Outpatient decolonization after recurrent skin infection with Panton-Valentine leukocidin (PVL)-producing S. aureus-The importance of treatment repetition

Epidemiology and clinical features of Skin and Soft Tissue Infections Caused by PVL-Positive and PVL-Negative Methicillin-Resistant Staphylococcus aureus Isolates in inpatients in China: a single-center retrospective 7-year study

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.

Detection of Staphylococcus aureus virulence gene pvl based on CRISPR strip

Introduction

Staphylococcus aureus (S. aureus) is a prominent pathogen responsible for both hospital-acquired and community-acquired infections. Among its arsenal of virulence factors, Panton-Valentine Leucocidin (PVL) is closely associated with severe diseases such as profound skin infections and necrotizing pneumonia. Patients infected with pvl-positive S. aureus often exhibit more severe symptoms and carry a substantially higher mortality risk. Therefore, it is crucial to promptly and accurately detect pvl-positive S. aureus before initiating protective measures and providing effective antibacterial treatment.

Methods

In this study, we propose a precise identification and highly sensitive detection method for pvl-positive S. aureus based on recombinase-assisted amplification and the CRISPR-ERASE strip which we previously developed.

Results

The results revealed that this method achieved a detection limit of 1 copy/μL for pvl-positive plasmids within 1 hour. The method successfully identified all 25 pvl-positive and 51 pvl-negative strains among the tested 76 isolated S. aureus samples, demonstrating its concordance with qPCR.

Discussion

These results show that the CRISPR-ERASE detection method for pvl-positive S. aureus has the advantages of high sensitivity and specificity, this method combines the characteristics of recombinase-assisted amplification at room temperature and the advantages of ERASE test strip visualization, which can greatly reduce the dependence on professional laboratories. It is more suitable for on-site detection than PCR and qPCR, thereby providing important value for rapid on-site detection of pvl.

Hiding in Plain Sight: Benefit of Abrasion and Laceration Swabs in Identification of Panton-Valentine Leucocidin (PVL)-Meticillin Resistant Staphylococcus aureus (MRSA) Colonisation in Military Personnel

Background Outbreaks of Panton-Valentine Leucocidin (PVL)-producing methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) are a recurrent challenge for the Royal Marines at the Commando Training Centre (CTCRM). The intensity of commando training, its impact on skin integrity, and persistent colonisation reservoirs within the training centre have thwarted attempts to prevent these outbreaks. Aim To present an outbreak of PVL-producing MRSA SSTIs at a military training centre, demonstrating the benefit of additional abrasion and laceration swabs on the identification of colonised personnel and showing the effectiveness of a 10-day decolonisation regime. Method Following the identification of the outbreak of PVL-producing MRSA, all 36 members of the Recruit Troop underwent nasal MRSA screening to identify MRSA carriers. The screening was repeated on day 16 after completing an enhanced 10-day decolonisation regime. A third screening was conducted on the 110th day after a second peak of infection was identified. Various infection control measures, such as enhanced cleaning, restriction of movement and adjustments to the military training serials, were introduced to prevent further spread through the training centre. Results In this outbreak, two-thirds (eighteen) of the Recruit Troop suffered MRSA-PVL skin infections requiring antibiotic therapy and three required hospital admission for surgical management of their abscesses. The outbreak lasted 130 days, with two spikes in infections 10 weeks apart. The outbreak was successfully confined to one troop. Conclusion With concerns about low identification rates of carriers using nasal screening for MRSA, in this outbreak, we improved the identification of asymptomatic carriage with the simple step of additional culture swabs for all cuts and abrasions. Improved identification of colonised recruits, along with an enhanced decolonisation regime and rigid infection control practices, prevented the further spread of the clone through the training centre. In a population with constant ongoing skin trauma, such as the military, contact sport athletes and iIV drug users, our results show that a culture of suitable abrasions/lacerations will improve the identification of MRSA colonisation compared with nasal swabs alone. Despite ongoing skin trauma and the logistical difficulties in delivering effective decolonisation during military training, decolonisation was successful in 79% of recruits after one decolonisation and 87% after the second 10-day decolonisation.

