240 research outputs found
Predominance of international clone 2 OXA-23-producing-Acinetobacter baumannii clinical isolates in Greece, 2015: results of a nationwide study
No full textIn a previous nationwide study in Greece, OXA-58 was the sole carbapenemase present among carbapenem-resistant Acinetobacter baumannii (CRAB) isolated between 2000 and 2009. In this study, the antibiotic resistances, carbapenemase gene content and clonal relatedness of 194 single-patient CRAB clinical isolates collected randomly during 2015 from 11 tertiary hospitals located throughout Greece were investigated. Antimicrobial susceptibility was determined using commercial and dilution methods. PCR assays for carbapenemase genes were performed. Clonality was tested by a scheme based on two multiplex PCRs and single-locus blaOXA-51-like sequence-based typing. Furthermore, Pasteur's multilocus sequence typing (MLST) scheme and pulsed-field gel electrophoresis (PFGE) were applied to 31 selected representative isolates. The most active antibiotics were trimethoprim/sulfamethoxazole (SXT) (34.6% of isolates susceptible), minocycline (71.6%), colistin (72.7%) and tigecycline (MIC50/90 values, 1/2 mg/L). The blaOXA-23-like gene was identified in 188 isolates (96.9%), blaOXA-23-like together with blaOXA-58-like in 3 isolates (1.5%), blaOXA-58-like in 2 isolates (1.0%) and blaOXA-40-like in 1 isolate (0.5%). ISAba1 was found upstream of the blaOXA-23-like gene in all isolates. International clone (IC) 2 comprised 157 isolates (80.9%), IC1 comprised 36 isolates (18.6%) and ST78 comprised 1 isolate (0.5%). All IC2 and IC1 isolates tested by MLST were ST2 and ST1, respectively. Seven PFGE types were detected. IC2 isolates were resistant to more antibiotics than IC1, except for SXT. This nationwide study showed that CRAB isolates in Greek hospitals currently produce almost uniformly the OXA-23 carbapenemase and belong mainly to IC2 and, to a lesser extent, IC1. Of particular concern, colistin susceptibility is recently severely reduced
Tracing day-zero and forecasting the COVID-19 outbreak in Lombardy, Italy: A compartmental modelling and numerical optimization approach.
Get PDFIntroductionItaly became the second epicenter of the novel coronavirus disease 2019 (COVID-19) pandemic after China, surpassing by far China's death toll. The disease swept through Lombardy, which remained in lockdown for about two months, starting from the 8th of March. As of that day, the isolation measures taken in Lombardy were extended to the entire country. Here, assuming that effectively there was one case "zero" that introduced the virus to the region, we provide estimates for: (a) the day-zero of the outbreak in Lombardy, Italy; (b) the actual number of asymptomatic infected cases in the total population until March 8; (c) the basic (R0)and the effective reproduction number (Re) based on the estimation of the actual number of infected cases. To demonstrate the efficiency of the model and approach, we also provide a tentative forecast two months ahead of time, i.e. until May 4, the date on which relaxation of the measures commenced, on the basis of the COVID-19 Community Mobility Reports released by Google on March 29.MethodsTo deal with the uncertainty in the number of the actual asymptomatic infected cases in the total population Volpert et al. (2020), we address a modified compartmental Susceptible/ Exposed/ Infectious Asymptomatic/ Infected Symptomatic/ Recovered/ Dead (SEIIRD) model with two compartments of infectious persons: one modelling the cases in the population that are asymptomatic or experience very mild symptoms and another modelling the infected cases with mild to severe symptoms. The parameters of the model corresponding to the recovery period, the time from the onset of symptoms to death and the time from exposure to the time that an individual starts to be infectious, have been set as reported from clinical studies on COVID-19. For the estimation of the day-zero of the outbreak in Lombardy, as well as of the "effective" per-day transmission rate for which no clinical data are available, we have used the proposed SEIIRD simulator to fit the numbers of new daily cases from February 21 to the 8th of March. This was accomplished by solving a mixed-integer optimization problem. Based on the computed parameters, we also provide an estimation of the basic reproduction number R0 and the evolution of the effective reproduction number Re. To examine the efficiency of the model and approach, we ran the simulator to "forecast" the epidemic two months ahead of time, i.e. from March 8 to May 4. For this purpose, we considered the reduction in mobility in Lombardy as released on March 29 by Google COVID-19 Community Mobility Reports, and the effects of social distancing and of the very strict measures taken by the government on March 20 and March 21, 2020.ResultsBased on the proposed methodological procedure, we estimated that the expected day-zero was January 14 (min-max rage: January 5 to January 23, interquartile range: January 11 to January 18). The actual cumulative number of asymptomatic infected cases in the total population in Lombardy on March 8 was of the order of 15 times the confirmed cumulative number of infected cases, while the expected value of the basic reproduction number R0 was found to be 4.53 (min-max range: 4.40- 4.65). On May 4, the date on which relaxation of the measures commenced the effective reproduction number was found to be 0.987 (interquartiles: 0.857, 1.133). The model approximated adequately two months ahead of time the evolution of reported cases of infected until May 4, the day on which the phase I of the relaxation of measures was implemented over all of Italy. Furthermore the model predicted that until May 4, around 20% of the population in Lombardy has recovered (interquartile range: ∼10% to ∼30%)
Acta Microbiologica Hellenica: A New Era of a Historical Journal
No full textThe first issue of Acta Microbiologica Hellenica, a bimonthly journal in Greek, was published in 1956 by the Hellenic Society for Microbiology, one of the oldest and most respected scientific Greek medical societies, founded in 1932 [...
