The impact of COVID-19 pandemic control on vaccine-preventable invasive bacterial diseases in Piedmont (Italy).

PURPOSE: The impact of SARS-CoV-2 pandemic on other pathogens is largely unknown. We aimed to compare the prevalence of vaccine-preventable invasive bacterial infections before and during the pandemic in Piedmont (Italy). METHODS: We defined the monthly incidence of S. pneumoniae, H. influenzae and N. meningitides-invasive diseases from January 2010 to June 2021. Then, we compared the mean monthly cases during the previous 5 years (2015-2019) and the monthly cases in 2020 or 2021. RESULTS: We found significant reductions for invasive pneumococcal diseases (IPDs) in adults and H. influenzae-invasive diseases in 2020 and 2021 in comparison to the previous years, but not for invasive meningococcal diseases and IPDs in children. CONCLUSIONS: Further data are needed to confirm these findings and define possible post-pandemic evolutions in the epidemiology of vaccine-preventable invasive bacterial diseases.

Safety and outcomes of routine endovascular thrombectomy in large artery occlusion recorded in the SITS Register: An observational study.

BACKGROUND AND OBJECTIVE: We aimed to evaluate the safety and outcomes of thrombectomy in anterior circulation acute ischaemic stroke recorded in the SITS-International Stroke Thrombectomy Register (SITS-ISTR) and compare them with pooled randomized controlled trials (RCTs) and two national registry studies. METHODS: We identified centres recording ≥10 consecutive patients in the SITS-ISTR with at least 70% of available modified Rankin Scale (mRS) at 3 months during 2014-2019. We defined large artery occlusion as intracranial internal carotid artery, first and second segment of middle cerebral artery and first segment of anterior cerebral artery. Outcome measures were functional independence (mRS score 0-2) and death at 3 months and symptomatic intracranial haemorrhage (SICH) per modified SITS-MOST. RESULTS: Results are presented in the following order: SITS-ISTR, RCTs, MR CLEAN Registry and German Stroke Registry (GSR). Median age was 73, 68, 71 and 75 years; baseline NIHSS score was 16, 17, 16 and 15; prior intravenous thrombolysis was 62%, 83%, 78% and 56%; onset to reperfusion time was 289, 285, 267 and 249 min; successful recanalization (mTICI score 2b or 3) was 86%, 71%, 59% and 83%; functional independence at 3 months was 45.5% (95% CI: 44-47), 46.0% (42-50), 38% (35-41) and 37% (35-41), respectively; death was 19.2% (19-21), 15.3% (12.7-18.4), 29.2% (27-32) and 28.6% (27-31); and SICH was 3.6% (3-4), 4.4% (3.0-6.4), 5.8% (4.7-7.1) and not available. CONCLUSION: Thrombectomy in routine clinical use registered in the SITS-ISTR showed safety and outcomes comparable to RCTs, and better functional outcomes and lower mortality than previous national registry studies.

Integrating rapid diagnostics in Gram-negative bloodstream infections of patients colonized by carbapenemase-producing Enterobacterales.

We implemented a fast-track diagnostic approach for Gram-negative bloodstram infections (BSIs) among carbapenemase-producing Enterobacterales (CPE) carriers. Within a large cohort of patients with CPE rectal carriage, 18.1% developed Gram-negative BSIs, of which 69.5% were caused by CPE. Direct matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis provided reliable identification in 97% and 53.8% of monomicrobical blood cultures positive to Enterobacterales and non-fermenting Gram-negative species, respectively. Overall, sensitivity and specificity of NG-Test Carba 5 compared with the composite reference method after discrepant analysis were 100%, in polimicrobial blood cultures too. The combined use of direct MALDI-TOF MS and NG-Test Carba 5 assay might be a reliable and cost-effective tool for accelerating the laboratory diagnosis of CPE BSI in cohorts of high-risk patients such as CPE carriers.

Ceftazidime-avibactam resistance and restoration of carbapenem susceptibility in KPC-producing Klebsiella pneumoniae infections: A case series.

