Clinical and microbiological features of ceftolozane/tazobactam-resistant Pseudomonas aeruginosa isolates in a university hospital in central Italy

Objectives: Ceftolozane/tazobactam (C/T) is a novel cephalosporin and β-lactamase inhibitor combination with great activity against Pseudomonas aeruginosa. To assess P. aeruginosa susceptibility to C/T, a surveil- lance study was conducted from October 2018 to March 2019 at the University Hospital ‘Ospedali Riuniti’ in Ancona, Italy. Methods: Minimum inhibitory concentrations (MICs) to C/T were determined by Etest strip. Resistant iso- lates were characterized by phenotypic (broth microdilution antimicrobial susceptibility testing and mod- ified Carbapenem Inactivation Method [mCIM]) and genotypic (Polymerase Chain Reaction [PCR], Pulsed Field Gel Electrophoresis [PFGE], and whole-genome sequencing [WGS]) methods. Clinical variables of patients infected by C/T-resistant P. aeruginosa were collected from medical records. Results: Fifteen of 317 P. aeruginosa collected showed resistance to C/T (4.7%). Ten strains demonstrated carbapenemase activity by mCIM method, and PCR confirmed that eight strains harbored a blaVIM gene while the other two were positive for blaIMP. Additionally, three isolates carried acquired extended spec- trum β-lactamase genes (two isolates carried blaPER and one carried blaGES). Eight strains were strictly related by PFGE and WGS analysis confirmed that they belonged to sequence type (ST)111. The other STs found were ST175 (two isolates), ST235 (two isolates), ST70 (one isolate), ST621 (one isolate), and the new ST3354 (one isolate). Most patients had received previous antibiotic therapies, carried invasive devices, and experienced prolonged hospitalization. Conclusion: This study demonstrated the presence of C/T-resistant P. aeruginosa isolates in a regional hospital carrying a number of resistance mechanisms acquired by different high-risk clone

La resistenza agli antibiotici in Pseudomonas aeruginosa: studio molecolare ed epidemiologico in un nosocomio marchigiano

Antibiotic resistance in Pseudomonas aeruginosa: molecular and epidemiological study in a hospital in the Marche region Background: In the last years P.aeruginosa has became one of most drug resistant microorganism. Despite introduction of new antibiotics such as Ceftolozane/tazobactam (C/T), a novel cephalosporin/β-lactamase inhibitor combination with a potent activity against Pseudomonas aeruginosa isolates, several resistant P. aeruginosa isolates have been reported. From November 2016 to April 2019 we performed both a retrospective study on C/T prescriptions and activity both a survey on clinical strains of P. aeruginosa isolated at “Ospedali Riuniti” of Ancona, Italy, characterising the resistant isolates. Materials/methods: From November 2016 to April 2019 we have collected data about C/T activity and efficacy against all multidrug resistant gram negative isolated at Ospedali Riuniti of Ancona. Particularly we have studied activity of C/T against P.aeruginosa, and microbiological and genetic charateristics of this microorganism. MICs to C/T were determined with gradient test for all P. aeruginosa recovered at the clinical laboratory of “Ospedali Riuniti” from October 2018 to March 2019. Resistant strains were characterized and typed by SpeI-PFGE. We have determined also AmpC production, we have performed DNA extraction and PCR exam. NGS with an Illumina Miseq platform was performed on representative strains to identify the mechanisms of C/T resistance. Results: Over 34 pt, who have received C/T as therapy against multidrug resistant gram negative infections, 53% had CCI >3, 21% underwent to surgery in the previous three months, 32% had pneumonia as acute comorbidities, 18%has died, 26% have experienced a therapeutic failure. CCI>3, pneumonia, P.aeruginosa infection and a previous corticosteroid therapy were a negative prognostic factors. P.aeruginosa resulted resistant to carbapenem, cephalosporin, piperacillina/tazobactam and fluorochinolons, but not to colistin. Over 317 isolated and screened isolates, 15 were resistant to C/T (MIC > 8 mg/L; 4.73%). PFGE showed that 8/15 were strictly related. NGS revealed 6 different STs. The resistance mechanisms to C/T included the metallo β-lactamase (MBL)-econding genes blaVIM-2 in 8 isolates belonging to ST111, and blaIMP in 2 isolates (blaIMP-19 in ST175 and blaIMP-13 in ST621). Additionally, blaPER-1 β-lactamase gene was detected in 2 isolates (ST235) and the blaGES β-lactamase gene in 1 isolate (ST175). Notably, in 2 strains (ST70 and ST3354) no acquired β-lactamase genes involved in C/T resistance has been detected but they showed alterations in ampC. Modifications in these genes and in ampC promoter (ampR) were also detected in all resistant strains except in ST175 isolates (possessing a wild type ampC and ampR). Conclusions: C/T has confirmed its high activity and efficacy against multidrug gram negative infections. There was a low rate of resistance to C/T, but several resistance mechanisms were identified, among which production of MBLs was the most common. Moreover, we found a possible mini-outbreak of blaVIM positive strains. Despite what has been pointed out, we must recognize that this study is limited by the low number of enrolled patients, by the retrospectivity and by being monocentric, but it can be considered an initial approach for further prospective future studies, involving other hospitals in the Region, to better to define both the therapeutic efficacy of C / T and the epidemiology of P. aeruginos

