• Title, Summary, Keyword: Salmonella

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Rapid and Sensitive Detection of Salmonella in Chickens Using Loop-Mediated Isothermal Amplification Combined with a Lateral Flow Dipstick

  • Liu, Zhi-Ke;Zhang, Qiu-Yu;Yang, Ning-Ning;Xu, Ming-Guo;Xu, Jin-Feng;Jing, Ming-Long;Wu, Wen-Xing;Lu, Ya-Dong;Shi, Feng;Chen, Chuang-Fu
    • Journal of Microbiology and Biotechnology
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    • v.29 no.3
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    • pp.454-464
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    • 2019
  • Salmonellosis is a highly contagious bacterial disease that threatens both human and poultry health. Tests that can detect Salmonella in the field are urgently required to facilitate disease control and for epidemiological investigations. Here, we combined loop-mediated isothermal amplification (LAMP) with a chromatographic lateral flow dipstick (LFD) to rapidly and accurately detect Salmonella. LAMP primers were designed to target the Salmonella invA gene. LAMP conditions were optimized by adjusting the ratio of inner to outer primers, $MgSO_4$ concentration, dNTP mix concentration, amplification temperature, and amplification time. We evaluated the specificity of our novel LAMP-LFD method using six Salmonella species and six related non-Salmonella strains. All six of the Salmonella strains, but none of the non-Salmonella strains, were amplified. LAMP-LFD was sensitive enough to detect concentrations of Salmonella enterica subsp. enterica serovar Pullorum genomic DNA as low as $89fg/{\mu}l$, which is 1,000 times more sensitive than conventional PCR. When artificially contaminated feed samples were analyzed, LAMP-LFD was also more sensitive than PCR. Finally, LAMP-LFD gave no false positives across 350 chicken anal swabs. Therefore, our novel LAMP-LFD assay was highly sensitive, specific, convenient, and fast, making it a valuable tool for the early diagnosis and monitoring of Salmonella infection in chickens.

Rapid Detection of Salmonella Species in Foods Using PCR (PCR을 이용한 식품 내 Salmonella 균주의 신속 검출방법)

  • Jung, Sang-Hun;Kim, Myo-Young;Kim, Hyun-Joong;Kim, Tae-Woon;Ryu, Sang-Ryeol;Kim, Hae-Yeong
    • Applied Biological Chemistry
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    • v.46 no.3
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    • pp.225-228
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    • 2003
  • This study was carried out to investigate the simple and rapid detection of Salmonella species in different kinds of food using PCR method. The specific primer sets (SIN1 and SIN2) was designed and utilized to amplify a 617 bp DNA fragment from salmonella species. The sensitivity of PCR was 1 pg of purified template DNA or $10^2$ cells from pure culture. The detection limit of Salmonella typhimurium on agarose gel electrophoresis was $10^3{\sim}10^4$ cells/g in the artificially contaminated food samples. These results suggested that this simple method could be applied to industrial fields for detection of Salmonella species in food.

Production and Characterization of Egg Yolk Antibodies (IgY) against Flagella Antigen of Salmonella sp. (살모넬라 편모 항원에 대한 난황항체(IgY)의 생산 및 특성)

  • 신순오;김도균;양시용;안태영;김정우
    • Korean Journal of Poultry Science
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    • v.30 no.3
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    • pp.191-196
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    • 2003
  • Egg yolk antibodies(IgY) from laying hens immunized with antigens from Salmonella choleraesuis, Salmonella typhimurium and Salmonella dublin were produced. The Antigenic proteins isolated from those flagella of Salmonella sp., determined by SDS-PAGE, were pure and had a molecular mass of approximately 53.4, 51 and 54.6 kDa, respectively. The IgY titers were found at two weeks after first immunization and increased gradually to maximum of 330,000 300,000 and 440,000 respectively. According to the results of specificity test by ELISA, the IgY raised against Salmonella sp. were found highly specific activity levels. Concentration of Salmonella sp. incubated with anti-Salmonella sp. IgY were drastically reduced to the levels of 2.8∼4.0 log CFU/ml. The contents of IgY in an egg yolk was approximately 31∼33 mg/ml.

