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1.
Rev Bras Parasitol Vet ; 29(1): e014919, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32267389

RESUMEN

This study investigated the seropositivity for five different tick-borne agents, namely Anaplasma marginale, Babesia bovis, Babesia bigemina, Coxiella burnetii, Anaplasma phagocytophilum, and Trypanosoma vivax in beef cattle in the Brazilian Pantanal. The serum samples collected from animals (200 cows; 200 calves) were used in indirect enzyme-linked immunosorbent assays (iELISA) to detect IgG antibodies against A. marginale, B. bovis, B. bigemina, and T. vivax, and Indirect Fluorescent Antibody Test (IFAT) for detecting IgG antibodies against C. burnetii and A. phagocytophilum. No correlation was observed between seropositivity for C. burnetii and A. phagocytophilum with other agents whereas moderate correlation was observed for A. marginalexB. bigemina x B. bovis. Cows were more seropositive for T. vivax whereas calves were more seropositive for B. bovis and B. bigemina. The highest number of seropositive animals by a single agent was observed for T. vivax (15.2%). Co-seropositivity for T. vivax + A. marginale was higher in cows (25.5%) and for T. vivax + B. bovis + B. bigemina + A. marginale was higher in calves (57.5%). The high seropositivity correlation for A. marginale x B. bovis x B. bigemina is probably due to the presence of the tick biological vector, Rhipicephalus microplus, in the studied farms. Common transmission pathways, mediated by hematophagous dipterans and fomites, may explain the high co-seropositivity of cows for A. marginale and T. vivax. Low seropositivity to C. burnetii is probably due to the type of breeding system employed (extensive). Seropositivity for A. phagocytophilum in only one animal suggests the occurrence of a cross-serological reaction with another agent of the genus Anaplasma.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Anticuerpos Antiprotozoarios/sangre , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/parasitología , Inmunoglobulina G/sangre , Enfermedades por Picaduras de Garrapatas/microbiología , Enfermedades por Picaduras de Garrapatas/parasitología , Animales , Bovinos , Ensayo de Inmunoadsorción Enzimática
2.
Int J Syst Evol Microbiol ; 70(3): 2115-2123, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31999237

RESUMEN

'Treponema phagedenis' was originally described in 1912 by Noguchi but the name was not validly published and no type strain was designated. The taxon was not included in the Approved Lists of Bacterial Names and hence has no standing in nomenclature. Six Treponema strains positive in a 'T. phagedenis' phylogroup-specific PCR test were isolated from digital dermatitis (DD) lesions of cattle and further characterized and compared with the human strain 'T. phagedenis' ATCC 27087. Results of phenotypic and genotypic analyses including API ZYM, VITEK2, MALDI-TOF and electron microscopy, as well as whole genome sequence data, respectively, showed that they form a cluster of species identity. Moreover, this species identity was shared with 'T. phagedenis'-like strains reported in the literature to be regularly isolated from bovine DD. High average nucleotide identity values between the genomes of bovine and human 'T. phagedenis' were observed. Slight genomic as well as phenotypic variations allowed us to differentiate bovine from human isolates, indicating host adaptation. Based on the fact that this species is regularly isolated from bovine DD and that the name is well dispersed in the literature, we propose the species Treponema phagedenis sp. nov., nom. rev. The species can phenotypically and genetically be identified and is clearly separated from other Treponema species. The valid species designation will allow to further explore its role in bovine DD. The type strain for Treponema phagedenis sp. nov., nom. rev. is B43.1T (=DSM 110455T=NCTC 14362T) isolated from a bovine DD lesion in Switzerland.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Dermatitis Digital/microbiología , Filogenia , Treponema/clasificación , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , Bovinos , ADN Bacteriano/genética , Ácidos Grasos/química , Humanos , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Suiza , Treponema/aislamiento & purificación
3.
Parasitol Int ; 74: 101925, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31077806

RESUMEN

Tick-borne diseases cause significant losses to livestock production in tropical and subtropical regions. However, information about the tick-borne infections in cattle in Xinjiang Uygur Autonomous Region (XUAR), northwestern China, is scarce. In this study, nested polymerase chain reaction (PCR) assays and gene sequencing were used to detect and analyze epidemiological features of Babesia bovis, B. bigemina, Coxiella burnetii and Anaplasma bovis infections in XUAR. Out of 195 samples tested, 24 (12.3%), 67 (34.4%), 40 (20.5%) and 10 (5.1%) were positive for B. bovis, B. bigemina, C. burnetii and A. bovis, respectively. Sequencing analysis indicated that B. bovis SBP-4, B. bigemina Rap1a, C. burnetii htpB and A. bovis 16S rRNA genes from XUAR showed 99%-100% identity with documented isolates from other countries. Phylogenetic analyses revealed that B. bovis SBP-4, B. bigemina Rap1a, C. burnetii htpB and A. bovis 16S rRNA gene sequences clustered in the same clade with isolates from other countries. To the best of our knowledge, this is the first report of C. burnetii infection of cattle in XUAR. Furthermore, this study provides important data for understanding the distribution of tick-borne pathogens, and is expected to improve the approach for prevention and control of tick-borne diseases in China.


