Evaluation of antibiofilm activity of cefiderocol alone and in combination with imipenem against Pseudomonas aeruginosa.

OBJECTIVES: The main aim of this study was to evaluate the antibiofilm activity of cefiderocol alone and in combination with imipenem vs. sessile cells of Pseudomonas aeruginosa, assessing a potential synergistic bactericidal effect. METHODS: Ten P. aeruginosa clinical isolates from infected implants and bloodstream were included in the study. Cefiderocol was tested alone and in combination with imipenem on 24-h-old P. aeruginosa biofilm formed on porous glass beads. For each antibiotic formulation, minimum bactericidal biofilm concentration (MBBC), defined as the lowest concentration that determined a reduction of at least 3 log10 CFU/mL compared with the untreated control, was evaluated. Scanning electron microscopy (SEM) was used to investigate the biofilm of P. aeruginosa treated with cefiderocol, imipenem, or their combination. RESULTS: Cefiderocol and imipenem were tested alone on P. aeruginosa biofilm and a reasonable reduction in the number of viable cells was observed, especially at high drug concentrations tested. The synergistic effect of cefiderocol in combination with imipenem was evaluated for five selected isolates. Cotreatment with the two drugs led to a remarkable reduction of cell viability by resulting in synergistic bactericidal activity in all tested strains and in synergistic eradicating activity in only one isolate. SEM analysis revealed that, in cefiderocol-treated biofilm, bacterial cells became more elongated than in the untreated control, forming filaments in which bacterial division seems to be inhibited. CONCLUSIONS: Cefiderocol exhibited an encouraging antibiofilm activity against tested strains, representing a valid option for the treatment of P. aeruginosa biofilm-associated infections, especially when administered in combination with imipenem.

Efficacy of Convalescent Plasma to Treat Long-Standing COVID-19 in Patients with B-Cell Depletion.

The use of antivirals, corticosteroids, and IL-6 inhibitors has been recommended by the WHO to treat COVID-19. CP has also been considered for severe and critical cases. Clinical trials on CP have shown contradictory results, but an increasing number of patients, including immunocompromised ones, have shown benefits from this treatment. We reported two clinical cases of patients with prolonged COVID-19 infection and B-cell depletion who showed rapid clinical and virological recovery after the administration of CP. The first patient in this study was a 73-year-old female with a history of follicular non-Hodgkin lymphoma previously treated with bendamustine followed by maintenance therapy with rituximab. The second patient was a 68-year-old male with chronic obstructive pulmonary disease, bipolar disorder, alcoholic liver disease, and a history of mantellar non-Hodgkin lymphoma treated with rituximab and radiotherapy. After the administration of CP, both patients showed a resolution of symptoms, improvement of their clinical conditions, and a negative result of the nasopharyngeal swab test. The administration of CP might be effective in resolving symptoms and improving clinical and virological outcomes in patients with B-cell depletion and prolonged SARS-CoV2 infections.

Application of Phage Therapy in a Case of a Chronic Hip-Prosthetic Joint Infection due to Pseudomonas aeruginosa: An Italian Real-Life Experience and In Vitro Analysis.

Background: Prosthetic joint infection (PJI) caused by Pseudomonas aeruginosa represents a severe complication in orthopedic surgery. We report the case of a patient with chronic PJI from P. aeruginosa successfully treated with personalized phage therapy (PT) in combination with meropenem. Methods: A 62-year-old woman was affected by a chronic right hip prosthesis infection caused by P. aeruginosa since 2016 . The patient was treated with phage Pa53 (I day 10 mL q8h, then 5 mL q8h via joint drainage for 2 weeks) in association with meropenem (2gr q12h iv) after a surgical procedure. A 2-year clinical follow up was performed. An in vitro bactericidal assay of the phage alone and in combination with meropenem against a 24-hour-old biofilm of bacterial isolate was also carried out. Results: No severe adverse events were observed during PT. Two years after suspension, there were no clinical signs of infection relapse, and a marked leukocyte scan showed no pathological uptake areas. In vitro studies showed that the minimum biofilm eradicating concentration of meropenem was 8 µg/mL. No biofilm eradication was observed at 24 hours incubation with phages alone (108 plaque-forming units [PFU]/mL). However, the addition of meropenem at suberadicating concentration (1 µg/mL) to phages at lower titer (103 PFU/mL) resulted in a synergistic eradication after 24 hours of incubation. Conclusions: Personalized PT, in combination with meropenem, was found to be safe and effective in eradicating P. aeruginosa infection. These data encourage the development of personalized clinical studies aimed at evaluating the efficacy of PT as an adjunct to antibiotic therapy for chronic persistent infections.

