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1.
A saprophytic bacterial flora is present on the penis and the distal part of the urethra of stallions. Little is known about the fungal flora of their reproductive tract. As micro organisms play an important role in mares fertility, the aim of the study was to describe the distribution of fungi and bacteria in the normal genital apparatus of stallions. The microbic flora of the reproductive tract of 11 healthy, fertile stallions was evaluated, collecting samples from 5 different locations: urethral fossa, penis/internal lamina of the prepuce, urethra pre- and post-ejaculation, and semen. For fungal examination samples were taken on 3 different occasions (N = 165), while for bacteriologic examination samples were taken on one occasion only (N = 55). There was a statistical difference in the presence of filamentous fungi between urethral fossa or penis/prepuce (45.4%) and urethra pre- or postejaculation or semen (15.1%, 6.0%, and 0.0%, respectively). Yeasts were isolated in 9.1% of the samples, never in semen. The most represented mycelial fungi were Penicillium spp., Aspergillus spp., Scopulariopsis spp., Trichosporon spp. and Mucoracee. The proportion of samples showing a total bacterial count ≥10 000 colony forming units (CFU) was higher for urethral fossa than for urethra pre- or postejaculation or for semen. Some bacterial growth was always observed in all locations, including the ejaculate. Differences between sampling locations were observed also for Staphylococci, both coagulase positive and negative. Salmonella enterica Abortus equi and sulphite reducing clostridia and other pathogens (including Klebsiella spp. and Pseudomonas spp.) were never isolated. Escherichia coli and coliforms always showed a low or absent flora. These data add information to the literature.  相似文献   

2.
In Cambodia, intestinal parasitic infections are prevalent in humans and particularly in children. Yet, information on potentially zoonotic parasites in animal reservoir hosts is lacking. In May 2012, faecal samples from 218 humans, 94 dogs and 76 pigs were collected from 67 households in Dong village, Preah Vihear province, Cambodia. Faecal samples were examined microscopically using sodium nitrate and zinc sulphate flotation methods, the Baermann method, Koga Agar plate culture, formalin-ether concentration technique and Kato Katz technique. PCR was used to confirm hookworm, Ascaris spp., Giardia spp. and Blastocystis spp. Major gastrointestinal parasitic infections found in humans included hookworms (63.3%), Entamoeba spp. (27.1%) and Strongyloides stercoralis (24.3%). In dogs, hookworm (80.8%), Spirometra spp. (21.3%) and Strongyloides spp. (14.9%) were most commonly detected and in pigs Isospora suis (75.0%), Oesophagostomum spp. (73.7%) and Entamoeba spp. (31.6%) were found. Eleven parasite species were detected in dogs (eight helminths and three protozoa), seven of which have zoonotic potential, including hookworm, Strongyloides spp., Trichuris spp., Toxocara canis, Echinostoma spp., Giardia duodenalis and Entamoeba spp. Five of the parasite species detected in pigs also have zoonotic potential, including Ascaris spp., Trichuris spp., Capillaria spp., Balantidium coli and Entamoeba spp. Further molecular epidemiological studies will aid characterisation of parasite species and genotypes and allow further insight into the potential for zoonotic cross transmission of parasites in this community.  相似文献   

3.
Antifungal activity of extracts of cinnamon (Cinnamomum zeylanicum), Cloves (Syzygium aromaticum), ginger (Zingiber officinale) and turmeric (Curcuma longa) were evaluated in vitro against 17 Penicillium spp. Seed disease and rotten fruit caused by these species cause considerable loss of quality for different agricultural products. Isolates of Penicillium spp. were screened for production of patulin an important serious mycotoxin. About 70.59% of Penicillium spp. produced this toxin in concentrations ranging from 4 to 31 ppb. The response of Penicillium spp.to plant extracts differed according to the plant extract and concentration. Cinnamon extract showed the greatest effect on P. asperosporum, P. aurintogriseum and P. brevicompactum, and cloves extract produced the greatest effect on P. chermesinum and P. duclauxii. Turmeric extract had less effect on P. duclauxii. Cloves extract was the most effective in reducing the growth of Penicillium spp. On the other hand, ginger extract with all concentrations used had less effect against most Penicillium spp in the laboratory. Plant extracts are promising as natural sources of environmentally friendly compounds in laboratory studies.  相似文献   

