1.Visualization method of type Ⅳ pili and its application in the study of pili function.
Chinese Journal of Biotechnology 2023;39(11):4534-4549
As an important protein structure on the surface of bacteria, type Ⅳ pili (TFP) is the sensing and moving organ of bacteria. It plays a variety of roles in bacterial physiology, cell adhesion, host cell invasion, DNA uptake, protein secretion, biofilm formation, cell movement and electron transmission. With the rapid development of research methods, technical equipment and pili visualization tools, increasing number of studies have revealed various functions of pili in cellular activities, which greatly facilitated the microbial single cell research. This review focuses on the pili visualization method and its application in the functional research of TFP, providing ideas for the research and application of TFP in biology, medicine and ecology.
Fimbriae, Bacterial/metabolism*
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Bacterial Proteins/genetics*
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Bacterial Physiological Phenomena
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Bacterial Adhesion/physiology*
2.Study of oral microbial adhesion and biofilm formation on the surface of nano-fluorohydroxyapatite/polyetheretherketone composite.
Lixin WANG ; Huan ZHANG ; Yi DENG ; Zuyuan LUO ; Xiyun LIU ; Shicheng WEI ; Email: SC-WEI@PKU.EDU.CN.
Chinese Journal of Stomatology 2015;50(6):378-382
OBJECTIVETo develop novel polyetheretherketone (PEEK) based nanocomposites which possess the favorable antibacterial property, and to investigate the oral microbial adhesion and biofilm formation on the surfaces of PEEK, nano-fluorohydroxyapatite (n-FHA)-PEEK and nano-hydroxyaptite (n-HA)-PEEK.
METHODSThe bacterial adhesion and biofilm formation on the surfaces of n-FHA-PEEK, n-HA-PEEK were investigated via microbial viability assay kit and laser scanning confocal microscope (LSCM), respectively, with pure PEEK as control group.
RESULTSNo significantly statistical difference were found in the bacterial adhesion amounts on the surfaces of n-FHA-PEEK, n-HA-PEEK and PEEK at 1 h and 4 h. However, the number of bacteria on the n-FHA-PEEK surface decreased dramatically at 2 h (0.496 ± 0.008) compared with n-HA-PEEK groups (0.543 ± 0.015, P < 0.01). Although the biofilms formation on surfaces observed by LSCM had similar morphology and thickness at 3, 7, 14 d, that on the n-FHA-PEEK surface showed the highest dead-to-live bacteria ratio among the three materials at 14 d.
CONCLUSIONSThe combination of n-HA, especially for the n-FHA could inhibit the bacteria adhesion and accelerate the bacterial death, eventually may have an influence on the structure of biofilms and reduce the risk of peri-implantitis. Therefore, n-FHA-PEEK nanocomposites presented a good prospect for clinical applications as dental implant materials.
Bacterial Adhesion ; physiology ; Bacterial Load ; Biofilms ; Dental Implants ; microbiology ; Hydroxyapatites ; Ketones ; Nanocomposites ; microbiology ; Polyethylene Glycols
4.Experimental study on attachment of bacillus Calmette-Guerin to bladder wall with different types of injury.
Guo-qing DING ; Zhou-jun SHEN ; Zhao-dian CHEN
Journal of Zhejiang University. Medical sciences 2004;33(1):65-67
OBJECTIVETo investigate whether different types of injury on bladder wall can influence bacillus Calmette-Guerin (BCG) attachment.
METHODSThe bladder mucosa of 24 rabbits were treated by electrocautery,cryocautery and incision on left lateral wall, right lateral wall and posterior wall, respectively. Then radiolabeled BCG ((3)H-BCG) was instilled into bladder. Two hours latter, the injured bladder wall with different methods and non-injured wall (anterior wall of bladder) were surgically removed and digested. The quantity of BCG of each specimen was determined by liquid scintillation counter.
RESULTThe quantity of BCG attachment to bladder wall with different injuries was significantly higher than that of non-injured wall (P<0.001), meanwhile there was no statistically difference among the BCG levels of different injury types (P>0.05).
CONCLUSIONBCG attachment is not influenced by different types of injury on the bladder wall.
