The in vitro effects of peptide-precipitating lignosulphonic acids on various biologically active substances produced by or with action on microorganisms

The effects of lignosulphonic acids on colicins, coliphages, different antibiotics, ß-toxin of Staphylococcus aureus, lecithinases of Clostridium perfringens and of Bacillus cereus, hemolysins of Bacillus cereus and Escherichia coli, the bactericidal effect of lysolecithin and on specific and naturally occurring serum proteinase inhibitors have been studied. It was found that lignosulphonic acids distinctly inhibit the biological activities tested, with the possible exceptions of the inhibitory effects of serum antiproteinases, naturally occurring inhibitors in serum, and the bacteriolytic effect of coliphages. The inhibiting effects are discussed in relation to the use of animal fodder containing lignosulphonic acids, and to the appearance of a selected microbial flora in sulphite spent liquor recipients.     

The Effects of Peptide-Precipitating Lignosulphonic Acids on the Proteolytic Activity of Pepsin in Vitro and on the Response of Pigs to an Ulcer Inducing Diet

The inhibitory effect of peptide-precipitating lignosulphonic acids on the proteolytic activity of pepsin in vitro has been studied. When an unfractionated lignosulphonic acid preparation was used, total inhibition of the activity of 5 µg crystalline pepsin was obtained by addition of about 15 mg of lignosulphonic acids.The greatest inhibitory effect was seen with the high-molecular weight lignosulphonic acids, but an effect was also seen with middle-and low-molecular weight lignosulphonic acids.A reduction in the inhibitory effect was seen when the experiments were performed in the presence of arginine. The inhibition mechanism is discussed in relation to the peptide-precipitating ability of the lignosulphonic acids.No obvious protection against the appearance of stomach ulcers in four pigs receiving an ulcerogenic diet was seen.     

The Effects of Feeding Peptide-Precipitating Lignosulphonic Acids in Various Concentrations to Growing Pigs

It is shown that lignosulphonic acids, at a concentration of 13 % in conventional feed given to growing pigs, lead to a marked reduction in the weight gain.When given 3 % and 6 % lignosulphonic acids in the feed, no effects on the weight gain were observed as compared to the controls.The weight gain reduction caused by lignosulphonic acids at high levels in the feed is discussed in relation to the inhibitory effects of these acids on a number of biological systems which have been studied previously.     

The interactions of peptide-precipitating lignosulphonic acids and the fermentation of various sugars by a strain of Candida utilis

The fermentation of various sugars by Gandida utilis in the presence of purified peptide-precipitating lignosulphonic acids has been studied. An inhibitory effect on the fermentation of sucrose, glucose, xylose and an equimolar mixture of glucose and fructose was found, the effect being most pronounced for xylose. Inhibition of the fermentation of xylose was seen when 0.5 % lignosulphonic acids were included, but not when 0.25 % were used. A difference in the inhibitory effect on the fermentation of sucrose and an equimolar mixture of glucose and fructose was observed, and the result is discussed in relation to a possible inhibitory mechanism of the lignosulphonic acids.The peptide-precipitating ability of the lignosulphonic acids seemed to be little influenced during the fermentation of the sugars by Gandida utilis.Keyword: lignosulphonic acids, fermentation, sugars, Gandida utilis     

Gel filtration of lignosulphonic acids and peptide-precipitating abilities of the separated fractions

Lignosulphonic acids in dialysed sulphite spent liquor and purified lignosulphonic acids were subjected to gel chromatography on Sephadex G-75, G-100 and G-200 and the fractions tested for peptide-precipitating ability. About 56 % of the total lignosulphonic acids in the dialysed sulphite spent liquor had estimated molecular weights above 90000 and about 72 % above 44000. About 94 % of the purified lignosulphonic acids had molecular weights above 90000 and the remaining 6 % had above 36000. The major peptide-precipitating activity of the lignosulphonic acids was due to fractions with molecular weights in excess of 90000. The percentage of peptides in the peptide-lignosulphonic acid precipitates was found to be 80–90. The molecular weights of the peptides used were found to have an upper limit of about 20000. The lower limit for molecular weights of lignosulphonic acid-precipitating peptides is estimated to be below 6000.Keyword: gel filtration, lignosulphonic acids, molecular weight, peptide-precipitating ability     

Peptide-lignosulphonic acid precipitation zones in agar gel. A direct micro quantitative procedure for the determination of peptide-precipitating lignosulphonic acids in aqueous solution

The effects of incubation time and incubation temperature on precipitation zones of peptide-lignosulphonic acid complexes in agar plates are studied in relation to the mathematical dependence of zone diameter as a function of the concentrations of lignosulphonic acids in serial 2-fold dilutions. Optimal conditions are given for obtaining regression lines with not significant second degree coefficients under defined conditions.A diffusion unit, proposed as a measure of peptide-precipitating lignosulphonic acids in aqueous solution, is defined. The possibility is discussed of using the described procedure as a micro quantitative method for the determination of peptide-precipitating lignosulphonic acids in aqueous solution.     

