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Penicillin
Terms modified by Penicillin Selected AbstractsPenicillin,G und Erysipel , noch immer?JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 4 2005Article first published online: 16 MAR 200 First page of article [source] Stabilization of penicillin V acylase from Streptomyces lavendulae by covalent immobilizationJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2001Jesús Torres-Bacete Abstract Penicillin,V acylase from the actinomycete Streptomyces lavendulae ATCC 13664 has been immobilized to epoxy-activated acrylic beads (Eupergit C®) by covalent binding. Further linkage of bovine serum albumin after enzyme immobilization was carried out in order to remove the remaining oxirane groups of the support. The obtained immobilized biocatalyst displayed double exponential deactivation kinetics at temperatures below 55,°C, while the native enzyme followed single exponential decay at the same temperatures. We concluded that soluble penicillin acylase was deactivated in one step, whereas the immobilized enzyme showed an enzymatic intermediate state which is highly thermostable. As a consequence of the immobilization process, the enzyme displayed a 10-fold increase in its half-life at 40,°C. At this temperature, the enzymatic intermediate state was progressively destabilized as the pH of the medium was increased. Thus, the optimum pH range for the immobilized enzyme preparation was established as being from 7.0 to 8.0. Higher pH values led to quicker enzyme deactivation. © 2001 Society of Chemical Industry [source] Restoration of antibacterial activity of ,-lactams by epigallocatechin gallate against ,-lactamase-producing species depending on location of ,-lactamaseJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2003Wei-Hua Zhao The combined effects of (,)-epigallocatechin gallate (EGCg) and ,-lactams were investigated against various ,-lactamase-producing clinical isolates, including 21 Staphylococcus aureus, 6 Escherichia coli, 3 Klebsiella pneumoniae and 8 Serratia marcescens strains. Penicillin in combination with EGCg at 12.5,g mL,1 showed the most potent synergy against 100% penicillinase-producing S. aureus. However, cefotaxime or imipenem in combination with higher concentration of EGCg (100 ,g mL,1) only showed slight synergy against 2 of 17 Gram-negative rods. Similar to the effect on the penicillinase from S. aureus, however, EGCg also directly inhibited the extracted ,-lactamases from the Gram-negative rods, thereby protecting ,-lactams from inactivation. The different effects of the combinations on different ,-lactamase-producing species were confirmed to be related to the cellular locations of ,-lactamases. In contrast to a 32.7% extracellular fraction of total ,-lactamase activity in a penicillinase-producing S. aureus, the fractions were 0.6%, 0.6% and 1.2% in a TEM-derived extended-spectrum ,-lactamase-producing E. coli, an inhibitor-resistant ,-lactamase-producing K. pneumoniae and an IMP-producing S. marcescens, respectively. In conclusion, the combination of penicillin with EGCg showed potent synergy against penicillinase-producing S. aureus in-vitro. The combinations of ,-lactams and EGCg against ,-lactamase-producing Gram-negative rods do indicate a limitation owing to the cellular location of ,-lactamases. [source] Unverzichtbar gegen Bakterien: Antibiotika.CHEMIE IN UNSERER ZEIT (CHIUZ), Issue 5 200980 Jahre Verwendung von Antibiotika in der Medizin Abstract Auch 80 Jahre nach der Entdeckung von Penicillin ist die Forschung nach neuen Antibiotika noch nicht abgeschlossen. Zunehmendes Auftreten von Resistenzen gegenüber den verwendeten Antibiotika erfordern einen verantwortungsvollen Einsatz bekannter Anibiotika und die Entwicklung verbesserter Medikamente. Mittlerweile existieren 8000 antibiotisch wirksame Substanzen, von denen ca. 100 in der Medizin angewandt werden. Trotzdem gibt es zahlreiche Infektionen, die nicht ausreichend behandelt werden können. Antibiotika werden in der Human- und Veterinärmedizin eingesetzt. Der bedenkliche Einsatz als Ergotropika, um die Infektionsraten von Masttieren zu vermindern und die Futterverwertung der Tiere zu steigern, konnte in den letzten Jahren zurückgedrängt werden. Die teils unsachgemäße Anwendung erzeugt einen selektiven Druck, der Resistenzen bei den Erregern hervorruft. Ihr bedrohlicher Einfluss auf die Therapie vor allem gramnegativer Bakterien könnten manche Teile der Welt in eine präantibiotische Ära zurückversetzen, da sich adäquate Therapiemöglichkeiten zunehmend verringern. Dies unterstreicht wiederum die Wichtigkeit neue Antibiotika bzw. neue Therapieansätze zu entwickeln. Ideen dazu gibt es genug. Eighty years after the recovery of Penicillin the search for new antibiotics is still ongoing. By now there exist 8000 effective antibiotics, from which 100 have medical applications. Nevertheless there exist a lot of infections, which cannot be sufficiently treated. New antibiotics should have a specific mode of function that differs from known antibiotics. Additionally they should avoid secondary effects on humans, have a good resorption and act at the right place in the body, without being immediately released. [source] Community-acquired pneumonia (CAP) in children in Oslo, NorwayACTA PAEDIATRICA, Issue 2 2009Anita C Senstad Abstract Aim: To investigate the epidemiology and clinical characteristics of community acquired pneumonia (CAP) in children before the introduction of the 7-valent pneumococcal vaccine in the national vaccination programme. Methods: For the period 21 May 2003 to 20 May 2005 hospitalization rates for pneumonia in children were obtained from retrospective studies of medical journals. Pneumonia was also studied prospectively in children less than sixteen years old referred to Ullevål University Hospital (Oslo) in the same time period. Results: The overall observed hospitalization rate of pneumonia was 14.7/10 000 (95% CI: 12.2,17.1), for children under five it was 32.8/10 000 (95% CI: 26.8,38.8), and for children under two 42.1/10 000 (95% CI: 32.0,52.3). In the clinical study 123 children, of whom 59% (73) were boys, met the inclusion criteria and were enrolled. Only 2.4% (3) had pneumonia complicated with pleural effusion and in general few complications were