RESUMO
Contamination of food chains by toxigenic fungi and aflatoxins is a global problem that causes damage to human health, as well as to crop and livestock production. The objective is to evaluate Aspergillus flavus and total aflatoxins (AFs) occurrence in totally mixed rations (TMRs) for dairy cows and aflatoxin M1 (AFM1) in milk for human consumption. Ninety-nine dairy production units located in Aguascalientes, Mexico, were randomly selected, and samples were collected from TMRs, raw milk, and milk marketed in the city in two consecutive agricultural cycles. AFs were quantified in TMRs and milk by indirect enzyme immunoassay and HPLC; aflatoxigenic and molecular (PCR) capacity of monosporic A. flavus isolates in the feed was characterized. All feed, raw, and pasteurized milk samples showed aflatoxin contamination (26.0 ± 0.4 µg/kg, 32.0 ± 1.0, and 31.3 ± 0.7 ng/L, respectively), and a significant proportion (90.4, 11.3, and 10.3%) exceeded the locally applied maximum permissible limits for feed and milk (20.0 µg/kg and 50 ng/L). Aflatoxin contamination in both TMRs and milk indicated a seasonal influence, with a higher concentration in the autumn-winter cycle when conditions of higher humidity prevail. The results obtained suggest the existence of contamination by aflatoxigenic A. flavus and aflatoxins in the diet formulated for feeding dairy cows and, consequently, in the dairy food chain of this region of the Mexican Highland Plateau.
Assuntos
Aflatoxina M1 , Aflatoxinas , Aflatoxina M1/análise , Aflatoxinas/análise , Animais , Aspergillus flavus , Bovinos , Feminino , México , Leite/químicaRESUMO
The datasets of records of the distribution of ticks and their hosts are invaluable tools to understand the phylogenetic patterns of evolution of ticks and the abiotic traits to which they are associated. Such datasets require an exhaustive collection of bibliographical references. In most cases, it is necessary the confirmation of reliable identification of ticks, together with an update of the scientific names of the vertebrate hosts. These data are not easily available, because many records were published in the so-called "grey literature". Herein, we introduced the Dataset of Ticks in South America, a repository that collates data on 4,764 records of ticks (4,124 geo-referenced) with a special reference to an extra 2,370 records of ticks on cattle, together with a set of abiotic traits, curated from satellite-derived information over the complete target region. The dataset includes details of the phylogenetic relationships of the species of hosts, providing researchers with both biotic and abiotic traits that drive the distribution and evolution of ticks in South America.
Assuntos
Bovinos/parasitologia , Filogenia , Carrapatos/classificação , Animais , América do SulRESUMO
Rhipicephalus microplus (formerly Boophilus microplus) ticks are potential vectors of several pathogens of livestock especially in tropical and subtropical regions where may have substantial effects on economic development. Among tick-borne pathogens, Anaplasma marginale is considered one of the most important in domestic and wild ruminants worldwide. Different molecular mechanisms have been employed by both ticks and these intracellular pathogens, in order to be able to adapt and survive. Subolesin, originally called 4D8, is an evolutionarily well-preserved protein among ixodid tick species. This new antigen was found to be protective against tick infestations when used as a vaccine, as it has an essential role in tick blood digestion, development and infection of host cells by A. marginale. Recent studies have demonstrated that infection of both tick and vertebrate host cells with this microorganism changed gene expression. Therefore, the main objective of this study was to investigate subolesin expression in uninfected and A. marginale-infected R. microplus salivary glands by real-time reverse transcriptase (RT)-PCR. To analyze the differential expression of the recombinant protein subolesin, the gene was previously expressed from ticks infected with A. marginale. Results from this study revealed that, the expression of subolesin was significantly higher in salivary glands of infected R. microplus in comparison to uninfected ones.
