Influence of Hydroxyproline on Mechanical Behavior of Collagen Mimetic Proteins Under Fraying Deformation-Molecular Dynamics Investigations.

Molecular dynamics modeling is used to simulate, model, and analyze mechanical deformation behavior and predictive properties of three different synthetic collagen proteins obtained from RSC-PDB, 1BKV, 3A08, and 2CUO, with varying concentrations of hydroxyproline (HYP). Hydroxyproline is credited with providing structural support for the collagen protein molecules. Hydroxyproline's influence on these three synthetic collagen proteins' mechanical deformation behavior and predictive properties is investigated in this paper. A detailed study and inference of the protein's mechanical characteristics associated with HYP content are investigated through fraying deformation behavior. A calculated Gibbs free energy value (ΔG) of each polypeptide α chain that corresponds with a complete unfolding of a single polypeptide α-chain from a triple-helical protein is obtained with umbrella sampling. The force needed for complete separation of the polypeptide α-chain from the triple-helical protein is analyzed for proteins to understand the influence of HYP concentration and is discussed in this paper. Along with a difference in ΔG, different unfolding pathways for the molecule and individual chains are observed. The correlation between the fraying deformation mechanical characteristics and the collagen proteins' hydroxyproline content is provided in this study via the three collagen proteins' resulting binding energies.

Randomized controlled trial of twice-daily versus alternate-day oral iron therapy in the treatment of iron-deficiency anemia.

Recent studies in iron-depleted women have challenged the current approach of treating iron-deficiency anemia (IDA) with oral iron in divided daily doses. Alternate day dosing leads to more fractional absorption of iron. In this randomized controlled trial, we looked at the efficacy and safety of alternate-day (AD) versus twice-daily (BD) oral iron in all severity of IDA. Total of 62 patients were randomized, 31 patients in BD arm received 60 mg elemental iron twice daily while 31 patients in AD arm received 120 mg iron on alternate days. The primary endpoint of 2 g/dl rise in hemoglobin was met in significantly more patients in the BD arm at 3 weeks (32.3% vs. 6.5%, p < 0.0001) and 6 weeks (58% vs. 35.5%, p = 0.001). There was a significant rise in the median hemoglobin at 3 (1.6 vs. 1.1, p = 0.02) and 6 weeks (2.9 vs. 2.0 g/dl, p = 0.03) in the BD arm. However, the median hemoglobin rise in the AD arm at 6 weeks was not significantly different than the BD arm at 3 weeks. Alternate-day dosing for 6 weeks and twice-daily dosing for 3 weeks resulted in the provision of the same total amount of iron. There were more reports of nausea in the BD arm (p = 0.03). In conclusion, the choice of twice-daily or alternate-day oral iron therapy should depend on the severity of anemia, the rapidity of response desired, and patient preference to either regimen due to adverse events. Trial Registration: CTRI reg. no. CTRI/2018/07/015106 http://ctri.nic.in/Clinicaltrials/login.php.

Hematopoietic stem cell donor with IgA nephropathy: Challenges and management algorithm.

Donor safety is of prime importance in allogeneic hematopoietic cell transplantation. The Worldwide Network for Blood and Marrow Transplantation (WBMT) standing committee on donor issues has issued a consensus statement regarding suitability criteria for related adult donors. This committee recommends that donors with a history of immune-mediated glomerulonephritis and abnormal urine tests should preferably undergo bone marrow harvest, to avoid the theoretical risk of granulocyte colony-stimulating factor (G-CSF) induced immune flare-up. We discuss here a unique situation where a related donor with a history of IgA nephropathy (IgAN) insisted on a peripheral blood stem cell harvest. We propose a management plan for this situation, which posed challenges about donor suitability.

Evaluation of trauma resources in rural northern Alberta identifies opportunities for improvement.

