An outbreak sustained by ST15 Klebsiella pneumoniae carrying 16S rRNA methyltransferases and blaNDM: evaluation of the global dissemination of these resistance determinants

The spread of extremely-drug resistant Klebsiella pneumoniae has become a major health threat worldwide. This is largely mediated by certain lineages, recognized as high-risk clones dispersed in all the world. The analysis of an outbreak of nine ST15, NDM-1 metallo-β-lactamase producing K. pneumoniae was performed. An IncC plasmid carrying the bla_NDM-1 gene also carried the rare rmtC gene, encoding for a 16S rRNA methyltransferases (16RMTases), conferring resistance to all aminoglycosides. We studied the global spread of NDM variants and their association with the 16RMTases among K. pneumoniae complete genomes available in GenBank, producing a complete overview of the association of 16RMTases and NDM in K. pneumoniae genomics. NDM is more and more often associated with16RMTases and both are spreading in K. pneumoniae, conferring resistance to every beta-lactam and aminoglycoside. Our analysis suggest that aminoglycosides have limited future as second line treatment against NDM-producing K. pneumoniae.

Real-life use of remdesivir-containing regimens in COVID-19: a retrospective case-control study

BACKGROUND

Remdesivir (REM) has shown potent antiviral activity in vitro and efficacy in animal models of COVID-19; nevertheless, clinical trials and real-life reports have shown conflicting data on its effectiveness. Aims of the study were to evaluate the impact of remdesivir on I) Intensive Care Unit (ICU) admission, II) need for orotracheal intubation (OTI) and III) in-hospital mortality. Furthermore, we estimated the kinetics of laboratory parameters and assessed the risk factors for in-hospital mortality in the remdesivir population.

METHODS

We conducted a retrospective, single-center, case-control (1:1) study including hospitalized patients with confirmed SARS-CoV-2 infection. Cases were patients treated with remdesivir for 5 days, controls were patients not receiving remdesivir.

RESULTS

A total of 192 patients (96 cases and 96 controls) were included in the study. Patients receiving remdesivir had a lower rate of ICU admission and need for OTI than controls, whereas no difference between cases and controls were observed as for mortality rate. However, at multivariable analysis remdesivir was not associated with ICU admission neither with OTI. Instead, presence of haematological malignancies, lower duration of symptoms, higher severity of infection and low lymphocytes count at admission were independently associated with in-hospital mortality. In patients treated with remdesivir a low albumin value and duration of lymphopenia were significantly associated with mortality.

CONCLUSIONS

Our real-life study showed that therapy with remdesivir did not have impact on either ICU admission, need for OTI or in-hospital mortality.

Persistent Systemic Microbial Translocation and Intestinal Damage During Coronavirus Disease-19

Microbial translocation (MT) and intestinal damage (ID) are poorly explored in COVID-19. Aims were to assess whether alteration of gut permeability and cell integrity characterize COVID-19 patients, whether it is more pronounced in severe infections and whether it influences the development of subsequent bloodstream infection (BSI). Furthermore, we looked at the potential predictive role of TM and ID markers on Intensive Care Unit (ICU) admission and in-hospital mortality. Over March–July 2020, 45 COVID-19 patients were enrolled. Markers of MT [LPB (Lipopolysacharide Binding Protein) and EndoCab IgM] and ID [I-FABP (Intestinal Fatty Acid Binding Protein)] were evaluated at COVID-19 diagnosis and after 7 days. As a control group, age- and gender-matched healthy donors (HDs) enrolled during the same study period were included. Median age was 66 (56-71) years. Twenty-one (46.6%) were admitted to ICU and mortality was 22% (10/45). Compared to HD, a high degree of MT and ID was observed. ICU patients had higher levels of MT, but not of ID, than non-ICU ones. Likewise, patients with BSI had lower EndoCab IgM than non-BSI. Interestingly, patients with high degree of MT and low ID were likely to be admitted to ICU (AUC 0.822). Patients with COVID-19 exhibited high level of MT, especially subjects admitted to ICU. COVID-19 is associated with gut permeability.

Determinants of prolonged viral RNA shedding in hospitalized patients with SARS-CoV-2 infection

OBJECTIVE

To evaluate determinants of prolonged viral RNA shedding in hospitalized patients with SARS-CoV-2 infection.

MATERIALS AND METHODS

Hospitalized patients with SARS-CoV-2 positive nasopharyngeal RT-PCR were included in a single-center, retrospective study. Patients were divided in 2 groups according to the timing of viral clearance [≤14 days, "early clearance (EC)" and >14 days, "late clearance (LC)"].