Assuntos
Anaplasma marginale/fisiologia , Antígenos/genética , Proteínas de Artrópodes/genética , Expressão Gênica , Rhipicephalus/genética , Rhipicephalus/microbiologia , Anaplasmose/imunologia , Anaplasmose/microbiologia , Animais , Antígenos/metabolismo , Proteínas de Artrópodes/metabolismo , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Feminino , Reação em Cadeia da Polimerase/veterinária , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rhipicephalus/metabolismo , Glândulas Salivares/metabolismo , Glândulas Salivares/microbiologiaRESUMO
Water buffalo (Bubalus bubalis) is a potential reservoir for Anaplasma marginale in livestock ecosystems of tropical countries. However, their participation in the epidemiological process of bovine anaplasmosis in endemic areas remains unclear. In the present study, the reservoir competence of water buffalo for A. marginale was explored by focusing on the analysis of rickettsemia levels in carrier animals, and the genetic characterization of A. marginale strains from cattle and buffalo. Eight groups of cattle and water buffaloes were randomly selected from cohabiting herds in four livestock ecosystems of Cuba, together with two control groups from unrelated cattle and buffalo herds. A total of 180 adult animals (88 water buffalo and 92 cattle) were sampled. Rickettsemia in carrier animals was determined by quantitative real-time PCR. The rickettsemia (parasitemia) levels in cattle were higher than in buffaloes, however the rickettsemia in buffalo may be enough to infect R. microplus ticks. The genetic diversity of A. marginale was assessed by strain characterization and phylogenetic analysis of 27 msp1α gene sequences. The results showed genetic similarity among strains from cattle and water buffalo, suggesting the occurrence of cross-species transmission.
Assuntos
Anaplasma marginale/genética , Anaplasmose/epidemiologia , Búfalos/microbiologia , Doenças dos Bovinos/epidemiologia , Reservatórios de Doenças/veterinária , Anaplasmose/transmissão , Animais , Proteínas da Membrana Bacteriana Externa/genética , Bovinos/microbiologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/transmissão , Estudos de Coortes , Cuba/epidemiologia , Reservatórios de Doenças/microbiologia , Variação Genética , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Carrapatos/microbiologiaRESUMO
The objective of this study was to screen and identify rickettsial organisms in ectoparasites collected from dogs in a shelter in Gomez Palacio, Durango, Mexico. One hundred dogs were inspected for ectoparasites. All the dogs were parasitized with Rhipicephalus sanguineus ticks, three with Heterodoxus spiniger lice and one with Ctenocephalides felis fleas. DNA was extracted from the ectoparasites found on each dog, and PCR with the primers for the Anaplasmataceae 16S rRNA and citrate synthase gltA genes were performed. Eight DNA samples obtained from ticks, three from lice and one from fleas were positive to 16S rRNA. Only one sample from C. felis and one from H. spiniger were positive to gltA. Sequence analysis of amplified products from C. felis showed identity to Rickettsia felis, Wolbachia pipientis, and Wolbachia spp., while a sequence from H. spiniger showed identity to Wolbachia spp. Herein we report the molecular detection of R. felis, W. pipientis, and Wolbachia spp. in C. felis and H. spiniger in northern Mexico. These results contribute to the knowledge of the microorganisms present in ectoparasites from dogs in Mexico.
Assuntos
DNA Bacteriano/genética , Doenças do Cão/parasitologia , Ectoparasitoses/veterinária , Rickettsia/genética , Animais , Sequência de Bases , Doenças do Cão/epidemiologia , Cães , Ectoparasitoses/epidemiologia , Ectoparasitoses/parasitologia , Abrigo para Animais , Ftirápteros/microbiologia , Filogenia , Reação em Cadeia da Polimerase , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Rickettsia/isolamento & purificação , Sifonápteros/microbiologia , Especificidade da Espécie , Carrapatos/microbiologiaRESUMO
The tick-borne pathogens Ehrlichia canis and Anaplasma platys are the causative agents of canine monocytic ehrlichiosis (CME) and canine cyclic thrombocytopenia (CCT). Although molecular evidence of E. canis has been shown, phylogenetic analysis of this pathogen has not been performed and A. platys has not been identified in Mexico, where the tick vector Rhipicephalus sanguineus sensu lato (s.l.) is common. The aim of this research was to screen, identify and characterize E. canis and A. platys by PCR and phylogenetic analysis in dogs from La Comarca Lagunera, a region formed by three municipalities, Torreon, Gomez-Palacio and Lerdo, in the Northern states of Coahuila and Durango, Mexico. Blood samples and five engorged R. sanguineus s.l. ticks per animal were collected from 43 females and 57 male dogs presented to veterinary clinics or lived in the dog shelter from La Comarca Lagunera. All the sampled dogs were apparently healthy and PCR for Anaplasma 16S rRNA, Ehrlichia 16S rRNA, and E. canis trp36 were performed. PCR products were sequenced and used for phylogenetic analysis. PCR products were successfully amplified in 31% of the samples using primers for Anaplasma 16S rRNA, while 10% and 4% amplified products using primers for Ehrlichia 16S rRNA and E. canis trp36 respectively. Subsequent sequencing and phylogenetic analyses of these products showed that three samples corresponded to A. platys and four to E. canis. Based on the analysis of trp36 we confirmed that the E. canis strains isolated from Mexico belong to a conservative clade of E. canis and are closely related to strains from USA. In conclusion, this is the first molecular identification of A. platys and the first molecular characterization and phylogenetic study of both A. platys and E. canis in dogs in Mexico.
