Biodegradable Polymeric Micro/Nano-Structures with Intrinsic Antifouling/Antimicrobial Properties: Relevance in Damaged Skin and Other Biomedical Applications

Bacterial colonization of implanted biomedical devices is the main cause of healthcare-associated infections, estimated to be 8.8 million per year in Europe. Many infections originate from damaged skin, which lets microorganisms exploit injuries and surgical accesses as passageways to reach the implant site and inner organs. Therefore, an effective treatment of skin damage is highly desirable for the success of many biomaterial-related surgical procedures. Due to gained resistance to antibiotics, new antibacterial treatments are becoming vital to control nosocomial infections arising as surgical and post-surgical complications. Surface coatings can avoid biofouling and bacterial colonization thanks to biomaterial inherent properties (e.g., super hydrophobicity), specifically without using drugs, which may cause bacterial resistance. The focus of this review is to highlight the emerging role of degradable polymeric micro- and nano-structures that show intrinsic antifouling and antimicrobial properties, with a special outlook towards biomedical applications dealing with skin and skin damage. The intrinsic properties owned by the biomaterials encompass three main categories: (1) physical–mechanical, (2) chemical, and (3) electrostatic. Clinical relevance in ear prostheses and breast implants is reported. Collecting and discussing the updated outcomes in this field would help the development of better performing biomaterial-based antimicrobial strategies, which are useful to prevent infections.

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GSDMD contributes to host defence against Staphylococcus aureus skin infection by suppressing the Cxcl1–Cxcr2 axis

Veterinary Research ◽

10.1186/s13567-021-00937-7 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Zhen-Zhen Liu ◽

Yong-Jun Yang ◽

Feng-Hua Zhou ◽

Ke Ma ◽

Xiao-Qi Lin ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Skin Infection ◽

Bacterial Colonization ◽

Critical Role ◽

Host Defence ◽

Skin Damage ◽

Microbial Infection ◽

Caspase 1 ◽

Deficient Mice

AbstractGasdermin D (GSDMD), a member of the gasdermin protein family, is a caspase substrate, and its cleavage is required for pyroptosis and IL-1β secretion. To date, the role and regulatory mechanism of GSDMD during cutaneous microbial infection remain unclear. Here, we showed that GSDMD protected against Staphylococcus aureus skin infection by suppressing Cxcl1–Cxcr2 signalling. GSDMD deficiency resulted in larger abscesses, more bacterial colonization, exacerbated skin damage, and increased inflammatory cell infiltration. Although GSDMD deficiency resulted in defective IL-1β production, the critical role of IL-1β was counteracted by the fact that Caspase-1/11 deficiency also resulted in less IL-1β production but did not aggravate disease severity during S. aureus skin infection. Interestingly, GSDMD-deficient mice had increased Cxcl1 secretion accompanied by increased recruitment of neutrophils, whereas Caspase-1/11-deficient mice presented similar levels of Cxcl1 and neutrophils as wild-type mice. Moreover, the absence of GSDMD promoted Cxcl1 secretion in bone marrow-derived macrophages induced by live, dead, or different strains of S. aureus. Corresponding to higher transcription and secretion of Cxcl1, enhanced NF-κB activation was shown in vitro and in vivo in the absence of GSDMD. Importantly, inhibiting the Cxcl1–Cxcr2 axis with a Cxcr2 inhibitor or anti-Cxcl1 blocking antibody rescued host defence defects in the GSDMD-deficient mice. Hence, these results revealed an important role of GSDMD in suppressing the Cxcl1–Cxcr2 axis to facilitate pathogen control and prevent tissue damage during cutaneous S. aureus infection.

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Intranasal Septal Splints: Prophylactic Antibiotics and Nasal Microbiology

Annals of Otology Rhinology & Laryngology ◽

10.1177/0003489419867976 ◽

2019 ◽

Vol 129 (1) ◽

pp. 5-11

Author(s):

Amit Ritter ◽

Uri Alkan ◽

Dafna Yahav ◽

Ethan Soudry ◽

Ella Reifen

Keyword(s):

