Leptospira Hardjo Antibody ELISA Kit

Leptospirosis is a zoonotic, naturally occurring disease caused by pathogenic Leptospira of different serotypes. The disease is widely prevalent in both humans and animals, with a large number of animal hosts, a wide geographic distribution, and a variety of clinical manifestations that are harmful to both humans and animals. Leptospira is spiral in shape, with one or both ends curved in a hook-like shape, showing an active rotational movement under the dark-field microscope, with strong tissue penetration. Its genome is about 5000kb, divided into 4400kb and 350kb parts, with a GC content of 35-41%. Based on genome-wide analyses, 66 species of Leptospira have been identified.

Animal leptospirosis is fundamentally different from human leptospirosis in terms of epidemiology, pathogenesis, clinical features, diagnostic requirements and control measures. Animal leptospirosis is characterized by acute clinical features of the human disease, but also by chronic infections that can cause significant economic losses due to reduced fertility. Bovine leptospirosis is one of the diseases causing the greatest economic losses in the cattle industry and poses a major obstacle to increasing livestock numbers, sustaining local demand for meat and dairy products, and improving the global competitiveness of these products.

Bovine leptospirosis is mainly caused by serovar Hardjo and has been recognised in two species, L. interrogans serovar Hardjo (HP) and L. borgpetersenii serovar Hardjo (HB), with the latter being the most prevalent globally. Because the rfb locus, which contains the genes coding for proteins involved in LPS biosynthesis, is highly conserved, the two species are similar in antigenicity. Both HB and HP were able to colonise and survive in the reproductive tracts of infected cows and bulls, suggesting that sexual transmission may be a factor in transmission. The main risk factors for Hardjo infection in cattle have been identified as open herds, co-grazing with sheep, use of contaminated water sources, and herd size. The acute phase of clinical disease in serotype Hardjo infection is usually subclinical, but lactating cows may develop agalactia. Abortion, stillbirths, preterm births, birth of weak calves and loss of birth weight are the most important economic problems associated with chronic leptospirosis in cattle. In episodic infections, abortion occurred 4-6 weeks after acute illness, but in Hardjo's infection the interval was longer, 6-12 weeks.

Figure 1. Schematic of key signs of bovine leptospirosis
(Source: Aymée L, et al. 2024)

Leptospira serovar Hardjo