Phage-Based Control of Methicillin Resistant Staphylococcus aureus in a Galleria mellonella Model of Implant-Associated Infection.

Staphylococcus aureus implant-associated infections are difficult to treat because of the ability of bacteria to form biofilm on medical devices. Here, the efficacy of Sb-1 to control or prevent S. aureus colonization on medical foreign bodies was investigated in a Galleria mellonella larval infection model. For colonization control assays, sterile K-wires were implanted into larva prolegs. After 2 days, larvae were infected with methicillin-resistant S. aureus ATCC 43300 and incubated at 37 °C for a further 2 days, when treatments with either daptomycin (4 mg/kg), Sb-1 (107 PFUs) or a combination of them (3 x/day) were started. For biofilm prevention assays, larvae were pre-treated with either vancomycin (10 mg/kg) or Sb-1 (107 PFUs) before the S. aureus infection. In both experimental settings, K-wires were explanted for colony counting two days after treatment. In comparison to the untreated control, more than a 4 log10 CFU and 1 log10 CFU reduction was observed on K-wires recovered from larvae treated with the Sb-1/daptomycin combination and with their singular administration, respectively. Moreover, pre-infection treatment with Sb-1 was found to prevent K-wire colonization, similarly to vancomycin. Taken together, the obtained results demonstrated the strong potential of the Sb-1 antibiotic combinatory administration or the Sb-1 pretreatment to control or prevent S. aureus-associated implant infections.

Bacteriophage therapy: an overview and the position of Italian Society of Infectious and Tropical Diseases.

In recent years, the increase of antibiotic resistance and the lack in the pipeline of novel antimicrobial molecules make bacterial infections difficult to treat. Among European countries, Italy is the one region with a higher number of deaths caused by antibiotic-resistant bacteria. Moreover, a major concern is represented by biofilm-related infections. The ability of bacteria to form biofilm in presence of implanted-medical devices represents a further challenge for the treatment of bacterial infections. Thus, the development of alternative strategies to fight multi-drug resistant bacteria embedded in biofilms is an urgent need. Nowadays, bacteriophage therapy represents one of the potential and promising treatment options to overcome antibiotic resistance phenomenon. Bacteriophages are viruses capable to infect and replicate within bacterial cell. They are widespread in soil and water and play a role in microbial physiology. Since their discovery at the beginning of the twentieth century bacteriophages were used with therapeutic purposes against bacterial infections. However, the advent of the antibiotic era spurred medical doctors to abandon phage therapy in return for the most promising antibiotic therapy. For historical reasons, only few countries in the world, including Georgia, Russia and Poland have carried on the use of phages for therapeutic purposes and have developed specialised research and treatment centres, where phage therapy is permitted and applied to cure infectious disease. Although the efficacy of bacteriophages for treatment of infections is widely documented, the introduction of phage therapy in common management of bacterial infections in European hospital is hindered by the lack of an appropriate legal and regulatory framework. Different strategies have been used to overcome this problem, like the "Magistral Phage" preparation in Belgium. Here, we provide a review of the fundamental concept on bacteriophage therapy and propose this treatment as a possible alternative choice when antibiotics and surgery are not enough to eradicate a bacterial infection. We believe that the introduction of phage therapy in Italy might improve the quality of life of patients suffering of chronic bacterial infections and fight antibiotic resistances problem. To reach this goal the support and the promotion of Italian government and the scientific authorities is essential. SIMIT, the Italian Society of Infectious and Tropical Diseases, proposes to support the creation of an Italian Task Force to improve knowledge on bacteriophage therapy, collect stronger evidence about their efficacy and develop appropriate protocols for phage administration.

Mild clinical manifestations of SARS-CoV-2 related pneumonia in two patients with multiple sclerosis under treatment with ocrelizumab.

