The ability of several species of streptococcus and staphylococcus to adhere to human buccal epithelial cells was studied in vitro by using bacteria and epithelial cells isolated from human buccal cavity. Viridans streptococci were found adhering in highest numbers(65 +/- 8 bacteria per epithelial cell) to epithelial cells. Streptococcus pyogenes adhered in great numbers (44 +/- 4), whereas Streptococcus pneumoniae (26 +/- 2), Staphylococcus aureus (21 +/- 2), Staphylococcus epidermidis (14 +/- 2) adhered poorly. These data showed that bacteria differed in their ability to adhere to human buccal epithelial cells. This difference in adhesive ability between bacterial species may correlate with the ability of the bacteria to colonize oral surface of human.
Bacterial Physiology* ; Cheek ; Epithelial Cells ; Human ; In Vitro ; Mouth/microbiology* ; Staphylococcus/physiology ; Streptococcus/physiology

OBJECTIVETo investigate the effect of annexin A2 (AnxA2) on epithelial growth factor receptor (EGFR)/nuclear factor-κB (NF-κB) signal transduction and mucin expression in human airway epithelial H292 cells treated with Mycoplasma pneumoniae (MP).

METHODSH292 cells were divided into control group, MP group, NC-siRNA+MP group, and AnxA2 siRNA+MP group. The cells in the MP group were incubated with 5 μg/mL MP antigen for 2 hours. The cells in the NC-siRNA+MP and AnxA2 siRNA+MP groups were transfected with NC-siRNA and AnxA2 siRNA for 24 hours, followed by MP antigen stimulation for 2 hours. The MTT method was used to measure cell viability; quantitative real-time PCR was used to measure the mRNA expression of AnxA2; Western blot was used to measure the protein expression of AnxA2, phosphorylated EGFR (p-EGFR), and phosphorylated p65 NF-κB (p-p65 NF-κB); ELISA was used to measure the secretion of mucin 5AC (MUC5AC) and mucin 5B (MUC5B).

RESULTSThe MP and NC-siRNA+MP groups had lower cell viability than the control group (P<0.05). The AnxA2 siRNA+MP group had higher cell viability than the MP and NC-siRNA+MP groups and lower cell viability than the control group (P<0.05). The MP and NC-siRNA+MP groups had significantly higher mRNA and protein expression of AnxA2 than the AnxA2 siRNA+MP group (P<0.05). Compared with the control group, the MP and NC-siRNA+MP groups had significant increases in the protein expression of p-EGFR, p-p65 NF-κB, MUC5AC, and MUC5B (P<0.05); the AnxA2 siRNA+MP group had lower protein expression than the MP and NC-siRNA+MP groups, but higher protein expression than the control group (P<0.05).

CONCLUSIONSAnxA2 is involved in the airway lesion induced by MP antigen via mediating EGFR/NF-κB signaling activation and mucin expression in human airway epithelial cells.

Annexin A2 ; physiology ; Bronchi ; physiology ; Cells, Cultured ; Epithelial Cells ; microbiology ; Humans ; Mucins ; analysis ; Mycoplasma pneumoniae ; pathogenicity ; NF-kappa B ; physiology ; Receptor, Epidermal Growth Factor ; physiology ; Signal Transduction ; physiology

OBJECTIVETo investigate the effects of baicalin against Candida albicans germ tube formation, and adherence to buccal epitherial and vaginal epitherial cells.

METHODVarious concentrations of baicalin (100, 50, 10 mg x L(-1)) were incubated with C. albicans suspension, the mixed suspension of C. albicans and human buccal epitherial cells, the mixed suspension of C. albicans and vaginal epitherial cells, respectively. The effects of baicalin on C. albicans germ tube formation, and adherence to buccal epitherial and vaginal epitherial cells were then assessed microscopically.

RESULTAll concentrations of baicalin could inhibit C. albicans germ tube formation, and adherent to buccal epitherial and vaginal epitherial cells,while there was no significant difference between standard and clinical strains.

CONCLUSIONBaicalin could inhibit C. albicans germ tube formation, and adherence to buccal epitherial and vaginal epitherial cells.

Adult ; Anti-Infective Agents ; pharmacology ; Candida albicans ; drug effects ; growth & development ; physiology ; Candidiasis ; drug therapy ; microbiology ; Cheek ; microbiology ; Epithelial Cells ; microbiology ; Female ; Flavonoids ; pharmacology ; Humans ; Mouth Mucosa ; microbiology ; Vagina ; microbiology ; Young Adult

OBJECTIVETo compare the ability of adhesion and invasion to epithelial cells by Porphyromonas gingivalis (Pg) strains with different fimA separated from Chinese.

METHODSCultured method and antibiotic protection method were used to determine the adhesive and invasive ability of Pg with different fimA genetypes. The adhesion was observed by scanning electron microscope.

RESULTSAll the strains adhered and invaded to KB cells, and the adhesion rate ranged from 0.523% to 37.125% and invasive rate from 0.017% to 3.750%.The adhesive and invasive ability among different fimA genotypes showed no significant difference (P > 0.05).

