Recent Advances in the Use of Drosophila melanogaster as a Model to Study Immunopathogenesis of Medically Important Filamentous Fungi

Airborne opportunistic fungi, including Aspergillus and other less common saprophytic molds, have recently emerged as important causes of mortality in immunocompromised individuals. Understanding the molecular mechanisms of host-fungal interplay in robust experimental pathosystems is becoming a research priority for development of novel therapeutics to combat these devastating infections. Over the past decade, invertebrate hosts with evolutionarily conserved innate immune signaling pathways and powerful genetics, such as Drosophila melanogaster, have been employed as a means to overcome logistic restrains associated with the use mammalian models of fungal infections. Recent studies in Drosophila models of filamentous fungi demonstrated that several genes implicated in fungal virulence in mammals also play a similarly important pathogenic role in fruit flies, and important host-related aspects in fungal pathogenesis are evolutionarily conserved. In view of recent advances in Drosophila genetics, fruit flies will become an invaluable surrogate model to study immunopathogenesis of fungal diseases

Fulminant listerial infection of the central nervous system in an otherwise healthy patient: a case report

<p>Abstract</p> <p>Introduction</p> <p>The mortality of listerial rhombo-encephalitis exceeds 26% and may involve otherwise healthy patients. A case is presented of a man with fatal listerial infection of the central nervous system that was monitored in an intensive care unit.</p> <p>Case presentation</p> <p>A 42-year-old, previously healthy man was admitted with fever of 39°C, blurred vision, confusion and headache. He had right-sided central facial paresis, bilateral absent gag reflex and bilateral cerebellar ataxia. After a few hours, he became septic and developed bilateral vocal cord paralysis and airway obstruction. He was intubated and put on mechanical ventilation. Computed tomography brain scans revealed multiple frontal hypodense areas and slight hydrocephalus. Cerebrospinal fluid findings included pleocytosis of 4200 cells/μL (77% neutrophils), protein of 114 mg/dL and normal glucose levels. Listerial infection was suspected; therefore ampicillin was added to his initial therapeutic regimen, already including ceftriaxone and gentamicin. All cultures were negative, and no immunologic abnormality could be documented, but the patient's clinical condition deteriorated rapidly. Continuous neuromonitoring by means of transcranial Doppler and optic nerve sonography along with follow-up computed tomography brain scans confirmed the severity of the brain damage; hence, dexamethasone and mannitol were also administered. The patient was clinically documented as 'brain dead' 7 days after his admission to the intensive care unit; thereafter, blood- and post-mortem brain tissue cultures grew <it>Listeria monocytogenes</it>.</p> <p>Conclusion</p> <p>This case report illustrates the importance of neuromonitoring in patients with severe brain damage. We also show that, despite prompt antibiotic treatment and dexamethasone administration, listerial infection of the central nervous system can be lethal.</p

Impact of prolonged treatment with high-dose ciprofloxacin on human gut flora: a case report

<p>Abstract</p> <p>Introduction</p> <p>Ciprofloxacin is a commonly marketed fluoroquinolone. It is not effective against obligate anaerobes, hence it is considered unlikely to have an impact on colonic microflora. We report the case of a patient who received prolonged treatment with high-dose ciprofloxacin for extensive pelvic osteomyelitis. We also report on the medication's effects on his bowel flora. To the best of our knowledge, this is the first report discussing the effects of prolonged administration of a quinolone on microbial flora.</p> <p>Case presentation</p> <p>A 62-year-old Caucasian man with diabetes presented with low back pain of four months' duration. A magnetic resonance imaging of his pelvis revealed sacroiliitis and extensive pelvic osteomyelitis. <it>Pseudomonas aeruginosa</it>, which is susceptible to ciprofloxacin, was noted as the offending pathogen. After seven weeks of intravenous treatment, he was prescribed with high-dose oral ciprofloxacin that he continued to take for the next 20 months. Quantitative stool cultures of our patient were obtained a month later as well as at the end of his treatment to record his corresponding sensitivities to the medication. The Gram-negative population of his bowel flora was restored fully upon the discontinuation of this medication. The Gram-negative population was shown to be fully sensitive to ciprofloxacin. His yeast levels were also found to be slightly increased, and no growth of resistant enterococci was noted.</p> <p>Conclusion</p> <p>The findings of this case report suggest that long term and high dose ciprofloxacin administration might be safe in preventing the risk of colonization with resistant Gram negative pathogens, overgrowth of anaerobes and the development of resistant enterococci.</p