Asunto(s)
Anaplasma/aislamiento & purificación , Babesia/aislamiento & purificación , Enfermedades de los Bovinos/epidemiología , Coxiella burnetii/aislamiento & purificación , Fiebre Q/veterinaria , Enfermedades por Picaduras de Garrapatas/veterinaria , Anaplasma/genética , Anaplasmosis/epidemiología , Animales , Babesia/genética , Babesiosis/epidemiología , Bovinos , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/parasitología , China/epidemiología , Coxiella burnetii/genética , ADN Bacteriano/genética , ADN Protozoario/genética , Filogenia , Fiebre Q/epidemiología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Enfermedades por Picaduras de Garrapatas/epidemiología , Garrapatas/microbiología
4.
Theriogenology ; 141: 41-47, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31518727

RESUMEN

Bovine leptospirosis is often associated with host-adapted leptospires infections, such as strains belonging to the Sejroe serogroup. Although bovine leptospirosis by adapted strains may result in abortions, fetal death, premature births and the birth of weak and/or low-weight calves, this infection is more closely associated with subtler syndromes, such as subfertility and early embryonic death. In this way, this silent disease can go unnoticed and undiagnosed, compromising reproductive efficiency with a consequent decrease in the productivity of herds over long periods. For many years, genital tract infection has been considered a secondary effect of renal infection with the assumption being that leptospires are found in the genital tract due to bacteremia caused by renal colonization. In contrast to this hypothesis, there is some evidence in the literature that suggests that genital leptospirosis should be considered a specific syndrome dissociated from renal/systemic disease. Therefore, this paper aims to gather and critically analyze information about genital leptospirosis in cattle, considering the disease a distinct syndrome, herein denominated bovine genital leptospirosis (BGL), that requires a unique approach to diagnosis and treatment.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Leptospirosis/veterinaria , Enfermedades Bacterianas de Transmisión Sexual/veterinaria , Aborto Veterinario/microbiología , Animales , Bovinos , Enfermedades de los Bovinos/transmisión , Leptospira/clasificación , Leptospira/fisiología , Leptospirosis/patología , Leptospirosis/transmisión , Enfermedades Bacterianas de Transmisión Sexual/patología
5.
Pol J Microbiol ; 68(3): 295-302, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31880874

RESUMEN

The article presents data on serological studies of 573 sera samples of cattle that were collected from the farms affected by leptospirosis in different regions of Ukraine in the period of 2014-2015. Samples were investigated by the microscopic agglutination test (MAT), which was conducted within eight serological groups of Leptospira and nine serovars: Sejroe (serovars polonica and hardjo), Hebdomadis (serovar kabura), Tarassovi (serovar tarassovi), Pomona (serovar pomona), Grippotyphosa (serovar grippotyphosa), Canicola (serovar canicola), Icterohaemorrhagiae (serovar copenhageni), and Australis (serovar bratislava). The circulation of L. interrogans serovar hardjo among cattle has been observed in all 11 regions of Ukraine investigated within 25.8-60.0% of the leptospirosis-positive serum samples in these regions. Antibodies in the cattle sera against serovar hardjo (serogroup Sejroe) were detected in 139 of the 370 cows reacting positively in MAT. Overall, they were detected in 24.3% animals out of the total of 573 cows investigated. These are the preliminary results, however, in our opinion, they should allow to include the serovar hardjo in a standard panel of strains for MAT in Ukraine.The article presents data on serological studies of 573 sera samples of cattle that were collected from the farms affected by leptospirosis in different regions of Ukraine in the period of 2014­2015. Samples were investigated by the microscopic agglutination test (MAT), which was conducted within eight serological groups of Leptospira and nine serovars: Sejroe (serovars polonica and hardjo), Hebdomadis (serovar kabura), Tarassovi (serovar tarassovi), Pomona (serovar pomona), Grippotyphosa (serovar grippotyphosa), Canicola (serovar canicola), Icterohaemorrhagiae (serovar copenhageni), and Australis (serovar bratislava). The circulation of L. interrogans serovar hardjo among cattle has been observed in all 11 regions of Ukraine investigated within 25.8­60.0% of the leptospirosis-positive serum samples in these regions. Antibodies in the cattle sera against serovar hardjo (serogroup Sejroe) were detected in 139 of the 370 cows reacting positively in MAT. Overall, they were detected in 24.3% animals out of the total of 573 cows investigated. These are the preliminary results, however, in our opinion, they should allow to include the serovar hardjo in a standard panel of strains for MAT in Ukraine.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Enfermedades de los Bovinos/sangre , Leptospira interrogans/inmunología , Leptospirosis/veterinaria , Pruebas de Aglutinación , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Femenino , Leptospira interrogans/clasificación , Leptospira interrogans/genética , Leptospira interrogans/aislamiento & purificación , Leptospirosis/sangre , Leptospirosis/microbiología , Masculino , Serogrupo , Ucrania
6.
Res Vet Sci ; 127: 27-32, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31670090

