1.Detection of virulence, specific genes and antibiotic resistance of isolated Salmonella spp. strains from rabbits infected with salmonellosis
Huynh Van CHUONG ; Nguyen Minh TUAN ; Nguyen Thi Nhu ANH ; Le Thi Lan PHUONG ; Nguyen Xuan HOA
Korean Journal of Veterinary Research 2023;63(2):e16-
Salmonella spp. are pathogens involved in most salmonellosis in rabbits. This study examined Salmonella disease in rabbits raised in Thua Thien Hue, Vietnam. Two hundred and 56 rectal swabs of rabbits were taken, and a carrier rate of 33.98% was found. In addition, all the isolated Salmonella spp. strains were 100% motile; positive for H2S, catalase, Voges Proskauer, coagulase, citrate, maltose, and dextrose; and negative for indole, methyl red, urease, oxidase, sucrose, and lactose. The Kirby-Bauer method showed that these Salmonella strains were susceptible to doxycycline (93.2%), tetracycline (84.1%), and levofloxacin (65.9%). On the other hand, they were highly resistant to streptomycin (95.5%), ampicillin (93.2%), colistin (40.9%), and gentamicin (34.1%). Furthermore, polymerase chain reaction used to screen for virulence and specific genes of Salmonella strains showed that all Salmonella strains isolated carried InvA, fimA, and Stn.
2.Probiotic potential of lactic acid bacteria isolated from Vietnamese sour-fermented fish product
Nguyen Pham Anh Thi ; Tran Huu Hau ; Nguyen Thi Nhu Huynh ; Huynh Van Liem ; Tran Kieu Dieu Thi ; Do Phuong Kieu ; Dang Huy Hoa ; Nguyen Thanh Nha ; Nguyen Pham Thien Trang ; Le Nguyen Khoi Nguyen ; Truong Thi Bich Van ; Do Tan Khang
Malaysian Journal of Microbiology 2022;18(2):222-226
Aims:
To isolate and characterize the lactic acid bacteria (LAB) strains from the “mam chua ca ro” (sour fermented fish) in the South of Vietnam and investigate their potential anti-bacterial properties.
Methodology and results:
Four LAB strains (MCR1, MCR2, MCR3 and MCR4) were isolated from the "mam chua ca ro" product and their anti-bacterial activity was determined using the spot assay and the paper disc diffusion method. The isolated LABs can inhibit Escherichia coli ATCC 25922, Staphyloccocus aureus ATCC 25923 and Vibrio parahaemolyticus BV016 and produce bacteriocin to control the growth of E. coli ATCC 25922 and S. aureus ATCC 25923, except V. parahaemolyticus. MCR2 was chosen to sequence 16S rRNA of Pediococcus acidilactic.
Conclusion, significance and impact of study
On the basis of their prominent anti-pathogenic bacteria activity, LAB strains isolated from Vietnamese sour-fermented fish products were verified as prospective probiotics.
Lactobacillales--isolation &
;
purification
;
Pediococcus acidilactici