Laboratorio de Virología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, calle 60 y 118 s/n, La Plata, Argentina; CONICET, Godoy Cruz 2290, CABA, Argentina.
CONICET, Godoy Cruz 2290, CABA, Argentina.
Infect Genet Evol. 2021 Apr;89:104735. doi: 10.1016/j.meegid.2021.104735. Epub 2021 Jan 29.
Porcine circovirus type 2 (PCV2) and protoparvovirus 1 (PPV) were detected as single infection (6/131) and (11/131) respectively, or co-infection (6/131) in fetuses and stillborn piglets from normal deliveries in a farm without reproductive problems. Twenty in twenty-three positive samples were over 70 days of gestation, which is when the fetus becomes immunocompetent, and the presence of a NADL-2 PPV strain suggests fetal immune system impairment. Phylogenetic analysis of sequences obtained showed that 8/9 sequences are related to cluster 13 and the remaining is grouped into cluster 11 sequences. An increase in variability in ORF2 sequences in Argentina was observed. It is not clear whether the detection of fetuses positive to PPV and PCV2 is of epidemiological importance in a subclinically affected farm. However, the results of this study showed that currently used vaccines and vaccine protocols do not fully protect against PPV or PCV2 fetus infection.
猪圆环病毒 2 型(PCV2)和细小病毒 1 型(PPV)分别作为单一感染(6/131)和(11/131),或在没有生殖问题的农场中正常分娩的胎儿和死胎仔猪中共同感染(6/131)被检测到。在 23 个阳性样本中,有 20 个处于妊娠 70 天以上,此时胎儿具有免疫能力,而 NADL-2 PPV 株的存在表明胎儿免疫系统受损。获得的序列的系统发育分析表明,9 个序列中的 8 个与第 13 簇有关,其余序列分为第 11 簇序列。在阿根廷观察到 ORF2 序列的变异性增加。目前尚不清楚在亚临床受影响的农场中,检测到对 PPV 和 PCV2 呈阳性的胎儿是否具有流行病学意义。然而,本研究结果表明,目前使用的疫苗和疫苗方案不能完全保护胎儿免受 PPV 或 PCV2 的感染。