Mycobacterium avium subsp. paratuberculosis (MAP) infection in the endangered huemul deer (Hippocamelus bisulcus) in Patagonia

In a huemul (Hippocamelus bisulcus) population sympatric with cattle, we found evidence of Mycobacterium avium subsp. paratuberculosis (MAP) infection. Three huemul faecal pellet samples and two cows pats were collected and cultured for MAP presence. DNA was then extracted for PCR analysis of all signal-positive cultures. To assess whether MAP isolates obtained from huemul faeces were associated with typical MAP isolated from livestock, positive confirmed culture samples were sub-typed using a combination of five Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat Analysis and one Short Sequence Repeat analysis markers. All faecal samples from both species were MAP positive. One huemul presented a different bacteria profile genotype not described before, suggesting that huemul and cattle in Patagonia could carry a unique MAP strain

Detection of pathogenic leptospira as a cause of abortion in cattle-observations on diagnosis

Leptospirosis 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

Evidence of Mycobacterium avium subsp. paratuberculosis (MAP) infection in huemul deer (Hippocamelus bisulcus) in patagonian fjords

In the Chilean coastal Patagonia, fourteen wild deer huemul faecal pellet samples were collected and cultured for Mycobacterium avium subsp. paratuberculosis detection. Six samples were positive, but only one was able to show a molecular type similar to the most common strain reported for cattle in Chile

Serratia strains isolated from the rhizosphere of raulí ( Nothofagus alpina ) in volcanic soils harbour PGPR mechanisms and promote raulí plantlet growth

[EN] Raulí is one of the most emblematic tree species of the Chilean temperate forests. Due to the high quality wood, this tree has been used for furniture and handicrafts manufacturing, which has positioned raulí as one of the most important commercial timber species in Chile. Currently, the international market demands sustainable production system for forest production, more specifically in plantlets production. In this regard, plant growthpromoting rhizobacteria (PGPR) inoculants may enhance the growth and survival of plantlets in nurseries, which means an increase in the effectiveness of replanting operations. Therefore, the aim of the present study was to isolate, characterize and screen rhizosphere-associated bacteria with PGPR potential, isolated from raulí that growth in volcanic soils in southern Chile. A total of 1,261 bacterial strains were isolated from different volcanic soils. Out of 1,261 isolates, 100 were selected based on their high levels of indole acetic acid (IAA) production. These isolates were then subjected to screening for 1-aminocyclopropane-1-carboxylic acid deaminase activity, and their ability to fix nitrogen was determined. From the 100 selected isolates, 7 were chosen for producing the highest amount of IAA to continue with genetic characterization based on their 16S rRNA gene sequences. These 7 isolates were characterized as members of the Serratia genus and were used to develop multi-strain inoculant mixtures. Later, a nursery study followed to determine the effect of inoculation with the Serratia strains on the growth of RA88 raulí clone plantlets. The nursery experiment demonstrated that Serratia strains have the potential to increase the root collar diameter, height, relative chlorophyll content, biomass and nitrogen content of raulí plantlets. The study concluded, that Serratia strains have the potential to be used as biofertilizers to increase plant growth in nursery conditions

Diagnostic accuracy of an immunomagnetic separation-PCR assay to detect pathogenic Leptospira spp. in urine from dairy cattle, using a Bayesian latent class model

Leptospirosis is a zoonotic disease that has spread worldwide and causes significant economic losses in the dairy industry. The causal agents of this infectious disease are members of the genus Leptospira, known as pathogenic Leptospira spp. Specific clinical signs of the infection are difficult to detect. Therefore, the disease is normally under-diagnosed, mostly due to the lack of a cost-effective technique for diagnosing animals with a low bacterial load in their urine. The aim of this study was to assess the diagnostic accuracy of a qPCR coupled with a previous Immunomagnetic separation (IMS) step (IMS-qPCR) against a qPCR without using IMS, using a Bayesian latent class model (2 tests, 3 populations) to determine the leptospirosis infectious status in naturally infected dairy cattle. The results revealed that IMS qPCR had a sensitivity (Se) of 95.7% (95% Probability Interval (PI) = 85.0; 99.4%) and a specificity (Sp) of 98% (95% PI = 96.1; 99.4%), indicating that it is more sensitive than conventional qPCR (Se = 69.7% (95% PI = 59.2; 79.0%); median difference = 25.2% (Monte Carlo Error = 10.2%); and the Sp = 98.8% (95% PI = 97.6; 99.5%), median difference = 0.8% (Monte Carlo Error = 2.1%). Therefore, results shows that IMS-qPCR is a more useful diagnostic tool in terms of accuracy for detecting infectious animals with pathogenic Leptospira in their urine