Transmission risk evaluation of transfusion blood containing low-density Babesia microti.

Background: Babesia is a unique apicomplexan parasite that specifically invades and proliferates in red blood cells and can be transmitted via blood transfusion, resulting in transfusion-transmitted babesiosis. However, detecting Babesia in blood before transfusion has not received enough attention, and the risk of transfusing blood containing a low density of Babesia microti (B. microti) is unclear, possibly threatening public health and wellness. Purpose: This study aimed to determine the lower detection limit of B. microti in blood and to evaluate the transmission risk of blood transfusion containing low-density B. microti. Methods: Infected BALB/c mouse models were established by transfusing infected whole blood with different infection rates and densities of B. microti. Microscopic examination, nested Polymerase Chain Reaction (nested PCR), and an enzyme-linked immunosorbent assay (ELISA) were used to evaluate the infection status of the mouse models. Meanwhile, the nested PCR detection limit of B. microti was obtained using pure B. microti DNA samples with serial concentrations and whole blood samples with different densities of B. microti-infected red blood cells. Thereafter, whole mouse blood with a B. microti density lower than that of the nested PCR detection limit and human blood samples infected with B. microti were transfused into healthy mice to assess the transmission risk in mouse models. The infection status of these mice was evaluated through microscopic examination, nested PCR tests, and ELISA. Results: The mice inoculated with different densities of B. microti reached the peak infection rate on different days. Overall, the higher the blood B. microti density was, the earlier the peak infection rate was reached. The levels of specific antibodies against B. microti in the blood of the infected mice increased sharply during the first 30 days of infection, reaching a peak level at 60 days post-infection, and maintaining a high level thereafter. The nested PCR detection limits of B. microti DNA and parasite density were 3 fg and 5.48 parasites/µL, respectively. The whole blood containing an extremely low density of B. microti and human blood samples infected with B. microti could infect mice, confirming the transmission risk of transfusing blood with low-density B. microti. Conclusion: Whole blood containing extremely low density of B. microti poses a high transmission risk when transfused between mice and mice or human and mice, suggesting that Babesia detection should be considered by governments, hospitals, and disease prevention and control centers as a mandatory test before blood donation or transfusion.

Systematic strategies for developing phage resistant Escherichia coli strains.

Phages are regarded as powerful antagonists of bacteria, especially in industrial fermentation processes involving bacteria. While bacteria have developed various defense mechanisms, most of which are effective against a narrow range of phages and consequently exert limited protection from phage infection. Here, we report a strategy for developing phage-resistant Escherichia coli strains through the simultaneous genomic integration of a DNA phosphorothioation-based Ssp defense module and mutations of components essential for the phage life cycle. The engineered E. coli strains show strong resistance against diverse phages tested without affecting cell growth. Additionally, the resultant engineered phage-resistant strains maintain the capabilities of producing example recombinant proteins, D-amino acid oxidase and coronavirus-encoded nonstructural protein nsp8, even under high levels of phage cocktail challenge. The strategy reported here will be useful for developing engineered E. coli strains with improved phage resistance for various industrial fermentation processes for producing recombinant proteins and chemicals of interest.

PLGA Porous Microspheres Dry Powders for Codelivery of Afatinib-Loaded Solid Lipid Nanoparticles and Paclitaxel: Novel Therapy for EGFR Tyrosine Kinase Inhibitors Resistant Nonsmall Cell Lung Cancer.

Combination therapy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR TKIs) with other chemotherapeutic agents is a feasible strategy to overcome resistance that often occurs after 9-13 months of EGFR TKIs administration in nonsmall cell lung cancer (NSCLC). In this study, a pulmonary microspheres system that codelivers afatinib and paclitaxel (PTX) is developed for treatment of EGFR TKIs resistant NSCLC. In this system, afatinib is loaded in stearic acid-based solid lipid nanoparticles, then these nanoparticles and PTX are loaded in poly-lactide-co-glycolide-based porous microspheres. These inhaled microspheres systems are characterized including geometric particle size, drug encapsulation efficiency, morphology by scanning electron microscopy, specific surface area, in vitro drug release, and aerodynamic particle size. Cell experiments indicate that afatinib and PTX have a synergistic effect and the codelivery system shows a superior treatment effect in drug-resistant NSCLC cells. The biocompatibility, pharmacokinetic, and tissue distribution experiments in Sprague-Dawley rats show that afatinib and PTX in the system can maintain 96 h of high lung concentration but low concentration in other tissues, with acceptable safety. These results demonstrate that this system may be a prospective delivery strategy for drug combination treatment in cancers developing resistance, especially drug-resistant lung cancer.