جستجوی مقالات مرتبط با کلیدواژه « gram positive bacteria » در نشریات گروه « پزشکی »

Ox-bile has been recommended as a natural remedy with several therapeutic potentials in traditional Persian medicine. It has had efficacy against inflammation and infection according to traditional medicine. Evidence revealed that bile disrupts bacterial cell membrane and degrades DNA structure, so it has anti-bacterial effects. However, there is no evidence of any approved medication composed of ox-bile in Iran.

The aim of this study was to evaluate the in vitro anti-bacterial effects of ox-bile.

Ox-bile was obtained under aseptic conditions and sterilized with a 0.22 msyringe filter, then examined for their sterility status through culture on different media. Following incubation under aerobic cultures for 48 hours and the anaerobic cultures for one week. Two different kinds of antimicrobial susceptibility tests, including well-diffusion method and serial dilution test were employed to characterize the inhibitory effect of ox-bile extraction on Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Propionibacterium acnes.

Based on our study, no anti-bacterial effect of ox-bile was observed against selected gram-positive and gram-negative bacteria.

No in-vitro evidence of inhibitory effect was observed against studied gram-positive and gram-negative bacteria. Though further evaluation of the anti-bacterial effects of different preparations of ox-bile seems is still required.

A new series of derivatives of N, 2-diphenylquinazolin-4-amine (3a-g) was synthesized through nucleophilic substitution. The structures of compounds were characterized by FTIR, 1H-NMR, and 13C-NMR spectroscopy. All synthesized compounds were evaluated for their antimicrobial activities against Gram-positive (Staphylococcus aureus, Bacillus subtilis, Lactobacillus rhamnosus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria and also for antifungal activities, against Candida albicans, using broth microdilution method to determine their minimum inhibitory concentrations (MIC). Most of the compounds have shown moderate to good antibacterial activities, significantly compound 3g at 0.0625 mg/mL concentration had the highest activity against P. aeruginosa. Also, the MIC of compound 3f was 0.0078 mg/mL against S. aureus. Furthermore, the tested compounds exhibited remarkable antifungal activities against C. albicans, significantly compounds 3c and 3g showed the least MIC (equal to 0.0625 mg/mL). Also, a docking study into DNA gyrase has been made for these compounds. The synthesized compounds showed dock score values between -3.05 and -6.13kcal/mol. The highest dock score among them was -6.13 kcal/mol, found for compound 3c.

Urinary tract infection (UTI) is the most prevalent infection among the community and hospitalized patients.

This study aimed to investigate the current antimicrobial susceptibility patterns among UTI agents in Tehran, Iran.

This retrospective study analyzed 9836 urine samples collected from hospitalized patients within 2019 - 2020. The antibiotic susceptibility for commonly-used antibiotics was tested according to Clinical and Laboratory Standards Institute guidelines.

Based on the findings, Escherichia coli was the most prevalent etiological agent of UTIs (72.3%), followed by Klebsiella spp. (13.4%), Pseudomonas aeruginosa (4.8%), Acinetobacter spp. (2.8%), and other species (6.7%). Of isolated microorganisms, 943 cases (97%) belonged to gram-negative bacilli; however, 32 cases (3.05 %) were gram-positive cocci. The susceptibility rates of E. coli to amikacin, nitrofurantoin, gentamicin, imipenem, and cefoperazone were 88.4%, 87.5%, 68.3%, 65.9%, and 62.6%, respectively. The sensitivity rates of Klebsiella spp. isolates for amikacin, nitrofurantoin, and imipenem were 87.6%, 71.5%, and 68.9%, respectively.

The results of the present study characterized the misuse of antibiotics in Iran. Iranian surveillance studies will assist clinicians in choosing the most appropriate empirical treatment and preventing infections caused by resistant organisms.

Fetal abortion is one of the critical and controversial issues in most societies’ scientific, social, and academic ceremonies due to known and unknown reasons. Furthermore, updating our knowledge about isolated bacteria, their antibiotic resistance pattern, and related factors is essential for designing and implementing appropriate interventions.

The current study was conducted to determine the prevalence of bacteria among fetal abortion cases and demonstrate the antimicrobial susceptibility among isolated bacteria.

