Environmental surveillance and in vitro activity of antimicrobial agents against Legionella pneumophila isolated from hospital water systems in Campania, South Italy: a 5-year study.

Abstract Background Legionellosis' treatment failures have been recently reported showing the possibility of resistance development to traditional therapy, especially in healthcare related disease cases. Environmental impact of antibiotic residues, especially in hospital waters, may act on the resistome of Legionella resulting in developing resistance mechanisms. Objectives In this study we investigate the antibiotic susceptibility of environmental Legionella pneumophila (Lpn) strains isolated from hospital water systems in Campania, a region located in Southwest Italy. Methods 5321 hospital water samples were investigated for the presence of Lpn. Among positive samples, antibiotic susceptibility was tested for a random subset of 125 Lpn strains (25 Lpn isolates from each of the following serogroups: 1, 3, 5, 6, 8). Susceptibility testing was performed, using the E-test on buffered charcoal yeast extract agar supplemented with α-ketoglutarate, for 10 antimicrobial drugs: azithromycin, cefotaxime, clarithromycin, doxycycline, erythromycin, rifampicin, tigecycline, ciprofloxacin, levofloxacin and moxifloxacin. Non parametric tests were used to determine and assess the significant differences in susceptibility to the different antimicrobics between the serogroups. Results Among the isolated strains, none showed resistance to the antibiotics tested. Rifampicin was the most active antibiotic against overall Legionella strains, followed by levofloxacin. Between the macrolides the clarithromycin was overall the most active drug, instead the azithromycin was the less active. Analyzing the different serogroups a significant difference was found between serogroup 1 and non-1 serogroup isolates for doxycycline and tigecycline. Conclusions Antibiotic susceptibility of environmental isolates of Legionella spp. might be useful for the early detection of resistance to antibiotics that directly impacts on mortality and length of hospital stay

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Detection of Agreement and Disagreement: An investigation of linguistic coordination and conversational features

Thesis (Master's)--University of Washington, 2014The focus of this thesis is detection of agreement and disagreement in multiparty conversations using existing transcripts from the ICSI corpus. We use an unsupervised lexicon-based method to create our baseline and then follow a supervised approach to study the effect on performance of different feature sets. The feature sets we are interested in are the following: a. lexicosyntactic, b. Dialog act tag-based features, c. Linguistic style coordination features and d. Conversational features (baseline, individual and non-individual ones). The results enabled us to study the presence of coordination in agreeing and disagreeing statements and showed that the performance can improve when adding further features on top of the lexicosyntactic ones. Additionally, we saw that non-individual conversational features can improve the performance of agreement detection while individual conversational ones appear to have a similar effect on disagreement detection

Fungal Pretreatment of Willow Sawdust with Abortiporus biennis for Anaerobic Digestion: Impact of an External Nitrogen Source

In this study the effect of nitrogen (N) supplementation in the fungal pretreatment of willow sawdust (WSD) via the white rot fungus Abortiporus biennis (A. biennis) was studied in terms of the fractionation of lignocellulosic biomass and biochemical methane potential (BMP). Thus, different external nitrogen sources (yeast extract (YE), urea (UR), and ammonium nitrate (AN)) at different ratios (N/C of 1/250 and 1/50) were added and the effect of the above parameters on the chemical composition of WSD during solid-state fermentation (SSF) experiments with A. biennis was assessed and compared to the experiment of fungal pretreatment without N supplementation (N/C was 1/500, control experiment). The results indicated that the addition of an external nitrogen source did not facilitate delignification, regardless of the type of nitrogen source and the ratio of N/C used. On the other hand, enhanced cellulose uptake was observed. Samples of the 28th day of cultivation, with and without N supplementation, were used for BMP tests, where a reduction in methane yield was observed, compared to the control experiment. In addition, a combination of fungal with alkali (20% NaOH w/w dry mass) pretreatment was performed in order to assess the effect of combined pretreatment on the lignocellulosic content and the BMP

Gaseous biofuels' production from food industry wastes through biological processes

