Dihydrostreptomycin Research Articles

Detection of incurred dihydrostreptomycin residues in milk by liquid chromatography and preliminary confirmation methods.

An LC method for the determination of the aminoglycosides streptomycin (STR) and dihydrostreptomycin (DHS) in milk was developed/modified on the basis of published papers. Mean recoveries were 87 and 95% for STR and DHS, respectively. Recoveries are dependent on the concentration level and batch of solid-phase extraction columns used, and independent of fat content and homogenization. The relative standard deviations are 15.6 and 9.6% for STR and DHS, respectively, at a level of 100 micrograms kg-1. Limits of detection (8 and 12 micrograms kg-1, respectively) and quantification (12 and 18 micrograms kg-1, respectively) are far below the EU maximum residue limit of 200 micrograms kg-1. Lyophilized DHS samples can be used for internal control of the analysis as the DHS concentration is not influenced by the lyophilization process and subsequent storage at 6 degrees C. In incurred milk samples no false negative results of preliminary confirmation tests (Charm II Aminoglycoside test, Ridascreen Streptomycin ELISA) with respect to DHS concentrations > or = 20 micrograms kg-1 as determined by the LC method are observed. DHS concentrations of incurred samples determined by ELISA are higher than those obtained by the LC method. These differences were more pronounced with incurred than with spiked milk samples, thus leading to the conclusion that in incurred samples substances are present which co-react in the ELISA and which are not detected by the LC method.

High Performance Liquid Chromatographic Determination of Dihydrostreptomycin Sulfate in Kidney and Meat Using Post Column Derivatization

A high performance liquid chromatographic method for the determination of dihydrostreptomycin sulfate in kidney and meat from cow, and swine, has been developed. The sample was treated with trichloroacetic acid, and the supernatant clean-up was performed using a Bond Elut Certify II pretreatment column. The lower limit of quantification was 40ng/g and the limit of detection close to 20ng/g. The recovery of dihydrostreptomycin sulfate varyied from 73.2 to 73.5% and from 80.0 to 82.9% for kidney and muscle, respectively.

Influence of season, age, breed and some other factors on the variation in sperm morphological abnormalities in Swedish dairy A.I. bulls

Abstract Fifty-two dairy A.I. bulls aged from 14 months to 6 and a 1 2 years old were used to study the effects of age, breed, season and, dehorning and dihydrostreptomycin treatments on the incidence of sperm morphological abnormalities in fresh semen. The highest mean value of sperm abnormalities was recorded for abnormal heads (6.1%), but most of the recorded abnormalities only occurred in approximately 1–2% of the studied spermatozoa. Significant seasonal variation occurred in the incidences of sperm head abnormalities and total sperm abnormalities. Least-squares means for sperm abnormalities were significantly higher during the warmer seasons (spring, summer) compared with the colder ones (autumn, winter). The incidence of sperm abnormalities (abnormal heads, proximal droplets, total abnormalities) was relatively constant over time within bull (repeatability estimates varied between 0.36 and 0.54), but was significantly affected by age (abnormal heads and acrosomes, total abnormalities) and breed (abnormal heads, detached heads). The incidence of total sperm abnormalities was also found to be significantly increased in semen from a group of bulls submitted to both dehorning and double injections of dihydrostreptomycin (DHS) when comparing pre- and posttreatment periods. The results indicate that age, breed and seasonal effects as well as repeated stressful treatments influence the sperm characteristics and must be considered when evaluating bulls for sperm morphological traits.

The binding site on cochlear stereocilia for antisera raised against renal Na + channels is blocked by amiloride and dihydrostreptomycin

The mechanoelectrical transduction channels on hair cells have been suggested to be operated by tip links that are stretched when the hair bundle is deflected in the direction of the tallest row of stereocilia. Localising these channels is therefore an important test of this hypothesis. The transduction channels are known to be amiloride-sensitive and immunogold labelling with antibodies raised against the amiloride-sensitive epithelial Na + channel from kidney (αNaCh), has suggested that sites with similar characteristics are located in the region where the tips of the shorter stereocilia appear to come into contact with the sides of the adjacent taller stereocilia rather than being associated directly with the tip links. Now, further immunocytochemical experiments have been performed to determine if amiloride and dihydrostreptomycin, both of which can block transduction, can affect this labelling. Immunofluorescent labelling of the stereocilia is obtained when surface preparations of the organ of Corti are fixed and incubated with αNaCh followed by an appropriate secondary antibody. This labelling is abolished by trypsinization prior to fixation but retained if the tissue is pretreated with amiloride and then trypsinized in its presence. Because amiloride is known to protect amiloride-binding sites from degradation by trypsin, these results suggest that αNaCh is revealing amiloride-binding sites on the stereocilia. Similarly, immunofluorescent labelling of the stereocilia is abolished if cochlear tissue is pretreated with dihydrostreptomycin (DHS) and fixed in its presence prior to incubation with αNaCh. Quantitative analysis of colloidal gold labelling using transmission electron microscopy shows that DHS treatment produces a significant reduction in the number of gold particles on stereocilia, especially in the region of contact between them. These results suggest that anti-Na + recognises a site with characteristics similar to the mechanoelectrical transduction channels.

