1
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Clarke OE, Pelling H, Bennett V, Matsumoto T, Gregory GE, Nzakizwanayo J, Slate AJ, Preston A, Laabei M, Bock LJ, Wand ME, Ikebukuro K, Gebhard S, Sutton JM, Jones BV. Lipopolysaccharide structure modulates cationic biocide susceptibility and crystalline biofilm formation in Proteus mirabilis. Front Microbiol 2023; 14:1150625. [PMID: 37089543 PMCID: PMC10113676 DOI: 10.3389/fmicb.2023.1150625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/06/2023] [Indexed: 04/08/2023] Open
Abstract
Chlorhexidine (CHD) is a cationic biocide used ubiquitously in healthcare settings. Proteus mirabilis, an important pathogen of the catheterized urinary tract, and isolates of this species are often described as "resistant" to CHD-containing products used for catheter infection control. To identify the mechanisms underlying reduced CHD susceptibility in P. mirabilis, we subjected the CHD tolerant clinical isolate RS47 to random transposon mutagenesis and screened for mutants with reduced CHD minimum inhibitory concentrations (MICs). One mutant recovered from these screens (designated RS47-2) exhibited ~ 8-fold reduction in CHD MIC. Complete genome sequencing of RS47-2 showed a single mini-Tn5 insert in the waaC gene involved in lipopolysaccharide (LPS) inner core biosynthesis. Phenotypic screening of RS47-2 revealed a significant increase in cell surface hydrophobicity and serum susceptibility compared to the wildtype, and confirmed defects in LPS production congruent with waaC inactivation. Disruption of waaC was also associated with increased susceptibility to a range of other cationic biocides but did not affect susceptibility to antibiotics tested. Complementation studies showed that repression of smvA efflux activity in RS47-2 further increased susceptibility to CHD and other cationic biocides, reducing CHD MICs to values comparable with the most CHD susceptible isolates characterized. The formation of crystalline biofilms and blockage of urethral catheters was also significantly attenuated in RS47-2. Taken together, these data show that aspects of LPS structure and upregulation of the smvA efflux system function in synergy to modulate susceptibility to CHD and other cationic biocides, and that LPS structure is also an important factor in P. mirabilis crystalline biofilm formation.
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Affiliation(s)
- O. E. Clarke
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - H. Pelling
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - V. Bennett
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - T. Matsumoto
- Department of Biotechnology and Life Sciences, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - G. E. Gregory
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - J. Nzakizwanayo
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - A. J. Slate
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - A. Preston
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - M. Laabei
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - L. J. Bock
- United Kingdom Health Security Agency, Salisbury, United Kingdom
| | - M. E. Wand
- United Kingdom Health Security Agency, Salisbury, United Kingdom
| | - K. Ikebukuro
- Department of Biotechnology and Life Sciences, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - S. Gebhard
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - J. M. Sutton
- United Kingdom Health Security Agency, Salisbury, United Kingdom
| | - B. V. Jones
- Department of Life Sciences, University of Bath, Bath, United Kingdom
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2
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The source of carbon and nitrogen differentially affects the survival of Neisseria meningitidis in macrophages and epithelial cells. Arch Microbiol 2022; 204:404. [PMID: 35723778 DOI: 10.1007/s00203-022-03037-y] [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: 02/12/2022] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 11/02/2022]
Abstract
Neisseria meningitidis is a commensal of human nasopharynx which under certain unidentified conditions could lead to fulminant meningitis or sepsis. Availability of nutrients is essential for bacterial growth and virulence. The metabolic adaptations allow N. meningitidis to utilize host resources, colonize and cause virulence functions which are a crucial for the invasive infection. During colonization meningococci encounters a range of microenvironments involving fluctuations in the availability of carbon and nitrogen source. Therefore, the characterization of virulence factors of N. meningitidis under different microenvironmental conditions is a prime requisite to understand pathogenesis; however, the role of nutrients is not well understood. Here, we explore the expression of virulence phenotype leading to symptomatic behaviour as affected by available carbon and nitrogen sources. We evaluate the effect of carbon or nitrogen source on growth, adhesion to epithelial cells, macrophage infectivity, capsule formation and virulence gene expression of N. meningitidis. It was found that lactate, pyruvate, and acetate facilitate survival of N. meningitidis in macrophages. While in epithelial cells, the survival of N. meningitidis is negatively affected by the presence of lactate and pyruvate.
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3
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Sriubas M, Bockute K, Palevicius P, Kaminskas M, Rinkevicius Z, Ragulskis M, Simonyte S, Ruzauskas M, Laukaitis G. Antibacterial Activity of Silver and Gold Particles Formed on Titania Thin Films. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:1190. [PMID: 35407308 PMCID: PMC9000426 DOI: 10.3390/nano12071190] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 02/07/2023]
Abstract
Metal-based nanoparticles with antimicrobial activity are gaining a lot of attention in recent years due to the increased antibiotics resistance. The development and the pathogenesis of oral diseases are usually associated with the formation of bacteria biofilms on the surfaces; therefore, it is crucial to investigate the materials and their properties that would reduce bacterial attachment and biofilm formation. This work provides a systematic investigation of the physical-chemical properties and the antibacterial activity of TiO2 thin films decorated by Ag and Au nanoparticles (NP) against Veillonella parvula and Neisseria sicca species associated with oral diseases. TiO2 thin films were formed using reactive magnetron sputtering by obtaining as-deposited amorphous and crystalline TiO2 thin films after annealing. Au and Ag NP were formed using a two-step process: magnetron sputtering of thin metal films and solid-state dewetting. The surface properties and crystallographic nature of TiO2/NP structures were investigated by SEM, XPS, XRD, and optical microscopy. It was found that the higher thickness of Au and Ag thin films results in the formation of the enlarged NPs and increased distance between them, influencing the antibacterial activity of the formed structures. TiO2 surface with AgNP exhibited higher antibacterial efficiency than Au nanostructured titania surfaces and effectively reduced the concentration of the bacteria. The process of the observation and identification of the presence of bacteria using the deep learning technique was realized.
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Affiliation(s)
- Mantas Sriubas
- Physics Department, Kaunas University of Technology, Studentu Str. 50, LT-51368 Kaunas, Lithuania; (M.S.); (M.K.); (G.L.)
| | - Kristina Bockute
- Physics Department, Kaunas University of Technology, Studentu Str. 50, LT-51368 Kaunas, Lithuania; (M.S.); (M.K.); (G.L.)
| | - Paulius Palevicius
- Department of Mathematical Modeling, Kaunas University of Technology, Studentu Str. 50, LT-51368 Kaunas, Lithuania; (P.P.); (M.R.)
| | - Marius Kaminskas
- Physics Department, Kaunas University of Technology, Studentu Str. 50, LT-51368 Kaunas, Lithuania; (M.S.); (M.K.); (G.L.)
| | - Zilvinas Rinkevicius
- Division of Theoretical Chemistry & Biology, KTH Royal Institute of Technology, School of Biotechnology, 109 61 Stockholm, Sweden;
| | - Minvydas Ragulskis
- Department of Mathematical Modeling, Kaunas University of Technology, Studentu Str. 50, LT-51368 Kaunas, Lithuania; (P.P.); (M.R.)
| | - Sandrita Simonyte
- Institute of Microbiology and Virology, Faculty of Veterinary Medicine, Veterinary Academy, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania; (S.S.); (M.R.)
- Institute of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Sukileliu Ave. 15, LT-50162 Kaunas, Lithuania
| | - Modestas Ruzauskas
- Institute of Microbiology and Virology, Faculty of Veterinary Medicine, Veterinary Academy, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania; (S.S.); (M.R.)
- Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania
| | - Giedrius Laukaitis
- Physics Department, Kaunas University of Technology, Studentu Str. 50, LT-51368 Kaunas, Lithuania; (M.S.); (M.K.); (G.L.)
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4
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Chen Y, Fang L, Ying X, Cheng M, Wang L, Sun P, Zhang Z, Shi L, Cao Y, Song H. Development of Whole Genome-Scale Base Editing Toolbox to Promote Efficiency of Extracellular Electron Transfer in Shewanella oneidensis MR-1. Adv Biol (Weinh) 2022; 6:e2101296. [PMID: 35182055 DOI: 10.1002/adbi.202101296] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/18/2022] [Indexed: 11/06/2022]
Abstract
Shewanella oneidensis MR-1, as a model electroactive microorganism (EAM) for extracellular electron transfer (EET) study, plays a key role in advancing practical applications of bio-electrochemical systems (BES). Efficient genome-level manipulation tools are vital to promote EET efficiency; thus, a powerful and rapid base editing toolbox in S. oneidensis MR-1 is developed. Firstly a CRISPR/dCas9-AID base editor that shows a relatively narrow editing window restricted to the "-20 to -16" range upstream of the protospacer adjacent motif (PAM) is constructed. Cas9 is also confined by its native PAM requirement, NGG. Then to expand the editable scope, the sgRNA and the Cas-protein to broaden the editing window to "-22 to -9" upstream of the PAM are engineered, and the PAM field to NNN is opened up. Consequently, the coverage of the editable gene is expanded from 89% to nearly 100% in S. oneidensis MR-1. This whole genome-scale cytidine deaminase-based base editing toolbox (WGcBE) is applied to regulate the cell length and the biofilm morphology, which enhances the EET efficiency by 6.7-fold. WGcBE enables an efficient deactivation of genes with full genome coverage, which would contribute to the in-depth and multi-faceted EET study in Shewanella.
