Austral Journal of Veterinary Sciences
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Adhesion mechanisms of Actinobacillus pleuropneumoniae to the porcine respiratory system and biofilm formation
Get PDFActinobacillus pleuropneumoniae is a Gram-negative bacterium and the causative agent of porcine pleuropneumonia, a highly contagious disease of pigs characterised by fibrinohaemorrhagic necrotising pneumonia. Although it has been well controlled in some developed countries, outbreaks can occur in pigs of all ages in contact with asymptomatic carriers, leading to significant economic losses to the swine industry due to the high morbidity and mortality rates. Adhesion is a critical step in the colonisation of the swine respiratory tract and the pathogenesis of the porcine pleuropneumonia; however, a literature review of this process is not available to date. Therefore, this review aims to provide information regarding the molecules that have been described in the adhesion of A. pleuropneumoniae to cells and tissues of the porcine respiratory tract. Since adhesion is the first step in biofilm formation, we included a section to describe the genes involved in this process; some of these genes could participate directly or indirectly in the adhesion of A. pleuropneumoniae to the porcine respiratory system. Although the role of biofilms in porcine pleuropneumonia is still not clear, these molecules could be considered in the future as candidates for vaccine development
Evaluation of the efficacy of essential oils of Lavandula angustifolia and Eucalyptus globulus for the control of Varroa destructor in Apis mellifera: A randomised field study
Get PDFVarroa destructor is the most harmful and widespread parasite that spreads disease in bees. Eucalyptus spp essential oils (EOs), has been shown to be effective against V. destructor. Additionally, Lavender spp EOs treatment, resulted in mite mortality rates of 95% to 97% of V. destructor. During the treatments, 20 mL of each oil or the placebo was distributed on two sheets of papier-mâché located on the frames of the brood chamber inside each hive. The miticidal effects of Lavandula angustifolia and Eucalyptus globulus EOs were analysed. Parasitic load and mite fall were evaluated under field conditions. The mean infestation rate obtained from each of three treatment groups at the beginning of the study was less than 3.6%. Then, the infestation rate increased gradually in each group until day 36. The infestation rates in the groups treated with L. angustifolia and E. globulus EOs were lower than those in the control by more than two percentage points and never exceeded 10%; the differences between the control group and the L. angustifolia group were statistically significant (p <0.05). Both EO treatments were applied in four doses, which produced a prolonged effect that lowered the rates of parasite birth and reinfestation. The L. angustifolia EO was effective; in that treatment, parasitic loads were maintained at levels lower than those in the control group starting at the second treatment dose due to the reproductive cycles of both species
Detection of pathogenic leptospira as a cause of abortion in cattle-observations on diagnosis
Get PDFLeptospirosis is a zoonotic infectious disease caused by members of the genus Leptospira, which affects domestic and wild animals. Cases of abortion in cattle have been associated with this infection, but these are often not adequately confirmed. To determine the best diagnostic strategy for leptospirosis-associated cases of abortion, we evaluated some of the techniques used in the veterinary laboratory and found that the key issues are sample type and timing. In a retrospective anatomical and histopathological analysis, we studied 42 aborted foetuses with lesions consistent with leptospirosis to check for the presence of pathogenic leptospira by qPCR, as well as ascertaining the serologic status of the cows. In addition, in a prospective analysis, cows that had aborted foetuses were analysed within 2 days of the event by MAT and qPCR using blood and urine samples. Analysis of the foetuses indicated that only 14.3% of the selected cases (6 of 42) gave a positive qPCR result. Regarding cows that had recently aborted foetuses, 4 out of 11 sampled showed a positive qPCR, while MAT tests showed only negative results. The evidence provided in this study indicates that the time that has elapsed since a clinical event has occurred and the type of clinical sample taken are key elements in the successful confirmation of pathogenic leptospira as the cause of abortion
Citizens’ attitudes and perceptions towards genetically modified food in Chile: Special emphasis in CRISPR technology
