Antagonistic effects of phenolic extracts of Chokeberry pomace on E. coli O157: H7 but not on probiotic and normal bacterial flora

The initial response to infection is recruitment of acute inflammatory cells to the involved site. Interleukin (IL)-8 is the prototypical effector molecule for this process. Transcription of the IL-8 gene is primarily governed by the nuclear transcription factor (NF)-κB. Intestinal epithelial cells produce IL-8 in response to infection by enteric pathogens yet remain quiescent in a milieu where they are literally bathed in normal bacterial flora. We therefore sought to investigate NF-κB activation in response to enteropathogenic Escherichia coli (EPEC), nonpathogenic E. coli, and bacterial lipopolysaccharide in an intestinal epithelial cell (T84) model and to determine whether EPEC-induced activation of NF-κB factor is causally linked to IL-8 production. We report herein that NF-κB is activated by EPEC, yet such a response is not extended to nonpathogenic organisms or purified E. coli lipopolysaccharide. Transcription factor decoys significantly diminished IL-8 production in response to EPEC, demonstrating a causal relationship. Furthermore, deletion of specific EPEC virulence genes abrogates the NF-κB-activating property of this pathogen, suggesting that specific bacterial factors are crucial for inducing this response. These studies show for the first time that infection of intestinal epithelial cells with EPEC activates NF-κB, which in turn initiates IL-8 transcription, and highlight the differential response of these cells to bacterial pathogens vs. nonpathogens.

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PROBIOTIC ANTAGONISTIC EFFECTS OF Lactobacillus collinoides FROM COW MILK ON COW-DIARRHEA-RECOVERED ENTEROTOXIGENIC E. coli: AN IN VIVO STUDY

10.36295/asro.2019.22124 ◽

2019 ◽

Vol 22 (12) ◽

pp. 25-33

Author(s):

Afrah S. Mhyson ◽

Wisam Raheem Atiyah ◽

Ali Abd Sharad

Keyword(s):

In Vivo Study ◽

Cow Milk ◽

Antagonistic Effects ◽

E Coli

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Inhibition of Escherichia coli Translocation from the Gastrointestinal Tract by Normal Cecal Flora in Gnotobiotic or Antibiotic-Decontaminated Mice

Infection and Immunity ◽

10.1128/iai.29.3.1073-1081.1980 ◽

1980 ◽

Vol 29 (3) ◽

pp. 1073-1081

Author(s):

Rodney D. Berg

Keyword(s):

Escherichia Coli ◽

Gastrointestinal Tract ◽

Lymph Nodes ◽

Bacterial Flora ◽

Specific Pathogen Free ◽

Mesenteric Lymph Nodes ◽

E Coli ◽

Mesenteric Lymph ◽

Specific Pathogen ◽

Gnotobiotic Mice

Escherichia coli C25 maintained population levels of 10 9 to 10 10 per g of cecum and translocated to 100% of the middle mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli C25. Intragastric inoculation of these mice with the cecal contents from specific-pathogen-free mice reduced the population levels of E. coli C25 to 10 6 per g of cecum and completely inhibited translocation to the mesenteric lymph nodes. Intragastric inoculation with heat-treated, Formalintreated, or filtered cecal contents did not reduce the population levels of E. coli C25 or reduce the incidence of translocation of E. coli C25 to the mesenteric lymph nodes. Thus, viable bacteria apparently are required in the cecal contents inocula to reduce the population levels and the incidence of translocation of E. coli C25. Treatment with streptomycin plus bacitracin decreased the anaerobic bacterial levels in these gnotobiotic mice, allowing increased population levels of E. coli C25 and increased translocation to the mesenteric lymph nodes. E. coli C25 also translocated to the mesenteric lymph nodes of specific-pathogen-free mice treated with streptomycin and bacitracin before colonization with E. coli C25. The high cecal population levels of E. coli C25 in these antibiotic-decontaminated specific-pathogen-free mice apparently overwhelm any barrier to translocation exerted by the immunologically developed lamina propria of the specific-pathogen-free mice. Inoculation of gnotobiotic mice with a cecal flora also reduced the population levels of an indigenous strain of E. coli with a concomitant inhibition of translocation of the indigenous E. coli to the mesenteric lymph nodes. Thus, bacterial antagonism of the gastrointestinal population levels of certain indigenous bacteria, such as E. coli , by other members of the normal bacterial flora appears to be an important defense mechanism confining bacteria to the gastrointestinal tract.

