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1.
Antimicrob Agents Chemother ; 68(4): e0172823, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38470133

RESUMO

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular Pseudomonas aeruginosa LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14-51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in P. aeruginosa endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.


Assuntos
Bacteriemia , Bacteriófagos , Coração Auxiliar , Terapia por Fagos , Infecções por Pseudomonas , Humanos , Pseudomonas aeruginosa , Coração Auxiliar/efeitos adversos , Infecções por Pseudomonas/terapia , Infecções por Pseudomonas/microbiologia , Antibacterianos/uso terapêutico , Prófagos , Bacteriemia/tratamento farmacológico
2.
Psychol Health Med ; 28(3): 629-639, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36124360

RESUMO

Altruistic organ donors represent a special population when compared to related living donors, requiring appropriate protection and attention regarding informed consent and psychological aspects related to the donation. Following the introduction of the Israeli Transplant Law of 2008, a retrospective study of altruistic donor files revealed that important psycho-diagnostic aspects were not emphasized in the existing guidelines. Thus, a new tool was formulated which incorporated those elements, including assessment of emotional maturity, ego strength, degree of interest in others, reality testing, degree of pressure to donate, anxiety, dysphoric and depressive factors and the ability to function under stress. The study examined 598 cases reviewed by the Central Evaluation Board over the period May 2008 - June 2016. Overall, 23.4% candidates were disqualified of whom 41% were declined on grounds related to mental health. Most of the donors were rejected based on 3-5 elements. Of these, a deficient assessment of reality in ambiguous situations, lack of emotional maturity, and lacking or partial ability to function effectively under stress, were most commonly cited as reasons for rejection. This model allowed the detection of important conditions previously not incorporated into existing guidelines and may serve as a model for other transplantation programs worldwide.


Assuntos
Transplante de Rim , Humanos , Transplante de Rim/psicologia , Israel/epidemiologia , Estudos Retrospectivos , Doadores Vivos/psicologia , Saúde Mental
3.
J Hand Surg Am ; 47(5): 484.e1-484.e4, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34049730

RESUMO

Snake bites are an uncommon injury requiring intervention by hand surgeons. While counteracting the effects of snake venom is the initial and urgent concern following a bite, infection caused by retention of a foreign body can present in a delayed fashion and may lead to increased morbidity. Standard radiographs of the injury should be carefully examined for foreign bodies, noting that retained snake teeth are somewhat radiolucent due to less mineralization as compared to bone and can be difficult to visualize. In our subject, a retained rattlesnake fang was found in association with a septic interphalangeal joint despite appropriate radiographic evaluation and thorough surgical irrigation and debridement upon initial presentation. This case report highlights a potential complication of snake bites, the importance of aggressive management, and the importance of increased suspicion for retained foreign bodies. Augmenting plain radiographs with additional imaging modalities, such as ultrasound, dark-field, and phase-contrast imaging, may aid in the diagnosis of retained foreign bodies after snake bites.


Assuntos
Artrite Infecciosa , Corpos Estranhos , Mordeduras de Serpentes , Animais , Crotalus , Corpos Estranhos/complicações , Humanos , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/terapia , Venenos de Serpentes
5.
J Cardiovasc Electrophysiol ; 30(9): 1652-1662, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31353683

RESUMO

INTRODUCTION: Catheter-tissue contact force is a determinant of radiofrequency (RF) ablation lesion effectiveness. However, ablation on a beating heart is subject to force variability, making it difficult to optimally deliver consistently durable and transmural lesions. This work evaluates improvements in contact force stability and lesion reproducibility by using a catheter contact-force controller (CFC) during lesion delivery in vitro and in vivo. METHODS AND RESULTS: Using a sheath and force-sensing catheter, an experienced operator attempted to maintain a constant force of 20 g at targets within the atria and left ventricle of a pig manually and using the CFC; the average force and contact-force variation (CFV) achieved using each approach were compared. Ablation lesions (20 W, 30 seconds, 17 mL/min irrigation) were created in bovine tissue samples mounted on a platform programmed to reproduce clinically relevant motion. CFC-assisted lesions were delivered to stationary and moving tissue with forces of 5 to 35 g. Mimicking manual intervention, lesions were also delivered to moving tissue while the CFC was disabled. Resultant lesion volumes were compared using two-way analysis of variance. When using the CFC, the average force was within 1 g of the set level, with a CFV less than 5 g, during both in vitro and in vivo experiments. Reproducible and statistically identical (P = .82) lesion volumes proportional to the set force were achieved in both stationary and moving tissue when the CFC was used. CONCLUSIONS: CFC assistance maintains constant force in vivo and removes effect of motion on lesion volume during RF lesion delivery.