Background: The care of rural trauma patients in northern Alberta can be extremely challenging because of the vast geographic area, the limited access to health care facilities and the lack of adequate resources to manage severe injuries. Identifying gaps in equipment and personnel in rural centres can provide opportunities for improving the care of injured patients in these environments. We conducted a survey based on Canadian Accreditation Council quality indicators to evaluate trauma infrastructure and human resources in rural centres across northern Alberta. Methods: A standardized survey was developed to assess the availability of trauma-specific equipment and personnel across the prehospital and emergency department (ED) settings. The survey was distributed to 50 peripheral hospitals biannually from January 2017 to September 2018. Two-tailed paired t tests were used to evaluate changes in survey responses; a p value of less than 0.05 was considered statistically significant. Results: The survey response rate was 100%. By the end of the study period, there were significant improvements in the number of providers (p = 0.04), nurses (p = 0.01) and dedicated trauma resuscitation bays (p = 0.04) in the ED for managing injured patients. There were also significant increases in the availability of equipment, including advanced airway management tools (p = 0.02), rapid infusion devices (p = 0.02) and warmers (p = 0.04). Access to x-ray equipment (p = 0.03) and computed tomography (CT) scanners (p = 0.04) as well as equipment to support telehealth and teleconferencing (p = 0.04) increased during the study period. Access to, and supply of, blood products also increased significantly (p = 0.02) during the study period. Conclusion: Our study demonstrates that the trauma resources of rural health care centres may be evaluated in a standardized fashion centres, and the results point to opportunities to remedy gaps in equipment and personnel. Our methods may be applied to any trauma network that serves geographically large areas with a sparse distribution of health care facilities, to provide critical information for the optimization of resources in rural trauma.

Contexte: Les soins aux patients victimes de traumatismes en région rurale dans le nord de l'Alberta peuvent être très difficiles en raison de la superficie de la région, de l'accès limité aux établissements de santé et du manque de ressources pour soigner adéquatement les blessures graves. En repérant les lacunes en équipement et en personnel dans les établissements en région rurale, on peut créer des occasions d'améliorer les soins aux patients blessés dans ces milieux. Nous avons mené un sondage fondé sur les indicateurs de qualité du Conseil d'accréditation canadien pour évaluer les infrastructures et les ressources humaines en traumatologie dans les établissements des régions rurales du nord de l'Alberta. Méthodes: Un sondage standardisé a été créé pour évaluer la disponibilité des équipements et des ressources humaines en traumatologie en contexte préhospitalier et aux services d'urgence. Le sondage a été distribué 2 fois par année à 50 hôpitaux entre janvier 2017 et septembre 2018. Des tests t appariés ayant une hypothèse non nulle ont été utilisés pour évaluer les changements dans les réponses au sondage; les résultats ayant une valeur p < 0,05 étaient considérés comme statistiquement significatifs. Résultats: Le taux de participation au sondage était de 100 %. À la fin de la période étudiée, il y avait une amélioration significative du nombre de fournisseurs (p = 0,04), de personnel infirmier (p = 0,01) et d'espaces de réanimation réservés à la traumatologie (p = 0,04) dans les services d'urgence. Il y avait aussi une augmentation significative de la disponibilité de l'équipement, notamment des outils de prise en charge avancée des voies respiratoires (p = 0,02), des appareils de perfusion rapide (p = 0,02) et d'armoires chauffantes (p = 0,04). Les équipements de radiographie (p = 0,03) et de tomographie par ordinateur (p = 0,04) ainsi que les équipements facilitant la télémédecine et les téléconférences (p = 0,04) sont devenus plus accessibles pendant la période étudiée. Les réserves de produits sanguins et l'accès à ces produits a aussi augmenté de manière significative (p = 0,02). Conclusion: Notre étude montre que les ressources en traumatologie dans les établissements de santé en région rurale peuvent être évaluées de manière standardisée, et les résultats indiquent qu'il y a des occasions de combler les lacunes en équipement et en personnel. Notres méthodes peuvent être reproduites dans tout réseau de traumatologie couvrant un grand territoire où les établissements de santé sont dispersés, pour fournir des données critiques sur l'organisation des ressources de traumatologie en région rurale.

