Cell Therapy of Vascular and Neuropathic Complications of Diabetes: Can We Avoid Limb Amputation?

Globally, a leg is amputated approximately every 30 seconds, with an estimated 85 percent of these amputations being attributed to complications arising from diabetic foot ulcers (DFU), as stated by the American Diabetes Association. Peripheral arterial disease (PAD) is a risk factor resulting in DFU and can, either independently or in conjunction with diabetes, lead to recurring, slow-healing ulcers and amputations. According to guidelines amputation is the recommended treatment for patients with no-option critical ischemia of the limb (CTLI). In this article we propose cell therapy as an alternative strategy for those patients. We also suggest the optimal time-frame for an effective therapy, such as implanting autologous mononuclear cells (MNCs), autologous and allogeneic mesenchymal stromal cells (MSC) as these treatments induce neuropathy relief, regeneration of the blood vessels and tissues, with accelerated ulcer healing, with no serious side effects, proving that advanced therapy medicinal product (ATMPs) application is safe and effective and, hence, can significantly prevent limb amputation.

Rationale for combined therapies in severe-to-critical COVID-19 patients

An unprecedented global social and economic impact as well as a significant number of fatalities have been brought on by the coronavirus disease 2019 (COVID-19), produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute SARS-CoV-2 infection can, in certain situations, cause immunological abnormalities, leading to an anomalous innate and adaptive immune response. While most patients only experience mild symptoms and recover without the need for mechanical ventilation, a substantial percentage of those who are affected develop severe respiratory illness, which can be fatal. The absence of effective therapies when disease progresses to a very severe condition coupled with the incomplete understanding of COVID-19's pathogenesis triggers the need to develop innovative therapeutic approaches for patients at high risk of mortality. As a result, we investigate the potential contribution of promising combinatorial cell therapy to prevent death in critical patients.

Monitoring sertraline and clozapine levels

Introduction

One of the most frequent side effects seen when prescribing sertraline and clozapine together is the appearance of a seizure crisis. This event is usually related to an increase of plasmatic concentration due to interactions of these drugs with blood components.

Objectives

To investigate the effects of clozapine when combined with other drugs, especially its effects increasing plasmatic concentration.

Methods

A patient was treated sith 300 mg/day of clozapine followed by a treatment with sertraline 50 mg/day, which increases plasmatic concentration. The combination of these treatments produced seizures. Other works published about interactions are reviewed.

Results

It is important to monitor clozapine dosages to avoid increasing plasmatic concentration, especially if other drugs that have this effect are also administered.

Conclusions

It is important to monitor clozapine dosages to avoid increasing plasmatic concentration, especially if other drugs that have this effect are also administered.

Disclosure

No significant relationships.

Suicide in the medical community

Introduction

Like in the general population, in the medical community the most common mental disorders reported are depression and anxiety. Suicide risk was increased, especially in medical-related professions.

Objectives

To evaluate male and female psysician suicide risk.

Methods

Review all studies involving suicides, suicide attempts or suicidal ideation in health-care workers published in the last five years.

Results

Suicide decreased over time, especially in Europe. Some specialties might be at higher risk such as psychiatrists, general surgeons and anesthesiologists.

Conclusions

Psysicians are an at-risk profession of suicide, with women particularly at risk.

Disclosure

No significant relationships.

The phylogenetic landscape and nosocomial spread of the multidrug-resistant opportunist Stenotrophomonas maltophilia

Recent studies portend a rising global spread and adaptation of human- or healthcare-associated pathogens. Here, we analyse an international collection of the emerging, multidrug-resistant, opportunistic pathogen Stenotrophomonas maltophilia from 22 countries to infer population structure and clonality at a global level. We show that the S. maltophilia complex is divided into 23 monophyletic lineages, most of which harbour strains of all degrees of human virulence. Lineage Sm6 comprises the highest rate of human-associated strains, linked to key virulence and resistance genes. Transmission analysis identifies potential outbreak events of genetically closely related strains isolated within days or weeks in the same hospitals.

