Chitosan and Chitosan Nanoparticles Differentially Alleviate Salinity Stress in Phaseolus vulgaris L. Plants.

Salinity stress can significantly cause negative impacts on the physiological and biochemical traits of plants and, consequently, a reduction in the yield productivity of crops. Therefore, the current study aimed to investigate the effects of chitosan (Cs) and chitosan nanoparticles (CsNPs) to mitigate salinity stress (i.e., 25, 50, 100, and 200 mM NaCl) and improve pigment fractions, carbohydrates content, ions content, proline, hydrogen peroxide, lipid peroxidation, electrolyte leakage content, and the antioxidant system of Phaseolus vulgaris L. grown in clay-sandy soil. Methacrylic acid was used to synthesize CsNPs, with an average size of 40 ± 2 nm. Salinity stress negatively affected yield traits, pigment fractions, and carbohydrate content. However, in plants grown under salt stress, the application of either Cs or CsNPs significantly improved yield, pigment fractions, carbohydrate content, proline, and the antioxidant system, while these treatments reduced hydrogen peroxide, lipid peroxidation, and electrolyte leakage. The positive effects of CsNPs were shown to be more beneficial than Cs when applied exogenously to plants grown under salt stress. In this context, it could be concluded that CsNPs could be used to mitigate salt stress effects on Phaseolus vulgaris L. plants grown in saline soils.

Metabolic stone workup abnormalities are not as important as stone culture in patients with recurrent stones undergoing percutaneous nephrolithotomy.

To investigate the association between metabolic urinary abnormalities and urinary tract infection (UTI) and the stone recurrence status in patients undergoing percutaneous nephrolithotomy (PCNL). A prospective evaluation was performed for patients who underwent PCNL between November 2019 and November 2021 and met the inclusion criteria. Patients with previous stone interventions were classified as recurrent stone formers. Before PCNL, a 24 h metabolic stone workup and midstream urine culture (MSU-C) were done. Renal pelvis (RP-C) and stones (S-C) cultures were collected during the procedure. The association between the metabolic workup and UTI results with stone recurrence was evaluated using univariate and multivariate analyses. The study included 210 patients. UTI factors that showed significant association with stone recurrence included positive S-C [51 (60.7%) vs 23 (18.2%), p < 0.001], positive MSU-C [37 (44.1%) vs 30 (23.8%), p = 0.002], and positive RP-C [17 (20.2%) vs 12 (9.5%), p = 0.03]. Other factors were mean ± SD GFR (ml/min) (65 ± 13.1 vs 59.5 ± 13.1, p = 0.003), calcium-containing stones [47 (55.9%) vs 48 (38.1%), p = 0.01], median (IQR) urinary citrate levels (mg/day) [333 (123-512.5) vs 221.5 (120.3-412), p = 0.04], and mean ± SD urinary pH (6.1 ± 1 vs 5.6 ± 0.7, p < 0.001). On multivariate analysis, only positive S-C was the significant predictor of stone recurrence (odds ratio: 9.9, 95% confidence interval [CI] (3.8-28.6), p < 0.001). Positive S-C, and not metabolic abnormalities, was the only independent factor associated with stone recurrence. A focus on preventing UTI might prevent further stone recurrence.

Investigation of Virulence Genes of the Predominant Bacteria Associated with Renal Stones and their Correlation with Postoperative Septic Complications.

Purpose: Nephrolithiasis is a worldwide disease, and 4.7% of the patients may develop postoperative sepsis. Characterization of virulence genes of bacteria associated with renal stones is still lacking in the literature. The study aimed to investigate the virulence genes of the predominant stone bacterial isolate and their association with postoperative septic complications in patients treated with percutaneous nephrolithotomy (PCNL). Methods: Stone and midstream urine samples were collected from 200 nephrolithiasis patients who underwent PCNL. Microbiological examination and virulence profile were studied for the common bacteria isolated from the stones. Results: Microbiological analysis revealed that Staphylococcus aureus was the predominant organism in stone samples (42.8%), while Escherichia coli (56.6%) was the dominant pathogen in midstream urine. Eight patients (4%) developed septic complications; stone culture was positive for S. aureus in seven and E. coli in one patient, while all but one had negative midstream urine. The patient with positive midstream urine culture had also S. aureus infection. Detection of virulence genes in S. aureus isolated from stones showed a high positivity of the hemolysine gene hla (93.3%) and adhesion gene fnbA (73.3%), whereas enterotoxin genes (sec and sea) were negative in all S. aureus stone cultures. Moreover, the adhesion genes (fnbB and can), hemolysine gene (hlb), panton-valentine leukocidin (pvl) gene and the enterotoxin gene (seb) were significantly higher in septic patients compared to the non-septic ones (p< 0.05). Interestingly, there was a significant relation between the existence of virulence genes and the resistance of antibiotics (p < 0.05). Conclusion: There has been a notable shift toward gram-positive organisms (S. aureus) in the stone culture. Moreover, S. aureus virulence genes were significantly attributed to the resistance of some antibiotics and postoperative septic complications, suggesting that the stone culture could be more informative than urine culture, especially in predicting the risk of postoperative sepsis.