In vitro studies on the pharmacological potential, anti-tumor, antimicrobial, and acetylcholinesterase inhibitory activity of marine-derived Bacillus velezensis AG6 exopolysaccharide.

In the current study, Bacillus velezensis AG6 was isolated from sediment samples in the Red Sea, identified by traditional microbiological techniques and phylogenetic 16S rRNA sequences. Among eight isolates screened for exopolysaccharide (EPS) production, the R6 isolate was the highest producer with a significant fraction of EPS (EPSF6, 5.79 g L-1). The EPSF6 molecule was found to have a molecular weight (Mw) of 2.7 × 104 g mol-1 and a number average (Mn) of 2.6 × 104 g mol-1 when it was analyzed using GPC. The FTIR spectrum indicated no sulfate but uronic acid (43.8%). According to HPLC, the EPSF6 fraction's monosaccharides were xylose, galactose, and galacturonic acid in a molar ratio of 2.0 : 0.5 : 2.0. DPPH, H2O2, and ABTS tests assessed EPSF6's antioxidant capabilities at 100, 300, 500, 1000, and 1500 µg mL-1 for 15, 60, 45, and 60 minutes. The overall antioxidant activities were dose- and time-dependently increased, and improved by increasing concentrations from 100 to 1500 µg mL-1 after 60 minutes and found to be 91.34 ± 1.1%, 80.20 ± 1.4% and 75.28 ± 1.1% respectively. Next, EPSF6 displayed considerable inhibitory activity toward the proliferation of six cancerous cell lines. Anti-inflammatory tests were performed using lipoxygenase (5-LOX) and cyclooxygenase (COX-2). An MTP turbidity assay method was applied to show the ability of EPSF6 to inhibit Gram-positive bacteria, Gram-negative bacteria, and antibiofilm formation. Together, this study sheds light on the potential pharmacological applications of a secondary metabolite produced by marine Bacillus velezensis AG6. Its expected impact on human health will increase as more research and studies are conducted globally.

Endoscopic Excision of Primary Tracheal Schwannoma: A Case Report.

BACKGROUND Primary tracheal schwannoma is a rare neurogenic tumor. Early stage presents with nonspecific symptoms, and asthma is sometimes misdiagnosed. However, as the tumor grows, it presents with obstructive symptoms of the tracheal lumen. This tumor has been managed by open resection surgery until recently, when endoscopic excision became an option. The endoscopic excision reduces complications, operative time, and postoperative recovery period and is indicated in nonrecurrent surgical cases in which tumors are up to 2 cm in size, are pedunculated, and have no extratracheal extension, or in cases of poor cardiopulmonary status. We present a rare case of primary tracheal schwannoma managed by endoscopic excision. CASE REPORT A 37-year-old man was referred to our clinic with progressive shortness of breath and wheezing that started 3 months prior to presentation. Computed tomography showed a well-defined rounded, solid intraluminal tracheal mass at the proximal segment (at the level of the thoracic inlet). There was no extratracheal extension or enlarged cervical lymph nodes. The patient underwent endoscopic excision of the mass. A sickle knife, micro scissor, and suction diathermy were used for incision, stripping, and hemostasis done through the tumor pedicle. The first postoperative visit after 2 weeks showed subjective symptom improvement, and the flexible bronchoscope showed a completely healed surgical site with patent airway. Histopathological examination and immunohistochemistry confirmed the diagnosis of primary tracheal schwannoma. CONCLUSIONS Primary tracheal schwannoma is rare. An endoscopic excision is an excellent option, but patients need to be appropriately selected and followed up to avoid recurrence.

Motivators and barriers to research participation among medical students in Saudi Arabia.

Little is known about the obstacles medical students face when conducting research in Saudi Arabia. Moreover, the proportion of medical students in research has been unknown in our region compared to other regions. We sought to identify the barriers and motivators that influence undergraduate medical students in pursuing research. This was a cross-sectional study design, utilizing an online survey distributed through social media platforms from the 17th of December 2021 to the 8th of April 2022. The survey was distributed to four universities in Saudi Arabia. Participants' characteristics, details regarding involvement in research, and attitude towards research were collected. Frequency measures were used to characterize the demographics and chi-squared tests to determine associations. A total of 435 students were included in the final analysis. The highest proportion of students that responded were second year, followed by first year medical students. Less than half (47.6%) of medical students were involved in research. A significant correlation was revealed between the involvement in research and higher participants' Grade Point Average (GPA). The top three incentives for pursuing undergraduate research were "admission into residency programs" (44.8%), "interest in research" (28.7%), and "financial return" (10.8%). However, the top three limitations were "lack of time" (29.2%), "lack of mentoring" (16.8%), and "lack of interest in research" (14.7%). System-related barriers and motivators were the main reasons behind the involvement of medical students in research. Our study is a call for action to raise awareness among medical students about the importance of research and to provide solutions to overcome these barriers.