Assuntos
Cateteres Cardíacos , Ablação por Cateter/instrumentação , Ventrículos do Coração/cirurgia , Animais , Ablação por Cateter/efeitos adversos , Bovinos , Desenho de Equipamento , Ventrículos do Coração/patologia , Modelos Animais , Movimento (Física) , Pressão , Sus scrofa , Fatores de Tempo
6.
Am J Emerg Med ; 35(5): 806.e1-806.e3, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27939516

RESUMO

Nonrheumatic myopericarditis is an uncommon complication of acute pharyngitis caused by Group A Streptococcal infection (GAS). While the natural history of carditis complicating acute rheumatic fever is well established, the incidence, pathophysiology and clinical course of nonrheumatic myopericarditis are ill defined. Advances in rapid bedside testing for both myocardial injury and GAS pharyngitis have allowed for increasing recognition of this uncommon complication in patients presenting with a sore throat with associated chest discomfort. We describe a case of a 34years old man with GAS pharyngitis complicated by acute myopericarditis who presented with chest pain, ST segment elevation on electrocardiogram, and elevated cardiac biomarkers.


Assuntos
Dor no Peito/etiologia , Miocardite/diagnóstico por imagem , Pericardite/diagnóstico por imagem , Faringite/complicações , Infecções Estreptocócicas/complicações , Adulto , Dor no Peito/microbiologia , Eletrocardiografia , Humanos , Masculino , Miocardite/microbiologia , Pericardite/microbiologia , Infecções Estreptocócicas/diagnóstico por imagem
7.
Appl Environ Microbiol ; 81(8): 2696-705, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25662974

RESUMO

Phage therapy has been proven to be more effective, in some cases, than conventional antibiotics, especially regarding multidrug-resistant biofilm infections. The objective here was to isolate an anti-Enterococcus faecalis bacteriophage and to evaluate its efficacy against planktonic and biofilm cultures. E. faecalis is an important pathogen found in many infections, including endocarditis and persistent infections associated with root canal treatment failure. The difficulty in E. faecalis treatment has been attributed to the lack of anti-infective strategies to eradicate its biofilm and to the frequent emergence of multidrug-resistant strains. To this end, an anti-E. faecalis and E. faecium phage, termed EFDG1, was isolated from sewage effluents. The phage was visualized by electron microscopy. EFDG1 coding sequences and phylogeny were determined by whole genome sequencing (GenBank accession number KP339049), revealing it belongs to the Spounavirinae subfamily of the Myoviridae phages, which includes promising candidates for therapy against Gram-positive pathogens. This analysis also showed that the EFDG1 genome does not contain apparent harmful genes. EFDG1 antibacterial efficacy was evaluated in vitro against planktonic and biofilm cultures, showing effective lytic activity against various E. faecalis and E. faecium isolates, regardless of their antibiotic resistance profile. In addition, EFDG1 efficiently prevented ex vivo E. faecalis root canal infection. These findings suggest that phage therapy using EFDG1 might be efficacious to prevent E. faecalis infection after root canal treatment.


