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Pasman R, Zhang J, Zaat SAJ, Brul S, Krom BP. A customizable and defined medium supporting culturing of Candida albicans, Staphylococcus aureus, and human oral epithelial cells. Appl Environ Microbiol 2024; 90:e0036024. [PMID: 39072650 PMCID: PMC11337806 DOI: 10.1128/aem.00360-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 06/27/2024] [Indexed: 07/30/2024] Open
Abstract
Candida albicans, an opportunistic oral pathogen, synergizes with Staphylococcus aureus, allowing bacteria to co-invade and systemically disseminate within the host. Studying human-microbe interactions creates the need for a universal culture medium that supports fungal, bacterial, and human cell culturing, while allowing sensitive analytical approaches such as OMICs and chromatography techniques. In this study, we established a fully defined, customizable adaptation of Dulbecco's modified Eagle medium (DMEM), allowing multi-kingdom culturing of S. aureus, C. albicans, and human oral cell lines, whereas minimal version of DMEM (mDMEM) did not support growth of S. aureus, and neither did supplementation with dextrose, MEM non-essential amino acids, pyruvate, and Glutamax. This new medium composition, designated as "mDMEM-DMP," promoted growth of all tested S. aureus strains. Addition of 25 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) further improved growth, while higher concentrations did not improve growth any further. Higher concentrations of HEPES did result in prolonged stabilization of medium pH. mDMEM-DMP promoted (hyphal) C. albicans monoculturing and co-culturing on both solid and semi-solid surfaces. In contrast to S. aureus, addition of HEPES reduced C. albicans maximum culture optical density (OD). Finally, only buffered mDMEM-DMP (100 mM HEPES) was successful in maintaining the metabolic activity of human oral Ca9-22 and HO1N1 cell lines for 24 hours. Altogether, our findings show that mDMEM-DMP is a versatile and potent culture medium for both microbial and human cell culturing, providing a customizable platform to study human as well as microbial molecular physiology and putative interactions. IMPORTANCE Interaction between microbes and the host are in the center of interest both in disease and in health. In order to study the interactions between microbes of different kingdoms and the host, alternative media are required. Synthetic media are useful as they allow addition of specific components. In addition, well-defined media are required if high-resolution analyses such as metabolomics and proteomics are desired. We describe the development of a synthetic medium to study the interactions between C. albicans, S. aureus, and human oral epithelial cells. Our findings show that mDMEM-DMP is a versatile and potent culture medium for both microbial and human cell culturing, providing a customizable platform to study human as well as microbial molecular physiology and putative interactions.
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Affiliation(s)
- Raymond Pasman
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Jianbo Zhang
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Sebastian A. J. Zaat
- Department of Medical Microbiology and Infection Prevention, Amsterdam institute for Infection and Immunity, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Stanley Brul
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Bastiaan P. Krom
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Free University Amsterdam, Amsterdam, the Netherlands
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Ardika KAR, Marzaman ANF, Kaharuddin KM, Parenden MDK, Karimah A, Musfirah CA, Pakki E, Permana AD. Development of chitosan-hyaluronic acid based hydrogel for local delivery of doxycycline hyclate in an ex vivo skin infection model. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2023; 34:2274-2290. [PMID: 37410591 DOI: 10.1080/09205063.2023.2234181] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/12/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023]
Abstract
Doxycycline hyclate (DOXY) is a tetracycline derivative known as the broad-spectrum bacteriostatic drug. DOXY has been suggested as the first-line antibiotic for diabetic foot ulcers (DFU). Unfortunately, the long-term availability of DOXY in both oral and conventional topical dosage forms reduces its therapeutic effectiveness, which is closely linked to gastrointestinal side effects and acute pain during therapy, as well as uncontrolled DOXY release at the wound site. To address these shortcomings, we present for the first time a DOXY hydrogel system (DHs) built on crosslinks between carboxymethyl chitosan (CMC) and aldehyde hyaluronic acid (AHA). Three formulations of DHs were developed with different ratios of CMC and AHA, consisting of F1 (3:7, w/w), F2 (5:5, w/w), and F3 (7:3, w/w). Viscosity, rheology, gel strength, pH, swelling, gel fraction, wettability, stability, in vitro drug release, ex vivo antibacterial, and dermatokinetic studies were used to evaluate the DHs. According to the in vitro release study, up to 85% of DOXY was released from DHs via the Fickian diffusion mechanism in the Korsmeyer-Peppas model (n < 0.45), which provides controlled drug delivery. Because of its excellent physicochemical characteristics, F2 was chosen as the best DHs formulation in this study. Essentially, the optimum DHs formulation could greatly improve DOXY's ex vivo dermatokinetic profile while also providing excellent antibacterial activity. As a consequence, this study had promising outcome as a proof of concept for increasing the efficacy of DOXY in clinical therapy. Further extensive in vivo studies are required to evaluate the efficacy of this approach.