Impact of Definitive Therapy with Beta-Lactam Monotherapy or Combination with an Aminoglycoside or a Quinolone for Pseudomonas aeruginosa Bacteremia

BACKGROUND: Bacteremia by Pseudomonas aeruginosa represents one severe infection. It is not clear whether beta-lactam monotherapy leads to similar rates of treatment success compared to combinations of beta-lactams with aminoglycosides or quinolones. METHODS: Retrospective cohort study from 3 tertiary hospitals (2 in Greece and 1 in Italy). Pseudomonas aeruginosa isolates were susceptible to a beta-lactam and an aminoglycoside or a quinolone. Patients received appropriate therapy for at least 48 hours. Primary outcome of interest was treatment success in patients with definitive beta-lactam combination therapy compared to monotherapy. Secondary outcomes were treatment success keeping the same empirical and definitive regimen, mortality, and toxicity. RESULTS: Out of 92 bacteremias there were 54 evaluable episodes for the primary outcome (20 received monotherapy). Treatment success was higher with combination therapy (85%) compared to beta-lactam monotherapy (65%), however not statistically significantly [Odds ratio (OR) 3.1; 95% Confidence Interval (CI) 0.69-14.7, p = 0.1]. Very long (>2 months) hospitalisation before bacteremia was the only factor independently associated with treatment success (OR 0.73; 95% CI 0.01-0.95, p = 0.046), however this result entailed few episodes. All-cause mortality did not differ significantly between combination therapy [6/31 (19%)] and monotherapy [8/19 (42%)], p = 0.11. Only Charlson comorbidity index was associated with excess mortality (p = 0.03). CONCLUSION: Our study, in accordance with previous ones, indicates that the choice between monotherapy and combination therapy may not affect treatment success significantly. However, our study does not have statistical power to identify small or moderate differences. A large randomized controlled trial evaluating this issue is justified

Venetian Rule and Control of Plague Epidemics on the Ionian Islands during 17th and 18th Centuries

One-sentence summary for tables of contents: Measures taken by the Venetian administration to combat plague were successful

Real-time ultrasound-guided catheterisation of the internal jugular vein: a prospective comparison with the landmark technique in critical care patients

INTRODUCTION: Central venous cannulation is crucial in the management of the critical care patient. This study was designed to evaluate whether real-time ultrasound-guided cannulation of the internal jugular vein is superior to the standard landmark method. METHODS: In this randomised study, 450 critical care patients who underwent real-time ultrasound-guided cannulation of the internal jugular vein were prospectively compared with 450 critical care patients in whom the landmark technique was used. Randomisation was performed by means of a computer-generated random-numbers table, and patients were stratified with regard to age, gender, and body mass index. RESULTS: There were no significant differences in gender, age, body mass index, or side of cannulation (left or right) or in the presence of risk factors for difficult venous cannulation such as prior catheterisation, limited sites for access attempts, previous difficulties during catheterisation, previous mechanical complication, known vascular abnormality, untreated coagulopathy, skeletal deformity, and cannulation during cardiac arrest between the two groups of patients. Furthermore, the physicians who performed the procedures had comparable experience in the placement of central venous catheters (p = non-significant). Cannulation of the internal jugular vein was achieved in all patients by using ultrasound and in 425 of the patients (94.4%) by using the landmark technique (p < 0.001). Average access time (skin to vein) and number of attempts were significantly reduced in the ultrasound group of patients compared with the landmark group (p < 0.001). In the landmark group, puncture of the carotid artery occurred in 10.6% of patients, haematoma in 8.4%, haemothorax in 1.7%, pneumothorax in 2.4%, and central venous catheter-associated blood stream infection in 16%, which were all significantly increased compared with the ultrasound group (p < 0.001). CONCLUSION: The present data suggest that ultrasound-guided catheterisation of the internal jugular vein in critical care patients is superior to the landmark technique and therefore should be the method of choice in these patients

