Ruggeri J, Pesciaroli M, Gaetarelli B, Scaglione F E, Pregel P, Ammendola S, Battistoni A, Bollo E, Alborali G L, Pasquali P
Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, 25124 Brescia, Italy.
Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, 00161 Rome, Italy; FAO Reference Center for Veterinary Public Health, Italy; VISAVET Health Surveillance Centre, Universidad Complutense Madrid, 28040 Madrid, Spain.
Vaccine. 2014 Jul 7;32(32):4032-8. doi: 10.1016/j.vaccine.2014.05.066. Epub 2014 Jun 4.
A major cause of salmonellosis in humans is the contamination of pork products. Infection in pigs can be controlled using bio-security programs, but they are not sufficient in countries where a high level of infection is recorded. In this context, the use of vaccines can represent a valid supplementary method of control. Recently, we have demonstrated that an attenuated strain of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium ΔznuABC) is protective against systemic and enteric salmonellosis in mouse and pig infection models, candidating this strain as an oral attenuated vaccine. In this study, we compared the efficacy of this attenuated Salmonella Typhimurium strain when administered orally or parenterally. Furthermore, in order to reproduce a pseudo-natural infection model, vaccinated pigs were allocated in the same pen with animals shedding virulent Salmonella Typhimurium. Animals were monitored weekly after vaccination and contact with infected piglets. Diarrhea and ataxia were recorded and Salmonella shedding was tested individually through bacterial culture. After four weeks of cohousing, piglets were euthanized, after which lymph nodes reactivity and gross lesions of the gut sections were scored at necropsy. Organs were submitted to microbiological and histological analyses. The data reported herein show that parenterally vaccinated animals do not shed the attenuated strain, and at the same time the absence of symptoms and decrease in virulent strain shedding in feces from day 6 after challenge demonstrated protection against infection induced by virulent Salmonella Typhimurium. In conclusion, our findings suggest that this is an alternative route of Salmonella Typhimurium ΔznuABC administration, without ignoring the advantages associated with oral vaccination.
人类沙门氏菌病的一个主要原因是猪肉产品受到污染。猪的感染可以通过生物安全计划来控制，但在记录到高感染水平的国家，这些计划并不充分。在这种情况下，使用疫苗可能是一种有效的补充控制方法。最近，我们已经证明，肠炎沙门氏菌鼠伤寒血清型的减毒株（鼠伤寒沙门氏菌ΔznuABC）在小鼠和猪感染模型中对全身性和肠道沙门氏菌病具有保护作用，使该菌株成为一种口服减毒疫苗的候选菌株。在本研究中，我们比较了这种减毒鼠伤寒沙门氏菌菌株经口服或胃肠外给药时的效果。此外，为了重现一个伪自然感染模型，将接种疫苗的猪与排出有毒力的鼠伤寒沙门氏菌的动物放在同一栏中。在接种疫苗以及与感染仔猪接触后，每周对动物进行监测。记录腹泻和共济失调情况，并通过细菌培养单独检测沙门氏菌的排出情况。混养四周后，对仔猪实施安乐死，然后在尸检时对淋巴结反应性和肠道切片的大体病变进行评分。将器官进行微生物学和组织学分析。本文报道的数据表明，经胃肠外接种疫苗的动物不会排出减毒株，同时在攻毒后第6天，粪便中无毒力菌株排出且无症状，这表明对有毒力的鼠伤寒沙门氏菌诱导的感染具有保护作用。总之，我们的研究结果表明，这是鼠伤寒沙门氏菌ΔznuABC给药的一种替代途径，同时也没有忽视口服疫苗的优点。
