Effect of Potassium Permanganate on Staphylococcal Isolates Derived from the Skin of Patients with Atopic Dermatitis

In atopic dermatitis (AD), Staphylococcus aureus frequently colonizes lesions, leading to superinfections that can then lead to exacerbations. The presence of biofilm-producing isolates has been associated with worsening of the disease. Potassium permanganate is used as a topical treatment of infected eczema, blistering conditions, and wounds. Little is known of its effects against microbes in AD skin. The aim of this study was to explore antibacterial and antibiofilm properties of potassium permanganate against staphylococcal isolates derived from AD skin. Viable count and radial diffusion assays were used to investigate antibacterial effects of potassium permanganate against planktonic staphylococcal isolates. The antibiofilm effects were assessed using biofilm assays and scanning electron microscopy. The Staphylococcus aureus isolates were completely killed when exposed to 0.05% of potassium permanganate. In concentrations of 0.01%, potassium permanganate inhibited bacterial biofilm formation. Eradication of established staphylococcal biofilm was observed in concentrations of 1%. Electron microscopy revealed dense formations of coccoidal structures in growth control and looser formations of deformed bacteria when exposed to potassium permanganate. This suggests antibacterial and antibiofilm effects of potassium permanganate against staphylococcal isolates derived from AD skin, when tested in vitro, and a potential role in the treatment of superinfected AD skin.

Insights into the role of the respiratory tract microbiome in defense against bacterial pneumonia

The respiratory tract microbiome (RTM) is a microbial ecosystem inhabiting different niches throughout the airway. A critical role for the RTM in dictating lung infection outcomes is underlined by recent efforts to identify community members benefiting respiratory tract health. Obligate anaerobes common in the oropharynx and lung such as Prevotella and Veillonella are associated with improved pneumonia outcomes and activate several immune defense pathways in the lower airway. Colonizers of the nasal cavity, including Corynebacterium and Dolosigranulum, directly impact the growth and virulence of lung pathogens, aligning with robust clinical correlations between their upper airway abundance and reduced respiratory tract infection risk. Here, we highlight recent work identifying respiratory tract bacteria that promote airway health and resilience against disease, with a focus on lung infections and the underlying mechanisms driving RTM-protective benefits.

Factors Associated With Blood Culture Contamination in Rural Hospitals in Japan: A Cross-Sectional Study

Background Blood culture, a cornerstone diagnostic test, is paramount for identifying bacteremia due to serious infections. However, its accuracy is jeopardized by contamination, often due to inappropriate collection procedures. Resource constraints and a limitation in specialized staff can heighten contamination risks in rural hospitals, underscoring the need to understand the associated demographics and conditions. This study aimed to elucidate the demographics and conditions associated with heightened blood culture contamination risk in rural hospitals to optimize testing practices and improve patient care. Methods A single-center, cross-sectional study was conducted in Unnan City Hospital, Unnan, Japan with participants suspected of having bacteremia. Data from the electronic medical records of 455 patients were analyzed using multivariate logistic regression with contamination as the dependent variable. Results Of the 455 patients who underwent blood culture testing, 321 and 134 tests were negative and positive for contamination, respectively. Older age and blood obtained from arteries were associated with a reduced risk of contamination (odds ratio (OR)=0.97; p=0.012, and OR=0.17; p=0.00069, respectively). Patients with dependencies exhibited an increase in contamination risk (OR=1.81; p=0.044). Patients admitted for infection demonstrated a reduced likelihood of sample contamination (OR=0.44; p=0.0034). The predominant organisms identified varied, with Escherichia coli being more frequent in uncontaminated blood samples and Staphylococcus epidermidis in the contaminated samples. Conclusion This study reveals a complex relationship between patient demographics, clinical practices, and the risk of contamination. Factors such as age, dependency status, and reason for admission were associated with sample contamination. Enhanced procedural stringency, microbial surveillance, and continuous training could mitigate these risks, particularly in resource-constrained settings. Identifying and understanding the factors influencing blood culture contamination can significantly bolster clinical practice in rural settings. While this study provides foundational insights, future research can deepen our understanding, ensuring the refinement of patient care protocols in similar environments.

Macrophage activation syndrome induced by Staphylococcus Epidermidis in a pediatric patient with cystic fibrosis and familial Mediterranean fever

Staphylococcus epidermidis (S. epidermidis) is the most frequently isolated member of the coagulase-negative staphylococci, which colonizes the skin and mucous membranes of the human body. Despite being a component of the normal flora, S. epidermidis can act as an opportunistic pathogen and is frequently implicated in both bacterial and nosocomial infections. Macrophage activation syndrome (MAS) is a rare but potentially fatal disease that occurs as a result of increased activation and proliferation of T lymphocytes and macrophages in response to infections and immune mediated diseases. It is very rare in patients with cystic fibrosis. Here we report a case of an 8-year-old girl with cystic fibrosis and familial Mediterranean fever who developed MAS after contracting a S. epidermidis infection.