Assuntos
Biofilmes , Cavidade Pulpar/microbiologia , Doenças da Polpa Dentária/prevenção & controle , Enterococcus faecalis/fisiologia , Genoma Viral , Infecções por Bactérias Gram-Positivas/prevenção & controle , Myoviridae/fisiologia , Doenças da Polpa Dentária/microbiologia , Enterococcus faecalis/virologia , Infecções por Bactérias Gram-Positivas/microbiologia , Dados de Sequência Molecular , Myoviridae/genética , Plâncton/fisiologia , Plâncton/virologia , Análise de Sequência de DNA , Esgotos/virologia
8.
STAR Protoc ; 5(2): 102949, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38691464

RESUMO

Phage therapy has re-emerged as a promising treatment for non-resolving infections. Given the lack of approved phage treatments, there is a need to establish a compassionate use pipeline. Here, we present a protocol for phage matching, treatment, and monitoring for compassionate bacteriophage use in non-resolving infections. We describe steps for consultation and request implementation, evaluating and comparing different aspects of phage activity, and phage production. We then detail procedures for multidisciplinary meetings, ethics approvals, phage therapy, and follow-up. For complete details on the use and execution of this protocol, please refer to Onallah et al.1,2.


Assuntos
Bacteriófagos , Ensaios de Uso Compassivo , Terapia por Fagos , Humanos , Bacteriófagos/fisiologia , Terapia por Fagos/métodos , Infecções Bacterianas/terapia
9.
Artigo em Inglês | MEDLINE | ID: mdl-37256153

RESUMO

Background: Varicella zoster virus (VZV) exposure seriously threatens immunocompromised hosts. Postexposure prophylaxis (PEP) using immune globulins is considered the standard of care; however, the available literature is mainly based on its use in pediatric patients. Here, we describe a widespread VZV exposure among immunocompromised adults treated with VZV-specific immunoglobulins (VZVSIG), and we discuss management and outcomes. Methods: We conducted a retrospective study to describe the exposure of immunocompromised patients to a single healthcare worker with primary VZV in 2019. Patients were grouped by their overall risk for infection, and those at risk received a single intramuscular dose of 625 IU of VZVSIG and were followed for 1 year. Results: In total, 83 patients received PEP at <96 hours of exposure: 14 were hospitalized, 68 were outpatients, and 1 was an immunocompromised staff member. The median age was 69 years (range, 21-92), and 49.4% were male. In addition, 30% of the patients were deemed high risk, 42% were intermediate risk, and 28% were considered low risk, although they were given PEP. Varicella infection was not diagnosed in any patient in the first weeks of follow-up. However, during the year of follow-up, 4 patients developed symptoms suspicious of VZV, all >3 months after exposure, thus were probably unrelated to the event. Adverse events related to VZVSIG (pyrexia) were reported in 2 patients (2.4%). Conclusions: Our findings demonstrate the utility of VZVSIG as PEP in one of the largest cohorts of immunocompromised adults to date. No early varicella infection was found following exposure, supporting the current recommendations of the VZVSIG administration.

10.
Mil Med ; 188(Suppl 6): 428-435, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37948204

RESUMO

BACKGROUND: Posttraumatic stress disorder (PTSD) is prevalent among military personnel and may arise following a wide range of traumatic exposures. Consciousness level following traumatic injury may play a role in the development of PTSD, but its effects have been primarily investigated in the context of traumatic brain injury. METHODS: Registry-based study surveying three databases documenting care from point of injury to long-term rehabilitation of traumatic injuries among military personnel. The study population was divided according to Glasgow Coma Scale (GCS) scores upon emergency department admission (GCS scores 15, 13 and 14, 9-12, and 3-8), with PTSD diagnoses being determined according to disability claim records. Multivariable logistic regression was utilized to determine the association between GCS score at admission and PTSD. RESULTS: Overall, 3,376 military personnel hospitalized following traumatic injuries between 1997 and 2020 were included. The majority were male (92.3%), with a median age of 20 (interquartile range 19-22) at the injury time. Of these, 569 (16.9%) were diagnosed with PTSD according to disability claims, with a median follow-up time of 10.9 years. PTSD diagnosis was most prevalent (30.3% of patients), with a GCS score of 13 and 14. In the adjusted multivariable model, a GCS score of 13 and 14 was associated with significantly higher odds of PTSD diagnosis when compared to a GCS score of 15 (odds ratio 2.19, 95% CI, 1.21-3.88). The associations of other GCS groupings with PTSD diagnosis were nonsignificant. CONCLUSIONS: Minimally impaired consciousness following traumatic injuries is associated with increased odds of PTSD. The role of patient awareness, analgesia, and sedation following an injury in developing PTSD warrants further investigation and could guide early diagnosis and preventive interventions.


