کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3395837 1592845 2009 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Fusobacterium necrophorum: A ruminal bacterium that invades liver to cause abscesses in cattle
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی میکروب شناسی
پیش نمایش صفحه اول مقاله
Fusobacterium necrophorum: A ruminal bacterium that invades liver to cause abscesses in cattle
چکیده انگلیسی

Fusobacterium necrophorum, a Gram-negative, rod-shaped, and an aerotolerant anaerobe, is a normal inhabitant of the rumen of cattle. The organism is in ruminal contents and adherent to the ruminal wall. Its role in ruminal fermentation is to metabolize lactic acid and degrade feed and epithelial proteins. The ruminal concentration is higher in grain-fed than forage-fed cattle. From the rumen, the organism gains entry into the portal circulation and is trapped in the liver to cause abscesses. The organism is an opportunistic pathogen and a primary causative agent of liver abscesses, an economically important disease of grain-fed cattle. Liver abscesses are often secondary to ruminal acidosis and rumenitis in grain-fed cattle. Two subspecies of F. necrophorum, subsp. necrophorum (biotype A) and subsp. funduliforme (biotype B), are recognized that can be differentiated based on morphological, biochemical, biological and molecular characteristics. The subsp. necrophorum is more virulent and is isolated more frequently from infections than the subsp. funduliforme. Several toxins or secreted products have been implicated as virulence factors. The major factors contributing to ruminal colonization and invasion into the liver are hemagglutinin, endotoxin and leukotoxin, of which leukotoxin is the protective antigen. In some conditions, the organism synergistically interacts with Arcanobacterium pyogenes, a facultative anaerobic organism and a secondary etiologic agent, to cause liver abscesses.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Anaerobe - Volume 15, Issues 1–2, February–April 2009, Pages 36–43
نویسندگان
, , , , ,