AIMTo study the influence of enterococci on human sperm membrane in vitro.

METHODSEjaculated human sperm were artificially infected with beta-hemolytic or non-beta-hemolytic enterococci at the bacteria: sperm ratio of 50:1 at 37 degrees . Sperm membrane integrity was examined after incubation for 1, 3 and 5 h by hypoosmotic swelling (HOS) test and electron microscopy.

RESULTSSperm infected with beta-hemolytic enterococci had lower HOS scores compared with non-beta-hemolytic strains or uninfected control (P < 0.01). The HOS test scores of sperm infected with beta-hemolytic enterococci increased in the presence of phosphatidylcholine, an inhibitor of hemolysin. Non-beta-hemolytic strains showed no significant difference in swelling rate, compared with the control group (P > 0.05). It was shown by electron microscopy that beta-hemolytic enterococci caused significant rupture of human sperm membrane.

CONCLUSIONBeta-hemolytic enterococci caused human sperm membrane injury, and might be mediated by the hemolysin of enterococci.

Cell Membrane ; drug effects ; microbiology ; Ejaculation ; Enterococcus ; physiology ; Feces ; microbiology ; Humans ; Male ; Phosphatidylcholines ; pharmacology ; Reference Values ; Spermatozoa ; drug effects ; microbiology ; ultrastructure

OBJECTIVETo investigate the postburn change in the intestinal biological barrier in severely burned rats.

METHODSWistar rats inflicted by 30% TBSA III degree scalding on the back were employed as the model. The samples were harvested at 24, 48, 72 and 96 postburn hours (PBHs), respectively with the employment of microorganism analysis, biochemical and radio-immune methods for the study. The membranous flora in cecum, the mucin and sIgA in intestinal content, the intestinal endotoxin and bacterial translocation rate and quantification analysis and the endotoxin content in cava vein were observed.

RESULTSThe total intestinal membranous flora amount decreased, especially and obviously did the anaerobic bacteria such as bifidobacteria. But aerobic ones increased. In addition, The fungus and enterobacteria exhibited rapid overgrowth. This lead to evident imbalance between anaerobic and aerobic bacteria and to the destruction of intestinal biological barrier and the decrease of colonization resistance. As a result, the intestinal bacterial translocation rate increased markedly. The endotoxin content in the cava and intestinal containing increased, while the mucin and sIgA contents decreased.

CONCLUSIONIntestinal biological barrier could be severely damaged after major burn, which might be one of the causes of postburn intestinal infection.

Animals ; Bacterial Infections ; etiology ; Burns ; complications ; Cell Membrane ; microbiology ; Female ; Intestinal Diseases ; etiology ; microbiology ; Intestinal Mucosa ; microbiology ; Male ; Rats ; Rats, Wistar

Orientia tsutsugamushi, a causative pathogen of Scrub typhus, is a gram-negative intracellular bacterium. Outer membrane vesicles (OMVs) are produced from the membrane of bacteria and play many roles related to the survival of the pathogen. However, there have been no reports confirming whether O. tsutsugamushi indeed produce OMVs. O. tsutsugamushi boryong was cultured in ECV-304 cells for the purification of OMVs. Western blot analysis and immunoenrichment using anti-O. tsutsugamushi monoclonal antibody and electron microscopy were employed for identification and characterization of OMVs. We confirm the presence of OMVs derived from O. tsutsugamushi, and also found that those OMVs contain a major surface antigen of 56-kDa protein and variant immunogenic antigens.
Antibodies, Monoclonal/*immunology ; Antigens, Bacterial/*immunology ; Antigens, Surface/*immunology ; Cell Line ; Cell Membrane/immunology ; Humans ; Microscopy, Electron ; Orientia tsutsugamushi/*immunology/metabolism ; Scrub Typhus/diagnosis/microbiology ; Secretory Vesicles/*immunology

OBJECTIVETo determine expression changes of major outer membrane protein(OMP) antigens of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai during infection of human macrophages and its mechanism.

METHODSOmpR encoding genes and OmpR-related histidine kinase (HK) encoding gene of L.interrogans strain Lai and their functional domains were predicted using bioinformatics technique. mRNA level changes of the leptospiral major OMP-encoding genes before and after infection of human THP-1 macrophages were detected by real-time fluorescence quantitative RT-PCR. Effects of the OmpR-encoding genes and HK-encoding gene on the expression of leptospiral OMPs during infection were determined by HK-peptide antiserum block assay and closantel inhibitive assays.

RESULTSThe bioinformatics analysis indicated that LB015 and LB333 were referred to OmpR-encoding genes of the spirochete, while LB014 might act as a OmpR-related HK-encoding gene. After the spirochete infecting THP-1 cells, mRNA levels of leptospiral lipL21, lipL32 and lipL41 genes were rapidly and persistently down-regulated (P <0.01), whereas mRNA levels of leptospiral groEL, mce, loa22 and ligB genes were rapidly but transiently up-regulated (P<0.01). The treatment with closantel and HK-peptide antiserum partly reversed the infection-based down-regulated mRNA levels of lipL21 and lipL48 genes (P <0.01). Moreover, closantel caused a decrease of the infection-based up-regulated mRNA levels of groEL, mce, loa22 and ligB genes (P <0.01).

