Molecular detection of SARS-CoV-2 in Argentina: Evaluation of alternative diagnostic tools for the decentralization of the diagnosis

Abstract The rocketing number of COVID-19 cases highlighted the critical role that diagnostic tests play in medical and public health decision-making to contain and mitigate the SARS-CoV-2 pandemic. This study reports the evaluation and implementation of different tests for the molecular detection of SARS-CoV-2 in the central region of Argentina. We evaluated 3 real time RT-PCR kits (GeneFinder COVID-19 Plus RealAmp Kit, DisCoVery SARS-CoV-2 RT-PCR Detection Kit and WGene SARS-CoV-2 RT Detection), 2 nucleic acid extraction methods [MagaBio plus Virus DNA/RNA Purification Kit II (BioFlux), 35-min vs. 9-min, a pre-analytical reagent (FlashPrep®) and 2 isothermal amplification tests (Neokit Plus and ELA CHEMSTRIP®). The order according to the best performance of the 3 real-time RT-PCR kits evaluated was: DisCoVery > GeneFinderTM> WGene. The 2 RNA extraction methods showed similar good results: MagaBio plus Virus RNA Purification Kit II (BioFlux) 9-min was selected due to its faster performance. FlashPrep® reagent showed excellent results to perform direct RNA detection. Isothermal amplification assays showed acceptable sensitivity and specificity values (>80%), except in samples with Ct> 30. Our data show optimal real time RT-PCR kits and alternative molecular methods for SARS-CoV-2 diagnostic. These alternative assays proved to be aceptable.

Resumen La explosión de casos de COVID-19 resaltó el papel fundamental que desempeñan las pruebas de diagnóstico en la toma de decisiones médicas y de salud pública para contener y mitigar la pandemia de SARS-CoV-2. Este estudio reporta la evaluación y la implementación de diferentes test para la detección molecular de SARS-CoV-2 en la región central de Argentina. Evaluamos tres kits de RT-PCR en tiempo real (GeneFinder COVID-19 Plus RealAmp Kit, DisCoVery SARS-CoV-2 RT-PCR Detection Kit y WGene SARS-CoV-2 RT Detection), dos métodos de extracción de ácidos nucleicos (MagaBio plus Virus DNA/RNA Purification Kit II [BioFlux, 35-min vs. 9-min), un reactivo pre-analítico (FlashPrep®) y dos test de amplificación isotérmica (Neokit Plus and ELA CHEMSTRIP®). El orden de rendimiento de los tres kits de RT-PCR en tiempo real evaluados fue el siguiente: DisCoVery GeneFinder™ WGene. Los dos métodos de extracción de RNA mostraron buenos y similares resultados; se seleccionó MagaBio plus Virus RNA Purification Kit II (BioFlux) 9-min debido a su rápido tiempo de procesamiento. El reactivo FlashPrep® mostró excelentes resultados para realizar detección directa de RNA. Los ensayos de amplificación isotérmica mostraron valores de sensibilidad y de especificidad aceptables (80%), excepto en muestras con Ct 30. Nuestros resultados muestran kits de RT-PCR en tiempo real óptimos, como así también métodos moleculares alternativos para el diagnóstico de SARS-CoV-2 que resultan aceptables para su uso en contextos adversos, de descentralización y en diferentes escenarios epidemiológicos, para la detección rápida y precisa del SARS-CoV-2.

Clinical and microbiological assessment in a subpopulation of young Argentine patients with severe periodontitis / Periodontitis severa en jóvenes argentinos. Evaluación clínica y microbiológica en jóvenes argentinos con periodontitis severa

ABSTRACT Aggressive periodontitis (AP) is the most serious entity of periodontal disease (stage III/IV, grade C periodontitis according to the latest classification, 2017). Aim: to enhance knowledge of periodontal microbiota in AP in native Argentine patients and describe the effect of a combined pharmacological-mechanicalperiodontal treatment on clinical and microbiological parameters. Materials andMethod: The study analyzed 42 periodontal sites in 11 patients diagnosed with AP. Clinical periodontal parameters were recorded at baseline, 45, 90 and 180 days. Microbiological samples were taken before treatment and at 180 days. PCR was used to determine presence of the periodontopathic bacteria Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn). Patients underwent periodontal therapy including antibiotics (Amoxicillin 500mg + Metronidazole 250mg; 8hs/7 days), and were reevaluated at 45, 90 and 180 days. Results: Mean age was 28.4 ± 7.9 years. The initial PCR detected the following frequencies: Aa 14.3%, Pi 61.9%, Pg 71.4%, Tf 81.0%, Fn 95.2% and Td 97.6%. Baseline microbiological samples revealed significantly higher prevalence of Pg over Aa (p=0.012). Clinical parameters improved significantly after treatment (73.8% PS<5 mm; PS, NIC, SS p<0.001). At 180 days, a significant decrease in microbiological detection rates was observed (Fn, Td, Tf, Pi, Aa p<0.05). Aa was no longer detectable while Pg did not decrease significantly (p=0.052). Fn was the only study species detected in 100% (n=11:42) of residual pockets (PS>5 mm) (p=0.053). Conclusion: In the initial samples, there was significant prevalence of Pg over Aa. Significant clinical improvement was achieved after the mechanical-pharmacological treatment, with undetectable levels ofAa, while Fn persisted in residual pockets, and Pg was present at most of the treated sites.

RESUMEN La periodontitis agresiva (PA) es la entidad más grave de la enfermedad periodontal (clasificación 2017: periodontitis estadio III/IV, grado C). Objetivo: mejorar el conocimiento sobre la microbiota periodontal de la PA en sujetos nativos argentinos y describir el efecto de un tratamiento mecánico-farmacológico periodontal sobre los parámetros clínicos y microbiológicos. Materiales y Método: se estudiaron 42 sitios periodontales correspondientes a 11 pacientes con PA. Los parámetros clínicos se registraron a 0, 45, 90 y 180 días. Las tomas microbiológicas se realizaron antes de iniciar el tratamiento y a los 180 días. La determinación de especies periodontopáticas (Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf, Treponema denticola (Td), Prevotella intermedia (Pi) y Fusobacterium nucleatum (Fn)) se realizó por PCR. Los pacientes iniciaron terapia básica periodontal junto con antibioticoterapia (Amoxicilina 500 mg + Metronidazol 250 mg; 8 hs/7 días) y fueron evaluados a los 45, 90 y 180 días. Resultados: la edad media fue 28,4 ± 7,9 años. Las detecciones iniciales fueron: Aa 14,3%, Pi 61,9%, Pg 71,4%, Tf 81,0%, Fn 95,2% y Td 97,6%. En las muestras iniciales la prevalencia de Pg sobre Aa fue significativamente superior (p=0,012). Los pacientes tuvieron una respuesta clínica favorable al tratamiento (73,8% PS<5 mm; PS, NIC, SS p<0,001). A 180 días, se observó una disminución estadísticamente significativa en la detección microbiana (Fn, Td, Tf, Pi, Aa p<0,05). En igual plazo, Aa no fue detectado, mientras que Pg mostró una disminución no significativa (p=0,052). Fn fue el único detectado en el 100% (n=11:42) de las bolsas periodontales residuales (PS>5 mm) (p=0,053). Conclusión: Las muestras iniciales evidenciaron prevalencia significativa de Pg sobre Aa. El tratamiento logró una significativa mejora clínica con niveles indetectables de Aa. La persistencia de Fn en las bolsas residuales y de Pg en la mayoría de los sitios tratados, caracterizaron la muestra poblacional estudiada.