For this, 153 blood samples were collected percutaneously from the heart blood of aborted fetuses 1 - 15 hours after birth; subsequently, the identification of bacteria and evaluation of antimicrobial susceptibility testing were performed.

Generally, 82 out of 153 test cultures were positive, comprising 66 and 26 Gram-negative and Gram-positive bacteria, respectively. The most isolated bacteria among Gram-negative isolates were Acinetobacter spp. (34/82) and Escherichia coli (17/82). Likewise, the highest antibiotic resistance was detected for Acinetobacter spp. against cefixime, amikacin, gentamycin, and ciprofloxacin (24/34). On the other hand, Staphylococcus spp. was the predominant Gram-positive cocci (10/82). Also, the highest resistance for Staphylococcus spp. was against cefoxitin and ciprofloxacin (100%).

It seems more focus on following the general hygiene of pregnant mothers is essential. However, further evidence of a clinical correlation between aborted fetuses and their mothers is required.

Curative misuse of medicinal plants are worrisome with the paucity of histological information. This led to the investigation of Ipomoea asarifolia in Swiss albino rats infected with Pseudomonas aeruginosa and Staphylococcus aureus.

Extraction was done using the cold maceration method. The minimum inhibitory concentrations (MIC) of the extracts were determined using the micro-dilution method. Swiss albino rats of 6 sub-groups with 6 animals each (36 animals/organism) were administered with 0.3 ml single oral dose of P. aeruginosa and S. aureus respectively. The animals received treatment for 5 days as follows: 0.5 ml of 5% dimethyl sulphoxide (DMSO) (negative control), 250 mg/kg of amoxicillin (positive control), 2 mg/kg of whole plant extract, 4 mg/kg of whole plant extract, 2 mg/kg of leaf extract, and 4 mg/kg of leaf extract, respectively. The packed cell volume (PCV) and white blood count (WBC) of the animals were determined before and after treatment with histology examination of vital organs.

MIC for S. aureus was 2 mg/mL; the mortality in S. aureus group at 2 mg/kg was 66.7%. The PCV values (50.5±0.5, 45.0±1.0, and 50.5±1.5) decreased after infection, and a corresponding increase in the PCV was observed after treatment with the extracts. Also, a significant increase in the WBC values (3.40±0.35, 4.10±0.15, and 3.30±0.40) following infection and a corresponding decrease after treatment were observed. Congestion of vessels in the kidney was also observed.

I. asarifolia has a dose-dependent antibacterial and curative activity, and could enhance innate immunity.

T Microorganisms cause many diseases for the human body such as urinary tract infection and, therefore, it is highly important to eliminate and control them. Bacterial resistance to different types of antibiotics was increased and it is necessary to find alternative agents to eliminate these microbes.

This study aimed was to evaluate the antimicrobial effect of different concentrations of titanium dioxide nanoparticles (TiO2 NPs) on some gram-positive bactria, gram-negative bacteria, and Candida albicans. TiO2 NPs were synthesized using the chemical methods, coated with carboxymethyl cellulose (CMC) and prepared in different concentrations (0.098, 0.196, 0.392, 0.784, 1.568, and 3.136 mg/mL). Eventually, a minimum inhibitory concentration (MIC) and a minimum biofilm inhibitory concentration (MBIC) were applied to investigate the effect of TiO2 NPs on microorganisms.

According to the study results, the MICs of TiO2 NPs were found to be 1.489, 1.208, and 1.166 mg/ mL for Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae as the Gram-negative bacteria, respectively; and they were discovered to be 0.512, 0.830, and 0.707 mg/mL for Streptococcus pneumoniae, Staphylococcus aureus, and Staphylococcus epidermidis as the Gram-positive bacteria, respectively. As for C. albicans, as the yeast strain, MIC was 0.253 mg/ mL. The MBIC of more than 90% of TiO2 NPs was 6.25 mg/mL for both Gram-negative and Gram-positive bacterial types and 1.562 mg/mL for C. albicans.

It was concluded that TiO2 NPs were effective antimicrobial agents for Gram-positive bacteria, Gram-negative bacteria, and C. albicans, but their inhibitory effect on yeast was greater than that of bacteria.

