جستجوی مقالات مرتبط با کلیدواژه « Anti-bacterial agents » در نشریات گروه « پزشکی »

Silver nanoparticles (AgNPs) can be considered as the new antibacterial agents. The antibacterial effects of synthesized AgNPs from Iranian pistachio hulls on several antibiotic-resistant bacteria were assessed in this study. 

In an experimental study, AgNPs were synthesized by reducing Ag+ ions using pistachio hulls. Several methods characterized the qualities of AgNPs. Antibacterial activities of the AgNPs against six gram-positive and gram-negative standard bacteria and 30 multidrug-resistant (MDR) clinical isolates were investigated by well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. 

The aqueous extract of pistachio hulls had an acceptable potential to synthesize AgNPs, and the formed nanoparticles displayed suitable size and acceptable stability in solutions. Antibacterial activities of the AgNPs were detected against two standard strains, Escherichia coli, and Staphylococcus aureus, with growth inhibition zones of 13 and 11 mm, respectively. MIC were 10 mg/ml for E. coli and 20 mg/ml for S. aureus. MBC for both bacteria was the same as MIC. MIC and MBC AgNPs against 15 methicillin-resistant S. aureus (MRSA) isolates ranged from 40 to 10 mg/ml. In extended-spectrum beta-lactamase (ESBL) E. coli isolates, 11 and 3 isolates have MIC equal to 20 and 10 mg/ml, respectively. Three ESBL E. coli isolates had 10, 5 and 2.5 mg/ml MBC; in other isolates, MBC and MIC were the same. 

The green synthesis of AgNPs using pistachio hull can replace common chemical and physical methods. AgNPs displayed antibacterial activities, and they could replace some antibiotics.

This study aimedto investigate the cytotoxic and antibacterial properties of essential oils and hydroalcoholic extracts from Elettaria cardamomum fruit (E. cardamomum).

Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) was used as the test subject for the agar diffusion test in this in-vitro investigation to determine the antibacterial effect of the extract and essential oil. The broth microdilution method was used to calculate their minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC). The methyl thiazolyl tetrazolium (MTT) assay was used to assess their cytotoxicity against human gingival fibroblasts. Tukey's test (alpha=0.05) and ANOVA wereused to evaluate the data.

The E. cardamomum hydroalcoholic extracts and essential oil demonstrated strong antibacterial activityon A. actinomycetemcomitans. E. cardamomum essential oil (91.5±1.1 mm) and E. cardamomum extract (9.5±0.4 mm) had thehighest and lowest growth inhibition zones, respectively. For E. cardamomum essential oil, the MIC and MBC were 1.45%, and for E. cardamomum extract, they were 11.5% (v/v). The essential oil exhibited appreciable cytotoxicity at low doses, while the extract did not.

Because of its antibacterial properties and low cytotoxicity at low concentrations, the hydroalcoholic extract of E. cardamomum, one of the compounds examined, may have applications as an organic mouthwash.

Ficus johannis Boiss. is a shrubby species in the family Moraceae, exclusively found in Iran, Afghanistan, and Pakistan. This research studies the total phenolic content, flavonoid concentrations, antioxidant capacity, and antimicrobial activity of this biologically unknown species.

The Leaves and fruits of the plant were gathered from the northern slope of Taftan Mountain in Sistan and Baluchestan, in the summer of 2022. After washing, drying, grinding, and obtaining hydroalcoholic extracts of the fruits and leaves, quantifying the phenolic and flavonoid concentrations was done spectrophotometrically utilizing the Folin-Ciocalteu and aluminum chloride colorimetric techniques, respectively. The anti-radical activity of the organs was assayed via the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) protocol and their antimicrobial effects were assessed using the broth microdilution and streak plate techniques against six bacterial, and three fungal pathogens including Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus epidermidis, Streptococcus pyogenes, Bacillus cereus, Aspergillus fumigatus, Fusarium oxysporum, and Candida albicans.

