Variation in number and proportion of rumen microbes examined both in vivo and in vitro using a simulation system

1998 ◽  
Vol 1998 ◽  
pp. 56-56
Author(s):  
Gisèle Gizzi ◽  
R. Zanchi ◽  
F. Sciaraffia

The use of in vitro techniques is rapidly expanding because of an increasing need for routine and reproducible methods to obtain bioavailability data in addition to chemical ones. Furthermore in vivo methods are very expensive, an invasive technique for animals and may give non homogeneous results. In vitro systems could be divided in simulation systems (e.g. Rusitec, Czerkawski and Brekenridge, 1977) that attempt to closely reproduce the animal rumen ecosystem and are characterised by a higher level of complexity; and techniques that are mainly targeted to obtain biavailability data, without trying to mimic rumen metabolism (e.g. enzyme tests, Antoniewicz and Kosmala, 1997). As the fate of feedstufis in the rumen is mostly regulated by the micro-organisms, a rumen simulation system should primarily be characterised by a representative rumen microflora. The aim was to evaluate the possibility of maintaining a normal rumen microflora in an in vitro simulation system.

1998 ◽  
Vol 1998 ◽  
pp. 56-56
Author(s):  
Gisèle Gizzi ◽  
R. Zanchi ◽  
F. Sciaraffia

The use of in vitro techniques is rapidly expanding because of an increasing need for routine and reproducible methods to obtain bioavailability data in addition to chemical ones. Furthermore in vivo methods are very expensive, an invasive technique for animals and may give non homogeneous results. In vitro systems could be divided in simulation systems (e.g. Rusitec, Czerkawski and Brekenridge, 1977) that attempt to closely reproduce the animal rumen ecosystem and are characterised by a higher level of complexity; and techniques that are mainly targeted to obtain biavailability data, without trying to mimic rumen metabolism (e.g. enzyme tests, Antoniewicz and Kosmala, 1997). As the fate of feedstufis in the rumen is mostly regulated by the micro-organisms, a rumen simulation system should primarily be characterised by a representative rumen microflora. The aim was to evaluate the possibility of maintaining a normal rumen microflora in an in vitro simulation system.


1998 ◽  
Vol 22 ◽  
pp. 309-311
Author(s):  
M. D. Carro ◽  
E. L. Miller

Rumen microbes utilize mainly ammonia as a nitrogen (N) source for their growth but some species also use a variety of amino acids (AA) or peptides. Several studies have shown both an enhanced fibre digestion and efficiency of rumen micro-organisms when N sources such as AA, peptides and protein were provided in addition to ammonia (Griswold et al.,1996). However, no difference either in digestion or in growth of rumen microbes was found in other in vivo(Fujimaki et al.,1989) and in vitro (Kernick, 1991) studies. The objective of this experiment was to investigate the effects of protein, peptides, AA and ammonia on microbial growth and fermentation of an all fibre basal diet in a semicontinuous culture system (RUSITEC; Czerkawski and Breckenridge, 1977).


Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 158
Author(s):  
Akshaya Tatke ◽  
Narendar Dudhipala ◽  
Karthik Janga ◽  
Bhavik Soneta ◽  
Bharathi Avula ◽  
...  

Delivering an effective drug load to the posterior section of the ocular tissues, while using a non-invasive technique, has always been a challenge. In this regard, the goal of the present study was to develop sustained release triamcinolone acetonide (TA) loaded polymeric matrix films for ocular delivery. The TA-films were prepared in two different polymer matrices, with drug loadings of 10% and 20% w/w, and they were evaluated for ocular distribution in vivo in a conscious rabbit model. A 4% w/v TA suspension (TA-C) was used as a control for in vitro and in vivo studies. The TA-films, prepared with melt-cast technology, used polyethylene oxide (PEO) and Soluplus® as the polymer matrix. The films were evaluated with respect to assay, content uniformity, excipient interaction, and permeability across isolated rabbit sclera. The distribution of TA in the ocular tissues, post topical administration, was determined in New Zealand male albino rabbits as a function of dose, and was compared against TA-C. The assay of the 10% and 20% w/w film was in the range from 70–79% and 92–94% for the Soluplus® and PEO films, respectively, and content uniformity was in the range of 95–103% for both the films. The assay of the TA from Soluplus® films was less compared with the PEO films and showed an interaction with TA, as revealed by Differential Scanning Calorimetry (DSC). Hence, Soluplus® films were not selected for further studies. No interaction was observed between the drug and PEO polymer matrix. The enhancement of trans-scleral flux and permeability of TA was about 1.16 and 1.33-folds, respectively, from the 10% w/w PEO and 3.5 and 2.12-folds, respectively, from the 20% w/w PEO films, as compared with TA-C formulations. The in vivo studies demonstrate that significantly higher TA levels were observed in the anterior and posterior segments of the eye at the end of 6h with the PEO films. Therefore, the PEO based polymeric films were able to deliver TA into the back of the eye efficiently and for prolonged periods.


