جستجوی مقالات مرتبط با کلیدواژه "mic" در نشریات گروه "پزشکی"

The antimicrobial activity of the methanol extract of Parietaria officinalis from Guilan Province in northern Iran was evaluated against Escherichia coli (E. coli) (Gram-negative) and Staphylococcus aureus (S. aureus) (Gram-positive) using the microtitre plate method to determine the Minimum Inhibitory Concentration (MIC). The Folin-Ciocalteu method was used to analyze the total phenolic compounds. The amount of flavonoids present was determined using the colorimetric aluminum chloride technique. The essential oil of P. officinalis was analyzed to identify its primary components through chemical analysis. Gas Chromatography with a flame ionization detector (GC-FID) and Mass Spectrometry (MS) using a gas chromatograph (GC) (GC-MS) were utilized to analyze the components of the essential oil from wild-grown P. officinalis in Iran. The lowest concentration that inhibits growth for Staphylococcus aureus is 0.01 mg/μL, while for Escherichia coli is 5 mg/μL. The extract showed greater effectiveness against S. aureus than the gram-negative bacteria, E. coli. The total phenolic content was measured at 72.06 (SD=1.48), equivalent to micrograms of phenolic compounds in terms of gallic acid per milligram of dry methanolic extract. The total flavonoid content was recorded at 48.14 (SD=5.05), equivalent to micrograms of flavonoid compounds per milligram of dry methanolic extract. Among 65 observed compounds, 62 components were identified, constituting approximately 98.2%. The oil was rich in geranyl acetate (15.0 %), Viridiflorol (8.9%), trans-β-Ionone (4.8%), Caryophyllene oxide (4.7%), Hexahydrofarnesyl acetone (4.2%), 2,3-Epoxygeranial (4.2%), Bornyl angelate (2.3%) and (-)-Spathulenol (2.2 %). This research found that P. officinalis could be a promising natural substitute for antibiotics in treating S. aureus infections. The antibacterial effects are likely due to its phytochemical components. Results indicated that the P. methanolic extract possessed significant potential for both flavonoid and phenolic content. The extract obtained by the proposed procedure is enriched with flavonoids and is a candidate for a wide range of pharmacological properties.

With the serial trend toward antibiotic resistance in Streptococcus pneumoniae, novel drug development is needed to deal with pathogenic microorganisms that have developed widespread microbial resistance to antibiotics.

Eighty-seven clinical samples were collected from six hospitals in Damascus. A polymerase chain reaction (PCR) was performed to identify the bacterial genus and type. Minimum inhibitory concentrations on Luria-Bertani agar were conducted using several antibiotics and essential oils (EOs).

Twenty-five isolates of S. pneumoniae were found, and amoxicillin and cephalosporins were the most effective antibiotics against 90% of S. pneumoniae bacteria. On the other hand, Thymus syriacus Boiss., Origanum syriacum L., Rosmarinus officinalis L., Cinnamomum zeylanicum L., and Juniperus foetidissima Willd were the most effective EOs.

Only T. syriacus Boiss., O. syriacum L., R. officinalis L., C. zeylanicum L., and J. foetidissima Willd oils had good inhibitory effects against S. pneumoniae.

In recent years, science and industry have focused on preparing nanoparticles (NPs). Due to the resistance of bacteria to antibiotics, there is an overwhelming need to find effective antimicrobials with fewer side effects.

The aim of this study was to synthesize silver and iron oxide NPs and investigate their antimicrobial effects on bacteria isolated from urinary stones.

Cases of urolithiasis from 45 patients with staghorn stones, extracted through percutaneous nephrolithotomy (PCNL), were included in the study. Urinary stone cultures were performed, and the isolation and identification of bacteria were done using standard microbiological techniques. Silver and iron oxide NPs were synthesized, and the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) were evaluated for the isolates.

