多重耐药猪沙门氏菌耐药机制及抑制剂研究

Porcine salmonella disease is a conditional infective disease caused by salmonella, which brought enormous economic lost and influenced human health, as it often leads to animal death,and which can be transferred to human. Recently, the drug resistance of porcine salmonella increased dramatically, and most of the drug resistance belongs to multidrug resistance, which was concerned world widely. In our previous study, we analyzed 9 porcine salmonella which identified from different porcine faces from different regions, and found that the strain 104, 105 and 134 were sensitive to antimicrobial,the strain 192, 193 and D12 were resistant to all the tested antimicrobial. In this project, we plan to.analyze the mechanism of multidrug resistance of porcine salmonella systematically through transcriptome sequencing and comparative proteomic analysis, and verify the multidrug resistance related candidate genes' function by depletion assay. Furthermore, we plan to determine the effect of the inhibitor of multidrug resistance to porcine salmonella. This study is valuable to understand the mechanism of multidrug resistance of porcine salmonella systematically and can provide clues for the new veterinary drug design.

猪沙门氏菌病是由致病性沙门氏菌引起的一种猪条件性传染病，常引起较高的畜禽死亡率，并可传播给人类，给养猪业及人类健康造成了很大的危害。近年来，猪沙门氏菌的耐药性逐渐增加，且以多重耐药为主，越来越引起世界范围的广泛关注。在前期研究中，对临床分离的猪沙门氏菌进行药敏性分析发现，菌株104、105 和134 等对供试抗生素较为敏感，菌株192、193和D12等耐药性较强，呈多重耐药。本研究拟通过比较转录组学和蛋白质组学等技术，分析多重抗生素作用下3株不同来源的多重耐药猪沙门氏菌的共同表达基因、3株不同来源的抗生素敏感猪沙门氏菌的共同表达基因及多重耐药菌与敏感菌的共同差异基因，获得多重耐药相关基因网络，并通过基因缺失验证多重耐药性相关主要候选基因的功能。进一步分析常见中草药及制剂对多重耐药猪沙门氏菌的作用效果。本研究有望系统认识猪沙门氏菌的多重耐药机制，可为猪沙门氏菌新药的开发提供理论依据。

本研究以临床分离的多重耐药沙门氏菌和非耐药沙门氏菌为研究对象，采用比较蛋白质组学的方法分析发现多重耐药菌中高表达的蛋白主要集中在四个生物学通路，包括鞭毛运动与细菌的趋化性、糖类和脂类代谢、氨基酸代谢和能量代谢，其中尤以鞭毛运动和细菌趋化性通路中蛋白差异最为显著，提示细菌的鞭毛运动能力和细菌趋化性可能和细菌的多重耐药性密切相关。进一步研究发现非耐药菌A60周身无鞭毛，其泳动性完全消失，鞭毛结构蛋白FliC不能正确表达和分泌，鞭毛结构蛋白FlgK、FliD、FlgL表达正常，但不能正确分泌，毒力因子SipA、SipB、SipC和SipD均表达正常和分泌正常。研究结果表明沙门氏菌的多重耐药性可能和其泳动性相关，A60泳动性缺陷与FliC基因的非正常表达有关，但FliC的表达调节机制还有待进一步阐明。研究结果对沙门氏菌的防控具有重要理论意义。