scholarly journals Survival of Enterococcus faecalis in Mouse Peritoneal Macrophages

1999 ◽  
Vol 67 (5) ◽  
pp. 2160-2165 ◽  
Author(s):  
Claudia R. Gentry-Weeks ◽  
RoxAnn Karkhoff-Schweizer ◽  
Andreas Pikis ◽  
Monica Estay ◽  
Jerry M. Keith
Keyword(s):  
Enterococcus Faecalis ◽  
Brain Heart Infusion ◽  
Extended Period ◽  
Peritoneal Macrophages ◽  
Bacterial Cells ◽  
Infection Period ◽  
E Coli ◽  
Significant Difference ◽  
The Difference ◽  
Mouse Peritoneal Macrophages

ABSTRACT Enterococcus faecalis was tested for the ability to persist in mouse peritoneal macrophages in two separate studies. In the first study, the intracellular survival of serum-passaged E. faecalis 418 and two isogenic mutants [cytolytic strain FA2-2(pAM714) and non-cytolytic strain FA2-2(pAM771)] was compared with that of Escherichia coli DH5α by infecting BALB/c mice intraperitoneally and then monitoring the survival of the bacteria within lavaged peritoneal macrophages over a 72-h period. All E. faecalis isolates were serum passaged to enhance the production of cytolysin. E. faecalis 418, FA2-2(pAM714), and FA2-2(pAM771) survived at a significantly higher level (P = 0.0001) than did E. coli DH5α at 24, 48, and 72 h. Internalized E. faecalis 418, FA2-2(pAM714), and FA2-2(pAM771) decreased 10-, 55-, and 31-fold, respectively, over the 72-h infection period, while internalizedE. coli DH5α decreased 20,542-fold. The difference in the rate of survival of E. faecalis strains and E. coli DH5α was most prominent between 6 and 48 h postinfection (P = 0.0001); however, no significant difference in killing was observed between 48 and 72 h postinfection. In the second study, additional E. faecalisstrains from clinical sources, including DS16C2, MGH-2, OG1X, and the cytolytic strain FA2-2(pAM714), were compared with the nonpathogenic gram-positive bacterium, Lactococcus lactis K1, for the ability to survive in mouse peritoneal macrophages. In these experiments, the E. faecalis strains and L. lactis K1 were grown in brain heart infusion (BHI) broth to ensure that there were equal quantities of injected bacteria. E. faecalis FA2-2(pAM714), DS16C2, MGH-2, and OG1X survived significantly better (P < 0.0001) than did L. lactis K1 at each time point. L. lactis K1 was rapidly destroyed by the macrophages, and by 24 h postinfection, viable L. lactis could not be recovered. E. faecalis FA2-2(pAM714), DS16C2, MGH-2, and OG1X declined at an equivalent rate over the 72-h infection period, and there was no significant difference in survival or rate of decline among the strains. E. faecalis FA2-2(pAM714), MGH-2, DS16C2, and OG1X exhibited an overall decrease of 25-, 55-, 186-, and 129-fold respectively, between 6 and 72 h postinfection. The overall reduction by 1.3 to 2.27 log units is slightly higher than that seen for serum-passaged E. faecalis strains and may be attributable to the higher level of uptake of serum-passaged E. faecalis than of E. faecalis grown in BHI broth. Electron microscopy of infected macrophages revealed that E. faecalis 418 was present within an intact phagocytic vacuole at 6 h postinfection but that by 24 h the infected macrophages were disorganized, the vacuolar membrane was degraded, and the bacterial cells had entered the cytoplasm. Macrophage destruction occurred by 48 h, and the bacteria were released. In conclusion, the results of these experiments indicate that E. faecaliscan persist for an extended period in mouse peritoneal macrophages.

scholarly journals Relationship of Sanitation Parameters with Microbial Diversity and Load in Raw Meat from the Outlets of the Metropolitan City Biratnagar, Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Sanjay Mahato
Keyword(s):  
Bacterial Contamination ◽  
Fungal Contamination ◽  
Raw Meat ◽  
E Coli ◽  
Significant Difference ◽  
The Difference ◽  
Meat Samples ◽  
Relationship Of ◽  
Operating Methods ◽  
Microbiological Procedures