CRISPR-based molecular diagnostics: a review / 生物工程学报

Rapid and accurate detection technologies are crucial for disease prevention and control. In particular, the COVID-19 pandemic has posed a great threat to our society, highlighting the importance of rapid and highly sensitive detection techniques. In recent years, CRISPR/Cas-based gene editing technique has brought revolutionary advances in biotechnology. Due to its fast, accurate, sensitive, and cost-effective characteristics, the CRISPR-based nucleic acid detection technology is revolutionizing molecular diagnosis. CRISPR-based diagnostics has been applied in many fields, such as detection of infectious diseases, genetic diseases, cancer mutation, and food safety. This review summarized the advances in CRISPR-based nucleic acid detection systems and its applications. Perspectives on intelligent diagnostics with CRISPR-based nucleic acid detection and artificial intelligence were also provided.

Prevalencia de Porphyromonas gingivalis en un grupo de pacientes con aparatología fija de ortodoncia / Prevalence of Porphyromonas gingivalis in a group of patients with fixed orthodontic appliances

Introducción: existen diversos patógenos que pueden afectar no sólo la salud periodontal, sino también la salud general de los pacientes. Objetivo: determinar la Porphyromonas gingivalis (PG) en el primer molar superior derecho de adolescentes, de entre 12 y 18 años, con al menos un mes de tratamiento de ortodoncia con aparatología fija. Material y métodos: se realizó un estudio observacional, descriptivo, transversal de casos en un grupo de 26 adolescentes con tratamiento de ortodoncia, compuesto de brackets metálicos, tubos o bandas, arcos NiTi termoactivos, módulos, cadenas o ligaduras; sin importar sexo, edad, tiempo de tratamiento o maloclusión. Se formaron dos pares de grupos 1 y 2 (15 mujeres y 11 hombres), A y B (13 mujeres y 13 hom- bres) comparando los resultados obtenidos entre los grupos. Resulta- dos: dentro del grupo 1 y 2 la detección molecular de microorganismos arroja que 80% fueron positivas a la PG, 58.33% presenta maloclusión y en promedio 89% de las pacientes son positivas a PG. La detección molecular del grupo A y B indica que 54.54% fueron positivos a PG, mientras que 83.3% presenta maloclusión y en promedio 47% son positivos a PG. Conclusión: la explicación de los eventos moleculares que se desencadenan en la cavidad oral y los sistemas afectados por PG contribuyen a la prevención de complicaciones al tener una mejor comprensión de los fenómenos infecciosos (AU)

Introduction: there are various pathogens that can affect not only periodontal health, but also the general health of patients. Objective: to determine Porphyromonas gingivalis (PG) in the upper right first molar of adolescents, between 12 and 18 years old, with at least one month of orthodontic treatment with fixed appliances. Material and methods: a cross-sectional descriptive observational study of cases was carried out in a group of 26 adolescents with orthodontic treatment, consisting of metal brackets, tubes or bands, thermoactive NiTi archwires, modules, chains or ligatures; regardless of sex, age, treatment time or malocclusion. Two pairs of groups 1 and 2 (15 women and 11 men), A and B (13 women and 13 men) were formed, comparing the results obtained between the groups. Results: within group 1 and 2, the molecular detection of microorganisms shows that 80% were positive for PG, 58.33% presented malocclusion and an average of 89% of patients were positive for PG. The molecular detection of group A and B indicates that 54.54% were positive for PG while 83.3% presented malocclusion and on average 47% were positive for PG. Conclusion: the explanation of the molecular events that are triggered in the oral cavity and the systems affected by PG contribute to the prevention of complications by having a better understanding of the infectious phenomena (AU)

Entomological survey of phlebotominae sand flies (diptera: psychodidae) and vector species in the tegumentary leishmaniasis endemic area in eastern brazilian Amazon, Amapá state / Levantamento entomológico de flebotomíneos (Diptera: Psychodidae) e espécies vetoras na área endêmica de leishmaniose tegumentar na Amazônia oriental brasileira, Estado do Amapá

American tegumentary leishmaniasis is an endemic that has increased considerably in recent decades in the Amazon region, sand flies are the vectors of the transmission of the protozoan that causes leishmaniasis, so the objective of this study was to carry out a survey of the diversity of species and the presence of Leishmania DNA in vectors circulating in three endemic counties for tegumentary leishmaniasis in the eastern Brazilian Amazon (Amapá state, Brazil). Using CDC light traps, a total of 10,773 specimens were collected between February 2019 and February 2020, representing 64 species in 15 genera. The vector specie Nyssomyia umbratilis Ward and Frahia, 1977 was the predominant species (13.20% of the total), being collected in all three counties, followed by Trichopygomyia trichopyga Floch & Abonnenc, 1945 (11.41%), Trichophoromyia ubiquitalis Mangabeira,1942 (9.47%) and Nyssomyia anduzei Rozeboom, 1942 (7.61%). For the identification of Leishmania DNA, 775 pools of unengorged females were used, of which 5 tested positive, 2 of Nyssomya umbratilis Ward & Fraiha,1977, 1 of Nyssomyia anduzei and 2 of Psychodopygus davisi Root,1934, demonstrating a natural total infection rate of 0.64%. This study increases the knowledge of vector diversity, as well as identifying Leishmania spp. in circulation in the eastern region of the Amazon.