Comparison of the effects of local and systemic dry cow therapy for staphylococcal mastitis control

The therapeutic effects of systemic injections of enrofloxacin ortylosin and intramammary infusions of an ointment containing naficillin, penicillin and dihydrostreptomycin were compared in the dry period against staphylococcal intramammary infection (IMI) in a large Holstein dairy herd. The frequency of IMI was 26.7% and samples were all negative for Mycoplasma spp. At the time of treatment, the prevalence of staphylococcal IMI in the three groups: (1) enrofloxacin (EN), (2) tylosin (TY) and (3) naficillin, penicillin and dihydrostreptomycin (DC) were 29.8%, 28.5% and 21.7%, respectively. The difference between the three figures were not statistically significant ( P = 0.17). The cure rates in the EN, TY and DC groups were 85.2%, 77.4% and 92.3%, respectively, which were also not significantly different ( p = 0.15). New infection rates in EN, TY and DC groups, after treatment, were 6.1%, 7.5% and 4.4%, respectively, showing no statistically significant difference between the three groups ( P = 0.46). We concluded that systemic dry cow therapy using enrofloxacin or tylosin can be an alternative to the conventional local method for elimination of staphylococcal IMI during the dry period, although, local dry cow therapy (using partially inserted cannulas) is still the most effective method when considering IMI at calving.

DRUG RESISTANCE AND CONJUGATIVE R PLASMIDS IN ESCHERICHIA COLI STRAINS ISOLATED FROM MIGRATORY WATERFOWL

We evaluated drug resistance and R plasmids of 554 stains of Escherichia coli isolated from feces of migratory watefowl, including whistling swans (Cygnus columbianus), pintails (Anas acuta) and black-tailed gulls (Larus crassirostris) collected from the San-in District, Japan, between each November and March, 1983 to 1984, 1984 to 1985, and 1985 to 1986. Seven antimicrobial agents were tested: dihydrostreptomycin (DSM), kanamycin, spectinomycin, ampicillin (ABPC), oxytetracycline (OTC), chloramphenicol, and sulfadimethoxine (SDMX). Many strains were resistant to several drugs; in particular, all strains were resistant to SDMX. Both multiple drug resistant strains and drug resistance patterns occurred most frequently in strains isolated from whistling swans, followed by black-tailed gulls, and pintails, respectively. Of 233 strains, 128 (55%) carried transmissible R plasmids. The drugs with the largest number of resistance patterns observed were, in descending order, OTC, DSM, ABPC, and SDXM.

Determination of Dihydrostreptomycin Sulfate in Milk by HPLC Using Ion-Pair and Postcolumn Derivatization

An isocratic, paired-ion reversed-phase high-performance liquid chromatographic method for the determination of dihydrostreptomycin sulfate in milk by postcolumn derivatization has been developed. The milk was treated with 85% trichloroacetic acid to precipitate proteins, and the supernatant clean-up was performed using a tC18 pretreatment column. The correlation coefficients were 0.999. The lower limit of quantification was 25 ng/ml and the limit of detection close to 15 ng/ml. The recovery of dihydrostreptomycin sulfate varying from 82.6 to 82.8%.

