Survey of vector-borne and nematode parasites involved in the etiology of anemic syndrome in sheep from Southern Brazil / Pesquisa de hemoparasitos transmitidos por vetores e nematódeos envolvidos na etiologia de síndrome anêmica em ovinos no Sul do Brasil

Abstract Although anemia has been historically linked to Haemonchus contortus infection, other infectious agents, such as hemotropic mycoplasmas and tick-borne disease pathogens, may also lead to anemic crisis in sheep. This study has aimed to investigate infections related to anemia in a sheep herd from Bandeirantes City, Paraná State, southern Brazil. Seven out of forty-two (16.6%; 95% CI: 8.32-30.6%) sheep were positive for hemoplasmas by a PCR targeting the 16S rRNA gene and all tested negative for A. marginale/A. ovis and Babesia/Theileria spp. by PCR based on msp4 and 18S rRNA genes, respectively. Two (4.7%; 95% CI: 1.32-15.79%) animals were infested with Rhipicephalus microplus ticks. Fecal egg counting was performed in 38 sheep and 24 (63.15%; 95% CI: 47.2-76.6%) presented > 500 eggs per gram. Phylogenetic analysis of partial sequences of the detected hemotropic Mycoplasma sp. 16S and 23S rRNA genes confirmed that the animals were infected with Mycoplasma ovis. Polymorphism analysis of partial 16S rRNA sequences showed three different genotypes of M. ovis infecting sheep assessed in the present study. Mycoplasma ovis and gastrointestinal nematodes occurs in sheep from the northern region of Paraná State.

Resumo Embora a principal causa de anemia seja historicamente relacionada à infecção por Haemonchus contortus, outros agentes infecciosos, como micoplasmas hemotrópicos e patógenos transmitidos por carrapatos, também podem causar quadros anêmicos em ovinos. O presente estudo objetivou investigar infecções relacionadas à anemia em um rebanho de ovinos, na cidade de Bandeirantes, Estado do Paraná, sul do Brasil. Sete (16,6%; 95% CI: 8,32-30,6%) de 42 ovinos foram positivos para hemoplasmas pela PCR do gene 16S rRNA, enquanto todos foram negativos para A. marginale/A. ovis e Babesia/Theileria spp. por ensaios da PCR baseados nos genes msp4 e 18S rRNA, respectivamente. Dois (4,7%; 95% CI: 1,32-15,79%) animais estavam infestados por carrapatos Rhipicephalus microplus. Dos 38 animais nos quais foi realizada a contagem de ovos por grama de fezes (OPG), 24 (63,15%; 95% CI: 47,2-76,6%) apresentaram valores >500 para OPG. A análise filogenética das sequências parciais dos genes 16S rRNA e 23S rRNA de hemoplasmas confirmou a infecção por Mycoplasma ovis. A análise de polimorfismos de um fragmento do gene 16S rRNA mostrou a ocorrência de três genótipos diferentes de M. ovis nos animais. Mycoplasma ovis e nematódeos gastrointestinais ocorrem em ovinos da região nordeste do Estado do Paraná.

Bacteria isolated from the lower respiratory tract of sheep and their relationship to clinical signs of sheep respiratory disease / Bactérias detectadas no trato respiratório inferior de ovinos e a relação com as manifestações clínicas da doença respiratória ovina

Respiratory diseases are among the most important diseases in sheep flocks. Herein was studied the bacterial etiology of respiratory disease and the clinical signs of 99 female and male sheep breed in the states of São Paulo (SP) and Rio de Janeiro (RJ), Brazil. After physical examination of animals, tracheobronchial flushing samples were obtained. The usual bacteria and Mycoplasma spp. were searched, as well as their association with the clinical status and clinical signs of sheep with respiratory disease. The main observed signs were: tachypnea (75%), increase of rectal temperature (09.4%), mucopurulent/purulent nasal discharge (21.9%), cough (25%), dyspnea (31.2%), changes of lung sounds at auscultation (87.5%) and chest percussion (28.1%) in pneumonic sheep. Non-fermenting gram-negative bacteria and Bacillus sp. were the most isolated bacteria. Microorganisms of the Mollicutes class were molecularly (PCR) detected in 33.3% of the animals. In addition, the specific detection of M. mycoides subsp. capri was described for the first time in sheep from the state of São Paulo, Brazil.(AU)

