Vertebral osteomyelitis caused by non-tuberculous mycobacteria is a rare disease, with only 31 cases and one nosocomial outbreak reported in the literature (MedLine review between 1965 and December 2003). The clinical features are often indistinguishable from those of pyogenic osteomyelitis. Early diagnosis of such infections is a major challenge because of the slow growth of these microorganisms. No consensus guidelines for the treatment of these infections exist. Prolonged anti-mycobacterial therapy in combination with surgical debridement is recommended.

The M protein is one of the most important virulence factors of group A streptococci (Streptococcus pyogenes) and may play an important role in the first steps of streptococcal infection. Since acute pharyngitis is a frequently occurring infectious disease caused by these bacteria, we wished to know whether antibodies to the M protein or other surface components inhibit adherence and internalization of streptococci to pharyngeal cells. We investigated the role of whole human secretory immunoglobulin A (sIgA), M6 protein-specific sIgA, and M6 protein-specific serum IgG in the inhibition of streptococcal adherence and internalization to cultured human pharyngeal cells. S. pyogenes D471, which produces a type 6 M protein (M+), and its isogenic M-negative (M−) derivative JRS75 were tested. Purified whole sIgA, M protein-specific sIgA, and sIgA preabsorbed with M protein were able to decrease significantly the adherence of streptococci to pharyngeal cells. Purified IgG against the M6 protein did not diminish the attachment of streptococci to the pharyngeal cells but did reduce internalization. Thus, our data suggest that secretory IgA may play a key role in preventing streptococcal infection at mucosal surfaces by blocking adherence while affinity-purified anti-M protein-specific IgG blocks epitopes responsible for invasion.

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We present a patient with skin ulcers that did not respond to a 3-week course of treatment with amoxicillin-clavulanic acid. As the patient maintained a fish aquarium, mycobacterial infection was suspected. Indeed, reassessment of histopathology revealed acid-fast bacilli, and mycobacterial cultures at 30 degrees C grew Mycobacterium marinum. Eventually, surgical reconstruction of the tendons was needed.