Does the treatment recommendation change if a swab culture grows Gram-positive cocci, Gram-positive bacillus, and Streptococcus anginosus?

Treatment Adjustment for Cultures Growing Gram-Positive Cocci, Gram-Positive Bacillus, and Streptococcus anginosus

When a swab culture grows Gram-positive cocci, Gram-positive bacillus, and Streptococcus anginosus, the treatment recommendation should be modified to include vancomycin or another agent with specific activity against these Gram-positive organisms, particularly if the infection is serious or the patient is at high risk.

Significance of These Organisms

• Streptococcus anginosus group (including S. anginosus, S. intermedius, and S. constellatus) is known for causing invasive pyogenic infections and has the ability to form abscesses in multiple organs 1
• Gram-positive cocci (such as Staphylococcus species) and Gram-positive bacilli (such as Bacillus species) may require specific antimicrobial coverage, with some strains being susceptible only to vancomycin 2
• The presence of multiple Gram-positive organisms suggests a potentially serious or polymicrobial infection that may not respond to standard empiric therapy 2

Treatment Recommendations

For Serious Infections:

• Include vancomycin in the initial therapeutic regimen when cultures grow Gram-positive cocci and S. anginosus, especially in high-risk patients 2
• For patients in whom vancomycin may not be an option, consider alternatives such as linezolid, daptomycin, or ceftaroline 2
• Tedizolid (Sivextro) is specifically indicated for acute bacterial skin and skin structure infections caused by susceptible Gram-positive organisms including Streptococcus anginosus Group 3

For Neutropenic Patients:

• When these organisms are identified in neutropenic patients, vancomycin should be added to the regimen if not already being administered 2
• Mortality due to viridans streptococci (which includes S. anginosus group) may be higher among neutropenic patients not initially treated with vancomycin 2, 4
• For non-enterococcal streptococcal infections, vancomycin may be used alone if the minimum bactericidal concentration is appropriate; otherwise, it should be combined with an aminoglycoside 5

Duration of Treatment

• For most bacterial skin and soft tissue infections (SSTIs), treatment duration should be 7-14 days 2
• Longer treatment courses may be necessary for invasive S. anginosus infections, particularly if abscesses are present 1

Surgical Considerations

• Consider surgical intervention for drainage if an abscess is present, especially after marrow recovery in neutropenic patients 2
• S. anginosus group infections often require surgical drainage in addition to antimicrobial therapy for optimal outcomes 1

Common Pitfalls to Avoid

• Failing to adjust therapy when cultures reveal resistant Gram-positive organisms 2
• Using narrow-spectrum antibiotics that don't adequately cover all identified pathogens 6
• Delaying appropriate treatment modification when a patient shows inadequate response to initial therapy 2
• Overlooking the need for surgical intervention in addition to antimicrobial therapy, particularly with S. anginosus infections 1

Special Considerations

• Some organisms, such as certain Gram-positive bacilli, may be susceptible only to vancomycin, making its inclusion in the regimen essential 2
• S. anginosus group infections are typically susceptible to penicillin G and cephalosporins, but broader coverage may be needed initially until susceptibilities are known 1
• When modifying therapy based on culture results, consider the clinical response to the current regimen - if improving, major changes may not be necessary 2