A leishmaniose tegumentar americana é uma endemia que aumentou consideravelmente nas últimas décadas na região amazônica, os flebotomíneos são os vetores da transmissão do protozoário causador da leishmaniose, portanto o objetivo deste estudo foi realizar um levantamento da diversidade de espécies e a presença de DNA de Leishmania em vetores que circulam em três municípios endêmicos de leishmaniose tegumentar na Amazônia oriental brasileira (Amapá, Brasil). Usando armadilhas luminosas do tipo CDC, um total de 10.773 espécimes foram coletados entre fevereiro de 2019 e fevereiro de 2020, representando 64 espécies em 15 gêneros. As espécie vetoras - singular Nyssomyia umbratilis Ward e Frahia 1977 foram as espécies predominantes (13,20% do total), sendo coletadas nos três municípios, seguido por Trichopygomyia trichopyga Floch & Abonnenc, 1945 (11,41%), Trichophoromyia ubiquitalis Mangabeira, 1942 (9,47%) e Nyssomyia anduzei Rozeboom, 1942 (7,61%). Para a identificação do DNA de Leishmania, foram utilizados 775 pools de fêmeas não ingurgitadas, dos quais 5 foram positivos, 2 de Nyssomya umbratilis Ward & Fraiha, 1977, 1 de Nyssomyia anduzei e 2 de Psychodopygus davisi Root, 1934, demonstrando uma taxa de infecção total de 0,64%. Este estudo aumenta o conhecimento da diversidade de vetores, bem como a identificação das espécies de Leishmania spp. em circulação na região oriental da Amazônia.

Standardization of molecular techniques for the detection and characterization of intestinal protozoa and other pathogens in humans

Background: The intrinsic sensitivity limitations of basic parasitological methods, along with the particular biological characteristics of parasites, make these methods ineffective to differentiate morphologically indistinguishable species. Molecular detection and characterization techniques could be used to overcome these problems. The purpose of this work was to standardize molecular polymerase chain reaction (PCR) techniques, described in the literature, for the detection and molecular characterization of intestinal protozoa and other pathogens in humans. Methods: DNA was extracted from human or animal feces, previously washed or cultured in Boeck Drbohlav's Modified Medium. DNA extraction was performed with Machery-Nagel extraction kits. The standardization of the PCR, nested-PCR or RFLP techniques was carried out according to the literature. For each molecular technique performed, the sensitivity of the test was determined based on the minimun quantity required of DNA (sensitivity A) and the minimum quantity of life forms that the test detected (sensitivity B). Results: Sensitivity A was 10 fg for G. duodenalis, 12.5 pg for Entamoeba histolytica or Entamoeba dispar, 50 fg for Cryptosporidium spp., 225 pg for Cyclospora spp. and 800 fg or 8 fg for Blastocystis spp. after performing a 1780 bp PCR or 310 bp nested PCR, respectively. The sensitivity B was 100 cysts for G. duodenalis, 500 cysts for E. histolytica or E. dispar, 1000 oocysts for Cyclospora spp. and 3600 or four vegetatives forms for PCR or nested PCR of Blastocystis spp., respectively. Conclusions: The molecular detection of protozoa and chromist was achieved and the molecular characterization allowed the genotyping of some of the parasites such as Giardia duodenalis, Cryptosporidium spp., and Blastocystis spp. This study summarizes the molecular techniques for epidemiological studies in humans and animals, and helps in the investigation of their transmission sources in countries where intestinal parasites are a public health problem.(AU)

Advances in the study of molecular identification technology of Echinococcus species

@#The larvae of Echinococcus (hydatidcyst) can parasitize humans and animals, causing a serious zoonotic disease-echinococcosis. The life history of Echinococcus is complicated, and as the disease progresses slowly after infection, early diagnosis is difficult to establish. Due to the limitations of imaging and immunological diagnosis in this respect, domestic and foreign scholars have established a variety of molecular detection techniques for the pathogen Echinococcus over recent years, mainly including nested polymerase chain reaction (PCR), multiplex PCR, real-time quantitative PCR, and nucleic acid isothermal amplification technology. In this article, the research progress of molecular detection technology for Echinococcus infection currently was reviewed and the significance of these methods in the detection and diagnosis of hydatid and hydatid diseases was also discussed.

Detección molecular de patógenos entéricos en niños con diarrea en un hospital centinela de vigilancia de rotavirus en Chile / Molecular detection of gastrointestinal pathogens among children under 5 years old with diarrhea in a hospital center for rotavirus sentinel surveillance in Chile

INTRODUCCIÓN: Las diarreas de causa infecciosa son un problema de salud pública, especialmente en niños bajo los cinco años. La identificación de los agentes etiológicos puede ser relevante para el manejo del cuadro clínico y, desde el punto de vista epidemiológico, para la implementación de medidas de control. OBJETIVO: Determinar la presencia de patógenos entéricos en niños bajo los cinco años que se hospitalizaron por diarrea aguda en uno de los centros centinelas de la red de vigilancia de rotavirus en Chile. PACIENTES Y MÉTODOS: Estudio observacional en niños menores de cinco años que se internaron por cuadros de diarrea en el Hospital Dr. Luis Calvo Mackenna, durante diciembre del 2015 a diciembre del 2019, el que forma parte de la red de vigilancia de rotavirus del Ministerio de Salud de Chile. Las muestras fecales se analizaron mediante un test molecular, FilmArray GI® panel, que permite la detección de 22 patógenos entéricos virales, bacterianos y parasitarios. RESULTADOS: Se analizaron 493 muestras fecales de niños con episodios de diarrea infecciosa, detectando al menos un patógeno en 427 muestras (87%). De estas muestras positivas, se detectó solo un patógeno en 174 muestras (41%) y dos o más patógenos en 253 muestras (59%). En el grupo de niños bajo un año y el grupo entre uno y cuatro años hubo un predominio de infecciones causadas por virus gastroentéricos, siendo rotavirus y norovirus los virus más detectados en ambos grupos de edad. Las bacterias más frecuentes fueron EPEC (27%), C. difficile (17%), EAEC (14%) y Campylobacter (9%). Respecto a los parásitos, se identificó Giardia lamblia y Cryptosporidium, en el 3 y 1% del total de las muestras, respectivamente. CONCLUSIÓN: La detección molecular utilizada permitió detectar un alto número de enteropatógenos en niños bajo los cinco años. La información generada por este tipo de vigilancia, podría ayudar a caracterizar en la población los episodios de diarrea causados por los principales patógenos entéricos y podría ser una herramienta para asesorar técnicamente a las autoridades en la toma de decisión para la implementación de medidas de control contra estos patógenos.

BACKGROUND: Infectious diarrhea is still a major problem in public health, especially in children under 5 years of age. The identification of the etiologic agent is important for the clinical management of the diarrhea episode and, from the epidemiological point of view, to implement control measures. AIM: To determine the presence of gastrointestinal pathogens in children under five years of age with diarrhea in a Chilean rotavirus surveillance center. METHODS: Observational study in children under five years of age who were hospitalized for diarrhea at the Dr. Luis Calvo Mackenna Hospital from December 2015 to December 2019. Molecular detection was performed using the FilmArray gastrointestinal (FilmArray GI®) panel. RESULTS: We analyzed 493 diarrheal stool samples of children, 427 samples (87%) were positive and 66 samples (13%) were negative. Of positive samples, 174 samples (41%) and 253 samples (59%) were positive for one or more pathogen, respectively. In children under one year and the group between one and four years there was a predominance of infections caused by enteric virus. Rotavirus and norovirus were the most common virus in both age groups. The most frequent bacteria were EPEC (27%), C. difficile (17%), EAEC (14%) and Campylobacter (9%). In parasites, Giardia lamblia and Cryptosporidium were identified, in 3% and 1% of the total samples, respectively. CONCLUSIONS: The molecular detection system used allowed an increase in the detection of enteropathogens in children under five years of age. The information generated by this type of surveillance could help to characterize the episodes of diarrhea in the population and might be a tool to technically advise the authorities in the decision-making process for the implementation of control measures.

