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Concerns about antibiotic residues in milk and emergence of antimicrobial resistant pathogens necessitate exploration of alternative therapeutic strategies for the treatment of mastitis. This study aims to investigate anti-infective properties of a Thai traditional polyherbal formula, namely Ya-Sa-Marn-Phlae (YSMP), its herbal components (Curcuma longa,Areca catechu,Oryza sativa, andGarcinia mangostana), and representative chemical constituents (catechin, α-mangostin, and curcumins). Ethanol extracts of YSMP andG. mangostana, and α-mangostin exhibited potent antibacterial effects againstStaphylococcusspp. isolated from mastitis cows with MIC values of 1–32 µg/mL. These tested agents inhibited biofilm formation of the isolates on both polypropylene (hydrophobic) and glass (hydrophilic) surfaces. The current study indicated that YSMP had strong antibacterial activity and anti-biofilm abilities against the tested isolates similar to that of α-mangostin andG. mangostana. The anti-staphylococcal effects were confirmed with both scanning and transmission electron microscopes. The main abnormalities in the microstructure of the treated cells were the severe alterations of the cell wall with the formation of holes and morphological disorganization. Therefore, it might be proposed thatG. mangostanais the major active component of YSMP and α-mangostin may be used as an active marker compound for YSMP to indicate its activity against bovine mastitis-isolated staphylococci. [ABSTRACT FROM PUBLISHER]

Virulence factors regulated by quorum sensing ( QS) play a critical role in the pathogenesis of an opportunistic human pathogen, Pseudomonas aeruginosa in causing infections to the host. Hence, in the present work, the anti-virulence potential of the medicinal plant extracts and their derived phytochemicals from Myrtaceae family was evaluated against P. aeruginosa. In the preliminary screening of the tested medicinal plant extracts, Syzygium jambos and Syzygium antisepticum demonstrated a maximum inhibition in QS-dependent violacein pigment production by Chromobacterium violaceum DMST 21761. These extracts demonstrated an inhibitory activity over a virulence factor, pyoverdin, production by P. aeruginosa ATCC 27853. Gas chromatography-mass spectrometric ( GC- MS) analysis revealed the presence of 23 and 12 phytochemicals from the extracts of S. jambos and S. antisepticum respectively. Three top-ranking phytochemicals, including phytol, ethyl linoleate and methyl linolenate, selected on the basis of docking score in molecular docking studies lowered virulence factors such as pyoverdin production, protease and haemolytic activities of P. aeruginosa to a significant level. In addition, the phytochemicals reduced rhamnolipid production by the organism. The work demonstrated an importance of plant-derived compounds as anti-virulence drugs to conquer P. aeruginosa virulence towards the host. [ABSTRACT FROM AUTHOR]

The increasing prevalence of microbial infections associated with wound healing in animal, caused by bacteria, are a serious health problem in animal. The new antimicrobial against from natural product has been wildly developed. Pyroligneous acid also called wood vinegar is brown-red transparent liquid as a by-product during pyrolysis to manufacture biomass charcoal. Pyroligneous acid prepared oil palm kernel shell has been a value-added product of biomass waste from oil palm industry in Southeast-Asia. The purpose of this study was to evaluate the antibacterial activity of semi-purified compound form pyroligneous acid of oil palm shell prepared by carbonization against important three pathogenic bacterial in animal including Staphylococcus aureus, Escherichia coli andPseudomonas aeruginosa. The resulted revealed that semi-purified compound was found to be effective against the investigated pathogens. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) on S. aureus and P. aeruginosa were 15.62 ug/ml and 31.25 ug/ml, respectively, while E. coli was inhibited and killed with concentration of 31.25 ug/ml and 62.50 ug/ml, respectively. However, the MICs of tetracycline against three bacterial stains range from 0.48 to 0.96 ug/ml. Time kill determination indicated that semi-purified compound form wood vinegar of oil palm shell at the concentration of 4 xMIC had rapid killing effect in all tested bacteria and eliminated all bacteria within 4 hours. However, efficacy of the compound was still lower than that of tetracycline at the concentration of 2 xMIC. The compounds and their concentrations in semi-purified sample were indicated by gas chromatography/fame ionize detector, which found that phenol and its derivative were major components with summary concentration of 1,013.54 mg/ml. Overall could be concluded that extracted compound isolated from wood vinegar of oil palm shell has potential to use as alternative antipathogenic bacteria against supported wound healing therapy in animal. [ABSTRACT FROM AUTHOR]

