Genetic diversity in the prion protein gene (PRNP) of domestic cattle and water buffaloes in Vietnam, Indonesia and Thailand.

There has been an accumulation of information on frequencies of insertion/deletion (indel) polymorphisms within the bovine prion protein gene (PRNP) and on the number of octapeptide repeats and single nucleotide polymorphisms (SNPs) in the coding region of bovine PRNP related to bovine spongiform encephalopathy (BSE) susceptibility. We investigated the frequencies of 23-bp indel polymorphism in the promoter region (23indel) and 12-bp indel polymorphism in intron 1 region (12indel), octapeptide repeat polymorphisms and SNPs in the bovine PRNP of cattle and water buffaloes in Vietnam, Indonesia and Thailand. The frequency of the deletion allele in the 23indel site was significantly low in cattle of Indonesia and Thailand and water buffaloes. The deletion allele frequency in the 12indel site was significantly low in all of the cattle and buffaloes categorized in each subgroup. In both indel sites, the deletion allele has been reported to be associated with susceptibility to classical BSE. In some Indonesian local cattle breeds, the frequency of the allele with 5 octapeptide repeats was significantly high despite the fact that the allele with 6 octapeptide repeats has been reported to be most frequent in many breeds of cattle. Four SNPs observed in Indonesian local cattle have not been reported for domestic cattle. This study provided information on PRNP of livestock in these Southeast Asian countries.

Antimicrobial susceptibility of indicator bacteria isolated from chickens in Southeast Asian countries (Vietnam, Indonesia and Thailand).

To determine the prevalence of indicator bacteria resistant to antimicrobials among poultry in three Southeast Asian countries (Vietnam, Indonesia and Thailand), we examined the antimicrobial susceptibilities of commensal bacteria isolated from chickens. In total, 125, 117 and 180 isolates of Escherichia coli, Enterococcus faecalis and Enterococcus faecium, respectively, were used to test for antimicrobial susceptibility. Bacterial resistance to antimicrobial treatment was most frequently observed with oxytetracycline with a prevalence of 73.6% (E. coli), 69.2% (E. faecalis) and 92.2% (E. faecium). Resistance to fluoroquinolones, which are critically important medicines, was also frequently observed in E. coli (48.8%), E. faecalis (17.9%) and E. faecium (82.8%). The prevalence of indicator bacteria resistant to most of the antimicrobials tested in these countries was higher than those for developed countries. The factors underlying antimicrobial resistance may include inappropriate and/or excessive use of antimicrobials. These results highlight the need for monitoring the emergence and prevalence of antimicrobial resistance in developing countries.