Macrolides are frequently used in veterinary medicine as therapeutic and preventive agents for various diseases. It is difficult to determine macrolides simultaneously with conventional methods due to their similar structures. A simultaneous analysis for erythromycin, roxithromycin, tiamulin and tylosin with LC/MS has been developed. Separation was performed on C18 reversed phase column. Mobile phase was gradiently flowed with 10 mM ammonium acetate and methanol. The mass spectrometer was run in the positive mode and selective ion monitoring mode. The molecular ions were [M+H]+ form at m/z 837.5 for erythromycin, at m/z 859.5 for roxithromycin, at m/z 494.2 for tiamulin and at m/z 916.7 for tylosin. Limits of detection were in the range from 0.001 to 0.01 microgram/g lower than their MRLs.
Anti-Bacterial Agents/*analysis ; Chromatography, Liquid/*methods ; Diterpenes/*analysis ; Erythromycin/*analysis ; Mass Spectrometry/*methods ; Molecular Structure ; Roxithromycin/*analysis ; Sensitivity and Specificity ; Tylosin/*analysis ; Veterinary Medicine

BACKGROUNDThe catheter related infection caused by Staphylococcus epidermidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy. The properties of biofilms that give rise to antibiotic resistance are only partially understood. This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm.

METHODSThe penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457, 1457-msrA, and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve. The RNA/DNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope, respectively.

RESULTSThe penetration ratios of erythromycin through the biofilms of 1457, 1457-msrA, and S68 after cultivation for 36 hours were 0.93, 0.55 and 0.4, respectively. The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours) was higher than that through the other two (0.499 and 0.31 after 24 hours). Lower growth rate of the cells in biofilm was shown, with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain. Compared with the control group observed by transmission electrmicroscope, the cell density of biofilm air face was lower than that of agar face, with more cell debris.

CONCLUSIONSErythromycin could penetrate to the Staphylococcus epidermidis biofilm, but could not kill the cells thoroughly. The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

Acridine Orange ; Anti-Bacterial Agents ; pharmacokinetics ; Biofilms ; DNA, Bacterial ; analysis ; Erythromycin ; pharmacokinetics ; pharmacology ; Microscopy, Electron, Transmission ; RNA, Bacterial ; analysis ; Staphylococcus epidermidis ; drug effects ; metabolism

OBJECTIVETo investigate whether erythromycin exerts anti-inflammatory effect on allergic airway inflammation and whether erythromycin modulate allergic airway inflammation by inhibiting nuclear factor kappa B (NF-kappa B) activation.

METHODSOvalbumin (OVA) together with aluminum hydroxide and Bordetella Pertussis was injected intraperitoneally to immunize SD rats and two weeks later 1% OVA was inhaled to challenge them for consecutive 7 days to mimic allergic airway inflammation. In treatment group, erythromycin was given orally (180 mg/kg.d) during the course of allergen exposure. WBC counts in bronchoalveolar lavage fluid (BALF) and lung specimen analysis were used to describe lung tissue inflammation. The expression of NF-kappa B subunit p65 in cell nucleus of lung tissue was measured by immunohistochemistry and NF-kappa B binding activation in lung tissue by electrophoresis mobility shift assay (EMSA).

RESULTSLung tissue specimen analysis indicated that the severity of allergic inflammation was reduced in treatment group. The number of total WBC in BALF (x 10(8)/L) (31 +/- 22) was lower than that in model group animals (66 +/- 28), P < 0.01. The number (x 10(3)/mm(2)) of cells with nuclear staining of NF-kappa B per square millimeter of submucosal region around large bronchus (1.4 +/- 0.4) was lower than that in model group animals (2.6 +/- 0.6), P < 0.01. NF-kappa B binding activity (32 +/- 14) was lower than that of model group (46 +/- 17), P < 0.05.

CONCLUSIONErythromycin had an obvious protective role in allergic airway inflammation. Erythromycin inhibited NF-kappa B transcriptional activity to exert anti-inflammatory effect.