Seventeen (60.7%) out of 28 positive cultured cases of the isolated bacteria were gram-negative, and 11 (39.3%) were gram-positive. The most abundant isolated bacterium was Escherichia coli , with 13 cases (46.4%). The antibacterial effects of silver and iron oxide NPs revealed that the maximum inhibitory zone for Ag NPs at 1000 ppm was 23 mm, and for Fe 3 O 4 NPs, it was 18.5 mm. The MIC was 180 µg/mL for Ag and 250 µg/mL for Fe 3 O 4 . The MBC was 228 µg/mL for Ag and 300 µg/mL for Fe 3 O 4 .

Nanoparticles exhibited antibacterial effects on the bacteria studied in a concentration-dependent manner. Ag NPs showed a more pronounced bactericidal effect than Fe 3 O 4 NPs. As a result, these two NPs demonstrated effective antibacterial activity against both gram-positive and gram-negative bacteria.

Even though dental implants have a high success rate, the most frequent implant dentistry problem is peri-implantitis. With increased bacterial resistance to antibiotic, the herbal products are more preferred. This study aimed to find a concentration of aqueous cinnamon extract that prevents the patient's anaerobic bacterial flora from growing with peri-implantitis and to evaluate the phytochemical composition of Aqueous Extract of cinnamon.

This experimental in vitro study was conducted using total anaerobic bacterial samples isolated from the implant pockets of 10 patients (male and female) aged 40-60 years suffering from chronic peri-implantation requiring the presence of a probing pocket depth≥10 mm and clinical attachment loss of (1-2) mm or more. Antibacterial assay was performed using well diffusion agar at an extract concentration of 5, 10, 12, 15, 20, and 25 mg/mL, which were chosen randomly according to the pilot study with a positive control as CH2% and a negative one as distilled water to measure the inhibition zone through the center from edge to edge of inhibition zone. Final concentrations (1, 3, 6, 12, 24, 48) mg of the extracts were used to find the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Secondary metabolites of the prepared cinnamon aqueous extract were detected using Gas Chromatography-Mass Spectrometry (GC-MS) and phytochemical test.

The present study showed that Cinnamon contains alkaloid, flavonoids, saponins, and glycoside, and it significantly inhibited the isolated bacteria with MBC at 24 mg/mL and Minimum Inhibitory Concentration (MIC) at 12 mg/mL. Well-diffusion assay revealed that the mean values of inhibition zone diameter were 1.15±0.118, 1.27±0.142, 1.38±0.132, 1.51±0.13 and 1.46±0.084 cm for concentrations of 12.5, 15, 20, 25 and Chlorhexidine (CHX) 2% mg/mL, respectively (p>0.05). The increase in inhibition zone diameters was associated with the increase in cinnamon extract concentration, while concentrations of (5.10) mg/mL revealed no zone of inhibition.

According to the results, this study determined that cinnamon was a potent antimicrobial agent, and that it can be used as anti-infective therapy against peri-implantitis to overcome implant failure.

 Effective brucellosis treatment necessitates antibiotics that can penetrate macrophages. This study systematic review and meta-analysis aimed at assessing the antibiotic susceptibility profile of Brucella spp. isolated from humans, addressing this critical gap in understanding Brucella infections and their treatment.

 Two authors conducted a systematic search across PubMed, Web of Science, and Scopus, with no time restrictions, encompassing English studies. Data extraction employed a standardized sheet, with two independent authors, and disagreements were resolved by a third. The data sheet included study characteristics and susceptibility/resistance information for various antibiotics. Statistical analysis involved random effects models, Mantel-Haenszel methods, I2 tests, z-tests, and funnel plots using R and RStudio.

 Based on the pooled susceptibility ratios, among the 630 samples of Brucella spp., 98% (95% CI: 85% - 100%) were susceptible to trimethoprim. Among the 1255 samples of Brucella spp., 82% (95% CI: 54% - 95%) were susceptible to rifampicin. Among the 1344 samples of Brucella spp., 100% (95% CI: 78% - 100%) were susceptible to doxycycline. Among the 942 samples of Brucella spp., 100% (95% CI: 85% - 100%) were susceptible to tetracycline. Among the 893 samples of Brucella spp., 100% (95% CI: 82% - 100%) were susceptible to ciprofloxacin. Among the 906 samples of Brucella spp., 97% (95% CI: 96% - 98%) were susceptible to gentamicin.