RESUMEN

Bovines are the primary reservoir of enterohemorrhagic Escherichia coli (EHEC) O157:H7 and the main source of its transmission to humans. Here, we present a one-year longitudinal study of fecal shedding of E. coli O157. E. coli O157 obtained from recto-anal mucosal samples were characterized by multiplex PCR. The E. coli O157 prevalence ranged from 0.84% in July to 15.25% in November. The confinement within pens resulted in prevalence of 11%. Most animals (61.86%; 75/118) shed E. coli O157 at least in one sampling occasion. Of the positive animals, 82.19%, 16.44%, and 1.37% were stx positive on one, two and three sampling occasions, respectively. All the E. coli O157 isolated strains carried the genes eae and rfbO157, whereas 11%, 33% and 56% contained stx1, stx2 and stx1/stx2, respectively. The stx1/stx2 and stx2 types were significantly higher during the grazing and finishing periods, respectively, in comparison with the rearing and grazing periods. The presence of stx2a subtype was evident in four isolates, whereas stx2c was present in at least seven. However, both subtypes were present simultaneously in two isolates. The stx1/stx2c, stx1/stx2d and stx1/stx2NT genotypes occurred in 24, 2 and 15 isolates, respectively. The simultaneous occurrence of stx1 and stx2c significantly increased during grazing. Some cases of within-pen and between-pen transmission occurred throughout the study. Contagion levels during in-field grazing were higher than during permanent confinement in the pens. Thus, the individual patterns of shedding varied depending on the proportion of animals shedding the bacteria within pens and the time of shedding.


Asunto(s)
Derrame de Bacterias , Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/fisiología , Adhesinas Bacterianas/análisis , Animales , Argentina , Bovinos , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/genética , Escherichia coli O157/patogenicidad , Proteínas de Escherichia coli/análisis , Heces/microbiología , Genotipo , Estudios Longitudinales , Masculino , Toxina Shiga/análisis , Virulencia
7.
Vet Clin North Am Food Anim Pract ; 35(3): 471-483, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31590898

RESUMEN

Host responses are often ineffective at clearing Mycoplasma bovis infection and may contribute to the pathogenesis of disease. M bovis possesses a surprisingly large repertoire of strategies to evade and modulate host responses. Unopsonized M bovis impairs phagocytosis and killing by neutrophils and macrophages. Apoptosis of neutrophils and lymphocytes is enhanced, whereas it is delayed in macrophages. Both proinflammatory and antiinflammatory cytokines are stimulated during M bovis infection depending on the cell type and location, and overall systemic responses tend to have a T-helper 2 bias. M bovis reduces proliferation of T cells and, in chronic infection, causes T-cell exhaustion.


Asunto(s)
Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/microbiología , Infecciones por Mycoplasma/veterinaria , Mycoplasma bovis/inmunología , Animales , Bovinos , Inmunidad Celular , Inmunidad Humoral , Infecciones por Mycoplasma/inmunología
8.
Vet Ital ; 55(3): 247-252, 2019 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-31599549

RESUMEN

Q fever is a widespread zoonotic disease caused by Coxiella burnetii, an obligate intracellular bacterium with a wide range of hosts. The aim of this study was to estimate the seroprevalence of C. burnetii infection in cattle in Sicilian farms. A total of 4,661 serum samples, from cattle belonging to 198 Sicilian farms, were examined by ELISA test and 246 resulted positive. The average seroprevalence at the farm level was 38.8% (77/198) (95% CI), while at the animal level it was 5.28% (246/4,661) (95% CI). The present study highlights the need for continuous monitoring of C. burnetii spread as it represents a serious risk for human health.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Coxiella burnetii/aislamiento & purificación , Fiebre Q/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Humanos , Fiebre Q/sangre , Fiebre Q/epidemiología , Estudios Seroepidemiológicos , Sicilia/epidemiología , Zoonosis
9.
PLoS Pathog ; 15(10): e1008003, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31581229

RESUMEN

Specific Escherichia coli isolates lysogenised with prophages that express Shiga toxin (Stx) can be a threat to human health, with cattle being an important natural reservoir. In many countries the most severe pathology is associated with enterohaemorrhagic E. coli (EHEC) serogroups that express Stx subtype 2a. In the United Kingdom, phage type (PT) 21/28 O157 strains have emerged as the predominant cause of life-threatening EHEC infections and this phage type commonly encodes both Stx2a and Stx2c toxin types. PT21/28 is also epidemiologically linked to super-shedding (>103 cfu/g of faeces) which is significant for inter-animal transmission and human infection as demonstrated using modelling studies. We demonstrate that Stx2a is the main toxin produced by stx2a+/stx2c+ PT21/28 strains induced with mitomycin C and this is associated with more rapid induction of gene expression from the Stx2a-encoding prophage compared to that from the Stx2c-encoding prophage. Bacterial supernatants containing either Stx2a and/or Stx2c were demonstrated to restrict growth of bovine gastrointestinal organoids with no restriction when toxin production was not induced or prevented by mutation. Isogenic strains that differed in their capacity to produce Stx2a were selected for experimental oral colonisation of calves to assess the significance of Stx2a for both super-shedding and transmission between animals. Restoration of Stx2a expression in a PT21/28 background significantly increased animal-to-animal transmission and the number of sentinel animals that became super-shedders. We propose that while both Stx2a and Stx2c can restrict regeneration of the epithelium, it is the relatively rapid and higher levels of Stx2a induction, compared to Stx2c, that have contributed to the successful emergence of Stx2a+ E. coli isolates in cattle in the last 40 years. We propose a model in which Stx2a enhances E. coli O157 colonisation of in-contact animals by restricting regeneration and turnover of the colonised gastrointestinal epithelium.