Staphylococcus epidermidis Bacteremia in an Older Patient With Guillain-Barré Syndrome With Fever of Unknown Origin: A Case Report

Guillain-Barré syndrome (GBS) is an immune-mediated disorder that affects the peripheral nerves, often leading to weakness, numbness, and paralysis. Although GBS does not induce immunosuppression, severe cases can render patients vulnerable to infection due to various complications. We present the case of a 70-year-old woman who developed GBS following a Mycoplasma infection. The patient's prolonged GBS symptoms led to an immunocompromised state, resulting in sepsis due to bacteremia caused by methicillin-resistant Staphylococcus epidermidis. Respiratory muscle paralysis necessitated intubation and mechanical ventilation, predisposing the patient to aspiration pneumonia. Prolonged hospitalization increases the risk of infection, as exemplified by catheter-related bloodstream infections and respiratory bacterial colonization. Although GBS does not inherently suppress immunity, its complications, such as musculoskeletal and respiratory failure, can mimic immunodeficiency, necessitating comprehensive management. A system-based approach should address neurological deficits and potential complications, emphasizing collaboration among medical specialties. This case highlights the importance of recognizing GBS-related challenges and adopting a holistic strategy for effective patient care.

Extensive spinal epidural abscess caused by Staphylococcus epidermidis: A case report and literature review

Background

Extensive spinal epidural abscess (SEA) is an exceptional and threatening condition that requires prompt recognition and proper management to avoid potentially disastrous complications. We aimed to find key elements of early diagnosis and rational treatments for extensive SEA.

Case presentation

A 70-year-old man complained of intense pain in the cervical-thoracic-lumbar spine that radiated to the lower extremity. Laboratory test results revealed a marked increase in all indicators of infection. The spinal magnetic resonance imaging (MRI) revealed a ventral SEA extending from C2 to L4. Owing to the patient's critical condition, laminectomy, drainage, and systemic antibiotic therapy were administered. And the multidrug-resistant Staphylococcus epidermidis was detected in the purulent material from this abscess.

Results

Postoperative MRI revealed diminished epidural abscess, and the clinical symptoms were dramatically and gradually relieved after two rounds of surgery and systemic antibiotic therapy involving the combination of ceftriaxone, linezolid, and rifampicin.

Conclusions

A comprehensive emergency assessment based on neck or back pain, neurological dysfunctions, signs of systemic infection, and MRI are important for early diagnosis of extensive SEA. Further, the combination of laminectomy, drainage, and systemic antibiotic therapy may be a rational treatment choice for patients with SEA, especially for extensive abscess or progressive neurological dysfunction.

Mycotic Popliteal Artery Aneurysm With Rapid Enlargement Post-Bypass

Popliteal artery aneurysms (PAAs) are the most common type of peripheral artery aneurysms. Mycotic aneurysms involving the popliteal artery are quite rare and can occur as either a primary de novo infection or a secondary infection from another site. To our knowledge, there are no previous case reports on mycotic PAA in which Staphylococcus epidermidis was the primary etiologic pathogen. We present the case of a 55-year-old male who presented with complaints of lower extremity pain and swelling, malaise, and low-grade temperatures for two weeks and was found to have a PAA. He underwent left femoral-popliteal bypass grafting with expanded polytetrafluoroethylene (ePTFE) graft and ligation of the aneurysm. On postoperative day 10, he experienced acute swelling and pain in his lower extremity with foot drop and was found to have rapid enlargement of his aneurysm sac on imaging. He was returned to the operating room emergently where he underwent aneurysmectomy via a posterior fossa approach. Cultures and gram staining of the aneurysm sac were consistent with Staphylococcus epidermidis. As noted above, this case of mycotic PAA was treated with standard vascular surgical techniques, yet it proceeded to enlarge acutely. PAAs that rapidly expand or rupture after surgical interventions may be a sign of infection.

Staphylococcal Vaccine Antigens related to biofilm formation

The number and frequency of multidrug-resistant (MDR) strains as a frequent cause of nosocomial infections have increased, especially for Methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis, in part due to device-related infections. The transition to antibiotic-resistance in related bacterial genes and the capability for immune escape have increased the sustainability of biofilms produced by these bacteria. The formation and changes in biofilms have been suggested as a target to prevent or treat staphylococcal infections. Thus, this study reviews the development of candidate staphylococcal vaccines by database searching, and evaluates the immunogenicity and efficacy profiles of bacterial components involved in biofilms. The literature suggests that using common staphylococcal vaccine antigens and multivalent vaccines should further enhance vaccine efficacy.

