Contamination of Environmental Surfaces WithStaphylococcus aureusin Households With Children Infected With Methicillin-ResistantS aureus

Abstract

IMPORTANCE Household environmental surfaces may serve as vectors for acquisition and spread of methicillin-resistant Staphylococcus aureus (MRSA) among household members, though few studies have evaluated which objects are important MRSA reservoirs. OBJECTIVES Determine the prevalence of environmental MRSA contamination in households of children with MRSA infection; define the molecular epidemiology of environmental, pet, and human MRSA strains within households; and identify factors associated with household MRSA contamination. DESIGN, SETTING, AND PARTICIPANTS Fifty households of children with active or recent culture-positive community-associated MRSA infection were enrolled from 2012–13 at St. Louis Children’s Hospital and community pediatric practices affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium. MAIN OUTCOMES AND MEASURES Participants’ nares, axillae, and inguinal folds were cultured to detect S. aureus colonization. Twenty-one environmental surfaces and pet dogs and cats were cultured. Molecular typing of S. aureus strains was performed by repetitive-sequence polymerase chain reaction to determine strain relatedness within households. RESULTS MRSA was recovered from environmental surfaces in 23 (46%) households, most frequently from the participant’s bed linens (18%), television remote control (16%), and bathroom hand towel (15%). MRSA colonized 12% of dogs and 7% of cats. At least 1 surface was contaminated with a strain type matching the participant’s isolate in 20 (40%) households. Participants colonized with S. aureus had a higher proportion of MRSA-contaminated surfaces (0.15 ± 0.17) than non-colonized participants [0.03± 0.06; mean difference 0.12 (95% CI 0.05, 0.20)]. A greater number of individuals per 1000 ft2 was also associated with a higher proportion of MRSA-contaminated surfaces (β=0.34, p=0.03). The frequency of cleaning household surfaces was not associated with S. aureus environmental contamination. CONCLUSIONS AND RELEVANCE MRSA strains concordant with infecting and colonizing strains are present on commonly handled household surfaces, a factor that likely perpetuates MRSA transmission and recurrent disease. Future studies are needed to determine methods to eradicate environmental contamination and prevent MRSA transmission in households.

Molecular Types of Methicillin-Resistant Staphylococcus aureus and Methicillin-Sensitive S. aureus Strains Causing Skin and Soft Tissue Infections and Nasal Colonization, Identified in Community Health Centers in New York City

“…Many of the isolates in our study (40/69 CC8 isolates) did not present with the complete characteristic pattern t008/ST8/SCCmecIVa/PVL ϩ /ACME ϩ . Both the cassette chromosome and the mobile element encoding enzymes involved with arginine catabolism are known to be susceptible to genetic modifications, including a total or partial loss from the bacteria (32). Over the years, evolution may have caused changes in the spa gene, generating variants that still belong to the same clonal complex (33).…”

Topical Decolonization Does Not Eradicate the Skin Microbiota of Community-Dwelling or Hospitalized Adults

“…Two participant cohorts comprised of individuals at risk for MRSA infection were enrolled. The community-dwelling cohort consisted of 8 adults living with a child (aged 6 months to 13 years) recently treated for a MRSA SSTI (these individuals represent a subset of participants in a study of MRSA transmission dynamics among households of children with MRSA infections [28]). Community-dwelling individuals completed a 5-day decolonization protocol with twice-daily application of 2% mupirocin (Teva Pharmaceuticals USA) to the anterior nares and daily bathing in dilute bleach water (1/4 cup of bleach [Clorox; The Clorox Company] to 1/4 bathtub-full of water), with soaking for Ն15 min (8,29).…”

Antimicrobial Susceptibility Profiles of Staphylococcus aureus Isolates Recovered from Humans, Environmental Surfaces, and Companion Animals in Households of Children with Community-Onset Methicillin-Resistant S. aureus Infections

“…Few studies have described the antimicrobial resistance profiles of Staphylococcus aureus strains in the community, specifically in household environments (4,5). Household vectors, including humans, environmental fomites, and companion animals, may serve as reservoirs for methicillin-resistant S. aureus (MRSA) transmission (5-7).…”

“…Following approval from the Washington University human and animal institutional review boards, pediatric patients (n ϭ 110) with community-onset MRSA infections and their household contacts (n ϭ 388) were enrolled through St. Louis Children's Hospital (SLCH) and community pediatric practices from January 2013 to May 2014, as previously described (4). Study visits were conducted in the participants' homes, occurring up to 10 times over 24 months at 3-month intervals.…”

“…Study visits were conducted in the participants' homes, occurring up to 10 times over 24 months at 3-month intervals. During each visit, cultures were obtained from the axillae, anterior nares, and inguinal folds (ESwabs; Becton Dickinson, Franklin Lakes, NJ) from all consenting household members, up to 21 frequently touched standardized household objects (Table 1; ESwabs and BairdParker agar contact plates; Hardy, Santa Maria, CA) (4,8), and the anterior nares and dorsal fur of indoor dogs and cats (BBL CultureSwab liquid Amies, regular aluminum wire; Becton Dickinson).…”