Community-acquired methicillin-resistant Staphylococcus aureus in pediatrics

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging problem in pediatrics, with clinical and microbiologic characteristics that differentiate it from hospital-acquired MRSA (HA-MRSA).

Relative to HA-MRSA, CA-MRSA tends to cause localized disease (although serious illness occurs), is susceptible to more antibiotics, and has the same risk factors for acquisition/disease as methicillin-susceptible S. aureus (MSSA). At the gene level, CA-MRSA is more similar to MSSA than HA-MRSA: its emergence is apparently due to acquisition by an MSSA of the Staphylococcal Cassette Chromosome that bears mecA: the gene that encodes the methicillin-resistant penicillin binding protein. Carriage of recognized staphylococcal virulence factors, particularly Panton-Valentine leukocidin, is common in CA-MRSA, emphasizing its potential for causing serious illness. CA-MRSA is usually susceptible to clindamycin, trimethoprim-sulfamethoxazole, and rifampin, but inducible macrolide-lincosamide-streptogramin resistance in a subset of CA-MRSA could be problematic when clindamycin is used.

The appearance and spread of CA-MRSA represents a new challenge in pediatric medicine. A high level of clinical suspicion and development of rapid methods for its identification are needs for the future.