Biofilm Formation by Gram-Negative Bacteria on Central Venous Catheter Connectors: Effect of Conditioning Films in a Laboratory Model

Murga, Ricardo; Miller, J. M.; Donlan, Rodney M.

doi:10.1128/jcm.39.6.2294-2297.2001

Cited by 112 publications

(66 citation statements)

References 15 publications

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“…As has been noted in the literature, conditioning films can render surfaces more favorable for bacterial adhesion (32,33). In our case, these conditioning films had the added effect of maintaining surface wetting.…”

Section: Discussionsupporting

confidence: 54%

Bacterial flagella explore microscale hummocks and hollows to increase adhesion

Friedlander

Vlamakis

Kim

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

256

238

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Biofilms, surface-bound communities of microbes, are economically and medically important due to their pathogenic and obstructive properties. Among the numerous strategies to prevent bacterial adhesion and subsequent biofilm formation, surface topography was recently proposed as a highly nonspecific method that does not rely on small-molecule antibacterial compounds, which promote resistance. Here, we provide a detailed investigation of how the introduction of submicrometer crevices to a surface affects attachment of Escherichia coli. These crevices reduce substrate surface area available to the cell body but increase overall surface area. We have found that, during the first 2 h, adhesion to topographic surfaces is significantly reduced compared with flat controls, but this behavior abruptly reverses to significantly increased adhesion at longer exposures. We show that this reversal coincides with bacterially induced wetting transitions and that flagellar filaments aid in adhesion to these wetted topographic surfaces. We demonstrate that flagella are able to reach into crevices, access additional surface area, and produce a dense, fibrous network. Mutants lacking flagella show comparatively reduced adhesion. By varying substrate crevice sizes, we determine the conditions under which having flagella is most advantageous for adhesion. These findings strongly indicate that, in addition to their role in swimming motility, flagella are involved in attachment and can furthermore act as structural elements, enabling bacteria to overcome unfavorable surface topographies. This work contributes insights for the future design of antifouling surfaces and for improved understanding of bacterial behavior in native, structured environments. microbial adhesion | structured surfaces | bacterial appendages | surface texture | surface wetting T he attachment of bacteria to solid surfaces is the first step in the formation of biofilms-communities of sessile microbes surrounded by a polymeric matrix (1, 2). A growing appreciation of the ubiquity and importance of biofilms in medicine and industry has led to a proliferation of antiadhesion strategies that include chemical, biological, and physical approaches (3-12). Attempts to block biofilm formation must also take into account the rapid evolution of bacteria and their ability to resist many chemical assaults (13)(14)(15)(16)(17). By preventing adhesion in a manner that is nontoxic for the bacteria as well as for the application (e.g., medical implants), there is hope that we may reduce the costs associated with biofilm formation without imposing selective pressures for the development of antibiotic resistance. Physical strategies, particularly the use of rationally designed surface topographies, have gained attention recently as highly nonspecific methods for prevention of attachment without the use of antimicrobials (6,8,11,(18)(19)(20).Understanding how bacteria interact with surfaces that have roughness on the micrometer and submicrometer length scales (i.e., comparable with th...

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Section: Discussionsupporting

confidence: 54%

Bacterial flagella explore microscale hummocks and hollows to increase adhesion

Friedlander

Vlamakis

Kim

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

256

238

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“…We recently confirmed a direct link between Pseudomonas aeruginosa biofilm genetics and resistance to components of the human innate immune system (35). During this time, other papers have been published supporting our idea that P. aeruginosa and biofilms in general manipulate the immune system to their advantage (41,55,56). Most recently, O'Toole and colleagues demonstrated that P. aeruginosa biofilms growing on airway epithelial cells exhibited decreased virulence in the presence of the antibiotic tobramycin (1).…”

supporting

confidence: 53%

Flagellum-Mediated Biofilm Defense Mechanisms of Pseudomonas aeruginosa against Host-Derived Lactoferrin

et al. 2009

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Chronic infection with the gram-negative organism Pseudomonas aeruginosa is a leading cause of morbidity and mortality in human patients, despite high doses of antibiotics used to treat the various diseases this organism causes. These infections are chronic because P. aeruginosa readily forms biofilms, which are inherently resistant to antibiotics as well as the host's immune system. Our laboratory has been investigating specific mutations in P. aeruginosa that regulate biofilm bacterial susceptibility to the host. To continue our investigation of the role of genetics in bacterial biofilm host resistance, we examined P. aeruginosa biofilms that lack the flgK gene. This mutant lacks flagella, which results in defects in early biofilm development (up to 36 h). For these experiments, the flgK-disrupted strain and the parental strain (PA14) were used in a modified version of the 96-well plate microtiter assay. Biofilms were challenged with freshly isolated human leukocytes for 4 to 6 h and viable bacteria enumerated by CFU. Subsequent to the challenge, both mononuclear cells (monocytes and lymphocytes) and neutrophils, along with tumor necrosis factor alpha (TNF-␣), were required for optimal killing of the flgK biofilm bacteria. We identified a cytokine cross talk network between mononuclear cells and neutrophils that was essential to the production of lactoferrin and bacterial killing. Our data suggest that TNF-␣ is secreted from mononuclear cells, causing neutrophil activation, resulting in the secretion of bactericidal concentrations of lactoferrin. These results extend previous studies of the importance of lactoferrin in the innate immune defense against bacterial biofilms.

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“…Murga et al investigated the effect of human blood on biofi lm formation on the inner lumen of needleless central venous catheter connectors by Enterobacter cloacae, P. aeruginosa , and Pantoea agglomerans ; and found that conditioning with whole blood resulted in signifi cantly higher viable colony counts than non-conditioned controls (Murga et al 2001 ). Another study examined gene expression of a single S. aureus USA300 isolate in response to human blood, and demonstrated that whole blood induced greater expression of fi bronectin binding protein and extracellular fi brinogen binding protein, which could potentially impact biofi lm formation (Malachowa et al 2011 ).…”

Section: Infl Uence Of Host Factors On Biofi Lm Formationmentioning

confidence: 98%

Biofilm Formation by Clinical Isolates and Its Relevance to Clinical Infections

Akers

Cardile

Wenke

et al. 2014

Advances in Experimental Medicine and Biology

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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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Biofilm Formation by Gram-Negative Bacteria on Central Venous Catheter Connectors: Effect of Conditioning Films in a Laboratory Model

Cited by 112 publications

References 15 publications

Bacterial flagella explore microscale hummocks and hollows to increase adhesion

Bacterial flagella explore microscale hummocks and hollows to increase adhesion

Flagellum-Mediated Biofilm Defense Mechanisms of Pseudomonas aeruginosa against Host-Derived Lactoferrin

Biofilm Formation by Clinical Isolates and Its Relevance to Clinical Infections

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