Strains Of Pathogenic Bacteria Research Articles

ANTIMICROBIAL ACTIVITY OF LANTANA CAMARA AGAINST PSEUDOMONAS AERUGINOSA, SERRATIA MARCESCENS AND STAPHYLOCOCCUS AUREUS TO DEVELOP OINTMENT BASED THERAPY

Plant extract (Lantana camara) and earthworm (Pheretima posthuma) extract have been used to treat many illnesses for centuries; they have been reported to suppress the growth of many pathogenic bacteria and are specially used for wound healing. We analyzed the antibacterial activity of the different organic extracts obtained from these species against pathogenic strains of bacteria and compared them to know which is more potent for developing antiseptic ointment. Ethanol and acetone solvents were used for the extraction and analyzed for their antibacterial activity by the disk diffusion and shake flask test. Then we identified the minimum inhibitory concentration of extracts against gram-positive and gram-negative strains. Lantana camara showed the largest growth inhibitory zone against Pseudomonas aeruginosa, followed by Serratia marcescens, and Staphylococcus aureus. MIC for plant extract was 150μg/ml, while earthworm extract inhibited growth at a minimum dose of 200μg/ml. We found that the plant's ethanol extract (L. camara) exhibited robust antimicrobial activity compared to the worm extract. Current investigation reinforces the application of Lantana camara extract to develop ointment to treat wound infections.

Sensitivity of pathogenic and opportunistic microorganisms to probiotic strains in the light of personalized probiotic therapy

BACKGROUND: Resistance of microorganisms to antimicrobial drugs (AMP) is one of the global problems of modern medicine, which poses a serious threat to human health. The formation of the resistance of pathogens to AMP forces us to look for new ways to combat them. Probiotic therapy is one of the promising and safe methods of treating many infectious diseases.
 AIM: This study assesses the sensitivity of clinical strains of pathogenic and opportunistic bacteria and fungi to microorganisms that are part of probiotic preparations.
 MATERIALS AND METHODS: The sensitivity of 93 cultures of pathogenic and opportunistic microorganisms (UPM) isolated from the feces of patients with intestinal dysbiosis to strains of probiotic bacteria isolated from commercial probiotic preparations was studied: Lactobacillus plantarum 8RA-3, Escherichia coli M-17, Bacillus subtilis strain VKPM B-10641, Enterococcus faecium SF-68, Saccharomyces boulardii CNCM I-745 by the delayed antagonism method.
 RESULTS: Pathogenic microorganisms showed low and moderate sensitivity to the probiotic strain of L. plantarum. Sensitivity to the probiotic strain of B. subtilis was detected in Staphylococcus aureus strains, low or completely absent in Pseudomonas aeruginosa, Klebsiella spp., Serratia marcescens. The most sensitive to the probiotic strain were clinical strains of E. coli.
 CONCLUSION: UPM and pathogenic microorganisms isolated from the gastrointestinal tract of patients with dysbiosis have different sensitivity to probiotic strains: from high to several probiotics to its complete absence. The empirical approach to prescribing a probiotic does not guarantee a therapeutic effect, which makes it prudent to individualize the selection of a probiotic based on an assessment of its antimicrobial activity against isolated pathogens.

Retrospective analysis of drug resistance characteristics and infection related risk factors of multidrug-resistant organisms (MDROs) isolated from the orthopedics department of a tertiary hospital

