Synthesis and evaluation of pyridine-3-carboxamide analogs as effective agents against bacterial wilt in tomatoes.

This study focused on developing novel pyridine-3-carboxamide analogs to treat bacterial wilt in tomatoes caused by Ralstonia solanacearum. The analogs were synthesized through a multistep process and their structures confirmed using spectroscopy. Molecular docking studies identified the most potent analog from the series. A specific analog, compound 4a, was found to significantly enhance disease resistance in tomato plants infected with R. solanacearum. The structure-activity relationship analysis showed the positions and types of substituents on the aromatic rings of compounds 4a-i strongly influenced their biological activity. Compound 4a, with a chloro group at the para position on ring C and hydroxyl group at the ortho position on ring A, was exceptionally effective against R. solanacearum. When used to treat seeds, the analogs displayed remarkable efficacy, especially compound 4a which had specific activity against bacterial wilt pathogens. Compound 4a also promoted vegetative and reproductive growth of tomato plants, increasing seed germination and seedling vigor. In plants mechanically infected with bacteria, compound 4a substantially reduced the percentage of infection, pathogen quantity in young tissue, and disease progression. The analogs were highly potent due to their amide linkage. Molecular docking identified the best compounds with strong binding affinities. Overall, the strategic design and synthesis of these pyridine-3-carboxamide analogs offers an effective approach to targeting and controlling R. solanacearum and bacterial wilt in tomatoes.

Discovery of 1-(5-bromopyrazin-2-yl)-1-[3-(trifluoromethyl)benzyl]urea as a promising anticancer drug via synthesis, characterization, biological screening, and computational studies.

Cancer and different types of tumors are still the most resistant diseases to available therapeutic agents. Finding a highly effective anticancer drug is the first target and concern of thousands of drug designers. In our attempts to address this concern, a new pyrazine derivative, 1-(5-bromopyrazin-2-yl)-1-[3-(trifluoromethyl)benzyl]urea (BPU), was designed via structural optimization and synthesized to investigate its anticancer/antitumor potential. The in-vitro anticancer properties of BPU were evaluated by MTT assay using selected cell lines, including the Jurkat, HeLa, and MCF-7 cells. The Jurkat cells were chosen to study the effect of BPU on cell cycle analysis using flow cytometry technique. BPU exhibited an effective cytotoxic ability in all the three cell lines assessed. It was found to be more prominent with the Jurkat cell line (IC50 = 4.64 ± 0.08 µM). When it was subjected to cell cycle analysis, this compound effectively arrested cell cycle progression in the sub-G1 phase. Upon evaluating the antiangiogenic potential of BPU via the in-vivo/ex-vivo shell-less chick chorioallantoic membrane (CAM) assays, the compound demonstrated very significant findings, revealing a complementary supportive action for the compound to act as a potent anticancer agent through inhibiting blood vessel formation in tumor tissues. Moreover, the docking energy of BPU computationally scored - 9.0 kcal/mol with the human matrix metalloproteinase 2 (MMP-2) and - 7.8 kcal/mol with the human matrix metalloproteinase 9 (MMP-9), denoting promising binding results as compared to the existing drugs for cancer therapy. The molecular dynamics (MD) simulation outcomes showed that BPU could effectively bind to the previously-proposed catalytic sites of both MMP-2 and MMP-9 enzymes with relatively stable statuses and good inhibitory binding abilities and parameters. Our findings suggest that the compound BPU could be a promising anticancer agent since it effectively inhibited cell proliferation and can be selected for further in-vitro and in-vivo investigations. In addition, the current results can be extensively validated by conducting wet-lab analysis so as to develop novel and better derivatives of BPU for cancer therapy with much less side effects and higher activities.

Isolation and Detection of Drug-Resistant Bacterial Pathogens in Postoperative Wound Infections at a Tertiary Care Hospital in Saudi Arabia.