Antibiotic Prophylaxis ◽

Bacterial Resistance ◽

Bacterial Colonization ◽

Prophylactic Antibiotic ◽

Prophylactic Antibiotic Therapy ◽

Prophylactic Antibiotic Treatment ◽

Resistant Strains ◽

Accepted Practice ◽

Type Strains

Objectives: Intranasal septal splints are often used in nasal septal surgeries. Routine use of postoperative antibiotics is an accepted practice, although data regarding its efficacy in preventing postsurgical complications are limited. This study aimed to examine bacterial colonization on septal splints following prophylactic antibiotic therapy and the association with postoperative infections. Methods: Fifty-five patients underwent septoplasty by a single surgeon between March 2015 and April 2016. All had intranasal septal splints and were given antibiotic prophylaxis for 7 days until removal of splints. Nasal cultures were taken before surgery, and septal splints were examined for bacterial colonization following their removal. Results: Thirty-six patients (65%) had positive nasal culture prior to surgery. The most common isolates were Staphylococcus aureus (30%) and Enterobacteriaceae species (66%). All these patients had postoperative bacterial colonization on septal splints. In 15 patients with negative preoperative cultures, bacteria were isolated postoperatively. An increased resistance profile was documented postoperatively in 9 patients (16%), including two with multidrug resistance. In two of these patients preoperative wild-type strains acquired antibiotic resistance postoperatively. No adverse drug reactions to antibiotics were reported. Conclusions: Increased bacterial growth and emergence of resistant strains were observed on intranasal septal splints despite prophylactic antibiotic treatment. Nonetheless, this did not translate into clinical infection. Thus, considering antibiotics overuse and increasing bacterial resistance, further research is needed to determine the role of antibiotic prophylaxis in the setting of intranasal splints.

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Meta-Analysis of the Adverse Effects of Long-Term Azithromycin Use in Patients with Chronic Lung Diseases

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02067-13 ◽

2013 ◽

Vol 58 (1) ◽

pp. 511-517 ◽

Cited By ~ 30

Author(s):

Hui Li ◽

Ding-Hui Liu ◽

Lu-Lu Chen ◽

Qi Zhao ◽

Yan-Zhe Yu ◽

...

Keyword(s):

Adverse Effects ◽

Adverse Events ◽

Lung Diseases ◽

Bacterial Resistance ◽

Bacterial Colonization ◽

Meta Analysis ◽

Placebo Treatment ◽

Chronic Lung Diseases

ABSTRACTThe adverse effects of azithromycin on the treatment of patients with chronic lung diseases (CLD) were evaluated in the present study. MEDLINE and other databases were searched for relevant articles published until August 2013. Randomized controlled trials that enrolled patients with chronic lung diseases who received long-term azithromycin treatment were selected, and data on microbiological studies and azithromycin-related adverse events were abstracted from articles and analyzed. Six studies were included in the meta-analysis. The risk of bacterial resistance in patients receiving long-term azithromycin treatment was increased 2.7-fold (risk ratio [RR], 2.69 [95% confidence interval {95% CI}, 1.249, 5.211]) compared with the risk in patients receiving placebo treatment. On the other hand, the risk of bacterial colonization decreased in patients receiving azithromycin treatment (RR, 0.551 [95% CI, 0.460, 0.658]). Patients receiving long-term azithromycin therapy were at risk of increased impairment of hearing (RR, 1.168 [95% CI, 1.030, 1.325]). This analysis provides evidence supporting the idea that bacterial resistance can develop with long-term azithromycin treatment. Besides the increasingly recognized anti-inflammatory role of azithromycin used in treating chronic lung diseases, we should be aware of the potential for adverse events with its long-term use.

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The Role of Orientation of Surface Bound Dihydropyrrol-2-ones (DHP) on Biological Activity

Molecules ◽

10.3390/molecules24142676 ◽

2019 ◽

Vol 24 (14) ◽

pp. 2676 ◽

Cited By ~ 1

Author(s):

Taunk ◽

Chen ◽

Iskander ◽

Ho ◽

Almohaywi ◽

...

Keyword(s):

Biological Activity ◽

Quorum Sensing ◽

Photoelectron Spectroscopy ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Bacterial Colonization ◽

Covalent Attachment ◽

Inhibition Mechanism ◽

Glass Surfaces

Quorum sensing (QS) signaling system is important for bacterial growth, adhesion, and biofilm formation resulting in numerous infectious diseases. Dihydropyrrol-2-ones (DHPs) represent a novel class of antimicrobial agents that inhibit QS, and are less prone to develop bacterial resistance due to their non-growth inhibition mechanism of action which does not cause survival pressure on bacteria. DHPs can prevent bacterial colonization and quorum sensing when covalently bound to substrates. In this study, the role of orientation of DHP compounds was investigated after covalent attachment by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) coupling reaction to amine-functionalized glass surfaces via various positions of the DHP scaffold. The functionalized glass surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements and tested for their in vitro biological activity against S. aureus and P. aeruginosa. DHPs attached via the N-1 position resulted in the highest antibacterial activities against S. aureus, while no difference was observed for DHPs attached either via the N-1 position or the C-4 phenyl ring against P. aeruginosa.