Patients infected with multidrug-resistant organisms (MDROs) are known to exhibit longer hospital stays and a significantly poorer prognosis. We performed a 6-year retrospective analysis of nosocomial infections reported in the orthopedics department of our institution, to gain valuable insights into antibiotic sensitivity and infectious characteristics of MDROs, in order to deduce effective measures to control the occurrence of multidrug-resistant infections in clinical practice. A retrospective, single center surveillance study (January 2012–December 2017) was performed on the nosocomial infections recorded in the department of orthopedics. A nosocomial infection is defined as one that develops when a patient is residing in a hospital but was not present at the time of admission. All relevant data, including basic patient information, cultivated bacterial strains, and antimicrobial resistance, was obtained from the hospital information system. A total of 1392 strains of pathogenic bacteria were isolated; 358 belonged to MDROs (detection rate = 25.7%). All the isolated strains of MDROs were mostly from secretions (52.2%). The number of cases infected with MDROs were 144 (40.2%) and 129 (36.0%) in the trauma and spinal wards, respectively. MRSA showed high resistance to β lactam antibiotics, but was sensitive to quinolone antibiotics, linezolid and cotrimoxazole. ESBL-positive strains showed more sensitivity to carbapenem antibiotics (resistance rate < 10%). MDR nonfermenters showed high resistance to most antibiotics. Logistic multivariate analysis revealed age, open injury, and central nervous system injury as independent risk factors for multidrug resistant infections. A high antibiotic resistance rate and an increasing prevalence of infections with MDROs was identified in the orthopedics department. Patients with open injury, central nervous system injury and those aged ≥ 60 years, were more prone to multidrug-resistant infections. Clinicians should pay more attention to such patients in order to actively prevent and control the occurrence of infections caused by MDROs.

The Advantages of Single-Room Management in an ICU and the Changing Trend of Drug-Resistant Bacteria over the Last 5 Years

ObjectiveWe reviewed the benefits of an all-single-room intensive care unit in the prevention of hospital-acquired infection.MethodThe intensive care medicine department of the First Affiliated Hospital of Bengbu Medical College commenced single-room management in 2019. This study reviewed the prevalence of pathogenic bacterial infection and altered drug resistance of major pathogens in patients hospitalized from January 2016 to December 2020. Results of bacterial resistance and changes in bacterial numbers were analyzed separately and the two time periods compared.ResultsIn 2016, 320 strains of pathogenic bacteria were identified compared with 601 in 2020. At both times, bacteria were predominantly gram-negative. The ratio of the number of pathogenic bacteria to the number of beds revealed a decreasing trend each year from 2016–2020: 22.86, 17.57, 28.36, 14.33, and 15.41 respectively (P < 0.05). The top five Gram-negative bacteria were Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Burkholderia cepacia. The source of bacteria was mainly sputum, followed by blood, and the site of infection was predominantly the respiratory tract. Staphylococcus aureus resistant to ciprofloxacin, levofloxacin and erythromycin had decreased significantly (P < 0.05). Among the multi-drug resistant bacteria detected, only penicillin-resistant Klebsiella pneumoniae and penicillin-resistant Pseudomonas aeruginosa decreased after the introduction of single-room wards (P = 0.025, P = 0.002 respectively).ConclusionIntroduction of a single-room ward directly or indirectly reduced the possibility of cross-infection. The establishment of single-room wards has no adverse effects and was beneficial to patients, the department and the hospital.

Chemical Composition and Antimicrobial Activity of New Honey Varietals.

Due to a widespread occurrence of multidrug-resistant pathogenic strains of bacteria, there is an urgent need to look for antimicrobial substances, and honey with its antimicrobial properties is a very promising substance. In this study, we examined for the first time antimicrobial properties of novel varietal honeys, i.e., plum, rapeseed, Lime, Phacelia, honeydew, sunflower, willow, and multifloral-P (Prunus spinosa L.), multifloral-AP (Acer negundo L., Prunus spinosa L.), multifloral-Sa (Salix sp.), multifloral-Br (Brassica napus L.). Their antimicrobial activity was tested against bacteria (such as Escherichia coli, Bacillus circulans, Staphylococcus aureus, Pseudomonas aeruginosa), yeasts (such as Saccharomyces cerevisiae and Candida albicans) and mold fungi (such as Aspergillus niger). In tested honeys, phenolic acids constituted one of the most important groups of compounds with antimicrobial properties. Our study found phenolic acids to occur in greatest amount in honeydew honey (808.05 µg GAE/g), with the highest antifungal activity aiming at A. niger. It was caffeic acid that was discovered in the greatest amount (in comparison with all phenolic acids tested). It was found in the highest amount in such honeys as phacelia-356.72 µg/g, multifloral (MSa) and multifloral (MBr)-318.9 µg/g. The highest bactericidal activity against S. aureus was found in multifloral honeys MSa and MBr. Additionally, the highest amount of syringic acid and cinnamic acid was identified in rapeseed honey. Multifloral honey (MAP) showed the highest bactericidal activity against E. coli, and multifloral honey (MSa) against S. aureus. Additionally, multifloral honey (MBr) was effective against E. coli and S. aureus. Compounds in honeys, such as lysozyme-like and phenolic acids, i.e., coumaric, caffeic, cinnamic and syringic acids, played key roles in the health-benefit properties of honeys tested in our study.

