Nano magnetic-based ELISA and nano magnetic-based latex agglutination test for diagnosis of experimental trichinellosis.

Human trichinellosis is a worldwide foodborne public health threat. Detecting circulating antigens of Trichinella spiralis "T. spiralis" allows for an early diagnosis before larval encystation develops in skeletal muscles. For the first time, the present study aimed to formulate an effective nanomagnetic beads based-ELISA and -latex agglutination test (NMB-ELISA and NMB-LAT) to recognize T. spiralis adult worm crude extract antigen (AWCEA) in sera of experimentally infected mice. The study included thirty-eight mice classified into 3 groups; T. spiralis-infected group (GI) which was euthanized 6, 8, 10, 12, 14 days post-infection (dpi), other parasitic infections group (GII) and healthy control group (GIII). Rabbit anti-T. spiralis polyclonal antibodies (pAbs) were utilized to detect AWCEA in serum samples by sandwich ELISA, NMB-ELISA, and NMB-LAT. Using NMB-ELISA, AWCEA was detected in sera collected at 6 and 8 dpi, with a sensitivity of 50% and 75%, respectively, and a specificity of 100%. Whereas, sandwich ELISA and NMB-LAT couldn't detect the antigen at the same time intervals. Both ELISA formats were able to detect the antigen in samples collected at 10, 12, and 14 dpi with a sensitivity of 100% for NMB-ELISA and 25%, 75%, and 100% respectively, for sandwich-ELISA. Yet, NMB-LAT couldn't detect AWCEA until 12 dpi with a sensitivity of 50% and specificity of 75%. In conclusion, NMB-ELISA is a promising sensitive tool for early and specific diagnosis of acute trichinellosis. The use of NMB-LAT could be a helpful screening procedure in field surveys.

Efficacy of netropsin dihydrochloride against the viability, cytopathogenicity and hemolytic activity of Trichomonas vaginalis clinical isolates.

Trichomonas vaginalis (T. vaginalis) is a common sexually transmitted infection, affecting the urogenital tract. Trichomoniasis is customarily treated with metronidazole (MTZ). MTZ is known to cause undesirable side effects and there is several reports on MTZ resistant T. vaginalis. Thus, the present study aimed to in-vitro evaluate the activity of DNA minor groove binder drug ''Netropsin dihydrochloride'' against metronidazole-sensitive T. vaginalis isolates (G and U isolates) and resistant T. vaginalis isolate (ATCC50138) (R isolate). Netropsin was tested at concentrations ranging from 3.5 to 200 µg/ml. It showed effectiveness against all isolates with MLC of 12.5 µg/ml for G and U isolates and of 25 µg/ml for R isolate. Cytotoxicity assay of isolates exposed to the respective MLC of netropsin for 42 h showed a highly significant reduction in the death percentage of MCDK cell line as compared to the effect elicited by drug free controls. The hemolytic activity was evaluated by hemolytic assay and by monitoring the interaction of T. vaginalis isolates with human erythrocytes by inverted microscopy and scanning electron microscopy. The hemolytic assay showed (0%) hemolysis of RBCs incubated with T. vaginalis isolates treated with the corresponding MLC of netropsin for 24 h. Scanning electron microscopy revealed cytoskeletal deformities of netropsin treated isolates. Taken together, these observations suggest that netropsin is a promising therapy for T. vaginalis infection affecting its viability, virulence, cytopathogenic and hemolytic activity with a mechanism of action that might overcome T. vaginalis resistance to metronidazole.

A comparative study between excretory/secretory and autoclaved vaccines against RH strain of Toxoplasma gondii in murine models.

Toxoplasma gondii is an obligate intracellular protozoan that has a major importance in public health, in addition to veterinary medicine. Therefore, the development of an effective vaccine for controlling toxoplasmosis is an important goal. Excretory/secretory antigens (ESA), were previously identified as potential vaccine candidates, proved to play important roles in the pathogenesis and immune escape of the parasite. In addition, autoclaved Toxoplasma vaccine (ATV) is a special type of killed vaccine, recently characterized. The aim of the present work was, to compare between excretory/secretory and ATV against RH strain of T. gondii in mice based on; parasitological and histopathological levels. Tachyzoites were harvested from peritoneal exudates of infected mice and were used for challenge infection and vaccine preparation. BCG was used as an adjuvant. Mice were allocated equally into five groups; they were vaccinated intradermally over the sternum. The results of this study showed that the survival time after challenge, extended up to 16 days in ESA vaccinated group and up to 15 days in autoclaved Toxoplasma vaccinated group. ESA vaccinated group exhibited a profound decrease in parasite load following parasite challenge with a higher percentage of reduction in parasite count in all examined organs than the autoclaved Toxoplasma vaccinated group. The histopathological picture of the liver in both immunized groups, revealed marked reduction in the pathological changes observed as compared to controls, especially in ESA vaccinated group. It was concluded that vaccination with ESA showed more promising results versus ATV, as demonstrated by the survival rate of vaccinated mice, tachyzoites count and histopathological examination.