Jacqueline I. Kelley

Recovery of bdellovibrios from submerged surfaces and other aquatic habitats.

The distribution of bdellovibrios was investigated over a wide geographical area of the Chesapeake Bay including some tributaries and subestuaries. Bdellovibrios were recovered from five aquatic habitats; water, sediment, oyster shell surface biofilm, zooplankton, and plants over a wide range of temperature and salinity measurements. Consistently, the greatest number of the predators was recovered from samples of biofilm irrespective of temperature and salinity. A decrease in the numbers and frequency of predators recovered from all habitats was observed at temperatures below 10°C. Only the shell surface biofilm samples yielded bdellovibrios 100% of the time. The organisms were recovered from 79% of water samples and 44% of sediment samples. The results reveal that bdellovibrios are surface-associated organisms and that this association appears to provide some protection for the predators at low temperatures.

Enhanced Interleukin-1β, Interleukin-6 and Tumor Necrosis Factor-α Production by LPS Stimulated Human Monocytes Isolated from HIV + Patients

Abstract Periodontal disease and tooth loss is a common finding among advanced HIV+ patients. In addition to local oral lipopolysaccharide (LPS) stimulation, systemic up-regulation of monocyte pro-inflammatory cytokine secretion may also be involved in the pathogenesis of HIV disease. A study was undertaken to investigate IL-1β, IL-6 and TNF-α production by resting and LPS stimulated monocytes isolated from HIV + patients and also to investigate the relationship of the patients HIV viral load status to the cytokine production. Whole blood samples in EDTA were collected from 39 HIV-1 infected patients and 20 age and sex matched uninfected controls. Plasma was separated by centrifugation. Viral load was determined using a quantitative RT-PCR. Monocytes were isolated by Ficoll-hypaque gradient separation followed by overnight plastic adherence. Cultured monocytes (1 × 106ml) were stimulated with LPS (1 μg/ml) of either P. gingivalis or F. nucleatum for 2, 8, 24 and 48 h and supernatant fluids were collected. IL-1β, IL-6, and TNF-α levels in supernatant fluids were estimated by ELISA. Increased overall production of IL-1β, IL-6 and TNF-α by LPS stimulated monocytes isolated from HIV-1 infected patients was observed when compared to HIV-1 uninfected controls. LPS stimulated monocytes from HIV-1 infected patients with high viral load (HVL) produced significant (p<0.05) elevations in these pro-inflammatory cytokines when compared to HIV-1 uninfected controls. Both LPS of P. gingivalis and F. nucleatum produced a comparable cytokine production by monocytes after 8 h of stimulation. These data suggest that enhanced IL-1β, IL-6 and TNF-α is produced by monocytes/macrophages isolated from HVL HIV + patients and may be involved in the overall pathogenesis of HIV-1 infection.

Efficacy of Listerine® Antiseptic in reducing viral contamination of saliva

Abstract Aim: The anti‐viral efficacy of oral antimicrobial rinses has not been adequately studied in terms of potential clinical significance. As a follow‐up to an in vitro study on the effect of oral antiseptics on Herpes simplex virus, Type 1, this study was undertaken to evaluate the in vivo effect of an essential oil containing oral antiseptic on the reduction of viral titer in saliva during active viral infection. Method: Patients were recruited and evaluated in a single visit protocol at the onset of a perioral outbreak, consistent historically and clinically with recurrent Herpes labialis. Direct immunofluorescence of cytological smears of the lesions/oral fluids was used to confirm Herpes simplex virus types I or II. Patients were randomly assigned to one of two treatment groups: (1) active ingredient and (2) sterile water control. The viral lesion was evaluated as to clinical stage according to standard protocol. Salivary fluid samples were taken: (1) at baseline; (2) immediately following a 30 s rinse; (3) 30 min. after the 30 s rinse; and (4) on the repeat trial, also at 60 min. after the 30 s rinse. All samples were evaluated for viral titer and results compared. Results: In Trial 1, the sample population consisted of 19 males and 21 females with an average age of 29.2 and in Trial 2, 21 males, 19 females with an average age of 28. In both Trials 1 and 2, recoverable infectious virions were reduced to zero after a 30 s experimental rinse; whereas, the control rinse resulted in a non‐significant (p>0.05) reduction. The experimental group also demonstrated a continued significant (p<0.05) reduction 30 min. post rinse when compared with baseline while the control group returned to baseline levels. In Trial 2, the 60 min. post rinse follow‐up demonstrated a 1–2 log residual reduction from baseline in the experimental group; however, this was not significant. Conclusions: There is clinical efficacy in utilizing an oral rinse with the antimicrobial agent Listerine® Antiseptic in reducing the presence of viral contamination in oral fluids for at least 30 min. after oral rinse. The risk of viral cross contamination generated from these oral fluids in person to person contact or during dental treatment may be reduced.

Functional changes in THP-1 human monocytic cells after stimulation with lipopolysaccharide of oral microorganisms and granulocyte macrophage colony stimulating factor

A human THP-1 monocyte cell line culture system has been utilized to observe the effect of granulocyte macrophage colony stimulating factor (GM-CSF) supplementation with lipopolysaccharide (LPS) of oral microorganisms to stimulate monocyte/macrophage functional activity. LPS of oral microorganisms, Fusobacterium nucleatum and Porphyromonas gingivalis was produced by phenol-water extraction and characterized. The phagocytosis assay was performed using F1TC labeled Saccharomyces yeast particles. Phagocytic functional activity was observed in 10-11% of resting THP-1 cells. Treatment of THP-1 cells with LPS of F. nucleatum or P. gingivalis increased the phagocytic activity of THP-1 cells 2-3 fold. GM-CSF significantly increased phagocytosis either alone or when supplemented with LPS of F. nucleatum or P. gingivalis. A chemotaxis assay was performed using a 48 well chemotaxis chamber. Chemotactic functional activity of THP-1 cells was increased 2-fold after 4 days of treatment with GM-CSF. Stimulation of THP-1 cells with LPS of F. nucleatum or P. gingivalis significantly reduced the chemotactic activity indicating the maturation towards a fixed macrophage. There were functional variations (chemotaxis and phagocytosis) in THP-1 cells in response to LPS of oral microorganisms following stimulation with GM-CSF.