Перспективные иммуномодулирующие эффекты бактериальных лизатов в профилактике и лечении острых и реккурентных респираторных инфекций у детей

The incidence of influenza and acute respiratory infections (ARI) continues to grow, including due to limited opportunities for immunoprophylaxis of the most common respiratory infections, in particular, acute respiratory viral infections (ARVI). Attempts are being made to reduce the children susceptibility to respiratory pathogens through the rational use of nonspecific immunoprophylactic agents, among which bacterial lysates (BL) occupy a special place. BL key patterns, contributing to the prevention of viral infections, are innate immune response activation, excessive inflammatory response prevention, adaptive immune response stimulation. BL contain fragments of inactivated various pathogenic bacteria strains that are important in the ARI etiology. Obtaining lysates of bacterial strains is possible by mechanical or chemical lysis. The article discusses the results of preclinical and clinical studies on BL, as well as suggests the expediency of further study concerning the BL pharmacodynamic effects within the modern concept of trained immunity. The authors conclude that BL as a trained immunity inducer according to the rationally selected regimen can contribute to the respiratory infections' prevention both during COVID-19 pandemic and post-pandemic period. KEYWORDS: acute respiratory infections, acute respiratory viral infections, influenza, trained immunity, immunoprophylaxis, bacterial lysate. FOR CITATION: Zaplatnikov A.L., Kanner E.V., Kanner I.D., Girina A.A., Farber I.M., Maximov M.L. Promising immunomodulatory effects of bacterial lysates in the prevention and treatment of acute and recurrent respiratory infections in children. Russian Journal of Woman and Child Health. 2023;6(3):290–297 (in Russ.). DOI: 10.32364/2618-8430-2023-6-3-12.

Distribution and Drug Resistance Analysis of 2287 Strains of Pathogenic Bacteria in Children’s Blood Culture

Background: Bloodstream infection is a serious infectious disease. In recent years, the drug resistance of pathogenic bacteria to commonly used anti-infective drugs has been widely concerned, which also makes the treatment of bloodstream infection face severe challenges. Objective: To explore the distribution characteristics of blood culture-positive pathogens and the resistance to antibacterial drugs, so as to provide clinicians with accurate laboratory evidence, so as to guide clinicians to rationally apply antibiotics, improve clinical treatment effects, and reduce the emergence of drug-resistant strains. Methods: From January 2019 to June 2022, 2287 positive blood culture specimens of patients in Guangzhou Women and Children’s Medical Center were retrospectively analyzed, and the proportion of different pathogenic bacteria, the distribution of pathogenic bacteria in different departments, and the multi-drug resistance of different pathogenic bacteria were counted. Results: Among the 2287 blood culture positive samples, 1560 strains (68.20%) of gram-positive bacteria and 727 strains (31.80%) of gram-negative bacteria were strained. The top three departments in the distribution of pathogenic bacteria were pediatric intensive care unit (600 strains), pediatric internal medicine (514 strains), and pediatric emergency comprehensive ward (400 strains). The pathogens with high detection rates were: Staphylococcus epidermidis (24.09%), Staphylococcus humans (23.74%), Escherichia coli (13.21%) and Klebsiella pneumoniae (8.71%). The pathogens with high multi-drug resistance rates were: Streptococcus pneumoniae (93%), Staphylococcus epidermidis (83.76%), Enterobacter cloacae (75.61%) and Staphylococcus humans (62.43%). Conclusion: In our hospital, gram-positive bacteria were the main pathogenic bacteria in the blood culture of children patients. The children’s intensive care unit was the department with the largest distribution of pathogenic bacteria, and the multiple drug resistance rate of Streptococcus pneumoniae was the highest.

Analysis of healthcare-associated infection in patients with pulmonary arterial hypertension associated with congenital heart disease in PICU: Evidence from a tertiary hospital in western China.