Value stream mapping for identification and assessment of material waste in construction: A case study.

Construction sites are plagued with numerous problems, such as improper planning and management, high amounts of waste generation and low awareness of waste reduction. Construction and demolition waste literature provides several best practises and prescriptive strategies that help minimise waste during construction. However, it lacks in the systematic identification and minimisation approach of all possibilities of waste. Therefore, studies focusing on principles and tools that help systematically analyse the inefficiencies of on-site processes leading to waste generation and philosophies addressing waste minimisation are necessary. As eliminating waste is one of the key lean principles, this article discusses the need and importance of integrating the lean construction with the construction and demolition waste management. This article aims to estimate and assess the causes of waste generation in a high-rise building construction through a case study in Chennai city (India) using value stream mapping, a key lean construction tool. Onsite monitoring and measurement were performed to quantify the amount of waste generated. A waste generation rate of 66.26 kg m-2 was identified, of which concrete, cement mortar and brick waste represented almost 90% of the total construction waste. Direct observation and interviews of site personnel were conducted to understand the causes of waste generation. A strategic framework has been proposed to improve construction and demolition waste minimisation depicting the synergy of combining lean construction principles with construction and demolition waste management strategies. The proposed framework helps in the systematic identification, assessment and minimisation of on-site construction waste generation.

Reverse Locked-In Syndrome.

BACKGROUND: Basilar artery occlusion can cause locked-in syndrome, which is characterized by quadriplegia, anarthria, and limited communication via eye movements. Here, we describe an uncommon stroke syndrome associated with endovascular recanalization of the top of the basilar artery: "reverse locked-in syndrome." METHODS: We report the case of a patient with atypical neurological deficits caused by acute ischemic stroke of the midbrain tegmentum. We perform neuroanatomic localization of the patient's infarcts by mapping the magnetic resonance imaging (MRI) data onto a brainstem atlas. RESULTS: A 61-year-old man presented with acute coma and quadriplegia due to top of the basilar artery occlusion. He underwent emergent endovascular thrombectomy, with successful recanalization of the basilar artery at 4 h and 43 min post-ictus. The patient regained consciousness and purposeful movement in all four extremities, but the post-procedure neurological examination demonstrated bilateral ptosis with complete pupillary and oculomotor paralysis. MRI revealed infarction of the bilateral oculomotor nuclei in the midbrain tegmentum. At 9-month follow-up, he had anisocoria and dysconjugate gaze, but was living at home and required minimal assistance in performing all activities of daily living. CONCLUSIONS: Since the patient's deficits were the exact opposite of those described in locked-in syndrome, we propose the term "reverse locked-in syndrome" to describe this neurological entity characterized by bilateral ptosis, non-reactive pupils, and ophthalmoplegia with preservation of consciousness and extremity motor function.

Pulmonary and Ear, Nose and Throat (ENT) Involvement in ANCA-Associated Vasculitis at Diagnosis-Experience from a Tertiary Care Centre in North India.

BACKGROUND AND AIMS: There is paucity of data on pulmonary and ENT involvement in ANCA associatd vasculitis from India. We aimed to review the pattern of lung and upper respiratory tract involvement in patients with AAV diagnosed at our centre. METHODS: A retrospective review of all AAV patients between January 2007 and June 2014 was done. A complete clinical evaluation for Pulmonary and ENT involvement was done. Advanced investigations including computed tomography (CT) bronchoscopy and nasal endoscopy were done when indicated. Proportion of involvement was noted and different variables among patient groups were compared. RESULTS: 92 patients (median age 42 years; 60% female) of AAV were included. Clinical and/or radiological evidence of lung involvement was seen in 70 (76.1%) patients. Diffuse alveolar haemorrhage was present in 6 (60%) patients with MPA and 7 (10.1%) patients with GPA (p=0.002). ENT involvement was present in 55 (59.8%) patients and was more in GPA (p=0.000). Absence of renal involvement [p=0.047] and absence of GI involvement [p=0.012] were associated with ENT involvement in GPA. CONCLUSION: Pulmonary involvement was common in GPA, MPA and CSS, ENT involvement was almost characteristic of GPA. DAH was common in MPA. Population based and multicentre studies are needed to assess the true burden of organ involvement in AAV in the Indian population.