OBJECTIVES: Since the introduction of the ß-lactam/ß-lactamase inhibitor ceftazidime-avibactam (CZA), rapid evolution of resistance has been reported in different KPC-producing Klebsiella pneumoniae isolates. In this multicenter retrospective study, we describe the emergence of CZA resistance and evaluate the mutations that might be responsible for the restoration of carbapenem susceptibility. METHODS: During a study period of 18 months, KPC-producing K. pneumoniae isolates of five hospitalized patients were collected with phenotypic development of CZA resistance. RESULTS: In vitro restoration of carbapenem susceptibility during treatment was observed in 3 isolates. Whole genome sequencing of these isolates showed a D179Y mutation in the KPC gene of 2 variants and a KPC-2 with a Δ242-GT-243 deletion (KPC-14). Two KPC-3 variants showed CZA resistance with sustained carbapenemase activity without genomic adaptations in the KPC gene. CONCLUSIONS: This study confirms the emergence of CZA resistance in KPC K. pneumoniae. The role of carbapenems in treating patients with these variants is unclear and combination therapies warrant further investigation.

RESIST-5 O.O.K.N.V. and NG-Test Carba 5 assays for the rapid detection of carbapenemase-producing Enterobacterales from positive blood cultures: a comparative study.

We prospectively compared the performance of RESIST-5 O.O.K.N.V. and NG-Test Carba 5 assays directly from blood cultures spiked with 130 characterized Enterobacterales isolates. Overall, both assays yielded 100% sensitivity to detect KPC-type carbapenemases and OXA-48-like carbapenemases. Both assays failed to detect KPC-31 and KPC-33, D179Y point mutation variants of KPC-3 and KPC-2, that are deprived of carbapenemase activity and confer resistance to ceftazidime-avibactam. On blood culture bacterial pellets, NDM- and VIM-type carbapenemases were detected in 50.0% and 52.2%, respectively, by RESIST-5 O.O.K.N.V. vs 100% by NG-Test Carba 5. The sensitivity of RESIST-5 O.O.K.N.V. improved to 100% and 95.6%, respectively, by performing the assay on 4-h early subculture.

Antibiotic Resistance and Therapy Outcome in H. pylori Eradication Failure Patients.

Helicobacter pylori (H. pylori) eradication fails in a definite amount of patients despite one or more therapeutic attempts. Curing these patients is progressively more difficult, due to development of antibiotic resistance. Current guidelines suggest testing antibiotic susceptibility in H. pylori isolates following two therapeutic attempts. AIM: to evaluate the development of antibiotic resistance, MIC values trends and therapeutic outcomes in patients who failed at least one H. pylori eradication therapy. METHODS: consecutive patients, referred to perform upper gastrointestinal endoscopy (UGIE) to our Unit from January 2009 to January 2019 following at least one therapeutic attempt were considered. Bacterial resistance towards clarithromycin, metronidazole and levofloxacin was tested. Patients received either a susceptibility-guided therapy or Pylera®. RESULTS: a total of 1223 patients were H. pylori positive, and antibiotic susceptibility was available for 1037. The rate of antibiotic resistance and MIC values significantly increased paralleling the number of previous therapeutic attempts. Eradication rates of antibiogram-tailored therapies remained stable, except for the sequential therapy if used as a third line. As a rescue treatment, the Pylera® therapy achieved cure rates comparable to those of the other culture-guided therapies. CONCLUSIONS: A significant increase in the secondary resistance towards the three tested antibiotics was observed, both as rate and MIC values, in correlation with the number of therapy failures. These findings should be considered when administering an empirical second-line therapy. Pylera® therapy eradication rates are comparable to culture-tailored therapies.

Accuracy of the ELITe MGB assays for the detection of carbapenemases, CTX-M, Staphylococcus aureus and mecA/C genes directly from respiratory samples.

