Bacteria That Masquerade as Fungi: Actinomycosis/Nocardia

Abstract

The order Actinomycetales includes phylogenetically diverse but morphologically similar aerobic and anaerobic bacteria that exhibit filamentous branching structures which fragment into bacillary or coccoid forms. The aerobic actinomyces are a large, diverse group of gram-positive bacteria including Nocardia, Gordona, Tsukamurella, Streptomyces, Rhodococcus, Streptomycetes, Mycobacteria, and Corynebacteria. The anaerobic genera of medical importance include Actinomyces, Arachnia, Rothia, and Bifidobacterium. Both Actinomyces and Nocardia cause similar clinical syndromes involving the lung, bone and joint, soft tissue, and the central nervous system. The medically important Actinomyces organisms cause infections characterized by chronic progression, abscess formation with fistulous tracts and draining sinuses. Called "great masqueraders," diagnosis of actinomycosis and nocardiosis is often delayed. Once recognized, treatment of these infections requires long courses of parenteral and oral therapy. This review will compare and contrast infections due to Actinomyces and Nocardia.

Diversity and frequency of Nocardia spp. in the soil of Isfahan province, Iran

“…In this study, Streptomyces were not isolated, which was probably due to the following reasons: 1) according to Rippon [41] , species of Streptomyces have been observed in soils with pH less than 6.5, whereas in this study, about 90% of soil samples were with pH>7; 2) another possible reason can be the sensitivity of Streptomyces to the amount of kanamycin used.…”

“…So far, more than 50 species in the genus Nocardia are described among which Nocardia asteroids (N. asteroids) complex, Nocardia brasiliensis (N. brasiliensis), Nocardia transvalensis (N. transvalensis), Nocardia otitidiscaviarum (N. otitidiscaviarum), Nocardia farcinica and Nocardia pseudobrasiliensis are more pathogenic in humans [2] . These organisms are found in sludge, soil, contaminated soils water, plants, spoiled material and plant and cause opportunistic infections in humans and animals [3][4][5][6][7][8][9][10] .…”

“…Increase in the infections caused by these organisms, with different clinical forms of systemic and disseminated forms of nocardiosis in transplant recipients, tuberculosis, liver cirrhosis, cancer, diabetes, AIDS and patients under treatment with immunosuppressive drugs and broad spectrum antibiotics in the world, reveals more importance of isolation and identification of these agents [2,[11][12][13][14][15][16][17][18][19][20][21][22][23][24] . Various studies have shown that identification and isolation of these agents in soil of different areas help to diagnose nocardiosis [1] .…”

“…Sampling locations in cities included squares, boulevards, sidewalk, area offices, coastal and forest parks, rivers, waterfall and samples were collected in villages from corral livestock and domestic animals, nests, farm land, fruit gardens, garden houses, etc. Soil samples to the amount of 100-200 g for each sample were collected from superficial layer with depth not exceeding [2][3][4][5] cm. The samples were placed in sterile polyethylene bags, transported immediately to the laboratory and were stored at low temperature (4 曟 ) until tested.…”

Nocardia Infection in Lung Transplantation

“…Some studies recommend a dual oral combination after severe infections, such as those involving the CNS (Sullivan & Chapman, 2010).…”