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The role of bacterial colonization in the pathophysiology of hidradenitis suppurativa

Infectio ro ◽

10.26416/inf.53.1.2018.1605 ◽

2018 ◽

Vol 1 (53) ◽

pp. 5

Author(s):

Bogdan Dima ◽

Mara Mădălina Mihai ◽

Gabriela-Loredana Popa ◽

Monica Beatrice Dima ◽

Olguţa Anca Orzan

Keyword(s):

Hidradenitis Suppurativa ◽

Bacterial Colonization

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Epidemiology and antimicrobial resistance of Acinetobacter

International Journal of Antibiotics and Probiotics ◽

10.31405/ijap.4-5.18.05 ◽

2018 ◽

Vol 2 (4) ◽

pp. 46-59

Author(s):

A.G. Salmanov ◽

O.M. Verner ◽

L.F. Slepova

Keyword(s):

Antibiotic Resistance ◽

Laboratory Testing ◽

Immunocompromised Host ◽

Clinical Problem ◽

Healthcare Associated Infections ◽

Opportunistic Bacteria ◽

Acinetobacter Spp ◽

Healthcare Associated ◽

Major Clinical Problem

Species of the Acinetobacter represent opportunistic bacteria with a growing clinical significance for Healthcare-associated infections (HAIs). In this literature review, we focus on the current role of Acinetobacter in infectious pathology and describe taxonomy, pathogenicity, and antibiotic resistance of these bacteria. Pathogenesis and regulation of virulence factors in Acinetobacter spp. are described in detail. The majority of acinetobacterial infections are associated with A. baumannii and occur predominantly in an immunocompromised host. Usually, acinetobacterial infections are characterized by local purulent inflammation; in severe cases, meningitis and sepsis may develop. Antibiotic resistance of Acinetobacter is a major clinical problem; therefore we give special attention to laboratory testing of resistance to antibiotics as well as identification of Acinetobacter.

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When a Neonate Is Born, So Is a Microbiota

Life ◽

10.3390/life11020148 ◽

2021 ◽

Vol 11 (2) ◽

pp. 148

Author(s):

Alessandra Coscia ◽

Flaminia Bardanzellu ◽

Elisa Caboni ◽

Vassilios Fanos ◽

Diego Giampietro Peroni

Keyword(s):

Bacterial Colonization ◽

Perinatal Period ◽

Delivery Mode ◽

Fetal Life ◽

Assisted Reproduction Techniques ◽

Neonatal Nutrition ◽

Short And Long Term ◽

Number Of Bacteria

In recent years, the role of human microbiota as a short- and long-term health promoter and modulator has been affirmed and progressively strengthened. In the course of one’s life, each subject is colonized by a great number of bacteria, which constitute its specific and individual microbiota. Human bacterial colonization starts during fetal life, in opposition to the previous paradigm of the “sterile womb”. Placenta, amniotic fluid, cord blood and fetal tissues each have their own specific microbiota, influenced by maternal health and habits and having a decisive influence on pregnancy outcome and offspring outcome. The maternal microbiota, especially that colonizing the genital system, starts to influence the outcome of pregnancy already before conception, modulating fertility and the success rate of fertilization, even in the case of assisted reproduction techniques. During the perinatal period, neonatal microbiota seems influenced by delivery mode, drug administration and many other conditions. Special attention must be reserved for early neonatal nutrition, because breastfeeding allows the transmission of a specific and unique lactobiome able to modulate and positively affect the neonatal gut microbiota. Our narrative review aims to investigate the currently identified pre- and peri-natal factors influencing neonatal microbiota, before conception, during pregnancy, pre- and post-delivery, since the early microbiota influences the whole life of each subject.

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Clinical and microbiological characteristics of nosocomial, healthcare-associated, and community-acquired Klebsiella pneumoniae infections in Guangzhou, China

Antimicrobial Resistance and Infection Control ◽

10.1186/s13756-021-00910-1 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Tingting Le ◽

Ling Wang ◽

Chaoying Zeng ◽

Leiwen Fu ◽

Zhihua Liu ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Klebsiella Pneumoniae ◽