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Affiliation(s)
- Yaru Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Lixia Fang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Xiang Ying
- College of Intelligence and Computing, Tianjin University, Tianjin, 300072, China
| | - Meijie Cheng
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Lin Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Panxing Sun
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Zhaoyu Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Liang Shi
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences in Wuhan, Wuhan, Hubei, 430074, China
| | - Yingxiu Cao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Hao Song
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
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5
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An Exposed Outer Membrane Hemin-Binding Protein Facilitates Hemin Transport by a TonB-Dependent Receptor in Riemerella anatipestifer. Appl Environ Microbiol 2021; 87:e0036721. [PMID: 33990314 DOI: 10.1128/aem.00367-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Iron is an essential element for the replication of most bacteria, including Riemerella anatipestifer, a Gram-negative bacterial pathogen of ducks and other birds. R. anatipestifer utilizes hemoglobin-derived hemin as an iron source; however, the mechanism by which this bacterium acquires hemin from hemoglobin is largely unknown. Here, rhuA disruption was shown to impair iron utilization from duck hemoglobin in R. anatipestifer CH-1. Moreover, the putative lipoprotein RhuA was identified as a surface-exposed, outer membrane hemin-binding protein, but it could not extract hemin from duck hemoglobin. Mutagenesis studies showed that recombinant RhuAY144A, RhuAY177A, and RhuAH149A lost hemin-binding ability, suggesting that amino acid sites at tyrosine 144 (Y144), Y177, and histidine 149 (H149) are crucial for hemin binding. Furthermore, rhuR, the gene adjacent to rhuA, encodes a TonB2-dependent hemin transporter. The function of rhuA in duck hemoglobin utilization was abolished in the rhuR mutant strain, and recombinant RhuA was able to bind the cell surface of R. anatipestifer CH-1 ΔrhuA rather than R. anatipestifer CH-1 ΔrhuR ΔrhuA, indicating that RhuA associates with RhuR to function. The sequence of the RhuR-RhuA hemin utilization locus exhibits no similarity to those of characterized hemin transport systems. Thus, this locus is a novel hemin uptake locus with homologues distributed mainly in the Bacteroidetes phylum. IMPORTANCE In vertebrates, hemin from hemoglobin is an important iron source for infectious bacteria. Many bacteria can obtain hemin from hemoglobin, but the mechanisms of hemin acquisition from hemoglobin differ among bacteria. Moreover, most studies have focused on the mechanism of hemin acquisition from mammalian hemoglobin. In this study, we found that the RhuR-RhuA locus of R. anatipestifer CH-1, a duck pathogen, is involved in hemin acquisition from duck hemoglobin via a unique pathway. RhuA was identified as an exposed outer membrane hemin-binding protein, and RhuR was identified as a TonB2-dependent hemin transporter. Moreover, the function of RhuA in hemoglobin utilization is RhuR dependent and not vice versa. The homologues of RhuR and RhuA are widely distributed in bacteria in marine environments, animals, and plants, representing a novel hemin transportation system of Gram-negative bacteria. This study not only was important for understanding hemin uptake in R. anatipestifer but also enriched the knowledge about the hemin transportation pathway in Gram-negative bacteria.
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6
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Lai H, Tang Y, Ren F, Li Z, Li F, Cui C, Jiao X, Huang J. An Investigation into the Critical Factors Influencing the Spread of Campylobacter during Chicken Handling in Commercial Kitchens in China. Microorganisms 2021; 9:microorganisms9061164. [PMID: 34071496 PMCID: PMC8227167 DOI: 10.3390/microorganisms9061164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 11/16/2022] Open
Abstract
Campylobacteriosis is the most common cause of bacterial gastroenteritis worldwide. Consumption of chicken meat is considered the main route for human infection with Campylobacter. This study aimed to determine the critical factors for Campylobacter cross-contamination in Chinese commercial kitchens during chicken handling. Five commercial kitchens were visited to detect Campylobacter occurrence from 2019 to 2020. Chicken samples (n = 363) and cotton balls from the kitchen surfaces (n = 479) were collected, and total bacterial counts and Campylobacter spp. were detected. Genotypic characterization of 57 Campylobacter jejuni isolates was performed by multilocus sequence typing (MLST). In total, 77.41% of chicken carcass samples and 37.37% of kitchen surfaces showed Campylobacter spp. contamination. Before chicken preparation, Campylobacter spp. were already present in the kitchen environment; however, chicken handling significantly increased Campylobacter spp. prevalence (p < 0.05). After cleaning, boards, hands, and knives still showed high bacterial loads including Campylobacter spp., which related to poor sanitary conditions and ineffective handling practices. Poor sanitation conditions on kitchen surfaces offer greater opportunities for Campylobacter transmission. Molecular typing by MLST revealed that Campylobacter cross-contamination occurred during chicken preparation. The most prevalent sequence types, ST693 and ST45, showed strong biofilm formation ability. Consequently, sanitary condition of surfaces and biofilm formation ability of isolates were the critical points contributing to spread of Campylobacter in kitchen environment. These results provide insight into potential targeted control strategies along the farm-to-plate chain and highlight the necessity for improvements in sanitary conditions. The implementation of more effective cleaning measures should be considered to decrease the campylobacteriosis risk.
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Affiliation(s)
- Honggang Lai
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225001, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Yuanyue Tang
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Fangzhe Ren
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Zeng Li
- Jiangsu College of Tourism, Yangzhou 225000, China;
| | - Fengming Li
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Chaoyue Cui
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Xinan Jiao
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Jinlin Huang
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (H.L.); (Y.T.); (F.R.); (F.L.); (C.C.); (X.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
- Correspondence: ; Tel.: +86-514-8799-0579
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7
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Tzeng YL, Stephens DS. A Narrative Review of the W, X, Y, E, and NG of Meningococcal Disease: Emerging Capsular Groups, Pathotypes, and Global Control. Microorganisms 2021; 9:microorganisms9030519. [PMID: 33802567 PMCID: PMC7999845 DOI: 10.3390/microorganisms9030519] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/21/2022] Open
Abstract
Neisseria meningitidis, carried in the human nasopharynx asymptomatically by ~10% of the population, remains a leading cause of meningitis and rapidly fatal sepsis, usually in otherwise healthy individuals. The epidemiology of invasive meningococcal disease (IMD) varies substantially by geography and over time and is now influenced by meningococcal vaccines and in 2020–2021 by COVID-19 pandemic containment measures. While 12 capsular groups, defined by capsular polysaccharide structures, can be expressed by N. meningitidis, groups A, B, and C historically caused most IMD. However, the use of mono-, bi-, and quadrivalent-polysaccharide-conjugate vaccines, the introduction of protein-based vaccines for group B, natural disease fluctuations, new drugs (e.g., eculizumab) that increase meningococcal susceptibility, changing transmission dynamics and meningococcal evolution are impacting the incidence of the capsular groups causing IMD. While the ability to spread and cause illness vary considerably, capsular groups W, X, and Y now cause significant IMD. In addition, group E and nongroupable meningococci have appeared as a cause of invasive disease, and a nongroupable N. meningitidis pathotype of the hypervirulent clonal complex 11 is causing sexually transmitted urethritis cases and outbreaks. Carriage and IMD of the previously “minor” N. meningitidis are reviewed and the need for polyvalent meningococcal vaccines emphasized.
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Affiliation(s)
- Yih-Ling Tzeng
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - David S. Stephens
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Correspondence: ; Tel.: +404-727-8357
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8
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Pili and other surface proteins influence the structure and the nanomechanical properties of Lactococcus lactis biofilms. Sci Rep 2021; 11:4846. [PMID: 33649417 PMCID: PMC7921122 DOI: 10.1038/s41598-021-84030-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/09/2021] [Indexed: 11/08/2022] Open
Abstract
Lactic acid bacteria, in particular Lactococcus lactis, are widely used in the food industry, for the control and/or the protection of the manufacturing processes of fermented food. While L. lactis has been reported to form compact and uniform biofilms it was recently shown that certain strains able to display pili at their surface form more complex biofilms exhibiting heterogeneous and aerial structures. As the impact of those biofilm structures on the biomechanical properties of the biofilms is poorly understood, these were investigated using AFM force spectroscopy and imaging. Three types of strains were used i.e., a control strain devoid of pili and surface mucus-binding protein, a strain displaying pili but no mucus-binding proteins and a strain displaying both pili and a mucus-binding protein. To identify potential correlations between the nanomechanical measurements and the biofilm architecture, 24-h old biofilms were characterized by confocal laser scanning microscopy. Globally the strains devoid of pili displayed smoother and stiffer biofilms (Young Modulus of 4-100 kPa) than those of piliated strains (Young Modulus around 0.04-0.1 kPa). Additional display of a mucus-binding protein did not affect the biofilm stiffness but made the biofilm smoother and more compact. Finally, we demonstrated the role of pili in the biofilm cohesiveness by monitoring the homotypic adhesion of bacteria to the biofilm surface. These results will help to understand the role of pili and mucus-binding proteins withstanding external forces.
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9
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Schulze A, Mitterer F, Pombo JP, Schild S. Biofilms by bacterial human pathogens: Clinical relevance - development, composition and regulation - therapeutical strategies. MICROBIAL CELL (GRAZ, AUSTRIA) 2021; 8:28-56. [PMID: 33553418 PMCID: PMC7841849 DOI: 10.15698/mic2021.02.741] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/08/2021] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
Notably, bacterial biofilm formation is increasingly recognized as a passive virulence factor facilitating many infectious disease processes. In this review we will focus on bacterial biofilms formed by human pathogens and highlight their relevance for diverse diseases. Along biofilm composition and regulation emphasis is laid on the intensively studied biofilms of Vibrio cholerae, Pseudomonas aeruginosa and Staphylococcus spp., which are commonly used as biofilm model organisms and therefore contribute to our general understanding of bacterial biofilm (patho-)physiology. Finally, therapeutical intervention strategies targeting biofilms will be discussed.
