scholarly journals Analysis of biofilm formation by intestinal lactobacilli

2015 ◽  
Vol 61 (6) ◽  
pp. 437-446 ◽  
Author(s):  
Magdaléna Slížová ◽  
Radomíra Nemcová ◽  
Marián Mad’ar ◽  
Jana Hadryová ◽  
Soňa Gancarčíková ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Spatial Organization ◽  
Lactobacillus Reuteri ◽  
Carbon Sources ◽  
Tween 80 ◽  
Microtiter Plate ◽  
Culture Conditions ◽  
De Man ◽  
Mrs Medium

In this study, the biofilm-forming potential of intestinal Lactobacillus reuteri strains under different culture conditions was characterized by microtiter plate biofilm assays. Moreover, the spatial organization of exogenously applied L. reuteri L2/6 (a pig isolate) at specific locations in gastrointestinal tract of monoassociated mice was investigated by fluorescence in situ hybridization. We did not detect biofilm formation by tested strains in nutrient-rich de Man–Rogosa–Sharpe (MRS) medium. On the contrary, a highly positive biofilm formation was observed in medium with lower accessibility to the carbon sources and lack of salts. The results obtained confirmed the significant role of Tween 80 and the quantity and nature of the sugars in the growth medium in biofilm formation. The omission of Tween 80 in MRS medium favored the formation of biofilm. Abundant biofilm formation was detected in the presence of lactose, galactose, and glucose. However, a gradual increase in sugar concentration triggered a significant decrease in biofilm formation. In addition, conditions related to the gastrointestinal environment, such as low pH and the presence of bile and mucins, highly modulated biofilm production. This effect seems to be dependent on the specificity and properties of the medium used for cultivation. From the evidence provided by this study we conclude that the biofilm formation capacity of L. reuteri is strongly dependent on the environmental factors and culture medium used.

scholarly journals Bifidogenic properties of cell-free extracts derived from probiotic strains of Bifidobacterium bifidum and Lactobacillus reuteri

2019 ◽  
Vol 10 (1) ◽  
pp. 124-128 ◽  
Author(s):  
O. V. Knysh
Keyword(s):  
Biofilm Formation ◽  
Proliferative Activity ◽  
Lactobacillus Reuteri ◽  
Probiotic Strain ◽  
Microtiter Plate ◽  
Inhibitory Effect ◽  
Bifidobacterium Bifidum ◽  
Careful Study ◽  
Structural Components ◽  
Probiotic Strains

Comprehensive study of the biological activity of structural components and metabolites of “beneficial” microorganisms opens the prospects of efficient and rational use of their biotechnological potential in the correction of microecological and related disorders. The study tested proliferative activity and biofilm formation by Bifidobacterium bifidum probiotic strain under the influence of cell-free extracts containing structural components and metabolites of the probiotic strains of B. bifidum and Lactobacillus reuteri. Cell-free extracts were obtained by disintegrating suspensions of probiotic cells by cyclic freezing-thawing, cultivating probiotic microorganisms in their own disintegrates and subsequent filtration of the obtained disintegrates and cultures. The proliferative activity and biofilm formation of the probiotic test culture were studied by spectrophotometric microtiter plate method with 10%vol, 30%vol and 50%vol content of cell-free extracts in the cultivation medium. All investigated extracts showed a significant concentration-dependent stimulatory effect on the proliferative activity of B. bifidum. According to the degree of stimulatory effect on the B. bifidum proliferation, cell-free extracts arranged in ascending order: MLG (filtrate of L. reuteri culture, grown in L. reuteri disintegrate supplemented with 0.8 M glycerol and 0.4 M glucose) < MB (filtrate of В. bifidum culture, grown in В. bifidum disintegrate) < B (filtrate of В. bifidum disintegrate) < ML (filtrate of L. reuteri culture, grown in L. reuteri disintegrate) < L (filtrate of L. reuteri disintegrate). With the same content in the culture medium, filtrates of disintegrates had a more pronounced stimulatory effect than filtrates of cultures grown in their own disintegrates. Cell-free extracts from L. reuteri (L and ML) exerted a more pronounced stimulatory effect than cell-free extracts from B. bifidum. Not all studied cell-free extracts stimulated the biofilm formation by B. bifidum. The effect of cell-free extracts on this process depended on their type and concentration. Extract L had a predominantly inhibitory effect on biofilm formation by B. bifidum. The most pronounced stimulatory effect on biofilm formation by B. bifidum came from extract MLG. ML, B and MB extracts stimulated this process approximately equally. The detection of significant bifidogenic effect of the studied cell-free extracts may contribute to their pharmaceutical applications. Cell-free extracts can be used as metabiotics or prebiotics for increasing the survival of the injected probiotic, facilitating its inoculation in the gastrointestinal tract when used together. The obtained data encourage further careful study of the biochemical composition of cell-free extracts and efforts to clarify the mechanism of their action.