The aim of the present study was to investigate fermentative hydrogen production and anaerobic digestion of food industry wastes. In particular, the wastes used as substrates for the aforementioned processes were seven different solid baby foods that were returned from the market to the company.Biofuels’ production experiments were conducted both at batch and continuous mode. Thus, initially, methane and hydrogen production were carried out in batch mode. The results showed that all wastes are promising substrates for biofuels production.In the sequence, continuous fermentative hydrogen production experiments were conducted, in order to investigate the effect of the alteration of some key parameters in reactors’ performance. In particular, the type of the reactor, the origin of the inoculum, the hydraulic retention time (HRT) and the pH value were tested. The types of the reactor that were used were three. Thus, a CSTR type reactor and a Draw-Fill reactor were used, while they were fed with the aquatic solution of the mixture of the seven baby foods at an initial carbohydrates’ concentration of 12.43 g/L. Also, an Upflow Column reactor with a support matrix was used which operated with the soluble fraction of the aquatic solution of the mixture of the seven baby foods at an initial carbohydrates’ concentration of 16.5 g/L.According to the results, the maximum hydrogen yields were obtained when using the CSTR type bioreactor. In particular, three different experiments were conducted with the indigenous microbial species in order to investigate the effect of the HRT and of the pH value in the reactors’ performance. The optimum HRT was found to be equal to 6 h, while the respective yield was equal to 101.75 ± 3.71 L H2/kg waste. Furthermore, the optimum pH value was equal to 5.40 ± 0.05, while the respective yield was equal to 141.47 ± 3.64 L H2/kg waste. During the third experiment, the whole reactor operation was done without pH adjustment. The experimental results showed that the indigenous microbial species were able to produce hydrogen without pH adjustment, although the reactor’s performance was quite unstable.Referring to continuous methane production was also conducted in a CSTR type reactor using the mixture of the seven baby foods and as well as the mixture of the effluents of the hydrogenogenic Upflow Column reactor. In the first case, the parameters tested were the HRT (from 10 to 20 d) and as well as the thermal treatment of the feed. The optimum operational period of the reactor was for an HRT value of 10 d, and the thermally treated feed with a concentration equal to 11 g substrate/L (yield 0.24 ± 0.02 L/Lreactor/d). When the reactor operated with the mixture of the effluents of the Upflow Column reactor, its operation was inhibited due to high substrate and chemicals’ concentration.Finally, three different mathematical models were used in order to describe the continuous anaerobic digestion experiments and fermentative hydrogen production experiments conducted in the Upflow Column reactor and in the CSTR type reactor.Στην παρούσα διδακτορική διατριβή μελετήθηκε η ζυμωτική παραγωγή υδρογόνου αλλά και η παραγωγή μεθανίου μέσω αναερόβιας χώνευσης από τα απόβλητα της βιομηχανίας τροφίμων. Συγκεκριμένα, τα απόβλητα που χρησιμοποιήθηκαν ως υποστρώματα για τις προαναφερθείσες διεργασίες ήταν επτά διαφορετικές στερεές βρεφικές τροφές οι οποίες αποτελούσαν επιστροφές από την αγορά προς τη βιομηχανία. Πειράματα παραγωγής αερίων βιοκαυσίμων διεξήχθησαν σε αντιδραστήρες διαλείποντος έργου αλλά και σε συνεχή συστήματα. Έτσι, αρχικά διερευνήθηκε η παραγωγή υδρογόνου και μεθανίου σε αντιδραστήρες διαλείποντος έργου. Τα πειραματικά αποτελέσματα έδειξαν ότι όλα τα απόβλητα αποτελούν υποσχόμενα υποστρώματα για την παραγωγή αερίων βιοκαυσίμων. Στη συνέχεια, διεξήχθησαν συνεχή πειράματα ζυμωτικής παραγωγής υδρογόνου στα οποία διερευνήθηκε η επίδραση διαφόρων λειτουργικών παραμέτρων στις αποδόσεις της διεργασίας. Συγκεκριμένα, μελετήθηκε ο τύπος του αντιδραστήρα, η προέλευση της μικτής αναερόβιας καλλιέργειας, η επίδραση του υδραυλικού χρόνου παραμονής αλλά και του pH. Οι τύποι αντιδραστήρα που χρησιμοποιήθηκαν ήταν τρεις. Έτσι, χρησιμοποιήθηκε αντιδραστήρας τύπου CSTR αλλά και αντιδραστήρας άντλησης – πλήρωσης οι οποίοι τροφοδοτήθηκαν με το υδατικό διάλυμα του μίγματος των επτά βρεφικών τροφών σε συγκέντρωση ολικών υδατανθράκων ίση με 12.43 g/L . Επίσης, χρησιμοποιήθηκε και αντιδραστήρας τύπου ανοδικής ροής με πληρωτικό υλικό, ο οποίος όμως, λειτούργησε με το διαλυτό μέρος του ομογενοποιημένου μίγματος των επτά βρεφικών τροφών σε συγκέντρωση υδατανθράκων ίση με 16.5 g/L.