Radiosynthesis, quality control, biodistribution, and infection-imaging study of a new 99mTc-labeled ertapenem radiopharmaceutical.

Ertapenem is a member of carbapenem antibiotics used for the treatment of moderate-to-severe intra-abdominal, urinary tract, acute pelvic, and post-surgical gynecologic infections. The antibacterial activity of ertapenem is mediated through binding to penicillin-binding proteins which results in inhibiting the cross-linking of the peptidoglycan layer of the bacterial cell wall. Therefore, ertapenem can be labeled with technetium-99m (99mTc), a gamma emitter radionuclide, for the diagnosis of deep-seated bacterial infections, such as urinary tract, intra-abdominal, osteomyelitis, and post-surgical gynecologic infections. The labeling procedure was carried out by varying the reaction conditions, such as the amount of the ligand and reducing agent, pH, reaction time and temperature, and radioactivity. At optimized reaction conditions more than 93% 99mTc-ertapenem radioconjugate was obtained. 99mTc-ertapenem was found 90% intact in saline medium up to 6 h, while 88% intact in human blood serum up to 3 h. Biodistribution study showed target-to-non-target ratios of 2.91 ± 0.19, 2.39 ± 0.31, and 1.23 ± 0.22 in S. aureus, E. coli, and turpentine oil-infected rat models, respectively. The SPECT scintigraphy showed high uptake of 99mTc-ertapenem in bacterial-infected abscesses, and low counts were recorded in normal and turpentine oil-inflamed tissues. In conclusion, 99mTc-ertapenem can be a potent infection-imaging agent, which can diagnosis deep-seated bacterial infections at early stage but need further pre-clinical evaluation in variety of infection models.

Prevalence, antibiotic profile, virulence determinants, ESBLs, and non-ß-lactam encoding genes of MDR Proteus spp. isolated from infected dogs.

This study investigated the prevalence, antibiogram, virulence, extended-spectrum ß-lactamases (ESBLs), and non-ß-lactam encoding genes of Proteus species isolated from infected dogs in Ismailia province, Egypt. The study was conducted on 70 fecal swabs collected from dogs with diarrhea for bacteriological identification of Proteus spp. The positive isolates were evaluated for antibiotic susceptibility, molecular tests of virulence, ESBLs, and non-ß-lactam encoding genes. Prevalence of Proteus spp. was 35.7% (25/70), including Proteus mirabilis (n = 23) and Proteus vulgaris (n = 2). The Proteus spp. prevalence revealed diversity, higher in males than females, in ages < 12 weeks. Investigation of antimicrobial resistance was found against penicillin and amoxicillin (100%), amoxicillin-clavulanic acid (32%), cephalosporins: cefotaxime and ceftazidime (36%), and monobactam: aztreonam (28%) as ESBLs, in addition to tetracycline (32%) and trimethoprim sulfamethoxazole (100%). The strains retrieved by PCR revealed ureC, zapA, and rsbA virulence genes with variant prevalence as 92%, 60%, and 52%, respectively. In addition, the recovered strains contained ESBL genes with a dramatic variable prevalence of 100%, 92%, 36%, and 32%, to bla TEM, bla SHV, bla CTX-M, and bla OXA-1, respectively, and non ß-lactam encoding genes with a prevalence of 100%, 48%, 44%, 20%, and 12%, to sul1, tetA, intI1, qnrA, and aadA1. Moreover, 28% (7/25) of recovering strains were MDR (multidrug-resistant) up to four classes of antimicrobials, and 48% (12/25) of the examined strains were MDR up to three antimicrobial classes. In conclusion, to the best of our knowledge, our study could be the first report recording MDR Proteus spp. in dogs in Egypt.

Effect of Inulin on Organic Acids and Microstructure of Synbiotic Cheddar-Type Cheese Made from Buffalo Milk.