observed. No patients required assisted ventilation, and none were transferred to the intensive care unit. Penicillin was effective as treatment for pneumonia. Conclusion: Pneumonia, seen in a paediatric department in Oslo, is a common but benign disease. Penicillin is effective as treatment for pneumonia in Norwegian children. [source] Development and validation of an HPLC method for the determination of seven penicillin antibiotics in veterinary drugs and bovine blood plasmaJOURNAL OF SEPARATION SCIENCE, JSS, Issue 9 2009Victoria F. Samanidou Abstract Herein a quantitative method for the determination of seven penicillins in bovine plasma and veterinary drugs has been developed. Amoxicillin (AMO), ampicillin (AMP), penicillin G (PENG), penicillin V (PENV), oxacillin (OXA), cloxacillin (CLO) and dicloxacillin (DICLO) were separated on a Perfectsil ODS-2 (250×4 mm, 5 ,m) column, using gradient elution, with a mobile phase of 0.1% v/v TFA and ACN,methanol (90:10 v/v). PDA detection was used at 240 nm. Penicillins were isolated from bovine plasma by SPE on Lichrolut RP-18 cartridges with mean recoveries from 85.7 to 113.5%. Colchicine (3 ng/,L) was used as an internal standard. The developed method was validated in terms of selectivity, linearity, accuracy, precision, stability and sensitivity. Repeatability (n = 5) and between-day precision (n = 5) revealed RSD < 12%. The detection limits in the bovine plasma were estimated as 18 ng for AMO and AMP, 25 for PENG, PENV and OXA, 3 ng for CLO and 12 ng for DICLO. Spiked plasma samples were stable for 1 wk, except for AMP and CLO, which were stable for 3 wk and OXA for 4 wk. AMO, PENG and PENV were stable for two freeze,thaw cycles, OXA, CLO and DICLO for four, while AMP only for one. [source] Immediate allergic reactions to cephalosporins and penicillins and their cross-reactivity in childrenPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2005-Markovi, Marina Atanaskovi Penicillins and cephalosporins are the most important betalactams inducing IgE-mediated reactions. The safety of administering cephalosporins to penicillin-allergic children is a particular problem, because cephalosporin allergenic determinants have not been properly identified. A study was undertaken to evaluate the frequency of anaphylactic reactions to cephalosporins and penicillins and their cross-reactivity in a pediatric population. A prospective survey was conducted in a group of 1170 children with suspected immediate allergic reactions to cephalosporins and/or penicillins, which were examined during a period of 8 yr. In vivo (skin tests and challenges) and in vitro tests (for specific IgE) were performed with standard concentration of penicillins and cephalosporins. When 1170 children with a clinical history of allergy to penicillins and/or cephalosporins were tested in vivo for immediate hypersensitivity to betalactams, 58.3% cases overall were found to be skin or challenge test positive. Among them, 94.4% patients were positive to penicillins and 35.3% to cephalosporins. The frequency of positive reactions in the in vivo testing was in the range from 36.4% to 88.1% for penicillins and from 0.3% to 29.2% for cephalosporins. However, 31.5% of the penicillin allergic children cross-reacted to some cephalosporin. If a child was allergic to a cephalosporin, the frequency of positive reactions to penicillin was 84.2%. The cross-reactivity between cephalosporins and penicillins varied between 0.3% and 23.9%. The cross-reactivity among different generations of cephalosporins varied between 0% and 68.8%, being the highest for first and second-generation cephalosporins and 0% for third generation cephalosporins. The frequency of immediate allergic reactions to cephalosporins is considerably lower compared to penicillins, and the degree of cross-reactivity between cephalosporins and penicillins depends on the generation of cephalosporins, being higher with earlier generation cephalosporins. The cross-reactivity among cephalosporins is lower compared to cross-reactivity between penicillins and cephalosporins. [source] Epidemiology of invasive pneumococcal infections in children aged 0,6 years in Denmark: a 19-year nationwide surveillance studyACTA PAEDIATRICA, Issue 2000MS Kaltoft The impact of the new pneumococcal conjugate vaccines on invasive disease burden in Danish children was evaluated by analysing the results from the last 19 years of a nationwide surveillance of invasive pneumococcal infections. During 1981,1999, the Streptococcus Unit at Statens Serum Institut, Copenhagen, received 1123 invasive pneumococcal isolates from children aged 0,6 years. Nearly 72% (71.8%) of the pneumococcal isolates were from children aged <2 y. The median ages of children with pneumococcal meningitis and bacteraemia were 10.2 mo and 15.9 mo, respectively. The incidence of pneumococcal meningitis remained stable during the study period. The mean annual incidence rates of pneumococcal meningitis among children aged <1, <2, and <7 years were 17.4, 12.4, and 4.3 per 100000, respectively, during 1981,1999 (overlapping age groups are used throughout this article to facilitate the comparison of incidence data from different countries or among different studies). The annual incidence of pneumococcal bacteraemia increased from 1981 to 1996, after which a slight fall was noted. During the last six years of the study period, the mean annual incidence rates of bacteraemia were 30.1, 32.5, and 14.0 per 100000 children aged <1, <2, and <7 years. In the 1990s, pneumococcal isolates with reduced sensitivity to penicillin (0,5% each year) and erythromycin (7.4% in 1999) emerged as a cause of invasive infections in children aged 0,6 years in Denmark. During 1981,1999, 10 serotypes (1, 4, 6A, 6B, 7F, 9V, 14, 18C, 19F, 23F) caused 82% of invasive infections in Danish children. Importantly, no significant temporal changes in overall serotype distribution or differences in serotype distributions between girls and boys could be documented during the study period. Conclusion: According to the Kaiser Permanente trial, the 7-, 9-, and 11-valent pneumococcal conjugate vaccines will probably cover around 60%, 70%, and 80%, respectively, of all invasive pneumococcal infections in Danish children aged 0,6 y, corresponding to 12,14 episodes of meningitis