Animals ; Bacterial Adhesion ; Female ; Male ; Mycobacterium bovis ; physiology ; Rabbits ; Urinary Bladder ; injuries ; microbiology
5.Adhesion of oral microorganisms on dental porcelain polished and glazed.
Yi-ning WANG ; Guo-jiang WEN ; Bin SHI ; Xin-hua PAN
Chinese Journal of Stomatology 2003;38(5):342-344
OBJECTIVEThis study compared the roughness of porcelain polished or glazed surfaces and the adhesion of oral streptococcus mutans to them in vitro.
METHODS30 porcelain samples were made. Porcelain samples in group A were polished with diamond paste. Porcelain samples were glazed in group B and were polished with Al2O3 (240#) bur in group C. Their roughness values were measured by profilometer. Standardized cell suspensions were incubated with test samples for one hour at 37 degrees C, then retained cells were counted by image analysis (percentage area of a microscopic field covered by cells).
RESULTSRoughness values of group A, B, C were respectively (0.1987 +/- 0.057) microm, (0.1990 +/- 0.091) microm, (0.4260 +/- 0.174) microm. There was no significantly difference between group A and group B. The roughness samples in group C were significantly rougher than that in the other groups. The amount of retained cells in group A, group B, group C was respectively (15.92 +/- 4.37)%, (16.39 +/- 6.31)% and (41.48 +/- 12.1)%. There was no significant difference between the cell adhesion on porcelain surface glazed and polished, but more bacteria adhered on the porcelain surface in group C.
CONCLUSIONSPorcelain surface polished treatment was clinically acceptable compared with its glazed. They all exhibited the least amount of bacteria adhesion. The more porcelain surface was rough, the more bacteria adhered on it.
Bacterial Adhesion ; Dental Polishing ; Dental Porcelain ; Humans ; Streptococcus mutans ; physiology ; Tooth ; microbiology
6.Effects of inhibitory peptide of Staphylococcus epidermidis biofilm on adhesion and biofilm formation of this bacterium.
Jing OUYANG ; Lirong XIONG ; Wei FENG ; Fengjun SUN ; Yongchuan CHEN ; Email: DRYONGCHUANCHEN@163.COM.
Chinese Journal of Burns 2015;31(4):285-289
OBJECTIVETo study the effects of inhibitory peptide of Staphylococcus epidermidis (SE) biofilm (briefly referred to as inhibitory peptide) on adhesion and biofilm formation of SE at early stage.
METHODSBy using peptide synthesizer, the inhibitory peptide was synthesized with purity of 96.8% and relative molecular mass of 874.4. (1) Solution of SE ATCC 35984 (the same below) was cultivated with inhibitory peptide in the final concentrations of 1-256 µg/mL, and the M-H broth without bacteria solution was used as blank control. The MIC of the inhibitory peptide against SE was determined (n=3). (2) Solution of SE was cultivated with trypticase soy broth (TSB) culture solution containing inhibitory peptide in the final concentrations of 16, 32, 64, 128, and 256 µg/mL (set as inhibitory peptide groups in corresponding concentration), and solution of SE being cultivated with TSB culture medium was used as negative control group. Growth of SE was observed every one hour from immediately after cultivation (denoted as absorbance value), and the growth curve of SE during the 24 hours of cultivation was drawn, with 3 samples in each group at each time point. (3) Solution of SE was cultivated with TSB culture solution containing inhibitory peptide in the final concentrations of 16, 32, 64, 128, and 256 µg/mL (set as inhibitory peptide groups in corresponding concentration), and solution of SE being cultivated with TSB culture medium was used as negative control group. Adhesive property of SE was observed after cultivation for 4 hours (denoted as absorbance value, n=10); biofilm formation of SE was observed after cultivation for 20 hours (denoted as absorbance value, n=10). (4) Solution of SE was cultivated with TSB culture solution containing inhibitory peptide in the final concentration of 128 µg/mL (set as 128 µg/mL inhibitory peptide group), and solution of SE being cultivated with TSB culture medium was used as negative control group. Adhesive property of SE and its biofilm formation were observed with confocal laser scanning microscope (CLSM), and the sample numbers were both 3. Data were processed with one-way analysis of variance, LSD test, and Dunnett T3 test.
