scholarly journals Evaluating the Effect of Metal Interference in Inhibition of Biofilm Formation by Uropathogenic Escherichia coli Isolated From Hospitalized Patients

2019 ◽  
Vol 3 (4) ◽  
pp. 172-177
Author(s):  
Fatemeh Khazaei ◽  
Somayeh Talebi ◽  
Farzaneh Hosseni
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Hospitalized Patients ◽  
Pcr Analysis ◽  
Maximum Effect ◽  
Biochemical Tests ◽  
Microtiter Plate Assay ◽  
E Coli ◽  
Bivalent Metals ◽  
Biofilm Development

Introduction: Bacteria that are able to form biofilms can lead to chronic antibiotic-resistant infections and immunomodulatory effects. Iron and other bivalent metals are essential requirements for biofilm formation by bacteria. Escherichia coli is the most predominant agent causing urinary tract infection (UTI). This study aimed to assess the effects of bivalent metals (iron, zinc, cobalt, and copper) on biofilm formation by E. coli isolated from hospitalized patients suffering from UTI. Methods: A total of 110 E. coli were isolated from 200 UTI patients referred to Farmanieh hospital in Tehran, Iran. E. coli was confirmed by culture specific media, biochemical tests, and polymerase chain reaction (PCR) analysis. To determine the antibiotic resistance, the Kirby-Bauer disk method was used and the biofilm formation was assessed using microtiter plate assay and electron microscopy. Finally, the data were analyzed via paired t test using the SPSS software. Results: Based on our results, out of 110 urine samples containing E. coli, the highest and the lowest resistance were observed to ampicillin (90%) and amikacin (53%), respectively. The biofilm development was intensified in the presence of glucose and iron. The results also indicated that biofilm formation was inhibited by the use of bivalent metal ions including zinc, cobalt, and copper, with the maximum effect obtained for zinc (P < 0.05).Conclusion: Our work led us to conclude that zinc, cobalt, and copper can inhibit biofilm formation by bacterial strains in medicine.

scholarly journals Sab, a Novel Autotransporter of Locus of Enterocyte Effacement-Negative Shiga-Toxigenic Escherichia coli O113:H21, Contributes to Adherence and Biofilm Formation

2009 ◽  
Vol 77 (8) ◽  
pp. 3234-3243 ◽  
Author(s):  
Sylvia Herold ◽  
James C. Paton ◽  
Adrienne W. Paton
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Gastrointestinal Disease ◽  
Pcr Analysis ◽  
Systemic Complications ◽  
E Coli ◽  
Acid Protein ◽  
Life Threatening ◽  
Uremic Syndrome ◽  
Enterocyte Effacement

ABSTRACT Shiga-toxigenic Escherichia coli (STEC) strains cause serious gastrointestinal disease, which can lead to potentially life-threatening systemic complications such as hemolytic-uremic syndrome. Although the production of Shiga toxin has been considered to be the main virulence trait of STEC for many years, the capacity to colonize the host intestinal epithelium is a crucial step in pathogenesis. In this study, we have characterized a novel megaplasmid-encoded outer membrane protein in locus of enterocyte effacement (LEE)-negative O113:H21 STEC strain 98NK2, termed Sab (for STEC autotransporter [AT] contributing to biofilm formation). The 4,296-bp sab gene encodes a 1,431-amino-acid protein with the features of members of the AT protein family. When expressed in E. coli JM109, Sab contributed to the diffuse adherence to human epithelial (HEp-2) cells and promoted biofilm formation on polystyrene surfaces. A 98NK2 sab deletion mutant was also defective in biofilm formation relative to its otherwise isogenic wild-type parent, and this was complemented by transformation with a sab-carrying plasmid. Interestingly, an unrelated O113:H21 STEC isolate that had a naturally occurring deletion in sab was similarly defective in biofilm formation. PCR analysis indicated that sab is present in LEE-negative STEC strains belonging to serotypes/groups O113:H21, O23, and O82:H8. These findings raise the possibility that Sab may contribute to colonization in a subset of LEE-negative STEC strains.

scholarly journals Genome-Wide Transposon Mutagenesis Reveals a Role for pO157 Genes in Biofilm Development in Escherichia coli O157:H7 EDL933

2010 ◽  
Vol 78 (6) ◽  
pp. 2377-2384 ◽  
Author(s):  
Supraja Puttamreddy ◽  
Nancy A. Cornick ◽  
F. Chris Minion
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Virulence Plasmid ◽  
Microtiter Plate Assay ◽  
Severe Diarrhea ◽  
Wide Range ◽  
Intergenic Regions ◽  
Biofilm Development