RESULTS

179 patients were included in the study (101 EC, 78 LC), with median age 62 years. Median time of viral shedding was 14 days (EC/LC 10 and 19 days, respectively, P < 0.0001). Univariate analyses showed that age, male gender, receiving corticosteroids, receiving tocilizumab, ICU admission, low albumin and NLR ratio were associated with late viral clearance. In the multivariable analysis, older age (P = 0.016), albumin level (P = 0.048), corticosteroids (P = 0.021), and tocilizumab (P = 0.015) were significantly associated with late viral clearance.

CONCLUSIONS

Age, albumin, tocilizumab and corticosteroid treatment were independently associated with a prolonged SARS-CoV-2 RNA shedding.

Ozone as adjuvant support in the treatment of COVID-19: A preliminary report of probiozovid trial

The evaluation of new therapeutic resources against coronavirus disease 2019 (COVID-19) represents a priority in clinical research considering the minimal options currently available. To evaluate the adjuvant use of systemic oxygen-ozone administration in the early control of disease progression in patients with COVID-19 pneumonia. PROBIOZOVID is an ongoing, interventional, randomized, prospective, and double-arm trial enrolling patient with COVID-19 pneumonia. From a total of 85 patients screened, 28 were recruited. Patients were randomly divided into ozone-autohemotherapy group (14) and control group (14). The procedure consisted in a daily double-treatment with systemic Oxygen-ozone administration for 7 days. All patients were treated with ad interim best available therapy. The primary outcome was delta in the number of patients requiring orotracheal-intubation despite treatment. Secondary outcome was the difference of mortality between the two groups. Moreover, hematological parameters were compared before and after treatment. No differences in the characteristics between groups were observed at baseline. As a preliminary report we have observed that one patient for each group needed intubation and was transferred to ITU. No deaths were observed at 7-14 days of follow up. Thirty-day mortality was 8.3% for ozone group and 10% for controls. Ozone therapy did not significantly influence inflammation markers, hematology profile, and lymphocyte subpopulations of patients treated. Ozone therapy had an impact on the need for the ventilatory support, although did not reach statistical significance. Finally, no adverse events related to the use of ozone-autohemotherapy were reported. Preliminary results, although not showing statistically significant benefits of ozone on COVID-19, did not report any toxicity.

Challenges in the Management of SARS-CoV2 Infection: The Role of Oral Bacteriotherapy as Complementary Therapeutic Strategy to Avoid the Progression of COVID-19

Background: Gastrointestinal disorders are frequent in COVID-19 and SARS-CoV-2 has been hypothesized to impact on host microbial flora and gut inflammation, infecting intestinal epithelial cells. Since there are currently no coded therapies or guidelines for treatment of COVID-19, this study aimed to evaluate the possible role of a specific oral bacteriotherapy as complementary therapeutic strategy to avoid the progression of COVID-19.

Methods: We provide a report of 70 patients positive for COVID-19, hospitalized between March 9th and April 4th, 2020. All the patients had fever, required non-invasive oxygen therapy and presented a CT lung involvement on imaging more than 50%. Forty-two patients received hydroxychloroquine, antibiotics, and tocilizumab, alone or in combination. A second group of 28 subjects received the same therapy added with oral bacteriotherapy, using a multistrain formulation.

Results: The two cohorts of patients were comparable for age, sex, laboratory values, concomitant pathologies, and the modality of oxygen support. Within 72 h, nearly all patients treated with bacteriotherapy showed remission of diarrhea and other symptoms as compared to less than half of the not supplemented group. The estimated risk of developing respiratory failure was eight-fold lower in patients receiving oral bacteriotherapy. Both the prevalence of patients transferred to ICU and mortality were higher among the patients not treated with oral bacteriotherapy.

Conclusions: A specific bacterial formulation showed a significant ameliorating impact on the clinical conditions of patients positive for SARS-CoV-2 infection. These results also stress the importance of the gut-lung axis in controlling the COVID-19 disease.

[Randomized controlled trial on the promotion of healthy lifestyles among adolescents in the orthodontic setting: study protocol]

Many studies have shown that the bad lifestyles are the major factors thought to influence susceptibility to many diseases in our society and often these habits during the adolescence begin. The aim of the study was to evaluate the health promotion intervention effect in an orthodontic adolescent sample, in particular: deterring adolescents from smoking; discourage the use and abuse of alcoholic beverages; encourage the adherence to the Mediterranean style diet. A blinded randomized controlled trial will be performed. The participants will be adolescents aged 10 to 14 years that will receive a medical examination in the Complex Unit of Orthodontics. The sample will be followed for three years. The collected evidence would be a scientific support for decisions in public health, in order to increase the health of the young generations.