Assuntos
Lesões Encefálicas Traumáticas , Militares , Transtornos de Estresse Pós-Traumáticos , Humanos , Masculino , Feminino , Escala de Coma de Glasgow , Transtornos de Estresse Pós-Traumáticos/complicações , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Lesões Encefálicas Traumáticas/diagnóstico
11.
Med ; 4(9): 600-611.e4, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37562400

RESUMO

BACKGROUND: A growing number of compassionate phage therapy cases were reported in the last decade, with a limited number of clinical trials conducted and few unsuccessful clinical trials reported. There is only a little evidence on the role of phages in refractory infections. Our objective here was to present the largest compassionate-use single-organism/phage case series in 16 patients with non-resolving Pseudomonas aeruginosa infections. METHODS: We summarized clinical phage microbiology susceptibility data, administration protocol, clinical data, and outcomes of all cases treated with PASA16 phage. In all intravenous phage administrations, PASA16 phage was manufactured and provided pro bono by Adaptive Phage Therapeutics. PASA16 was administered intravenously, locally to infection site, or by topical use to 16 patients, with data available for 15 patients, mainly with osteoarticular and foreign-device-associated infections. FINDINGS: A few minor side effects were noted, including elevated liver function enzymes and a transient reduction in white blood cell count. Good clinical outcome was documented in 13 out of 15 patients (86.6%). Two clinical failures were reported. The minimum therapy duration was 8 days with a once- to twice-daily regimen. CONCLUSIONS: PASA16 with antibiotics was found to be relatively successful in patients for whom traditional treatment approaches have failed previously. Such pre-phase-1 cohorts can outline potential clinical protocols and facilitate the design of future trials. FUNDING: The study was funded in part by The Israeli Science Foundation IPMP (ISF_1349/20), Rosetrees Trust (A2232), United States-Israel Binational Science Foundation (2017123), and the Milgrom Family Support Program.


Assuntos
Bacteriófagos , Infecções por Pseudomonas , Fagos de Pseudomonas , Humanos , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Ensaios de Uso Compassivo , Antibacterianos/uso terapêutico
12.
Phage (New Rochelle) ; 3(2): 85-94, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36157284

RESUMO

The fascinating scientific history of phage therapy has been documented in numerous publications. In this study, however, we focus on an angle of the story that hitherto has remained relatively neglected, namely, phage therapy treatments, and the protagonists that conducted these in Mandatory-Palestine and subsequently the state of Israel, as part of a global trend. We complete the story by describing efforts in the new era of phage therapy in present-day Israel.

13.
Microbiol Resour Announc ; 11(4): e0009222, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35258339

RESUMO

PASA16 is a Pseudomonas aeruginosa phage isolated from a soil sample and used to treat several patients suffering from persistent infections in various countries. PASA16's genome was sequenced, analyzed, and deposited in GenBank.

14.
Viruses ; 13(5)2021 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-34063251

RESUMO

Streptococcus mutans is a key bacterium in dental caries, one of the most prevalent chronic infectious diseases. Conventional treatment fails to specifically target the pathogenic bacteria, while tending to eradicate commensal bacteria. Thus, caries remains one of the most common and challenging diseases. Phage therapy, which involves the use of bacterial viruses as anti-bacterial agents, has been gaining interest worldwide. Nevertheless, to date, only a few phages have been isolated against S. mutans. In this study, we describe the isolation and characterization of a new S. mutans phage, termed SMHBZ8, from hundreds of human saliva samples that were collected, filtered, and screened. The SMHBZ8 genome was sequenced and analyzed, visualized by TEM, and its antibacterial properties were evaluated in various states. In addition, we tested the lytic efficacy of SMHBZ8 against S. mutans in a human cariogenic dentin model. The isolation and characterization of SMHBZ8 may be the first step towards developing a potential phage therapy for dental caries.


