• Journal of Life Science
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• v.10 no.1
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• pp.6-9
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• 2000

Salmonella typhimurium is a causative agent of the common worldwide disease, salmonellosis. To identify putative invasion genes involved in Samonella infections, a S. typhimurium cosmid library was constructed in noninvasive E. coli DJl. The invasion efficiencies of the cosmid library for cultured HEp-2 and HeLa cells were estimated by tissue-culture invasion assay. 2 out of 1,000 transductants, DHl(pSI623) and DHl(pSI511) were able to invade the cells. Compared to E. coli by DHl(pSI511) increased 25- and 33 fold, respectively. The invasion efficiencies of HeLa cells by DHl(pSI623) increased 31- and 35 fold, respectively. This illustrates that the cosmid clones, DHl(pSI623) and DHl(pSI511) could harbor the invasion determinants derived from genomic DNA of S. typhimurium 82/6915, conferring the invasive characters for the cells.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.878-884
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• 2013

Salmonella is a major foodborne pathogen that causes a variety of human diseases. Development of ligands directly and specifically binding to the Salmonella will be crucial for the rapid detection of, and thus for efficient protection from, the virulent bacteria. In this study, we identified a RNA aptamer-based ligand that can specifically recognize Salmonella Typhimurium through SELEX technology. To this end, we isolated and characterized an RNase-resistant RNA aptamer that bound to the OmpC protein of Salmonella Typhimurium with high specificity and affinity ($K_d$ ~ 20 nM). Of note, the selected aptamer was found to specifically bind to Salmonella Typhimurium, but neither to Gram-positive bacteria (Staphylococcus aureus) nor to other Gram-negative bacteria (Escherichia coli O157:H7). This was evinced by aptamer-immobilized ELISA and aptamer-linked precipitation experiments. This Salmonella species-specific aptamer could be useful as a diagnostic ligand against pathogen-caused foodborne sickness.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.407-412
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• 2000

The presence of the nitric oxide synthase (NOS) enzyme from Salmonella typhimurium (S. typhimurium) was identified by measuring radiolabeled L-$[^3H]$citrulline and NO, and Western blot analysis. NOS was partially purified by both Mono Q ion exchange and Superose 12HR size exclusion column chromatography, sequentially. The molecular weight of NOS was estimated to be 93.3 kDa by Western blot analysis. The enzyme showed a significant dependency on the typical NOS cofactors; an apparent Km for L-arginine of 34.7 mM and maximum activity between $37^{\circ}C$ and $43^{\circ}C$. The activity was inhibited by NOS inhibitors such as aminoguanidine and $N^{G}$ $N^{G}$-dimethyl-L-arginine. taken together, partially purified NOS in S. typhimurium is assumed to be a different isoform of mammalian NOSs.OSs.

• Korean Journal of Veterinary Service
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• v.26 no.1
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• pp.39-50
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• 2003

Non-typhoidal Salmonella serovars remain a potential threat to human health and many animals including beef cattle, broiler chickens, and pigs which possible sources of non-typhoidal salmonellosis in human. In this study, the cecal contents of slaughtered pigs were examined for Salmonella serovar prevalence. The characteristics of the isolates, including antimicrobial resistance patterns and virulence genes, were studied along with the reference strain S typhimurium ATCC 13311. Out of 640 sample, 137 Salmonella(21.4%) were isolated and their serovar were identified S typhimurium 83 strains(60.6%), S agona 10 strains(7.3%), S schwarzengrund 4 strains(2.9%), S derby 4 strains(2.9%), S ayinde 1 strains(0.7%), and untypable 35 strains(25.5%). All 83 S typhimurium strains(100%) were multi-drug resistance to at least 7 antibiotics, and 20 strains(24.1%) of 83 isolates were R-type ACSSuT. Examination of virulent gene by PCR revealed that 73 S typimurium field isolates(88%) have a invA gene and 24 strains(28.9%) have a spvC gene. Consequently, S typhimurium infection in slaughtered pigs was relatively to appear high prevalence in their herds which suggested that it should be necessary for herd health monitoring and surveillance.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.71-75
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• 2015

Porcine salmonellosis is an economically important disease affecting the global pig industry today. Salmonella (S.) Typhimurium is highly contagious and may rapidly spread within pig populations of herd. To investigate the prevalence of porcine salmonellosis in Jeju, a total of 12,885 blood sera of 96 pig farms from 2009 to 2012 were analyzed by microplate agglutination test. Antibodies to S. Typhimurium were detected in all of pig farms tested in Jeju Province, and the mean of seropositive rate of individual pig was 18.8%. The mean seropositive rate of S. Typhimurium in sows (46.7%) was 7 times higher than that of weaned or growing pigs (6.7%). The lowest seropositive rate (3.0%) was detected in 40 day-old pigs, and this result might be closely associated with the marked decrease of maternal passive immunity. The seropositive rate in winter (42.7%) was higher than in other seasons.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.501-510
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• 1994