Animals ; Anti-Inflammatory Agents ; pharmacology ; Asthma ; drug therapy ; Erythromycin ; pharmacology ; Lung ; pathology ; Male ; NF-kappa B ; analysis ; metabolism ; Rats ; Rats, Sprague-Dawley

BACKGROUND: Group A streptococcus (Streptococcus pyogenes) is the most common cause of bacterial pharyngitis and an important cause of a variety of suppurative and nonsuppurative diseases. The molecular genetic analysis of group A streptococci in clinical isolates is rarely reported in Korea. In this study, molecular genetic analysis using serotyping and emm sequence analysis, testing the presence of the SpeA and SpeB gene, and the determination of an antimicrobial resistance pattern were investigated. METHODS: Sixty nine strains of S. pyogenes from clinical isolates in Korea during 1999-2002 were examined by T agglutination, serum opacity reaction, and emm sequence analysis. Also investigated were antimicrobial susceptibility and the frequency of SpeA and SpeB genes. RESULTS: The antibiotic resistance rates for S. pyogenes isolates were shown at 28.9% of erythromycin, 14.2% of ampicillin, 9.5% of chloramphenicol, and 6.3% of levofloxacin. However, all strains were susceptible to penicillin, vancomycin, and teicoplanin. By T agglutination typing, forty-one (59.4%) among sixty-nine isolates were identified as T28 (13%), T6 (13%), T1 (10%), T12 (8.7%), T4 (4%), T5/27/44 (4%), T3/B3264 (2.9%), T11/12 (1.4%), and TB3264 (1.4%). Thirty-five (50.7%) among sixty nine isolates were positive in serum opacity reaction. The SpeB gene showed positive in all strains but the SpeA gene in eleven (15.9%) strains. By emm gene sequence analysis, forty-seven (68.1%) CONCLUSIONS: Our data showed that antimicrobial resistance of clinical isolates to erythromycin were higher than those reported from the United States and Europe, and emm genotyping could be used for a reliable and efficient typing method.
Agglutination ; Ampicillin ; Chloramphenicol ; Drug Resistance, Microbial ; Erythromycin ; Europe ; Korea ; Levofloxacin ; Molecular Biology* ; Penicillins ; Pharyngitis ; Sequence Analysis ; Serotyping ; Streptococcus ; Streptococcus pyogenes* ; Teicoplanin ; United States ; Vancomycin

BACKGROUND: Group A streptococcus (GAS) is the most common cause of bacterial pharyngitis in children. Antibiotic resistance rates and emm genotypes of GAS isolated from patients with acute pharyngitis were studied in 2009. METHODS: Throat cultures were taken from 499 children with acute pharyngitis in Jinju, Korea, in 2008-2009. A total of 174 strains (34.9%) of GAS were isolated, and antimicrobial susceptibility testing was performed using the disk diffusion method. The phenotypes of macrolide resistance and macrolide resistance genes were determined. The emm genotypes were identified using PCR and sequencing. The data were compared with those acquired in 2002 in the same region. Data on the annual macrolide production were collected between 1999 and 2008. RESULTS: The resistance rates of GAS to erythromycin, clindamycin, and tetracycline were 4.6%, 2.9%, and 2.3%, respectively. The constitutive resistance rate was 62.5% for the erm(B) gene and 37.5% for the M phenotype of the mef(A) gene. emm4 was most frequently detected (28.2%), followed by emm89 (20.1%). Most of the erythromycin resistant strains had the emm28 genotype. We noted a gradual increase in macrolide production during the study period. CONCLUSIONS: The erythromycin resistance rate of GAS isolated from children with acute pharyngitis was significantly lower in 2009 (4.6%) than in 2002 (44.8%). We observed a remarkable change in the distribution of emm genotypes during the 7-yr period. The significant decline in erythromycin resistance in 2009 might be associated with a prominent decrease in the resistant genotype emm12 (3.4% in 2009 vs. 28.0% in 2002) rather than restriction of macrolide use.
Acute Disease ; Adolescent ; Anti-Bacterial Agents/*pharmacology ; Child ; Child, Preschool ; Disk Diffusion Antimicrobial Tests ; Drug Resistance, Bacterial/genetics ; Erythromycin/*pharmacology ; Female ; Genotype ; Humans ; Male ; Pharyngitis/drug therapy/*microbiology ; Phenotype ; Sequence Analysis, DNA ; Streptococcus pyogenes/*drug effects/*genetics/isolation & purification

OBJECTIVETo analyze the clinical manifestations and intervention against fulminant scrub typhus-associated hemophagocytic syndrome.