and 40,60 episodes of bacteraemia per year. [source] Epidemiology of invasive and other pneumococcal disease in children in England and Wales 1996,1998ACTA PAEDIATRICA, Issue 2000E Miller The results of enhanced national surveillance of pneumococcal disease in children <15y of age in England and Wales are reported for the period 1996,1998. Of the 1985 cases of laboratory-confirmed invasive disease (annual incidence 6.6 per 100000 overall and 39.7 per 100000 in infants <1 y of age), 485 (24%) were meningitis (annual incidence of 1.6 per 100000 overall and 15.7 per 100000 in infants <1 y of age). Fifty-nine deaths in children with invasive disease were identified-3% of the total reports. Thirty-one different serogroups/types were identified, with organisms in the 7-valent conjugate vaccine responsible for 69% of the infections in children <5 y of age; this rose to 77% and 82%, respectively, for the 9-and 11-valent vaccines. Resistance to penicillin varied from 2.3% to 6.2% in different years, but erythromycin resistance remained constant at 17%. The vast majority of resistant isolates were in vaccine serotype/groups. Computerized hospital admission records for all children <15 y of age with a discharge diagnosis code indicating probable pneumococcal disease were also analysed for 1997. The annual incidence for cases with a code specifically mentioning S. pneumoniae was 9.9 per 100000 compared with 71.2 per 100000 for lobar pneumonia; the mean duration of stay for both was < 1 wk. The incidence of admission for pneumococcal meningitis (1.9 overall and 19.6 for infants < 1 y of age) was similar to that derived from laboratory reports and resulted in an average duration of stay of 2 wk. Conclusion: This surveillance has confirmed the substantial burden of morbidity attributable to pneumococcal disease in British children and the potential public health benefits that could be achieved by the use of pneumococcal conjugate vaccines. [source] Etiologic spectrum and pattern of antimicrobial drug susceptibility in bacterial meningitis in Sokoto, NigeriaACTA PAEDIATRICA, Issue 8 2000FE EmeleArticle first published online: 2 JAN 200 Etiologic agents of meningitis were prospectively investigated among patients admitted to Usman Danfodio University Teaching Hospital, Sokoto. Of 1097 cerebrospinal fluid (CSF) samples submitted to the microbiology laboratory from various wards of the hospital, 289 (26%) were microscopically, culturally and/or serologically proven to be bacterial meningitis. The etiologic spectrum was as follows: Neisseria meningitidis (61%), Streptococcus pneumoniae (18%), Haemophilus influenzae (10%), Staphylococcus aureus (6%), Coliform bacilli (3%), Escherichia coli (0.7%), Mycobacterium tuberculosis (0.7%), Listeria monocytogenes (0.4%), Flavobacterium meningosepticum (0.4%) and Pseudomonas putrifasciens (0.4%). Bacterial meningitis was most prevalent (195 or 68%) among children aged 1-9 y, while adults and neonates were least affected. Coliform bacilli caused five of eight neonatal cases. Males were more frequently affected than females (x2=12.50;p < 0.05). Culture and microscopy were comparatively less efficient than the search for bacterial antigens, especially in the diagnosis of Haemophilus meningitis. Antimicrobial susceptibility of N. meningitidis to ampicillin and benzyl penicillin reduced progressively over the years (F = 406.98;p < 0.001). Nineteen (11%) of the isolates (5 Meningococci, 7 Staph. aureus, 1 Haem. influenza and 6 others) showed simultaneous resistance to chloramphenicol, ampicillin and benzyl penicillin. [source] Neuropsychiatric movement disorders following streptococcal infectionDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2005K G Walker MB BS The aim of this study was to describe post-streptococcal movement disorders that form part of the acute rheumatic fever complex. The clinical records of patients diagnosed with Sydenham's chorea were analyzed retrospectively to investigate epidemiology, the significance of socioeconomic deprivation, clinical manifestations, treatments, outcomes, long-term morbidity, and disease evolution. Forty-two patients (21 males, 21 females) were diagnosed with Sydenham's chorea. The median presentation age was 9 years 8 months (range 3y 5mo to 13y 2mo). Nineteen patients were of indigenous African ancestry; 23 were of mixed ancestry. All patients lived in poverty and had poor access to medical care. Twelve of the total group had disabling symptoms for longer than 2 years; six of these patients developed paediatric autoimmune neuropsychiatric disorder associated with Streptococcus (Paediatric autoimmune neuropsychiatric disorder associated with Streptococcus [PANDAS]), five Tourette syndrome (TS), and one learning difficulties. Poor outcome was significantly more prevalent in patients of mixed ancestry, in those with a positive family history, previous behavioural problems, or a failure to complete 10 days of penicillin and ,bed-rest'/hospitalization. Sydenham's chorea is one manifestation of post-streptococcal neuropsychiatric movement disorders. This study demonstrates that patients can present with one diagnosis and evolve other neuropsychiatric conditions such as TS and PANDAS. In the South African context, it is important to delineate neuropsychiatric movement disorders associated with streptococcal infections. The potential genetic susceptibility should be explored. [source] The Effects of Ascorbic Acid on Penicillin-induced Epileptiform Activity in RatsEPILEPSIA, Issue 7 2007Mustafa Ayyildiz Summary:,Purpose: Epileptic seizure results from excessive discharge in a population of hyperexcitable neurons. A number of studies help to document the effects of active oxygen free radical scavengers such as ,-tocopherol or ascorbic acid (vitamin C). In the present study, we examined the effects of ascorbic acid, at the six different doses, on penicillin-induced epileptiform activity. Methods: A single microinjection of penicillin (2.5 ,l, 500 units, intracortically) into the left sensorimotor cortex induced epileptiform activity within 2,5 min, progressing to full seizure activity lasting ,3,5 h. In the first set of experiments, 30 min after penicillin injection, six different doses of ascorbic acid (25, 50, 100, 200, 400, or 800 mg/kg) were administered