fungal soilborne pathogens through the application of its vegetative propagules and putative bioactive crude extracts via filtrate culture. The results obtained confirm a significant effectiveness of CARA17 strain to control the severity of both fungal soilborne pathogens during two different experiments: when it is used as vegetative propagules and as a culture filtrate containing putative bioactive metabolites in vitro and in vivo conditions. These preliminary results demonstrated that the actinomycetes CARA17 strain is valid as a biocontrol agent (BCA) against both the severe phytopathogens used in this study. The biocontrol action performed from the CARA17 strain is clearly and mainly due to the putative bioactive crude extracts produced, but further studies are necessary to identify which metabolites (polyphenols, terpenes, fatty acids, etc.) are produced from this Streptomyces strain.

For the control of biofouling, some paints based on compounds that are toxic to marine organisms have been used. There is an intensive search for biodegradable solutions that are friendly to non-target organisms. Bacteria have been shown to be a source of compounds with antifouling potential. In this work, the antifouling activity of a strain of Staphylococcus aureus was evaluated. Extracts activity against biofilm-forming bacteria and the toxicity against Artemia franciscana were evaluated. The extracts were incorporated in a hard gel and a paint matrix, and they were exposed to the sea. In both the laboratory and field, we found that the compounds produced by S. aureus have antifouling activity. The non-toxicity of the tested extracts against Artemia franciscana nauplii suggests that the extracts obtained from S. aureus could have a low ecological impact over non-target organisms. Significant differences were found in the percentage of organisms cover in hard gels with extracts and control. After 90 days, important differences were also observed between the percentage of organisms cover of the paints that contained extracts and the control. Dichloromethane extract is the most effective for the inhibition or delay of the settlement of organisms For this reason, they could be used in matrices with different applications, such as in the shipping industry, aquaculture, or any other in which biofouling is a cause of inconvenience.

UNASSIGNED: Endophytic fungi are believed to possess compounds as antibacterial agents. This study was designed to determine in vivo antibacterial activity of the crude extracts from Lasiodiplodia pseudotheobromae IBRL OS-64 against pathogenic bacteria.
UNASSIGNED: The qualitative and quantitative screenings were performed using agar plug and disk diffusion antimicrobial tests, respectively. Besides that, the MIC and MBC value of the extracts were determined using broth microdilution assay and morphological changes of the bacterial cells exposed to the extract were observed under Scanning Electron Microscope (SEM).
UNASSIGNED: Agar plug diffusion assay revealed that V. parahaemolyticus ATCC 17802 and Exiguobacterium profundum IBRL MA6 were the most sensitive to the extract with the size of inhibition zones of 11 to ≤ 20 mm. The MIC and MBC values of the extract varied depending on the test bacteria. Observation through SEM revealed that the bacterial cells exposed to the extract experienced severe damage such as irregular shape with crumpled and shrunken cells which led to cell death.
UNASSIGNED: The data suggest that the crude extracts of L. pseudotheobromae IBRL OS-64 exert antibacterial activity against test bacteria and principally affect the cell wall in growing pathogenic bacterial cells.

Emergence of antimicrobial resistance complicates treatment of infections by antibiotics. This has driven research on novel and combination antibacterial therapies. The present study evaluated synergistic antimicrobial activity of plant extracts and cefixime in resistant clinical isolates. Preliminary susceptibility profiling of antibiotics and antibacterial activity of extracts was done by disc diffusion and microbroth dilution assays. Checker-board, time-kill kinetics and protein content studies were performed to validate synergistic antibacterial activity. Results showed noteworthy quantities of gallic acid (0.24-19.7 µg/mg), quercetin (1.57-18.44 µg/mg) and cinnamic acid (0.02-5.93 µg/mg) in extracts of plants assessed by reverse-phase high performance liquid chromatography (RP-HPLC). Gram-positive (4/6) and Gram-negative (13/16) clinical isolates were intermediately susceptible or resistant to cefixime, which was used for synergistic studies. EA and M extracts of plants exhibited total synergy, partial synergy and indifferent characteristics whereas aqueous extracts did not show synergistic patterns. Time-kill kinetic studies showed that synergism was both time and concentration-dependent (2-8-fold decrease in concentration). Bacterial isolates treated with combinations at fractional inhibitory concentration index (FICI) showed significantly reduced bacterial growth, as well as protein content (5-62 %) as compared to extracts/cefixime alone treated isolates. This study acknowledges the selected crude extracts as adjuvants to antibiotics to treat resistant bacterial infections.