The present study intends to analyze the targeted surveillance and risk factors for healthcare-associated infection (HAI) in patients with pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) in a Pediatric intensive care unit (PICU), and provide basis for formulating relevant prevention and control measures of HAI. Children (≤14 years old) who were admitted to the PICU for ≥2 calendar days from January 2018 to December 2021 were included. Targeted surveillance of HAI was described. A total of 7,828 patients in PICU were monitored, and the total hospitalization days of the patients were 36,174. 108 cases of HAI occurred, with a per-case infection rate of 1.38% and a per-thousand day infection rate of 2.99. 1,129 patients with CHD-PAH were included, among which the total hospitalization days were 1,483. In this subpopulation, 38 cases of HAI were diagnosed, with a per-case infection rate of 3.37% and a per-thousand day infection rate of 25.62. The main site of HAI was lower respiratory tract (43.51%), followed by blood infection (34.26%) and surgical site infection (9.26%). 36 strains of pathogenic bacteria were detected from patients with HAI. The top three pathogens with the highest detection rate were Klebsiella pneumoniae (6 episodes, 16.67%), Enterococcus faecium (6 episodes, 16.67%) and Acinetobacter baumannii (4 episodes, 11.11%). The incidence of VAP, CAUTI and CLABSI was 2.78, 0.08 and 1.66 per 1,000 catheter days respectively. Analysis revealed that patients with CHD-PAH were younger and prone to receive surgical corrections. CHD-PAH could significantly increase the length of ICU stay, ventilator days, times of central venous catheterization and central venous catheterization days. The choice of different central venous catheter types differed significantly between the two groups. Patients with CHD-PAH are characterized with excessive central venous catheterization operations, prolonged indwelling time, and more types of catheterization, which are considered to be risk factors for HAI, thus increasing the length of hospital stay. The clinical etiology is mainly G-bacteria, which requires reasonable selection of antibiotics and strict aseptic operation. Limiting unnecessary invasive procedures is helpful for reducing the incidence of postoperative HAI in PICU.

Value of inflammatory mediator profiles and procalcitonin in predicting postoperative infection in patients with hypertensive cerebral hemorrhage.

Hypertensive cerebral hemorrhage (HICH) is a common clinical cerebrovascular disease and one of the most serious complications of hypertension. Early warning of the occurrence of infection during treatment and timely anti-infective treatment are of great significance for the early prevention and treatment of postoperative infection in patients with HICH. Changes in the levels of inflammatory mediators, which are closely related to the occurrence and development of postoperative infection, and procalcitonin (PCT), which is a sensitive indicator for diagnosing bacterial infections, are widely used in clinical practice. To explore the application value of inflammatory mediator profiles and PCT in predicting postoperative infection in patients with HICH. A total of 271 patients who underwent HICH surgery at our hospital between March 2019 and March 2021 were selected and divided into the infection (n = 80) and non-infection (n = 191) groups according to whether postoperative infection occurred. The postoperative infection status and etiological characteristics of the infective pathogens in the infection group were analyzed. Changes in inflammatory mediator profile indices and PCT levels were compared between the two groups, pre- and postoperatively. A total of 109 strains of pathogenic bacteria were detected in the infection group, including 67 strains (61.47%) of gram-negative bacteria, 32 strains (29.36%) of gram-positive bacteria, and 10 strains (9.17%) of fungi. The main infection site of the patients in the infection group was the respiratory system (63.75%). Preoperative interleukin (IL)-4, IL-6, IL-10, tumor necrosis factor-α, interferon-γ, and PCT levels were higher in the infection group than in the non-infection group (P < 0.05), and there were no significant differences in the IL-2 Levels between the two groups (P > 0.05). The inflammatory mediator profile indices and PCT levels were higher in the two groups of patients on the first postoperative day than preoperatively (P < 0.05), and were higher than those in the non-infection group (P < 0.05). Logistic regression analysis showed that preoperative IL-6 and PCT levels correlated with postoperative infection (P < 0.05). Operating characteristic curve analysis results showed that the area under the curve (AUC) values of preoperative IL-6 and PCT levels in predicting postoperative infection in patients with HICH were 0.755 and 0.824, respectively. The AUC value of joint detection was 0.866, which was significantly higher than that of the single index (P < 0.05). Preoperative IL-6 and PCT levels are correlated with postoperative infection in patients with HICH. Their detection is clinically significant for early identification of patients at high risk for postoperative infection.