Σύμφωνα με τα αποτελέσματα που προέκυψαν οι χαμηλότερες αποδόσεις σε υδρογόνο καταγράφηκαν στην περίπτωση του αντιδραστήρα άντλησης –πλήρωσης, ο οποίος λειτούργησε σε υδραυλικό χρόνο παραμονής ίσο με 32 h, και με μικτή καλλιέργεια η οποία προήλθε από τον αναερόβιο χωνευτήρα μονάδας επεξεργασίας αστικών λυμάτων. Οι αποδόσεις αυτές ήταν ίσες με 7.37 ± 0.65 L H2/kg.Στον αντιδραστήρα ανοδικής ροής, ο οποίος λειτούργησε με την ενδογενή μικροβιακή καλλιέργεια, διεξήχθη πείραμα στο οποίο διερευνήθηκε η βέλτιστη τιμή του υδραυλικού χρόνου παραμονής, ο οποίος βρέθηκε να είναι ίσος με 12 h. Οι αποδόσεις που καταγράφηκαν για αυτές τις συνθήκες ήταν ίσες με 8.01 ± 0.76 L H2/kg αποβλήτου. Όσον αφορά τον αντιδραστήρα τύπου CSTR, ο οποίος λειτούργησε επίσης με την ενδογενή μικροβιακή καλλιέργεια, διεξήχθησαν τρία διαφορετικά πειράματα στα οποία διερευνήθηκε η επίδραση του υδραυλικού χρόνου παραμονής, της ρύθμισης του pH αλλά και της μη ρύθμισης του pH στη λειτουργία του αντιδραστήρα. Σύμφωνα με τα πειραματικά αποτελέσματα, η βέλτιστη τιμή του ΥΧΠ βρέθηκε να είναι ίση με 6 h, ενώ η απόδοση που καταγράφηκε για αυτές τις συνθήκες ήταν ίση με 101.75 ± 3.71 L H2/kg αποβλήτου. Επιπρόσθετα, η βέλτιστη τιμή του pH ήταν ίση με 5.40 ± 0.05, ενώ η απόδοση που καταγράφηκε ήταν ίση με 141.47 ± 3.64 L H2/kg αποβλήτου. Στο τρίτο πείραμα, η εκκίνηση και όλη η λειτουργία του αντιδραστήρα διεξήχθησαν χωρίς τη ρύθμιση του pH. Τα αποτελέσματα έδειξαν ότι ο ενδογενής μικροβιακός πληθυσμός είχε την ικανότητα να παράγει υδρογόνο χωρίς τη ρύθμιση του pH, όμως η λειτουργιά του αντιδραστήρα ήταν αρκετά ασταθής. Επίσης, πραγματοποιήθηκε συνεχές πείραμα παραγωγής μεθανίου μέσω αναερόβιας χώνευσης σε αντιδραστήρα CSTR. Τα απόβλητα που χρησιμοποιήθηκαν ήταν το μίγμα των επτά βρεφικών τροφών αλλά και το μίγμα των απορροών του υδρογονοπαραγωγού αντιδραστήρα ανοδικής ροής. Στην πρώτη περίπτωση οι παράμετροι που ελέγχθηκαν ήταν ο υδραυλικός χρόνος παραμονής (από 10 έως 20 d) αλλά και η θερμική επεξεργασία της τροφοδοσίας του αντιδραστήρα. Η βέλτιστη λειτουργία του αντιδραστήρα καταγράφηκε για υδραυλικό χρόνο παραμονής ίσο με 10 d, και για θερμικά κατεργασμένη τροφοδοσία σε συγκέντρωση ίση με 11 g υποστρώματος/L. Ο ρυθμός παραγωγής μεθανίου στην περίπτωση αυτή ήταν ίσος με 0.24 ± 0.02 L/Lαντιδραστήρα/d. Στην περίπτωση της λειτουργίας του χωνευτήρα με το μίγμα των απορροών του αντιδραστήρα ανοδικής ροής η διεργασία της αναερόβιας χώνευσης παρεμποδίστηκε λόγω της υψηλής συγκέντρωσης υποστρώματος αλλά και των χημικών που υπήρχαν στις απορροές του οξεογόνου αντιδραστήρα για τη ρύθμιση του pH, με αποτέλεσμα η διεργασία να αποτύχει. Στα πλαίσια της αξιοποίησης των πειραματικών δεδομένων που προέκυψαν από τα συνεχή πειράματα, χρησιμοποιήθηκε το μαθηματικό μοντέλο ADM1 έτσι ώστε να προβλεφθεί αλλά και να βελτιστοποιηθεί η λειτουργία του αναερόβιου χωνευτήρα CSTR. Τα αποτελέσματα έδειξαν ότι, μετά από την εύρεση των σημαντικότερων κινητικών παραμέτρων το μοντέλο ήταν ικανό να προβλέψει ικανοποιητικά τη λειτουργία του αναερόβιου χωνευτήρα με υπόστρωμα το μίγμα των επτά στερεών βρεφικών τροφών. Σχετικά με τη διεργασία της ζυμωτικής παραγωγής υδρογόνου στα συνεχή συστήματα, δυο καινούρια μαθηματικά μοντέλα σχεδιάστηκαν και εφαρμόστηκαν στο λογισμικό Aquasim έτσι ώστε να περιγραφούν τα αντίστοιχα πειράματα. Στα μοντέλα αυτά, όλες οι βιομετατροπές που έχουν θεωρηθεί, έχουν σταθερή στοιχειομετρία και αποδόσεις βιομάζας, οι οποίες έχουν προσδιοριστεί μέσω ημίσεων αντιδράσεων ενώ οι ρυθμοί των αντιδράσεων διαφέρουν. Σε όλες τις περιπτώσεις τα μαθηματικά μοντέλα μπόρεσαν να προβλέψουν ικανοποιητικά τις λειτουργίες των αντιδραστήρων, αποδεικνύοντας ότι τα μοντέλα αυτά αποτελούν απαραίτητα εργαλεία για την περιγραφή βιοδιεργασιών όπως η ζυμωτική παραγωγή υδρογόνου

