Investigation of the transmission of Mycobacterium bovis from deer to cattle through indirect contact

OBJECTIVE: To investigate the infection of calves with Mycobacterium bovis through oral exposure and transmission of M. bovis from experimentally infected white-tailed deer to uninfected cattle through indirect contact. ANIMALS: 24 11-month-old, white-tailed deer and 28 6-month-old, crossbred calves. PROCEDURE: In the oral exposure experiment, doses of 4.3 x 10(6) CFUs (high dose) or 5 x 10(3) CFUs (low dose) of M. bovis were each administered orally to 4 calves; as positive controls, 2 calves received M. bovis (1.7 x 10(5) CFUs) via tonsillar instillation. Calves were euthanatized and examined 133 days after exposure. Deer-to-cattle transmission was assessed in 2 phases (involving 9 uninfected calves and 12 deer each); deer were inoculated with 4 x 10(5) CFUs (phase I) or 7 x 10(5) CFUs (phase II) of M. Bovis. Calves and deer exchanged pens (phase I; 90 days' duration) or calves received uneaten feed from deer pens (phase II; 140 days' duration) daily. At completion, animals were euthanatized and tissues were collected for bacteriologic culture and histologic examination. RESULTS: In the low- and high-dose groups, 3 of 4 calves and 1 of 4 calves developed tuberculosis, respectively. In phases I and II, 9 of 9 calves and 4 of 9 calves developed tuberculosis, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that experimentally infected deer can transmit M. bovis to cattle through sharing of feed. In areas where tuberculosis is endemic in free-ranging white-tailed deer, management practices to prevent access of wildlife to feed intended for livestock should be implemented.     

Synthesis and insecticidal activity of lipophilic amides. Part 4: The effect of substituents on the phenyl group of 6-phenylhexa-2,4-dienamides

Substituted phenylacetaldehydes, made by homologation of the benzaldehydes by Wittig condensation with a methoxymethylene ylid, were condensed under Wadsworth-Emmons conditions to give the substituted N-(2-methylpropyl)-6-phenylhexa-2,4-dienamides. Electron withdrawing substituents favoured the formation of the unwanted 3,5-diene isomer. Insecticidal activity was lowered by most substituents examined, but was retained or even enhanced by halogen atoms at the m- or p-positions. At the m-position, activity decreased as size of halogen increased.     

Adsorptive effects of di-tri-octahedral smectite on Clostridium perfringens alpha, beta, and beta-2 exotoxins and equine colostral antibodies

OBJECTIVE: To determine the adsorptive capability of di-tri-octahedral smectite (DTOS) on Clostridium perfringens alpha, beta, and beta-2 exotoxins and equine colostral antibodies. SAMPLE POPULATION: 3 C perfringens exotoxins and 9 colostral samples. PROCEDURES: Alpha, beta, and beta-2 exotoxins were individually co-incubated with serial dilutions of DTOS or bismuth subsalicylate, and the amount of toxin remaining after incubation was determined via toxin-specific ELISAs. Colostral samples from healthy mares were individually co-incubated with serial dilutions of DTOS, and colostral IgG concentrations were determined via single radial immunodiffusion assay. RESULTS: Di-tri-octahedral smectite decreased the amount of each C perfringens exotoxin in co-incubated samples in a dose-dependent manner and was more effective than bismuth subsalicylate at reducing exotoxins in vitro. Decreases in the concentration of IgG were detected in samples of colostrum that were combined with DTOS at 1:4 through 1:16 dilutions, whereas no significant decrease was evident with DTOS at the 1:32 dilution. CONCLUSIONS AND CLINICAL RELEVANCE: Di-tri-octahedral smectite effectively adsorbed C perfringens exotoxins in vitro and had a dose-dependent effect on the availability of equine colostral antibodies. Results suggested that DTOS may be an appropriate adjunctive treatment in the management of neonatal clostridiosis in horses. In vivo studies are necessary to fully assess the clinical efficacy of DTOS treatment.     

Bioactivities of Lipid Extracts and Complex Lipids from Seaweeds: Current Knowledge and Future Prospects

While complex lipids of seaweeds are known to display important phytochemical properties, their full potential is yet to be explored. This review summarizes the findings of a systematic survey of scientific publications spanning over the years 2000 to January 2021 retrieved from Web of Science (WoS) and Scopus databases to map the state of the art and identify knowledge gaps on the relationship between the complex lipids of seaweeds and their reported bioactivities. Eligible publications (270 in total) were classified in five categories according to the type of studies using seaweeds as raw biomass (category 1); studies using organic extracts (category 2); studies using organic extracts with identified complex lipids (category 3); studies of extracts enriched in isolated groups or classes of complex lipids (category 4); and studies of isolated complex lipids molecular species (category 5), organized by seaweed phyla and reported bioactivities. Studies that identified the molecular composition of these bioactive compounds in detail (29 in total) were selected and described according to their bioactivities (antitumor, anti-inflammatory, antimicrobial, and others). Overall, to date, the value for seaweeds in terms of health and wellness effects were found to be mostly based on empirical knowledge. Although lipids from seaweeds are little explored, the published work showed the potential of lipid extracts, fractions, and complex lipids from seaweeds as functional ingredients for the food and feed, cosmeceutical, and pharmaceutical industries. This knowledge will boost the use of the chemical diversity of seaweeds for innovative value-added products and new biotechnological applications.     

