Green algal peritonitis in 2 cows

Toxic or Otherwise Harmful Algae and the Built Environment

This article gives a comprehensive overview on potentially harmful algae occurring in the built environment. Man-made structures provide diverse habitats where algae can grow, mainly aerophytic in nature. Literature reveals that algae that is potentially harmful to humans do occur in the anthropogenic environment in the air, on surfaces or in water bodies. Algae may negatively affect humans in different ways: they may be toxic, allergenic and pathogenic to humans or attack human structures. Toxin-producing alga are represented in the built environment mainly by blue green algae (Cyanoprokaryota). In special occasions, other toxic algae may also be involved. Green algae (Chlorophyta) found airborne or growing on manmade surfaces may be allergenic whereas Cyanoprokaryota and other forms may not only be toxic but also allergenic. Pathogenicity is found only in a special group of algae, especially in the genus Prototheca. In addition, rare cases with infections due to algae with green chloroplasts are reported. Algal action may be involved in the biodeterioration of buildings and works of art, which is still discussed controversially. Whereas in many cases the disfigurement of surfaces and even the corrosion of materials is encountered, in other cases a protective effect on the materials is reported. A comprehensive list of 79 taxa of potentially harmful, airborne algae supplemented with their counterparts occurring in the built environment, is given. Due to global climate change, it is not unlikely that the built environment will suffer from more and higher amounts of harmful algal species in the future. Therefore, intensified research in composition, ecophysiology and development of algal growth in the built environment is indicated.

Protothecosis and chlorellosis in sheep and goats: a review

Protothecosis and chlorellosis are sporadic algal diseases that can affect small ruminants. In goats, protothecosis is primarily associated with lesions in the nose and should be included in the differential diagnosis of causes of rhinitis. In sheep, chlorellosis causes typical green granulomatous lesions in various organs. Outbreaks of chlorellosis have been reported in sheep consuming stagnant water, grass from sewage-contaminated areas, and pastures watered by irrigation canals or by effluents from poultry-processing plants. Prototheca and Chlorella are widespread in the environment, and environmental and climatic changes promoted by anthropogenic activities may have increased the frequency of diseases produced by them. The diagnosis of these diseases must be based on gross, microscopic, and ultrastructural lesions, coupled with detection of the agent by immunohistochemical-, molecular-, and/or culture-based methods.

Algal Lymphadenitis in a Dog Caused by Scenedesmus Species

A 6-year-old, spayed female Labrador/Weimaraner cross-breed dog that had previously lived in Arizona presented in Montana for an annual examination with an incidentally enlarged popliteal lymph node, which was subsequently biopsied. Histologically, the lymph node was expanded by eosinophil-rich granulomas with both extracellular and intrahistiocytic green algae. These algae had intracytoplasmic, birefringent, and refractile granules; readily formed 2 to 3 mm green colonies on Columbia blood agar medium; and ultrastructurally had a multilayered cell wall and intracytoplasmic chloroplasts. Amplified product from the internal transcribed spacer and D1/D2 regions of the 28S ribosomal RNA gene had high sequence identity to Scenedesmus sp. Despite similar infection in the retropharyngeal lymph node 1 year later, the animal remained otherwise healthy with no clinical signs. To the authors' knowledge, this is the first case of Scenedesmus species infection in a dog and is a differential diagnosis for Coccidioides immitis.

The photosynthetic eukaryote Nannochloris eukaryotum as an intracellular machine to control and expand functionality of human cells

To construct an intracellular machine, we sought a symbiotic relationship between a photosynthetic green alga and human cells. Human cells selectively take up the minimal eukaryote Nannochloris eukaryotum and the resulting symbionts are able to survive and proliferate. Host cells can utilize N. eukaryotum's photosynthetic apparatus for survival, and expression of cellular vascular endothelial growth factor can be controlled with input of photonic energy. This seemingly rare spontaneous association provides an opportunity to fabricate light-controlled, intracellular machines.