Molecular Epidemiology of Invasive Staphylococcus aureus Infections and Concordance with Colonization Isolates.

OBJECTIVES: To characterize Staphylococcus aureus isolates recovered from hospitalized children and to determine the concordance between colonizing and invasive isolates. STUDY DESIGN: Children with culture-confirmed, community-onset, invasive S aureus infections were enrolled in this prospective case series from a large children's hospital over a 5-year period. Colonization isolates were obtained from the anterior nares, oropharynx, and inguinal folds and were compared with invasive isolates via repetitive-element, sequence-based polymerase chain reaction testing. Isolates with a ≥96% genetic match were characterized as concordant. RESULTS: A total of 86 S aureus isolates (44 invasive, 42 colonization) were collected from 44 children with invasive infections. Clinical isolates were genetically diverse, 64% of invasive isolates were methicillin-susceptible S aureus (MSSA), and 59% of cases had a colonizing S aureus isolate at the time of hospitalization. Of those who were colonized, at least 1 of their colonization isolates was indistinguishable from the infecting isolate in 88% of cases. Patients with invasive MSSA were significantly more likely to have a concordant MSSA colonization isolate present compared with patients with invasive methicillin-resistant S aureus (MRSA) (61% vs 38%, P < .05). CONCLUSIONS: Invasive MSSA infection was more common than MRSA infection in this pediatric cohort, and patients with MSSA infection were significantly more likely than those with MRSA infection to have concordant colonizing isolates across multiple anatomic sites. These findings warrant larger scale validation and may have important infection control and epidemiologic implications, as unlike MRSA, transmissibility of MSSA largely is ignored in healthcare settings.

Unrecognized viral respiratory tract infections in premature infants during their birth hospitalization: a prospective surveillance study in two neonatal intensive care units.

OBJECTIVE: To determine the frequency and effects of nosocomial respiratory viral infections (RVIs) in premature neonates, including those who may be asymptomatic. STUDY DESIGN: We performed a year-long surveillance for RVIs in infants <33 weeks gestational age admitted to 2 Syracuse neonatal intensive care units. Infants were enrolled within 3 days of neonatal intensive care unit admission and were sampled for RVIs until discharge using a multiplex polymerase chain reaction assay capable of detecting 17 different respiratory viruses or subtypes. RESULTS: Twenty-six of 50 prematurely born infants (52%) tested positive for a respiratory virus at least once during their birth hospitalization. Testing positive for a respiratory virus was significantly associated with longer length of stay (70 days vs 35 days, P = .002) and prolonged ventilatory support (51 vs 13 days, P = .002). Infants who tested positive for a respiratory virus during their birth hospitalization had more than twice the rate of developing bronchopulmonary dysplasia (P < .05). CONCLUSION: Nosocomial RVIs were frequent in our study population, despite the absence of clinical indicators of illness. Length of hospital stay was significantly longer and a diagnosis of bronchopulmonary dysplasia was more common in infants who had respiratory viruses detected.

Empyema of preexisting subdural hemorrhage caused by a rare salmonella species after exposure to bearded dragons in a foster home.

An infant had a subdural empyema caused by the rare Salmonella species enterica subspecies houtenae (IV) serotype 44:z4,z23:- after only indirect exposure to exotic reptiles in her foster home. Infants recovering from preexisting subdural hematoma are at risk for development of empyema.

Incidence of invasive community-onset Staphylococcus aureus infections in children in Central New York.

We determined the incidence of invasive community-onset Staphylococcus aureus infections, clinical characteristics, and antibiotic susceptibilities in 128 hospitalized children in central New York. The prevalence of invasive S aureus infections in our institution remained <1% between 1996 and 2006, although the proportion of methicillin-resistant S aureus infections significantly increased.