Myasthenia gravis exacerbation and diarrhea associated with erythromycin treatment

An important problem in management of the case with myasthenia gravis (MG) is the control of exacerbation. There are several possible causes of exacerbation of MG including the use of drug. Here, the authors report a case of MG exacerbation and diarrhea associated with erythromycin treatment.

Molecular Epidemiological Analysis of Group A Streptococci Isolated from Children in Chaoyang District of Beijing, 2011:emm Types, Virulence Factor Genes and Erythromycin Resistant Genes

Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.

Preparation, Characterization, and in vitro Release of Biodegradable Erythromycin-gelatin Microspheres

Blank and erythromycin-loaded gelatin microspheres were successfully fabricated via emulsion chemical- crosslinking technique. The surface morphology of the microspheres was characterized by scanning electron microscope（SEM） and optical microscope. The results show that the microspheres were spherical and smooth. The particle average size of erythromycin-loaded microspheres was found to be 20.6 μm, with a high purity of more than 90% and with a good dispersibility. The microspheres could be obtained in a high yield. Erythromycin released from the microspheres was monitored in buffer and artificial body fluid at 37 ℃. Average drug content was 27.2%, and erythromycin-loaded gelatin microspheres showed good release profiles with a nearly constant release during 4-8 h in artificial body fluid in vitro degradation studies. These gelatin microspheres are useful for studying and developing various drug-delivery systems.

Chiral Separation of Erythromycin as a New Chiral Selector on CE

Erythromycin as a new chiral selector was first used for chrial separation of four derivatives of biphenyldimethylester enantiomers on CE. The influence of pH, the chiral selector concentration and organic modifiers were preliminarily studied. Experiments show that the erythromycin as chiral selector is useful to CE.

Beckmann Rearrangement of Erythromycin A 9(E)-Oxime

Deoxo 6 deoxy 6,9 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (1), 9 deoxo 11 deoxy 9,11 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (2) and 9 a aza 9 a homoerythromycin cyclic lactam (3) were synthesized by the Beckmann rearrangement of erythromycin A 9 (E) oxime (4). The structures of compounds (1), (2) and (3) have been identified by their spectral data. The reaction mechanism was also discussed. The yield of the Beckmann rearrangement of compounds (4) was better than that reported in literatures.

Effects of erythromycin on pressure in pyloric antrum and plasma motilin and somatostatin content in dogs

ＥｆｅｃｔｓｏｆｅｒｙｔｈｒｏｍｙｃｉｎｏｎｐｒｅｓｓｕｒｅｉｎｐｙｌｏｒｉｃａｎｔｒｕｍａｎｄｐｌａｓｍａｍｏｔｉｌｉｎａｎｄｓｏｍａｔｏｓｔａｔｉｎｃｏｎｔｅｎｔｉｎｄｏｇｓＨＵＡＮＧＹｕＸｉｎ１，ＣＨＥＮＹｕｅＸｉａｎｇ１，ＨＵＩＤｅＳ...

Synthesis and Antibacterial Activities of Erythromycin Derivatives

Ten new erythromycin antibacterial agents containing amidino group were designed and synthesized from erythromycin via oximation, reduction and condensation. Their structures were confirmed by MS and 13C NMR; the synthetic condition(reaction medium)was explored; and their in vtiro antibacterial activities were tested. Compound HMA-3 showed antibacterial activity against staphylococcus aureus, which is equivalent to that of erythromycin A. Compounds HMA-8 and HMA-4 also showed an antibacterial activitiy. But no compound showed bactericidal activity.

Antitumor Activity of Erythromycin on Human Neuroblastoma Cell Line(SH-SY5Y)

Antitumor effects of erythromycin and the related mechanism were investigated in the present study.Neuroblastoma cells（SH-SY5Y） were exposed to erythromycin at different concentrations for different durations.Cell proliferation was measured by cell counting,and cell viability was examined by MTT assay.Cell cycle phase distribution and the cytosolic calcium level were detected by flow cytometry.Mitochondrial membrane potential was measured by the JC-1 probe staining and fluorescent microscopy.The expression of an oncogene（c-Myc） and a tumor suppressor [p21（WAF1/Cip1）] proteins was analyzed by using Western blotting.Erythromycin could inhibit the proliferation of SH-SY5Y cells in a concentration-and time-dependent manner.The cell cycle was arrested at S phase.Mitochondrial membrane potential collapsed and the cytosolic calcium was overloaded in SH-SY5Y cells when treated with erythromycin.The expression of c-Myc protein was down-regulated,while that of p21（WAF1/Cip1） protein was up-regulated.It was concluded that erythromycin could restrain the proliferation of SH-SY5Y cells.The antitumor mechanism of erythromycin might involve regulating the expression of c-Myc and p21（WAF1/Cip1） proteins.

