Commercial bivalent killed Salmonella vaccine Salenvac-T has been used in several countries in order to prevent salmonellosis with Salmonella enterica serovars Enteritidis (SE) and Typhimurium (ST) in poultry. However, this vaccine has not been used in poultry farms in South Korea. In this study, we evaluated the efficacy of Salenvac-T vaccine to protect against the challenge of virulent SE and ST, and the effect of the vaccine on egg production and mortality in layer hens. The colonization of liver, spleen and cecum with challenged SE and ST was reduced in vaccinated chickens compared with that of unvaccinated control group. The twice vaccination with Salenvac-T induced elevated antibody responses against both SE and ST detected by enzyme-linked immunosorbent assay (ELISA). The higher average hen-day production was observed in the vaccinated layer hens than in the unvaccinated layer hens without significance. The average mortality was lower in the vaccinated layer hens during the experiment period. The antibody responses to both SE and ST were persistently detected in the vaccinated layers. In summary, vaccination with Salenvac-T reduces colonization of internal organs and induces good antibody responses, thereby results in higher performance and lower egg contamination with SE and ST in layer hens.
Antibody Formation ; Cecum ; Chickens ; Colon ; Enzyme-Linked Immunosorbent Assay ; Liver ; Ovum ; Poultry ; Republic of Korea ; Salmonella ; Salmonella enterica ; Salmonella enteritidis ; Salmonella Infections ; Salmonella typhimurium ; Spleen ; Vaccination

In the present study, we investigated the protection conferred by a live attenuated Salmonella enterica serovar Typhimurium (ST) strain against Salmonella Typhimurium, Salmonella Gallinarum (SG), and Salmonella Enteritidis (SE) infection in layer chickens. Birds were orally primed with the attenuated ST strain at 7 days of age and then boosted at 4 weeks post prime immunization (PPI). Sequential monitoring of plasma IgG and mucosal secretory IgA (sIgA) levels revealed that inoculation with ST induced a significant antibody response to antigens against ST, SE, and SG. Moreover, significant lymphoproliferative responses to the 3 Salmonella serovars were observed in the immunized group. We also investigated protection against virulent ST, SE, and SG strain challenge. Upon virulent SG challenge, the immunized group showed significantly reduced mortality compared to the non-immunized group. The reduced persistence of the virulent ST and SE challenge strains in the liver, spleen, and cecal tissues of the immunized group suggests that immunization with the attenuated ST strain may not only protect against ST infection but can also confer cross protection against SE and SG infection.
Antibody Formation ; Birds ; Chickens* ; Cross Protection ; Immunization ; Immunoglobulin A, Secretory ; Immunoglobulin G ; Liver ; Mortality ; Plasma ; Salmonella enterica ; Salmonella enteritidis* ; Salmonella typhimurium* ; Salmonella* ; Spleen

The studies on the standard plate count, most probable number(MPN) and isolation of the Enterobacteriaceae, especially Salmonella species from stream waters of Kyong-Ju city were carried out from June to July, 1988. The relationship between water temperature, weather and standard plate count were observed. The locations where all of the MPN was higher than 1,600 were Mun-chon bridge, Wol-song bridge, Go-hun bridge and the area adjoining the Hyong-san river. The higher the water temperature, the more the viable counts without rain. Bacteriological survey of the Salmonella species was performed with the total 80 specimens isolated from 16 areas which are the main streams in Kyong-Ju city. The author identified 5 strains(2.36%) of Salmonella typhi, 5 strains(2.3%) of Salmonella paratyphi, 2 strains(1.42%) of Salmonella paratyphi B, 63 strains(29.72%) of other Salmonella groups by biochemical tests and serotyping tests with slide agglutination.
Agglutination ; Enterobacteriaceae ; Gyeongsangbuk-do* ; Rain ; Rivers* ; Salmonella ; Salmonella paratyphi A ; Salmonella paratyphi B ; Salmonella typhi ; Serotyping ; Water ; Weather

Outbreaks caused by highly industrialized food companies are characterized by cross-border, trans-regional, rapid and unpredictable, related to serious disease and economic burden. A cluster of cases with monophasic salmonella enterica serovar Typhimurium ST34 infection suspected to be associated with consumption of contaminated chocolate products have been reported in several Europe countries since December 2021. After retrospective investigations, the buttermilk circuit in the Belgian factory was suspected to be the point of origin of the contamination. This outbreak could provide a reference for the risk management of foodborne pathogens contamination in China. The objective of this paper was to summarize the process and characteristics of the outbreak of monophasic S. Typhimurium caused by contaminated chocolate products, analyze the characteristics of ST34 monophasic S. Typhimurium and the microbial management measures in the process of chocolate products, and systematically discuss the suggestions for the risk management of foodborne pathogens contamination and countermeasures for the rapid development of industrialization of food enterprises in China, in order to provide scientific and technological support for the prevention and control, prediction and early warning of sudden cases in China.
Humans ; Salmonella typhimurium ; Serogroup ; Salmonella Infections/prevention & control* ; Chocolate ; Retrospective Studies ; Salmonella enterica ; Disease Outbreaks/prevention & control* ; Risk Management

