Clinical Pathogenic Microorganisms Research Articles

Antimicrobial activity of emodin – secondary metabolites from Trichoderma against some human pathogenic bacteria in Wasit province, Iraq

Objective: To evaluate the antibacterial activity of emodin isolated from trichoderma longibrachiatum against certainpathogens in patients with bacterial disease.Methods: The cross-sectional study was conducted at Al-Zahraa Teaching Hospital, Wassit, Iraq, from December 2021to March 2022, and comprised tichoderma longibrachiatum taken from the Wasit University’s garden soil and weresubjected to plate morphology, microscopic examination, and polymerase chain reaction-internal transcribed spacertesting. Emodin was extracted by ethyl acetate with final yield of 58mg/L. Using the agar well diffusion method,emodin extract doses of 0.ug/ml, 1ug/ml, 2ug/ml and 4ug/ml were tested against clinical pathogenicmicroorganisms. Data was analysed using SPSS 22.Results: Emodin 0.5ug/ml showed high antibacterial activity against proteus mirabilis, with growth inhibition zoneof 8.7mm, followed by staphylococcus epidermidis 7mm, streptococcus pyogenes 7.6mm, staphylococcus aureus7.5mm, escherichia coli 6.7mm and klebsiella species 0.4mm. Pseudomonas aeruginosa was resistant to emodin0.5ug/ml.Conclusion: Emodin extract of trichoderma longibrachiatum showed high antimicrobial activity against humanpathogenic bacteria.5Keywords: Pseudomonas aeruginosa, Staphylococcus aureus, Proteus mirabilis, Escherichia coli, Trichoderma, Ethyl acetate,emodin, Agar, Mirabilis, Klebsiella, Bacterial, Polymerase.

Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry as Internship Teaching Content in Laboratory Medicine.

Matrix-assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) is one of the preferred detection techniques for identification of clinical microorganisms and it has the characteristics of rapid identification, simple operation, low cost, and updatable databases. For laboratory medicine undergraduates, clinical internship is an important stage for the connection of basic theoretical knowledge and clinical practice. Internship teaching choosing MALDI-TOF MS as the content will greatly increase the popularity and applicability of the new technology in the clinical microbiology laboratory. With the help of electronic databases on the network, we conducted a systematic review. According to the purpose of research, we singled out forty papers. Latest studies on history, basic principles, clinical features, and applications of MALDI-TOF MS and the internship teaching contents introducing new technologies are summarized and focused on. In internship teaching, firstly we explain the historical development, basic principle and widespread applications of MALDI-TOF MS in the identification of clinical pathogenic microorganisms and the detection of antibiotic resistance. Subsequently, we instruct the students to perform the experimental operations, analyze the common problems, and find solutions. Finally, we highlight quality control and laboratory biosafety. Most of the reviews published previously report the clinical features and applications of MALDI-TOF MS and the internship teaching contents choosing other new technologies. It is the first study selecting MALDI-TOF MS technology as an internship teaching content creatively. Primary outcome is that the students understand the theoretical knowledge in detail, master the operation skills of MALDI-TOF MS quickly, and obtain excellent internship performances in the clinical internship through the internship teaching. Secondary outcome is that it is a help to cultivate medical students' train of thought for scientific research and to understand the application of the new technology in clinical testing and scientific research. Laboratory medicine undergraduates should cherish the opportunity to learn the new technology during the internship period and should master basic principle and operation. As internship teachers, it is necessary to introduce the new technology to students during the internship and encourage undergraduates to cultivate creative and innovative thinking of scientific research.

Network Analysis Guided Designing of Multi-Targeted Anti-Fungal Agents: Synthesis and Biological Evaluation

During the ongoing pandemic, there have been increasing reports of invasive fungal disease (IFD), particularly among immunocompromised populations. Candida albicans is one of the most common clinical pathogenic microorganisms which have become a serious health threat to population either infected with Covid-19 or on treatment with immunosuppressant's/broad-range antibiotics. Currently, benzothiazole is a well-explored scaffold for anti-fungal activity, especially mercapto substituted benzothiazoles. It is reported that exploring the 2nd position of benzothiazoles yield improved anti-fungal molecules. Therefore, in the current study, a lead optimization approach using a bioisosteric replacement protocol was followed to improve the anti-fungal activity of an already reported benzothiazole derivative, N-(1,3-benzothiazole-2-yl)-2-(pyridine-3-ylformohydrazido) acetamide. To rationally identify the putative anti-candida targets of this derivative, network analysis was carried out. Complexes of designed compounds and identified putative targets were further analyzed for the docking interactions and their consequent retention after the completion of exhaustive MD simulations. Top six designed compounds were synthesized and evaluated for in-vitro anti-fungal property against Candida, which indicated that compounds 1.2c and 1.2f possess improved and comparable anti-fungal activity to N-(1,3-benzothiazole-2-yl)-2-(pyridine-3-ylformohydrazido) acetamide and Nystatin, respectively.

