Towards a better understanding of adult idiopathic epidermal necrolysis: a retrospective study of 19 cases

BACKGROUND

Most cases of Stevens-Johnson syndrome and toxic epidermal necrolysis are drug-induced. A small subset of cases remain with unknown aetiology (idiopathic epidermal necrolysis [IEN]).

OBJECTIVE

We sought to better describe adult IEN and understand the aetiology.

METHODS

This retrospective study was conducted in 4 centres of the French national reference centre for epidermal necrolysis. Clinical data were collected for the 19 adults hospitalized for IEN between January 2015 and December 2019. Wide toxicology analysis of blood samples was performed. Histology of IEN cases was compared with blinding to skin biopsies of drug-induced EN (DIEN, 'controls'). Available baseline skin biopsies were analysed by shotgun metagenomics and transcriptomics and compared to controls.

RESULTS

IEN cases represented 15.6% of all EN cases in these centres. The median age of patients was 38 (range 16-51) years; 68.4% were women. Overall, 63.2% (n = 12) of cases required intensive care unit admission and 15.8% (n = 3) died at the acute phase. Histology showed the same patterns of early- to late-stage EN with no difference between DIEN and IEN cases. One toxicology analysis showed unexpected traces of carbamazepine; results for other cases were negative. Metagenomics analysis revealed no unexpected pathological microorganism. Transcriptomic analysis highlighted a different pro-apoptotic pathway in IEN compared to DIEN, with an overexpression of apoptosis effectors TWEAK/TRAIL.

CONCLUSIONS

IEN affects young people and is a severe form of EN. A large toxicologic investigation is warranted. Different pathways seem involved in IEN and DIEN, leading to the same apoptotic effect, but the primary trigger remains unknown.

Lactic acid bacteria biofilms and their ability to mitigate Escherichia coli O157:H7 surface colonization

Lactic acid bacteria (LAB) exert antagonistic activities against diverse microorganisms, including pathogens. In this work, we aimed to investigate the ability of LAB strains isolated from food to produce biofilms and to inhibit growth and surface colonization of Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 at 10°C. The ability of 100 isolated LAB to inhibit EHEC O157:H7 NCTC12900 growth was evaluated in agar diffusion assays. Thirty-seven LAB strains showed strong growth inhibitory effect on EHEC. The highest inhibitory activities corresponded to LAB strains belonging to Lactiplantibacillus plantarum, Pediococcus acidilactici and Pediococcus pentosaceus species. Eighteen out of the 37 strains that showed growth inhibitory effects on EHEC also had the ability to form biofilms on polystyrene surfaces at 10°C and 30°C. Pre-established biofilms on polystyrene of four of these LAB strains were able to reduce significantly surface colonization by EHEC at low temperature (10°C). Among these four strains, Lact. plantarum CRL 1075 not only inhibited EHEC but also was able to grow in the presence of the enteric pathogen. Therefore, this strain proved to be a good candidate for further technological studies oriented to its application in food-processing environments to mitigate undesirable surface contaminations of E. coli.

Airborne vocal communication in adult neotropical otters (Lontra longicaudis)

Most aquatic mammals have complex social and communication systems. Interestingly, little is known about otters' vocal communication compared to other aquatic mammals. Here, for the first time, we acoustically describe vocalizations of the neotropical otter (Lontra longicaudis), a solitary and endangered New World otter species. We recorded vocalizations and behavioral contexts from six captive neotropical otters at Projeto Lontra, Santa Catarina Island, Brazil. Analysis of acoustic parameters were used to classify the vocalizations according to structure and context. We describe six call types with highly tonal as well as chaotic vocalizations with fundamental frequencies ranging from 90 to 2500 Hz. Additionally, we identified sex differences in the usage of calls. Results suggest that the neotropical river otter has a rich vocal repertoire, similar in complexity to other solitary otter species, but less complex than that of the social giant otter. Despite differences in sociality, phylogeny and ecology, L. longicaudis seems to possess vocalizations homologous to those found in other otters (e.g. hah and chirp), suggesting phylogenetic inertia in otter communicative repertoire. Otters thus offer an interesting but neglected group to explore the evolution of communication systems.