1995 ◽  
Vol 1 (5) ◽  
pp. 462-478 ◽  
Author(s):  
Waltraud Eggert-Kruse ◽  
Gerhard Rohr ◽  
Wolfram Ströck ◽  
Susanne Pohl ◽  
Beate Schwalbach ◽  
...  

Abstract The clinical significance of micro-organisms in semen samples of asymptomatic subfertile patients is a matter of constant debate. Usually little attention is paid to anaerobic bacteria as they are sensitive to transportation and culturing, and differentiation is difficult, costly and time-consuming. In the present study, special screening was carried out for anaerobes in ejaculates in addition to the routine microbial cultures of genital secretions of both partners. In addition to standard semen analysis and evaluation of sperm ability to penetrate cervical mucus (CM) in vivo (postcoital testing) and in vitro using a standardized test system, semen samples from 126 randomly chosen males of couples with a median duration of infertility of 4 years were examined for colonization with anaerobic bacteria. All couples were without clinical signs or symptoms of genital tract infection. The special care taken for anaerobic growth in semen samples gave a high rate of positive cultures and showed that nearly all ejaculates (99%) were colonized with anaerobic micro-organisms, and potentially pathogenic species were found in 71% of men. This rate was more than four times higher than that obtained with routine cultures and standard transportation (16%). Anaerobic bacterial growth of ≥106 colony forming units (CFU)/ml was seen in 42% (total range 103-108 CFU/ml). In addition, aerobic growth was found in 96%(≥106 CFU/ml in 21%), potentially pathogenic species in 61% of semen specimens. There were no marked differences in the prevalence of anaerobic micro-organisms in patients with reduced or normal sperm count, motility or morphology. Nor was there any significant difference in anaerobic colonization between samples with impaired or good ability to penetrate CM of female partners (in vivo or in vitro), or the CM of fertile donors in the in-vitro sperm-cervical mucus penetration test (SCMPT) in this asymptomatic group of patients. There was no clear association between microbial colonization and subsequent fertility in vivo within an observation period of 6 months. The results of this study suggest that anaerobic bacteria are often not detected when routine methods for microbial evaluation are used. This should be considered during assisted reproduction and in patients with symptoms of genital tract infection and should lead to further studies in infertile patients where subclinical infection or inflammation is indicated by specific markers in semen samples.


2019 ◽  
Vol 570 ◽  
pp. 118641 ◽  
Author(s):  
Christian J.F. Bertens ◽  
Shuo Zhang ◽  
Roel J. Erckens ◽  
Frank J.H.M. van den Biggelaar ◽  
Tos T.J.M. Berendschot ◽  
...  

2009 ◽  
Vol 90 (4) ◽  
pp. 810-817 ◽  
Author(s):  
Aniuska Becerra ◽  
Rajas V. Warke ◽  
Kris Xhaja ◽  
Barbara Evans ◽  
James Evans ◽  
...  

The depletion of l-tryptophan (L-Trp) has been associated with the inhibition of growth of micro-organisms and also has profound effects on T cell proliferation and immune tolerance. The enzyme indoleamine 2,3-dioxygenase (IDO) catalyses the rate-limiting step in the catabolic pathway of L-Trp. Gene expression analysis has shown upregulation of genes involved in L-Trp catabolism in in vitro models of dengue virus (DENV) infection. To understand the role of IDO during DENV infection, we measured IDO activity in sera from control and DENV-infected patients. We found increased IDO activity, lower levels of L-Trp and higher levels of l-kynurenine in sera from DENV-infected patients during the febrile days of the disease compared with patients with other febrile illnesses and healthy donors. Furthermore, we confirmed upregulation of IDO mRNA expression in response to DENV infection in vitro, using a dendritic cell (DC) model of DENV infection. We found that the antiviral effect of gamma interferon (IFN-γ) in DENV-infected DCs in vitro was partially dependent on IDO activity. Our results demonstrate that IDO plays an important role in the antiviral effect of IFN-γ against DENV infection in vitro and suggest that it has a role in the immune response to DENV infections in vivo.