Ecofriendly synthesis of silver nanoparticles using Kei-apple (Dovyalis caffra) fruit and their efficacy against cancer cells and clinical pathogenic microorganisms

Green fabrication has become a safe approach for producing nanoparticles. Plant-based biogenic synthesis of silver nanoparticles (AgNPs) has emerged as a possible alternative to traditional chemical production. In this paper, we provide a low-cost, green synthesis of AgNPs utilizing using Kei-apple (Dovyalis caffra) fruit extract. Ultraviolet–visible (UV–Vis) spectroscopy, Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Scanning-Electron Microscope (SEM), and Dynamic Light Scattering (DLS) analyses were used to characterize green produced AgNPs. The formation of AgNPs was shown to have a surface resonance peak of 415 nm in UV–visible spectra, and FTIR spectra verified the participation of biological molecules in Synthesis of AgNPs. The TEM revealed that the biosynthesized AgNPs were mostly spherical in form, with size range of 12–53 nm. XRD diffractogram was used to demonstrate the face cubic centre (fcc) character of AgNPs. Excellent anticancer activity of AgNPs was recorded where more than 80% of Prostate Cancer (PC-3) cell lines was inhibited by 100–150 µg/mL of AgNPs, while 38% only was recorded using AgNO3 and 55.62% was recorded D. caffra fruit extract at 150 µg/mL. Destructions of PC-3 cell was observed as a result of exposed to AgNPs, followed by D. caffra fruit extract, while minor alterations were recorded as exposed to AgNO3. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging using AgNPs was three fold using fruit extract at 100 µg/mL indicating good antioxidant activity. Excellent inhibitory activity of AgNPs was recorded against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus with inhibition diameter zone 28.22 ± 0.25 mm, 23.21 ± 0.35 mm, 27.25 ± 0.03 mm, 28.40 ± 0.15 mm, 29.23 ± 0.44 mm, and 9.52 ± 0.5 mm, respectively compared with AgNO3. D. caffra fruits considered a promising and safe source for fabrication of AgNPs with multi-biological functions.

Fabrication and characterization of surgical sutures with propolis silver nano particles and analysis of its antimicrobial properties

ObjectivesThe objective of this work was to synthesize propolis – silver nanoparticles, coat the prepared nanoparticles on surgical sutures, characterize the coated sutures and to study the antimicrobial activity of coated sutures against human pathogenic microorganisms. MethodsSilver nanoparticles were synthesized with ethanolic propolis extract and analyzed by UV spectrophotometry analysis. Absorption peak was detected at 430 nm to confirm silver nanoparticle synthesis. Propolis – silver nanoparticles were coated over plain Cal Gut surgical sutures with the help of sodium alginate by slurry dipping technique. The characterization of coated sutures was done by Fourier-Transform Infrared analysis (FTIR) analysis and Scanning Electron Microscopy (SEM). The antimicrobial activity of propolis silver nanoparticles was determined by disc diffusion method against pathogenic bacteria like Staphylococcus aureus, E.coli and Aspergillus flavus obtained from clinical samples. ResultsFTIR confirmed the presence of silver through its various peaks and the various functional groups were detected. The SEM characterization revealed the particles size and shape of the nanoparticle at a magnification of 20KV. The size is about 20 nm and its mostly spherical in shape. The surface of the coated sutures was rough indicating the coating of propolis – silver nanoparticles (AgNPs) over the sutures. The in-vitro antimicrobial assay showed that the propolis – silver nanoparticles and the also coated sutures possessed a significant anti-microbial activity against the clinical pathogenic microorganisms. ConclusionPropolis is a natural product which is an asset to the mankind. The combined effect of the propolis and silver nanoparticles and also the antimicrobial activity of propolis nanoparticle coated sutures were extensively studied. So, this synergistic drug can be used as antimicrobial materials for clinical practice and bio medical use. It is proved that propolis silver nanoparticle loaded sutures are a beneficial in preventing the surgical site infections.

