Human Campylobacter spp. infections in Italy.

PURPOSE: Campylobacter is a frequent cause of enteric infections with common antimicrobial resistance issues. The most recent reports of campylobacteriosis in Italy include data from 2013 to 2016. We aimed to provide national epidemiological and microbiological data on human Campylobacter infections in Italy during the period 2017-2021. METHODS: Data was collected from 19 Hospitals in 13 Italian Regions. Bacterial identification was performed by mass spectrometry. Antibiograms were determined with Etest or Kirby-Bauer (EUCAST criteria). RESULTS: In total, 5419 isolations of Campylobacter spp. were performed. The most common species were C. jejuni (n = 4535, 83.7%), followed by C. coli (n = 732, 13.5%) and C. fetus (n = 34, 0.6%). The mean age of patients was 34.61 years and 57.1% were males. Outpatients accounted for 54% of the cases detected. Campylobacter were isolated from faeces in 97.3% of cases and in 2.7% from blood. C. fetus was mostly isolated from blood (88.2% of cases). We tested for antimicrobial susceptibility 4627 isolates (85.4%). Resistance to ciprofloxacin and tetracyclines was 75.5% and 54.8%, respectively; resistance to erythromycin was 4.8%; clarithromycin 2% and azithromycin 2%. 50% of C. jejuni and C. coli were resistant to ≥ 2 antibiotics. Over the study period, resistance to ciprofloxacin and tetracyclines significantly decreased (p < 0.005), while resistance to macrolides remained stable. CONCLUSION: Campylobacter resistance to fluoroquinolones and tetracyclines in Italy is decreasing but is still high, while macrolides retain good activity.

Identification of IncA Plasmid, Harboring blaVIM-1 Gene, in S. enterica Goldcoast ST358 and C. freundii ST62 Isolated in a Hospitalized Patient.

In the present study, we analyzed the genome of two S. enterica strains TS1 and TS2 from stool and blood cultures, respectively, and one strain of C. freundii TS3, isolated from a single hospitalized patient with acute myeloid leukemia. The S. enterica Goldcoast ST358 (O:8 (C2-C3) serogroup), sequenced by the MiSeq Illumina system, showed the presence of ß-lactamase genes (blaVIM-1, blaSHV-12 and blaOXA-10), aadA1, ant(2″)-Ia, aac(6')-Iaa, aac(6')-Ib3, aac(6')-Ib-cr, qnrVC6, parC(T57S), and several incompatibility plasmids. A wide variety of insertion sequences (ISs) and transposon elements were identified. In C. freundii TS3, these were the blaVIM-1, blaCMY-150, and blaSHV-12, aadA1, aac(6')-Ib3, aac(6')-Ib-cr, mph(A), sul1, dfrA14, ARR-2, qnrVC6, and qnrB38. IncA plasmid isolated from E.coli/K12 transconjugant and C. freundii exhibited a sequence identity >99.9%. The transfer of IncA plasmid was evaluated by conjugation experiments.

A urokinase-associated outbreak of Ralstonia mannitolilytica bloodstream infections in haemodialysis patients in north-eastern Italy, January to April 2023.

An outbreak of Ralstonia mannitolilytica bloodstream infections occurred in four hospitals in north-eastern Italy, involving 20 haemodialysis patients with tunnelled central vascular catheter access. We identified as the outbreak source a batch of urokinase vials imported from India contaminated with R. mannitolilytica. Whole genome sequences of the clinical and urokinase strains were highly related, and only urokinase-treated patients were reported with R. mannitolilytica infections (attack rate = 34%; 95% confidence interval: 22.1-47.4). Discontinuation of the contaminated urokinase terminated the outbreak.

Candida lipolytica Bloodstream Infection in an Adult Patient with COVID-19 and Alcohol Use Disorder: A Unique Case and a Systematic Review of the Literature.

