Sapporo City General Hospital, Sapporo, Hokkaido, Japan.
National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan.
J Med Microbiol. 2020 Oct;69(10):1249-1252. doi: 10.1099/jmm.0.001252. Epub 2020 Sep 14.
is a zoonotic pathogen that causes erysipelas in a variety of animals. In humans, in contrast to the cutaneous form called erysipeloid, which is an occupational disease and common in individuals who handle raw meat and fish, invasive systemic infections are unusual. expresses an immunogenic surface protein, Spa (surface protective antigen), which is involved in virulence. Among the antigenically different Spa proteins (SpaA, B and C), which are mostly associated with serovars, SpaA is by far the most prevalent in isolates from diseased animals. However, the Spa type has not been examined for human isolates, and it is unknown whether SpaB- or SpaC-possessing isolates can cause disease in humans. A Gram-positive, rod-shaped bacterium isolated from a case of human pyogenic spondylitis was analysed. The bacterium was identified as by a routine biochemical test and MS, and ultimately confirmed by an -specific PCR assay. Spa typing by sequencing revealed the SpaB type, and the serovar of the strain was identified as untypeable by a conventional agar gel precipitation test, but determined to be serovar 6 by a serotyping PCR assay. Sequence analysis of the serovar-defining chromosomal region revealed that the isolate displayed the same gene organization as the serovar 6 reference strain, but the region was disrupted by an insertion sequence element, suggesting that the isolate originated from a serovar 6 strain. These results highlight that unusual, -possessing strains can potentially pose serious risks to humans.
是一种人畜共患病病原体，可引起多种动物的丹毒。与职业性的、常见于处理生肉和生鱼人群的皮肤型丹毒（称类丹毒）不同，人类发生侵袭性全身感染较为罕见。表达一种免疫原性表面蛋白 Spa（表面保护性抗原），该蛋白与毒力有关。在抗原性不同的 Spa 蛋白（SpaA、B 和 C）中，大多数与血清型相关，SpaA 是迄今为止在患病动物分离株中最常见的。然而，尚未对人类分离株进行 Spa 型分析，也不知道是否具有 SpaB 或 SpaC 的分离株可引起人类疾病。从一例人类化脓性脊椎炎病例中分离出一株革兰阳性、杆状细菌进行了分析。通过常规生化试验和 MS 鉴定该细菌为 ，最终通过特异性 PCR 检测得到确认。通过测序进行 Spa 型分析显示为 SpaB 型，该菌株的血清型通过常规琼脂凝胶沉淀试验无法定型，但通过血清分型 PCR 检测确定为血清型 6。对血清型决定染色体区的序列分析显示，该分离株显示与血清型 6 参考株相同的基因组织，但该区域被插入序列元件破坏，提示该分离株源自血清型 6 菌株。这些结果强调了具有不常见血清型和 Spa 型的 菌株可能对人类构成严重威胁。