Multidrug resistance of the opportunistic pathogen Stenotrophomonas maltophilia is an increasing problem. Here, analyzing strains from 22 countries, the authors show that the S. maltophilia complex is divided into 23 monophyletic lineages and find evidence for intra-hospital transmission.

Pathogenicity of Clinical OXA-48 Isolates and Impact of the OXA-48 IncL Plasmid on Virulence and Bacterial Fitness

OXA-48 is the most common carbapenemase in Enterobacterales in Germany and one of the most frequent carbapenemases worldwide. Several reports have associated bla_OXA–48 with a virulent host phenotype. To challenge this hypothesis, 35 OXA-48-producing clinical isolates of Escherichia coli (n = 15) and Klebsiella pneumoniae (n = 20) were studied in vitro, in vivo employing the Galleria mellonella infection model and by whole-genome sequencing. Clinical isolates belonged to 7 different sequence types (STs) in E. coli and 12 different STs in K. pneumoniae. In 26/35 isolates bla_OXA–48 was located on a 63 kb IncL plasmid. Horizontal gene transfer (HGT) to E. coli J53 was high in isolates with the 63 kb IncL plasmid (transconjugation frequency: ∼10³/donor) but low in isolates with non-IncL plasmids (<10^–6/donor). Several clinical isolates were both highly cytotoxic against human cells and virulent in vivo. However, 63 kb IncL transconjugants generated from these highly virulent isolates were not more cytotoxic or virulent when compared to the recipient strain. Additionally, no genes associated with virulence were detected by in silico analysis of OXA-48 plasmids. The 63 kb plasmid was highly stable and did not impair growth or fitness in E. coli J53. In conclusion, OXA-48 clinical isolates in Germany are diverse but typically harbor the same 63 kb IncL plasmid which has been reported worldwide. We demonstrate that this 63 kb IncL plasmid has a low fitness burden, high plasmid stability and can be transferred by highly efficient HGT which is likely the cause of the rapid dissemination of OXA-48 rather than the expansion of a single clone or gain of virulence.

Identification of the novel class D β-lactamase OXA-679 involved in carbapenem resistance in Acinetobacter calcoaceticus

OBJECTIVES

The aim of this study was to characterize the Acinetobacter calcoaceticus clinical isolate AC_2117 with the novel carbapenem-hydrolysing class D β-lactamase (CHDL) OXA-679.

METHODS

Identification of the species and β-lactamases was verified by genome sequencing (PacBio) and phylogenetic analyses. Antibiotic susceptibility of AC_2117 and transformants harbouring cloned blaOXA-679 was evaluated using antibiotic gradient strips and microbroth dilution. OXA-679 was purified heterologously and kinetic parameters were determined using spectrometry or isothermal titration calorimetry. The impact of OXA-679 production during imipenem therapy was evaluated in the Galleria mellonella infection model.

RESULTS

Sequencing of the complete genome of the clinical A. calcoaceticus isolate AC_2117 identified a novel CHDL, termed OXA-679. This enzyme shared sequence similarity of 71% to each of the families OXA-143 and OXA-24/40. Phylogenetic analyses revealed that OXA-679 represents a member of a new OXA family. Cloning and expression of blaOXA-679 as well as measurement of kinetic parameters revealed the effective hydrolysis of carbapenems which resulted in reduced susceptibility to carbapenems in Escherichia coli and A. calcoaceticus, and high-level carbapenem resistance in Acinetobacter baumannii. Infection of larvae of G. mellonella with a sublethal dose of blaOXA-679-expressing A. baumannii could not be cured by high-dose imipenem therapy, indicating carbapenem resistance in vivo.

CONCLUSIONS

We identified blaOXA-679 in a clinical A. calcoaceticus isolate that represents a member of the new OXA-679 family and that conferred high-level carbapenem resistance in vitro and in vivo.