The current study aimed to produce synbiotic cheese, adding inulin and Bifidobacterium animalis subsp. lactis as prebiotics and probiotics, respectively. The physicochemical analysis, minerals and organic acids content, sensory evaluation, and probiotic count of the cheese were performed during the ripening. The significant effect of inulin (p ≤ 0.01) was found during the ripening period, and changes in physiochemical composition, minerals, and organic acid contents were also observed. Scanning electron microscopy (SEM) of the cheese revealed that inulin could improve the cheese structure. Meanwhile, inulin increased the likeliness of the cheese, and its probiotic viability remained above 107 colony forming unit (CFU) per gram during ripening.

Clinical otorhinolaryngological presentation of COVID-19 patients in Saudi Arabia: A multicenter study.

OBJECTIVES: To assess the otorhinolaryngological (ORL) symptoms, including their prevalence, severity, and early presentations among coronavirus disease-19 (COVID-19) patients in the Saudi population. METHODS: This was a multicentric, cross-sectional study carried out on severe acute respiratory syndrome coronavirus-2 positive patients at 3 COVID-19 centres; Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, ALKhobar, Qatif Central Hospital, AlQatif, and Ohud Hospital, Al Madinah Al Munawarah, Saudi Arabia. The validated survey consisted of sociodemographic data, general symptoms of COVID-19, and ORL manifestations. RESULTS: A total of 1734 COVID-19 positive patients were included in the study (mean age: 37.7±11.6 years). Most of the cases were mild (51.8%), followed by moderate (45.6%), and severe (2.6%) cases. Approximately 33.7% were asymptomatic. Severity of symptoms was significantly associated with male gender (p=0.017), higher age-group (p=0.04), and smoking (p<0.001). The most common initial ORL presentations were sore throat (20.9%), anosmia (15.5%), hyposmia (10%), and loss of taste (11.4%). Overall, 79.5% showed ORL symptoms as the initial presenting symptoms for COVID-19, with anosmia and sore throat being the most common symptoms. CONCLUSION: This study confirmed the prevalence of ORL symptoms among COVID-19 patients in Saudi Arabia. Moreover, these symptoms could also be considered for early detection of COVID-19 as they might appear prior to other symptoms.

Production of biodiesel from oleaginous fungal lipid using highly catalytic bimetallic gold-silver core-shell nanoparticle.

AIMS: This study aims to synthesize, characterize and apply gold-silver core-shell nanoparticles (Au@Ag NPs), a nanocatalyst, to maximize biodiesel production from fungal isolate Fusarium solani (FS12) via a transesterification one-step reaction. METHODS AND RESULTS: The Au@Ag NPs structure was examined by UV-vis spectrophotometer, transmission electron microscopy, X-ray diffraction and Fourier transform infrared (FTIR). All devices were used to characterize Au@Ag NPs and confirmed successful synthesis of nanoparticles. Fungal lipid was quantitatively determined by sulfo-phospho-vanillin colorimetric method. Among 15 F. solani isolates obtained from rhizospheric soils of the date palm, F. solani (AF12) was chosen as the highly significant producer that accumulates above 20% lipid. The maximum biodiesel yield was 91.28 ± 0.19%, obtained under the optimum reaction conditions of 3% Au@Ag NPs as nanocatalyst concentration, and 1:20 oil to methanol molar ratio at 70℃ for 30 min. HPLC method was applied for monitoring in situ transesterification reaction. FTIR spectroscopy was used in qualitative analysis of biodiesel by verifying the presence of unique characteristic peaks of diagnostic significance. The quality of the biodiesel produced was confirmed by the high purity of fatty acid methyl esters analysis content up to >99%. CONCLUSIONS: These findings propose the applicability of F. solani (FS12) as a promising isolate to accumulate lipids and biodiesel production as a feedstock. SIGNIFICANCE AND IMPACT OF THE STUDY: The link between nanotechnology and fungi. Au@Ag NPs were synthesized at room temperature, which displayed high catalytic activity for in situ transesterification reaction. Catalytic activity appeared at low temperature, mole ratio and short reaction time. Oleaginous fungi are described as easily grown, have short life cycle, are cost-effective, and they utilized various sources of carbon up to waste and a simplified process to develop scale-up production as well, economic value, opposite the usage of vegetable oils which need for large agricultural areas.

Hydrocarbon biodegradation and transcriptome responses of cellulase, peroxidase, and laccase encoding genes inhabiting rhizospheric fungal isolates.