The phenolic compounds were found to be evenly distributed in both leaf and fruit extracts (around 43 mg GAE/g dry extract) while flavonoids were detected in significantly higher concentrations in the fruit extract (14.62 vs 9.57 mg QrE/g dry extract). The leaf extract was better at scavenging free radicals compared to the fruit extract (IC50 93.79 vs 239.62 μg/ml, respectively), while both extracts showed higher IC50 values than the positive control. The leaf extract showed better inhibitory effects on the tested microorganisms compared to the fruit extract. The leaf extract was effective against all tested bacteria, whereas, among the investigated fungi, only Aspergillus fumigatus was vulnerable to it. Conversely, the fruit extract was able to prevent the growth of all investigated fungal strains, but only two bacterial strains (Streptococcus pyogenes and Klebsiella pneumonia) were affected by it. Moreover, both lea and fruit extracts showed the best antimicrobial activity against Aspergillus fumigatus with MIC values of 128 and 512, repectively.

The Ficus johannis fruits and leaves are great sources of phenolic and flavonoid compounds with moderate anti-radical capacity. Moreover, the fruit extract mainly contains antifungal ingredients while the leaf extract chiefly includes antibacterial agents.

There is a global threat of methicillin-resistant Staphylococcus aureus (S. aureus or MRSA), which has been regarded as a priority pathogen by the world health organization (WHO). Livestock and its products are the sources of MRSA which can often occur in poor breeding conditions. The present study aims to investigate the prevalence of MRSA and the rate of antibiotic residue in pasteurized and raw farm milk.

This was a cross-sectional study conducted from April to July 2020. 250 samples (200 samples of raw milk in farms around Tehran and 50 samples of pasteurized milk) were cultured to evaluate the occurrence of S. aureus and its antimicrobial susceptibility profile to 7 antimicrobial panels. Hansen Kit was used to monitor antibiotic residue in milk.

63 S. aureus isolates (25.2%) were detected from 250 milk samples. Among 200 raw milk samples, 48 (24%) S. aureus isolates were detected and no strain of S. aureus was isolated from pasteurized milk. The highest rates of resistance belonged to ampicillin (95.8%), amoxicillin/clavulanic acid (87.5%), tetracycline (50%), and cefoxitin (45.8%). Moreover, 43 (17.2%) out of 250 milk samples had antibiotic residue in the antibiotic residue test using Danish Hansen kit.

The present study indicates a high prevalence of subclinical S. aureus in dairy herds in Tehran, Iran. The milk contaminated with S. aureus and MRSA, posed a risk to public health owing to the presence of a phenotype resistant to very common antibiotics

Antibiotic resistance within the poultry sector presents a considerable health concern due to treatment inefficacy and resistance transmission to humans and the environment. The investigation of plasmid-mediated quinolone resistance (PMQR) in Escherichia coli, acknowledged for its role in advancing resistance, remains inadequately studied in Iranian poultry. This study aimed to evaluate PMQR gene prevalence as well as to determine correlation between resistance phenotype and genotype in E. coli obtained from poultry colibacillosis.

A collection of 100 E. coli isolates from the viscera of broilers suspected to colibacillosis was assessed. Using the Kirby-Bauer disk diffusion method, antimicrobial susceptibility tests were conducted for ofloxacin, nalidixic acid, levofloxacin, ciprofloxacin, and ampicillin. Additionally, PCR was employed to screen for qnrS, qnrB, and aac(6)Ib-cr genes.

Among the analyzed E. coli isolates, 51% demonstrated resistance to at least one of the tested antibiotics, with 17% exhibiting resistance to four different antibiotics. Nalidixic acid displayed the highest resistance rate at 48%, while ampicillin had the lowest at 16%. PMQR genes were detected in 28% of the E. coli isolates, with aac(6′)-Ib-cr being the most prevalent at 14%, followed by qnrB in 13%, and qnrS in 7%.