Use of malathion against ectoparasites on lactating cows

The clinical effect, residues in milk and toxicological properties of a non-commercial formulation of malathion used as an ectoparasitic agent on cattle were investigated. The results show that the malathion preparation has a desired clinical effect. The maximum concentration of malathion in milk after topical application of 5 g malathion was 0.054 μg/ml 4–6 h post-treatment, and declined to 0.005 and 0.002 μg/ml 24 and 48 h post-treatment, respectively. Totally 0.006–0.03 % of the applied dose was excreted in the milk. No toxic effect, measured as inhibition of the cholinesterases in erythrocytes and plasma, could be detected after therapeutic use of malathion.The pharmacokinetic evaluation after 2.5 g intravenous administration of malathion, indicated that the kinetics could probably be described by a multicompartment model.     

The precipitation of peptides and proteins by lignosulphonic acids

The precipitation of peptide- and protein-lignosulphonic acid complexes can be demonstrated and studied in agar plates in the form of precipitation zones. The effects on the precipitates caused by variations in incubation temperature, incubation time, concentration of the reagents and in pH in the mixture of reagents, are described, and the nature of the peptide-lignosulphonic acid bond is discussed. The central lysis zones which appeared in some precipitation zones were found to be probably caused by excess of lignosulphonic acids. The possibility of developing the agar precipitation method described as a direct micro quantitative procedure for the determination of certain lignosulphonic acids in aqueous solution is suggested.     

The Limulus Amoebocyte Lysate test: detection of endotoxin in plasma of swine and cattle. II. In vivo investigations

Endotoxin was detected by the LAL test in the plasma of swine and cattle following in vivo injection of endotoxin in order to evaluate the applicability of the test in veterinary medicine for detection of endotoxemia.Clinical symptoms of endotoxemia occurred after the injection into 3 swine of 0.10–0.25 mg endotoxin/100 kg bwt and after the infusion during 1–1½ h of 2.0–2.2 mg endotoxin/100 kg bwt into 3 calves. The concentration of endotoxin detected by the LAL test in the experimental animals ranged from 0.15 ng to 6.0 ng endotoxin per ml crude plasma. As positive LAL reactions were obtained only in close connection to the administration of endotoxin, clearance of endotoxin to levels below the sensitivity of the test was fast. In spite of the fast clearance, light symptoms of endotoxemia could be seen as long as 24 h after the last sample showing a positive test result. The applied technique for LAL analysis on blood, therefore, was not adequate for detection of endotoxin at sufficiently low concentrations and some possibilities of improving the technique are discussed.Though leukocytosis were found not to influence the outcome of the LAL test on blood, leukocytic mediators released by endotoxin or endotoxin-derived injuries may still have caused the persistence of the symptoms of endotoxemia, and this question is disputed in relation to the benefit of improving the technique.Especielly in the veterinary clinic, great precautions are necessary to obviate false positive test samples resulting from, e.g., external contamination or transient stress caused by excitement, and it is concluded that the possible application of the LAL test for detection of endotoxemia in veterinary medicine is restricted to surveillance of hospitalized animals and to research purposes.     

Seasonal variation of selenium status of Norwegian dairy cows and effects of selenium supplementation

Blood selenium levels were found to fluctuate throughout the year, being highest during the indoor season when the greatest amounts of compound concentrates were fed. From October to January the average blood selenium levels increased from 0.10 μg/ml to 0.18 μg/ml (15 cows). Subcutaneous injections of barium selenate (500 mg selenium) increased the blood selenium levels significantly. The treated group (15 cows) reached average levels of about 0.21 μg/ml blood during the indoor season.The effect of oral supplementation of sodium selenite (for 2 months) on the levels of plasma selenium, blood selenium and glutathione peroxidase activity was investigated. Plasma selenium was found to give an immediate reflection of the daily selenium intake. Maximum activity of glutathione peroxidase was reached 1 month after the end of the supplementation period.It is concluded that if selenium enriched concentrates are used in a normal feeding regimen, further supplementation with selenium does not seem to be necessary.     

