Maddock Kelli J, Stenger Brianna L S, Pecoraro Heidi L, Roberts Jill C, Loy John Dustin, Webb Brett T
Veterinary Diagnostic Laboratory, North Dakota State University, Fargo, ND, USA.
College of Public Health, University of South Florida, Tampa, FL, USA.
J Vet Diagn Invest. 2025 May 24:10406387251342528. doi: 10.1177/10406387251342528.
Hemorrhagic septicemia-causing strains of are endemic in Asia and Africa, but naturally occurring hemorrhagic septicemia has not been described in livestock in the United States since 1993. There are 5 capsular types of : A, B, D, E, and F. Two capsular types (B, E) cause hemorrhagic septicemia, whereas capsular types A and, to a lesser extent, D are associated with enzootic bovine pneumonia. Here we describe 2 naturally occurring cases of hemorrhagic septicemia caused by capsular type B:3,4 in the United States, including molecular characterization of these strains, with a comparison to available reference strains and publicly available genomes of capsular type B. Genomic analyses demonstrated that our case strains are similar to a strain isolated from New Jersey cattle in 1968 and to contemporaneous strains from New Zealand and Canada. These strains are different from those circulating globally, as demonstrated by the need to assign new sequence types for our isolates. Hemorrhagic septicemia appears to be re-emerging globally in countries that have not seen outbreaks in decades and may be poised for re-emergence in the United States given the identification of these novel strains.
引起出血性败血症的菌株在亚洲和非洲呈地方性流行，但自1993年以来，美国牲畜中尚未有自然发生的出血性败血症的报道。有5种荚膜类型：A、B、D、E和F。两种荚膜类型（B、E）会引起出血性败血症，而荚膜类型A以及程度较轻的D与地方流行性牛肺炎有关。在此，我们描述了美国2例由B型荚膜菌株引起的自然发生的出血性败血症病例：3,4，包括这些菌株的分子特征，并与可用的参考菌株以及公开可用的B型荚膜基因组进行了比较。基因组分析表明，我们的病例菌株与1968年从新泽西州牛分离出的菌株以及来自新西兰和加拿大的同期菌株相似。这些菌株与全球流行的菌株不同，这从为我们的分离株指定新的序列类型可以看出。出血性败血症似乎在数十年来未出现疫情的国家全球范围内再度出现，鉴于这些新菌株的发现，美国也可能会再度出现疫情。