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Natural and innate immunity

Revision Notes for MCEM Part A ◽

10.1093/med/9780199583836.003.0008 ◽

2011 ◽

pp. 151-153

Author(s):

Dr Mark Harrison

Keyword(s):

Fatty Acids ◽

Innate Immunity ◽

Free Fatty Acids ◽

Bacterial Flora ◽

Sebaceous Glands ◽

Skin Flora ◽

Normal Bacterial Flora

1.1 Barriers to infection, 151 1.2 Normal bacterial flora, 152 1.3 Phagocytes and complement, 152 • Anatomical barrier physically preventing invasion of microorganisms. • Chemical barrier providing unfavourable conditions for most organisms to survive due to: ▪ Free fatty acids produced by the sebaceous glands and skin flora...

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Validation of a real-time PCR assay for high-throughput detection of Avibacterium paragallinarum in chicken respiratory sites

Journal of Veterinary Diagnostic Investigation ◽

10.1177/1040638719866484 ◽

2019 ◽

Vol 31 (5) ◽

pp. 714-718 ◽

Cited By ~ 2

Author(s):

Kristin A. Clothier ◽

Simone Stoute ◽

Andrea Torain ◽

Beate Crossley

Keyword(s):

Real Time ◽

High Throughput ◽

Real Time Pcr ◽

Limit Of Detection ◽

Bacterial Flora ◽

Clinical Samples ◽

Single Tube ◽

Avibacterium Paragallinarum ◽

Normal Bacterial Flora ◽

Close Relatives

Avibacterium paragallinarum is the causative agent of infectious coryza, a highly contagious respiratory disease in chickens. Given its fastidious nature, this bacterium is difficult to recover and identify, particularly from locations colonized by normal bacterial flora. Standard PCR methods have been utilized for detection but are labor-intensive and not feasible for high-throughput testing. We evaluated a real-time PCR (rtPCR) method targeting the HPG-2 region of A. paragallinarum, and validated a high-throughput extraction for this assay. Using single-tube extraction, the rtPCR detected 4 A. paragallinarum (ATCC 29545T and 3 clinical) isolates with a limit of detection (LOD) of 10 cfu/mL and a PCR efficiency of 89–111%. Cross-reaction was not detected with 33 non– A. paragallinarum, all close relatives from the family Pasteurellaceae. Real-time PCR testing on extracts of 66 clinical samples (choana, sinus, or trachea) yielded 98.2% (35 of 36 on positives, 30 of 30 on negatives) agreement with conventional PCR. Duplicate samples tested in a 96-well format extraction in parallel with the single-tube method produced equivalent LOD on all A. paragallinarum isolates, and 96.8% agreement on 93 additional clinical samples extracted with both procedures. This A. paragallinarum rtPCR can be utilized for outbreak investigations and routine monitoring of susceptible flocks.

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Study of aerobic bacterial conjunctival flora in patients with diabetes mellitus

Nepalese Journal of Ophthalmology ◽

10.3126/nepjoph.v5i1.7818 ◽

2013 ◽

Vol 5 (1) ◽

pp. 28-32 ◽

Cited By ~ 11

Author(s):

D Karimsab ◽

SK Razak

Keyword(s):

Diabetes Mellitus ◽

Diabetic Retinopathy ◽

Proliferative Diabetic Retinopathy ◽

Bacterial Flora ◽

Diabetic Patients ◽

Coagulase Negative Staphylococci ◽

Ocular Infections ◽

Patients With Diabetes ◽

Conjunctival Flora ◽

Normal Bacterial Flora

Introduction: Normal bacterial flora may be altered by a variety of factors. Objective: To study the aerobic bacterial conjunctival flora in patients with diabetes mellitus and to find its clinical significance by comparing the results to the conjunctival flora of non-diabetic subjects. Materials and methods: A total of 75 diabetic patients were included as cases and 25 nondiabetics as controls to compare the results. Specimens for the study of conjunctival flora were taken by rubbing sterile cotton-tipped swabs to the inferior palbebral conjunctiva. The conjunctival culture report of the patients with diabetic mellitus was compared to that of nondiabetic subjects. Results: Positive conjunctival cultures were seen in a higher percentage of patients with diabetes (unilateral and bilateral positive conjunctival cultures 34.66 % and 58.66 % respectively) compared to that in non-diabetic controls (unilateral and bilateral positive conjunctival cultures 24 % and 16 % respectively). Diabetics showed a higher proportion of coagulase negative staphylococci (45.33 %), compared to the non-diabetic group (16 %). Among the diabetic patients, positive conjunctival cultures were detected more frequently in those with diabetic retinopathy compared to those without retinopathy. A higher proportions of bilateral positive conjunctival cultures were seen in cases with proliferative diabetic retinopathy (38.63 %) in comparison to patients with no retinopathy and different stages of non-proliferative diabetic retinopathy. Conclusion: The conjunctival floral pattern with increased bacteria in diabetics is a predominant cause of many diabetes-related ocular infections. The presence of diabetic retinopathy is an indicator for increased colonization of conjunctiva, and its severity correlates with the severity of diabetic retinopathy. Nepal J Ophthalmol 2013; 5(9):28-32 DOI: http://dx.doi.org/10.3126/nepjoph.v5i1.7818