ABSTRACT Enterohemorrhagic Escherichia coli O157:H7, a world-wide human food-borne pathogen, causes mild to severe diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. The ability of this pathogen to persist in the environment contributes to its dissemination to a wide range of foods and food processing surfaces. Biofilms are thought to be involved in persistence, but the process of biofilm formation is complex and poorly understood in E. coli O157:H7. To better understand the genetics of this process, a mini-Tn5 transposon insertion library was constructed in strain EDL933 and screened for biofilm-negative mutants using a microtiter plate assay. Ninety-five of 11,000 independent insertions (0.86%) were biofilm negative, and transposon insertions were located in 51 distinct genes/intergenic regions that must be involved either directly or indirectly in biofilm formation. All of the 51 biofilm-negative mutants showed reduced biofilm formation on both hydrophilic and hydrophobic surfaces. Thirty-six genes were unique to this study, including genes on the virulence plasmid pO157. The type V secreted autotransporter serine protease EspP and the enterohemolysin translocator EhxD were found to be directly involved in biofilm formation. In addition, EhxD and EspP were also important for adherence to T84 intestinal epithelial cells, suggesting a role for these genes in tissue interactions in vivo.

scholarly journals Biofilm Formation and Dispersal under the Influence of the Global Regulator CsrA of Escherichia coli

2002 ◽  
Vol 184 (1) ◽  
pp. 290-301 ◽  
Author(s):  
Debra W. Jackson ◽  
Kazushi Suzuki ◽  
Lawrence Oakford ◽  
Jerry W. Simecka ◽  
Mark E. Hart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Rna Binding ◽  
Glycogen Synthase ◽  
Regulatory Protein ◽  
Ectopic Expression ◽  
Knockout Mutant ◽  
E Coli ◽  
K 12 ◽  
Biofilm Development

ABSTRACT The predominant mode of growth of bacteria in the environment is within sessile, matrix-enclosed communities known as biofilms. Biofilms often complicate chronic and difficult-to-treat infections by protecting bacteria from the immune system, decreasing antibiotic efficacy, and dispersing planktonic cells to distant body sites. While the biology of bacterial biofilms has become a major focus of microbial research, the regulatory mechanisms of biofilm development remain poorly defined and those of dispersal are unknown. Here we establish that the RNA binding global regulatory protein CsrA (carbon storage regulator) of Escherichia coli K-12 serves as both a repressor of biofilm formation and an activator of biofilm dispersal under a variety of culture conditions. Ectopic expression of the E. coli K-12 csrA gene repressed biofilm formation by related bacterial pathogens. A csrA knockout mutation enhanced biofilm formation in E. coli strains that were defective for extracellular, surface, or regulatory factors previously implicated in biofilm formation. In contrast, this csrA mutation did not affect biofilm formation by a glgA (glycogen synthase) knockout mutant. Complementation studies with glg genes provided further genetic evidence that the effects of CsrA on biofilm formation are mediated largely through the regulation of intracellular glycogen biosynthesis and catabolism. Finally, the expression of a chromosomally encoded csrA′-′lacZ translational fusion was dynamically regulated during biofilm formation in a pattern consistent with its role as a repressor. We propose that global regulation of central carbon flux by CsrA is an extremely important feature of E. coli biofilm development.

scholarly journals Biofilm Formation by and Multicellular Behavior of Escherichia coli O55:H7, an Atypical Enteropathogenic Strain

2010 ◽  
Vol 76 (5) ◽  
pp. 1545-1554 ◽  
Author(s):  
Michal Weiss-Muszkat ◽  
Dana Shakh ◽  
Yizhou Zhou ◽  
Riky Pinto ◽  
Eddy Belausov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Genetic Relatedness ◽  
Liquid Interface ◽  
E Coli ◽  
Wild Type Phenotype ◽  
Enteropathogenic Strain ◽  
Biofilm Development ◽  
Air Liquid Interface ◽  
High Degree