Asunto(s)
Enfermedades de los Bovinos/transmisión , Células Epiteliales/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/efectos de los fármacos , Íleon/microbiología , Organoides/microbiología , Toxina Shiga II/farmacología , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Células Epiteliales/citología , Células Epiteliales/metabolismo , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/aislamiento & purificación , Íleon/citología , Íleon/metabolismo , Masculino , Organoides/crecimiento & desarrollo , Organoides/metabolismo , Virulencia
10.
Aust Vet J ; 97(12): 505-508, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31588995

RESUMEN

Chlamydial infections in dairy cattle are common and have been sporadically associated with reduced performance and severe disease manifestations. While chlamydial infections are well described in sheep, very little is known about the epidemiology of these infections in dairy cattle in Australia. In this study, we screened for chlamydial infections and assessed on-farm risks in dairy cattle herds from Southeast Queensland (SE Qld) region of Australia. In total, 228 paired vaginal and rectal swabs were collected from 114 visually healthy dairy cows from four farms in SE Qld. Risk factors were rated by observational study and included: hygiene and cleanliness of cows, walkway and parlour, incidence of perinatal mortality, external replacements, mode of breeding, calving pen management, heat reduction strategies, and feed ration usage. Testing for chlamydial pathogens (Chlamydia pecorum, Chlamydia psittaci and Chlamydia abortus) was done using species-specific quantitative polymerase chain reaction (qPCR) assays. Detected rates of chlamydial infection were evaluated against the on-farm risk factors. C. pecorum infection was widespread in all four farms, with 56.1% (64/114) of individual animals shedding this organism from vaginal and rectal, or both sites. C. abortus and C. psittaci were not detected in any animals. No association was found to exist with risk factors and C. pecorum infection rates in our study, however the number of Chlamydia positive animals was statistically different between the herds. This study suggests that subclinical chlamydial infections may impact on dairy herd health at the production level rather than affecting individual animal.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Infecciones por Chlamydia/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/diagnóstico , Chlamydia/aislamiento & purificación , Infecciones por Chlamydia/diagnóstico , Infecciones por Chlamydia/epidemiología , Industria Lechera , Granjas , Femenino , Queensland/epidemiología , Recto/microbiología , Factores de Riesgo , Vagina/microbiología
11.
Prev Vet Med ; 172: 104803, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31634754

RESUMEN

The objective of this study was to investigate the new differential somatic cell count (DSCC) as a supplementary indicator to SCC for the identification of intramammary infection (IMI) in dairy cows at the end of the lactation period. Different approaches for identification of cows with IMI (i.e. often based on SCC) and targeted antimicrobial treatment of those rather than of all cows have been developed (i.e. selective dry cow treatment). Recently, DSCC representing the proportion of polymorphonuclear neutrophils and lymphocytes, has been introduced as an additional indicator for the presence of IMI. We used the last dairy herd improvement (DHI) samples taken within 42 d prior to dry-off as well as hand-stripped samples collected within 5 days prior to dry-off to measure DSCC and SCC. The bacteriological status was determined using quarter foremilk samples collected close to drying off. In total, 582 cows were dried off during our study but not all of them could be included in the data analysis for different reasons (e.g. incomplete data, samples too old for reliable determination of SCC and DSCC, contamination). Eventually, the final data set comprised of 310 cows of which 64 and 149 were infected with major and minor pathogens, respectively, and 97 were uninfected. The area under receiver-operating characteristics curves (AUC) were calculated to compare the diagnostic abilities of the different parameters. The AUC for identification of IMI by major pathogens when using the combination of DSCC and SCC was 0.64 compared to 0.62 for SCC alone and 0.62 for DSCC alone. The different parameters were further compared based on test characteristics and predictive values. For example, classifying cows as infected based on a cut-off of 200,000 cells/ml for SCC alone and in terms of using DSCC combined with SCC based on either >60% and/or >200,000 cells/ml, the sensitivity changed from 47 to 66% and the specificity from 74 to 54%. At the same time, the negative predictive value changed from 84 to 86% and the positive predictive value from 32 to 27%. Test characteristics and predictive values of the parameters DSCC and SCC were similar using DHI and hand-stripped samples. In conclusion, our study provides first indications on test characteristics and predictive values for the combination of DSCC and SCC. However, more work on this subject and the actual practical application is needed.


