UNASSIGNED: To analyze the antibiotic resistance profile, virulence genes, and molecular typing of Staphylococcus aureus (S. aureus) strains isolated in skin and soft tissue infections at the First Affiliated Hospital, Gannan Medical University, to better understand the molecular epidemiological characteristics of S. aureus.
UNASSIGNED: In 2023, 65 S. aureus strains were isolated from patients with skin and soft tissue infections. Strain identification and susceptibility tests were performed using VITEK 2 and gram-positive bacteria identification cards. DNA was extracted using a DNA extraction kit, and all genes were amplified using polymerase chain reaction. Multilocus sequence typing (MLST) was used for molecular typing.
UNASSIGNED: In this study, of the 65 S. aureus strains were tested for their susceptibility to 16 antibiotics, the highest resistance rate to penicillin G was 95.4%. None of the staphylococcal isolates showed resistance to ceftaroline, daptomycin, linezolid, tigecycline, teicoplanin, or vancomycin. fnbA was the most prevalent virulence gene (100%) in S. aureus strains isolated in skin and soft tissue infections, followed by arcA (98.5%). Statistical analyses showed that the resistance rates of methicillin-resistant S. aureus isolates to various antibiotics were significantly higher than those of methicillin-susceptible S. aureus isolates. Fifty sequence types (STs), including 44 new ones, were identified by MLST.
UNASSIGNED: In this study, the high resistance rate to penicillin G and the high carrying rate of virulence gene fnbA and arcA of S.aureus were determine, and 44 new STs were identified, which may be associated with the geographical location of southern Jiangxi and local trends in antibiotic use. The study of the clonal lineage and evolutionary relationships of S. aureus in these regions may help in understanding the molecular epidemiology and provide the experimental basis for pathogenic bacteria prevention and treatment.

Previous studies have mainly focused on outpatient cases of skin and soft tissue infections (SSTIs), with limited attention to inpatient occurrences. Thus, we aimed to compare the clinical parameters of inpatients with SSTIs, performed genomic characterization, and determined the subtypes of Panton-Valentine leucocidin (PVL) bacteriophages of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from these patients. We found that PVL-positive patients had shorter hospital stays (mean, 9 vs. 24 days; p < 0.001) and abscess resolution durations (mean, 8 vs. 13 days; p < 0.01). PVL-positive MRSA-induced SSTIs were more frequently associated with abscesses [36/55 (65.5%) vs. 15/124 (12.1%), p < 0.001], with 52.7% undergoing incision and drainage; over 80% of PVL-negative patients received incision, drainage, and antibiotics. In PVL-positive patients receiving empirical antibiotics, anti-staphylococcal agents such as vancomycin and linezolid were administered less frequently (32.7%, 18/55) than in PVL-negative patients (74.2%, 92/124), indicating that patients with PVL-positive SSTIs are more likely to require surgical drainage rather than antimicrobial treatment. We also found that the ST59 lineage was predominant, regardless of PVL status (41.3%, 74/179). Additionally, we investigated the linear structure of the lukSF-PV gene, revealing that major clusters were associated with specific STs, suggesting independent acquisition of PVL by different strain types and indicating that significant diversity was observed even within PVL-positive strains detected in the same facility. Overall, our study provides comprehensive insights into the clinical, genetic, and phage-related aspects of MRSA-induced SSTIs in hospitalized patients and contributes to a more profound understanding of the epidemiology and evolution of these pathogens in the Chinese population.

Vibrio parahaemolyticus is distributed worldwide in seafood such as fish, shrimp, and shellfish and is a major cause of seafood-borne diarrhoeal disease. Previous studies have reported infections contacting with contaminated seafood seawater. So far, 11 cases reported of skin and soft tissue infections (SSTIs) caused by V. parahaemolyticus, which 5 patients died and 6 survived. We found that transmission through contact with contaminated water also causes infection. We report a 46-year-old male contracted V. parahaemolyticus after being splashed with market sewage. His condition deteriorated rapidly and he died eventually, suggesting that more atypical modes of V. parahaemolyticus transmission may be possible in the future. Literature review revealed that SSTIs due to V. parahaemolyticus are rare, so, detailed questioning of the patient\'s exposure history can help with empirical drug administration early. Patients with immunodeficiency disease and progressive blistering need mandatory debridement urgently. If fascial necrosis is found during debridement, early amputation may save the patient\'s life.

Staphylococcus aureus integrated with mecA gene, which codes for penicillin-binding protein 2a, is resistant to all penicillins and other beta-lactam antibiotics, resulting in poor treatment expectations in skin and soft tissue infections. The development of a simple, sensitive and portable biosensor for mecA gene analysis in S. aureus is urgently needed. Herein, we propose a dual-toehold-probe (sensing probe)-mediated exonuclease-III (Exo-III)-assisted signal recycling for portable detection of the mecA gene in S. aureus. When the target mecA gene is present, it hybridizes with the sensing probe, initiating Exo III-assisted dual signal recycles, which in turn release numerous \"3\" sequences. The released \"3\" sequences initiate catalytic hairpin amplification, resulting in the fixation of a sucrase-labeled H2 probe on the surface of magnetic beads (MBs). After magnet-based enrichment of an MB-H1-H2-sucrase complex and removal of a liquid supernatant containing free sucrase, the complex is then used to catalyze sucrose to glucose, which can be quantitatively detected by a personal glucose meter. With a limit of detection of 4.36 fM for mecA gene, the developed strategy exhibits high sensitivity. In addition, good selectivity and anti-interference capability were also attained with this method, making it promising for antibiotic tolerance analysis at the point-of-care.