This paper deals with the distribution, reservoir and mode of spread of infection on 6 hatcheries in Taegu, Kyungpook and 5 broiler farms in Kyungpook during the period from June 1991 to June 1992. Isolated Salmonella were examined for serotypes, biotyping of Salmonella(S) typhimurtum, antibiotic susceptibility and some biochemical characteristics. Forty two Salmonella strains were isolated from 42(2.7% of 1,577 caecal samples of chicks, and their serotypes were S typhimurium 10, S typhimurium var Copenhagen 5, S infantis 4, S thompson 3, and untypable 20. The isolation rate of Salmonella varied from 0 to 5.1% in 6 hatcheries and that of Salmonella from 5 broiler farms was 10. 5%. Biotypes of 10 S typhimurium and 5 S typhimurium var Copenhagen strains isolated from chicks of hatcheries and broiler farms were biotype 2(86.6%), 8(6.7%), and 10a(6.7%), and 26i(6.7%) according to Duguid's scheme. Antibiotic susceptibility test of Salmonella isolated were performed by agar dilution method, using 9 antibiotics as follows: ampicillin(Am), chloramphenicol(Cm), gentamicin(Gm), kanamycin(Km), nalidixic acid(Na), rifampicin(Rf), streptomycin(Sm), sulfadimethoxine(Su), and tetracycline(Tc), All the strains were sensitive to RF. But 8 strans(23.8%) were resistant to one or more drugs and the most common resistance patterns of transferred R plasmids were SmSuGm and SmSu. Among 42 isolates, one had transferable citrate utilizing plasmid. S typhimurium and S typhimurium var copenhagen strains were resistant to killing by 90% normal guinea pig serum.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1616-1621
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• 2007

We have established a SYBR Green-based realtime PCR method using AnyDirect solution, which enhances PCR from whole blood, for direct amplification of the virA gene of Shigella flexneri and the invA gene of Salmonella typhimurium from human feces without prior DNA purification. When we compared the efficiency of conventional or realtime PCR amplification of the virA and invA genes from the supernatant of boiled feces supplemented with S. flexneri and S. typhimurium in the presence or absence of AnyDirect solution, amplification products were detected only in reactions to which AnyDirect solution had been added. The detection limit of real-time PCR was $1{\times}10^4\;CFU/g$ feces for S. flexneri and $2{\times}10^4\;CFU/g$ feces for S. typhimurium; this sensitivity level was comparable to other studies. Our real-time PCR assay with AnyDirect solution is simple, rapid, sensitive, and specific, and allows simultaneous detection of S. flexneri and S. typhimurium directly from fecal samples without prior DNA purification.

• YAKHAK HOEJI
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• v.51 no.5
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• pp.355-360
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• 2007

The essential oil fraction from the aerial parts of A. annua was analyzed by GC-MS. As the results, caryophyllene oxide (11.7%), caryophyllene (7.54%), camphor (7.32%), 1,8-cineol (4.98%), and borneol (3.99%) were confirmed as the main components of the oil fraction. The effects of this oil and its main components on antibiotic-susceptible and -resistant strains of Salmonella enteritidis and S. typhimurium were assessed. A. annua oil fraction significantly inhibited all strains of the two Salmonella species examined, with minimum inhibiting concentrations (MICs) ranging from 2.0 mg/ml to 8.0 mg/ml. Among the main components of the oil, borneol and camphor showed relatively strong inhibiting activity with MICs between 1.0 mg/ml and 4.0 mg/ml. The MICs of caryophyllene and caryophyllene oxide were higher than 16 mg/ml. The combination effects of the oils with kanamycin were evaluated using a checkerboard microtiter assay. Against S. typhimurium KCCM11862 and CCARM8009 strains, the oil fraction of A. annua, camphor, and 1,8-cineol exhibited significant synergistic with kanamycin with fractional inhibitory concentration (FIC) indices in the range of 0.085 to 0.375. In conclusion, a combination of kanamycin and A. annua oil or its main component, camphor, and cineol, may be useful for reducing the minimum effective dose of antibiotic required for the treatment of resistant S. typhimurium infections.

• Journal of Microbiology
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• v.38 no.1
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• pp.8-10
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• 2000

In order to rapidly identify and differentiate Salmonella typhimurium from the intestinal gram-negative bacteria, randomly amplified polymorphic DNA (RAPD) fingerprinting of Salmonella typhimurium was carried out using random primers designated OPA-13 (5'-CAGCACCCAC-3'), OPB-10 (5'-CGTCTGGGAC-3'), OPB-18 (5'-CCACAGCAGT-3'), and OPJ-10 (5'-AAGCCCGAGG-3'), and its patterns compared with 6 representive intestinal, gram-negative bacterial strains, Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, Escherichia coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., which are often found in foods. S. typhimurium had unique and distinct fingerprinting patterns. RAPD fingerprinting is thus concluded to be a rapid and sensitive method for the identification of S. typhimurium compared to conventional culturing procedures or immunoassays.

• Journal of Microbiology
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• v.38 no.4
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• pp.270-274
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• 2000

Pathogenic Salmonella typhimurium can invade the intestinal epithelium and cause a wide range of diseases including gastroenteritis and bacteremia in human and animals. To identify the genes involved in the infection, the invasion determinant was obtained from S. typhimurium 82/6915 and was subcloned into pGEM-7Z. A subclone DHl (pSV6235) invaded HEp-2 and Chinese hamster ovary epithelial cells and contained a 4.4 kb fragment of S. typhimurium genomic region. Compared with the host strain E. coli DHl, the subclone DHl (pSV6235) invaded cultured HEp-2 and Chinese hamster ovary cells at least 75- and 68-fold higher, respectively. The invasion rate of E. coli DHl for the cells significantly increased by harbouring the genomic region derived from pathogenic S. typhimurium 82/6915.