INTRODUCTION: Bacterial lower respiratory tract infections (BLRTI) may represent serious clinical conditions which can lead to respiratory failure, intensive care unit admission and high hospital costs. The detection of carbapenemase- and extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales, as well as meticillin-resistant Staphylococcus aureus (MRSA), has become a major issue, especially in healthcare-associated infections. This study aimed to determine whether molecular assays could detect genes encoding carbapenemases, ESBL and MRSA directly from respiratory samples in order to expedite appropriate therapy and infection control for patients with BLRTI. METHODS: The carbapenem-resistant enterobacterales (CRE), ESBL and MRSA/SA ELITe MGB assays were performed directly on 354 respiratory specimens sampled from 318 patients admitted with BLRTI. Molecular results were compared with routine culture-based diagnostics results. RESULTS: Positive (PPV) and negative (NPV) predictive values of the CRE ELITe MGB kit were 75.9% [95% confidence interval (CI) 60.3-86.7] and 100%, respectively. PPV and NPV of the ESBL ELITe MGB kit were 80.8% (95% CI 63.6-91.0) and 99.1% (95% CI 96.6-99.8), respectively. PPV and NPV of the MRSA/SA ELITe MGB kit were 91.7% (95% CI 73.7-97.7)/100% and 98.3% (95% CI 89.8-99.3)/96.8% (95% CI 81.6-99.5), respectively. DISCUSSION: Validity assessment of molecular assays detecting the main antibiotic resistance genes directly from respiratory samples showed high accuracy compared with culture-based results. Molecular assays detecting the main carbapenemase, ESBL, S. aureus and meticillin resistance encoding genes provide an interesting tool with potential to expedite optimization of antibiotic therapy and infection control practices in patients with BLRTI.

Reduction of turnaround time for non-tuberculous mycobacteria detection in heater-cooler units by propidium monoazide-real-time polymerase chain reaction.

BACKGROUND: Invasive non-tuberculous mycobacteria (NTM) infections are emerging worldwide in patients undergoing open-chest cardiac bypass surgery exposed to contaminated heater-cooler units (HCUs). Although this outbreak has been investigated by culturing bacteria isolated from HCU aerosol and water samples, these conventional methods have low-analytic sensitivity, high rates of sample contamination, and long turnaround time. AIM: To develop a simple and effective method to detect NTM in HCUs by real-time polymerase chain reaction (PCR), with a short laboratory turnaround time and reliable culture results. METHODS: A total of 281 water samples collected from various HCUs at seven Italian hospitals were simultaneously screened for NTM by a propidium monoazide (PMA)-PCR assay and by conventional culture testing. The results were analysed with culture testing as the reference method. FINDINGS: (i) The agreement between culture testing and PMA-PCR was 85.0% with a cycle threshold (CT) cut-off value of <38 vs 80.0% with a CT of <43, with a moderate Cohen's κ-coefficient; (ii) the CT cut-off value of <42 was deemed more suitable for predicting positive specimens; (iii) given the low concentration of target DNA in water samples, the minimum volume to be tested was 1 L. CONCLUSION: The use of PMA-PCR for fast detection of NTM from environmental samples is highly recommended in order to ascertain whether HCUs may represent a potential source of human exposure to NTM. This reliable and simple method reduces laboratory turnaround time compared to conventional methods (one to two days vs eight weeks, respectively), thereby improving control strategies and effective management of HCUs.

V348I mutation in UL23 gene of human herpesvirus 1 in a case of herpetic hepatitis and haemophagocytic lymphohistiocytosis.

We herein report the case of a young immunocompetent adult patient with a rapidly fatal haemophagocytic lymphohistiocytosis syndrome related to human herpesvirus 1 (HHV-1) infection, with herpetic hepatitis and persistent high-level viraemia despite treatment with acyclovir. Haemophagocytic lymphohistiocytosis was confirmed in the patient's spleen and bone marrow. HHV-1 DNA was extracted from whole blood and liver biopsy and the UL23 gene was sequenced. A V348I natural polymorphism of the TK protein was found in blood and liver specimens. Further studies are needed to investigate the role of this polymorphism in the development of systemic immune dysregulation.

Detection of antibiotic resistance genes from blood cultures: performance assessment and potential impact on antibiotic therapy management.

