The CovRS Environmental Sensor Directly Controls the ComRS Signaling System To Orchestrate Competence Bimodality in Salivarius Streptococci

Combining production of antibacterial compounds and uptake of DNA material released by dead cells, competence is one of the most efficient survival strategies in streptococci. Yet, this powerful tactic is energy consuming and reprograms the metabolism to such an extent that cell proliferation is transiently impaired.

Discovery of a novel class of small-molecule antibacterial agents against Staphylococcus aureus

Background: With constantly increasing resistance against the known antibiotics, the search for novel antibacterial compounds is a challenge. The number of synthetic antibacterial agents is limited. Materials & methods: We discovered novel small-molecule antibacterial agents that are accessible via a simple two-step procedure. The evaluation against Staphylococcus aureus showed antibacterial effects depending on the substituent positioning at the residues of the molecular scaffold. Additionally, we investigated the potential of the compounds to increase the antibacterial activity of tetracycline. Results: The most effective antibacterial compounds possessed a 3-methoxy function at an aromatic residue. In combination with tetracycline, we found a strong effect for a few compounds in boosting the antibacterial activity, so the first promising lead compounds with dual activities could be identified.

Novel Small-Molecule Hybrid-Antibacterial Agents against S. aureus and MRSA Strains

Ongoing resistance developments against antibiotics that also affect last-resort antibiotics require novel antibacterial compounds. Strategies to discover such novel structures have been dimerization or hybridization of known antibacterial agents. We found novel antibacterial agents by dimerization of indols and hybridization with carbazoles. They were obtained in a simple one-pot reaction as bisindole tetrahydrocarbazoles. Further oxidation led to bisindole carbazoles with varied substitutions of both the indole and the carbazole scaffold. Both the tetrahydrocarbazoles and the carbazoles have been evaluated in various S. aureus strains, including MRSA strains. Those 5-cyano substituted derivatives showed best activities as determined by MIC values. The tetrahydrocarbazoles partly exceed the activity of the carbazole compounds and thus the activity of the used standard antibiotics. Thus, promising lead compounds could be identified for further studies.

Pelatihan Pembuatan Hand Sanitizer kepada Masyarakat Desa Tangguh di Kp. Pasir Honje, Ds. Sukawening Kec. Ciwidey Kab. Bandung

The Covid-19 pandemic that has been attacked almost all countries in the world since 2020 has changed the lifestyle and habits of peoples globally. Since this outbreak until now, peoples in all countries including in Indonesia must implement the health protocols to reduce the rate of virus transmission. One of them is by maintaining hand hygiene by washing hands using soap or hand sanitizer (HS). HS is used as an alternative in conditions which is difficult to washing hand. But, rural communities, especially in Tangguh Village in Kampung Pasir Honje, Sukawening, Ciwidey, Bandung Regency, are currently unable to use it due to limited access and economy. Training of making HS for the community can be a solution in overcoming this problem. Thie aims of this activity to provide skills to the people of Tangguh Village to make hand sanitizers made from alcohol and non alcohol. Method: conducted by lectures and do questions and answers about HS and then direct practice of making HS. Result: All participants can make hand sanitizers well. There are 2 types of HS that have been successfully made by the community, namely HS containing alcohol and HS free of alcohol. The alcohol content in the first type is around 60-70%, while the alcohol-free HS is made from betel leaf extract because it contains antibacterial compounds. The results of the evaluation show that 50% of the participants stated that they were very satisfied with the implementation of this activity and about 92% stated that this activity was very beneficial for them.

Design, Synthesis, Reactions and Antibacterial Properties of 2-hydrazinyl-3-methyl-6-nitroquinoxaline Derivatives

Aims: This aims of this study was to synthesis new quinoxaline-based heterocycles and study its antibacterial properties. Objective: This study was designed to synthesis some 3-methyl-6-nitroquinoxaline-2-one with hydrazine moiety, characterize the synthesized compounds, and study their antibacterial properties on some bacterial strains. Materials and Methods: Six 3-methylquinoxaline-2-hydrazone derivatives were synthesized by reacting 2-hydrazinyl-3-methyl-6-nitroquinoxaline with various substituted acetophenones. The hydrazones were screened for their potential antibacterial properties. Results: All the test compounds were found to possessed promising antibacterial properties against a panel of bacterial strains screened for this study. The MIC values exhibited by these compounds ranged between 0.0313 and 0.250 mg/mL. The lowest MBC of the compounds against the test organism was 0.0625 mg/mL while the highest MBC was 0.250 mg/mL. Discussion and Conclusion: The study concluded that all the compounds exhibited appreciable bactericidal effects against all the bacterial strains, which is an indication that such synthetic compounds possessed broad spectrum activities and such compounds could be useful in formulation of antibacterial compounds which could be used to mitigates infections caused by pathogens that are now developing resistance against the available antibiotics.