The main aim of this study is to assess the microbial load of raw meat from outlets of Biratnagar and its relationship with several sanitation parameters. Samples were taken from meat outlets, and required microbiological procedures were followed as per guidelines. Approximately 63.6% of microbes were present in meat with poor sanitation while 36.4% were present in meat with good sanitation. Fungal contamination in poorly kept mutton was one and half times greater than chicken/mutton of good sanitation. Fungi such asPenicillium(21.3%),Mucor(16.3%),Aspergillus(15%), andTrichosporon(13.8%) were most predominant. 73.8% of meat samples containedStaphylococcusspp., 61.3% containedE. coli,48.8% ofPseudomonasspp., and 37.5% samples containedSalmonellaspp. Outlets selling both types of meat showed no significant difference in microbial types. Mean of TVC of meat is 8.2 log CFU/g. Mean TVC of mutton (7.6 log CFU/g) is lower than mean TVC of chicken/meat (8.5 log CFU/g) and differed significantly. Tiled outlets showed comparatively lower bacterial contamination than cemented outlets which was statistically significant (t = −3.16,p=0.002). With the difference among microbial type and few sanitation parameters being statistically significant, it can be suggested that outlets should be tiled (p=0.002), showcased (p=0.001), and the meat-handling employee must wear washed apron (p=0.013). Proper cleaning of water supply and use area (p≤0.001) and drainage (p=0.048) maintain a good meat sanitation (p≤0.001) which reduces microbial contamination significantly. To diminish microbiological load on meat sold in the Biratnagar city, standard operating methods should be practiced.

scholarly journals The interaction of Gram negative bacteria and S. mansoni in mice with experimental Schistosomiasis

1980 ◽  
Vol 75 (1-2) ◽  
pp. 161-172 ◽  
Author(s):  
Heonir Rocha ◽  
Vanete S. Oliveira ◽  
Moema Magnavita G. de Oliveira
Keyword(s):  
Portal System ◽  
Saline Control ◽  
Control Group ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Sterile Saline ◽  
E Coli ◽  
Significant Difference ◽  
The Difference ◽  
Gram Negative Organisms

Animals (122 mice) were infected each with eighty cercariae of S. mansoni and subsequently challenged intravenously eight weeks later with the following gram-negative organisms. S. typhi, E. coli, Klebsiella-enterobacter species, Proteus mirabilis and Pseudomonas aeruginosa. Enumeration of bacteria in the liver, spleen and blood and S. mansoni from the portal sistem was performed from one to four weeks later in infected animals. A significant difference between infection produced by S. typhi and other gram negative organisms was observed: S. typhi persisted longer in the spleen and liver and could be recovered from S. mansoni worms up to three weeks following bacterial infection. Other gram negative bacteria disappeared from S. mansoni worms after two weeks of initial challenge. Additional animals (51 mice) infected with S. mansoni were given S. typhi, E. coli or sterile saline. After two weeks, animals were sacrificed and the recovery rate of worms from the portal system, and the mesenteric and hepatic oogram were determined. in animals infected with E. coli a significant decrease in the number of worms was observed compared to the saline control group; thirty worms were recovered in the control group compared to two worms in e. coli infected animals. In addition, the patterns of oviposition was significantly different in these latter animals suggesting complete inhibition of this process. Following S. typhi infection the difference in recovery of worms and pattern of oviposition was minimal. These findings suggest a difference in the interaction of various gram negative bacteria and S. mansoni and are consistent with the clinical observation of prolonged salmonella bacteremia in patients with schistosomiasis.

Withdrawal of Neuroleptic Medications from Institutionalized Dementia Patients: Results of a Double-Blind, Baseline-Treatment—Controlled Pilot Study

1997 ◽  
Vol 10 (3) ◽  
pp. 119-126 ◽  
Author(s):  
Sarah Bridges-Parlet ◽  
David Knopman ◽  
Susan Steffes
Keyword(s):  
Aggressive Behavior ◽  
Objective Assessment ◽  
Extended Period ◽  
Good Clinical Practice ◽  
Chi Square ◽  
Double Blind ◽  
Term Care ◽  
Dementia Patients ◽  
Significant Difference ◽  
The Difference

