Background: Staphylococcus aureus is the most common cause of acute hematogenous osteoarticular infections (AHOAIs) in children. The risk factors for the development of orthopedic complications (OC) after AHOAI are poorly understood. We sought to describe clinical and microbiologic variables present on the index admission that may predict OC in S. aureus AHOAI. Methods: Staphylococcus aureus AHOAI cases were identified from 2011–2017 at Texas Children’s Hospital and reviewed for the development of OC. OC included chronic osteomyelitis, growth arrest, avascular necrosis, chronic dislocation, and pathologic fracture. All S. aureus isolates were characterized by pulsed-field gel electrophoresis and agr group. Results: A total of 286 cases were examined of which 27 patients (9.4%) developed OC. Patients who developed OC more often had infection with an agr group III organism (P = .04), bacteremia (P = .04), delayed source control (P < .001), ≥2 surgical procedures (P < .001), intensive care unit admission (P = .09), and fever >4 days after admission (P = .008). There was no association with OC and patient age, methicillin resistance, or choice/route of antibiotics. In multivariable analyses of OC, infection with agr group III S. aureus, prolonged fever, and delayed source control remained statistically significant. Conclusions: OC develop following S. aureus AHOAI in 9.4% of cases. Although the development of OC is likely multifactorial, agr group III organisms, prolonged fever, and delayed source control are independently associated with OC. Moreover, early aggressive surgical source control may be beneficial in children with S. aureus AHOAI.

BACKGROUND AND OBJECTIVE: Acute hematogenous osteomyelitis (AHO) is a severe infection in children. Drainage of purulent collections in bones provides specimens for culture as well as therapeutic benefit. Interventional radiology (IR)-guided procedures may serve as a less invasive means of culture in select patients. We examined the impact of IR and surgically obtained cultures in the diagnosis and management of AHO. METHODS: A retrospective review of cases of AHO was performed from 2011 to 2014. Patients with chronic disease, orthopedic hardware, puncture wounds, or an infected contiguous focus were excluded. RESULTS: A total of 250 cases met inclusion criteria. Blood cultures were positive in 107 of 231 cases (46.3%), and 123 of 150 patients had positive cultures (82%) obtained by orthopedic surgery. Of these 123 patients, 62 (50.4%) had organisms identified only through operating room (OR) cultures. Of the 66 patients who had cultures obtained by IR, 34 (51.5%) had positive IR cultures. For those with positive IR cultures, 18 (52.9%) had negative blood cultures. Among the 80 patients with negative blood culture and positive OR/IR culture, the results changed antibiotic therapy in 68 (85%) patients. CONCLUSIONS: IR or OR culture was the only means of identifying a pathogen in 80 of 216 cases (37%), and in >80% changed medical management. IR can be used effectively to obtain bone cultures in children with AHO not requiring open surgical drainage. Further research is needed to better understand the optimal utilization of IR and OR culture in pediatric AHO.

Masking and social distancing have been adopted to mitigate the severe acute respiratory syndrome coronavirus 2 pandemic. We evaluated the indirect impact of severe acute respiratory syndrome coronavirus 2 prevention strategies on invasive Staphylococcus aureus, Streptococcus pneumoniae (pneumococcus) and Group A Streptococcus in Houston area children. We observed a decline in invasive pneumococcal disease and invasive Group A Streptococcus temporally associated with social distancing/masking/school closures.