Evaluation of Extractive Value and In-Vitro antimicrobial potential of Curcuma longa using disk diffusion method

The efficiency of turmeric fractions, such as petroleum ether, chloroform, benzene, methanol and aqueous were evaluated for their inhibitory effect on clinical and standard strains of pathogenic bacteria and fungus. The methanolic fraction of Curcuma longa rhizome had high potential to inhibit some pathogenic bacteria i.e. S. aureus to a greater degree than other fractions of Curcuma longa. In our study the results show that the different fractions (petroleum ether, methanol etc.) of Curcuma longa rhizome were more effective antimicrobial agents than the crude extract of Curcuma longa. Methanolic extract of curcuma longa was evaluated against gram positive and gram-negative bacteria. The bacteria isolates include Bacillus subtilis and Escherichia coli. Antimicrobial activities were estimated by Well diffusion method and antifungal activity was evaluated against Candida Albicans and Aspergillus Niger. The results were pointed as the methanol extract was more effective on both bacteria and fungus then water also similar effective on both bacteria and fungus but against Aspergillus Nigerit has outstand results. &#x0D; Keywords: Curcuma longa, Phytochemical, Antimicrobial, Free radical, Scavenging Potential

Synthesis, characterization and antimicrobial activities of Schiff base complexes derived from Salicylaldehyde and amino acid (isoleucine)

Complexes of Fe(II), Co(II), Cu(II), and Zn(II) with a Schiff base derived from salicylaldehyde and isoleucine were successfully synthesized. All complexes were distinctly colored and were characterized by molar conductance, magnetic susceptibility, infrared and UV spectroscopy. Infrared spectroscopy shows the Schiff base ligand is coordinated to the central metal ion in a tridentate manner through the N-atom of the azomethine and two oxygen of the phenol and carboxylate. All complexes contain two ligands molecules per metal ion (ML2). An octahedral geometry is proposed for the metal complexes. Antimicrobial study of the complexes was undertaken against five pathogenic bacteria strains and two fungi, mucus species and Aspergillus fumigates. The result reveal that most of the complexes and particularly Co (II) and Zn (II) have a much enhanced activity against Staphyllococcus aureus, Escherichia coli and Klebsiella pneumoniae.

Bioactive Activities of the Phenolic Extract from Sterile Bracts of Araucaria angustifolia.

Sterile bracts can represent 80% of Araucaria angustifolia pinecone and are a rich source of phenolic compounds. This study aimed to optimize the extraction of the phenolic compounds from Araucaria angustifolia bracts using response surface methodology; the bioactivity properties were also investigated. The effects of the ethanol concentration, solute/solvent ratio, and temperature in relation to the phenolic composition and antioxidant activity were evaluated. The quantification and identification of the individual phenolic compounds (using high-performance liquid chromatography) and their bioactivity were evaluated. The optimized extraction conditions, which detected gallic acid, catechin, epicatechin, quercetin, and kaempferol, were obtained using 60% ethanol at a ratio of 1:38 (w/v) and a temperature of 80 °C. The extract showed high levels of phenolic classes and antioxidant activity. The extract also showed an inhibitory activity for pathogenic (approximately 80%, 10,000 µg/mL) and lactic acid (27.9%, 15,000 µg/mL) bacteria strains. The α-glucosidase inhibitory activity was approximately ten times greater than acarbose, demonstrating its high antiglycemic potential. No antioxidant and anti-inflammatory cellular activity were determined; however, a high cytotoxicity for non-tumor cells and the antiproliferative activity against the tumor cells were observed. Overall, the phenolic extract showed promising action in relation to the fight against the diseases related to oxidative stress and, hopefully, the application of the safe concentrations of the extract, based on bioavailability assays, can be verified.