Green synthesis of novel antifungal 1,2,4-triazoles effective against γ-irradiated Candida parapsilosis.

This study reports the green synthesis of 11 novel 3-substituted-4-amino-5-mercapto-1,2,4-triazole derivatives using water as a readily available nontoxic solvent. Evaluation of their antimicrobial potential against several clinical pathogenic microorganisms was carried out. The newly synthesized cysteine derivative 6 showed promising antifungal activity against both γ-irradiated and nonirradiated Candida parapsilosis 216, with the lowest MIC (minimum inhibitory concentration) value of 3.125 µg/ml, probably through inhibition of 14α-demethylase. In addition, compound 6 showed complete inhibition of gelatinase, a virulence enzyme of C. parapsilosis. Also, scanning electron microscopy was carried out. Interestingly, compound 6 acted as a dual agent as it also showed good antibacterial activity against strains of Gram-positive bacteria used in the study. The synthesized compounds showed no cytotoxicity.

Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) Analysis for the Identification of Pathogenic Microorganisms: A Review.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been used in the field of clinical microbiology since 2010. Compared with the traditional technique of biochemical identification, MALDI-TOF MS has many advantages, including convenience, speed, accuracy, and low cost. The accuracy and speed of identification using MALDI-TOF MS have been increasing with the development of sample preparation, database enrichment, and algorithm optimization. MALDI-TOF MS has shown promising results in identifying cultured colonies and rapidly detecting samples. MALDI-TOF MS has critical research applications for the rapid detection of highly virulent and drug-resistant pathogens. Here we present a scientific review that evaluates the performance of MALDI-TOF MS in identifying clinical pathogenic microorganisms. MALDI-TOF MS is a promising tool in identifying clinical microorganisms, although some aspects still require improvement.

The synergistic antifungal activity of resveratrol with azoles against Candida albicans.

Candida albicans is one of the most common clinical pathogenic microorganisms and it is becoming a serious health threat, particularly to immunocompromised populations. Drug resistance of Candida species has also frequently emerged, and combination therapy for fungal infections has attracted considerable attention. In this study, we established the Qinling Mountains myxobacterial secondary metabolites library and a synergic assay in combination with ketoconazole against C. albicans was introduced for metabolites screening. Two active compounds with synergic anticandidal activities were obtained, which were identified as trans-resveratrol and cis-resveratrol. According to our study, resveratrol can reduce the dosage to 1/64 of ketoconazole as well as itraconazole. Furthermore, synergistic anticandidal activity of resveratrol combined with azoles was verified against a panel of clinical C. albicans isolates, and the combination strategy enhanced the azoles susceptibility of three fluconazole-resistant isolates. These findings suggest that resveratrol enhances the efficacy of azoles and provides a promising application in therapy of C. albicans infection.

Evaluation of the Antibacterial Potential of Ethyl Alcohol Leaf Extract of Chrysophyllum albidum (G. Don) against Five Bacterial Isolates

Background: In contributing to solving the global challenge of antimicrobial resistance, an in- vitro experiment was conducted to evaluate the antibacterial potential of ethyl alcohol leaf extract of Chrysophyllum albidum (G. Don)against five clinical pathogenic microorganisms namely: Escherichia coli (EC), Proteus mirabilis (PM), Pseudomonas aeruginosa (PA), Staphylococcus aureus (SA), and Salmonella typhimurium (ST).Methods: Agar well diffusion method was adopted and the exhibited zones of inhibition by the isolates were measured, and taken as the antimicrobial potential of the extract. Phytochemical screening of the leaf extract revealed the presence of tannins, saponins, terpenoids, steroids, flavonoids and cardiac glycosides. Sixteen different concentrations (0.003 – 100 mg/mL) of the extract were prepared to establish the minimum inhibitory concentrations (MICs). Results: The MICs ranged between 0.006 - 0.195 mg/mL. SA with MIC of0.006 mg/mL was the most sensitive isolate to the extract while E. coli was actively resistant. PA was resistant to all the tested (control) commercial antibiotics but highly sensitive to the extractwith MIC of 0.195mg/mL. Conclusion: It was concluded that C. albidum is a medicinal plant possessing a broad spectrum antimicrobial activities and hence could be explored for the production of antibiotic by phyto-pharmaceutical establishments.