Candida lipolytica is an uncommon Candida species causing invasive fungemia. This yeast is mainly associated with the colonisation of intravascular catheters, complicated intra-abdominal infections, and infections in the paediatric population. Here, we report a case of C. lipolytica bloodstream infection in a 53-year-old man. He was admitted for an alcohol withdrawal syndrome and mild COVID-19. Among the primary risk factors for candidemia, only the use of broad-spectrum antimicrobials was reported. The empiric treatment was commenced with caspofungin and then targeted with intravenous fluconazole. Infective endocarditis was ruled out using echocardiography, and PET/TC was negative for other deep-seated foci of fungal infection. The patient was discharged after blood culture clearance and clinical healing. To the best of our knowledge, this is the first case of C. lipolytica candidemia in a patient with COVID-19 and alcohol use disorder. We performed a systematic review of bloodstream infections caused by C. lipolytica. Clinicians should be aware of the possibility of C. lipolytica bloodstream infections in patients with alcohol use disorder, especially in a COVID-19 setting.

Seven Years of Culture Collection of Neisseria gonorrhoeae: Antimicrobial Resistance and Molecular Epidemiology.

The emergence of Neisseria gonorrhoeae isolates displaying resistance to antimicrobials, in particular to ceftriaxone monotherapy or ceftriaxone plus azithromycin, represents a global public health concern. This study aimed to analyze the trend of antimicrobial resistance in a 7-year isolate collection retrospective analysis in Italy. Molecular typing on a subsample of gonococci was also included. A total of 1,810 culture-positive gonorrhea cases, collected from 2013 to 2019, were investigated by antimicrobial susceptibility, using gradient diffusion method, and by the N. gonorrhoeae multiantigen sequence typing (NG-MAST). The majority of infections occurred among men with urogenital infections and 57.9% of male patients were men who have sex with men. Overall, the cefixime resistance remained stable during the time. An increase of azithromycin resistance was observed until 2018 (26.5%) with a slight decrease in the last year. In 2019, gonococci showing azithromycin minimum inhibitory concentration above the EUCAST epidemiological cutoff value (ECOFF) accounted for 9.9%. Ciprofloxacin resistance and penicillinase-producing N. gonorrhoeae (PPNG) percentages increased reaching 79.1% and 18.7% in 2019, respectively. The most common sequence types identified were 5,441, 1,407, 6,360, and 5,624. The predominant genogroup (G) was the 1,407; moreover, a new genogroup G13070 was also detected. A variation in the antimicrobial resistance rates and high genetic variability were observed in this study. The main phenotypic and genotypic characteristics of N. gonorrhoeae isolates were described to monitor the spread of drug-resistant gonorrhea.

Anaerobic bloodstream infections in Italy (ITANAEROBY): A 5-year retrospective nationwide survey.

INTRODUCTION: A lack of updated data on the burden and profile of anaerobic bloodstream infections (ABIs) exists. We assessed the incidence of ABIs and trends in antimicrobial resistance in anaerobes isolated from blood in Italy. MATERIAL AND METHODS: We conducted a retrospective study on 17 Italian hospitals (2016-2020). Anaerobes isolated from blood culture and their in vitro susceptibility profiles (EUCAST-interpreted) were registered and analyzed. RESULTS: A total of 1960 ABIs were identified. The mean age of ABIs patients was 68.6 ± 18.5 years, 57.6% were males. The overall incidence rate of ABIs was 1.01 per 10.000 patient-days. Forty-seven% of ABIs occurred in medical wards, 17% in ICUs, 14% in surgical wards, 7% in hemato-oncology, 14% in outpatients. The three most common anti-anaerobic tested drugs were metronidazole (92%), clindamycin (89%) and amoxicillin/clavulanate (83%). The three most common isolated anaerobes were Bacteroides fragilis (n = 529), Cutibacterium acnes (n = 262) and Clostridium perfringens (n = 134). The lowest resistance rate (1.5%) was to carbapenems, whereas the highest rate (51%) was to penicillin. Clindamycin resistance was >20% for Bacteroides spp., Prevotella spp. and Clostridium spp. Metronidazole resistance was 9.2% after excluding C. acnes and Actinomyces spp. Bacteroides spp. showed an increased prevalence of clindamycin resistance through the study period: 19% in 2016, 33% in 2020 (p ≤ 0.001). CONCLUSIONS: Our data provide a comprehensive overview of the epidemiology of ABIs in Italy, filling a gap that has existed since 1995. Caution is needed when clindamycin is used as empirical anti-anaerobic drug.

