Presence Of Microbial Biofilm Research Articles

(128) Characterizing Antibiotic Susceptibility of the Penile Prosthesis Microbiome

Abstract Introduction Inflatable penile prostheses (IPP) are the gold standard treatment for erectile dysfunction refractory to conservative therapies. However, infection remains a significant concern and the presence of microbial biofilms on both infected and non-infected devices has recently been demonstrated. Various antimicrobials are used for prophylaxis intraoperatively and postoperatively. It remains unknown how these antimicrobials affect the growth of bacteria and their associated biofilms. We sought to assess how commonly used antimicrobials influenced growth of bacterial isolates previously isolated from both non-infected and infected devices, obtained during revisional surgery. Objective The goal of this study was to evaluate growth of bacterial isolates previously obtained from non-infected and infected IPPs. Isolates were exposed to single or multi-antibiotic combinations to assess degree of inhibition of bacterial growth. Methods In this IRB-approved study, 35 bacterial isolates had been previously obtained from patients who had been consented for IPP revision or replacement secondary to mechanical failure, pain, or device infection. Bacteria were plated on brain-heart-infusion (BHI) agar plates and allowed to incubate for 48 hours. Standard-sized antibiotic discs were introduced into the grown bacterial colonies consisting of the following single or multi-agent regimens: bacitracin, cefaclor, cephazolin, gentamicin, levofloxacin, trimethoprim-sulfamethoxazole, tobramycin, vancomycin, piperacillin/tazobactam, gentamicin + piperacillin/tazobactam, gentamicin + cephazolin, and gentamicin + vancomycin. Zones of inhibition (ZOI) were measured after placement of the antibiotic discs in the bacterial colonies. Statistics were analyzed with false discovery rate corrected, one-sample t-tests. Quantification of antibiotic resistance was defined as follows: Resistant: ZOI not significantly different from 0 in one sample t-test Susceptible: ZOI significantly greater than 0, but mean is <10mm Highly susceptible: ZOI significantly greater than 0, but mean is 10-20mm Exceptionally susceptible: ZOI significantly greater than 0, but mean is >20mm Taxonomic classification of bacterial isolates was provided by extracting DNA from pure cultures and sequencing the full length 16S rRNA gene using Sanger sequencing, after amplification with two different primer sets to provide overlapping sequence regions. Results Of the antibiotics tested, TMP-SMX was found to have the highest percentage of resistant isolates (54.3%) of the 35 tested, with bacitracin having the second most (40%). Both tobramycin and TMP-SMX had 0.0% of isolates be exceptionally susceptible. Combination piperacillin/tazobactam was found to have the highest percentage of exceptionally susceptible isolates (11.4%). A large majority of isolates were highly susceptible to gentamicin + piperacillin/tazobactam (91.4%), piperacillin/tazobactam (74.3%), gentamicin + cefazolin (74.3%), and levofloxacin (88.6%), while greater than half of isolates were highly susceptible to cefazolin (62.9%) and cefaclor (54.3%)." Conclusions Our results demonstrate that cefaclor or bacitracin prevented growth of bacterial isolates obtained from IPPs explanted for mechanical failure, pain or infection. Further investigation is needed to characterize how intraoperative and postoperative antibiotic influences a symbiotic or dysbiotic community of microbes on the surface of penile prostheses. By better understanding the interactions between microbes, antibiotics and host, novel therapeutics might promote a non-infected, symbiotic microenvironment. Disclosure Yes, this is sponsored by industry/sponsor: Coloplast corporation. Clarification: Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast, boston scientific.