Variation in plant species and extraction solvents play a crucial role in the recovery of their bioactive compounds and antifungal efficacy. Thus, in this study, a comparative investigation was carried out using extraction solvents: 70% acetone and 95% ethanol to obtain crude aqueous extracts from Helichrysum odoratissimum and H. patulum. Crude aqueous extracts were screened using gas chromatography-mass spectrometry (GC-MS), to gain insight into their chemical composition. Phytochemical properties (total polyphenols (TP) and radical scavenging capacity via 2,2-diphenyl-1-picrylhydrazyl (DPPH)), and antifungal activity against Botrytis cinerea of the crude extracts were evaluated. Fungicide (Rovral® WP) and extraction solvents were used as controls. Variation in Helichrysum spp. and extraction solvent had influence on the chemical composition, phytochemicals, and antifungal activities. Metabolites such as γ-terpinene (≈0.1%), α-amorphene (≈0.6%) α-gurjunene (≈1.4%), β-selinene (2.2-3.2%), γ-gurjunene (≈3.3%), and methyl cinnamate (≈20%) were detected only in extracts of H. patulum. Crude extract of H. odoratissimum using 70% acetone had the highest TP (19.3 ± 0.76 g GA 100 g-1), and DPPH capacity (13,251.5 ± 700.55 µmol Trolox g-1) compared to H. patulum (p ≤ 0.05). Ethanolic extracts of H. patulum showed highest antifungal efficacy (≈65%) against B. cinerea (p ≤ 0.05) compared to other crude extracts. This study showed that Helichrysum spp. differ in their potential as a source for bioactive compounds and antifungal treatments/formulations.

Antiretroviral treatment has significantly reduced human immunodeficiency virus infection and mortality. However, the current treatment regimen is limited by adverse side effects, the emergence of drug resistance, and the inability to eliminate viral reservoirs. Here, fifteen endophytic fungi were isolated from Sclerocarya birrea and Hypoxis plants. Crude extracts of Alternaria alternata (strain ID PO4PR1, PO4PR2, and PO2PL1) of the fifteen isolate\'s crude extracts showed anti-HIV-1 activity in TZM-bl cell line at inhibitory concentration (IC50) values ranging from 0.017 to 1.170 μg/ml. The three crude extracts also maintained the virus replication inhibition profile on PBMCs and CD4+ T cells at concentrations ranging from 0.3 to 50.2 ng/ml. Partial purification using the solid phase extraction and analysis with Gas Chromatography-Mass spectrophotometry showed a diverse profile. The bioactive compounds were identified based on peak area, retention time, similarity index. The major compounds from GC-MS analysis of A. Alternata revealed the existence of cyclotrisiloxane octamethyl (22.92%); Propaninitrile (16,67%); Pyrrolol[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl) (10.42%); Silane, diethylethoxy(2-ethoxyethyloxy) (4.17%); Coumarin, 3,4-dihydro-4,5,7-trimethyl- 4,5,7-Trimethyl-2-chromanone (13.7%) and 1,2-Cyclobutanedicarbonitrile (2.08%) with previously reported biological activities such as antimicrobial, anti-inflammatory and antioxidant properties. Therefore, these bioactive compounds from A. alternata fungal endophytes could be repurposed as potential anti-HIV agents. This study showed the potential of endophytic fungi, Alternaria alternata from S. birrea, and Hypoxis species as producers of anti-HIV compounds.

UNASSIGNED: The emerging of antimicrobial resistance has become a problem as it is threatening public health worldwide.
UNASSIGNED: To extract crude extracts from three different medicinal plants, test activity against Mycobacterium smegmatis, Staphylococcus aureus and Escherichia coli and screen for phytochemicals of those that showed activity against the targeted bacteria.
UNASSIGNED: KirkiaacuminataOliv., Dichrostachyscinerea (L.) Wight &Arn. and MimusopszeyheriSond. plants were collected at Thengwe area, Mafukani village, Limpopo Province, South Africa. The plant materials collected were extracted using four solvents. Antimicrobial screening was accomplished using the agar well diffusion method and the crude extracts that showed activity against the targeted organisms were screened for phytochemicals using different tests.
UNASSIGNED: With all solvents used for extraction, methanol had a greater yield of 14.1% from Dichrostachyscinerea crude extracts. Kirkiaacuminata and Dichrostachyscinerea were medicinal plants that inhibited Mycobacterium smegmatis and Staphylococcus aureus at the lowest concentration of 2.5 mg/ml and 1.25 mg/ml.
UNASSIGNED: The results from this study show that the selected medicinal plants are active against Mycobacterium smegmatis and Staphylococcus aureus and their pharmacological properties can be further analyzed for the development of new drugs.

The aim of this study was to identify novel milk coagulants to be used in cheesemaking. For this purpose, aqueous extracts from safflower (Carthamus tinctorius), sunflower (Helianthus annuus), flax (Linum usitatissimum) and sesame (Sesamum indicum) seeds were tested for their caseinolytic (CA) and milk coagulating properties (MCA) in skim milk at temperatures of 25, 37, 50, 65 and 80 °C. The seed oil samples with the highest temperature ranges in regard to coagulation efficiency were then tested in cow, buffalo, goat and sheep milks and the MCA and curd yield (CY) parameters were measured at different temperatures. Due to their high milk coagulation efficiency (CE) in all types of milk and at different temperatures, the sesame and sunflower seed extracts proved to be particularly interesting and their CY parameters were similar to those obtained with animal rennet. Moreover, our results confirm that oilseed coagulants are capable of coagulating milk and can also be considered as potential animal rennet substitutes. This study provides valuable insights into the development of potential vegetable coagulants that could be used for various production processes aimed at specific target consumers.