47 research outputs found
Rapid diagnosis of sepsis pathogens
Sepsis is a growing global healthcare concern and is related to high morbidity and mortality. Studies have repeatedly demonstrated that the rapid administration of appropriate antimicrobial treatment is crucial for patient survival. Thus, receiving timely and actionable information from the laboratory on identification of the microorganism causing sepsis is crucial for patient management.
In today’s routine diagnostics, blood culture is the standard method for diagnosing sepsis and identification of microorganisms is based on sub-culturing the positive blood culture bottles.
The overall aim of this thesis was to evaluate and improve the use of rapid identification methods in identification of microorganisms directly from blood culture bottles.
The thesis focused on two methods, FilmArray and MALDI-TOF MS. The present studies showed that the identification of microorganisms from a blood culture bottle by FilmArray and MALDI-TOF MS were ready in 65 min and 30 minutes respectively.
The most common form of sepsis is caused by a single microorganism. In paper 1 we studied the performance of FilmArray in identification of microorganism’s form blood culture bottles. The FilmArray could identify the microorganism in 91.6% of the blood culture bottles.
The anaerobic bacteria are not covered by current rapid identification methods including FilmArray. In study 3, we analyzed the performance of MALDI-TOF MS in identification of anaerobic bacteria from four different blood culture bottle types. MALDI-TOF MS could identify anaerobic bacteria in between 75-79% of the different blood culture bottle types.
The incidence of detection of polymicrobial growth in blood culture bottles is increasing. This is an obvious challenge both for conventional and rapid identification methods. In study 1 and 4 we evaluated the performance of rapid methods in identification of polymicrobial growth directly from blood culture (BC) bottles after positivity. FilmArray correctly identified all microorganisms in 17/24 (71%) and 99/115 (86.1%) of the BC bottles in study 1 and 4 respectively. In contrast, the present MALDI-TOF MS method showed poor performance and could identify both microorganisms in only 2/115 (1.7%) blood culture bottles.
The high analytical performance of the current rapid methods stimulated us to ask the question if we can identify microorganisms from bottles before the blood cultures signals positive. We called this unique approach as semi-culture based identification since the full- term culture is not needed.
In study 2, we analyzed the semi-culture based identification by FilmArray and MALDI-TOF MS. We analyzed both simulated and clinical blood cultures with this approach. MALDI- TOF MS failed to identify the microorganisms prior to positivity even in the simulated blood culture bottles. Interestingly, FilmArray could identify microorganisms from bottles before the blood cultures signals positive both in simulated and clinical blood culture bottles. In simulated samples, the median time to detection (TTD) of growth for the bottles in the blood culture system was 11.1 h, whereas FilmArray could identify microorganisms after 5 h incubation in the system.
In conclusion, the present thesis shows that the FilmArray is a reliable method for identification of microorganisms from positive blood culture bottles with mono- as well as polymicrobial growth. The data from the studies showed also that it is possible to improve the use of rapid identification methods as in the case of semi-culture based identification
Integrated Pangenome Analysis and Pharmacophore Modeling Revealed Potential Novel Inhibitors against Enterobacter xiangfangensis
Enterobacter xiangfangensis is a novel, multidrug-resistant pathogen belonging to the Enterobacter genus and has the ability to acquire resistance to multiple antibiotic classes. However, there is currently no registered E. xiangfangensis drug on the market that has been shown to be effective. Hence, there is an urgent need to identify novel therapeutic targets and effective treatments for E. xiangfangensis. In the current study, a bacterial pan genome analysis and subtractive proteomics approach was employed to the core proteomes of six strains of E. xiangfangensis using several bioinformatic tools, software, and servers. However, 2611 nonredundant proteins were predicted from the 21,720 core proteins of core proteome. Out of 