Veterinary Science & Technology

The incidence of multi-drug resistant Salmonella has increased globally over the past several decades and has become a major public health concern. Isolates of Salmonella enterica serovar Typhimurium DT104 are resistant to five or more antibiotics, including florfenicol, and have been associated with enhanced virulence in livestock and humans. Because sub-inhibitory concentrations of some antibiotics have been found to modulate invasion of certain bacteria under specific conditions, the effect of florfenicol on S. Typhimurium DT104 invasion was evaluated. Three clinical bovine isolates were exposed to sub-inhibitory concentrations of florfenicol for 30 minutes to establish the initial response to the antibiotic. HEp-2 cellular invasion assays, as well as expression analyses of invasion-related genes, demonstrated that the invasiveness of the S. Typhimurium DT104 isolates was not enhanced after exposure to sub-inhibitory concentrations of florfenicol. These results suggest that cattle and swine can be treated with florfenicol for respiratory illness without exacerbating Salmonella Typhimurium DT104 virulence in carrier animals.

Cypermethrin is a synthetic pyrethroid insecticide used worldwide in agriculture, home pest control and as an ectoparasiticide in animals. The aim of the present study was to investigate the ability of piperine, a natural alkaloid compound, to attenuate subacute cypermethrin-induced changes in serum biochemical markers and lipid peroxidation, and alteration in antioxidant enzyme activity in the liver and kidney of rats. The rats were divided into five groups of six each; the first group served as control and second group was used as vehicle control. While, groups III, IV and V were orally treated with piperine (50 mg/kg body weight), cypermethrin (25 mg/kg body weight) and cypermethrin plus piperine, respectively for 28 days. Cypermethrin administration caused elevated levels of biochemical markers in serum and lipid peroxidation in liver and kidney. While the activities of non-enzymatic and enzymatic antioxidants levels were decreased except superoxide dismutase in liver and kidney. Administration of piperine along with cypermethrin significantly decreased the level of lipid peroxidation and significantly increased the reduced glutathione, catalse and glutathione peroxidase level both in liver and kidney. The results indicate that piperine ameliorate the cypermethrin induced biochemical alterations and oxidative damage in rats.

By combining size-fraction and a rapid determination system for viral RNA sequences (RDV), a method for sequence independent detection from virus-infected cultured cells was developed as “RDV-size fraction (RDV-SF)”. Using RDV- SF, we succeeded in detecting nucleotide fragment sequences of feline calicivirus (FCV) and Yokose virus (YOKV) from Vero E6 cells infected with FCV and YOKV, respectively. RDV-SF was useful in identifying RNA viruses with a genome size of more than 5 kb from virus-infected cultured cells.