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Affiliation(s)
- Adina Schulze
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Joao P. Pombo
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed Graz, Austria
- Field of Excellence Biohealth – University of Graz, Graz, Austria
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10
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Mashbat B, Bellos E, Hodeib S, Bidmos F, Thwaites RS, Lu Y, Wright VJ, Herberg JA, Klobassa DS, Zenz W, Hansel TT, Nadel S, Langford PR, Schlapbach LJ, Li MS, Redinbo MR, Di YP, Levin M, Sancho-Shimizu V. A Rare Mutation in SPLUNC1 Affects Bacterial Adherence and Invasion in Meningococcal Disease. Clin Infect Dis 2021; 70:2045-2053. [PMID: 31504285 PMCID: PMC7201419 DOI: 10.1093/cid/ciz600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 06/28/2019] [Indexed: 01/06/2023] Open
Abstract
Background Neisseria meningitidis (Nm) is a nasopharyngeal commensal carried by healthy individuals. However, invasive infections occurs in a minority of individuals, with devastating consequences. There is evidence that common polymorphisms are associated with invasive meningococcal disease (IMD), but the contributions of rare variants other than those in the complement system have not been determined. Methods We identified familial cases of IMD in the UK meningococcal disease study and the European Union Life-Threatening Infectious Disease Study. Candidate genetic variants were identified by whole-exome sequencing of 2 patients with familial IMD. Candidate variants were further validated by in vitro assays. Results Exomes of 2 siblings with IMD identified a novel heterozygous missense mutation in BPIFA1/SPLUNC1. Sequencing of 186 other nonfamilial cases identified another unrelated IMD patient with the same mutation. SPLUNC1 is an innate immune defense protein expressed in the nasopharyngeal epithelia; however, its role in invasive infections is unknown. In vitro assays demonstrated that recombinant SPLUNC1 protein inhibits biofilm formation by Nm, and impedes Nm adhesion and invasion of human airway cells. The dominant negative mutant recombinant SPLUNC1 (p.G22E) showed reduced antibiofilm activity, increased meningococcal adhesion, and increased invasion of cells, compared with wild-type SPLUNC1. Conclusions A mutation in SPLUNC1 affecting mucosal attachment, biofilm formation, and invasion of mucosal epithelial cells is a new genetic cause of meningococcal disease.
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Affiliation(s)
- Bayarchimeg Mashbat
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Evangelos Bellos
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Stephanie Hodeib
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Fadil Bidmos
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Ryan S Thwaites
- National Heart and Lung Institute, Imperial College London, United Kingdom
| | - Yaxuan Lu
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Victoria J Wright
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Jethro A Herberg
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Daniela S Klobassa
- Department of Pediatric and Adolescence Surgery, Division of General Pediatric Surgery, Medical University Graz, Austria
| | - Werner Zenz
- Department of Pediatric and Adolescence Surgery, Division of General Pediatric Surgery, Medical University Graz, Austria
| | - Trevor T Hansel
- National Heart and Lung Institute, Imperial College London, United Kingdom
| | - Simon Nadel
- Paediatric Intensive Care Unit, St. Mary's Hospital, Imperial College Healthcare Trust, London, United Kingdom
| | - Paul R Langford
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Luregn J Schlapbach
- Faculty of Medicine Brisbane, The University of Queensland Brisbane, Australia.,Paediatric Critical Care Research Group, The University of Queensland Brisbane, Australia.,Paediatric Intensive Care Unit, Lady Cilento Children's Hospital, Children's Health Queensland, Brisbane, Australia.,Department of Pediatrics, Bern University Hospital, Inselspital, University of Bern, Switzerland
| | - Ming-Shi Li
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Matthew R Redinbo
- Department of Chemistry, University of North Carolina, Chapel Hill.,Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill
| | - Y Peter Di
- Department of Environmental and Occupational Health, University of Pittsburgh, Pennsylvania
| | - Michael Levin
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Vanessa Sancho-Shimizu
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
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11
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Browning S, Walker HN, Ryan T, Pickles R, Loftus M, Trubiano JA, Hardidge A, Davis JS. Treatment of Neisseria meningitidis prosthetic joint infections with short-course antibiotics: three cases and a literature review. J Bone Jt Infect 2020; 6:33-37. [PMID: 32983846 PMCID: PMC7517647 DOI: 10.5194/jbji-6-33-2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/27/2020] [Indexed: 11/11/2022] Open
Abstract
Neisseria meningitidis is a rare cause of prosthetic joint infection (PJI), with only three cases previously reported. Here we report three further cases, all of which were successfully treated with implant retention and short-course antibiotics ( < 6 weeks).
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Affiliation(s)
- Sarah Browning
- Department of Infectious Diseases, John Hunter Hospital, Newcastle, NSW, Australia.,School of Medicine and Public Health, University of Newcastle, Callaghan, NSW, Australia
| | - Harry N Walker
- Department of Infectious Diseases, Austin Health, Heidelberg, VIC, Australia
| | - Thomas Ryan
- Department of Orthopaedic Surgery, John Hunter Hospital, Newcastle, NSW, Australia
| | - Robert Pickles
- Department of Infectious Diseases, John Hunter Hospital, Newcastle, NSW, Australia.,School of Medicine and Public Health, University of Newcastle, Callaghan, NSW, Australia
| | - Michael Loftus
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Jason A Trubiano
- Department of Infectious Diseases, Austin Health, Heidelberg, VIC, Australia.,Department of Medicine (Austin Health), University of Melbourne, Heidelberg, VIC, Australia.,Department of Infectious Diseases and The National Centre for Infections in Cancer (NCIC), Peter MacCallum Cancer Centre, Parkville, VIC, Australia
| | - Andrew Hardidge
- Department of Orthopaedic Surgery, Austin Health, Heidelberg, VIC, Australia.,Department of Medicine (Austin Health), University of Melbourne, Heidelberg, VIC, Australia
| | - Joshua S Davis
- Department of Infectious Diseases, John Hunter Hospital, Newcastle, NSW, Australia.,School of Medicine and Public Health, University of Newcastle, Callaghan, NSW, Australia.,Global and Tropical Health Division, Menzies School of Health Research, Darwin, NT, Australia
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12
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Abstract
Bacteroides thetaiotaomicron is one of the most abundant gut symbiont species, whose contribution to host health through its ability to degrade dietary polysaccharides and mature the immune system is under intense scrutiny. In contrast, adhesion and biofilm formation, which are potentially involved in gut colonization and microbiota structure and stability, have hardly been investigated in this intestinal bacterium. To uncover B. thetaiotaomicron biofilm-related functions, we performed a transposon mutagenesis in the poorly biofilm-forming reference strain VPI-5482 and showed that capsule 4, one of the eight B. thetaiotaomicron capsules, hinders biofilm formation. We then showed that the production of capsules 1, 2, 3, 5, and 6 also inhibits biofilm formation and that decreased capsulation of the population correlated with increased biofilm formation, suggesting that capsules could be masking adhesive surface structures. In contrast, we showed that capsule 8 displayed intrinsic adhesive properties. Finally, we demonstrated that BT2934, the wzx homolog of the B. thetaiotaomicron glycosylation locus, competes with capsule production and impacts its adhesion capacity. This study therefore establishes B. thetaiotaomicron capsule regulation as a major determinant of B. thetaiotaomicron biofilm formation, providing new insights into how modulation of different B. thetaiotaomicron surface structures affects in vitro biofilm formation.IMPORTANCE The human gut harbors a complex bacterial community that plays important roles in host health and disease, including nutrient acquisition, maturation of the immune system, and resistance to infections. The capacity to adhere to surfaces and form communities called biofilms is believed to be important for niche colonization and maintenance of gut bacteria. However, little is known about the adhesion capacity of most gut bacteria. In this study, we investigated biofilm formation in Bacteroides thetaiotaomicron, one of the most abundant bacteria of the normal mammalian intestine. We identified that B. thetaiotaomicron capsules, a group of eight surface-exposed polysaccharidic layers mediating important interactions with the gut environment, are also major determinants of biofilm formation that mask or unmask adhesion factors. Studying how B. thetaiotaomicron regulates its adhesion properties will allow us to better understand the physiology and specific properties of this important gut symbiont within anaerobic biofilms.
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13
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Priyodip P, Balaji S. Probiotic Validation of a Non-native, Thermostable, Phytase-Producing Bacterium: Streptococcus thermophilus. Curr Microbiol 2020; 77:1540-1549. [PMID: 32248282 DOI: 10.1007/s00284-020-01957-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 03/21/2020] [Indexed: 10/24/2022]
Abstract
Phytate-linked nutritional deficiency disorders have plagued poultry for centuries. The application of exogenous phytases in poultry feed has served as a solution to this problem. However, they are linked to certain limitations which include thermal instability during prolonged feed processing. Therefore, in this study, Streptococcus thermophilus 2412 based phytase stability was assessed at higher temperatures up to 90 °C. This was followed by probiotic validation of the same bacterium in an in vitro intestinal model. Bacterial phytase showed thermostability up to 70 °C with a recorded activity of 9.90 U. The bacterium was viable in the intestinal lumen as indicated by the cell count of 6.10 log(CFU/mL) after 16 h. It also showed acid tolerance with a stable cell count of 5.01 log(CFU/mL) after 16 h of incubation at pH 2. The bacterium displayed bile tolerance yielding a cell count of 6.36 log(CFU/mL) in the presence of 0.3% bile. Bacterial susceptibility was observed toward all tested antibiotics with a maximum zone of 20 mm against clindamycin. The maximum antagonistic activity was observed against Staphylococcus aureus, Serratia marcescens, and Escherichia coli with inhibition zone diameters up to 10 mm. The above characteristics prove that S. thermophilus 2412 can be used as an effective phytase-producing poultry probiotic.
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Affiliation(s)
- Paul Priyodip
- Department of Biotechnology, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Seetharaman Balaji
- Department of Biotechnology, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
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14
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Stadnyk I, Sabadosh G, Hushtan T, Yevchuk Y. Formation of microbial biofilms on stainless steel with different surface roughness. POTRAVINARSTVO 2019. [DOI: 10.5219/1190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The physical essence of the formation and influence of bacteria on the surface of technological equipment in the dairy industry is considered as an essential factor leading to contamination of dairy products and is a major hygienic problem. The ability of microorganisms on the surfaces of technological equipment to form biofilm forms and requirements for steel grade, relief, and its roughness were analysed. The effect of surface roughness on promoting or preventing adhesion and reproduction of biofilm forms of bacteria, which reduce the efficiency of sanitary processing of dairy equipment and thereby increase the microbial contamination of dairy products with shortened shelf life, is substantiated. Research about the process of bacterial adhesion to the surface of metals with different roughness depending on the size and shape is presented. It is found that on the surface of stainless steel with roughness 2.687 ±0.014 micron film formation process in Escherichia coli and Staphylococcus aureus are similar from 3 to 24 hours and does not depend on the size of the bacteria, and accordingly allows us to argue that rod-shaped and coccid bacteria attach freely in the hollows of the roughness are the beginning of the process of the first stage of biofilm formation. It is found that on the surface of stainless steel with roughness 0.95 ±0.092 micron film formation process in S. aureus is more intense than in E. coli. Thus, within 3 hours of incubation, the density of biofilms formed S. aureus was 1.2 times bigger than biofilms E. coli, by the next 15 hours of incubation formed biofilms S. aureus were, on average, 1.3 times denser. It is established that S. aureus due to its spherical shape is able to fit in the hollows of the roughness 0.95 ±0.092 μm and faster to adhere to the surface at the same time. E. coli, due to its rod-like shape, with such surface roughness, can adhere to the cavities only over its entire length. It is proved that by surface roughness 0.63 ±0.087 μm film intensity S. aureus was, on average, 1.4 times faster than E. coli, for roughness 0.16 ±0.018 micron film formation process took place equally for S. aureus and E. coli, but biofilms were lower in density than those formed on roughness 0.63 ±0.087 micron. Studies suggest that the use of equipment in the dairy industry with a roughness of less than 0.5 microns will reduce the attachment of microorganisms to the surface and reduce the contamination of dairy products.