4.
Previously we showed in laboratory studies that the fungivorus nematode, Aphelenchoides hylurgi, was attracted to and fed upon the chestnut blight fungus, Cryphonectria parasitica, from American chestnut bark cankers and was a carrier of biocontrol, white hypovirulent C. parasitica strains. In the present field study, we recovered Aphelenchoides spp. in almost all (97.0 %) of 133 blight canker tissue assays (three 5-g samples each) from four eastern states. High mean population densities (227 to 474 nematodes per 5 g tissue) of Aphelenchoides spp. were recovered from cankers in Virginia, West Virginia, and Tennessee but not from New Hampshire (mean = 75 nematodes per 5 g tissue). Overall, most canker assays yielded population densities less than 200 nematodes per 5 g tissue. All of 12 very small or young cankers yielded a few to many Aphelenchoides spp. Regression analysis indicated greatest recovery of Aphelenchoides spp. occurred in the month of May (r = 0.94). The results indicate that Aphelenchoides spp. appear to be widespread in blight cankers on American chestnut trees and could play a role in biocontrol of chestnut blight.  相似文献   

5.
The microbial spoilage of beef was monitored during storage at 5°C under three different conditions of modified-atmosphere packaging (MAP): (i) air (MAP1), (ii) 60% O2 and 40% CO2 (MAP2), and (iii) 20% O2 and 40% CO2 (MAP3). Pseudomonas, Enterobacteriaceae, Brochothrix thermosphacta, and lactic acid bacteria were monitored by viable counts and PCR-denaturing gradient gel electrophoresis (DGGE) analysis during 14 days of storage. Moreover, headspace gas composition, weight loss, and beef color change were also determined at each sampling time. Overall, MAP2 was shown to have the best protective effect, keeping the microbial loads and color change to acceptable levels in the first 7 days of refrigerated storage. The microbial colonies from the plate counts of each microbial group were identified by PCR-DGGE of the variable V6-V8 region of the 16S rRNA gene. Thirteen different genera and at least 17 different species were identified after sequencing of DGGE fragments that showed a wide diversity of spoilage-related bacteria taking turns during beef storage in the function of the packaging conditions. The countable species for each spoilage-related microbial group were different according to packaging conditions and times of storage. In fact, the DGGE profiles displayed significant changes during time and depending on the initial atmosphere used. The spoilage occurred between 7 and 14 days of storage, and the microbial species found in the spoiled meat varied according to the packaging conditions. Rahnella aquatilis, Rahnella spp., Pseudomonas spp., and Carnobacterium divergens were identified as acting during beef storage in air (MAP1). Pseudomonas spp. and Lactobacillus sakei were found in beef stored under MAP conditions with high oxygen content (MAP2), while Rahnella spp. and L. sakei were the main species found during storage using MAP3. The identification of the spoilage-related microbiota by molecular methods can help in the effective establishment of storage conditions for fresh meat.  相似文献   

6.
The responses of the efficiencies of photosystems I and II, stromal redox state (as indicated by NADP-malate dehydrogenase activation state), and activation of the Benson-Calvin cycle enzymes ribulose 1,5-bisphosphate carboxylase and fructose 1,6-bisphosphatase to varying irradiance were measured in pea (Pisum sativum L.) leaves operating close to the CO2 compensation point. A comparison of the relationships among these parameters obtained from leaves in air was made with those obtained when the leaves were maintained in air from which the CO2 had been removed. P700 was more oxidized at any measured irradiance in CO2-free air than in air. The relationship between the quantum efficiencies of the photosystems in CO2-free air was distinctly curvilinear in contrast to the predominantly linear relationship obtained with leaves in air. This nonlinearity may be consistent with the operation of cyclic electron flow around photosystem I because the quantum efficiency of photosystem II was much more restricted than the quantum efficiency of photosystem I. In CO2-free air, measured NADP-malate dehydrogenase activities varied considerably at low irradiances. However, at high irradiance the activity of the enzyme was low, implying that the stroma was oxidized. In contrast, fructose-1,6-bisphosphatase activities tended to increase with increasing electron flux through the photosystems. Ribulose-1,5-bisphosphate carboxylase activity remained relatively constant with respect to irradiance in CO2-free air, with an activation state 50% of maximum. We conclude that, at the CO2 compensation point and high irradiance, low redox states are favored and that cyclic electron flow may be substantial. These two features may be the requirements necessary to trigger and maintain the dissipative processes in the thylakoid membrane.  相似文献   