The study underscores the vital need for careful antibiotic usage in poultry to curb the emergence of antibiotic-resistant bacteria. The results illuminate the prevalence of PMQR genes and their association with resistance trends in Iranian poultry, forming a pivotal basis for forthcoming approaches to combat antibiotic resistance within the poultry sector.

Nosocomial infections are significant parts of the treatment challenges of hospitals. Different species of the Artemisia genus are widely distributed in Iran. The present study aimed to compare the in vitro effects of different aqueous extracts of Artemisia species against nosocomial bacterial strains.  style="font-family:"B Traffic""

 24 different aqueous extracts, including decoctions and infusions were prepared from the aerial parts of Artemisia ciniformis, A. turanica, A. kopetdaghensis, A. khorasanica, A. vulgaris, and A. sieberi. Total phenolic contents were determined by the Folin-Ciocalteu method.  The minimum inhibitory concentration (MIC) values of the extracts against the bacterial strains including Staphylococcus aureus, Streptococcus pyogenes, Acinetobacter sp., Pseudomonas aeruginosa, Enterococcus faecalis, Staphyloccocus epidermidis, Micrococcus luteus, Klebsiella  neumonia and Escherichia coli were measured using the microdilution broth method.

The lowest MIC value was observed for the decoction</span> of A. turanica (0.25 mg/ml) against S. pyogenes. The largest range of bacterial sensitivity (3 strains) was related to the decoction of A. sieberi. The growth of S. epidermidis was inhibited by a larger group of extracts. The highest total phenolic content was recorded for decoction and infusion of A. turanica.

 The decoctions of the aerial parts of A. sieberi and A. turanica were superior to the other extracts in terms of the in vitro antibacterial spectrum and selective potency, respectively.

 Natural pigments from microbial sources are a class of compounds with various structures and a wide range of uses, which have become an important source of antibiotic production.

 This study aimed to screen and identify a new type of pigment-producing microorganism from purple soil in the Sichuan Basin. At the same time, this study aimed to purify and identify the produced pigment, preliminarily optimize its fermentation conditions, and characterize its antibacterial activity.

 Through morphology, physiology, biochemistry, and molecular sequencing, the strain LS-2 was identified. The pigment was purified by column chromatography, and its antibacterial activity was characterized by a disc diffusion assay. Through the analysis of the ultraviolet-visible (UV-vis) absorption spectrum, infrared (IR) absorption spectrum, and liquid chromatography-mass spectrometry (LC-MS), the yellow pigment was identified.

 An actinomycin D-producing Streptomyces parvulus was isolated from the purple soil in the Sichuan Basin. Its optimal fermentation conditions were culture at 34°C on Gause’s synthetic medium with pH 6.5, and the yield reached 540 mg/L after 48 hours. The actinomycin D produced by the strain has excellent antibacterial activity against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli).

 A new actinomycin D-producing strain of Streptomyces parvulus LS-2 was isolated and identified. The strain has a high production of actinomycin D, which has excellent antibacterial activity.

To develop a probiotic formulation for poultry feed, a few poultry gastrointestinal derived lactic acid bacteria (pGIT-d-LAB) were isolated from chicken intestinal specimens and in vitro experiment was performed to evaluate their efficacy as potential probiotic candidate.

A total of 6 strains of LAB: Lactobacillus brevis (L. brevis), Lactobacillus acidophilus (L. acidophilus), Lactobacillus casei (L. casei), Pediococci spp, Lactobacillus fermentum (L. fermentum) and Lactobacillus plantarum (L. plantarum) were isolated and cultured for collection of Cell Free Supernatant (CFS). CFS collected was tested against pathogenic bacterial isolated from chicken feces as well as prevalent fungal pathogens, utilizing agar-well diffusion techniques. A preliminary investigation into the susceptibility of the pathogens to diverse antibiotics and antifungal drugs was conducted. Bacterial pathogens exhibiting resistance to a minimum of three classes of antibiotics were subsequently identified for pGIT-d-LAB CFS screening.