The study was carried out to evaluate and compare the immune responses in mice experimentally infected with either wild-type or isogenic mutants of Salmonella enterica serovars Enteritidis (SE), Salmonella Typhimurium (ST) and Gallinarum (SG). The mutant strains were constructed by allelic replacement of some virulence-associated genes in the wild-type strains. Seven-week-old female BALB/c mice were orally or intraperitoneally inoculated by injecting bacterial suspension. To evaluate the immune responses, enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay were conducted with serum and fecal samples. As a result, the mice group infected orally with the SE mutant strain showed the highest level of specific IgA-secreting splenocytes, compared to the other groups. The peritoneally injected groups showed the greater levels of IgG1 than the orally injected groups, which was in a good agreement with the previous studies. In addition, the mutant infected groups had the similar secretion levels of antibodies with the wild-type infected groups. These results demonstrated that the SE mutant strain elicited humoral immune response as much as wild-type, implying that it can be useful as a delivery vehicle as well as a candidate of a live attenuated vaccine.
Animals ; Antibodies ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunity, Humoral ; Immunity, Mucosal ; Immunoglobulin G ; Mice ; Salmonella ; Salmonella enterica ; Salmonella typhimurium ; Sprains and Strains

A 48-year-old woman was presented to our clinic with some fever and neck pains for about one month. Based on the symptoms and results of image, an empirical diagnosis of tuberculous cervical spondylitis was made. The pain was not significantly decreased after anti-tuberculosis therapy. And, 3 weeks later, she was re-admitted to our hospital for the unbearable pain. An exploration of the C4/5 by the anterior medial approach was recommended to evaluate the germ and debridement. Bacteriological tests showed that the pathogen was Salmonella Enteritidis. The pain was relieved significantly after operation and sensitive antibiotic treatments. Infections with Salmonella Typhi or Salmonella Paratyphi have been well-documented, while there are few reports of cervical spondylitis caused by Salmonella Enteritidis. We reported a case of a healthy woman with whom pyogenic cervical spondylitis of Salmonella Enteritidis was corroborated and treated and reviewed according to previous reports about spondylitis caused by Salmonella Enteritidis in the literature.
Cervical Vertebrae ; Debridement ; Diagnosis ; Female ; Fever ; Humans ; Middle Aged ; Neck Pain ; Salmonella enteritidis* ; Salmonella paratyphi A ; Salmonella typhi ; Salmonella* ; Spondylitis*

BACKGROUND: Typhoid fever, caused by Salmonella enterica serotype Typhi, remams an important public health problem in Korea, and asymptomatic chronic carriers play a role in the endemicity. However, the molecular studies of S. typhi isolates are very limited. We characterized clinical isolates of S. typhi by molecular and phage typing tools for the extent of genetic diversity and relatedness among the isolates. METHODS: A total of 49 S. typhi isolates from sporadic cases of typhoid fever were collected in 3 university hospitals in Seoul during 1992 to 1998 and examined for in vitro susceptibility to 14 antimicrobials by disk diffusion method, ribotyping using PstI restriction enzyme, and pulsed-field gel electrophoresis (PFGE) using XbaI and Vi phage typing. The distribution of the epidemiological types and genomic DNA relatedness were analyzed. RESULTS: Forty-five out of 49 isolates were susceptible to all drugs tested. Thirty-two out of 47 were typable by phage typing and 56.3% possessed the phage type El or Ml. Forty-nine isolates divided into 6 different ribotypes (A to F) and 19 different PFGE types (AO through A17, BO) by ribotyping and PFGE analysis, respectively. Based on the 3 typing systems, 32 isolates divided into 17 different epidemiological types. The E1-A-A12 (phage type-ribotype-PFGE type) was most prevalent (18.8Fo) and isolated only in 1998, but distributed in various areas of isolation. The next prevalent M1-A-A1 (15.6%) was isolated from 1992 through 1998. The genetic relatedness based on PFGE analysis revealed that F (coefficient of similarity) values are 0.64 to 1.0 and 0.52 for A subtypes and BO type, respectively. CONCLUSIONS: We conclude that the circulating S. typhi strains in Seoul city show considerable genetic diversity, whereas most of them seems to be clonally related.
Bacteriophage Typing ; Bacteriophages ; Diffusion ; DNA ; Electrophoresis, Gel, Pulsed-Field ; Genetic Variation ; Hospitals, University ; Korea ; Public Health ; Ribotyping ; Salmonella enterica* ; Salmonella typhi ; Salmonella* ; Seoul* ; Typhoid Fever

