Histological assessment, anti-quorum sensing, and anti-biofilm activities of Dioon spinulosum extract: in vitro and in vivo approach.

Pseudomonas aeruginosa is an opportunistic bacterium causing several health problems and having many virulence factors like biofilm formation on different surfaces. There is a significant need to develop new antimicrobials due to the spreading resistance to the commonly used antibiotics, partly attributed to biofilm formation. Consequently, this study aimed to investigate the anti-biofilm and anti-quorum sensing activities of Dioon spinulosum, Dyer Ex Eichler extract (DSE), against Pseudomonas aeruginosa clinical isolates. DSE exhibited a reduction in the biofilm formation by P. aeruginosa isolates both in vitro and in vivo rat models. It also resulted in a decrease in cell surface hydrophobicity and exopolysaccharide quantity of P. aeruginosa isolates. Both bright field and scanning electron microscopes provided evidence for the inhibiting ability of DSE on biofilm formation. Moreover, it reduced violacein production by Chromobacterium violaceum (ATCC 12,472). It decreased the relative expression of 4 quorum sensing genes (lasI, lasR, rhlI, rhlR) and the biofilm gene (ndvB) using qRT-PCR. Furthermore, DSE presented a cytotoxic activity with IC50 of 4.36 ± 0.52 µg/ml against human skin fibroblast cell lines. For the first time, this study reports that DSE is a promising resource of anti-biofilm and anti-quorum sensing agents.

Comparative In Vitro Activities of New Antibiotics for the Treatment of Skin Infections.

Bacterial skin infections result in significant morbidity and have contributed to enhanced health-care resource utilization. The problem is heightened by emerging antimicrobial resistance. Multiple novel agents active against resistant pathogens that cause skin infections-including dalbavancin, tedizolid phosphate, oritavancin, and delafloxacin-have been approved over the past 5 years. Common features of these agents include gram-positive activity and favorable safety. Of these agents, delafloxacin is unique in being active against both gram-positive and gram-negative pathogens that cause skin infections, including those resistant to other antimicrobial agents. It is, therefore, an effective option for the treatment of skin infections.

Ceftaroline fosamil therapy in patients with acute bacterial skin and skin-structure infections with systemic inflammatory signs: A retrospective dose comparison across three pivotal trials.

This post-hoc analysis compared the pharmacokinetics and clinical outcomes of ceftaroline fosamil 600 mg every 12 (q12h) versus every 8 hours (q8h) in patients with acute bacterial skin and skin-structure infection (ABSSSI) and signs of sepsis. Clinical outcomes at test-of-cure in patients with ABSSSI and systemic inflammatory signs/systemic inflammatory response syndrome (SIRS) as well as ceftaroline minimum inhibitory concentrations (MICs) against baseline pathogens were compared between the COVERS trial (ceftaroline fosamil 600 mg q8h, 2-h infusion) and the CANVAS 1 and 2 trials (ceftaroline fosamil 600 mg q12h, 1-h infusion). Ceftaroline exposure among patients in COVERS with or without markers of sepsis was compared using population pharmacokinetic modelling. In COVERS, 62% (312/506) and 41% (208/506) of ceftaroline fosamil-treated patients had ≥1 systemic inflammatory sign or SIRS, respectively, compared with 55% (378/693) and 22% (155/693), respectively, in the CANVAS trials. Clinical cure rates for the modified intent-to-treat population in COVERS and CANVAS were similar for ceftaroline fosamil-treated patients with ≥1 sign of sepsis [82% (255/312) and 85% (335/394)] and for those with SIRS [84% (168/199) and 85% (131/155)]. Ceftaroline MIC distributions were similar across trials. Sepsis did not affect predicted individual steady-state ceftaroline exposure. Clinical cure rates in patients with ≥1 systemic inflammatory sign or SIRS were comparable for both ceftaroline fosamil dosage regimens. Pathogen susceptibilities to ceftaroline were similar across trials. Ceftaroline exposure was not affected by disease severity. Ceftaroline fosamil 600 mg q12h is a robust dosage regimen for most ABSSSI patients with sepsis [ClinicalTrials.gov ID: NCT01499277, NCT00424190, NCT00423657].

pH-triggered charge-reversible of glycol chitosan conjugated carboxyl graphene for enhancing photothermal ablation of focal infection.