A doença respiratória é uma das doenças mais importantes em rebanhos ovinos. Esta pesquisa teve como objetivo determinar a etiologia bacteriana da doença respiratória e sua relação com sinais clínicos em ovinos criados nos estados de São Paulo e Rio de Janeiro, Brasil. Noventa e nove ovelhas machos e fêmeas dos Estados de São Paulo (SP) e Rio de Janeiro (RJ) foram estudadas. Após o exame físico, amostras de lavagem traqueobrônquica foram obtidas. A presença de bactérias aeróbias e Mycoplasmaspp. foram estudados, assim como a associação entre os microrganismos e estado clínico e sinais clínicos de doença respiratória em ovinos. As principais manifestações clínicas observadas foram: taquipneia (75%), alta temperatura retal (09,4%), secreção nasal mucopurulenta/purulenta (21,9%), tosse (25%), dispneia (31,2%), sons pulmonares alterados na ausculta (87,5%) e na percussão torácica (28,1%) em ovelhas pneumônicas. Bactérias gram-negativas não fermentadoras e Bacillus sp. foram as bactérias mais isoladas. Microrganismos da classe Mollicutes foram detectados molecularmente (PCR) em 33,3% dos ovinos. Além disso, descreve-se pela primeira vez no estado de São Paulo, Brasil, a detecção do M. mycoides subsp. capri na espécie ovina utilizando a reação de polimerase em cadeia.(AU)

First molecular detection of Mycoplasma ovis (Hemotropic mycoplasmas) from Sheep in Brazil / Primeira detecção molecular de Mycoplasma ovis (Micoplasmas Hemotrópicos) em Ovinos no Brasil

Abstract Mycoplasma ovis is an emerging zoonotic pathogen with a worldwide distribution and can cause mild to severe hemolytic anemia, icterus, and poor weight gain in animals. Although M. ovis has been described in small ruminants worldwide, data on M. ovis in sheep in Brazil is unknown. The objective of the present study was to present the first report of hemotropic mycoplasma (HM) in sheep from Brazil. We evaluated factors associated with this infection, such age group, tick presence, and anemia. Blood samples were collected from 33 sheep from a farm in southern Brazil and screened for hemoplasmas using PCR. Out of 33 samples, 26 (78.8%) tested positive for M. ovis. The sequencing of positive samples showed 100% identity with multiple M. ovis 16S rDNA sequences. No association was observed between the presence of M. ovis and the FAMACHA© score (p = 0.620). Rhipicephalus (Boophilus) microplus (15/33, 45.4%) was the tick species found on the animals. No significant association between M. ovis infection and presence of ticks (p = 0.4134) and age group (p = 0.4221) was observed. This is the first report of M. ovis infection in sheep from Brazil and only the second report of this pathogen in sheep in Latin America.

Resumo Mycoplasma ovis é um patógeno zoonótico emergente com distribuição mundial e pode causar anemia hemolítica de leve a grave, icterícia e baixo ganho de peso em animais. Embora M. ovis tenha sido descrito em pequenos ruminantes em todo o mundo, os dados sobre M. ovis em ovinos no Brasil são desconhecidos. O objetivo deste estudo foi apresentar o primeiro relato de micoplasmas hemotrópicos em ovinos no Brasil. Avaliamos os fatores associados a essa infecção, como faixa etária, presença de carrapatos e anemia. Amostras de sangue foram coletadas de 33 ovelhas de uma fazenda no sul do Brasil e testadas para hemoplasmas usando a PCR. Das 33 amostras, 26 (78,8%) apresentaram resultado positivo. O sequenciamento das amostras positivas mostrou 100% de identidade com múltiplas sequências de M. ovis 16S rDNA. Não foi observada associação entre a presença de M. ovis e o escore FAMACHA© (p = 0,620). Rhipicephalus (Boophilus) microplus (15/33, 45,4%) foi a espécie de carrapato encontrada nos animais. Não houve associação significativa entre infecção por M. ovis e presença de carrapatos (p = 0,4134) e faixa etária (p = 0,4221). Este é o primeiro relato de infecção por M. ovis em ovinos no Brasil e o segundo relato deste patógeno em ovinos na América Latina.