CONCLUSIONSThere is no significant correlation between fimA genotype and ability in adhesion and invasion to KB cells.

Bacterial Adhesion ; Chronic Periodontitis ; microbiology ; Epithelial Cells ; microbiology ; Fimbriae Proteins ; genetics ; physiology ; Genetic Variation ; Genotype ; Humans ; KB Cells ; microbiology ; ultrastructure ; Microscopy, Electron, Scanning ; Porphyromonas gingivalis ; genetics ; isolation & purification ; physiology

Escherichia coli (E. coli) has ability to express thin aggregative fimbriae, known as curli, on the cell surface. Previously, a few example of curli expression in serogroup O157:H7 of enterohemorrhagic E. coli (EHEC) were reported, compared to other E. coli groups. However, significance of curliation in the EHEC pathobiology has not been described well in the literature. A highly curliated O157:H7 strain was used in this study in order to elucidate role of curliation in EHEC adherence to cultured HEp-2 cells. The expression of curli in the EHEC isolate was consistent with strong positive indication of Congo-red (CR) binding and formation of clumps in the bottom of the tube containing Luria-Bertani (LB) broth when cultured overnight at 37 degress C. A few CR-binding negative (CR-) colonies occurred spontaneously within the population of CR+ isolate. The CR+ EHEC showed massive aggregative adhesion pattern, whereas the spontaneous CR- strain showed typical localized adherence on HEp-2 cells. Electron microscopy confirmed highly curliated bacteria in the CR+ EHEC sample. Interestingly, the curliation disappeared in a msbB1 and msbB2 double mutant derived from the CR+ EHEC. These results suggest that the compromised outer membrane integrity caused by msbB mutations may abrogate curli production in the CR+ EHEC harbouring penta-acylated lipid A structure in their outer membrane.
Bacterial Adhesion/*physiology ; Bacterial Outer Membrane Proteins/*physiology ; Cell Aggregation ; Cells, Cultured ; Epithelial Cells/*microbiology ; Escherichia coli O157/pathogenicity/*physiology/ultrastructure ; Fimbriae, Bacterial/*metabolism/ultrastructure ; Humans ; Larynx/cytology/microbiology ; Microscopy, Electron

Lactobacillus species in the female genital tract are thought to act as a barrier to infection. Several studies have demonstrated that lactobacilli can adhere to vaginal epithelial cells. However, little is known about how the adherence of lactobacilli to vaginal epithelial cells affects the acidity, cell viability, or proliferation of the lactobacilli themselves or those of vaginal epithelial cells. Lactobacillus acidophilus was co-cultured with immortalized human vaginal epithelial cells (MS74 cell line), and the growth of L. acidophilus and the acidity of the culture medium were measured. MS74 cell density and viability were also assessed by counting cell numbers and observing the cell attachment state. L. acidophilus showed exponential growth for the first 6 hr until 9 hr, and the pH was maintained close to 4.0-5.0 at 24 hr after culture, consistent with previous studies. The growth curve of L. acidophilus or the pH values were relatively unaffected by co-culture with MS74 cells, confirming that L. acidophilus maintains a low pH in the presence of MS74 cells. This co-culture model could therefore potentially be used to mimic vaginal conditions for future in vitro studies. On the other hand, MS74 cells co-cultured with L. acidophilus more firmly attached to the culture plate, and a higher number of cells were present compared to cells cultured in the absence of L. acidophilus. These results indicate that L. acidophilus increases MS74 cell proliferation and viability, suggesting that lactobacilli may contribute to the healthy environment for vaginal epithelial cells.
Cell Adhesion ; Cell Line ; Cell Survival ; Coculture Techniques ; Culture Media/chemistry ; Epithelial Cells/*microbiology/*physiology ; Female ; Humans ; Hydrogen-Ion Concentration ; Lactobacillus acidophilus/growth & development/metabolism/*physiology ; Time Factors

OBJECTIVE: To determine the signaling pathway required for Chlamydial induction of IL-8 expression in epithelial cells. METHODS: The production and localization of IL-8 in Chlamydia-infected Hela 229 cells were monitored using Western blot, immunoflourescence, and ELISA. Activation of MAPK and NF-kappaB signaling pathways were detected by Western blot and immunoflourescence. The effect of different signaling pathways on Chlamydia-induced Il-8 was measured by experiments of chemical inhibitors. RESULTS: IL-8 was induced by Chlamydia and was time-dependant. Chlamydial infection activated MAPK/ERK and MAPK/p38 pathways but not NF-kappaB pathway. Chlamydial induction of IL-8 was blocked by small molecule inhibitors targeting the ERK and p38 pathways. CONCLUSION Chlamydia-induced IL-8 in cervical epithelial cells, the natural target cell type of Chlamydia trachomatis infection, is dependent on MAPK pathway but not NF-kappaB pathway, which provides important information for further understanding the molecular mechanism of Chlamydia-induced inflammatory pathologies.
Chlamydia Infections ; metabolism ; Chlamydia trachomatis ; physiology ; Epithelial Cells ; metabolism ; microbiology ; HeLa Cells ; Humans ; Interleukin-8 ; biosynthesis ; NF-kappa B ; metabolism ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases ; metabolism

