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Abstract Introduction: Aminoglycoside-induced acute kidney injury (AKI) is a pathology closely linked to oxidative and inflammatory reactions. Taking into account the previous reported antioxidant and anti-inflammatory effects of D-005, a lipid extract obtained from Cuban palm Acrocomia crispa (Arecaceae) fruits, this work aimed to evaluate the effects of D-005 on kanamycin-induced AKI. Methods: Male Wistar rats were divided into 7 groups: negative control (vehicle, Tween 65/H2O) and six groups treated with kanamycin to induce AKI: positive control (vehicle), D-005 (25, 100, 200, and 400 mg/kg) and grape seed extract (GSE, 200 mg/kg). D-005, vehicle, and GSE oral treatments were administered once daily for seven days, 1 h before kanamycin (500 mg/kg, i.p.). Serum uric acid and urea concentrations, renal histopathology, and oxidative markers (malondialdehyde (MDA), sulfhydryl (SH) groups, and catalase (CAT) activity) were assessed. Results: D-005 significantly reduced uric acid and urea levels, starting from D-005 100 mg/kg. Histopathologically, D-005, at all the tested doses, protected renal parenchyma structures (glomeruli, proximal tubules, and interstitium). These findings were accompanied by a significant reduction of MDA and SH group concentrations as well as restoration of CAT activity. The highest percentages of inhibition were obtained with the dose of 400 mg/kg. GSE, the reference substance, also prevented kanamycin-induced biochemical and histopathological changes, as well as reduced MDA and SH groups and restored CAT activity. Conclusion: The administration of repeated oral doses of D-005 significantly protected against kanamycin-induced AKI, which could be associated with the antioxidant and anti-inflammatory effects of this extract.
Resumo Introdução: Lesão renal aguda induzida por aminoglicosídeos é uma patologia intimamente ligada a reações oxidativas e inflamatórias. Considerando efeitos antioxidantes e anti-inflamatórios relatados anteriormente do D-005, um extrato lipídico de frutos da palmeira cubana Acrocomia crispa (Arecaceae), este trabalho avaliou efeitos do D-005 na LRA induzida por canamicina. Métodos: Dividiu-se ratos Wistar machos em 7 grupos: controle negativo (veículo, Tween 65/H2O) e seis grupos tratados com canamicina para induzir LRA: controle positivo (veículo), D-005 (25, 100, 200, 400 mg/kg) e extrato de semente de uva (ESU, 200 mg/kg). D-005, veículo, e tratamentos orais com ESU foram administrados uma vez por dia durante sete dias, 1 h antes da canamicina (500 mg/kg, i.p.). Avaliou-se concentrações séricas de ácido úrico e ureia, histopatologia renal e marcadores oxidativos (malondialdeído (MDA), grupos sulfidrila (SH), atividade de catalase (CAT)). Resultados: D-005 reduziu significativamente níveis de ácido úrico e ureia, partindo de D-005 100 mg/kg. Histopatologicamente, D-005, em todas as doses testadas, protegeu estruturas do parênquima renal (glomérulos, túbulos proximais e interstício). Estes achados foram acompanhados por uma redução significativa das concentrações de MDA e grupo SH, e pela restauração da atividade CAT. As maiores porcentagens de inibição foram obtidas com a dose de 400 mg/kg. ESU, a substância de referência, também evitou alterações bioquímicas e histopatológicas induzidas por canamicina, reduziu MDA e grupos SH e restaurou atividade CAT. Conclusão: A administração de doses orais repetidas de D-005 protegeu significativamente contra LRA induzida por canamicina, que pode estar associada aos efeitos antioxidantes e anti-inflamatórios deste extrato.
