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Hui Y, Liu R, Lan J, Sun T, Xu A. Recyclable chitosan adsorbent: Facile functionalization strategy, excellent removal capacity of dyes and adsorption mechanism. CHEMOSPHERE 2024; 359:142291. [PMID: 38750728 DOI: 10.1016/j.chemosphere.2024.142291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/18/2024] [Accepted: 05/07/2024] [Indexed: 05/19/2024]
Abstract
The development of chitosan-based adsorbents with facile preparation, high adsorption performance and reusability for the removal of contaminant dyes remains a persistent challenge. To overcome this challenge, herein, we have developed a novel and extremely facile one-step strategy by which a new high-performance chitosan/polyethyleneimine/polyethylene glycol diglycidyl ether adsorbent (named as CC/PEI/PGDE) has been successfully fabricated via direct functionalization of CC by PEI at ambient temperature followed by subsequent freeze-drying. The Box-Behnken Design was employed to optimize the concentrations of adsorbent components. Attractively, this adsorbent exhibit outstanding adsorption performances to congo red (RED), acid blue-25 (BLUE) and amino black-10B (BLACK) with 2901 mg g-1 (90.9 %), 3434 mg g-1 (90.9 %), and 1438 mg g-1 (90.1 %) of adsorption capacities (removal efficiencies), respectively, and maintains nearly the same adsorption behaviors to original adsorbent even after 6 cycles of adsorption-desorption processes. Meanwhile, three kinetic models, three isothermal models, and the Vant Hoff model are employed to further investigate the adsorption behaviors of RED, BLUE, and BLACK dyes by CC/PEI/PGDE. The results from SEM, EDS, BET, FT-IR, pHZPC and XPS confirm that hydrogen bond interactions and electrostatic attractions play crucial roles in facilitating dyes adsorption by CC/PEI/PGDE. It is expected that this work can bring forward a new perspective for the facile design of high-performance adsorbent for removing anionic dyes from wastewater.
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Affiliation(s)
- Yao Hui
- School of Chemistry and Chemical Engineering, Henan University of Science and Technology, Luoyang, Henan, 471003, PR China
| | - Rukuan Liu
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Jingwen Lan
- School of Chemistry and Chemical Engineering, Henan University of Science and Technology, Luoyang, Henan, 471003, PR China
| | - Tiantian Sun
- School of Chemistry and Chemical Engineering, Henan University of Science and Technology, Luoyang, Henan, 471003, PR China
| | - Airong Xu
- School of Chemistry and Chemical Engineering, Henan University of Science and Technology, Luoyang, Henan, 471003, PR China.
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Desai SK, Zhou Y, Dilawari R, Routh AL, Popov V, Kenney LJ. RpoS activates formation of Salmonella Typhi biofilms and drives persistence in the gall bladder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.26.564249. [PMID: 37961640 PMCID: PMC10634867 DOI: 10.1101/2023.10.26.564249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The development of strategies for targeting the asymptomatic carriage of Salmonella Typhi in chronic typhoid patients has suffered owing to our basic lack of understanding of the molecular mechanisms that enable the formation of S. Typhi biofilms. Traditionally, studies have relied on cholesterol-attached biofilms formed by a closely related serovar, Typhimurium, to mimic multicellular Typhi communities formed on human gallstones. In long-term infections, S. Typhi adopts the biofilm lifestyle to persist in vivo and survive in the carrier state, ultimately leading to the spread of infections via the fecal-oral route of transmission. In the present work, we studied S. Typhi biofilms directly, applied targeted as well as genome-wide genetic approaches to uncover unique biofilm components that do not conform to the CsgD-dependent pathway established in S. Typhimurium. We undertook a genome-wide Tn5 mutation screen in a highly successful parental lineage of S. Typhi, strain H58, in gallstone-mimicking conditions. We generated New Generation Sequencing libraries based on the ClickSeq technology to identify the key regulators, IraP and RpoS, and the matrix components as Sth fimbriae, Vi capsule and lipopolysaccharide. We discovered that the starvation sigma factor, RpoS, was required for the transcriptional activation of matrix-encoding genes in vitro, and for S. Typhi colonization in persistent infections in vivo, using a heterologous fish larval model. An rpoS null mutant failed to colonize the gall bladder in chronic zebrafish infections. Overall, our work uncovered a novel RpoS-driven paradigm for the formation of cholesterol-attached Typhi biofilms, and emphasized the role(s) of stress signaling pathways for adaptation in chronic infections. Our identification of the biofilm regulators in S. Typhi paves the way for the development of drugs against typhoid carriage, which will ultimately control the increased incidence of gall bladder cancer in typhoid carriers.