Skin and soft tissue infections (SSTIs) are among the most common bacterial infections reported in outpatients. Drug-resistant bacteria are the major cause of treatment failure and increased mortality rate in patients with SSTIs, posing significant challenges to human health. In this study, new-generation rhodium nanoplates (RhNPs) and glycol chitosan- and polydopamine-functionalized RhNPs (Rh@GCS) are developed for the treatment of drug-resistant SSTIs. RhNPs exhibited favorable antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Ag-resistant MRSA. The modified Rh@GCS exhibited enhanced antibacterial activity and can directly kill various drug-resistant bacteria by increasing the permeability of cell membranes, including gram-positive MRSA and gram-negative multidrug-resistant Escherichia coli (E.coli) and Pseudomonas aeruginosa (PA). Moreover, Rh@GCS effectively inhibited bacterial growth and promoted the healing of skin lesions in MRSA-induced SSTI mouse models. These results suggest that Rh@GCS is a promising nonantibiotic antimicrobial agent for the treatment of drug-resistant SSTIs.

Vancomycin is recommended for the treatment of skin and soft tissue infections (SSTI) and bone and joint infections (BJI). However, a detailed investigation of the pharmacokinetic profile and optimal dosing regimens of vancomycin in pediatric patients with SSTI and BJI is lacking. We successfully developed a new PopPK model of vancomycin in this population by using scavenged blood samples with the typical values for clearance (CL) of 0.14 L/h/kg and volume of distribution (V) of 0.5 L/kg. Body weight was confirmed as the significant covariate on CL and V. The optimal dosing regimens of 75 mg/kg/day and 80 mg/kg/day were recommended for this specific population.

Many observational studies have shown that obesity strongly affects skin and soft tissue infections (SSTIs). However, whether a causal genetic relationship exists between obesity and SSTIs is unclear.
A two-sample Mendelian randomization (MR) study was used to explore whether obesity is causally associated with SSTIs using a publicly released genome-wide association study (GWAS). An inverse-variance weighted (IVW) analysis was used as the primary analysis, and the results are reported as the odds ratios (ORs). Heterogeneity was tested using Cochran\'s Q test and the I2 statistic, and horizontal pleiotropy was tested using the MR-Egger intercept and MR pleiotropy residual sum and outlier (MR-PRESSO).
The results of the MR analysis showed a positive effect of BMI on SSTIs (OR 1.544, 95% CI 1.399-1.704, P= 5.86 × 10-18). After adjusting for the effect of type 2 diabetes (T2D) and peripheral vascular disease (PVD), the positive effect still existed. Then, we further assessed the effect of BMI on different types of SSTIs. The results showed that BMI caused an increased risk of impetigo, cutaneous abscess, furuncle and carbuncle, cellulitis, pilonidal cyst, and other local infections of skin and subcutaneous tissues, except for acute lymphadenitis. However, the associations disappeared after adjusting for the effect of T2D and PVD, and the associations between BMI and impetigo or cellulitis disappeared. Finally, we assessed the effects of several obesity-related characteristics on SSTIs. Waist circumference, hip circumference, body fat percentage, and whole-body fat mass, excluding waist-to-hip ratio, had a causal effect on an increased risk of SSTIs. However, the associations disappeared after adjusting for the effect of BMI.
This study found that obesity had a positive causal effect on SSTIs. Reasonable weight control is a possible way to reduce the occurrence of SSTIs, especially in patients undergoing surgery.

Due to the changes in pathogenic species and the absence of research on topical skin antibiotics, the therapy of skin and soft tissue infections (SSTIs) is facing more and more severe challenges. It is particularly urgent to look for alternative therapies without induction of drug resistance. UV C (UVC) light within the range of 200 to 280 nm is one of the most common techniques used to kill and/or inactivate pathogenic microorganisms. However, the traditional most commonly used wavelength of 254 nm irradiated from a low-pressure mercury lamp is hazardous to human health, being both carcinogenic and damaging to eye tissues, which limits its applications in vivo. This research aimed to investigate the antimicrobial properties and influence of 275-nm UVC light from a light-emitting diode (UVC-LED light) on wound healing time. Five bacteria, three fungi, and scalded-mouse models combined with SSTIs were used to evaluate the antimicrobial effect in vitro and in vivo. 275-nm UVC-LED light inactivated both bacteria and fungi with a very short irradiation time in vitro and induced neither DNA damage nor epidermal lesions in the mice\'s skin. Furthermore, in mouse models of SSTIs induced by either methicillin-resistant Staphylococcus aureus (MRSA) or Candida albicans, the 275-nm UVC-LED light showed significant antimicrobial effects and shortened the wound healing time compared with that in the no-irradiation group. UVC-LED light at 275 nm has the potential to be a new form of physical therapy for SSTIs. IMPORTANCE As a common clinical problem, the therapy of SSTIs is facing growing challenges due to an increase in the number of drug-resistant bacteria and fungi. UV C (UVC) light sterilization has been widely used in all aspects of daily life, but there are very few reports about in vivo therapy using UVC light. It is well known that prolonged exposure to UVC light increases the possibility of skin cancer. In addition, it is also very harmful for eyes. UV irradiation with 254-nm UVC light can cause corneal damage, like thinning of the corneal epithelial layer, superficial punctate keratitis, corneal erosion, etc. In this study, we focused on looking for a more accessible light source and safer UVC wavelength, and 275-nm UVC LED light was chosen. We investigated its applicability for SSTIs therapy with relative skin safety and expected that it could be used as a new physical therapy method for SSTIs.