The effects of TGF-β1 on staphylococcus epidermidis biofilm formation in a tree shrew biomaterial-centered infection model

Background

Transforming growth factor-β1 (TGF-β1) has a wide range of biological functions. It antagonizes lymphocyte response, inhibits pro-inflammatory cytokines, and serves as a signal to turn off the immune response and inflammatory response. To study the correlation between TGF-β1 and T helper (Th)1/Th2 cytokine levels in tree shrews, and to explore the effects of different levels of TGF-β1 on central venous catheter (CVC)-centered Staphylococcus epidermidis biofilm formation in tree shrews.

Methods

Tree shrews were injected with different concentrations of TGF-β1, and venous blood was drawn after 48 h to measure the levels of Th1 and Th2 cytokines. A CVC was placed into the femoral vein, and TGF-β1 at different concentrations and PIA− (ATCC12228) and PIA+ (ATCC35984) standard strains of Staphylococcus epidermidis were injected into the tree shrews to establish a biomaterial-centered infection (BCI) model. After 72 h, the CVC was removed, and biofilm formation was detected using the API bacterial identification system, semi-quantitative biofilm formation assay, and scanning electron microscopy.

Results

In the groups treated with TGF-β1 at different concentrations, the levels of Th1 cytokines interleukin-2 (IL-2), tumor necrosis factor (TNF), and interferon-γ (IFN-γ) were lower than those of normal group, while the levels of Th2 cytokines IL-6, IL-4 and IL-10 were higher than those of normal group. In the TGF-β1 groups at different concentrations, the positive rate of Staphylococcus epidermidis ATCC35984 biofilm formation was higher than that in non-TGF-β1 group, while there was no significant difference in the positive rate of Staphylococcus epidermidis ATCC12228 biofilm formation compared with that of the non-TGF-β1 group.

Conclusions

TGF-β1 causes the imbalance of Th1/Th2 cytokines and Th1/Th2 shift in tree shrews, leading to Th1 cell-led decline in cellular immune function. TGF-β1 promotes PIA+ Staphylococcus epidermidis biofilm formation in the tree shrew BCI model, but it has no significant influence on PIA-Staphylococcus epidermidis biofilm formation on the surface of CVCs.

Staphylococcus epidermidis Endophthalmitis Masquerading as Panuveitis After an Imperceptible Ocular Trauma

Endophthalmitis after a penetrating trauma occurs in 3% to 30% of cases. Prompt recognition and treatment are paramount to avoid irreversible visual loss. We present a case of severe panuveitis following ocular trauma with a tree branch that did not cause any evident ocular wound and discuss the difficulties in achieving a diagnosis that can allow proper treatment. A healthy 21-year-old man presented with acute anterior uveitis. He was managed elsewhere with oral acyclovir and topical steroids for presumed herpetic uveitis. He subsequently developed severe panuveitis with profound decrease in vision. Diagnostic vitrectomy was performed and vitreous samples were positive for Staphylococcus epidermidis. Systemic and intravitreal antibiotic therapy was initiated and after 5 days, the patient recovered with a remarkable improvement in visual acuity to 6/12. Post-traumatic endophthalmitis can result from an imperceptible trauma with no obvious compromise of the globe.

Evaluation of Biofilm Formation and Presence of Ica Genes in Staphylococcus epidermidis Clinical Isolates

Objectives

Biofilm formation is one of the important features of Staphylococcus epidermidis, particularly in nosocomial infections. We aimed to investigate the biofilm production by phenotypic methods and the presence of ica genes in S epidermidis.

Methods

A total of 41 S epidermidis isolates were recovered from different clinical specimens. Biofilm formation was evaluated by microtiter plate, tube method and Congo red agar method. The presence of icaA and icaD genes was investigated by PCR. Validity of methods (sensitivity and specificity), and metrics for test performance (positive/negative predictive value, and positive/negative likelihood ratio) were determined.

Results

By both microtiter plate and tube method, 53.6% of S epidermidis isolates were able to produce biofilm, whilst only 24.4% of isolates provided a biofilm phenotype on Congo red agar plates. icaA and icaD genes were found in 100% and 95.1% of isolates, respectively. Biofilm phenotypes accounted for 4.8% by microtiter plate assay, despite the absence of the ica gene. Congo red agar and PCR exhibited a lower sensitivity (18% and 45.5%, respectively) for identifying the biofilm phenotype in comparison to microtiter plate.