scholarly journals Biofilm Formation and Adherence Characteristics ofListeria ivanoviiStrains Isolated from Ready-to-Eat Foods in Alice, South Africa

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mirriam E. Nyenje ◽  
Ezekiel Green ◽  
Roland N. Ndip
Keyword(s):  
South Africa ◽  
Biofilm Formation ◽  
Food Industry ◽  
Microtiter Plate ◽  
Cross Contamination ◽  
Bacterial Strains ◽  
Cell Surface Properties ◽  
Listeria Ivanovii ◽  
Multispecies Biofilms

The present study was carried out to investigate the potential ofListeria ivanoviiisolates to exist as biofilm structures. The ability ofListeria ivanoviiisolates to adhere to a surface was determined using a microtiter plate adherence assay whereas the role of cell surface properties in biofilm formation was assessed using the coaggregation and autoaggregation assays. Seven reference bacterial strains were used for the coaggregation assay. The degree of coaggregation and autoaggregation was determined. The architecture of the biofilms was examined under SEM. A total of 44 (88%) strains adhered to the wells of the microtiter plate while 6 (12%) did not adhere. The coaggregation index ranged from 12 to 77% while the autoaggregation index varied from 11 to 55%. The partner strains ofS. aureus,S. pyogenes,P. shigelloides, andS. sonneidisplayed coaggregation indices of 75% each, whileS. Typhimurium,A. hydrophila, andP. aeruginosaregistered coaggregation indices of 67%, 58%, and 50%, respectively. The ability ofL. ivanoviiisolates to form single and multispecies biofilms at 25°C is of great concern to the food industry where these organisms may adhere to kitchen utensils and other environments leading to cross-contamination of food processed in these areas.

scholarly journals Biofilm Formation by Psychrobacter arcticus and the Role of a Large Adhesin in Attachment to Surfaces

2013 ◽  
Vol 79 (13) ◽  
pp. 3967-3973 ◽  
Author(s):  
Shannon M. Hinsa-Leasure ◽  
Cassandra Koid ◽  
James M. Tiedje ◽  
Janna N. Schultzhaus
Keyword(s):  
Biofilm Formation ◽  
Time Course ◽  
Microtiter Plate ◽  
Bacterial Attachment ◽  
Wild Type ◽  
Microtiter Plate Assay ◽  
Content Type ◽  
Reading Frame ◽  
Transposon Mutants

ABSTRACTPsychrobacter arcticusstrain 273-4, an isolate from a Siberian permafrost core, is capable of forming biofilms when grown in minimal medium under laboratory conditions. Biofilms form at 4 to 22°C when acetate is supplied as the lone carbon source and with 1 to 7% sea salt.P. arcticusis also capable of colonizing quartz sand. Transposon mutagenesis identified a gene important for biofilm formation byP. arcticus. Four transposon mutants were mapped to a 20.1-kbp gene, which is predicted to encode a protein of 6,715 amino acids (Psyc_1601). We refer to this open reading frame ascat1, for cold attachment gene 1. Thecat1mutants are unable to form biofilms at levels equivalent to that of the wild type, and there is no impact on the planktonic growth characteristics of the strains, indicating a specific role in biofilm formation. Through time course studies of the static microtiter plate assay, we determined thatcat1mutants are unable to form biofilms equivalent to that of the wild type under all conditions tested. In flow cell experiments,cat1mutants initially are unable to attach to the surface. Over time, however, they form microcolonies, an architecture very different from that produced by wild-type biofilms. Our results demonstrate that Cat1 is involved in the initial stages of bacterial attachment to surfaces.