Direct acting antivirals (DAAs) for the treatment of HCV infection in HIV/HCV coinfected patients: a clinical experience.

Background HIV/hepatitis C virus (HCV) coinfection has an unfavourable influence on the natural history of HCV, resulting in an increased rate of progression to cirrhosis, HCC and end stage liver disease. Although direct acting antivirals (DAAs) have proven to be effective in eradicating HCV infection in coinfected individuals, few data on cost effectiveness in clinical practice are available to date. Purpose This prospective study aims to assess efficacy and costs of DAAs in an outpatient population of HIV/HCV coinfected subjects. Material and methods A database for DAA prescription monitoring was created, including information on the overall cost of the anti-­‐HCV regimen for each patient. Patients were treated according to the local prescription regulations. Virologic response to DAAs was assessed at weeks 4, 12 and 24 after treatment initiation. Additional clinical and laboratory data were obtained from the medical records. Results 35 subjects were studied (males 80%, mean age 51 years), 23 undergoing a 12 week treatment course and 12 a 24 week course. Prior to initiation, 74% of patients had HIV plasma viral load below the detection limit. 80% changed at least one HIV medication to minimise the risk of drug-­‐drug interactions; eventually, 71% switched to an integrase inhibitor based regimen. 87% of patients undergoing a 12 week DAA regimen had HCV genotype 1 infection whereas 67% of patients on a 24 week regimen had genotype 3. An interferon free regimen was chosen for 91% of patients. Ribavirin was used in combination with DAAs in 57% of subjects. Preferred combinations were simeprevir/sofosbuvir for the treatment of genotype 1 and sofosbuvir/ribavirin or daclatasvir/sofosbuvir for genotype 3. Other combinations were paritaprevir/dasabuvir/ombitasvir/ritonavir and ledipasvir/sofosbuvir. 55% of patients showed undetectable HCV viraemia at week 4 and 86% at week 12. To date, 22 patients have completed the full treatment course (19 patients 12 weeks, 3 patients 24 weeks), all showing undetectable HCV viraemia. Among these, 23% experienced mild side effects, all related to ribavirin co-­administration (anaemia, fatigue). Mean treatment cost was approximately 55,000€ per patient. Conclusion This prospective study shows the effectiveness and safety of DAA therapy in HIV/HCV coinfected individuals in the clinical setting, despite the high cost. Data collection on sustained virologic response after treatment discontinuation is still ongoing

Spread of colistin resistance gene mcr-1 in Italy: characterization of the mcr-1.2 allelic variant in a colistin-resistant blood isolate of Escherichia coli

mcr-1.2, an allelic variant of the transferable colistin resistance gene mcr-1, was characterized in a colistin-resistant blood isolate of Escherichia coli. It was harbored by an IncX4-type plasmid (33,293 bp). Despite its low prevalence, the potentially worrying spread of the mcr-1 gene, particularly its mcr-1.2 variant, in Italy requires increasing surveillance

Efficacy and costs of Direct Acting Antivirals (DAAS) for the treatment of HCV Iinfection amnog HCV-monoinfected and HIV/HCV co-infected patients in real-life setting