Comparative Process for the Preparation of 9-Oxime Erythromycin A

The comparative process for preparing 9-oxime erythromycin A (EMAO) is investigated. EMAO was synthesized and compared by the reaction of erythromycin and hydroxylamine hydrochloride with various bases such as sodium acetate, triethylamine, etc. A new synthetic method is established. The oximation is performed under dynamic buffer system; less degradation impurities are formed. The yield of EMAO reaches more than 95%, HPLC analysis shows that the purity of EMAO is more than 90%, and the E/Z isomeric ratio preponderates over 7∶1.

Streptococcus peumoniae in an Egyptian urban community:incidence of erythromycin-resistance determinants and antibiotic susceptibility profile

Objectives:To determine the incidence of resistance of Streptococcus(Strep).pneumoniae isolated in our locality to erythromycin,to screen for the two resistance determinants erm(B) and mef(A) genes,and to identify the susceptibility profile to commonly used antibiotics.Methods:Samples were collected from patients attending the Outpatient Department of Zagazig University Hospital,Zagazig,Egypt,between February 2006 and March 2007.Strep.pneumoniae was identified by conventional procedures.Susceptibilities to erythromycin and 15 antibiotics were identified by disc diffusion method,as outlined by CLSI.E-test was used for MIC determination of erythromycin.erm(B) and mef(A) genes were detected by PCR.Results:Eighty-one Strep. pneumoniae strains were identified.Fifty- one of them(63%) were erythromycin-resistant,and mef(A) gene was the predominant resistance determinant.Vancomycin,imipenem and gatifloxacin had the best activity against the isolates,whereas tetracycline had the least.Forty-two(51.85%) out of the 81 Strep.pneumoniae strains were multidrug-resistant.Conclusions:High incidence of resistance to erythromycin and multiple antimicrobials existed.mef(A) was the principal erythromycin-resistance gene.

Syntheses and Antibacterial Activities of Novel Erythromycin O-Alkylamidoximes

Nine novel erythromycin O-alkylamidoxime derivatives were prepared in excellent yields via the condensation of different O-alkylhydroxylamines with erythromycin imino ether. The structures of all the compounds prepared were confirmed by ^1 H NMR, 13C NMR, IR and MS, and their in vtiro antibacterial activities were tested. Among the compounds, two of them showed good antibacterial aetivities.

Erythromycin Resistance of Streptococcus suis Isolates In Vivo

In order to study erythromycin resistance of Streptococcus suis under high or low concentration of selective drug pressure, Streptococcus suis strain LN was isolated from a diseased pig in 2005 and showed to be susceptible to erythromycin as determined by disc diffusion and tube dilution tests. In this study, clean level rabbits were divided into three groups of six rabbits each, including a prevention dosage group, a treatment dosage group, and a control group. After injection with S. suis strain LN, erythromycin （20 μg mL^-1） was taken orally in the prevention dosage group, erythromycin （5 mg kg^-1） was injected intramuscularly in the treatment dosage group, and no treatment was given in the control group. S. suis with intermediate resistance to erythromycin was isolated on the 5th day after infection from the prevention dosage group （5th PDG） and on the 7th day after infection from the treatment dosage group （7th TDG）. Both isolates were determined to be the constitutive macrolide-lincosamide-streptogramin B （cMLSB） resistance phenotype. The resistance gene ermB was detected in all of the isolates. The results suggested that both the 5th PDG and 7th TDG isolates had a mutation （A2372T） in the 23S rRNA gene. In addition, the 5th PDG isolates had a mutation in ribosomal protein L4 （detected as G268A） and a mutation in ribosomal protein L22 （A345C）; and the 7th TDG isolates had a C insertion at site 564. Each of these mutations is considered as a possible mechanism of erythromycin resistance in S. suis strain LN. This study demonstrated that erythromycin resistance was readily induced in S. suis at a low erythromycin dose creating selective pressure in vivo. Resistance appeared to be mediated by ribosome methylation, encoded by the ermB gene.