Molecular detection of visceral leishmaniasis in dogs from Barão de Melgaço, Pantanal region of Mato Grosso, Brazil / Detecção molecular de leishmaniose visceral em cães do município de Barão de Melgaço, Pantanal Mato-Grossense, Brasil

The increasing expansion of visceral leishmaniasis (VL) in the Brazilian territory evidences the need for studies focused on the main reservoir of this parasite: the dog. This study aimed to conduct an epidemiological survey in the municipality of Barão de Melgaço, Pantanal region of the state of Mato Grosso (MT), Brazil. Conventional polymerase chain reaction (PCR) and qualitative SYBR®Green real-time PCR (qPCR) were used to diagnose canine VL (CVL) and characterize the factors associated with this infection. Of the 402 dogs that had blood samples collected, 31 presented the parasite DNA, representing a prevalence of 7.71% in the population studied. Positivity indices for PCR and qPCR were 3.48 (14/402) and 7.21% (29/402), respectively. Comparison of the results obtained by both techniques showed moderate agreement (Kappa = 0.5364). Of the independent variables analyzed, presence of clinical signs (p≤0.05) was the only one associated with CVL. Based on this study, we conclude that VL is a circulating disease, with relatively low prevalence, in dogs of Barão de Melgaço/MT, and that the presence of clinical signs is the only variable associated with canine infection.(AU)

A crescente expansão da leishmaniose visceral (LV) no território brasileiro evidencia a necessidade de estudos voltados ao principal reservatório doméstico do parasito: o cão. Sendo assim, o objetivo deste estudo foi realizar um inquérito epidemiológico no município de Barão de Melgaço, região do Pantanal Mato-grossense, utilizando as técnicas de reação em cadeia pela polimerase convencional (PCR) e teste qualitativo SYBR®Green real-time PCR (qPCR) para o diagnóstico da LV canina (LVC), além de caracterizar os fatores associados a infecção. Do total de 402 cães que tiveram amostras sanguíneas coletadas, 31 apresentaram o DNA do parasito, perfazendo uma prevalência de 7,71% na população estudada. Os índices de positividade para a PCR e qPCR foram de 3,48% (14/402) e 7,21% (29/402), respectivamente. A comparação dos resultados obtidos por ambas técnicas apresentou moderada concordância (Kappa = 0,5364). Das variáveis independentes analisadas, a presença de sinais clínicos (p≤0,05) foi a única associada a ocorrência de LVC. Com base neste estudo, concluímos que a LV está circulando, com prevalência relativamente baixa, em cães de Barão de Melgaço/MT, sendo a presença de sinais clínicos a única variável associada à infecção canina.(AU)

Molecular detection of Apicomplexa protozoa in tissues from Alouatta guariba clamitans / Detecção molecular de protozoários Apicomplexa em tecidos de Alouatta guariba clamitans

The brown howler monkey (Alouatta guariba clamitans) is a primate species widely distributed in South America. Infections by protozoa are common in primates. However, studies on protozoa in primates in Brazil are scarce, so the goal of this study was to investigate DNA from the apicomplexan protozoa Neospora caninum, Sarcocystis spp. and Toxoplasma gondii in tissues of A. guariba clamitans. DNA extraction was performed on tissue samples from the heart, brain, liver, spleen, lung and intestine of six A. guariba clamitans from Santa Maria, Central Region of Rio Grande do Sul, Brazil. Conventional PCR was performed using 18S rRNA gene general primers for Apicomplexa and also specific primers to amplify Neosporaspp. and Toxoplasma gondii DNA. All animals were positive in the 18S PCR and the genetic sequencing confirmed the presence of Sarcocystis spp. DNA in the tissues of four animals belonging to at least two species (S. neurona and S. gigantea) and T. gondii DNA in the other two animals. One positive sample for T. gondii was genotypically characterized as atypical by the restriction fragment length polymorphism technique. N. caninum DNA was not detected in the tested samples. The presence of Apicomplexa protozoan DNA in the tissues of the six animals tested in this study highlights the importance of howler monkeys as maintainers of these pathogens in nature.(AU)

O bugio ruivo (Alouatta guariba clamitans) é uma espécie de primata amplamente distribuída na América do Sul. As infecções por protozoários são comuns em primatas. Entretanto, estudos sobre protozoários em primatas no Brasil são escassos, portanto o objetivo deste estudo foi pesquisar DNA dos protozoários Apicomplexa Neospora caninum, Sarcocystisspp. e Toxoplasma gondii em tecidos de A. guariba clamitans. A extração de DNA foi realizada em amostras de tecido do coração, cérebro, fígado, baço, pulmão e intestino de seis A. guariba clamitans oriundos de Santa Maria, Região Central do Rio Grande do Sul, Brasil. Foi realizada PCR convencional utilizando primers geral do gene 18S rRNA para Apicomplexa e também primers específicos para amplificação de DNA de Neospora spp.e Toxoplasma gondii. Todos os animais foram positivos no PCR geral para Apicomplexa e no sequenciamento genético confirmou-se a presença de DNA de Sarcocystis nos tecidos de quatro animais pertencentes a pelo menos duas espécies (S. neurona e S. gigantea), e DNA de T. gondii foi detectado nos outros dois animais. Uma amostra positiva para T. gondii foi caracterizada genotipicamente como atípico pela técnica de polimorfismo do comprimento do fragmento de restrição. Não foi detectado DNA de N. caninum nas amostras testadas. A presença de DNA de protozoários apicomplexa nos tecidos dos seis animais testados neste estudo destaca a importância dos bugios ruivos como mantenedores desses patógenos na natureza.(AU)

New sensitive real-time PCR targeting p28 gene for detection of Ehrlichia canis in blood samples from dogs / Novo PCR em tempo real sensível que visa o gene p28 para a detecção de Ehrlichia canis em amostras de sangue de cães

ABSTRACT: This study aims to describe a new detection method of a quantitative real-time polymerase chain reaction (qPCR) targeting the 28 kDa outer membrane protein gene (p28) as well as to compare this method with a conventional PCR (cPCR), which targets the same gene, in order to evaluate the performance of the technique designed in this study in detecting Ehrlichia canis (E. canis). Optimum oligonucleotides concentrations were reached, and the analytical sensitivity and specificity of the qPCR were performed. A total of 218 dogs' whole blood samples were conventionally collected for this study. The DNA was extracted from each sample. Subsequently, the samples were tested by an established cPCR and the new qPCR to compare each technique's performances. This new qPCR method for the molecular detection of E. canis presented a detection limit of ten copies of the fragment and was considered specific for E. canis according to analytical specificity analyses performed in vitro and in silico. The standard curve revealed 100% efficiency and a coefficient of determination (R2) equivalent to 99.8%. Among the samples examined by qPCR, 24.31% were considered positive, significantly greater than those detected by cPCR (15.13%). The qPCR technique reached a higher sensitivity than the cPCR when targeting the p28 gene in detecting E. canis. The qPCR standardized in this study is an efficient method for confirming canine monocytic ehrlichiosis (CME) diagnosis and might provide the parasitemia monitoring during the disease treatment.

