ABSTRACT
BACKGROUND: The CRISPR-Cas system is a widespread prokaryotic defense system which targets and cleaves invasive nucleic acids, such as plasmids or viruses. So far, a great number of studies have focused on the components and mechanisms of this system, however, a direct visualization of CRISPR-Cas degrading invading DNA in real-time has not yet been studied at the single-cell level. METHODS: In this study, we fluorescently label phage lambda DNA in vivo, and track the labeled DNA over time to characterize DNA degradation at the single-cell level. RESULTS: At the bulk level, the lysogenization frequency of cells harboring CRISPR plasmids decreases significantly compared to cells with a non-CRISPR control. At the single-cell level, host cells with CRISPR activity are unperturbed by phage infection, maintaining normal growth like uninfected cells, where the efficiency of our anti-lambda CRISPR system is around 26%. During the course of time-lapse movies, the average fluorescence of invasive phage DNA in cells with CRISPR activity, decays more rapidly compared to cells without, and phage DNA is fully degraded by around 44 minutes on average. Moreover, the degradation appears to be independent of cell size or the phage DNA ejection site suggesting that Cas proteins are dispersed in sufficient quantities throughout the cell. CONCLUSIONS: With the CRISPR-Cas visualization system we developed, we are able to examine and characterize how a CRISPR system degrades invading phage DNA at the single-cell level. This work provides direct evidence and improves the current understanding on how CRISPR breaks down invading DNA.
ABSTRACT
Bacillus megaterium is a large spore-forming bacterium found widely in the environment. Phages infecting B. megaterium can be used as genetic tools to expand the array of uses of B. megaterium in research and industry. Here, we present the complete genome of Pavlov, a podophage infecting B. megaterium.
ABSTRACT
Alport syndrome with diffuse leiomyomatosis (ASDL) is a complex combination that doesn't have a specific course of treatment. In this case report, we present a 44-year-old woman with ASDL and detail her treatment. The patient presented at the emergency room (ER) with symptoms of anemia, bronchial asthma, and abnormal uterine bleeding (AUB). The patient had diffuse myomas in different areas of her body, including the esophagus and genital tract. She was treated by a multidisciplinary team that included members from the hematology/oncology, pulmonary, interventional radiology, anesthesia, surgery, and gynecology services. A physician from interventional radiology performed an embolization of the uterine arteries to treat the patient's AUB. Surgery was done in May 2011 to remove the esophageal leiomyomas to improve her pulmonary function. Surgery included a distal esophagectomy, a proximal gastrostomy, and the resection of the leiomyomatous mass. In order to shrink the tumor in her genito pelvic region so that it could be extirpated with the highest likelihood of success, the patient was treated with gonadotropin-releasing hormone agonist (leuprolide acetate, 3.75 mg/month for 4 months). In May 2012, the patient had a total abdominal hysterectomy (TAH), with a bilateral salpingo-ophorectomy (BSO), the excision of a leiomyoma, and a posterior colporrhaphy.
Subject(s)
Leiomyomatosis/surgery , Nephritis, Hereditary/surgery , Adult , Antineoplastic Agents, Hormonal/therapeutic use , Case Management , Child , Combined Modality Therapy , Embolization, Therapeutic , Esophageal Neoplasms/genetics , Esophageal Neoplasms/surgery , Esophagectomy , Female , Gastrostomy , Genital Neoplasms, Female/drug therapy , Genital Neoplasms, Female/genetics , Genital Neoplasms, Female/surgery , Genital Neoplasms, Female/therapy , Humans , Hysterectomy , Leuprolide/therapeutic use , Male , Ovariectomy , Patient Care Team , Radiography, InterventionalABSTRACT
Three cases of cutaneous loxoscelism in patients under two years of age from Valdivia are described. Clinical and epidemiological aspects of loxoscelism are commented
Subject(s)
Humans , Female , Infant, Newborn , Infant , Skin Diseases/epidemiology , Spider Bites/epidemiology , Chile/epidemiology , Diagnosis, Differential , Skin Diseases/diagnosis , Spider Bites/diagnosisABSTRACT
Se comunican cinco casos detectados en los últimos 3 añosde infecciones sistémicas producidas por H.Influenzae resistentes a ampicilina ycloramfenicol, en el Servicio de Pediatría del Hospital Reginal de Valdivia
Subject(s)
Humans , Male , Female , Infant , Haemophilus Infections/drug therapy , Haemophilus influenzae/drug effects , Ampicillin Resistance , Chloramphenicol ResistanceABSTRACT
Se presentan los hallazgos de biopsia cerebral realizada en una menor de 2 años de edad, con evidencias clínicas de una encefalitis aguda grave. La biopsia se efectuó en el lóbulo temporal derecho basado en la signología clínica de focalización neurológica y la TAC que demostró mayor compromiso en áreas temporales. Mediante microscopía electrónica se visualizaron múltiples partículas virales intranucleares morfológicamente idénticas al virus herpes simplex. A través del método peroxidasa anti peroxidasa (PAP) se observó una marcada positividad para herpes simplex tipo II. Se realizó tratamiento antiviral con Aciclovir a partir del 6º día de enfermedad. Sobrevivió con grandes secuelas neurológicas