Comparison of biofilm production and virulence genes distribution among human and canine isolates of Staphylococcus aureus

Background

Staphylococcus aureus is an important human and animal pathogen that can cause a wide range of infections due to numerous virulence factors.

Aims

The aim of this study was to compare biofilm formation ability with different virulence factors such as bacterial motility, genes encoding biofilm associated proteins, and Panton-Valentine leukocidin (PVL) among human and canine isolates of S. aureus.

Methods

A total of 60 human (30 methicillin sensitive S. aureus (MSSA) and 30 methicillin resistant S. aureus (MRSA)) and 17 canine (all MSSA) isolates of S. aureus were tested for the capability of biofilm production, motility assay, and presence of genes encoding virulence factors: ica (encoding intercellular adhesion), bap (encoding biofilm-associated protein), fnbA (encoding fibronectin-binding protein A), cna (encoding collagen-binding protein), and pvl (encoding PVL).

Results

Animal isolates of S. aureus performed better biofilm production than the human strains (P=0.042), as well as human MSSA compared to the MRSA isolates (P=0.013). Our results showed that cna, fnbA, and ica genes (67.5%, 66.2%, and 42.9%, respectively) were more prevalent than bap and pvl genes (0%, and 7.8%, respectively). The ica gene was significantly more prevalent in human isolates compared to animal isolates (n=31/60 vs. n=2/17, P=0.008), whereas the cna gene was more frequent in animal isolates than in human ones (n=15/17 vs. n=37/60, P=0.0201). Significant correlations were found between the biofilm formation of animal isolates, and the presence of fnbA (P=0.029) and ica genes (P=0.001).

Conclusion

This study showed a correlation between biofilm production and the presence of certain biofilm-related genes in animal isolates, as well as stronger biofilm production among MSSA human and animal isolates.

Hanitsch L, Krüger R, K. Lindner A, S. Stegemann M, Nurjadi D. Skin Infections Due to Panton-Valentine Leukocidin-Producing S. Aureus

BACKGROUND

Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus (PVL-SA) strains are frequently associated with large, recurring abscesses in otherwise healthy young individuals. The typical clinical presentation and the recommended diagnostic evaluation and treatment are not widely known.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, with special attention to international recommendations.

RESULTS

PVL-SA can cause leukocytolysis and dermatonecrosis through specific cell-wall pore formation. Unlike other types of pyoderma, such conditions caused by PVL-SA have no particular site of predilection. In Germany, the PVL gene can be detected in 61.3% (252/411) of skin and soft tissue infections with S. aureus. Skin and soft tissue infections with PVL-SA recur three times as frequently as those due to PVL-negative S. aureus. They are diagnosed by S. aureus culture from wound swabs and combined nasal/pharyngeal swabs, along with PCR for gene detection. The acute treatment of the skin abscesses consists of drainage, followed by antimicrobial therapy if needed. Important secondary preventive measures include topical cleansing with mupirocin nasal ointment and whole-body washing with chlorhexidine or octenidine. The limited evidence (level IIb) concerning PVL-SA is mainly derived from nonrandomized cohort studies and experimental analyses.

CONCLUSION

PVL-SA skin infections are easily distinguished from other skin diseases with targeted history-taking and diagnostic evaluation.

Randomized controlled trial of chlorhexidine gluconate, intranasal mupirocin, rifampin, and doxycycline versus chlorhexidine gluconate and intranasal mupirocin alone for the eradication of methicillin-resistant Staphylococcus aureus (MRSA) colonization

BACKGROUND

Several decolonization regimens have been studied to prevent recurrent methicillin-resistant Staphylococcus aureus (MRSA) infections. Clinical equipoise remains with regard to the role of MRSA decolonization. We compared initial MRSA clearance and subsequent MRSA recolonization rates over a 12-month period after standard decolonization (using topical chlorhexidine gluconate, and intranasal mupirocin) or systemic decolonization (using topical chlorhexidine gluconate, intranasal mupirocin, oral rifampin, and oral doxycycline).