Microcalorimetric Study on the Antibiotic Activity of Clarithromycin and Erythromycin

By using LKB-2277 Bioactivity Monitoring System, the heat effect changes in the process of inhibitory action of clarithromycin and erythromycin onEscherichia coli at 37°C were determined. Quantitative analysis showed that relationship between antibiotic concentrationc and rate contantk ofEscherichia coli growth, and half inhibitory ratio concentration IC50: clarithromycin:k=0. 030 03–1. 1736×10?3 c, 8. 45 mg ·L?1; erythromycin:k=0.031 08–8.4657×10?4 c, 14. 45 mg·L?1. As a result of the microcalorimetry experiments, it not only indicated that antibacterial activity of clarithromycin was stronger than that of erythromycin, but also reported the changeable features of thermodynamics of the bacterial cell in biological, biochemical and metabolic process under different drug action.

EFECT OF ERYTHROMYCIN ON INTERDIGESTIVE MIGRATING MOTOR COMPLEX IN HUMANS

Objective To investigate the effect of erythromycin (EM) on interdigestive migrating motor complex (MMC) in healthy volunteers. Methods 20 healthy volunteers were randomly divided into 2 groups: EM group (n=11) and placebo group (n=9). The changes of MMC were observed by gastrointestinal manometry before and after oral administration of EM or placebo. Results Gastric antral MMCs that evoked by EM were similar to spontaneous MMCs. EM orally intaking decreased MMC cycle duration significantly (P<0.05). EM orally intaking decreased the percentage of phase Ⅱ duration to MMC cycle duration significantly (P<0.05). But EM orally intaking increased the percentage of phase Ⅲ duration to MMC cycle duration significantly (P<0.05). The amplitude of antral waves of phase Ⅲ increased significantly after EM orally intaking (P<0.05). Placebo orally intaking didn't affect MMC cycle duration, propagation velocity of phase Ⅲ and percentages of phase Ⅰ, phase Ⅱ, phase Ⅲ duration to MMC cycle duration. Conclusion EM has stimulating effect on gastrointestinal motor activity.

Characterization and structure analysis of the heterosolvate of erythromycin thiocyanate

Erythromycin thiocyanate is widely used for the production of other macrolide antibiotics. In this work, a novel heterosolvate of this pharmaceutical compound has been obtained and characterized for the first time, which was transformed from the dihydrate form in the acetone solvent through evaporation crystallization. Thermal behavior together with compositional analysis revealed that both water and acetone molecules participated in the formation of the crystal lattice which is rarely reported before. The general chemical name of the heterosolvate may be defined as erythromycin thiocyanate sesquihydrate hemiacetonate. Furthermore, studies on solid-state spectral analysis provided strong evidence of intermolecular hydrogen bonds in heterosolvate crystals. According to the crystal structure determined by single crystal X-ray diffraction, the formation mechanism of the heterosolvate is proposed in which strong multihydrogen bondings between water and solute molecules form the layer structure. While acetone molecules form single-hydrogen bonds with solutes and reside in channels between layers. This well explains why acetone solvent is easy to escape from the crystal structure during desolvation.

Pharmacochemical Aspects of the Evolution from Erythromycin to Neomacrolides, Ketolides and Neoketolides

Antibiotic macrolides are experiencing renewed interest in anti-infective therapy since the advent of ketolides. This therapeutic class was introduced in order to broaden the narrow antibacterial spectrum of macrolides and to cope with the emergence of germs resistant to Erythromycin A and its hemisynthetic derivatives or neomacrolides (Clarithromycin, Roxithromycin, Azithromycin, Dirithromycin). From a pharmacochemical point of view, ketolides were first of all obtained by operating chemical modulations on Erythromycin A to obtain the neomacrolides, then, by replacing the neutral sugar (L-cladinose) in C3 by a ketone function coupled with the creation of an oxazolidinone like heterocycle in C11 and C12 in place of the hydroxyls present in these positions (Telithromycin, Cethromycin, Solithromycin). These modulations have enabled the improvement of the chemical stability of ketolides in gastric acid medium and increase their affinity for the ribosomal target, hence the broadening of their spectrum of action towards Gram positive germs including strains resistant to other macrolides and to neomacrolides. Therefore, the objective of this systematic review is to report the various pharmacochemical aspects undertaken since 1952 in the macrolide series based on the structure of Erythromycin A. These aspects will focus on the pharmacomodulations that have led, year after year, to the optimization of stability, the improvement of the pharmacodynamic and pharmacokinetic profile and that have allowed the development of neomacrolides, ketolides and neoketolides, which are today essential in the management of severe bronchopulmonary infections.