Estimation of construction and demolition waste using waste generation rates in Chennai, India.

A large amount of construction and demolition waste is being generated owing to rapid urbanisation in Indian cities. A reliable estimate of construction and demolition waste generation is essential to create awareness about this stream of solid waste among the government bodies in India. However, the required data to estimate construction and demolition waste generation in India are unavailable or not explicitly documented. This study proposed an approach to estimate construction and demolition waste generation using waste generation rates and demonstrated it by estimating construction and demolition waste generation in Chennai city. The demolition waste generation rates of primary materials were determined through regression analysis using waste generation data from 45 case studies. Materials, such as wood, electrical wires, doors, windows and reinforcement steel, were found to be salvaged and sold on the secondary market. Concrete and masonry debris were dumped in either landfills or unauthorised places. The total quantity of construction and demolition debris generated in Chennai city in 2013 was estimated to be 1.14 million tonnes. The proportion of masonry debris was found to be 76% of the total quantity of demolition debris. Construction and demolition debris forms about 36% of the total solid waste generated in Chennai city. A gross underestimation of construction and demolition waste generation in some earlier studies in India has also been shown. The methodology proposed could be utilised by government bodies, policymakers and researchers to generate reliable estimates of construction and demolition waste in other developing countries facing similar challenges of limited data availability.

Collagen-graft mixed cellulose esters membrane maintains undifferentiated morphology and markers of potential pluripotency in feeder-free culture of induced pluripotent stem cells.

Induced pluripotent stem cells (iPSCs) are unique and unlimited clinical sources of stem cell therapy for the regenerative medicine. Feeder layer preparation is an important step for iPSCs production, which is expensive, time-consuming and requires conversance. In the present study, we investigated the maintenance of pluripotency, and stemness of the iPSCs through feeder-free culture on a collagen-grafted Mixed Cellulose Esters membrane (MCE-COL) after three passages during twelve days. Results have demonstrated that the iPSCs cultured on MCE-COL membrane had a fine, typical undifferentiated morphology, increased proliferation rate and significant multi-lineage differentiation potential. Alkaline phosphatase (ALP) staining and pluripotency associated gene markers expression further confirmed that iPSCs cultured on the surface of MCE-COL had more ALP positive colonies and enhanced expression of Oct-4, Nanog, Sox-2 and ALP in comparison with MCE and control groups. Since MCE-COL membrane has three dimensional structure and bioactivity, it has the potential for usage in the feeder-free culture of iPSCs, and could be a suitable candidate to use as a feeder layer in stem cells preparation.

Cryopreserved Adipose Tissue-Derived Stromal/Stem Cells: Potential for Applications in Clinic and Therapy.

Adipose-Derived Stromal/Stem Cells (ASC) have considerable potential for regenerative medicine due to their abilities to proliferate, differentiate into multiple cell lineages, high cell yield, relative ease of acquisition, and almost no ethical concerns since they are derived from adult tissue. Storage of ASC by cryopreservation has been well described that maintains high cell yield and viability, stable immunophenotype, and robust differentiation potential post-thaw. This ability is crucial for banking research and for clinical therapeutic purposes that avoid the morbidity related to repetitive liposuction tissue harvests. ASC secrete various biomolecules such as cytokines which are reported to have immunomodulatory properties and therapeutic potential to reverse symptoms of multiple degenerative diseases/disorders. Nevertheless, safety regarding the use of these cells clinically is still under investigation. This chapter focuses on the different aspects of cryopreserved ASC and the methods to evaluate their functionality for future clinical use.