2611 nonredundant proteins, 372 were obtained from Geptop2.0 as essential proteins. After the subtractive proteomics and subcellular localization analysis, only 133 proteins were found in cytoplasm. All cytoplasmic proteins were examined using BLASTp against the virulence factor database, which classifies 20 therapeutic targets as virulent. Out of these 20, 3 cytoplasmic proteins: ferric iron uptake transcriptional regulator (FUR), UDP-2,3diacylglucosamine diphosphatase (UDP), and lipid-A-disaccharide synthase (lpxB) were chosen as potential drug targets. These drug targets are important for bacterial survival, virulence, and growth and could be used as therapeutic targets. More than 2500 plant chemicals were used to molecularly dock these proteins. Furthermore, the lowest-binding energetic docked compounds were found. The top five hit compounds, Adenine, Mollugin, Xanthohumol C, Sakuranetin, and Toosendanin demonstrated optimum binding against all three target proteins. Furthermore, molecular dynamics simulations and MM/GBSA analyses validated the stability of ligand–protein complexes and revealed that these compounds could serve as potential E. xiangfangensis replication inhibitors. Consequently, this study marks a significant step forward in the creation of new and powerful drugs against E. xiangfangensis. Future studies should validate these targets experimentally to prove their function in E. xiangfangensis survival and virulence
Green Synthesis of Zn(OH)<sub>2</sub>/ZnO-Based Bionanocomposite using Pomegranate Peels and Its Application in the Degradation of Bacterial Biofilm
The ability and potency of bacterial species to form biofilms, which show antibiotic resistance thereby avoiding antibiotic surfaces, is a major cause of prolonged infections. Various advanced approaches have been employed to prevent or damage bacterial biofilms, formed by a variety of bacterial strains, to help prevent the associated infectious disease. In this context, zinc-based nanostructures have been recognized as a potential antibiotic agent against a broad spectrum of bacterial communities. As a result, a sustainable and green synthesis method was adapted in the present study to synthesize a Zn(OH)(2)/ZnO-based bionanocomposite, in which aqueous extracts of waste pomegranate peels (Punica granatum) were employed as a natural bioreducing agent to prepare the bionanocomposite at room temperature. Furthermore, FT-IR, XRD, DLS, UV-Visible, PL spectroscopy, FE-SEM, and TEM were used to characterize the green route synthesized a Zn(OH)(2)/ZnO bionanocomposite. The average crystallite size was determined using the Scherrer relation to be 38 nm, and the DLS results indicated that the Zn(OH)(2)/ZnO bionanocomposite had a hydrodynamic size of 170 nm. On the other hand, optical properties investigated through UV-Vis and PL spectroscopy explored the energy bandgap between 2.80 and 4.46 eV, corresponding to the three absorption edges, and it covered the blue spectrum when the sample was excited at 370 nm. Furthermore, the impact of this green route synthesized a Zn(OH)(2)/ZnO bionanocomposite on the biofilm degradation efficiency of the pathogenic bacterial strain Bacillus subtilis PF_1 using the Congored method was investigated. The Congored assay clearly explored the biofilm degradation efficiency in the presence of a 50 mg/mL and 75 mg/mL concentration of the Zn(OH)(2)/ZnO bionanocomposite against the bacterial strain Bacillus subtilis PF_1 grown for 24 h. This study can be further applied to the preparation of bionanocomposites following a low-cost green synthesis approach, and thus prepared nanostructures can be exploited as advanced antimicrobial agents, which could be of great interest to prevent various infectious diseases
Insight into the phytochemical profile and antimicrobial activities of Amomum subulatum and Amomum xanthioides: an in vitro and in silico study
