The world’s ten most feared fungi

An account is provided of the world’s ten most feared fungi. Within areas of interest, we have organized the entries in the order of concern. We put four human pathogens first as this is of concern to most people. This is followed by fungi producing mycotoxins that are highly harmful for humans; Aspergillus flavus, the main producer of aflatoxins, was used as an example. Problems due to indoor air fungi may also directly affect our health and we use Stachybotrys chartarum as an example. Not everyone collects and eats edible mushrooms. However, fatalities caused by mushroom intoxications often make news headlines and therefore we include one of the most poisonous of all mushrooms, Amanita phalloides, as an example. We then move on to the fungi that damage our dwellings causing serious anxiety by rotting our timber structures and flooring. Serpula lacrymans, which causes dry rot is an excellent example. The next example serves to represent all plant and forest pathogens. Here we chose Austropuccinia psidii as it is causing devastating effects in Australia and will probably do likewise in New Zealand. Finally, we chose an important amphibian pathogen which is causing serious declines in the numbers of frogs and other amphibians worldwide. Although we target the top ten most feared fungi, numerous others are causing serious concern to human health, plant production, forestry, other animals and our factories and dwellings. By highlighting ten feared fungi as an example, we aim to promote public awareness of the cost and importance of fungi.     

Extracellular DNA Acidifies Biofilms and Induces Aminoglycoside Resistance in Pseudomonas aeruginosa

Biofilms consist of surface-adhered bacterial communities encased in an extracellular matrix composed of DNA, exopolysaccharides, and proteins. Extracellular DNA (eDNA) has a structural role in the formation of biofilms, can bind and shield biofilms from aminoglycosides, and induces antimicrobial peptide resistance mechanisms. Here, we provide evidence that eDNA is responsible for the acidification of Pseudomonas aeruginosa planktonic cultures and biofilms. Further, we show that acidic pH and acidification via eDNA constitute a signal that is perceived by P. aeruginosa to induce the expression of genes regulated by the PhoPQ and PmrAB two-component regulatory systems. Planktonic P. aeruginosa cultured in exogenous 0.2% DNA or under acidic conditions demonstrates a 2- to 8-fold increase in aminoglycoside resistance. This resistance phenotype requires the aminoarabinose modification of lipid A and the production of spermidine on the bacterial outer membrane, which likely reduce the entry of aminoglycosides. Interestingly, the additions of the basic amino acid l-arginine and sodium bicarbonate neutralize the pH and restore P. aeruginosa susceptibility to aminoglycosides, even in the presence of eDNA. These data illustrate that the accumulation of eDNA in biofilms and infection sites can acidify the local environment and that acidic pH promotes the P. aeruginosa antibiotic resistance phenotype.     

Antimicrobial resistance in Campylobacter strains isolated from French broilers before and after antimicrobial growth promoter bans

OBJECTIVES: The antimicrobial susceptibility of Campylobacter strains isolated from standard and free-range broilers in 1992-1996 and 2001-2002 was studied. METHODS: Strains were isolated from caeca or skin samples collected from standard or free-range broilers arriving in slaughterhouses. The MICs of ampicillin, nalidixic acid, enrofloxacin, tetracycline, erythromycin and gentamicin were determined by agar dilution and compared according to species (Campylobacter jejuni or Campylobacter coli), production system and sampling period. RESULTS: Results showed that all chickens harboured Campylobacter. An increase over time of the C. coli/C. jejuni ratio for standard chickens occurred. A wide range of MICs was observed among isolates from the same broiler or from the same farm. Strains collected on entry to the slaughterhouse and after storage showed no significant difference in their antibiotic resistance. C. coli was more resistant than C. jejuni to tetracycline and erythromycin during the first period and to all tested molecules (except gentamicin) during the second period. Strains isolated from standard chickens were also more often resistant than those isolated from free-range broilers. The percentage of C. jejuni strains resistant to ampicillin decreased from 1992-1996 to 2001-2002, whereas no change could be observed for the other antimicrobial agents. However, for C. coli the resistance to ampicillin, nalidixic acid, enrofloxacin, tetracycline and erythromycin significantly increased. CONCLUSION: There was an increase in the incidence of antibiotic resistance of C. coli between 1992-1996 and 2001-2002.     