In vivo antimicrobial activity of 0.6% povidone-iodine eye drops in patients undergoing intravitreal injections: a prospective study.

To investigate the antimicrobial activity of a preservative-free 0.6% povidone-iodine eye drop as an antiseptic procedure in decreasing the conjunctival bacterial load in eyes scheduled for intravitreal treatment and to compare its efficacy to the untreated fellow eye used as the control group. Prospective cohort analysis in which 208 patients received preservative-free 0.6% povidone-iodine eye drops three times a day for three days before intravitreal injection. Before and after the prophylactic treatment, a conjunctival swab was collected from both the study eye and the untreated contralateral eye, used as control. The swab was inoculated on different culture media and the colony-forming units were counted. Bacteria and fungi were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Treatment with 0.6% povidone-iodine eye drops significantly reduced the conjunctival bacterial load from baseline (p < 0.001 for blood agar and p < 0.001 for chocolate agar) with an eradication rate of 80%. The most commonly isolated pathogen at each time-point and in both groups was coagulase-negative Staphylococci, isolated in 84% of the positive cultures. The study provides evidence about the effectiveness of 0.6% povidone-iodine eye drops treatment in reducing the conjunctival bacterial load in eyes scheduled for intravitreal treatment.

Interplay of OpdP Porin and Chromosomal Carbapenemases in the Determination of Carbapenem Resistance/Susceptibility in Pseudomonas aeruginosa.

Carbapenem resistance in Pseudomonas aeruginosa strains responsible for chronic lung infections in cystic fibrosis (CF) patients is mainly due to loss of the OprD protein and, limited to meropenem and doripenem, to overexpression of efflux pumps. However, recent reports of isolates showing inconsistent genotype-phenotype combinations (e.g., susceptibility in the presence of resistance determinants and vice versa) suggest the involvement of additional factors whose role is not yet fully elucidated. Among them, the OpdP porin as an alternative route of entry for carbapenems other than OprD and the overexpression of two chromosomal carbapenemases, the Pseudomonas-derived cephalosporinase (PDC) and the PoxB oxacillinase, have recently been reconsidered and studied in specific model strains. Here, the contribution of these factors was investigated by comparing different phenotypic variants of three strains collected from the sputum of colonized CF patients. Carbapenem uptake through OpdP was investigated both at the functional level, by assessing the competition exerted by glycine-glutamate, the OpdP's natural substrate, against imipenem uptake, and at the molecular level, by comparing the expression levels of opdP genes by quantitative real-time PCR (qRT-PCR). Moreover, overexpression of the chromosomal carbapenemases in some of the isolates was also investigated by qRT-PCR. The results showed that, even if OprD inactivation remains the most important determinant of carbapenem resistance in strains infecting the CF lung, the interplay of other determinants might have a nonnegligible impact on bacterial susceptibility, being able to modify the phenotype of part of the population and consequently complicating the choice of an appropriate therapy. IMPORTANCE This study examines the interplay of multiple factors in determining a pattern of resistance or susceptibility to carbapenems in clinical isolates of Pseudomonas aeruginosa, focusing on the role of previously poorly understood determinants. In particular, the impact of carbapenem permeability through OprD and OpdP porins was analyzed, as well as the activity of the chromosomal carbapenemases AmpC and PoxB, going beyond the simple identification of resistance determinants encoded by each isolate. Indeed, analysis of the expression levels of these determinants provides a new approach to determine the contribution of each factor, both individually and in coexistence with the other factors. The study contributes to understanding some phenotype-genotype discordances closely related to the heteroresistance frequently detected in P. aeruginosa isolates responsible for pulmonary infections in cystic fibrosis patients, which complicates the choice of an appropriate patient-specific therapy.

Zidovudine in synergistic combination with fosfomycin: an in vitro and in vivo evaluation against multidrug-resistant Enterobacterales.