Asunto(s)
Enfermedades de los Bovinos/diagnóstico , Recuento de Células/veterinaria , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/diagnóstico , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Recuento de Células/métodos , Femenino , Mastitis Bovina/microbiología , Sensibilidad y Especificidad
12.
BMC Vet Res ; 15(1): 368, 2019 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-31653234

RESUMEN

BACKGROUND: The obligate intracellular bacterium Coxiella burnetii causes globally distributed zoonotic Q fever. Ruminant livestock are common reservoirs of C. burnetii. Coxiella burnetii are shed in large numbers in the waste of infected animals and are transmitted by inhalation of contaminated aerosols. This study was conducted to evaluate the prevalence of C. burnetii infection in domestic animals and ticks in areas of Slovenia associated with a history of Q fever outbreaks. RESULTS: A total of 701 ticks were collected and identified from vegetation, domestic animals and wild animals. C. burnetii DNA was detected in 17 out of 701 (2.4%) ticks. No C. burnetii DNA was found in male ticks. Ticks that tested positive in the PCR-based assay were most commonly sampled from wild deer (5.09%), followed by ticks collected from domestic animals (1.16%) and ticks collected by flagging vegetation (0.79%). Additionally, 150 animal blood samples were investigated for the presence of C. burnetii-specific antibodies and pathogen DNA. The presence of pathogen DNA was confirmed in 14 out of 150 (9.3%) blood samples, while specific antibodies were detected in sera from 60 out of 150 (40.4%) animals. CONCLUSIONS: Our results indicate that ticks, although not the primary source of the bacteria, are infected with C. burnetii and may represent a potential source of infection for humans and animals. Ticks collected from animals were most likely found to harbor C. burnetii DNA, and the infection was not lost during molting. The persistence and distribution of pathogens in cattle and sheep indicates that C. burnetii is constantly present in Slovenia.


Asunto(s)
Coxiella burnetii/aislamiento & purificación , Fiebre Q/veterinaria , Garrapatas/microbiología , Animales , Anticuerpos Antibacterianos/sangre , Bovinos , Enfermedades de los Bovinos/microbiología , Coxiella burnetii/genética , Coxiella burnetii/inmunología , ADN Bacteriano/sangre , Ciervos/microbiología , Femenino , Masculino , Muda , Reacción en Cadena de la Polimerasa/veterinaria , Prevalencia , Fiebre Q/epidemiología , Ovinos , Enfermedades de las Ovejas/microbiología , Eslovenia/epidemiología , Zoonosis
13.
BMC Vet Res ; 15(1): 371, 2019 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-31655595

RESUMEN

BACKGROUND: Mycoplasma bovis is a causative agent of disease in cattle causing many clinical conditions. Currently there are no commercial M. bovis vaccines in Europe and treatment is difficult with decreased antimicrobial susceptibility of M. bovis field isolates. Using an M. bovis calf infection model the effectiveness of enrofloxacin given alone; in combination with flunixin meglumine, a nonsteroidal anti-inflammatory drug; and a group with an additional treatment of pegbovigrastim, an immunostimulator, was evaluated. RESULTS: Enrofloxacin given alone stimulated a strong immune response, reduced the clinical manifestation and lung lessions of the M. bovis infection. In contrast the combination therapy appeared ineffective. CONCLUSIONS: In this experiment enrofloxacin given alone appeared to be the most effective treatment of the M. bovis affected calves, whereas co-administration with flunixin meglumine, and pegbovigrastim was not beneficial in this trial.


Asunto(s)
Enfermedades de los Bovinos/tratamiento farmacológico , Infecciones por Mycoplasma/veterinaria , Neumonía/veterinaria , Adyuvantes Inmunológicos/uso terapéutico , Animales , Antibacterianos/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Bovinos , Enfermedades de los Bovinos/microbiología , Clonixina/análogos & derivados , Clonixina/uso terapéutico , Quimioterapia Combinada/veterinaria , Enrofloxacina/uso terapéutico , Femenino , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Infecciones por Mycoplasma/tratamiento farmacológico , Mycoplasma bovis/efectos de los fármacos , Neumonía/tratamiento farmacológico , Proteínas Recombinantes/uso terapéutico
14.
J Vet Diagn Invest ; 31(6): 893-898, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31646958

RESUMEN

We investigated deaths in a group of feedlot steers in Argentina. The main findings in 3 steers autopsied were pulmonary congestion and edema, necrotizing myocarditis, pericarditis, suppurative leptomeningitis, and bronchopneumonia. Histophilus somni was detected by bacterial culture and immunohistochemistry in the hearts of the 3 animals. Partial sequences of the 16S rRNA gene of a H. somni isolate had 99% similarity with other H. somni sequences in GenBank. Most reports of H. somni septicemia in cattle originate from North America and western Europe. There is scant information about cardiac histophilosis in South America. A survey of diagnostic laboratory personnel in 7 South American countries documented various forms of bovine histophilosis in Argentina, Brazil, Uruguay, and Venezuela.


