METHODS: We used the genome-wide screening tool TraDIS (Transposon Directed Insertion-site Sequencing) to identify B. pseudomallei essential genes. Transposon-flanking regions were sequenced and gene essentiality was assessed based on the frequency of transposon insertions within each gene. Transposon mutants were grown in LB and M9 minimal medium to determine conditionally essential genes required for growth under laboratory conditions. The Caenorhabditis elegans infection model was used to assess genes associated with in vivo B. pseudomallei survival. Transposon mutants were fed to the worms, recovered from worm intestines, and sequenced. Two selected mutants were constructed and evaluated for the bacteria's ability to survive and proliferate in the nematode intestinal lumen.
RESULTS: Approximately 500,000 transposon-insertion mutants of B. pseudomallei strain R15 were generated. A total of 848,811 unique transposon insertion sites were identified in the B. pseudomallei R15 genome and 492 genes carrying low insertion frequencies were predicted to be essential. A total of 96 genes specifically required to support growth under nutrient-depleted conditions were identified. Genes most likely to be involved in B. pseudomallei survival and adaptation in the C. elegans intestinal lumen, were identified. When compared to wild type B. pseudomallei, a Tn5 mutant of bpsl2988 exhibited reduced survival in the worm intestine, was attenuated in C. elegans killing and showed decreased colonization in the organs of infected mice.
DISCUSSION: The B. pseudomallei conditional essential proteins should provide further insights into the bacteria's niche adaptation, pathogenesis, and virulence.
PURPOSE: The present study investigates the stability, toxicity, and antibacterial potential of gallic acid-loaded graphene oxide (GAGO) on several MRSA strains.
METHODS: The stability of a synthesized and characterized GAGO was monitored in different physiological media. The toxicity profile of GAGO was evaluated in 3T3 murine fibroblast cells and the embryonic zebrafish model. The antibacterial activity of GAGO against MRSA, methicillin-susceptible S. aureus (MSSA), and community-acquired MRSA; with or without Panton-valentine leucocidin gene (MRSA-pvl+ and MRSA-pvl-) was investigated through disk diffusion, CFU counting method, time-kill experiment, and high-resolution transmission electron microscopy (HRTEM) observation.
RESULTS: A stable GAGO nanocomposite has shown an improved toxicity profile in 3T3 murine fibroblast cells and zebrafish embryos, besides exhibiting normal ROS levels than graphene oxide (GO) and GA (gallic acid). The nanocomposite inhibited the growth of all bacterial strains employed. The effectiveness of the GAGO nanocomposite was comparable to cefoxitin (CFX), at ≥150 µg/mL in MRSA and MSSA. GAGO exhibited a significantly delayed response towards MRSA-pvl+ and MRSA-pvl-, with increased inhibition following 8 to 24 h of exposure, while comparable activity to native GA was only achieved at 24 h. Meanwhile, for MRSA and MSSA, GAGO had a comparable activity with native GA and GO as early as 2 h of exposure. HRTEM observation further reveals that GAGO-exposed cells were membrane compromised.
CONCLUSION: In summary, the present study indicates the antibacterial potential of GAGO against MRSA strains, but further study is warranted to understand the mechanism of action of GAGO and its resistance in MRSA strains.
METHODS: After the extraction of the crude oil of the plant, they were tested against a Gentamycin (GM)-treated group of Swiss Albino mice for their nephroprotective action. Animals were divided into six (6) equal groups with five (5) animals in each group. These groups were: control group (0.5 mL normal saline via intraperitoneal -i.p), gentamycin group (gentamycin 100 mg/kg i.p), Silymarin + gentamycin group (Silymarin 50 mg/kg and gentamycin 100 mg/kg i.p), plant extract (AHcr1) and gentamycin group (AHcr1 250 mg/kg and gentamycin 100 mg/kg i.p), AHcr2 + gentamycin group (AHcr2; 500 mg/kg and gentamycin 100 mg/kg i.p) and the hexane oil fraction (AHO) + gentamycin (AHO 1 mL/kg and GM 100 mg/kg i.p). After completion of doses, animals were sacrificed for the collection of blood to further investigate biochemical changes and histopathological changes in kidney tissues.
RESULTS: Serum creatinine, urea, and blood urea nitrogen significantly increased (p < 0.001) in the gentamycin-treated group as compared to the control group. The elevated level of serum creatinine, urea, and blood urea nitrogen was decreased significantly (p < 0.001) in groups treated with AHcr and AHO compared to the gentamycin group. Similarly, the histopathological study of kidney tissues from the gentamycin group showed tubular necrosis, vacuolation, and fibrosis.
CONCLUSIONS: The effect of crude extract and hexane soluble fraction of AH caused a significant reversal of gentamycin-induced nephrotoxicity.
MATERIAL AND METHODS: The mice were divided randomly into a control group (aqua bidest and mercury acetate) and an experimental group for this purpose. The experimental mice group was given orally nano Ca supplementation in three dose groups (9 mg, 18 mg, and 27 mg/200 g animal body weight) once a day for 21 consecutive days. The mice are then given mercury acetate (1300 µg/200 g animal body weight intraperitoneally) on the 21st day. One hour after giving the nano Ca supplement, the mice's blood was taken. Liver and kidney were autopsied two days later to check quantitative and qualitative changes caused by mercury concentrations in liver and kidney histopathologies.
RESULTS: The results demonstrated the importance of nano Ca supplementation before mercury acetate induction, which has been shown to reduce necrotic depletion and hepatocyte degeneration.
CONCLUSION: Nano Ca supplementation has decreased the concentration of Hg in the blood of mice so that it can be used as a potential health supplement to detoxify mercury toxins.