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Affiliation(s)
| | | | | | | | - Aulia Karimah
- Faculty of Mathemathics and Natural Science, Hasanuddin University, Makassar, Indonesia
| | | | - Ermina Pakki
- Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia
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Chen T, Xu H, Yao X, Luo Z. Role of sodium pyruvate in maintaining the survival and cytotoxicity of Staphylococcus aureus under high glucose conditions. Front Microbiol 2023; 14:1209358. [PMID: 37405167 PMCID: PMC10315490 DOI: 10.3389/fmicb.2023.1209358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 06/02/2023] [Indexed: 07/06/2023] Open
Abstract
Glucose is a crucial carbon source for the growth of Staphylococcus aureus, but an excess of glucose is detrimental and even leads to cell death. Pyruvate, the central metabolite of glycolysis, has been shown to have anti-inflammatory and antioxidant properties. This study aimed to investigate the protective effect of pyruvate on S. aureus under high glucose conditions. Sodium pyruvate greatly increased the cytotoxicity of S. aureus strain BAA-1717 to human erythrocytes and neutrophils in vitro. However, the cytotoxicity and survival of S. aureus were significantly reduced by high glucose, which was restored to normal levels by the addition of sodium pyruvate. The expression of hlg and lukS in S. aureus was higher in the LB-GP cultures than that in LB-G cultures, but there was no significant difference in cytotoxicity between LB-GP and LB-G cultures. Furthermore, the hemolytic activity of S. aureus supernatants could be inhibited by the cell-free culture medium (CFCM) of LB-G cultures, suggesting that high levels of extracellular proteases were presence in the CFCM of LB-G cultures, resulting in degradation of the hemolytic factors. The expression of sarA, which negatively regulates extracellular protease secretion, was higher in LB-GP cultures than that in LB-G cultures. Additionally, sodium pyruvate increased acetate production in S. aureus, which helps maintain cell viability under acidic environment. In conclusion, pyruvate plays an important role in the survival and cytotoxicity of S. aureus under high glucose conditions. This finding may aid in the development of effective treatments for diabetic foot infections.
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Affiliation(s)
- Ti Chen
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Huan Xu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoyan Yao
- Department of Medical Laboratory Science, School of Medicine, Hunan Normal University, Changsha, China
| | - Zhen Luo
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
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Chen F, Yin Y, Chen H, Li S, Yin G, Wang H. mleS in Staphylococcus aureus Contributes to Microaerobic Metabolic Activity, Abscess Formation, and Survival in Macrophages. Microbiol Spectr 2023; 11:e0090923. [PMID: 37052483 PMCID: PMC10269618 DOI: 10.1128/spectrum.00909-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 03/24/2023] [Indexed: 04/14/2023] Open
Abstract
Staphylococcus aureus is subdivided into lineages termed sequence types (STs), infections of which necessitate the expression of virulence factors and metabolic adaptation to the host niche. Given that mechanisms underlying the dynamic replacement of sequence types in S. aureus populations have yet to be sufficiently determined, we investigated the role of metabolic determinants in epidemic clones. mleS, encoding the NAD+-dependent malolactic enzyme, was found to be carried by the epidemic clones ST59 and ST398, although not by ST239 and ST5. The genomic location of mleS in the metabolism-associated region flanked by the thiol-specific redox system and glycolysis operon implies that it plays significant roles in metabolism and pathogenesis. Mouse skin abscess caused by the BS19-mleS mutant strain (isogenic mleS mutant in an ST59 isolate) was significantly attenuated and associated with reductions in interleukin-6 (IL-6) and lactic acid production. mleS deletion also impaired S. aureus biofilm formation and survival in RAW264.7 cells. The BS19-mleS-mutant was also characterized by reduced ATP and lactic acid production under microaerobic conditions; however, NAD+/NADH levels remained unaffected. mleS is thus identified as an epidemiological marker that plays an important role in the microaerobic metabolism and pathogenesis of epidemic S. aureus clones. IMPORTANCE Given the importance of metabolic adaptation during infection, new insights are required regarding the pathogenesis of S. aureus, particularly for epidemic clones. We accordingly investigated the role of metabolic determinants that are unique to the epidemic clones ST59 and ST398. Our results provide evidence that the NAD+-dependent malolactic enzyme-coding gene mleS is an epidemiological marker that plays an important role in the microaerobic metabolism and pathogenesis of epidemic S. aureus clones.