Association between Hospital Volume and Within-Hospital Intensive Care Unit Transfer for Sickle Cell Disease in Children's Hospitals.

OBJECTIVE: To assess the relationship between hospital volume and intensive care unit (ICU) transfer among hospitalized children with sickle cell disease (SCD). STUDY DESIGN: We conducted a retrospective cohort study of 83,477 SCD-related hospitalizations at children's hospitals (2009-2012) using the Pediatric Health Information System database. Hospital-level all-cause and SCD-specific volumes were dichotomized (low vs high). Outcomes were within-hospital ICU transfer (primary) and length of stay (LOS) total (secondary). Multivariable logistic/linear regressions assessed the association of hospital volumes with ICU transfer and LOS. RESULTS: Of 83,477 eligible hospitalizations, 1741 (2.1%) involving 1432 unique children were complicated by ICU transfer. High SCD-specific volume (OR 0.77, 95% CI 0.64-0.91) was associated with lower odds of ICU transfer while high all-cause hospital volume was not (OR 0.87, 95% CI 0.73-1.04). A statistically significant interaction was found between all-cause and SCD-specific volumes. When results were stratified according to all-cause volume, high SCD-specific volume was associated with lower odds of ICU transfer at low all-cause volume (OR 0.46, 95% CI 0.38-0.55). High hospital volumes, both all-cause (OR 0.94, 95% CI 0.92-0.97) and SCD-specific (OR 0.86, 95% CI 0.84-0.88), were associated with shorter LOS. CONCLUSIONS: Children's hospitals vary substantially in their transfer of children with SCD to the ICU according to hospital volumes. Understanding the practices used by different institutions may help explain the variability in ICU transfer among hospitals caring for children with SCD.

The Relative Functionality of Freshly Isolated and Cryopreserved Human Adipose-Derived Stromal/Stem Cells.

The capability of multipotent mesenchymal stem cells to maintain cell viability, phenotype and differentiation ability upon thawing is critical if they are to be banked and used for future therapeutic purposes. In the present study, we examined the effect of 9-10 months of cryostorage on the morphology, immunophenotype, colony-forming unit (CFU) and differentiation capacity of fresh and cryopreserved human adipose-derived stromal/stem cells (ASCs) from the same donors. Cryopreservation did not reduce the CFU frequency and the expression levels of CD29, CD73, CD90 and CD105 remained unchanged with the exception of CD34 and CD45; however, the differentiation capacity of cryopreserved ASCs relative to fresh cells was significantly reduced. While our findings suggest that future studies are warranted to improve cryopreservation methods and agents, cryopreserved ASCs retain sufficient features to ensure their practical utility for both research and clinical applications.

Familial syndromes associated with intracranial tumours: a review.

BACKGROUND: Most cancers of the central nervous system (CNS) occur sporadically in the absence of any known underlying familial disorder or multi-systemic syndrome. Several syndromes are associated with CNS malignancies, however, and their recognition has significant implications for patient management and prognosis. Patients with syndrome-associated CNS malignancies often have multiple tumours (either confined to one region or distributed throughout the body), with similar or different histology. OBJECTIVE: This review examines syndromes that are strongly associated with CNS cancers: the phakomatosis syndromes, familial syndromes such as Li-Fraumeni and familial polyposis syndromes and dyschondroplasia.

Adult Stem Cells Freezing Processes and Cryopreservation Protocols.

The development of simple but effective storage protocols for adult stem cells will greatly enhance their use and utility in tissue-engineering applications. Cryopreservation has shown the most promise but is a fairly complex process, necessitating the use of chemicals called cryoprotective agents (CPAs), freezing equipment, and obviously, storage in liquid nitrogen. The purpose of this chapter is to present a general overview of cryopreservation storage techniques and the optimal protocols/results obtained in our laboratory for long-term storage of adult stem cells using freezing storage.

Durability performance of alkali-activated concrete with pre-treated coarse recycled aggregates for pavements.