Serological diagnosis and risk factors for Coxiella burnetii in goats and sheep in a semi-arid region of Northeastern Brazil / Diagnóstico sorológico e fatores de risco para Coxiella burnetii em caprinos e ovinos da região semiárida do nordeste do Brasil

Abstract Coxiella burnetii is a zoonotic agent transmitted mainly by small ruminants. In Brazil the disease has been classified as a notifiable disease since 2013, when human cases were reported. This study aimed to identify risk factors associated with the presence of anti- Coxiella burnetii antibodies in goats and sheep in a semiarid region of Northeastern Brazil. Sera of 412 goats and 403 sheep from municipality of Petrolina, Pernambuco, were examined by the Indirect Fluorescent Antibody Test (IFAT) against antigens of C. burnetii. Information about management variables (independent variables) that could be associated with the presence of the microorganism (dependent variables) were obtained from the supervisor of each farm. It was determined that 2.2% (9/412) of the goats and 2.1% (9/403) of the sheep had antibodies reactive to C. burnetii. The presence of anti-C. burnetii antibodies was associated with the dry area of the Sequeiro (a region in the northern part of the municipality of Petrolina) (P = 0.025), male sheep (P = 0.020), and intensive goat breeding (P = 0.005). This study therefore showed the presence of anti-C. burnetii antibodies in goat and sheep, confirming for the first time that this agent is likely circulating among goat herds in the Caatinga Biome, semi-arid of Brazil.

Resumo Coxiella burnetii é um agente zoonótico transmitido principalmente por pequenos ruminantes. No Brasil, a doença foi classificada como de notificação compulsória desde 2013, quando casos humanos foram relatados. O objetivo deste estudo foi identificar os fatores de risco associados à presença de anticorpos anti-Coxiella burnetii em caprinos e ovinos em uma região semiárida do Nordeste do Brasil. Este estudo envolveu um inquérito sorológico de 412 caprinos e 403 ovinos em fazendas do município de Petrolina, no estado de Pernambuco. Os soros foram examinados pela Reação de Imunofluorescência Indireta (RIFI) contra antígenos de C. burnetii . Informações sobre variáveis ​​de manejo (variáveis ​​independentes) que poderiam estar associadas à presença do microrganismo (variáveis ​​dependentes) foram obtidas do proprietário de cada fazenda. Foi determinado que 2,2% (9/412) dos caprinos e 2,1% (9/403) dos ovinos tinham anticorpos reativos a C. burnetii. A presença de anticorpos anti-C. burnetii foram associados com a área seca do Sequeiro (região no norte do município de Petrolina) (P = 0,025), ovinos machos (P = 0,020) e criação intensiva de caprinos (P = 0,005). Este estudo, portanto, observou a presença de anticorpos anti-C. burnetii em pequenos ruminantes, confirmando pela primeira vez que este agente pode estar circulando em rebanhos caprinos no bioma Caatinga, semiárido do Brasil.

Histophilus somni-associated syndromes in sheep from Southern Brazil

Abstract Histophilus somni is a Gram-negative bacterium that is associated with a disease complex (termed histophilosis) that can produce several clinical syndromes predominantly in cattle, but also in sheep. Histophilosis is well described in North America, Canada, and in some European countries. In Brazil, histophilosis has been described in cattle with respiratory, reproductive, and systemic disease, with only one case described in sheep. This report describes the occurrence of Histophilus somni-associated disease in sheep from Southern Brazil. Eight sheep with different clinical manifestations from five farms were investigated by a combination of pathological and molecular diagnostic methods to identify additional cases of histophilosis in sheep from Brazil. The principal pathological lesions were thrombotic meningoencephalitis, fibrinous bronchopneumonia, pulmonary abscesses, and necrotizing myocarditis. The main clinical syndromes associated with H. somni were thrombotic meningoencephalitis (n = 4), septicemia (n = 4), bronchopneumonia (n = 4), and myocarditis (n = 3). H. somni DNA was amplified from multiple tissues of all sheep with clinical syndromes of histophilosis; sequencing confirmed the PCR results. Further, PCR assays to detect Pasteurella multocida and Mannheimia haemolytica were negative. These findings confirmed the participation of H. somni in the clinical syndromes investigated during this study, and adds to the previous report of histophilosis in sheep from Brazil.