By using the indigenous micro-organisms of the polluted environment to be treated, bioremediation can be a successful strategy. PCR and RT-PCR molecular techniques were applied to examine the evolution of fungal isolates through putative genes f ligninolytic enzymes like lignin peroxidase (LiP), laccase (LaC), manganese peroxidase (MnP), and cellulase (Cx) as a response to polluting of the environment by hydrocarbons. In this study, isolation of rhizospheric fungal isolates, molecular identification, crude oil tolerance, and enzyme excretions were demonstrated. From the date palm rhizosphere, 3 fungal isolates were isolated and characterized morphologically and molecularly by ITS ribosomal RNA (rRNA) sequencing. The isolates were identified as Aspergillus flavus AF15, Trichoderma harzianum TH07, and Fusarium solani FS12 through using the BLAST tool in NCBI. All fungal isolates showed high tolerance to crude oil and survived with various responses at the highest concentration (20%). Aspergillus flavus AF15 and Trichoderma harzianum TH07 demonstrated promising oil-degrading tolerance ability based on the dose inhibition response percentage (DIRP) of the fungal isolates. A. flavus had a powerful capacity to production Cx, LaC, LiP and MnP with a range from 83.7 to 96.3 mL. Molecularly, nine genes of the ligninolytic enzymes, cbh (cbhI.1, cbhI.1, cbhII) lcc, lig (1, 2, 4 and 6) and mnp were tested for presence and expression (by PCR and RT-PCR, respectively). PCR showed that all isolates contained all the nine genes examined, regardless of capacity to enzymes production profiles, so the presence responses of nine genes did not correlate with enzymes-production ability. Gene expression analysis shows a more diverse pattern for tested isolates for example, Aspergillus flavus AF15 had over-expression of lig and mnp genes, Fusarium solani FS12 have a weak signal with lcc gene while, Trichoderma harzianum TH07 showed moderate expression of mnp and lcc genes. The power of the transcription of the gene leads to increased enzyme secretion by fungal isolates. Fungi are important microorganisms in the clean-up of petroleum pollution. They have bioremediation highly potency that is related to their diverse production of these catalytic enzymes.

Catalytic degradation of methylene blue using silver nanoparticles synthesized by honey.

This investigation displayed the good catalytic activity of silver nanoparticles (AgNPs) on the reduction of methylene blue dye. During this work, Honey was chosen for environmentally reducing and stabilizing agents for preparation of silver nanoparticles then characterized these nanoparticles by ultraviolet-visible spectroscopy (UV-Vis), functional biomolecules were confirmed by Fourier transform infrared spectroscopy (FTIR). Via transmission electron microscopy (TEM), the size and shape of silver nanoparticles revealed that the particles are spherical and monodispersed without major agglomeration, the particle size ranging from 5 to 25 nm, in addition, the largest particle density levels are 5-10 nm, ZETA Seizers studied the size distribution of the colloidal solution. UV/Vis spectrophotometer and HPLC were used to study and analyze the degradation performance of silver nanoparticles on methylene blue. The results show that 92% of methylene blue has been degraded after 72 h. additionally, several new peaks have appeared after treatment of the samples by using HPLC.

Bioremediation of Crude Oil by Rhizosphere Fungal Isolates in the Presence of Silver Nanoparticles.

BACKGROUND: This research work focuses on the utilization of indigenous fungi for in situ bioremediation of crude oil in the presence of silver nanoparticles. METHODS: Two fungi belonging to two different genera showed promising crude oil-degrading abilities. Fungal isolates were identified based on internal transcribed spacer rDNA sequence analysis. Gas chromatography-mass spectrometry analysis of the crude oil remaining in the culture medium after seven days was performed. The response surface method (RSM) designed by Box-Behnken was used to establish a mathematical model. Inter-simple sequence repeat (ISSR) primers were used to examine the genetic variation of fungal isolates. RESULTS: Gas chromatography-mass spectrometry (GC-MS) analysis after seven days showed that the optimum biodegradation of crude oil was 57.8%. The crude oil degradation rate was significantly affected by a temperature of 30 °C, pH value of 7, crude oil concentration of 4 g/L, a 1:1 ratio between A. flavus AF15 and T. harzianum TH07, and an silver nanoparticle (AgNP) concentration of 0.05 g. Molecular characterization in fungal isolates is extremely valuable when using ISSR markers. CONCLUSIONS: Two fungal isolates showed promising crude oil-degrading abilities with positive effect of low concentrations of AgNPs on biodegradation. RSM is an efficient mathematical method to optimize the microbial biodegradation of crude oil.