Skin and soft tissue infections (SSTIs) refer to infections involving the skin, subcutaneous tissue, fascia, and muscle. In transplant populations with hematological malignancies, an immunocompromised status and the routine use of immunosuppressants increase the risk of SSTIs greatly. However, to date, the profiles and clinical outcomes of SSTIs in hematopoietic stem cell transplantation (HSCT) patients remain unclear. This study included 228 patients (3.67%) who developed SSTIs within 180 days after allogeneic HSCT from January 2004 to December 2019 in Peking University People\'s Hospital. The overall annual survival rate was 71.5%. We compared the differences between survivors and non-survivors a year after transplant and found that primary platelet graft failure (PPGF), comorbidities of acute kidney injury (AKI), and hospital-acquired pneumonia (HAP) were independent risk factors for death in the study population. A PPGF-AKI-HAP risk stratification system was established with a mortality risk score of 1×PPGF+1×AKI+1×HAP. The areas under the curves of internal and external validation were 0.833 (95% CI 0.760-0.906) and 0.826 (95% CI 0.715-0.937), respectively. The calibration plot revealed the high consistency of the estimated risks, and decision curve analysis showed considerable net benefits for patients.

Necrotizing fasciitis (NF) has emerged as rare but rapidly progressive, life-threatening severe skin and soft tissue infection. We conducted a study to investigate whether Th1/Th2 cytokines could serve as biomarkers to distinguish NF from class III skin and soft tissue infections (SSTIs).
A retrospective review was performed for 155 patients suffering from serious skin and soft tissue infections from October 2020 to February 2022. Th1/Th2 cytokines were obtained from peripheral blood and wound drainage fluid samples. Data on demographic characteristics, causative microbiological organisms, Th1/Th2 cytokines, c-reactive protein, procalcitonin and white blood cell (WBC) were extracted for analysis. Factors with statistical difference(p < 0.1) were included in the multivariate logistic regression model. The clinical differential diagnostic values of interleukin-2(IL-2), IL-6, IL-10, tumor necrosis factor-α (TNF-α) and interferon-r (IFN-r) were analyzed by receiver operating characteristic (ROC) curve.
Among the 155 patients, 66(43%) patients were diagnosed as NF. We found no significant difference for sex, age, location of infection, coexisting condition, predisposition, duration of symptoms before admission and micro-organisms, WBC, procalcitonin and c-reactive protein in NF and class III SSTIs group. NF had higher levels of IL-6 in serum (50.46 [24.89, 108.89] vs. 11.87 [5.20, 25.32] pg/ml; p＜0.01), IL-10 in serum (3.45 [2.03, 5.12] vs. 2.51 [1.79, 3.29] pg/ml; p＜0.01), IL-2 in wound drainage fluid (0.89 [0.49, 1.33] vs. 0.63 [0.14, 1.14] pg/ml; p = 0.02), IL-6 in wound drainage fluid (5000.84 [1392.30, 13287.19] vs. 1927.82 (336.65, 6759.27) pg/ml; p＜0.01), TNF-a in wound drainage fluid (5.20 [1.49, 22.97] vs. 0.96 [0.12, 3.21] pg/ml; p＜0.01) and IFN-r in wound drainage fluid (1.32 [0.47, 4.62] vs. 0.68 [0.10, 1.88] pg/ml; p = 0.02) as compared to the class III SSTIs. Multivariate logistic regression analyses showed that IL-6 in serum, IL-10 in serum and TNF-a in wound drainage fluid exhibited independently significant associations with diagnosis of NF(p＜0.05). In ROC curve analysis of IL-2, IL-6, IL-10, TNF-a and IFN-r for diagnosis of NF, the area under the curve (AUC) of IL-6 in serum could reach to 0.80 (p＜0.001). Using 27.62 pg/ml as the cut off value, the sensitivity was 74% and the specificity was 79% in IL-6 in serum.
Th1/Th2 cytokines, IL-6 in serum in particular, are potential biomarkers for the diagnosis of NF in the early stage. However, larger patient populations with multiple centers and prospective studies are necessary to ensure the prognostic role of Th1/Th2 cytokines.