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Supernak M, Makurat-Kasprolewicz B, Kaczmarek-Szczepańska B, Pałubicka A, Sakowicz-Burkiewicz M, Ronowska A, Wekwejt M. Chitosan-Based Membranes as Gentamicin Carriers for Biomedical Applications-Influence of Chitosan Molecular Weight. MEMBRANES 2023; 13:542. [PMID: 37367746 DOI: 10.3390/membranes13060542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/05/2023] [Accepted: 05/15/2023] [Indexed: 06/28/2023]
Abstract
Over the past decade, much attention has been paid to chitosan as a potential drug carrier because of its non-toxicity, biocompatibility, biodegradability and antibacterial properties. The effect of various chitosan characteristics on its ability to carry different antibiotics is discussed in the literature. In this work, we evaluated the influence of the different molecular weights of this polymer on its potential as an antibacterial membrane after adding gentamicin (1% w/w). Three types of chitosan membranes without and with antibiotic were prepared using a solvent casting process. Their microstructures were analyzed with a 4K digital microscope, and their chemical bonds were studied using FTIR spectroscopy. Furthermore, cytocompatibility on human osteoblasts and fibroblasts as well as antibacterial activity against Staphylococcus aureus (S. aureus.) and Escherichia coli (E. coli) were assessed. We observed that the membrane prepared from medium-molecular-weight chitosan exhibited the highest contact angle (≈85°) and roughness (10.96 ± 0.21 µm) values, and its antibacterial activity was unfavorable. The maximum tensile strength and Young's modulus of membranes improved and elongation decreased with an increase in the molecular weight of chitosan. Membranes prepared with high-molecular-weight chitosan possessed the best antibacterial activity, but mainly against S. aureus. For E. coli, is not advisable to add gentamicin to the chitosan membrane, or it is suggested to deplete its content. None of the fabricated membranes exhibited a full cytotoxic effect on osteoblastic and fibroblast cells. Based on our results, the most favorable membrane as a gentamicin carrier was obtained from high-molecular-weight chitosan.
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Affiliation(s)
- Milena Supernak
- Institute of Naval Architecture and Ocean Engineering, Gdańsk University of Technology, 80-233 Gdańsk, Poland
| | - Balbina Makurat-Kasprolewicz
- Department of Materials Science and Technology, Faculty of Mechanical Engineering and Ship Technology, Gdańsk University of Technology, 80-233 Gdańsk, Poland
| | - Beata Kaczmarek-Szczepańska
- Department of Biomaterials and Cosmetics Chemistry, Faculty of Chemistry, Nicolaus Copernicus University in Torun, 87-100 Toruń, Poland
| | - Anna Pałubicka
- Department of Laboratory Diagnostics and Microbiology with Blood Bank, Specialist Hospital in Kościerzyna, 83-400 Kościerzyna, Poland
| | | | - Anna Ronowska
- Department of Laboratory Medicine, Medical University of Gdańsk, 80-210 Gdańsk, Poland
| | - Marcin Wekwejt
- Department of Biomaterials Technology, Faculty of Mechanical Engineering and Ship Technology, Gdańsk University of Technology, 80-233 Gdańsk, Poland
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Malika M, Pargaonkar A, Sonawane SS. Application of emulsion nanofluid membrane for the removal of methylene blue dye: stability study. CHEMICAL PAPERS 2023. [DOI: 10.1007/s11696-023-02757-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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Kempf F, La Ragione R, Chirullo B, Schouler C, Velge P. Super Shedding in Enteric Pathogens: A Review. Microorganisms 2022; 10:2101. [PMID: 36363692 PMCID: PMC9692634 DOI: 10.3390/microorganisms10112101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 06/24/2024] Open
Abstract
Super shedding occurs when a small number of individuals from a given host population shed high levels of a pathogen. Beyond this general definition, various interpretations of the shedding patterns have been proposed to identify super shedders, leading to the description of the super shedding phenomenon in a wide range of pathogens, in particular enteric pathogens, which are of considerable interest. Several underlying mechanisms may explain this observation, including factors related to the environment, the gut microbiota, the pathogen itself (i.e., genetic polymorphism), and the host (including immune factors). Moreover, data suggest that the interplay of these parameters, in particular at the host-pathogen-gut microbiota interface, is of crucial importance for the determination of the super shedding phenotype in enteric pathogens. As a phenomenon playing an important role in the epidemics of enteric diseases, the evidence of super shedding has highlighted the need to develop various control strategies.