Assuntos
Anaplasma/isolamento & purificação , Anaplasmose/microbiologia , Doenças do Cão/microbiologia , Ehrlichia canis/isolamento & purificação , Ehrlichiose/veterinária , Anaplasma/genética , Anaplasmose/epidemiologia , Animais , Vetores Aracnídeos/microbiologia , Doenças do Cão/epidemiologia , Cães , Ehrlichia canis/genética , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Feminino , Masculino , México/epidemiologia , Filogenia , RNA Ribossômico 16S/genética , Rhipicephalus sanguineus/microbiologia , Análise de Sequência de DNA/veterináriaRESUMO
BACKGROUND: In rural parts of Africa, dogs live in close association with humans and livestock, roam freely, and usually do not receive prophylactic measures. Thus, they are a source of infectious disease for humans and for wildlife such as protected carnivores. In 2011, an epidemiological study was carried out around three conservation areas in Uganda to detect the presence and determine the prevalence of vector-borne pathogens in rural dogs and associated ticks to evaluate the risk that these pathogens pose to humans and wildlife. METHODS: Serum samples (n = 105), blood smears (n = 43) and blood preserved on FTA cards (n = 38) and ticks (58 monospecific pools of Haemaphysalis leachi and Rhipicephalus praetextatus including 312 ticks from 52 dogs) were collected from dogs. Dog sera were tested by indirect immunofluorescence to detect the presence of antibodies against Rickettsia conorii and Ehrlichia canis. Antibodies against R. conorii were also examined by indirect enzyme immunoassay. Real time PCR for the detection of Rickettsia spp., Anaplasmataceae, Bartonella spp. and Babesia spp. was performed in DNA extracted from FTA cards and ticks. RESULTS: 99% of the dogs were seropositive to Rickettsia spp. and 29.5% to Ehrlichia spp. Molecular analyses revealed that 7.8% of the blood samples were infected with Babesia rossi, and all were negative for Rickettsia spp. and Ehrlichia spp. Ticks were infected with Rickettsia sp. (18.9%), including R. conorii and R. massiliae; Ehrlichia sp. (18.9%), including E. chaffeensis and Anaplasma platys; and B. rossi (1.7%). Bartonella spp. was not detected in any of the blood or tick samples. CONCLUSIONS: This study confirms the presence of previously undetected vector-borne pathogens of humans and animals in East Africa. We recommend that dog owners in rural Uganda be advised to protect their animals against ectoparasites to prevent the transmission of pathogens to humans and wildlife.
Assuntos
Doenças do Cão/epidemiologia , Ixodidae , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Anaplasma/genética , Anaplasma/isolamento & purificação , Animais , Babesia/genética , Babesia/isolamento & purificação , Bartonella/genética , Bartonella/isolamento & purificação , Sequência de Bases , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Ehrlichia/imunologia , Ehrlichia/isolamento & purificação , Feminino , Humanos , Ixodidae/microbiologia , Ixodidae/parasitologia , Masculino , Dados de Sequência Molecular , Prevalência , Rickettsia/imunologia , Rickettsia/isolamento & purificação , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , Uganda/epidemiologiaRESUMO
Anaplasma marginale is an economically important tick-borne pathogen of cattle that causes bovine anaplasmosis. A wide range of geographic strains of A. marginale have been isolated from cattle, several of which have been characterized using genomics and proteomics. While many of these strains have been propagated in tick lines, comparative analyses after propagation in tick cells have not been reported. The overall purpose of this research therefore was to compare the degree of conservation of selected genes after propagation in tick cell culture among A. marginale strains from the U.S. (the Virginia strain) and Brazil (UFMG1 and UFMG2 strains). The genes studied herein included those which encode the proteins HSP70 and SODB involved in heat shock and stress responses, respectively, and two genes that encode major surface proteins MSP4 and MSP5. Strain identities were first confirmed by sequencing the tandem repeats of the msp1a gene which encodes for the adhesin, MSP1a. The results of these studies demonstrated that the genes encoding for both stress response and heat shock proteins were highly conserved among the three A. marginale strains. Antibodies specific for MSP4, MSP5, SODB and HSP70 proteins were used to further characterize the A. marginale strains, and they reacted with all of these strains propagated in tick cell culture, providing further evidence for antigenic conservation. Although antigenic differences were not found among the three A. marginale strains, multi-locus sequence analysis (MLSA) performed with nucleotide sequences of these genes demonstrated that the A. marginale Brazilian and U.S. strains fall in different clades. These results showed that phylogenetically distant strains of A. marginale are antigenically conserved, even after several in vitro passages, supporting the use of some of the above conserved proteins as candidates for universal vaccines.