Multidrug-resistant (MDR) Enterobacterales are a priority health issue with few treatment options. Recently, fosfomycin has been reconsidered for MDR bacterial infections. Zidovudine, licensed for the treatment of human immunodeficiency virus (HIV), has unexploited antibacterial properties and has been considered for drug repurposing. The aim of this study was to assess the effect of the combination of fosfomycin plus zidovudine against clinical MDR Enterobacterales isolates. Minimum inhibitory concentration (MIC) determination and checkerboard assays for 36 MDR Enterobacterales strains were performed. In addition, fosfomycin-resistant strains were evaluated using time-kill assay and in an in vivo Galleria mellonella infection model. Zidovudine and fosfomycin MICs ranged between 0.06 to >64 mg/L and 0.125 to >512 mg/L, respectively. A synergistic effect [fractional inhibitory concentration index (FICI) ≤0.5] was observed in 25 isolates and no antagonistic effect was observed in the remaining isolates. For 7 of 8 fosfomycin-resistant strains (MIC > 32 mg/L), zidovudine combination was able to restore fosfomycin susceptibility. These results were confirmed by time-kill assays. Fosfomycin + zidovudine presented greater larval survival (20-50%) than monotherapy. Synergistic activity was observed for fosfomycin + zidovudine in 69.4% of the tested strains. In vivo experiments confirmed the enhanced effectiveness of the combination. The zidovudine concentrations tested here can be reached in human serum using the actual licensed dosage, therefore this combination deserves further clinical investigation.

Is ultrasonography mandatory in all children at their first febrile urinary tract infection?

BACKGROUND: This study investigated whether performing kidney ultrasound (KUS) only in children presenting either a pathogen other than E. coli at their first febrile urinary tract infection (fUTI) or experiencing fUTI recurrence would increase missed diagnoses of kidney anomalies. METHODS: Patients aged 2-36 months with fUTI who underwent KUS evaluation from 2 January 2013 to 31 June 2018 were enrolled. Cystourethrography was performed after pathological KUS or recurring fUTIs. Thereafter, we retrospectively assessed the detection rate of kidney anomalies through performing KUS only in patients with atypical pathogen at first fUTI or with recurring fUTIs. RESULTS: In 263 patients included, the isolated pathogen was E. coli in 223 cases (84.8%) and atypical in 40 cases (15.2%). KUS detected kidney anomalies in 14/223 (6.3%) of fUTIs caused by E. coli and in 11/40 (27.5%) of fUTIs caused by an atypical pathogen (OR 5.5, 95%CI 2.5-14.5). Cystourethrography was performed in 40 patients and vesicoureteral reflux (VUR) found in 20 cases. None of the high grade VUR diagnoses or other kidney anomalies would have been lost through a different diagnostic protocol that required the presence of an atypical pathogen at the first fUTI or a fUTI recurrence to perform the KUS. CONCLUSIONS: A diagnostic protocol that requires presence of an atypical pathogen at the first fUTI or a second episode of fUTI to perform the KUS would allow a reduction in the number of negative ultrasounds with a negligible risk of missed diagnoses of kidney anomalies.

Trends in the Incidence and Antibiotic Resistance of Enterococcal Bloodstream Isolates: A 7-Year Retrospective Multicenter Epidemiological Study in Italy.

The spread of resistance to vancomycin and other last-resort drugs in Enterococcus spp. remains of concern. In Italy, surveillance data for enterococcal bloodstream isolates in humans are scant. The aim of our study was to assess the incidence trends of bacteremias due to Enterococcus species and their prevalence trends of antimicrobial resistance. We retrospectively included all consecutive not-duplicate Enterococcus species isolated from blood cultures, in patients from 11 Italian hospitals (2011-2017). Incidence was defined as the number of isolates per 10,000 patient-days, while resistance prevalence was defined as the number of resistant strains divided by the number of tested strains. We included 4,858 isolates (59%, 36%, and 5% due to Enterococcus faecalis, E. faecium, and other Enterococcus spp., respectively). Over the study period, the incidence of bacteremias due to E. faecalis (incidence rate ratio [IRR]: 1.02, 95% confidence interval [CI]: 1.00-1.04, p = 0.008) and E. faecium increased (IRR: 1.03, 95% CI: 1.01-1.05, p < 0.001) alongside with the whole enterococcal bacteremias trend (IRR: 1.02, 95% CIs: 1.01-1.04, p = 0.002). A progressive increase in vancomycin-resistant E. faecium (VREfm) bacteremias was observed. Resistance to tigecycline and linezolid was rarely reported. The incidence of enterococcal bloodstream isolates is increasing in Italy, together with the prevalence of VREfm. Resistance to linezolid, a cornerstone drug used in the treatment of VRE bloodstream infection, remains negligible.