BACKGROUND Although several studies analyzing the effectiveness of DAAs have showed no differences between HCV-monoinfected and HIV/HCV-coinfected patients,data in real-life setting are still limited. PURPOSE To compare efficacy and costs of DAAs in HCV-monoinfected and HIV/HCV-coinfected subjects. METHODS A database of HCV-monoinfected and HIV/HCV-coinfected adults who started HCV therapy between January 2015 and July 2016 was created in order to collect the following data:sustained virological response to DAAs therapy at week 12(SVR12) and at week 24(SVR24) after treatment initiation, treatment regimen, and overall cost of anti-HCV regimens.Patients were treated as follows: sofosbuvir/ribavirin ± peg-INF (n=37), sofosbuvir/daclatasvir(n=72), sofosburiv/ledipasvir(n=68), sofosburiv/simeprevir(n=77), simeprevir/peg-interferon(n=13) or ombitasvir/paritaprevir/ritonavir/dasabuvir(n=14). Overall, ribavirin was used in combination with DAAs in 67% of patients. RESULTS The study enrolled 281 subjects(81% monoinfected and 19% co-infected), treated for 12(54% of monoinfected and 50% of co-infected) or 24 weeks(46% of monoinfected and 50% of co-infected). Two hundred and twenty nine patients had cirrhosis or high degree fibrosis (≥F3) at the beginning of DAAs (79% of HCV-monoinfected and 91% of HIV/HCV co-infected);other 23 subjects(all but one HCV-monoinfected) were treated after liver transplantation. Two hundreds and ten (93%) HCV-monoinfected patients completed the treatment; 96% achieved SVR12 and 97% reached SVR24. The most prescribed regimens were 12-week sofosburiv/simeprevir(27%) or sofosburiv/ledipasvir(17%), and 24-week sofosbuvir/daclatasvir(17%). The average cost of a complete HCV-treatment in monoinfected population was € 49.633 per patient. Among the 47 HIV/HCV-coinfected patients(87%) who completed the treatment, 94% achieved SVR12 and 96% obtained SVR24;12-week sofosburiv/simeprevir was prescribed to 24% of them, whereas the most frequent 24-week treatments were sofosburiv/daclatasvir and sofosburiv/ledipasvir(20% each). The average cost of a complete HCV-treatment in coinfected population was € 53.573 per patient. CONCLUSION This study confirms the high effectiveness of DAAs in the treatment of HCV infection in real life setting, both in HCV-monoinfected and HIV/HCV-coinfected patients. The average cost of single treatment was also similar between the two groups

Efficacy of the Combination of Tachyplesin III and Clarithromycin in Rat Models of Escherichia coli Sepsis▿

We investigated the efficacy of tachyplesin III and clarithromycin in two experimental rat models of severe gram-negative bacterial infections. Adult male Wistar rats were given either (i) an intraperitoneal injection of 1 mg/kg Escherichia coli 0111:B4 lipopolysaccharide or (ii) 2 × 1010 CFU of E. coli ATCC 25922. For each model, the animals received isotonic sodium chloride solution, 1 mg/kg tachyplesin III, 50 mg/kg clarithromycin, or 1 mg/kg tachyplesin III combined with 50 mg/kg clarithromycin intraperitoneally. Lethality, bacterial growth in the blood and peritoneum, and the concentrations of endotoxin and tumor necrosis factor alpha (TNF-α) in plasma were evaluated. All the compounds reduced the lethality of the infections compared to that for the controls. Tachyplesin III exerted a strong antimicrobial activity and achieved a significant reduction of endotoxin and TNF-α concentrations in plasma compared to those of the control and clarithromycin-treated groups. Clarithromycin exhibited no antimicrobial activity but had a good impact on endotoxin and TNF-α plasma concentrations. A combination of tachyplesin III and clarithromycin resulted in significant reductions in bacterial counts and proved to be the most-effective treatment in reducing all variables measured

Antiretroviral therapy management and rationalisation of available resources

The treatment of HIV disease has led to a new division of management costs by shifting most of the necessary resources from inpatient treatment to outpatient management. Among the initiatives aimed at rationalising the resources available, we compared efficacy, tolerability and pharmacoeconomic impact of different regimes of antiretroviral therapy (ART). The survey covered the first 50 patients, clinically stable and with good viro-immunological response, who switched in June 2012 from an ART based on the triple combination of tenofovir (TDF), emtricitabine (FTC) and a protease inhibitor boosted with ritonavir (PI/r) or a non-nucleoside reverse transcriptase inhibitor (NNRTI), to a treatment based on abacavir (ABC), lamivudine (3TC) and a PI/r or NNRTI. Of the 50 patients who operated the switch, 39 replaced a PI with nevirapine (NVP), for which the largest group of patients was treated with ABC + 3TC + NVP. On 31 May 2015, all patients completed the observation period of 96 weeks, with a mean observation period of 132 weeks and clinical-laboratory checks every four months. Laboratory analysis revealed an optimal maintenance of viral suppression and absolute and relative number of CD4 + lymphocytes and improving trend of creatinine, proteinuria, serum phosphate and bone alkaline phosphatase. There was a variable effect on lipids, with a drop in triglycerides associated with a modest increase in total cholesterol. Much of the HIV-positive population reporting to our hospitals (>50%) comprises individuals who have for years been in stable viraemic suppression, making a satisfactory immune recovery while in good overall clinical condition. This type of patient was the target of the present survey. At the end of 96 weeks of observation the new regimes were well tolerated and did not lead to viro-immunological or clinical deterioration. Pharmacoeconomic analysis showed better containment of the overall costs. No patient needed to be hospitalised during the observation period