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OBJECTIVE: To establish a high performance liquid chromatography combined with pulsed amperometric detection(HPLC-PAD)method for determination of potency of neomycin sulfate. METHODS: An improved HPLC-PAD method from EP method for determination of the content and related substances of neomycin sulfate was established and validated. The study of impurity profile of neomycin sulfate was completed by LC-IT-TOF method with the help of on-line desalination using a suppressor; and the main components in neomycin sulfate were clarified combining the RESULTS of impurity profile and minimum inhibitory concentrations of the main components and impurities. The semi-preparative liquid chromatography-evaporative light scattering detector(ELSD) was self-assembled, highly purified neomycin B and neomycin C were prepared and their structural confirmation was also conducted. The contents of highly purified neomycin B and neomycin C were determined by means of mass balance method. The potencies of highly purified neomycin B and neomycin C were determined by three-dose antibiotic microbial assay and the conversion factors between contents of neomycin B and neomycin C and their potencies were calculated separately and then a formula for the calculation of potency of neomycin sulfate from the content of main components of neomycin B and neomycin C was obtained.At last, a verification experiment for the accuracy of the conversion factor and the formula were designed and a serial of tests were carried out to investigate the interaction and the verification for the actual sample. RESULTS: The improved HPLC-PAD method was superior to the European Pharmacopoeia method in the separation ability and stability, and was suitable for accurate quantification of various components of neomycin sulfate and related substance inspection. The successful removal of trifluoroacetic acid in the mobile phase by the technology of desalination on-line using a suppressor broke a new way for the study of impurity profile of aminoglycoside such as neomycin sulfate. Combining the impurity profile with the RESULTS of MIC it was clarified that the main activity components of neomycin sulfate were neomycin B and neomycin C. Highly purified neomycin B and neomycin C were successfully prepared. A conversion factor for the transition from potency to purity of neomycin sulfate was obtained through experiments and calculations and was verified successfully. CONCLUSION: It is feasible to replace the microbial assay by HPLC-PAD method for determining the potency of neomycin sulfate.
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OBJECTIVE: To establish an improved LG method combined with pulsed electrochemical detection for the analysis of etimicin sulfate. METHODS: The mobile phase was composed of 40 mL of acetonitrile and 960 mL of an aqueous solution containing 15 mL · L-1 of trifluoroacetic acid, 500 μL · L-1 of pentafluoropropionic acid, 8 mL · L-1 of sodium hydroxide (50%) and 1.5 g · L-1 of sodium sulfate. The pH of the aqueous solution was adjusted to 3.5 with 50% NaOH solution. A pulsed electrochemical detector, which was kept at 35 C in a hot air oven was adopted. The electrochemical cell consisted of a working electrode, a pH-Ag/AgCl reference electrode and a titanium counter electrode. The working electrode was a gold electrode (diameter 3 mm) and a quadruple-potential waveform (QPW) was selected as detection waveform. The 0.8 mol · L-1 NaOH solution was added post column at a flow rate of 0.4 mL · min-1. RESULTS In total, 22 impurities could be separated. The LOD and LOQ of etimicin were found to be 2 ng and 6 ng respectively. The linearity of the calibration curve for etimicin ranged from 0.24 to 45 μg · mL-1 with a coefficient of correlation equal to 0.9997. The repeatability RSDs (n=6) of the content and total impurities in one sample were 0.7% and 1.72% respectively. The inter-day repeatability RSDs (n=18) of the content and total impurities in one sample were 0.98% and 1.71% respectively. The sample solution was stable within 12 h. CONCLUSION: Compared with previously published methods, this improved method shows higher sensitivity, better separation ability and robustness and has been incorporated by the Chinese Pharmacopoeia (Ch. P.) 2015 for analysis of etimicin sulfate.
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OBJECTIVE: To establish an LC/MSn method for identification of the related substances in etimicn sulfate detected under the chromatographic condition described in Chinese Pharmacopoeia 2010. METHODS: The HPLC separation was carried out on a Welch Ultimate LP-C18 column (4.6 mm × 300 mm, 5 μm) with mobile phase consisting of 0.2 mol · L-1 trifluoroacetic acid (containing 0.1% propionic acid ) -methanol (84: 16) at a flow rate of 1.0 mL · min-1. Thirty percent of the eluent was detected by ion trap mass spectrometry, and the parent ions and the corresponding product spectra of all the related substances in etimicin sulfate were determined and elucidated. RESULTS: Addition of 0.1% propionic acid into the mobile phase significantly enhanced the sensitivity of MS detector without altering the chromatographic behavior such as retention time and elution order of the related substances. Twenty-eight related substances were separated and detected by the LC/MSn method in a typical sample. Nine of them were identified with the help of corresponding impurity reference substances and 14 of them were elucidated by MS fragment information, while the other five were not identified due to limitated information. CONCLUSION: The established method can be applied to the identification of the related substances in etimicn sulfate detected under the chromatographic condition described in Chinese Pharmacopoeia 2010, which is helpful to the quality improvement and process optimization of etmicin sulfate.
