Formation of Biofilms by Listeria monocytogenes under Various Growth Conditions

2005 ◽  
Vol 68 (1) ◽  
pp. 92-97 ◽  
Author(s):  
ANDREW G. MOLTZ ◽  
SCOTT E. MARTIN

Eight strains of Listeria monocytogenes (7644, 19112, 15313, Scott A, LCDC, 10403S, SLCC, and 1370) produce biofilms when grown on polyvinyl chloride microtiter well plates. The growth medium (tryptic soy broth [TSB] or modified Welshimer's broth [MWB] at 32°C) influenced the amount of biofilm formed; maximum biofilms were formed in MWB by six strains and in TSB by the remaining two strains. This result suggests that the growth medium is critical in development of L. monocytogenes biofilm. This organism also produced biofilms on stainless steel chips. Biofilm formation on these chips was observed following growth in TSB at 4, 20, and 37°C. After 20 h of incubation at 20 or 37°C, the cell density was approximately 106 CFU per chip, and after 4 days incubation at 4°C, the cell density was 105 CFU per chip. L. monocytogenes strain Scott A biofilm formation on stainless steel chips was visualized using scanning electron microscopy, which revealed dense aggregates of cells held together by meshlike webbing.

2009 ◽  
Vol 59 (4) ◽  
pp. 423-435 ◽  
Author(s):  
Milanov Dubravka ◽  
Asanin Ruzica ◽  
Vidic Branka ◽  
Krnjaic D. ◽  
Petrovic Jelena ◽  
...  

2014 ◽  
Vol 8 (34) ◽  
pp. 3136-3143
Author(s):  
Alessandra P. Sant’Anna Salimena ◽  
◽  
Alexandre C. Santos ◽  
Maria das Graças Cardoso ◽  
Eduardo Alves ◽  
...  

1991 ◽  
Vol 54 (12) ◽  
pp. 925-929 ◽  
Author(s):  
ALEXANDRA T. SPURLOCK ◽  
E. A. ZOTTOLA

The growth and potential attachment of Listeria monocytogenes to cast iron in drains was investigated in this study. L. monocytogenes was grown in rich and dilute nutritive media in free-standing cast iron drains. The pH in the drain was adjusted over the growth period to pH 4.5, 7.0, and 9.0. L. monocytogenes was found to survive pH adjustments in drains for 28 d. Scanning electron microscopy (SEM) was used to investigate the attachment of L. monocytogenes to cast iron chips. SEM observation showed L. monocytogenes cells apparently attached to the iron surface of the chip. Listeria does not appear to attach as readily to cast iron as to stainless steel surfaces.


2020 ◽  
Vol 20 (24) ◽  
pp. 2186-2191
Author(s):  
Lialyz Soares Pereira André ◽  
Renata Freire Alves Pereira ◽  
Felipe Ramos Pinheiro ◽  
Aislan Cristina Rheder Fagundes Pascoal ◽  
Vitor Francisco Ferreira ◽  
...  

Background: Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses. Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05). Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound. Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.


2019 ◽  
Vol 67 (10) ◽  
pp. 1708
Author(s):  
Dipankar Das ◽  
Harsha Bhattacharjee ◽  
Krishna Gogoi ◽  
JayantaK Das ◽  
Puneet Misra ◽  
...  

2020 ◽  
Vol 8 (3) ◽  
pp. 71
Author(s):  
Masaaki Minami ◽  
Hiroshi Takase ◽  
Masayo Taira ◽  
Toshiaki Makino

Streptococcus mutans, a bacterium that causes dental plaques, forms a biofilm on tooth surfaces. This biofilm can cause gingivitis by stimulating the gingival margin. However, there is no established treatment for biofilm removal. Hainosan (Painongsan), a traditional Japanese Kampo formula, has been used to treat gingivitis. Therefore, we investigated the biofilm suppressive effects of the hainosan extract (HNS) and its components on S. mutans. We conducted scanning electron microscopy and confocal laser microscopy analyses to clarify the anti-biofilm activities of HNS and its crude drugs. We also performed a quantitative RT-PCR assay to assess the biofilm-related gene expression. HNS showed a significant dose-dependent suppressive effect on biofilm formation. Both the scanning electron microscopy and confocal laser microscopy analyses also revealed the significant inhibitory effects of the extract on biofilm formation. Transmission electron microscopy analysis showed that HNS disrupted the surface of the bacterial wall. Furthermore, HNS reduced the hydrophobicity of the bacteria, and suppressed the mRNA expression of β-glucosyltransferase (gtfB), glucosyltransferase-SI (gtfC), and fructosyltransferase (ftf). Among the constituents of hainosan, the extract of the root of Platycodon grandiflorum (PG) showed the strongest biofilm suppression effect. Platycodin D, one of the constituent natural compounds of PG, inhibited S. mutans-associated biofilm. These findings indicate that hainosan eliminates dental plaques by suppressing biofilm formation by S. mutans.


2011 ◽  
Vol 183-185 ◽  
pp. 1837-1841
Author(s):  
Lei Sha ◽  
Yan Lai Wang ◽  
Shi Liang Ban

CuInSe2 thin films were obtained by selenization of the Cu-In precursors in the atmosphere of Se vapour, which were prepared on stainless steel and titanium substrates by electrodeposition. The films were characterized by XRD, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The respective influences of composition, phases and surface morphology of Cu-In precursors on indium loss were investigated. The results indicate that the indium loss occurs in selenization process because of volatile In2Se arising. The indium loss is less in selenization process of Cu-In precursors contained CuIn, Cu2In and In phases.


2011 ◽  
Vol 189-193 ◽  
pp. 129-136
Author(s):  
Xiao Qiu Zheng ◽  
Shi Kun Xie ◽  
Rong Xi Yi

In order to research the adhesion of sputtering protective coating of Gd. Gd substrates was coated with 1Cr18Ni9Ti by means of DC magnetron sputtering technology. The characteristics of the film were investigated by scanning electron microscopy (SEM), EDS, SPM and the adhesions of film was tested by tension test. The results show that the films of 1Cr18Ni9Ti are distributed by means of islands when the sputtering was initiated and the grains are like thin fiber. After a few minutes, the films are smooth and perfect, the interferences between 1Cr18Ni9Ti and Gd join together strongly, and the largest strength of adhesion is 24.7MPa when the sputtering density is 966 w/cm2 and the sputtering time is 8 minutes.


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