Potential links between COVID-19-associated pulmonary aspergillosis and bronchiectasis as detected by high resolution computed tomography.

PURPOSE: The aim of this observational study was to highlight high resolution CT scan characteristics of COVID-19-associated pulmonary aspergillosis (CAPA) with a focus on the detection of de-novo appeared or evolved bronchiectasis. METHODS: From March 2020 to May 2021, we enrolled 350 consecutive mechanically ventilated ICU patients with COVID-19. Patients with CAPA and at least one chest CT scan performed within 15 days from the diagnosis were included. Two radiologists were asked to identify typical and atypical signs of COVID-19 pneumonia. Bronchiectasis locations were described and a modified Reiff score was calculated, as severity score. A total of 19 CAPA patients (median age 71.0, Interquartile range (IQR) 62.5-75.0; male 16, 84.2%) were included. RESULTS: According to the 2020 ECMM/ISHAM criteria, 18 patients had probable CAPA and one had proven CAPA. The median time between hospital admission and CT scan was 21 days (IQR 14.5-25.0). The incidence of bronchiectasis in the study population was 57.9% (n = 11). Tubular bronchiectasis was detected in 10 patients and were scored as follows: three patients had a score of 1, three patients had a score of score 2, one patient had a score of 5 and four patients had a score of 6. Eight patients had a previous CT scan (performed at hospital admission), among them: 5 patients developed de-novo bronchiectasis, while 2 patients demonstrated a volumetric increase of bronchiectasis. At the 6-months follow-up, the mortality rate for patients with CAPA was >60%. CONCLUSION: the radiologic detection of de-novo appearance or volumetric increase of bronchiectasis in COVID-19 should lead clinicians to search for fungal superinfections.

Clinical Features and Mortality of Nosocomial Candidemia in Very Old Patients: A Multicentre Italian Study.

INTRODUCTION: Being elderly is a well-known risk factor for candidemia, but few data are available on the prognostic impact of candidemia in the very old (VO) subjects, as defined as people aged ≥75 years. OBJECTIVE: The aim of this study was to assess risk factors for nosocomial candidemia in two groups of candidemia patients, consisting of VO patients (≥75 years) and adult and old (AO) patients (18-74 years). In addition, risk factors for death (30-day mortality) were analysed separately in the two groups. METHODS: We included all consecutive candidemia episodes from January 2011 to December 2013 occurring in six referral hospitals in north-eastern Italy. RESULTS: A total of 683 nosocomial candidemia episodes occurred. Of those, 293 (42.9%) episodes were in VO and 390 (57.1%) in AO patients. Hospitalization in medical wards, chronic renal failure, urinary catheter, and peripheral parenteral nutrition (PPN) were more common in VO than in AO patients. In the former patient group, adequate antifungal therapy (73.2%) and central venous catheter (CVC) removal (67.6%) occurred less frequently than in AO patients (82.5 and 80%, p < 0.002 and p < 0.004, respectively). Thirty-day mortality was higher in VO compared to AO patients (47.8 vs. 23.6%, p < 0.0001). In AO patients, independent risk factors for death were age (OR 1.04, 95% CI 1.00-1.09, p = 0.038), recent history of chemotherapy (OR 22.01, 95% CI 3.12-155.20, p = 0.002), and severity of sepsis (OR 40.68, 95% CI 7.42-223.10, p < 0.001); CVC removal was associated with higher probability of survival (OR 0.10, 95% CI 0.03-0.33, p < 0.001). In VO patients, independent risk factors for death were PPN (OR 3.5, 95% CI 1.17-10.47, p = 0.025) and hospitalization in medical wards (OR 2.58, 95% CI 1.02-6.53, p = 0.046), while CVC removal was associated with improved survival (OR 0.40, 95% CI 0.16-1.00, p = 0.050). CONCLUSION: Thirty-day mortality was high among VO patients and was associated with inadequate management of candidemia, especially in medical wards.

