Two cases of pyomyositis caused by Klebsiella pneumoniae and review of the literature.

Two patients with diabetes mellitus developed Klebsiella pneumoniae pyomyositis involving multiple muscles and other metastatic foci associated with bacteraemia. The cases are presented here, and the 22 cases of gram-negative pyomyositis reported previously in the literature are reviewed. As gram-positive cocci cause 99% of pyomyositis, it is postulated that the pathogenesis of pyomyositis may be associated with the ability of the bacteria to adhere to muscles by various cell surface adhesins that are not present in gram-negative bacilli. It is also postulated that a high serum glucose concentration may facilitate the growth and formation of the Klebsiella pneumoniae capsule, hence increasing its virulence and causing serious disseminated Klebsiella infections in diabetic patients.