Bioactivity of Khaya Senegalensis (Desr.) A. Juss. and Tamarindus indica L. extracts on Selected Pathogenic Microbes

Khaya senegalensis and Tamarindus indica are widely used medicinal plant in many parts of Africa to manage infectious diseases. The barks of these plants were screened for their phytochemicals and their bioactivity activity against some clinical pathogenic microorganisms. Results of the phytochemical screening showed that tha a queous, methanolic and ethanolic extracts of the barks of the plants contain saponins, tannins, basalms, glycosides, steriods, terpenoids and flavonoids. The antimicrobial susceptibility test showed that bark extracts of Khaya senegalensis and Tamarindus indica had varying inhibition strength on the test organisms. The aqueous, ethanolic and methanolic extracts of Khaya senegalensis had the highest zone of inhibition on three of the isolates which were; Pseudomonas 27853, Klebsiella pneumonia and Escherichia coli (Carbapenem-resistant strain). While the aqueous, ethanolic and methanolic extracts of Tamarindus indica barks inhibited Methicillin-resistant Staphylococcus aureus 4330, Klebsiella pneumonia and Echerichia coli (non-carbapenem strain). The minimum inhibitory concentration of the bark extracts ranged from 400mg/ml to 25mg/ml. There was no minimum bactericidal concentration observed from the extracts. Antibiotics susceptibility test using standard antibiotics indicated multidrug resistance by the test organisms which Ceftriaxone (CRO) 30µg and Cefepime (FEP) 30µg elicited inhibitory activity against Carbapenem-resistant pseudomonas species, Pseudomonas aerigunosa ATCC 27853, and Echerichia coli (non- carbapenem strain) respectively. The result of this study, therefore suggest the possibility of using Khaya senegalensis and Tamarindus indica extracts as antimicrobial agents, which can be a great asset to drug development for purpose of health care delivery in Nigeria.

Thymus musilii Velen. as a promising source of potent bioactive compounds with its pharmacological properties: In vitro and in silico analysis

For the first time, we reported the phytochemical composition of the volatile oil from Thymus musilii Velen (T. musilii). The antioxidant and antimicrobial activities against various food-borne and clinical pathogenic microorganisms were also tested. The thyme oil was particularly rich in thymol (67.697 ± 0.938%), and thymyl acetate (12.993 ± 0.221%). The strongest antioxidant activity of the essential oil was registered with the tests: ABTS (IC50 = 5.6 × 10−4 mg/mL) and β-carotene/linoleic acid (IC50 = 3.2 × 10−3 mg/mL). This thymol-chemotype oil was active against all microorganisms tested with an inhibition growth zone ranging from 21.33 ± 1.52 mm for Proteus mirabilis (P. mirabilis) to 37.33 ± 1.15 mm for Candida vaginalis (C. vaginalis) strain. Overall, the tested oil exhibited bactericidal and fungicidal activities and only a small quantity of the tested essential oil was found to be sufficient for inhibiting the growth of the tested microorganisms. Furthermore, molecular docking results implies that, among the bioactive compounds, β-caryophyllene interacted strongly with the active site residues of TyrRS, GLMS and Gyrase enzymes and consequently support our in vitro results with the highest inhibition potential of this essential oil against tested pathogens, especially Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Our results suggested that essential oil of T. musiliii exhibited strong biological activities with a promising source of various natural compounds.

Diagnostic Accuracy of MALDI-TOF Mass Spectrometry for the Direct Identification of Clinical Pathogens from Urine.

Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has become one of the most popular methods for the rapid and cost-effective detection of clinical pathogenic microorganisms. This study aimed to evaluate and compare the diagnostic performance of MALDI-TOF MS with that of conventional approaches for the direct identification of pathogens from urine samples. A systematic review was conducted based on a literature search of relevant databases. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the summary receiver operating characteristic (SROC) curve of the combined studies were estimated. Nine studies with a total of 3920 subjects were considered eligible and included in the meta-analysis. The pooled sensitivity was 0.85 (95% CI 0.79-0.90), and the pooled specificity was 0.93 (95% CI 0.82-0.97). The PLR and NLR were 11.51 (95% CI 4.53-29.26) and 0.16 (95% CI 0.11-0.24), respectively. The area under the SROC curve was 0.93 (95% CI 0.91-0.95). Sensitivity analysis showed that the results of this meta-analysis were stable. MALDI-TOF MS could directly identify microorganisms from urine samples with high sensitivity and specificity.

