Alpha-mannosidosis caused by toxic plants in ruminants of Argentina.

It is well known that several of the swainsonine-containing plant species found widespread around the world have a negative economic impact in each country. In Argentina, most of the information on the poisonous plant species that produce α-mannosidosis is published in Spanish and thus not available to most English-speaking researchers interested in toxic plants. Therefore, the aim of this review is to summarize the information about swainsonine-containing plants in Argentina, which are extensively distributed throughout different ecoregions of the country. To date, five species from three genera have been shown to induce α-mannosidosis in livestock in Argentina: Ipomoea carnea subsp. fistulosa, Ipomoea hieronymi subsp. calchaquina (Convolvulaceae), Astragalus garbancillo, Astragalus pehuenches (Fabaceae), and Sida rodrigoi (Malvaceae). These species contain the indolizidine alkaloid swainsonine, which inhibits the lysosomal enzyme α-mannosidase and consequently affects glycoprotein metabolism, resulting in partially metabolized sugars. The prolonged consumption of these poisonous plants produces progressive weight loss and clinical signs related to a nervous disorder, characterized by tremors of head and neck, abnormalities of gait, difficulty in standing, ataxia and wide-based stance. Histological lesions are mainly characterized by vacuolation of different cells, especially neurons of the central nervous system. The main animal model used to study α-mannosidosis is the guinea pig because, when experimentally poisoned, it exhibits many of the characteristics of naturally intoxicated livestock.

Principal Metabolites in Extracts of Different Plants Responsible for Antibacterial Effects.

The increase in bacterial resistance and decreased effectiveness of antibacterial agents has forced researchers to look for new antibacterial agents from environmentally friendly sources such as essential oils and oil extracts. The functional group of the metabolites present in the essential oils or plant extract and the synergy effects between them play an important role in the biological activity and can be the principal factor affecting the antibacterial effect. All of these bioactive oils showed the same action mechanism, and the best way to implement them is by extracting them without changing their original properties, whereby the characterization and evaluation of the compounds are important steps. All of these themes are extensively reviewed, analyzed, and discussed in this work.

Fatal stagger poisoning by consumption of Festuca argentina (Speg.) Parodi in goats from Argentine Patagonia.

The present study describes the spontaneous and experimental poisoning of goats by Festuca argentina in Argentine Patagonia. In April 2017, eight seven-month-old Creole male goats were accidentally introduced into a paddock that contained F. argentina. After four days, two of the goats were found dead and four out of the six remaining goats were clinically affected. Two of the latter had to be later euthanized in extremis. The main clinical signs were progressive nervous signs, starting with moderate muscle tremors, wide-based stance and ataxia. Postmortem examination was performed on the two euthanized goats. Epidermal fragments of F. argentina were found in the rumen samples from the necropsied goats and the fecal samples from the four affected goats. For the experimental poisoning, fresh sheaths of F. argentina collected from the paddock were offered to two goats at 10 g/kg body weight for 3 days. After 24-36 h, both animals exhibited severe muscle tremors, reluctance to move, tetanic convulsions, and opisthotonus. In both the spontaneously and experimentally poisoned goats, gross lesions were similar and consisted of dehydration, petechial hemorrhages in the epicardium and congestion. The main microscopic findings consisted of degeneration and loss of Purkinje cells and torpedoes in the granular layer of the cerebellum. The F. argentina sheaths collected from the pasture were found to contain tremorgenic indole-diterpene alkaloids. Taken together, the results of the present study suggest that the tremorgenic syndrome observed in the spontaneously poisoned goats was due to poisoning by F. argentina.

Molecular characterization of Brucella ovis in Argentina.