Subcutaneous abscesses infected by multidrug-resistant bacteria are becoming an increasing challenge to human health. To address this challenge, a surface-adaptive and biocompatible glycol chitosan conjugated carboxyl graphene (GCS-CG) is developed, which exhibits unique self-adaptive target to the acidic microenvironment of abscess (∼pH 6.3) and no damage to the healthy tissue (pH 7.4) around the abscess. Originally, following conjugated with GCS, the absorbance of CG obviously increases in the near-infrared (NIR) region, enabling GCS-CG to generate an increment amount of heat. GCS-CG shows fast pH-responsive surface charge transition from negative to positive, which presents strong adherence to negatively charged bacteria surface in abscess, while exhibits poor affinity to host cells in healthy tissues. The local temperature of NIR-irradiated GCS-CG is estimated to be higher than their ambient temperature, ensuring targeted heating and eradicating the bacteria to reduce the damage to tissue; hence, wound healing is accelerated. Moreover, the in vitro and in vivo biosafety results demonstrate that GCS-CG presents greatly biocompatible even at a high concentration of 1 mg·mL-1. Given the above advantages as well as the simple preparation, graphene developed here may provide a new potential application as a useful antibacterial agent in the areas of healthcare. STATEMENT OF SIGNIFICANCE: A surface-adaptive nanomaterial, glycol chitosan conjugated carboxyl graphene (GCS-CG) is developed, which realizes the acidity-triggered bacteria targeting. GCS-CG can result in direct thermal ablation of bacteria and enhancement of the infected wound healing, but exhibit no damage to healthy tissues. The pH-responsive GCS-CG described here, containing no antibiotics, has great potentials in treating bacterial infection and even multidrug-resistant bacteria.

A quantitative model for dermal infection and oedema in BALB/c mice pinna.

BACKGROUND: Pharmaceutical industry demands innovation for developing new molecules to improve effectiveness and safety of therapeutic medicines. Preclinical assays are the first tests performed to evaluate new therapeutic molecules using animal models. Currently, there are several models for evaluation of treatments, for dermal oedema or infection. However, the most common or usual way is to induce the inflammation with chemical substances instead of infectious agents. On the other hand, this kind of models require the implementation of histological techniques and the interpretation of pathologies to verify the effectiveness of the therapy under assessment. This work was focused on developing a quantitative model of infection and oedema in mouse pinna. The infection was achieved with a strain of Streptococcus pyogenes that was inoculated in an injury induced at the auricle of BALB/c mice, the induced oedema was recorded by measuring the ear thickness with a digital micrometer and histopathological analysis was performed to verify the damage. The presence of S. pyogenes at the infection site was determined every day by culture. RESULTS: Our results showed that S. pyogenes can infect the mouse pinna and that it can be recovered at least for up to 4 days from the infected site; we also found that S. pyogenes can induce a bigger oedema than the PBS-treated control for at least 7 days; our results were validated with an antibacterial and anti-inflammatory formulation made with ciprofloxacin and hydrocortisone. CONCLUSIONS: The model we developed led us to emulate a dermal infection and allowed us to objectively evaluate the increase or decrease of the oedema by measuring the thickness of the ear pinna, and to determine the presence of the pathogen in the infection site. We consider that the model could be useful for assessment of new anti-inflammatory or antibacterial therapies for dermal infections.

Mycobacterium abscessus skin infection after tattooing--Case report.