Asunto(s)
Enfermedades de los Bovinos/diagnóstico , Meningitis/veterinaria , Miocarditis/veterinaria , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/aislamiento & purificación , Animales , Argentina , Brasil , Bovinos , Enfermedades de los Bovinos/microbiología , Masculino , Meningitis/diagnóstico , Meningitis/microbiología , Miocarditis/diagnóstico , Miocarditis/microbiología , Pasteurellaceae/clasificación , Infecciones por Pasteurellaceae/diagnóstico , Infecciones por Pasteurellaceae/microbiología , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , Uruguay , Venezuela
15.
J Dairy Sci ; 102(12): 11470-11475, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31629518

RESUMEN

The objectives of this study were (a) to evaluate skin biopsies of udder sores and negative control cows for the presence of mange and nonbacterial pathogens via histopathology and (b) to identify and compare bacterial abundance in the lesions of cows with udder sores and from the skin of healthy controls from the same farms. Cows from 3 dairy farms with (n = 23) and without (n = 12) udder sore lesions were enrolled, and punch biopsies (23 lesions, 23 negative control samples of cows with lesions, and 12 control samples of cows without lesions) were collected. The biopsies were evaluated histopathologically, and their 16S metagenome was analyzed. No signs of mange or viral or fungal infections were detected histopathologically in any samples. The α diversity of microbial populations decreased in lesions, across all farms, and the abundance of spirochaetes did not notably change, compared with controls. However, compared with control samples, the microbial fractions of Fusobacterium, Helcococcus spp., Anaerococcus spp., Porphyromonas spp., Prevotella spp., and Trueperella spp. increased several-fold in lesions. In summary, our results suggest that spirochaetes, viruses, and mange are unlikely to cause udder sores. Instead, sores were associated with a marked increase in the abundance of Fusobacterium, Helcococcus, Anaerococcus, Porphyromonas, Prevotella, and Trueperella. Future studies are needed to determine which of these bacteria initiates this polymicrobial infection.


Asunto(s)
Enfermedades de los Bovinos/patología , Glándulas Mamarias Animales/patología , Mastitis Bovina/patología , Piel/patología , Animales , Bacterias/clasificación , Bacterias/genética , Biopsia/veterinaria , Bovinos , Enfermedades de los Bovinos/microbiología , Femenino , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/microbiología , Metagenoma , Piel/microbiología
16.
J Dairy Sci ; 102(12): 11359-11369, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31548072

RESUMEN

The primary objective of this randomized controlled challenge study was to investigate the effect of ampicillin on ultrasonographic (US) lung consolidation after experimental challenge with Pasteurella multocida in preweaned dairy calves. The secondary objectives were to determine whether ampicillin affected respiratory score, gross consolidation, or the detection of P. multocida in lung tissue at postmortem exam (PME). Holstein bull calves (n = 39) were transported to the University of Wisconsin-Madison School of Veterinary Medicine isolation facility at the mean (±SD) age of 52 ± 6 d. After a 7-d acclimation period, 30 calves were inoculated intratracheally with 1010 cfu of ampicillin-sensitive P. multocida. Lung US and respiratory scoring were performed 2, 6, 12, and 24 h post-challenge, then US once daily and respiratory scoring twice daily until d 14. Calves were randomized to receive ampicillin [n = 17, treatment (TX), 6.6 mg/kg i.m. once daily for 3 d] or placebo [n = 11, control (CON), saline, equal volume, i.m. once daily for 3 d] when ≥1 cm2 of lung consolidation was observed and ≥6 h had elapsed since challenge. Lung lesions ≥1 cm2 were considered positive for consolidation. Calves were respiratory score positive if ≥2 in 2 or more categories based on the Wisconsin respiratory health score chart. Area under the curve (AUC) was calculated for US score and respiratory score as a proxy for time with consolidation and clinical respiratory disease, respectively. Gross lung lesions and pathogens were quantified following PME. At the time of first treatment, consolidation had developed in 28/30 calves (TX, n = 17; CON, n = 11) and 6% (1 out of 17) of TX and 9% (1 out of 11) of CON calves had a positive respiratory score. The TX calves had a significantly lower median (interquartile range given in parentheses) AUC for US score [TX: 23 (20, 29), CON: 47 (33, 53)], whereas mean AUC for respiratory score was not different between groups (TX: 93 ± 28, CON: 96 ± 17). On d 14, 70% (12 out of 17) of TX and 100% (11 out of 11) of CON calves had lung consolidation, and 24% (4 out of 17) of TX and 27% (3 out of 11) of CON calves had clinical respiratory disease. On PME, median consolidation was 10% (6, 15) for TX and 10% (2, 28) for CON calves. Lung cultures were positive for P. multocida in 77% (13 out of 17) of TX and 91% (10 out of 11) of CON calves. Lung health benefited from a 3-d ampicillin therapy, but benefits were short-lived. Treatment failures might be due to incomplete resolution of the initial lung infection. Future studies are needed to optimize TX strategies to improve long-term lung health.