intraperitoneally (IP). The other group of animals received the effective dose of ascorbic acid (100 mg/kg, IP) for 7 days. Ascorbic acid administration was stopped 24 h before penicillin treatment. Another group of rats received the effective dose of ascorbic acid (100 mg/kg, IP) 30 min before penicillin treatment. In the second set of experiments, the lipid peroxidation (MDA) and reduced glutathione (GSH) levels of brain were measured in the control, control + ascorbic acid, penicillin, and penicillin + ascorbic acid groups. Results: Ascorbic acid, at the low dose (50, 100 mg/kg, 30 min after penicillin injection), decreased both the frequency and amplitude of penicillin-induced epileptiform activity in rats. Ascorbic acid, at intermediate doses (200, 400 mg/kg, 30 min after penicillin injection), decreased the frequency of epileptiform activity without changing the amplitude. Ascorbic acid, at the lowest dose (25 mg/kg) and highest dose (800 mg/kg) (30 min after penicillin injection), did not change either the frequency or amplitude of epileptiform activity. Ascorbic acid, at the low dose (100 mg/kg) was the most effective dose in changing the frequency and amplitude of penicillin-induced epileptiform activity. Pretreatment with ascorbic acid (100 mg/kg) 30 min before penicillin treatment caused a significant delay in the onset of penicillin-induced epileptiform activity. Pretreatment with ascorbic acid (100 mg/kg) for 7 days did not change the latency of epileptiform activity. The most effective dose of ascorbic acid (100 mg/kg) prevented both the decrease in GSH level and the increase in lipid peroxidation level (MDA) occurring after penicillin-induced epileptiform activity. Conclusions: These data indicate that ascorbic acid has neuroprotective activity against penicillin-induced epileptiform electrocorticogram activity. [source] A Sheep Model for the Study of Focal Epilepsy with Concurrent Intracranial EEG and Functional MRIEPILEPSIA, Issue 8 2002Helen I. Opdam Summary: ,Purpose: We describe a sheep model of penicillin-induced seizure activity using electroencephalography (EEG) and functional MRI (fMRI). Methods: Ten adult sheep were used. Spikes and seizures were generated by instillation of 8,000,10,000 IU of penicillin into the right prefrontal cortex via a specially designed port. Bilateral intracranial EEG was acquired by using carbon fiber electrodes. Animals had behavioral characterization of their seizures and were then anesthetized for fMRI studies. Functional MRI was performed at 1.5 and 3 Tesla by measuring blood oxygen level,dependent (BOLD) weighted signal intensity at different times during the evolution of seizures. Results: Behavioral seizures were associated with electrographic seizures. Intracranial EEG obtained in the MR scanner was of high quality. Focal spiking and seizures were seen in all animals and developed 11.3 ± 11.2 s and 17.3 ± 12.1 min after penicillin administration, respectively. An average of 13 ± 4.8 seizures were seen per animal, each lasting 27.3 ± 12.3 s. Functional MR images with little parenchymal artefact were obtained. Regional BOLD signal-intensity changes were observed during seizures at the seizure focus and ipsilateral amygdala. Conclusions: We have developed an animal model of partial epilepsy in which seizures can be reliably elicited with concurrent fMRI and intracranial EEG. During unilateral electrographic seizures, focal BOLD signal changes occurred at the seizure focus and ipsilateral amygdala, suggesting the presence of a cortico,subcortical loop. This observation illustrates the potential of the model for understanding seizure generation, spread, and possibly the consequences of repeated seizures on the brain. [source] Distribution and Initiation of Seizure Activity in a Rat Brain with Subcortical Band HeterotopiaEPILEPSIA, Issue 5 2000Zong-Fu Chen Summary: Purpose: Misplaced (heterotopic) cortical neurons are a common feature of developmental epilepsies. To better understand seizure disorders associated with cortical heterotopia, the sites of aberrant discharge activity were investigated in vivo and in vitro in a seizure-prone mutant rat (tish) exhibiting subcortical band heterotopia. Methods: Depth electrode recordings and postmortem assessment of regional c- fos mRNA levels were used to characterize the distribution of aberrant discharge activity during spontaneous seizures in vivo. Electrophysiologic recordings of spontaneous and evoked activity also were performed by using in vitro brain slices from the tish rat treated with proconvulsant drugs (penicillin and 4-aminopyridine). Results: Depth electrode recordings demonstrate that seizure activity begins almost simultaneously in the normotopic and heterotopic areas of the tish neocortex. Spontaneous seizures induce c- fos mRNA in normotopic and heterotopic neocortical areas, and limbic regions. The threshold concentrations of proconvulsant drugs for inducing epileptiform spiking were similar in the normotopic and heterotopic areas of tish brain slices. Manipulations that blocked communication between the normotopic and heterotopic areas of the cortex inhibited spiking in the heterotopic, but not the normotopic, area of the cortex. Conclusions: These findings indicate that aberrant discharge activity occurs in normotopic and heterotopic areas of the neocortex, and in certain limbic regions during spontaneous seizures in the tish rat. Normotopic neurons are more prone to exhibit epileptiform activity than are heterotopic neurons in the tish cortex, and heterotopic neurons are recruited into spiking by activity initiated in normotopic neurons. The findings indicate that seizures in the tish brain primarily involve telencephalic structures, and suggest that normotopic neurons are responsible for initiating seizures in the dysplastic neocortex. [source] Study of faecal shedding of Clostridium difficile in horses treated with penicillinEQUINE VETERINARY JOURNAL, Issue 2 2004A. Gustafsson No abstract is available for this article. [source] Prevention of life-threatening infections due to encapsulated bacteria in children with hyposplenia or asplenia: a brief review of current recommendations for practical purposesEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2003Elio Castagnola Abstract: The aim of the