Molecular characterization of ureaplasmas isolated from reproductive tract of goats and sheep from Brazil

Abstract Ovine/caprine ureaplasmas have not yet been assigned a species designation, but they have been classified into nine serotypes. Herein ureaplasmas were searched for in 120 samples of vulvo vaginal mucous from sheep and 98 samples from goats at 17 farms. In addition, semen samples were collected from 11 sheep and 23 goats. The recovered ureaplasma were from sheep and goats from animals without any reproductive disorder symptoms, but not all animals presented positive cultures. In sheep, 17 (68%) cultures of vulvovaginal mucous were positive for ureaplasma and 11 (27%) samples of semen presented positive cultures in animals with clinical signs of orchitis, balanoposthitis or low sperm motility. In goats four ureaplasma isolates were obtained from vulvovaginal mucus, but the semen samples were all negative. The isolates were submitted to Pulsed-field gel electrophoresis methodology and their 16S rRNA genes were sequenced. Fifty percent of ureaplasma recovered from sheep allowed for PFGE typing. Eleven isolates showed eight profiles genetically close to the bovine ureaplasmas. The 16S rRNA gene sequencing showed differences or similarities of isolates from sheep and goats, and the reference strains of bovine and human ureaplasma. Four clinical isolates from sheep were grouped separately. The studied ureaplasma isolates showed to be a diverse group of mollicutes.

Epidemiología de la brucelosis caprina y ovina en la provincia de Formosa, Argentina / Epidemiology of caprine and ovine brucellosis in Formosa province, Argentina

Se realizó un estudio epidemiológico de brucelosis en 516 majadas caprinas o mixtas (caprinos/ovinos) de las 3 regiones agroecológicas de la provincia de Formosa, Argentina. Mediante las pruebas de aglutinación en placa con antígeno tamponado y de fijación del complemento en suero se estudiaron un total de 25.401 caprinos y 2.453 ovinos. Además, se realizaron cultivos bacteriológicos y PCR en muestras de leche de cabras de 3 majadas con brucelosis y abortos recientes. Se detectó brucelosis en 4 de los 9 departamentos de la provincia, la prevalencia global fue del 2 % y la intrapredial varió entre el 1 y el 40%. La proporción de majadas positivas fue del 3,6, el 12 y el 36 % para las regiones este, centro y oeste, respectivamente. Se aisló Brucella melitensis bv. 1 de cabras por primera vez en la provincia. La PCR amplificó fragmentos esperados de 827 pb correspondiente al gen omp2ab (Brucella spp.) y de 731 pb correspondiente al inserto IS711 (B. melitensis). La detección de anticuerpos en ovinos que cohabitan con caprinos sugiere que las infecciones habrían sido causadas por B. melitensis, lo que constituye un riesgo adicional para la salud pública. Los programas de control y erradicación de la brucelosis deberían considerar las majadas mixtas como una sola unidad epidemiológica. Los resultados indican que la brucelosis por B. melitensis bv. 1 es altamente endémica en las regiones centro y oeste de la provincia de Formosa.

An epidemiological study of brucellosis was carried out in 516 goats and mixed flocks (goat/sheep) from the three agro-ecological regions of Formosa province, Argentina. Serum samples from a total of 25401 goats and 2453 sheeps were analyzed using buffered plate agglutination test (BPAT) and complement fixation test (CFT). Bacteriological and PCR analyses on milk samples from goats in three flocks with a history of brucellosis and recent abortions were also performed. Brucellosis was detected in four of the nine departments of the province with an overall prevalence of 2 % and an intra-flock prevalence ranging between 1 % and 40 %. The proportion of infected flocks was 3.6 %, 12 % and 36 % for the eastern, central and western regions, respectively. Brucella melitensis bv. 1 was isolated efrom goats for the first time in the province. The expected fragments of 827 bp from the omp2ab gene (Brucella spp.) and 731 bp from the insert IS711 (B. melitensis) were amplified by PCR. Detection of antibodies by BPAT and FCT in sheep cohabiting with goats suggests that infections could have been caused by B. melitensis, posing an additional risk to public health. Control and eradication programs for brucellosis should consider mixed flocks as a single epidemiological unit. The results indicate that brucellosis by B. melitensis bv1 is highly endemic in the central and western regions of Formosa province.

Differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis

The aim of this study was to determine the differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis. Thirty-two strains of Moraxella spp. isolated from cattle and sheep with infectious keratoconjunctivitis were tested via broth microdilution method to determine their susceptibility to ampicillin, cefoperazone, ceftiofur, cloxacillin, enrofloxacin, florfenicol, gentamicin, neomycin, oxytetracycline and penicillin. The results demonstrated that Moraxella spp. strains could be considered sensitive for most of the antimicrobials tested in this study, but differences between the antimicrobial susceptibility profiles of these three Moraxella species were found. M. bovis might differ from other species due to the higher MIC and MBC values it presented.

Molecular typing of Argentinian Mycobacterium avium subsp. paratuberculosis isolates by multiple-locus variable number-tandem repeat analysis

Multiple-locus variable number-tandem repeat analysis (MLVA) of Mycobacterium avium subspecies paratuberculosis (MAP) isolates may contribute to the knowledge of strain diversity in Argentina. Although the diversity of MAP has been previously investigated in Argentina using IS900-RFLP, a small number of isolates were employed, and a low discriminative power was reached. The aim of the present study was to test the genetic diversity among MAP isolates using an MLVA approach based on 8 repetitive loci. We studied 97 isolates from cattle, goat and sheep and could describe 7 different patterns: INMV1, INMV2, INMV11, INMV13, INMV16, INMV33 and one incomplete pattern. INMV1 and INMV2 were the most frequent patterns, grouping 76.3% of the isolates. We were also able to demonstrate the coexistence of genotypes in herds and co-infection at the organism level. This study shows that all the patterns described are common to those described in Europe, suggesting an epidemiological link between the continents.

First identification of Mycobacterium avium paratuberculosis sheep strain in Argentina

We here identified for the first time the presence of Mycobacterium avium paratuberculosis (MAP) sheep (S) strain in Argentina. IS900 polymerase chain reaction (PCR) was positive. The S strain was compared with MAP cattle (C) strains by using IS1311 PCR-restriction endonuclease analysis (PCR-REA), multiplex PCR and restriction fragment length polymorphism (RFLP) analysis.

Histopathological and molecular characterization of encephalitic listeriosis in small ruminants from northern Paraná, Brazil

Listeriosis is a disease primarily of ruminants caused by the Gram-positive bacterium Listeria monocytogenes. Ruminants either demonstrate manifestations of the encephalitic, septicemic, or reproductive form of listeriosis. The pathological and molecular findings with encephalitic listeriosis in a 5.5-month-old, male, mixed-breed goat and a 3-year-old Texel-crossed sheep from northern Paraná, Brazil are described. Clinically, the kid demonstrated circling, lateral protrusion of the tongue, head tilt, and convulsions; the ewe presented ataxia, motor incoordination, and lateral decumbency. Brainstem dysfunctions were diagnosed clinically and listeriosis was suspected. Necropsy performed on both animals did not reveal remarkable gross lesions; significant histopathological alterations were restricted to the brainstem (medulla oblongata; rhombencephalitis) and were characterized as meningoencephalitis that consisted of extensive mononuclear perivascular cuffings, neutrophilic and macrophagic microabscesses, and neuroparenchymal necrosis. PCR assay and direct sequencing, using genomic bacterial DNA derived from the brainstem of both animals, amplified the desired 174 base pairs length amplicon of the listeriolysin O gene of L. monocytogenes. Phylogenetic analyses demonstrated that the strains associated with rhombencephalitis during this study clustered with known strains of L. monocytogenes lineage I from diverse geographical locations and from cattle of the state of Paraná with encephalitic listeriosis. Consequently, these strains should be classified as L. monocytogenes lineage I. These results confirm the active participation of lineage I strains of L. monocytogenes in the etiopathogenesis of the brainstem dysfunctions observed during this study, probably represent the first characterization of small ruminant listeriosis by molecular techniques in Latin America, and suggest that ruminants within the state of Paraná were infected by the strains of the same lineage of L. monocytogenes.

