Quantitative Analysis of Colistin-Resistant Escherichia coli in Retail Meat from Local Vietnamese Markets.

The spread of drug-resistant bacteria via food has contributed to the dissemination of resistant bacteria among humans. However, the status of food contamination with resistant bacteria, particularly the quantitative level of resistant bacteria in food, has not yet been well elucidated. In this study, the abundance of colistin-resistant Escherichia coli in meat samples was quantified to understand the origin of the contamination of meat available in local Vietnamese markets. Fifteen samples each of chicken and pork meat purchased from local Vietnamese markets were assessed for the presence of colistin-resistant E. coli with the mobile colistin resistance gene, mcr. The results showed that 40% (6/15) and 66% (10/15) of the pork and chicken meat samples, respectively, were contaminated with colistin-resistant E. coli. The median quantitative levels of colistin-resistant E. coli in the contaminated pork and chicken samples were 1.8 × 104 and 4.2 × 103 CFU/g, respectively. The results of phylogenetic analysis of isolates from a chicken meat sample showed that the contaminated colistin-resistant E. coli was a mix of multiple phylogenetical clones of bacteria that may have multiplied during sale. This is the first study to quantify the abundance of colistin-resistant E. coli in meat samples.

A Vietnamese human genetic variation database.

Large scale human genome projects have created tremendous human genome databases for some well-studied populations. Vietnam has about 95 million people (the 14th largest country by population in the world) of which more than 86% are Kinh people. To date, genetic studies for Vietnamese people mostly rely on genetic information from other populations. Building a Vietnamese human genetic variation database is a must for properly interpreting Vietnamese genetic variants. To this end, we sequenced 105 whole genomes and 200 whole exomes of 305 unrelated Kinh Vietnamese (KHV) people. We also included 101 other previously published KHV genomes to build a Vietnamese human genetic variation database of 406 KHV people. The KHV database contains 24.81 million variants (22.47 million single nucleotide polymorphisms (SNPs) and 2.34 million indels) of which 0.71 million variants are novel. It includes more than 99.3% of variants with a frequency of >1% in the KHV population. Noticeably, the KHV database revealed 107 variants reported in the human genome mutation database as pathological mutations with a frequency above 1% in the KHV population. The KHV database (available at https://genomes.vn) would be beneficial for genetic studies and medical applications not only for the Vietnamese population but also for other closely related populations.