Use of Dalbavancin in Skin, Bone and Joint Infections: A Real-Life Experience in an Italian Center

Dalbavancin is a lipoglycopeptide approved for the treatment of acute bacterial skin and skin structure infections (ABSSSI). The aim of the study was to evaluate the efficacy and safety in all patients who received at least one administration of dalbavancin. Methods: We carried out a retrospective study of the use of dalbavancin in 55 patients at the Azienda Ospedaliera Ospedali Riuniti Umberto I (Ancona, Italy) from February 2017 to May 2020 and compared “on label” and “off label” use of dalbavancin in ABSSSI and non-ABSSSI. Results: A total of 55 patients were included in the study. The median age was 61 years; 51% had ABSSSI; 24% had prosthetic joint infections, and 14% had osteomyelitis. A total of 53% received a single 1500 mg infusion of dalbavancin, and 18% received a second dose 14 days later; 24% of patients received further doses at 14-day intervals. In 91% of cases, patients achieved clinical objectives with dalbavancin: 96% of patients with ABSSSI and 69% of those with prosthetic joint infections. Conclusions: Dalbavancin was shown to have an excellent tolerability profile and to be a highly successful therapeutic approach even in those cases treated “off-label”

Ceftazidime–Avibactam for the Treatment of Multidrug-Resistant Pathogens: A Retrospective, Single Center Study

Background: Ceftazidime/avibactam is a new cephalosporin/beta-lactamase inhibitor combination approved in 2015 by the FDA for the treatment of complicated intra-abdominal and urinary tract infection, hospital-acquired pneumoniae and Gram-negative infections with limited treatment options. Methods: In this retrospective study, we evaluate the efficacy of ceftazidime/avibactam treatment in 81 patients with Gram-negative infection treated in our center from January 2018 to December 2019. The outcome evaluated was 30-days survival or relapse of infection after the first positive blood culture. Results: the majority of patients were 56 male (69%), with median age of 67. Charlson’s Comorbidity Index was >3 in 58 patients. In total, 46% of the patients were admitted into the medical unit, 41% in the ICU, and 14% in the surgical ward. Of the patients, 78% had nosocomial infections, and 22% had healthcare-related infections. The clinical failure rate was 35%: 13 patients died within 30 days from the onset of infection. The outcome was influenced by the clinical condition of the patients: solid organ transplantation (p = 0.003) emerged as an independent predictor of mortality; non-survival patients most frequently had pneumonia (p = 0.009) or mechanical ventilation (p = 0.049). Conclusion: Ceftazidime–avibactam showed high efficacy in infections caused by MDR Gram-negative pathogens with limited therapeutic options

Ceftazidime-Avibactam for the Treatment of Multidrug-Resistant Pathogens: A Retrospective, Single Center Study

Background: Ceftazidime/avibactam is a new cephalosporin/beta-lactamase inhibitor combination approved in 2015 by the FDA for the treatment of complicated intra-abdominal and urinary tract infection, hospital-acquired pneumoniae and Gram-negative infections with limited treatment options. Methods: In this retrospective study, we evaluate the efficacy of ceftazidime/avibactam treatment in 81 patients with Gram-negative infection treated in our center from January 2018 to December 2019. The outcome evaluated was 30-days survival or relapse of infection after the first positive blood culture. Results: the majority of patients were 56 male (69%), with median age of 67. Charlson’s Comorbidity Index was >3 in 58 patients. In total, 46% of the patients were admitted into the medical unit, 41% in the ICU, and 14% in the surgical ward. Of the patients, 78% had nosocomial infections, and 22% had healthcare-related infections. The clinical failure rate was 35%: 13 patients died within 30 days from the onset of infection. The outcome was influenced by the clinical condition of the patients: solid organ transplantation (p = 0.003) emerged as an independent predictor of mortality; non-survival patients most frequently had pneumonia (p = 0.009) or mechanical ventilation (p = 0.049). Conclusion: Ceftazidime–avibactam showed high efficacy in infections caused by MDR Gram-negative pathogens with limited therapeutic options