METHODS

MRSA-colonized patients were randomized to receive either standard or systemic decolonization. Follow-up with MRSA screening was obtained at approximately 3, 6, and 12 months after completion of therapy. Kaplan-Meier survival curves were calculated and assessed for significant differences using log-rank tests.

RESULTS

Of 98 enrolled patients (25 standard decolonization, 73 systemic decolonization), 24 patients (7 standard decolonization, 17 systemic decolonization) did not complete the study. Univariate analysis showed a marginally significant difference in the probability of remaining MRSA-negative post-treatment (p = 0.043); patients who received standard decolonization had a 31.9% chance of remaining MRSA-negative compared with a 49.9% chance among those who received systemic decolonization. With multivariate analysis, there was no difference in the probability of remaining MRSA-negative between systemic and standard decolonization (p = 0.165). Initial MRSA clearance was more readily achieved with systemic decolonization (79.1%; 95% CI 32.4% to 71.6%) than with standard decolonization (52.0%; 95% CI 69.4% to 88.8%; p = 0.0102).

CONCLUSIONS

Initial MRSA clearance is more readily achieved with systemic decolonization than with standard decolonization. There is no significant difference in the probability of sustained MRSA clearance.

Methicillin-resistant Staphylococcus aureus colonization of infectious and non-infectious skin and soft tissue lesions in patients in Tehran

Background

The most common clinical manifestations of Staphylococcus aureus strains in the community are skin and soft-tissue infections. S. aureus could colonize the body sites and complicate the pathogenesis of skin diseases. S. aureus colonization is a risk factor for severe conditions such as bone and joint infections, pneumonia, bacteremia, and endocarditis. This study aimed to investigate the prevalence of S. aureus strains in skin and soft tissue infections and other skin disorders in patients referring to dermatology clinics and to evaluate the antibiotic resistance pattern and molecular characteristics of S. aureus isolates.

Methods

Skin swabs were collected from the lesional sites in 234 outpatients referring to dermatology clinics in three hospitals in Tehran. Antibiotic susceptibility, biofilm formation, and hemolysis tests were performed for isolates. PCR was done for SCCmec typing, agr grouping, and virulence genes detecting.

Results

The prevalence of S. aureus strains among patients with skin and soft-tissue infections and other skin lesions was 44.77% (30/67) and 44.91% (75/167), respectively. Also, 59 (56.19%) isolates were MRSA, 35.57% were HA-MRSA, and 30.5% were CA-MRSA. The psmα gene was more prevalent (62.8%) among isolates, followed by hlaα (56.1%), tsst-1 (15.2%) eta (13.3%), etb (6.6%), and pvl (2.8%). The agr specificity groups I, II, III, and IV were identified in 49.5, 21.9, 11.4, and 14.2% of S. aureus isolates, respectively. Most (56%) S. aureus isolates produced a moderate biofilm, and 23.8% of them produced strong biofilms. α-hemolysin (46.6%), β-hemolysin (25.7%), γ-hemolysin (19%), and both α and β-hemolysin (5.7%) were also produced by isolates.

Conclusion

The present study results indicated high colonization of skin lesions by HA-MRSA and CA-MRSA clones; MRSA strains were more resistant to antibiotics, contained various toxin genes, and were able to form biofilms. Therefore, they could play a vital role in the pathogenesis of various skin diseases; also, they could spread and cause infections in other body sites. Eradication and decolonization strategies could prevent recurrent infections and the spread of resistant strains and improve skin conditions.