The observed results revealed that the CFS derived from the isolates exhibited varying degrees of growth inhibition against different pathogens. Among the tested pGIT-d-LAB isolates, L. acidophilus demonstrated the most prominent zone of inhibition, measuring 18 mm against Klebsiella pneumoniae ZTAC 1233. Notably, Citrobacter diversus ZTAC 1255 showed resistance to all tested pGIT-d-LAB. Quantification of the metabolites produced was performed, and peak production levels was determined. L. acidophilus produced the highest amount of lactic acid (1.789g/l), Pediococci spp. produced the highest amount of diacetyl and H202 (1.918g/l) (0.0025g/l) at 48 hr peak values respectively.

The test isolates are potential probiotic candidates for controlling pathogens in poultry.

Drugs used in treating patients who contracted the coronavirus disease of 2019 (COVID-19) include chloroquine or hydroxychloroquine (CQ, HCQ), antiviral, steroid, and antibiotic. Treatment outcomes were characterized by positive and adverse reactions as therapeutic options were based on clinical trials coupled with diagnostic constraints. This study assesses the diagnostic processes and critically examines the drugs used in the clinical settings to treat COVID-19 in Nigeria.

The search was conducted on various databases with a focus on diagnoses and drugs used to treat COVID-19. Articles that did not meet selection criteria were excluded and the data collected from sampled articles were collated, analyzed, and evaluated. 

The finding showed a lack of sufficient evidence-based data to support the use of CQ/HCQ, remdesivir, lopinavir/ritonavir, and antibiotics, such as azithromycin as treatment options for COVID-19, even though patients responded partly to the drugs probably due to their action mechanisms. 

There is a lack of evidence-based scientific data to guide the definitive treatment of COVID-19 patients during the pandemic. Drugs used in the emergency were based on clinical trials. The efficacy of the drugs depends partly on the innate capability of the immune system of an affected individual.

 Sepsis is a leading cause of morbidity and mortality in neonates.

 This study aimed to investigate the bacterial profile and antibiotic sensitivity in infants with sepsis.

 This cross-sectional study was conducted on 90 neonates with sepsis admitted to the neonatal intensive care unit of Namazi Hospital, a tertiary-level hospital, in Shiraz, Iran, from 2020 to 2021. Demographic and clinical data including gestational age, previous diseases, maternal infectious, underlying diseases, history and duration of premature rupture of the membrane and delivery, clinical symptoms (fever, reduced breastfeeding, and lethargy), laboratory results (complete blood cell and C-reactive protein), and results of blood and urine cultures were recorded and analyzed.

 Among 90 neonates with sepsis, the average age was 6.7 ± 7.6 days; 54 were male (60.0%), and 36 were female (40.0%). Fifty (55.5%) neonates had early sepsis. Gram-negative organisms were grown in 61% of positive blood cultures; the most common was Klebsiella. Among Gram-positive organisms, Staphylococcus epidermidis was the most common. Most organisms were sensitive to colistin, and most were resistant to cefotaxime. There was a significant relationship between the age of onset of sepsis symptoms and birth weight in infants with positive blood cultures (P = 0.004) (r = 0.3).

 Gram-negative bacteria are the most common causes of sepsis, mainly resistant to aminoglycosides and cefotaxime. Therefore, increasing awareness about the optimal use of antibiotics is necessary to curb the increase in resistance levels.

Antibacterial activity against endodontic pathogens is a desirable feature for root canal sealers. The objective of this study was to compare the antibacterial effect of three resin-based endodontic sealers (AH26, Adseal, and Beta RCS) against Enterococcus faecalis in vitro.

The antibacterial properties of the sealers were assessed against E. faecalis using agar diffusion test (ADT) for fresh state (N=10) and direct contact test (DCT) for freshly-mixed and set states of the materials (N=10). In ADT, the diameter of the zones of inhibition was measured after 24h of contact. In DCT, the colony-forming units of the bacteria were counted after 30 minutes and 180 minutes of exposure. The results were analyzed with two-way ANOVA and independent sample t-test. P<0.05 was considered significant.