Hematological toxicities are considerable side effects of linezolid, which can restrict its administration. This study aims to evaluate the protective effect of vitamin B6 on linezolid-induced hematological dyscrasia, i.e., thrombocytopenia and anemia in poisoned patients. In this quasi-experimental (non-randomized, non-blinded) study, a number of 28 patients treated with linezolid and vitamin B6 were matched with 50 patients who received only linezolid. The hematological factors, including red blood cells (RBCs), hemoglobin (Hb), hematocrit (Hct), and platelets (PLTs) were assessed at baseline and on days 0, 1, 3, 5, and 7 during the linezolid treatment coarse. There were no considerable differences between the two groups in demographic characteristics, poisoning, vital signs, baseline laboratory test results, and mortality rates. Overall, patients who received linezolid+B6 had significantly higher RBCs, Hb, and Hct than those treated with linezolid alone (P < 0.05). Unexpectedly, patients in the treatment group had lower PLT counts compared to the control group with no significant differences (P > 0.05). According to our findings, the co-administration of vitamin B6 and linezolid was accompanied by a lower risk of anemia but no impact on preventing or reducing thrombocytopenia in patients with gram-positive bacterial infections.

 Bacteria are the most common causes of clinical infectious diseases. The distribution and antimicrobial resistance (AMR) rates of bacteria provide important guidelines for clinical antibacterial treatment; however, the information in this region is still missing.

 This study aimed to evaluate the changes in the distribution and AMR rates of clinical isolates from inpatients.

 We conducted a retrospective cross-sectional analysis of the distribution and antimicrobial susceptibility of all non-duplicate Gram-negative bacterial (GNB) and Gram-positive bacterial (GPB) isolates collected from January 1, 2013, to December 31, 2018, in our hospital.

 In total, 56,535 and 3,518 non-repetitive isolates were detected in the whole hospital and intensive care units (ICUs), respectively. The isolates included GPB (26.3% and 18.4%, respectively) and GNB (73.7% and 81.6%, respectively). The five dominant bacteria were the same in the whole hospital and ICUs, but Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii percentages were different. The detection rates of all isolates and five dominant bacteria were significantly different between the ICUs and the whole hospital (P < 0.05). The detection rate of extended-spectrum β-lactamase (ESBL)-E. coli (54.1%) was significantly higher than that of K. pneumoniae (26.1%). The detection rates of carbapenem-resistant (CR) and extensively drug-resistant (XDR)-A. baumannii were the highest in both the ICUs (87.1% and 21.8%, respectively) and the whole hospital (65.5% and 12.9%, respectively). The methicillin-resistant S. aureus (MRSA) detection rate was high (26.5%) but showed a significant decreasing trend (P < 0.05). The detection rates of ESBL and XDR-E. coli, CRAB, and XDR-S. aureus were significantly different between the ICUs and the whole hospital (P < 0.05). Gram-negative bacteria were highly susceptible to amikacin (> 90%) and tigecycline (> 98%). Staphylococcus aureus showed 100% susceptibility to vancomycin and linezolid. Acinetobacter baumannii had the highest resistance to imipenem (62.8%) and meropenem (64.0%). Except for A. baumannii and E. coli (P < 0.05), the AMR levels and the trends of the other isolates were similar between the ICUs and the whole hospital (P > 0.05).

 Currently, the appropriate antimicrobial agents in our hospital include amikacin and tigecycline for the treatment of GNB infections and vancomycin and linezolid for the treatment of GPB infections. Moreover, it is still necessary to monitor AMR in the ICUs and the whole hospital simultaneously.

Diabetic foot ulcers (DFUs) are responsible for days of costly hospitalization and are the major cause of medical lower limb amputations. Determining the appropriate antimicrobial therapy for DFUs is highly dependent on recognizing the microorganisms that cause them. Many reports have indicated that there has been a remarkable increase in antibiotic resistance.

The present study examined various cultures of patients with DFUs to detect the prevalence of microorganisms and their antibiotic sensitivity profiles.