Brucellosis in rams is caused by Brucella ovis or Brucella melitensis and it is considered one of the most important infectious diseases of males in sheep-raising countries. Molecular characterization of Brucella spp. achieved by multi-locus variable number of tandem repeats analysis (MLVA) is a powerful tool to genotype Brucella spp. However, data regarding B. ovis genotyping is scarce. Thus, the aim of this study was to characterize the molecular diversity of B. ovis field-strains in Argentina. A total of 115 isolates of B. ovis from Argentina and Uruguay were genotyped using MLVA-16 and analyzed altogether with 14 publicly available B. ovis genotypes from Brazil. The Discriminatory Power (D) was 0.996 for MLVA-16 and 0.0998 for MLVA-8 and MLVA-11. Analysis of MLVA-16 revealed 100 different genotypes, all of them novel, including 90 unique ones. There was no correlation between geographical distribution and genotype and results showed a higher diversity within provinces than between provinces. Clustering analysis of the strains from Argentina, Uruguay and Brazil revealed that the 129 isolates were grouped into two clades. Whole Genome Sequencing analysis of the 19 B. ovis genomes available in public databases, and including some of the Argentinian strains used in this study, revealed clustering of the Argentinian isolates and closer relationship with B. ovis from New Zealand and Australia. This work adds new data to the poorly understood distribution map of genotypes regionally and worldwide for B. ovis and it constitutes the largest study of B. ovis molecular genotyping until now.

Detection of swainsonine-producing endophytes in Patagonian Astragalus species.

Swainsonine has been identified as the toxin in legumes belonging to the genera Astragalus and Oxytropis throughout the world including China, North America, and South America. Several South American Astragalus species have been reported to contain swainsonine; however, data is lacking to support the presence of a fungal symbiont in South American Astragalus species as has been shown for North American and Chinese Astragalus and Oxytropis species. The objective of this study was to investigate several South American species that have been reported to contain swainsonine for the presence of the fungal symbiont using culturing and PCR. Swainsonine was detected in field collections of A. pehuenches, A. illinii and A. chamissonis but not A. moyanoi, which is consistent with reports of toxicity regarding these species. The symbiont Alternaria section Undifilum was detected by PCR in all three species that contained swainsonine but not in A. moyanoi. A fungal symbiont was isolated from seeds of Astragalus pehuenches and A. illinii. The isolated symbiont from both respective species produced swainsonine in vitro, and was demonstrated to belong to the genus Alternaria section Undifilum by analysis of the nuclear ribosomal DNA. It is highly likely that Alternaria section Undifilum isolates will be associated with other South American Astragalus species that are reported to contain swainsonine.

Spontaneous outbreak of Astragalus pehuenches (Fabaceae) poisoning in cattle in Argentina.

This is the first report of a spontaneous outbreak of Astragalus pehuenches poisoning on a farm in Argentine Patagonia, where 63 out of 70 cattle died. The main clinical signs of affected animals were ataxia, balance loss and progressive emaciation. Purkinje cells presented vacuolation and marginalization of the nucleus. Astragalus pehuenches was detected in the paddock as well as in the ruminal content and fecal matter samples of the affected animals. Swainsonine concentrations in Astragalus specimens were found to be as high as 0.096%.

Variables Influencing the Accuracy of 3D Modeling of Existing Roads Using Consumer Cameras in Aerial Photogrammetry.

Point cloud (PC) generation from photogrammetry⁻remotely piloted aircraft systems (RPAS) at high spatial and temporal resolution and accuracy is of increasing importance for many applications. For several years, photogrammetry⁻RPAS has been used to recover civil engineering works such as digital elevation models (DEMs), triangle irregular networks (TINs), contour levels, orthophotographs, etc. This study analyzes the influence of variables involved in the accuracy of PC generation over asphalt shapes and determines the most influential variable based on the development of an artificial neural network (ANN) with patterns identified in the test flights. The input variables were those involved, and output was the three-dimension root mean square error (3D-RMSE) of the PC in each ground control point (GCP). The result of the study shows that the most influential variable over PC accuracy is the modulation transfer function 50 (MTF50). In addition, the study obtained an average 3D-RMSE of 1 cm. The results can be used by the scientific and civil engineering communities to consider MTF50 variables in obtaining images from RPAS cameras and to predict the accuracy of a PC over asphalt based on the ANN developed. Also, this ANN could be the beginning of a large database containing patterns from several cameras and lenses in the world market.