 Based on our results, trimethoprim, doxycycline, tetracycline, ciprofloxacin, and gentamicin were effective, but rifampicin had lower susceptibility. This informs antibiotic selection for Brucella infections, underscoring its importance in managing the disease.

One of the major concerns of the health system of countries is resistance to common fungicides by pathogenic strains. The World Health Organization places special emphasis on finding natural compounds with antifungal properties. Therefore, in the present study, the antifungal and antitumor effects of ethanol extract of propolis were studied. For this purpose, at first, M. furfur MF7 strain was prepared and cultivated. Then, propolis ethanol extract was prepared. The microbioassay method was used to study the effects of different concentrations of propolis extract on the growth of M. furfur, and the broth microdilution method was used to determine the MIC and MFC. Also, the effect of this extract on ergosterol biosynthesis was studied. The results of the study showed that the MIC of propolis ethanol extract on this pathogenic fungus is 10 mg/ml and its MFC is 20 mg/ml. The decrease in fungus growth was seen with the increase in the concentration of propolis ethanol extract, so that there was no growth in the concentration of 20 mg/ml ethanol extract of propolis. Also, with the increase in the concentration of the extract, the biosynthesis of ergosterol decreased, and at the concentrations of 15 and 20 mg/ml, a severe decrease in the biosynthesis of this compound was seen. Propolis reduced HT-29 cell line viability at 2000µg/mL. In general, it was concluded that propolis ethanol extract is a suitable option for treating diseases caused by M. furfur. Studies in clinical conditions are needed.

 Cryptococcal meningoencephalitis is a life-threatening fungal infection in human immunodeficiency virus (HIV)-infected patients. Cryptococcus neoformans var. grubii and neoformans are the causative agents that usually respond well to fluconazole and amphotericin B. However, resistance/ non-responding cryptococcal meningitis cases to fluconazole and amphotericin B have been reported globally.

 The causative Cryptococcus was identified by phenotypic and singleplex polymerase chain reaction (PCR) targeting the putative sugar transporter (STR1) gene. In addition, the phospholipase and proteinase enzymatic activities of the isolates were determined by the plate method using egg yolk agar and bovine serum albumin agar plates, respectively. Finally, the in-vitro minimal inhibitory concentration (MIC) of fluconazole, voriconazole, and amphotericin B against isolated C. neoformans strains was determined by the broth microdilution method.

 A total of 50 C. neoformans strains were isolated from the cerebrospinal fluid of HIV-infected patients, which were further identified as variety grubii by simplex polymerase chain reaction (PCR). All the isolated strains producing phospholipase and proteinase enzymes were determined by the calculation of Pz, a ratio of colony diameter and diameter of colony plus the precipitation zone. A comparative high proteinase enzyme activity was observed, and these strains produced medium to high phospholipase (mean Pz 0.3720±0.082, range 0.23-0.56) and proteinase activity (Mean Pz 0.3069±0.086, range 0.012- 0.54). A varied antifungal MIC was detected, and voriconazole had the lowest MIC50 and MIC90 (0.03 & 0.06 µg/mL) in comparison to fluconazole and amphotericin B.

 Cryptococcus neoformans var. grubii is the commonest cause of cryptococcal meningoencephalitis in HIV-infected patients. The isolates had varied extracellular hydrolytic enzyme activities. The emergence of C. neoformans strains with higher fluconazole MIC (≥4 mcg/mL) could have resulted in treatment failure.