METHODThe medical records for the onset time of hemophagocytic syndrome, the clinical course, the chest radiographic findings, laboratory data, antibiotic therapy, clinical outcome and its prognosis were retrospectively reviewed.

RESULT(1) Four patients were diagnosed as scrub typhus based on clinical manifestations only, while 15 patients met the criteria of laboratory diagnosis. All 19 patients with scrub typhus had hemophagocytic syndrome. Eschar lesion was identified in 12 patients, 7 patients were described as an ulcer. A seasonal pattern (78.9% from June through September in 15 patients) was observed. Clinical misdiagnosis was common (all 19 cases). There were 9 patients with admitting diagnosis of scrub typhus, 10 patients were not diagnosed as scrub typhus after admission. In 5 cases within 3 days after admission diagnosis was corrected as scrub typhus. Until discharge from the hospital, 5 cases were not diagnosed with scrub typhus. In this study, the length of time from the illness onset (beginning of fever) to the occurrence of clinical symptoms was (9 ± 4) days. (2) All 19 patients had changed AST levels (149 ± 37) U/L, albumin levels (23 ± 4) g/L, C-reactive protein levels (103 ± 51) mg/L, and platelet count (48 ± 41) × 10⁹/L; bone marrow aspiration revealed in 16 patients marked hemophagocytosis. Weil-Felix agglutination test revealed positive results in 6 of 15 cases. Diagnostic IFA results were positive for 14 patients; 19 patients had interstitial pneumonitis and 17 patients had pleural effusion. (3) Five cases with failure to diagnose the disease had ineffective antibiotics treatment (imipenem or β-lactam-based regimens). These patients did not receive appropriate treatment with antibiotics against scrub typhus. Fourteen patients with admitting diagnosis of scrub typhus were successfully treated with appropriate antibiotics, 8 cases with chloramphenicol, 3 cases with azithromycin, and in 3 patients (2 cases of azithromycin and one case of erythromycin), therapy was then switched to chloramphenicol. Four patients were treated with methylprednisolone and 10 patients with dexamethasone. (4) During their hospitalization, the clinical course in five cases with failure to diagnose the disease rapidly developed and progressed to the life-threatening MODS, four of five cases died. However, the course in 14 patients were relieved and did not progress to MODS.

CONCLUSIONThe diagnosis of scrub typhus was frequently delayed, the early course of scrub typhus could be associated with hemophagocytic syndrome. Serious complications of MODS generally occur without antibiotic treatment. Scrub typhus-associated hemophagocytic syndrome should be taken into consideration among patients with acute systemic febrile illness, significant increases in levels of CRP, hypoalbuminemia, thrombocytopenia, splenomegaly, pneumonitis with pleural effusion, especially those with suspected exposure history. It was not easily recognized without careful observation and was present for a few days in each patient.

Anti-Bacterial Agents ; therapeutic use ; Azithromycin ; therapeutic use ; C-Reactive Protein ; analysis ; Clinical Laboratory Techniques ; Diagnosis, Differential ; Erythromycin ; therapeutic use ; Humans ; Imipenem ; therapeutic use ; Lymphohistiocytosis, Hemophagocytic ; epidemiology ; Pneumonia ; Retrospective Studies ; Scrub Typhus ; diagnosis ; drug therapy ; epidemiology

