Bacterial infection or Demodex infestation has been reported to contribute to chronic blepharitis. The association between Demodex mites and bacterial flora in this disease remains to be elucidated. Fifty-six consecutive patients diagnosed with chronic blepharitis and 46 healthy volunteers were recruited for this study. Using specimens of three epilated eyelashes and lid margin swabs, Demodex were identified microscopically and bacteria were determined by cultures, followed by colony counting and mass spectrometry. We found 191 Demodex mites, 161 D. folliculorum and 30 D. brevis, in 45 patients. Correspondingly, 101 Demodex, 63 D. folliculorum and 38 D. brevis, were found in 21 controls (p < 0.05, both). Bacterial culture-positivity was obtained in samples (eyelashes, lid margins, or both) from 54 patients and in eyelashes from 37 controls. The total colony counts and the incidences and colony counts of Propinibacterium acnes and Staphylococcus aureus from patients’ eyelashes were significantly higher than that of the controls. Furthermore, bacterial colony counts in blepharitis patients’ eyelashes with D. folliculorum were higher than that of controls with D. folliculorum (p < 0.01). Similarly, P. acnes colonies increased significantly in patients’ eyelashes with D. folliculorum (p < 0.05). These results suggest that D. folliculorum and P. acnes have a role in the occurrence of the chronic blepharitis. Further studies are required to reveal the relationship between these two organisms in blepharitis.
AIM: To investigate the effect of Staphylococcus aureus (S. aures) lysates (SALs) on herpes simplex virus type-I (HSV1) infection in human corneal epithelial (HCE) cells and in a mouse model of HSV1 keratitis. METHODS: HCE, Vero, HeLa, and BV2 cells were infected with HSV1 [HSV1 f strain, HSV1f; HSV-1-H129 with green fluorescent protein (GFP) knock-in, HSV1g]. Pre- or post-infection, SAL at various concentrations was added to the culture medium for 24h. GFP fluorescence in HSV1g or plaque formation by HSV1f were examined. The effects of heat-treated SAL, precooled acetone-precipitated SAL, and SAL subjected to ultrafiltration (100 kDa) were evaluated. The effects of other bacterial components and lysates on HSV1 infection were also tested, including lipoteichoic acid (LTA), peptidoglycan (PGN), staphylococcal protein A (SPA), and α-hemolysin from S. aureus (α-toxin) as well as lysates from a wild-type S. aureus strain, S. epidermidis, and Escherichia coli (W-SAL, SEL, and ECL, respectively). In addition, SAL eye drops were applied topically to BALB/c mice with HSV1 keratitis, followed by in vivo observations. RESULTS: The cytopathic effect, plaque formation (HSV1f), and GFP expression (HSV1g) in infected cells were inhibited by SAL in a dose-dependent manner. The active component of SAL (≥100 kDa) was heat-sensitive and retained activity after acetone precipitation. In HSV1g-infected cells, treatment with LTA-sa, α-toxin, PGN-sa, or SPA did not inhibit GFP expression. SAL, W-SAL, and SEL (but not ECL) decreased GFP expression. In mice with HSV1 keratitis, SAL reduced corneal lesions by 71%. CONCLUSION: The results of this study demonstrate that SAL can be used to inhibit HSV1 infection, particularly keratitis. Further studies are needed to determine the active components and mechanism underlying the effects of SAL.
In the present study, eight strains were isolated from 20 cow vagina samples and identified using phenotype, biochemical analysis, sugar fermentation tests, and 16S rRNA sequence analysis. Among eight strains, only SQ0048 was identified as Lactobacillus johnsonii based on a series of biochemical testing (including the adhesion test, catalase test, bacteriocin production test, antibacterial test, and pH value), suggesting that its biological activity was superior to the other seven strains. Furthermore, SQ0048 had the lowest pH value (4.32) and the shortest fermentation time (8 h) compared with the other strains. The adhesion rate of SQ0048 was significantly higher than that of Lactobacillus delbrueckii, with an average adhesion number of 304 ± 2.67. The hydrogen peroxide production testing in SQ0048 was positive; in addition, bacteriocin gene of SQ0048, encoding an approximately 10-kDa product, was successfully cloned, expressed, and detected using the SDS-PAGE method. Meanwhile, SQ0048 had a weak inhibitory effect on Staphylococcus aureus and Escherichia coli. However, the expression products of the bacteriocin gene of SQ0048 had a very strong inhibitory effect on S. aureus and E. coli, with inhibition zone sizes of 18 ± 0.45 mm and 15 ± 0.60 mm, respectively. These data showed that SQ0048 has excellent antibacterial properties compared with other isolated
Background Lactic acid bacteria with probiotic and antibacterial properties were isolated from the vagina of healthy cows. The purpose of the study is to isolation and screening of lactic acid bacteria strains with antibacterial properties from the vagina of healthy cows, which could be used to treat cow vaginal inflammation. Results Isolation and identification of eight dominant lactic acid bacteria strains from 55 isolates was performed using classic microbiology methods and fermentation engineering. Eight strains were selected that had no spores and capsules, exhibited strong acid production capacity (pH <4.5) and had a rapid acid production (time ≤12 h) at the lowest pH. These strains were screened using fermentation engineering, pharmacology, cell biology and molecular biology methods. Lactobacillus johnsonii (SQ0048) had the lowest pH (4.32) and shortest acid-producing time (8 h). L. johnsonii (SQ0048) could produce hydrogen peroxide, inhibit the growth of Staphylococcus aureus and Escherichia coli and adhere to the vaginal epithelial cells of cows. The average number adhering to each cell was 304±2.67. Bacteriocin genes were detected in L. johnsonii (SQ0048), and the bacteriocin gene of a positive clone of this strain was 100% similar to that of Lactobacillus johnsonii NCC 533 (NC_005362.1). Expression of the bacteriocin genes had inhibitory activity against S. aureus and E. coli. Conclusions These advantages indicate that SQ0048 is a promising candidate for use in antimicrobial preparations.
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