7.
The aim of the study was to identify ticks present in the environment and wild Tunisian ruminants and to detect tick-borne pathogens and Trypanosoma evansi DNA in these specimens. Sampling was done throughout each season from the environment in three protected areas around Tunisia: El Feidja, Haddaj and Oued Dekouk. Ticks were collected also, from one fawn of Barbary red deer and eight naturally deceased wild ruminants (one Barbary red deer, five Scimitar-horned oryx, one Addax antelope and one Dorcas gazelle), all of which lived in various protected areas. PCR and nested PCRs were performed to detect the presence of Theileria spp., Babesia spp., Trypanosoma evansi, Ehrlichia spp., Anaplasma spp., Anaplasma bovis and Anaplasma phagocytophilum DNA in these tick specimens. A total of 352 ticks were collected, belonging to six different species: Hyalomma excavatum (80.6%), Hyalomma dromedarii (10.2%), Hyalomma marginatum (0.5%), Rhipicephalus bursa (0.5%), Rhipicephalus sanguineus sensu lato (5.1%) and Ixodes ricinus (2.8%). Pathogens have been detected in 25% of H. dromedarii, 9.1% of H. excavatum and 5% of R. sanguineus sensu lato. The percentage of detection of T. evansi was 0.2%. Ehrlichia spp.-Anaplasma spp. were detected in 10.1% of ticks. Anaplasma spp. and A. bovis were detected in 7.6%, and 0.8% of examined ticks, respectively. None of the Theileria spp., Babesia spp., or A. phagocytophilum DNA was detected in the tested ticks. To our knowledge, the present study represents the first identification of these six tick species and the first detection of rickettsial pathogens and T. evansi in North African wild ruminants' species. These results extend the knowledge about the diversity of ticks and tick-borne pathogens in wildlife and justify further investigations of the possible role of R. sanguineus sensu lato in the transmission of T. evansi.  相似文献   

8.
Jaffe LF 《Plant physiology》1966,41(2):303-306
The mutual orientation of the germination of nearby pairs of Botrytis spores growing in a simple, dilute medium was studied. If the medium is equilibrated with room air, they show a very strong tendency to germinate both toward each other and in a cis arrangement, i.e., toward the same side of the line joining their centers. If the medium is equilibrated with air enriched with 0.3% or 3% CO2, (i.e., 10 or 100 times the normal CO2 concentration) then the cells show an equally strong tendency to germinate away from each other. The interaction shows little dependence upon pH.  相似文献   

9.
The red seaweed Hypnea spinella (Gigartinales, Rhodophyta), was cultured at laboratory scale under three different CO2 conditions, non-enriched air (360?ppm CO2) and CO2-enriched air at two final concentrations (750 and 1,600?ppm CO2), in order to evaluate the influence of increased CO2 concentrations on growth, photosynthetic capacity, nitrogen removal efficiency, and chemical cellular composition. Average specific growth rates of H. spinella treated with 750 and 1,600?ppm CO2-enriched air increased by 85.6% and 63.2% compared with non-enriched air cultures. CO2 reduction percentages close to 12% were measured at 750?ppm CO2 with respect to 5% and 7% for cultures treated with air and 1,600?ppm CO2, respectively. Maximum photosynthetic rates were enhanced significantly for high CO2 treatments, showing P max values 1.5-fold higher than that for air-treated cultures. N–NH 4 + consumption rates were also faster for algae growing at 750 and 1,600?ppm CO2 than that for non-enriched air cultures. As a consequence of these experimental conditions, soluble carbohydrates increased and soluble protein contents decreased in algae treated with CO2-enriched air. However, internal C and N contents remained constant at the different CO2 concentrations. No significant differences in data obtained with both elevated CO2 treatments, under the assayed conditions, indicate that H. spinella is saturated at dissolved inorganic carbon concentrations close by twice the actual atmospheric levels. The results show that increased CO2 concentrations might be considered a key factor in order to improve intensively cultured H. spinella production yields and carbon and nitrogen bioremediation efficiencies.  相似文献   

10.
Effects of red (RL) and blue (BL) light on acclimation of the unicellular green alga Chlamydomonas reinhardtii to the low level of ambient CO2 were studied. C. reinhardtii cells grown at 5% CO2 and under white light (170 μmol/(m2s)) had a relatively low activity of extracellular carbonic anhydrase (CA), a low affinity for dissolved inorganic carbon, and a low rate of photosynthesis under CO2-limiting conditions. These cells readily started acclimation to the low CO2 concentration when they were exposed to atmospheric air (~ 0.03% CO2) under RL or BL (150 μmol/(m2 s) each). The acclimation was manifested in a significant increase in the CO2-limited rate of photosynthesis, the affinity for dissolved inorganic carbon, and the extracellular CA activity with no difference between RL-and BL-cells. Independently of light quality, the acclimation was completed for 5–7 h after cell exposure to air. As is evident from RL-and BL-dependent changes in the sum of chlorophylls and chlorophyll a/b ratio, transfer of C. reinhardtii cells to air and RL or BL triggered also the process of algal photosynthetic adaptation to light quality. However, this process did not interfere with acclimation to low CO2 because started 4 h later. On the basis of similarity in the low CO2-induced changes under RL and BL, it is concluded that acclimation of C. reinhardtii to CO2-limiting conditions does not depend on light quality.  相似文献   

