Molecular characterization of Cryptosporidium parvum detected in Japanese black and Holstein calves in Iwate Prefecture and Tanegashima Island,Kagoshima Prefecture,Japan

Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequences of the 18S rRNA gene. C. parvum oocyst-positive calves ranged in age from 6 to 13 days old and significantly have watery diarrhea (P<0.05). Sequences of the gene encoding the 60-kDa glycoprotein (GP60) in 43 Cryptosporidium oocyst-positive samples were identical to that of the zoonotic IIaA15G2R1 subtype. We therefore suggest that calves could be potential sources of C. parvum infections in humans.     

Quantitative structure-activity relationships of the fungicidal methyl N-phenylcarbamates

For 69 methyl N-phenylcarbamates having various benzene ring substituents, the fungicidal activity was determined against Botrytis cinerea resistant to benzimidazole fungicides by the agar medium dilution method. The structure-activity relationships were analyzed quantitatively using such physicochemical substituent parameters as hydrophobic π, steric B₅, and HB (hydrogen bonding) with the Hansch-Fujita method (C. Hansch and T. Fujita, J. Amer. Chem. Soc.86, 1616 1964). The hydrophobicity of substituents was favorable to the acitivity. The effect was position-specific, the importance being in the order of ortho meta > para. The activity was related parabolically to the maximum width of one of the m-substituents having the larger dimension. The hydrogen acceptability of p-substituents enhanced the activity. The preventive activity of compounds against gray mold of cucumber caused by the resistant B. cinerea, which was determined by the foliar application in pot tests, was dependent on the magnitude of the fungicidal activity and hydrophobicity of the compounds as analyzed by the adaptive least-squares method.