BACKGROUND: Recently SARS-CoV-2 has spread worldwide causing a pandemic. Little is known about disease severity in immunocompromised hosts and people receiving disease modifying therapies (DMTs). In the last decades DMTs have been widely employed, and ocrelizumab represents one of the newest therapies for the relapsing remitting and progressive forms of multiple sclerosis (MS). OBJECTIVES: to describe SARS-CoV-2 related pneumonia in two MS patients under ocrelizumab treatment. METHODS: Case series. RESULTS: Patients showed a mild clinical course of SARS-CoV-2 related pneumonia without complications or sequelae. CONCLUSION: Ocrelizumab treatment is not necessarily associated to increased severity in MS patients with SARS-CoV-2 infection.

Subjective neurological symptoms frequently occur in patients with SARS-CoV2 infection.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) represents a novel pneumonia leading to severe acute respiratory syndrome (SARS). Recent studies documented that SARS-Coronavirus2 (SARS-CoV2), responsible for COVID-19, can affect the nervous system. The aim of the present observational study was to prospectively assess subjective neurological symptoms (sNS) in patients with SARS-CoV2 infection. METHODS: We included patients hospitalized at the University Hospital of Rome "Tor Vergata", medical center dedicated to the treatment of patients with COVID-19 diagnosis, who underwent an anamnestic interview about sNS consisting of 13 items, each related to a specific symptom, requiring a dichotomized answer. RESULTS: We included 103 patients with SARS-CoV2 infection. Ninety-four patients (91.3%) reported at least one sNS. Sleep impairment was the most frequent symptom, followed by dysgeusia, headache, hyposmia, and depression. Women more frequently complained hyposmia, dysgeusia, dizziness, numbeness/paresthesias, daytime sleepiness, and muscle ache. Moreover, muscle ache and daytime sleepiness were more frequent in the first 2 days after admission. Conversely, sleep impairment was more frequent in patients with more than 7 days of hospitalization. In these patients we also documented higher white blood cells and lower C-reactive protein levels. These laboratory findings correlated with the occurrence of hyposmia, dysgeusia, headache, daytime sleepiness, and depression. CONCLUSIONS: Patients with SARS-CoV2 infection frequently present with sNS. These symptoms are present from the early phases of the disease. The possibly intrinsic neurotropic properties of SARS-CoV2 may justify the very high frequency of sNS. Further studies targeted at investigating the consequences of SARS-CoV2 infection on the CNS should be planned.

HBcAb seropositivity is correlated with poor HIV viremia control in an Italian cohort of HIV/HBV-coinfected patients on first-line therapy.

The morbidity and mortality rates of human immunodeficiency virus (HIV)-hepatitis B virus (HBV) coinfection are higher than that of either infection alone. Outcomes and the virological response to antiretrovirals (combination antiretroviral therapy, cART) were explored in HIV/HBV subjects in a cohort of Italian patients treated with cART. A single-center retrospective analysis of patients enrolled from January 2007 to June 2018 was conducted by grouping patients by HBV status and recording baseline viro-immunological features, the history of virological failure, the efficacy of cART in achieving HIV viral undetectability, viral blip detection and viral rebound on follow up. Among 231 enrolled patients, 10 (4.3%) were HBV surface (s) antigen (HBsAg)-positive, 85 (36.8%) were positive for antibodies to HBV c antigen (HBcAb) and with or without antibodies to HBV s antigen (HBsAb), and 136 were (58.9%) HBV-negative. At baseline, HBcAb/HBsAb+/--positive patients had lower CD4+ cell counts and CD4+ nadirs (188 cell/mmc, IQR 78-334, p = 0.02 and 176 cell/mmc, IQR 52-284, p = 0,001, respectively). There were significantly higher numbers of AIDS and non-AIDS events in the HBcAb+/HBsAb+/--positive subjects than in the HBV-negative patients (41.1% vs 19.1%, p = 0.002 and 56.5% vs 28.7%, respectively, p ≤ 0.0001); additionally, HIV viremia undetectability was achieved a significantly longer time after cART was begun in the former than in the latter population (6 vs 4 months, p = 0.0001). Cox multivariable analysis confirmed that after starting cART, an HBcAb+/HBsAb+/--positive status is a risk factor for a lower odds of achieving virological success and a higher risk of experiencing virological rebound (AHR 0.63, CI 95% 0.46-0.87, p = 0.004 and AHR 2.52, CI 95% 1.09-5.80, p = 0.030). HBcAb-positive status resulted in a delay in achieving HIV < 50 copies/mL and the appearance of viral rebound in course of cART, hence it is related to a poor control of HIV infection in a population of coinfected patients.