present work was to summarise in a single paper all the options for prevention of life-threatening infections due to encapsulated bacteria in patients with hyposplenism or asplenia. Prevention of these infections should be obtained in all patients with 1) patient and family education, 2) prophylaxis by means of vaccination against Haemophilus influenzae and Streptococcus pneumoniae, 3) antibiotic prophylaxis, based primarily on penicillin, 4) delay of elective splenectomy or use methods of tissue salvage in splenic trauma. Vaccination is not effective against all serotypes of S. pneumoniae and Neisseria meningitidis causing life-threatening infections in hypo/asplenic patients. Moreover, antibacterial prophylaxis could select antibacterial-resistant pathogens and is highly conditioned by patient's compliance. Therefore, empirical antibacterial therapy of fever and/or suspected infection should be recommended to all splenectomised patients independently from time elapsing from splenectomy, vaccinal status and assumption of antibacterial prophylaxis. [source] A Combined Theoretical and Experimental Research Project into the Aminolysis of ,-Lactam Antibiotics: The Importance of Bifunctional CatalysisEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 21 2003Natalia Díaz Abstract This paper reports the results of experimental work on the aminolysis of penicillin (6-APA) and monobactam (aztreonam) antibiotics by propylamine or ethanolamine. In general, aztreonam is slightly more reactive than 6-APA, despite the common assumption that the amide bond should be less activated in monobactams. Intriguingly, when ethanolamine acts as the nucleophile, the corresponding rate law has a kinetic term proportional to [RNH2][RNH3+]. To complement the experimental observations, the rate-determining free energy barriers in aqueous solution for various mechanistic pathways were computed by standard quantum chemical methodologies. From previous theoretical work it was assumed that the aminolysis of ,-lactams proceeds through mechanisms in which either a water molecule or a second amine molecule may act as bifunctional catalysts, assisting proton transfer from the attacking amine molecule to the leaving amino group. The energy barriers as computed have moderate values (ca. 26,34 kcal·mol,1) and reproduce most of the experimentally observed kinetic trends. Furthermore, the calculations predict that positively charged ethanolamine molecules can act as bifunctional catalysts as well, thus explaining the presence of the kinetic term proportional to [RNH2][RNH3+] in the rate law. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Quantum chemical study of penicillin: Reactions after acylationINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 10 2007Rui Li Abstract The density functional theory methods were used on the model molecules of penicillin to determine the possible reactions after their acylation on ,-lactamase, and the results were compared with sulbactam we have studied. The results show that, the acylated-enzyme tetrahedral intermediate can evolves with opening of ,-lactam ring as well as the thiazole ring; the thiazole ring-open products may be formed via ,-lactam ring-open product or from tetrahedral intermediate directly. Those products, in imine or enamine form, can tautomerize via hydrogen migration. In virtue of the water-assisted, their energy barriers are obviously reduced. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source] ,Lues maligna" bei insulinpflichtigem Diabetes mellitusJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 10 2005"Lues maligna" in a female patient with diabetes Zusammenfassung Bei einer 40-jährige Patientin mit insulinpflichtigem Diabetes mellitus traten innerhalb weniger Wochen vor allem am Stamm multiple bis 2,5,cm große, lividrote Knoten und Plaques auf, die rasch ulzerierten. Einige Monate zuvor habe beim Partner ein kleines Ulkus am Penis bestanden. Die HIV-negative Patientin hatte eine hochtitrig positive Syphilisserologie (TPPA-Titer >,1 : 20.480, VDRL-Titer 1 : 128). Die nüchtern Blutglukosewerte lagen über 275,mg/dl. Nach Ausschluss einer Neurolues stellten wir die Diagnose einer ,Lues maligna" bei schlecht eingestelltem Diabetes mellitus. Unter einer Therapie mit 3,Injektionen Benzylpenicillin-Benzathin (2,4,Mio.,IE) i. m. in wöchentlichen Abständen und Einstellung des Diabetes heilten die Hautveränderungen komplett ab. Im Verlauf war der VDRL-Titer negativ. Die ,Lues maligna" tritt seit einigen Jahren wieder gehäuft auf und wird vor allem bei HIV-positiven Männern beobachtet. Das Auftreten dieser Erkrankung bei durch Diabetes mellitus bedingter Immunsuppression ist ausgesprochen selten. Summary A 40-year-old female patient with diabetes mellitus presented with multiple erythematous ulcerated nodules and plaques predominantly on the trunk. A few months ago her partner had a small ulcer on the penis. She was HIV negative but showed markedly elevated syphilis serology titers (TPPA titer >,1 : 20.480, VDRL titer 1 : 128). The serum glucose levels exceeded 275,mg/dl. After exclusion of neurological involvement, we made the diagnosis of ,lues maligna" arising in the setting of diabetes mellitus. The patient was treated with 2.4 million units benzathine penicillin intramuscularly weekly for three weeks. Simultaneously, diabetes therapy was improved with insulin injections. The syphilitic lesions cleared rapidly. In the follow-up VDRL titer was negative. ,Lues maligna" is an unusual ulcerative variant of secondary syphilis which has been observed more frequently in HIV-infected patients in the last years. The occurrence of this aggressive variant in the clinical setting of diabetes mellitus is extremely rare. [source] Virulence genes of bovine Staphylococcus aureus from persistent and nonpersistent intramammary infections with different clinical characteristicsJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2007M. Haveri Abstract Aims:, To screen putative virulence genes in Staphylococcus aureus causing persistent and nonpersistent bovine intramammary infections (IMI) with different clinical characteristics. To examine, whether a possible relationship exists between genetic profile and infection persistence, clinical signs of infection, clonal type determined by pulsed-field gel