11.
Regulation of spore germination in the fern Onoclea sensibilis L. was investigated by applying CO2 alone and in combination with ethylene. Sterile spores were sown aseptically on Knops solution in loosely capped culture tubes, enclosed individually in 2-liter chambers, and grown under continuous white light. When maintained in enclosed containers with the ethylene-absorbent mercuric perchlorate and with atmospheres enriched up to 2% CO2 (v/v), spores germinated without any inhibition. Higher levels of applied CO2 were progressively inhibitory. Inhibition by CO2 was reversible. When CO2 was permitted to escape and spores were exposed subsequently to ambient laboratory air, recovery from inhibition occurred within 48 hours. Also, inhibition by CO2 was specific, since the same degree of inhibition resulted regardless of whether spores were treated with exogenous CO2 for 48, 72, or 96 hours. The effect on germination of 1 μl/l added ethylene depended upon the amount of applied CO2. When containers of KOH were enclosed and ambient CO2 was absorbed, inhibition of germination by 1 μl/l exogenous ethylene was 90%. When CO2 was applied in concentrations from 0.25 to 1.0% (v/v), CO2 increasingly antagonized the inhibitory action of 1 μl/l added ethylene. Thus, photoinduced germination of spores was regulated by competitively interacting levels of CO2 and ethylene.  相似文献   

12.
13.
The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia (a tropical fruit plant, Family- Rutaceae) was studied. Carbon dioxide available in the ambient air of the growth room was insufficient for in vitro growth of the shoots alone. Also, the presence of sucrose only as the C-source in the medium (without CO2), was found to be inadequate for sustainable growth and multiplication of shoots. The carbon dioxide enrichment promoted shoot multiplication and overall growth. The promotory effect of CO2 was independent of the presence of sucrose in the medium. In the presence of both CO2 and sucrose, an additive effect was observed producing maximum shoot growth. In the absence of sucrose a higher concentration of CO2 (10.0)g m−3 was required to achieve photoautotrophic shoot multiplication comparable to ambient air controls. Highest leaf area per shoot cluster promoting shoot growth and multiplication was recorded under this treatment. Shoots growing on sucrose containing medium under controlled CO2 environment of 0.6 g m−3 concentration evoked better response than ambient air controls (shoots growing on sucrose containing medium) in growth room. This treatment produced the overall best response. The present study highlighted the possibility of photoautotrophic multiplication which might prove useful for successful hardening and acclimatization in tissue culture plants.  相似文献   

14.
Carbon dioxide (CO2) is an important component for activating and attracting host-seeking mosquitoes. The BG-Sentinel(r) trap is a well-established monitoring tool for capturing Culicidae, but CO2 role for the trap effectiveness has not been evaluated in highly urbanised areas. The objective was to evaluate the effectiveness of BG-Sentinel traps baited with and without CO2 for capturing urban mosquitoes. Fifteen areas were selected within the city of Manaus, Brazil, where four BG-Sentinels were operated for 24 h, two of them with CO2 and two without CO2. Captured Aedes aegypti females were dissected for the determination of their parity status. A significantly higher proportion of traps (from 32-79%) were positive for female Ae. aegypti when using the BG-Sentinel with CO22 = 11.0271, p ≤ 0.001). Catches of female Culex spp were six times higher in CO2 traps (Mann-Whitney U test = 190.5; p = 0.001). Parity rates were similar for both traps. This study showed that CO2 has primarily an enhancing effect on the efficacy of BG-Sentinel for capturing Culex spp in Manaus. For Ae. aegypti, the positivity rate of the trap was increased, when CO2 was added.  相似文献   

