Copper (II), cobalt (II), nickel (II), and zinc (II) complexes of 2-hydrazino-4-hydroxy-6-methylpyrimidine were synthesized, and their infrared (IR) and nuclear magnetic resonance (NMR) spectra were examined. In the IR spectra of the complexes, the amide-I (carbonyl) bands were present and it was assumed that the ligand molecules were coordinated in the keto form of the isocytosine ring. The low frequency shift of the NH2 stretching bands by about 40-45 cm-1 on combining with Cu and Co indicated the formation of a metal-nitrogen bond. Preferential broadening of methine proton to methyl proton in the NMR spectra of the complexes of 2-hydrazino-4-hydroxy-6-methylpyrimidine can be explained by the binding of Co (II), Cu (II), and Ni (II) to N (3) site of the isocytosine ring. An ESR spectrum of the copper (II) complex would suggest the presence of copper (II) ion in a square-pyramidal conformation.
An iodometric method was developed for the quantitative determination of new semisynthetic penicillins, sodium (2S, 5R, 6R)-6-[(R)-2-(4-hydroxy-1, 5-naphthyridine-3-carboxamido-2-phenyl acetamido]-3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylate (PC-904, apalcillin sodium) and sodium (2S, 5R, 6R)-6-[(R)-2-(4-hydroxy-1, 5-naphthyridine-3-carboxamido)-2-(4-hydroxyphenyl) acetamido]-3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylate (PC-462). These antibiotics were hydrolyzed to form corresponding penicilloic acids which consumed iodine. Accuracy and precision of this method depended upon the pH at which their penicilloic acids reacted with iodine, and pH 1.5±0.2 was found to be optimum. One mole of PC-904, PC-462, ampicillin or amoxycillin consumed 9.7 gramatom of iodine. The analytical results obtained by the iodometric method were in good agreement with those obtained by bioassay, including some samples partially decomposed.
The crystal structure of fac-[bis-(adeninato)(dien) copper (II)] monohydrate has been determined from three-dimensional X-ray diffractometer data by heavy atom Fourier methods. Crystals of fac-[Cu (Ade)2 (dien)]·H2O are monoclinic with unit cell dimensions a=16.015 (2), b=14.577 (2), c=7.959 (1) A, β=90.11 (1)°, space group P21/n, and Z=4. Block-diagonal least-squares refinement using 2695 independent reflexions yielded the R value of 0.068. The copper ion assumes a distorted square pyramidal coordination with five coordination sites of which four square planar sites are occupied by the nitrogen N (9) atoms of two unidentate adenine monoanions and the two (terminal and central) nitrogen atoms of tridentate dien, and the axial site (apical position) is occupied by another terminal nitrogen atom of dien. Therefore, the present dien-copper (II) complex takes a bent form (facial coordination). The propensity of adenine to occupy the cis position in equatorial plane of the copper (II) coordination is much stronger than that of dien to take a planar coordination form.
Analytical methods were developed for the determination of a new antibacterial agent, 5, 8-dihydro-5-methoxy-8-oxo-2H-1, 3-dioxolo [4, 5-g] quinoline-7-carboxylic acid (miloxacin) by high performance liquid chromatography (HPLC) and ultraviolet spectrophotometry (UV). Miloxacin was separated from its impurities or degradation compounds by HPLC under the following condition : stainless steel column (2.1 mm i.d.×1 m) packed with strong anionic ion exchanger ; column temperature, 40°; mobile phase, pH 5.0 solution containing 0.01 M citrate buffer and 0.03 M sodium nitrate at the flow rate of 0.7 ml/min ; detector, a UV detector at the wavelength of 254 nm. Miloxacin could be determined with a relative standard deviation of 1% using picolinic acid as internal standard and its impurities were also determined at the same time. Moreover, miloxacin was dissolved in 1% sodium carbonate solution and determined by measuring the absorbance of the solution at the wavelength of 344 nm with a relative standard deviation of 0.3%. The impurities did not interfere with the determination of miloxacin and the results obtained by UV were in good agreement with those obtained by HPLC within experimental error, including some samples partially decomposed.
Antimicrobial resistance (AMR) in pathogens has become a social problem across humans and wild animals. In particular, the environmental contamination caused by AMR should be monitored. In this study, we analyzed the prevalence of Escherichia coli and its AMR, as well as the distribution and genotype of E. coli in environmental soil and water samples from the habitat of the Hypotaenidia okinawae (Okinawa rail), to elucidate the potential of AMR pollution between the bird and its habitat. The habitat of Okinawa rail was divided into a livestock farm area (LA) near human settlements and a forest area (FA) as a non-human living environment. We found that the prevalence of E. coli in environmental samples collected from the LA was 38.2% (13/34), of which 84.6% (11/13) were antimicrobial resistant. In contrast, the prevalence of E. coli in environmental samples collected from the FA was 25.5% (12/47), of which 16.7% (2/12) were antimicrobial resistant. These results indicate that antimicrobial resistant E. coli was more prevalent in the LA than FA. Furthermore, pulsed-field gel electrophoresis analysis revealed a similar pattern of E. coli prevalence. This suggests that the occurrence of environmental pollution of AMR from livestock farms and that the Okinawa rail may become a carrier of antimicrobial-resistant E. coli in the Yambaru region of Okinawa.
As one aspect of research to clarify the defence mechanism in enteric infection, comparison of phagocytosis to adherent cells from peritoneal cavity (macrophages) and infectivity to HeLa cells between Shigella flexneri 2b 17-A (a virulent strain) and Shigella flexneri 2b 17-N (an avirulent strain) was carried out. The findings of the experiments may be summarized as follows:1) Bacillus suspensions of both strains were contacted with macrophages or HeLa cells at 37°C for 1 or 2 hours. After separating bacillus by washing, these cells were incubated further for the confirmation of their phagocytic or infection rates. Phagocytic rates of the virulent strain or the avirulent one in macrophages reached about 20% in 0-2 hours after incubation. The rate of the former increased with the lapse of incubation time but that of the latter trended to decrease. HeLa cells were infected with the virulent strain but not with the avirulent strain.2) In the case of phagocytosis of macrophages with larger contact dose of bacteria or longer contact time, initial phagocytic rates (at the incubation on 0 hr) were increased and destractive degree of macrophages were enlarged. So, there could hardly be found any difference on an initial phagocytic rate and destructive degree of macrophages between the virulent strain and the avirulent one.3) Macrophages were contacted by both strains treated with 70% alcohol for 30 minutes or 100°C for 30 minutes, thereafter they were incubated further. Initial phagocytic rates of them showed about 20% and then they decreased along with the incubation time. Eight hours after incubation, there were not found bacteria in any macrophage. The same experiment was carried out with HeLa cells, and bacteria were not found in HeLa cells at any time of incubation.4) A morphological analysis of phagocytes was performed using transmission electron microscope. Immediately after inoculation of the virulent or the avirulent strain into the peritoneal cavity of guinea pigs, their phagocytes began to ingest them. In phagocytes from the guinea pigs 4 hours after the injection of the virulent strain, most of their phagocytic vacules were of a loosed type, but that in phagocytes from the animal injected with avirulent strain trended to be of a tight type.A limiting membrane was recognized around the bacilli in phagocytes from animal inoculated with both strains, irrespective of their virulence. On the contrary, the membrane did not found around the bacilli in HeLa cells.