electrophoresis (PFGE), and antimicrobial resistance. Methods and Results:, One-hundred and sixty-one S. aureus isolates derived from bovine IMI, consisting of 17 different PFGE types, were screened by conventional and multiplex-polymerase chain reaction (PCR) for 24 virulence genes for haemolysins (hla-hlg), leukocidins (lukED, lukM), exfoliative toxins (eta, etb), enterotoxins (sea-seo, seu), toxic-shock syndrome toxin (tst), and genes encoding penicillin (blaZ) and methicillin resistance (mecA). The majority of S. aureus isolated at the onset of mastitis carried haemolysin genes (76·7,97·4%), lukED (96·6%), and at least one gene for pyrogenic toxin superantigen (PTSAg) (69·0%). Strains carrying PTSAg-encoding genes were more common among predominant PFGE types and in persistent IMI. Strains concomitantly possessing sed, sej, and blaZ, putatively plasmid-encoded, were typically found in connection with persistent IMI. Conclusions:, Our results suggest that certain genetic elements are over-representative in S. aureus isolates especially from persistent bovine mastitis. This phenomenon seems to be in connection with clonal type and is often concomitant with penicillin resistance. Significance and Impact of the Study:, This is the first study to investigate associations between a large number of bacterial factors and outcome of S. aureus mastitis. The finding that widespread clonal types of S. aureus causing bovine mastitis of low treatment response may harbour characteristic genes could be improved for strain-specific diagnostic purposes. [source] Antimicrobial profiles of periodontal pathogens isolated from periodontitis patients in the Netherlands and SpainJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2005A. J. Van Winkelhoff Abstract Background and Aim: Antimicrobial resistance of periodontal pathogens towards currently used antibiotics in periodontics has been investigated in a previous study. Microbial resistance in the periodontal microflora was more frequently observed in Spanish patients in comparison with Dutch patients. The aim of the present study was to compare antimicrobial susceptibility profiles of five periodontal bacteria isolated from periodontitis patients in Spain and in the Netherlands. Material and Methods: Subgingival plaque samples from adult patients with periodontitis were collected and cultured on selective and non-selective plates. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum and Micromonas micros were isolated and used for minimal inhibitory concentration tests using the Epsilometer (E-test) technique. Eight different antibiotics were tested on all bacterial isolates. MIC50 and MIC90 values for each antibiotic and each species were determined and the percentage of resistant strains was calculated. Results: Significantly higher MIC values were noted in Spanish strains of F. nucleatum for penicillin, ciprofloxacin, of P. intermedia for penicillin, amoxicillin and tetracycline, of M. micros for tetracycline, amoxicillin and azithromycin, and of P. gingivalis for tetracycline and ciprofloxacin. Based on breakpoint concentrations, a higher number of resistant strains in Spain were found in F. nucleatum for penicillin, amoxicillin and metronidazole, in Prevotella intermedia for tetracycline and amoxicillin, and in A. actinomycetemcomitans for amoxicillin and azithromycin. Resistance of P. gingivalis strains was not observed for any of the antibiotics tested both in Spain and the Netherlands. Conclusions: Differences exist in the susceptibility profiles of periodontal pathogens isolated from periodontitis patients in Spain and in the Netherlands. This implicates that antibiotic susceptibility testing is necessary to determine efficacy of antimicrobial agents. Also, clinical studies with antibiotics should take these differences into account. The information from the present study indicates that it may not be possible to develop uniform protocols for usage of antibiotics in the treatment of severe periodontitis in the European Union. [source] Antimicrobial resistance in the subgingival microflora in patients with adult periodontitisJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2000A comparison between The Netherlands, Spain Abstract Background: The widespread use of antibiotics for prophylaxis and treatment of bacterial infections has lead to the emergence of resistant human pathogens. Great differences have been documented between European countries in the use of systemic antibiotics. In parallel, significant differences in levels of resistant pathogens have been documented. Aim: To investigate whether differences in antibiotic use influence the level of antimicrobial resistance of the subgingival microflora of untreated patients with adult periodontitis in The Netherlands and Spain. Method: Blood agar plates containing breakpoint concentrations of penicillin, amoxicillin, amoxicillin and clavunalate, metronidazole, erythromycin, azithromycin, clindamycin and tetracycline were used to determine the proportion of bacteria from the subgingival plaque that was resistant to these antibiotics. In the Spanish patients, statistically significant higher mean levels of resistance were found for penicillin, amoxicillin, metronidazole, clindamycin and tetracycline. The mean number of different bacterial species growing on the selective plates was higher in the Spanish patients, as was the % of resistant strains of most periodontal pathogens. A striking difference was observed in the frequency of occurrence of tetracycline-resistant periodontal pathogens. In Spain, 5 patients had 3 tetracycline resistant periodontal pathogens, whereas this was not observed in any of the Dutch patients. Conclusions: The widespread use of antibiotics in Spain is reflected in the level of resistance of the subgingival microflora of adult patients with periodontitis. [source] Treatment of acute otitis media in patients with a reported penicillin allergyJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 3 2000Falconer Otitis media occurs commonly in children, and is usually treated with an antibiotic. In this case report, amoxicillin was prescribed for a 6-year-old boy suffering from acute otitis media. As he had previously experienced a rash after the administration of a penicillin, the medication order