Rapid Detection of Salmonella spp. by Antibody-Immobilized Piezoelectric Crystal Biosensor (고정화법을 달리하여 제조한 압전류적 항체 센서에 의한 Salmonella spp.의 신속 검출)

  • 박인선;김우연;김남수
    • Journal of Food Hygiene and Safety
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    • v.13 no.3
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    • pp.206-212
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    • 1998
  • An improved antibody-coated sensor system based on quartz crystal microbalance was developed for the detection of Salmonella spp. An antibody against Salmonella common structural antigen was immobilized onto one gold electrode of the piezoelectric quartz crystal surface by various immobilization procedures. The best results in sensitivity and stability were obtained with the thin layers of protein A and 3,3'-dithiopropionimidate.2HCI(DTBP), a homobifunctional thiol-cleavable crosslinker. After the addition of a S. typhimurium suspension into a reaction cell with 0.1 M sodium phosphate buffer, pH 7.2, the resonant frequency owing to S. typhimurium adsorption decreased conspicuously. The antibody-immobilized crystals prepared by the gold-protein A complex formation and DTBP thiolation showed the frequency shifts of 80 and 283 Hz, respectively. The time required for maximum frequency shift was about 30~60 min. The antibody-coated crystal could be reused for 6~8 consecutive assays.

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Transcriptomic Approach for Understanding the Adaptation of Salmonella enterica to Contaminated Produce

  • Park, Sojung;Nam, Eun woo;Kim, Yeeun;Lee, Seohyeon;Kim, Seul I;Yoon, Hyunjin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.11
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    • pp.1729-1738
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    • 2020
  • Salmonellosis is a form of gastroenteritis caused by Salmonella infection. The main transmission route of salmonellosis has been identified as poorly cooked meat and poultry products contaminated with Salmonella. However, in recent years, the number of outbreaks attributed to contaminated raw produce has increased dramatically. To understand how Salmonella adapts to produce, transcriptomic analysis was conducted on Salmonella enterica serovar Virchow exposed to fresh-cut radish greens. Considering the different Salmonella lifestyles in contact with fresh produce, such as motile and sessile lifestyles, total RNA was extracted from planktonic and epiphytic cells separately. Transcriptomic analysis of S. Virchow cells revealed different transcription profiles between lifestyles. During bacterial adaptation to fresh-cut radish greens, planktonic cells were likely to shift toward anaerobic metabolism, exploiting nitrate as an electron acceptor of anaerobic respiration, and utilizing cobalamin as a cofactor for coupled metabolic pathways. Meanwhile, Salmonella cells adhering to plant surfaces showed coordinated upregulation in genes associated with translation and ribosomal biogenesis, indicating dramatic cellular reprogramming in response to environmental changes. In accordance with the extensive translational response, epiphytic cells showed an increase in the transcription of genes that are important for bacterial motility, nucleotide transporter/metabolism, cell envelope biogenesis, and defense mechanisms. Intriguingly, Salmonella pathogenicity island (SPI)-1 and SPI-2 displayed up- and downregulation, respectively, regardless of lifestyles in contact with the radish greens, suggesting altered Salmonella virulence during adaptation to plant environments. This study provides molecular insights into Salmonella adaptation to plants as an alternative environmental reservoir.

Prevalence of Salmonella Enterotoxin Gene(stn) among Clinical Strains Isolated in Korea and Regulation of stn Expression (한국에서 분리된 병원성 Salmonella 균주의 장독소 유전자(stn) 분포와 발현조절 기작)

  • 임상용;유상렬
    • Microbiology and Biotechnology Letters
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    • v.28 no.6
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    • pp.316-321
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    • 2000
  • Role of enterotoxin from Salmonella in pathogenesis is not know. Enterotoxin gene from Salmonella typhimurium(stn) encodes a 29kDa toxin that has no homology to any other known enterotoxins. Expression of stn is enthanced upon contact with epithelial cell but not all strains having the stn gene express Stn, Based on PCR analysis, we found that all 36 clinical strains of Salmonella isolated in Korea tested carried the stn gene. To understand the trgulation of the stn transcription, the expression of stn was studies in vitro. RNA polymerase was purified by polymin P fraction-ation, DNA-agarose affinity chromatography, and Mono-Q ion exchange chromatography from Salmonella. The expression of stn was inhibited by cAMP·CRP complex by about 50%.

