Lowest Minimum Bactericidal Concentration Values Research Articles

Antimicrobial Activity of Clove Plant Flower Bud Extract (Syzygium aromaticum) on Escherichia coli

The continuous use of antibiotics for the treatment of bacterial infections has led to the increase in bacterial resistance to these antibiotics. Many bacteria, including E. coli are currently multi-drug resistant, which poses a great problem to the medical and pharmaceutical industry [1]. This research was conducted to investigate the antimicrobial properties of Syzygium aromaticum against the above-mentioned organisms. The plant extracts were in Hot water, Cold water, and Ethanol, and the susceptibility of the organisms was tested using agar well diffusion and disk diffusion methods. The plant extracts showed antimicrobial activity on all isolates used i.e E.coli. From the result, the minimum inhibitory concentration (MIC) was 0.24mg/ml, and the minimum bactericidal concentration (MBC) was 3.91mg/ml. The diameter zone of Inhibition in (mm) against the plant concentration in (mg/ml) conentrations were 500mg/ml, 250mg/ml, 125mg/ml, 62.50mg/ml, 31.25mg/ml, and 15.63mg/ml. The values of the diameter zone of inhibition against the plant concentrations ranged from 16mm to 0mm while control ranged from 38mm to 10mm. The Phytochemical components determined in Cloves were Alkaloids, Saponin, Phenols, Tannins, Flavonoids, Steroids, Soluble Carbohydrate, Glycosides, Terpenes. This research showed that all the clove extracts against E. coli had the lowest MBC values, which proved to be the most effective and all the clove extracts against E. coli had the lowest MIC value of 0.24mg/ml, which proved to be the most effective of the three.

The Efficacy of Silver-Based Electrospun Antimicrobial Dressing in Accelerating the Regeneration of Partial Thickness Burn Wounds Using a Porcine Model.

(1) Background: Wounds with damages to the subcutaneous are difficult to regenerate because of the tissue damages and complications such as bacterial infection. (2) Methods: In this study, we created burn wounds on pigs and investigated the efficacy of three biomaterials: polycaprolactone-gelatin-silver membrane (PCLGelAg) and two commercial burn dressings, Aquacel® Ag and UrgoTulTM silver sulfadiazine. In vitro long-term antibacterial property and in vivo wound healing performance were investigated. Agar diffusion assays were employed to evaluate bacterial inhibition at different time intervals. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assays were used to compare antibacterial strength among samples. Second-degree burn wounds in the pig model were designed to evaluate the efficiency of all dressings in supporting the wound healing process. (3) Results: The results showed that PCLGelAg membrane was the most effective in killing both Gram-positive and Gram-negative bacteria bacteria with the lowest MBC value. All three dressings (PCLGelAg, Aquacel, and UrgoTul) exhibited bactericidal effect during the first 24 h, supported wound healing as well as prevented infection and inflammation. (4) Conclusions: The results suggest that the PCLGelAg membrane is a practical solution for the treatment of severe burn injury and other infection-related skin complications.

In vitro antibacterial activity of crude extracts of 9 selected medicinal plants against UTI causing MDR bacteria

Urinary tract infection (UTI) has become a more grievous problem today, due to multidrug resistance of infecting Gram-positive (GP) and Gram-negative (GN) bacteria, sometimes even with multiple infections. This study examines effectivity of 9 tropical flowering plants (Anogeissus acuminata, Azadirachta indica, Bauhinia variegata, Boerhaavia diffusa, Punica granatum, Soymida febrifuga, Terminalia chebula, Tinospora cordifolia and Tribulus terrestris) for possible use as source of antimicrobials for multidrug resistant (MDR) bacteria, along with main-stream antibiotics. Pathogenic bacteria were isolated from urine samples of patients attending and admitted in the hospital. Antibiograms of 11 isolated bacteria (GPs, Enterococcus faecalis and Staphylococcus aureus; and GNs, Acinetobacter baumannii, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa) were ascertained by the disc-diffusion method, and antibacterial effectivity of plant extracts was monitored by the agar-well diffusion method. Isolated bacteria were floridly MDR to most antibiotics of the day. Methanol extracts of 9 plants were used, and extracts of 3 plants, A. acuminata, P. granatum and S. febrifuga at least caused 25–29mm as the maximum size of zone of inhibition on bacterial lawns. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of methanol extracts of 9 plants were recorded. The methanol extract of A. acuminata had 0.29mg/ml as the lowest MIC value and 0.67mg/ml as the lowest MBC value, against MDR S. aureus, signifying effectivity; but, it had the highest MIC value of 3.41mg/ml. and the highest MBC value of 4.27mg/ml for most other MDR bacteria including E. coli. Qualitative phytochemical analysis was done for these 9 plants and information on leading phytochemicals was presented retrieved from PubChem database. Thus, three effective-most plants in controlling MDR-UTI bacteria in vitro were A. acuminata, P. granatum and S. febrifuga, which can be promoted as complementary medicine.

Biocide and antimicrobial susceptibility of methicillin-resistant staphylococcal isolates from horses

The aim of this study was to evaluate the biocide and antimicrobial susceptibility of methicillin-resistant staphylococcal isolates from horses. Fourteen methicillin-resistant staphylococci (MRS) were subjected to an extensive genotype characterization, including SCCmec, dru, spa, PFGE and MLST typing. Antimicrobial susceptibility testing was performed and resistance genes were detected by PCR. Minimum bactericidal concentrations (MBCs) of four biocides [chlorhexidine acetate (CHA), benzalkonium chloride (BAC), triclosan (TCL) and glutaraldehyde (GLA)] were determined following the recommendations of document NF EN 1040. The presence of qac and sh-fabI genes was investigated by PCR. Several antimicrobial resistance patterns and genes were detected. When MRS strains were exposed for a longer period of time, a lower concentration of the biocide was needed to achieve lethality. TCL had the lowest MBC values. All MBC values were lower than the recommended in-use concentrations for veterinary medicine. S. haemolyticus and S. cohnii subsp. cohnii carried plasmid-borne qacA and sh-fabI or qacB and a qacH-like genes, respectively. Biocides appear to be a reliable antiseptic option against MRS, since even in the presence of bacterial efflux mechanisms, the recommended concentration is much higher than the in vitro MBC.