Long-term persistence of sequence type 89 methicillin-resistant Staphylococcus aureus isolated from cases of staphylococcal scalded skin syndrome in a Korean community

Staphylococcal scalded skin syndrome: Clinical features, ancillary testing, and patient management

BACKGROUND/OBJECTIVES

The utility of ancillary testing in improving diagnostic precision or improving patient outcomes in staphylococcal scalded skin syndrome (SSSS) is unclear. Similarly, an optimal antibiotic regimen has yet to be established. Our goal was to describe clinical characteristics and ancillary work-up of SSSS, report bacterial resistance patterns, and examine patient outcomes under varying therapeutic strategies with the aim of developing an evidence-based management algorithm.

METHODS

We performed a retrospective review of pediatric patients diagnosed with SSSS at Intermountain Healthcare facilities between 2010 and 2021. A Kruskal-Wallis rank sum test was used to assess median length of stay between different antibiotic regimens.

RESULTS

Eighty-five cases were identified. The most common ancillary tests obtained were a complete blood count (88%), followed by chemistry analysis (80%). Blood cultures were collected in more patients (79%) compared to aerobic cultures (60%). No blood culture was positive for Staphylococcus aureus. All S. aureus isolates were methicillin-sensitive. Of those found resistant to clindamycin (36%), all demonstrated macrolide-induced clindamycin resistance. None were constitutively resistant to clindamycin. There was no statistical difference between antibiotic regimen and length of stay (p = .691). Receiving opiate medications was the only risk factor associated with prolonged hospitalization (p = .001).

CONCLUSIONS

Ancillary testing does not improve diagnostic precision and can be reduced. Clindamycin does not improve patient outcomes, suggesting beta-lactams should be considered first line. Susceptibility patterns in our cohort demonstrate inducible clindamycin resistance as opposed to constitutive.

Antimicrobial Resistance and Molecular Analysis of Staphylococcus aureus in Staphylococcal Scalded Skin Syndrome among Children in Korea

BACKGROUND

Staphylococcal scalded skin syndrome (SSSS) is a skin disease characterized by blistering and desquamation caused by exfoliative toxins (ETs) of Staphylococcus aureus (S. aureus). Although many countries show predominance of methicillin-susceptible S. aureus (MSSA), cases of methicillin-resistant S. aureus (MRSA) have been reported.

METHODS

Twenty-six children aged <15 years diagnosed with SSSS from January 2010 to December 2017 from three hospitals were included. S. aureus isolates from cases were analyzed for multilocus sequence types and ETs. Medical records were reviewed for clinical characteristics, treatment, and antimicrobial susceptibility patterns of S. aureus.

RESULTS

Among the 26 cases, mean age was 2.3 years. According to skin manifestations patients were classified as generalized (n = 10, 38.5%), intermediate (n = 11, 42.3%), and abortive (n = 5, 19.2%). Among all cases, 96.2% (25/26) were due to MRSA and the macrolide-resistance rate was 92.3% (24/26). ST89 (n = 21, 80.8%) was the most prevalent clone, followed by single clones of ST1, ST5, ST72, ST121, and ST1507. The eta gene was detected in one (3.8%) isolate which was MSSA. The etb gene was detected in 14 (53.8%) isolates, all of which were ST89. Nafcillin or first-generation cephalosporin was most commonly prescribed (n=20, 76.9%). Vancomycin was administered in four patients (15.4%) and clindamycin in nine patients (34.6%). Among MRSA cases, there was no difference in duration of treatment when comparing the use of antimicrobials to which the causative bacteria were susceptible or non-susceptible (9.75 vs. 8.07 days, P > 0.05).

CONCLUSION

S. aureus isolated from children with SSSS in Korea demonstrated a high prevalence of methicillin-resistant ST89 clones that harbored the etb gene. The predominance of MRSA suggests that antibiotics to which MRSA are susceptible may be considered for empirical antibiotic treatment in children with SSSS in Korea. Further studies on the role and effectiveness of systemic antibiotics in SSSS are warranted.

Mupirocin and Chlorhexidine Genotypic Resistance Found in Staphylococcus aureus Isolated From Young Infants Below 90 Days Old: A Genetic Basis for Eradication Failure

OBJECTIVES

To investigate the genetic characteristics associated with eradication failure of Staphylococcus aureus in infants below 90 days old.

METHODS

S. aureus isolated from clinical specimen cultures (blood, surgical tissue, or drainage, pus, etc.) and routine screening cultures in the neonatal intensive care unit (nasal and axillary skin swab) from patients below 90 days old were collected prospectively for 1 year, from August 2017 to July 2018. The isolates underwent typing and screening for genes associated with chlorhexidine (qacA/B), quaternary ammonium (smr), and mupirocin resistance (iles mutation, mupA, mupB), as well as Panton-Valentine leukocidin (PVL) toxin.

RESULTS

During the study period, 40 nonduplicate isolates were included for analyses, of which 70.0% were methicillin-resistant S. aureus (MRSA). Mupirocin resistance was found in 25% of the total isolates; 17.4% of the colonizers; and 35.3% of the pathogens (P = 0.196). Chlorhexidine resistance gene was found in 3 MRSA isolates colonized in the nares of preterm infants. All isolates harbored the disinfectant quaternary ammonium compound (QAC) resistance gene. PVL toxin gene was found in 57.5%, and the presence of PVL gene among colonizers and pathogens was similar (69.6% vs. 41.2%, P = 0.072).

CONCLUSIONS

Mupirocin, chlorhexidine, and QAC-resistant MRSAs harboring the PVL toxin gene were found in the nasal carriages of preterm infants. In this highly vulnerable patient population, one-fourth of the isolates harbored mupirocin-resistant genes, and all were resistant to QAC disinfectants. These strains are associated with persistence in both carriage and environmental reservoirs within the hospitals.

Antibiotic resistance of &lt;italic&gt;Staphylococcus aureus&lt;/italic&gt; colonized in children with staphylococcal scalded skin syndrome

Objectives Systemic antibiotic therapy with semisynthetic penicillinase-resistant penicillin or vancomycin and clindamycin are recommended for the treatment of staphylococcal scalded skin syndrome (SSSS). This study assessed the rate of antibiotic resistance of Staphylococcus aureus isolated from the anterior nares or skin of children diagnosed with SSSS. Methods A retrospective review of the medical records of 25 patients with SSSS between July 2010 and October 2014 was conducted. The clinical characteristics of patients were collected and the antibiotic susceptibility of S. aureus were analyzed using automated systems. Results The median age of the patients was 22 months (range: 2-95). Ninety-two percent of patients were less than 5 years of age. Nasal swab samples of all patients and skin swab samples of 17 patients were cultured to isolate S. aureus . Twenty-one (84%) of 25 patients were colonized with methicillin-resistant S. aureus (MRSA). The results of swab samples of the other four patients were no growth or isolation of bacteria other than S. aureus . Among 20 strains isolated from the anterior nares, 1 strain (5%) was methicillin-susceptible S. aureus . All 15 strains isolated from the skin were MRSA. All 21 strains isolated from anterior nares or skin were found to be resistant to clindamycin upon evaluation using automated systems. Conclusions The rates of methicillin and clindamycin resistance in S. aureus colonized in children with SSSS were very high. Further studies evaluating proper antibiotic regimens and the effectiveness of systemic antibiotic therapy are needed.