Molecular and serological characterization of pathogenic Leptospira spp. isolated from symptomatic dogs in a highly endemic area, Brazil.

Background: Leptospirosis is an endemic zoonosis in Brazil, with a great impact on human and animal health. Although dogs are frequently infected by pathogenic Leptospira, the current epidemiological understanding of canine leptospirosis is mainly based on serological tests that predict the infecting serogroup/serovar. Thus, the present study aimed at identifying the causative agent for severe cases of canine leptospirosis in a highly endemic area through the isolation and characterization of the isolated strains.

Improvement of the enrichment used in the EMJH medium (Ellinghausen-McCullough-Johnson-Harris) for the cultivation of Leptospira spp.

Changes were made to the original formulation of the EMJH medium (Ellinghausen-McCullough-Johnson-Harris) enrichment and some aspects such as growth time of Leptospira and utilization in the microscopic agglutination test (MAT) were evaluated and compared to the original enrichment and to a commercially available enrichment (DIFCO™). Leptospira samples (24 antigens) that make up our panel of antigens used in MAT were used, among them, reference and autochthonous strains isolated in Brazil. The samples were grown individually in the EMJH medium under the three previously mentioned conditions (adapted enrichment, original enrichment and commercial enrichment).

Isolation of an atypical Leptospira strain assigned to the Sejroe serogroup from a water buffalo in Brazil.

The isolation of leptospires from buffaloes worldwide is still limited to a few strains. Thus, the aim of this study was to describe the first Leptospira isolate from buffalo urine, assigned to the Sejroe serogroup, which does not belong to the Wolffi subgroup, traditionally isolated in Brazil. A total of 244 urine samples of water buffaloes (Bubalus bubalis) raised in the Brazilian Amazon were subjected to bacteriological culturing and polymerase chain reaction (PCR) for the detection of leptospires.

Usefulness of the Ranking Technique in the Microscopic Agglutination Test (MAT) to Predict the Most Likely Infecting Serogroup of .

The microscopic agglutination test (MAT) used for the serological diagnosis of leptospirosis, as a robust and inexpensive method, is still the reality in many laboratories worldwide. Both the performance and the interpretation of the MAT vary from region to region, making standardization difficult. The prediction of the probable infecting serogroup using this test is indispensable for elucidating the epidemiology of the disease; however, in veterinary medicine, many studies consider any reaction detected with a titer of 100, which may ultimately overestimate some serogroups.

Leptospira interrogans serogroup Pomona strains isolated from river buffaloes.

At present, little is known regarding the prevalence of buffalo leptospirosis worldwide, especially with respect to which Leptospira strains may infect this animal species. Furthermore, most investigations into this disease in buffaloes have only been performed with serological studies. In Brazil, particularly in the Amazon, buffalo production is growing and is just as important as cattle production, although few studies have been performed on buffalo compared to cattle.

Leptospira strains isolated from cattle in the Amazon region, Brazil, evidence of a variety of species and serogroups with a high frequency of the Sejroe serogroup.

In Brazil, there have been few leptospires isolated from cattle, especially in the Amazon, implying that the epidemiology of the disease in this region is still largely unclear. In a previous study, 52 Leptospira isolates were obtained from urine of cattle raised in the Brazilian Amazon and, to achieve a greater understanding of Leptospira infection in cattle of this region, the present study aimed to serologically and molecularly characterizes all these isolates. The laboratory assays used were the microscopic agglutination test (MAT) adopting a panel of polyclonal antisera against Leptospira spp.

Leptospira transport medium (LTM): A practical tool for leptospires isolation.

The isolation of Leptospira is challenging, since the bacteria of this genus are susceptible to adverse environmental conditions and may not remain viable for extend periods in urine samples. This study attempted to develop and evaluate a simple and practical method to isolate leptospires from bovine urine samples. A culture medium for sample transport, named Leptospira Transport Medium (LTM), was described and validated using reference serovars of Leptospira spp.

Identification of Pathogenic Species in the Urogenital Tract of Water Buffaloes () From the Amazon River Delta Region, Brazil.

In the current context of deforestation and fire in the Amazon, buffaloes could be a cost-effective and sustainable alternative for cattle production in the region, as they can convert low-quality foods and be raised in floodplain areas. However, little is known about the reproductive diseases that affect these animals; thus, the purpose of this study was to perform the molecular characterization of spp. in the urogenital tract of water buffaloes () raised in the Amazon River Delta region in Brazil.

Prevalence of Leptospira serogroups in buffaloes from the Brazilian Amazon.

Although Brazil has one of the largest buffalo populations in the Americas, buffalo leptospirosis is still poorly explored when compared to that in bovines; thus, the aim of this research was to carry out a large serological study for leptospirosis in this species in the Brazilian Amazon. For this, we collected 1,405 serum samples from buffaloes raised in the Amazon delta region, which is considered a major area of buffalo production in Brazil. The test used was a microscopic agglutination test (MAT) adopting 34 Leptospira antigens, some of which have never been tested for buffaloes in Brazil, including autochthonous strains; in total, 20 serogroups were evaluated.

Frequency of anti- spp. antibodies in dogs and wild small mammals from rural properties and conservation units in southern Brazil.

Leptospirosis is a disease of worldwide distribution that affects man and several animal species. Domestic and wild animals can behave as reservoirs of the agent. The aim of this study was to evaluate the frequency of anti- spp.

Development of a pooled antigen for use in the macroscopic slide agglutination test (MSAT) to detect Sejroe serogroup exposure in cattle.

This study aimed to develop and evaluate a pooled antigen for use in the macroscopic slide agglutination test (MSAT) to detect cattle positive for the Sejroe serogroup. To this end, 193 bovine serum samples from different Pará State regions (Amazonia) were subjected to a reference microscopic agglutination test (MAT) for the serological diagnosis of leptospirosis using 11 serovars representing the Sejroe serogroup: Hardjo-prajitno; Hardjo-bovis; Sejroe; Wolffi; Guaricura (Bov.G.

Circulating Leptospira species identified in cattle of the Brazilian Amazon.

The present study aimed to detect the most prevalent serogroups and circulating Leptospira species in cows from Brazilian Amazon. Samples of blood serum, urine and kidney of 208 animals were collected at a municipal slaughterhouse in the Baixo Tocantins region of Pará State, Northern Brazil. The tests used were microscopic agglutination test (MAT), bacteriological isolation, polymerase chain reaction (PCR) and DNA sequencing.