The Value of a “One Health” Approach—The Updated Scope of Acta Microbiologica Hellenica
No full textThe COVID-19 pandemic has challenged the resilience of public health sectors worldwide [...
Correction to: Development, Current Status, and Remaining Challenges for Respiratory Syncytial Virus Vaccines (Vaccines, (2025), 13, 2, (97), 10.3390/vaccines13020097)
No full textThe authors would like to make the following corrections to this published paper [1]. In the original publication, there was an inaccuracy in Table 1 as the CDC instead of the FDA indications had been reported erroneously for RSVPreF in the United States. The corrected Table 1 is attached below. Corrections were also necessary in Table 2 since the way we had originally presented vaccine efficacy gave the impression that the data are directly comparable. As already mentioned in the last sentence of the introduction of Section 5 (Approval Status, Safety, and Efficacy of Approved RSV Vaccines) and in the first paragraph of Section 7 (Remaining Challenges for RSV Vaccines) of the original publication, the definitions of the endpoints of the three RSV vaccines differ, and comparisons are difficult to interpret [1]. The edited Table 2 is attached below. Consequent to these changes, the last two sentences of the fourth paragraph in Section 5.1.2, “RSVPreF (Abrysvo, Pfizer)”, should be replaced with the following: “This overview of the available data indicates that, although it is not currently recommended, revaccination may be needed for protection against RSV-LRTD in the seasons to come, independently of which RSV vaccine is used [52].” The last sentence of the fifth paragraph in Section 5.1.2 of the original publication should be changed simply to “the GBS reports were 4.4 cases per million administered doses of Abrysvo [59]” because the increased incidence of GBS following RSVPreF was not statistically significant. Finally, the Conflicts of Interest should be changed to “Prof. Tsakris participated once in an Advisory Board meeting on RSV prevention in adults held in Athens by Pfizer in 2023. All the other authors declare no conflicts of interest.” This information/potential minor conflict of interest was inadvertently omitted in the original version of the article. With this correction, the order of some references has been adjusted accordingly. The authors would like to apologize for any inconvenience caused to the readers by these changes. The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated. © 2025 by the authors
Impaired Metabolism of Selenomethionine in Graves’ Disease: A Biokinetics Study of Soft Gel Capsule Formulation
No full textAbstractPatients with Graves’ disease are known to have low selenium (Se) status, Se supplementation resulting in clinical and biochemical improvement. Selenomethionine (SeMet) in a new soft gel capsule formulation was used in a pilot study in 6 patients with acute Graves’ disease and low selenium levels (61.3±12.9 μg/l) before and in 4/6 patients 3 months after combined treatment with methimazole and SeMet 200 μg/day (113.3±46.3 μg/l), as well as in 6 euthyroid controls (82±11.8 μg/l). The biokinetics were studied following ingestion of 200 μg SeMet (single dose) soft gel capsule, Se serum concentrations being measured at various time points within 24 h. Se levels rose variably in all patients and controls. While levels peaked in all subjects following 8 h of intake, the increase was somewhat slower in acute hyperthyroidism as compared to 3 months later when these patients had been rendered euthyroid, this possibly due to derangement of Se storage capacity by SEPP or increased requirements in the acute phase of the disease, leading to depletion of the trace element. The compound was shown to be bioavailable and safe and patients treated for 3 months exhibited higher Se levels at the different time points. These findings are of major importance for sufferers of GD since they indicate that early Se supplementation, with its beneficial antioxidant impact on inflammatory activity, could slow, or possibly even forestall, the clinical progression of the disease.</jats:p
Comparative Genomics of an Emerging Multidrug-Resistant blaNDM-Carrying ST182 Lineage in Enterobacter cloacae Complex
No full textBackground: Enterobacter cloacae, E. hormaechei and related subspecies remain the most clinically relevant among the Enterobacter cloacae complex (ECC). Carbapenemase-producing ECC strains are increasingly identified in hospital-acquired infections and usually belong to four main multilocus sequence types (MLST STs) named ST114, ST93, ST90 and ST78. Instead, ST182 has been sporadically reported among E. hormaechei strains, and recently, outbreaks of blaNDM-producing ST182 clonal strains have emerged. Herein, we aimed to investigate the presence of ST182 and explore its evolution and modes of blaNDM acquisition. Methods: A phylogenetic analysis of 646 MLST STs identified among 4685 E. hormaechei whole-genome sequencing (WGS) assemblies deposited in public repositories was performed, as well as an in silico comparative and phylogenomic analyses for 55 WGS assemblies of ST182. blaNDM-harboring contigs were also compared to published plasmid sequences. Results: ST182 E. hormaechei strains were recovered from patients on five continents during 2011–2021. They were divided into three major genomic clusters, comprising a separate clonal complex with six other STs. In 30 out of 55 ST182 WGS assemblies, blaNDM-harboring structures were identified that were similar to the plasmids predominant in Gram-negative bacteria, harboring resistance genes to multiple antibiotic classes and virulence genes. No associations between the genomic clusters and the country/continent of isolation or the presence and the plasmid types of the blaNDM-harboring contigs were observed. Conclusions: Our findings show that ST182 E. hormaechei strains have been identified in the past decade worldwide; 54.5% of them carried diverse blaNDM genetic structures, suggesting recent acquisition of the blaNDM alleles. Thus, blaNDM-harboring ST182 is an emerging multidrug-resistant and virulent lineage in ECC strains that requires close monitoring
