Background: The present study was aimed to searching for CTX-M-type extended-spectrum beta-lactamases in community- and hospital-acquired Escherichia coli (E. coli) collected in western Austria and ...to investigate their clonal relatedness and their ability to spread. Patients and Methods: All patients with E. coli positive cultures collected from a catchment population of 186,000 between January and July 2006 were enrolled into the study. CTX-M-producing E. coli were identified by antibiotic susceptibility testing and blaCTX-M multiplex PCR. Clonal relatedness was analyzed by pulsed-field gel electrophoresis (PFGE). Results: In 2,042 E. coli isolates, 20 isolates (16 from urine, 4 from blood cultures) demonstrated CTX-M-1-related genes and no CTX-M-2- or CTX-M-9-related enzymes or CTX-M-15-producing strains were identified. We did not find clonal relatedness among CTX-M-1 producers isolated from the same referring center. E. coli were investigated for plasmid transfer ability of CTX-M-1-encoding genes. Plasmid digest patterns were not consistent with episomal spread of resistance loci. Transfection of CTX-M-encoding plasmids failed. Conclusion: Our data suggest that the emergence of CTX-M-1-producing E. coli in western Austria may be attributed to multiple independent events.
Group Milleri streptococci (GMS), a heterogeneous group of streptococci, are associated with purulent infections. This study was a retrospective analysis of all consecutive thoracic infections of GMS ...between 2001 and 2004. Of 246 surgical GMS infections, thoracic infections accounted for 4.5 per cent, including 10 pleural infections (eight empyemas and two infected pleural effusions) and one mediastinal infection. The etiology of pleural infection was parapneumonic (7), second to esophageal perforation (1), liver transplantation (1), and liver resection (1). Polymicrobial infections were present in 64 per cent. All patients underwent removal of the infected masses, including drainage (3), thoracoscopic decortication (5), thoracotomy with debridement (2), and incision with drainage (1). The case fatality rate was 9 per cent (there was one patient with congestive heart disease unfit to undergo surgical empyema evacuation) and the recurrence rate was 27.3 per cent (three patients). Combined antibiotic/surgical treatment was successful in all other cases. GMS isolates were susceptible to clindamycin and all beta-lactam antibiotics except ceftazidime, but were resistant to aminoglycosides. If found intrathoracically, GMS frequently progress to severe empyema. Therefore, timely removal of pleural collection by percutaneous drainage or surgical intervention seems indicated. If surgery is required, thoracoscopic decortication may be the preferred approach.
Group Milleri Streptococci (GMS), a subgroup of viridans streptococci, are commensals of the human respiratory, gastrointestinal and urogenital tracts. GMS tend to cause purulent infections often ...resulting in abscess formation. Little is known about the significance of these organisms in children.
For this retrospective study, a collection of 636 GMS positive isolates from 475 patients was used to identify 39 (8.2 %) paediatric patients (age < 18 years) with GMS infections (46 isolates) during a four-year period.
There were 19 intra-abdominal, eleven dental/oropharyngeal, seven soft tissue and two central nervous system infections. Thirty-five patients (95 %) underwent primary surgical interventions. Furthermore, two patients - one with GMS meningitis that progressed to cerebral empyema and another with a liver abscess - initially treated with antibiotic agents alone eventually required surgical intervention to cure the infection. Only two children were treated with antibiotics alone. Polymicrobial infection was found in 22 (48 %) isolates; polymicrobial infection was most common in patients with intra-abdominal infection with 74 % and lowest in dental/oropharyngeal patients with 9 % (p = 0.001); Escherichia coli (n = 9) and Bacteroides fragilis (n = 9) were the most common secondary pathogens. Complications due to GMS infections were found in five cases (13 %). No patient died from GMS infection. Preferred antibiotics were penicillins (56 %) and cephalosporins (37 %). GMS tested susceptible to penicillin, cephalosporins, carbapenems in 100 % and clindamycin in 93 %.
GMS infections in paediatric patients usually require both antibiotic therapy and surgical drainage. These infections may become life-threatening if not diagnosed in a timely fashion and treated aggressively.
Objectives In contrast to most antimicrobial classes, there is a doubt about the impact of protein binding (PB) on the antimicrobial activity of fluoroquinolones. We set out to evaluate the ...suitability of previously used models for investigating the influence of PB on bacterial killing by fluoroquinolones. Methods PB of moxifloxacin and trovafloxacin was determined in Mueller–Hinton broth (MHB) containing different concentrations of human serum or albumin. Bacterial growth curves of Staphylococcus aureus and Pseudomonas aeruginosa were determined in pure serum, pure MHB and MHB containing different amounts of serum or albumin. Killing of both strains at concentrations equal to the MIC was investigated for moxifloxacin and trovafloxacin in MHB and also in medium that showed PB values identical to those of pure serum. Results Frequently used media for investigating the impact of PB, i.e. MHB containing 20% to 70% serum or 4% albumin, did not reach the level of PB achieved in pure serum or significantly hampered bacterial growth compared with pure MHB. PB in MHB containing 12% albumin was identical to that in pure serum but did not impair bacterial growth. Addition of 12% albumin significantly reduced bacterial killing by both fluoroquinolones compared with that found in pure MHB. Conclusions For fluoroquinolones, standard media might be insufficient to investigate the impact of PB on bacterial killing. MHB containing 12% albumin seems to be a promising medium in this context. For moxifloxacin and trovafloxacin, PB leads to significant reduction of antimicrobial activity.
The most frequent indication for placement of a central venous access device in hemophiliacs is in very young boys (ages 1-2 years) with severe hemophilia who are started on a program of long-term ...factor prophylaxis designed to eliminate target joint bleeding and the development of chronic musculoskeletal disease. Although expensive, this strategy is extremely successful. It involves intravenous infusion of 25-40 factor units per kg on alternate days (minimum 3 times a week) for boys with severe hemophilia A, and twice a week for boys with severe hemophilia B. To facilitate this prophylaxis regimen some hemophilia clinics routinely recommend placement of a central venous access device; others, more concerned about associated complications such as sepsis, stress the importance of using peripheral veins wherever possible, with central access devices reserved for occasional, selected cases only. A decision to use such a device should only be made after discussion of the risks/benefits with parents (or guardians) and with patients if of an appropriate age. If such a system is to be used, we recommend that a totally implantable device (Port-A-Cath) be placed because of the lower risk of infection, and because totally implantable devices allow children to take part in activities such as swimming. Important complications include catheter-related sepsis, which may occur in 25% or more of devices over time and, much less frequently, catheter-related deep vein thrombosis.
Objectives Fosfomycin penetrates well into cerebrospinal fluid (CSF) and is considered for treatment of infections of the central nervous system (CNS). This study evaluated the influence of human CSF ...on the antimicrobial activity of fosfomycin. Methods Time–kill curves were performed in Mueller–Hinton broth (MHB) and in pooled human CSF using fosfomycin concentrations ranging from 0.25× to 8× MIC for a clinical Staphylococcus aureus isolate. To estimate the activity of fosfomycin at the target site, the concentration–time curve measured in CSF of a patient at steady state was simulated in vitro in human CSF using two S. aureus isolates. Results In CSF a higher fosfomycin concentration (8× MIC) was required to achieve sustained bacterial killing than in MHB (1× MIC). In vitro simulation of the pharmacokinetic profile measured in CSF of the selected patient showed initial killing, but terminal re-growth of both test strains. Conclusions The antibacterial activity of fosfomycin is lower in CSF than in MHB, and drug concentrations slightly exceeding the MIC may not be sufficient to achieve bactericidal effects in the CNS.
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