RESUMO: Este estudo tem como objetivo descrever um novo método de detecção de uma reação em cadeia da polimerase quantitativa em tempo real (qPCR) visando o gene da proteína da membrana externa de 28 kDa (p28), bem como comparar este método com um PCR convencional (cPCR), que visa o mesmo gene, a fim de avaliar o desempenho da técnica desenhada neste estudo na detecção de Ehrlichia canis (E. canis). As concentrações ideais de oligonucleotídeos foram alcançadas e a sensibilidade analítica e a especificidade do qPCR foram determinadas. Um total de 218 amostras de sangue total de cães foram coletadas convencionalmente para este estudo. O DNA foi extraído de cada amostra. Posteriormente, as amostras foram testadas por um cPCR estabelecido e o novo qPCR para comparar os desempenhos entre cada técnica. A curva padrão revelou 100% de eficiência e coeficiente de determinação (R2) equivalente a 99,8%. Dentre as amostras examinadas por qPCR, 24,31% foram consideradas positivas, percentual significativamente maior do que as detectadas por cPCR (15,13%). A técnica qPCR atingiu uma sensibilidade maior do que a cPCR na detecção de E. canis. A qPCR padronizada neste estudo é um método eficiente para a confirmação do diagnóstico de erliquiose monocítica canina (EMC) e pode fornecer o monitoramento de níveis de parasitemia ao longo do tratamento da doença.

Molecular detection of visceral leishmaniasis in dogs from Barão de Melgaço, Pantanal region of Mato Grosso, Brazil

ABSTRACT: The increasing expansion of visceral leishmaniasis (VL) in the Brazilian territory evidences the need for studies focused on the main reservoir of this parasite: the dog. This study aimed to conduct an epidemiological survey in the municipality of Barão de Melgaço, Pantanal region of the state of Mato Grosso (MT), Brazil. Conventional polymerase chain reaction (PCR) and qualitative SYBR®Green real-time PCR (qPCR) were used to diagnose canine VL (CVL) and characterize the factors associated with this infection. Of the 402 dogs that had blood samples collected, 31 presented the parasite DNA, representing a prevalence of 7.71% in the population studied. Positivity indices for PCR and qPCR were 3.48 (14/402) and 7.21% (29/402), respectively. Comparison of the results obtained by both techniques showed moderate agreement (Kappa = 0.5364). Of the independent variables analyzed, presence of clinical signs (p0.05) was the only one associated with CVL. Based on this study, we conclude that VL is a circulating disease, with relatively low prevalence, in dogs of Barão de Melgaço/MT, and that the presence of clinical signs is the only variable associated with canine infection.

RESUMO: A crescente expansão da leishmaniose visceral (LV) no território brasileiro evidencia a necessidade de estudos voltados ao principal reservatório doméstico do parasito: o cão. Sendo assim, o objetivo deste estudo foi realizar um inquérito epidemiológico no município de Barão de Melgaço, região do Pantanal Mato-grossense, utilizando as técnicas de reação em cadeia pela polimerase convencional (PCR) e teste qualitativo SYBR®Green real-time PCR (qPCR) para o diagnóstico da LV canina (LVC), além de caracterizar os fatores associados a infecção. Do total de 402 cães que tiveram amostras sanguíneas coletadas, 31 apresentaram o DNA do parasito, perfazendo uma prevalência de 7,71% na população estudada. Os índices de positividade para a PCR e qPCR foram de 3,48% (14/402) e 7,21% (29/402), respectivamente. A comparação dos resultados obtidos por ambas técnicas apresentou moderada concordância (Kappa = 0,5364). Das variáveis independentes analisadas, a presença de sinais clínicos (p0,05) foi a única associada a ocorrência de LVC. Com base neste estudo, concluímos que a LV está circulando, com prevalência relativamente baixa, em cães de Barão de Melgaço/MT, sendo a presença de sinais clínicos a única variável associada à infecção canina.

Molecular detection of Apicomplexa protozoa in tissues from Alouatta guariba clamitans

ABSTRACT: The brown howler monkey (Alouatta guariba clamitans) is a primate species widely distributed in South America. Infections by protozoa are common in primates. However, studies on protozoa in primates in Brazil are scarce, so the goal of this study was to investigate DNA from the apicomplexan protozoa Neospora caninum, Sarcocystis spp. and Toxoplasma gondii in tissues of A. guariba clamitans. DNA extraction was performed on tissue samples from the heart, brain, liver, spleen, lung and intestine of six A. guariba clamitans from Santa Maria, Central Region of Rio Grande do Sul, Brazil. Conventional PCR was performed using 18S rRNA gene general primers for Apicomplexa and also specific primers to amplify Neosporaspp. and Toxoplasma gondii DNA. All animals were positive in the 18S PCR and the genetic sequencing confirmed the presence of Sarcocystis spp. DNA in the tissues of four animals belonging to at least two species (S. neurona and S. gigantea) and T. gondii DNA in the other two animals. One positive sample for T. gondii was genotypically characterized as atypical by the restriction fragment length polymorphism technique. N. caninum DNA was not detected in the tested samples. The presence of Apicomplexa protozoan DNA in the tissues of the six animals tested in this study highlights the importance of howler monkeys as maintainers of these pathogens in nature.

