[Serotype distribution of non-polio enterovirus in patients with acute flaccid paralysis during 2011-2012 in Hebei Province, China].

This study aims to investigate the serotype distribution of non-polio enterovirus (NPEV) isolated from patients with acute flaccid paralysis (AFP) during 2011-2012 in Hebei Province, China and to analyze the relationship between these viruses and AFP. NPEV strains were isolated from the stool specimens from AFP cases in Hebei using human rhabdomyosarcoma cells (RD) and the mouse cell line expressing the gene for the human cellular receptor for poliovirus (L20B) according to the WHO requirements. The nucleotide sequence of VP1 region was determined, and the serotypes of NPEV were identified by molecular typing. The results showed that among the 82 strains of NPEV isolated from the AFP cases during 2011-2012, 42 isolates (55.3%) were identified as human enterovirus A (HEV-A), which were classified into 4 serotypes, 34 (44.7%) as human enterovirus B (HEV-B), which were classified into 13 serotypes, 2 as adenovirus, and 4 were untyped; human enteroviruses C and D were not found in these cases. Enterovirus A71 (EV-A71) was the main type of HEV-A, accounting for 85.7% of all HEV-A strains. HEV-A, especially EV-A71, was predominant among the NPEV strains isolated from AFP patients during 2011-2012 in Hebei Province.

Expression and purification of active recombinant human bikunin in Pichia pastoris.

Bikunin is a proteoglycan exhibiting broad-spectrum inhibitory activity against serine proteases and could potentially suppress tumor cell invasion and metastasis. Here, we have successfully expressed recombinant human bikunin (rh-bikunin) in the methylotrophic yeast Pichia pastoris and established the purification procedure. The cDNA encoding human bikunin was cloned by PCR and inserted into the expression vector pPICZalphaC. After expressed in shake flask, rh-bikunin was produced in an 80-L fermenter and purified by cation exchange chromatography and reverse phase chromatography. The rh-bikunin was active by trypsin inhibition test. The final expression levels were 55 mg/L and we got totally 1.44 g (5600 inhibitor units/mg) of purified rh-bikunin (purity is 95%) from 40 L of fermentation broth. The rh-bikunin consists of two forms with molecular masses of 24 and 21 kDa, respectively. Both forms were immunoreactive by Western blotting and N-terminals were correctly processed by amino-terminal sequencing. This study provided a new method for expression and purification of active rh-bikunin.