IntroductionMedicinal plants have been considered as potential source of therapeutics or as starting materials in drugs formulation.MethodsThe current study aims to shed light on the therapeutic potential of the Amomum subulatom and Amomum xanthioides Fruits by analyzing the phytochemical composition of their seeds and fruits using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) techniques to determine the presence of bioactive components such as flavonoids, phenols, vitamins, steroids, and essential oils.Results and DiscussionThe protein content is usually higher than the total lipids in both species except the fruit of A. subulatum which contain more lipids than proteins. The total protein contents for A. subulatum were 235.03 ± 21.49 and 227.49 ± 25.82 mg/g dry weight while for A. xanthioides were 201.9 ± 37.79 and 294.99 ± 37.93 mg/g dry weight for seeds and fruit, respectively. The Carvacrol levels in A. subulatum is 20 times higher than that in A. xanthioides. Lower levels of α-Thujene, Phyllanderenes, Ascaridole, and Pinocarvone were also observed in both species. According to DPPH (2,2-diphenylpicrylhydrazyl) assay, seed the extract of A. subulatum exhibited the highest antioxidant activity (78.26±9.27 %) followed by the seed extract of A. xanthioides (68.21±2.56 %). Similarly, FRAP (Ferric Reducing Antioxidant Power) assay showed that the highest antioxidant activity was exhibited by the seed extract of the two species; 20.14±1.11 and 21.18±1.04 µmol trolox g−1 DW for A. subulatum and A. xanthioides, respectively. In terms of anti-lipid peroxidation, relatively higher values were obtained for the fruit extract of A. subulatum (6.08±0.35) and the seed extract of A. xanthioides (6.11±0.55). Ethanolic seed extracts of A. subulatum had the highest efficiency against four Gram-negative bacterial species which causes serious human diseases, namely Pseudomonas aeruginosa, Proteus vulgaris, Enterobacter aerogenes, and Salmonella typhimurium. In addition, P. aeruginosa was also inhibited by the fruit extract of both A. subulatum and A. xanthioides. For the seed extract of A. xanthioides, large inhibition zones were formed against P. vulgaris and the fungus Candida albicans. Finally, we have in silico explored the mode of action of these plants by performing detailed molecular modeling studies and showed that the antimicrobial activities of these plants could be attributed to the high binding affinity of their bioactive compounds to bind to the active sites of the sterol 14-alpha demethylase and the transcriptional regulator MvfR.ConclusionThese findings demonstrate the two species extracts possess high biological activities and therapeutical values, which increases their potential value in a number of therapeutic applications
Cinnamon and ginger extracts attenuate diabetes-induced inflammatory testicular injury in rats and modulating SIRT1 expression
The current study aimed to evaluate the efficacy of simultaneous administration
of Zingiber officinale (ginger) and Cinnamomum cassia
(cinnamon) extracts in mitigating testicular changes associated with diabetes
mellitus in rats and to investigate its molecular mode of action. After induction
of diabetes using streptozotocin, 36 male rats were divided to six groups namely
control, diabetic, metformin-treated, cinnamon-treated, ginger-treated and
combined, each group having 6 rats. Fasting blood glucose, serum insulin,
testosterone was measured. Expression of inflammatory mediators; tumor necrosis
factor-alpha (TNF-α), Nuclear factor kappa B (NF-κB) and
Sirtuin 1 (SIRT1) was assessed in the testicular tissue. Histopathological
changes in the testis were observed and spermatogenesis and apoptosis were
assessed immunohistochemically. The histological and biochemical studies
of the untreated group confirmed structural changes in testes induced by
diabetes. Oral administration of ginger and cinnamon increased insulin level
significantly increased while the blood glucose level significantly decreased in
diabetic rats, improving structural testicular changes considerably. Joint intake
of ginger and cinnamon increased antihyperglycemic, antioxidant and
anti-inflammatory effects markedly improving the testicular injury compared to
the administration of either of them. SIRT1 expression in the testis
significantly increased in ginger plus cinnamon-treated rats. These results
indicate that when administrated together, ginger and cinnamon synergistically
enhanced antioxidant, antiapoptotic and anti-inflammatory effects and induced
antihyperglycemic effect comparable to metformin. The combination of ginger and
cinnamon also upregulated SIRT1 in the testis
Bacterial Endophytes as a Promising Approach to Enhance the Growth and Accumulation of Bioactive Metabolites of Three Species of Chenopodium Sprouts