Mode of action of trabectedin in myxoid liposarcomas

To elucidate the mechanisms behind the high sensitivity of myxoid/round cell liposarcoma (MRCL) to trabectedin and the suggested selectivity for specific subtypes, we have developed and characterized three MRCL xenografts, namely ML017, ML015 and ML004 differing for the break point of the fusion gene FUS-CHOP, respectively of type I, II and III. FUS-CHOP binding to the promoters of some target genes such as Pentraxin 3 or Fibronectin 1, assessed by chromatin immunoprecipitation, was strongly reduced in the tumor 24 h after the first or the third weekly dose of trabectedin, indicating that the drug at therapeutic doses causes a detachment of the FUS-CHOP chimera from its target promoters as previously shown in vitro. Moreover, the higher sensitivity of MRCL types I and II appears to be related to a more prolonged block of the transactivating activity of the fusion protein. Doxorubicin did not affect the binding of FUS-CHOP to target promoters. Histologically, the response to trabectedin in ML017 and ML015 was associated with a marked depletion of non-lipogenic tumoral cells and vascular component, as well as lipidic maturation as confirmed by PPARγ2 expression in western Blot. By contrast, in ML004 no major changes either in the cellularity or in the amount of mature were found, and consistently PPARγ2 was null. In conclusion, the data support the view that the selective mechanism of action of trabectedin in MRCL is specific and related to its ability to cause a functional inactivation of the oncogenic chimera with consequent derepression of the adypocytic differentiation.

ALK-gene rearrangement: a comparative analysis on circulating tumour cells and tumour tissue from patients with lung adenocarcinoma

BACKGROUND

A subgroup of anaplastic lymphoma kinase (ALK)-rearranged lung tumours can respond to ALK inhibitors. Until now, the ALK status in circulating tumour cells (CTCs) isolated from patients with lung cancer has not been characterised. We assessed the ALK status in CTCs detected in patients with lung cancer and correlated the results to the ALK status defined in the corresponding tumour tissue.

PATIENTS AND METHODS

A total of 87 patients with lung adenocarcinoma showing CTCs isolated using the isolation by size of epithelial tumour cell method were screened for their ALK status both in tumour samples and in CTCs. ALK break-apart fluorescence in situ hybridisation (FISH) and immunoreactivity analyses using an anti-ALK antibody (5A4 clone) were carried out on CTCs and compared with the results obtained in the corresponding tissue specimens.

RESULTS

A total of five patients showed ALK-gene rearrangement and strong ALK protein expression in CTCs and in the corresponding tumour samples. Both ALK-FISH and ALK immunoreactivity analyses show negative results in CTCs and corresponding tumour samples for 82 patients. Conclusions We demonstrated that the ALK status can be determined in CTCs isolated from patients with lung cancer by immunocytochemistry and FISH analyses. These results favour non-invasive, ALK-gene status pre-screening on a routine basis on CTCs isolated from patients with lung cancer and open new avenues for real-time monitoring for adapted targeted therapy.

Aberrant Cytoplasmic Accumulation of Connexin 43 in Human Testicular Seminoma

In the present study Cx43 mRNA and protein were analyzed in germ cells of men with normal spermatogenesis and in human testicular seminoma. In normal testis Cx43 mRNAs were basally located within seminiferous tubules and expressed in the most basally located germ cells (spermatogonia, early spermatocytes, and pachytene spermatocytes) and in Sertoli cells. Immunofluorescence analysis showed that Cx43 signal was mainly located in the basal compartment of seminiferous tubules and was stage-dependent. Cx43 mRNAs were also detected in human testicular seminoma. Transcripts were present within seminoma cells identified by PLAP staining. However, Cx43 protein exhibited an intracytoplasmic accumulation, within an intracellular compartment distinct from the Golgi apparatus and was undetectable at the plasma membrane level, suggesting post-translational rather than transcriptional abnormalities. This aberrant intracytoplasmic accumulation of Cx43 is due neither to a dysfunction of the protein trafficking machinery nor to a specific alteration of its major protein partner, ZO-1, since the tight junction associated protein was detected at the plasma membrane level and did not colocalize with Cx43.

Reg I protein in healthy and seminoma human testis

Regenerating gene (Reg), encodes a secretory protein with growth and differentiation stimulating effects mostly in digestive tissues. Overexpression of Reg proteins and specifically of Reg I, one member of the Reg family, is associated with several human diseases and cancers. In the present study we analyzed the expression of Reg I in normal rodent and human testes where germ cells normally proliferate and differentiate into spermatozoa, and in seminoma testis, the most common cancer of young men. Western blot analyses demonstrated the presence of a specific band at 19 kDa in human and rodent testis extracts. Immunofluorescence and deconvolution microscopy demonstrated that Reg I was present within the seminiferous tubules in both Sertoli and germ cells. By using a Sertoli cell line we demonstrated that Reg I was localized at the plasma membrane even in the absence of contact between neighboring cells and appeared before the tight junction associated protein ZO-1 was revealed at this location. Reg I was strongly expressed in human seminoma testis tissue and in a human tumor germ cell line where the immunoreactive signal was mainly detected at the plasma membrane level. These data showing for the first time the weak presence of Reg I in the normal testis and its strong expression in the testis cancer suggest a potential role of Reg I in normal and neoplastic germ cell proliferation.