Mycobacterium abscessus is a rapidly growing mycobacterium that has been affecting people undergoing invasive procedures, such as videosurgery and mesotherapy. This bacterium has global distribution, being found in numerous niches. The frequency of published reports of infection by rapidly growing mycobacteria associated with tattooing procedures has increased in recent years. However, in Brazil there were no case reports of M. abscessus after tattooing in the literature until now. In this paper, we describe the case of a patient with a nine-month history of lesion on a tattoo site. The diagnosis of infection with Mycobacterium abscessus was established by correlation between dermatological and histopathological aspects, culture and molecular biology techniques. The patient had significant improvement of symptoms with the use of clarithromycin monotherapy.

Mycobacterium abscessus skin infection after tattooing - Case report

AbstractMycobacterium abscessus is a rapidly growing mycobacterium that has been affecting people undergoing invasive procedures, such as videosurgery and mesotherapy. This bacterium has global distribution, being found in numerous niches. The frequency of published reports of infection by rapidly growing mycobacteria associated with tattooing procedures has increased in recent years. However, in Brazil there were no case reports of M. abscessus after tattooing in the literature until now. In this paper, we describe the case of a patient with a nine-month history of lesion on a tattoo site. The diagnosis of infection with Mycobacterium abscessus was established by correlation between dermatological and histopathological aspects, culture and molecular biology techniques. The patient had significant improvement of symptoms with the use of clarithromycin monotherapy.

Mycobacterium chelonae infections associated with bee venom acupuncture.

We report 3 cases of Mycobacterium chelonae infections after bee venom acupuncture. All were treated with antibiotics and surgery. Mycobacterium chelonae infections should be included in the differential diagnosis of chronic skin and soft tissue infections following bee venom acupuncture.

Study of streptococcal hemoprotein receptor (Shr) in iron acquisition and virulence of M1T1 group A streptococcus.

Streptococcus pyogenes (group A streptococcus, GAS) is a human bacterial pathogen of global significance, causing severe invasive diseases associated with serious morbidity and mortality. To survive within the host and establish an infection, GAS requires essential nutrients, including iron. The streptococcal hemoprotein receptor (Shr) is a surface-localized GAS protein that binds heme-containing proteins and extracellular matrix components. In this study, we employ targeted allelic exchange mutagenesis to investigate the role of Shr in the pathogenesis of the globally disseminated serotype M1T1 GAS. The shr mutant exhibited a growth defect in iron-restricted medium supplemented with ferric chloride, but no significant differences were observed in neutrophil survival, antimicrobial peptide resistance, cell surface charge, fibronectin-binding or adherence to human epithelial cells and keratinocytes, compared with wild-type. However, the shr mutant displayed a reduction in human blood proliferation, laminin-binding capacity and was attenuated for virulence in in vivo models of skin and systemic infection. We conclude that Shr augments GAS adherence to laminin, an important extracellular matrix attachment component. Furthermore, Shr-mediated iron uptake contributes to GAS growth in human blood, and is required for full virulence of serotype M1T1 GAS in mouse models of invasive disease.

A randomized trial of the efficacy and safety of sequential intravenous/oral moxifloxacin monotherapy versus intravenous piperacillin/tazobactam followed by oral amoxicillin/clavulanate for complicated skin and skin structure infections.