ABSTRACT Enteropathogenic Escherichia coli (EPEC) is an important causal agent of diarrheal illness throughout the world. Nevertheless, researchers have only recently begun to explore its capacity to form biofilms. Strain O55:H7 (DMS9) is a clinical isolate belonging to the atypical EPEC (aEPEC) group, which displays a high degree of genetic relatedness to enterohemorrhagic E. coli. Strain DMS9 formed a robust biofilm on an abiotic surface at 26�C, but not at 37�C. It also formed a dense pellicle at the air-liquid interface and developed a red, rough, and dry (RDAR) morphotype on Congo red agar. Unlike a previously described E. coli O157:H7 strain, the aEPEC strain seems to express cellulose. Transposon mutagenesis was used to identify biofilm-deficient mutants. One of the mutants was inactivated in the csgFG genes, required for assembly and secretion of curli fimbriae, while a second mutant had a mutation in crl, a thermosensitive global regulator that modulates σS activity and downstream expression of curli and cellulose. The two mutants were deficient in their biofilm formation capabilities and did not form a pellicle at the air-liquid interface. Unlike in Salmonella, the csgFG mutant in aEPEC completely lost the RDAR phenotype, while the crl mutant displayed a unique RDAR “pizza”-like morphotype. Genetic complementation of the two mutants resulted in restoration of the wild-type phenotype. This report is the first to describe and analyze a multicellular behavior in aEPEC and support a major role for curli and the crl regulator in biofilm development at low temperatures corresponding to the nonmammalian host environment.

scholarly journals The pgaABCD Locus of Escherichia coli Promotes the Synthesis of a Polysaccharide Adhesin Required for Biofilm Formation

2004 ◽  
Vol 186 (9) ◽  
pp. 2724-2734 ◽  
Author(s):  
Xin Wang ◽  
James F. Preston ◽  
Tony Romeo
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Growth Conditions ◽  
Lytic Enzymes ◽  
Surface Binding ◽  
Intact Cells ◽  
E Coli ◽  
Dependent Cell ◽  
Biofilm Dispersal ◽  
Biofilm Development

ABSTRACT Production of a polysaccharide matrix is a hallmark of bacterial biofilms, but the composition of matrix polysaccharides and their functions are not widely understood. Previous studies of the regulation of Escherichia coli biofilm formation suggested the involvement of an unknown adhesin. We now establish that the pgaABCD (formerly ycdSRQP) locus affects biofilm development by promoting abiotic surface binding and intercellular adhesion. All of the pga genes are required for optimal biofilm formation under a variety of growth conditions. A pga-dependent cell-bound polysaccharide was isolated and determined by nuclear magnetic resonance analyses to consist of unbranched β-1,6-N-acetyl-d-glucosamine, a polymer previously unknown from the gram-negative bacteria but involved in adhesion by staphylococci. The pga genes are predicted to encode envelope proteins involved in synthesis, translocation, and possibly surface docking of this polysaccharide. As predicted, if poly-β-1,6-GlcNAc (PGA) mediates cohesion, metaperiodate caused biofilm dispersal and the release of intact cells, whereas treatment with protease or other lytic enzymes had no effect. The pgaABCD operon exhibits features of a horizontally transferred locus and is present in a variety of eubacteria. Therefore, we propose that PGA serves as an adhesin that stabilizes biofilms of E. coli and other bacteria.

scholarly journals Escherichia coli and its lipopolysaccharide modulate in vitro Candida biofilm formation

2009 ◽  
Vol 58 (12) ◽  
pp. 1623-1631 ◽  
Author(s):  
H. M. H. N. Bandara ◽  
J. Y. Y. Yau ◽  
R. M. Watt ◽  
L. J. Jin ◽  
L. P. Samaranayake
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Cell Activity ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
E Coli ◽  
Cell Numbers ◽  
Cell Counts ◽  
Biofilm Development

Demystification of microbial behaviour in mixed biofilms could have a major impact on our understanding of infectious diseases. The objectives of this study were to evaluate in vitro the interactions of six different Candida species and a Gram-negative coliform, Escherichia coli, in dual-species biofilms, and to assess the effect of E. coli LPS on Candida biofilm formation. A single isolate of E. coli ATCC 25922 and six different species of Candida, Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA-646, were studied using a standard biofilm assay. Each Candida species was co-cultured with E. coli on a polystyrene surface and biofilm formation was quantified by a c.f.u. assay. The biofilm was then analysed by Live/Dead staining and fluorescence microscopy (confocal laser-scanning microscopy, CLSM), whilst scanning electron microscopy (SEM) was employed to visualize the biofilm architecture. The effect of E. coli LPS on Candida biofilm cell activity at defined time intervals was assessed with an XTT reduction assay. A significant quantitative reduction in c.f.u. counts of C. tropicalis (after 90 min), C. parapsilosis (after 90 min and 24 h), C. krusei (after 24 h) and C. dubliniensis (after 24 and 48 h) was noted on incubation with E. coli in comparison with their monospecies biofilm counterparts (P <0.05). On the other hand, a simultaneous and significant reduction in E. coli cell numbers occurred on co-culture with C. albicans (after 90 min), and an elevation of E. coli cell numbers followed co-culture with C. tropicalis (after 24 h) and C. dubliniensis (after 24 h and 48 h) (P <0.05). All quantitative findings were confirmed by SEM and CLSM analyses. By SEM observation, dual-species biofilms demonstrated scanty architecture with reduced visible cell counts at all stages of biofilm development, despite profuse growth and dense colonization in their single-species counterparts. Significantly elevated metabolic activity, as assessed by XTT readings, was observed in E. coli LPS-treated C. tropicalis and C. parapsilosis biofilms (after 48 h), whilst this had the opposite effect for C. dubliniensis (after 24 h) (P <0.05). These data indicate that E. coli and Candida species in a mixed-species environment mutually modulate biofilm development, both quantitatively and qualitatively, and that E. coli LPS appears to be a key component in mediating these outcomes.

