Subharat S, Wilson P R, Heuer C, Collins-Emerson J M, Smythe L D, Dohnt M F, Craig S B, Burns M A
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
N Z Vet J. 2011 May;59(3):139-42. doi: 10.1080/00480169.2011.561780.
To investigate the prevalence of Leptospira spp. and possible novel serovar Arborea infection in farmed deer in New Zealand.
In September 2006, five serum samples from a serum bank from each of 70 farms sampled for a previous national prevalence survey were forwarded to the World Health Organisation/Food and Agriculture Organisation/World Organisation for Animal Health (WHO/FAO/OIE) reference laboratory for leptospirosis in Brisbane, Australia, to test for reactivity to a reference panel of 23 serovars, most believed to be exotic to New Zealand, using the microscopic agglutination test (MAT). Eleven farms were seropositive for Arborea, a serovar novel to New Zealand. In July 2007, 126 additional banked serum samples from nine of those 11 farms (n=8-20/farm) were sent to the reference laboratory for similar serology. Two farms in the Southland region were considered positive for serovar Arborea. Tissue from deer kidneys (n=43) from these two farms collected at a deer slaughter premises (DSP) was cultured in November 2007 and November 2008. Sera from those deer were also sent to the laboratory in Brisbane.
From the initial 350 sera, 96 (27.4%) and 19 (5.4%) samples were positive for Leptospira borgpetersenii serovar Hardjo-bovis and Leptospira interrogans serovar Pomona respectively. There were cross-reactions between serovar Hardjo-bovis with serovars Medanensis and Szwajizak. Serological evidence of serovars Tarassovi, Grippotyphosa, Celledoni, Australis, Zanoni, Robinsoni, Canicola, Kremastos, Bulgarica, Cynopteri, Ballum, Bataviae, Djasiman, Javanica, Panama, Shermani and Topaz was negative or sporadic, generally with titres of 1:50 and therefore likely non-specific. Fourteen (4.0%) samples from 11 farms were positive for serovar Arborea, justifying further investigation. The prevalence of serovar Arborea was 15% and 30% on two farms, from the 126 samples. None of 43 kidney and serum samples collected subsequently from those two farms were positive by culture or serology for serovar Arborea.
While there were samples serologically positive for serovar Arborea in deer, attempts to isolate the organism were unsuccessful. The sample size for the follow-up investigation was insufficient to validate the presence or absence of infection, so further study should be undertaken to verify the status of this serovar of Leptospira spp. in New Zealand, in both deer and other livestock species.
调查新西兰养殖鹿群中钩端螺旋体属物种及可能的新型阿勒博雷亚血清型感染的流行情况。
2006年9月，从先前全国流行率调查采样的70个农场的血清库中各选取5份血清样本，送至澳大利亚布里斯班的世界卫生组织/联合国粮食及农业组织/世界动物卫生组织（WHO/FAO/OIE）钩端螺旋体病参考实验室，采用显微镜凝集试验（MAT）检测对一组23种血清型参考菌株的反应性，其中大多数血清型被认为是新西兰外来的。11个农场的阿勒博雷亚血清型呈血清学阳性，该血清型是新西兰的新型血清型。2007年7月，从这11个农场中的9个农场（每个农场8 - 20份）再选取126份储备血清样本送至参考实验室进行类似的血清学检测。南岛地区的两个农场被认为阿勒博雷亚血清型呈阳性。2007年11月和2008年11月，在一家鹿屠宰场（DSP）采集了这两个农场的鹿肾组织（n = 43）进行培养。这些鹿的血清也被送至布里斯班的实验室。
在最初的350份血清中，波摩那钩端螺旋体血清型哈焦 - 博维斯和问号钩端螺旋体血清型波摩那的阳性样本分别为96份（27.4%）和19份（5.4%）。哈焦 - 博维斯血清型与棉兰老岛血清型和斯瓦伊扎克血清型之间存在交叉反应。塔拉索维血清型、致热钩端螺旋体血清型、塞莱多尼血清型、澳大利亚血清型、扎诺尼血清型、罗宾索尼血清型、犬型钩端螺旋体血清型、克雷马斯托血清型、保加利亚血清型、犬蝠血清型、巴鲁姆血清型、爪哇血清型、雅加达血清型、巴拿马血清型、谢尔曼尼血清型和黄玉血清型的血清学证据为阴性或呈散发性，通常效价为1:50，因此可能是非特异性的。来自11个农场的14份（4.0%）样本的阿勒博雷亚血清型呈阳性，有必要进一步调查。在这126份样本中两个农场的阿勒博雷亚血清型流行率分别为15%和30%。随后从这两个农场采集的43份肾和血清样本，经培养或血清学检测，阿勒博雷亚血清型均为阴性。
虽然鹿群中有样本阿勒博雷亚血清型呈血清学阳性，但分离该病原体的尝试未成功。后续调查的样本量不足以验证感染的存在与否，因此应进一步开展研究以核实新西兰鹿及其他家畜物种中该钩端螺旋体血清型的状况。