Microdiversity of Enterococcus faecalis isolates in cases of infective endocarditis: selection of non-synonymous mutations and large deletions is associated with phenotypic modifications

Context: Today, infective endocarditis (IE) caused by Enterococcus faecalis represents 10% of all IE and is marked by its difficult management and the frequency of relapses. Although the precise reasons for that remain to be elucidated, the evolution of the culprit strain under selective pressure through microdiversification could be, at least in part, involved. Material and methods: To further study the in situ genetic microdiversity and its possible phenotypic manifestations in E. faecalis IE, we sequenced and compared multiple isolates from the valves, blood culture and joint fluid of five patients who underwent valvular surgery. Growth rate and early biofilm production of selected isolates were also compared. Results: By sequencing a total of 58 E. faecalis genomes, we detected a considerable genomic microdiversity, not only among strains from different anatomical origins, but also between isolates from the same studied cardiac valves. Interestingly, deletions of thousands of bases including the well-known virulence factors ebpA/B/C, and srtC, as well as other large prophage sequences containing genes coding for proteins implicated in platelet binding (PlbA and PlbB) were evidenced. The study of mutations helped unveil common patterns in genes related to the cell cycle as well as central metabolism, suggesting an evolutionary convergence in these isolates. As expected, such modifications were associated with a significant impact on the in-vitro phenotypic heterogeneity, growth, and early biofilm production. Conclusion: Genome modifications associated with phenotypic variations may allow bacterial adaptation to both antibiotic and immune selective pressures, and thus promote relapses.

SARS-CoV-2 IgG response in symptomatic and asymptomatic COVID-19-infected healthcare workers

Background

Healthcare workers (HCWs) accounted for a significant proportion of COVID-19 infections worldwide. Retrospective seroprevalence surveys are often used to screen for unidentified previous infection with SARS-CoV-2. However, the rate of humoral response in HCWs affected by COVID-19 is not well-defined.

Aims

To assess the specific IgG humoral response in symptomatic and asymptomatic SARS-CoV-2-infected HCWs and identify potential factors associated with humoral response.

Methods

We prospectively recruited 204 HCWs with RT-PCR-confirmed COVID-19 infection to evaluate SARS-CoV-2 humoral response. Serum-IgG antibodies against SARS-CoV-2 were analysed using two commercially available serological assays. A logistic regression was performed to identify independent factors associated with positive IgG serology test.

Results

Overall, the SARS-CoV-2 IgG seropositivity rate was 77%. This seropositivity rate was higher in symptomatic than in asymptomatic COVID-19 infection (83% versus 57%; P < 0.001) and in older HCWs.. The seropositivity rate did not diminish with time. In logistic regression, only a history of COVID-19 symptoms and age were identified as independent factors associated with the detection of anti-SARS-CoV-2 IgG antibodies.

Conclusions

SARS-CoV-2 IgG antibodies are found significantly more frequently in symptomatic and in older HCWs. The fact that not all COVID-19 HCWs develop detectable IgG is vital for the interpretation of COVID-19 seroprevalence surveys.

A Rare Presentation of Posterior Cerebral Artery Stroke With Monocular Hemianopia After Diesel Exposure

Acute ischemic stroke of the posterior cerebral artery (PCA) presents with variable symptoms that may initially make it challenging to diagnose. Common etiologies of PCA stroke include large and small artery disease, atherosclerosis, and cardioembolism. We present a 69-year-old male, initially diagnosed with sinusitis at an urgent care facility, who presented with worsening headache and peripheral vision loss following exposure to diesel vapor and exhaust. Physical examination revealed a right monocular temporal hemianopia and subsequent imaging showed infarction of the left occipital lobe. Due to the length of time between the onset of the infarct and medical treatment, angiography and physical intervention were not indicated and management was done medically. This case presents a unique exposure prior to the development of a PCA stroke, as well as an atypical visual defect and suggests that physicians should consider neuroimaging in patients with nonspecific neurological findings such as new-onset headache and vision changes.

Optimization and validation of a liquid chromatography-tandem mass spectrometry method for the determination of glyphosate in human urine after pre-column derivatization with 9-fluorenylmethoxycarbonyl chloride

In 2015, glyphosate was classified as "Group 2A - probably carcinogenic to humans" by the International Agency for Research on Cancer (IARC). Therefore, public concerns about the environmental and health risks of this substance have rapidly increased. Considering its toxicokinetic characteristics, urinary levels of glyphosate could be a powerful tool for human biomonitoring. Nevertheless, the physicochemical properties of this molecule and the complexity of the matrix make this purpose particularly challenging. In order to solve this problem, the presented study describes a simple LC-MS/MS method for the quantification of glyphosate in human urine after pre-column derivatization with FMOC-Cl. Method development was focused on the optimization of the derivatization reaction in human urine, adjusting critical variables such as pH of borate buffer, FMOC-Cl concentration and derivatization time. Besides, chromatographic separation and spectrometric parameters were also established. The analytical method was fully validated according international guidelines for selectivity, carry over, linearity, accuracy, precision, lower limit of quantitation, matrix effect and stability under different conditions. All performance parameters were within the acceptance criteria. In addition, the method was successfully applied to 52 urine samples obtained from exposed subjects from northern Argentina, laying the foundation for future epidemiological studies.