Sprouts are regarded as an untapped source of bioactive components that display various biological properties. Endophytic bacterium inoculation can enhance plant chemical composition and improve its nutritional quality. Herein, six endophytes (Endo 1 to Endo 6) were isolated from Chenopodium plants and morphologically and biochemically identified. Then, the most active isolate Endo 2 (strain JSA11) was employed to enhance the growth and nutritive value of the sprouts of three Chenopodium species, i.e., C. ambrosoides, C. ficifolium, and C. botrys. Endo 2 (strain JSA11) induced photosynthesis and the mineral uptake, which can explain the high biomass accumulation. Endo 2 (strain JSA11) improved the nutritive values of the treated sprouts through bioactive metabolite (antioxidants, vitamins, unsaturated fatty acid, and essential amino acids) accumulation. These increases were correlated with increased amino acid levels and phenolic metabolism. Consequently, the antioxidant activity of the Endo 2 (strain JSA11)-treated Chenopodium sprouts was enhanced. Moreover, Endo 2 (strain JSA11) increased the antibacterial activity against several pathogenic bacteria and the anti-inflammatory activities as evidenced by the reduced activity of cyclooxygenase and lipoxygenase. Overall, the Endo 2 (strain JSA11) treatment is a successful technique to enhance the bioactive contents and biological properties of Chenopodium sprouts
Preoperative Imaging Modalities to Predict the Risk of Regional Nodal Recurrence in Well-Differentiated Thyroid Cancers
Abstract
Introduction Thyroid cancer incidence has increased in the previous 2 decades. Preoperative identification of lymph node metastasis is a suggested risk factor associated with recurrence following thyroidectomy.
Objectives We aimed to evaluate the accuracy of preoperative radiologic investigations of nodal status in determining the postoperative risk of regional nodal recurrence in cases of well-differentiated thyroid cancer.
Methods This is a case series. We retrospectively reviewed data, including preoperative ultrasonography and/or computed tomography results, on patients who underwent total thyroidectomy for thyroid cancer at our hospital between 2006 and 2012. Prognostic factors for predicting recurrence, including age, sex, tumor diameter, and nodal diameter, were evaluated.
Results Total thyroidectomy was performed on 24 male and 74 female patients (median age, 43 years). The median follow-up time was 21 months. Sixty-eight patients had papillary thyroid cancer, and 30 had follicular cancer. Nodal recurrence was evident in 30% of patients, and 4% of patients died. Identification of lymph node involvement during preoperative radiologic investigations was strongly prognostic for recurrence: 35.3% of patients with positive preoperative ultrasonography findings and 62.5% of those with positive preoperative computed tomography findings had recurrence (p = 0.01).
Conclusions Preoperative identification of lymph node metastasis on radiologic studies was correlated with an increased risk of regional nodal recurrence in well-differentiated thyroid cancer. Computed tomography was superior to ultrasonography in detecting metastatic nodal involvement preoperatively and is therefore recommended for preoperative assessment and postoperative follow-up
Distinction between Antimicrobial Resistance and Putative Virulence Genes Characterization in <i>Plesiomonas shigelloides</i> Isolated from Different Sources
Plesiomonas shigelloides are gram-negative, thermotolerant, motile, and pleomorphic microorganisms that are only distantly related to those of the Enterobacteriaceae and Vibrionaceae families. One of the most common sources of P. shigelloides contamination is human stool, but it may also be found in a wide range of other animals, plants, and aquatic habitats. Antimicrobial resistance in P. shigelloides from seawater and shellfish was investigated, and pathogenicity involved genes were characterized as part of this study. Out of 384 samples of shellfish, 5.7% included P. shigelloides. The presence of P. shigelloides was also discovered in 5% of the seawater sampled. The antimicrobial resistance of 23 P. shigelloides isolates derived from those samples was investigated. All isolates were sensitive to nalidixic acid, carbenicillin, cephalothin, erythromycin, kanamycin, tetracycline, and ciprofloxacin in the study. Several strains isolated from diseased shellfish were tested for virulence in shellfish by intraperitoneal injections. The LD50 values ranged from 12 × 108 to 3 × 1012 cfu/shellfish. When looking for possible virulence factors that may play a significant role in bacterial infection in the current study, we found that all of these genes were present in these strains. These include genes such as elastase, lipase, flagellin, enterotoxin, and DNases. According to these findings, shellfish may serve as a reservoir for multi-resistant P. shigelloides and help spread virulence genes across the environment