was switched from amoxicillin to trimethoprim/sulfamethoxazole (TMP/SMX). In an effort to determine whether or not this intervention was appropriate, references were found using Medline, International Pharmaceutical Abstracts and the Cochrane Library. Issues to be addressed included the need for antibiotics in acute otitis media, the comparative efficacy and tolerability of antimicrobial agents and the reliability of reported penicillin allergies. Amoxicillin and TMP/SMX were found to be first-line agents in the treatment of acute otitis media owing to their efficacy, safety and cost, with neither drug being significantly better than the other. The need to treat otitis media with antibiotics remains controversial. Reported penicillin allergies were found to be an unreliable indicator of a potentially serious reaction. In conclusion, it was found that treatment with TMP/SMX was an appropriate intervention. [source] Secondary Syphilis Presenting as Cutaneous T-Cell Lymphoma in an HIV-Positive PatientJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005A. Laungani We present the case of an HIV-positive 38-year-old Caucasian male with a history of fevers, chills, and disseminated nonpruritic erythematous papules that began on his abdomen. An initial skin biopsy revealed a lymphohistiocytic infiltrate at the dermoepidermal junction, exocytosis of atypical lymphocytes, and minimal spongiosis. Immunohistochemistry showed increased CD8-positive cells but only scattered CD30-positive cells. PCR analysis demonstrated T-cell receptor gamma gene rearrangement. RPR, blood and tissue cultures were all negative. The patient was thought to have a cytotoxic cutaneous T-cell lymphoma. Over time, the lesions progressed to the palms and soles and the patient remained febrile. Repeat biopsy demonstrated a lichenoid interface dermatitis with a superficial and deep perivascular, interstitial, and periadnexal lymphohistiocytic infiltrate and the formation of epithelioid granulomas throughout the dermis. The epidermis showed blurring of the dermoepidermal junction, spongiosis, and exocytosis of lymphocytes and neutrophils. Few spirochetes were demonstrated by Steiner stain. Repeat RPR and FTA-Abs serologies were positive. The patient was diagnosed with late secondary syphilis and was successfully treated with benzathine penicillin. This case demonstrates that atypical lymphoid infiltrates can simulate mycosis fungoides in an HIV-positive patient with secondary syphilis and also reiterates that syphilis is a great mimicker of other entities. [source] PREVALENCE AND ANTIMICROBIAL RESISTANCE OF LISTERIA SPECIES IN FOOD PRODUCTS IN BANGKOK, THAILANDJOURNAL OF FOOD SAFETY, Issue 1 2010SIRIPORN STONSAOVAPAK ABSTRACT A total of 380 meat and meat products, dairy and dairy products, fresh vegetables, fresh seafood, and ready-to-eat food samples from supermarkets in Bangkok, Thailand were collected and analyzed for the occurrence of Listeria spp. and of Listeria monocytogenes. The overall incidence of Listeria spp. was 16.8%, most of them were isolated from raw meat and vegetables. L. monocytogenes was isolated from 18 (4.7%) out of 380 studied samples. Other species isolated were L. innocua (6.6%), L. ivanovii (0.8%), L. seeligeri (0.5%), L. grayi (1.6%) and L. welshimeri (2.6%). The antimicrobial susceptibilities of the 64 isolate of Listeria spp. were also examined by the standard disk diffusion method. Listeria spp. were resistant to penicillin (6.3%), chloramphenicol (3.1%) and tetracycline (1.6%), but sensitive to amoxicillin, vancomycin, ampicillin, rifampicin and sulfamethoxazole. PRACTICAL APPLICATIONS Listeria monocytogenes prevalence in food products in Bangkok has been documented. More studies on the occurrence of L. monocytogenes are needed to establish microbiological criteria of foods in the country. The findings of our study, increases in antibiotic resistance among Listeria spp. will provide useful information for the development of public health policy in the use of antimicrobials in food animal production. [source] Trancranial Doppler Monitoring of Response to Therapy for Meningovascular SyphilisJOURNAL OF NEUROIMAGING, Issue 1 2003Roger E. Kelley MD ABSTRACT Meningovascular syphilis is now quite uncommon, but there have been increasing reports in patients immunocompromised with human immunodeficiency virus. The response of syphilis affecting the central nervous system to antibiotic therapy remains a challenge. This is an even greater challenge in patients who have underlying compromise of the immune system. The authors present a 46-year-old male with recurrent stroke who was found to have cerebrospinal fluid compatible with syphilitic involvement of the central nervous system and a cerebral arteriogram, which revealed focal narrowing of the right middle cerebral artery. The baseline transcranial Doppler study demonstrated increased mean and peak flow velocity within the right middle cerebral artery. Despite a 10-day course of intravenous penicillin, with substantial improvement in the cerebrospinal fluid results, this flow velocity elevation persisted, in a remarkably consistent pattern, over a 4-month follow-up period. Thus, the involved vessel remained patent following treatment, but no clear resolution of the stenotic lesion was observed. [source] Restoration of antibacterial activity of ,-lactams by epigallocatechin gallate against ,-lactamase-producing species depending on location of ,-lactamaseJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2003Wei-Hua Zhao The combined effects of (,)-epigallocatechin gallate (EGCg) and ,-lactams were investigated against various ,-lactamase-producing clinical isolates, including 21 Staphylococcus aureus, 6 Escherichia coli, 3 Klebsiella pneumoniae and 8 Serratia marcescens strains. Penicillin in combination with EGCg at 12.5,g mL,1 showed the most potent synergy against 100% penicillinase-producing S. aureus. However, cefotaxime or imipenem in combination with higher concentration of EGCg (100 ,g mL,1) only showed slight synergy against 2 of 17 Gram-negative rods. Similar to the effect on the penicillinase from S. aureus, however, EGCg also directly inhibited the extracted ,-lactamases from the Gram-negative rods, thereby protecting ,-lactams from inactivation. The different effects