This cross-sectional study was carried out on 92 patients with DFUs admitted to Shar Teaching Hospital and Shahid Hemin Teaching Hospital. Wagner Classification was used to assess the severity and location of the DFUs. Patients were asked questions about their practices of foot care and hygiene, and their answers were recorded. Samples required for testing were taken using sterile swabs.

A total of 100 microorganisms were isolated from 92 patients with DFUs, 10 of which were polymicrobial and 2 were culture-negative. There was a highly significant association between the isolated gram-negative microorganisms and higher grades of DFU (P < 0.001). A highly significant association was also observed between bad patient knowledge of hygiene practices and gram-negative microorganisms (P < 0.001). Osteomyelitis was present in 40 (43.4%) patients.

Among gram-positive and gram-negative bacteria, Staphylococcus spp. and E. coli were, respectively, the most frequent organisms isolated. The antibiotic imipenem was found to be effective against microorganisms. Tetracycline, erythromycin, and ceftriaxone, however, were highly resistant to antibiotics. To sum up, since different microorganisms are involved and multidrug-resistant strains might emerge, clinicians are recommended to take cultures into account before they initiate empirical therapy.

Endophytic actinomycetes have been known as a promising source for new antibiotics discovery against susceptible and resistant forms of pathogenic microorganisms. This study was aimed at determining antibacterial compound from Streptomyces sp. strain B-92 isolated from a medicinal plant Neesia altissima.

Streptomyces sp. strain UICC B-92 was endophytic actinomycetes of N. altissima that obtained from Universitas Indonesia Culture Collection (UICC). Isolation and determination of bioactive compound were carried out using thin layer chromatography (TLC), nuclear magnetic resonance spectroscopy (NMR), and liquid chromatography mass spectrometry (LC-MS) analyses. An in vitro antibacterial assay of pure bioactive compound from the endophytic actinomycetes strain was performed against Bacillus cereus strain ATCC 10876, Escherichia coli strain ATCC 25922, Salmonella typhimurium strain ATCC 25241, Shigella flexneri strain ATCC 12022 and Staphylococcus aureus strain ATCC 25923.

The bioactive compound was identified as 4-((3S,4R,5S)-3,4,5-trihydroxy-6-(hydroxymethyl) tetrahydro-2H-pyran-2-yloxy) phenazine-1-carboxylic acid. In vitro antimicrobial assay showed that bioactive compound of Streptomyces sp. strain UICC B-92 exhibited antagonistic activities against two Gram-positive bacteria, viz, B. cereus strain ATCC 10876 and S. aureus strain ATCC 25923.

The findings of this research showed that, bioactive compound of Streptomyces sp. strain UICC B-92 is suggested a new compound based on glycoside structure and its position.

Urinary tract infections are common health problem affecting millions worldwide. Antibiotic resistance among uropathogens (Ups) is prevalent in many countries. In the absence of any available data in the region, this hospital-based study investigated the pattern, frequency and susceptibility of Ups at Prince Mutaib Bin Abdulaziz Hospital, Aljouf Region, Saudi Arabia.

A retrospective assessment of UPs and their antibiotics susceptibility was conducted from January 2017 to December 2017 using the fully automated Vitek2 system (BioMérieux, France).

Among the 415 uropathogens isolates, the most prevalent bacteria were Gram-negatives comprising 137 (51%) E. coli; 46 (17.2%) Klebsiella spp.; 30 (11.2%) Pseudomonas spp.; 25 (9.3%) Proteus spp.; 14 (5.2%) Acinetobacter baumanii and 16 (5.9%) others. On the other hand, Enterococcus spp. were predominant among Gram-positive isolates representing 54 (36.7%), 47 (32.0%) Staphylococcus spp., 22 (15.1%) Streptococcus spp., and 13 (8.8%) S. aureus, and 11 (7.5%) others. Gram-negative Ups showed multidrug resistance towards the majority of the tested antimicrobials (ampicillins, cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, fosfomycin, aztreonam, and nitrofurantoin). While high resistance patterns by Gram-positives was also seen against cephalosporins, penicillins, amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole, clindamycin, erythromycin and tetracycline.

The observed widespread multidrug resistance clearly warrant implementing stricter control measures, local guidelines of antimicrobials usage, and continuous epidemiological surveys at hospitals and communities.