The effect of chromic oxide (Cr2O3) on aerobic bacterial populations associated with the intestinal epithelial mucosa of Arctic charr, Salvelinus alpinus (L.)

1993 ◽  
Vol 39 (12) ◽  
pp. 1169-1173 ◽  
Author(s):  
Einar Ringø
Keyword(s):  
Heterotrophic Bacteria ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Bacterial Flora ◽  
Chromic Oxide ◽  
Intestinal Epithelial ◽  
Gram Positive ◽  
Bacterial Populations ◽  
Gram Negative ◽  
Attachment Sites

Populations of aerobic heterotrophic bacteria present in the gastrointestinal tract of healthy Arctic charr, Salvelinus alpinus (L.), were estimated using the dilution plate technique. The gastrointestinal bacterial flora of fish fed an unsupplemented diet was dominated by Gram-negative bacteria of the genera Acinetobacter, Aeromonas, Agrobacterium, Alcaligenes, Cytophaga, Flavobacterium, Pseudomonas, and Vibrio, and Gram-positive bacteria of the genera Arthrobacter, Brevibacterium, Corynebacterium, Kurthia, Lactobacillus, Microbacterium, Micrococcus, Staphylococcus, and Streptococcus. The composition of the indigenous aerobic bacterial flora in the digestive tract, and especially the microorganisms isolated from the midgut and hindgut regions, was affected by inclusion of 1% chromic oxide (Cr2O3) in the diet. Many of the Gram-negative bacterial genera and some of the Gram-positive bacterial genera were not detectable in the Cr2O3-fed fish. The midgut and hindgut regions in the Cr2O3-fed fish were dominated by Gram-positive microorganisms of the genera Lactobacillus and Streptococcus. It is suggested that the increased accumulation of Cr2O3 in the alimentary tract, as dietary compounds are removed, affects the attachment sites for the gastrointestinal microflora or affects the gut epithelium directly.Key words: chromic oxide, aerobic bacterial flora, Arctic charr.

scholarly journals Bacteriological, Physical And Chemical Properties Of The Pagla Sewage Treatment Plant’s Water

1970 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Mihir Lal Saha ◽  
Ashraful Alam ◽  
Mahbubar Rahman Khan ◽  
Sirajul Hoque
Keyword(s):  
Heterotrophic Bacteria ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Properties ◽  
Bacillus Sphaericus ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Treated Water

Samples from Pagla sewage treatment plant at different treatment stages showed more or less similar temperature (26.9 - 27.5°C). The pH ranged from 7.2 - 7.9. Influent water and primary sedimentation tank water were brownish in colour while sludge water was light black. The lagoon water and treated water were greenish. The ammonium?nitrogen (NH+4-N) and nitrate?nitrogen (NO-3?N) ranged from 5.24 - 61.94 mg/l and 2.55 - 11.02 mg/l, respectively. Phosphorus of the water was 1.34 - 4.50 mg/l. The suspended solids (SS) ranged from 25.48 ? 374.69 mg/l. In the present study the amount of SS in the treated water were found to be quite satisfactory. The total bacterial population in Pagla sewage treatments plant was in between 2.9 × 104 and 2.5 × 106 cfu/ml. The qualitative bacterial spectrum showed a potential consortium of bacteria associated with the treatment plant. Both Gram positive and Gram negative bacteria were present. Gram positive bacteria were represented by the different species of the genus Bacillus, Aureobacterium and Kurthia. Among them Bacillus was the dominant genus. The different species of Bacillus were Bacillus sphaericus, B. fastidiosus, B. circulans and B. pasteurii. Gram negative bacteria were Zoogloea, Yersinia, Citrobacter and Pseudomonas. A good number of microorganisms were found to be associated with the bio-oxidation of the organic compounds of the influent. The Zoogloea along with other free flowing aerobic heterotrophic bacteria like Bacillus, Pseudomonas could play the major role in the sewage treatment.DOI: http://dx.doi.org/10.3329/dujbs.v21i1.9739 DUJBS 2012 21(1): 1-7

scholarly journals THE GASTROINTESTINAL EPITHELIUM AND ITS AUTOCHTHONOUS BACTERIAL FLORA

1968 ◽  
Vol 127 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Dwayne C. Savage ◽  
René Dubos ◽  
Russell W. Schaedler
Keyword(s):  
Gastrointestinal Tract ◽  
Bacterial Flora ◽  
Normal Flora ◽  
Culture Methods ◽  
Gram Positive ◽  
Histological Techniques ◽  
Gram Negative ◽  
Mucous Layer ◽  
Histological Sections ◽  
Gram Positive Cocci