Green synthesized silver nanoparticles using carrot extract exhibited strong antibacterial activity against multidrug resistant bacteria

Antimicrobial resistance is a worldwide problem. Pathogenic microorganisms develop antibiotic resistance as a result of exposure to inappropriate quantity of antibiotics and accumulation of mutations. Bio-friendly nanomaterial scan be developed as antimicrobial agents. Present study aimed to investigate the activity of biosynthesized silver nanoparticles (AgNPs) obtained from carrot extract of three different regions namely Gilgit, Haripur and Sheikhupura from Pakistan, having significant difference in climate and altitude. UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis were carried out for the morphological characterization of synthesized nanoparticles. Analysis of XRD revealed crystalline nature of AgNPs and average size calculated was about 22, 17 and 10 nm from Gilgit, Haripur and Sheikhupura samples respectively. The antibacterial efficacy of AgNPs was carried out against 7 American type culture collection strains of pathogenic bacteria and three macrolide resistant clinical isolates with promising results. Moreover, antioxidant activity indicated maximum DPPH radical scavenging effects as 47 % using a concentration of 250 μg/mL. Hemolysis assays indicated biocompatibility of AgNPs at lower concentration like 7 μg/mL and 15 μg/mL. Comparative analysis of bioactivity from different sites of sampling had indicated minute differences which may be due to the change in altitude, soil texture and other local environmental changes.

Microbial and microscopic investigations to assess the susceptibility of Candida parapsilosis and Prototheca ciferrii to phyco-synthesized titanium dioxide nanoparticles and antimicrobial drugs

Nowadays, several pathogenic strains of bacteria and fungi have become resistant against many therapeutic drugs. Therefore, using novel biologically synthesized nanomaterials as antimicrobial drugs against the human pathogens is of great concern. Consequently, here, the study was aimed to assess the antimicrobial activity of titanium dioxide nanoparticles (TiO2NPs) phycosynthesized from Spirulina platensis and some conventional antifungal (clotrimazole, itraconazole, ketoconazole, micconazole, and nystatin) and antibacterial (amoxicillin and gentamicin) drugs against both Candida parapsilosis and Prototheca ciferrii. The TiO2NPs-and clotrimazole-induced ultrastructure changes on the microbes using transmission electron microscope were also investigated. The TiO2NPs significantly inhibited the growth of C. parapsilosis. The clotrimazole and ketoconazole showed the highest inhibitory effect against both tested microorganisms. The ultrastructure changes affected by TiO2NPs or clotrimazole were represented by damage in the cell wall, invagination in the cell membrane, and discrimination of peroxisomes. Furthermore, accumulation of TiO2NPs inside C. parapsilosis cells led to abnormality in nuclear division, irregular shape of the nucleus (crescent shape). We conclude that the studied TiO2NPs offer promising potential for the development of novel technologies that control contaminations and infections caused by Candida parapsilosis and Prototheca ciferrii. The findings of the present study create a novel antimicrobial drug exploited to prevent candidiasis and protothecosis. However, further studies are needed to understand clearly the mechanism of action of these nanoparticles. • TiO 2 NPs and antimicrobial drugs against Candida parapsilosis and Prototheca ciferrii (P. zopfii var. hydrocarbonea). • TiO 2 NPs, Clotrimazole and ketoconazole significantly inhibit C. parapsilosis growth. • Cell wall and membrane damage and discrimination of peroxisomes. • Abnormality in nuclear division, irregular shape of the nucleus (crescent shape). • A novel antimicrobial drug (TiO2NPs) was exploited to prevent candidiasis and protothecosis.

Soluble soybean polysaccharide/TiO2 nanocomposites: Biological activity, release behavior, biodegradability, and biosafety

AbstractThis study aimed to produce and characterize eco‐friendly SSPS nanocomposites incorporated with various concentrations of TiO2 nanoparticles (NPs) (1%, 3%, and 7%). The antimicrobial activity of the nanocomposite films against five strains of pathogenic bacteria was examined. Salmonella typhi PTCC 1609 was the most sensitive species to TiO2 NPs at concentrations equal to the synthetic antibiotic. The migration of TiO2 to ethanol and acetic acid, as two food simulants increased when the initial nano‐TiO2 content increased. The release profiles for TiO2 in two simulants of ethanol and acetic acid indicated a non‐Fickian release, and the release kinetics were concentration‐dependent. SSPS/TiO2 nanocomposites degraded easily and thus have the potential to be applied as an eco‐friendly packaging system. Oral administration of doses of 1, 12.5, 25, 50, and 75 mg/kg TiO2 revealed that the dose of 50 and 75 mg/kg increased malondialdehyde (p &lt; .001) concentration in the liver tissue. In addition, it decreased glutathione (p &lt; .001) concentration in the liver tissue.