Antimicrobial Properties of Cooked African Locust Beans (Parkia biglobosa) Effluent with and without Its Chaff

Aim: This study aim to determine the antimicrobial properties of the Parkia biglobosa (Jacque Benth.) effluents (waste water from the preparation of Parkia biglobosa). The effluents were tested against some typed and clinical pathogenic microorganisms for their antimicrobial properties using the conventional antibiotics as the control.
 Study Design: Effluent with and without chaff is to serve as agents used to determine its antimicrobial properties on the clinical and typed isolates.
 Place and Duration of Study: This study was carried out between November- 2015 and July- 2016 at the Department of Microbiology Laboratory, Federal University of Technology Akure, Ondo State, Nigeria.
 Methodology: Locust beans bought from “Oja Oba” market, Ikare-Akoko, Ondo state were cooked until the coat was soft and the effluent (waste water from the locust beans) was decanted, cooked again and the effluent with chaffs was also decanted. Both effluents (with and without chaffs) were used against the test and clinical microorganisms using agar well diffusion method. The Minimum inhibitory concentration was carried out using tube dilution method using Mueller Hinton broth.
 Results: The typed pathogenic microorganisms were subjected to antimicrobial tests using the P. biglobosa effluents at 100mg/mL; the effluents were able to inhibit S. pyogenes (ATCC 29212) S. aureus (ATCC 43300), S. typhi (ATCC 35240) and E. coli (ATCC 35218) while P. aeruginosa (ATCC 27853) and K. pneumonia (ATCC 48891) were resistant to the effluents. E. coli (ATCC 35218) had the lowest susceptibility at 6.33 ± 0.58bmm and S. pyogenes (ATCC 29212) had the highest susceptibility with 13.00 ± 1.73amm zones of inhibition for the locust beans effluent. For the clinical isolate, the effluent (waste water from the boiled locust beans) and effluent containing chaffs were also able to inhibit S. aureus, S. typhi, E. coli and S. pyogenes. For the effluent containing chaffs, S. aureus had the lowest susceptibility at 2.33 ± 0.58a mm while S. pyogenes had the highest susceptibility at 9.33 ± 0.58a mm. P. aeruginosa and K. pneumoniae isolates were resistant to the effluents.
 Conclusion: This study has provided useful information on the antimicrobial activities of the effluents against clinical and typed microorganisms used in this study.

Probiotic Potential of Lactobacillus plantarum LD1 Isolated from Batter of Dosa, a South Indian Fermented Food

Lactobacillus plantarum LD1 was isolated from dosa batter and identified by biochemical, physiological and genetic methods. Species level identification was done by 16S rDNA amplification and sequencing. The probiotic potential of strain LD1 was assessed by different standard parameters. Cell surface hydrophobicity was recorded to be 62% with SAT value <0.007 M. Seventy-eight percent of viable count was found after treatment with simulated gastric juice containing pepsin (pH 2.0). Bile salt tolerance and bile salt hydrolase activity were also demonstrated by strain LD1. The culture supernatant was able to inhibit food-borne as well as clinical pathogenic microorganisms such as Staphylococcus aureus, Salmonella typhimurium, Shigella flexneri, Pseudomonas aeruginosa, urogenic Escherichia coli and Vibrio sp. Strain LD1 was found to be sensitive to most of the antibiotics used in the study. Since strain has been isolated from food source that is most typical of Southern India, it would be safe for further consumption in probiotic products.

Antimicrobial activities of two Nigerian edible macro-fungi-&lt;i&gt;lycoperdon pusilum&lt;/i&gt;(Bat. Ex)and lycoperdon giganteum(Pers.))

Two edible Nigerian macro-fungi Lycoperdon pusilum and Lycoperdon giganteum were assayed in-vitro for their antimicrobial activities using water, methanol and ethanol as extractive solvents. Generally, the extracts were selectively active on few clinical pathogenic microorganisms. Ethanol was the best extractive solvent followed in order by methanol and water (P< 0.05). The best inhibitory zone (24.0mm) was recorded in ethanol extract of L. giganteum with inhibitory zone of 21.0mm. The least inhibitory zone, (4.0mm) was recorded with the aqueous extract of L. pusilum against Proteus vulgaris. The best antifungal activity (17.0mm), was recorded in L. giganteum extract against Microsporum boulardii. The minimuminhibitory concentration (MIC) for the ethanolic extract was between 0.75 and 4.0mg/ml for bacteria, and between 9.00 and 13.75mg/ml for fungi. The extracts were found to be stable at temperatures up to 50oC. As the temperature was increased from 60 to 100oC, there was asignificant decrease in stability of the extract. The implications of these observations are discussed.