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15
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Sigurlásdóttir S, Wassing GM, Zuo F, Arts M, Jonsson AB. Deletion of D-Lactate Dehydrogenase A in Neisseria meningitidis Promotes Biofilm Formation Through Increased Autolysis and Extracellular DNA Release. Front Microbiol 2019; 10:422. [PMID: 30891026 PMCID: PMC6411758 DOI: 10.3389/fmicb.2019.00422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/18/2019] [Indexed: 11/23/2022] Open
Abstract
Neisseria meningitidis is a Gram-negative bacterium that asymptomatically colonizes the human nasopharyngeal mucosa. Pilus-mediated initial adherence of N. meningitidis to the epithelial mucosa is followed by the formation of three-dimensional aggregates, called microcolonies. Dispersal from microcolonies contributes to the transmission of N. meningitidis across the epithelial mucosa. We have recently discovered that environmental concentrations of host cell-derived lactate influences N. meningitidis microcolony dispersal. Here, we examined the ability of N. meningitidis mutants deficient in lactate metabolism to form biofilms. A lactate dehydrogenease A (ldhA) mutant had an increased level of biofilm formation. Deletion of ldhA increased the N. meningitidis cell surface hydrophobicity and aggregation. In this study, we used FAM20, which belongs to clonal complex ST-11 that forms biofilms independently of extracellular DNA (eDNA). However, treatment with DNase I abolished the increased biofilm formation and aggregation of the ldhA-deficient mutant, suggesting a critical role for eDNA. Compared to wild-type, the ldhA-deficient mutant exhibited an increased autolytic rate, with significant increases in the eDNA concentrations in the culture supernatants and in biofilms. Within the ldhA mutant biofilm, the transcription levels of the capsule, pilus, and bacterial lysis genes were downregulated, while norB, which is associated with anaerobic respiration, was upregulated. These findings suggest that the absence of ldhA in N. meningitidis promotes biofilm formation and aggregation through autolysis-mediated DNA release.
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Affiliation(s)
- Sara Sigurlásdóttir
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Gabriela M Wassing
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Fanglei Zuo
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Melanie Arts
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Ann-Beth Jonsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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16
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Guo X, Wang H, Cheng Y, Zhang W, Luo Q, Wen G, Wang G, Shao H, Zhang T. Quinolone resistance phenotype and genetic characterization of Salmonella enterica serovar Pullorum isolates in China, during 2011 to 2016. BMC Microbiol 2018; 18:225. [PMID: 30587131 PMCID: PMC6307136 DOI: 10.1186/s12866-018-1368-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 12/06/2018] [Indexed: 12/15/2022] Open
Abstract
Background Pullorum disease, caused by Salmonella enterica serovar Pullorum (S. Pullorum), is one of the most important bacterial infections in the poultry industry in developing countries, including China. To examine the prevalence and characteristics of S. Pullorum, the Multilocus Sequence Typing (MLST) genotypes, fluoroquinolones resistance, and biofilm-forming abilities of S. Pullorum isolates were investigated, collected from 2011 to 2016 in China. Results Thirty S. Pullorum isolates collected from 2011 to 2016 were analyzed. Quinolones susceptibility testing showed that 90% of the isolates were resistant to the first generation of quinolines nalidixic acid, but the resistance rates to different fluoroquinolones agents were lower than 13.3%; for some there was even no resistance. Multilocus sequence typing (MLST) showed that ST-92 was the dominating genotype, accounting for 90.0% of all S. pullorum strains. The remaining three isolates were of the new reported sequence type ST-2151. Interestingly, the Asp87Gly substitution in quinolone resistance-determining regions (QRDR) of GyrA was only observed in the three strains of ST-2151, suggesting a potential correlation between Asp87Gly substitution and sequence type (p < 0.05). However, Asp87Gly substitution could not confer the resistant to ofloxacin and ciprofloxacin of these isolates. The plasmid-mediated quinolone resistance (PMQR) gene was not found in any of the tested isolates. Furthermore, an assay measuring biofilm-forming abilities showed that 46.7% of the isolates were non-biofilm producers, while 53.3% could form very weak biofilms, which might explain the relatively lower resistance to fluoroquinolones. Conclusions We reported a high resistance rate to the first generation of quinolines nalidixic acid and relatively low resistance rates to fluoroquinolones in S. Pullorum isolates. In addition, weak biofilm-forming abilities were found, which might be an important reason of the low fluoroquinolones resistance rates of S. Pullorum isolates. ST-92 was the dominating genotype demonstrated by MLST, and the new sequence type ST-2151 showed a potential correlation with Asp87Gly substitution in QRDR of GyrA. We believe the characterization of these S. Pullorum isolates will be helpful to develop prevention and control strategies. Electronic supplementary material The online version of this article (10.1186/s12866-018-1368-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaodong Guo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Honglin Wang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Engineering Technology Center of Veterinary Diagnostic products, Wuhan, 430070, China
| | - Yiluo Cheng
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Wenting Zhang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Qingping Luo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Engineering Technology Center of Veterinary Diagnostic products, Wuhan, 430070, China
| | - Guoyuan Wen
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Guijun Wang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Huabin Shao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China. .,Hubei Engineering Technology Center of Veterinary Diagnostic products, Wuhan, 430070, China.
| | - Tengfei Zhang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China. .,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China.
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17
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Abstract
Pasteurella multocida is an important multihost animal and zoonotic pathogen that is capable of causing respiratory and multisystemic diseases, bacteremia, and bite wound infections. The glycosaminoglycan capsule of P. multocida is an essential virulence factor that protects the bacterium from host defenses. However, chronic infections (such as swine atrophic rhinitis and the carrier state in birds and other animals) may be associated with biofilm formation, which has not been characterized in P. multocida. Biofilm formation by clinical isolates was inversely related to capsule production and was confirmed with capsule-deficient mutants of highly encapsulated strains. Capsule-deficient mutants formed biofilms with a larger biomass that was thicker and smoother than the biofilm of encapsulated strains. Passage of a highly encapsulated, poor-biofilm-forming strain under conditions that favored biofilm formation resulted in the production of less capsular polysaccharide and a more robust biofilm, as did addition of hyaluronidase to the growth medium of all of the strains tested. The matrix material of the biofilm was composed predominately of a glycogen exopolysaccharide (EPS), as determined by gas chromatography-mass spectrometry, nuclear magnetic resonance, and enzymatic digestion. However, a putative glycogen synthesis locus was not differentially regulated when the bacteria were grown as a biofilm or planktonically, as determined by quantitative reverse transcriptase PCR. Therefore, the negatively charged capsule may interfere with biofilm formation by blocking adherence to a surface or by preventing the EPS matrix from encasing large numbers of bacterial cells. This is the first detailed description of biofilm formation and a glycogen EPS by P. multocida. Pasteurella multocida is an important pathogen responsible for severe infections in food animals, domestic and wild birds, pet animals, and humans. P. multocida was first isolated by Louis Pasteur in 1880 and has been studied for over 130 years. However, aspects of its lifecycle have remained unknown. Although formation of a biofilm by P. multocida has been proposed, this report is the first to characterize biofilm formation by P. multocida. Of particular interest is that the biofilm matrix material contained a newly reported amylose-like glycogen as the exopolysaccharide component and that production of capsular polysaccharide (CPS) was inversely related to biofilm formation. However, even highly mucoid, poor-biofilm-forming strains could form abundant biofilms by loss of CPS or following in vitro passage under biofilm growth conditions. Therefore, the carrier state or subclinical chronic infections with P. multocida may result from CPS downregulation with concomitant enhanced biofilm formation.
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18
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Zhang T, Dong J, Cheng Y, Lu Q, Luo Q, Wen G, Liu G, Shao H. Genotypic diversity, antimicrobial resistance and biofilm-forming abilities of Campylobacter isolated from chicken in Central China. Gut Pathog 2017; 9:62. [PMID: 29151896 PMCID: PMC5680748 DOI: 10.1186/s13099-017-0209-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022] Open
Abstract
Background Campylobacter is considered to be the leading cause of human bacterial gastroenteritis, of which poultry is the main reservoir. Campylobacter contaminated chicken products are a major cause of human Campylobacter infection. In this study, the prevalence of Campylobacter in chicken in central China was investigated, and the genotypic diversity, antimicrobial resistance and biofilm of these isolates were characterized. Results A total of 206 Campylobacter isolates, including 166 C. jejuni and 40 C. coli, were isolated from chicken farms and live poultry markets in central China. Multilocus sequence typing and phylogenetic analysis showed that the Campylobacter isolates had diverse genetic backgrounds, which covered most of the dominant clone complexes (CCs) reported throughout China. The most prevalent CCs were CC-464, CC-1150, CC-353, and CC-828. All the isolates showed resistance to norfloxacin, ciprofloxacin and Cefazolin, and a prevalent resistance to fluoroquinolones, β-lactams and tetracyclines was also observed. Among all the isolates, 133 strains showed the ability to form biofilm, thereinto, the isolates in two genetic branches, mainly including CC-21, CC-48, CC-677 and CC-45, showed a significantly lower ability to form biofilm than other genetic branches (p < 0.05). However, in general, the ability to form biofilm varied among different genetic branches, suggesting a complex genetic background to biofilm formation, but not only the genetic lineages. Compared with the strains unable to form biofilm, biofilm-producing strains possessed a significantly higher resistance to ampicillin, neomycin, sulfamethoxazole, amikacin, clindamycin and erythromycin (p < 0.05). Conclusions To the best of our knowledge, this is the first report on the relationship of the genotypic diversity, antimicrobial resistance and biofilm-forming abilities of Campylobacter isolated from chicken in Central China, which showed the potential importance of biofilm in antimicrobial resistance. This study will help us better understand the epidemiology and antimicrobial resistance of Campylobacter.