Effects of phytogenic substances on growth and biofilm formation of Escherichia coli and Salmonella field isolates

2021 ◽  
Vol 72 (1) ◽  
pp. 1-8
Author(s):  
Sonja Axmann ◽  
Anika Schorpp ◽  
Julia Strassgüttl ◽  
Tobias Aumiller
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Feed Additives ◽  
Similar Response ◽  
General Effect ◽  
Microtiter Plate Assay ◽  
E Coli ◽  
Thyme Oil ◽  
Field Isolates ◽  
Garlic Oil

Abstract The aim of this study was to investigate the effects of garlic oil, cinnamaldehyde, carvacrol, thymol, and thyme oil on growth and biofilm formation of Escherichia coli and Salmonella serotypes, including field isolates from livestock animals. Minimum inhibitory concentrations (MIC) were determined using broth micro-dilution method. Biofilm biomass was assessed by measuring the attached biomass with microtiter plate assay and crystal violet (CV) staining. The strongest antimicrobial effects on E. coli serotypes were observed for thymol at 150 ppm, followed by carvacrol and cinnamaldehyde at 300 ppm and thyme oil at 600 ppm. Similar results were obtained with Salmonella serotypes except for carvacrol (MIC value at 150 ppm). Garlic oil showed no growth inhibition on serotypes of E. coli and Salmonella up to 10000 ppm. Cinnamaldehyde proved to be the most effective substance in reducing E. coli CV-biofilm formation at sub-MIC level with a threshold concentration of 5 ppm, followed by carvacrol, thymol, and thyme oil at 40 ppm and garlic oil at 10000 ppm. CV-biofilm formation of Salmonella serotypes at sub-MIC level was clearly reduced with 40 ppm cinnamaldehyde and 80 ppm carvacrol, thymol, and thyme oil. No reduction of CV-biofilm formation was observed with garlic oil. The present study demonstrates a strong antibacterial activity of cinnamaldehyde, carvacrol, thymol, and thyme oil. Similar response of field isolates and type strains to these phytogenics suggests a general effect within the bacterial species tested. All four substances were also able to reduce CV-biofilm formation at sub-MIC level. Investigating phytogenics with bacterial field isolates contributes to the development of feed additives as alternatives to antibiotics in animal feed to increase productivity and animal welfare in modern livestock production.

scholarly journals Biofilm Formation on Biotic and Abiotic Surfaces in the Presence of Antimicrobials by Escherichia coli Isolates from Cases of Bovine Mastitis

2014 ◽  
Vol 80 (19) ◽  
pp. 6136-6145 ◽  
Author(s):  
Vitor O. Silva ◽  
Larissa O. Soares ◽  
Abelardo Silva Júnior ◽  
Hilário C. Mantovani ◽  
Yung-Fu Chang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Expression Profiles ◽  
Bovine Mastitis ◽  
Pcr Analysis ◽  
Content Type ◽  
E Coli ◽  
Biofilm Production ◽  
Abiotic Surfaces

ABSTRACTEscherichia coliis a highly adaptive microorganism, and its ability to form biofilms under certain conditions can be critical for antimicrobial resistance. The adhesion of fourE. coliisolates from bovine mastitis to bovine mammary alveolar (MAC-T) cells, biofilm production on a polystyrene surface, and the expression profiles of the genesfliC,csgA,fimA, andluxSin the presence of enrofloxacin, gentamicin, co-trimoxazole, and ampicillin at half of the MIC were investigated. Increased adhesion ofE. coliisolates in the presence of antimicrobials was not observed; however, increased internalization of some isolates was observed by confocal microscopy. All of the antimicrobials induced the formation of biofilms by at least one isolate, whereas enrofloxacin and co-trimoxazole decreased biofilm formation by at least one isolate. Quantitative PCR analysis revealed that all four genes were differentially expressed when bacteria were exposed to subinhibitory concentrations of antimicrobials, with expression altered on the order of 1.5- to 22-fold. However, it was not possible to associate gene expression with induction or reduction of biofilm formation in the presence of the antimicrobials. Taken together, the results demonstrate that antimicrobials could induce biofilm formation by some isolates, in addition to inducing MAC-T cell invasion, a situation that might occurin vivo, potentially resulting in a bacterial reservoir in the udder, which might explain some cases of persistent mastitis in herds.