RESUMO: O bugio ruivo (Alouatta guariba clamitans) é uma espécie de primata amplamente distribuída na América do Sul. As infecções por protozoários são comuns em primatas. Entretanto, estudos sobre protozoários em primatas no Brasil são escassos, portanto o objetivo deste estudo foi pesquisar DNA dos protozoários Apicomplexa Neospora caninum, Sarcocystisspp. e Toxoplasma gondii em tecidos de A. guariba clamitans. A extração de DNA foi realizada em amostras de tecido do coração, cérebro, fígado, baço, pulmão e intestino de seis A. guariba clamitans oriundos de Santa Maria, Região Central do Rio Grande do Sul, Brasil. Foi realizada PCR convencional utilizando primers geral do gene 18S rRNA para Apicomplexa e também primers específicos para amplificação de DNA de Neospora spp.e Toxoplasma gondii. Todos os animais foram positivos no PCR geral para Apicomplexa e no sequenciamento genético confirmou-se a presença de DNA de Sarcocystis nos tecidos de quatro animais pertencentes a pelo menos duas espécies (S. neurona e S. gigantea), e DNA de T. gondii foi detectado nos outros dois animais. Uma amostra positiva para T. gondii foi caracterizada genotipicamente como atípico pela técnica de polimorfismo do comprimento do fragmento de restrição. Não foi detectado DNA de N. caninum nas amostras testadas. A presença de DNA de protozoários apicomplexa nos tecidos dos seis animais testados neste estudo destaca a importância dos bugios ruivos como mantenedores desses patógenos na natureza.

Evaluation of an active and early surveillance methodology for visceral leishmaniasis by molecular detection in road-killed wild fauna / Avaliação de metodologia de vigilância ativa e precoce da leishmaniose visceral por detecção molecular em fauna silvestre atropelada

Abstract The present study aimed to evaluate a methodology for active surveillance of visceral leishmaniasis by detecting Leishmania DNA in organs of wild road-killed animals from November 2016 to October 2018 in the North of Paraná, Brazil. The collection points of road-killed wild animals were georeferenced. The animals were autopsied and samples of bone marrow, lymph node, liver, spleen, and ear skin were collected. Genomic DNA was extracted and subjected to PCR for amplification of Leishmania spp. 18S, kinetoplastic DNA (kDNA), HSP70, and ITS1 genes, and DNA sequencing was performed. The primers used for the amplification of kDNA, ITS1, and HSP70 genes presented non-specific results. Of the 66 mammals collected from 24 different municipalities, one Southern Tamandua (Tamandua tetradactyla) presented DNA of Leishmania spp. in lymph nodes by 18S PCR. DNA sequencing confirmed the results of the subgenus, Viannia, identification. We suggest using the methodology showed in the present study in the active and early surveillance of visceral leishmaniasis in a non-endemic area.

Resumo O objetivo do presente estudo foi avaliar uma metodologia de vigilância ativa da leishmaniose visceral por meio da detecção de DNA de Leishmania em órgãos de animais silvestres atropelados, de novembro de 2016 a outubro de 2018, no Norte do Paraná, Brasil. Os pontos de coleta dos animais silvestres atropelados foram georreferenciados. Os animais foram autopsiados e amostras de medula óssea, linfonodo, fígado, baço, e pele de orelha foram coletados. DNA genômico foi extraído e submetido à PCR para amplificação de quatro diferentes regiões de Leishmania spp.: 18S, kDNA, HSP70 e ITS1, sequenciamento de DNA foi realizado. Os iniciadores utilizados para a amplificação dos genes kDNA, ITS1 e HSP70 apresentaram resultados inespecíficos. Dos 66 mamíferos coletados em 24 diferentes municípios, um tamanduá-mirim (Tamandua tetradactyla) apresentou DNA de Leishmania spp. em linfonodo na PCR, que amplificou o gene 18S. O sequenciamento de DNA confirmou o resultado e demonstrou a presença do subgênero Viannia. Sugere-se o uso da metodologia apresentada no presente estudo na vigilância ativa e precoce da leishmaniose visceral em área não endêmica.

Analytical and clinical performance of molecular assay used by the Brazilian public laboratory network to detect and discriminate Zika, Dengue and Chikungunya viruses in blood

ABSTRACT In response to the Zika epidemics in Brazil, the ZDC molecular assay (Bio-Manguinhos) was developed and registered at the Brazilian Regulatory Agency of Health Surveillance - ANVISA. The circulation of Zika (ZIKV) Dengue (DENV) and Chikungunya (CHIKV) viruses and their clinical similarities are challenges to correctly diagnose these viruses. The simultaneous detection of ZIKV, DENV and CHIKV is an important tool for diagnosis and surveillance. Here, we present the analytical and clinical performance evaluation of ZDC molecular assay (Bio-Manguinhos) at the public health laboratories three years after its registration at ANVISA. The clinical performance demonstrates the ZDC molecular assay (Bio-Manguinhos) has 100% sensitivity and 100% specificity to detect and discriminate ZIKV, CHIKV, and DENV from clinical plasma samples. The ZDC molecular assay (Bio-Manguinhos) results were highly reproducible and no cross-reactivity was seen during testing with a panel of other infectious agents. In conclusion, the ZDC molecular assay (Bio-Manguinhos) is an accurate and reliable tool to monitor Zika, dengue and chikungunya infections in countries like Brazil with simultaneous circulation of the three viruses.

DNA extraction methods for molecular detection of Eimeria spp. in cattle and sheep / Métodos de extração de DNA para detecção molecular de Eimeria spp. em bovinos e ovinos

Molecular detection of Eimeria species in fecal samples can be useful for experimental and diagnostic purposes. However, the parasite quantity presence in feces and the oocyst wall are an obstacle in DNA extraction protocols. Therefore, adequate sampling and effective disruption of the oocysts are essential to improve the accuracy of DNA detection by PCR. The aims of this study were to evaluate the suitability of six protocols for DNA extraction from Eimeria spp. present in bovine and sheep. Twenty pools of fecal samples from cattle (10 pools) and sheep (10 pools) were distributed to six DNA extraction protocols: commercial kit, commercial kit with modification, DNAzol, cetyl-trimethyl ammonium bromide (CTAB), glass beads and commercial kit for fecal samples. Fecal samples were submitted to DNA extraction and PCR. Among the protocols tested, CTAB was determined to be most suitable for DNA extraction from oocysts (90% of DNA detection by PCR); DNAzol and CTAB resulted in higher DNA detection from bovine samples (80%). CTAB and commercial kit with modification improved PCR detection of Eimeria spp. in sheep samples, with positive amplification of DNA in all tested samples.(AU)

A detecção molecular de espécies de Eimeria em amostras fecais pode ser útil para fins experimentais e de diagnóstico. No entanto, a quantidade de parasitas nas fezes e a parede do oocisto são um obstáculo nos protocolos de extração de DNA. Portanto, uma amostragem adequada e a ruptura efetiva dos oocistos são essenciais para melhorar a precisão da detecção de DNA por PCR. Os objetivos deste estudo foram avaliar seis protocolos para extração de DNA de Eimeria spp. em amostras de bovinos e ovinos. Foram distribuídos 20 grupos de amostras fecais de bovinos (10 grupos) e ovinos (10 grupos) em seis protocolos de extração de DNA: kit comercial, kit comercial com modificação, DNAzol, brometo de cetil-trimetil amônio (CTAB), pérolas de vidro e kit comercial para amostras fecais. As amostras fecais foram submetidas à extração de DNA e PCR. Entre os protocolos testados, CTAB foi considerado o mais adequado para extração de DNA de oocistos (90% de detecção de DNA por PCR); DNAzol e CTAB resultaram em maior detecção de DNA em amostras de bovinos (80%). CTAB e kit comercial com modificação melhoraram a detecção por PCR de Eimeria spp. em amostras de ovinos, amplificação positiva de DNA em todas as amostras testadas.(AU)