Whole-genome sequencing reveals nosocomial Clostridioides difficile transmission and a previously unsuspected epidemic scenario

To trace the routes and frequencies of transmission of Clostridioides difficile in a tertiary-care hospital in Madrid (Spain), we sequenced the genomes from all C. difficile isolates collected over 36 months (2014-2016) that were indistinguishable from any other isolate by PCR ribotyping. From a total of 589 C. difficile infection cases, we cultivated and PCR-ribotyped 367 C. difficile isolates (62%), of which 265 were genome-sequenced. Based on close relatedness of successively collected isolates (≤2 SNPs difference in their genomes), whole-genome sequencing revealed a total of 17 independent, putative transmission clusters, caused by various C. difficile strains and each containing 2 to 18 cases, none of which had been detected previously by standard epidemiological surveillance. Proportions of linked isolates varied widely among PCR ribotypes, from 3% (1/36) for ribotype 014/020 to 60% (12/20) for ribotype 027, suggesting differential aptitudes for nosocomial spread. Remarkably, only a minority (17%) of transmission recipients had direct ward contact to their presumed donors and specific C. difficile genome types frequently went undetectable for several months before re-emerging later, suggesting reservoirs for the pathogen outside of symptomatic patients. Taken together, our analysis based on genome sequencing suggested considerable within-hospital epidemic spread of C. difficile, even though epidemiological data initially had been inconspicuous.

Genomes of Alteromonas australica, a world apart

BACKGROUND

Alteromonas is a genus of marine bacteria that is very easy to isolate and grow in the laboratory. There are genomes available of the species Alteromonas macleodii from different locations around the world and an Alteromonas sp. isolated from a sediment in Korea. We have analyzed the genomes of two strains classified by 16S rRNA (>99% similarity) as the recently described species Alteromonas australica, and isolated from opposite ends of the world; A. australica DE170 was isolated in the South Adriatic (Mediterranean) at 1000 m depth while A. australica H17T was isolated from a sea water sample collected in St Kilda Beach, Tasman Sea.

RESULTS

Although these two strains belong to a clearly different species from A. macleodii, the overall synteny is well preserved and the flexible genomic islands seem to code for equivalent functions and be located at similar positions. Actually the genomes of all the Alteromonas species known to date seem to preserve synteny quite well with the only exception of the sediment isolate SN2. Among the specific metabolic features found for the A. australica isolates there is the degradation of xylan and production of cellulose as extracellular polymeric substance by DE170 or the potential ethanol/methanol degradation by H17T.

CONCLUSIONS

The genomes of the two A. australica isolates are not more different than those of strains of A. macleodii isolated from the same sample. Actually the recruitment from metagenomes indicates that all the available genomes are found in most tropical-temperate marine samples analyzed and that they live in consortia of several species and multiple clones within each. Overall the hydrolytic activities of the Alteromonas genus as a whole are impressive and fit with its known capabilities to exploit sudden inputs of organic matter in their environment.

Genomic diversity of "deep ecotype" Alteromonas macleodii isolates: evidence for Pan-Mediterranean clonal frames

We have compared genomes of Alteromonas macleodii “deep ecotype” isolates from two deep Mediterranean sites and two surface samples from the Aegean and the English Channel. A total of nine different genomes were analyzed. They belong to five clonal frames (CFs) that differ among them by approximately 30,000 single-nucleotide polymorphisms (SNPs) over their core genomes. Two of the CFs contain three strains each with nearly identical genomes (∼100 SNPs over the core genome). One of the CFs had representatives that were isolated from samples taken more than 1,000 km away, 2,500 m deeper, and 5 years apart. These data mark the longest proven persistence of a CF in nature (outside of clinical settings). We have found evidence for frequent recombination events between or within CFs and even with the distantly related A. macleodii surface ecotype. The different CFs had different flexible genomic islands. They can be classified into two groups; one type is additive, that is, containing different numbers of gene cassettes, and is very variable in short time periods (they often varied even within a single CF). The other type was more stable and produced the complete replacement of a genomic fragment by another with different genes. Although this type was more conserved within each CF, we found examples of recombination among distantly related CFs including English Channel and Mediterranean isolates.

