FITOTERAPIA NO CONTROLE DO Rhipicephalus (boophilus) microplus, AGENTE CAUSADOR DA DOENÇA “TRISTEZA PARASITÁRIA”: UMA REVISÃO DE LITERATURA

Os Rhipicephalus (boophilus) microplus, carrapatos bovinos são hematófagos e vetores de agentes patogênicos (bactéria Anaplasma marginale e protozoários do gênero Babesia sp.) aos animais e seres humanos. São ectoparasitos causadores de prejuízos econômicos na produção de leite, na produção de carne e mortalidade dos animais. Os bovinos sofrem com reações alérgicas, estresse, ferimentos causados no couro e por outras doenças relacionadas. A perda de peso e a diminuição leiteira das matrizes podem ocorrer devido ao agravo ocasionado. A doença Tristeza Parasitária correlaciona duas patogenias a Babesiose e a Anaplasmose. A resistência destes vetores para a Tristeza Parasitária nos rebanhos se deu, devido ao uso abusivo de acaricidas no tratamento químico. Este tratamento além de não ser garantia de cura aos bovinos, seu efeito agride os animais e o meio ambiente através de resíduos deixados. Os fitoterápicos utilizados como carrapaticidas oferecem menores danos aos animais e ao meio ambiente. Os fitoterápicos: Óleo de Neen (Azadirachta indica), Citronela de Java (Cymbopogon winterianus) e Citronela de Ceilão (Cymbopogon nardus L.), Hortelã ou Mentha piperita, Eucalipto (Eucalyptus spp.), Extrato de Jenipapo (Genipa americana), Alho orgânico (Allium sativum L.), Fumo em corda (Nicotiana tabacum), Melaleuca alternifólia, apresentaram um controle eficiente aos parasitos e repeliram também, outras doenças oportunistas recorrentes. Além de contribuírem para a saúde dos bovinos, bem como para a preservação do meio ambiente, e um impacto econômico de menor custo aos criadores. O objetivo deste trabalho é salientar o efeito dos fitoterápicos sobre essa classe de agentes patogênicos causadores da Tristeza Parasitária em Bovinos.

Failure to Eliminate Persistent Anaplasma marginale Infection from Cattle Using Labeled Doses of Chlortetracycline and Oxytetracycline Antimicrobials

Bovine anaplasmosis, caused by the intracellular rickettsial pathogen Anaplasma marginale, is the most prevalent tick-transmitted disease of cattle worldwide. In the U.S., tetracycline antimicrobials are commonly used to treat and control anaplasmosis. Oxytetracycline, administered by injection, is indicated for treatment of clinical anaplasmosis in beef and dairy cattle and calves. Chlortetracycline, administered orally, is indicated for control of active anaplasmosis infection in beef and nonlactating dairy cattle. Tetracyclines have been demonstrated to be effective for treating active anaplasmosis, but their ability to eliminate A. marginale at currently approved therapeutic doses or dosing regimens remains unclear. In the absence of approved dosing regimens for A. marginale clearance, a study was conducted to determine the effect of approved oxytetracycline and chlortetracycline indications on A. marginale bacteremia. Fifteen animals with persistent anaplasmosis were enrolled and divided into three treatment groups. Group 1 (n = 6) received oral chlortetracycline (1.1 mg/kg bodyweight) administered via hand-fed medicated feed for 60 consecutive days. Group 2 (n = 6) received injectable oxytetracycline administered subcutaneously at 19.8 mg/kg bodyweight three times in 3-week intervals. Group 3 (n = 3) served as an untreated control. After 60 days, bacteremia failed to permanently decrease in response to treatment. This result indicates that clearance of A. marginale is unlikely to be reliably achieved using currently approved tetracycline-based regimens to manage anaplasmosis.

Coinfection of cattle in Virginia with Theileria orientalis Ikeda genotype and Anaplasma marginale

Theileria orientalis Ikeda is a newly identified agent of bovine infectious anemia in the United States. Although T. orientalis Ikeda is transmitted by ticks other than the tick that transmits Anaplasma marginale—a bacterial etiology of bovine infectious anemia—the geographic distributions of these 2 infectious organisms overlap, with coinfection reported in some cattle. Only anaplasmosis has an approved effective treatment in the United States. To provide rapid diagnostic information for producers with anemic animals, we developed a duplex real-time PCR (rtPCR) for A. marginale and T. orientalis. With a cutoff of 38 cycles, the duplex assay has a sensitivity of 97.0% and a specificity of 100% for A. marginale; with a cutoff of 45 cycles, the duplex assay has a sensitivity and a specificity of 100% for T. orientalis, compared to existing tests. In addition to providing a tool for improved clinical decision-making for veterinarians and producers, our rtPCR facilitates the study of coinfection of cattle in Virginia. Of 1,359 blood samples analyzed, 174 were positive for T. orientalis, 125 were positive for A. marginale, and 12 samples were positive for both T. orientalis and A. marginale. Hence, coinfection by these 2 agents of bovine infectious anemia does occur within Virginia. It is likely that this pattern of infection will be seen in other regions where T. orientalis and A. marginale infections are endemic, despite the difference in tick vectors.