OBJECTIVES: The primary aim of the RELIEF study was to evaluate the efficacy and safety of two sequential intravenous (iv)/oral regimens: moxifloxacin iv/oral versus piperacillin/tazobactam (TZP) iv followed by oral amoxicillin/clavulanate (AMC). PATIENTS AND METHODS: The study had a prospective, randomized, double-dummy, double-blind, multicentre design. Patients ≥18 years were prospectively stratified according to complicated skin and skin structure infection (cSSSI) subtype/diagnosis (major abscess, diabetic foot infection, wound infection or infected ischaemic ulcer), surgical intervention and severity of illness. Diagnoses and disease severity were based on predetermined criteria, documented by repeated photographs, and confirmed by an independent data review committee. Patients were randomized to receive either 400 mg of moxifloxacin iv once daily followed by 400 mg of moxifloxacin orally once daily or 4.0/0.5 g of TZP iv thrice daily followed by 875/125 mg of AMC orally twice daily for 7-21 days. The primary efficacy variable was clinical response at test of cure (TOC) for the per-protocol (PP) population. Clinical efficacy was assessed by the data review committee based on repeated photographs and case descriptions. Clinical trials registry number: NCT 00402727. RESULTS: A total of 813 patients were randomized. Clinical success rates at TOC were similar for moxifloxacin and TZP-AMC in the PP [320/361 (88.6%) versus 275/307 (89.6%), respectively; P = 0.758] and intent-to-treat (ITT) [350/426 (82.2%) versus 305/377 (80.9%), respectively; P = 0.632] populations. Thus, moxifloxacin was non-inferior to TZP-AMC. Bacteriological success rates were high in both treatment arms [moxifloxacin: 432/497 (86.9%) versus TZP-AMC: 370/429 (86.2%), microbiologically valid (MBV) population]. Moxifloxacin was non-inferior to TZP-AMC at TOC in both the MBV and the ITT populations. Both treatments were well tolerated. CONCLUSIONS: Once-daily iv/oral moxifloxacin monotherapy was clinically and bacteriologically non-inferior to iv TZP thrice daily followed by oral AMC twice daily in patients with cSSSIs.

Evaluation of antibacterial activity of proteins and peptides using a specific animal model for wound healing.

Wound healing is a complex process involving the integrated actions of numerous cell types, soluble mediators, and extracellular matrix (ECM). In this study, phospholipase A(2) (PLA(2)) purified from crotalid snake venom was found to express in vitro bactericidal activity against a group of clinical human pathogens. Based on the sequence homology of PLA(2), a series of peptides were derived from the C-terminal region of crotalid PLA(2). These short synthetic peptides were found to reproduce the bactericidal activity of its parent molecule. In vitro assays for bactericidal and cytolytic activities of these peptides showed very high microbicidal potency against Gram-negative and Gram-positive (Staphylococcus aureus) bacteria. Variants of the peptides showed reduced toxicity toward normal human cells, while retaining high bactericidal potency. Here we describe the protocol for evaluating the wound healing process by antibacterial peptides. We evaluated the biological roles of the candidate peptides in skin wound healing, using a specific BALB/c mice model. Peptide-treated animals showed accelerated healing of full-thickness skin wounds, with increased reepithelialization, collagen synthesis, and angiogenesis observed during the healing process. Healing wounds in protein/peptide-treated mice had higher densities of neutrophils, macrophages, and fibrocytes. Along with increased leukocyte infiltration, levels of macrophage-derived chemokine expression were also upregulated. These results demonstrate that the protein/peptide derived from snake venoms promotes healing of skin wounds. The primary mechanism seems to be an increase in leukocyte infiltration, leading to locally elevated synthesis and release of collagen and growth factors.

Cutaneous Mycobacterium haemophilum infection in a kidney transplant recipient after acupuncture treatment.

Mycobacterium haemophilum is a slow-growing nontuberculous mycobacterium that can cause disease in both immunocompetent and immunocompromised patients. The most common clinical presentations of infection are the appearance of suppurative and ulcerated skin nodules. For the diagnosis, samples collected from suspected cases must be processed under the appropriate conditions, because M. haemophilum requires lower incubation temperatures and iron supplementation in order to grow in culture. In this case report, we describe the occurrence of skin lesions in a kidney transplant recipient, caused by M. haemophilum, associated with acupuncture treatment. The diagnosis was established by direct smear and culture of material aspirated from cutaneous lesions. Species identification was achieved by characterization of the growth requirements and by partial sequencing of the hsp65 gene. The patient was successfully treated with clarithromycin and ciprofloxacin for 12 months. Considering that the number of patients receiving acupuncture treatment is widely increasing, the implications of this potential complication should be recognized, particularly in immunosuppressed patients.

