Isolation and molecular characterization of Leptospira borgpetersenii serovar Hardjo strain Hardjobovis in the urine of naturally infected cattle in Brazil.

Most epidemiologic studies on bovine leptospirosis are based on serological tests that use antibodies against several serotypes, including the serovar Hardjo, which is widespread and considered to be the most adapted to bovine hosts. However, using only serological studies is not sufficient to identify and distinguish species of leptospires. The aim of this study was report the first isolation in Brazil of two strains serovar Hardjo obtained in urine samples from naturally infected cows in a small Brazilian dairy herd and find the genetic species and consequently the type strain Hardjobovis by molecular characterization. Fifteen dairy cows with a history of reproductive failure, such as abortion and infertility, were selected. Urine samples obtained from each animal were immediately seeded in tubes containing Ellinghausen-McCullough-Johnson-Harris culture medium. The identification of the isolates was performed by Multilocus variable-number tandem-repeat analysis (MLVA) technique and phylogenetic analysis of partial sequence of gene sec Y. From the 15 urine samples evaluated, two Leptospira were found and identified as the Londrina 49 and Londrina 54 strains. The MLVA profiles and sequencing of gene sec Y characterized the isolates as L. borgpetersenii serovar Hardjo strain Hadjobovis because it has different genetic pattern of Leptospira interrogans serovar Hardjo strain Hardjoprajitno. Therefore, more studies are needed including isolation and molecular characterization from regional strains to obtain a better knowledge about epidemiology of serovar Hardjo in bovine which may assist in future strategies of prevention and control of bovine leptospirosis.

Eficácia do dipropionato de imidocarb, da enrofloxacina e do cloridrato de oxitetraciclina no tratamento de bovinos naturalmente infectados por Anaplasma marginale / Efficacy of imidocarb dipropionate, enrofloxacin and oxytetracycline chlorydrate on the treatment of cattle naturally infected by Anaplasma marginale

O agente de maior importância, em relação à anaplasmose bovina, é o Anaplasma marginale. Os principais sinais clínicos dessa enfermidade são anemia hemolítica, icterícia, dispneia, taquicardia, febre, fadiga, lacrimejamento, sialorreia, micção frequente, anorexia, perda de peso, aborto e morte. A terapia antimicrobiana é o principal protocolo terapêutico. O objetivo do presente trabalho foi avaliar a eficácia do dipropionato de imidocarb, da enrofloxacina e do cloridrato de oxitetraciclina no tratamento de bovinos leiteiros naturalmente infectados por Anaplasma marginale. Para isso, foram avaliados 48 zebuínos mestiços que apresentavam os sinais clínicos sugestivos da doença. Os animais foram submetidos à coleta de sangue para a realização de hemograma e à extração de DNA para a confirmação da presença de A. marginale, por meio da reação em cadeia pela polimerase (PCR). Os animais foram divididos em três grupos experimentais, para realização dos protocolos terapêuticos, utilizando-se dipropionato de imidocarb, oxitetraciclina e enrofloxacina. Trinta e seis animais (75%) apresentaram reação positiva ao PCR. Os animais positivos não apresentaram diferenças significativas quanto ao hemograma e ao leucograma quando comparados com os negativos, no entanto os níveis de proteínas séricas foram inferiores nos animais positivos (P<0,05). Os três protocolos terapêuticos foram capazes de reduzir a infecção ao longo do tratamento (P<0,01), porém, após cinco dias de tratamento, a enrofloxacina apresentou maior efetividade em relação aos demais (P<0,01). Após o final do tratamento, nenhum protocolo foi capaz de eliminar totalmente a infecção pelo A. marginale em bovinos naturalmente infectados e manejados a campo.

Anaplasma marginale is the most important agent regarding cattle anaplasmosis. The main clinical signs of this disease are hemolitic anemia, jaundice, dyspnea, tachycardia, fever, fatigue, lacrimation, salivation, frequent urination, anorexia, weight loss, abortion and death. Antimicrobial therapy is the main therapeutic protocol. The aim of this paper was to assess the efficacy of this therapy frequently used in field conditions. In order to do so, 48 crossbred zebu cattle presenting suggestive clinical signs of the disease were assessed. The animals were submitted to blood sample collection to perform a CBC and DNA extraction to confirm the presence of A. marginale by the polymerase chain reaction (PCR) test. The animals were divided into three experimental groups to perform the therapeutic protocols, using imidocarb dipropionate, enrofloxacin and oxytetracycline. Thirty-six animals (75%) presented positive reaction to PCR. The positive animals do not present significant differences in the CBC and WBC when compared to the negative ones. However, the serum protein levels were lower in positive animals (P<0.05). All the treatments were able to reduce the infection throughout the treatment (P<0.01). However, in time 1, enrofloxacin presented greater effectiveness in relation to the other ones (P<0.01). After the end of the treatment no protocol was able to totally eliminate the infection by A. marginale in cattle naturaly infected and handled on the field.