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Affiliation(s)
- Florent Kempf
- INRAE, Université de Tours, ISP, F-37380 Nouzilly, France
| | - Roberto La Ragione
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Barbara Chirullo
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 000161 Rome, Italy
| | | | - Philippe Velge
- INRAE, Université de Tours, ISP, F-37380 Nouzilly, France
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Shatila F, Yaşa İ, Yalçın HT. Biofilm Formation by Salmonella enterica Strains. Curr Microbiol 2021; 78:1150-1158. [PMID: 33609163 DOI: 10.1007/s00284-021-02373-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
Abstract
Biofilm formation by five different Salmonella enterica strains was assessed qualitatively and quantitatively under different incubation conditions. The strains exhibited different adherence abilities to test tubes. The isolates revealed Red Dry and Rough (RDAR) and Brown Dry and Rough (BDAR) morphotypes when cultured on Congo Red Agar (CRA). The pellicles formed by the tested strains ranged from strong to fragile when incubated in LB without NaCl at 27 °C. Smooth and White (SAW) morphotype on CRA and very weak pellicles were observed when the bacterial strains were incubated at 37 °C. The effect of temperature and media on biofilm formation by the tested strains was significant. Among the five Salmonella isolates, S. enteritidis TM 6 and S. enteritidis TM 68 formed strong biofilms when incubated in LB without NaCl at 27 °C for 24 h and consequently selected to be analysed under scanning electron microscope (SEM). Scanning electron micrographs revealed that S. enteritidis TM 6 formed more complex colonies when compared to those formed by S. enteritidis TM 68. As far as we know, this is the first study that provides quantitative and qualitative data for 5 Salmonella enterica isolates in different media mimicking four different nutritional conditions at two different temperatures after 24 and 48 h. The strains included two serovars S. bredeney and S. anatum, which are rarely accounted for. Additionally, the studies that described S. enteritidis biofilms under SEM are extremely limited, which makes it among the first comprehensive studies that screened for S. enteritidis biofilms.
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Krishna D, Dhanashree B. Antibiogram, Virulence Genes, and Biofilm-Forming Ability of Clinical Salmonella enterica Serovars: An In Vitro Study. Microb Drug Resist 2020; 27:871-878. [PMID: 33305986 DOI: 10.1089/mdr.2020.0419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica serovar Typhi and Salmonella Paratyphi are causative agents of enteric fever. Salmonella Typhi persists as a biofilm on gallstones. Hence, we studied the biofilm formation, antibiogram, and virulence genes of S. enterica serovars. Antibiogram of S. enterica serovars from human blood and stool samples were studied by Kirby-Bauer disk diffusion method and biofilm by microtiter plate method. We studied the minimum inhibitory concentration of the isolates by Vitek-2 semiautomated system. Polymerase chain reaction was done to detect invA and spvC genes. Of the 55 isolates studied, 36 (65.45%) were Salmonella Typhi, 13 (23.63%) were Salmonella Paratyphi A, 2 (3.64%) were Salmonella Typhimurium, and 4 (7.28%) were Salmonella spp. Resistance to ciprofloxacin and nalidixic acid were found to be 81.8% and 92.7%, respectively. Chloramphenicol and cotrimoxazole-susceptible strains were 98.18%. One each of Salmonella Typhi, Salmonella Paratyphi A, and S. enterica isolates formed weak biofilm at 28°C. However, at 37°C eight Salmonella Typhi produced weak biofilm in the presence of bile. One Salmonella Paratyphi A and two Salmonella spp. formed weak biofilm in the absence of bile. All the isolates had the invA gene. Salmonella Typhimurium had invA and spvC genes. Bile may contribute to biofilm formation and persistence of the Salmonella Typhi on gallstones, which may lead to carrier state. Changing antibiotic susceptibility pattern of Salmonella serovars is observed in our geographic area. The presence of invA and spvC genes indicate the ability of invasiveness and intracellular survival.