Pestivirus spillover effect: molecular detection of bovine viral diarrhea virus in domestic and feral pigs / Efeito spillover de pestivírus: detecção molecular do vírus da diarreia viral bovina em suínos domésticos e javalis

Pestivirus infections are important in the livestock industries, with infection occurring in cattle, sheep and pigs. The Pestivirus genus of the family Flaviviridae, includes four recognized species: bovine viral diarrhea virus 1 (BVDV-1), bovine viral diarrhea virus 2 (BVDV-2), border disease virus (BDV), and classical swine fever virus (CSFV). All pestivirus species can infect pigs, therefore accurate and specific pestivirus detection and differentiation is of great importance to assure control measures in swine populations. The aim of the study was the molecular detection of different pestiviruses in domestic and feral pigs. A total of 527 samples (92 pigs and 435 wild boars) were tested for pestiviruses detection using molecular assays. Eleven positive samples (6 wild boars and 5 domestic pigs) were identified using panpestivirus primers targeting the 5'- UTR region of the pestivirus RNA genome. Further all the positive samples were sequentially tested for detection of CSFV, BVDV-1 and BVDV-2 using specific primers. All RNAs were identified as positives for BVDV-1 and no amplification signals were obtained from BVDV-2 and CSFV. The current detection of BVDV-1 in clinical swine specimens highlights the important risk factor of swine population as reservoir and consequently carrier for BVDV.(AU)

As infecções por pestivírus são importantes nas indústrias pecuárias, com infecções em bovinos, ovinos e suínos. O gênero Pestivirus da família Flaviviridae inclui quatro espécies reconhecidas: vírus da diarreia viral bovina 1 (BVDV-1), vírus da diarreia viral bovina 2 (BVDV-2), vírus da doença de fronteira (VDF) e vírus da peste suína clássica (VPSC). Todas as espécies de pestivírus podem infectar porcos, portanto a detecção e diferenciação precisas e específicas de pestivírus são de grande importância para garantir medidas de controle nas populações suínas. O objetivo do estudo foi a detecção molecular de diferentes pestivírus em suínos domésticos e javali. Um total de 527 amostras (92 porcos e 435 javalis) foram testados para detecção de pestivírus usando ensaios moleculares. Onze amostras positivas (6 javalis e 5 porcos domésticos) foram identificadas usando iniciadores de panpestivírus visando a região 5'-UTR do genoma do RNA do pestivírus. Além disso, todas as amostras positivas foram testadas sequencialmente para detecção de VPSC, BVDV-1 e BVDV-2 usando iniciadores específicos. Todos os RNAs foram identificados como positivos para BVDV-1 e nenhum sinal de amplificação foi obtido do BVDV-2 e CSFV. A detecção atual do BVDV-1 em amostras clínicas de suínos destaca o importante fator de risco da população suína como reservatório e consequentemente portador do BVDV.(AU)

First report of Sugarcane mosaic virus in achira (Canna edulis Ker.) in Nariño, Colombia / Primer registro del Sugarcane mosaic virus en achira (Canna edulis Ker.) en Nariño, Colombia

ABSTRACT Achira (Canna edulis Ker.) is a cultivated species for handcrafted food products and starch production. In Colombia is estimated an achira cultivated area of 800 ha; in the department of Nariño there has been a disturbance of viral etiology, known by farmers as Streak Virus, due to its symptoms in the leaves, but without previous records in the area. The disease causes losses in performance, although they have not been established precisely. In order to clarify the nature of this pathology and the identity of the pathogen associated with the problem, an investigation was carried out at the University of Nariño, by means of molecular tests of PCR and RT-PCR, sequencing, serology and electron microscopy, of foliar samples collected in the producing areas. The most outstanding symptoms in affected tissues were yellow mosaic, mottled, chlorotic streak and ribs discoloration, among others. There were no cytoplasmic inclusions similar to those produced by Potyvirus, nor viral particles were observed, nor serology positive results, but it was possible to achieve the amplification of a cDNA fragment, with specific primers for Potyvirus and 98% of homology of the sequences with Sugarcane mosaic virus. This is the first SCMV report in achira in Nariño, Colombia.

RESUMEN La achira (Canna edulis Ker.) es una especie utilizada para la producción de almidón y alimentos artesanales. En Colombia, se estima un área cultivada de 800ha; en el departamento de Nariño, se viene presentando un disturbio de etiología viral, conocido por los agricultores como el rayado, por sus síntomas en las hojas, pero sin registros previos en esta zona. La enfermedad causa pérdidas en el rendimiento, aunque no se ha establecido con precisión. Con el objetivo de esclarecer la naturaleza de dicha patología y la identidad del patógeno asociado al problema, en la Universidad de Nariño, se realizó una investigación, mediante pruebas moleculares de PCR y RT-PCR, secuenciación, serología y microscopía electrónica, de muestras foliares colectadas en las zonas productoras. Los síntomas más sobresalientes en tejidos afectados fueron mosaico amarillo, moteado, rayado clorótico, aclaramiento de nervaduras entre otros. No se detectaron inclusiones citoplasmáticas similares a las producidas por Potyvirus, ni se observaron partículas virales, tampoco hubo resultados positivos con serología, pero sí se logró amplificación de un fragmento de cDNA, con cebadores específicos para Potyvirus y homología de 98% de las secuencias con el virus Sugarcane mosaic virus SCMV. Este es el primer reporte de SCMV en achira en Nariño, Colombia.