Control and prevention measures for legionellosis in hospitals: A cross-sectional survey in Italy.

Risk assessment, environmental monitoring, and the disinfection of water systems are the key elements in preventing legionellosis risk. The Italian Study Group of Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine, and Public Health and the Italian Multidisciplinary Society for the Prevention of Health Care-Associated Infections carried out a national cross-sectional survey to investigate the measures taken to prevent and control legionellosis in Italian hospitals. A multiple-choice questionnaire was developed, comprising 71 questions regarding hospital location, general characteristics, clinical and environmental surveillance, and control and preventive measures for legionellosis in 2015. Overall, 739 hospitals were enrolled from February to June 2017, and 178 anonymous questionnaires were correctly completed and evaluated (response rate: 24.1%). The survey was conducted using the SurveyMonkey® platform, and the data were analyzed using Stata 12 software. Of the participating hospitals, 63.2% reported at least one case of legionellosis, of which 28.2% were of proven nosocomial origin. The highest case numbers were reported in the Northern Italy, in hospitals with a pavilion structure or cooling towers, and in hospitals with higher numbers of beds, wards and operating theaters. Laboratory diagnosis was performed using urinary antigen testing alone (31.9%), both urinary antigen testing and single antibody titer (17.8%), or with seroconversion also added (21.5%). Culture-based or molecular investigations were performed in 28.8% and 22.1% of the clinical specimens, respectively. The water systems were routinely tested for Legionella in 97.4% of the hospitals, 62% of which detected a positive result (> 1000 cfu/L). Legionella pneumophila serogroup 2-15 was the most frequently isolated species (58.4%). The most common control measures were the disinfection of the water system (73.7%), mostly through thermal shock (37.4%) and chlorine dioxide (34.4%), and the replacement (69.7%) or cleaning (70.4%) of faucets and showerheads. A dedicated multidisciplinary team was present in 52.8% of the hospitals, and 73% of the hospitals performed risk assessment. Targeted training courses were organized in 36.5% of the hospitals, involving nurses (30.7%), physicians (28.8%), biologists (21.5%), technicians (26.4%), and cleaners (11%). Control and prevention measures for legionellosis are present in Italian hospitals, but some critical aspects should be improved. More appropriate risk assessment is necessary, especially in large facilities with a high number of hospitalizations. Moreover, more sensitive diagnostic tests should be used, and dedicated training courses should be implemented.

Emergence of quinolone-resistant Shigella flexneri in Italy (March 2017).

In March 2017, a 45-year-old Italian man who has sex with men was admitted to the Infectious Diseases Department of Trieste Hospital (northeast Italy), because of fever, abdominal pain and dysentery. The patient had neither foreign travel history nor sexual contact with non-Italian partners. Stool cultures grew multidrug-resistant Shigella flexneri (resistant to ampicillin, chloramphenicol, streptomycin, tetracycline, trimethoprim, amoxicillin/clavulanic acid and ciprofloxacin) and whole genome sequencing detailed the resistance features. The phylogenetic analysis showed that the strain was unrelated to any previously reported strain. The patient was treated successfully with ceftriaxone. We hereby report the first case of locally-acquired, multidrug-resistant S. flexneri infection in Italy and also the emergence of a new clone.

Spread of Vancomycin-Resistant Enterococcus faecium Isolates Despite Validated Infection Control Measures in an Italian Hospital: Antibiotic Resistance and Genotypic Characterization of the Endemic Strain.