Among dementia patients in long-term care facilities, neuroleptics (NL) are frequently prescribed for the treatment of agitation. Although good clinical practice and federal law mandate attempts at withdrawal of these medications, empiric data regarding the cessation of NL treatment are limited in this population. The objective of the present study was to assess through direct observation the effects of short-term NL withdrawal on physically aggressive behavior and other aspects of agitation. We carried out a randomized, double-blind, baseline NL-controlled 4-week trial of the effects of NL withdrawal in 36 institutionalized patients with possible or probable Alzheimer's disease. Patients were directly observed for four 2-hour sessions during baseline, a prerandomization week, and during weeks 1, 2, and 4 of the double-blind portion of the study. Completion of the 4 weeks of double-blind medication and number of observed episodes of physically aggressive behavior (PAB) were the two primary outcome measures. Of the 22 patients who were withdrawn from NL, 20 (91%) completed the 4-week double-blinded withdrawal. Two patients were discontinued from the study due to unacceptable levels of agitation at the request of their nursing staff. Of the 14 patients not withdrawn, all completed the 4-week trial. The chi-square test for the difference between groups was not significant ( P > .05). Based on the observed instances of PAB, there was no significant difference ( P > .05) between withdrawn and not-withdrawn subjects. Half of the withdrawn patients remained off NLs for an extended period of time after the end of the study, even after the blind was broken. Withdrawing institutionalized dementia patients from NLs was successful in most but not all study patients. Generalization of these results is limited by the highly selected nature of the participants. Unmasking of unmanageable agitation and physical aggressiveness in a small minority must be weighed against the benefits of removing unnecessary medication in the majority of dementia patients in whom NL withdrawal is attempted. PAB itself should not drive continuing NL use without regard to objective assessment of efficacy of the NL treatment.

Changes in Activity of Selected Lysosomal Enzymes in Peritoneal Macrophages of Renal Failure Patients on Peritoneal Dialysis

1989 ◽  
Vol 9 (4) ◽  
pp. 313-317 ◽  
Author(s):  
Wladyslaw Sulowicz ◽  
Tadeusz Cichocki ◽  
Zygmunt Hanicki
Keyword(s):  
Renal Failure ◽  
Peritoneal Dialysis ◽  
Lysosomal Enzymes ◽  
Peritoneal Macrophages ◽  
Significant Rise ◽  
Control Group ◽  
Significant Difference ◽  
The Difference ◽  
End Stage ◽  
Dialytic Treatment

Activity of acid phosphatase (AP), beta-glucuronidase (GR), N-acetyl-beta-D-glucosaminidase (GZ), and peroxidase (P) was assessed using a semiquantitative cytochemical method in peritoneal macro phages of 30 patients with end-stage renal failure treated by intermittent peritoneal dialysis and of 30 control patients with normal renal function. The dialysed patients showed a significantly higher activity of GR and P at the beginning of the treatment as compared with the respective activities observed in the control group and a further significant rise of these activities after 4 months of dialysis. Activity of AP at the beginning of the treatment was insignificantly lower than in the control group and the difference became significant at the end of the investigated period. There was no significant difference between the dialysed patients and the control group in the activity of GZ assessed at the beginning of the dialytic treatment and after 4 months of dialysis. A significant decrease in that activity was, however, observed in the course of dialysis.

scholarly journals Detection of Enterococcus faecalis in Necrotic Teeth Root Canals by Culture and Polymerase Chain Reaction Methods

2007 ◽  
Vol 01 (04) ◽  
pp. 216-221 ◽  
Author(s):  
Dilsah COGULU ◽  
Atac UZEL ◽  
Ozant ONCAG ◽  
Semiha d AKSOY ◽  
Cemal ERONAT
Keyword(s):  
Polymerase Chain Reaction ◽  
Enterococcus Faecalis ◽  
Permanent Teeth ◽  
Deciduous Teeth ◽  
Chain Reaction ◽  
Test Species ◽  
Root Canals ◽  
Significant Difference ◽  
Polymerase Chain ◽  
The Difference

ABSTRACTObjectives: The aim of this study was to investigate the presence of Enterococcus faecalis in endodontic infections in both deciduous and permanent teeth by culture and polymerase chain reaction (PCR) methods.Methods: A total of 145 children aged 5-13 years old were involved in this study. The presence of E. faecalis in necrotic deciduous and permanent teeth root canals was studied using culture and polymerase chain reaction methods.Results: Among 145 molar teeth, 57% (n=83) presented necrotic asymptomatic pulp tissues and were included in this study. Culture and PCR methods detected the test species in 18 and 22 of 83 teeth involved, respectively. E. faecalis was cultured from 8 (18%) of 45 necrotic deciduous teeth and from 10 (26%) of 38 necrotic permanent teeth. PCR detection identified the target species in 10 (22%) and 12 (32%) of necrotic deciduous and permanent teeth respectively. Statistically significant difference in the presence of E. faecalis in deciduous and permanent teeth was found by culture and PCR methods (P=0.03 and 0.02, respectively). The difference in the presence of E. faecalis between two different methods was not statistically significant (P>.05).Conclusions: The results of the present study confirm that both culture and PCR methods are sensitive to detect E. faecalis in root canals. (Eur J Dent 2007;1:216-221)

scholarly journals CsgA Production by Escherichia coli O157:H7 Alters Attachment to Abiotic Surfaces in Some Growth Environments

