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

The Clinical Characteristics and Antimicrobial Resistance of Staphylococcus aureus Isolated from Patients with Staphylococcal Scalded Skin Syndrome (SSSS) in Southwestern China

Staphylococcal scalded skin syndrome (SSSS) is a rare, toxin-mediated, desquamating bacterial infectious dermatosis. So far, data from Southwestern China is scarce. This study aimed to investigate the clinical characteristics of SSSS patients in our hospital, the relative proportion of methicillin-resistant Staphylococcus aureus (MRSA) in skin and soft tissue secretions, and the drug sensitivity of S. aureus to better assist dermatologists in the diagnosis and treatment of SSSS. We reviewed the demographic characteristics, clinical manifestations, treatment regimens, therapeutic efficacy, laboratory test results, drug sensitivity, and outcome data of 79 SSSS patients from January 2012 to December 2021. Statistical analysis was performed using t tests and chi-square tests. Among the 79 SSSS patients, MRSA was detected in 35 (44.3%) isolates: 34 community-acquired (CA)-MRSA (97.1%) and 1 hospital-acquired (HA)-MRSA. The SSSS incidence increased annually from 2012 to 2014 and then decreased gradually after peaking in 2015. All the isolates were sensitive to vancomycin, tigecycline, linezolid, moxifloxacin, levofloxacin, and ciprofloxacin; were completely resistant to penicillin; and had low sensitivity to clindamycin and erythromycin. Interestingly, the sensitivity of MRSA to tetracycline increased annually after 2015. The resistance rates to common drugs previously used to treat SSSS increased. These findings may accelerate diagnosis and improve empirical antibiotic use, suggesting that clinicians should prescribe drugs according to antimicrobial susceptibility.

Associated Outcomes of Different Intravenous Antibiotics Combined with 2% Mupirocin Ointment in the Treatment of Pediatric Patients with Staphylococcal Scalded Skin Syndrome

Purpose

To compare treatment duration, influencing factors, and costs among intravenous antibiotic groups combined with 2% mupirocin ointment for treating staphylococcal scalded skin syndrome (SSSS).

Patients and Methods

Sex, age, onset days before admission, febrile status, white blood cell (WBC) count, and C-reactive protein (CRP) level were recorded as baseline characteristics for 253 included patients. The antibiotic sensitivity results were statistically compared by Cochran's Q test. Kruskal-Wallis tests were used to compare days and the total costs of hospitalization with different intravenous antibiotic applications. Mann-Whitney U-tests or Spearman's rank correlation tests were used for the univariate analysis. Finally, a multivariate linear regression model was employed to determine the variables with statistical significance.

Results

The sensitivity rates of oxacillin (84.62%), vancomycin (100%), and mupirocin (100%) were significantly higher than those of clindamycin (7.69%) (p<0.0001). The duration of intravenous ceftriaxone administration was significantly longer than that of amoxicillin-clavulanic acid, cefathiamidine, and cefuroxime (p<0.01). The total hospitalization costs for cefathiamidine were significantly higher than those for amoxicillin-clavulanic acid and cefuroxime (p<0.05). According to the multiple linear regression, ages ≥60 months old were correlated with shorter treatment duration (β=-1.48, [95% CI: -2.29, -0.66] for amoxicillin-clavulanic acid, and β=-1.44, [95% CI: -2.06, -0.83] for cefathiamidine, and β=-0.96, [95% CI: -1.58, -0.34] for cefuroxime) (all p<0.01). In multivariate analysis for cefathiamidine, higher WBC count (β=0.05, [95% CI: 0.01, 0.10], p<0.05) and CRP level (β=1.12, [95% CI: 0.14, 2.10], p<0.05) were associated with longer treatment course.

Conclusion

Oxacillin resistance was rare, and clindamycin resistance was high in pediatric patients with SSSS in our district. Intravenous amoxicillin-clavulanic acid and cefuroxime combined with topical mupirocin were favorable due to a shorter intravenous treatment course and lower costs. Younger age, elevated WBC count, and CRP levels could indicate a longer course of treatment with intravenous antibiotics.

Prevalence and clinical characteristics of methicillin-resistant Staphylococcus aureus infections among dermatology inpatients: A 7-year retrospective study at a tertiary care center in southwest China

Background

Increased rates of methicillin-resistant Staphylococcus aureus (MRSA) antibiotic resistance and the associated morbidity have increased dermatologists' attention to skin and soft tissue MRSA infections. However, the clinical characterization of MRSA skin and soft tissue infections (SSTIs) in Southwest China is lacking, which precludes optimal prevention and treatment of these infections.

Objectives

This study was conducted to characterize the prevalence, clinical comorbidities and antibiotic susceptibility of MRSA isolates from SSTIs, including community-associated (CA) and healthcare-associated (HA) isolates.

Methods

In the Dermatology Inpatient Department of the First Affiliated Hospital of Guangxi Medical University, a retrospective study was conducted on data, including patient demographics and clinical information, from culture-confirmed S. aureus isolated from skin and soft tissue between January 1, 2015, and December 31, 2021. Isolate susceptibility to 13 antibiotics was determined using the Vitek 2 system.