Colonization of the gastrointestinal tract by bacteria of the normal flora was followed by bacteriological and special histological techniques in mice from several colonies. These histological techniques were designed to preserve the intimate associations that become established between particular strains of microorganisms and the epithelium of the mucosa of certain areas of the gut. The findings were as follows: 1. The various strains of bacteria of the normal flora became established in the different areas of the guts of infant mice according to a definite time sequence. 2. The first types of bacteria that could be cultured from the gut were lactobacilli and Group N streptococci. Within the first day after birth, these bacteria colonized the entire digestive tract and formed layers on the stratified squamous epithelium of the nonsecreting portion of the stomach and of the distal esophagus. 3. The bacterial types that appeared next were coliforms and enterococci. From about the 9th to the 18th day after birth, these bacteria could be cultured in extremely high numbers from the cecum and the colon. Histological sections of those organs taken during the first 2 or 3 days of that interval revealed microcolonies of Gram-positive cocci in pairs and tiny Gram-negative rods embedded in the mucous layer of the epithelium. The microcolonies were well separated from the mixture of digesta and bacteria that occupied the center of the lumen; they may have consisted of the coliforms and enterococci mentioned above; but this possibility remains to be proved. 4. Histological sections also revealed that, at about the 12th day after birth, long, thin Gram-variable rods with tapering ends were present, side by side, with the small Gram-negative rods and Gram-positive cocci in the mucous layer. By the 15th day after birth, the fusiform bacteria formed thick layers in the mucus, and seemed to be the only bacteria remaining in that location. It has not yet been possible to enumerate these tapered rods by culture methods, but as judged by visual appearances in the histological sections, they seemed to outnumber all other bacteria in the cecum and the colon by a factor of as much as 1000. It must be stressed that these bacterial layers are readily disrupted and even washed away by conventional histological techniques; their discovery was largely due to the use of the special histological techniques described in the text. The bacteriological and histological findings described here constitute further evidence for the hypothesis that symbiotic associations exist between microorganisms and animals, and that a very large percentage of the bacteria in the gastrointestinal tract constitutes a true autochthonous flora. The constant occurrence of several distinct associations of bacteria with the special histological structures of the animal host renders obsolete the notion that the intestine constitutes a chemostat in which the bacterial populations are randomly mixed. For a full understanding of the ecology of the normal microflora, it is necessary to think of body surfaces as distinct microenvironments in which virtually pure cultures of a few species of microorganisms interact with their host and the adjacent microbial populations. Experiments based on this hypothesis are admittedly difficult to design, but on the other hand studies based on the assumption that microorganisms exist as mixtures in the gastrointestinal tract will be only of limited value and may often be misleading.

Bacterial Flora in the External Ear Canal and in Induced Cholesteatoma in the Mongolian Gerbil

1993 ◽  
Vol 102 (7) ◽  
pp. 559-561 ◽  
Author(s):  
Joan C. Fortuny ◽  
Victor M. Palomar ◽  
Antonio Nogués
Keyword(s):  
Mongolian Gerbil ◽  
Bacterial Flora ◽  
Meriones Unguiculatus ◽  
Mongolian Gerbils ◽  
External Ear ◽  
Ear Canal ◽  
Gram Positive ◽  
Gram Negative ◽  
External Ear Canal ◽  
Gram Negative Organisms

We report on the bacterial flora of the external ear canal and of induced aural cholesteatoma in 14 Mongolian gerbils ( Meriones unguiculatus). In the control, nonmanipulated external ear canal, gram-positive and gram-negative organisms were isolated. In the contents of the cholesteatoma sac, only monomicrobial, gram-negative isolates were found; in each animal they were different from the isolates from the nonmanipulated external ear canal. Obligate anaerobes were absent in all cases. Ligation of the external ear canal in the left ear provoked cholesteatoma in all cases.

Microbiological and Chemical Changes of Spotted Shrimp (Pandalus platyceros) Stored Under Modified Atmospheres

1984 ◽  
Vol 47 (6) ◽  
pp. 453-457 ◽  
Author(s):  
MIGUEL E. LAYRISSE ◽  
JACK R. MATCHES
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Bacterial Growth ◽  
Bacterial Flora ◽  
Modified Atmosphere ◽  
Gram Positive ◽  
Gram Negative ◽  
Modified Atmospheres ◽  
Low Levels ◽  
Pandalus Platyceros

Shrimp (Pandalus platyceros) were packed head-on and head-off in pouches with air or 50 or 100% CO2 and stored at 0 to 2°C for up to 23 d. Carbon dioxide in modified atmosphere pouches dissolved in the liquid phase and the pH decreased. As storage progressed, the pH increased. Only 100% CO2 was effective in extending the lag in bacterial growth, but the greatest weight or drip was also obtained with this atmosphere. The bacterial flora changed from mixed gram-negative and gram-positive organisms to a predominantly gram-positive flora. Ammonia was produced throughout storage in all atmospheres, but was delayed longer in head-off than in head-on shrimp. Indole was produced readily in air packs but only at low levels in CO2 packs.