CONCLUSIONExpression levels of L.interrogans strain Lai major OMP antigens present notable changes during infection of human macrophages. There is a group of OmpR-and HK-encoding genes which may play a major role in down-regulation of expression levels of partial OMP antigens during infection.

Antigens, Bacterial ; genetics ; metabolism ; Bacterial Outer Membrane Proteins ; genetics ; metabolism ; Cell Line ; Chaperonin 60 ; genetics ; metabolism ; Humans ; Leptospira interrogans ; genetics ; immunology ; pathogenicity ; Lipoproteins ; genetics ; metabolism ; Macrophages ; microbiology

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

OBJECTIVETo study the role of outer membrane protein T (OmpT) in the pathogenesis of uropathogenic Escherichia.coli.

METHODSIn cultured human bladder epithelial cell line 5637, we examined the adhesion ability of wild-type (CFT073), ompT gene knockout (COTD), and revertant (pST) strains of E.coli to the cells and the extracellular matrix (ECM). The expressions of the adhesion gene iha and virulence gene iroN were detected by real-time PCR. Murine models of urinary tract infection with the 3 strains were established to evaluate the bacterial burden of the bladder and kidney tissue and bacterial counts in blood. We also detected the expressions of interleukin-6 (IL-6) and IL-8 in the bladder and kidney tissues of the mice.

RESULTThe COTD strain showed a significantly lower cell adhesion rate than CFT073 strain [(4.62∓0.39)% vs (8.81∓1.13)%, P<0.05] with also a lower ECM-adhesion rate [(4.95∓0.59)% vs (8.85∓0.79)%, P<0.05]. The mRNA expressions of iha and iroN in CFT073 strain were 2.1 and 3.8 times that of COTD strain. In the mouse model, the mean bacterial load of CFT073 strain in the bladder tissue was 6.36∓0.06, significantly greater than that of COTD (6.01∓0.07) and revertant (6.29∓0.06) strains (P<0.05); the bacterial load of CFT073 strain in the kidney tissue was also significantly higher than that of COTD strain (6.25∓0.05 vs 5.87∓0.06, P<0.05). In mice infected with the wild-type, knockout, and revertant strains, the detection rates of IL-6, which were identical to those of IL-8, in the inflammatory bladder and kidney tissues were 60%, 12.5%, and 50%, respectively.

CONCLUSIONSOmpT may regulate the expression of the adhesion gene iha and the transferrin gene iroN to affect the adhesion of uropathogenic E.coli to host cells.

Animals ; Bacterial Adhesion ; Bacterial Load ; Bacterial Outer Membrane Proteins ; metabolism ; Cell Line, Tumor ; Escherichia coli Infections ; pathology ; Escherichia coli Proteins ; metabolism ; Gene Knockout Techniques ; Humans ; Inflammation ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Kidney ; microbiology ; Mice ; Peptide Hydrolases ; metabolism ; Receptors, Cell Surface ; metabolism ; Urinary Bladder ; microbiology ; Urinary Tract Infections ; microbiology ; pathology ; Uropathogenic Escherichia coli ; pathogenicity

A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine. The aim of this study was to compare the antimicrobial activity of 1% alexidine with that of 2% chlorhexidine using Enterococcus faecalis-infected dentin blocks. Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each. E. faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2% chlorhexidine or 1% alexidine solutions for 5 and 10 min, respectively. Sterile saline was used as a control. The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope. Significantly fewer bacteria were observed in the 2% chlorhexidine- or 1% alexidine-soaked groups than in the control group (P<0.05). However, there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups (P>0.05). Ruptured or antiseptic-attached bacteria were more frequently observed in the 10-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups. In conclusion, 10-min soaking with 1% alexidine or 2% chlorhexidine can be effective against E. faecalis infection.
Animals ; Anti-Bacterial Agents ; pharmacology ; Bacterial Adhesion ; drug effects ; Bacterial Load ; drug effects ; Biguanides ; pharmacology ; Cattle ; Cell Membrane ; drug effects ; Chlorhexidine ; pharmacology ; Dentin ; microbiology ; Enterococcus faecalis ; drug effects ; Microscopy, Electron, Scanning ; Random Allocation ; Time Factors

OBJECTIVETo determine the impact of Ureaplasma urealyticum (Uu) infection on the integrity of sperm plasma membrane in infertile males.

METHODSSixty-three semen samples were divided into a Uu infection group (n = 32) and a normal control group (n = 31). Conventional semen analyses were performed by computer-assisted semen analysis (CASA) and Uu detected by the culture method. The semen samples were washed with PBS and dyed by SYBR-14/PI double fluorescent staining, followed by detection of the integrity of sperm plasma membrane by flow cytometry. The percentage of the sperm with intact plasma membrane was indicated as the percentage of sperm emitting green fluorescence (SYBR-14+/PI-%).