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Affiliation(s)
- Fengning Chen
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Yuyao Yin
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
| | - Hongbin Chen
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
| | - Shuguang Li
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
| | - Guankun Yin
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
| | - Hui Wang
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China
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Suppression of Methicillin-Resistant Staphylococcus aureus and Reduction of Other Bacteria by Black Soldier Fly Larvae Reared on Potato Substrate. Microbiol Spectr 2022; 10:e0232122. [PMID: 36197291 PMCID: PMC9602475 DOI: 10.1128/spectrum.02321-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Larvae of black soldier flies, Hermetia illucens, are increasingly used for biological conversion of animal and plant wastes into ingredients of animal feeds on an industrial scale. The presence of pathogenic microorganisms in harvested larvae may be a serious problem for wide-scale adoption of this technology. Fortunately, black soldier fly larvae may have some antimicrobial properties. Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium associated with various environments that can be pathogenic to humans and farmed animals. We tested whether black soldier fly larvae suppress MRSA on potato substrate. Autoclaved potatoes containing black soldier fly larvae (P+BSFL), potatoes inoculated with MRSA and containing black soldier fly larvae (P+MRSA+BSFL), and potatoes inoculated with MRSA (P+MRSA) were incubated in glass jars. Substrate samples were taken after 3 and 7 days of incubation and plated on Trypticase soy agar (TSA) and Staphylococcus medium 110 agar (SA) to quantify total bacteria and MRSA, respectively. DNA was extracted from potato substrates on both days and sequenced to assess bacterial and fungal diversity using 515F/806R and internal transcribed spacer (ITS) 1/2 primers, respectively, and QIIME 2.0 software. Both total bacterial and MRSA-specific CFU were reduced in the presence of black soldier fly larvae, with a larger reduction for the latter. Twenty-five bacterial genera and 3 fungal genera were detected. Twenty bacterial genera were shared among the treatments and the days, but their relative abundances often varied. Among the most abundant genera, only Enterococcus and Lactococcus were universally present. Our findings confirm antimicrobial properties of black soldier fly larvae. IMPORTANCE Larvae of black soldier flies, Hermetia illucens, may be used to provide an environmentally sustainable and economically viable method for biological conversion of animal and plant wastes into ingredients of animal feeds on an industrial scale. However, contamination of harvested larvae by pathogenic microorganisms inhabiting decaying substrates may be a serious problem for wide-scale adoption of this technology. Fortunately, black soldier fly larvae may have some antimicrobial properties, including suppression of several common pathogens. Our study showed that such a suppression applies to methicillin-resistant Staphylococcus aureus, which is a ubiquitous bacterium pathogenic to animals (including humans).
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Investigation of the Mechanism and Chemistry Underlying Staphylococcus aureus ' Ability to Inhibit Pseudomonas aeruginosa Growth In Vitro. J Bacteriol 2022; 204:e0017422. [PMID: 36218351 DOI: 10.1128/jb.00174-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa inhibits or eradicates Staphylococcus aureus in most in vitro settings. Nonetheless, P. aeruginosa and S. aureus are commonly isolated from chronically infected, nonhealing wounds and lungs of people with cystic fibrosis (CF). Therefore, we hypothesized that S. aureus could protect itself from P. aeruginosa through glucose-derived metabolites, such as small organic acids, preventing it from being eradicated. This in vitro study demonstrated that S. aureus populations, in the presence of glucose, secrete one or more substances that efficiently eradicate P. aeruginosa in a concentration-dependent manner. These substances had a molecular mass lower than three kDa, were hydrophilic, heat- and proteinase-resistant, and demonstrated a pH-dependent effect. Nuclear magnetic resonance analysis identified acetoin, acetic acid, and oligopeptides or cyclic peptides in glucose-grown S. aureus supernatants. All the tested wild-type and clinical S. aureus strain inhibited P. aeruginosa growth. Thus, we proposed a model in which a cocktail of these compounds, produced by established S. aureus populations in glucose presence, facilitated these two species' coexistence in chronic infections. IMPORTANCE Chronic infections affect a growing part of the population and are associated with high societal and personal costs. Multiple bacterial species are often present in these infections, and multispecies infections are considered more severe than single-species infections. Staphylococcus aureus and Pseudomonas aeruginosa often coexist in chronic infections. However, the interactions between these two species and their coexistence in chronic infections are not fully understood. By exploring in vitro interactions, we found a novel S. aureus-mediated inhibition of P. aeruginosa, and we suggested a model of the coexistence of the two species in chronic infections. With this study, we enhanced our understanding of the pathogenesis of chronic multispecies infections, which is crucial to paving the way for developing improved treatment strategies.
