Presence Of Minimum Inhibitory Concentrations Research Articles

Biofilm Growth of Pseudomonas Aeruginosa Tgc04 Exposed to Metformin and Variations in Cod Content

Purpose: This work aimed to evaluate the biofilm formation of Pseudomonas aeruginosa TGC04 exposed to 100 and 200 µg/mL of metformin, varying the Chemical Oxygen Demand (COD) and flow regime. Theoretical framework: Metformin is an oral antidiabetic agent with antimicrobial properties, excreted in an active and unmetabolized form. Like some non-antibiotic drugs, subinhibitory concentrations of metformin may contribute to the expression of microbial resistance in wild-type strains. Methods: After the Minimum Inhibitory Concentration (MIC) of metformin was known, nine microcosms were filled with 500 mL of synthetic wastewater with Chemical Oxygen Demand (COD) at 10,000 and 1,000 mg/L in the presence of MIC and sub-MIC of metformin. Two incubation conditions were tested, with and without aeration (4 L/min). Biofilms were quantified after 2 and 24 hours at 25ºC by the crystal violet test. Results and conclusion: It was observed reductions and increases in biofilm growth around 13 and 64%, respectively. The greatest biofilm growth occurred in cells exposed to 200 µg/mL of metformin. Both the flow regime and COD concentration were important for the development of the biofilm, whose cells were mostly weakly to moderately adhered. Research implications: This work showed that wild strain P. aeruginosa colonize biofilms in the presence of non-antibiotic drug with antimicrobial activity. Originality/value: The study provides evidence that in polluted aquatic systems with turbulent regimes, the inhibitory concentration of metformin promoted the least disturbances to the biofilm.

The Antimicrobial Activity of Red Palm (Cyrtostachys renda) In Leaf Ethanolic Extract Against Staphylococcus aureus

Medicinal plants are a rich source of secondary metabolites and been utilized since time immemorial as powerful drugs in traditional or alternative healthcare systems. In the light of this marvel, Cyrtostachys renda (Red Palm) is known to possess phytochemicals such as flavonoids, tannins, and steroids. Previous phytochemical studies on Cyrtostachys renda has revealed, the presence of steroids, tannins and flavonoids but none have tested its antimicrobial capabilities. In this study, the researchers used the red palm tree (Cyrtostachys renda) leaves extract as a viable antimicrobial concoction against Staphylococcus aureus. The determination of the Minimum Inhibitory Concentration (MIC) as well as the Zone of Inhibition (ZI) was highlighted in this study for the researchers to assess the overall capability of the Red Palm leaf ethanolic extract as a viable antimicrobial concoction. Apart from the Red Palm ethanolic extract, the researchers had used the ampicillin vial as their positive control and distilled water as their negative control in order to have a point of comparison and synthesis. This study utilized a post test experimental design with three treatments and three repetitions following a complete randomized design format (CRD) to ensure the validity and integrity of the experimental process. Results had shown that Red Palm (Cyrtostachys renda) showed potential viability as an antimicrobial extract as there was a notable presence of Minimum Inhibitory Concentration of (30 mm) using a 30 ml solution and a Zone of Inhibition with a mean of 9.33 mm. The researchers recommend to venture out different species of Palm for comparison of its potential antimicrobial viability.

Perbandingan Uji Aktivitas Antibakteri Umbi Bawang Merah (Allium Cepa L) Dan Umbi Bawang Putih (Allium Sativum) Terhadap Pertumbuhan Bakteri Shigella Dysenteriae

Background :Diarrhea is one of the causes of morbidity and mortality in infants and children around the world. One of the causes of diarrhea is Shigella sp bacteria or shigellosis. Nowadays, many antibiotics resistant to the Shigella sp bacteria are one example of chloramphenicol, so it is necessary to have other alternatives such as natural ingredients. Objective: Determine the activity of the red onion (Allium cepa L) and garlic (Allium sativum), which is known to possess antibacterial phytochemical compounds against the Shigella dysenteriae bacteria. Method: This research is a laboratory experimental study to determine antibacterial activity using the Kirby-Bauer or diffusion method of discs and to determine the presence of Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC). The study uses five treatments i.e., onion extracts and garlic extracts with a concentration of 30%, 40%, 50%, 60%, 70%, control positive (Ciprofloxacin), and negative control (aquadest). Results: Red onion diffusion has the best antibacterial activity at concentrations 70% while garlic has the best antibacterial activity at a concentration of 70%. In this study, there were no MIC and MBC. The MIC data analyzed with the crucial test of Kruskal-Wallis (p 0.05) i.e., in onion extract p = 0.003 and in garlic P = 0.003, which means significant. The MBC Data is analyzed by crucial test (P 0.05) in the onion extract p = 0.003 and on garlic p = 0.04. Conclusion : the disc diffusion and the MBC can be concluded that garlic extract can inhibit the growth of S. dysenteriae compared to red onion extracts. onion extracts).

Stability of GES-type extended-spectrum ß-lactamase genes during antibiotic exposure

Selective antibiotic pressure has recently been implicated in possible selection behind point mutations observeriinbla GES-type genes. This studysubjectedI two well-characterised clinical isolates with class 1 integron-borne blaGES-type genes to five days incubation in the presence of minimum inhibitory concentrations (MICs) of 15 different antibiotics, including ß-lactams, aminoglycosides and quinolones. Restriction enzyme analysis and DNA sequencing of blaGES-1 and blaGES-2 and their immediate upstream genetic environments failed to demonstrate any changes compared to non-exposed controls. Short-term exposure of resistant pathogens to the MIC of a single antimicrobial agent is thus unlikely to cause significant changes in these ßlactamase genes or their immediate genetic regulatory mechanisms.

Effects of oxacillin and tetracycline on autolysis, autolysin processing and atl transcription in Staphylococcus aureus

Autolysins are peptidoglycan hydrolases involved in cell growth and cell lysis. Atl is an important autolysin of Staphylococcus aureus and is essential for penicillin-induced autolysis. The objective of our study was to examine the effect of oxacillin, chloramphenicol and tetracycline on autolysis, peptidoglycan hydrolase profiles and transcription of atl encoding the major S. aureus autolysin on cells grown in the presence of minimum inhibitory concentrations of the antibiotics. Growth of methicillin-susceptible strains in the presence of oxacillin led to increased autolysis, a loss of low molecular weight and a gain of high molecular weight peptidoglycan hydrolase bands suggesting altered proteolytic processing of peptidoglycan hydrolases, and a decrease in atl transcription. In contrast, growth in the presence of tetracycline led to a decrease in autolysis, an increase in atl transcription, and a drastic decrease in the protein concentration of freeze–thaw extracts obtained for peptidoglycan hydrolase analysis. Growth of methicillin-resistant strains in the presence of oxacillin had only moderate effects on autolysis and peptidoglycan hydrolase profiles.