RESULTSThe Uu infection group showed a significantly decreased integrity of sperm plasma membrane ([45.14 +/- 10.69]%) and reduced percentage of grade a + b sperm ([23.29 +/- 8.81]%) as compared with the normal control group ([72.68 +/- 9.91]% and [46.32 +/- 9.54]%) (P < 0.01). But there were no significant differences in the semen volume, pH value, and sperm concentration between the two groups (P > 0.05).

CONCLUSIONUu infection decreases the integrity of sperm plasma membrane, which might be an important factor of male infertility.

Adult ; Case-Control Studies ; Cell Membrane ; pathology ; Flow Cytometry ; Humans ; Infertility, Male ; microbiology ; pathology ; physiopathology ; Male ; Organic Chemicals ; Semen Analysis ; methods ; Spermatozoa ; metabolism ; pathology ; Ureaplasma Infections ; pathology ; physiopathology ; Ureaplasma urealyticum ; Young Adult

Investigation was undertaken for the purpose of examining any possible correlation between flocculence of a self-flocculating fusant of Schizosaccharomyces pombe mutant and Saccharomyces cerevisiae mutant (called fusant SPSC for short) and the tolerance of this strain to ethanol. When exposed to 18% (V/V) ethanol for 7 h at 30 degrees C, 52%, 37% and 9% of viability levels remained for the cells of fusant SPSC and its two parental strains, Sch. pombe mutant and S. cerevisiae mutant respectively. Analysis of phospholipid fatty acid composition of plasma membrane showed that the content of palmitic acid of each flocculating yeast (fusant SPSC or Sch. pombe mutant) was around 2-fold higher than that of free S. cerevisiae mutant, with remarkably lower contents of palmitoleic and oleic acids than the latter. When 0.1 mol/L sodium citrate was initially included in the medium in which cells of each flocculating yeast were grown, free cells rather than aggregates were finally obtained. Furthermore, the content of palmitic acid in the phospholipid fatty acid composition of the plasma membranes of the free cells of each flocculating yeast was found to decrease significantly, with a marked increase in the contents of palmitoleic and oleic acids. As a result, the characteristics of the phospholipid fatty acid composition of the plasma membranes of the free cells of each flocculating yeast were similar to those of S. cerevisiae mutant. Meanwhile, the disappearance of flocculence of each flocculating yeast caused by the action of sodium citrate brought about a steeply decreased tolerance of the free cells to ethanol, thus being equivalent to that of S. cerevisiae mutant. These data suggest that the stronger ethanol tolerance of each flocculating yeast is related to the higher content of palmitic acid in the phospholipid fatty acid composition of the plasma membranes. Thus, the enhancement by flocculence on the tolerance of yeast cells to ethanol as well as its mechanism are first reported in this work.
Bioreactors ; microbiology ; Carbohydrates ; Cell Membrane ; metabolism ; Drug Tolerance ; Ethanol ; metabolism ; pharmacology ; Fatty Acids ; metabolism ; Fermentation ; Flocculation ; Phospholipids ; metabolism ; Saccharomyces cerevisiae ; drug effects ; metabolism ; Schizosaccharomyces ; drug effects ; metabolism ; Zea mays ; metabolism

OBJECTIVETo investigate the effects of Huchang Qingfei concentrated pellets on the expression of E-cadherin (E-cd) in the lung tissue from mice infected with Mycoplasma pneumoniae (MP).

METHODA mice model of Mycoplasmal pneumonia (MPP) was developed by repeatedly intranasal infectious route. Transmission electronic microscope (TEM) and immunohistochemistry stain were performed to observe the pathological changes and expression of E-cd in lung tissues.

RESULTUnder TEM it was found that the cellular membrane was ruptured, mitochondria was denatured, crista was broken in the pulmonary cells of the model group; the all above parameters in Huchang medicated group were improved obviously. The immunohistochemistry test showed that strong positive brown stain of E-cd expression was found in the pulmonary epithelial cell membrane and bronchial periphery in the model group, however, in the medicated group, the E-cd expression level in the cellular membrane was decreased and the expression ratio was dropped significantly as compared with the model controls.

CONCLUSIONHuchang Qingfei concentrated pellets can inhibit the overexpression of E-cd in the lung tissue of mice with MP-infection, which may be helpful for prevention and treatment of pulmonary injury caused by MPP.

Animals ; Cadherins ; metabolism ; Cell Membrane ; metabolism ; Drug Combinations ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Epithelial Cells ; metabolism ; Female ; Lung ; metabolism ; pathology ; Male ; Mice ; Mycoplasma pneumoniae ; isolation & purification ; Plants, Medicinal ; chemistry ; Pneumonia, Mycoplasma ; metabolism ; microbiology ; pathology ; Random Allocation