Calf pyomyositis caused by Enterococcus faecalis

Primary pyomyositis (PP) is a purulent infection of skeletal muscle, which is not caused by a contiguous infection from the bone, soft tissues or skin or by deep injuries.1 Rather, it is considered a local complication of a transient bacteremia. This infection is quite rare given the inherent resistance of normal muscle to bacterial colonization. For that reason, underlying pathologic factors in the muscle or in the host, such as HIV infection, diabetes, malnutrition, cancer or steroid treatment,2 are necessary to allow infection of the muscle.3 PP is the most common in the first and second decades of life, although it has been seen in all age groups.2,3 Pyomyositis is exceedingly rare in patients >80 years of age (<5%) and the micro-organisms most commonly isolated in this age group are Gram-negative bacteria.3 In temperate climates, cultures of pus obtained by puncture or surgical drainage are usually positive and the microorganism is identified in 91% of cases. Nonetheless, blood cultures have a low sensitivity, around 40%.3 The most common bacteria isolated is Staphylococcus aureus (75%), 25% of which are methicillin resistant, followed by Group A Streptococcus and Gram-negative bacilli.1 Enterococcus is associated with urinary tract infections, meningitis, bacteremia and endocarditis. However, after an exhaustive review of the medical literature (searching in PubMed for a combination of the terms ‘pyomyositis’ or ‘muscle infection’ and ‘Enterococcus’ or ‘group D Streptococcus’), we have not found any published cases of enterococcal pyomyositis. The objective of this article is to …