Post-COVID Syndrome: An Insight on Its Pathogenesis
No full textPost-COVID syndrome is increasingly recognized as a new clinical entity in the context of SARS-CoV-2 infection. Symptoms persisting for more than three weeks after the diagnosis of COVID-19 characterize the post-COVID syndrome. Its incidence ranges from 10% to 35%, however, rates as high as 85% have been reported among patients with a history of hospitalization. Currently, there is no consensus on the classification of post-COVID syndrome. We reviewed the published information on post-COVID syndrome, putting emphasis on its pathogenesis. The pathogenesis of post-COVID syndrome is multi-factorial and more than one mechanism may be implicated in several clinical manifestations. Prolonged inflammation has a key role in its pathogenesis and may account for some neurological complications, cognitive dysfunction, and several other symptoms. A multisystem inflammatory syndrome in adults (MIS-A) of all ages has been also described recently, similarly to multisystem inflammatory syndrome in children (MIS-C). The post-infectious inflammatory pathogenetic mechanism of MIS-A is supported by the fact that its diagnosis is established through serology in up to one third of cases. Other pathogenetic mechanisms that are implicated in post-COVID syndrome include immune-mediated vascular dysfunction, thromboembolism, and nervous system dysfunction. Although the current data are indicating that the overwhelming majority of patients with post-COVID syndrome have a good prognosis, registries to actively follow them are needed in order to define the full clinical spectrum and its long-term outcome. A consensus-based classification of post-COVID syndrome is essential to guide clinical, diagnostic, and therapeutic management. Further research is also imperative to elucidate the pathogenesis of post-COVID syndrome
Data-based analysis, modelling and forecasting of the COVID-19 outbreak
No full textSince the first suspected case of coronavirus disease-2019 (COVID-19) on December 1st, 2019, in Wuhan, Hubei Province, China, a total of 40,235 confirmed cases and 909 deaths have been reported in China up to February 10, 2020, evoking fear locally and internationally. Here, based on the publicly available epidemiological data for Hubei, China from January 11 to February 10, 2020, we provide estimates of the main epidemiological parameters. In particular, we provide an estimation of the case fatality and case recovery ratios, along with their 90% confidence intervals as the outbreak evolves. On the basis of a Susceptible-Infectious-Recovered-Dead (SIDR) model, we provide estimations of the basic reproduction number (R0), and the per day infection mortality and recovery rates. By calibrating the parameters of the SIRD model to the reported data, we also attempt to forecast the evolution of the outbreak at the epicenter three weeks ahead, i.e. until February 29. As the number of infected individuals, especially of those with asymptomatic or mild courses, is suspected to be much higher than the official numbers, which can be considered only as a subset of the actual numbers of infected and recovered cases in the total population, we have repeated the calculations under a second scenario that considers twenty times the number of confirmed infected cases and forty times the number of recovered, leaving the number of deaths unchanged. Based on the reported data, the expected value of R0 as computed considering the period from the 11th of January until the 18th of January, using the official counts of confirmed cases was found to be ∼4.6, while the one computed under the second scenario was found to be ∼3.2. Thus, based on the SIRD simulations, the estimated average value of R0 was found to be ∼2.6 based on confirmed cases and ∼2 based on the second scenario. Our forecasting flashes a note of caution for the presently unfolding outbreak in China. Based on the official counts for confirmed cases, the simulations suggest that the cumulative number of infected could reach 180,000 (with a lower bound of 45,000) by February 29. Regarding the number of deaths, simulations forecast that on the basis of the up to the 10th of February reported data, the death toll might exceed 2,700 (as a lower bound) by February 29. Our analysis further reveals a significant decline of the case fatality ratio from January 26 to which various factors may have contributed, such as the severe control measures taken in Hubei, China (e.g. quarantine and hospitalization of infected individuals), but mainly because of the fact that the actual cumulative numbers of infected and recovered cases in the population most likely are much higher than the reported ones. Thus, in a scenario where we have taken twenty times the confirmed number of infected and forty times the confirmed number of recovered cases, the case fatality ratio is around ∼0.15% in the total population. Importantly, based on this scenario, simulations suggest a slow down of the outbreak in Hubei at the end of February.</div
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