Conclusion

The microtiter plate method remains generally a better tool to screen biofilm production in S epidermidis. In addition, the ability of S epidermidis to form biofilm is not always dependent on the presence of ica genes, highlighting the importance of ica-independent mechanisms of biofilm formation. The use of reliable methods to specifically detect biofilms can be helpful to treat the patients affected by such problematic bacteria.

New Parameters to Quantitatively Express the Invasiveness of Bacterial Strains from Implant-Related Orthopaedic Infections into Osteoblast Cells

Complete eradication of bacterial infections is often a challenging task, especially in presence of prosthetic devices. Invasion of non-phagocytic host cells appears to be a critical mechanism of microbial persistence in host tissues. Hidden within host cells, bacteria elude host defences and antibiotic treatments that are intracellularly inactive. The intracellular invasiveness of bacteria is generally measured by conventional gentamicin protection assays. The efficiency of invasion, however, markedly differs across bacterial species and adjustments to the titre of the microbial inocula used in the assays are often needed to enumerate intracellular bacteria. Such changes affect the standardisation of the method and hamper a direct comparison of bacteria on a same scale. This study aims at investigating the precise relation between inoculum, in terms of multiplicity of infection (MOI), and internalised bacteria. The investigation included nine Staphylococcus aureus, seven Staphylococcus epidermidis, five Staphylococcus lugdunensis and two Enterococcus faecalis clinical strains, which are co-cultured with MG63 human osteoblasts. Unprecedented insights are offered on the relations existing between MOI, number of internalised bacteria and per cent of internalised bacteria. New parameters are identified that are of potential use for qualifying the efficiency of internalization and compare the behaviour of bacterial strains.

Propionibacterium acnes Has Low Susceptibility to Chlorhexidine Digluconate

BACKGROUND

The skin bacterium Propionibacterium acnes has been reported to be responsible for surgical site infections (SSIs). Skin disinfection before surgery therefore is of the utmost importance in the prevention of SSIs caused by skin bacteria.

METHODS

We assessed the susceptibility of clinical isolates of two skin bacteria, P. acnes and Staphylococcus epidermidis, to disinfectants.

RESULTS

The range of chlorhexidine digluconate (CHG) minimum inhibitory concentrations (MICs) for P. acnes isolates was 0.25-1 mcg/mL. Furthermore, the minimum bactericidal concentrations (MBCs) for a range of disinfectants were determined to evaluate their rapid bactericidal activity. The MBC range of CHG against the P. acnes isolates was 4,096->32,768 mcg/mL (MBC₈₀ 16,384 mcg/mL) after one minute of exposure and 1,024-32,768 mcg/mL (MBC₈₀ 8,192 mcg/mL) after five minutes, indicating that some strains required a CHG MBC higher than the commercial concentration of 2% (20,000 mcg/mL). In contrast, the MBCs of glutaraldehyde, sodium hypochlorite, povidone-iodine, ethanol, benzalkonium chloride, and olanexidine gluconate were all sufficiently lower than their commercial concentrations. In S. epidermidis, the MBC range of CHG was 128-1,024 mcg/mL at one minute of exposure and 4-8 mcg/mL at five minutes.

CONCLUSIONS

Different skin bacteria have different susceptibilities to disinfectants. To prevent SSIs, the selected disinfectant agent and the disinfection time should have bactericidal activity toward all the bacteria that pose a risk of infection.

Intravitreal Infliximab Injection to Treat Experimental Endophthalmitis

Objective

The purpose of this study was to compare the use of an intravitreal injection of infliximab and of dexamethasone combined with vancomycin to treat experimental endophthalmitis induced by Staphylococcus epidermidis.

Materials and Methods

The study was conducted between March 25 and April 13, 2012. Twenty-five six-month-old healthy rabbits were used, each weighing 2.5-3 kg. The rabbits were randomized into five groups with five animals per group. Endophthalmitis was induced by 0.1 mL (103 colony-forming units) S. epidermidis in all groups. In group 1, injection was not implemented after the occurrence of endophthalmitis. In groups 2, 3, and 4, the following intravitreal injections were given 24 h after the occurrence of endophthalmitis: group 2, 0.1 mg/0.1 mL vancomycin; group 3, 1 mg/0.1 mL vancomycin and 1 mg/0.1 mL dexamethasone; and group 4, 1 mg/0.1 mL vancomycin and 2 mg/0.1 mL infliximab. Group 5 was the control/uninfected group. The rabbits were clinically assessed each day for seven days. On day 9, a histopathologic evaluation was performed after enucleation.

