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Zuo J, Yin H, Hu J, Miao J, Chen Z, Qi K, Wang Z, Gong J, Phouthapane V, Jiang W, Mi R, Huang Y, Wang C, Han X. Lsr operon is associated with AI-2 transfer and pathogenicity in avian pathogenic Escherichia coli. Vet Res 2019; 50:109. [PMID: 31831050 PMCID: PMC6909531 DOI: 10.1186/s13567-019-0725-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 11/12/2019] [Indexed: 12/26/2022] Open
Abstract
The function of Autoinducer-2 (AI-2) which acts as the signal molecule of LuxS-mediated quorum sensing, is regulated through the lsr operon (which includes eight genes: lsrK, lsrR, lsrA, lsrC, lsrD, lsrB, lsrF, and lsrG). However, the functions of the lsr operon remain unclear in avian pathogenic Escherichia coli (APEC), which causes severe respiratory and systemic diseases in poultry. In this study, the presence of the lsr operon in 60 APEC clinical strains (serotypes O1, O2, and O78) was investigated and found to be correlated with serotype and has the highest detection rate in O78. The AI-2 binding capacity of recombinant protein LsrB of APEC (APEC-LsrB) was verified and was found to bind to AI-2 in vitro. In addition, the lsr operon was mutated in an APEC strain (APEC94Δlsr(Cm)) and the mutant was found to be defective in motility and AI-2 uptake. Furthermore, deletion of the lsr operon attenuated the virulence of APEC, with the LD50 of APEC94Δlsr(Cm) decreasing 294-fold compared with wild-type strain APEC94. The bacterial load in the blood, liver, spleen, and kidneys of ducks infected with APEC94Δlsr(Cm) decreased significantly (p < 0.0001). The results of transcriptional analysis showed that 62 genes were up-regulated and 415 genes were down-regulated in APEC94Δlsr(Cm) compared with the wild-type strain and some of the down-regulated genes were associated with the virulence of APEC. In conclusion, our study suggests that lsr operon plays a role in the pathogenesis of APEC.
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Affiliation(s)
- Jiakun Zuo
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China.,College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Huifang Yin
- College of Life Science, Longyan University, Longyan, 364000, People's Republic of China
| | - Jiangang Hu
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China.,College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, People's Republic of China
| | - Jinfeng Miao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Zhaoguo Chen
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China
| | - Kezong Qi
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, People's Republic of China
| | - Zhihao Wang
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China.,College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, People's Republic of China
| | - Jiansen Gong
- Poultry Institute, Chinese Academy of Agricultural Sciences, Yangzhou, 225125, People's Republic of China
| | - Vanhnaseng Phouthapane
- Biotechnology and Ecology Institute, Ministry of Science and Technology (MOST), Vientiane, 22797, Lao PDR
| | - Wei Jiang
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China
| | - Rongsheng Mi
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China
| | - Yan Huang
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China
| | - Chen Wang
- College of Animal Science and Technology, Henan University of Science and Technology, No. 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China.
| | - Xiangan Han
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, 200241, People's Republic of China.
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Koutsoumanis K, Allende A, Alvarez-Ordóñez A, Bolton D, Bover-Cid S, Chemaly M, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Dewulf J, Hald T, Michel V, Niskanen T, Ricci A, Snary E, Boelaert F, Messens W, Davies R. Salmonella control in poultry flocks and its public health impact. EFSA J 2019; 17:e05596. [PMID: 32626222 PMCID: PMC7009056 DOI: 10.2903/j.efsa.2019.5596] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
An increase in confirmed human salmonellosis cases in the EU after 2014 triggered investigation of contributory factors and control options in poultry production. Reconsideration of the five current target serovars for breeding hens showed that there is justification for retaining Salmonella Enteritidis, Salmonella Typhimurium (including monophasic variants) and Salmonella Infantis, while Salmonella Virchow and Salmonella Hadar could be replaced by Salmonella Kentucky and either Salmonella Heidelberg, Salmonella Thompson or a variable serovar in national prevalence targets. However, a target that incorporates all serovars is expected to be more effective as the most relevant serovars in breeding flocks vary between Member State (MS) and over time. Achievement of a 1% target for the current target serovars in laying hen flocks is estimated to be reduced by 254,400 CrI95[98,540; 602,700] compared to the situation in 2016. This translates to a reduction of 53.4% CrI95[39.1; 65.7] considering the layer-associated human salmonellosis true cases and 6.2% considering the overall human salmonellosis true cases in the 23 MSs included in attribution modelling. A review of risk factors for Salmonella in laying hens revealed that overall evidence points to a lower occurrence in non-cage compared to cage systems. A conclusion on the effect of outdoor access or impact of the shift from conventional to enriched cages could not be reached. A similar review for broiler chickens concluded that the evidence that outdoor access affects the occurrence of Salmonella is inconclusive. There is conclusive evidence that an increased stocking density, larger farms and stress result in increased occurrence, persistence and spread of Salmonella in laying hen flocks. Based on scientific evidence, an impact of Salmonella control programmes, apart from general hygiene procedures, on the prevalence of Campylobacter in broiler flocks at the holding and on broiler meat at the end of the slaughter process is not expected.
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