Regarding DCT results, all test materials indicated an antibacterial effect, both in freshly-mixed and set states. The highest antibacterial effect was related to Adseal, whereas the lowest was observed in Beta RCS. There was a significant difference between all study groups (different sealers, setting states, and contact times; P<0.001), except for freshly-mixed AH26 and Adseal at 180 minutes (P>0.05). According to ADT, AH26 and Adseal represented the widest and the smallest inhibition zones, respectively (P<0.001).

Within the limitations of this in vitro study, AH26, Adseal, and Beta RCS showed antibacterial effects against E. faecalis in both freshly-mixed and set states. The antibacterial effect increased over time in all of the studied sealers.

  Urinary tract infection (UTI) is one of the most important health care issues with a major role in occurrence of nosocomial infections. Rise in antibiotic resistance rate by UTIs not only lead to morbidity and mortality, but also impose a remarkable financial burden on health care infrastructure. This study was undertaken to evaluate the prevalence of UTIs and identify common microorganisms responsible for infection and their antibiotic resistance profile in our Intensive Care Unit (ICU).

  In this perspective cross-sectional study, data from patients admitted to the ICU of two main referral hospitals in Yasouj, Southern-west Iran from 2015- 2016 was collected. Patients were selected in a subsequent manner and were asked to provide a midstream urine sample. Positive cultures were subsequently placed in differential culture medium for the diagnosis of the causative pathogen, while also evaluating with Muller Hinton Agar culture for antibiogram through disc diffusion method, to evaluate the pathogens sensitivity and resistance towards the tested antibiotics.

 Based on bacterial culture results among a total of 112 obtained urine samples, 100 (89.2%) were negative while 12 (10.8%) were positive, in which the majority were gram-negative (6.25%) and the most frequent pathogen was Escherichia coli (5.3%). All cases of UTI in our population were fully resistant to cephalexin, ampicillin, and amoxicillin. Also, all gram-negative cultures were sensitive to amikacin. There was also no significant association between the antibiogram results with age, gender, and gram results.

 we report actual data on the resistance patterns of uro-pathogens in a public hospital in Iran. Escherichia coli showed a high prevalence among all UTIs with lower resistance rates to the antibiotics. Resistance to nalidixic acid and trimethoprim-sulfamethoxazole were significantly lower than other oral antibiotics, making both a suitable and cheap alternative for the empirical treatment.

Medicinal plants have played crucial roles in the traditional health care system since the origin of mankind. Among them, cinnamon is used not only as a spice in food but also as a substance with many health-beneficial effects. The aim of the present study was to identify the antibacterial activity of cinnamon bark extract against bacterial isolates from patient pus samples that might help treat infections.

The antibacterial potential of cinnamon bark extract in both ethanol and methanol against 6 bacterial isolates obtained from pus samples received in the Microbiology Laboratory was identified by agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) using standard techniques.

By agar well diffusion, the highest inhibitory activity of ethanol and methanol extracts of cinnamon was shown by Staphylococcus aureus, followed by coagulase-negative Staphylococci. The lowest inhibitory effect was shown by Proteus mirabilis. The ethanol extract of cinnamon MIC and MBC ranged from 6.25 mg/mL to 12.5 mg/mL and 12.5 mg/mL to 50 mg/mL. The methanol extract of cinnamon MIC showed a value of 12.5 mg/mL, and the methanol extract of MBC ranged from 12.5 mg/mL to 50 mg/mL against all bacterial isolates of the present study.

Staphylococcus aureus is sensitive to the alcoholic extract of cinnamon bark, but its effect is less than that of the selected antibiotic.

Formation of white spot lesions, due to plaque accumulation and bacterial biofilm growth, is a common complication in orthodontic treatment. The present study aimed to compare the antibacterial properties of an orthodontic composite containing silver (Ag) and amorphous tricalcium phosphate (ATCP) nanoparticles against Streptococcus mutans (S. mutans).  

