title: Carriage of community-associated methicillin-resistant Staphylococcus aureus in a cohort of infants in southern Israel: risk factors and molecular features.
abstract: There are few data about the epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) among children in Israel. This study was intended to identify risk factors for CA-MRSA colonization in healthy infants, to characterize the molecular features of colonizing organisms, and to determine whether they are responsible for health care-associated (HA) infections. Nasal cultures and demographic details were collected from a cohort of healthy infants at 5 visits between the ages of 2 and 12 months. Clinical characteristics of pediatric MRSA bloodstream infections (2001 to 2006) and wound cultures collected over 6 months were also studied. Clonal structure was evaluated by multilocus sequence typing. Isolates were studied for the staphylococcal cassette chromosome mec (SCCmec) type and for the presence of Panton-Valentine leukocidin (PVL) genes. MRSA was cultured at least once from 45 of 659 infants (346 Jewish and 313 Bedouin infants). Forty of 45 (89%) isolates were from Bedouin infants. Twenty-nine of 45 (64.4%) belonged to a new clonal complex, designated CC913, that carries SCCmec IV but not the PVL genes. CC913 was also isolated from 9/14 blood cultures and 7/8 wounds. All CC913 infections occurred in Bedouin children, and all but two were HA. In conclusion, Bedouin origin was the main risk factor for carriage of CA-MRSA. CC913 was dominant both in healthy carriers and as a cause of pediatric HA-MRSA bloodstream infections.
authors.affiliation: Department Clinical Microbiology and Infectious Disease, Hadassah Hebrew University Medical Center, Jerusalem, Israel. amosad@gmail.com
authors.forename: Amos
authors.initials: A
authors.lastname: Adler
authors.forename: Noga
authors.initials: N
authors.lastname: Givon-Lavi
authors.forename: Allon E
authors.initials: AE
authors.lastname: Moses
authors.forename: Colin
authors.initials: C
authors.lastname: Block
authors.forename: Ron
authors.initials: R
authors.lastname: Dagan
mesh_terms: D000293:Adolescent; D016470:Bacteremia / Q000382:microbiology; D001427:Bacterial Toxins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D005098:Exotoxins / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007557:Israel / Q000453:epidemiology; D007956:Leukocidins / Q000235:genetics; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D017720:Molecular Epidemiology; D009297:Nasal Mucosa / Q000382:microbiology; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D014946:Wound Infection / Q000382:microbiology
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin