Evaluation of mono and combined nitrofurantoin therapy for toxoplasmosis in vivo using murine model.

Toxoplasmosis is a frequent disease with an estimated prevalence of more than one billion human cases worldwide and over one million new infections each year. It is classified as a neglected tropical disease by the CDC since 2019. The disease may pass unnoticed in healthy individuals but could be fatal in the immunocompromised. Moreover, no effective treatment is available against the chronic form of the disease. Available anti-Toxoplasma drugs are associated with many side effects. Therefore, search for new more reliable, more efficient, and less toxic therapeutic agents is a continuous endeavor. This study assesses the potential use of nitrofurantoin, a compound with well-established antimicrobial properties, as a potential anti-Toxoplasma drug in vivo. It compares its efficacy to the commonly used anti-Toxoplasma agent spiramycin by molecular and histopathological methods in acute and chronic infection. The results demonstrate a significant ability to eliminate the parasite (P < 0.001) whether used as mono- or combined therapy with spiramycin in the acute and chronic stages. When compared to the anti-Toxoplasma drug spiramycin, nitrofurantoin achieved similar efficacy in the acute and chronic infection (P = 0.65 and P = 0.096, respectively). However, better results were obtained when using a combination of both drugs (P < 0.001). Additionally, nitrofurantoin showed good inhibitory effects on the inflammatory process in the liver, kidney, and uterus of the experimentally infected animals. In conclusion, nitrofurantoin can be considered as a potential anti-Toxoplasma agent. Nevertheless, further studies are recommended before consideration for clinical trials.

Combined Mini-Parasep SF and Nanogold Immunoassay Show Potential in Stool Antigen Immunodetection for Giardiasis Diagnosis.

Covalent loading or directional binding of biomolecules on gold nanoparticles (AuNPs) could lead to better results than simple direct adsorption for an enhanced ELISA application. The use of Mini-Parasep solvent-free (SF) without ether or ethyl acetate for the clean and efficient concentration of protozoa cysts, it is a single-use device for in vitro diagnostic use only. In this work, we used Mini-Parasep SF for the detection of giardia cysts in comparison to direct smear and Merthiolate-Iodine Formaldehyde Concentration (MIFC) technique in addition to its use in antigen detection by AuNPs biomolecule loading using rabbit polyclonal antibodies (pAb) against purified Giardia antigen (PGA). As a result, Mini-Parasep SF was the most effective method for Giardia cyst detection and regarding optimization of Mini-Parasep antigen detection, our data showed increased sensitivity and specificity of nano-sandwich ELISA to 92% and 94% respectively and increased positive predictive value (PPV) and negative predictive value (NPV) to 88.64% and 95.91% respectively. In conclusion, this research provides that Mini-Parasep SF concentrator enhanced Giardia cyst detection and improved antigen preparation for AuNPs sandwich ELISA in giardiasis diagnosis. The advantages of this method are the short assay time and the raised accuracy of antigen detection providing concentrated samples without the risk of solvent use and being a disposable Mini-Parasep it helps in giardia antigen purification as well as raising the sensitivity and specificity of ELISA through binding AuNPs.

Dose-response relationship in Schistosoma mansoni juvenile and adult stages following limonin treatment in experimentally infected mice.

Preventive chemotherapy with praziquantel is the mainstay of schistosomiasis control. However, drug resistance is an imminent threat, particularly with large-scale administration of praziquantel, in addition to much less efficacy against young schistosomes. Several biological activities of limonin have been explored such as insecticidal, insect antifeedant, and growth-regulating activity on insects as well as antimalarial, antiviral, anticancer, cholesterol-lowering, and antioxidant activities. This study investigates limonin as an alternative antischistosomal compound using two novel, single, oral dose regimens. In the current work, the therapeutic efficacy of different limonin dosing protocols was evaluated in experimentally infected mice harboring Schistosoma mansoni (Egyptian strain) juvenile or adult stages. Oral administration of limonin in a single dose of 50 or 100 mg/kg on day 21 post-infection (p.i.) resulted in a significant worm burden reduction of 70.0 and 83.33 %, respectively. The same dose given on day 56 p.i. reduced total worm burdens by 41.09 and 60.27 %, respectively. In addition, significant reductions of 34.90 and 47.16 % in the hepatic and 46.67 and 56.1 % in the intestinal tissue egg loads, respectively, associated with significant alterations in the oogram pattern with elevated dead egg levels. Limonin produced ameliorations of hepatic pathology with reduction in dimensions and number of granulomas. Limonin also produced a variety of tegumental alterations in treated worms including tubercular disruption, edema, blebbing, and ulcerations. Results obtained by this work elucidated promising limonin bioactivity against S. mansoni juvenile and adult stages and provided a basis for subsequent experimental and clinical trials.

Acanthamoeba DNA can be directly amplified from corneal scrapings.

This study evaluated the performance of direct amplification of Acanthamoeba-DNA bypassing DNA extraction in the diagnosis of Acanthamoeba keratitis in clinically suspected cases in comparison to direct microscopic examination and in vitro culture. Corneal scrapings were collected from 110 patients who were clinically suspected to have Acanthamoeba keratitis, 63 contact lens wearers (CLW), and 47 non-contact lens wearers (NCLW). Taken samples were subjected to direct microscopic examination, cultivation onto the non-nutrient agar plate surface seeded with Escherichia coli, and PCR amplification. The diagnostic performance of these methods was statistically compared. The results showed that Acanthamoeba infection was detected in 21 (19.1%) of clinically suspected cases (110); 17 (81%) of them were CLW and the remaining 4 (19%) positive cases were NCLW. Regarding the used diagnostic methods, it was found that direct amplification of Acanthamoeba DNA bypassing nucleic acid extraction was superior to microscopy and culture in which 21 cases (19.1%) were positive for Acanthamoeba by PCR compared to 19 positive cases by culture (17.3%) and one case (0.9%) by direct smear. The difference in detection rates between culture and direct smear was highly statistically significant (P = 0.001). On the other hand, there was no significant difference in detection rates between culture and PCR (P = 0.86). On using culture as the gold standard, PCR showed three false-positive samples that were negative by culture and one false-negative sample that was positive by culture. At the same time, direct smear showed 18 false-negative samples. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of PCR were 94.7, 96.7, 85.7, 98.9, and 96.4, respectively, while those of direct smear were 5.3, 100, 100, 83.5, and 83.6, respectively. In conclusion, direct amplification of Acanthamoeba-DNA bypassing DNA extraction is a reliable, specific, sensitive method in the diagnosis of Acanthamoeba keratitis in clinically suspected cases. It should set up in ophthalmological centers as an easy diagnostic tool.