Intra- and intergenomic variation of ribosomal RNA operons in concurrent Alteromonas macleodii strains

Biodiversity estimates based on ribosomal operon sequence diversity rely on the premise that a sequence is characteristic of a single specific taxon or operational taxonomic unit (OTU). Here, we have studied the sequence diversity of 14 ribosomal RNA operons (rrn) contained in the genomes of two isolates (five operons in each genome) and four metagenomic fosmids, all from the same seawater sample. Complete sequencing of the isolate genomes and the fosmids establish that they represent strains of the same species, Alteromonas macleodii, with average nucleotide identity (ANI) values >97 %. Nonetheless, we observed high levels of intragenomic heterogeneity (i.e., variability between operons of a single genome) affecting multiple regions of the 16S and 23S rRNA genes as well as the internally transcribed spacer 1 (ITS-1) region. Furthermore, the ribosomal operons exhibited intergenomic heterogeneity (i.e., variability between operons located in separate genomes) in each of these regions, compounding the variability. Our data reveal the extensive heterogeneity observed in natural populations of A. macleodii at a single point in time and support the idea that distinct lineages of A. macleodii exist in the deep Mediterranean. These findings highlight the potential of rRNA fingerprinting methods to misrepresent species diversity while simultaneously failing to recognize the ecological significance of individual strains.

Genomes of surface isolates of Alteromonas macleodii: the life of a widespread marine opportunistic copiotroph

Alteromonas macleodii is a marine gammaproteobacterium with widespread distribution in temperate or tropical waters. We describe three genomes of isolates from surface waters around Europe (Atlantic, Mediterranean and Black Sea) and compare them with a previously described deep Mediterranean isolate (AltDE) that belongs to a widely divergent clade. The surface isolates are quite similar, the most divergent being the Black Sea (BS11) isolate. The genomes contain several genomic islands with different gene content. The recruitment of very similar genomic fragments from metagenomes in different locations indicates that the surface clade is globally abundant with little effect of geography, even the AltDE and the BS11 genomes recruiting from surface samples in open ocean locations. The finding of CRISPR protospacers of AltDE in a lysogenic phage in the Atlantic (English Channel) isolate illustrates a flow of genetic material among these clades and a remarkably wide distribution of this phage.

Polyclonality of concurrent natural populations of Alteromonas macleodii

We have analyzed a natural population of the marine bacterium, Alteromonas macleodii, from a single sample of seawater to evaluate the genomic diversity present. We performed full genome sequencing of four isolates and 161 metagenomic fosmid clones, all of which were assigned to A. macleodii by sequence similarity. Out of the four strain genomes, A. macleodii deep ecotype (AltDE1) represented a different genome, whereas AltDE2 and AltDE3 were identical to the previously described AltDE. Although the core genome (~80%) had an average nucleotide identity of 98.51%, both AltDE and AltDE1 contained flexible genomic islands (fGIs), that is, genomic islands present in both genomes in the same genomic context but having different gene content. Some of the fGIs encode cell surface receptors known to be phage recognition targets, such as the O-chain of the lipopolysaccharide, whereas others have genes involved in physiological traits (e.g., nutrient transport, degradation, and metal resistance) denoting microniche specialization. The presence in metagenomic fosmids of genomic fragments differing from the sequenced strain genomes, together with the presence of new fGIs, indicates that there are at least two more A. macleodii clones present. The availability of three or more sequences overlapping the same genomic region also allowed us to estimate the frequency and distribution of recombination events among these different clones, indicating that these clustered near the genomic islands. The results indicate that this natural A. macleodii population has multiple clones with a potential for different phage susceptibility and exploitation of resources, within a seemingly unstructured habitat.

Wavelet-based estimation of generalized fractional process

OBJECTIVES

This paper aims to propose an estimation procedure for the parameters of a generalized fractional process, a fairly general model of long-memory applicable in modeling biomedical signals whose autocorrelations exhibit hyperbolic decay.

METHODS

We derive a wavelet-based weighted least squares estimator of the long-memory parameter based on the maximal-overlap estimator of the wavelet variance. Short-memory parameters can then be estimated using standard methods. We illustrate our approach by an example applying ECG heart rate data.