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Aims: To determine resistance rates and patterns of certain uropathogens, including E. coli, Klebsiella spp. and Pseudomonas spp., isolated from hospitalized urinary tract infections patients, to aminoglycoside antibiotics and to detect the most prevalent plasmidmediated aminoglycoside modifying enzymes (AMEs). Methods: Uropathogenic isolates (150) were recovered from urine specimens of hospitalized UTI patients in Cairo, Egypt and identified by conventional methods. The recovered uropathogens (E. coli, Klebsiella spp. and Pseudomonas spp.) were tested for their susceptibility to gentamicin, tobramycin, amikacin, neomycin, netilmicin, and kanamycin by disc diffusion method. Plasmid-mediated aminoglycoside resistance was determined by transformation experiments as well as by using plasmids as templates for PCR screening of the AMEs-coding genes aph(3')-I, aac(6')-I, aac(3)-I, aac(3)-II and ant(2'')-I in all resistant isolates. Results: Of a total of 150 uropathogenic clinical isolates, 110 isolates were of the above mentioned genera and were selected for the current study. Sixty three isolates (57.2%) were resistant to at least one aminoglycoside antibiotic. Highest and lowest resistance rates were observed to kanamycin (53.6%) and amikacin (7.2%), respectively. The resistance rates to gentamicin, neomycin, tobramycin and netilmicin were 33.6%, 24.5%, 23.6% and 14.5%, respectively. AMEs-coding genes were detected on the plasmids of 93.6% of resistant isolates with prevalence rates of 53.9% for ant(2'')-I, 38% for both aac(6')-I and aac(3)-II and 33.3% for aph(3')-I, while aac(3)-I gene was not detected in any of the tested resistant isolates. Double and triple combinations of AMEs-coding genes were detected in ich49.2% of resistant isolates. Conclusion: A high prevalence of plasmid-mediated resistance to aminoglycoside antibiotics in Gram negative uropathogens from hospitalized patients was observed. Uropathogens may represent potential reservoirs of panaminoglycoside resistance in hospitals, having on their plasmids combinations of AMEs-coding genes. Good infection control measures in Egyptian hospitals together with periodic screening of prevalence rates of different resistance genes are required.
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Aim: To clone and over-express the gene encoding aminoglycoside(AG)phosphotransferase(APH)from clinical MRSA isolates in E.coli and to develop an assay method for the recombinant APH.Methods: The susceptibility of clinical MRSA isolates to AGs was tested by disk diffusion.A nucleic acid sequence encoding APH was amplified from the genomic DNA of an isolate and ligated to expression vector pET-28a,and then trans-formed into E.coli BL21(DE3).After purification of the recombinant protein by affinity chromatography,the phosphorylation activity of the enzyme was determined by ESI-MS and disk diffusion.Flesults: All 6 clinical MRSA isolates were unsusceptible to AGs.After cloning and expression,the recombinant APH was purified to90%.The in vitro activity assay indicated that the recombinant protein could inactivate kanamycin B in the assay mixture within 2 h.Conclusion: The recombinant APH showed excellent enzymatic activity.The assay method was simple and convenient,which may provide the basis of developing a screening model for APH inhibitors.