Assuntos
Cárie Dentária/terapia , Terapia por Fagos , Fagos de Streptococcus/isolamento & purificação , Streptococcus mutans/virologia , Cárie Dentária/microbiologia , Cárie Dentária/virologia , Genoma Viral , Humanos , Saliva/virologia , Fagos de Streptococcus/classificação , Fagos de Streptococcus/genética , Fagos de Streptococcus/fisiologia , Streptococcus mutans/fisiologia
15.
Lancet Microbe ; 2(10): e555-e563, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-35544180

RESUMO

Phage therapy is a promising solution for bacterial infections that are not eradicated by conventional antibiotics. A crucial element of this approach is appropriate matching of bacteriophages and antibiotics to the bacterial target according to the clinical setting. However, there is currently little consistency in the protocols used for the laboratory evaluation of bacteriophages intended for antibacterial treatment. In this Personal View, we suggest a framework aimed to match appropriate bacteriophage-based treatments in clinical microbiology laboratories. This framework, which we have termed Clinical Phage Microbiology, is based on the current research on phage treatments. In addition, we discuss special cases that might require additional relevant evaluation, including bacteriophage interactions with the host immune response, biofilm-associated infections, and polymicrobial infections. The Clinical Phage Microbiology pipeline could serve as the basis for future standardisation of laboratory protocols for personalised phage therapy.


Assuntos
Infecções Bacterianas , Bacteriófagos , Terapia por Fagos , Antibacterianos/uso terapêutico , Infecções Bacterianas/terapia , Biofilmes , Humanos
16.
ERJ Open Res ; 7(4)2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34760998

RESUMO

Phage therapy is a promising antibacterial strategy for resistant respiratory tract infections. Phage inhalation may serve this goal; however, it requires a careful assessment of their delivery by this approach. Here we present an in vitro model to evaluate phage inhalation. Eight phages, most of which target pathogens common in cystic fibrosis, were aerosolised by jet nebuliser and administered to a real-scale computed tomography-derived 3D airways model with a breathing simulator. Viable phage loads reaching the output of the nebuliser and the tracheal level of the model were determined and compared to the loaded amount. Phage inhalation resulted in a diverse range of titre reduction, primarily associated with the nebulisation process. No correlation was found between phage delivery to the phage physical or genomic dimensions. These findings highlight the need for tailored simulations of phage delivery, ideally by a patient-specific model in addition to proper phage matching, to increase the potential of phage therapy success.

17.
Viruses ; 13(9)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34578366

RESUMO

Phage therapy is an experimental therapeutic approach used to target multidrug-resistant bacterial infections. A lack of reliable data with regard to its efficacy and regulatory hurdles hinders a broad application. Here we report, for the first time, a case of vancomycin-resistant Enterococcus faecium abdominal infection in a one-year-old, critically ill, and three times liver transplanted girl, which was successfully treated with intravenous injections (twice per day for 20 days) of a magistral preparation containing two Enterococcus phages. This correlated with a reduction in baseline C-reactive protein (CRP), successful weaning from mechanical ventilation and without associated clinical adverse events. Prior to clinical use, phage genome was sequenced to confirm the absence of genetic determinants conferring lysogeny, virulence or antibiotic resistance, and thus their safety. Using a phage neutralization assay, no neutralizing anti-phage antibodies in the patient's serum could be detected. Vancomycin-susceptible E. faecium isolates were identified in close relation to phage therapy and, by using whole-genome sequencing, it was demonstrated that vancomycin-susceptible E. faecium emerged from vancomycin-resistant progenitors. Covering a one year follow up, we provide further evidence for the feasibility of bacteriophage therapy that can serve as a basis for urgently needed controlled clinical trials.