Background: Bacteremia is often one factor used in deciding the need for prolonged intravenous antimicrobial therapy in osteoarticular infections (OAIs). We examined treatment practices and outcomes of Staphylococcus aureus bacteremic osteoarticular infections (BOAIs) evaluated at Texas Children’s Hospital. Methods: Cases of acute hematogenous OAI in children with positive blood cultures for S. aureus at Texas Children’s Hospital between 2011 and 2014 were reviewed. Orthopedic complications included chronic osteomyelitis, growth arrest, pathologic fracture, avascular necrosis and chronic dislocation. Acute kidney injury was defined as a doubling of the baseline creatinine. Results: One hundred and ninety-two cases of S. aureus OAI were identified with 102 cases of BOAI included [35 methicillin-resistant S. aureus (MRSA)]. Twenty-five patients were discharged home on oral antibiotics. Patients discharged on oral antibiotics had a shorter duration of fever, had a more rapid decline in C-reactive protein and were less likely to have MRSA. The frequency of orthopedic complications did not increase in patients who received early transition to oral antibiotics. For patients with MRSA bacteremia, the rates of complications between those who received ≥7 days versus 15 µg/mL were not associated with a decreased duration of fever, bacteremia or hospitalization, need for repeat operation or orthopedic complications but were associated with acute kidney injury. Conclusions: S. aureus BOAIs are associated with substantial morbidity. Early transition to oral therapy may be a safe option for select patients with S. aureus BOAI, including those due to MRSA. Prolonged courses of vancomycin and vancomycin troughs >15 μg/mL were not associated with improved outcomes for MRSA OAI.

Topical antimicrobial and antiseptic agents are commonly used in the management of minor skin and soft tissue infections (SSTIs). Resistance to mupirocin has been documented in Staphylococcus aureus isolates causing SSTIs. Data are limited, however, on the prevalence of retapamulin resistance or tolerance to antiseptics. We sought to determine the prevalence of decreased susceptibility to retapamulin and mupirocin as well as the potential for decreased chlorhexidine susceptibility of S. aureus isolates from SSTIs in children. Two hundred isolates from patients with a single SSTI and 200 isolates from patients with ≥3 previous episodes from the years 2010 to 2012 were selected from an S. aureus surveillance study. Screening for retapamulin resistance was performed by the broth macrodilution method; mupirocin MICs were determined by Etest. PCR was performed for the presence of the smr gene associated with elevated MICs/minimum bactericidal concentrations (MBCs) to chlorhexidine. Among the isolates screened, 38 isolates (9.5%) exhibited retapamulin resistance, of which 22 (57.9%) were methicillin-resistant S. aureus (MRSA). Two isolates (0.5%) displayed cross-resistance to retapamulin and linezolid. Thirty-nine isolates (9.8%) were found to have mupirocin resistance. smr -positive S. aureus accounted for 14% of isolates. The proportion of smr -positive organisms increased during the study ( P = 0.005). The prevalence of in vitro resistance to topical antimicrobials among S. aureus isolates causing SSTI in healthy children in our community is almost 10%. Retapamulin resistance was associated with cross-resistance to linezolid in 0.5% of isolates. In addition, there was an increase in the proportion of smr -positive isolates. Further research including clinical correlations with these findings is warranted.

Background: Patients with malignancies represent a population at high risk for drug-resistant infections. We sought to determine the clinical spectrum and molecular epidemiology of Staphylococcus aureus infections in pediatric oncology patients followed at Texas Children’s Hospital (Houston, TX). Furthermore, we determined the prevalence of the chlorhexidine resistance gene qacA/B from isolates in this unique population. Methods: Patients with a history of malignancy and a culture-proven S. aureus infection were identified from 2001 to 2011. Antibiotic susceptibility, pulsed-field gel electrophoresis and detection of qacA/B by polymerase chain reaction were performed on all isolates. Medical records for all patients were reviewed. Results: During the study period, 213 isolates were identified from 179 patients with malignancies. Thirty-one percent of the isolates were methicillin-resistant S. aureus. The most common infectious diagnosis was bacteremia (85/213 [39.9%], with 72/85 [84.7%] being catheter-associated). Thirteen patients with bacteremia were found to have pulmonary nodules at the time of presentation; only S. aureus was found in tissue in 5 of the 6 patients who underwent lung biopsy. After 2007, 18.2% of isolates were qacA/B positive with a steady increase in prevalence every year (χ² for trend P = 0.04). Conclusions: S. aureus is a significant cause of morbidity and mortality in pediatric oncology patients at Texas Children’s Hospital. In addition to the more well-known clinical manifestations, this pathogen can also be associated with pulmonary nodules. Furthermore, the prevalence of S. aureus isolates carrying antiseptic resistance genes increased in this population. Additional clinical and molecular studies and surveillance among pediatric oncology patients are warranted to further explore these findings.