1.Virulence factors in Escherichia coli isolated from calves with diarrhea in Vietnam.
Tan Duc NGUYEN ; Thin Thanh VO ; Hung VU-KHAC
Journal of Veterinary Science 2011;12(2):159-164
This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.
Animals
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Cattle
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Cattle Diseases/epidemiology/*microbiology
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DNA, Bacterial/chemistry/genetics
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Diarrhea/epidemiology/microbiology/*veterinary
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Escherichia coli/genetics/*isolation & purification/pathogenicity
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Escherichia coli Infections/epidemiology/microbiology/*veterinary
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Feces/microbiology
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Fimbriae, Bacterial/genetics
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Polymerase Chain Reaction/veterinary
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Polymorphism, Restriction Fragment Length
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Vietnam/epidemiology
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Virulence Factors/*genetics
2.Prevalence of Zoonotic Metacercariae in Two Species of Grouper, Epinephelus coioides and Epinephelus bleekeri, and Flathead Mullet, Mugil cephalus, in Vietnam.
Dung The VO ; Darwin MURRELL ; Anders DALSGAARD ; Glenn BRISTOW ; Dung Huu NGUYEN ; Thanh Ngoc BUI ; Dung Thi VO
The Korean Journal of Parasitology 2008;46(2):77-82
Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters locate in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.
Animals
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Bass/*parasitology
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Fish Diseases/*epidemiology/parasitology
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Fresh Water/parasitology
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Humans
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Prevalence
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Seawater/parasitology
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Smegmamorpha/*parasitology
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Time Factors
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Trematoda/*isolation & purification
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Trematode Infections/epidemiology/parasitology/*veterinary
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Vietnam/epidemiology
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Zoonoses/*epidemiology/parasitology
3.Systematic sequencing of imported cases leads to detection of SARS-CoV-2 B.1.1.529 (Omicron) variant in central Viet Nam
Do Thai Hung ; Nguyen Bao Trieu ; Do Thi Thu Thuy ; Allison Olmsted ; Trinh Hoang Long ; Nguyen Duc Duy ; Huynh Kim Mai ; Bui Thi Thu Hien ; Nguyen Van Van ; Tran Van Kiem ; Vo Thi Thuy Trang ; Nguyen Truong Duy ; Ton That Thanh ; Huynh Van Dong ; Philip L Gould ; Matthew R Moore
Western Pacific Surveillance and Response 2022;13(4):82-85
As authorities braced for the arrival of the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), infrastructure investments and government directives prompted action in central Viet Nam to establish capacity for genomic surveillance sequencing. From 17 November 2021 to 7 January 2022, the Pasteur Institute in Nha Trang sequenced 162 specimens from 98 150 confirmed SARS-CoV-2 cases in the region collected from 8 November to 31 December 2021. Of these, all 127 domestic cases were identified as the B.1.617.2 (Delta) variant, whereas 92% (32/35) of imported cases were identified as the B.1.1.529 (Omicron) variant, all among international flight passengers. Patients were successfully isolated, enabling health-care workers to prepare for additional cases. Most (78%) of the 32 Omicron cases were fully vaccinated, suggesting continued importance of public health and social measures to control the spread of new variants.
4.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 &
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purification
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Pediococcus acidilactici