Green Synthesis is a method for synthesizing nanoparticles using protein, carbohydrates, plant extracts, and similar structures, which has made it a simple, cost-effective, environmentally friendly, and repeatable method compared to chemical methods. This study was conducted to investigate the antibacterial effect of silver nanoparticles (Ag-NP), synthesized by the extract fruit of Prosopis fracta, on Streptococcus mutans bacteria as the cause of tooth decay. The synthesized nanoparticles were identified through the UV-Vis spectrophotometer, transmission electron microscope (TEM), and powder X-ray diffraction (PXRD) methods, while their antibacterial effect was evaluated by the usage of microbroth dilution test. UV-Vis spectroscopic analysis displayed the presence of a peak in the range of 425-445 nm and indicated the successful synthesis of nanoparticles in the extract. Meanwhile, the average size of our product was determined by the TEM image to be about 30 nm. According to the investigation results, the synthesized nanoparticles exhibited satisfying antibacterial effects against the studied bacteria.

Bacteria are responsible for a large part of the food poisoning. Application of natural preservatives for protection foods from microbial spoilage and to control the occurrence of foodborne pathogens has become an important issue worldwide. The aim of this study was to investigate the composition of sumac (Rhus coriaria L.) essential oil and its antimicrobial effect on some food borne bacteria. The antimicrobial activity of R. coriaria L. essential oil was tested against some foodborne bacteria including: Pseudomonas aeruginosa, Yersinia enterocolitica, Klebsiella pneumonia, Listeria monocytogenes and Streptococcus pyogenes by microdilution method. Furthermore, sumac fruit essential oil was also investigated to determine the chemical compositions by the gas chromatography (GC/MS) method. The essential oil showed a strong antimicrobial activity with a concentration dependence and a broad antimicrobial spectrum for all tested bacteria species. Streptococcus pyogenes was found to be the most sensitive Gram positive bacteria with a minimum inhibitory concentration (MIC) of 0.156 mg/ml and Pseudomonas aeruginosa was the most resistant bacteria with a minimum inhibitory concentration (MIC) of 2.5 mg/ml. Sumac essential oil showed more antibacterial effect against Streptococcus pyogenes and Listeria monocytogenes isolates in comparison with other tested bacteria (P<0.05). Eleven constituents in the fruit’s essential oil were identified. The predominant compounds in the essential oil were trans-Caryophyllene (22.3%) and Butanedioic acid, and diethyl ester (21.01%). Our findings suggest the possibility of using the essential oil of R. coriaria L. as a novel source of natural antimicrobial agents for the food and pharmaceutical industries and herbal therapeutic.

Candida species are the second most common cause of vulvovaginitis worldwide. Vulvovaginal Candidiasis (VVC) is a common disease affecting more than 75% of all women at least once in their lifetime and 5 to 8% of those individuals also develop recurrent infections. Correct identification of the isolated Candida species is essential to direct the empirical antifungal therapy. The aim of this study were to isolate Candida from VVC patients, show its characterization and in vitro antifungal susceptibility against six antifungal drugs by the broth microdilution method. Vaginal swabs were collected from infected women. One sample was processed for direct microscopic examination and other one was used for culture on Sabouraud dextrose agar (SDA) and CHROMagar. Isolates was identified by battery of tests and antifungal susceptibility testing of Candida species was done by Microdilution method. A total of 145 isolates of candida species were obtained. Candida albicans was found to be the most frequently isolated species, i.e. 114 (78.6%) of the total isolates, followed by C. glabrata 17 (11.7%), C. krusei 11 (7.5 %), C. parapsilosis 2 (1.3 %), and C. tropicalis 1 (0.68%). All drugs were active against all of the isolates except for Nystatin and Econazole, two (5%) of C. albicans were non-susceptible to it and three (7%) of C. albicans isolates were non-susceptible to Tioconazole. Identification of Candida to species level and their antifungal susceptibility testing should be done to achieve better clinical results.