RESULTS AND CONCLUSION

The proposed method is relatively computationally and statistically efficient. It allows for estimation of the long-memory parameter without knowledge of the short-memory parameters. Moreover it provides a more general model of biomedical signals that exhibit periodic long-range dependence, such as ECG data, whose relatively unobtrusive recording may be advantageous in assessing or predicting some physiological or pathological conditions from the estimated values of the parameters.

Factor concentrates for haemophilia in the developing world

The success in the management of haemophilia in the last two decades has been predominantly due to the availability of sufficient quantities of safe factor concentrates. Unfortunately, the prohibitive cost of these products has prevented this benefit from being available to the vast majority (approximately 80%) of haemophiliacs living in the developing world. A few developing countries have established facilities for the production of low- to intermediate-purity factor concentrates locally. The infrastructure required to achieve this can be very basic. The experience in South Africa, Thailand, Cuba and Brazil, described herein, shows that this approach provides factor concentrates which are very economical in comparison with more purified commercial products. This has had a major impact on the quality of haemophilia care in these countries. Wide availability of low-cost factor concentrates has made these products accessible to a large number of haemophiliacs and even made home therapy possible. The effort to provide these products results in improvement of the blood transfusion services. This, in turn, contributes to better facilities for patients with other transfusion-dependent diseases and society in general. Installation of small plasma fractionation plants is also a viable option. This not only allows processing of large pools of plasma for greater quantities of factor concentrates but also provides albumin and immunoglobulin. The revenue generated from the sale of the other products has been used to improve and subsidize haemophilia care. It is concluded that local production of intermediate purity factor concentrates in developing countries is absolutely necessary. A well organized transfusion service is required to collect adequate quantities of plasma for fractionation.

[Auricular fibrillation. Antiarrhythmic treatment revisited]

Atrial fibrillation is one of the most common symptomatic sustained arrhythmias seen in clinical practice. Long-term control of heart rate and maintenance of sinus rhythm often require chronic antiarrhythmic therapy. For patients with disabling symptoms of atrial fibrillation that cannot be controlled with pharmacologic therapy, catheter ablation techniques of the atrioventricular junction and surgical procedures aimed at maintaining sinus rhythm have now been effectively used. The efficacy, risks and limitations of pharmacologic and non-pharmacologic therapies are presented in this review article.

HIV-1, HIV-2, and HTLV-I infection in high-risk groups in Brazil

We conducted a serologic survey for antibodies to human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) and human T-cell lymphotropic virus Type I (HTLV-I) in 704 Brazilians with the acquired immunodeficiency syndrome (AIDS) or at risk for it. The study population included 70 homosexual men (11 of whom were prostitutes), 58 bisexual men (19 of whom were prostitutes), 101 female prostitutes from three socioeconomic groups, 13 wives of men with hemophilia who were seropositive for HIV-1 antibodies, and 47 blood donors with positive Venereal Disease Research Laboratory tests for syphilis, all from Rio de Janeiro; 86 female prostitutes from two rural towns in Minas Gerais; 133 patients with AIDS from São Paulo; and 196 men with bleeding disorders who were seropositive for HIV-1 antibodies on enzyme-linked immunosorbent assay, from São Paulo and Rio de Janeiro. The prevalence of HIV-1 infection was highest in the homosexual male prostitutes (45 percent), the wives of patients with hemophilia (38 percent), the bisexual men (28 percent), the homosexual men who were not prostitutes (19 percent), and the female prostitutes from the lower class (9 percent). Combined HIV-1 and HIV-2 infection was found in 3 percent of the patients with AIDS and in 1 percent of the homosexual men. The prevalence of HTLV-I infection ranged from 1 percent in rural female prostitutes to 13 percent in HIV-1-positive men with bleeding disorders in Rio de Janeiro. Combined HIV-1 and HTLV-I infection occurred in 1 to 11 percent of some male subgroups. We conclude that in Brazil HIV-1 infection is already well established among homosexuals, bisexuals, and lower-class female prostitutes, with bisexual men probably acting as a bridge between the heterosexual and homosexual communities, that HTLV-I infection is prevalent in groups at risk for AIDS, and that HIV-2 infection has already been introduced into the country.