Case report of a dissociative identity disorder

Introduction

Patients with dissociative identity disorder (DID) present two or more identities, where one of them is the main one. Although it is a widely questioned diagnosis, it is currently found in the main DSM-5 and ICD-10 diagnostic manuals.

Objectives

Present a case of dissociative identity disorder.

Methods

46-year-old woman who attended the CSM referred for her MAP due to anxiety-depressive symptoms. Throughout the interviews the patient brings up to 4 identities with alterations in memory, consciousness, multiple dissociative symptoms, sound thinking, constant fluctuations in mood. She is separated, has two children, takes care of them, although she is not able to maintain work functionality. The patient is seen once a week for 45 minutes. Psychotherapeutic treatment is carried out, the objective of which is to establish a safe therapist-patient bond to favor the integration of their parts, and pharmacological treatment, which was carried out with haloperidol, lorazepam and desvenlafaxine.

Results

Throughout sessions, the anxious symptoms diminished, being able to carry out psychotherapeutic work. Dissociative symptoms were slightly reduced, partially integrating some of the identities. There was a slight stabilization in mood and decrease in psychotic symptoms.

Conclusions

There is no well-established treatment for DID. Combined therapy (psychotherapy and pharmacological) may be an option for these patients. The therapeutic framing of the sessions, working the link, and the low-dose antipsychotic treatment were favorable.

Keyword

dissociative identity framing link

Galactorrhea as a side effect of antidepressant drugs. A case report

Introduction

Galactorrhea wiht antidepressants SSRIs or SNRI is a rarely adverse effect. Some authors believe that the risk of galactorrhea in women who use SSRIs is 8 times higher than in patients treated with other types of drugs. Serotonin is believed to be a potent physiological stimulator of prolactin release.Prolactin stimulates the growth of the mammary glands and the galactorrhea. The SSRIs would activate the serotonergic pathways, these in turn would stimulate the release of prolactin directly in the pituitary and in the hypothalamus, inhibiting the release of dopamine and increasing the release of stimulating factors. The main inhibitor of prolactin secretion is dopamine.

Objectives

The objective is to reveal this rare complication through the report of a clinical case

Methods

A 45-year-old woman with a diagnosis of mixed anxiety-depressive disorder. Treatment with 20 mg of escitalopram was started, with a good therapeutic response, but with breast pain and swelling. She was switched to duloxetine 60 mg, with a good response and adequate tolerance. At 6 months of treatment, she begins to present breast pain and yellow-green breast discharge, with elevated prolactin levels and normal cranial MRI.

Results

She was diagnosed with functional hyperprolactinemia, and treatment with vortioxetine was started. Finally, the Prolactin levels normalize.

Conclusions

Galactorrhea is a very rare and annoying side effect that can lead to discontinuation of treatment and requires a change in the therapeutic strategy.

Disclosure

No significant relationships.

Description of the consumption of toxics in patients with assertive community treatment and prolonged release treatment

Introduction

The Assertive Community Treatment (ACT) was developed by Leonard Stein and Mary Ann. The objective is the treatment of serious Mental Disorders in an integral way and in the community.

Objectives

The Assertive Community Treatment (ACT) was developed by Leonard Stein and Mary Ann. The objective is the treatment of serious Mental Disorders in an integral way and in the community.

Methods

This is a retrospective study with a total of 69 patients whose main diagnosis is Schizophrenia undergoing CT follow-up in 2018-2019. The data obtained have been analyzed by the SPSS statistical program.

Results

Our sample is mainly composed of men (60.9%) with an average age of 48 years (+ - 11.56). The main diagnosis is schizophrenia (62.3%) and the most commonly used long-term injectable treatment is paliperidone palmitate with a dose range of 150mg. Of the total number of patients, 29% of the cases did not maintain active use of any toxic, and the most commonly used toxic is tobacco (49.3% of cases).

Conclusions

The inclusion of patients in a ACT program requires a diagnosis of severe Mental Disorder and poor therapeutic adherence. After analyzing our data, we observed that most of them also have active toxic consumption and high doses of psychotropic drugs.

Disclosure

No significant relationships.

Machine learning in the clinical microbiology laboratory: has the time come for routine practice?

BACKGROUND

Machine learning (ML) allows the analysis of complex and large data sets and has the potential to improve health care. The clinical microbiology laboratory, at the interface of clinical practice and diagnostics, is of special interest for the development of ML systems.

AIMS

This narrative review aims to explore the current use of ML In clinical microbiology.

