Kuruca Ljiljana, Klun Ivana, Uzelac Aleksandra, Nikolić Aleksandra, Bobić Branko, Simin Stanislav, Lalošević Vesna, Lalošević Dušan, Djurković-Djaković Olgica
Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, Novi Sad, 21 000, Serbia.
National Reference Laboratory for Toxoplasmosis (NRLToxo), Centre of Excellence for Food- and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, Belgrade, 11129, Serbia.
Parasitol Res. 2017 Nov;116(11):3117-3123. doi: 10.1007/s00436-017-5623-7. Epub 2017 Sep 27.
Insufficiently cooked pork is considered as an important source of human infection with Toxoplasma gondii. The aim of our study was to investigate the presence of T. gondii in pigs intended for human consumption from Northern Serbia. Blood and diaphragm samples were collected from 182 naturally infected market-weight pigs, originating from both commercial farms and smallholdings. Sera were examined using modified agglutination test (MAT), and diaphragms from seropositive, as well as from some MAT-negative pigs, were bioassayed in mice. In addition, digests were examined for the presence of T. gondii DNA using a real-time polymerase chain reaction (qPCR) which was targeted at the 529 bp repetitive element of the T. gondii genome. The overall seroprevalence of T. gondii in pigs was 17% (31/182), with no difference between pigs from large commercial farms (17.8%) and those raised on smallholdings (16.3%). However, the seroprevalence in farm pigs was largely influenced by the findings on a single farm, where all examined animals tested positive. Parasites and/or parasite DNA were detected in the tissues of 15 of the 45 (25 seropositive and 20 seronegative) animals examined by either direct method. Tissue cysts were isolated in eight bioassays and an additional bioassay was positive by serology; all nine were confirmed positive by qPCR. All positive bioassays originated from seropositive pigs, but no correlation was observed between isolation rate and antibody titer. T. gondii DNA was detected in diaphragm tissues of eight pigs, of which three were seronegative. The results of our study provide further evidence for pork as a source of human T. gondii infection.
未煮熟的猪肉被认为是人类感染弓形虫的重要来源。我们研究的目的是调查塞尔维亚北部供人类食用的猪中弓形虫的存在情况。从182头自然感染的市场体重猪采集血液和膈肌样本，这些猪来自商业农场和小农户。血清采用改良凝集试验（MAT）检测，对血清阳性猪以及部分MAT阴性猪的膈肌在小鼠中进行生物测定。此外，使用针对弓形虫基因组529 bp重复元件的实时聚合酶链反应（qPCR）检测消化物中弓形虫DNA的存在情况。猪中弓形虫的总体血清阳性率为17%（31/182），大型商业农场的猪（17.8%）和小农户饲养的猪（16.3%）之间没有差异。然而，农场猪的血清阳性率在很大程度上受到单个农场检测结果的影响，该农场所有检测动物均呈阳性。通过直接方法检测的45只动物（25只血清阳性和20只血清阴性）中的15只动物组织中检测到寄生虫和/或寄生虫DNA。在8次生物测定中分离出组织囊肿，另有1次生物测定血清学呈阳性；所有9次均通过qPCR确认为阳性。所有阳性生物测定均来自血清阳性猪，但未观察到分离率与抗体滴度之间的相关性。在8头猪的膈肌组织中检测到弓形虫DNA，其中3头为血清阴性。我们的研究结果为猪肉作为人类弓形虫感染源提供了进一步的证据。