1998 ◽  
Vol 22 ◽  
pp. 158-160
Author(s):  
J. Dijkstra ◽  
J. France ◽  
S. Tamminga

In protein evaluation systems for ruminants, the microbial protein supply is calculated from the amounts of rumen degradable organic matter and nitrogen (N) using empirical equations. A variable part of the rumen synthesized microbial protein does not reach the duodenum but is recycled within the rumen (review Firkins, 1996). Since energy is required for its re-synthesis and degraded microbial protein is subject to deamination, the efficiency of substrate conversion into microbial protein in the rumen is affected by microbial recycling. Rumen protozoa have a major impact upon this recycling through engulfment of micro-organisms and autolysis. In vitro, bacterial protein breakdown is proportionately reduced by some 0·9 upon removal of protozoa (Wallace and McPherson, 1987). Defaunation of the rumen increases the efficiency of microbial protein synthesis in vivo significantly (review Jouany et al., 1988).


1995 ◽  
Vol 1995 ◽  
pp. 110-110 ◽  
Author(s):  
S Akhter ◽  
E Owen ◽  
M K Theodorou ◽  
S L Tembo ◽  
E R Deaville

Previous studies (El Shaer, Omed and Axford, 1987; Akhter, Owen, Fall, O'Donovan and Theodorou, 1994) with the two-stage in vitro procedure of Tilley and Terry (1963) have shown a high correlation between digestibilities of forages as determined using either sheep rumen liquor, sheep faeces or cow faeces as the microbial inoculum. In the first study of the of the present investigation one objective was to examine the repeatability of these digestibility measurements when made on different occasions. A second objective was to assess whether the correlations between faecal and rumen fluid based inocula could be improved if microorganisms were obtained from pairs rather than individual animals. The objective in the second study using forages of known in vivo digestibility, was to investigate the effect of freezing or freeze-drying of faeces on the repeatability of digestibilities of forages determined in vitro using micro-organisms from cow faeces.


1998 ◽  
Vol 1998 ◽  
pp. 168-168 ◽  
Author(s):  
A. Hussain ◽  
E. L. Miller

Inclusion of lactose in dairy cow rations increases dry matter intake (DMI) and milk yield (Garnsworthy 1996). This may be due to the relatively slow rate of lactose fermentation ( Hussain and Miller, 1998) sustaining better regulation of rumen pH and also possible consequence for microbial protein synthesis (Chamberlain et al., 1993).This experiment was conducted to study the changes in rumen environment over the adaptation period and effect of these changes on the fermentation of lactose itself.Three Suffolk wethers (b.wt 56± 7.36 kg) maintained on hay and concentrate (600:400) were offered 50g lactose per day for 16 days. Rumen liquor collected on dayO (before offering lactose), 4, 8, 12 and 16 was used to measure gas production from sucrose and lactose ( Menke et al., 1979). On these days rumen samples were collected at 0, 1, 2, 4, 6 and 8 hrs after the morning feed. Rumen pH, ammonia N (NH3N) and volatile fatty acids (VFA) were measured. At 8 hrs time rumen samples were also taken for protozoa enumeration. Data obtained were analysed using ANOVA procedure of Genstat 5.


2002 ◽  
Vol 80 (11) ◽  
pp. 1930-1937 ◽  
Author(s):  
Iain J Gordon ◽  
F Javier Pérez-Barbería ◽  
Paloma Cuartas

The rumen microflora ecosystem adapts to the diet consumed by the animal. We tested the extent to which this adaptation facilitates or retards the digestion of plant-based forages. Following adaptation of sheep (Ovis aries) and red deer (Cervus elaphus) to diets containing different mixtures of alfalfa, grass, and heather (a dwarf shrub), an in vitro digestion technique was used to compare the ability of the rumen microflora to digest the mixtures of substrates to which they were adapted with their ability to digest different mixtures of the same substrates. In vitro digestion of different substrates was slightly greater in rumen liquor derived from sheep than in that derived from red deer for each of the different substrates, but the effect was not significant. Digestibility in sheep was independent of how the feed was presented (diet of equal proportions of alfalfa, grass, and heather in each meal (D-EQ): mean in vitro digestibility = 37.3%; alfalfa, grass, and heather presented sequentially on different days (D-SEQ): mean in vitro digestibility = 37.7%, SE of differences = 1.30%, p > 0.05). However, in red deer there was a significant effect of method of diet presentation (D-EQ: mean in vitro digestibility = 36.9%; D-SEQ: mean in vitro digestibility = 34.2%, SE of differences = 1.30%, p < 0.05), digestibility being substantially lower for D-SEQ than for D-EQ. Overall, the results demonstrated that whilst there were no species-specific differences in overall digestion efficiency, dietary adaptation had an effect on substrate digestion efficiency, with rumen microbes adapted to high-quality diets digesting these more efficiently than low-quality diets.


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