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A rigorous time Floquet method for the calculation of scattering of electromagnetic waves by a homogeneous spherical object, characterized by a periodically varying-in-time isotropic permittivity, is presented. The method is applied to the study ofMie scattering by such a modulated dielectric particle.Our results are in excellent agreement with the quasistatic adiabatic approximation in the slow-modulation limit. At higher modulation frequencies, a remarkable spectral response, including resonant inelastic scattering and frequency conversion as well as energy transfer between the dynamic sphere and the electromagnetic field, is revealed and consistently explained. © 2021 Optical Society of America.

Carbapenemase-producing Klebsiella pneumoniae strains (CP-Kps) are currently among the most important nosocomial pathogens. An observational study was conducted during 2009 to 2010 in two hospitals located in a high-prevalence area (Athens, Greece). The aims were (i) to evaluate the clinical outcome of patients with CP-Kp bloodstream infections (BSIs), (ii) to identify predictors of mortality, and (iii) to evaluate the various antibiotic schemes employed. A total of 205 patients with CP-Kp BSIs were identified: 163 (79.5%) were infected with KPC or KPC and VIM, and 42 were infected with VIM producers. For definitive treatment, 103 patients received combination therapy (two or more active drugs), 72 received monotherapy (one active drug), and 12 received therapy with no active drug. The remaining 18 patients died within 48 h after the onset of bacteremia. The all-cause 28-day mortality was 40%. A significantly higher mortality rate was observed in patients treated with monotherapy than in those treated with combination therapy (44.4% versus 27.2%; P = 0.018). The lowest mortality rate (19.3%) was observed in patients treated with carbapenem-containing combinations. In the Cox proportion hazards model, ultimately fatal disease (hazards ratio [HR], 3.25; 95% confidence interval [CI], 1.51 to 7.03; P = 0.003), the presence of rapidly fatal underlying diseases (HR, 4.20; 95% CI, 2.19 to 8.08; P < 0.001), and septic shock (HR, 2.15; 95% CI, 1.16 to 3.96; P = 0.015) were independent predictors of death. Combination therapy was strongly associated with survival (HR of death for monotherapy versus combination, 2.08; 95% CI, 1.23 to 3.51; P = 0.006), mostly due to the effectiveness of the carbapenem-containing regimens. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The in vitro activity of plazomicin was evaluated against 300 multidrug resistant (MDR) (carbapenemase and/or ESBL-producing) isolates from four hospitals in Athens, an area where carbapenemase-producing organisms are endemic. Most of the isolates were also resistant to the legacy aminoglycosides with the MIC50/MIC90 to tobramycin, amikacin and gentamicin being 32/>32, 32/>32 and 4/>8 μg/ml, respectively. ACHN-490 retained activity (MICs≤4 mu;g/ml) against all isolates of Klebsiella pneumoniae, Escherichia coli, and Enterobacter spp. tested with MIC50 and MIC90 of 1 and 2 μg/ml, respectively, irrespective of their MDR phenotype and it represents a promising alternative for the treatment of the most problematic Gram-negative pathogens. © 2012 Edizioni Scientifiche per l'Informazione su Farmaci e Terapia.

We present 2 cases of HIV-related cryptococcal meningitis, persisting after 3 and 9 months, respectively, of standard treatment. Both patients were treated successfully with a salvage regimen consisting of the combination of liposomal amphotericin B (3 mg/kg), intravenous voriconazole, and subcutaneous recombinant interferon γ-1b (200 μg thrice weekly). Voriconazole was administered at an increased dose (5 mg/kg, twice daily) to overcome interactions with co-administered ritonavir. In both patients, resolution of clinical signs and symptoms, as well as sterilization of cerebrospinal fluid cultures occurred after 10 weeks of salvage therapy. No major side effects were encountered. At the end of treatment, both patients were placed on maintenance therapy with oral fluconazole; no recurrence has been observed after 4 years of follow-up. © 2012 Elsevier Inc.

In order to investigate differences among infections due to Gram-negative anaerobic bacteria (Bacteroides, Prevotella and Fusobacterium spp.), clinical, epidemiological, and microbiological data were collected and evaluated from 206 anaerobic infections. The most frequently isolated species was Bacteroides fragilis. The majority of the cases were intra-abdominal infections (49%) followed by skin and soft tissue infections (24.7%). Logistic regression analysis showed that Bacteroides spp. strains were more often isolated from intra-abdominal infections (p = 0.002), whereas Prevotella spp. were isolated more frequently from cases with shorter duration of hospitalization (p = 0.026), and less frequently from bloodstream infections (p = 0.049). In addition, Bacteroides spp. were associated with coinfection due to Enterobacteriaceae species (p = 0.007), whereas Prevotella spp. were associated with coinfection due to Staphylococcus spp. (p = 0.002). Patients with an infection due to B. fragilis, were more frequently admitted in a general surgical ward (p = 0.017), or have been treated with a 2nd generation cephalosporin before anaerobic infection onset (p = 0.05). Total mortality was 10.9% and was associated with bacteremia (p = 0.026), and hematological (p = 0.028), or solid organ malignancy (p = 0.007). Metronidazole resistance was detected only among Prevotella spp. (16.2%) and B. fragilis group (0.8%) isolates. In conclusion, this study indicated differences between infections due to the most frequently isolated Gram-negative anaerobic species, differences that may affect the design and implementation of empirical antimicrobial chemotherapy guidelines. © 2011 Elsevier Ltd.