Assuntos
Anaplasma marginale/isolamento & purificação , Anaplasmose/imunologia , Vetores Aracnídeos/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Doenças dos Bovinos/imunologia , Carrapatos/microbiologia , Anaplasma marginale/classificação , Anaplasma marginale/genética , Anaplasma marginale/crescimento & desenvolvimento , Anaplasmose/microbiologia , Animais , Variação Antigênica , Brasil , Bovinos , Doenças dos Bovinos/microbiologia , Sequência Conservada , Dados de Sequência Molecular , Filogenia , Estados UnidosRESUMO
Anaplasma marginale is the most prevalent pathogen of cattle in tropical and subtropical regions of the world and causes the disease bovine anaplasmosis. The importance of water buffalo in the world economy is increasing. In addition, while water buffalo may serve as a reservoir host for A. marginale, the susceptibility of this host for A. marginale cattle strains in Brazil has not been reported. The major surface protein 1 alpha (msp1α) gene has been shown to be a stable genetic marker for identification of A. marginale strains. Herein, we analyzed blood samples from 200 water buffalo and identified the A. marginale strains in an endemic area of Rio de Janeiro, Brazil, where ticks were present and water buffalo and cattle co-mingled. Ticks that were feeding on the study buffalo were collected and identified. The prevalence of A. marginale in water buffalo in this study was low (10%). Sequence analysis of the msp1α gene demonstrated the presence of 8 different A. marginale strains. Two A. marginale strains in the water buffalo, (α-ß-ß-ß-Γ) and (α-ß-ß-Γ), were similar to those reported in cattle from nearby regions. The results of this study suggested that water buffalo in this region are naturally infected with the same strains of A. marginale found in cattle.
Assuntos
Anaplasma marginale/isolamento & purificação , Anaplasmose/epidemiologia , Búfalos/microbiologia , Doenças dos Bovinos/epidemiologia , Carrapatos/microbiologia , Sequência de Aminoácidos , Anaplasma marginale/genética , Anaplasmose/microbiologia , Animais , Proteínas da Membrana Bacteriana Externa/genética , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/microbiologia , Reservatórios de Doenças/microbiologia , Marcadores Genéticos/genética , Genótipo , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
The rickettsia Anaplasma marginale is the etiologic agent of bovine anaplasmosis, an important tick-borne disease affecting cattle in tropical and subtropical regions of the world. In endemic regions, the genetic diversity of this pathogen is usually related to the high prevalence of the disease in cattle. The major surface protein 1 alpha (MSP1a) has been used as a marker to characterize the genetic diversity and for geographical identification of A. marginale strains. The present study reports the characterization of A. marginale MSP1a diversity in water buffaloes. Blood samples were collected from 200 water buffaloes on Marajó Island, Brazil where the largest buffalo herd is located in the Western hemisphere. Fifteen buffaloes (7.5%) were positive for A. marginale msp1α by PCR. Four different strains of A. marginale with MSP1a tandem repeat structures (4-63-27), (162-63-27), (78-24-24-25-31) and (τ-10-10-15) were found, being (4-63-27) the most common. MSP1a tandem repeats composition in buffalos and phylogenetic analysis using msp1α gene showed that the A. marginale strains identified in buffaloes are closely related to A. marginale strains from cattle. The results demonstrated low genetic diversity of A. marginale associated with low bacterial prevalence in buffaloes and suggested that buffaloes may be reservoirs of this pathogen for cattle living in the same area. The results also suggested that mechanical transmission and not biological transmission by ticks might be playing the major role for pathogen circulation among water buffaloes in Marajó Island, Brazil.