Background: Antibiotic resistance is a global public health concern that has been exacerbated by the overuse and misuse of antibiotics, leading to the emergence of resistant bacteria. The gut microbiota, often influenced by antibiotic usage, plays a crucial role in overall health. Therefore, this study aimed to investigate the prevalence of antibiotic resistant genes in the gut microbiota of Indonesian coastal and highland populations, as well as to identify vancomycin-resistant bacteria and their resistant genes., Methods: Stool samples were collected from 22 individuals residing in Pacet, Mojokerto, and Kenjeran, Surabaya Indonesia in 2022. The read count of antibiotic resistant genes was analyzed in the collected samples, and the bacterium concentration was counted by plating on the antibiotic-containing agar plate. Vancomycin-resistant strains were further isolated, and the presence of vancomycin-resistant genes was detected using a multiplex polymerase chain reaction (PCR)., Results: The antibiotic resistant genes for tetracycline, aminoglycosides, macrolides, beta-lactams, and vancomycin were found in high frequency in all stool samples (100%) of the gut microbiota. Meanwhile, those meant for chloramphenicol and sulfonamides were found in 86% and 16% of the samples, respectively. Notably, vancomycin-resistant genes were found in 16 intrinsically resistant Gram-negative bacterial strains. Among the detected vancomycin-resistant genes, vanG was the most prevalent (27.3%), while vanA was the least prevalent (4.5%)., Conclusion: The presence of multiple vancomycin resistance genes in intrinsically resistant Gram-negative bacterial strains demonstrated the importance of the gut microbiota as a reservoir and hub for the horizontal transfer of antibiotic resistant genes., Competing Interests: None declared., (Copyright: © Iranian Journal of Medical Sciences.)

Rhodomyrtone (Rom) is an acylphloroglucinol antibiotic originally isolated from leaves of Rhodomyrtus tomentosa . Rom targets the bacterial membrane and is active against a wide range of Gram-positive bacteria but the exact mode of action remains obscure. Here we isolated and characterized a spontaneous Rom-resistant mutant from the model strain Staphylococcus aureus HG001 (Rom R ) to learn more about the resistance mechanism. We showed that Rom-resistance is based on a single point mutation in the coding region of farR [regulator of fatty acid (FA) resistance] that causes an amino acid change from Cys to Arg at position 116 in FarR, that affects FarR activity. Comparative transcriptome analysis revealed that mutated farR affects transcription of many genes in distinct pathways. FarR represses for example the expression of its own gene ( farR ), its flanking gene farE (effector of FA resistance), and other global regulators such as agr and sarA . All these genes were consequently upregulated in the Rom R clone. Particularly the upregulation of agr and sarA leads to increased expression of virulence genes rendering the Rom R clone more cytotoxic and more pathogenic in a mouse infection model. The Rom-resistance is largely due to the de-repression of farE . FarE is described as an efflux pump for linoleic and arachidonic acids. We observed an increased release of lipids in the Rom R clone compared to its parental strain HG001. If farE is deleted in the Rom R clone, or, if native farR is expressed in the Rom R strain, the corresponding strains become hypersensitive to Rom. Overall, we show here that the high Rom-resistance is mediated by overexpression of farE in the Rom R clone, that FarR is an important regulator, and that the point mutation in farR (Rom R clone) makes the clone hyper-virulent.