Asunto(s)
Ampicilina/administración & dosificación , Antibacterianos/administración & dosificación , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades Pulmonares/veterinaria , Pasteurella multocida/fisiología , Enfermedades Respiratorias/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Pulmón/microbiología , Enfermedades Pulmonares/tratamiento farmacológico , Enfermedades Pulmonares/microbiología , Masculino , Distribución Aleatoria , Enfermedades Respiratorias/tratamiento farmacológico , Enfermedades Respiratorias/microbiología
17.
J Dairy Sci ; 102(12): 11280-11290, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31563303

RESUMEN

Feeding pasteurized milk to suckling calves is a popular practice used increasingly on dairy farms. Waste milk is frequently fed to calves because of its high nutritional value and economic benefits compared to milk replacement products. However, one of the disadvantages of feeding waste milk is the potential for exposure to a high number of bacterial contaminants, which may lead to serious illnesses or infections in calves. One of these contaminants is Mycobacterium avium ssp. paratuberculosis (MAP), the causative agent of Johne's disease (paratuberculosis). The transmission and distribution of paratuberculosis in dairy herds occurs mostly through the feeding newborn calves with contaminated colostrum or milk, because this age group is believed to be most susceptible to infection. To reduce the risk of transmission of pathogens, on-farm pasteurization of milk has become increasingly popular. In this study, we analyzed the efficacy of a new commercial high-temperature, short-time pasteurizer (73.5°C for 20 to 25 s) in terms of MAP inactivation under experimental on-farm conditions. The pasteurizer uses a newly developed steam-heating technique, allowing for the pasteurization of the transition milk without clumping. In 3 independent trials, we spiked fresh raw milk samples to a level of 107 or 104 viable MAP cells/mL before pasteurization. We examined the thermal inactivation and viability of MAP using culture and a D29 bacteriophage-based assay. To verify the identity and number of MAP cells, we also performed PCR assays. Pasteurization of the inoculated milk (107 and 104 MAP cells/mL) resulted in a remarkable reduction in viable MAP cells. The mean inactivation rate of MAP ranged from 0.82 to 2.65 log10 plaque-forming units/mL, depending on the initial MAP amount inoculated and the addition of conservative agents to the pasteurized milk. Nevertheless, approximately 103 MAP cells/mL remained viable and could be transferred to calves after high-temperature, short-time pasteurization of milk.


Asunto(s)
Alimentación Animal , Enfermedades de los Bovinos/prevención & control , Leche , Mycobacterium avium subsp. paratuberculosis , Paratuberculosis/prevención & control , Pasteurización , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Calostro/microbiología , Industria Lechera , Femenino , Calor , Leche/microbiología , Mycobacterium avium subsp. paratuberculosis/fisiología , Pasteurización/métodos , Reacción en Cadena de la Polimerasa , Embarazo
18.
J Dairy Sci ; 102(12): 11260-11267, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31563316

RESUMEN

Bovine paratuberculosis (Johne's disease) is a bacterial, chronic, and wasting intestinal disease caused by Mycobacterium avium ssp. paratuberculosis (MAP). Johne's disease causes severe losses in dairy farm productivity and is also suspected to be a potential trigger for Crohn's disease in humans. The fecal-oral infection of MAP to neonates is recognized as an important within-herd transmission route. Our objective was to recommend diagnostic methods for herds with suspected paratuberculosis requiring fast results, as well as for herds with breeding programs or others that aim at being nonsuspected of paratuberculosis infection. We determined a period of 8 wk from sampling to diagnostic findings suitable for testing of cows during the dry period. We therefore tested environmental and individual fecal samples with one rapid and one highly sensitive diagnostic method. Environmental samples (boot swabs) were taken as a first step in 3 herds and tested using a DNA extraction protocol for feces and subsequent real-time PCR (referred to as fecal PCR). Additionally, cultivation in liquid medium for 6 wk was performed and verified with real-time PCR (referred to as liquid culture). Automation of DNA extraction based on magnetic beads and the PCR setup was performed with pipetting robots. As a result, we successfully detected MAP in boot swabs of all herds by both methods. In a second step, 245 individual fecal samples from the 3 herds were examined using also fecal PCR and liquid culture. The results obtained by fecal PCR were compared with detection of MAP using cultivation in liquid medium for 6 wk. Testing individual cows, we identified MAP-specific DNA in 53 fecal samples using the liquid culture. Using fecal PCR, we revealed 43 positive samples of which 39 also tested positive in the liquid culture, revealing MAP-positive cows in all 3 herds. The fecal PCR procedure allows rapid detection of MAP-specific DNA with 74% of the sensitivity of liquid culture. For the purpose of testing with maximal sensitivity, cultivation in liquid medium is recommended. Cultivation of MAP in liquid medium M7H9C means a significant time gain in comparison to cultivation on solid media, which requires twice as much time. Thus, this testing fits within the 6- to 8-wk dry period of gravid cows and provides test results before calving, a prerequisite to prevent fecal-oral transmission to newborn calves.