Bacterial resistance against antibiotics has caused many problems in treating humans and animal infections worldwide. Nowadays, researchers are continuously seeking to develop novel antibacterial to tackle the issue of microbial resistance. Antimicrobial peptides have been introduced as new effective strategies that kill bacteria quickly and cause less antibiotic resistance. In this study, we evaluated the antibacterial and cytotoxic effects of a synthesized peptide (NRWCFAGRR-NH2) on some Gram-positive and –negative bacteria and eukaryotic cells.

Twelve bacterial strains were selected to study the antimicrobial effect of the NRWC peptide. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays were used to study the bacteriostatic and bactericidal activity of these peptides, respectively. The cytotoxic effect of the peptide was evaluated on Hela cell line and human RBC using the MTT assay and hemoglobin release measurement, respectively. The J774 macrophage cell line was used to measure nitric oxide production in response to the peptide.

The results showed that NRWCFAGRR peptide has a bactericidal and inhibitory effect on all 12 bacterial strains' growth in a dosedependent manner. It has also been proven that the toxic effect of the peptide on human cells is evitable at the MIC and MBC concentration. The highest amount of nitric oxide production was induced after 48 hours of treatment.

Considering the research conducted in the field of antimicrobial peptides, our designed peptide has antimicrobial properties that kill some of the pathogenic microorganisms directly and can theoretically kill some organisms indirectly via induction of nitric oxide by macrophages.

Klebsiella pneumonia (K.pneumonia) is one of the causative agents of lung infections, wound infections, urinary tract, and bloody diarrhea. One of the most common ways of transmission in neonatal and surgical wards is through hospital staff, nurses, and physicians. It could be transmitted to hospitalized patients and personnel through feces, respiratory secretions, contaminated equipment, and hands. To prevent the transmission of nosocomial infections, hand washing of employees with biocides can be effective.

The minimum inhibitory concentration of 65 K.pneumonia isolates was determined according to CLSI guidelines compared to common biocides used in educational hospitals in Urmia, Iran, such as benzalkonium chloride and chlorhexidine. PCR was performed to evaluate the presence of cepA genes.

The results showed a significant relationship between the presence of cepA gene and high MIC compared to chlorhexidine bioside in K. pneumoniae. But there was no significant relationship between the presence of cepA gene and multidrug-resistant (MDR) isolates.

It is concluded that, detection of cepA gene or other genes involving drug resistance should be extended by using another tests with more reliability and reproducibility like gene expressions and gene cloning methods.

Mycobacterium is a genus of Actinobacteriaceae and the Mycobacterium family, including important pathogens, such as Mycobacterium tuberculosis (i.e., the cause of tuberculosis) and Mycobacterium leprae (i.e., the cause of leprosy). Tuberculosis is still a major cause of death in human societies.

The current study aimed to evaluate the effect of ethanolic extract of garlic on Mycobacterium tuberculosis isolated from patients in Zabol, Iran, and investigate the presence of antibiotic-resistant genes in Mycobacterium tuberculosis.

Garlic (Allium sativum) was collected from Zabol, and the ethanolic extract of garlic leaf was obtained. In this study, 50 strains of Mycobacterium tuberculosis were obtained from the patients in Zabol. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Some antibiotics, such as isoniazid, pyrazinamide, ethambutol, amikacin, streptomycin, and rifampicin, were used for positive control. Genomic deoxyribonucleic acid was extracted by the sodium dodecyl sulfate method. Furthermore, the presence of antibiotic-resistant genes, namely KatG, PncA, embC, embA1, embA2, embB1, embB2, rrs, rpsL, and ropB, in Mycobacterium tuberculosis was investigated using polymerase chain reaction.

The lowest MIC and MBC of garlic ethanolic extract against Mycobacterium tuberculosis were 3.25 and 7.5 ppm, respectively. The highest MIC and MBC were 60 and 120 ppm, respectively. Following the investigation of the presence of antibiotic-resistant genes in Mycobacterium tuberculosis, it was determined that it contains KatG, PncA, embC, embA1, embA2, ropB, rpsL, rrs, embB2, and embB1 genes. The highest resistance of Mycobacterium tuberculosis was against rifampin (81%) and then amikacin (76.6%) belonging to ropB and rrs genes, respectively.