Detection of Ureaplasma spp. in semen samples from sheep in Brazil

A study was conducted to verify the presence of mycoplasmas and ureaplasmas DNA in sheep semen samples from the State of Pernambuco. The PCR assay was conducted of according with standard protocols with generic primers. Mollicutes DNA was detected in 26.0% and Ureaplasma spp. in 12.0% of semen samples.

Respuesta humoral y consecuencias reproductivas en ovejas desafiadas con Brucella ovis al final de la gestación / Immune response and reproductive consequences in experimentally infected ewes with Brucella ovis during late pregnancy

La brucelosis ovina por Brucella ovis es una enfermedad de prevalencia alta en Argentina. Para evaluar la patogenicidad de B. ovis y la respuesta serológica durante el último mes de gestación, 6 ovejas se distribuyeron en dos grupos: G1, ovejas preñadas, n = 4 y G2, ovejas no preñadas, n = 2. Tres ovejas del G1 (15 días preparto) y una del G2 fueron inoculadas con B. ovis. Se analizaron muestras de suero mediante diferentes pruebas serológicas. Se realizó aislamiento y PCR a partir de mucus cérvico-vaginal (mcv), placenta y leche. En las muestras de placenta se realizó histopatología. Las hembras del G1 parieron corderos vivos; se detectaron anticuerpos en las ovejas desafiadas del G1 a partir de los 5 días posinoculación. El mcv de las ovejas desafiadas resultó negativo al aislamiento en ambos grupos. Las muestras de leche del G1 fueron positivas por cultivo y PCR a B. ovis. La técnica de PCR resultó positiva en las placentas de las ovejas desafiadas del G1. La histopatología reveló una placentitis necrótica supurativa en una de las ovejas desafiadas. El desafío con B. ovis preparto resultó en la invasión de la placenta y de la glándula mamaria, con la consecuente excreción de la bacteria por leche. La infección con B. ovis indujo una respuesta humoral temprana en las ovejas. La colonización de la placenta por B. ovis y la excreción de la bacteria por la leche sugieren un potencial riesgo de infección activa para los corderos y la posibilidad de que estos se comporten como portadores latentes de la infección.

Ovine brucellosis by Brucella ovis is a highly prevalent disease in Argentina. This study aimed to evaluate the pathogenicity of B. ovis and the serological response in ewes during late pregnancy and in their offspring. Six adult ewes were distributed in two groupsGI (pregnant females, n = 4) and G2 (nonpregnant females, n = 2). Three pregnant ewes at 15 days prepartum and one nonpregnant eve were inoculated with B. ovis. Sera of sheep and their offspring were analyzed by different serological tests. Samples of cervicovaginal mucus, placenta and milk were studied by bacteriology. A Brucella genus-specific PCR assay was carried out in placenta and milk samples. Placenta samples were hystopathologically processed. G1 females gave birth to live lambs, but one died hours postpartum. Serological techniques employed detected antibodies in serum of inoculated pregnant animal 5 days postchallenge. Sera of female controls G1 and G2 remained negative throughout the study. Cervicovaginal mucus of infected ewes in G1 and G2 yielded negative results to bacteriology, but B. ovis was isolated from milk. The PCR assay was positive for the placenta and milk from inoculated pregnant ewes. Histopathology revealed necrotic suppurative placentitis in one placenta. However, although results demonstrated that B. ovis can invade the placenta and mammary gland, this bacterium did not cause abortion when it was inoculated intravenously at 15 days prepartum. B. ovis infection induced an early humoral response in pregnant ewes, but their lambs remained seronegative, indicating that there was no transfer of antibodies in infancy. Placenta colonization and milk excretion of B. ovis involves a potential source of infection for lambs, which could play a role as latent carriers of infection.

Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil

Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr)locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high -77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e.