Bacterial Resistance ◽

Empirical Therapy ◽

Clonal Diversity ◽

Extended Spectrum Beta Lactamase ◽

Microbiological Characteristics ◽

Carbapenemase Gene ◽

Cross Transmission ◽

Healthcare Associated

Abstract Background Klebsiella pneumoniae (K. pneumoniae) is a common pathogen associated with hospital and community-onset infections. This study aimed to compare the clinical and microbiological characteristics of nosocomial, healthcare-associated (HCA), and community-acquired (CA) K. pneumoniae infections. Methods Clinical data were extracted from electronic medical records and analyzed retrospectively. Antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) production were determined for all identified strains. Carbapenemase and ESBL genes were amplified by PCR. Genotyping of carbapenem-resistant K. pneumoniae (CRKP) and ESBL-producing strains was performed by pulsed-field gel electrophoresis (PFGE). Results Of 379 K. pneumoniae infections, 98 (25.9%) were nosocomial, 195 (51.5%) were healthcare-associated, and 86 (22.6%) were community-acquired. Hematological malignancy (OR = 4.467), and hypertension (OR = 2.08) and cerebral vascular disease (OR = 2.486) were associated with nosocomial and HCA infections respectively, when compared to CA infections. Overall, the incidence of antimicrobial resistance for the majority of agents tested was similar between nosocomial and HCA infections (P > 0.05) and both groups had a higher incidence than CA infections (P < 0.05). Moreover, 95.1% (78/82) of CRKP strains were isolated from the nosocomial and HCA groups. The blaKPC was the most prevalent carbapenemase gene among CRKP strains (80.5%, 66/82). ESBL-producing strains were prevalent among nosocomial (40.8%), HCA (35.9%) and CA groups (24.4%). The blaCTX-M-9-group and blaCTX-M-1-group genes were predominant in nosocomial (65.0%) and CA strains (66.7%), respectively. PFGE results showed ESBL-producing and CRKP strains were genetically diverse. Identical PFGE profiles were observed among HCA and nosocomial strains. Conclusions Nosocomial and HCA K. pneumoniae infections presented similar clinical features and antimicrobial resistance, and both two types of infections were different to CA infections. CRKP and ESBL-producing strains were disseminated mainly in HCA and nosocomial groups, and showed a clonal diversity. The cross transmission of CRKP was existed among HCA and nosocomial patients. This finding suggests that similar empirical therapy should be considered for patients with nosocomial and HCA K. pneumoniae infections and bacterial resistance surveillance of these infections is necessary.

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Protein and Polysaccharide-Based Electroactive and Conductive Materials for Biomedical Applications

Molecules ◽

10.3390/molecules26154499 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4499

Author(s):

Xiao Hu ◽

Samuel Ricci ◽

Sebastian Naranjo ◽

Zachary Hill ◽

Peter Gawason

Keyword(s):

Cell Biology ◽

Biomedical Applications ◽

Human Life ◽

Electrically Conductive ◽

Conductive Materials ◽

Production Strategies ◽

Integral Role ◽

Material Sciences ◽

Novel Drug

Electrically responsive biomaterials are an important and emerging technology in the fields of biomedical and material sciences. A great deal of research explores the integral role of electrical conduction in normal and diseased cell biology, and material scientists are focusing an even greater amount of attention on natural and hybrid materials as sources of biomaterials which can mimic the properties of cells. This review establishes a summary of those efforts for the latter group, detailing the current materials, theories, methods, and applications of electrically conductive biomaterials fabricated from protein polymers and polysaccharides. These materials can be used to improve human life through novel drug delivery, tissue regeneration, and biosensing technologies. The immediate goal of this review is to establish fabrication methods for protein and polysaccharide-based materials that are biocompatible and feature modular electrical properties. Ideally, these materials will be inexpensive to make with salable production strategies, in addition to being both renewable and biocompatible.

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Effect of tungsten disulfide nanotubes on crystallization of polylactide under uniaxial deformation and annealing

Functional Composite Materials ◽

10.1186/s42252-021-00016-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Fausta Loffredo ◽

Loredana Tammaro ◽

Tiziana Di Luccio ◽

Carmela Borriello ◽

Fulvia Villani ◽

...

Keyword(s):

Biomedical Applications ◽

Structural Evolution ◽

Tungsten Disulfide ◽

Fine Tuning ◽

Nanocomposite Films ◽

Uniaxial Deformation ◽

Scanning Calorimetry ◽

X Ray ◽

X Ray Scattering

AbstractTungsten disulfide (WS2) nanotubes (NTs) are examined here as a filler for polylactide (PLA) for their ability to accelerate PLA crystallization and for their promising biocompatibility in relevant to biomedical applications of PLA-WS2 nanocomposites. In this work, we have studied the structural and thermal properties of PLA-WS2 nanocomposite films varying the concentration of WS2 NTs from 0 (neat PLA) to 0.6 wt%. The films were uniaxially drawn at 90 °C and annealed at the same temperature for 3 and 10 min. Using wide angle x-ray scattering, Raman spectroscopy and differential scanning calorimetry, we probed the effects of WS2 NT addition on the structure of the PLA films at various stages of processing (unstretched, stretching, annealing). We found that 0.6 wt% of WS2 induces the same level of crystallinity in as stretched PLA-WS2 as annealing in neat PLA for 10 min. These data provide useful insights into the role of WS2 NTs on the structural evolution of PLA-WS2 composites under uniaxial deformation, and extend their applicability to situations where fine tuning of PLA crystallinity is desirable.

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