Structure of a new nervous system glycoprotein, Nr-CAM, and its relationship to subgroups of neural cell adhesion molecules

We have identified and characterized a new glycoprotein in the chicken nervous system using immunological and molecular biological methods and we have examined its tissue distribution. Analysis revealed that this protein is very similar in structure to the chicken neuron-glia cell adhesion molecule, Ng-CAM, and to mouse L1. cDNA clones encompassing the entire coding sequence of this Ng-CAM related molecule, called Nr-CAM, have been isolated and sequenced. A glycoprotein containing one major component of Mr 145,000 on SDS-PAGE was purified from brain by lentil lectin affinity chromatography and FPLC, and its amino-terminal sequence was identical to that predicted from the Nr-CAM cDNA. The complete cDNA sequence encodes six Ig-like domains, five fibronectin type III repeats, a predicted transmembrane domain, and a short cytoplasmic domain. On Northern blots, nucleic acid probes for Nr-CAM recognized one major RNA species of approximately 7 kb and much lesser amounts of larger RNAs. Most of the same probes hybridized to single bands on genomic Southern blots, suggesting that Nr-CAM is encoded by a single gene that may be alternatively processed to yield several mRNAs. In support of this notion, two Nr-CAM cDNA clones had a 57-bp sequence located between the second and third Ig-like domains that was not found in two other Nr-CAM cDNA clones, and two other clones were isolated that lacked the 279-bp segment encoding the fifth fibronectin-like type III repeat. Antibodies against the purified protein and synthetic peptides in Nr-CAM both recognized a predominant Mr 145,000 species and a much less prevalent species of Mr 170,000 in neural tissues. Levels of Nr-CAM expression increased in the brain until approximately embryonic day (E) 12, followed by slightly lower levels of expression at E18 and after hatching. Immunofluorescent staining with anti-Nr-CAM antibodies showed that most neurons in the retina were positive at E7 and the pattern of expression became restricted to several layers on neuronal cell bodies and fibers during development. Anti-Nr-CAM antibodies labeled specifically cell surfaces on neurons in culture. Although the structure of Nr-CAM resembles that of chicken Ng-CAM and mouse L1, the identity with each of these neural CAMs does not exceed 40%. The differences indicate that Nr-CAM is distinct from Ng-CAM and L1, but there are sufficient similarities to suggest that all of these molecules are members of a subgroup of neural CAMs in the N-CAM superfamily.(ABSTRACT TRUNCATED AT 400 WORDS)

Structure of the chicken neuron-glia cell adhesion molecule, Ng-CAM: origin of the polypeptides and relation to the Ig superfamily

The neuron-glia cell adhesion molecule (Ng-CAM) mediates both neuron-neuron and neuron-glia adhesion; it is detected on SDS-PAGE as a predominant 135-kD glycoprotein, with minor components of 80, 190, and 210 kD. We have isolated cDNA clones encoding the entire sequence of chicken Ng-CAM. The predicted extracellular region includes six immunoglobulin-like domains followed by five fibronectin-type III repeats, structural features that are characteristic of several neural CAMs of the N-CAM superfamily. The amino acid sequence of chicken Ng-CAM is most similar to that of mouse L1 but the overall identity is only 40% and Ng-CAM contains a short fibronectin-like segment with an RGD sequence that has no counterpart in L1. These findings suggest that Ng-CAM and L1 may not be equivalent molecules in chicken and mouse. The amino-terminal sequences of the 210-, 190-, and 135-kD components of Ng-CAM are all the same as the predicted amino terminus of the molecule, whereas the 80-kD component begins within the third fibronectin repeat. The cDNA sequence is continuous across the junction between the 135- and 80-kD components, and a single 170-kD Ng-CAM polypeptide was isolated from tunicamycin-treated cells. In addition, all cDNA probes hybridized on Northern blots to a 6-kb RNA, and most hybridized to single bands on Southern blots. These results indicate that the Ng-CAM components are derived from a single polypeptide encoded by a single gene, and that the 135- and 80-kD components are generated from the 210/190-kD species by proteolytic cleavage. The 135-kD component contains most of the extracellular region including all of the immunoglobulin-like domains. It has no transmembrane segment, but it is tightly associated with the membrane. The 80-kD component contains two and a half type III repeats plus the RGD-containing segment, as well as the single transmembrane and cytoplasmic domains. These structural features of Ng-CAM provide a framework for understanding its multiple functions in neuron-neuron interactions, neurite fasciculation, and neuron-glia interactions.