Evolution of Erythromycin Resistance among Streptococcus pneumoniae Isolates in Malaysia from 2005 and 2010

Objectives: This study focuses on the antibiotic susceptibility pattern and distribution of the ermB and mefA virulence genes among the Streptococcus pneumoniae due to an increase in erythromycin resistance in S. pneumoniae worldwide. Methodology: We investigated 255 clinical isolates collected from 2005-2010 to determine the serotype distribution and resistance to erythromycin in comparison to penicillin, clindamycin, clarithromycin, azithromycin, and trimethoprim sulfamethoxazole. Multiplex PCR was carried out to detect erythromycin resistance genes (ermB and mefA). Results: There were 146 (57.3%) isolates resistant to erythromycin. MIC90 for erythromycin is at >256 mg/L and MIC50 is at 16 mg/L. The ermB gene was detected in 25.3% of the erythromycin-resistant isolates and mefA gene was detected in 50.7% of the isolates. The four most common serotypes encountered are 19F, 19A, 23F and 14. The serotype distribution among the erythromycin resistant isolates was 19F (42.0%) followed by serotype 19A (11.3%), serotype 23F (9.2%) and serogroup 14 (7.0%). Conclusion: In conclusion, there is a significant rise in erythromycin resistance among the Malaysian pneumococcal isolates. The emergence of serotype 19A together with increasing prevalence of resistance to macrolide warrants for a more extensive surveillance study.

Parenteral erythromycin for potential use to empty retained gastric contents encountered during upper gastrointestinal endoscopic procedures

Background: Erythromycin, a prokinetic agent facilitates gastric emptying. We report our experience with the use of IV erythromycin for emptying retained gastric contents encountered during elective upper gastrointestinal endoscopy (UGIE) procedures in an effort to complete of the procedure on the same day. Patients and methods: This retrospective case series includes 15 patients who were found to have a signifycant amount of retained gastric contents while undergoing an UGIE procedure. After aborting the procedure, a repeat endoscopic examination was performed 30 - 120 minutes following administration of 250 - 500 mg erythromycin intravenously. Results: During repeat endoscopy, ten patients had complete emptying of the gastric contents, three patients had partial emptying and in two patients the amount of residual contents was largely unchanged. Both these patients were later found to have high grade mechanical gastric outlet obstruction. No anesthesia or procedure related complications were noted. Conclusion: Parenteral erythromycin can rapidly empty retained gastric contents encountered during UGIE procedures in a significant proportion of patients. Erythromycin can potentially be tried for safe completion of procedure on the same day.

Validated HPTLC Method for Simultaneous Estimation of Isotretinoin and Erythromycin in Bulk Drug and Topical Gel Form

A simple, precise and accurate high performance thin layer chromatographic method has been developed for the simultaneous estimation of Isotretinoin and Erythromycin in pharmaceutical gel. The separation was carried out on Merck TLC aluminum sheets of silica gel 60 F254, (20 × 10 cm) with 250 μm thickness using toluene: DMSO: methanol (6.5:0.2:2.5, v/v/v) as a mobile phase. HPTLC separation of the two drugs followed by densitometric measurement of their spots at 340 nm for Isotretinoin before derivatization and 410 nm for Erythromycin after derivatization with 10% H2SO4 and heating at 100°C for 15 min. The drugs were satisfactorily resolved with RF values of 0.38 ± 0.02 and 0.55 ± 0.02 for Isotretinoin and Erythromycin, respectively. The accuracy and reliability of the method was assessed by evaluation of linearity (30-150 ng spot-1 for Isotretinoin and 1200-6000 ng spot-1 for Erythromycin), precision (intra-day RSD 0.62-0.79% and inter-day RSD 0.43-0.71 % for Isotretinoin and intra-day RSD 0.47-1.71 % and inter-day RSD 0.42-1.49 % for Erythromycin), accuracy (98.91 ± 0.92 % for Isotretinoin and 99.27 ± 0.72 % for Erythromycin), and specificity, in accordance with ICH guidelines.