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Affiliation(s)
- Dhiraj Krishna
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Mangalore, India
| | - Biranthabail Dhanashree
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Mangalore, India
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Balakrishnan S, Ibrahim KS, Duraisamy S, Sivaji I, Kandasamy S, Kumarasamy A, Kumar NS. Antiquorum sensing and antibiofilm potential of biosynthesized silver nanoparticles of Myristica fragrans seed extract against MDR Salmonella enterica serovar Typhi isolates from asymptomatic typhoid carriers and typhoid patients. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:2844-2856. [PMID: 31836973 DOI: 10.1007/s11356-019-07169-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Globally, Salmonella infection poses a major public health problem. Here, we report antibiofilm activity and quorum sensing inhibition of aqueous seeds extract of Myristica fragrans (nutmeg) and biosynthesized silver nanoparticles (AgNPs) against multidrug resistant (MDR) Salmonella enterica serovar Typhi (S. Typhi) isolated from typhoid patients and asymptomatic carriers. S. Typhi isolates revealed higher percentage (46%) of biofilm production identified by tissue culture plate (TCP) than Congo red agar (CRA) and tube adherence (TA) methods. The inhibition of biofilm-producing MDR S. Typhi isolates and pigment production of Chromobacterium violaceum (indicator bacteria) demonstrated the quorum sensing potential of nutmeg. The aqueous seed extract of nutmeg exhibited 87% of antibiofilm activity, while the biosynthesized AgNPs showed 99.1% of antibiofilm activity. Molecular docking studies of bioactive compounds of nutmeg against transcriptional regulatory protein RcsB and sensor kinase protein RcsC revealed interaction with the target proteins. It is proposed that biosynthesized AgNPs could be used as one of the effective candidates in treating asymptomatic typhoid carriers or typhoid patients and to control the subsistence of biofilm-producing S. Typhi strains or other pathogenic bacteria in the environment or industrial settings.
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Affiliation(s)
- Senthilkumar Balakrishnan
- Department of Medical Microbiology, College of Health and Medical Sciences, Haramaya University, Harar Campus, P.O. Box 235, Harar, Ethiopia.
| | - Kalibulla Syed Ibrahim
- PG and Research Department of Botany, PSG College of Arts & Science, Coimbatore, Tamil Nadu, 641014, India
- Department of Biotechnology, Mizoram University, Aizawl, Mizoram, 796004, India
| | - Senbagam Duraisamy
- Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620024, India
| | - Ilakkia Sivaji
- Department of Biotechnology, Muthayammal College of Arts & Science, Rasipuram, Tamil Nadu, 637408, India
| | - Selvam Kandasamy
- PG & Research Department of Biotechnology, Mahendra Arts and Science College (Autonomous), Kalippatti, Tamil Nadu, 637501, India
| | - Anbarasu Kumarasamy
- Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620024, India
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Molecular Detection, Virulence Genes, Biofilm Formation, and Antibiotic Resistance of Salmonella enterica Serotype enteritidis Isolated from Poultry and Clinical Samples. Jundishapur J Microbiol 2018. [DOI: 10.5812/jjm.69504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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10
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Dantas STA, Rossi BF, Bonsaglia ECR, Castilho IG, Hernandes RT, Fernandes A, Rall VLM. Cross-Contamination and Biofilm Formation by Salmonella enterica Serovar Enteritidis on Various Cutting Boards. Foodborne Pathog Dis 2018; 15:81-85. [DOI: 10.1089/fpd.2017.2341] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Stéfani T. A. Dantas
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
| | - Bruna F. Rossi
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
| | - Erika C. R. Bonsaglia
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
| | - Ivana G. Castilho
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
| | - Rodrigo T. Hernandes
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
| | - Ary Fernandes
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
| | - Vera L. M. Rall
- Department of Microbiology and Immunology, Institute of Biosciences of Botucatu, Sao Paulo State University, Sao Paulo, Brazil
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González JF, Alberts H, Lee J, Doolittle L, Gunn JS. Biofilm Formation Protects Salmonella from the Antibiotic Ciprofloxacin In Vitro and In Vivo in the Mouse Model of chronic Carriage. Sci Rep 2018; 8:222. [PMID: 29317704 PMCID: PMC5760579 DOI: 10.1038/s41598-017-18516-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/13/2017] [Indexed: 12/05/2022] Open
Abstract
Typhoid fever is caused by the human-restricted pathogen Salmonella enterica sv. Typhi. Approximately 5% of people that resolve the disease become chronic carriers, with the gallbladder as the main reservoir of the bacteria. Of these, about 90% present with gallstones, on which Salmonella form biofilms. Because S. Typhi is a human-restricted pathogen, these carriers are the main source of dissemination of the disease; unfortunately, antibiotic treatment has shown to be an ineffective therapy. This is believed to be caused by the inherent antibiotic resistance conferred by Salmonella biofilms growing on gallstones. The gallstone mouse model with S. Typhimurium has proven to be an excellent surrogate for S. Typhi chronic infection. In this study, we test the hypothesis that the biofilm state confers Salmonella with the increased resistance to antibiotics observed in cases of chronic carriage. We found that, in the biofilm state, Salmonella is significantly more resistant to ciprofloxacin, a common antibiotic used for the treatment of Salmonella, both in vitro (p < 0.001 for both S. Typhi and S. Typhimurium with respect to planktonic cells) and in vivo (p = 0.0035 with respect to control mice).