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Affiliation(s)
- Tengfei Zhang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Jun Dong
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,College of Animal Science, Yangtze University, Jingzhou, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Yiluo Cheng
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,College of Animal Science, Yangtze University, Jingzhou, China
| | - Qin Lu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Qingping Luo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Guoyuan Wen
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Guoping Liu
- College of Animal Science, Yangtze University, Jingzhou, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Huabin Shao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China.,College of Animal Science, Yangtze University, Jingzhou, China.,Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
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19
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Use of Natural Transformation To Establish an Easy Knockout Method in Riemerella anatipestifer. Appl Environ Microbiol 2017; 83:AEM.00127-17. [PMID: 28258143 DOI: 10.1128/aem.00127-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 02/22/2017] [Indexed: 01/08/2023] Open
Abstract
Riemerella anatipestifer is a member of the family Flavobacteriaceae and a major causative agent of duck serositis. Little is known about its genetics and pathogenesis. Several bacteria are competent for natural transformation; however, whether R. anatipestifer is also competent for natural transformation has not been investigated. Here, we showed that R. anatipestifer strain ATCC 11845 can uptake the chromosomal DNA of R. anatipestifer strain RA-CH-1 in all growth phases. Subsequently, a natural transformation-based knockout method was established for R. anatipestifer ATCC 11845. Targeted mutagenesis gave transformation frequencies of ∼10-5 transformants. Competition assay experiments showed that R. anatipestifer ATCC 11845 preferentially took up its own DNA rather than heterogeneous DNA, such as Escherichia coli DNA. Transformation was less efficient with the shuttle plasmid pLMF03 (transformation frequencies of ∼10-9 transformants). However, the efficiency of transformation was increased approximately 100-fold using pLMF03 derivatives containing R. anatipestifer DNA fragments (transformation frequencies of ∼10-7 transformants). Finally, we found that the R. anatipestifer RA-CH-1 strain was also naturally transformable, suggesting that natural competence is widely applicable for this species. The findings described here provide important tools for the genetic manipulation of R. anatipestiferIMPORTANCERiemerella anatipestifer is an important duck pathogen that belongs to the family Flavobacteriaceae At least 21 different serotypes have been identified. Genetic diversity has been demonstrated among these serotypes. The genetic and pathogenic mechanisms of R. anatipestifer remain largely unknown because no genetic tools are available for this bacterium. At present, natural transformation has been found in some bacteria but not in R. anatipestifer For the first time, we showed that natural transformation occurred in R. anatipestifer ATCC 11845 and R. anatipestifer RA-CH-1. Then, we established an easy gene knockout method in R. anatipestifer based on natural transformation. This information is important for further studies of the genetic diversity and pathogenesis in R. anatipestifer.
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Ampattu BJ, Hagmann L, Liang C, Dittrich M, Schlüter A, Blom J, Krol E, Goesmann A, Becker A, Dandekar T, Müller T, Schoen C. Transcriptomic buffering of cryptic genetic variation contributes to meningococcal virulence. BMC Genomics 2017; 18:282. [PMID: 28388876 PMCID: PMC5383966 DOI: 10.1186/s12864-017-3616-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/10/2017] [Indexed: 01/06/2023] Open
Abstract
Background Commensal bacteria like Neisseria meningitidis sometimes cause serious disease. However, genomic comparison of hyperinvasive and apathogenic lineages did not reveal unambiguous hints towards indispensable virulence factors. Here, in a systems biological approach we compared gene expression of the invasive strain MC58 and the carriage strain α522 under different ex vivo conditions mimicking commensal and virulence compartments to assess the strain-specific impact of gene regulation on meningococcal virulence. Results Despite indistinguishable ex vivo phenotypes, both strains differed in the expression of over 500 genes under infection mimicking conditions. These differences comprised in particular metabolic and information processing genes as well as genes known to be involved in host-damage such as the nitrite reductase and numerous LOS biosynthesis genes. A model based analysis of the transcriptomic differences in human blood suggested ensuing metabolic flux differences in energy, glutamine and cysteine metabolic pathways along with differences in the activation of the stringent response in both strains. In support of the computational findings, experimental analyses revealed differences in cysteine and glutamine auxotrophy in both strains as well as a strain and condition dependent essentiality of the (p)ppGpp synthetase gene relA and of a short non-coding AT-rich repeat element in its promoter region. Conclusions Our data suggest that meningococcal virulence is linked to transcriptional buffering of cryptic genetic variation in metabolic genes including global stress responses. They further highlight the role of regulatory elements for bacterial virulence and the limitations of model strain approaches when studying such genetically diverse species as N. meningitidis. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3616-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Biju Joseph Ampattu
- Institute for Hygiene and Microbiology, Joseph-Schneider-Straße 2, University of Würzburg, 97080, Würzburg, Germany
| | - Laura Hagmann
- Institute for Hygiene and Microbiology, Joseph-Schneider-Straße 2, University of Würzburg, 97080, Würzburg, Germany
| | - Chunguang Liang
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Marcus Dittrich
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.,Department of Human Genetics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Andreas Schlüter
- Center for Biotechnology (CeBiTec), Bielefeld University, Universitätsstr. 27, 33615, Bielefeld, Germany
| | - Jochen Blom
- Institute for Bioinformatics and Systems Biology, Justus Liebig University Gießen, Heinrich-Buff-Ring 58, 35392, Gießen, Germany
| | - Elizaveta Krol
- LOEWE-Center for Synthetic Microbiology, Hans-Meerwein-Straße, 35032, Marburg, Germany
| | - Alexander Goesmann
- Institute for Bioinformatics and Systems Biology, Justus Liebig University Gießen, Heinrich-Buff-Ring 58, 35392, Gießen, Germany
| | - Anke Becker
- LOEWE-Center for Synthetic Microbiology, Hans-Meerwein-Straße, 35032, Marburg, Germany
| | - Thomas Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Tobias Müller
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Christoph Schoen
- Institute for Hygiene and Microbiology, Joseph-Schneider-Straße 2, University of Würzburg, 97080, Würzburg, Germany.
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Pérez-Ortega J, Rodríguez A, Ribes E, Tommassen J, Arenas J. Interstrain Cooperation in Meningococcal Biofilms: Role of Autotransporters NalP and AutA. Front Microbiol 2017; 8:434. [PMID: 28382026 PMCID: PMC5360712 DOI: 10.3389/fmicb.2017.00434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/02/2017] [Indexed: 12/18/2022] Open
Abstract
Neisseria meningitidis (Nm) and Neisseria lactamica (Nl) are commensal bacteria that live in the human nasopharynx, where they form microcolonies. In contrast to Nl, Nm occasionally causes blood and/or meningitis infection with often fatal consequences. Here, we studied interactions between neisserial strains during biofilm formation. Fluorescent strains were engineered and analyzed for growth in single- and dual-strain biofilms with confocal laser-scanning microscopy. Different strains of diverse Neisseria species formed microcolonies of different sizes and morphologies. Pair-wise combinations of two invasive Nm strains and one Nm carrier isolate showed that these strains can coexist in spite of the fact that they produce toxins to combat congeners. This lack of competition was even observed when the biofilms were formed under nutrient limitation and can be explained by the observation that the separate microcolonies within mixed biofilms are mostly lineage specific. However, these microcolonies showed different levels of interaction. The coexistence of two strains was also observed in mixed biofilms of Nm and Nl strains. Inactivation of the autotransporter NalP, which prevents the release of the heparin-binding antigen NHBA and the α-peptide of IgA protease from the cell surface, and/or the production of autotransporter AutA increased interactions between microcolonies, as evidenced by close contacts between microcolonies on the substratum. Qualitative and quantitative analysis revealed an altered spatial distribution of each strain in mixed biofilms with consequences for the biomass, biofilm architecture and bacterial viability depending on the synthesis of NalP and AutA, the expression of which is prone to phase variation. Being in a consortium resulted in some cases in commensalism and cooperative behavior, which promoted attachment to the substratum or increased survival, possibly as result of the shared use of the biofilm matrix. We hypothesize that Nm strains can cooperate during host colonization, but, possibly, the different capacities of the microcolonies of each strain to resist the host's defenses limits the long-term coexistence of strains in the host.
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Affiliation(s)
- Jesús Pérez-Ortega
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Antonio Rodríguez
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Eduardo Ribes
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Jan Tommassen
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Jesús Arenas
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
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22
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Arenas J, Tommassen J. Meningococcal Biofilm Formation: Let's Stick Together. Trends Microbiol 2017; 25:113-124. [DOI: 10.1016/j.tim.2016.09.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/13/2016] [Accepted: 09/16/2016] [Indexed: 11/26/2022]
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23
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Kaplan JB, Sampathkumar V, Bendaoud M, Giannakakis AK, Lally ET, Balashova NV. In vitro characterization of biofilms formed by Kingella kingae. Mol Oral Microbiol 2016; 32:341-353. [PMID: 27714987 DOI: 10.1111/omi.12176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2016] [Indexed: 01/29/2023]
Abstract
The Gram-negative bacterium Kingella kingae is part of the normal oropharyngeal mucosal flora of children <4 years old. K. kingae can enter the submucosa and cause infections of the skeletal system in children, including septic arthritis and osteomyelitis. The organism is also associated with infective endocarditis in children and adults. Although biofilm formation has been coupled with pharyngeal colonization, osteoarticular infections, and infective endocarditis, no studies have investigated biofilm formation in K. kingae. In this study we measured biofilm formation by 79 K. kingae clinical isolates using a 96-well microtiter plate crystal violet binding assay. We found that 37 of 79 strains (47%) formed biofilms. All strains that formed biofilms produced corroding colonies on agar. Biofilm formation was inhibited by proteinase K and DNase I. DNase I also caused the detachment of pre-formed K. kingae biofilm colonies. A mutant strain carrying a deletion of the pilus gene cluster pilA1pilA2fimB did not produce corroding colonies on agar, autoaggregate in broth, or form biofilms. Biofilm forming strains have higher levels of pilA1 expression. The extracellular components of biofilms contained 490 μg cm-2 of protein, 0.68 μg cm-2 of DNA, and 0.4 μg cm-2 of total carbohydrates. We concluded that biofilm formation is common among K. kingae clinical isolates, and that biofilm formation is dependent on the production of proteinaceous pili and extracellular DNA. Biofilm development may have relevance to the colonization, transmission, and pathogenesis of this bacterium. Extracellular DNA production by K. kingae may facilitate horizontal gene transfer within the oral microbial community.