Influence of Azospirillum brasilense on micro-propagated sugarcane seedlings

Sugarcane is an essential crop in the Brazilian economy. The adoption of techniques in the acclimatization of plants in vitro contributes to success in the field. The present work aims to evaluate the effect of Azospirillum brasilense on the acclimatization of sugarcane seedlings. The experiment was conducted with six treatments and twelve replications. There were two control treatments without inoculation, one with N fertilization and one without, and four with A. brasilense (2.0x108 CFU) at different doses (19.92mL + N fertilization, 9.84mL, 19.92mL, and 39.84mL). Evaluations were seedling height (SH), stem diameter (SD), number of shoots per tube (NS), number of leaves (NL), fresh aerial weight (AFM), root fresh weight (RFM), total chlorophyll (TC), foliar nitrogen (FN) and visual microscopic study of the roots. The results showed that the recommended dose of A. brasilense + N fertilization increased by 36% in seedling height, 29% in stem diameter, 85% in aerial fresh mass, 21% in total chlorophyll, 142% in foliar N, and also increased root hairs and the presence of microbial biofilm. Therefore, the bacterium A. brasilense can be used in association with nitrogen fertilizers or alone, where it obtained great benefits in the increase of biomass.

Inhibitory Effect of Cold Atmospheric Plasma on Chronic Wound-Related Multispecies Biofilms

The presence of microbial biofilms in the wounds affects negatively the healing process and can contribute to therapeutic failures. This study aimed to establish the effective parameters of cold atmospheric plasma (CAP) against wound-related multispecies and monospecies biofilms, and to evaluate the cytotoxicity and genotoxicity of the protocol. Monospecies and multispecies biofilms were formed by methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Enterococcus faecalis. The monospecies biofilms were grown in 96 wells plates and multispecies biofilm were formed on collagen membranes. The biofilms were exposed to helium CAP for 1, 3, 5 and 7 min. In monospecies biofilms, the inhibitory effect was detected after 1 min of exposure for E. faecalis and after 3 min for MRSA. A reduction in P. aeruginosa biofilm’s viability was detected after 7 min of exposure. For the multispecies biofilms, the reduction in the overall viability was detected after 5 min of exposure to CAP. Additionally, cytotoxicity and genotoxicity were evaluated by MTT assay and static cytometry, respectively. CAP showed low cytotoxicity and no genotoxicity to mouse fibroblastic cell line (3T3). It could be concluded that He-CAP showed inhibitory effect on wound-related multispecies biofilms, with low cytotoxicity and genotoxicity to mammalian cells. These findings point out the potential application of CAP in wound care.

Antimicrobial photodynamic therapy mediated by methylene blue in surfactant vehicle on periodontopathogens.

Periodontal disease (PD) is a chronic inflammatory disease caused by the presence of microbial biofilm. The aim of this study was to evaluate antimicrobial effect of antimicrobial photodynamic therapy (A-PDT) mediated by methylene blue (MB) in monomer form on A. actinomycetemcomitans and P. gingivalis. A. actinomycetemcomitans ATCC 29523 and P. gingivalis ATCC 33577 were cultured on anaerobic jars at 37 °C for 48 h, and we tested APDT in the presence of 0.25% sodium dodecyl sulfate (SDS) in phosphate-buffered saline (PBS) or in PBS alone. APDT was carried out with 100 μM MB under laser radiation (PhotolaseIII, DMC, Brazil) at ʎ =660 nm and parameters as following (P =100 mW; I =250 mW/cm2, and doses of 15, 45 and 75 J/cm2). Following A-PDT, PBS groups of A. actinomycetemcomitans presented 4 Logs of microbial death after 5 min irradiation. However, there was no bacterial reduction in SDS groups. On the other hand, P. gingivalis was sensitive to APDT in the presence of 0.25% SDS with 2 logs reduction from dark toxicity. The presence of 0.25% SDS can lead to different responses depending on the different microbial species.

Proclivity of nervous system preservation in Cambrian Burgess Shale-type deposits.