Aerosol therapy in intensive and intermediate care units: prospective observation of 2808 critically ill patients

Purpose

Unlike in the outpatient setting, delivery of aerosols to critically ill patients may be considered complex, particularly in ventilated patients, and benefits remain to be proven. Many factors influence aerosol delivery and recommendations exist, but little is known about knowledge translation into clinical practice.

Methods

Two-week cross-sectional study to assess the prevalence of aerosol therapy in 81 intensive and intermediate care units in 22 countries. All aerosols delivered to patients breathing spontaneously, ventilated invasively or noninvasively (NIV) were recorded, and drugs, devices, ventilator settings, circuit set-up, humidification and side effects were noted.

Results

A total of 9714 aerosols were administered to 678 of the 2808 admitted patients (24 %, CI₉₅ 22–26 %), whereas only 271 patients (10 %) were taking inhaled medication before admission. There were large variations among centers, from 0 to 57 %. Among intubated patients 22 % (n = 262) received aerosols, and 50 % (n = 149) of patients undergoing NIV, predominantly (75 %) inbetween NIV sessions. Bronchodilators (n = 7960) and corticosteroids (n = 1233) were the most frequently delivered drugs (88 % overall), predominantly but not exclusively (49 %) administered to patients with chronic airway disease. An anti-infectious drug was aerosolized 509 times (5 % of all aerosols) for nosocomial infections. Jet-nebulizers were the most frequently used device (56 %), followed by metered dose inhalers (23 %). Only 106 (<1 %) mild side effects were observed, despite frequent suboptimal set-ups such as an external gas supply of jet nebulizers for intubated patients.

Conclusions

Aerosol therapy concerns every fourth critically ill patient and one-fifth of ventilated patients.

     

In vitro activities of 7-substituted 9-chloro and 9-amino-2-methoxyacridines and their bis- and tetra-acridine complexes against Leishmania infantum

9-Chloro and 9-amino-2-methoxyacridines bearing different substituents in position 7, as well as their corresponding unsubstituted dimeric and tetrameric complexes, were investigated for in vitro antiproliferative properties against Leishmania infantum compared to toxicity towards human monocytes. The results clearly confirmed that several compounds of the 2-methoxyacridine series, together with their corresponding dimeric and tetrameric derivatives, had strong in vitro antiparasitic properties. Antileishmanial activity was shown to depend on the nature of both 7- and 9-substituted groups in monoacridines, while it varied according to the nature of the 9-substituted group and the length of the linker among bis- and tetra-acridines. The effects of acridine derivatives on DNA synthesis raised the hypothesis that DNA metabolism constituted their main target in Leishmania promastigotes; however, secondary effects on other biochemical pathways, including protein and lipid metabolism, were observed, suggesting that acridine compounds could be considered multitarget drugs.     

Corticosteroid avoidance in adult kidney transplant recipients under rabbit anti‐T‐lymphocyte globulin,mycophenolate mofetil and delayed cyclosporine microemulsion introduction