Mesotherapy and cutaneous Mycobacterium fortuitum infection.

BACKGROUND: Cutaneous infections caused by Mycobacterium fortuitum usually are a complication of trauma or postsurgical wounds. CASE REPORT: A 41-year-old woman presented with numerous dusky red nodules, abscesses and sinuses on the right buttock and on the lateral surfaces of both thighs. The lesions developed at the injection sites of mesotherapy treatment. M. fortuitum was cultured from a biopsy specimen and purulent fluid drained from lesions. The lesions had cleared completely with ciprofloxacin 500 mg b.d. for 3 weeks, and then 250 mg b.d. for another 3 weeks. CONCLUSIONS: This case demonstrates the importance of suspecting mycobacterial etiology in patients with nodules and abscesses in the areas of mesotherapy treatment.

Clinical manifestations and diagnosis of lyme borreliosis.

Lyme borrelosis is a multi-systemic disease caused byBorrelia burgdorferisensu lato. A complete presentation of the disease is an extremely unusual oberservation, in which a skin lesion follows a tick bite, the lesion itself is followed by heart and nervous system involvement, and later on by arthritis; late involvement of the eye, nervous system, joints and skin may also occur. Information on the relative frequency of individual clinical manifestations of Lyme borreliosis is limited; however, the skin is most frequently involved and skin manifestations frequently represent clues for the diagnosis. The only sign that enables a reliable clinical diagnoisis of Lyme borreliosis is a typical erythema migrans. Laboratory confirmation of a borrelial infection is needed for all manifestations of Lyme borreliosis, with the exception of typical skin lesions.

Nontuberculous mycobacteria infection after mesotherapy: preliminary report of 15 cases.

BACKGROUND: Mesotherapy is an increasingly used technique which is currently causing several mycobacterial infections owing to contaminated substances being injected, and also to poor aseptic measures being held by nonprofessional practitioners. PATIENTS AND METHODS: We collected 15 cases of nontuberculous mycobacteria (NTM) infection after mesotherapy in a 6-month period. RESULTS: All patients were female with ages ranging from 19 to 52 years; the main substances injected were procaine and lecithin, and the time between mesotherapy and the appearance of the lesions varied between 1 and 12 weeks. Clinical lesions were mostly nodules and abscesses, which were localized in the abdomen and buttocks in the majority of cases. The main patient complaint was local pain but some presented with systemic symptoms such as fever and malaise. Biopsies reported granulomatous chronic inflammation in the majority of cases. Skin cultures were positive for NTM and Mycobacterium chelonae. DISCUSSION AND CONCLUSIONS: Mesotherapy not performed with quality controlled substances can be a predisposing factor for NTM infection.

Iatrogenic Mycobacterium abscessus infection associated with acupuncture: clinical manifestations and its treatment.

BACKGROUND: Mycobacterial infections transmitted by acupuncture are an emerging problem. There have been two reports of mycobacterial infections complicating acupuncture in the English literature. AIM: To describe the clinical manifestations and treatment of patients who acquired localized Mycobacterium abscessus infection in the process of acupuncture. METHODS: Clinical manifestations and responses to different methods of treatment were reviewed in 40 patients who developed various skin lesions after acupuncture at a Korean oriental medicine clinic. Results The morphology of the lesions which developed at the acupuncture sites varied. Although the lesions disappeared with the combined administration of clarithromycin and amikacin for 3 months in most cases, five out of 25 patients (20%) showed residual lesions at the end of treatment, and had to be treated with a higher dosage of clarithromycin or alternative antibiotics based on sensitivity tests. CONCLUSIONS: We recommend at least 3 months of treatment with clarithromycin for treating skin infections caused by M. abscessus, with supplementary antibiotics selected based on patients' drug sensitivity tests.