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Affiliation(s)
- J B Kaplan
- Department of Biology, American University, Washington, DC, USA
| | - V Sampathkumar
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ, USA
| | - M Bendaoud
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ, USA
| | - A K Giannakakis
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - E T Lally
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - N V Balashova
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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24
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Arenas J, Paganelli FL, Rodríguez-Castaño P, Cano-Crespo S, van der Ende A, van Putten JPM, Tommassen J. Expression of the Gene for Autotransporter AutB of Neisseria meningitidis Affects Biofilm Formation and Epithelial Transmigration. Front Cell Infect Microbiol 2016; 6:162. [PMID: 27921012 PMCID: PMC5118866 DOI: 10.3389/fcimb.2016.00162] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/07/2016] [Indexed: 11/15/2022] Open
Abstract
Neisseria meningitidis is a Gram-negative bacterium that resides as a commensal in the upper respiratory tract of humans, but occasionally, it invades the host and causes sepsis and/or meningitis. The bacterium can produce eight autotransporters, seven of which have been studied to some detail. The remaining one, AutB, has not been characterized yet. Here, we show that the autB gene is broadly distributed among pathogenic Neisseria spp. The gene is intact in most meningococcal strains. However, its expression is prone to phase variation due to slipped-strand mispairing at AAGC repeats located within the DNA encoding the signal sequence and is switched off in the vast majority of these strains. Moreover, various genetic disruptions prevent autB expression in most of the strains in which the gene is in phase indicating a strong selection against AutB synthesis. We observed that autB is expressed in two of the strains examined and that AutB is secreted and exposed at the cell surface. Functionality assays revealed that AutB synthesis promotes biofilm formation and delays the passage of epithelial cell layers in vitro. We hypothesize that this autotransporter is produced during the colonization process only in specific niches to facilitate microcolony formation, but its synthesis is switched off probably to evade the immune system and facilitate human tissue invasion.
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Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
| | - Fernanda L Paganelli
- Department of Medical Microbiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Patricia Rodríguez-Castaño
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
| | - Sara Cano-Crespo
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
| | - Arie van der Ende
- Department of Medical Microbiology, Academic Medical Center Amsterdam, Netherlands
| | - Jos P M van Putten
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University Utrecht, Netherlands
| | - Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
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25
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Bacterial Metabolism in the Host Environment: Pathogen Growth and Nutrient Assimilation in the Mammalian Upper Respiratory Tract. Microbiol Spectr 2016; 3. [PMID: 26185081 DOI: 10.1128/microbiolspec.mbp-0007-2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pathogens evolve in specific host niches and microenvironments that provide the physical and nutritional requirements conducive to their growth. In addition to using the host as a source of food, bacterial pathogens must avoid the immune response to their presence. The mammalian upper respiratory tract is a site that is exposed to the external environment, and is readily colonized by bacteria that live as resident flora or as pathogens. These bacteria can remain localized, descend to the lower respiratory tract, or traverse the epithelium to disseminate throughout the body. By virtue of their successful colonization of the respiratory epithelium, these bacteria obtain the nutrients needed for growth, either directly from host resources or from other microbes. This chapter describes the upper respiratory tract environment, including its tissue and mucosal structure, prokaryotic biota, and biochemical composition that would support microbial life. Neisseria meningitidis and the Bordetella species are discussed as examples of bacteria that have no known external reservoirs but have evolved to obligately colonize the mammalian upper respiratory tract.
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26
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Abstract
Microbes produce a biofilm matrix consisting of proteins, extracellular DNA, and polysaccharides that is integral in the formation of bacterial communities. Historical studies of polysaccharides revealed that their overproduction often alters the colony morphology and can be diagnostic in identifying certain species. The polysaccharide component of the matrix can provide many diverse benefits to the cells in the biofilm, including adhesion, protection, and structure. Aggregative polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as surfaces. Adhesion facilitates the colonization of both biotic and abiotic surfaces by allowing the bacteria to resist physical stresses imposed by fluid movement that could separate the cells from a nutrient source. Polysaccharides can also provide protection from a wide range of stresses, such as desiccation, immune effectors, and predators such as phagocytic cells and amoebae. Finally, polysaccharides can provide structure to biofilms, allowing stratification of the bacterial community and establishing gradients of nutrients and waste products. This can be advantageous for the bacteria by establishing a heterogeneous population that is prepared to endure stresses created by the rapidly changing environments that many bacteria encounter. The diverse range of polysaccharide structures, properties, and roles highlight the importance of this matrix constituent to the successful adaptation of bacteria to nearly every niche. Here, we present an overview of the current knowledge regarding the diversity and benefits that polysaccharide production provides to bacterial communities within biofilms.
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27
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Abstract
Bacterial-bacterial interactions play a critical role in promoting biofilm formation. Here we show that NagZ, a protein associated with peptidoglycan recycling, has moonlighting activity that allows it to modulate biofilm accumulation by Neisseria gonorrhoeae. We characterize the biochemical properties of NagZ and demonstrate its ability to function as a dispersing agent for biofilms formed on abiotic surfaces. We extend these observations to cell culture and tissue explant models and show that in nagZ mutants, the biofilms formed in cell culture and on human tissues contain significantly more biomass than those formed by a wild-type strain. Our results demonstrate that an enzyme thought to be restricted to peptidoglycan recycling is able to disperse preformed biofilms.
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28
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Gasparini R, Panatto D, Bragazzi NL, Lai PL, Bechini A, Levi M, Durando P, Amicizia D. How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare Effective Neisseria meningitidis Vaccines. J Immunol Res 2015; 2015:189153. [PMID: 26351643 PMCID: PMC4553322 DOI: 10.1155/2015/189153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/09/2015] [Indexed: 01/17/2023] Open
Abstract
In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity of Neisseria meningitidis at a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics). Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against the N. menigitidis serogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.
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Affiliation(s)
- R. Gasparini
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Panatto
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - N. L. Bragazzi
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - P. L. Lai
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - A. Bechini
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - M. Levi
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - P. Durando
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Amicizia
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
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Uberos J, Molina-Oya M, Martinez-Serrano S, Fernández-López L. Surface adhesion and host response as pathogenicity factors of Neisseria meningitidis. World J Clin Infect Dis 2015; 5:37-43. [DOI: 10.5495/wjcid.v5.i2.37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/12/2014] [Accepted: 03/09/2015] [Indexed: 02/06/2023] Open
Abstract
Neisseria meningitidis (N. meningitidis) is an exclusively human pathogen that has been identified in 10%-35% of the adult population and in 5.9% of the child population. Despite the high prevalence of carriers of N. meningitidis, it only occasionally causes meningococcal disease in the context of endemic disease, in certain geographic areas or in isolated epidemic outbreaks. After the N. meningitidis genome is described, progress has been made toward understanding the pathogenic mechanisms of the bacteria, although some aspects concerning its interaction with the environment and the host remain unclear. Some studies have reported that oxidative stress in the environment can modify the surface characteristics of N. meningitidis, increasing its adhesive properties and favouring an asymptomatic carrier state. The antigenic structure of N. meningitidis can be modified by its importing genetic material from other bacteria in its ecological niche. Some structures of lipopolysaccharides help it to evade the immune response, and these are observed more frequently in N. meningitidis isolated from blood than in healthy nasopharyngeal carriers. There is evidence that pili and capsule are downregulated upon contact with target cells. This paper reviews current knowledge on host-environment-bacteria mechanisms and interactions, with the aim of contributing to our understanding of the pathogenic mechanisms of N. meningitidis.
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30
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Antimicrobial peptide resistance in Neisseria meningitidis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:3026-31. [PMID: 26002321 DOI: 10.1016/j.bbamem.2015.05.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 05/06/2015] [Accepted: 05/12/2015] [Indexed: 12/26/2022]
Abstract
Antimicrobial peptides (AMPs) play an important role as a host defense against microbial pathogens and are key components of the human innate immune response. Neisseria meningitidis frequently colonizes the human nasopharynx as a commensal but also is a worldwide cause of epidemic meningitis and rapidly fatal sepsis. In the human respiratory tract, the only known reservoir of N. meningitidis, meningococci are exposed to human endogenous AMPs. Thus, it is not surprising that meningococci have evolved effective mechanisms to confer intrinsic and high levels of resistance to the action of AMPs. This article reviews the current knowledge about AMP resistance mechanisms employed by N. meningitidis. Two major resistance mechanisms employed by meningococci are the constitutive modification of the lipid A head groups of lipooligosaccharides by phosphoethanolamine and the active efflux pump mediated excretion of AMPs. Other factors influencing AMP resistance, such as the major porin PorB, the pilin biogenesis apparatus, and capsular polysaccharides, have also been identified. Even with an inherently high intrinsic resistance, several AMP resistance determinants can be further induced upon exposure to AMPs. Many well-characterized AMP resistance mechanisms in other Gram-negative bacteria are not found in meningococci. Thus, N. meningitidis utilizes a limited but highly effective set of molecular mechanisms to mediate antimicrobial peptide resistance. This article is part of a Special Issue entitled: Bacterial Resistance to Antimicrobial Peptides.