Results

After a clinical evaluation, no statistically significant difference was found between the vancomycin+infliximab and vancomycin+dexamethasone groups (p>0.05). The difference was significant when both groups were compared with the vancomycin group (p<0.001). After the histopathologic evaluation, no statistically significant difference was found among the three groups (p>0.05).

Conclusion

An intravitreal injection of infliximab and of dexamethasone combined with vancomycin have similar clinical and histopathologic effects. To supplement the antibiotic treatment of endophthalmitis, infliximab in a safe dose range can be used as an alternative to dexamethasone to suppress inflammation and prevent ocular damage.

[The microbiology of chronic rhinosinusitis with nasal polyps in different phenotype of peripheral blood eosinophils]

Objective:To investigate the association between immune status and microbial community in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) in different phenotype of peripheral blood eosinophils (PBEOS).Method:Retrospective analysis of clinical data of 125 patients with CRSwNP and and 49 control subjects was performed. According to the proportion of peripheral blood eosinophils, the patients with CRSwNP were divided into PBEOS normal group and PBEOS elevated group. The samples of nasal secretions in middle meatus were collected, and then isolated and identified by microbial culture. Differences of microbial colonization rate between the groups were analyzed. SPSS 19.0 software was used to analyze the data.Result:There were 61 cases in PBEOS normal group (0<PBEOS≤ 5%), 64 cases in PBEOS elevated group (PBEOS> 5%) and 49 control subjects.In patient with CRSwNP, the positive rate of microbial culture was 84.4%, and the main microorganisms were Gram positive Aerobic and facultative anaerobic bacteria. The most common bacteria were coagulase negative staphylococci, Staphylococcus epidermidis (S. epidermidis) and Corynebacterium. The average positive rate of Staphylococcus aureus (S.aureus) was 10.4%, and S. epidermidis was 20.0%. The positive rate of S. aureus in the elevated group was higher than that in the normal group (17.2%, 3.3%), and the rate of S. epidermidis was lower (10.9%, 29.5%). The positive rate of S. epidermidis in the elevated group was also lower than that in control subjects (10.9%, 30.6%).Conclusion:In different PBEOS phenotypes, the colonization rate of S. aureus and S. epidermidis showed the opposite trend. In contrast to the normal goup, the colonization rate of S. aureus in the elevated group increased, and the rate of S. epidermidis decreased. At the same time, the colonization rate of S.epidermidis decreased in elevate group in contrast to the control subjests. This suggests that S. aureus may promote eosinophilic inflammatory response and S. epidermidis may promote noneosinophilic inflammatory response, which plays protective role.

Oxidation-sensing regulator AbfR regulates oxidative stress responses, bacterial aggregation, and biofilm formation in Staphylococcus epidermidis

Staphylococcus epidermidis is a notorious human pathogen that is the major cause of infections related to implanted medical devices. Although redox regulation involving reactive oxygen species is now recognized as a critical component of bacterial signaling and regulation, the mechanism by which S. epidermidis senses and responds to oxidative stress remains largely unknown. Here, we report a new oxidation-sensing regulator, AbfR (aggregation and biofilm formation regulator) in S. epidermidis. An environment of oxidative stress mediated by H(2)O(2) or cumene hydroperoxide markedly up-regulates the expression of abfR gene. Similar to Pseudomonas aeruginosa OspR, AbfR is negatively autoregulated and dissociates from promoter DNA in the presence of oxidants. In vivo and in vitro analyses indicate that Cys-13 and Cys-116 are the key functional residues to form an intersubunit disulfide bond upon oxidation in AbfR. We further show that deletion of abfR leads to a significant induction in H(2)O(2) or cumene hydroperoxide resistance, enhanced bacterial aggregation, and reduced biofilm formation. These effects are mediated by derepression of SERP2195 and gpxA-2 that lie immediately downstream of the abfR gene in the same operon. Thus, oxidative stress likely acts as a signal to modulate S. epidermidis key virulence properties through AbfR.

Nuclease of staphylococcus epidermidis isolated from mastitic milk. Production and some properties

Nuclease was produced by 47 % of the Staphylococcus epidermidis strains isolated from bovine quarter milk samples. The quantity of enzyme produced by different strains varied considerably. The nuclease of bovine S. epidermidis strains was heat-stable, the average D-value at 120°G being estimated to be 19 min. The nucleases of S. epidermidis and S. aureus could be identified, and consequently differentiated by serological methods.

S. epidermidis was a less severe udder pathogen than S. aureus. However, no difference was observed in udder pathogenicity between S. epidermidis strains with low or high in vitro nuclease production.