SOURCES

References for this review were identified through searches of MEDLINE/PubMed, EMBASE, Google Scholar, biorXiv, arXiV, ACM Digital Library and IEEE Xplore Digital Library up to November 2019.

CONTENT

We found 97 ML systems aiming to assist clinical microbiologists. Overall, 82 ML systems (85%) targeted bacterial infections, 11 (11%) parasitic infections, nine (9%) viral infections and three (3%) fungal infections. Forty ML systems (41%) focused on microorganism detection, identification and quantification, 36 (37%) evaluated antimicrobial susceptibility, and 21 (22%) targeted the diagnosis, disease classification and prediction of clinical outcomes. The ML systems used very diverse data sources: 21 (22%) used genomic data of microorganisms, 19 (20%) microbiota data obtained by metagenomic sequencing, 19 (20%) analysed microscopic images, 17 (18%) spectroscopy data, eight (8%) targeted gene sequencing, six (6%) volatile organic compounds, four (4%) photographs of bacterial colonies, four (4%) transcriptome data, three (3%) protein structure, and three (3%) clinical data. Most systems used data from high-income countries (n = 71, 73%) but a significant number used data from low- and middle-income countries (n = 36, 37%). Performance measures were reported for the 97 ML systems, but no article described their use in clinical practice or reported impact on processes or clinical outcomes.

IMPLICATIONS

In clinical microbiology, ML has been used with various data sources and diverse practical applications. The evaluation and implementation processes represent the main gap in existing ML systems, requiring a focus on their interpretability and potential integration into real-world settings.

Pathogen identification by shotgun metagenomics of patients with necrotizing soft-tissue infections

BACKGROUND

Necrotizing soft-tissue infections (NSTIs) are life threatening, requiring broad-spectrum antibiotics. Their aetiological diagnosis can be limited by poor performance of cultures and administration of antibiotics before surgery.

OBJECTIVES

We aimed (i) to compare 16S-targeted metagenomics (TM) and unbiased semiquantitative panmicroorganism DNA- and RNA-based shotgun metagenomics (SM) with cultures, (ii) to identify patients who would best benefit from metagenomics approaches and (iii) to detect the microbial pathogens in surrounding non-necrotic 'healthy' tissues by SM-based methods.

METHODS

A prospective observational study was performed to assess the analytical performance of standard cultures, TM and SM on tissues from 34 patients with NSTIs. Pathogen identification obtained with these three methods was compared.

RESULTS

Thirty-four necrotic and 10 healthy tissues were collected from 34 patients. The performance of TM was inferior to that of the other methods (P < 0·05), whereas SM performed better than standard culture, although the result was not statistically significant (P = 0·08). SM was significantly more sensitive than TM for the detection of all bacteria (P = 0·02) and more sensitive than standard culture for the detection of anaerobic bacteria (P < 0·01). There was a strong correlation (r = 0·71, Spearman correlation coefficient) between the semiquantitative abundance of bacteria in the culture and the bacteria-to-human sequence ratio in SM. Low amounts of bacterial DNA were found in healthy tissues, suggesting a bacterial continuum between macroscopically 'healthy' and necrotic tissue.

CONCLUSIONS

SM showed a significantly better ability to detect a broader range of pathogens than TM and identify strict anaerobes than standard culture. Patients with diabetes with NSTIs appeared to benefit most from SM. Finally, our results suggest a bacterial continuum between macroscopically 'healthy' non-necrotic areas and necrotic tissues. What's already known about this topic? Necrotizing soft-tissue infections (NSTIs) are characterized by rapidly progressive necrosis of subcutaneous tissues and high mortality, despite surgical debridement combined with broad-spectrum antibiotics. The spectrum of potentially involved pathogens is very large, and identification is often limited by the poor performance of standard cultures, which may be impaired by previous antibiotic intake. Metagenomics-based approaches show promise for better identification of the pathogens that cause these infections, but they have not been evaluated in this medical context. What does this study add? Shotgun metagenomics (SM) showed higher sensitivity than 16S rRNA gene sequencing and a better ability than culture to detect anaerobic bacteria. As a result, a significant proportion of infections with bacteria, such as Pasteurella multocida or Clostridium perfringens, were detected only by SM. SM bacterial quantification enabled better detection of low amounts of bacterial DNA from macroscopically 'healthy' tissue, suggesting a subclinical infectious extension. What is the translational message? The high analytical performance of SM shown in this study should allow its future implementation for the diagnosis of necrotizing fasciitis, complementing or replacing routine methods. The large amount of data, including additional information on antimicrobial resistance, virulence profiles and metabolic adaptation of the pathogens, will improve microbiological documentation. Our results will improve our understanding of infectious pathophysiology in the future, leading to potentially better medical care.