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Squarzanti DF, Zanetta P, Ormelli M, Manfredi M, Barberis E, Vanella VV, Amoruso A, Pane M, Azzimonti B. An animal derivative-free medium enhances Lactobacillus johnsonii LJO02 supernatant selective efficacy against the methicillin (oxacillin)-resistant Staphylococcus aureus virulence through key-metabolites. Sci Rep 2022; 12:8666. [PMID: 35606510 PMCID: PMC9126979 DOI: 10.1038/s41598-022-12718-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 05/09/2022] [Indexed: 12/15/2022] Open
Abstract
The spread of multidrug-resistant bacteria, such as the skin commensal Staphylococcus aureus, is a worldwide health challenge; new methods to counteract opportunistic pathogen growth and virulence are urgent. We compared the activity of Lacticaseibacillus rhamnosus LR06 (DSM 21981) and Lactobacillus johnsonii LJO02 (DSM 33828) cell-free supernatants (CFSs) produced in the conventional animal derivative-based MRS medium and an innovative animal derivative-free broth (TIL) versus the MDR S. aureus (ATCC 43300). CFS influence was assessed towards the viability, metabolic activity, and ability to form biofilm of the MDR strain through optical density, alamarBlue assay, and crystal violet staining; their content in short-chain fatty acids, lactic acid, and proteins was analysed via high-resolution mass spectrometry and gas chromatography. All CFSs reduce viable and metabolically active S. aureus, being TIL more efficient compared to MRS in stimulating lactic acid bacteria metabolism and decreasing S. aureus biofilm formation. Particularly, the CFS from LJO02 grown in TIL has the best efficacy, revealing a high amount of lactic acid and 59 peculiar proteins; its effectiveness is partially maintained upon trypsin and proteinase K treatments, but not by pepsin and pH basification. Therefore, antagonistic CFSs may represent a strategic prevention approach, with bacteriotherapeutic and bio-repair potential.
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Affiliation(s)
- Diletta Francesca Squarzanti
- Laboratory of Applied Microbiology, Department of Health Sciences (DiSS), Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy
| | - Paola Zanetta
- Laboratory of Applied Microbiology, Department of Health Sciences (DiSS), Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy
| | - Margherita Ormelli
- Laboratory of Applied Microbiology, Department of Health Sciences (DiSS), Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy
| | - Marcello Manfredi
- Laboratory of Biological Mass Spectrometry, Department of Translational Medicine (DiMeT), Center for Translational Research On Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy
| | - Elettra Barberis
- Laboratory of Biological Mass Spectrometry, Department of Translational Medicine (DiMeT), Center for Translational Research On Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy
| | - Virginia Vita Vanella
- Laboratory of Biological Mass Spectrometry, Department of Translational Medicine (DiMeT), Center for Translational Research On Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy
| | - Angela Amoruso
- Probiotical Research S.R.L, Via Mattei 3, 28100, Novara, Italy
| | - Marco Pane
- Probiotical Research S.R.L, Via Mattei 3, 28100, Novara, Italy
| | - Barbara Azzimonti
- Laboratory of Applied Microbiology, Department of Health Sciences (DiSS), Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), School of Medicine, Università del Piemonte Orientale (UPO), Corso Trieste 15/A, 28100, Novara, Italy.
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Deutch CE. Moving a Journal Article-Based Upper-Level Microbiology Dry Lab from In-Person to Online Instruction. JOURNAL OF MICROBIOLOGY & BIOLOGY EDUCATION 2021; 22:jmbe-22-32. [PMID: 33884074 PMCID: PMC8012045 DOI: 10.1128/jmbe.v22i1.2521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
During the spring semester of 2020, a journal article-based upper-level microbiology laboratory course was offered through Western New Mexico University at Glendale Community College in Glendale, AZ. Because most of the students had taken a lower-level microbiology class with a traditional wet laboratory, a dry lab format was used instead. In the first period of each 2-week cycle, a microbiology article selected by the instructor from the primary literature was discussed using a PowerPoint presentation and a detailed study sheet. Students then turned in answers to five specific questions about the article. In the second period of each 2-week cycle, students met to discuss possible research projects based on that article. They then turned in a two- to three-page research proposal describing their project. Before the COVID-19 pandemic became severe and the college moved to online instruction, there were active discussions between the instructor and the students in both class periods. After the campus was shut down, discussions of the journal articles and preparation of the research proposals were done online using Canvas as the learning platform. Students were provided with discussion sites, but no video instruction systems were used. In general, the answers to the journal article questions and the quality of the research proposals were better during in-person instruction. Instructors may be able to adapt this journal article-based lab approach to a fully online format, but it will require extensive training and the use of Zoom or other video instruction methods.