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Ruhal R, Antti H, Rzhepishevska O, Boulanger N, Barbero DR, Wai SN, Uhlin BE, Ramstedt M. A multivariate approach to correlate bacterial surface properties to biofilm formation by lipopolysaccharide mutants of Pseudomonas aeruginosa. Colloids Surf B Biointerfaces 2015; 127:182-91. [PMID: 25679490 DOI: 10.1016/j.colsurfb.2015.01.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/19/2014] [Accepted: 01/19/2015] [Indexed: 11/15/2022]
Abstract
Bacterial biofilms are involved in various medical infections and for this reason it is of great importance to better understand the process of biofilm formation in order to eradicate or mitigate it. It is a very complex process and a large range of variables have been suggested to influence biofilm formation. However, their internal importance is still not well understood. In the present study, a range of surface properties of Pseudomonas aeruginosa lipopolysaccharide mutants were studied in relation to biofilm formation measured in different kinds of multi-well plates and growth conditions in order to better understand the complexity of biofilm formation. Multivariate analysis was used to simultaneously evaluate the role of a range of physiochemical parameters under different conditions. Our results suggest the presence of serum inhibited biofilm formation due to changes in twitching motility. From the multivariate analysis it was observed that the most important parameters, positively correlated to biofilm formation on two types of plates, were high hydrophobicity, near neutral zeta potential and motility. Negative correlation was observed with cell aggregation, as well as formation of outer membrane vesicles and exopolysaccharides. This work shows that the complexity of biofilm formation can be better understood using a multivariate approach that can interpret and rank the importance of different factors being present simultaneously under several different environmental conditions, enabling a better understanding of this complex process.
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Affiliation(s)
- Rohit Ruhal
- Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Henrik Antti
- Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Olena Rzhepishevska
- Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | | | | | - Sun Nyunt Wai
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Madeleine Ramstedt
- Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.
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Biofilm formation by clinical isolates and its relevance to clinical infections. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 830:1-28. [PMID: 25366218 DOI: 10.1007/978-3-319-11038-7_1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Reports of biofilms have increased exponentially in the scientific literature over the past two decades, yet the vast majority of these are basic science investigations with limited clinical relevance. Biofilm studies involving clinical isolates are most often surveys of isolate collections, but suffer from lack of standardization in methodologies for producing and assessing biofilms. In contrast, more informative clinical studies correlating biofilm formation to patient data have infrequently been reported. In this chapter, biofilm surveys of clinical isolates of aerobic and anaerobic bacteria, mycobacteria, and Candida are reviewed, as well as those pertaining to the unique situation of cystic fibrosis. In addition, the influence of host components on in vitro biofilm formation, as well as published studies documenting the clinical impact of biofilms in human infections, are presented.
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Abstract
The exclusive reservoir of the genus Neisseria is the human. Of the broad range of species that comprise the Neisseria, only two are frequently pathogenic, and only one of those is a resident of the nasopharynx. Although Neisseria meningitidis can cause severe disease if it invades the bloodstream, the vast majority of interactions between humans and Neisseria are benign, with the bacteria inhabiting its mucosal niche as a non-invasive commensal. Understandably, with the exception of Neisseria gonorrhoeae, which preferentially colonises the urogenital tract, the neisseriae are extremely well adapted to survival in the human nasopharynx, their sole biological niche. The purpose of this review is to provide an overview of the molecular mechanisms evolved by Neisseria to facilitate colonisation and survival within the nasopharynx, focussing on N. meningitidis. The organism has adapted to survive in aerosolised transmission and to attach to mucosal surfaces. It then has to replicate in a nutrition-poor environment and resist immune and competitive pressure within a polymicrobial complex. Temperature and relative gas concentrations (nitric oxide and oxygen) are likely to be potent initial signals of arrival within the nasopharyngeal environment, and this review will focus on how N. meningitidis responds to these to increase the likelihood of its survival.
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Arenas J, Cano S, Nijland R, van Dongen V, Rutten L, van der Ende A, Tommassen J. The meningococcal autotransporter AutA is implicated in autoaggregation and biofilm formation. Environ Microbiol 2014; 17:1321-37. [PMID: 25059714 DOI: 10.1111/1462-2920.12581] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 07/22/2014] [Indexed: 11/29/2022]
Abstract
Autotransporters (ATs) are proteins secreted by Gram-negative bacteria that often play a role in virulence. Eight different ATs have been identified in Neisseria meningitidis, but only six of them have been characterized. AutA is one of the remaining ATs. Its expression remains controversial. Here, we show that the autA gene is present in many neisserial species, but its expression is often disrupted by various genetic features; however, it is expressed in certain strains of N. meningitidis. By sequencing the autA gene in large panels of disease isolates and Western blot analysis, we demonstrated that AutA expression is prone to phase variation at AAGC nucleotide repeats located within the DNA encoding the signal sequence. AutA is not secreted into the extracellular medium, but remains associated with the bacterial cell surface. We further demonstrate that AutA expression induces autoaggregation in a process that, dependent on the particular strain, may require extracellular DNA (eDNA). This property influences the organization of bacterial communities like lattices and biofilms. In vitro assays evidenced that AutA is a self-associating AT that binds DNA. We suggest that AutA-mediated autoaggregation might be particularly important for colonization and persistence of the pathogen in the nasopharynx of the host.
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Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, Paudalaan 8, Utrecht, 3584 CH, The Netherlands
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Müller MG, Ing JY, Cheng MKW, Flitter BA, Moe GR. Identification of a phage-encoded Ig-binding protein from invasive Neisseria meningitidis. THE JOURNAL OF IMMUNOLOGY 2013; 191:3287-96. [PMID: 23926326 DOI: 10.4049/jimmunol.1301153] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ig-binding proteins are employed by a variety of organisms to evade the immune system. To our knowledge, we now report for the first time that meningococcal strains from several capsular groups exhibit Ig-binding activity that is dependent on human serum factors. A protein mediating Ig binding was identified as T and B cell-stimulating protein B (TspB) by immunoprecipitation and by mass spectroscopic analysis of tryptic peptides. Recombinant TspB and derivatives verified Ig binding, with a preference for human IgG2 Fc, and localized the IgG-binding region to a highly conserved subdomain of TspB. Antiserum produced in mice against the conserved subdomain detected the presence of TspB on the cell surface by flow cytometry when bacteria were grown in the presence of human serum. By fluorescence microscopy, we observed formation of an extracellular matrix having characteristics of a biofilm containing TspB, human IgG, DNA, and large aggregates of bacteria. TspB is encoded by gene ORF6 in prophage DNA, which others have shown is associated with invasive meningococcal strains. Knocking out ORF6 genes eliminated IgG binding and formation of large bacterial aggregates in biofilm. Reintroduction of a wild-type ORF6 gene by phage transduction restored the phenotype. The results show that TspB mediated IgG binding and aggregate/biofilm formation triggered by factors in human serum. As has been observed for other Ig-binding proteins, the activities mediated by TspB may provide protection against immune responses, which is in accordance with the association of prophage DNA carrying ORF6 with invasive meningococcal strains.
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Affiliation(s)
- Maike G Müller
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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Hung MC, Christodoulides M. The biology of Neisseria adhesins. BIOLOGY 2013; 2:1054-109. [PMID: 24833056 PMCID: PMC3960869 DOI: 10.3390/biology2031054] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/01/2013] [Accepted: 07/03/2013] [Indexed: 01/15/2023]
Abstract
Members of the genus Neisseria include pathogens causing important human diseases such as meningitis, septicaemia, gonorrhoea and pelvic inflammatory disease syndrome. Neisseriae are found on the exposed epithelia of the upper respiratory tract and the urogenital tract. Colonisation of these exposed epithelia is dependent on a repertoire of diverse bacterial molecules, extending not only from the surface of the bacteria but also found within the outer membrane. During invasive disease, pathogenic Neisseriae also interact with immune effector cells, vascular endothelia and the meninges. Neisseria adhesion involves the interplay of these multiple surface factors and in this review we discuss the structure and function of these important molecules and the nature of the host cell receptors and mechanisms involved in their recognition. We also describe the current status for recently identified Neisseria adhesins. Understanding the biology of Neisseria adhesins has an impact not only on the development of new vaccines but also in revealing fundamental knowledge about human biology.
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Affiliation(s)
- Miao-Chiu Hung
- Neisseria Research, Molecular Microbiology, Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.
| | - Myron Christodoulides
- Neisseria Research, Molecular Microbiology, Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.
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Abstract
Neisseria meningitidis is a worldwide cause of meningitis and septicemia leading at least to 50,000 deaths every year. Nevertheless, N. meningitidis is also a commensal bacterium that asymptomatically colonizes the epithelial cells of the nasopharynx of 10 to 30% of healthy individuals. Occasionally, N. meningitidis crosses the nasopharyngeal barrier and enters the bloodstream. During bacteremia, N. meningitidis may adhere to endothelial cells of brain vessels and invade meninges. To identify the genes required for meningococcal host colonization, we screened a signature-tagged transposon mutagenesis library using an innovative in vitro colonization model in order to identify mutants displaying decreased capacity to colonize human epithelial cells. Approximately 1,600 defined insertion mutants of invasive serogroup C strain NEM8013 were screened. Candidate mutants were tested individually for quantification of bacterial biomass with confocal microscope and COMSTAT software. Five mutants were demonstrated to exhibit significantly decreased colonization ability. The identified genes, including narP and estD, appeared to be involved in adaptation to hypoxic conditions and stress resistance. Interestingly, the genes fadD1, nnrS, and NMV_2034 (encoding a putative thioredoxin), prior to this study, had not been shown to be involved in colonization. Therefore, we provide here insights into the meningococcal functions necessary for the bacterium to adapt to growth on host cells.
