Antibiotic-resistant Staphylococcus aureus in community-acquired pediatric neck abscesses

SummaryObjectiveTo determine the microbiology, particularly the prevalence of MRSA, in pediatric patients with community-acquired bacterial lymphadenitis. Long considered a nosocomial organism, methicillin-resistant Staphylococcus aureus (MRSA) has recently emerged as a cause of community-acquired infections. Resistance to other classes of antibiotics, including clindamycin, is prevalent amongst S. aureus, as well.MethodsA retrospective review of the medical records and culture results of patients under the age of 18 who underwent trans-cervical surgical drainage of abscessed lymph nodes between the years 2000 and 2006.ResultsSixty-two patients were identified for whom microbiology data were available. Six infections were classified as parapharyngeal on imaging; the remainder involved cervical chain lymph nodes. Forty-nine patients grew microorganisms on culture while 13 collections had no growth. The most common organism was S. aureus (63% of positive cultures); followed by beta-hemolytic group A Streptococcus (22%). Of S. aureus isolates, 27% were oxacillin-resistant (MRSA). All MRSA isolates were sensitive to clindamycin and trimethoprim/sulfamethoxazole; 63% were sensitive to ciprofloxacin, and 25% sensitive to erythromycin. Of methicillin-sensitive S. aureus isolates, 100, 86, and 82% were sensitive to trimethoprim/sulfamethoxazole, clindamycin, and ciprofloxacin, respectively. All MRSA isolates were identified during the latter half of the study period (2003–2006); none grew prior to 2003.ConclusionsMRSA is a common pathogen in community-acquired lymphadenitis, and its incidence is rising. Resistance to clindamycin, a drug commonly used to treat MRSA, is prevalent amongst methicillin-sensitive S. aureus. This has important implications regarding the empiric treatment of lymphadenitis in children.