Bioactive Potential of Several Actinobacteria Isolated from Microbiologically Barely Explored Desert Habitat, Saudi Arabia
Biomolecules from natural sources, including microbes, have been the basis of treatment of human diseases since the ancient times. Therefore, this study aimed to investigate the potential bioactivity of several actinobacteria isolates form Al-Jouf Desert, Saudi Arabia. Twenty-one actinobacterial isolates were tested for their antioxidant (flavonoids, phenolics, tocopherols and carotenoids) content, and biological activities, namely FRAP, DPPH, ABTS, SOS and XO inhibition, anti-hemolytic and anti-lipid peroxidation as well as their antibacterial and antiprotozoal activities. Accordingly, five isolates (i.e., Act 2, 12, 15, 19 and 21) were selected and their 90% ethanolic extracts were used. The phylogenetic analysis of the 16S rRNA sequences indicated that the most active isolates belong to genus Streptomyces. The genus Streptomyces has been documented as a prolific producer of biologically active secondary metabolites against different cancer types. Thus, the anti-blood cancer activity and the possible molecular mechanisms by which several Streptomyces species extracts inhibited the growth of different leukemia cells, i.e., HL-60, K562 and THP-1, were investigated. In general, the five active isolates showed cytotoxic activity against the tested cell lines in a dose dependent manner. Among the potent isolates, isolate Act 12 significantly decreased the cell viability and showed maximum cytotoxic activities against both HL-60 and K562 cells, while isolate Act 15 exhibited maximum cytotoxic activity against THP-1 cells. Moreover, Act 2 and Act 12 reduced cyclooxygenase (COX-2) and lipoxygenase (LOX) activity, which is involved in the proliferation and differentiation of cancer cells and may represent a possible molecular mechanism underlying leukemia growth inhibition. The bioactive antioxidant extracts of the selected Streptomyces species inhibited leukemia cell growth by reducing the COX-2 and LOX activity. Overall, our study not only introduced a promising natural alternative source for anticancer agents, but it also sheds light on the mechanism underlying the anticancer activity of isolated actinomycetes
In vitro and in silico biopotentials of phytochemical compositions and antistaphylococcal and antipseudomonal activities of volatile compounds of Argania spinosa (L.) seed oil
Active components in medicinal plants provide unlimited useful and traditional medicines. Antimicrobial activities are found in secondary metabolites in plant extracts such as argan oil. This experimental investigation aims to determine argan oil’s volatile compounds and examine their in vitro antimicrobial properties. In silico simulations, molecular docking, pharmacokinetics, and drug-likeness prediction revealed the processes underlying the in vitro biological possessions. Gas chromatography–mass spectrometry (GC/MS) was used to screen argan oil’s primary components. In silico molecular docking studies were used to investigate the ability of the selected bioactive constituents of argan oil to act effectively against Pseudomonas aeruginosa and Staphylococcus aureus (S. aureus) isolated from infections. The goal was to study their ability to interact with both bacteria’s essential therapeutic target protein. The 21 chemicals in argan oil were identified by GC/MS. Docking results for all compounds with S. aureus and P. aeruginosa protease proteins ranged from −5 to −9.4 kcal/mol and −5.7 to −9.7 kcal/mol, respectively, compared to reference ligands. Our docking result indicates that the 10-octadecenoic acid, methyl ester was the most significant compound with affinity scores of −9.4 and −9.7 kcal/mol for S. aureus and P. aeruginosa proteins, respectively. The minimal bactericidal concentration (MBC) and minimal inhibitory concentration (MIC) of argan oil were 0.7 ± 0.03 and 0.5 ± 0.01 for S. aureus and 0.4 ± 0.01 and 0.3 ± 0.02 for P. aeruginosa, respectively. We confirmed the antimicrobial properties of argan oil that showed significant growth inhibition for S. aureus and P. aeruginosa