Treatment of Gram-Positive Cocci in Chains

Introduction to Treatment

The American College of Physicians and Infectious Diseases Society of America recommends penicillin as the first-line treatment for infections caused by gram-positive cocci in chains, with clindamycin added for severe invasive infections like necrotizing fasciitis to suppress toxin production 1, 2

Groups B, C, and G streptococci can cause skin infections, bacteremia, and occasionally necrotizing fasciitis 1
Enterococcus species, technically streptococci, are found in 7.7-16.5% of intra-abdominal cases and are associated with worse outcomes in secondary peritonitis 2

For necrotizing fasciitis or streptococcal toxic shock syndrome caused by Group A streptococci, the Infectious Diseases Society of America recommends the combination of penicillin PLUS clindamycin 1, 2
For polymicrobial infections involving streptococci, such as intra-abdominal infections or polymicrobial necrotizing fasciitis, the Infectious Diseases Society of America recommends ampicillin-sulbactam plus clindamycin plus ciprofloxacin 1, 3

For patients with severe penicillin hypersensitivity, the Infectious Diseases Society of America recommends vancomycin, linezolid, quinupristin/dalfopristin, or daptomycin 1, 4

The Infectious Diseases Society of America recommends adding vancomycin empirically when gram-positive cocci are identified in blood cultures before final identification, or in patients with clinically suspected serious catheter-related infections, known colonization with penicillin/cephalosporin-resistant pneumococci or MRSA, hypotension or cardiovascular impairment, or neutropenia with fever 2, 5

The Infectious Diseases Society of America advises against relying on oral antibiotics for severe illness, nausea/vomiting, or intestinal hypermotility, as absorption is unreliable, and against using ceftazidime alone due to its lack of adequate gram-positive coverage 5
The Infectious Diseases Society of America also recommends avoiding empiric vancomycin overuse, as it has no survival benefit for all gram-positive bacteremia and promotes resistance 2, 6

The Infectious Diseases Society of America recommends surgical debridement as mandatory for necrotizing fasciitis, with return to the operating room every 24-36 hours until no further debridement is needed 1, 3

Enterococcus species (including E. faecalis and E. faecium) are among the most frequent pathogens causing gram‑positive cocci‑in‑chains bloodstream infections. 7

The Infectious Diseases Society of America (IDSA) recommends adding empiric vancomycin when a patient with neutropenia and fever has blood cultures showing gram‑positive cocci in chains, to ensure coverage of potential resistant organisms. 8

The IDSA advises against routine empiric vancomycin in low‑risk situations, as unnecessary use promotes vancomycin resistance without improving survival in gram‑positive bacteremia where the morphology suggests streptococci or enterococci. 8

Streptococci (including β‑hemolytic groups and viridans species) are common pathogens isolated from wound and blood cultures in patients with infections caused by gram‑positive cocci in chains. 9, 10
In patients with diabetic foot infections, streptococci represent important causative organisms, although Staphylococcus aureus is the most frequently isolated overall. 11, 9
In intra‑abdominal infections, enterococci are relatively frequent isolates but generally play a secondary role in the clinical course. 11

A Gram‑stained smear from a wound that shows gram‑positive cocci in chains has a positive predictive value of approximately 75 % for the presence of gram‑positive organisms, supporting its use to guide empiric antimicrobial selection. 12
Cultures should be obtained preferentially from tissue (deep specimens) rather than superficial swabs, because deep specimens are more likely to contain true pathogens, whereas swabs often yield a mixture of pathogens, colonizers, and contaminants. 10
When interpreting culture results, organisms that are typical colonizers (e.g., coagulase‑negative staphylococci, corynebacteria) should not be targeted unless they are repeatedly isolated from reliable specimens, to avoid treating contaminants. 9

After culture and susceptibility data become available, clinicians should consider narrowing therapy to a regimen that specifically targets the isolated pathogens, thereby reducing the risk of promoting antibiotic resistance. 12
If the patient’s infection is clinically improving on the empiric regimen, there may be no need to modify therapy even when some isolated organisms display in‑vitro resistance, provided the overall response remains favorable. 12