In adult liver, CYP3A4 plays an important role in the metabolism of a wide range of endogenous and exogenous compounds. To investigate whether there is a single nucleotide polymorphism (SNP) of CYP3A4 intron 2 in the liver and its effects on the mRNA expression and enzymatic activity of CYP3A4, genomic DNA was extracted from 96 liver tissue samples obtained from patients who had undergone liver surgery. An SNP of CYP3A4 intron 2 was identified by polymerase chain reaction (PCR)-single-strand confirmation polymorphism and DNA sequencing. The mRNA expression of CYP3A4 was determined by the fluorescence quantitative PCR technique. The enzymatic activity of CYP3A4 was measured using erythromycin and testosterone as probe substrates. Twelve patients were found to have the SNP/T4127G CYP3A4 within intron 2. The mRNA levels of CYP3A4 in wild-type and SNP/T4127G samples were 2.62±1.09 and 2.79±1.63, respectively (P>0.05). Erythromycin N-demethylase activity in wild-type and SNP/T4127G samples were 121.2±32.8 and 124.7±61.6 nmol·mg(-1)·min(-1), respectively (P>0.05). The activity of testosterone 6β-hydroxylase was significantly different between wild-type (648±173 pmol·mg(-1)·min(-1)) and SNP/T4127G samples (540±196 pmol·mg(-1)·min(-1); P<0.05). In conclusion, the SNP/T4127G of CYP3A4 intron 2 exists in the liver. This SNP does not affect the mRNA expression of CYP3A4 but significantly decreases the hepatic microsomal testosterone 6β-hydroxylase activity of CYP3A4. Furthermore, this study indicates that the appropriate selection of probe substrates is very important in studying the relationship between the genotype and phenotype of CYP3A4.
Adult ; Asian Continental Ancestry Group ; genetics ; China ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Erythromycin ; metabolism ; Genotype ; Humans ; Introns ; Liver ; enzymology ; Phenotype ; Polymorphism, Single Nucleotide ; RNA, Messenger ; genetics ; Sequence Analysis, DNA ; methods ; Testosterone ; metabolism

BACKGROUND: Carefully switching from intravenous to oral antibiotic therapy has shown to reduce treatment costs and lengths of hospital stay as well as increase safety and comfort in patients with infections. The aim of this study was to compare the clinical efficacy and safety between the patients treated with glycopeptides (case group), and the patients given oral antibiotics, as the initial or step-down therapy (control group), in the treatment of patients with methicillin-resistant Staphylococcus aureus (MRSA) infection. MATERIALS AND METHODS: A multicenter observational study was retrospectively performed in 7 teaching hospitals in Korea from January to December 2012. The study included adult patients (> or = 18 years) with infection caused by MRSA isolates, susceptible to clindamycin, erythromycin, and ciprofloxacin. The primary end point was treatment outcome, including all-cause mortality and switching of antibiotics. Drug-related adverse events and the lengths of hospital stay were also compared between the two treatment groups. RESULTS: During the study period, 107 patients (43 cases and 64 controls) with MRSA infections were enrolled from the participating hospitals. The most common sites of MRSA infection were skin and soft tissue (n = 28) and bone and joint (n = 26). The median Charlson comorbidity index (P = 0. 560), the frequency of severe sepsis (P = 0.682) or thrombocytopenia (P = 1.000), and median level of serum C-reactive protein (P = 0.157) at the onset of MRSA infections were not significantly different between the case and control groups. The oral antibiotics most frequently prescribed in the case group, were fluoroquinolones (n = 29) and clindamycin (n = 8). The median duration of antibiotic treatment (P = 0.090) and the occurrence of drug-related adverse events (P = 0.460) did not reach statistically significant difference between the two groups, whereas the total length of hospital stay after the onset of MRSA infection was significantly shorter in the case group than the control group [median (interquartile range), 23 days (8-41) vs. 32 days (15-54), P = 0.017]. In multivariate analyses, the type of antibiotic used was not an independent risk factor for treatment failure. The statistically significant factors associated with treatment failure included underlying hepatic diseases, prior receipt of antibiotics, and foreign body retention. CONCLUSIONS: This study indicates that oral antibiotic therapy with active agents against MRSA isolates can be considered as the initial or step-down therapy for the treatment of MRSA infections and also reduce the length of hospital stay.
Adult ; Anti-Bacterial Agents ; C-Reactive Protein ; Ciprofloxacin ; Clindamycin ; Comorbidity ; Erythromycin ; Fluoroquinolones ; Foreign Bodies ; Glycopeptides ; Health Care Costs ; Hospitals, Teaching ; Humans ; Joints ; Korea ; Length of Stay* ; Methicillin-Resistant Staphylococcus aureus* ; Mortality ; Multivariate Analysis ; Observational Study ; Retrospective Studies ; Risk Factors ; Sepsis ; Skin ; Thrombocytopenia ; Treatment Failure ; Treatment Outcome