scholarly journals Label-free quantitative proteomic analysis of the inhibition effect of Lactobacillus rhamnosus GG on Escherichia coli biofilm formation in co-culture

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Huiyi Song ◽  
Ni Lou ◽  
Jianjun Liu ◽  
Hong Xiang ◽  
Dong Shang
Keyword(s):  
Escherichia Coli ◽  
Proteomic Analysis ◽  
Biofilm Formation ◽  
Lactobacillus Rhamnosus ◽  
Differentially Expressed ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Quantitative Proteomic Analysis ◽  
E Coli ◽  
Protein Ubiquitination

Abstract Background Escherichia coli (E. coli) is the principal pathogen that causes biofilm formation. Biofilms are associated with infectious diseases and antibiotic resistance. This study employed proteomic analysis to identify differentially expressed proteins after coculture of E. coli with Lactobacillus rhamnosus GG (LGG) microcapsules. Methods To explore the relevant protein abundance changes after E. coli and LGG coculture, label-free quantitative proteomic analysis and qRT-PCR were applied to E. coli and LGG microcapsule groups before and after coculture, respectively. Results The proteomic analysis characterised a total of 1655 proteins in E. coli K12MG1655 and 1431 proteins in the LGG. After coculture treatment, there were 262 differentially expressed proteins in E. coli and 291 in LGG. Gene ontology analysis showed that the differentially expressed proteins were mainly related to cellular metabolism, the stress response, transcription and the cell membrane. A protein interaction network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis indicated that the differentiated proteins were mainly involved in the protein ubiquitination pathway and mitochondrial dysfunction. Conclusions These findings indicated that LGG microcapsules may inhibit E. coli biofilm formation by disrupting metabolic processes, particularly in relation to energy metabolism and stimulus responses, both of which are critical for the growth of LGG. Together, these findings increase our understanding of the interactions between bacteria under coculture conditions.

scholarly journals Molecular surveillance of shiga toxigenic Escherichia coli in selected beef abattoirs in Osun State Nigeria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Femi Ayoade ◽  
Judith Oguzie ◽  
Philomena Eromon ◽  
Omolola E. Omotosho ◽  
Tosin Ogunbiyi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sequence Analysis ◽  
Block Design ◽  
Latex Agglutination ◽  
Pcr Analysis ◽  
Accession Number ◽  
E Coli ◽  
Representative Isolate ◽  
Randomized Block Design ◽  
Toxigenic Strains

AbstractShiga toxigenic strains of E. coli (STEC) known to be etiological agents for diarrhea were screened for their incidence/occurrence in selected abattoirs sources in Osogbo metropolis of Osun State, Nigeria using a randomized block design. Samples were plated directly on selective and differential media and E. coli isolates. Multiplex PCR analysis was used to screen for the presence of specific virulence factors. These were confirmed serologically as non-O157 STEC using latex agglutination serotyping kit. Sequence analysis of PCR products was performed on a representative isolate showing the highest combination of virulence genes using the 16S gene for identification purposes only. Results showed that the average cfu/cm2 was significantly lower in the samples collected at Sekona-2 slaughter slab compared with those collected at Al-maleek batch abattoir and Sekona-1 slaughter slab in ascending order at P = 0.03. Moreover, the average cfu/cm2E. coli in samples collected from butchering knife was significantly lower when compared with that of the workers’ hand (P = 0.047) and slaughtering floor (P = 0.047) but not with the slaughter table (P = 0.98) and effluent water from the abattoir house (P = 0.39). These data suggest that the abattoir type may not be as important in the prevalence and spread of STEC as the hygiene practices of the workers. Sequence analysis of a representative isolate showed 100% coverage and 96.46% percentage identity with Escherichia coli O113:H21 (GenBank Accession number: CP031892.1) strain from Canada. This sequence was subsequently submitted to GenBank with accession number MW463885. From evolutionary analyses, the strain from Nigeria, sequenced in this study, is evolutionarily distant when compared with the publicly available sequences from Nigeria. Although no case of E. coli O157 was found within the study area, percent occurrence of non-O157 STEC as high as 46.3% at some of the sampled sites is worrisome and requires regulatory interventions in ensuring hygienic practices at the abattoirs within the study area.

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