Assuntos
Antibacterianos/farmacologia , Enterococcus faecium/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/terapia , Transplante de Fígado/efeitos adversos , Terapia por Fagos/métodos , Vancomicina/farmacologia , Infecção Hospitalar , Farmacorresistência Bacteriana Múltipla , Enterococcus faecium/genética , Feminino , Genoma Bacteriano , Infecções por Bactérias Gram-Positivas/etiologia , Humanos , Lactente , Testes de Sensibilidade Microbiana , Resultado do Tratamento , Enterococos Resistentes à Vancomicina , Sequenciamento Completo do Genoma
18.
Viruses ; 11(10)2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623253

RESUMO

Currently, effective options are needed to fight vancomycin-resistant Enterococcus faecalis (VRE). The present study shows that combinations of phage and vancomycin are highly efficient against VRE, despite being resistant to the antibiotic. Vancomycin-phage EFLK1 (anti-E. faecalis phage) synergy was assessed against VRE planktonic and biofilm cultures. The effect of the combined treatment on VRE biofilms was determined by evaluating the viable counts and biomass and then visualized using scanning electron microscopy (SEM). The cell wall peptidoglycan was stained after phage treatment, visualized by confocal microscopy and quantified by fluorescence activated cell sorting (FACS) analysis. The combined treatment was synergistically effective compared to treatment with phage or antibiotic alone, both in planktonic and biofilm cultures. Confocal microscopy and FACS analysis showed that fluorescence intensity of phage-treated bacteria increased eight-fold, suggesting a change in the peptidoglycan of the cell wall. Our results indicate that with combined treatment, VRE strains are not more problematic than sensitive strains and thus give hope in the continuous struggle against the current emergence of multidrug resistant pathogens.


Assuntos
Antibacterianos/farmacologia , Bacteriófagos/fisiologia , Biofilmes/efeitos dos fármacos , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Enterococos Resistentes à Vancomicina/virologia , Vancomicina/farmacologia , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana
19.
iScience ; 19: 545-558, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31470363

RESUMO

The Growth Advantage in Stationary Phase (GASP) phenomenon, described in bacteria, reflects the genetic adaptation of bacteria to stress, including starvation, for a long time. Unlike in stationary phase where no cell division occurs, GASP harbors active cell division, concurrent with genetic adaptation. Here we show that GASP occurs also in eukaryotes. Two strains of Saccharomyces cerevisiae (Sc404 and Sc424) have been isolated from 2-year-old sealed bottles of beer. These strains presented advantage in survival and growth over the parent during stress. The differences between the strains are irreversible and therefore genetic in origin rather than epigenetic. Direct competition assays show that Sc404 and Sc424 outcompete the parent in direct competition. DNA sequencing shows changes of the genome: the TOR complexes are mutated, and DNA repair gene mutations confer a mutator phenotype. The differences between the strains are reflected in a difference in taste between beers brewed from them.

20.
mBio ; 10(2)2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31040238

RESUMO

Ancient fermented food has been studied based on recipes, residue analysis, and ancient-DNA techniques and reconstructed using modern domesticated yeast. Here, we present a novel approach based on our hypothesis that enriched yeast populations in fermented beverages could have become the dominant species in storage vessels and their descendants could be isolated and studied today. We developed a pipeline of yeast isolation from clay vessels and screened for yeast cells in beverage-related and non-beverage-related ancient vessels and sediments from several archaeological sites. We found that yeast cells could be successfully isolated specifically from clay containers of fermented beverages. The findings that genotypically the isolated yeasts are similar to those found in traditional African beverages and phenotypically they grow similar to modern beer-producing yeast strongly suggest that they are descendants of the original fermenting yeast. These results demonstrate that modern microorganisms can serve as a new tool in bio-archaeology research.IMPORTANCE So far, most of the study of ancient organisms has been based mainly on the analysis of ancient DNA. Here we show that it is possible to isolate and study microorganisms-yeast in this case-from ancient pottery vessels used for fermentation. We demonstrate that it is highly likely that these cells are descendants of the original yeast strains that participated in the fermentation process and were absorbed into the clay matrix of the pottery vessels. Moreover, we characterized the isolated yeast strains, their genomes, and the beer they produced. These results open new and exciting avenues in the study of domesticated microorganisms and contribute significantly to the fields of bio- and experimental archaeology that aim to reconstruct ancient artifacts and products.


Assuntos
Arqueologia/métodos , Fósseis/microbiologia , Sedimentos Geológicos/microbiologia , Técnicas Microbiológicas/métodos , Leveduras/isolamento & purificação , Genótipo
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