In vitro susceptibilities of Leptospira spp. and Borrelia burgdorferi isolates to amoxicillin, tilmicosin, and enrofloxacin

Antimicrobial susceptibility testing was conducted with 6 different spirochetal strains (4 strains of Leptospira spp. and 2 strains of Borrelia burgdorferi) against 3 antimicrobial agents, commonly used in equine and bovine practice. The ranges of MIC and MBC of amoxicillin against Leptospira spp. were 0.05-6.25 µg/ml and 6.25-25.0 µg/ml, respectively. And the ranges of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of amoxicillin against B. burgdorferi were 0.05-0.39 µg/ml and 0.20-0.78 µg/ml, respectively. The ranges of MIC and MBC of enrofloxacin against Leptospira spp. were 0.05-0.39 µg/ml and 0.05-0.39 µg/ml, respectively. Two strains of B. burgdorferi were resistant to enrofloxacin at the highest concentration tested for MBC (≥100 µg/ml). Therefore, the potential role of tilmicosin in the treatment of leptospirosis and borreliosis should be further evaluated in animal models to understand whether the in vivo studies will confirm in vitro results. All spirochetal isolates were inhibited (MIC) and were killed (MBC) by tilmicosin at concentrations below the limit of testing (≤0.01 µg/ml).     

石榴皮止泻散体外抑菌效果研究

为评价石榴皮止泻散的体外抑菌效果，将石榴皮止泻散制成水煎液，采用平板法进行体外抑菌试验，并采用试管稀释法测定其最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果显示，平板法体外抑菌试验中每1 mL含1 g生药的石榴皮止泻散水煎液孔周围有明显的抑菌圈，平均抑菌圈直径分别为14.0和15.7 mm;试管稀释法测定石榴皮止泻散对大肠杆菌的MIC为25 mg/mL,MBC为50 mg/mL。结论，石榴皮止泻散水煎液在体外对大肠杆菌具有抑制和杀灭作用。     

Acaricidal activity of Palicourea marcgravii, a species from the Amazon forest, on cattle tick Rhipicephalus (Boophilus) microplus

Leaves of Palicourea marcgravii were extracted successively with hexane, ethyl acetate and ethanol in order to evaluate their acaricidal activity on larvae and adult stages of the cattle tick Rhipicephalus (Boophilus) microplus. The ethyl acetate extract showed the highest bioactivity of the tested extracts, which contained 0.12% monofluoroacetic acid. On engorged female, the ethyl acetate extract showed a lethal concentration 50% - LC(50)=30.08 mg ml(-1), inhibitory concentration 50% - IC(50)=5.79 mg ml(-1) and lethal time 50% - LT(50)=4.72 days; 100% reproduction was controlled at concentrations of 50 mg ml(-1) and on larvae the ethyl acetate extract showed a LC(50)=2.46 mg ml(-1). No alkaloids were detected in any of the extracts. This is the first report on the acaricidal activity of P. marcgravii extracts against R. microplus as well as the acaricidal properties of a plant species containing monofluoroacetic acid.     

Vitamin E status of healthy Swedish cattle

Using high pressure liquid chromatography the serum concentration of vitamin E was measured in dairy cows fed either hay or silage as their main roughage, in calves fed milk-replacer, and in young intensively fed bulls. The concentrates fed to the cows, calves and bulls were supplemented with 5–10, 25 and 5–10 mg DL-α-tocopheryl acetate per kg, respectively, and the milk-replacer for the calves was supplemented with 50 mg DL-α-tooopheryl acetate per kg powder. Cows fed silage as their main roughage had higher serum vitamin E concentrations (: 3.8–5.2 mg/l) than cows fed only hay (: 2.5–4.1 mg/1). Lactating cows had higher vitamin E concentrations than dry cows (: 4.1–5.2 and 2.5–3.8 mg/l, respectively) and calves and bulls had much lower vitamin E concentrations (: 1.4 and 1.2 mg/l, respectively) than cows. Thirty per cent of the calves and 41 % of the bulls had serum vitamin E concentrations less than 1.0 mg/l, suggesting that in these animals the conventional level of supplementation of feeds with DL-α-tocopheryl acetate in Sweden is probably inadequate for the prevention of nutritional muscular degeneration and other negative effects.     