Recent investigations on neurological tissues preserved in Cambrian fossils have clarified the phylogenetic affinities and head segmentation in pivotal members of stem-group Euarthropoda. However, palaeoneuroanatomical features are often incomplete or described from single exceptional specimens, raising concerns about the morphological interpretation of fossilized neurological structures and their significance for early euarthropod evolution. Here, we describe the central nervous system (CNS) of the short great-appendage euarthropod Alalcomenaeus based on material from two Cambrian Burgess Shale-type deposits of the American Great Basin, the Pioche Formation (Stage 4) and the Marjum Formation (Drumian). The specimens reveal complementary ventral and lateral views of the CNS, preserved as a dark carbonaceous compression throughout the body. The head features a dorsal brain connected to four stalked ventral eyes, and four pairs of segmental nerves. The first to seventh trunk tergites overlie a ventral nerve cord with seven ganglia, each associated with paired sets of segmental nerve bundles. Posteriorly, the nerve cord features elongate thread-like connectives. The Great Basin fossils strengthen the original description—and broader evolutionary implications—of the CNS in Alalcomenaeus from the early Cambrian (Stage 3) Chengjiang deposit of South China. The spatio-temporal recurrence of fossilized neural tissues in Cambrian Konservat-Lagerstätten across North America (Pioche, Burgess Shale, Marjum) and South China (Chengjiang, Xiaoshiba) indicates that their preservation is consistent with the mechanism of Burgess Shale-type fossilization, without the need to invoke alternative taphonomic pathways or the presence of microbial biofilms.

A Study of Infected Drivelines from Ventricular Assist Device Patients: The Presence of Microbial Biofilms and Micro-Gaps in the Driveline Tunnel

Purpose Driveline infections remain a major complication of ventricular assist device (VAD) implantation. This study aimed to characterize in vivo microbial biofilms causing driveline infections and the degree of tissue integration into the velour of explanted drivelines. Methods Drivelines were obtained from ten VAD patients undergoing heart transplantation at the Alfred Hospital, Melbourne and St Vincent Hospital, Sydney between June 2017 to October 2018. Four uninfected drivelines and six infected drivelines were aseptically sectioned into 10 pieces of 1.5 cm in length, from the smooth tube section at the exit site to the velour section adjacent to the VAD. Organisms on each section were isolated and identified. Microbial biofilms on the infected driveline sections were assessed using scanning electron microscopy (SEM) and viable counts. Computed tomography (micro-CT) and SEM were used to assess tissue integration into each section. All sections were analysed histologically to confirm human matrix protein deposition. Results No organisms were isolated from non-infected drivelines using microbiological culture. Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis were found on the velour sections of infected drivelines and correlated with the microbiological culture results from patient swabs of the infected exit site. Although histological analysis found considerable collagen fiber and fibroblast deposition on both the smooth tube and the velour, SEM and micro-CT suggested insufficient tissue integration throughout the driveline velour. Microgaps were observed between the velour fibres, with evidence of microbial biofilms within these gaps. Such biofilms were morphologically distinct from in vitro biofilms grown on biomaterials and might be responsible for the antimicrobial treatment failure. Conclusion This study demonstrated inadequate tissue integration of clinical drivelines in the subcutaneous tissue tunnel, with associated microbial biofilms formed within the microgaps between velour fibres. These data provide important insights into a potentially novel therapeutic strategy against driveline infections that is focused on enhancing tissue integration into the velour, thereby preventing microbial adherence, biofilm formation and migration.

Mixed community biofilms and microbially influenced corrosion

Metals are used in most marine infrastructures for energy extraction and production. Metal corrosion is a serious concern, due to the environmental, safety, and replacement costs associated with it. Microbially influenced corrosion (MIC) contributes to the overall corrosion process, through several chemical, electrochemical and biochemical mechanisms, particularly in the presence of microbial biofilms. In this short article, we discuss briefly recent advances in MIC research, comparing corrosion in single species and mixed species biofilms, and outline possible strategies for biofilm and corrosion control.

An in-vitro urinary catheterization model that approximates clinical conditions for evaluation of innovations to prevent catheter-associated urinary tract infections