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Gentamicin is a broad-spectrum antibiotic complex produced by actinomycetes belonging to Micromonospora genus and classified among aminoglycoside antibiotics, used in the treatment of serious infections derived from Gram-negative microorganisms. Alterations of their antimicrobial activity not shown in chemical assays can be evaluated through microbiological assays. The aim of this work was to compare 5 x 1, 2 x 2 and 3 x 1 experimental designs, evaluating validation parameters of specificity, linearity, range, precision, and accuracy for each experimental design in different levels of concentration, presentation, and lots. It consisted of 81 assays (in 3 replicas) of gentamicin microbiological dosage. The concentrations of the solutions used were employed in a range from 1.0 μg/mL to 5.0 μg/mL, diluted in phosphate buffer 0.1 M pH 8.0. Antibiotic medium number 11 was used, with Staphyloccocus epidermis (ATCC 12228). 21ml of medium were used as base layer and 4 ml of medium inoculated at 1 percent were used as surface layer. The dishes were incubated for 18 hours at 37 ± 1 ºC. The three designs employed showed adequate specificity for analysis of dermatological cream and injectable solution containing gentamicin sulphate. They also showed accuracy and linearity in the range evaluated, but not a significant difference concerning precision. The results were compared by means of the determination of the rates of measurement system capacity. The statistical analysis demonstrated that there is no significant difference among the results obtained through 5 x 1, 2 x 2, and 3 x 1, being these equivalent and interchangeable.
A gentamicina é um complexo antibiótico de largo espectro, produzido por actinomicetos do gênero Micromonospora e classificado entre os antibióticos aminoglicosídeos, utilizado no tratamento de infecções graves, devidas a microrganismos Gram-negativos. Alterações da sua atividade antimicrobiana, não demonstradas pelos ensaios químicos, podem ser avaliadas pelos ensaios microbiológicos. O objetivo deste trabalho foi comparar os delineamentos experimentais 5 x 1, 2 x 2 e 3 x 1, avaliando-se os parâmetros de validação de especificidade, linearidade, faixa ou intervalo, precisão e exatidão para cada delineamento experimental em diferentes níveis de concentração, apresentações e lotes. O plano de trabalho constituiu-se na realização de 81 ensaios (em 3 réplicas) de doseamento microbiológico de gentamicina. As concentrações das soluções empregadas foram preparadas numa faixa de 1,0 μg/mL a 5,0 μg/mL, diluídos em tampão fosfato 0,1 M pH 8,0. O meio utilizado foi o meio antibiótico no. 11, com Staphyloccocus epidermidis (ATCC 12228). Empregou-se 21 mL de meio como camada base e 4 mL de meio inoculado à 1 por cento como camada superfície. As placas foram incubadas por 18 horas à 37 ± 1 ºC. Os três delineamentos empregados apresentaram especificidade adequada para análise de creme dermatológico e solução injetável contendo sulfato de gentamicina. Também apresentaram exatidão e linearidade no intervalo avaliado. Os delineamentos não apresentaram diferença significativa quanto a precisão. Os resultados foram comparados através da determinação de índices de capacidade do sistema de medição. A analise estatística demonstrou que não há diferença significativa entre os resultados obtidos pelos delineamentos 5 x 1, 2 x 2 e 3 x 1, sendo equivalentes e intercambiáveis.
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Humans , Female , Adult , Gentamicins , HIV , Pregnant Women , Infectious Disease Transmission, Vertical/prevention & control , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/pharmacology , Aminoglycosides/antagonists & inhibitorsABSTRACT
Objective To analyze the sequences of two component signaling system PhoP/PhoQ encoding genes of Pseudomonas aeruginosa strains sensitive or resistant to aminoglycoside antibiotics and to determine the correlation between the PhoQ/PhoP and the resistance. Methods The segments of entire pimQ and phoP genes of P. aeruginosa were obtained by PCR and then sequenced after T-A cloning. Two prokaryotic expression systems of phoQ and phoP genes were constructed and the target recombinant expres-sion products rPhoQ and rPhoP were extracted by Ni-NTA chromatography. Rabbits were intracutaneoualy immunized with rPhoQ and rPhoP to obtain antisera and double immunodiffusion test was used to detect the titers of antisera. The phoQ genes of aminloglycoside antibiotics-resistant P. aeruginosa strains were knocked out by using Red recombination system, and phoQ mutants were identified by PCR plus sequencing and Western blot assay. Tube dilution method was applied to determine MIC values of wild and mutant strains of P. aeruginosa to four different aminoglycoside antibiotics. Results In comparison with the corresponding sequences in GenBank, the similarities of nueleotide and putative amino acid sequences of the cloned phop and phoQ genes were 98.7%-99.6% and 98.7%-100% , and 98.4%-99.8% and 99.1%-100%, respec-tively. Both rPhoQ and rPhoP were successfully expressed using pET-42a and E. coil BL21 DE3 system, and their rabbit antisera with 1 : 4 and 1 : 8 double immunodiffusion titers were also obtained. The deletion of phoQ genes and absence of the products in the two phoQ mutants were confirmed by PCR, sequencing and West-ern blot assay. MIC values of the four different aminoglycoside antibiotics to the two mutants were 1/512-1/2048 as those of their wild strains. Conclusion PboQ/PhoP is a sequence conserved two component sig-naling system of P. aeruginosa, and this system mediates resistance of the microbe to aminoglycoside antibiotics.
