Identification and antimicrobial susceptibility of enterococci isolated from dogs and cats subjected to differing antibiotic pressures.

The purpose of the present study was to determine the prevalence of antibiotic-resistant enterococci in dogs and cats subjected to differing antibiotic pressures, and the prevalence of vancomycin resistance genes in isolates from these animals. Enterococci were isolated from fecal samples of 65 healthy dogs and 29 healthy cats brought to animal hospitals, from rectal swabs of 73 puppies and 15 kittens from five breeders and two pet shops, and from fecal samples of 20 dogs and 9 cats that were treated with antibiotics in Nippon Veterinary and Life Science University Animal Medical Center. The rates of resistance to ampicillin among isolates from the kitten-puppy group and healthy dog-cat group were 6.

Formation of highly stabilized intramolecular dimer radical cation and pi-complex of [3n]cyclophanes (n = 3, 5, 6) during pulse radiolysis.

Formation of radical cation and charge-transfer complex of [3n]cyclophanes (n = 3, 5, 6) was investigated by transient absorption spectroscopy during pulse radiolysis. Radical cations of [3n]cyclophanes showed the charge resonance band around 700 nm which exhibited a blue-shift as the number of trimethylene bridges increased, indicating formation of highly stabilized intramolecular dimer radical cation of [3n]cyclophanes. The absorption peak of the charge-transfer complex with chlorine atom also showed the shift in accord with the oxidation potential of [3n]cyclophanes.

Transannular distance dependence of stabilization energy of the intramolecular dimer radical cation of cyclophanes.

The intramolecular dimer radical cation and charge-transfer complex of various cyclophanes were investigated by using pulse radiolysis measurements. The charge resonance band due to the dimer radical cation of cyclophanes appeared in the near-IR region, which showed a blue-shift as the distance between the two benzene rings of cyclophane decreased. The stabilization energy of the dimer radical cation, which was estimated from the peak position of the charge resonance band, was explained by the exchange interaction, while the substituent effect was small.