2011 ◽  
Vol 77 (20) ◽  
pp. 7339-7344 ◽  
Author(s):  
R. M. Goulter-Thorsen ◽  
E. Taran ◽  
I. R. Gentle ◽  
K. S. Gobius ◽  
G. A. Dykes
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Epifluorescence Microscopy ◽  
Clear Correlation ◽  
Bacterial Cells ◽  
Content Type ◽  
E Coli ◽  
Abiotic Surfaces ◽  
Significant Difference ◽  
Force Mapping

ABSTRACTThe role of curli expression in attachment ofEscherichia coliO157:H7 to glass, Teflon, and stainless steel (SS) was investigated through the creation ofcsgAknockout mutants in two isolates ofE. coliO157:H7. Attachment assays using epifluorescence microscopy and measurements of the force of adhesion of bacterial cells to the substrates using atomic force microscopy (AFM) force mapping were used to determine differences in attachment between wild-type (wt) andcsgA-negative (ΔcsgA) strains following growth in four different media. The hydrophobicity of the cells was determined using contact angle measurements (CAM) and bacterial adhesion to hydrocarbons (BATH). The attachment assay results indicated that ΔcsgAstrains attached to glass, Teflon, and SS surfaces in significantly different numbers than their wt counterparts in a growth medium-dependent fashion (P< 0.05). However, no clear correlation was seen between attachment numbers, surface type, or growth medium. No correlation was seen between BATH and CAM results (R2< 0.70). Hydrophobicity differed between the wt and ΔcsgAin some cases in a growth medium- and method-dependent fashion (P< 0.05). AFM force mapping revealed no significant difference in the forces of adhesion to glass and SS surfaces between wt and ΔcsgAstrains (P> 0.05) but a significantly greater force of adhesion to Teflon for one of the two wt strains than for its ΔcsgAcounterpart (P< 0.05). This study shows that CsgA production byE. coliO157:H7 may alter attachment behavior in some environments; however, further investigation is required in order to determine the exact relationship between CsgA production and attachment to abiotic surfaces.

Decontaminating Beef for Escherichia coliO157:H7

1998 ◽  
Vol 61 (5) ◽  
pp. 547-550 ◽  
Author(s):  
IVONE DELAZARI ◽  
SEBASTIÃO TIMO IARIA ◽  
HANS P. RIEMANN ◽  
DEAN O. CLIVER ◽  
THEODORE MORI
Keyword(s):  
Opposite Effect ◽  
Tap Water ◽  
Escherichia Coli O157 ◽  
Bacterial Cells ◽  
Connective Tissues ◽  
Lean Tissue ◽  
E Coli ◽  
Significant Difference ◽  
Before And After ◽  
Control Samples

Beef lean, fat, and connective tissues were inoculated with Escherichia coli O157:H7 before and after a prewashing procedure to compare the efficacy of prewashing and no prewashing on bacterial adherence and, consequently, on the removal of bacteria from the inoculated surfaces. Prewashing consisted of spraying tissues with tap water before inoculation. Final washing with disinfectant solutions compared the efficacy of several chemicals for the removal or destruction of E. coli O157:H7. The results showed that prewashing was very effective in reducing the numbers of bacterial cells on beef tissues, mainly lean tissue, in the control samples which received final washing with water. An opposite effect of prewashing was observed when disinfectant Solutions were used for final washing; this may be due to dilution by water carried on the tissues after prewashing. The efficacy of Chemicals was dependent on the type of exposed tissue. Hydrogen peroxide (3%) was more efficient in the removal of E. coli O157:H7 from connective tissues, with reductions greater than 4 log CFU/cm2, compared to a normally washed control (P &lt; 0.01). Chlorhexidine (0.1%) was very efficient on fat and lean tissues, causing reductions over 5 log CFU/cm2 on not prewashed fat and lean tissues, compared to the control (P &lt; 0.01). Acetic acid (5%) was the least effective, decreasing the number of CFU by under 1 log/cm2 as compared to the control; and no statistically significant difference was found among tissues, even though the removal of bacteria seemed less in lean tissue compared to fat or connective tissues.