Phylogenetic Analysis of ORF Viruses From Five Contagious Ecthyma Outbreaks in Argentinian Goats.

Orf virus (ORFV) is the etiological agent of Contagious Ecthyma (CE) disease that mainly affects sheep, goats, wild ruminants, and humans with a worldwide distribution. To date, only two strains from Argentinian sheep have been characterized at the molecular level and there is little information on ORFV strains circulating in Argentina. Here we describe and analyze five outbreaks of CE in goats in three geographic regions of the country: Northwest, Center, and Southwest. The phylogenetic analysis based on four molecular markers of ORFV (orf011 partial sequence and orf020, orf109, and orf127 complete sequence genes) revealed that there are different strains circulating in Argentina and pointed out the importance of knowing the health status of animals traded between farms.

Screening for swainsonine among South American Astragalus species.

Swainsonine is a toxic alkaloid found in several plant genera worldwide. The objective of this study was to screen several South American Astragalus species for the toxin swainsonine. Swainsonine was detected in 16 of 30 Astragalus species using liquid and gas chromatography coupled with mass spectrometry. Information in regard to the swainsonine content of these species may provide important information on the risk of grazing these toxic species.

Development and evaluation of a species-specific PCR assay for the detection of Brucella ovis infection in rams.

Brucella ovis infection is a major cause of epididymitis and infertility in rams, resulting in reproductive failure and significant economic losses worldwide. The goal of this study was to develop a PCR test targeting specific B. ovis genomic sequences. Specific primer pairs were designed targeting 12 of those ORFs. Samples of blood, serum, semen, urine, and preputial wash were collected from experimentally infected rams (n=9) every other week up to 180 days post infection (dpi), when tissue samples were obtained. Blood, serum, semen, urine, and preputial wash samples were obtained, in weekly intervals for 1 month, from eight rams belonging to a B. ovis-free flock. Semen samples were also obtained from rams belonging to naturally infected flocks (n=40). The limit of detection of this PCR protocol was 100, 10, and 1 CFU/mL for semen, urine and prepucial wash samples, respectively. Sensitivity and specificity values obtained with this PCR method were similar to that of bacteriology when evaluating biological samples. Agreement between PCR and bacteriology results was greater than 90%. These results clearly indicate that this species-specific PCR method is highly efficient for the diagnosis of B. ovis infection in semen, urine, preputial wash and tissue samples from infected rams.

Pulmonary aspergillosis in a great rhea (Rhea americana).

A 5-mo-old great rhea (Rhea americana) gradually became emaciated over a 1-wk period and died. Necropsy revealed several small yellow nodules in the lungs. Microscopically, the nodules consisted of granulomas containing numerous thin, 4-microm-diameter, septate, branching fungal hyphae. Aspergillus fumigatus grew readily on Sabouraud dextrose agar. This report appears to be the first of mycotic pneumonia in great rheas.

Hematology and serum chemistry values of the lesser rhea (Pterocnemia pennata) raised in Patagonian farms (Argentina).

Hematologic and serum chemistry values were determined for chicks, juveniles, and adult farmed lesser rheas (Prerocnemia pennata). Blood samples were taken during March-April 1998 from the brachial veins of lesser rhea, including 64 chicks, 24 juveniles, and 36 adults, raised in Patagonian farms (Argentina). Lesser rhea chicks had significantly lower erythrocyte counts, hematocrit, hemoglobin, red cell indices, and copper than did the juveniles and adult individuals. No significant differences were observed between females and males. Most values were similar to those reported for other ratites. The data obtained provide hematologic and serum chemistry values for lesser rhea from farms.