Asunto(s)
Enfermedades de los Bovinos/diagnóstico , Heces/microbiología , Mycobacterium avium subsp. paratuberculosis , Paratuberculosis/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Animales , Cruzamiento , Bovinos , Enfermedades de los Bovinos/microbiología , Microbiología Ambiental , Femenino , Mycobacterium avium subsp. paratuberculosis/genética , Paratuberculosis/microbiología
19.
J Anim Sci ; 97(11): 4567-4578, 2019 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-31563955

RESUMEN

Liver abscesses in feedlot cattle are detrimental to animal performance and economic return. Tylosin, a macrolide antibiotic, is used to reduce prevalence of liver abscesses, though there is variable efficacy among different groups of cattle. There is an increased importance in better understanding the etiology and pathogenesis of this condition because of growing concern over antibiotic resistance and increased scrutiny regarding use of antibiotics in food animal production. The objective of this study was to compare the microbiomes and antimicrobial resistance genes (resistomes) of feces of feedlot cattle administered or not administered tylosin and in their pen soil in 3 geographical regions with differing liver abscess prevalences. Cattle (total of 2,256) from 3 geographical regions were selected for inclusion based on dietary supplementation with tylosin (yes/no). Feces and pen soil samples were collected before harvest, and liver abscesses were identified at harvest. Shotgun and 16S rRNA amplicon sequencing were used to evaluate the soil and feces. Microbiome and resistome composition of feces (as compared by UniFrac distances and Euclidian distances, respectively) did not differ (P > 0.05) among tylosin or no tylosin-administered cattle. However, feedlot location was associated with differences (P ≤ 0.05) of resistomes and microbiomes. Using LASSO, a statistical model identified both fecal and soil microbial communities as predictive of liver abscess prevalence in pens. This model explained 75% of the variation in liver abscess prevalence, though a larger sample size would be needed to increase robustness of the model. These data suggest that tylosin exposure does not have a large impact on cattle resistomes or microbiomes, but instead, location of cattle production may be a stronger driver of both the resistome and microbiome composition of feces.


Asunto(s)
Antibacterianos/administración & dosificación , Enfermedades de los Bovinos/prevención & control , Suplementos Dietéticos/análisis , Absceso Hepático/veterinaria , Microbiota/efectos de los fármacos , Tilosina/administración & dosificación , Alimentación Animal/análisis , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Farmacorresistencia Bacteriana , Heces/microbiología , Femenino , Geografía , Absceso Hepático/epidemiología , Absceso Hepático/microbiología , Absceso Hepático/prevención & control , Masculino , Metagenómica , Microbiota/genética , Modelos Estadísticos , Prevalencia , Microbiología del Suelo
20.
Lett Appl Microbiol ; 69(5): 366-372, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31508837

RESUMEN

We evaluate the efficacy of recombinant DNA vaccine ABA392 against haemorrhagic septicaemia infection through intranasal administration route by targeting the mucosal immunity. The DNA vaccine was constructed and subjected to animal study using the Sprague Dawley (SD) rat. The study was divided into two major parts: (i) active and (ii) passive immunization studies, involving 30 animals for each part. Each group was then divided into five test groups: two test samples G1 and G2 with 50 and 100 µg ml-1 purified DNA vaccine; one positive control G5 with 106  CFU per ml formalin-killed PMB2; and two negative controls, G3 and G4 with normal saline and pVAX1 vector. Both studies were conducted for the determination of immunogenicity by total white blood cell count (TWBC), indirect ELISA and histopathological changes for the presence of the bronchus-associated lymphoid tissue (BALT). Our findings demonstrate that TWBC, IgA and IgG increased after each of the three vaccination regimes: groups G1, G2 and G5. Test samples G1 and G2 showed significant differences (P < 0·05) compared to the negative controls, G3 and G4, but no significant differences from the positive control G5. Groups G1, G2 and G5 showed more formation of BALT compared to the negative controls, G3 and G4. Our results show that intranasal inoculation of recombinant DNA vaccine ABA392 can provoke mucosal immunity which makes it a potential prophylactic against HS. SIGNIFICANCE AND IMPACT OF THE STUDY: New approach of combating haemorrhagic septicaemia disease among bovines by recombinant DNA vaccine is crucial to overcome the loss of edible products from the infected bovines. DNA vaccine can potentially serve as a better immunogen which would elicit both cellular and humoral immunity, and it is also stable for its molecular reproduction. This research report demonstrates an effective yet simple way of administering the DNA vaccine via the intranasal route in rats, to provoke the mucosal immunity through the development of immunoglobulins IgA, IgG and bronchus-associated lymphoid tissue which guard as the first-line defence at the host's mucosal lining.


Asunto(s)
Vacunas Bacterianas/administración & dosificación , Enfermedades de los Bovinos/prevención & control , Septicemia Hemorrágica/veterinaria , Pasteurella multocida/inmunología , Vacunas de ADN/administración & dosificación , Administración Intranasal , Animales , Anticuerpos Antibacterianos/inmunología , Vacunas Bacterianas/genética , Vacunas Bacterianas/inmunología , Bovinos , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/microbiología , ADN Recombinante/administración & dosificación , ADN Recombinante/genética , ADN Recombinante/inmunología , Ensayo de Inmunoadsorción Enzimática , Septicemia Hemorrágica/inmunología , Septicemia Hemorrágica/microbiología , Septicemia Hemorrágica/prevención & control , Inmunización Pasiva , Masculino , Pasteurella multocida/genética , Ratas , Ratas Sprague-Dawley , Vacunas de ADN/genética , Vacunas de ADN/inmunología
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