Comparative Effectiveness Study of Home-Based Interventions to Prevent CA-MRSA Infection Recurrence

Recurrent skin and soft tissue infections (SSTI) caused by Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) or Methicillin-Sensitive Staphylococcus aureus (CA-MSSA) present treatment challenges. This community-based trial examined the effectiveness of an evidence-based intervention (CDC Guidelines, topical decolonization, surface decontamination) to reduce SSTI recurrence, mitigate household contamination/transmission, and improve patient-reported outcomes. Participants (n = 186) were individuals with confirmed MRSA(+)/MSSA(+) SSTIs and their household members. During home visits; Community Health Workers/Promotoras provided hygiene instructions; a five-day supply of nasal mupirocin; chlorhexidine for body cleansing; and household disinfecting wipes (Experimental; EXP) or Usual Care Control (UC CON) pamphlets. Primary outcome was six-month SSTI recurrence from electronic health records (EHR). Home visits (months 0; 3) and telephone assessments (months 0; 1; 6) collected self-report data. Index patients and participating household members provided surveillance culture swabs. Secondary outcomes included household surface contamination; household member colonization and transmission; quality of life; and satisfaction with care. There were no significant differences in SSTI recurrence between EXP and UC in the intent-to-treat cohort (n = 186) or the enrolled cohort (n = 119). EXP participants showed reduced but non-significant colonization rates. EXP and UC did not differ in household member transmission, contaminated surfaces, or patient-reported outcomes. This intervention did not reduce clinician-reported MRSA/MSSA SSTI recurrence. Taken together with other recent studies that employed more intensive decolonization protocols, it is possible that a promotora-delivered intervention instructing treatment for a longer or repetitive duration may be effective and should be examined by future studies.

Skin infections due to Panton-Valentine leukocidin (PVL)-producing S. aureus-Cost effectiveness of outpatient treatment

Introduction

Skin and soft tissue infections (SSTI) caused by Panton-Valentine leukocidin (PVL)-producing strains of Staphylococcus aureus (PVL-SA) are associated with recurrent skin abscesses. Secondary prevention, in conjunction with primary treatment of the infection, focuses on topical decolonization. Topical decolonization is a standard procedure in cases of recurrent PVL-SA skin infections and is recommended in international guidelines. However, this outpatient treatment is often not fully reimbursed by health insurance providers, which may interfere with successful PVL-SA decolonization.

Aim

Our goal was to estimate the cost effectiveness of outpatient decolonization of patients with recurrent PVL-SA skin infections. We calculated the average cost of treatment for PVL-SA per outpatient decolonization procedure as well as per in-hospital stay.

Methods

The study was conducted between 2014 and 2018 at a German tertiary care university hospital. The cohort analyzed was obtained from the hospital’s microbiology laboratory database. Data on medical costs, DRG-based diagnoses, and ICD-10 patient data was obtained from the hospital’s financial controlling department. We calculated the average cost of treatment for patients admitted for treatment of PVL-SA induced skin infections. The cost of outpatient treatment is based on the German regulations of drug prices for prescription drugs.

Results

We analyzed a total of n = 466 swabs from n = 411 patients with recurrent skin infections suspected of carrying PVL-SA. PVL-SA was detected in 61.3% of all patients included in the study. Of those isolates, 80.6% were methicillin-susceptible, 19.4% methicillin-resistant. 89.8% of all patients were treated as outpatients. In 73.0% of inpatients colonized with PVL-SA the main diagnosis was SSTI. The median length of stay was 5.5 days for inpatients colonized with PVL-SA whose main diagnosis SSTI; the average cost was €2,283. The estimated costs per decolonization procedure in outpatients ranged from €50-€110, depending on the products used.

Conclusion

Our data shows that outpatient decolonization offers a highly cost-effective secondary prevention strategy, which may prevent costly inpatient treatments. Therefore, health insurance companies should consider providing coverage of outpatient treatment of recurrent PVL-SA skin and soft tissue infections.