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Detection of invA and spvC in Salmonella spp. isolated from duck farms (오리 농장에서 분리한 Salmonella속 균에서 invA 및 spvC gene의 검출)

  • Cho, Jae-Keun
    • Korean Journal of Veterinary Service
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    • v.33 no.4
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    • pp.341-344
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    • 2010
  • Poultry and poultry products have been implicated as a major source of Salmonella infection in human, and infection due to Salmonella serotypes continue to be a major health problem. The presence of two virulence genes, invA and spvC, in 34 Salmonella isolates obtained from duck farms was investigated. All isolates contained the invA gene, and spvC gene was found in 20 (58.8%) of 34 Salmonella isolates : S. Typhimurium (n=8), S. Fyris (n=5), S. Enteritidis (n=3), S. Typhimurium var. copenhagen (n=1), S. Haardt (n=1) and S. Mbandaka (n=1). This study showed the presence of the spvC gene was widely distributed in between different Salmonella enterica isolates.

Serovars distribution and antimicrobial resistance patterns of Salmonella spp. isolated from the swine farms and slaughter houses

  • Jung, Hokyoung;Lee, Sungseok;Kim, Chiyoung;Sunwoo, Sunyoung;Lyoo, Young S.
    • Korean Journal of Veterinary Research
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    • v.51 no.2
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    • pp.123-128
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    • 2011
  • Salmonella spp. is an important pathogen to both public and swine industry. The aim of this study was to investigate the distribution of Salmonella serovar and antibiotics susceptibility of the isolates from Korean swine producing systems. A total of 63 (5.28%) Salmonella spp. was isolated from 1,194 samples (977 fecal materials and 67 organ samples). The predominant Salmonella (S.) enterica serotype and serovar was group B (69.8%) and S. Typhimurium (47.6%), S. Derby (20.6%) and S. Heidelberg (1.6%). But S. Cholerasuis which is characterized host specific by septicemia and enteritis to pigs was not isolated. Antimicrobial susceptibility of the isolates varies as follows: Norfloxacine (75%), Ciprofloxacin (67.5%), Amikacin (60%), Colistin (60%), Enrofloxacin (55%). All of isolates were resistant to Erythromycin, Penicillin, Tetracycline and Lincomycin. The results of this study provided useful information regarding antimicrobial susceptibility and resistance patterns to treat salmonellosis and to prevent emergence of multidrug resistance Salmonella.

Studies on Salmonella isolated from chicks (초생추 유래 Salmonella속균의 생물학적 특성)

  • Oh, Gang-hee;Choi, Won-pil
    • 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.

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Evaluation of the extract from lymph nodes for Salmonella monitoring in pig herds (돈군의 Salmonella 모니터링을 위한 림프절 추출액 사용에 대한 평가)

  • Jung, Byeong-Yeal;Choo, Ji-Hoon;Kim, Ji-Hun;Jung, Jae-Yun
    • Korean Journal of Veterinary Research
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    • v.46 no.2
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    • pp.119-125
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    • 2006
  • The objective of this study was to investigate the use of extract from mesenteric lymph nodes as an alternative to serum for ELISA to detect Salmonella antibodies in slaughter pigs. Among 324 slaughter pigs, 65 (20.1 %) were positive in the serum ELISA and 76 (23.5%) were positive in the ELISA with extract from lymph nodes. A total of 24 (7.4%) Salmonella representing 6 serotypes were isolated from mesenteric lymph nodes and 35 (10.8%) Salmonella belonging to 2 serotypes were also recovered from cecal contents of slaughter pig samples, respectively. The most prevalent serogroup was B (55.9% of isolates) and serotype was Typhimurium (52.5% of isolates). In the comparison of the results of between the serum ELISA and Salmonella isolation, kappa value was 0.28 with mesenteric lymph nodes and 0.37 with cecal contents, respectively. However, the extract ELISA had sensitivity of 98.5%, specificity of 95.4% and kappa value of 0.88 as compared with the serum ELISA. Because high degree of concordance between the serum ELISA and the extract ELISA was observed (P=0.24), extract from lymph nodes could be used as an alternative to serum for the detection of Salmonella antibodies in the ELISA.