scholarly journals Functional modulation of enterocytes by gram-positive and gram-negative microorganisms

2004 ◽  
Vol 286 (4) ◽  
pp. G613-G626 ◽  
Author(s):  
Jan-Michel Otte ◽  
Daniel K. Podolsky
Keyword(s):  
Molecular Mechanisms ◽  
Protein S ◽  
Probiotic Bacteria ◽  
Intestinal Epithelial ◽  
Gram Positive ◽  
Epithelial Surface ◽  
Single Strain ◽  
Gram Negative ◽  
Cell Extracts ◽  
Mucin Expression

Clinical studies have suggested that so-called probiotic bacteria may be effective as therapy in inflammatory bowel disease. However, the molecular mechanisms of their interaction with the intestinal surface remain undefined. The influence of whole probiotic bacteria [ Escherichia coli Nissle 1917 (EcN); probiotic mixture VSL#3 (PM)], bacterial cell lysates, and conditioned media on transepithelial resistance (TER), IL-8 secretion, mucin gene expression, and tight junction proteins were determined in T84 and HT-29 intestinal epithelial cells (IEC). In addition, effects on pathogen ( Salmonella dublin)-induced alterations were analyzed. EcN as well as debris and cell extracts induced IL-8 secretion from IEC, whereas no such effect was observed following incubation with the PM. The PM and soluble protein(s) released from the PM increased TER, prevented pathogen-induced decrease in TER, and were shown to stabilize tight junctions. The PM induced expression of mucins in IEC, and these organisms as well as EcN diminished S. dublin-induced cell death. Inhibition of MAPKs with PD-98059 or SB-203580 significantly decreased alterations in IL-8 synthesis and mucin expression and affected the regulation of TER. Probiotics and protein(s) released by these organisms may functionally modulate the intestinal epithelium of the host by different mechanisms, including the competition of whole organisms for contact with the epithelial surface as well as stabilization of the cytoskeleton and barrier function and the induction of mucin expression. Gram-negative and gram-positive organisms differ in the mechanisms activated, and a combination of organisms might be more effective than the application of a single strain.

Prophylaxis of Predisposed Otitis Externa

1975 ◽  
Vol 84 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Jimmie L. Hutchison ◽  
D. N. Wright
Keyword(s):  
Otitis Externa ◽  
Bacterial Flora ◽  
Water Repellent ◽  
External Ear ◽  
Ear Canal ◽  
Gram Positive ◽  
Gram Negative ◽  
Ear Canals ◽  
Therapeutic Compounds

Evaluation, in the guinea pig ear, of fourteen water repellent or therapeutic compounds has resulted in the recommended use of 360 Medical Fluid® as a prophylactic agent for those persons with a high risk of otitis externa. This compound was found to adhere well, be easy to apply and was nonirritating. Use of this material prevented adverse bacterial growth in ear canals exposed to water for up to seven days. The significance of maintaining the normal Gram positive bacterial flora in the external ear canal and the role of cerumen in maintaining a healthy meatal surface is discussed. A system for monitoring the health of the ear canal through measurement of the Gram positive/Gram negative bacterial ratio is suggested.

scholarly journals Human skin bacterial flora differ with altitudes in different ethnic groups of Nepal

2019 ◽  
Vol 10 (6) ◽  
pp. 11-17
Author(s):  
Dipendra Shrestha ◽  
Raju Shrestha ◽  
Rene S. Hendriksen ◽  
Luna Bhatta Sharma ◽  
Dwij Raj Bhatta
Keyword(s):  
Sea Level ◽  
Ethnic Groups ◽  
Human Skin ◽  
Bacterial Flora ◽  
P Value ◽  
Normal Flora ◽  
Gram Positive ◽  
Gram Negative ◽  
Cultured Skin ◽  
Geographical Variations