Desarrollo de una prueba de ELISA para detectar anticuerpos en carneros vacunados o infectados con Corynebacterium pseudotuberculosis / Development of an ELISA test to detect antibodies in vaccinated sheep or infected Corynebacterium pseudotuberculosis

El objetivo de este trabajo fue evaluar un ELISA indirecto desarrollado para medir la respuesta inmune humoral en carneros vacunados contra la linfoadenitis caseosa (LC) y/o desafiados con una cepa de Corynebacterium pseudotuberculosis homóloga. Se distribuyeron corderos de 4 meses clínicamente sanos en 4 grupos: grupo 1, corderos vacunados (G1, n = 5); grupo 2, corderos vacunados e inoculados (G2, n = 8); grupo 3, corderos inoculados (G3, n = 2); y grupo 4, control (G4, n = 2). Los animales del G1 y del G2 recibieron dos dosis de una bacterina experimental; los del G2 y del G3 fueron desafiados con una cepa de C. pseudotuberculosis cuatro semanas posvacunación. Se estudiaron por ELISA los títulos serológicos durante 7 meses y se efectuaron las necropsias en los grupos G2, G3 y G4. Se tomaron muestras de pulmón y linfonódulos para efectuar estudios bacteriológicos e histopatológicos. La cepa inoculada en los animales del G2 y del G3 reprodujo las lesiones macroscópicas y microscópicas típicas de la LC; ésta fue aislada del sitio de inoculación, de linfonódulos o de pulmón en 7/8 animales del G2 y en 2/2 animales del G3. La prueba de ELISA, con una sensibilidad del 98% y una especificidad del 100%, detectó diferencias significativas entre los serorreactores de los diferentes grupos experimentales y permitió establecer una relación con el tipo de tratamiento aplicado. Se concluye que el ELISA desarrollado puede ser una herramienta útil para identificar animales infectados y con clínica positiva a la LC.

The aim of this study was to evaluate an indirect specific ELISA developed for the detection of humoral immune response in vaccinated sheep and/or challenged with a Corynebacterium pseudotuberculosis strain. Healthy 4 month-old lambs were distributed into 4 groups: Group 1 immunized (G1, n = 5), Group 2 vaccinated/inoculated (G2, n = 8), Group 3 inoculated (G3, n = 2) and Group 4 control (G4, n = 2). Groups G1 and G2 received two doses of an experimental bacterin. Four weeks postvaccination, G2 and G3 groups were challenged with a C. pseudotuberculosis strain. Serological titers were studied by ELISA for 7 months and pathological studies were performed in groups G2, G3 and G4 by taking lung and lymph node samples for bacteriology and histopathology. The inoculated strain in G2 and G3 animals reproduced the macroscopic and microscopic lesions typical of caseous lymphadenitis (CL) and was isolated from the inoculation site, lymph nodes and/or lung in 7/8 animals from G2, and 2/2 animals of G3. The developed ELISA test had sensitivity and specificity of 98% and 100% respectively, detected significant differences between serological reactors of different experimental groups and allowed to establish a relationship with the type of treatment. We conclude that the developed ELISA may be a useful tool to identify infected animals with positive clinical CL.

Potential Clinical Role of Propolis in Treatment of Clinical Ovine and Caprine Listeriosis

In this study, we have tested the possible use of propolis, one of the few natural remedies that exhibits potential therapeutics properties, in combination with some antibacterial drugs for treatment of clinical ovine and caprine listeriosis that was described and diagnosed. Three private sheep flocks of 485 sheep and 2 private goat flocks of 275 goats were carefully clinically examined after appearance of different forms of suspected clinical listeriosis. The clinical diagnosis was confirmed by histopathological and bacteriological examinations. The infected sheep and goats were divided into groups based on the clinical form of listeriosis for field treatment. In ovine listeriosis, 73 out of 485 sheep were affected with 15.05% overall morbidity and 10.96% case fatality rates, respectively. In eaprine listeriosis, 55 out of 275 goats were affected with 20% overall morbidity rate and no case fatality rate. Encephalitic listeriosis was more prevalent among sheep while listerial abortion and septicaemic listeriosis were more prevalent among goats. Histopathologically, the brain tissues showed extensive perivascular mononuclear cuffing with microabscesses. Bacteriologicailly, L. monocytogenes was isolated from [31.09%] and [26 .9 8%] of collected samples in sheep and goats respectively. The field treatment revealed that the affected sheep and goats treated with biopropolis alone or with antibiotic combination regimen reduced the overall severity of listeriosis better than those treated with antibiotic alone [ampicillin or cefotaxime alone] or cefotaxime alternative with gentamicin and trimethoprimsuiphadimethoxine combination. Combined treatment with ampicillin-biopropolis dosage regimen was found to be the most effective