icaA Gene of Staphylococcus aureus Responds to NaCl, Leading to Increased Biofilm Formation

2018 ◽  
Vol 81 (3) ◽  
pp. 412-416 ◽  
Author(s):  
Soomin Lee ◽  
Sejeong Kim ◽  
Heeyoung Lee ◽  
Jimyeong Ha ◽  
Jeeyeon Lee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Deletion Mutant ◽  
Microtiter Plate ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Microtiter Plate Assay ◽  
Nacl Concentration ◽  
Icaa Gene

ABSTRACT The objective of this study was to elucidate the role of the icaA gene in biofilm formation of Staphylococcus aureus exposed to NaCl. The icaA-deletion mutant of S. aureus ATCC 13565 was constructed with the temperature-sensitive plasmid pIMAY. Microtiter plate assays were performed to confirm biofilm formation for both the wild type and the mutant at 0% (control), 2, 4, and 6% NaCl. The microtiter plate assay revealed that biofilm formation by the wild type increased (P &lt; 0.05) as NaCl concentration increased, but biofilm formation of the mutant was not affected by NaCl concentration. Biofilm formation by the mutant was lower (P &lt; 0.05) than that by the wild type. These results indicate that icaA plays an important role in biofilm formation by S. aureus when the pathogen is exposed to NaCl.

scholarly journals Influence of cell-free extracts of Bifidobacterium bifidum and Lactobacillus reuteri on proliferation and biofilm formation by Escherichia coli and Pseudomonas aeruginosa

2019 ◽  
Vol 10 (2) ◽  
pp. 251-256 ◽  
Author(s):  
O. V. Knysh ◽  
O. Y. Isayenko ◽  
Y. V. Voyda ◽  
O. O. Kizimenko ◽  
Y. M. Babych
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Proliferative Activity ◽  
Lactobacillus Reuteri ◽  
Microtiter Plate ◽  
Inhibitory Effect ◽  
Bifidobacterium Bifidum ◽  
Plate Method ◽  
E Coli ◽  
Test Cultures

