Pathogen genomic surveillance status among lower resource settings in Asia.

Asia remains vulnerable to new and emerging infectious diseases. Understanding how to improve next generation sequencing (NGS) use in pathogen surveillance is an urgent priority for regional health security. Here we developed a pathogen genomic surveillance assessment framework to assess capacity in low-resource settings in South and Southeast Asia.

Invasion of a murine in vitro blood-brain barrier co-culture model by dengue virus serotypes 1 to 4.

The blood-brain barrier (BBB) is a physical barrier that restricts the passage of cells and molecules as well as pathogens into the central nervous system (CNS). Some viruses enter the CNS by disrupting the BBB, while others can reach the CNS without altering the integrity of the BBB. Even though dengue virus (DENV) is not a distinctive neurotropic virus, the virus is considered to be one of the leading causes of neurological manifestations.

Complete genome sequence of a human enterovirus 71 strain isolated in brunei in 2006.

The complete genome sequence of a human enterovirus 71 strain isolated in Brunei in 2006 was determined. Phylogenetic analysis based on the complete genome sequence classified this strain into subgenogroup B5.

A single mutation in capsid protein VP1 (Q145E) of a genogroup C4 strain of human enterovirus 71 generates a mouse-virulent phenotype.

We modified the capsid protein of a human enterovirus 71 (HEV71) belonging to subgenogroup C4 (HEV71-C4) to generate a mouse virulent strain, based on the genetic information derived from our previous subgenogroup B3 mouse-adapted virus. Infectious clone-derived mutant virus populations containing the capsid protein mutations VP1-Q145E and VP1-Q145G were generated by site-directed mutagenesis of an infectious clone of a subgenogroup C4 strain. Viruses expressing the VP1-Q145E were virulent in 5-day-old BALB/c mice with 100 % mortality rate observed.

Mouse adaptation of a sub-genogroup B5 strain of human enterovirus 71 is associated with a novel lysine to glutamic acid substitution at position 244 in protein VP1.

Most human enterovirus 71 (HEV71) strains infect only primates and are unable to cause clinically apparent infection in mice. Here we describe a mouse-adapted HEV71 strain that belongs to sub-genogroup B5 with increased virulence in newborn BALB/c mice. The mouse-virulent strain was initially selected by serial passage of a HEV71 clinical isolate (HEV71-B5) in Chinese hamster ovary (CHO) cells (CHO-B5), followed by serial passage in newborn mice.

A reverse genetic study of the adaptation of human enterovirus 71 to growth in Chinese hamster ovary cell cultures.

We selected Chinese hamster ovary (CHO) cell-adapted strains of human enterovirus 71 (HEV71) belonging to sub-genogroups B5 (HEV71-B5) and C2 (HEV71-C2) by serial passage in CHO cells at a high multiplicity of infection. During the course of CHO cell passage, virus growth improved significantly, with increasing virus titres and the presence of cytopathic effect observed. A study of virus growth kinetics revealed that the CHO cell-adapted strains of HEV71-B5 (CHO-B5) and HEV71-C2 (CHO-C2) grew efficiently in CHO cells with maximum titres >100-fold higher than unadapted parental virus.