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Gong J, Xu M, Zhu C, Miao J, Liu X, Xu B, Zhang J, Yu Y, Jia X. Antimicrobial resistance, presence of integrons and biofilm formation ofSalmonellaPullorum isolates from eastern China (1962–2010). Avian Pathol 2013; 42:290-4. [DOI: 10.1080/03079457.2013.788129] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Arenas J, Nijland R, Rodriguez FJ, Bosma TNP, Tommassen J. Involvement of three meningococcal surface-exposed proteins, the heparin-binding protein NhbA, the α-peptide of IgA protease and the autotransporter protease NalP, in initiation of biofilm formation. Mol Microbiol 2012; 87:254-68. [DOI: 10.1111/mmi.12097] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes; Utrecht University; Padualaan 8; 3584 CH; Utrecht; the Netherlands
| | - Reindert Nijland
- Department of Medical Microbiology,; University Medical Center Utrecht; Heidelberglaan 100, G04.614; 3584 CX; Utrecht; the Netherlands
| | - Francisco J. Rodriguez
- Department of Molecular Microbiology and Institute of Biomembranes; Utrecht University; Padualaan 8; 3584 CH; Utrecht; the Netherlands
| | - Tom N. P. Bosma
- Department of Earth Sciences; Utrecht University; 3584 CD; Utrecht; the Netherlands
| | - Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes; Utrecht University; Padualaan 8; 3584 CH; Utrecht; the Netherlands
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Wang L, Hu X, Tao G, Wang X. Outer membrane defect and stronger biofilm formation caused by inactivation of a gene encoding for heptosyltransferase I in Cronobacter sakazakii ATCC BAA-894. J Appl Microbiol 2012; 112:985-97. [DOI: 10.1111/j.1365-2672.2012.05263.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Quinn GA, Maloy AP, McClean S, Carney B, Slater JW. Lipopeptide biosurfactants from Paenibacillus polymyxa inhibit single and mixed species biofilms. BIOFOULING 2012; 28:1151-1166. [PMID: 23113815 DOI: 10.1080/08927014.2012.738292] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Although biofilms are recognised as important in microbial colonisation, solutions to their inhibition are predominantly based on planktonic assays. These solutions have limited efficacy against biofilms. Here, a series of biofilm-orientated tests were used to identify anti-biofilm compounds from marine micro-flora. This led to the isolation of a complex of anti-biofilm compounds from an extract of Paenibacillus polymyxa (PPE). A combination of rpHPLC and mass spectrometry identified the principle components of PPE as fusaricidin B (LI-FO4b) and polymyxin D1, with minor contributions from surfactins. This complex (PPE) reduced the biofilm biomass of Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus bovis. In contrast, ampicillin was only effective against S. aureus. PPE also inhibited a self-assembling marine biofilm (SAMB) in co-incubation assays by 99.3% ± 1.9 and disrupted established SAMB by 72.4% ± 4.4, while ampicillin showed no significant reduction. The effectiveness of this complex of lipopeptides against single and multispecies biofilms suggests a future role in biofilm prevention strategies.
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Affiliation(s)
- Gerry A Quinn
- Centre of Applied Marine Biotechnology, Letterkenny Institute of Technology, Letterkenny, County Donegal, Republic of Ireland.
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Trivedi K, Tang CM, Exley RM. Mechanisms of meningococcal colonisation. Trends Microbiol 2011; 19:456-63. [PMID: 21816616 DOI: 10.1016/j.tim.2011.06.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/16/2011] [Accepted: 06/28/2011] [Indexed: 01/05/2023]
Abstract
Despite advances against infectious diseases over the past century, Neisseria meningitidis remains a major causative agent of meningitis and septicaemia worldwide. Its adaptation for survival in the human nasopharynx makes the meningococcus a highly successful commensal bacterium. Recent progress has been made in understanding the mechanisms that enable neisserial colonisation, in terms of the role of type IV pili, the impact of other adhesins, biofilm formation, nutrient acquisition and resistance to host immune defences. Refinements in cell-based and in vivo models will lead to improved understanding of the colonisation process, and hopefully to more effective vaccines and therapeutic strategies.
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Affiliation(s)
- Kaushali Trivedi
- Centre for Molecular Microbiology and Infection, Faculty of Medicine, Flowers Building, Imperial College London, London SW7 2AZ, UK
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McQueary CN, Actis LA. Acinetobacter baumannii biofilms: variations among strains and correlations with other cell properties. J Microbiol 2011; 49:243-50. [PMID: 21538245 DOI: 10.1007/s12275-011-0343-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 12/20/2010] [Indexed: 11/28/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen that causes serious infections in humans by colonizing and persisting on surfaces normally found in hospital settings. The capacity of this pathogen to persist in these settings could be due to its ability to form biofilms on inanimate surfaces. This report shows that although the ATCC 19606(T) type strain and 8 different clinical isolates form biofilms, there are significant variations in the cell density and microscopic structures of these cell aggregates, with 3 of the isolates forming pellicles floating on the surface of stagnant broth cultures. PCR indicated that, like ATCC 19606(T), all 8 clinical isolates harbor all the genetic components of the CsuA/BABCDE chaperone-usher pili assembly system, which is needed for biofilm formation on plastic. Pili detection in cells of all strains examined supports the presence and function of a pilus assembly system. However, only one of them produced the putative ATCC 19606(T) CsuA/B pilin subunit protein. Hydrophobicity tests and motility assays also showed significant variations among all tested strains and did not result in direct correlations between the biofilm phenotype and cell properties that could affect biofilm formation on abiotic surfaces. This lack of correlation among these 3 phenotypes may reflect some of the variations already reported with this pathogen, which may pose a challenge in the treatment of the infections this pathogen causes in humans using biofilm formation on abiotic surfaces as a target.
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van Alen T, Claus H, Zahedi RP, Groh J, Blazyca H, Lappann M, Sickmann A, Vogel U. Comparative proteomic analysis of biofilm and planktonic cells of Neisseria meningitidis. Proteomics 2010; 10:4512-21. [PMID: 21136603 DOI: 10.1002/pmic.201000267] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Neisseria meningitidis is a commensal of the human nasopharynx occasionally causing invasive disease. In vitro biofilms have been employed to model meningococcal carriage. A proteomic analysis of meningococcal biofilms was conducted and metabolic changes related to oxygen and nutrient limitation and upregulation of proteins involved in ROS defense were observed. The upregulated MntC which protects against ROS was shown to be required for meningococcal biofilm formation, but not for planktonic growth. ROS-induced proteomic changes might train the biofilm to cope with immune effectors.
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Affiliation(s)
- Tessa van Alen
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
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Smirnov TA, Didenko LV, Tiganova IG, Andreevskaya SG, Alekseeva NV, Stepanova TV, Romanov YM. Study of the structures of biofilms formed by Salmonella typhimurium bacteria on abiotic surfaces by the methods of light and transmission electron microscopy. APPL BIOCHEM MICRO+ 2010. [DOI: 10.1134/s0003683810070057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Smirnova TA, Didenko LV, Azizbekyan RR, Romanova YM. Structural and functional characteristics of bacterial biofilms. Microbiology (Reading) 2010. [DOI: 10.1134/s0026261710040016] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Biofilm formation by the human pathogen Neisseria meningitidis. Med Microbiol Immunol 2010; 199:173-83. [PMID: 20376486 DOI: 10.1007/s00430-010-0149-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Indexed: 10/19/2022]
Abstract
The past decade has seen an increasing interest in biofilm formation by Neisseria meningitidis, a human facultative pathogen causing life-threatening childhood disease commencing from asymptomatic nasopharyngeal colonization. Studying the biology of in vitro biofilm formation improves the understanding of inter-bacterial processes in asymptomatic carriage, of bacterial aggregate formation on host cells, and of meningococcal population biology. This paper reviews publications referring to meningococcal biofilm formation with an emphasis on the role of motility and of extracellular DNA. The theory of sub-dividing the meningococcal population in settler and spreader lineages is discussed, which provides a mechanistic framework for the assumed balance of colonization efficacy and transmission frequency.
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Lappann M, Claus H, van Alen T, Harmsen M, Elias J, Molin S, Vogel U. A dual role of extracellular DNA during biofilm formation ofNeisseria meningitidis. Mol Microbiol 2010; 75:1355-71. [DOI: 10.1111/j.1365-2958.2010.07054.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tanabe SI, Bonifait L, Fittipaldi N, Grignon L, Gottschalk M, Grenier D. Pleiotropic effects of polysaccharide capsule loss on selected biological properties of Streptococcus suis. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2010; 74:65-70. [PMID: 20357962 PMCID: PMC2801315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 10/01/2008] [Indexed: 05/29/2023]
Abstract
In this study, an unencapsulated Streptococcus suis mutant was used to investigate the pleiotropic effects resulting from capsule loss. The capsule deficient mutant of S. suis acquired a biofilm-positive phenotype, which was associated with significantly increased cell surface hydrophobicity. Cell-associated fibrinogen-binding and chymotrypsin-like activities were decreased in the unencapsulated mutant. The mutant did not differ significantly from the encapsulated parent strain for minimal inhibitory concentrations to penicillin G, ampicillin, and tetracycline. However, while the encapsulated strain was highly resistant to the bactericidal action of penicillin G and ampicillin, the unencapsulated mutant was approximately 60-fold more sensitive. Compared with the parent strain, the unencapsulated mutant induced a much higher inflammatory response in monocyte-derived macrophages resulting in an increased secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and IL-8. The capsule appears to hinder important adhesins or hydrophobic molecules that mediate biofilm formation, as well as cell wall components capable of stimulating immune cells.
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Affiliation(s)
| | | | | | | | | | - Daniel Grenier
- Address all correspondence to Dr. Grenier; telephone: (418) 656-7341; fax: (418) 656-2861; e-mail:
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Neil RB, Apicella MA. Clinical and laboratory evidence for Neisseria meningitidis biofilms. Future Microbiol 2009; 4:555-63. [PMID: 19492966 DOI: 10.2217/fmb.09.27] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Neisseria meningitidis is the etiologic agent of meningococcal meningitis. Carriage of the organism is approximately 10% while active disease occurs at a rate of 1:100,000. Recent publications demonstrate that N. meningitidis has the ability to form biofilms on glass, plastic or cultured human bronchial epithelial cells. Microcolony-like structures are also observed in histological sections from patients with active meningococcal disease. This review investigates the possible role of meningococcal biofilms in carriage and active disease, based on the laboratory and clinical aspects of the disease.
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Affiliation(s)
- R Brock Neil
- University of Iowa, Hygienic Laboratory, 102 Oakdale Campus, H101 OH, Iowa City, IA 52242-5002, USA
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