Background: Surgical site infections (SSIs), especially when caused by multidrug-resistant (MDR) bacteria, are a major healthcare concern worldwide. For optimal treatment and prevention of antimicrobial resistance, it is important for clinicians to be aware of local drug-resistant bacterial pathogens that cause SSIs. Objective: To determine the frequency patterns of drug-resistant bacterial strains causing SSIs at a tertiary care hospital in Saudi Arabia. Methods: This retrospective study was conducted at the Microbiology laboratory of Al-Noor Specialist Hospital, Makkah, Saudi Arabia, and included wound swab samples from all cases of SSI between January 01, 2017, and December 31, 2021. The swabs were processed for the identification of bacterial strains and their resistance pattern to antibiotics according to the Clinical and Laboratory Standards Institute. Results: A total of 5409 wound swabs were analyzed, of which 3604 samples (66.6%) were from male. Most samples were from the Department of Surgery (43.3%). A total of 14 bacterial strains were isolated, of which 9 were Gram-negative bacteria. The most common isolates were Klebsiella pneumoniae, followed by Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), and vancomycin-resistant S. aureus (VRSA). In terms of MDR in 2021, the highest rate of carbapenem-resistance was in A. baumannii (97%). MDR was as follows: A. baumannii, 97%; K. pneumoniae, 81%; E. coli, 71%; MRSA, 60%; P. aeruginosa, 33%; VRE, 22%; and VRSA, 2%. Conclusion: This study showed that in the city of Makkah, Saudi Arabia, the rates of MDR bacteria are high, with the majority being Gram-negative.

Green synthesis of MgO nanoparticles and its antibacterial properties.

Magnesium oxide nanostructured particles (NP) were prepared using a simple solution combustion technique using different leaf extracts such as Mangifera indica (Mango - Ma), Azadirachta indica (Neem-Ne), and Carica papaya (Papaya-Pa) as surfactants. The highly crystalline phase of MgO nanostructures was confirmed by PXRD and FTIR studies for 2 h 500°C calcined samples. To analyze the characteristics of obtained material-MaNP, NeNP, and PaNP for dosimetry applications, thermoluminescence (TL) studies were carried out for Co-60 gamma rays irradiated samples in the dose range 10-50 KGy; PaNP and NeNP exhibited well-defined glow curve when compared with MaNP samples. In addition, it was observed that the TL intensity decreases, with increase in gamma dose and the glow peak temperature is shifted towards the higher temperature with the increase in heating rate. The glow peak was segregated using glow curve deconvolution and thermal cleaning method. Kinetic parameters estimated using Chen's method, trap depth (E), and frequency factor (s) were found to be 0.699, 7.408, 0.4929, and 38.71, 11.008, and 10.71 for PaNP, NeNP, and MaNP respectively. The well-resolved glow curve, good linear behavior in the dose range of 10-50, KGy, and less fading were observed in PaNP as compared with MaNP and NeNP. Further, the antibacterial activity was checked against human pathogens such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. A visible zone of clearance was observed at 200 and 100 µg/mL by the PaNP and NeNP, indicating the death of colonies by the nanoparticles. Therefore, PaNP nanomaterial is a potential phosphor material for dosimetry and antibacterial application compared to NeNP and MaNP.

Pneumococcal Surface Protein A: A Promising Candidate for the Next Generation of Pneumococcal Vaccines.

Streptococcus pneumoniae is the bacterium that causes pneumococcal disease which often results in pneumonia, meningitis, otitis media, septicemia and sinusitis. Pneumonia, particularly, is a significant cause of worldwide morbidity and a global health burden as well. Treatment often relies on antimicrobials, to which the pathogen is frequently mutating and rendering infective. Consequently, vaccination is the most effective approach in dealing with pneumococcal antimicrobial resistance (AMR). Unfortunately, the current pneumococcal polysaccharide and conjugate vaccines have a narrow serotype coverage. Therefore, the current need for vaccines with a broader serotype coverage cannot be overstated. Pneumococcal Surface Protein A and C are potential vaccine candidate antigens present in over 90% of the strains from clinical isolates as well as laboratory non-encapsulated strains. Pneumococcal Surface Protein A is an active virulent factor that pneumococci use to evade complement-mediated host immune responses and has been shown to elicit immune responses against pneumococcal infections. This review explores the potential utilization of Pneumococcal Surface Protein A to immunize against S. pneumoniae.