Get PDFTo date, there has been an increase in genome modification biotechnologies that improve production and food security but the process has not been accompanied by the delivery of information about them intended for citizens. This is essential considering that to achieve better health, food security and sustainability these biotechnologies need to be incorporated into production systems. This study aimed to explore perceptions and attitudes of Chilean citizens towards the use of genome modifications with an emphasis on transgenes and genome editing (CRISPR). An electronic questionnaire was applied, and afterwards the results were analysed through descriptive statistics, GLM, Spearman’s correlation and Wilcoxon Signed Rank test. A total of 702 questionnaires were analysed. High awareness of concepts such as transgenic and cloning was reported with CRISPR being the least known term. Most respondents perceived negative effects on health regarding the consumption of genetically modified products, with women having a significantly more negative attitude. Still, a high willingness to use CRISPR for improving animal and human health was reported. When comparing vegetable and animal products that underwent CRISPR or transgenes, the willingness to consume these products was higher for vegetables. The results show that changes in perception can be achieved after providing the definition of CRISPR and transgenic, therefore, consumer education seems to be essential. Science communication focused on making information about genome modification biotechnologies available to citizens could promote more positive attitudes and perceptions and facilitate their future implementation in the country
Virulence and antimicrobial resistance of Escherichia coli isolated from chicken meat, beef, and raw milk
Get PDFTwo hundred and thirty-five strains of E. coli were recovered from beef, chicken meat, and raw milk sold in butcher shops and markets in the town of Jijel, East Algeria. A PCR investigation revealed the predominance of bacterial strains with extraintestinal pathogenic E. coli (ExPEC) genes (19.91%). Enteroaggregative (EAEC) and enteroinvasive (EIEC) bacteria were also detected. Strains from phylogenetic groups A and B1 were the most common; they accounted for 62.35% and 21.17% in chicken meat, 67.53% and 16.88% in raw milk and 64.38% and 25.97% in beef, respectively, followed by the strains from phylogenetic groups B2 and D. Moreover, E. coli from phylogenetic group D was more abundant in chicken than in beef or raw milk samples (P<0.05). Antibiogram results revealed the presence of three major antibiotic-susceptibility groups and more than a hundred antibiotypes. Between 50% and 70% of strains were resistant to antibiotics of the first group (ampicillin, amoxicillin, trimethoprim, sulfonamide and tetracycline), 20% to 50% to antibiotics of the second group (amoxicillin plus clavulanic acid, kanamycin, streptomycin, ciprofloxacin, flumequine and neomycin) and less than 20% to those of the third group (cephalothin, gentamicin and colistin). Additionally, the resistance to flumequine, trimethoprim, sulfamethoxazole-trimethoprim and tetracycline was more frequent in chicken meat strains than in those from beef and milk. It is important to point out that the strains carrying more than two virulence factors belonged to the B2 or D phylogenetic groups and had weaker resistance to antibiotics. The strains from the A and B1 groups had fewer virulence factors and showed high resistance to antibiotics.
Aneurysm of the pulmonary artery in a sheep with pulmonary adenocarcinoma
Get PDFAneurysm of the pulmonary artery is a rare condition in animals, and to our knowledge it has never been reported in association with pulmonary neoplasia. This report describes a case of an adult female sheep of the “Churra Galega Bragançana” breed with an aneurysm of the pulmonary artery associated with lung cancer (ovine pulmonary adenocarcinoma)
Multiple cervical spondylolisthesis and thoracic vertebral malformation in an 11 month-old Chilean Caballo Raza Chilena colt
Get PDFCompressive myelopathy caused by developmental cervical and thoracic malformation was diagnosed in an 11-month-old Chilean Caballo Raza Chilena colt. The patient evidenced an abnormal wide-based stance, neck muscle atrophy, upside-down neck conformation and tetra ataxia. Ataxia was exacerbated when the colt was walked down and uphill, walked with elevated head, backing and turning in tight circles. The patient showed no improvement following medical therapy, therefore, the colt was euthanised due to a poor prognosis after myelogram findings. Cervical spine malalignment (spondylolisthesis) associated with multi-level compression of the spinal cord was suspected based on cervical radiographs and myelogram findings and was confirmed postmortem. Thoracic vertebral malformation retained cartilage matrix spicules and a flare of the cranial vertebral epiphysis of the first thoracic vertebrae (T1) were also diagnosed at necropsy
Characterisation of dairy female calf management practices in southern Chile
Get PDFThe objective of this study was to characterise husbandry and technical-productive practices at the calf rearing stage in dairy farms in Los Lagos Region, southern Chile. A face-to-face survey was applied to 22 dairy farms in Los Lagos Region in 2017. All farms performed artificial calf rearing under either of two systems: total barn confinement (48%) or a mixed system that considers the first stage with confinement and the second stage in open-air paddocks (52%). More than half (52%) of the farms supplied fresh colostrum to the calf from its dam and the rest of the farms used bottle or oesophageal tube. Only 30% of the farms evaluated colostrum quality using colostrometer (densimeter) or refractometer. After the colostrum supply, milk replacers, waste milk, or a mixture of both were used for calf feeding. Most of the farms (66.7%) did not have automated milk-feeding systems and used bottles (88.9%) and buckets (11.1%) instead. On average, calves were handled by 1.5 caretakers (SD: 0.63) of which 63.4% (SD: 40.2) were men. The average age for caretakers was 43.9 years (SD: 12.7), with 23.8% being less than 35 years old. Overall, results from this study can be used to identify key managements that could improve calves’ rearing productive traits