This study examines the effect of coarse recycled aggregates (CRAs) and processed coarse recycled aggregates (PCRAs) on the behaviour of alkali-activated concrete (AAC) before and after exposure to marine seawater and acidic environments (5% HCl and 5% H2SO4 solutions). Measurements of compressive strength and the microstructure changes were conducted over periods of 56 and 90 days to assess these effects. The experimental design included varying the replacement levels of NAs with CRAs and PCRAs from (0-100%) and using ground-granulated blast furnace slag and fly ash as constant components. In addition to durability tests, sorptivity assessments were conducted to gauge the material's porosity and water absorption capabilities. Advanced microstructure techniques, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD), were employed to detail the pre and post-exposure mineralogical and microstructural transformations within the AAC blends. The AAC mixtures incorporating PCRAs emerged as durable, showcasing better strength and a denser, more compact matrix facilitated by the synergistic formation of NASH and CASH gels after exposure to aggressive agents compared to untreated CRAs. In addition, the results show that the samples exposed to marine seawater exhibited improved mechanical performance compared to those exposed to acidic environments. The novelty of this study lies in its exploration of the effects of recycling plant-based CRAs and PCRAs on AAC for marine and acid exposure.

Dysfunctional tumor-infiltrating Vδ1 + T lymphocytes in microsatellite-stable colorectal cancer.

Although γδ T cells are known to participate in immune dysregulation in solid tumors, their relevance to human microsatellite-stable (MSS) colorectal cancer (CRC) is still undefined. Here, using integrated gene expression analysis and T cell receptor sequencing, we characterized γδ T cells in MSS CRC, with a focus on Vδ1 + T cells. We identified Vδ1+ T cells with shared motifs in the third complementarity-determining region of the δ-chain, reflective of antigen recognition. Changes in gene and protein expression levels suggested a dysfunctional effector state of Vδ1+ T cells in MSS CRC, distinct from Vδ1+ T cells in microsatellite-instable (MSI). Interaction analysis highlighted an immunosuppressive role of fibroblasts in the dysregulation of Vδ1+ T cells in MSS CRC via the TIGIT-NECTIN2 axis. Blocking this pathway with a TIGIT antibody partially restored cytotoxicity of the dysfunctional Vδ1 phenotype. These results define an operative pathway in γδ T cells in MSS CRC.

Nox2 and Nox4 influence neonatal c-kit(+) cardiac precursor cell status and differentiation.

Redox status has emerged as critical in modulating stemness and lineage commitment in several precursor cell types. However, a role for redox genes, specifically NADPH oxidases (Nox), in cardiac precursor cells (CPCs) has not been established. We tested whether CPCs marked by type III receptor tyrosine kinase c-kit (c-kit(+)) exhibit a unique NADPH oxidase signature that confers precursor status and whether alterations in this profile are functionally linked to changes in lineage specification. Dihydroethidium (DHE) microfluorography indicated reduced basal reactive oxygen species (ROS) formation within early postnatal c-kit(+) CPCs. Real-time quantitative PCR revealed downregulation of ROS generator Nox2 and its subunit p67(phox) in c-kit(+) CPCs under basal conditions but upregulation of Nox2 and Nox4 over the course of differentiation. Adenoviral silencing of Nox2 and Nox4 increased expression of CPC markers c-kit and Flk-1 and blunted smooth and cardiac muscle differentiation, respectively, while overexpression of Nox2 and Nox4 significantly reduced c-kit expression. These changes were accompanied by altered expression of transcription factors regulating cardiac lineage commitment, Gata6 and Gata4, and cytokine transforming growth factor (TGF)-ß1. Similar to other precursor cell types, RT(2)Profiler PCR Arrays revealed that c-kit(+) CPCs also exhibit enhanced antioxidant capacity at the mRNA level. In conclusion, we report that c-kit(+) CPCs demonstrate reduced Nox2 expression and ROS levels and that increases in Nox2 and Nox4 influence their differentiation into mature cells. We speculate that ROS generators Nox2 and Nox4, along with the antioxidant genes identified by PCR Arrays, may be novel targets in CPCs that could prove useful in cell-based therapy of the heart.