An alarming increase of vancomycin-resistant Enterococcus faecium (VREfm) isolates was detected in an Italian referral hospital subjected to policies of infection control validated by the Joint Commission International. Analysis of the population structure of 122 consecutive, nonreplicate VREfm isolates collected over an 18-month period identified a single major clone that spread around the whole hospital, rapidly establishing an endemic state. It belonged to sequence type (ST) 17 and showed a highly multidrug-resistant phenotype, being resistant to all antimicrobial classes for the carriage of several resistance determinants. Furthermore, some strains with decreased susceptibility to daptomycin were detected. Eighteen out of the 122 isolates did not group in the major clone. They showed a low spreading potential inside the hospital wards, even if most of them displayed a multidrug-resistant phenotype and belonged to a hospital-adapted lineage. Causes that led to the VREfm endemic state have not been fully elucidated. However, it is conceivable that the increase in systemic antibiotic consumption and the use of selective digestive tract decontamination, including vancomycin in critically ill patients during the period before 2014, may have played a role in the ST17 clone dissemination, but additional traits conferring high fitness in hospital environment cannot be excluded.

Evaluation of a biomimetic 3D substrate based on the Human Elastin-like Polypeptides (HELPs) model system for elastolytic activity detection.

Elastin is a fibrous protein that confers elasticity to tissues such as skin, arteries and lung. It is extensively cross-linked, highly hydrophobic and insoluble. Nevertheless, elastin can be hydrolysed by bacterial proteases in infectious diseases, resulting in more or less severe tissue damage. Thus, development of substrates able to reliably and specifically detect pathogen-secreted elastolytic activity is needed to improve the in vitro evaluation of the injury that bacterial proteases may provoke. In this work, two human biomimetic elastin polypeptides, HELP and HELP1, as well as the matrices derived from HELP, have been probed as substrates for elastolytic activity detection. Thirty strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients were analyzed in parallel with standard substrates, to detect proteolytic and elastolytic activity. Results point to the HELP-based 3D matrix as an interesting biomimetic model of elastin to assess bacterial elastolytic activity in vitro. Moreover, this model substrate enables to further elucidate the mechanism underlying elastin degradation at molecular level, as well as to develop biomimetic material-based devices responsive to external stimuli.

Correlation between antibiotic consumption and resistance of bloodstream bacteria in a University Hospital in North Eastern Italy, 2008-2014.

PURPOSE: The spread of multidrug-resistant bacteria is a worrisome problem worldwide. This study investigated the correlation between antibiotic consumption and antimicrobial resistance trends of the most important bacteria causing bacteremia at the University hospital of Trieste, Italy, from 2008 to 2014. METHODS: Antibiotic consumption (Defined Daily Dose-DDD-per 100 patient/days) and antibiotic resistance (percentage of antibiotic intermediate o resistant isolates) were analyzed independently with linear correlation by year. Potential correlations between antibiotic consumption and bacteria resistance rates were investigated through the Pearson's correlation. RESULTS: The overall consumption of antibiotic grew from 80 to 97 DDD 100 patient/days (p = 0.005) during the study period. The increased consumption of amoxicillin/clavulanate and piperacillin/tazobactam was associated with the reduction of MRSA rate from 48.5 to 25.9% (p = 0.007 and p = 0.04, respectively). The increased consumption of piperacillin/tazobactam was associated with the reduction of ESBL-positive Enterobacteriaceae rate from 28.9 to 20.9% (p = 0.01). The increased consumption of carbapenems was associated with the increased rate of carbapenem-resistant Acinetobacter baumannii from 0 to 96.4% (p = 0.03). No carbapenem-resistant Enterobacteriaceae isolates were reported. The consumption of vancomycin grew significantly (p = 0.005). A dramatic spread of vancomycin-resistant Enterococcus faecium occurred in 2014. The consumption of fluoroquinolones and extended-spectrum cephalosporins remained stable. CONCLUSIONS: An antibiotic stewardship program targeted to limit the consumption of extended-spectrum cephalosporins and fluoroquinolones in favor of amoxicillin/clavulanate and piperacillin/tazobactam correlates with a decreasing rate of MRSA and ESBL-positive Enterobacteriaceae. The analysis of correlations between antibiotic consumption and bacterial resistance rates is a useful tool to orient antimicrobial stewardship policies at local level.