scholarly journals Role of Methionine Sulfoxide Reductases A and B of Enterococcus faecalis in Oxidative Stress and Virulence

2010 ◽  
Vol 78 (9) ◽  
pp. 3889-3897 ◽  
Author(s):  
Chen Zhao ◽  
Axel Hartke ◽  
Marilena La Sorda ◽  
Brunella Posteraro ◽  
Jean-Marie Laplace ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Enterococcus Faecalis ◽  
Galleria Mellonella ◽  
Methionine Sulfoxide ◽  
Peritoneal Macrophages ◽  
Infection Model ◽  
Repair Enzymes ◽  
Methionine Sulfoxide Reductases ◽  
Mouse Peritoneal Macrophages

ABSTRACT Methionine sulfoxide reductases A and B are antioxidant repair enzymes that reduce the S- and R-diastereomers of methionine sulfoxides back to methionine, respectively. Enterococcus faecalis, an important nosocomial pathogen, has one msrA gene and one msrB gene situated in different parts of the chromosome. Promoters have been mapped and mutants have been constructed in two E. faecalis strains (strains JH2-2 and V583) and characterized. For both backgrounds, the mutants are more sensitive than the wild-type parents to exposure to H2O2, and in combination the mutations seem to be additive. The virulence of the mutants has been analyzed in four different models. Survival of the mutants inside mouse peritoneal macrophages stimulated with recombinant gamma interferon plus lipopolysaccharide but not in naïve phagocytes is significantly affected. The msrA mutant is attenuated in the Galleria mellonella insect model. Deficiency in either Msr enzyme reduced the level of virulence in a systemic and urinary tract infection model. Virulence was reconstituted in the complemented strains. The combined results show that Msr repair enzymes are important for the oxidative stress response, macrophage survival, and persistent infection with E. faecalis.

scholarly journals Evaluation of 4% Sodium Hypochlorite in eliminating Enterococcus faecalis from the Root Canal when Used with Three Irrigation Methods: An in vitro Study

2017 ◽  
Vol 18 (3) ◽  
pp. 214-217
Author(s):  
Vinisha Pandey ◽  
Harsh Priyank ◽  
Abhishek Bagul ◽  
Kishore Kumar Majety ◽  
Parul Verma ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Sodium Hypochlorite ◽  
Root Canal ◽  
Saline Solution ◽  
Brain Heart Infusion ◽  
Root Canals ◽  
Irrigation Methods ◽  
Group I ◽  
Significant Difference

ABSTRACT Introduction Endodontic treatment removes all pathogens, such as Enterococcus faecalis from pulp and root canals. The aim of this study is to assess the usefulness of sodium hypochlorite (NaOCl) in removing E. faecalis from the root canal used with three different irrigation methods. Materials and methods This study was conducted on freshly extracted maxillary incisors. After biomechanical preparation, root canals were injected with E. faecalis. Three groups were made which contained 30 teeth in each group; 2 mL of NaOCl solution was used for irrigation followed by agitation with K-files in group I; 2 mL of NaOCl solution was used for irrigation and ultrasonic agitation was done in group II. In group III, an alternate irrigation with NaOCl and 3% hydrogen peroxide was done. The fourth group (control) was irrigated with sterile saline solution. E. faecalis bacteria were sampled to the root canals with paper points and were transferred to tubes that contained 5 mL of brain heart infusion broth. Tubes were incubated and the presence of broth turbidity was suggestive of bacteria remaining in the root canal. Results All three groups showed no statistically significant difference. However, difference existed between experimental groups and control groups. Conclusion The author concluded that all three methods of application of NaOCl were effective in disinfecting the root canal than the saline solution. Clinical significance No single irrigant has 100% efficiency. Thus by this study, a best irrigating solution with maximum properties can be established. How to cite this article Priyank H, Pandey V, Bagul A, Majety KK, Verma P, Choudhury BK. Evaluation of 4% Sodium Hypochlorite in eliminating Enterococcus faecalis from the Root Canal when Used with Three Irrigation Methods: An in vitro Study. J Contemp Dent Pract 2017;18(3):214-217.

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