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Affiliation(s)
- Juan F González
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
| | - Halley Alberts
- School of Mathematics and Natural Sciences, University of Rio Grande, P.O. Box 500, Rio Grande, OH, USA
| | - Joel Lee
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
| | - Lauren Doolittle
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
| | - John S Gunn
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA.
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Kantele A. Should close contacts of returning travellers with typhoid fever be protected by vaccination? Vaccine 2015; 33:1419-21. [PMID: 25678244 DOI: 10.1016/j.vaccine.2015.01.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 01/13/2015] [Accepted: 01/20/2015] [Indexed: 10/24/2022]
Abstract
Increasing international travel to areas endemic for typhoid fever correlates with increased risk for travellers to contract the disease. At home, the acutely ill/convalescent patients may pose some risk to their close contacts. In Finland an unofficial guideline suggests vaccination for close contacts of patients with acute typhoid fever; in other developed countries, routine typhoid vaccinations are only recommended to contacts of chronic carriers. This paper discusses the possibilities and limitations of prophylactic/post-exposure typhoid vaccination for contacts of patients with acute disease.
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Affiliation(s)
- A Kantele
- Inflammation Center, Clinic of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Finland; Department of Clinical Medicine, University of Helsinki, Helsinki, Finland.
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Structural and evolutionary analyses show unique stabilization strategies in the type IV pili of Clostridium difficile. Structure 2015; 23:385-96. [PMID: 25599642 DOI: 10.1016/j.str.2014.11.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 11/18/2014] [Accepted: 11/22/2014] [Indexed: 01/17/2023]
Abstract
Type IV pili are produced by many pathogenic Gram-negative bacteria and are important for processes as diverse as twitching motility, biofilm formation, cellular adhesion, and horizontal gene transfer. However, many Gram-positive species, including Clostridium difficile, also produce type IV pili. Here, we identify the major subunit of the type IV pili of C. difficile, PilA1, and describe multiple 3D structures of PilA1, demonstrating the diversity found in three strains of C. difficile. We also model the incorporation of both PilA1 and a minor pilin, PilJ, into the pilus fiber. Although PilA1 contains no cysteine residues, and therefore cannot form the disulfide bonds found in all Gram-negative type IV pilins, it adopts unique strategies to achieve a typical pilin fold. The structures of PilA1 and PilJ exhibit similarities with the type IVb pilins from Gram-negative bacteria that suggest that the type IV pili of C. difficile are involved in microcolony formation.
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Perni S, Preedy EC, Prokopovich P. Success and failure of colloidal approaches in adhesion of microorganisms to surfaces. Adv Colloid Interface Sci 2014; 206:265-74. [PMID: 24342736 DOI: 10.1016/j.cis.2013.11.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/31/2022]
Abstract
Biofilms are communities of cells attached to surfaces, their contributions to biological process may be either a benefit or a threat depending on the microorganism involved and on the type of substrate and environment. Biofilm formation is a complex series of steps; due to the size of microorganisms, the initial phase of biofilm formation, the bacterial adhesion to the surface, has been studied and modeled using theories developed in colloidal science. In this review the application of approaches such as Derjaguin, Landau, Verwey, Overbeek (DLVO) theory and its extended version (xDLVO), to bacterial adhesion is described along with the suitability and applicability of such approaches to the investigation of the interface phenomena regulating cells adhesion. A further refinement of the xDLVO theory encompassing the brush model is also discussed. Finally, the evidences of phenomena neglected in colloidal approaches, such as surface heterogeneity and fluid flow, likely to be the source of failure are defined.
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Gopinath S, Carden S, Monack D. Shedding light on Salmonella carriers. Trends Microbiol 2012; 20:320-7. [DOI: 10.1016/j.tim.2012.04.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 04/03/2012] [Accepted: 04/10/2012] [Indexed: 01/10/2023]
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