Molecular detection of bat coronaviruses in three bat species in Indonesia

Bats are an important reservoir of several zoonotic diseases. However, the circulation of bat coronaviruses (BatCoV) in live animal markets in Indonesia has not been reported. Genetic characterization of BatCoV was performed by sequencing partial RdRp genes. Real-time polymerase chain reaction based on nucleocapsid protein (N) gene and Enzyme-linked immunosorbent assay against the N protein were conducted to detect the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA and antibody, respectively. We identified the presence of BatCoV on Cynopterus brachyotis, Macroglossus minimus, and Rousettus amplexicaudatus. The results showed that the BatCoV included in this study are from an unclassified coronavirus group. Notably, SARS-CoV-2 viral RNA and antibodies were not detected in the sampled bats.     

First detection of spring viraemia of carp virus in common carp (Cyprinus carpio L.) affected by a septicaemic disease in Mexico

Spring viraemia of carp (SVC) is an infectious disease responsible for severe economic losses for various cyprinid species, particularly common carp (Cyprinus carpio carpio). The causative agent is the SVC virus (SVCV), a member of the Sprivivirus genus, Rhabdoviridae family, and a List 1 pathogen notifiable by the World Organization for Animal Health. This study describes the diagnosis of an SVCV pathogen isolated in October 2015 from wild common carp inhabiting a natural lagoon in central Mexico. While neither an epidemic nor fish mortalities were reported, the collected killed specimens exhibited clinical signs of disease (e.g., exopthalmia, moderate abdominal distension and haemorrhaging, as well as internal haemorrhages and adhesions). Histological results of injuries were consistent with the pathology caused by SVCV. This finding was supported by the isolation of a virus in EPC and BF‐2 cells and subsequent RT‐PCR confirmation of SVCV. The phylogenetic analyses of partial SVCV glycoprotein gene sequences classified the isolates into the Ia genogroup. These findings make this the first report of SVCV detection in Mexico, extending the southern geographical range of SVCV within North America. However, since this pathogen was detected in fish inhabiting a natural body of water without tributaries or effluents, it is difficult to estimate the risk of SVCV for other wild/feral cohabitating cyprinid species in the lagoon. The status of this virus is also unknown for other bodies of water within this region.     

Applying biofloc technology in the culture of juvenile of Piaractus brachypomus (Cuvier, 1818): Effects on zootechnical performance and water quality

The aim of this study was to assess the zootechnical performance and water quality of a cachama blanca (Piaractus brachypomus) culture using biofloc technology (BFT) versus a system with daily water exchange (DWE). To do this, 180 juveniles (mean initial weight: 5.40 ± 0.19 g) were distributed in 12 circular plastic tanks with stocking densities of 20 or 40 individuals m³; then, they were cultured for 91 days. BFT treatments kept a C:N ratio approximately of 15:1. Temperature, pH and oxygen were monitored daily, while the other variables were measured weekly. Most productive variables were significantly influenced by both culture system and stocking density with significantly higher values of daily weight gain, total weight gain and total length for fish kept in DWE 20. However, only minor differences were observed within the BFT system. With the exception of the toxic nitrogen compounds (NH₄⁺ and NO₂^?), all the other water quality parameters were within the acceptable ranges for the cultivation of tropical fish. Microorganisms started to settle from the first week. A total of 23 genera were present, the most outstanding of which being seven genera of ciliates and three rotifers, rhizopods and chlorophytes. In conclusion, both systems BFT and DWE are useful for increasing the production of P. brachypomus in captivity. Additionally, the BFT system can potentially be applied for growing juveniles of this specie in regions with scarce water resources.     

Regions of strong coupling between soil moisture and precipitation

Previous estimates of land-atmosphere interaction (the impact of soil moisture on precipitation) have been limited by a lack of observational data and by the model dependence of computational estimates. To counter the second limitation, a dozen climate-modeling groups have recently performed the same highly controlled numerical experiment as part of a coordinated comparison project. This allows a multimodel estimation of the regions on Earth where precipitation is affected by soil moisture anomalies during Northern Hemisphere summer. Potential benefits of this estimation may include improved seasonal rainfall forecasts.