Microbiological and molecular detection of Mycoplasma bovis in milk samples from bovine clinical mastitis / Detecção microbiológica e molecular de Mycoplasma bovis em amostras de leite oriundas de mastite clínica bovina

The genus Mycoplasma includes more than 200 bacterial species that cause disease in animals. It is responsible for causing mastitis in bovines and may be related to other manifestations, such as arthritis and pneumonia in calves and heifers. The present study aimed to detect Mycoplasma bovis isolated from milk samples of bovine clinical mastitis, and to compare the isolation rates in two culture media: Hayflick and SP4. An initial screening was performed in order to detect the presence of the class Mollicutes in 1166 milk samples from clinical mastitis by the conventional Polymerase Chain Reaction (PCR) technique. According to the 1166 milk samples evaluated, 8.6% (100/1166) were positive to class Mollicutes. Regarding molecular analyses, 1.1% (13/1166) of conventional PCR for positive M. bovis was obtained and 0.9% (11/1166) in real-time PCR. The results of the microbiological culture of the 100 samples previously screened demonstrated that 6% (6/100) of colony growth have been developed when using the Hayflick medium, and 11% (11/100) when using the SP4 medium (including the positive on Hayflick medium). Concerning the 11 isolates obtained in the microbiological culture, conventional PCR confirmed M. bovis in nine of them, and two cultures were negative. In the phylogenetic analysis of the isolates, all of them were grouped in M. bovis and M. agalactiae clusters. The results confirmed the importance of the presence of M. bovis in the etiology of bovine clinical mastitis and reinforced the need for further studies to elucidate other Mycoplasma species that may be involved in bovine clinical mastitis in Brazil.(AU)

O gênero Mycoplasma inclui mais de 200 espécies que causam doenças nos animais. É responsável por quadros de mastite em bovinos, podendo também estar relacionado à outras manifestações como artrite e pneumonia em bezerros e novilhas. O presente estudo objetivou a detecção de Mycoplasma bovis isolados a partir de amostras de leite de mastite clínica bovina, bem como, a comparação da taxa de isolamento em dois meios de cultura: Hayflick e SP4. Para efeito de triagem amostral, foram avaliadas quanto à presença da classe Mollicutes 1166 amostras de leite de casos de mastite clínica pela técnica de PCR convencional. Das 1166 amostras de leite avaliadas, 8,6% (100/1166) foram positivas à classe. Nas análises moleculares, obteve-se 1,1% (13/1166) de positividade para Mycoplasma bovis na PCR convencional e 0,9% (11/1166) na PCR em tempo real. Os resultados do cultivo microbiológico das 100 amostras triadas previamente demonstraram 6% (6/100) de crescimento de colônias ao se utilizar o meio Hayflick e 11% (11/100) ao se utilizar o meio SP4 (incluindo as positivas ao primeiro). A partir dos 11 isolados obtidos no cultivo microbiológico, a PCR convencional confirmou Mycoplasma bovis em nove deles, e dois foram negativos para o agente. Na análise filogenética dos isolados, todos agruparam no cluster Mycoplasma bovis e Mycoplasma agalactiae. Frente aos resultados, ressalta-se a importância da presença de Mycoplasma bovis na etiologia da mastite clínica bovina e reforça a necessidade de estudos mais aprofundados para a elucidação de outras espécies de micoplasmas que possam estar envolvidas na mastite bovina.(AU)

High proportion of cattle and sheep seropositive and renal carriers of Leptospira sp. under semiarid conditions / Alta proporção de bovinos e ovinos soropositivos e portadores renais de Leptospira sp. em condições semiáridas

The aims of this study were to perform serological and molecular detection of Leptospira sp. infection in cattle and sheep under semiarid conditions. Based on a preliminary study performed in our research group, we selected six rural properties showing a positivity ≥ 60% for Sejroe serogroup with titer ≥ 200 measured in serological tests from cattle. In the present study, blood and urine samples were collected from 99 females of reproductive age (51 cattle and 48 sheep) for serological diagnosis, molecular detection and Leptospira sp. attempt to strain recovery. Of the 99 analyzed animals 38.4% (38/99) were positively reactive at the serological tests. Of them, 49% (25/51) were cattle and 27.1% (13/48) sheep. The serogroups detected in cattle were Sejroe (36.8%), Hebdomadis (26.3%), Australis (10.5%), Djasiman (10.5%), Ballum (5.3%), Pomona (5.3%), and Cynopteri (5.3%) with titers of 100­800. In sheep, the reactive serogroups were Australis (27.3%), Ballum (27.3%), Djasiman (18.1%), Tarassovi (9.1%), Icterohaemorrhagiae (9.1%), and Cynopteri (9.1%) with titers of 100­400.Leptospiral DNA was detected in nine urine samples, including five cattle and four sheep. Property 1 showed the highest serological positivity frequencies for both cattle (70.6%) and sheep (70.6%). Similarly, the highest frequency of DNA detection was also found (eight samples, 89%). In this property, we observed the existence of consorted rearing of cattle and sheep with close coexistence between these species. In semiarid conditions, transmission among animals of the same species seems to be the main form of Leptospira sp. dissemination in cattle and sheep herds. However, the contribution of other domestic and wild animals cannot be discarded. The practice of consorted rearing of cattle and sheep and their close coexistence may facilitate the spread of the pathogen in rural properties.

Os objetivos deste estudo foram realizar detecção sorológica e molecular da infecção por Leptospira sp. em bovinos e ovinos em condições semiáridas. Com base em estudo preliminar realizado em nosso grupo de pesquisa, foram selecionadas seis propriedades rurais com soropositividade ≥ 60% para o sorogrupo Sejroe com título ≥ 200 em bovinos. No presente estudo, amostras de sangue e urina foram coletadas de 99 fêmeas em idade reprodutiva (51 bovinos e 48 ovinos) para diagnóstico sorológico, detecção molecular e tentativa de recuperação de estirpesde Leptospira sp. Dos 99 animais analisados, 38,4% (38/99) foram sororeativos nos testes sorológicos. Destes, 49% (25/51) eram bovinos e 27,1% (13/48) ovinos. Os sorogrupos detectados em bovinos foram Sejroe (36,8%), Hebdomadis (26,3%), Australis (10,5%), Djasiman (10,5%), Ballum (5,3%), Pomona (5,3%) e Cynopteri (5,3%) com títulos de 100 a 800. Nos ovinos, os sorogrupos reativos foram Australis (27,3%), Ballum (27,3%), Djasiman (18,1%), Tarassovi (9,1%), Icterohaemorrhagiae (9,1%) e Cynopteri (9,1%) com títulos de 100-400. O DNA leptospiral foi detectado em nove amostras de urina, incluindo cinco bovinos e quatro ovinos. A propriedade 1 apresentou as maiores frequências de positividade sorológica para bovinos (70,6%) e ovinos (70,6%). Da mesma forma, a maior frequência de detecção de DNA também foi encontrada (oito amostras, 89%). Nesta propriedade observou-se a existência de criação consorciada de bovinos e ovinos com estreita convivência entre estas espécies. Em condições semiáridas, a transmissão entre animais da mesma espécie parece ser a principal forma de disseminação de Leptospira sp. em rebanhos bovinos e ovinos. No entanto, a contribuição de outros animais domésticos e selvagens não pode ser descartada. A prática de criação consorciada de bovinos e ovinos e sua estreita convivência podem facilitar a disseminação do patógeno em propriedades rurais.