No abstract

Encephalitozoon cuniculi, a spore-forming obligate intracellular parasitic pathogen belonging to the phylum Microsporidia, has a unique and highly specialized organelle called the polar tube. Using an enzyme immunostaining assay in which germinated E. cuniculi spores were coated onto plastic surfaces, we tested healthy and human immunodeficiency virus (

Microsporidian Encephalitozoon cuniculi has a unique organelle called a polar tube (PT), the extrusion of which is absolutely required to invade a host cell. We recently detected anti-E. cuniculi PT immunoglobulin (Ig) M antibodies in sera from many healthy individuals. The present one-dimensional (1-D) immunoblot analysis predominantly detected a band at 52 kDa in all of the examined human sera with anti-PT IgM. The use of mouse monoclonal antibody confirmed that the 52-kDa band detected in 1-D immunoblots was an antigen derived from the PT, which represents a glycoprotein nature. In addition, from changes in the immunoreactivity of the 52-kDa band before and after treatment with NaOH, we determined that the 24 human serum samples with anti-PT IgM activities could be roughly grouped into three types: (i) sera containing antibodies against only a saccharic determinant (n=3); (ii) sera containing antibodies against only a proteinic determinant (n=11); and (iii) sera showing dual recognition of saccharic and proteinic determinants (n=10). Further two-dimensional (2-D) immunoblot analysis followed by proteomic analysis confirmed that human sera with anti-PT IgM reacted with E. cuniculi polar tube protein 1 (PTP1). Such circulating IgM antibodies may be important in the first line of defence against E. cuniculi infection.

An analytical method has been developed for the determination of 2,4,6-tri-tert-butylphenol (TTBP) in foods. TTBP was determined by GC/MS (SIM) after extraction from food samples using a steam distillation technique. The developed method was able to determine simultaneously 2,4-di-tert-butylphenol (2,4-DTBP), 2,6-di-tert-butylphenol (2,6-DTBP), 3,5-di-tert-butylphenol (3,5-DTBP) and 2,4-di-tert-pentylphenol (2,4-DTPP).The method was applied to analyze the residues of the 5 phenolic compounds in 101 food samples purchased from markets. TTBP was found in some samples of meat, liver and fish (muscle) at the levels of trace (tr)ῑ0.50 ng/g, tr and trῑ1.83 ng/g, respectively. 2,4-DTBP was found in some samples of vegetables, meat, liver, fish (muscle) and fish (viscera) at the levels of 1.4ῑ10.6 ng/g, 2.7ῑ26.4 ng/g, trῑ34.2 ng/g, trῑ21.6 ng/g and tr, respectively. 2,6-DTBP was found in some samples of fish (muscle) and fish (viscera) at the levels of trῑ3.9 ng/g and tr, respectively. 3,5-DTBP and 2,4-DTPP were not found in any of the analyzed samples.

The microsporidian Encephalitozoon cuniculi is a spore-forming, obligate, intracellular parasitic pathogen with a unique organelle called a polar tube, the extrusion of which is essential for invading a host cell. The polar tube consists of three proteins: polar tube protein 1 (PTP1), PTP2, and PTP3. We established three mouse monoclonal antibodies (MAb1, MAb2, and MAb4) against E. cuniculi PTP1. An enzyme-linked immunosorbent assay (ELISA) indicated that all three MAbs reacted with the outer surface of extruded polar tubes and that they also strongly bound to an intracellular antigen in infected host cells. Two-dimensional (2-D) immunoblot analysis showed that MAb1 and MAb2 recognized PTP1 spots at 52 kDa and some spotty smears at molecular weights of less than 50 kDa, whereas MAb4 recognized only PTP1 spots at 52 kDa. Interestingly, all three MAbs were of the immunoglobulin (Ig) E class, suggesting that, in addition to the highly immunogenic or antigenic nature, the PTP1 antigen may have the potential to induce specific IgE antibody production in mice. These antibodies may be useful in the study of allergenic PTP1 as well in the purification and detection of the PTP1 antigen.