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Natural and innate immunity

10.1093/med/9780198765875.003.0008 ◽

2017 ◽

Author(s):

Mark Harrison

Keyword(s):

Emergency Medicine ◽

Innate Immunity ◽

Bacterial Flora ◽

Normal Bacterial Flora

This chapter describes the microbiology of natural and innate immunity as it applies to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of barriers to infection, normal bacterial flora, and phagocytes and complement. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.

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In vitro Antimicrobial Effects of Virus Block, Which Contains Multiple Polyoxometalate Compounds, and Hygienic Effects of Virus Block-Supplemented Moist Hand Towels

Pharmacology ◽

10.1159/000500897 ◽

2019 ◽

Vol 104 (1-2) ◽

pp. 98-112 ◽

Cited By ~ 3

Author(s):

Katsuaki Dan ◽

Naohiro Katoh ◽

Takaaki Matsuoka ◽

Katsuyuki Fujinami

Keyword(s):

Inductively Coupled Plasma ◽

Metal Ion ◽

Bacterial Flora ◽

Atomic Emission ◽

Time Dependent ◽

Antimicrobial Effects ◽

Inductively Coupled ◽

Before And After ◽

Normal Bacterial Flora

Background: Historical evidence has verified the multifaceted antiviral efficacy of polyoxometalates (PMs). Methods: We carried out a study to investigate the antimicrobial effects of each of the 5 substances comprising virus block (VB): 3 PMs that have antibacterial and antiviral activity, an antibiotic agent, and an antibacterial agent. We also investigated the effectiveness of the addition of VB to moist hand towels in a study involving 120 volunteers. The time-dependent changes in metal ion concentrations in aqueous VB solution were analyzed using inductively coupled plasma atomic emission spectroscopy. Results: The metal elements in the aqueous VB solution remained stable for 12 weeks without undergoing time-dependent changes. Discussion: Further investigations were performed to study hand hygiene using moist hand towels in daily life settings. To this end, 120 volunteers provided 240 specimens that were used to investigate the presence of antibacterial compounds on the volunteers’ hands before and after hand towel use. An aliquot of each specimen was suspended in phosphate-buffered saline and plated on agar media, and the number of colonies formed was counted. Normal bacterial flora found on the hands of the volunteers was investigated before and after the use of 4 different moist hand towels. Conclusions: The effects of VB and PMs were superior to those of commercial moist hand towels, indicating that effective data were obtained that may be useful for the practical application of the tested items.

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Differences in outer membrane characteristics between gallstone-associated bacteria and normal bacterial flora

The Lancet ◽

10.1016/s0140-6736(94)92691-3 ◽

1994 ◽

Vol 343 (8895) ◽

pp. 444-448 ◽

Cited By ~ 25

Author(s):

L.A. Wetter ◽

R.M. Hamadeh ◽

J. McL Griffis ◽

A. Oesterie ◽

B. Aagaard ◽

...

Keyword(s):

Outer Membrane ◽

Bacterial Flora ◽

Associated Bacteria ◽

Normal Bacterial Flora

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THE EFFECT OF COPPER ON DISTILLED WATER QUALITY FOR USE IN MILK AND WATER LABORATORIES

Journal of Milk and Food Technology ◽

10.4315/0022-2747-30.10.305 ◽

1967 ◽

Vol 30 (10) ◽

pp. 305-309 ◽

Cited By ~ 1

Author(s):

Gene W. Ronald ◽

R. L. Morris

Keyword(s):

Water Quality ◽

Milk Sample ◽

Bacterial Flora ◽

Copper Toxicity ◽

Test Organism ◽

Raw Milk ◽

Distilled Water ◽

Aerobacter Aerogenes ◽

Normal Bacterial Flora ◽

Effect Of Copper

Summary Levels of copper toxicity have been established in distilled water using the distilled water suitability test. It is shown that levels of copper, toxic by the distilled water suitability test, are not toxic to the test organism, Aerobacter aerogenes, in sterile milk or to the normal bacterial flora of a raw milk sample. It is the contention of this paper that the distilled water suitability test is an unrealistically severe yardstick of distilled water quality for use in routine milk and water laboratories.

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