Catheter-associated urinary tract infections (CAUTI) account for approximately 25% of nosocomial infections globally, and often result in increased morbidity and healthcare costs. An additional concern is the presence of microbial biofilms which are major reservoirs of bacteria, especially antibiotic-resistant bacteria, in catheters. Since introduction of the use of closed drainage systems, innovations to combat CAUTI have not led to significant improvements in clinical outcomes. The lack of a robust laboratory platform to test new CAUTI preventive strategies may impede development of novel technologies. To establish an in-vitro catheterization model (IVCM) for testing of technological innovations to prevent CAUTI. The IVCM consists of a continuous supply of urine medium flowing into a receptacle (bladder) where the urine is drained through a urinary catheter connected to an effluent collection vessel (drainage bag). Test organism(s) can be introduced conveniently into the bladder via a rubber septa port. Development of bacteriuria and microbial biofilm on the catheter can be determined subsequently. With an initial inoculum of Escherichia coli [∼5×105colony-forming units (cfu)/mL] into the bladder, a 100% silicone catheter and a commercially available silver-hydrogel catheter showed heavy biofilm colonization (∼108cfu/cm and ∼107cfu/cm, respectively) with similar bacterial populations in the urine (bacteriuria) (∼108cfu/mL and ∼107cfu/mL, respectively) within three days. Interestingly, an antimicrobial peptide (CP11-6A)-coated catheter showed negligible biofilm colonization and no detectable bacteriuria. The IVCM is a useful preclinical approach to evaluate new strategies for the prevention of CAUTI.

Antibiotic Release from Calcium Phosphate Materials in Oral and Maxillofacial Surgery. Molecular, Cellular and Pharmaceutical Aspects.

Calcium phosphate materials (CPM) are widely used in dentistry and maxillofacial surgery. The presence of microbial biofilms and external infections is responsible for the failure of many procedures of dental implants and bone grafts. In an attempt to reduce the percentage of these infectious processes antibiotics have been associated with CPM improving certain conditions. For instance, antibiotics administered orally or intravenously have less effect and the blood flow in relation to this is poor near implants and grafts. Tissue engineering (TE) has employed CPM as a local drug delivery vehicle to be more effective and efficient in bone infections. This review is presented to describe current antibiotics used and the physical and chemical properties of scaffolds.

Association of Microbial Growth on Silicone Breast Implants with Capsular Contracture: A Systematic Review

Background: Capsular contracture is the most common complication following breast implant surgery. Previous evidence suggests that the presence of microbial biofilms on and surrounding the implant may contribute to the development of contracture. Objective: Our goal was to systematically review the literature and summarize the evidence to date regarding the identification of biofilm-forming bacteria on breast implants and the association with capsular contracture. Furthermore, we aimed to describe specific microbial species associated with capsular contracture and assess if species correlates with contracture severity. Exposure and outcomes of included studies: 10 studies were included in the present review, consisting of cross sectional studies of patients undergoing breast implant removal, as well as experimental animal models. All studies assessed for the presence of microbial growth and subsequently assessed capsular contracture using the Baker’s scale. Conclusion: Results of all studies support the hypothesis that the presence of microbial biofilm is a major contributor to capsular contracture, with the primary causal species being Staphylococcus epidermidis and Propionibacterium acne, part of the normal breast flora. Better powered and better controlled studies are needed to further investigate this phenomenon in order to inform surgeons on how to mitigate the risk of capsular contracture for patients.

Early effects of Staphylococcus aureus biofilm secreted products on inflammatory responses of human epithelial keratinocytes.

BackgroundChronic wounds such as diabetic foot ulcers, pressure ulcers, and venous leg ulcers contribute to a considerable amount of mortality in the U.S. annually. The inability of these wounds to heal has now been associated with the presence of microbial biofilms. The aim of this study was to determine if products secreted by S. aureus biofilms play an active role in chronic wounds by promoting inflammation, which is a hallmark of chronic wounds.MethodsIn vitro experiments were conducted to examine changes in gene expression profiles and inflammatory response of human epithelial keratinocytes (HEKa) exposed to products secreted by S. aureus grown in biofilms or products secreted by S. aureus grown planktonically.ResultsAfter only two hours of exposure, gene expression microarray data showed marked differences in inflammatory, apoptotic, and nitric oxide responses between HEKa cells exposed to S. aureus biofilm conditioned media (BCM) and HEKa cells exposed to S. aureus planktonic conditioned media (PCM). As early as 4 hours post exposure, ELISA results showed significant increases in IL-6, IL-8, TNFα, and CXCL2 production by HEKa cells exposed to BCM compared to HEKa cells exposed to PCM or controls. Nitric oxide assay data also showed significant increases in nitric oxide production by HEKa cells treated with BCM compared to HEKa cells treated with PCM, or controls.ConclusionsTaken together, these results support and extend previous findings that indicate products secreted by S. aureus biofilms directly contribute to the chronic inflammation associated with chronic wounds.