15.
The net photosynthetic rate (P N), the sample room CO2 concentration (CO2S) and the intercellular CO2 concentration (C i) in response to PAR, of C3 (wheat and bean) and C4 (maize and three-colored amaranth) plants were measured. Results showed that photorespiration (R p) of wheat and bean could not occur at 2 % O2. At 2 % O2 and 0 μmol mol?1 CO2, P N can be used to estimate the rate of mitochondrial respiration in the light (R d). The R d decreased with increasing PAR, and ranged between 3.20 and 2.09 μmol CO2 m?2 s?1 in wheat. The trend was similar for bean (between 2.95 and 1.70 μmol CO2 m?2 s?1), maize (between 2.27 and 0.62 μmol CO2 m?2 s?1) and three-colored amaranth (between 1.37 and 0.49 μmol CO2 m?2 s?1). The widely observed phenomenon of R d being lower than R n can be attributed to refixation, rather than light inhibition. For all plants tested, CO2 recovery rates increased with increasing light intensity from 32 to 55 % (wheat), 29 to 59 % (bean), 54 to 87 % (maize) and 72 to 90 % (three-colored amaranth) at 50 and 2,000 μmol m?2 s?1, respectively.  相似文献   

16.
Immobilization of insects is necessary for various experimental purposes, and CO2 exposure remains the most popular anaesthetic method in entomological research. A number of negative side effects of CO2 anaesthesia have been reported, but CO2 probably brings about metabolic modifications that are poorly known. In this work, we used GC/MS-based metabolic fingerprinting to assess the effect of CO2 anaesthesia in Drosophila melanogaster adults. We analysed metabolic variation of flies submitted to acute CO2 exposure and assessed the temporal metabolic changes during short- and long-term recovery. We found that D. melanogaster metabotypes were significantly affected by the anaesthetic treatment. Metabolic changes caused by acute CO2 exposure were still manifested after 14 h of recovery. However, we found no evidence of metabolic alterations when a long recovery period was allowed (more than 24 h). This study points to some metabolic pathways altered during CO2 anaesthesia (e.g. energetic metabolism). Evidence of short-term metabolic changes indicates that CO2 anaesthesia should be used with utmost caution in physiological studies when a short recovery is allowed. In spite of this, CO2 treatment seems to be an acceptable anaesthetic method provided that a long recovery period is allowed (more than 24 h).  相似文献   

17.
The CO2-concentrating mechanism confers microalgae a versatile and efficient strategy for adapting to a wide range of environmental CO2 concentrations. LCIB, which has been demonstrated as a key player in the eukaryotic algal CO2-concentrating mechanism (CCM), is a novel protein in Chlamydomonas lacking any recognizable domain or motif, and its exact function in the CCM has not been clearly defined. The unique air-dier growth phenotype and photosynthetic characteristics in the LCIB mutants, and re-localization of LCIB between different subcellular locations in response to different levels of CO2, have indicated that the function of LCIB is closely associated with a distinct low CO2 acclimation state. Here, we review physiological and molecular evidence linking LCIB with inorganic carbon accumulation in the CCM and discuss the proposed function of LCIB in several inorganic carbon uptake/accumulation pathways. Several new molecular characteristics of LCIB also are presented.  相似文献   

18.
19.
When division synchronized cultures of Euglena gracilis Klebs (strain Z) were aerated with 5% CO2 in air the specific activity of glycollate dehydrogenase was only 13% of that in cultures receiving unsupplemented air. The concentrations of 10-formyltetrahydrofolate synthetase (EC 6.3.4.3) and formylfolate derivatives were also lowered by this treatment. In contrast, the specific activity of serine hydroxymethyltransferase (EC 2.1.2.1) and the concentration of methylfolates were raised by supplying CO2-supplemented air. These effects on enzyme levels were reversed when air was supplied following a period of CO2 treatment. The levels of glycollate dehydrogenase, 10-formyl-tetrahydrofolate synthetase and formylfolate derivatives were decreased when cells were aerated in media containing 5 mM α-hydroxy-2-pyridinemethane sulphonate. Cell free extracts had the ability to decarboxylate glyoxylate, producing ca equal amounts of CO2 and formate from C-1 and C-2 respectively. Cells receiving 5% CO2 in air had a decreased ability to incorporate formate-[14C] into serine and methionine. It is concluded that during growth at low CO2 concentrations glycollate metabolism will provide substrate for the formyltetrahydrofolate synthetase reaction.  相似文献   

20.
The effects of temperature, O2, and CO2 on titratable acid content and on CO2 exchange were measured in detached pineapple (Ananas comosus) leaves during the daily 15-hour light period. Comparative measurements were made in air and in CO2-free air. Increasing the leaf temperature from 20 to 35 C decreased the total CO2 uptake in air and slightly increased the total CO2 released into CO2-free air. Between 25 and 35 C, the activation energy for daily acid loss was near 12 kcal mol−1, but at lower temperatures the activation energy was much greater.  相似文献   

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