RESULTS(1) The MIC of inhibitory peptide against SE exceeded 256 µg/mL. (2) There was no significant difference in the growth curve of SE between inhibitory peptide groups in different concentrations and negative control group. (3) After 4 hours of cultivation, the absorbance values of adhesive property of SE in 256, 128, 64, and 32 µg/mL inhibitory peptide groups were respectively 0.20 ± 0.04, 0.27 ± 0.03, 0.35 ± 0.04, and 0.40 ± 0.04, which were significantly lower than the absorbance value in negative control group (0.53 ± 0.10, P<0.05 or P<0.01); the absorbance value of adhesive property of SE in 16 µg/mL inhibitory peptide group was 0.47 ± 0.09, which was close to the absorbance value in negative control group (P>0.05). After 20 hours of cultivation, the absorbance values of biofilm formation of SE in 256, 128, and 64 µg/mL inhibitory peptide groups were respectively 0.49 ± 0.10, 0.68 ± 0.06, and 0.93 ± 0.13, which were significantly less than the absorbance value in negative control group (1.21 ± 0.18, P<0.05 or P<0.01); the absorbance values of biofilm formation in 32 and 16 µg/mL inhibitory peptide groups were respectively 1.18 ± 0.22 and 1.15 ± 0.26, which were close to the absorbance value in negative control group (with P values above 0.05). (4) CLSM showed that more adhering bacteria and compact structure of biofilm were observed in negative control group, but less adhering bacteria and loose structure of biofilm were observed in 128 µg/mL inhibitory peptide group.
CONCLUSIONSThe inhibitory peptide can inhibit adhesion and biofilm formation of SE at early stage, but its structure still needs to be further modified.
Bacterial Adhesion ; Biofilms ; growth & development ; Humans ; Microscopy, Confocal ; Peptides ; Staphylococcus epidermidis ; genetics ; metabolism ; physiology
7.Extracellular polysaccharides matrix--an often forgotten virulence factor in oral biofilm research.
Hyun KOO ; Jin XIAO ; Marlise I KLEIN
International Journal of Oral Science 2009;1(4):229-234
Antigens, Bacterial
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metabolism
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Bacterial Adhesion
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physiology
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Biofilms
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growth & development
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Dental Caries
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microbiology
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Extracellular Matrix
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physiology
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Glucosyltransferases
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metabolism
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Humans
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Mouth
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microbiology
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Polysaccharides, Bacterial
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physiology
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Streptococcus mutans
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enzymology
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pathogenicity
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physiology
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Virulence
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Virulence Factors
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physiology
8.Phase Variation of Biofilm Formation in Staphylococcus aureus by IS 256 Insertion and Its Impact on the Capacity Adhering to Polyurethane Surface.
Sungmin KIEM ; Won Sup OH ; Kyong Ran PECK ; Nam Yong LEE ; Ji Young LEE ; Jae Hoon SONG ; Eung Soo HWANG ; Eui Chong KIM ; Chang Yong CHA ; Kang Won CHOE
Journal of Korean Medical Science 2004;19(6):779-782
While ica gene of Staphylococcus epidermidis is known to undergo phase variation by insertion of IS256, the phenomenon in Staphylococcus aureus has not been evaluated. Six biofilm-positive strains were tested for the presence of biofilm-nega-tive phase-variant strains by Congo red agar test. For potential phase-variant strains, pulsed-field gel electrophoresis was done to exclude the possibility of contamination. To investigate the mechanism of the biofilm-negative phase variation, PCR for each ica genes were done. Changes of ica genes detected by PCR were confirmed by southern hybridization, and their nucleotides were analyzed by DNA sequencing. Influence of ica genes and biofilm formation on capacity for adherence to biomedical material was evaluated by comparing the ability of adhering to polyurethane sur-face among a biofilm-negative phase-variant strain and its parent strain. A biofilm-negative phase-variant S. aureus strain was detected from 6 strains tested. icaC gene of the phase-variant strain was found to be inactivated by insertion of additional gene segment, IS256. The biofilm-negative phase-variant strain showed lower adher-ing capacity to polyurethane than its parent strain. This study shows that phase variation of ica gene occurs in S. aureus by insertion of IS256 also, and this biofilm-neg-ative phase variation reduces adhering capacity of the bacteria.