Results

From among 864 S. aureus strains, we identified 283 MRSA (32.75%) isolates comprising 203 CA-MRSA and 80 HA-MRSA isolates. The average rate of CA-MRSA isolation for MRSA SSTIs was 71.73%. The HA-MRSA isolation rate for MRSA SSTIs increased significantly. HA-MRSA-infected patients were older. The most common dermatological presentation of CA-MRSA infection was staphylococcal scalded skin syndrome, while the comorbidity severe drug eruption was significantly associated with HA-MRSA infection. One CA-MRSA strain was resistant to linezolid, and one HA-MRSA strain had an intermediate phenotype for vancomycin; both strains had low sensitivity to clindamycin and erythromycin (3.70%~19.40%). However, HA-MRSA isolates were more susceptible to trimethoprim/sulfamethoxazole.

Conclusions

CA-MRSA is a predominant pathogen causing SSTIs, and HA-MRSA infection incidence is increasing gradually. Both strains showed increasing antibiotic resistance. Our data on MRSA susceptibility may guide dermatologist antibiotic treatment decisions. Dermatologists should consider these identified comorbidities of MRSA SSTIs when patients are admitted and initiate early prevention and treatment of MRSA.

Current molecular approach for diagnosis of MRSA: a meta-narrative review

Introduction:

Detection and diagnosis of methicillin-resistant Staphylococcus aureus (MRSA) are important in ensuring a correct and effective treatment, further reducing its spread. A wide range of molecular approaches has been used for the diagnosis of antimicrobial resistance (AMR) in MRSA. This review aims to study and appraise widely used molecular diagnostic methods for detecting MRSA.

Methods:

This meta-narrative review was performed by searching PubMed using the following search terms: (molecular diagnosis) AND (antimicrobial resistance) AND (methicillin-resistant Staphylococcus aureus). Studies using molecular diagnostic techniques for the detection of MRSA were included, while non-English language, duplicates and non-article studies were excluded. After reviewing the libraries and a further manual search, 20 studies were included in this article. RAMESES publication standard for narrative reviews was used for this synthesis.

Results:

A total of 20 full papers were reviewed and appraised in this synthesis, consisting of PCR technique (n = 7), deoxyribonucleic acid (DNA) Microarray (n = 1), DNA sequencing (n = 2), Xpert MRSA/SA BC assay (n = 2), matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) (n = 2), MLST (n = 4), SCCmec typing (n = 1) and GENECUBE (n = 1).

Discussion:

Different diagnostic methods used to diagnose MRSA have been studied in this review. This study concludes that PCR has been extensively used due to its higher sensitivity and cost-effectiveness in the past five years

Staphylococcal Scalded Skin Syndrome in Neonates: Case Series and Overview of Outbreaks

Skin and soft tissue infections caused by Staphylococcus aureus (S. aureus) cover a wide spectrum of diseases in neonates, including staphylococcal scalded skin syndrome (SSSS). We describe a representative case of SSSS in neonatal twins, which despite recurrence showed a mild clinical disease course. This case was part of a small outbreak on a neonatal intensive care unit and therefore exemplifies the existence of neonatal outbreaks with skin and soft tissue infections by S. aureus. Diagnosis is generally based on the clinical picture and response to antibiotics, but can be aided by histology and cultures. Sequence-based molecular techniques are available to evaluate typing and virulence of S. aureus in outbreak or surveillance settings. The pillars of treatment are antibiotics and supportive care. Methicillin resistance remains a topic of concern, especially in outbreak settings. Our overview of numerous outbreaks of neonatal S. aureus skin infections underlines the importance of outbreak management strategies, including screening to identify the source of the outbreak, and limiting exposure through hygienic measures and establishment of physical boundaries.

Screening of Toxin Genes in Methicillin-Resistant Staphylococcus aureus Clinical Isolates from a Hospital Setting in a Tertiary Hospital in Northern Cyprus

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant opportunistic pathogen with a wide repertoire of virulence characteristics. Data regarding the molecular profile of MRSA in Northern Cyprus is limited. The current study aimed to examine the virulence profiles of MRSA with a focus on toxin-associated factors. Ninety-one S. aureus isolates collected at a university hospital were included in the study. Identification and antibiotic susceptibility testing were performed with BD Phoenix™ automated system. Methicillin resistance was evaluated by the disc diffusion assay and mecA detection. The presence of nuc was confirmed by conventional PCR. Confirmed MRSA isolates were assessed for the presence of virulence genes hla, eta, etb, etd and tst using molecular methods. Among 91 S. aureus isolates identified as MRSA using the BD Phoenix™ platform, 80.85% (n = 76/91) were confirmed as MRSA using phenotypic and genotypic methods. All confirmed MRSA isolates (n = 76, 100%) were positive for the nuc. MRSA rates were statistically higher in elderly inpatients. The prevalence of toxin-encoding genes was 97.3% (n = 74/76) for hla, 2.63% (n = 2/76) for eta, 1.3% (n = 1/76) for etb, and 2.63% (n = 2/76) for tst. None of the screened isolates harbored the etd gene. These results represent the first report to investigate multiple virulence factors in MRSA isolates in Northern Cyprus.

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.