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Luo Z, Yue S, Chen T, She P, Wu Y, Wu Y. Reduced Growth of Staphylococcus aureus Under High Glucose Conditions Is Associated With Decreased Pentaglycine Expression. Front Microbiol 2020; 11:537290. [PMID: 33224107 PMCID: PMC7667020 DOI: 10.3389/fmicb.2020.537290] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 10/07/2020] [Indexed: 11/13/2022] Open
Abstract
The high-glucose-induced cytotoxicity in diabetes has been widely recognized. Staphylococcus aureus is the most frequent pathogen isolated from diabetic foot ulcers, but the properties of this bacterium under high glucose conditions remain unclear. S. aureus grew in medium usually forms weak biofilm, and which was significantly increased by addition of glucose. However, extracellular DNA (eDNA), an important component of biofilms, was markedly decreased in presence of 15 mM glucose. The reduced eDNA content was not caused by degradation, because the nuclease activity of biofilm supernatants with glucose was significantly decreased due to the acidic pH of the medium. Under planktonic state, the growth of S. aureus was significantly decreased in the Luria-Bertani (LB) medium supplemented with 25 mM glucose, and the reduced growth of S. aureus by glucose was dose-dependent. Except for glucose, the growth of planktonic S. aureus was also markedly decreased by fructose or sucrose. Amounts of acid metabolites were produced under high glucose conditions, but the survival of planktonic S. aureus was unaffected by these acidic conditions. Cells of S. aureus from the culture medium with glucose had a thinner cell wall and highly resistant to lysostaphin compared with the bacteria cultured in LB medium. mRNA expression of genes encoding pentaglycine bridges, the substrate of lysostaphin, was significantly decreased in S. aureus by glucose. In addition to S. aureus, the growth of Staphylococcus haemolyticus and Staphylococcus epidermidis was also significantly decreased by an excess of glucose, but strains of Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa were unaffected by glucose. In conclusion, the reduced growth of S. aureus under high glucose conditions is due to impairment of the unique cell-wall structure, pentaglycine bridges.
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Affiliation(s)
- Zhen Luo
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Shan Yue
- Department of Laboratory Medicine, Hunan Normal University School of Medicine, Changsha, China
| | - Ti Chen
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Pengfei She
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yuan Wu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yong Wu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
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Xiao X, Zhao W, Liang J, Sauer K, Libera M. Self-defensive antimicrobial biomaterial surfaces. Colloids Surf B Biointerfaces 2020; 192:110989. [PMID: 32361372 PMCID: PMC7308212 DOI: 10.1016/j.colsurfb.2020.110989] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/11/2020] [Accepted: 03/23/2020] [Indexed: 01/16/2023]
Abstract
Self-defensive biomaterial surfaces are being developed in order to mitigate infection associated with tissue-contacting biomedical devices. Such infection occurs when microbes colonize the surface of a device and proliferate into a recalcitrant biofilm. A key intervention point centers on preventing the initial colonization. Incorporating antimicrobials within a surface coating can be very effective, but the traditional means of antimicrobial delivery by continuous elution can often be counterproductive. If there is no infection, continuous elution creates conditions that promote the development of resistant microbes throughout the patient. In contrast, a self-defensive coating releases antimicrobial only when and only where there is a microbial challenge to the surface. Otherwise, the antimicrobial remains sequestered within the coating and does not contribute to the development of resistance. A self-defensive surface requires a local trigger that signals the microbial challenge. Three such triggers have been identified as: (1) local pH lowering; (2) local enzyme release; and (3) direct microbial-surface contact. This short review highlights the need for self-defensive surfaces in the general context of the device-infection problem and then reviews key biomaterials developments associated with each of these three triggering mechanisms.
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Affiliation(s)
- Xixi Xiao
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, USA
| | - Wenhan Zhao
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, USA
| | - Jing Liang
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, USA
| | - Karin Sauer
- Binghamton Biofilm Research Center (BBRC), Binghamton University Binghamton, NY USA
| | - Matthew Libera
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, USA.
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