Antibacterial Screening of Endophytic Fungus Xylaria sp. derived from Andrographis paniculata (Sambiloto)

AIM: The purpose of this research is to evaluate the antibacterial activity of endophytic fungi derived from the flowers of Andrographis paniculata (Sambiloto). METHODS: The endophytic fungi were obtained following the dilution method with potato dextrose agar as media. Four isolates of fungi have been obtained and then fermented with rice media for 3 weeks. The fermented fungi were extracted with ethyl acetate (EtOAc) and evaporated to yield the EtOAc extract. All EtOAc extracts were evaluated for their antibacterial activity using agar diffusion method. RESULTS: The results indicated that the EtOAc extract from fungus RG-2 was the potential source of antibacterial compounds. Molecular identification showing fungus RG-2 was Xylaria sp. CONCLUSION: Further investigation of the antibacterial compounds produced by fungus Xylaria sp. derived from the flowers of A. paniculata will be performed in the future. To the best of our knowledge, endophytic fungal Xylaria sp. is firstly isolated from A. paniculata.

Design, Synthesis and Antibacterial Activity of some 3,6-Dimethlyquinoxaline-2-Hydrazone Derivatives

Aims: This aims of this study was to continue the effort to synthesis new quinoxaline-based heterocycles and study its antibacterial properties. Objective: This study was designed to reacts 3,6-dimethylquinoxaline-2-hydrazine with some substituted aromatic ketones and study their antibacterial properties on some locally and clinically isolated bacterial strains. Materials and Methods: Five 3,6-dimethylquinoxaline-2-hydrazone derivatives were synthesized from the reactions of 3,6-dimethylquinoxaline-2-hydrazine with various substituted aromatic ketones. The products were then tested for their potential antibacterial properties. Results: All the synthesized compounds were found to be active against all the bacterial strains investigated in this study. It was observed that the zones of inhibition observed for the synthesized compounds against the test organisms ranged between 15 mm and 38 mm. The MIC observed for the synthesized compounds ranged between 0.0313mg/mL and 0.125 mg/mL, while that of the standard antibiotic, streptomycin, varied between 0.0313 mg/mL and 0.500 mg/mL and those observed for tetracycline falls between 0.0313 mg/mL and 0.500 mg/mL. The minimum bactericidal concentrations exhibited by the synthesized compounds ranged between 0.0625 mg/mL and 0.250 mg/mL Discussion and conclusion: The study concluded that all the compounds exhibited appreciable bactericidal effects against all the bacterial strains, which is an indication that such synthetic compounds possessed broad spectrum activities and such compounds could be useful in formulation of antibacterial compounds which could be used to mitigates infections caused by pathogens that are now developing resistance against the available antibiotics.

Bioprospecting of cow's ruminal microbiota from a slaughterhouse in Ambarawa, Central Java, Indonesia

Murwani R, Sibero MT, Silitonga PRA, Ambariyanto A. 2021. Bioprospecting of cow's ruminal microbiota from a slaughterhouse in Ambarawa, Central Java, Indonesia. Biodiversitas 22: 5030-5038. Ruminal microorganisms play essential roles in maintaining ruminant health. However, most studies focused only on ruminal lactic acid bacteria (LAB), although other ruminal microorganisms might have biological properties for biotechnological purposes. Therefore, the current study aimed to isolate ruminal bacteria (LAB and non-LAB) and fungi from ruminal material and conducted a bioprospecting study to understand their ability to produce antibacterial compounds and polysaccharide-degrading enzymes. The ruminal bacteria were isolated on MRS and ISP4 agar, while PDA was used to isolate the different fungi. The antibacterial property was tested against multidrug-resistant Escherichia coli and Salmonella enterica ser. Typhi. The ability to produce agarase, alginate-lyase, and carrageenase was screened. Prospective isolates were identified using DNA barcoding approach. Twelve bacteria were isolated using MRS agar, six from ISP4 agar, and four fungi from PDA. Among twelve bacteria from MRS agar, eleven were considered LAB, which consisted of Lactobacillus plantarum and Pediococcus acidilactici. Several classes of bacteria such as actinobacteria, firmicutes, ?-proteobacteria, and ?-proteobacteria were isolated during this study. In addition, three fungal classes, namely Saccharomycetes, Eurotiomycetes, and Mucoromycetes were also isolated. All bacteria from MRS agar were suggested to have potential compounds with antimicrobial activity, while all ruminal fungi exhibited potential sources of polysaccharide-degrading enzymes.