Skin and Soft Tissue Infections in Patients with Solid Tumours

Background. Skin and soft tissue infections (SSTIs) in cancer patients represent a diagnostic challenge, as etiologic diagnosis is often missing, and clinical assessment of severity is difficult. Few studies have described (SSTIs) in patients with solid tumours (STs). Patients and Methods. Records of patients with ST and SSTI, cared for at the University Hospital of Heraklion, from 2002 to 2006 were retrospectively studied. Results. A total of 81 episodes of SSTIs, occurring in 71 patients with ST, have been evaluated. Their median age was 65 years (34–82). The most common underlying malignancy was breast cancer in 17 patients (24%). Most episodes (89%) occurred in nonneutropenics. Cellulitis/erysipelas was the most common clinical presentation (56; 69%). Bacterial cultures were possible in 29 (36%) patients. All patients received antimicrobial therapy, while in 17 episodes (21%) an incision and drainage was required. Treatment failure occurred in 20 episodes (25%). Five patients (7%) died due to sepsis. None was neutropenic. Severe sepsis on admission (=0.002) and prior blood transfusion (=0.043) were independent predictors of treatment failure. Conclusion. SSTIs can be life threatening among patients with ST. Early diagnosis and appropriate treatment are of the utmost importance, since sepsis was proven a significant factor of unfavourable outcome

Calcium sequestration by fungal melanin inhibits calcium-calmodulin signalling to prevent LC3-associated phagocytosis

LC3-associated phagocytosis (LAP) is a non-canonical autophagy pathway regulated by Rubicon, with an emerging role in immune homeostasis and antifungal host defence. Aspergillus cell wall melanin protects conidia (spores) from killing by phagocytes and promotes pathogenicity through blocking nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent activation of LAP. However, the signalling regulating LAP upstream of Rubicon and the mechanism of melanin-induced inhibition of this pathway remain incompletely understood. Herein, we identify a Ca2+ signalling pathway that depends on intracellular Ca2+ sources from endoplasmic reticulum, endoplasmic reticulum-phagosome communication, Ca2+ release from phagosome lumen and calmodulin (CaM) recruitment, as a master regulator of Rubicon, the phagocyte NADPH oxidase NOX2 and other molecular components of LAP. Furthermore, we provide genetic evidence for the physiological importance of Ca2+-CaM signalling in aspergillosis. Finally, we demonstrate that Ca2+ sequestration by Aspergillus melanin inside the phagosome abrogates activation of Ca2+-CaM signalling to inhibit LAP. These findings reveal the important role of Ca2+-CaM signalling in antifungal immunity and identify an immunological function of Ca2+ binding by melanin pigments with broad physiological implications beyond fungal disease pathogenesis.Onassis Foundation under the ‘Special Grant and Support Program for Scholars’ Association Members’ (Grant no. R ZM 003-1/2016-2017); G.C. was supported by grants from the Greek State Scholarship Foundation (I.K.Y.), the Hellenic General Secretariat for Research and Technology-Excellence program (ARISTEIA) and a Research Grant from Institut Mérieux; J.P.L. was supported by European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement 260338 ALLFUN and ANR-10-BLAN-1309 HYDROPHOBIN, and the Association Vaincre La Mucoviscidose (RF20140501052/1/1/141); H.F. and N.M.N. were supported by the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e Tecnologia (FCT) project SPARTAN (PTDC/CTM-BIO/4388/2014), funded through the PIDDAC Program. A.C. and C.C. were supported by NORTE 2020, under the Portugal 2020 Partnership Agreement, through the ERDF (NORTE-01-0145-FEDER-000013), and by FCT (IF/00735/2014 and SFRH/BPD/96176/2013). G.S.D. and J.L.F. were supported by NIH grant AI-106269. K.J.K-C is supported by the Division of Intramural Research (DIR), NIAID, NIHinfo:eu-repo/semantics/publishedVersio