Molecular assays may constitute a valid method for timely prediction of antimicrobial resistance and optimization of empirical antibiotic therapies. This study assessed ELITe MGB assays of blood cultures to detect the main carbapenemase and extended-spectrum beta-lactamase (ESBL) genes, Staphylococcus aureus and mec genes in less than 3 h. Excellent agreement was found between the results of genotypic and conventional phenotypic approaches. Retrospective analysis of medical records revealed that approximately 50% of bloodstream infections caused by ESBL-producing Enterobacteriaceae, carbapenemase-producing Enterobacteriaceae or meticillin-resistant S. aureus were initially treated with inactive drugs. Overall, 36.3% of patients could have been treated with appropriate therapy at least 24 h earlier if molecular data had been used.

Grain-size-independent plastic flow at ultrahigh pressures and strain rates.

A basic tenet of material science is that the flow stress of a metal increases as its grain size decreases, an effect described by the Hall-Petch relation. This relation is used extensively in material design to optimize the hardness, durability, survivability, and ductility of structural metals. This Letter reports experimental results in a new regime of high pressures and strain rates that challenge this basic tenet of mechanical metallurgy. We report measurements of the plastic flow of the model body-centered-cubic metal tantalum made under conditions of high pressure (>100 GPa) and strain rate (∼10(7) s(-1)) achieved by using the Omega laser. Under these unique plastic deformation ("flow") conditions, the effect of grain size is found to be negligible for grain sizes >0.25 µm sizes. A multiscale model of the plastic flow suggests that pressure and strain rate hardening dominate over the grain-size effects. Theoretical estimates, based on grain compatibility and geometrically necessary dislocations, corroborate this conclusion.

Biotechnological potential of the seaweed Cladophora rupestris (Chlorophyta, Cladophorales) lipidic extract.

Recently, with the advent of modern technologies, various marine organisms including algae are being studied as sources of natural substances effective on classical microorganisms and able to also combat the new trend of acquired resistance in microbes. In the present study the antimicrobial activity of the lipidic extract of the green seaweed Cladophora rupestris collected in a Mediterranean area, in two sampling periods (January and April), was assayed. The chemical characterization of the lipidic fractions was performed by gas-chromatography and multinuclear and multidimensional NMR spectroscopy. In the lipidic extract of C. rupestris collected in January an antibacterial activity against Enterococcus sp., Streptococcus agalactiae and Vibrio cholerae non-O1 was recorded; by contrast, bacterial inhibition was measured on several Vibrio species only in April. The fatty acid profile of C. rupestris lipidic extract, analyzed by gas chromatography, resulted mainly composed of palmitic, myristic, oleic, α linolenic, palmitoleic and linoleic acids. Moreover, since α-linolenic acid was the predominant ω3 fatty acid in April, we suggest its involvement in the antibacterial activity observed in this month, taking also into account that pure α-linolenic acid resulted effective towards some vibrios strains. C. rupestris fatty acid profile revealed also an interesting composition in polyunsaturated fatty acids in both the considered periods with the ω6/ω3 ratio lower than 1, leading to conclude that this macroalga may be employed as a natural source of ω3. Finally, the (1)H NMR spectrum in CDCl3 of algal lipid fractions showed the characteristic signals of saturated (SAFAs) and unsaturated fatty acids (UFAs) as well as other metabolites and a marked difference in free fatty acids (FFAs) content for the two examined algal lipid fractions. It is noteworthy that C. rupestris lipidic extracts show, by NMR spectroscopy, the signal pattern of polyhydroxybutyrate, a natural biocompatible and biodegradable polymer. In conclusion, on account of its antimicrobial activity, nutritional value and bioplastic content, C. rupestris lipidic extract can be considered a promising source for future biotechnological applications.

Mar Piccolo of Taranto: Vibrio biodiversity in ecotoxicology approach.

