Background: Salmonella typhi (S.typhi) is the major cause of human typhoid fever outbreaks. In fact, there were various typhoid fever outbreaks that occurred in China, and India that was caused by S.typhi strain without Vi antigen. Objective: To determine whether the S.typhi strains with mutation of gene encoding Vi antigen exists in Vietnam and the rate of mutation (if they exists). Subject and methods: 450 S.typhi isolates were collected in the Northern, Central and Southern Region of Vietnam during 1995 and 2005. The isolates were analyzed by the PCR method in order to detect mutants by using 2 primer pairs of tviB and DE. Results and Conclusion: There was no clear evidence on the relationship between the widely used Typhi Vi vaccine in Vietnam and the existence and spread of the mutation of gene encoding Vi antigen of S.typhi. 30 out of 450 isolates mutated losing the gene encoding of Vi antigen, making it 6.67%. These isolates were spread out between 1995 and 2005 throughout the Northern, Central and Southern Regions of Vietnam, with a peak in 1999. A noteworthy point was the rate of mutation of S.typhi losing the gene encoding of Vi antigen in Vietnam during the period of study. However, the mutation rate of S.typhi in Vietnam was still higher than the ratio of similar mutations being published in the other countries worldwide and higher than the recommended level of the World Health Organization.
gene mutation ; Salmonella typhi

129 isolates of S.typhi multi-drug resistant to Cm, Ap, Te, Tr, Su from Northern, Southern and Central regions of Vietnam during 1995-1997 were examined to detect the ability to transfer gene encoding the resistance to antibiotics and to study molecular characters of it’s R-plasmids. Results indicated the presence of self-transferable plasmid in 90% S.typhi strains from Southern, and 100% strains from Northern and Central regions. These strains carried from 1 to 2 plasmids of molecular weighed 110 MD and 80 MD. Gene encoding the resistance to Cm, Ap, Te, Tr, and Su were found to be located on a large plasmid of 100 MD. All S.typhi strains from 3 regions showed to have large plasmids with identical molecular structure, this indicated the same origin of these S.typhi strains.
Drug resistance ; Salmonella typhi

126 multiply resistant S.typhi isolates were screened among 363 isolates collected from Northern, Central and Southern regions of Vietnam during the period 1995-1997. Transfer experiments of the resistance to E.coli K12-J53 from these S.typhi isolates were performed to determine their transferable capacity of resistance factors and its frequency. The results indicated that 74.78% of multiply resistant S.typhi isolates (AM, CL, TE, TR, SU) have R-factors, most of them contained all resistance genes characterizing the resistance of wild strains. The frequency of transfer of the resistance varied from 10-5 to 10-8.
Drug resistance ; Salmonella typhi

No abstract available.
Arthritis* ; Hip Joint* ; Hip* ; Salmonella typhi* ; Salmonella*

By Kirby-Bauer technique, authors determined the resistence to antibiotics of 2193 strains of Salmonella typhi isolated in various Hospital of Dong Thap, Pasteur Hospital in Ho Chi Minh city, Binh Dinh, Da Nang, Hue, Thanh Hoa, Ha Noi, Hai Phong and Quang Ninh. The antibiotic resistances were very high to ampicillin, chloramphenicol, co-trimoxazole. 93.5% of salmonella typhy strains were resistant to nalidixic acid. After 6 years of treatment, only < 1% resistant to ciprofloxacine and ceftriaxone
Anti-Bacterial Agents ; Salmonella ; Salmonella typhi

No abstract available.
Arthritis* ; Knee Joint* ; Knee* ; Salmonella typhi* ; Salmonella*

No abstract available.
Bacteriolysis* ; Galactose* ; Lipopolysaccharides* ; Salmonella typhi* ; Salmonella*

No abstract available.
Polymerase Chain Reaction* ; Salmonella typhi* ; Salmonella*

The study was performed on 90 Salmonella typhi strains isolated from patients in Hanoi, Hue and Ho Chi Minh city. The results showed that: the multi-antibiotic resistant Salmonella typhi strains have already spread over the country; 2 plasmid with size about 120 kilobase (Kb) and 102 Kb. Plasmid 120 Kb is conjugated, self-transmitted R-plasmid and carrying at least 5 antibiotic resistant genes to chloramphenicol, ampicillin, tetracycline and trimethoprim/sulfamethoxazole. The initial analysis by a restricted enzyme of EcoRi showed that these self-transmitted R-plasmid in S.typhi strains isolated in 3 areas Hanoi, Hue and Hochiminh city maybe the same origin.
Salmonella typhi ; R Factors ; epidemiology

Background: Salmonella enterica ser. Typhi and Salmonella enterica ser. Paratyphi are agents of typhoid fever, a severe systemic disease, which remains to be a public health concern in the Philippines. Infection due to non-typhoidal Salmonella (NTS), on the other hand, most often results in a self-limiting acute gastroenteritis but may result in invasive disease in some cases. There is scarcity of information on the Salmonella serotypes in the Philippines which limits understanding of the distribution, transmission and antimicrobial resistance of these bacteria. Objective: This study describes the serotype distribution and antimicrobial resistance of Salmonella in the Philippines over a 15-year period. Methodolgy: Salmonella isolates were collected through the Philippine Department of Health-Antimicrobial Resistance Surveillance Program (DOH-ARSP) from January 1, 2004 to December 31, 2018. The isolates were serotyped using Sven Gard method for slide agglutination using antigens from Denka Seiken (Japan), and S and A serotest (Thailand). Antigenic formula obtained were classified according to White-Kauffmann-LeMinor scheme. Antimicrobial susceptibility testing for ampicillin, ceftriaxone, cefotaxime, chloramphenicol, ciprofloxacin, and trimethoprim-sulfamethoxazole, were performed using both automated and conventional methods (Kirby Bauer disk diffusion and gradient diffusion method). Antimicrobial susceptibility results were interpreted using Clinical and Laboratory Standards Institute (CLSI) 2018 interpretive criteria (M100Ed28E). Results: A total of 2,387 isolates were collected from human specimens during the 15-year study period. There were 69 serotypes of Salmonella identified with the most common being Salmonella enterica ser. Typhi: n=1895 (79.39%), Salmonella enterica ser. Enteritidis: n=182 (7.62%), Salmonella enterica ser. Typhimurium: n=87 (3.64%), Salmonella enterica ser. Weltevreden: n=24 (1.00%), Salmonella enterica ser. Paratyphi A: n=17 (0.71%), Salmonella enterica ser. Stanley: n=17 (0.71%), Salmonella enterica ser. Anatum: n=13 (0.54%), Salmonella enterica ser. Heidelberg: n=12 (0.50%), Salmonella enterica ser. Choleraesuis var. Kunzendorf: n=9 (0.38%). The multidrug resistant Salmonella serotypes reported in this study were mostly resistant to ampicillin, cefotaxime, ciprofloxacin combinations. Conclusion This present study showed that prevailing Salmonella serotypes in the Philippines were similar with Salmonella serotypes reported from other Asian countries. Typhoidal isolates were high among 6-17 years old and were mostly from males. The antimicrobial resistance rates for typhoidal Salmonella isolates to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, ciprofloxacin, ceftriaxone and cefotaxime were lower compared with the antimicrobial resistance rates for non-typhoidal Salmonella isolates. Multidrug resistance for both Salmonella Typhi and NTS were relatively low. Continued and enhanced surveillance is needed to monitor the rising levels of antimicrobial resistance, determine risk factors and exposures associated with Salmonella Typhi and NTS infection to guide prevention and control measures.
Salmonella typhi ; Drug Resistance, Multiple