Mycobacterium fortuitum abortion in a sow

Two aborted Chester White pig fetuses were presented to a veterinary diagnostic laboratory in Illinois. Postmortem examination identified no gross abnormalities. Histologic evaluation revealed multifocal necrosis of chorionic epithelial cells, coalescing areas of mineralization in the placenta, and focal accumulations of viable and degenerate neutrophils in the lung. Intra- and extracellular acid-fast bacilli were identified in the lesions in both the placenta and lungs. Bacterial culture of stomach contents yielded heavy growth of Mycobacterium fortuitum, a rapidly growing nontuberculous mycobacterium (NTM), which was further confirmed through whole-genome sequencing. NTM are opportunistic pathogens commonly found in the soil and in contaminated water supplies. In animals, M. fortuitum is typically introduced through cutaneous wounds leading to infections limited to the skin, with systemic infection being uncommon. To our knowledge, abortion caused by M. fortuitum has not been reported previously.     

Botrytis cinerea Infection of Grape Flowers: Light and Electron Microscopical Studies of Infection Sites

ABSTRACT Specific floral organs including the calyptra, stigma, and receptacle area of glasshouse-grown grapevines (Vitis vinifera cv. Cabernet Sauvignon) were inoculated with aqueous suspensions of Botrytis cinerea conidia, and the initial steps involved in colonization and infection of the host tissues were studied for several days postinoculation using light microscopy as well as scanning and transmission electron microscopy. Conidia germinated on all floral organs examined and became attached to the host surface within 48 h after inoculation. However, in all cases the vast majority of conidia accumulated in a channel-like gap between the ovary and the calyx that extended in a narrowing fashion into the flower interior where the ovary joined the receptacle. Very few conidial germ tubes were detected in the style following inoculation of the stigma, and no evidence for their growth toward the ovaries could be found. In contrast, hyphae were more abundant in the receptacle area, regardless of the site of inoculation. Tips of the calyx became necrotic and mycelium formed in the gap between ovary and calyx within 72 h following inoculation, providing a major point of colonization and infection. B. cinerea colonized dehiscent calyptras within 72 h of inoculation, providing a potential source of inoculum from calyptras that remained stuck in the cluster. The results suggest that the grape flower's receptacle area is the predominant site of infection for B. cinerea, although a minor portion of infections may also occur through the stigma and style.     

Chloride toxicity in citrus

Summary Citrus orchards (cv. Valencia and cv. Washington Navel Orange) on sandy soils in semi-arid South Australia (evaporation 1,900 mm, rainfall 240 mm) are irrigated with water from the River Murray having a chloride content of less than one to over 10 meq/1 (electrical conductivity 0.35–1.4 dS/m). Field observations and the literature suggest that at irrigation water salinities above 4 meq/1 Cl-, yield losses might be expected due to toxic effects of chloride rather than osmotic effects.To assess these effects irrigations at four salinity levels (range 2 to 5 meq/1 Cl^–) were applied to mature oranges trees (cv. Washington Navel) grown on Rough Lemon rootstock. Irrigations were carefully scheduled, with a total annual application of about 1,100 mm. The treatments resulted in soil salinities of 0.9 to 1.5 mS/cm (as measured with 4-electrode probes, at a depth of 0–50 cm), leaf chloride content on individual trees of 0.2% to 1.2%, and individual tree yields of 300 to 340 kg of fruit. On this orchard, a yield decrement of about 20% per 1 meq/1 chloride in the irrigation water was calculated, above a threshold level of about 4.3 meq/1 (Fig. 5). Reasons are given to support the view that the yield decrements found were probably due to chloride toxicity rather than osmotic stress.     

Acetyl-CoA Carboxylase—a Graminicide Target Site

Acetyl-CoA carboxylase catalyses the first committed step in fatty acid (and acyl lipid) formation. The enzyme has been shown to exert a high degree of flux control for lipid biosynthesis in leaves and, therefore, it is not surprising that chemicals which can inhibit it effectively are successful herbicides. These chemicals belong mainly to the cyclohexanedione and aryloxyphenoxypropionate classes and are graminicides. The reason for the selectivity of these herbicides towards grasses lies in the nature of the target site, acetyl-CoA carboxylase. Recent advances in our knowledge of acetyl-CoA carboxylases from sensitive and resistant plants has revealed some important facts. Dicotyledons, which are resistant, have a multi-enzyme complex type of carboxylase in their chloroplasts while grasses have a multifunctional protein. Both divisions of plants have two isoforms of the enzyme, the second being in the cytosol. Detailed study of multifunctional forms of acetyl-CoA carboxylases, which have different sensitivities to herbicides, suggests that herbicide resistance is correlated with cooperativity of herbicide binding to the native dimeric form of the carboxylase. © 1997 SCI.     

TRANS-SPLENIC PORTAL SCINTIGRAPHY IN NORMAL DOGS

The purpose of this study was to (1) establish a technique for ultrasound-guided trans-splenic portal scintigraphy (TSPS) using 99mTcO4(-), (2) evaluate portal vein morphology, (3) compare the radiation exposures for TSPS vs. per-rectal portal scintigraphy (PRPS), and (4) compare the quality of numerical data from the TSPS vs. PRPS. Eight juvenile dogs underwent PRPS and TSPS (minimum of 48h between studies) after initial screening tests. PRPS was done according to established protocol using 425 +/- 36MBq (mean +/- SD) of 99mTcO4(-). TSPS was done with the dogs in right lateral recumbency over the gamma camera. 99mTcO4(-) (57 +/- 13.9 MBq) was injected into the spleen 1-2s following initiation of the dynamic acquisition. The frame rate was 4 frames/s for 5 min. There was significantly lower radioactivity of 99mTcO4(-) given and significantly higher total counts recorded in the liver and heart during the TSPS compared with PRPS. The total counts for the TSPS and PRPS were 7120 +/- 4386 and 830 +/- 523, respectively. Percent absorption from the spleen was 52.5 +/- 19.1% compared with 9.2 +/- 5.7% for the colon. Calculated transit time for the TSPS studies was 7 +/- 2.3s. In TSPS studies, the splenic and portal veins were clearly identified. Radiation exposure levels of the dogs were significantly lower following TSPS than after PRPS. TSPS appears superior to PRPS as a method to image the portal venous system representing a valid alternative diagnostic test for animals with suspected portosystemic shunts.