The development of new effective preparations for the correction of microecological disorders based on probiotic derivatives requires a comprehensive study of the biological activity of the latter. We studied the proliferative activity and biofilm formation by clinical isolates: Escherichia coli and Pseudomonas aeruginosa under the influence of cell-free extracts containing structural components and metabolites of the Bifidobacterium bifidum and Lactobacillus reuteri probiotic strains. Cell-free extracts were obtained from disintegrates and cultures of probiotics. Disintegrates were prepared by cyclic freezing-thawing of probiotic cell suspensions. The cultures were obtained by cultivating probiotic microorganisms in their own disintegrates. The obtained disintegrates and cultures were filtered. The proliferative activity of the test cultures was studied using the spectrophotometric microtiter plate method after an hour-long exposure in undiluted cell-free extracts and subsequent cultivation in a nutrient medium containing 30%vol of the studied extracts at 37 °C for 24 hours. The biofilm formation of the test cultures was studied with 30% vol content of cell-free extracts in the cultivation medium using the spectrophotometric microtiter plate method. All the studied extracts exerted a similar effect on the proliferative activity and biofilm formation by E. coli and P. aeruginosa. Exposure of the test cultures in all undiluted extracts during an hour led to a significant decrease in the optical density of the test samples: optical density of the test wells ranged from 36.5% to 49.8% of the control wells. The test cultures that were exposed to the extracts: filtrate of L. reuteri disintegrate (L), filtrate of В. bifidum disintegrate (B) and filtrate of В. bifidum culture, grown in В. bifidum disintegrate (MB) after dilution and subsequent cultivation over the next 24 hours completely restored the ability to proliferate. The proliferative activity of the test cultures that were exposed to the extracts: filtrate of L. reuteri culture, grown in L. reuteri disintegrate (ML) and filtrate of L. reuteri culture, grown in L. reuteri disintegrate supplemented with 0.8 M glycerol and 0.4 M glucose (MLG), was significantly inhibited after dilution and subsequent cultivation. The inhibition indices calculated for the ML extract were: 25.9% (E. coli) and 53.0% (P. aeruginosa). Inhibition indices calculated for the MLG extract were: 62.0% (E. coli) and 96.9% (P. aeruginosa). MLG extract had more pronounced inhibitory effect on the proliferation of the test cultures than ML extract. All the studied extracts exerted significant inhibitory effect on the biofilm formation of the test cultures. Analysis of the results of the study shows that cell-free extracts of L. reuteri culture grown in its disintegrate without supplementation or supplemented with glycerol and glucose have the highest antimicrobial activity and can be used as metabiotics to prevent overgrowth of potentially pathogenic bacteria, as well as inoculation and proliferation of pathogenic gram-negative bacteria in the gastrointestinal tract. They can be used alone or in combination with cellular probiotics to enhance their probiotic action. This study encourages further careful investigation of the biochemical composition of cell-free extracts and clarifying the mechanism of their action.

Investigate of the Ability of Cronobacter sakazakii Isolated from Clinical Samples of Children Under Two Years to Induce Swimming, Swarming and Biofilm

2018 ◽  
pp. 123
Author(s):  
Luma Abdal Hady Zwein ◽  
Tharieyt Abdulrahman Motlag ◽  
Mohamed Mousa
Keyword(s):  
Cerebrospinal Fluid ◽  
Congo Red ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Clinical Samples ◽  
Cronobacter Sakazakii ◽  
Yellow Color ◽  
Golden Yellow ◽  
Vitek 2 ◽  
Biochemical Examination

      The study included 200 samples were collected   from   children  under two   years included (50 samples from each of Cerebrospinal fluid, Blood, Stool and Urine) from, Central Children Hospital and Children's Protections Educational Hospital. Isolates bacterial were obtained cultural, microscopic and biochemical examination and diagnosed to the species by using vitek2 system. The results showed there were contamination in 6.5% of clinical samples. The diagnosed colonies which gave pink color on the MacConkey agar , golden yellow color on the Trypton Soy agar and green color on the Birillent Enterobacter sakazakii agar and gave  a probability of 99% in the vitek 2 and were identified as Cronobacter sakazakii. The identification revealed of thirteen isolates: 6(46.16%) isolated from Cerebrospinal fluid samples, 7(53.84%) isolated from blood samples and not isolated bacteria from stool and urine samples. The results of the investigation of some virulence factors showed that all bacteria isolates were able to swimming with a diameter ranging (1-9 mm) and swarming with a diameter ranging (1-40 mm) and their  ability to biofilm formation  by using three methods. The results show the ability  of  isolates to form biofilm by using  Congo red media  methods where it is 12 (92.30 %) out of 13 isolated bacteria belonging to C. sakazakii  able to form biofilm on the Congo red media  which is 3 (23.07%) were  strong production  biofilm ,   8 (61.53%)  were intermediate  production  biofilm and  1 (7.69% ) were weak  biofilm formation , while the 1 (7.69%)  unable to form biofilm.  Tubes method were all isolates were able to form biofilm, it were found that 3 (23.07%)  isolates strong, and 8 (61.53%) intermediate  and 2( 15.38%)  weak biofilm formation. Microtiter plate method  gave 5 (38.46 %) isolates strong, 6 (46.15%) intermediate and 1 (7.69%) weak biofilm formation.  

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

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