SINGLE AND MIXED BLOOD PROTOZOA INFECTION WITH ANAPLASMA AND THEILERIA IN BUFFALOES (BUBALUS BUBALIS ) IN BAGHDAD - IRAQ

One hundred & six blood smears from buffaloes, slaughtered at Al- Futhaliya slaughter house in Baghdad, were examined. Ages of buffaloes ranged from 6 months to 10 years. Numbers of positive blood smears were 48 (45.28%), of them only one showed clinical signs. Single, double, and triple protozoal infections with Anaplasma centrali , Anaplasma marginale, and Theileria annulata, were found. The most common type of infection was the Anaplasma marginale (22.64%), while Anaplasma centrali and Anaplasma centrali + Theileria annulata (0.94%) each. This investigation confirmed the presence of Anaplasma centrali infection in buffaloes for the first time.

Screening and Analysis of Anaplasma marginale Tunisian Isolates Reveal the Diversity of lipA Phylogeographic Marker and the Conservation of OmpA Protein Vaccine Candidate

Bovine anaplasmosis caused by Anaplasma marginale is a disease responsible for serious animal health problems and great economic losses all over the world. Thereby, the identification of A. marginale isolates from various bioclimatic areas in each country, the phylogeographic analysis of these isolates based on the most informative markers, and the evaluation of the most promising candidate antigens are crucial steps in developing effective vaccines against a wide range of A. marginale strains. In order to contribute to this challenge, a total of 791 bovine samples from various bioclimatic areas of Tunisia were tested for the occurrence of A. marginale DNA through msp4 gene fragment amplification. Phylogeographic analysis was performed by using lipA and sucB gene analyses, and the genetic relationship with previously characterized A. marginale isolates and strains was analyzed by applying similarity comparison and phylogenetic analysis. To evaluate the conservation of OmpA protein vaccine candidate, almost complete ompA nucleotide sequences were also obtained from Tunisian isolates, and various bioinformatics software were used in order to analyze the physicochemical properties and the secondary and tertiary structures of their deduced proteins and to predict their immunodominant epitopes of B and T cells. A. marginale DNA was detected in 19 bovine samples (2.4%). Risk factor analysis shows that cattle derived from subhumid bioclimatic area were more infected than those that originated from other areas. The analysis of lipA phylogeographic marker indicated a higher diversity of Tunisian A. marginale isolates compared with other available worldwide isolates and strains. Molecular, phylogenetic, and immuno-informatics analyses of the vaccine candidate OmpA protein demonstrated that this antigen and its predicted immunodominant epitopes of B and T cells appear to be highly conserved between Tunisian isolates and compared with isolates from other countries, suggesting that the minimal intraspecific modifications will not affect the potential cross-protective capacity of humoral and cell-mediated immune responses against multiple A. marginale worldwide strains.

Molecular Prevalence of Anaplasma marginale and Ehrlichia in Domestic Large Ruminants and Rhipicephalus (Boophilus) microplus Ticks From Southern Luzon, Philippines

Anaplasmosis and ehrlichiosis are tick-borne rickettsial diseases that cause significant economic losses in the livestock industry worldwide. Although bovine anaplasmosis is known to be endemic in the Philippines, epidemiological data is fragmented. Moreover, little is known about bovine ehrlichiosis in the country. In this study, the prevalence of Anaplasma marginale and Ehrlichia in cattle and water buffalo from provinces in the southern part of Luzon, Philippines, was investigated through PCR. Blood samples from 620 animals comprised of 512 cattle and 108 water buffalo and 195 tick samples were subjected to nested PCR targeting the groESL gene of Anaplasmataceae. Positive samples were further subjected to another nested PCR and conventional PCR to amplify the A. marginale groEL gene and the Ehrlichia dsbA gene, respectively. Selected A. marginale-positive samples were also subjected to nested PCR targeting the msp5 gene. Regardless of the animal host, the overall prevalence in blood samples obtained was 51.9% for Anaplasmataceae, 43% for A. marginale, and 1.1% for Ehrlichia. No water buffalo were positive for Ehrlichia. Meanwhile, 15.9, 6.7, and 2% of the tick samples, all morphologically identified as Rhipicephalus (Boophilus) microplus, were positive for Anaplasmataceae, A. marginale, and Ehrlichia, respectively. Sequence analysis of selected A. marginale msp5 amplicons showed that the isolates from the region share 94–98% identity to reported A. marginale from other countries. The phylogenetic tree showed clustering of isolates in the region and a close relationship with A. marginale isolates from other countries. Sequences of Ehrlichia amplicons from cattle and ticks were 97–100% similar to reported Ehrlichia minasensis isolates. This study showed the high prevalence of A. marginale in Luzon, Philippines, and provided the first molecular evidence of E. minasensis in the country.