Petri Fernando Moreira, Nogueira Giovana da Silva, Simão Gustavo M R, Panneitz Ana K, de Aguiar Gabriel A, de Lima Ana Clara A, Braga Eduarda R, do Carmo Kellem, Kuchiishi Suzana S, Reis Adrienny T, Vannucci Fabio A, de Oliveira Luís Guilherme
School of Agricultural and Veterinary Sciences, São Paulo State University (Unesp), Jaboticabal 14884-900, São Paulo, Brazil.
Agroceres PIC Company, Rio Claro 13502-741, São Paulo, Brazil.
Transbound Emerg Dis. 2025 Sep 5;2025:5618952. doi: 10.1155/tbed/5618952. eCollection 2025.
(.) is an emerging pathogen previously described in fish and more recently isolated from a clinical outbreak in swine. This study aimed to evaluate the course of infection and pathological outcomes of in pigs using an experimental intradermal challenge model. Twenty-six 70-day-old pigs were randomly allocated into three groups: high-dose (HD group, = 10) and low-dose (LD group, = 10) were challenged intradermally with 10 colony forming units (CFUs) and 10 CFU using a Brazilian field isolate obtained from a pig with erysipelas-like lesions and confirmed by whole-genome sequencing (WGS) and average nucleotide identity (ANI), respectively, while CONT (control, = 6) served as a negative control. Clinical monitoring, hematological assessments, acute-phase proteins (APPs) quantification, bacteriological culture, and quantitative PCR (qPCR) targeting the gene were performed over 14 days. Challenged pigs developed mild clinical signs, including transient fever and characteristic rhomboid skin lesions resembling classical swine erysipelas. No mortality occurred. Hematological analysis revealed significant reductions in red blood cell (RBC) count, hemoglobin (HGB), and hematocrit (HCT), particularly in the LD group at 7 and 14 days post-challenge (dpc) ( < 0.05), suggestive of inflammatory anemia. APP analysis showed a significant increase in ceruloplasmin across all groups over time, whereas transferrin levels decreased only in the control group. Bacterial isolation was unsuccessful; however, qPCR detected deoxyribonucleic acid (DNA) in blood, skin, liver, and spleen samples, confirming systemic dissemination, particularly at 7 dpc. These findings demonstrate that can induce clinical and pathological alterations in swine, although with mild severity under experimental conditions. Moreover, the study highlights the importance of differentiating from in diagnostics, given the potential limitations of current vaccine strategies.
（.）是一种新兴病原体，此前在鱼类中有所描述，最近从猪的一次临床疫情中分离出来。本研究旨在使用实验性皮内攻击模型评估（.）在猪体内的感染过程和病理结果。26头70日龄仔猪被随机分为三组：高剂量组（HD组，n = 10）和低剂量组（LD组，n = 10）分别使用从一头患有类丹毒病变的猪身上获得的巴西田间分离株进行皮内攻击，剂量分别为10个菌落形成单位（CFU）和10 CFU，并分别通过全基因组测序（WGS）和平均核苷酸同一性（ANI）进行确认，而CONT组（对照组，n = 6）作为阴性对照。在14天内进行了临床监测、血液学评估、急性期蛋白（APPs）定量、细菌培养以及针对（.）基因的定量PCR（qPCR）。受攻击的猪出现了轻度临床症状，包括短暂发热和类似经典猪丹毒的特征性菱形皮肤病变。未发生死亡。血液学分析显示红细胞（RBC）计数、血红蛋白（HGB）和血细胞比容（HCT）显著降低，尤其是在攻击后7天和14天的LD组（P < 0.05），提示炎症性贫血。APP分析显示，随着时间的推移，所有组的铜蓝蛋白均显著增加，而转铁蛋白水平仅在对照组中降低。细菌分离未成功；然而，qPCR在血液、皮肤、肝脏和脾脏样本中检测到了（.）脱氧核糖核酸（DNA），证实了全身播散，尤其是在攻击后7天。这些发现表明，（.）可在猪体内诱导临床和病理改变，尽管在实验条件下严重程度较轻。此外，鉴于当前疫苗策略的潜在局限性，该研究强调了在诊断中区分（.）与（.）的重要性。