Bacterial Adhesion/*physiology
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Biofilms/*growth & development
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Cell Adhesion Molecules/genetics/*metabolism
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Comparative Study
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Equipment Contamination/prevention & control
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Mutagenesis, Insertional/methods
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Mutagenesis, Site-Directed/genetics
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Phase Transition
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Polysaccharides, Bacterial/genetics/*metabolism
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*Polyurethanes
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Species Specificity
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Staphylococcus aureus/cytology/*physiology
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Structure-Activity Relationship
9.Preliminary study of effects of andrographolide on Staphylococcus epidermidis biofilms.
Yan GUAN ; Jiuyun ZHANG ; Changzhong WANG ; Ning WANG ; Zhifang LIU ; Jingjin SHI
China Journal of Chinese Materia Medica 2012;37(14):2147-2150
OBJECTIVETo provide a new therapeutic approach for Staphylococcus epidermidis biofilm-associated infections by the study of inhibitory effect of andrographolide (AG) on S. epidermidis biofilm.
METHODS. epidermidis biofilms were set up in vitro, erythromycin was acted as the positive control agent, XTT reduction assay was used to evaluate AG on the initial adhesion of S. epidermidis and bacterial metabolism within biofilm, microscope was applied to observe biofilm morphology, and Congo red assay was used to detect polysacchatide interc-ellular adhesion (PIA)formation when exposed to AG.
RESULTAG showed inhibitory effects against the initial adhesion of S. epidermidis at concentrations of 1 000,100, 10 mg x L(-1), respectively,and inhibited metabolism of biofilm bacteria at the concentration of 31.25 mg x L(-1), and exhibited significantly inhibition against the biofilm morphology at the concentration of 250 mg x L(-1), while did not display inhibition against PIA formation at the concentration of 10 mg x L(-1).
CONCLUSIONAG could remarkably inhibit biofilm formation of S. epidermidis, although it was less potent than erythromycin.
Bacterial Adhesion ; drug effects ; Biofilms ; drug effects ; Diterpenes ; pharmacology ; Dose-Response Relationship, Drug ; Erythromycin ; pharmacology ; Staphylococcus epidermidis ; drug effects ; physiology
10.A study of the physicochemical and biological properties of mutanase from Trichoderma harzianum.
Yu GAN ; Liu-yan MENG ; Ming-wen FAN ; Bin PENG ; Zhi CHEN ; Zhuan BIAN
Chinese Journal of Stomatology 2006;41(1):33-36
OBJECTIVETo determine the physicochemical properties of the mutanase of Trichoderma harzianum isolated from China and to study the influence of mutanase on the adherence of oral Streptococci and the structure of oral biofilms.
METHODSSix fungal strains belonging to Trichoderma were tested for mutanase production in the same cultural condition, the strain producing the highest mutanase activity was studied further and the pH and temperature optimum of the enzyme was determined. The RT-PCR method was used to obtain the gene coding for mutanase and the product was cloned to pMD18-T simple vector for sequencing. Inhibition effects of mutanase on the adherence of Streptococcus sobrinus OMZ176, Streptococcus sobrinus 6715, Streptococcus mutans MT8148 were studied by adherence test. The optical sectioning of biofilms with or without mutanase supplementation were analyzed by confocal laser scanning microscopy (CLSM).
RESULTSThe highest enzymatic activity was achieved by Trichoderma harzianum Th1, the maximum activity was at pH 5.5 and at 40 degrees C. The nucleotide sequence was 92% homology with that of a known gene coding a mutanase (GenBank accession No. AJ243799). The adherence of Streptococcus sobrinus OMZ176, Streptococcus sobrinus 6715, Streptococcus mutans MT8148 was significantly inhibited by mutanase. Compared with control, the biofilms with mutanase supplementation had lower height and sparser structure.
CONCLUSIONSThe mutanase from Trichoderma harzianum Th1 can inhibit the adherence of oral Streptococci and had an influence on the structure of oral biofilms.
Bacterial Adhesion ; drug effects ; Biofilms ; Glycoside Hydrolases ; chemistry ; physiology ; Streptococcus mutans ; drug effects ; Streptococcus sobrinus ; drug effects ; Trichoderma ; enzymology ; pathogenicity