BACKGROUND: We recently encountered a case of typhoid fever in a patient who visited us after travelling India. The patient received ciprofloxacin therapy, but developed typhoid pneumonia and typhoid hepatitis, and nalidixic acid resistance Salmonella Typhi (NARST) was identified. The aim of this study was to assess the in vitro efficacy of several antimicrobial combinations, which are commonly used in clinical practice. MATERIALS AND METHODS: Time-kill studies were performed for a clinical NARST strain to evaluate synergy. Synergy was defined as a > or = 2 log10 decrease (100-fold drop) in CFU per mL at 24 hours by a drug combination compared to the most active constituent. RESULTS: The combination regimen of cefotaxime plus ciprofloxacin significantly reduced the bacterial counts (> 3 log CFU) at 3/4 MIC and at 24 hours compared to the ciprofloxacin or cefotaxime alone and showed synergistic effect against a NARST strain. CONCLUSION: In conclusion, our time-kill studies showed that ciprofloxacin plus cefotaxime was the best in vitro combination against a NARST. This combination may improve efficacy compared to fluoroquinolone alone in typhoid fever patient with NARST. Time kill studies with more NARST strains and clinical studies are required to test the relevance of our findings
Anti-Bacterial Agents ; Bacterial Load ; Cefotaxime ; Ciprofloxacin ; Hepatitis ; Humans ; India ; Nalidixic Acid ; Pneumonia ; Salmonella ; Salmonella enterica ; Salmonella typhi ; Sprains and Strains ; Typhoid Fever

Typhoid fever is a class I legally designated communicable disease in Korea; and if remains as an important public health problem in many developing countries. It takes at least 3-5 days to detect and identify Salmonella Typhi (S. Typhi) by classical diagnostic method. For this reason, multiplex PCR (mPCR) was evaluated in detecting and identifying S. Typhi. In this study, forty-three bacterial strains, which consisted of 42 Salmonella enterica serovars and one Citrobacter freundii. were used to evaluate the promptness of mPCR in detecting and identifying S. Typhi. mPCR was performed with four genes which were known for representing Salmonella spp and/or S. Typhi: invA, fliC-d, viaB and prt. invA and prt gene was amplified in all strains and viaB gene was in only S. Typhi. fliC-d gene was amplified in three serovars: S. Typhi, S. Schwarzengrund and S. Livingstone. After specificity test, mPCR was modified as triplex PCR with three genes (invA, fliC-d, and viaB) and the sensitivity test was performed against S. Typhi-inoculated stool samples. mPCR was able to detect S. Typhi cell suspension of 1x105 cfu/mL. We found that modified multiplex PCR was useful to detect S. Typhi from stool samples within 24h whereas it takes 3-5days to detect by classic diagnosis method.
Citrobacter freundii ; Communicable Diseases ; Developing Countries ; Multiplex Polymerase Chain Reaction ; Public Health ; Salmonella ; Salmonella enterica ; Salmonella typhi ; Sensitivity and Specificity ; Typhoid Fever

BACKGROUND: We recently encountered a case of typhoid fever in a patient who visited us after travelling India. The patient received ciprofloxacin therapy, but developed typhoid pneumonia and typhoid hepatitis, and nalidixic acid resistance Salmonella Typhi (NARST) was identified. The aim of this study was to assess the in vitro efficacy of several antimicrobial combinations, which are commonly used in clinical practice. MATERIALS AND METHODS: Time-kill studies were performed for a clinical NARST strain to evaluate synergy. Synergy was defined as a > or = 2 log10 decrease (100-fold drop) in CFU per mL at 24 hours by a drug combination compared to the most active constituent. RESULTS: The combination regimen of cefotaxime plus ciprofloxacin significantly reduced the bacterial counts (> 3 log CFU) at 3/4 MIC and at 24 hours compared to the ciprofloxacin or cefotaxime alone and showed synergistic effect against a NARST strain. CONCLUSION: In conclusion, our time-kill studies showed that ciprofloxacin plus cefotaxime was the best in vitro combination against a NARST. This combination may improve efficacy compared to fluoroquinolone alone in typhoid fever patient with NARST. Time kill studies with more NARST strains and clinical studies are required to test the relevance of our findings
Anti-Bacterial Agents ; Bacterial Load ; Cefotaxime ; Ciprofloxacin ; Hepatitis ; Humans ; India ; Nalidixic Acid ; Pneumonia ; Salmonella ; Salmonella enterica ; Salmonella typhi ; Sprains and Strains ; Typhoid Fever