Determination of ternary mixtures of antibiotics, by ratio-spectra zero-crossing first- and third-derivative spectrophotometry

The ratio-spectra zero-crossing first- and third-derivative spectrophotometry have been used for determining ternary mixtures of penicillin-G sodium, penicillin-G procain and dihydrostreptomycin sulphate salts. The procedures are accurate, nondestructive and do not require resolutions of equations. In both methods, calibration graphs are linear, with zero-intercept, up to 30 μg ml −1 of penicillin-G sodium and penicillin-G procain, and up to 42 μg ml −1 of dihydrostreptomycin sulphate. r = 0.9999 in each instance. Working wavelengths, 218.5, 211 and 236 nm, respectively, in the first-derivative mode, and 222.5, 311.5 and 242 nm in the third-derivative mode. Detection limits for each drug at p = 0.01 level of significance were calculated to be 0.058, 0.010 and 0.014 μg ml −1 and 0.14, 0.012 and 0.34 μg ml −1, in the first- and third-derivative methods, respectively. Both methods apply favourably to either laboratory mixtures or commercial injections.

The effects of ototoxic drugs on mechano-electric transduction channels in chick cochlear hair cells

The effects of ototoxic drugs on mechano-electrical transduction (MET) currents were investigated in dissociated cochlear hair cells of the chick, using a whole-cell patch-electrode voltage-clamp technique. Dihydrostreptomycin (DHSM) and cisplatin (cis-dichlorodiammine platinum II, CDDP) blocked the MET channel in a dose- and voltage-dependent manner. In contrast, acetyl salicylate did not suppress the MET current. At -50 mV, DHSM and CDDP blocked the MET channel with a Hill coefficient of 0.93 and 2.1, respectively. These findings suggest that a single DHSM molecule or more than one CDDP molecule binds to a single MET channel.

Determination of a ternary mixture of penicillin-G sodium salt, penicillin-G procain salt and dihydrostreptomycin sulphate, by third-derivative spectrophotometry

Ternary mixtures of antibiotics, i.e. penicillin-G sodium salt, penicillin-G procain salt and dihydrostreptomycin sulphate salt, are assayed by ‘zero-crossing’ third-derivative spectrophotometry. Calibration plots follows Beer's law up to 40 μg/ml of penicillin-G sodium at 222.5 nm ( r = 0.9997), 46 μg/ml of penicillin-G procain at 217 nm ( r = 0.9999) and 36 μg/ml of dihydrostreptomycin sulphate at 211.5 nm ( r = 0.9999), in the presence of one another. Detection limits at p = 0.05 level of significance were calculated to be, respectively, 0.66, 0.41 and 0.25 μg/ml. The procedure is rapid, simple, nondestructive and does not require solution of equations. The method was successfully applied for determining laboratory mixtures and commercial injections.

Dihydrostreptomycin modifies adaptation and blocks the mechano-electric transducer in chick cochlear hair cells

Block of the mechano-electric transduction (MET) channel by dihydrostreptomycin (DHSM) and its effects on adaptation were investigated in dissociated cochlear hair cells of the chick with a whole-cell patch-electrode voltage clamp technique. DHSM reversibly blocked the MET channel in a dose- and voltage-dependent manner. At −50 mV, DHSM blocked the MET channel with a Hill coefficient of approximately 1 and a dissociation constant ( K d) of2 × 10 −5M. Rate constants for the DHSM to bind and to unbind to and from the channel were estimated, and could be larger than5 × 10 7M −1 ·s −1 and1 × 10 3s −1, respectively. The amplitude of MET current decreased during a constant displacement of the hair bundle. This current decay, the adaptation, disappeared in the DHSM medium. The disappearance and the emergence of adaptation did not have a simple relationship with the block of MET channel by DHSM, but appeared with some delay.

Residues of aminoglycoside antibiotics in eggs after medication of laying hens

1. The transfer of aminoglycoside antibiotics into eggs was determined separately from albumen, yolk or whole egg after oral administration of dihydrostreptomycin (DHS), neomycin and spectinomycin and after an intramuscular injection of DHS. Residues were assayed by an agar plate diffusion method in cylinders with a specific test organism for each antibiotic. 2. Only DHS, administered by the intramuscular route, led to detectable residues in eggs. The total amount of DHS excreted via the eggs represented 1% of the dose administered. 3. Residues in the whole egg were detected for 8 d.