Influence of Bacterial Extracellular Polymeric Substances on the Formation of Carbonaceous and Nitrogenous Disinfection Byproducts

Considering the regulatory presence of residual chlorine in water distribution systems, untreated organic matter may not be the sole contributor to disinfection byproduct (DBP) formation, given the presence of microbial biofilm with extracellular polymeric substances (EPS). This study investigated the influence of bacterial EPS on the formation of carbonaceous DBPs (C-DBPs) and nitrogenous DBPs (N-DBPs), reacting chlorine with Pseudomonas strains that produce different quantities and composition of EPS. When biomass is reacted in excess to chlorine, both C-DBPs and N-DBPs were produced without preference for speciation. However, under an excess of chlorine compared to biomass, increased EPS content led to enhanced formation of DBPs. The DBP yield of haloacetic acids (HAAs) was higher than that of trihalomethanes where dichloroacetic acid was dominant in HAA species. Additionally, chemical composition of EPS influenced the yields of DBPs. The N-DBP yield from P. putida EPS was two times higher than that of P. aeruginosa EPS, which suggested that higher organic nitrogen content in EPS contributes to higher N-DBP yield. Moreover, time-based experiments revealed that DBP formation from biomass occurs rapidly, reaching a maximum in less than four hours. Combined results suggest that bacterial EPS have significant roles in both the formation and fate of DBPs.

Sampling and detection of skin Propionibacterium acnes: Current status

A connection between acne vulgaris and Propionibacterium acnes has long been suggested. Over the years, several human skin microbiota sampling methods have been evolved and applied, e.g. swab, scrape, extraction techniques including cyanoacrylate gel sampling as well as punch biopsy. Collected samples have been processed following various methodologies ranging from culture studies to probe labelling and molecular analysis. Direct visualization techniques have recently shown the existence of anatomically distinct skin P. acnes populations: epidermal and follicular. P. acnes biofilms appear to be a common phenomenon. Current sampling approaches target different skin populations of P. acnes and the presence of microbial biofilms can influence the retrieval of P. acnes. The anatomical considerations must be taken into account while interpreting microbiological data.

Prevalência de Candida spp. em biofilme dentário de usuários de aparelhos ortodônticos fixos

OBJETIVOS: O presente estudo tem como objetivo avaliar a prevalência de Candida spp. em biofilme dentário de usuários de aparelhos ortodônticos fixos (AOF) e relacionar com seus hábitos e características.
 MATERIAIS E MÉTODOS: Foram isolados e identificados cepas de Candida em amostras de saliva em indivíduos usuários de AOF com presença de biofilme microbiano e indivíduos usuários de AOF mas sem presença de biofilme (grupo controle), a partir do cultivo em laboratório. 
 RESULTADOS: Neste estudo foram analisadas 108 amostras de indivíduos com biofilme, e 51 indivíduos no grupo controle. Das 108 amostras analisadas, 52 (48,1%) foram negativas para o gênero Candida e 56 (55,2%) foram positivas, sendo que em oito pacientes foram isolados duas espécies de Candida, quatro pacientes com C. albicans e C. krusei, um com C. albicans e C. tropicalis, um com C. albicans e C. glabrata, um com C. tropicalis e C. glabrata e um com C. tropicalis e C. krusei. No grupo controle 33,3% apresentaram isolamento de Candida, mesmo não apresentando biofilme.
 CONCLUSÃO: Foram detectadas espécies de Candida patogênicas e intrinsicamente resistentes aos convencionais antifúngicos, ressaltando a importância do diagnóstico micológico para um tratamento adequado das infecções causadas por este grupo de fungos presentes na cavidade oral dos indivíduos. 
 