Objectives: To determine the current frequency and study the characteristics of VIM-1-producing Klebsiella pneumoniae isolates from bloodstream infections in Greek hospitals. Methods: All blood isolates of K. pneumoniae were prospectively collected during 2004-06 in three teaching hospitals located in Athens. MICs of antibiotics were determined by the Etest. Extended-spectrum- (ESBL) and metallo-β-lactamase (MBL) production was examined by clavulanate- and EDTA-based techniques, respectively. Isolates were typed by PFGE of Xba I-digested genomic DNA. Detection of blaVIM-1 and mapping of the VIM-1-encoding integrons were performed by PCR and sequencing. β-Lactamase activities were analysed by IEF and imipenem hydrolysis was assessed by spectrophotometry. VIM-1-encoding plasmids were transferred to Escherichia coli by conjugation and transformation and characterized by Inc/rep typing and RFLP. Results: Sixty-seven (37.6%) of 178 K. pneumoniae blood isolates were blaVIM-1-positive (VPKP); 77.8% of these were from ICUs. All VPKP isolates were multidrug-resistant. The MICs of carbapenems for VPKP varied from the susceptible range to high-level resistance overlapping with those of MBL-negative isolates. The EDTA-imipenem synergy methods had reduced sensitivity in detecting VPKP isolates when the MICs were in the susceptible range. ESBL production was common among VPKP isolates (n = 45, 67.2%) as indicated by resistance to aztreonam and confirmed by a clavulanate-based double-disc synergy test. The responsible ESBL was always an SHV-5-type enzyme as indicated by IEF. PFGE identified eight clusters (A-H) of VPKP isolates with related (>80%) patterns, as well as four unique types. Both inter-hospital spread of several clones and genotypic similarities among susceptible, ESBL-positive and VPKP isolates were also observed. Location of blaVIM-1 and expression of VIM-1 were studied in 12 isolates representing the eight PFGE clusters. In all isolates, blaVIM-1 was part of a class 1 integron that also carried aacA4, dhfrI, aadA and sulI. In eight isolates (clusters C, D, G and H), the blaVIM-1 integron was located in transferable IncN plasmids. A cluster F isolate carried a VIM-1-encoding, self-transferable plasmid that was not typeable by Inc/rep typing. VIM-1-encodingreplicons were not identified in three isolates (PFGE clusters A, B and E). VPKP isolates exhibited differences in imipenem-hydrolysing activities which, however, were not correlated with the respective carbapenem MICs. Conclusions: A multiclonal epidemic of blaVIM-1-carrying K. pneumoniae is under way in the majorhospitals in Greece. Microorganisms producing both VIM-1 and SHV-5 constitute the prevalent multidrug-resistant population of K. pneumoniae in this setting. © The Author 2007. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