Discrimination of Aminoglycoside Antibiotics (Dihydrostreptomycin, Kanamycin, Fradiomycin) with Drug-inactivating Enzymes

A simple method employing aminoglycoside-inactivating enzymes from Escherichia coil for identification of aminoglycosides (AGs) such as dihydrostreptomycin (DHSM), kanamycin (KM) and fradiomycin (FRM) in food was developed.The crude enzyme (S105) fraction was prepared by ultrasonic treatment of cells of drug-resistant E. coil, followed by centrifugation at 105, 000×g. DHSM was inactivated by the S105 fraction of SM-resistant E. coli in the presence of both adenosine triphosphate (ATP) and Mg2+, KM and FRM were also inactivated by the S105 fraction of KM-resistant E. coli in the presence of both ATP and Mg2+ Discrimination of KM from FRM was done by the inactivation of the former by commercial kanamycin-6′-acetyltransferase (AAC(6′)-1) in the presence of ATP, Mg2+ and acetyl CoA. KM was inactivated by the action of AAC(6′)-1, while FRM was not.Treatment of serum and kidney samples of rats, which had been intramuscularly injected with DHSM and KM and FRM, with these S105 fractions and AAC(6′)-1 resulted in the loss of the respective antimicrobial activities.When this method was applied to 4 bovine kidney samples in which AGs had been detected by the ordinary method, the AGs were identified as DHSM in two samples and KM in two other samples.This method is useful for identification of DHSM, KM and FRM in AGs-contaminated samples.

Effects of outer hair cell loss on the frequency selectivity of the patas monkey auditory system

This report describes a study that took advantage of the unique reactivity of the patas monkey (Erythrocebus patas) to dihydrostreptomycin-sulfate (DHSM) to investigate the effects of selective outer hair cell (OHC) lesions on psychophysical tuning curves (PTC). Four patas monkeys were trained using operant reinforcement techniques to perform forward masking PTCs at frequencies of 500 Hz, 2, 4, and 8 kHz, at 10 dB SL. Steady and pulsed-tone thresholds were also measured from 63 Hz to 40 kHz in half-octave steps. The animals were given daily i.m. injections of DHSM at 20 mg/kg per day until shifts in absolute threshold at 16 kHz exceeded 10 dB, at which time the drug was discontinued. Initial changes in PTC shape included elevations in the tip region associated with the increase in threshold and no elevation or a hypersensitivity of the low-frequency tail region. In general, threshold and therefore PTC tip elevations of at least 40 dB were required before any increase in the low-frequency tail became evident. Following completion of psychophysical testing, animals were sacrificed and cytochochleograms were determined. At frequencies corresponding to regions of complete OHC loss and complete IHC retention a lack of selectivity was evident and PTCs closely resemble low-pass filters. This residual low-pass tuning is similar to that seen in VIIIth nerve fibers in ears devoid of OHCs and in basilar membrane transfer functions from traumatized ears. PTCs taken at frequencies corresponding to areas with no loss of receptors showed no systematic changes in sensitivity or selectivity. Because loss of normal OHC function results in greater than a 50-dB loss in sensitivity, as well as a detuned PTC, these findings strongly support the suggestion that the role of the OHC system is to increase the sensitivity and selectivity of the auditory system.

Liposomal ophthalmic drug delivery system. II. Dihydrostreptomycin sulfate

The carrier ability of liposomes for a model hydrophilic compound vas investigated in the rabbit eye. Dihydrostreptomycin sulfate was encapsulated in various types of liposomes, i.e. large and small uni- and multilamellar vesicles having either positive or neutral surface charge. An aqueous solution served as control preparation. Results indicated that liposomal encapsulation reduced the ocular drug con- centration. Addition of empty liposomes to the control solution did not alter drug levels in most of the ocular tissues. Among the liposomal preparations the large multi- and unilamellar vesicles provided higher drug concentration in all ocular tissue than the small unilamellar ones. Introduction of a positive charge on liposome surface enhanced liposome-conjunctiva interactions. The results suggest that liposomal encapsulation alters drug disposition in the eye lepending on the type of liposomes and the physicochemical properties of the encapsulated drug. In the case of the dihydrostreptomycin sulfate and possibly other hydrophilic drugs the liposomal encapsulation provides no advantages as far as drug delivery is concerned.

Synthesis of 3″-epidihydrostreptomycin

3″-Epidihydrostreptomycin has been prepared from dihydrostreptomycin (DHSM) by a sequence of reactions involving selective 3′,3′a; 4″,6″-di- O-isopropylidenation of 2″- N-(benzyloxycarbonyl)-DHSM, N G, O-peracetylation, N-de(benzyloxycarbonyl)ation, selective removal of the 3″- O-acetyl group, 2″- N-(benzyloxycarbonyl)ation, and epimerization of the 3″-hydroxyl group via the intermediary 2″- N-(benzyloxycarbonyl)-3″- O-(trifluoromethylsulfonyl) derivative, with the 2″,3″- N, O-carbonylallopyranoside as the intermediate. For use as a reference compound in the structural determination of 3″-epidihydrostreptomycin, methyl 2-deoxy-2-(methylamino)-α- d-allopyranoside was also prepared.