The results of the present study showed that the ethanolic extract of garlic was very effective in Mycobacterium tuberculosis and the most effective genes in mycobacteria were ropB and rrs. Although garlic is very effective in Mycobacterium tuberculosis, it is not recommended to directly use the results of this study. Therefore, it is required to perform clinical trials to confirm the results.

The ginger root extract has shown remarkable antimicrobial effects. Nanocarriers based on biodegradable polymers (like chitosan) are promising drug delivery vehicles for antibacterial compounds. In this study, aqueous and methanolic extracts of ginger root were prepared, loaded on chitosan nanoparticles (NPs), and their antimicrobial effects were investigated.

The NPs were prepared using the ionic gelation technique. The central composite design model was employed to optimize the formulation variables and achieve the minimum particle size and maximum zeta potential. The total phenol content of the powdered extracts was determined. The antimicrobial activity of the NPs was evaluated by the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).

The optimum size of NPs containing methanolic or aqueous extract were 188.3 and 154.7 nm, with a zeta potential of 29.1 and 32.1 mv, and entrapment efficiency percent (E.E.%) of 61.57±3.12% and 44.26±2.57%, respectively. Transmission electronic microscopy images confirmed the spherical particles in the low nanometer range. The phenol content of methanol extract was higher than the aqueous one (60.216 ± 1.83 and 39.835 ± 1.72 mg gallic acid equivalent/100 g), respectively). According to the results of the MIC and MBC, methanol extract NPs showed more potent antimicrobial effects, which seems to be associated with higher concentrations of phenolic compounds. The FTIR spectrophotometry showed no chemical interaction between the extracts and other ingredients.

The results demonstrated that current NPs significantly increased the antibacterial effects of ginger extracts and could be selected for further evaluation.

 This study was done to investigate the antimicrobial activity of rosemary and olive extracts on antibiotic-resistant Escherichia coli isolated from quail feces in Zabol city.

 Ethanolic and methanolic extracts of rosemary (leaf) and olive (leaf) plants were prepared using a rotary apparatus. Also, E. coli strains were isolated from poultry feces samples, the minimum inhibitory concentration and the minimum bactericidal concentration were determined by the microdilution method.

 The lowest values of MIC and MBC against E. coli were 12.5 ppm and 25 ppm for rosemary ethanolic extract and 25 ppm and 50 ppm for rosemary methanolic extract, respectively. The lowest values of MIC and MBC against E. coli were 12.5 ppm and 25 ppm for olive ethanolic extract and 6.25 ppm and 12.5 ppm for olive methanolic extract, respectively.

 In general, methanol solvent and olive extract are highly effective against E. coli. Due to the obtained results and increasing resistance of bacteria to chemical antibiotics, it is suggested that with further studies on olives and the use of methanol solvent in the extraction of plant extracts, antibacterial compounds of olives and other plants be used in the treatment of bacterial infections.
 

 This study aimed to investigate the inhibitory and lethal effect of artichoke on pathogenic strains of Staphylococcus aureus and compare it with antibiotics in vitro.

 Ten strains of S. aureus were isolated from the vagina of women in Amir Al-Momenin Hospital of Zabol, Iran. The resistance pattern was determined by the disk diffusion method. Finally, the effect of the extract on bacteria was determined by the 96-well microplate method.

 The results of the antibiotic resistance pattern showed that S. aureus samples had the highest resistance to oxacillin antibiotic and were sensitive to other antibiotics, and only one sample was sensitive to vancomycin antibiotic. The lowest inhibitory concentration of artichoke against S. aureus was 3.1 mg/mL, but five strains were inhibited at a concentration of 6.25 mg/mL.

 Ethanolic extract had a significant inhibitory effect on the growth of S. aureus pathogens. Further clinical research is necessary for clinical use of these extracts.