A prospective observational study was conducted to identify factors associated with bloodstream infections (BSIs) caused by integron-carrying Enterobacteriaceae and to evaluate the clinical significance of integron carriage. Consecutive patients with Enterobacteriaceae BSIs were identified and followed up until discharge or death. Identification of blood isolates and susceptibility testing were performed by the Wider I automated system. int-1-specific PCR, conserved-segment PCR, and DNA sequencing were used to determine the presence, length, and content of integrons. The relatedness among the isolates was examined by pulsed-field gel electrophoresis. Two hundred fifty episodes of Enterobacteriaceae BSI occurred in 233 patients; 109 (43.6%) were nosocomial, 82 (32.8%) were community acquired, and 59 (23.6%) were health care associated. Integrons were detected in 11 (13.4%) community-acquired, 24 (40.7%) health care-associated, and 46 (42.2%) nosocomial isolates. Integron-carrying organisms were more likely to exhibit resistance to three or more classes of antimicrobials (odds ratio [OR], 9.84; 95% confidence interval [95% CI], 5.31 to 18.23; P < 0.001) or to produce extended-spectrum β-lactamases (OR, 5.75; 95% CI, 2.38 to 13.89; P < 0.001) or a VIM-type metallo-β- lactamase (P, 0.003). Inter- or intraspecies integron transfer and cross-transmission of integron-carrying clones were observed. Use of cotrimoxazole (OR, 4.77; 95% CI, 1.81 to 12.54; P < 0.001) and a nosocomial or other health care setting (OR, 3.07; 95% CI, 1.30 to 7.22; P, 0.01) were independently associated with BSIs caused by integron-carrying Enterobacteriaceae. Patients with a nonurinary source of bacteremia (OR, 9.46; 95% CI, 2.77 to 32.32; P < 0.001) and a Pitt bacteremia score of ≥4 (OR, 23.36; 95% CI, 7.97 to 68.44; P < 0.001) had a significantly higher 14-day mortality rate, whereas integron carriage did not affect clinical outcomes. These findings may have implications affecting antibiotic policies and infection control measures. Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Campylobacter species are well-recognized common causes of gastrointestinal infections. White Campylobacter jejuni is probably the most common Campylobacter isolated in humans, Campylobacter fetus is rather infrequent and mostly related with bacteraemia. Even on such occasions, it seems that immunocompetent individuals are spared. We report a case of C. fetus bacteraemia in a healthy-except for impaired fasting glucose (IFG) levels-farmer, presenting as an acute febrile syndrome and treated successfully as brucellosis. (C) 2005 The British Infection Society. Published by Elsevier Ltd. All rights reserved.

Intracoronary stenting has been shown to reduce acute closure and restenosis rate in patients treated with coronary angioplasty. The use of high inflation pressures and intravascular ultrasound guidance allowed the substitution of anticoagulants with antiplatelet agents but increased the cost. The aim of this study was to investigate the effectiveness, safety, and long-term outcome of the elective implantation of a relatively new type of stent (Micro-Stent II™), without the use of quantitative coronary angiog raphy or intravascular ultrasound guidance and without subsequent anticoagulation. The study included 361 patients who underwent elective microstent implantation. Stent expansion was performed at 8 atm followed by higher inflation pressure at 14-20 atm. Heparin was given intraarterially only once immediately after the arterial sheath insertion. Ticlopidine was started at least 48 hours before the procedure and continued for 1 month while aspirin was continued indefinitely. All patients were followed up for 12.9 ±3.6 months. Short term outcome (first month): Stent implantation was successfully achieved in 361 of 366 patients (98.6%). Seven patients (1.9%) were excluded from the study and received anticoagulants because of a suboptimal result. In total, 423 stents were implanted. There was no subacute thrombosis, but acute vessel closure occurred in one patient (0.3%). Non-Q wave myocardial infarction occurred in six patients (1.7%), Q wave myocardial infarction occurred in one patient (0.3%), and only one death (0.3%) of nonischemic origin was reported. No major peripheral vascular complications were observed. Late results: Q or non-Q wave infarction occurred in 13 patients (3.6%), 26 patients (7.2%) underwent a repeat angioplasty, eight patients (2.2%) underwent coronary artery bypass grafting, and four patients (1.1%) died. Overall, 284 patients (78.7%) were free of symptoms, while 77 (21.3%) had recurrent coronary ischemia. In conclusion, Micro-Stent II™ implantation without quantitative coronary angiog raphy or intravascular ultrasound guidance and without anticoagulation was found to be effective, safe, and with good long-term outcome.

We report the first case of Cryptococcus laurentii meningitis and a rare case of Cryptococcus albidus crytopcoccaemia in AIDS patients. Both infections were treated with amphotericin B and flucytosine. The C. laurentii meningitis was controlled after 2 weeks of treatment with no evidence of infection 20 months later. The patient with C. albidus cryptococcaemia, despite the amphotericin B/flucytosine combination therapy, died on the 14th day of treatment. The minimum inhibitory concentrations (MICs) for C. laurentii, as determined by Etest on RPMI 1640 agar, were 0.25 mu g ml(-1) of amphotericin B, 1.25 mu g ml(-1) flucytosine, 4 mu g ml(-1) fluconazole, 0.50 mu g ml(-1) itraconazole and 1.0 mu g ml(-1) of ketoconazole 0.25 mu g ml(-1). The MIC of amphotericin B for C. albidus was 0.5 mu g ml(-1), flucytosine 0.25 mu g ml(-1), fluzonazole 4 mu g ml(-1), itraconazole 0.5 mu g ml(-1) and ketonazole 0.25 mu g ml(-1). The agreement of the amphotericin B MIC values obtained in antibiotic medium 3 by the broth microdilution method, with those obtained on casitone medium by Etest, was within a two-dilution range for both isolates. C. laurentii may cause meningitis and may also involve the lungs in AIDS patients.

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