Bioassay for Diluents of Honey Bee Semen1

A bioassay was developed to evaluate diluents of honey bee ( Apis mellifera L.) semen. Using a simple diluent (1.1% NaCl, 0.1% glucose, 0.01% each L-arginine HCl, L-glutamic acid, L-lysine, 0.02% dihydrostreptomycin sulfate, and 0.012% penicillin G sodium in 0.05 M Tris buffer at pH 8.7), 100-fold dilution, incubation at 35 ± 1°C for 10 min. and reconcentration did not reduce the number of spermatozoa that reached the spermathecae of instrumentally inseminated queens. Undiluted control semen had a 10.9% transfer efficiency when 15 × 106 spermatozoa were injected into the oviducts of each queen. Treated groups of semen incubated for 0.17, 1.5, 3.0, 4.5, 6.0, 7.5, and 19.5 h had transfer efficiencies of 10.7, 8.8, 9.8, 5.1, 2.1, 4.3, and 2.4%, respectively.

Production of Axenic Gonyaulax Cultures by Treatment with Antibiotics

The effects of amphotericin B, chloramphenicol, dihydrostreptomycin sulfate, neomycin sulfate, polymyxin B sulfate, potassium penicillin G, and streptomycin sulfate (used singularly and in various combinations at different concentrations) on the growth and development of four marine dinoflagellates of the genus Gonyaulax and associated bacteria were studied. The combination of amphotericin B, dihydrostreptomycin, neomycin, and penicillin G was highly effective in eliminating bacteria and fungi without reducing dinoflagellate growth and provided a useful method for obtaining axenic cultures of two Gonyaulax species, G. catenella and G. excavata.

母体へ投与した薬物による次世代の聴覚機能障害の検出法

To study the auditory impairment induced by prenatal administration of aminoglycosides in the offspring, the shuttle box method to measure the auditory threshold of rats (Kameyama et al., Folia pharmacol. japon. 77, 15, 1981) was employed. Four groups of pregnant rats were administered 200 mg/kg kanamycin sulfate (KM), 200 mg/kg dihydrostreptomycin sulfate (DHSM), 100 mg/kg neomycin sulfate (NM), or 1 ml/kg saline intramuscularly from the 10th to the 19th day of pregnancy. The auditory threshold of the offspring could be measured by the shuttle box method in about 90% of the live born rats at the age of 100 days. The auditory thresholds of the groups were as follows (mean +/- S.E.): saline group, 53.8 +/- 0.6 dB (N = 36); KM group, 63.8 +/- 1.1 dB (N = 34); DHSM group, 60.0 +/- 1.2 dB (N = 29); NM group, 62.4 +/- 1.2 dB (N = 24). Auditory thresholds of drug-treated groups were significantly higher than that of the saline group. However, no increase in the auditory threshold of the mother rat was detected after treatment with aminoglycosides. In addition, the experimental procedure of the shuttle box method is very easy, and the auditory threshold of a large number of rats could be measured in a short period. These findings suggest that this method is a very useful one for screening for auditory impairment induced by prenatal drug treatment in rat offspring.

Determination of streptomycin sulfate and dihydrostreptomycin sulfate by high-performance liquid chromatography

An isocratic, paired-ion reversed-phase high-performance liquid chromatographic method for the determination of streptomycin and dihydrostreptomycin has been developed. The method employs a microparticulate reversed-phase column (μBondapak C18, LiChrosorb RP-18 or Ultrasphere Ion Pair), and a mobile phase composed of 0.02 M sodium hexanesulfonate and 0.025 M tribasic sodium phosphate in acetonitrile-water (8:92, v/v) at pH 6.0 with detection by ultraviolet absorbance at 195 nm. Resolution and simultaneous quantitation of streptomycin A, dihydrostreptomycin A, streptomycin B, streptidine and process-related substances can be achieved in less than 25 min, with a relative standard deviation of ca. 1.1% for the assay of either streptomycin sulfate or dihydrostreptomycin sulfate. The chromatographic bioequivalency data for streptomycin sulfate and dihydrostreptomycin sulfate were statistically identical with results obtained by the officially recognized microbiological assay. The method is designed for applicability to the analysis of other aminoglycoside antibiotics and antituberculous agents.