Microorganisms play an indispensable role in the ecological functioning of marine environment. Some species are sensitive while others are insensitive for a specific pollutant. The aim of this work is a preliminary study of the quantitative and qualitative distribution of cultivable vibrios in sediments and water samples characterized by different toxicity levels. For 1 year, in three suitably selected sampling stations of Mar Piccolo in Taranto (Ionian Sea, Italy), we have evaluated the toxicity level by Microtox® system, vibrios, total, and fecal coliform densities. The results of the Microtox® tests showed sediments characterized by an elevated level of toxicity, while the interstitial water of the same sites always showed biostimulatory phenomenon. The quantitative results show that vibrios and coliforms are more abundant in water than in sediment samples. The most often isolated strains were: Vibrio alginolyticus, Vibrio mediterranei, Vibrio metschinkovii, and Vibrio splendidus II. This work is the first example of study on the distribution of Vibrio species related to toxicity evaluation conducted by the Microtox® bioassay. The results show the different distribution of Vibrionaceae in two environmental matrices analyzed and characterized by different levels of toxicity.

Tailored cytomegalovirus management in lung transplant recipient: a single-center experience.

INTRODUCTION: Among solid organ recipients lung transplant recipients are at highest risk to be affected by cytomegalovirus infection (CMV) or to die from CMV disease. Two strategies are usually adopted in the clinical management of transplant recipients: antiviral prophylaxis and pre-emptive therapy. METHODS: In our center we adopted from 2007 a combined prophylaxis with anti-CMV immunoglobulins in the first post-transplant year and antiviral therapy (gancyclovir or valgancyclovir) from post-transplant day 15 for 3 weeks and in case of CMV bronchoalveolar lavage specimen positivity (polymerase chain reaction or shell vial). Moreover, we studied specific cellular immune response by an Elispot assay to define responder patients by the number of spot forming units (<5 nonresponders, 5-20 weeks, 20-100 good, >100 very good responders). RESULTS: We reduced acute rejections (from 17% to 6%, odds ratio 3.25), lymphocytic bronchitis bronchiolitis (from 11% to 2%), and first-year CMV pneumonia after the first post-transplant month (from 6.4% to 1%). We showed in nonresponders an earlier onset (68 vs 204 post-transplant days) and a longer duration (>14 days vs <14 days) of infection (P < .05 for all referred data). DISCUSSION: The morbility reduction has been obtained by antiviral therapy, increasing costs and risk of side effects. Our more recent studies show a population with a good immune response that probably doesn't need a pharmacological intervention but just a strict follow-up. CONCLUSION: Our proposed strategy is now tailoring the therapy on immune response clinical application, limiting to the specimen positivity in nonresponders.

Evaluation of Epstein-Barr virus-specific immunologic response in solid organ transplant recipients with an enzyme-linked ImmunoSpot assay.

Epstein-Barr virus (EBV) is a γ-herpes virus, responsible for infectious mononucleosis in immunocompetent hosts. Cellular immunity appears rapidly during EBV primary infection, keeping it silent despite long-life persistence in B lymphocytes. Defects of the EBV-specific cellular immunity are supposed to be the basis of post-transplantation lymphoproliferative disorders, promoted by high levels of immunosuppression. We retrospectively reviewed 197 solid organ transplant recipients to investigate EBV-specific lymphocyte responsiveness using Enzyme-linked ImmunoSpot assay (EliSpot), which assesses the EBV-specific interferon (IFN)-γ producing peripheral blood mononuclear cells, and kinetics of EBV infection/reactivation post-transplantation using quantitative real-time polymerase chain reaction (PCR) on whole blood. Overall, 102 of the 197 patients (51.8%) showed EBV responsiveness at the EBV-EliSpot assay: 68 (66.6%) showed a persistently positive EBV response in 3 or more determinations and 34 (33.3%) had transient episodes of nonresponsiveness. Ninety-five (48.2%) patients were persistently EBV nonresponders. EBV-DNAemia data were available for 58 patients: 27.6% presented at least one episode of EBV-DNA occurrence. No differences were found in EBV-EliSpot response stratification between the groups of patients who experienced episodes of EBV reactivation and those without EBV-DNAemia. However, EBV DNAemia peak values tended to be higher in the first year post-transplantation in the group of patients with a persistent positive EBV-specific immune response. EBV viral load quantitation in blood and EliSpot EBV-specific immune response determination may represent a powerful tool for monitoring solid organ transplant recipients, guiding immunosuppression modulation in patients with active EBV replication.