 Palavras-chave: Candidíase oral, Candida spp., aparelho ortodôntico fixo.
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 ABSTRACT 
 OBJECTIVES: This study aims to evaluate the prevalence of Candida spp. in dental plaque of users of fixed orthodontic appliances (FOA) and relate to their habits and characteristics.
 MATERIALS AND METHODS: We isolated and identified strains of Candida in saliva samples from individuals using FOA with the presence of microbial biofilm and individuals without the presence of biofilm (control group) in the laboratory cultivation. 
 RESULTS: We analyzed 108 samples from individuals with biofilm and 51 individuals in the control group. Of the 108 samples analyzed, 52 (48.1%) were negative for Candida and 56 (55.2%) were positive, with eight patients were isolated two species of Candida, four patients with C. albicans and C. krusei, with one C. albicans and C. tropicalis, with one C. albicans and C. glabrata, with one C. tropicalis and C. glabrata and with one C. tropicalis and C. krusei. In the control group 33.3% had isolated Candida, even showing no biofilm.
 CONCLUSION: Were detected and pathogenic Candida species intrinsically resistant to conventional antifungal agents, emphasizing the importance of mycological diagnosis for appropriate treatment of infections caused by this group of fungi present in the oral cavity of individuals.
 
 Key-words: Oral Candidiasis, Candida spp., fixed orthodontic braces.
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Antimicrobial effects of azulene induced by light

Periodontal disease (PD) is a chronic inflammatory disease caused by the presence of microbial biofilm. The aim of this study was to evaluate antimicrobial effect of antimicrobial photodynamic therapy (A-PDT) mediated by methylene blue (MB) in monomer form on A. actinomycetemcomitans and P. gingivalis.A. actinomycetemcomitans ATCC 29523 and P. gingivalis ATCC 33577 were cultured on anaerobic jars at 37 °C for 48 h, and we tested APDT in the presence of 0.25% sodium dodecyl sulfate (SDS) in phosphate-buffered saline (PBS) or in PBS alone. APDT was carried out with 100 μM MB under laser radiation (PhotolaseIII, DMC, Brazil) at ʎ =660 nm and parameters as following (P =100 mW; I =250 mW/cm2, and doses of 15, 45 and 75 J/cm2).Following A-PDT, PBS groups of A. actinomycetemcomitans presented 4 Logs of microbial death after 5 min irradiation. However, there was no bacterial reduction in SDS groups. On the other hand, P. gingivalis was sensitive to APDT in the presence of 0.25% SDS with 2 logs reduction from dark toxicity.The presence of 0.25% SDS can lead to different responses depending on the different microbial species.

Evidence for microbial life in synsedimentary cavities from 2.75 Ga terrestrial environments

Fluviolacustrine sediments of the 2.75 Ga Hardey Formation (Fortescue Group, Australia) preserve pendant columnar structures with stromatolitic lamination within synsedimentary cavities. The millimeter-sized, finger-like columns strongly resemble microbialites from modern basaltic caves and indicate the likely presence of microbial biofilms. The ancient microbial columns are preserved by chert and locally occur as reworked clasts, indicating a near-depositional age for the structures. Sulfur isotopic analysis of pyrite in the columns and adjacent carbonaceous matrix yields δ34SCDT (CDT—Canyon Diablo troilite) values between −8.5‰ and +19‰, showing significant fractionation characteristic of biological cycling of sulfur. Organic matter in cavity ceilings and shale matrix has δ13CPDB (PDB—Peedee belemnite) values between −55‰ and −43‰, suggesting the presence of methanotrophs. Our results suggest that 2.75 Ga terrestrial environments supported a microbial ecosystem, including microbes that inhabited synsedimentary hollows, extending the fossil record of coelobionts by ~1.5 b.y. Subsurface cavities represent a new habitable microenvironment for early life on Earth, and an analogue for ancient life on Mars.

Substratum location and zoospore behaviour in the fouling alga Enteromorpha

The green alga Enteromorpha is the most important macroalga that fouls ships, submarines and underwater structures. Major factors in its success in colonising new substrata are the production of enormous numbers of swimming spores and their ability to locate surfaces on which to settle. Factors facilitating the settlement and adhesion of asexual zoospores are examined in this article. Settlement and adhesion may be regulated by topographical, biological, chemical and physico‐chemical cues, all of which are modified by the presence of microbial biofilm. The level of gregarious zoospore settlement is related to spore density and may be mediated by a number of external cues including fatty acids and ‘detritus’.