Human Lymphadenitis Due to Corynebacterium pseudotuberculosis: Report of Ten Cases from Australia and Review

Abstract

Corynebacterium pseudotuberculosis commonly causes caseous lymphadenitis in Australian sheep. We describe 10 cases of human lymphadenitis due to C. pseudotuberculosis; in all cases, isolates were submitted to a reference laboratory in Victoria, Australia. Most of the patients were occupationally exposed to sheep. We also review the 12 previously published cases of this infection, most of which were reported from Australia. No patient had any underlying disease or predisposing condition. Surgical excision of the affected lymph glands is the mainstay of management, and antibiotic therapy is supplementary treatment. Diagnosis was delayed for some patients, and some patients had a protracted or recurrent clinical course and/or a slow recovery. These 10 additional cases from one Australian state indicate that human lymphadenitis caused by C. pseudotuberculosis has not been as rare as the number of published reports indicates, at least in Australia. However, the increasing use of a vaccine against caseous lymphadenitis in sheep in Australia should result in the decreasing human incidence of this zoonosis.

Molecular genotyping of multinational ovine and caprineCorynebacterium pseudotuberculosisisolates using pulsed-field gel electrophoresis

“…Corynebacterium pseudotuberculosis is the causative organism of a variety of chronic suppurative conditions and has been isolated from sheep, goats, cattle, horses, deer, buffaloes, camels, mules and more rarely man [1,3,6,10,26,44]. The most significant disease syndromes are caseous lymphadenitis (CLA) in sheep and goats, ulcerative lymphangitis and contagious pustular dermatitis in horses, and ulcerative lymphangitis and mastitis in cattle and buffaloes [10].…”

The Genus Corynebacterium and Other Medically Relevant Coryneform-Like Bacteria

“…The zoonotic agents Corynebacterium pseudotuberculosis (the cause of caseous lymphadenitis primarily in sheep and goats) (3), transmitted to humans by contact with diseased animals (38) and C. ulcerans, historically thought to cause disease in humans after contact with contaminated milk or farm animals, but more recently linked to transmission between humans and their companion pets such as cats and dogs (13,51), are also able to produce diphtheria toxin and cause diphtheria-like disease in humans. It is therefore recommended that those in frequent contact with animals (veterinarians, animal care technologists, or farm workers) ensure that they maintain adequate vaccine coverage against diphtheria.…”

Mesenteric caseous lymphadenitis in a cow calf caused by Corynebacterium pseudotuberculosis: a case report

“…The disease is also of zoonotic importance as it may on rare occasions cause regional lymphadenitis in humans, particularly in farm workers and meat inspectors (Peel et al 1997). Caseous lymphadenitis is characterized by the formation of caseous abscesses in superficial lymph nodes and/ or internal lymph nodes and organs.…”