In this in vitro study, 0.3% w/w Ag nanoparticles and 3% w/w ATCP nanoparticles were added to Transbond XT orthodontic composite. Totally, 48 composite discs were fabricated in three groups) n=16). The experimental groups included composite specimens containing nanoparticles and the control group included composite specimens without nanoparticles. The antibacterial effects of composite discs with and without nanoparticles against S. mutans (ATCC 35668) in the three groups were assessed by the direct contact test after 24 hours and 30 days. The number of bacterial colonies was visually counted in the three groups and compared. Data were analyzed by one-way ANOVA and Duncan's multiple comparisons test. P-values under 0.05 were considered significant.

The antibacterial properties of nano-composites significantly increased in both experimental groups of composites containing Ag and ATCP nanoparticles, compared to the control group (P<0.001). The highest antibacterial activity was observed in the orthodontic composite containing ATCP nanoparticles.

Addition of Ag and ATCP nanoparticles to orthodontic light-cure composite increases its antibacterial activity against S. mutans.

Improper prescription of the type, dose, and duration of antibiotics imposes a financial burden on the health system, can cause many side effects for the patient, and can lead to the emergence of drug-resistant bacteria. This study aimed to determine the profile of prescribing antibiotics in different wards of a hospital and compare it with references.

This study was conducted on the recorded information of 342 patients in the emergency, infectious diseases, pulmonary, and surgical wards of Sayad Shirazi Hospital in Gorgan (north of Iran) in 2019-2020. The type, dose, and duration of the prescribed antibiotics were extracted from each patient's file and compared with references. The compatibility and inconsistency of the prescribed antibiotics were identified and analyzed accordingly.

A total of 13 types of antibiotics were prescribed for the patients. There was a 43.7% inconsistency in antibiotic prescription with the references. The most prescribed antibiotic was ceftriaxone (25.6%). Ceftriaxone (11.26%), followed by cefazolin (8.30%), had the most inconsistency in prescription. The most inconsistency in total was respectively observed in the pulmonary (47.9%), general surgery (44.8%), emergency (44.4%), and infectious diseases wards (40.6%). No significant difference was observed between the wards in terms of the total inconsistency of prescribed antibiotics with the references (P = 0.692).

The most prescribed antibiotic was ceftriaxone. A high percentage of its prescriptions are without indication and are actually prescribed as empiric. Therefore, it is necessary to monitor the prescription of antibiotics in medical centers based on the indications and available evidence.

Brassicaceae is a medium-sized family of flowering plants. The family contains more than 327 genera. Cardamine uliginosa is a type of plant of this species. Chemical and biochemical findings of this genus are very limited. This study aimed to investigate the chemical compounds and antioxidant and antibacterial properties of C. uliginosa.

Essential oil was prepared by hydrodistillation method and microwave assisted hydrodistillation (MAHD). The chemical composition of essential oil was evaluated by GC and GC-MS methods. The antioxidant property of the hydroalcoholic extract was investigated by 2, 2-dipheny1-1-picrylhydrazyl (DPPH) solution. Finally, the antibacterial activity of C. uliginosa was investigated using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods.

Phetalic acid, Phenil, Caryophyllene, Eicosane, and other chemical compounds were found in the essential oil of C. uliginosa. The half maximum inhibitory concentration (IC50) of hydroalcoholic extract was 0.42 μg/mL. The MIC and the MBC against both Escherichia coli and Staphylococcus aureus were 15.62 and 31.25 respectively. The major compounds in the essential oils were 3-methyl-4-isopropylphenol (15.20%) and 1, 2-benzenedicarboxylic acid (16.75%).

Considering the chemical compounds of C. uliginosa and the finding of the antibacterial and antioxidant activity of C. uliginosa in vitro, capability of this plant needs to be further investigated for use in health and medical industries.