Background: Largest organ of human body, the skin, is colonized by millions of microorganisms, most of which are not only harmless but also beneficial to the host. Human skin microbes depend upon geographical variations, ethnicity and various host factors. Despite several studies on human skin microbiota in various parts of the globe, it has not been studied in Nepalese population. Aims and Objective: To identify skin bacterial normal flora in different ethnic groups residing in different altitude of Nepal. Materials and Methods: We cultured skin swabs of 166 randomly selected volunteers belonging to 10 major ethnic groups from 3 distinct geographical altitudes of Nepal, viz. Bharatpur (415 m from sea level), Kathmandu (1,400 m from sea level) and Lukla (2,860 m from sea level). The isolated organisms were characterized and tested for their susceptibility against different antibiotics. Results: Altogether 231 bacterial isolates were characterized from 166 skin samples. Among them, 140 isolates (60.60 %) were Gram positive and 91 isolates (39.40 %) were Gram negative bacteria. Staphylococcus aureus (35.49%) was the most dominant skin bacterial flora followed by Escherichia coli (22.51%) and Streptococcus spp. (17.75%). Medium altitude Kathmandu exhibited the highest growth (120 isolates) followed by low land Bharatpur (66 isolates) and high land Lukla (51 isolates) which is statistically significant (p value =0.0124). Theantibiotic susceptibility testing against 14 antibiotics exhibited the Gram positive isolates were the most sensitive to Imipenem (94.93 %) whereas the least sensitive to Cephalexin (31.36 %) and the Gram negative isolates were the most sensitive to Amikacin (100%) whereas the least sensitive to Amoxycillin (28.57 %). Conclusion: Our data indicates that the skin bacterial normal flora; which is directly exposed to external environment; has significant relationship with altitudes where individuals live. The result desires further study for the adaptability of normal flora found in different altitudes. Some bacterial commensals were found resistant even against new generations of antibiotics as well, and hence can cause life-threatening infections if they happen to cross the skin physical barrier.

scholarly journals Pattern of Cytokine Responses to Gram-Positive and Gram-Negative Commensal Bacteria Is Profoundly Changed when Monocytes Differentiate into Dendritic Cells

2004 ◽  
Vol 72 (5) ◽  
pp. 2671-2678 ◽  
Author(s):  
Helen Karlsson ◽  
Pia Larsson ◽  
Agnes E. Wold ◽  
Anna Rudin
Keyword(s):  
Dendritic Cells ◽  
Bacterial Flora ◽  
Surface Expression ◽  
Commensal Bacteria ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Bifidobacterium Adolescentis ◽  
Gram Negative ◽  
E Coli

ABSTRACT The normal gastrointestinal bacterial flora is crucial for the maturation of acquired immunity via effects on antigen-presenting cells (APCs). Here we investigated how two types of APCs, monocytes and dendritic cells (DCs), react to different bacterial strains typical of the commensal intestinal microflora. Purified human monocytes and monocyte-derived DCs were stimulated with UV-inactivated gram-positive (Lactobacillus plantarum and Bifidobacterium adolescentis) and gram-negative (Escherichia coli and Veillonella parvula) bacterial strains. Monocytes produced higher levels of interleukin 12p70 (IL-12p70) and tumor necrosis factor (TNF), as detected by an enzyme-linked immunosorbent assay, in response to L. plantarum than in response to E. coli and V. parvula. In contrast, DCs secreted large amounts of IL-12p70, TNF, IL-6, and IL-10 in response to E. coli and V. parvula but were practically unresponsive to L. plantarum and B. adolescentis. The lack of a response to the gram-positive strains correlated with lower surface expression of Toll-like receptor 2 (TLR2) on DCs than on monocytes. The surface expression of TLR4 on DCs was undetectable when it was analyzed by flow cytometry, but blocking this receptor decreased the TNF production in response to V. parvula, indicating that TLR4 is expressed at a low density on DCs. Gamma interferon increased the expression of TLR4 on DCs and also potentiated the cytokine response to the gram-negative strains. Our results indicate that when monocytes differentiate into DCs, their ability to respond to different commensal bacteria dramatically changes, and they become unresponsive to probiotic gram-positive bacteria. These results may have important implications for the abilities of different groups of commensal bacteria to regulate mucosal and systemic immunity.

Chlortetracycline and sulfonamide resistance of fecal bacteria in swine receiving medicated feed

1979 ◽  
Vol 25 (6) ◽  
pp. 789-792 ◽  
Author(s):  
B. Welch ◽  
C. W. Forsberg
Keyword(s):  
Bacterial Flora ◽  
Fecal Bacteria ◽  
Fecal Flora ◽  
Gram Positive ◽  
Gram Negative ◽  
M 10 ◽  
Sulfonamide Resistance

The fecal bacterial flora of swine receiving a ration supplemented with chlortetracycline, sulfamethazine, and penicillin was tested for resistance to chlortetracycline and sulfamethazine using anaerobic techniques and medium M-10. Approximately 15.5 and 1.4% of the flora grew in the presence of 25 and 100 μg of tetracycline/mL, respectively. Higher numbers of bacteria grew in the presence of similar concentrations of sulfamethazine.Thirty-five chlortetracycline-resistant isolates were tentatively identified by genera. Nine different genera were identified, four of these were Gram-positive and five were Gram-negative. The most common genera isolated were Streptococcus and Eubacterium.This demonstrates that in the fecal flora of swine fed rations supplemented with chlortetracycline, a wide variety of bacterial genera can be resistant to this antibiotic.

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