Fungal Pretreatment of Willow Sawdust with Abortiporus biennis for Anaerobic Digestion: Impact of an External Nitrogen Source

In this study the effect of nitrogen (N) supplementation in the fungal pretreatment of willow sawdust (WSD) via the white rot fungus Abortiporus biennis (A. biennis) was studied in terms of the fractionation of lignocellulosic biomass and biochemical methane potential (BMP). Thus, different external nitrogen sources (yeast extract (YE), urea (UR), and ammonium nitrate (AN)) at different ratios (N/C of 1/250 and 1/50) were added and the effect of the above parameters on the chemical composition of WSD during solid-state fermentation (SSF) experiments with A. biennis was assessed and compared to the experiment of fungal pretreatment without N supplementation (N/C was 1/500, control experiment). The results indicated that the addition of an external nitrogen source did not facilitate delignification, regardless of the type of nitrogen source and the ratio of N/C used. On the other hand, enhanced cellulose uptake was observed. Samples of the 28th day of cultivation, with and without N supplementation, were used for BMP tests, where a reduction in methane yield was observed, compared to the control experiment. In addition, a combination of fungal with alkali (20% NaOH w/w dry mass) pretreatment was performed in order to assess the effect of combined pretreatment on the lignocellulosic content and the BMP

A Proactive Environmental Approach for Preventing Legionellosis in Infants: Water Sampling and Antibiotic Resistance Monitoring, a 3-Years Survey Program

A proactive environmental monitoring program was conducted to determine the risk and prevent nosocomial waterborne infections of Legionella spp. in infants. Sink taps in a neonatal intensive care unit (NICU) and two obstetric clinics were monitored for Legionella spp. A total of 59 water samples were collected during a 3-year period and 20 of them were found colonized with Legionella pneumophila. Standard culture, molecular, and latex agglutination methods were used for the detection and identification of Legionella bacteria. Hospital personnel also proceeded with remedial actions (hyperchlorination and thermal shock treatment) in the event of colonization. The minimal inhibitory concentration (MIC) values of erythromycin, ciprofloxacin was determined for Legionella isolates using the e-test method. Our data indicate that the majority of neonatal sink-taps were colonized at least once during the study with Legionella spp. Among 20 isolates, 5 were considered as low-level resistant, 3 in erythromycin and 2 in ciprofloxacin, while no resistant strains were detected. Environmental surveillance in neonatal and obstetric units is suggested to prevent waterborne infections, and thus to reduce the risk of neonatal nosocomial infections