J Vet Diagn Invest. Epub Dec 4. Natural lymphatic "atypical" actinobacillosis in cattle caused by Actinobacillus lignieresii. Bovine actinobacillosis is typically characterized by pyogranulomatous glossitis wooden tongue.
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Abstract Bovine actinobacillosis is typically characterized by pyogranulomatous glossitis wooden tongue. The involvement of other tissues, generally the skin or lymph nodes, has been regarded as atypical or cutaneous.
We describe herein 2 outbreaks of actinobacillosis affecting primarily the lymph nodes of the head and neck. The disease affected 40 of lactating cows in a dairy herd, and 5 of two-y-old steers in a beef herd. Multiple or single, occasionally ulcerated nodules were observed in the region of the mandible, neck, and shoulder, including the parotid, submandibular, retropharyngeal, and prescapular lymph nodes.
The histologic lesions were multifocal pyogranulomatous lymphadenitis, dermatitis, and cellulitis with Splendore—Hoeppli material. One steer had an exophytic pyogranuloma in the gingiva and another died because of ruminal tympany secondary to oropharyngeal and esophageal obstruction by a pyogranulomatous mass. Actinobacillus lignieresii was isolated from the lesions and identified by amplification, sequencing, and analysis of the 16S ribosomal r DNA gene.
Seven of 8 cows recovered after treatment with sodium iodide. Lymphatic actinobacillosis is a frequent disease in Uruguay, southern Brazil, and Argentina. Later, lesions may extend to the subcutaneous tissue and the skin, causing ulceration. Affected cattle with draining pyogranulomas contaminate the environment, favoring disease transmission, and should be treated with sodium iodide or antibiotics and isolated from the herd in order to control the disease. Keywords: Actinobacillus lignieresii, bovine, draining abscesses, lymphadenitis, pyogranulomas Introduction Actinobacillosis, a disease with worldwide distribution, is caused by Actinobacillus lignieresii, a natural inhabitant of the upper respiratory and digestive tracts of ruminants.
Materials and methods Between October and July , outbreaks of actinobacillosis were studied in a dairy herd in Florida and in a beef herd in Colonia, Uruguay. In the dairy herd of lactating Holstein cows, 12 cows and 1 bull were examined clinically. Core needle biopsies of the lesions were used for direct microscopic observation of the exudate and for microbiologic and histologic studies.
In one case, the affected prescapular lymph node and the surrounding subcutaneous tissue were excised surgically and processed for bacteriologic and histologic examination. The beef cattle herd included two-y-old Hereford, Aberdeen Angus, and crossbred steers.
Five steers with nodular lesions in the lymph nodes 3 , gingiva 1 and oropharynx, and the lung 1 were examined. Samples of the lymph nodes were obtained by core needle biopsies, and samples of the gingiva were obtained postmortem at the slaughterhouse 3 d after the first observation of the lesion. A steer with oropharyngeal and pulmonary lesions died spontaneously of ruminal tympany secondary to pharyngeal and esophageal obstruction and was autopsied. Samples of the lesions in the pharynx and the lungs were collected for bacteriologic and histologic studies.
Samples of other organs were also collected for histologic examination. Selected sections were also stained with Gram and Ziehl—Neelsen stains and processed with periodic acid—Schiff PAS reaction for the identification of intralesional microorganisms. Additionally, immunohistochemistry IHC was performed on selected sections of lymph node and gingival pyogranulomas using a rabbit polyclonal antibody against bacille Calmette—Guerin BCG; Dako, Carpinteria, CA , an attenuated strain of Mycobacterium bovis that cross-reacts with various other microorganisms, including bacteria and fungi.
Exudates from lymph nodes, gingiva, pharynx, and lung were observed microscopically for the presence of club-shaped clusters, which are characteristic of bovine actinobacillosis.
Additionally, the samples were inoculated into brain-heart infusion broth Oxoid and incubated under the same conditions for 24 h. Bacterial colonies obtained from the microaerophilic cultures that were morphologically similar to those of Actinobacillus spp. Louis, MO , and molecular identification was performed by amplification and sequencing of the almost complete 16S ribosomal r DNA gene using a commercial sequencing service Macrogen, Seoul, South Korea. Six of the 8 treated cattle were pregnant cows with gestational ages of 90— d.
All affected steers in the beef herd were sent to a slaughterhouse. Results From February to October, because of a forage shortage during a dry season, the dairy herd was maintained in stables and fed tall fescue Festuca arundinacea, syn.
Lolium arundinaceum hay, alfalfa Medicago sativa , annual ryegrass Lolium multiflorum haylage, and Sorghum sp.
The herd also grazed in a tall fescue pasture for 3 h daily. The first affected cows had cutaneous nodules in the region of the mandible and neck in July , nearly 3 mo before the initial veterinary consultation.
At the time of the veterinary consultation in October , the practitioner mentioned that 40 7. Of the 13 cattle examined during a visit to the farm 12 lactating cows and 1 bull , 7 had multiple nodules in the region of the parotid, submandibular, and retropharyngeal lymph nodes Fig.
The nodules, 1—20 cm diameter, were firm, occasionally with a fluctuant surface. Most of the nodules were ulcerated, with granulation tissue around the ulcers, or were covered by alopecic skin Fig. The ulcers did not heal and occasionally had yellow exudate overlying the surface. In 3 cases, small nodules, up to 3 cm diameter, were arranged linearly along the lymphatic vessels of the neck.
The excisional biopsy of the prescapular nodule in one cow had a lymph node in the center of the nodule, surrounded by a white fibrous capsule. The lymph node had lost its normal structure, and its cut surface was yellow and contained numerous 1—2-mm granules Fig. Small, yellow, round, pyogranulomas with irregular surfaces were also observed in the lymph node capsule and the subcutaneous tissue Fig.
Overview of Actinobacillosis
The disease has a chronic course, and the general condition can remain quite good. There is a swelling of the maxilla and mandible. Later on, a granuloma will form in the place of fistulisation. The bony lesions are followed by periostitis , with permanent deformation of the facial bones.
Actinomycosis in animals
Also known as: Actinobacillosis Wooden tongue is a bacterial infection as a result of abrasions in the mouth. It is caused by Actinobacillus lignieresii, part of the normal bacterial flora of the upper digestive tract. The bacteria usually invade the skin through a wound or minor trauma caused by sticks, cereal awns or similar. The disease is fairly acute , with swelling in the affected part, under the jaw and in the regional lymph nodes. The clinical symptoms are excess salivation, difficult mastication and inappetence. Additionally, cutaneous actinobacillosis has been reported Milne et al.