of the combinations on different ,-lactamase-producing species were confirmed to be related to the cellular locations of ,-lactamases. In contrast to a 32.7% extracellular fraction of total ,-lactamase activity in a penicillinase-producing S. aureus, the fractions were 0.6%, 0.6% and 1.2% in a TEM-derived extended-spectrum ,-lactamase-producing E. coli, an inhibitor-resistant ,-lactamase-producing K. pneumoniae and an IMP-producing S. marcescens, respectively. In conclusion, the combination of penicillin with EGCg showed potent synergy against penicillinase-producing S. aureus in-vitro. The combinations of ,-lactams and EGCg against ,-lactamase-producing Gram-negative rods do indicate a limitation owing to the cellular location of ,-lactamases. [source] Antibiotics modulate the stimulated cytokine response to endotoxin in a human ex vivo, in vitro modelACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2006S. Ziegeler Background:, Sepsis may lead to the suppression of stimulated cytokine release after Gram-negative stimuli, correlating with a fatal outcome. Treatment of sepsis includes adequate therapy with antibiotics. The aim of this study was to investigate the role of antibiotics in the modulation of the lipopolysaccharide (LPS)-stimulated cytokine response of human monocytes. Methods:, In this ex vivo, in vitro study, whole blood samples were taken from 10 healthy volunteers, stimulated with LPS in the presence or absence of various antibiotics (penicillin, amoxicillin, cefuroxime, ceftazidime, cefotaxime, piperacillin/tazobactam, imipenem/cilastatin, gentamicin, netilmicin, ciprofloxacin, vancomycin) and cultured for 24 h. Thereafter, tumor necrosis factor-, (TNF-,) and interleukin-10 (IL-10) were measured in the supernatants by enzyme-linked immunosorbent assay (ELISA). Furthermore, CD14 and HLA-DR expression on monocytes was assessed using flow cytometry. Results:, All cephalosporins decreased LPS-stimulated IL-10 release. Cefuroxime and cefotaxime also decreased the expression density of the LPS recognition molecule CD14 on monocytes. An increase in LPS-stimulated IL-10 release was observed with vancomycin. A suppression of LPS-stimulated TNF-, and IL-10 release was observed in the presence of ciprofloxacin. Conclusion:, These results indicate a modulation of the expression density of CD14 on monocytes, together with a shift from a balanced to an inflammatory cytokine release pattern, by cefuroxime and cefotaxime. Vancomycin changes the response to an anti-inflammatory release pattern. After ciprofloxacin, a profound unresponsiveness of immune-competent cells to LPS stimulation is observed. Because of the critical role of a balanced innate immune response, these data may be of importance for the selection of antibiotics in septic patients. [source] Kinetics and residues after intraperitoneal procaine penicillin G administration in lactating dairy cowsJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2009A. L. CHICOINE This paper describes the pharmacokinetic profile of procaine penicillin G after intraperitoneal (IP) administration in eight lactating dairy cows. Procaine pencillin G (PPG, 21 000 IU/kg) was deposited into the abdominal cavity of each cow following an incision in the right paralumbar fossa. Blood and milk samples were taken over the following 10 days, at which point the cows were euthanized. Plasma, milk, muscle, liver, and kidney penicillin concentrations were determined by HPLC, with a limit of quantification of 5 ng/mL for plasma and milk and 40 ng/g for tissue samples. A noncompartmental method was used to analyze plasma kinetics. The mean pharmacokinetic parameters (±SD) were: Cmax, 5.5 ± 2.6 ,g/mL; Tmax, 0.75 ± 0.27 h; AUC0-,, 10.8 ± 4.9 ,g·h/mL; MRT, 2.2 ± 0.9 h. All milk from treated cows contained detectable penicillin residues for a minimum of three milkings (31 h) and maximum of five milkings (52 h) after administration. Concentrations of penicillin in all muscle, liver, and kidney samples taken 10 days postadministration were below the limit of quantification. Necropsy examinations revealed foci of hemorrhage on the rumenal omentum of most cows but peritonitis was not observed. Systemic inflammation as determined by change in leukogram or plasma fibrinogen was noted in one cow. The results of this study demonstrate that IP PPG is absorbed and eliminated rapidly in lactating dairy cows. [source] Meta-analysis: antibiotic prophylaxis to prevent peristomal infection following percutaneous endoscopic gastrostomyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2007N. S. JAFRI Summary Background Despite numerous guidelines recommending prophylactic antibiotics prior to percutaneous endoscopic gastrostomy, their use remains controversial. Aim To conduct a systematic literature review and performed meta-analyses to determine the benefit of antibiotic prophylaxis for percutaneous endoscopic gastrostomy placement. Methods We performed a systematic literature review by searching healthcare databases and grey literature for randomized-controlled trials of antibiotic prophylaxis against wound infection after percutaneous endoscopic gastrostomy. Relative risks were calculated for individual trials and data pooled using fixed-effects model. Relative risk reduction, absolute risk reduction and number needed to treat were calculated and are reported with 95% confidence intervals. Results Ten randomized-controlled trials met the inclusion criteria and 1059 cases were pooled. Overall findings indicated that antibiotic prophylaxis resulted in a relative risk reduction of 64% and an absolute risk reduction of 15%. Number needed to treat to prevent one wound infection was 8. Cephalosporin prophylaxis was associated with a relative risk reduction of 64%, absolute risk reduction of 10% and number needed to treat of 10, whereas penicillin-based prophylaxis was associated with a relative risk reduction of 62%, absolute risk reduction of 13% and number needed to treat of 8. Conclusions Antibiotic prophylaxis prior to percutaneous endoscopic gastrostomy is effective in reducing the incidence of percutaneous endoscopic gastrostomy site wound infection. Based on sensitivity analyses, penicillin-based prophylaxis should be the prophylaxis of choice. [source] | |||||||||||||||||||||||||||||||||||||||||||