In vitro activities of linezolid, meropenem, and quinupristin-dalfopristin against group C and G streptococci, including vancomycin-tolerant isolates

Invasive group G streptococcal infection in a paediatric patient

We present a paediatric case of group G streptococcal bacteraemia and vertebral osteomyelitis. The patient is a 14-year-old girl with Gaucher disease type 1 who presented with severe thoracolumbar pain. She was treated with a 4-week course of antibiotics for presumed osteomyelitis with clinical improvement.

Streptococcus canis infections in humans: Retrospective study of 54 patients

This 5-year retrospective study reports 54 patients with infection, caused by Streptococcus canis, a pyogenic Lancefield group G streptococcus initially isolated from various animal sources. During 1997-2002, Streptococcus canis accounted for 1% of all streptococci isolated. The clinical signs, outcome and bacteriological characteristics were reviewed. All except eight were symptomatic. Clinical manifestations were: soft tissue infection (n=35), bacteremia (n=5), urinary infection (n=3), bone infection (n=2) and pneumonia (n=1). The course was favorable in 52 cases while two died from sepsis. Cultures were often polymicrobial (n=42, 77.8%) apart from hemocultures. The isolates were sensitive to most antibiotics. Presence of the bacteria did not always signify infection owing to the possible occurrence of colonization. The frequency of S. canis infections is rare and likely underestimated owing to the fact that streptococci are sought only on the basis of the Lancefield classification. The search for S. canis is recommended whenever patients present with symptoms evocative of exposure to a potentially contaminated animal.

Deep sternal wound infection caused by group g streptococcus after open-heart surgery

We report the first case of deep sternal wound infection caused by group G Streptococcus after open-heart surgery. The patient's clinical presentation was nonspecific and his diagnosis was delayed. Surgical debridement and a 4-week course of intravenous antibiotics consisting of sequential penicillin plus gentamicin/ceftriaxone led to recovery. Group G Streptococcus should be suspected as an important postoperative pathogen.

Streptococcus equi subspecies equi (Lancefield group C) meningitis in a child

We present a case of Streptococcus equi subsp. equi meningitis in a young boy. This case represents the first report in the literature of meningitis caused by this organism, as far as we know.

[Role of linezolid in antimicrobial therapy]

The progressive emergence of multi-resistant gram-positive strains has prompted the search for new molecules (quinolones, streptogramins, oxazolidinones, ketolides, glycopeptides, daptomycin) to add to the current therapeutic arsenal. Linezolid, the first commercially available member of the oxazolidinone family, has evidenced activity against multi-resistant gram-positive strains (methicillin-resistant Staphylococcus aureus, S. aureus with decreased glycopeptide sensitivity, vancomycin-resistant Enterococcus spp., Streptococcus pneumoniae with decreased sensitivity to penicillin and cephalosporins), thereby providing a new option for treating infections by these microorganisms. This work reviews the microbiologic and pharmacologic aspects of this agent in order to establish its position among the available options for antimicrobial chemotherapy.

The Oxazolidinones

The need for effective antibiotics to manage the ever increasing frequency of antibiotic-resistant gram-positive infections in much of the developed world has led to the clinical development of the first oxazolidinone antibiotic, linezolid. Linezolid possesses bacteriostatic activity against both antibiotic-susceptible and resistant strains of staphylococci, enterococci, and streptococci of relevance to human infection. Clinical trials have confirmed its effectiveness in the treatment of serious infections of skin and soft tissue and the lower respiratory tract. Linezolid has also provided improved outcomes in the treatment of serious vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus infections in a compassionate use program. Emergence of linezolid-resistant gram-positive cocci during clinical use has recently been described, suggesting that its present role in therapy should be reserved for the treatment of antibiotic-resistant gram-positive infections.