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Summary: To investigate the underlying mechanism of the exacerbation of myasthenia gravis by aminoglycoside antibiotics. C57/BL6 mice were immunized with acetylcholine receptor (AChR), extracted from electric organ of Narcine timilei according to Xu Haopeng's methods, in complete Fruend's adjuvant (CFA) to establish experimental autoimmune myasthenia gravis (EAMG). EAMG mice were divided randomly into 5 groups: MG group, NS group and three antibiotics groups. The clinical symptom scores of mice were evaluated on d7 after the last immunization and d14 of antibiotics treatment. Repetitive nerve stimulation (RNS) was performed and the levels of anti-AChR antibody (AChR-Ab) were tested at the same time. The mean clinical symptom grades of gentamycin group (1.312, 2.067), amikacin group (1.111, 1.889) and etimicin group (1.263, 1.632) were significantly higher than those of MG group (1.000, 1.200) (P<0.05). The positive rates of RNS of three antibiotics groups were 69.23 %, 58.82 % and 63.16 % respectively, which were significantly higher than those of MG group and NS group (40.00 %, 40.00 %, P<0.05). The AChR-Ab level in serum and the expression of AChR on neuromuscular junction (NMJ) of mice in three antibiotics groups were also higher than those of MG group. Our results indicated that aminoglycoside antibiotics could aggravate the symptom of myasthenia gravis. The exacerbation of myasthenia gravis by these antibiotics probably involves competitively restraining the release of acetylcholine from presynaptic membrane, impairing the depolarization of postsynaptic membrane, depressing the irritability of myocyte membrane around the end-plate membrane and consequently leading to the blockade of neuromuscular junction.
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Objective To identify the possible mutations other than A1555G in mitochondrial 12S and 16S rRNA genes that responsible for aminoglycoside-induced deafness, and to provide the basis for genetic diagnosis for this disease. Methods A total of twenty-seven blood samples were obtained from five families with aminoglycoside-induced deafness for screening the A1555G mutation and other possible mutations by PCR- Alw26 I digestion and sequence analysis. Results All samples examined in four families (A, C, D and E) carried the same homoplasmic A1555G mutation, but no A1555G mutation was found in family B. Sequencing of the DNA samples from this family displayed a rare insertion of "AA" at nucleotide 2227 in 16S rRNA gene. Conclusions Our findings suggested that the 1555 G mutation was not the only genetic defect associated with aminoglycoside-induced deafness since we did not find the A1555G mutation in one family, in which the typical maternal inheritance pattern of the aminoglycoside-induced deafness was seen. It is not enough to identify prospectively patients who are likely to be hypersensitive to aminoglycoside ototoxicity by screening A1555G mutation only. Other possible mutations in mitochondrial DNA that associated with aminoglycoside -induced deafness should be tested also.
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ISE. Conclusion The neuromuscular blocking effects of 4 antibiotics were significantly greater in diaphragm muscle than those in limb muscles.
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The medium and process parameters were optimized in batchaminoglycoside antibiotic JI-20A fennentation. The optimal medium consists mainly of comstarch 60g/L, peanut meal 30g/L, com slurry 8g/L, maltose 10g/L, inorganic compound and amylase moderate , methionin 1g/L and cobalt chloride 6?g/mL. It was significant to adjust medium pH after autoclaving and oxygenate the fennentation medium for the cell growth and JI-20A product.