Disposition kinetics and dosage regimen of levofloxacin on concomitant administration with paracetamol in crossbred calves

The disposition kinetics of levofloxacin was investigated in six male crossbred calves following single intravenous administration, at a dose of 4 mg/kg body weight, into the jugular vein subsequent to a single intramuscular injection of paracetamol (50 mg/kg). At 1 min after the injection of levofloxacin, the concentration of levofloxacin in plasma was 17.2 ± 0.36 µg/ml, which rapidly declined to 6.39 ± 0.16 µg/ml at 10 min. The drug level above the MIC₉₀ in plasma, was detected for up to 10 h. Levofloxacin was rapidly distributed from blood to the tissue compartment as evidenced by the high values of the distribution coefficient, α (17.3 ± 1.65 /h) and the ratio of K₁₂/K₂₁ (1.83 ± 0.12). The values of AUC and Vd_area were 12.7 ± 0.12 µg.h/ml and 0.63 ± 0.01 l/kg. The high ratio of the AUC/MIC (126.9 ± 1.18) obtained in this study indicated the excellent antibacterial activity of levofloxacin in calves. The elimination half-life, MRT and total body clearance were 1.38 ± 0.01 h, 1.88 ± 0.01 h and 0.32 ± 0.003 l/kg/h, respectively. Based on the pharmacokinetic parameters, an appropriate intravenous dosage regimen for levofloxacin would be 5 mg/kg repeated at 24 h intervals when prescribed with paracetamol in calves.     

Embryo transplantation in cattle. Non-surgical transfer of 6 1/2--7 1/2 day old embryos to lactating dairy cows under farm conditions.

Previous attempts to transfer embryos non-surgically to heifers have been rather discouraging. The present experiment describes a simple non-surgical technique where the 6½–7½ -day old embryo is placed in a 0.25 ml ministraw, fitted into a common insemination gun and transferred cervically to synchronized lactating dairy cows. Thirty-two viable embryos were transferred to the middle part of the uterine horn ipsilateral to the ovary containing the corpus luteum. It was easy to pass the cervix, and most embryos could be deposited in the horn within 1 or 2 min. Eighteen animals were diagnosed pregnant (56% ). It is conceivable that the easy atraumatic transfers and good management (feeding, oestrus control) of the recipients contributed to the high pregnancy rate.     

Apramycin: minimal inhibitory concentrations for avian Escherichia coli and serum levels after intramuscular injection in turkeys

The minimal inhibitory concentrations (MIC) of apramycin, a unique aminocyclitol antibiotic, for 100 Escherichia coli isolates recovered from clinical cases of avian colibacillosis were determined using the agar dilution method. All isolates were inhibited at apramycin concentration of 8.0 micrograms/ml; 90 and 50% of the isolates were inhibited at 6.6 and 3.4 micrograms/ml, respectively. A commercial injectable product containing 200 mg apramycin/ml was administered intramuscularly (i.m.) to groups of 6- and 12-week-old turkeys at 10, 15 and 20 mg/kg. Apramycin was quickly absorbed from the i.m. injection site. Mean peak serum drug concentrations were reached 1 h after treatment and were 19.5, 27.5 and 36.0 micrograms/ml, respectively. The serum elimination half-life (t 1/2) of the drug ranged between 1.75 h for the 10 mg/kg dose and 2.5 h for the 20 mg/kg dose. Very low concentrations of the drug were found 24 h after treatment. Duration of serum apramycin concentrations in relation to the MIC, dose, and age of birds was determined.     

Comparison of Four Enrichment Media in the Recovery of Campyloracter Jejuni

The effectiveness of 4 enrichment media for the recovery of low levels of inoculated cells of Campylobacter jejuni was evaluated. The media contained antibiotics or antibiotics and bile acids as selective compounds. Three of the media recovered most of the inoculated low numbers of 6 C. jejuni strains. In the 3 media the growth rate of 3 strains, indicated by the increase in the log number of cells during 24 h or 48 h incubation at 42 ° C, was about the same as in the control medium without selective compounds. The same 3 media also recovered a low number of Campylobacter cells from artificially contaminated raw milk or ground meat samples. The enrichment medium B containing 40 I.U. Colistin, 5 μg novobiocin, 2 mg Na-cholic acid and 50 mg cycloheximide per ml was inhibitory for most Campylobacter strains studied.     

The distribution of cadmium between cellular subfractions in cadmium-sensitive and cadmium-resistant Staphyloccus aureus.

The accumulation and distribution of cadmium (Cd) between cellular subfractions were studied in Cd-resistant Staphylococcus 3719 + and its plasmid-negative Cd-sensitive variant 3719–, grown in media containing 0.01, 0.1 or 50 mg of Cd/litre. In the media containing 0.01 and 0.1 mg of Cd/1 the uptake of Cd by the Gd-resistant S. aureus was significantly less than that by Cd-sensitive S. aureus, both in toto and in terms of the cell wall fractions. Only variant 3719 + grew in the medium containing 50 mg of Cd/1. The finding of a lag phase in the growth of both variants is interpreted to suggest that the resistance is of inducible character, even in the sensitive S. aureus. The mechanism of resistance to Cd could consist of both barrier and clearance functions.