We conducted the first prospective, randomized, open‐label multicenter study in low‐immunologic risk adult recipients of primary cadaver kidney transplants receiving rabbit anti‐T‐lymphocyte globulin, mycophenolate mofetil, cyclosporine microemulsion introduced on day 5, with and without corticosteroids. Patients were randomly assigned according to age and cold ischemia time to receive corticosteroids for at least 6 months or no corticosteroids at all. The main efficacy evaluation criterion was acute rejection (including all treated episodes and those biopsy‐confirmed) during the first year following transplantation. For this purpose, this report includes the actual results of the whole 12‐month follow‐up of all randomized patients. For efficacy analysis, 98 patients were evaluated in the Steroid avoidance group and 99 in the Steroid maintenance group. Taken as a whole, 81% of the patients (n = 159) never received anti‐rejection treatment. From the 38 patients who received anti‐rejection treatment, 25 (25.5%) were in the Steroid avoidance group and 13 (13.1%) in the Steroid maintenance group (P < 0.031), experiencing respectively 17 (17.3%) and 7 (7.1%) biopsy‐proven first episodes of acute rejection (P < 0.031). Borderline changes (6 vs. 3) were not considered as biopsy‐proven acute rejections. Onset of first rejection was significantly shorter in the Steroid avoidance group (P < 0.027). First‐line anti‐rejection treatment response, need for any rescue therapy, as well as histologic severity of rejection episodes did not statistically differ between the groups. One‐year post‐transplantation analysis showed no differences in delayed graft function, serum creatinine, creatinine clearance, 24‐h proteinuria, as well as serious adverse events between the groups. De novo diabetes (P < 0.07) or dyslipidemia (P < 0.01) as well as newly diagnosed malignancies (P < 0.059) were however more frequently observed in the Steroid maintenance group. At the end of the first post‐transplant year, 99% of patients in the Steroid avoidance group and 97% of patients in the Steroid maintenance group were respectively alive (P = 0.34), with respectively 95% and 93.2% of functioning kidney grafts (P = 0.62). Our results showed that total avoidance of corticosteroids from the day of transplantation was associated with a significantly increased number of clinically diagnosed and treated, and biopsy‐proven acute rejections during the first year of transplantation. Nevertheless, overall outcome, 1‐year patient and graft survival as well as renal function were similar, and the patients in the Steroid avoidance group exhibited a lower incidence of de novo dyslipidemia, diabetes mellitus and malignancies often associated with steroid treatment (Clinical Trials.gov NCT00200551).     

Guanidino compounds as cause of cardiovascular damage in chronic kidney disease: an in vitro evaluation

Chronic kidney disease is considered a major cause of cardiovascular risk and non-traditional risk factors remain largely unknown. The in vitro toxicity of 10 guanidino compounds (GCs) was evaluated via a standardized approach on different cell systems of relevance in cardiovascular disease. The parameters evaluated were production of reactive oxygen species, expression of surface molecules, cell proliferation, cytotoxicity and calcification. Several GCs had a stimulatory effect on monocytes and granulocytes (SDMA, creatine and guanidinobutyric acid (GBA)). Some GCs (guandine (G), guanidinosuccinic acid (GSA) and SDMA) inhibited endothelial cell proliferation or reduced calcification in osteoblast-like human VSMC (ADMA, GSA and SDMA). Stimulation of osteoclastogenesis could be demonstrated for ADMA, G, guanidinoacetic acid and GBA in a RAW264.7 cell line. No compounds were cytotoxic to AoSMC or endothelial cells, nor influenced their viability. GCs, especially SDMA, likely contribute to cardiovascular complications in uremia, mainly those related to microinflammation and leukocyte activation.     

Effects of protein binding on the biodistribution of PEGylated PLGA nanoparticles post oral administration

The surface of nanoparticles is often functionalised with polymeric surfactants, in order to increase systemic circulation time. This has been investigated mainly for intravenously administered nanoparticles. This study aims to elucidate the effect of surface coating with various concentrations of polymeric surfactants (PEG and Pluronics F127) on the in vitro protein binding as well as the tissue biodistribution, post oral administration, of PLGA nanoparticles. The in vitro protein binding varied depending on the polymeric surfactant used. However, in vivo, 1% PEG and 1% Pluronics F127 coated particles presented similar biodistribution profiles in various tissues over seven days. Furthermore, the percentage of PEG and Pluronics coated particles detected in plasma was higher than that of uncoated PLGA particles, indicating that systemic circulation time can also be increased with oral formulations. The difference in the in vitro protein binding as a result of the different poloxamers used versus similar in vivo profiles of these particles indicates that in vitro observations for nanoparticles cannot represent or be correlated to the in vivo behaviour of the nanoparticles. Our results therefore suggest that more studies have to be conducted for oral formulations to give a better understanding of the kinetics of the particles.