Community-Acquired Methicillin-Resistant Staphylococcus aureus in Southern New England Children

Abstract

ABSTRACT. Objective. This study was performed to understand the epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in southern New England children.Methods. A retrospective review was conducted of the medical records of children 0 to 18 years old with MRSA isolated by the Rhode Island Hospital microbiology laboratory (Providence, RI) between 1997 and 2001. A case was classified as either health care-associated MRSA (HCA-MRSA) or CA-MRSA based on time of culture and other strict criteria. The spectrum of illness of the HCA-MRSA and CA-MRSA cases was compared, as were the antibiotic-susceptibility patterns of their isolates. Risk factors for CA-MRSA acquisition were identified, and molecular subtyping of selected isolates was performed.Results. 6,7 In the early 1980s, the first reports of communityacquired (CA)-MRSA in adults emerged. 8 -10 These isolates were found initially in intravenous drug users or members of other high-risk groups with frequent contact with the health care system. In the late 1980s, the first cases of CA-MRSA in children were reported. 11 Most of these children also had a history of frequent health care contact. Thus, although the infections occurred in a community setting, these MRSA strains are better described as health careassociated (HCA) rather than truly CA.From the 1990s to the present, CA-MRSA has emerged as a pathogen in adults and children without traditional risk factors for MRSA acquisition. [12][13][14][15][16] More-recent reports have suggested that other risk factors also may exist, such as household contacts with risk factors for MRSA and child-care attendance. [17][18][19] Notably, the CA-MRSA isolates described in the past decade differ significantly from previous strains of MRSA in that they have distinct DNA-fingerprinting patterns 20 and lack multidrug resistance. 21 Recent research has demonstrated that these strains have novel resistance and virulence genes. Resistance to ␤-lactam antibiotics is conveyed by acquisition of a chromosomal mecA gene that encodes for a penicillin-binding protein with a low affinity for this antibiotic class. The mecA genes are found on mobile genetic elements called staphylococcal chromosomal cassettes (SCCmec). CA-MRSA strains have been found to have a novel allelic form of SCCmec type IV, thus differing from HCA-MRSA strains that carry types I, II, or III SCCmec cassettes. The mecA gene of HCA-MRSA strains is flanked by insertion sequencelike elements, acquired through horizontal gene transfer, which act as a trap for additional unrelated antibiotic-resistance genetic determinants leading to by guest on May 9, 2018 http://pediatrics.aappublications.org/ Downloaded from the multidrug resistance seen in these strains. The smaller type IV SCCmec cassette found in CA-MRSA does not carry any such multiresistance genes 22,23 ; however, these strains can still cause fatal disease. 24 Additionally, CA-MRSA strains, unlike HCA-MRSA strains, have been found to carry virulence genes encoding a leu...

Epidemiologic Similarities in Pediatric Community-Associated Methicillin-Resistant and Methicillin-Sensitive Staphylococcus aureus in the San Francisco Bay Area

“…Surveillance studies and reports from outbreaks suggest that children from low socioeconomic status or racial minority groups, such as black or African-Americans, Pacific Islanders, and Native Americans are at risk [14]. There is documentation of transmission in daycare centers [15], households [16], and sports teams [17]. However, these studies are subject to bias as they are mostly retrospective, with data limited to chart reviews or specific outbreaks.…”

CA-MRSA em furunculose: relato de caso do sul do Brasil

“…O acometimento cutâneo é o mais prevalente, podendo alcançar 94% das manifestações clínicas decorrentes da infecção por essa bactéria. 5,7,8 Os abscessos e as furunculoses são as lesões mais relatadas. 2,3,5,6,8 Também são descritos celulite, pápulas ou nódulos eritematosos, placas com crostas (impetigo) ou ainda FIGURA 1: Lesões furunculoides em coxa FIGURA 2: Linha 1. amostra da paciente deste caso; Linha 2. amostra pertencente a uma variante do clone OSPC, usada para comparação; Linha 3. amostra do clone BEC (Brazilian epidemic clone), típica do MRSA hospitalar a combinação desses quadros clínicos.…”

“…São reconhecidos, atualmente, cinco tipos de SCCmec: I, II, III, IV e V. Os três primeiros estão presentes predominantemente nos MRSA hospitalares, enquanto os últimos são encontrados nos MRSA adquiridos na comunidade. 2,7,9 Por ser uma molécula pequena, acredita-se que o mec IV tenha maior facilidade de disseminação do que os elementos genéticos carreadores dos mec I, II e III.…”

“…A PVL está associada, também, a pneumonia necrotizante. 2,7,10,11 Os pacientes sem lesões graves, sem história de exposição a ambientes nosocomiais e em locais de baixa prevalência podem iniciar tratamento com penicilinas resistentes à penicilinase (oxacilina) ou com cefalosporinas de primeira geração (cefazolina, cefalexina), enquanto aguardam o resultado definitivo da cultura. 2,12 Para os pacientes com infecções menos graves ou crônicas, pode ser aconselhável aguardar resultados de cultura, otimizando o tratamento.…”

Measurement and Impact of Staphylococcus aureus Colonization Pressure in Households

“…Community-associated MRSA has been associated with asymptomatic nasal colonization, superficial cutaneous abscesses, and invasive infections [3][4][5][6][7]. S aureus infections cluster in households [8][9][10][11][12][13]. Frequent skin-to-skin contact, sharing personal hygiene items, and contamination of household fomites may play an important role in the spread of S aureus [10,14].…”