In recent years,the prevalence of porcine infectious pleuropneumonia caused by Actinoba-cillus pleuropneumoniae(APP)has significantly increased in large-scale pig farms in China.The i-solation,identification,and biological characteristic testing of newly prevalent strains have impor-tant clinical significance.This study isolated four suspected APP strains(named XB2T-56,JMTLP-443,YD-THB-755,SYZJ-291)from lung samples of pig farms suspected of outbreaks of porcine infectious pleuropneumonia in Hubei Province.They were identified by PCR amplification,and multiplex PCR serological typing,the biological properties were tested by detecting the growth a-bility,hemolytic activity and biofilm forming ability.The drug resistance of the strains was ana-lyzed by drug sensitivity testing,and the virulence of one strain(XB2T-56)in mice and piglets was evaluated.The PCR identification result showed that all four clinical isolates were APP serotype 15 strains.These four strains grew slower than serotype 1 standard strains,had weaker hemolytic activity,but could form stronger biofilms.These strains are all less sensitive to cephalosporin,tylo-sin,sulfamethoxazole,and doxycycline,but sensitive to cefotaxime and enrofloxacin.The mice and piglet infection experiments showed that the isolated strain XB2T-56 has strong virulence.Artifi-cial intranasal infection causes acute death in piglets,with typical symptoms of pleuropneumonia in the lungs,and serotype 15 strains can be isolated from the lesion site.This study indicates that the APP serotype 15 strain has strong virulence,providing new date for the clinical epidemiological characteristics of APP.

In recent years,the prevalence of porcine infectious pleuropneumonia caused by Actinoba-cillus pleuropneumoniae(APP)has significantly increased in large-scale pig farms in China.The i-solation,identification,and biological characteristic testing of newly prevalent strains have impor-tant clinical significance.This study isolated four suspected APP strains(named XB2T-56,JMTLP-443,YD-THB-755,SYZJ-291)from lung samples of pig farms suspected of outbreaks of porcine infectious pleuropneumonia in Hubei Province.They were identified by PCR amplification,and multiplex PCR serological typing,the biological properties were tested by detecting the growth a-bility,hemolytic activity and biofilm forming ability.The drug resistance of the strains was ana-lyzed by drug sensitivity testing,and the virulence of one strain(XB2T-56)in mice and piglets was evaluated.The PCR identification result showed that all four clinical isolates were APP serotype 15 strains.These four strains grew slower than serotype 1 standard strains,had weaker hemolytic activity,but could form stronger biofilms.These strains are all less sensitive to cephalosporin,tylo-sin,sulfamethoxazole,and doxycycline,but sensitive to cefotaxime and enrofloxacin.The mice and piglet infection experiments showed that the isolated strain XB2T-56 has strong virulence.Artifi-cial intranasal infection causes acute death in piglets,with typical symptoms of pleuropneumonia in the lungs,and serotype 15 strains can be isolated from the lesion site.This study indicates that the APP serotype 15 strain has strong virulence,providing new date for the clinical epidemiological characteristics of APP.

AIM:To explore the effect of component II of broccoli polypeptide on the apoptosis in glioma cells . METHODS:Human glioma SHG-44 cells were cultured and divided into control group and 3, 10, 30 and 100 mg/L com-ponent II of broccoli polypeptide groups .Cell viability was detected by MTT assay .The apoptotic rates were examined by Annexin V/PI staining.The morphological changes of the cells were observed under inverted microscope .The protein ex-pression of Bax and Bcl-2 was detected by immunocytochemistry and Western blotting .The protein level of caspase-3 was also examined by Western blotting .RESULTS:Treatment with component II of broccoli polypeptide for 24 h, 48 h or 72 h induced significant inhibition of viability of SHG-44 cells in a time-and dose-dependent manner .The results of Annexin V/PI staining showed that the apoptotic rates were increased in treatment groups in a dose -dependent manner .The density of glioma cells was decreased after treated with increasing concentrations of the drug , and the apoptotic bodies were ob-served under inverted microscope at 72 h.The results of immunocytochemistry and Western blotting showed that the expres-sion of Bax protein was increased but Bcl-2 protein expression was decreased , and the ratio of Bax/Bcl-2 was increased sig-nificantly compared with control group (P<0.05 or P<0.01).The level of caspase-3 protein was increased in 30 and 100 mg/L component II of broccoli polypeptide groups compared with control group (P<0.01).CONCLUSION:The compo-nent II of broccoli polypeptide increases the ratio of Bax /Bcl-2 and activates caspase-3 protein, thus inducing the apoptosis of glioma cells.