Low numbers of intestinal Shiga toxin-producing E. coli correlate with a poor prognosis in sheep infected with bovine leukemia virus

Healthy ruminants carry intestinal Shiga toxin (Stx)-producing Escherichia coli (STEC). Stx has antiviral activities in vitro and STEC numbers correlate with reduced early viremia in sheep experimentally infected with bovine leukemia virus (BLV). This study assessed the impact of intestinal STEC on BLV-induced disease for one year post-BLV-challenge. High STEC scores (CFU/g feces x frequency of STEC-positive samples) correlated with good health, whereas poor weight gain, distress, and tumor development occurred only among animals with low STEC scores. STEC carriage was associated with increased percentages of B cells in peripheral blood.

Epididimitis ovina: estudios bacteriológico y serológico / Ovine epididymytis a Bacteriological and serological studies

La brucelosis en ovinos puede ser causada por Brucella ovis y por brucelas lisas, en ambos casos puede presentarse epididimitis u orquitis, las cuales también se asocian con otros agentes infecciosos como Actinobacillus seminis e histophilus ovis. El objetivo de este trabajo fue aislar e identificar los agentes bacterianos involucrados en la epididimits ovina y establecer la relación en el diagnóstico serológico y bacteriológico de brucelas lisas, de B. ovis Y A. seminis con la presencia de epididimitis clínica. Se trabajó en 6 rebaños ovinos localizados en los estados de México, Hidalgo y el Distrito Federal, se tomaron muestras de suero de 111 machos, y muestras de semen y testículos de 17 carneros. La presencia de epididimitis se determinó por palpación y observación. A los sueros se les aplicó la prueba diagnóstica de tarjeta al 3 por ciento para brucelas lisas, las pruebas de ELISA indirecta e inmunodifusión doble (IDD) con el antígeno proteínico de extracción salina caliente para B. ovis, e IDD con antígeno solubre para A. seminis. Se realizó análisis bacteriológico a las muestras de semen y testículos de machos con epididimitis, a las cepas aisladas se les efectuaron pruebas de identificación bioquímica rutinarias; para A. seminis se realizó además IDD con antígeno obtenido por lisis de cepas aisladas y de referencia. En los 6 rebaños se diagnósticó la presencia de anticuerpos para B. ovis, por IDD, se encontraron 10 positivos (9.0 por ciento), en ELISA indirecta se obtuvieron 25 sueros positivos (22.5 por ciento), para brucelas lisas se encontraron 20 sueros positivos (18.01 por ciento). Para A. seminis se identificaron 10 seros positivos (9.0 por ciento), pertenecientes a 3 de los 6 rebaños muestreados. Se lograron aislar dos cepas de B. ovis a partir de testículos, y de dos cepas de A. seminis de semen

Estudio comparativo de medios de cultivo para aislar Brucella ovis / Comparative study of culture media for isolating Brucella ovis

Se compararon los medios de cultivo agar Thayer-Martin modificado adicionado con 0,01 *g/mlde timetropina y 100 UI de nistatina (TMM) y Agar Skirrow (SK) para el aislamiento de Brucella ovis. Se utilizaron 11 cepas de B. ovis y se evaluaron mediante la técnica de recuento de viables comparando los resultados con agar base Columbia con sangre bovina 7% (ASC). También se cultivaron en los mismos medios 94 muestras de semen pertenecientes a 33 carneros de una majada con antecedentes de infección. El crecimiento de las cepas de B. ovis fue similar en los 3 médios, excepto una cepa que no desarrolló en TMM. Los resultados de las siembras de semen fueron similares para los medios TMM y SK, aislándose B. ovis del 27% de las muestras. Los resultados indican que los medios TMM y SK ofrecen excelentes alternativas para aislar B. ovis del semen de carneros en condiciones de campo