Successful vitrification and autografting of baboon (Papio anubis) ovarian tissue.

STUDY QUESTION: Can a vitrification protocol using an ethylene glycol/dimethyl sulphoxide-based solution and a cryopin successfully cryopreserve baboon ovarian tissue? SUMMARY ANSWER: Our results show that baboon ovarian tissue can be successfully cryopreserved with our vitrification protocol. WHAT IS KNOWN ALREADY: Non-human primates have already been used as an animal model to test vitrification protocols for human ovarian tissue cryopreservation. STUDY DESIGN, SIZE, DURATION: Ovarian biopsies from five adult baboons were vitrified, warmed and autografted for 5 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: After grafting, follicle survival, growth and function and also the quality of stromal tissue were assessed histologically and by immunohistochemistry. The influence of the vitrification procedure on the cooling rate was evaluated by a computer model. MAIN RESULTS: After vitrification, warming and long-term grafting, follicles were able to grow and maintain their function, as illustrated by Ki67, anti-Müllerian hormone (AMH) and growth differentiation factor-9 (GDF-9) immunostaining. Corpora lutea were also observed, evidencing successful ovulation in all the animals. Stromal tissue quality did not appear to be negatively affected by our cryopreservation procedure, as demonstrated by vascularization and proportions of fibrotic areas, which were similar to those found in fresh ungrafted ovarian tissue. LIMITATIONS, REASONS FOR CAUTION: Despite our promising findings, before applying this technique in a clinical setting, we need to validate it by achieving pregnancies. WIDER IMPLICATIONS OF THE FINDINGS: In addition to encouraging results obtained with our vitrification procedure for non-human ovarian tissue, this study also showed, for the first time, expression of AMH and GDF-9 in ovarian follicles. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (grant Télévie No. 7.4507.10, grant 3.4.590.08 awarded to Marie-Madeleine Dolmans), Fonds Spéciaux de Recherche, Fondation St Luc, Foundation Against Cancer, and Department of Mechanical Engineering at Louisiana State University (support to Ram Devireddy), and donations from Mr Pietro Ferrero, Baron Frère and Viscount Philippe de Spoelberch. None of the authors has any competing interests to declare.

Fournier's gangrene of the penis caused by Streptococcus dysgalactiae subspecies equisimilis: case report and incidence study in a tertiary-care hospital.

BACKGROUND: Fournier's gangrene is a rare necrotizing soft tissue infection of the scrotum and penis. We report, to our knowledge, the first case of Fournier's gangrene caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE), a strain of pyogenic ß-hemolytic streptococci that is increasingly being recognized as an important human pathogen. CASE PRESENTATION: We describe a healthy 59 year-old Caucasian male who presented to the emergency department with Fournier's gangrene of the penis and scrotum, with extension to the anterior abdominal wall. He underwent urgent surgical debridement of his scrotum, penis, and anterior abdomen. Swabs from the scrotum grew Gram-positive cocci, which were initially identified as Streptococcus anginosus group by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). However, polymerase chain reaction (PCR) amplification and sequencing of the 16S rRNA gene identified the isolate as Streptococcus dysgalatiae subspecies equisimilis (SDSE). The incidences of invasive S. anginosus group and SDSE infections at the London Health Sciences Centre, a tertiary-care institution in southwestern Ontario, were determined between August 1, 2011 and August 31, 2012, revealing a slightly lower rate of SDSE (3.2 cases per 100,000 population) than other studies. CONCLUSIONS: This case highlights a unique disease manifestation of the emerging human pathogen Streptococcus dysgalatiae subspecies equisimilis that has not been previously reported. This case also underscores the limitations of MALDI-TOF MS in differentiating between closely-related streptococcal species which may have different pathogenic profiles.