Staphylococcus (S.) aureus is a common infectious agent of bovine chronic mastitis, a disease that is difficult to eradicate. The abilities of Staphylococci to be internalized and form a biofilm can contribute to host immunological defence evasion that subsequently impairs antimicrobial therapy. The invasive capability of six S. aureus field isolates with different biofilm-forming profiles was compared in vitro using a bovine mammary epithelial cell line. This was further confirmed in primary cell cultures using fluorescent rRNA probes against S. aureus. The results suggest that S. aureus invasion levels are not related to biofilm formation.
Animals ; *Biofilms ; Cattle ; Cell Line ; Colony Count, Microbial/veterinary ; Epithelial Cells/microbiology ; Female ; In Situ Hybridization, Fluorescence ; Mastitis, Bovine/*microbiology ; Portugal ; Staphylococcal Infections/*veterinary ; Staphylococcus aureus/classification/genetics/immunology/*physiology ; Virulence Factors/i

OBJECTIVE: To observe the effect of chloroquine on the apoptosis of intestinal mucosa epithelial cell and enterogenous bacteria-endotoxin translocation after total hepatic ischemia-reperfusion in rats. METHODS: The rat total hepatic ischemia-reperfusion model was built by blocking the hepatic portal, suprahepatic and infrahepatic vena cava for 20 minutes. Ninety Sprague-Dawley rats were assigned randomly into the sham operation group (Group A, n = 30), total hepatic ischemia-reperfusion treatment group (Group B, n = 30), and chloroquine administrated group (Group C, n = 30). Each group was subdivided randomly into 3 subgroups (n = 10) according to different experiment time phases as follows: after 20 minutes of total hepatic vascular exclusion (T0), 4 hours after reperfusion (T1), and the 48 hours of survival. Group A and Group B were intravenously injected with normal saline 1 mL/kg while Group C received chloroquine 10 mg/kg which dissolved in 1 mL/kg normal saline intravenously. The levels of portal blood D-lactate, TNF-alpha, endotoxin, and the intestinal mucosa MDA concentration were measured at T0 and T1; the portal blood, mesenteric lymph node, and spleen tissues were cultured for bacteria; and the apoptotic index of intestinal mucosa epithelial cells at T0 and T1 and the survival rate after 48 hour reperfusion were obtained. RESULTS: Compared with Group A, the levels of portal blood D-lactate, TNF-alpha, endotoxin and the intestinal mucosa MDA in Group B and Group C were significantly higher (P < 0.05 or P < 0.01). These indexes of Group C were lower than those of Group B (P < 0.05). The portal vein blood, mesenteric lymph node and spleen tissues existed the bacterium translocation both in Group B and Group C, and the positive rate in Group C was lower than that in Group B (P < 0.05). Apoptotic index of the intestinal mucosa epithelial cell increased significantly in Group B (P < 0.01) and Group C (P < 0.05), but the apoptotic index in Group C was lower than that in Group B (P < 0.05); the 48 hour survival rate of the rats in Group C was higher than that in group B (P < 0.05). CONCLUSION Chloroquine may decrease the intestinal mucosa epithelial cell apoptosis and the enterogenous bacteria-endotoxin translocation after total hepatic ischemia-reperfusion and increase the survival rate of the rats.
Animals ; Bacterial Translocation ; drug effects ; Chloroquine ; pharmacology ; Epithelial Cells ; pathology ; Escherichia coli ; physiology ; Female ; Intestinal Mucosa ; pathology ; Intestine, Small ; microbiology ; pathology ; Liver ; blood supply ; Male ; Phospholipases A ; antagonists & inhibitors ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; microbiology ; pathology

BACKGROUNDAspergillus fumigatus (A. fumigatus) is a ubiquitous saprophytic fungus responsible for the majority of invasive mold infections in patients undergoing chemotherapy, organ transplantation or with persistent neutropenia. This study aimed to determine the role of E-cadherin for adhesion and endocytosis of A. fumigatus blastospores in the human epithelial cell line A549.

METHODSA. fumigatus blastospores were incubated with the total protein of A549 to investigate the binding of E-cadherin and blastospores followed by an affinity purification procedure. After establishing the adhesion model, the adhesion and endocytosis of A. fumigatus blastospores by A549 cells were evaluated by down-regulating E-cadherin of A549 cells using blocking antibody or small interfering RNA (siRNA).

RESULTSE-cadherin was adhered to the surface of A. fumigatus blastospore. Adhesion and endocytosis of the blastospores were reduced by blocking or down-regulating E-cadherin in A549 cells.

CONCLUSIONSE-cadherin is a receptor for adhesion and endocytosis of A. fumigatus blastospores in epithelial cells. This may open a new approach to treat this fungal infection.

Aspergillus fumigatus ; cytology ; Cadherins ; genetics ; metabolism ; Cell Line ; Endocytosis ; physiology ; Epithelial Cells ; metabolism ; microbiology ; Fungal Proteins ; chemistry ; metabolism ; Humans ; In Vitro Techniques ; Protein Binding ; physiology ; RNA, Small Interfering ; Spores, Fungal ; cytology