Conjugation of a WOW Peptide with silver nanoparticles to face the increase of antimicrobial resistance during COVID 19 pandemic

Bacterial resistance is a difficult limitation in the treatment of infections. The potential antibacterial activity of WOW peptide conjugation with silver nanoparticles against selected pathogens is investigated in this study. The peptide WOW was created by combining two tryptophan subunits and one ornithine amino acid, and its purity was determined using reverse phase high performance liquid chromatography. Mass spectrometry and electrospray ionization mass spectrometry were used to confirm the WOW peptide. Silver nanoparticles conjugated with WOW were created by adding WOW to a solution of silver nitrate in the presence of the reducing agent sodium borohydride. The yellow-brown color indicated the presence of WOW-AgNPs, which was confirmed by ultraviolet/visible spectrophotometry. The minimum inhibitory and bactericidal concentrations of WOW nanoparticles were determined using the micro dilution method against Staphylococcus aureus, Escherichia coli, Methicillin resistant Staphylococcus aureus (MRSA), and ESBL Escherichia coli. The Erythrocyte Hemolytic Assay was used to assess the toxicity of nanoparticles conjugated with WOW. WOW alone was effective (MICs between 120 and 215 µgml-1) against both standard and resistant strains of bacteria. WOW –AgNPs, on the other hand, were more effective, with MICs ranging from 30 to 100 µgml-1 depending on the bacteria used. WOW -–after 30 minutes of incubation, silver nanoparticles at a concentration of 100 µgml-1 caused only 3% hemolysis in human erythrocytes.in conclusion, WOW –silver nanoparticles were found to have good antibacterial activity against pathogenic strains of gram positive and gram negative bacteria. Furthermore, the conjugate demonstrated low hemolytic activity and cytotoxicity. As a result, WOW conjugation with AgNPs is a promising treatment candidate for bacterial infection with low toxicity.

Photocatalytic dye degradation and antibacterial activities of CeO2/g-C3N4 nanomaterials for environmental applications.

The uncontrolled dumping of synthetic dyes into water sources has posed severe hazards to the ecosystem. For decades, several materials with low cost and high efficiency have been investigated for dye degradation. Photocatalytic degradation is regarded as a successful strategy since it utilizes sunlight to transform harmful pollutants into nontoxic compounds without using oxidative agents. The photocatalytic potentials of CeO2/g-C3N4 (CG) were investigated in this work using a simplistic ultrasonication process. Here, the amount of CeO2 was fixed, and g-C3N4 was varied in the ratio (1:x, where x = 1, 2, and 3) and abbreviated as CG1, CG2, and CG3. Characterization techniques such as Fourier transforms-infrared spectroscopy, thermal gravimetric analysis (TGA), powdered X-ray diffraction, ultraviolet-visible spectroscopy, etc. were used to characterize structural analysis, optical properties, particle size, and chemical bonds of the prepared nanocomposites. The photocatalytic results showed that CG2 effectively degraded rose bengal (RB) and crystal violet (CV) dyes when exposed to visible light irradiation as compared to pure GCN and CeO2. The antibacterial activity analysis further supported the potential application of prepared photocatalyst as a disinfectant agent against both gram-positive (Staphylococcus aureus and Bacillus cereus) and gram-negative (Salmonella abony and Escherichia coli) pathogenic strains of bacteria.

Antioxidant Properties and Antimicrobial Effect of Zingiber officinale Extract towards Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa

Bacterial infection and emergence of multi-drug resistant bacteria have been a great obstacle in today’s medicine development. Emergence of multi-drug resistant bacteria strains reduces the efficiency of currently available antimicrobial agents. Besides, oxidative stress, which is commonly correlated to numerous amounts of diseases also need to be tackled. Previous studies found that consumption of food containing natural antioxidant may help in reducing the risk of death-threatening diseases. Therefore, this study aimed to discover potential antioxidant and antimicrobial activity of Zingiber officinale against pathogenic bacteria strains such as E. coli, S. aureus and P. aeruginosa. Z. officinale rhizome ethanol extract was tested for antimicrobial activity through well diffusion method. Antioxidant property of the extract was tested using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method. According to the findings on antimicrobial assay, Z. officinale able to inhibit S. aureus and P. aeruginosa while E. coli remain resistant against ginger extract. At the concentration of 80 to 100mg/ml of ginger extract, the mean zone of inhibition against S. aureus ranged from 11mm to 15mm. Meanwhile, at concentration of 5 to 100mg/ml of extract, the inhibition zone of P. aeruginosa, ranged from 40mm to 64mm (±9mm). Additionally, IC50 value for Z. officinale extract is 0.4623μg/ml compared to ascorbic acid with IC50 value of 4.1602μg/ml. It is evident that Z. officinale has higher antioxidant property than ascorbic acid. Present findings and data gained through this study can be used to boost the application of natural or plant-based products in medicine to combat the emergence of drug-resistant bacteria.

Adenosine-Mimicking Derivatives of 3-Aminopyrazine-2-Carboxamide: Towards Inhibitors of Prolyl-tRNA Synthetase with Antimycobacterial Activity

Multidrug-resistant tuberculosis (MDR-TB) poses a significant threat to mankind and as such earned its place on the WHO list of priority pathogens. New antimycobacterials with a mechanism of action different to currently used agents are highly required. This study presents the design, synthesis, and biological evaluation of 3-acylaminopyrazine-2-carboxamides derived from a previously reported inhibitor of human prolyl-tRNA synthetase. Compounds were evaluated in vitro against various strains of mycobacteria, pathogenic bacteria, and fungi of clinical significance. In general, high activity against mycobacteria was noted, while the antibacterial and antifungal activity was minimal. The most active compounds were 4'-substituted 3-(benzamido)pyrazine-2-carboxamides, exerting MIC (Minimum Inhibitory Concentration) from 1.95 to 31.25 µg/mL. Detailed structure-activity relationships were established and rationalized in silico with regard to mycobacterial ProRS as a probable target. The active compounds preserved their activity even against multidrug-resistant strains of Mycobacterium tuberculosis. At the same time, they were non-cytotoxic against HepG2 human hepatocellular carcinoma cells. This project is the first step in the successful repurposing of inhibitors of human ProRS to inhibitors of mycobacterial ProRS with antimycobacterial activity.

Antibacterial and Antioxidant Properties of Extracts of Yucca Baccata, a Plant of Northwestern Mexico, against Pathogenic Bacteria.

Bacterial agents and oxidative reactions are involved in health and food preservation issues, and Yucca baccata (Y. baccata) can be a source of compounds with practical applications in both areas, but its investigation remains limited. Butanolic (YBE) and aqueous (YAE) extracts were obtained from the stem of Y. baccata. The total saponin, phenolic, and flavonoid contents were analyzed in the YBE and YAE. The antioxidant capacity of the extracts was determined by the DPPH, TEAC, FRAP, and ORAC assays. Seven Gram-positive and five Gram-negative pathogenic bacteria strains were used to determine the MIC and MBC. Saponin contents were 30% and 1.81% (w/w) in the YBE and YAE, respectively. The total phenolic and flavonoid contents in the extracts were 29.5 μg GAEmg-1 (2.95%) and 5.58 μg GAEmg-1 (0.56%) in the YBE and 69.92 μg QEmg-1 (7.0%) and 1.65 μg QEmg-1 (0.165%) in the YAE. The antioxidant capacity values of YBE were 29.18 μg TEmg-1, 121.8 μg TEmg-1, 33.41 μg TEmg-1, and 156.84 μg TEmg-1 by the DPPH, TEAC, FRAP, and ORAC assays, respectively. YAE had lower antioxidant values than YBE (P < 0.05). Values of 80 mgmL-1 and 100 mgmL-1 were estimated for MIC and MBC of YBE against the Gram-positive bacteria. Values of 100 mgmL-1 and 120 mgmL-1 for MIC and MBC of YBE were estimated against the Gram-negative bacteria. No MIC and MBC were obtained for YAE. YBE exhibited higher antioxidant activity than YAE. Apparently, antibacterial properties of the YBE tended to be higher than those of the YAE.