Antimicrobial residues, non-typhoidal Salmonella, Vibrio spp. and associated microbiological hazards in retail shrimps purchased in Ho Chi Minh city (Vietnam) by Yen, NTP, Nhung, NT, Van, NTB, Cuong, NV, Chau, LT, Trinh, HN, Tuat, CV, Tu, ND, Lan, N, Campbell, J, Thwaites, G, Baker, S, Carrique-Mas, J