Genomic and Biochemical Characterization of Acinetobacter Podophage Petty Reveals a Novel Lysis Mechanism and Tail-Associated Depolymerase Activity.

The increased prevalence of drug-resistant, nosocomial Acinetobacter infections, particularly from pathogenic members of the Acinetobacter calcoaceticus-baumannii complex, necessitates the exploration of novel treatments such as phage therapy. In the present study, we characterized phage Petty, a novel podophage that infects multidrug-resistant Acinetobacter nosocomialis and Acinetobacter baumannii Genome analysis reveals that phage Petty is a 40,431-bp ϕKMV-like phage, with a coding density of 92.2% and a G+C content of 42.3%. Interestingly, the lysis cassette encodes a class I holin and a single-subunit endolysin, but it lacks canonical spanins to disrupt the outer membrane. Analysis of other ϕKMV-like genomes revealed that spaninless lysis cassettes are a feature of phages infecting Acinetobacter within this subfamily of bacteriophages. The observed halo surrounding Petty's large clear plaques indicated the presence of a phage-encoded depolymerase capable of degrading capsular exopolysaccharides (EPS). The product of gene 39, a putative tail fiber, was hypothesized to possess depolymerase activity based on weak homology to previously reported phage tail fibers. The 101.4-kDa protein gene product 39 (gp39) was cloned and expressed, and its activity against Acinetobacter EPS in solution was determined. The enzyme degraded purified EPS from its host strain A. nosocomialis AU0783, reducing its viscosity, and generated reducing ends in solution, indicative of hydrolase activity. Given that the accessibility to cells within a biofilm is enhanced by degradation of EPS, phages with depolymerases may have enhanced diagnostic and therapeutic potential against drug-resistant Acinetobacter strains.IMPORTANCE Bacteriophage therapy is being revisited as a treatment for difficult-to-treat infections. This is especially true for Acinetobacter infections, which are notorious for being resistant to antimicrobials. Thus, sufficient data need to be generated with regard to phages with therapeutic potential, if they are to be successfully employed clinically. In this report, we describe the isolation and characterization of phage Petty, a novel lytic podophage, and its depolymerase. To our knowledge, it is the first phage reported to be able to infect both A. baumannii and A. nosocomialis The lytic phage has potential as an alternative therapeutic agent, and the depolymerase could be used for modulating EPS both during infections and in biofilms on medical equipment, as well as for capsular typing. We also highlight the lack of predicted canonical spanins in the phage genome and confirm that, unlike the rounding of lambda lysogens lacking functional spanin genes, A. nosocomialis cells infected with phage Petty lyse by bursting. This suggests that phages like Petty employ a different mechanism to disrupt the outer membrane of Acinetobacter hosts during lysis.

Role of the 4-phosphopantetheinyl transferase of Trichoderma virens in secondary metabolism and induction of plant defense responses.

Trichoderma virens is a ubiquitous soil fungus successfully used in biological control due to its efficient colonization of plant roots. In fungi, 4-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary and secondary metabolism. Therefore, we cloned the PPTase gene ppt1 from T. virens and generated PPTase-deficient (?ppt1) and overexpressing strains to investigate the role of this enzyme in biocontrol and induction of plant defense responses. The ?ppt1 mutants were auxotrophic for lysine, produced nonpigmented conidia, and were unable to synthesize nonribosomal peptides. Although spore germination was severely compromised under both low and high iron availability, mycelial growth occurred faster than the wild type, and the mutants were able to efficiently colonize plant roots. The ?ppt1 mutants were unable of inhibiting growth of phytopathogenic fungi in vitro. Arabidopsis thaliana seedlings co-cultivated with wild-type T. virens showed increased expression of pPr1a:uidA and pLox2:uidA markers, which correlated with enhanced accumulation of salicylic acid (SA), jasmonic acid, camalexin, and resistance to Botrytis cinerea. Co-cultivation of A. thaliana seedlings with ?ppt1 mutants compromised the SA and camalexin responses, resulting in decreased protection against the pathogen. Our data reveal an important role of T. virens PPT1 in antibiosis and induction of SA and camalexin-dependent plant defense responses.

Willingness to undergo colorectal cancer screening in first-degree relatives of hospitalized patients with colorectal cancer.

AIMS: To evaluate whether willingness to undergo colonoscopy screening is influenced by being a first-degree relative of hospitalized patients with or without colorectal cancer after briefing and surgeon recommendation. METHODS: We performed a cross-sectional study of 327 first-degree relatives of hospitalized patients aged higher than 40 years, divided into Group A (151 relatives of colorectal cancer patients) and Group B (176 relatives of non-cancer patients) at the University Hospital of the Canary Islands, Spain. All were personally briefed by a surgeon, aided by a colorectal cancer pamphlet, and encouraged to accept screening colonoscopy with sedation. RESULTS: Willingness to undergo colonoscopy screening was greater in Group A (66.9%) than in Group B (29.0%); (odds ratio: 11.1; 95% confidence interval = 4.27 to 29.14; P < 0.001). Pre-briefing awareness of screening colonoscopy was also significantly higher in Group A (76.8% vs. 33.5%; P < 0.001), the main source of information being a close relative with colorectal cancer. CONCLUSIONS: Being a close relative of a colorectal cancer patient is positively related with willingness to undergo colonoscopy screening in this study. This cross-sectional study outlines a strategy for increasing the level of willingness to undergo colorectal cancer screening in a group of people at risk.

[Mesenteric panniculitis: experience in our center]. / Paniculitis mesentérica: experiencia en nuestro centro.

Although several etiological factors have been associated with mesenteric panniculitis, the exact etiology in some cases remains unknown. Herein, we present a retrospective analysis of 8 patients affected with this disorder performed between May 2000 and December 2006. In our series the mean age at which patients presented was 63 years. The majority of the patients were male (with a male: female ratio of 3:1). The most common clinical manifestations were abdominal pain (n = 4) and asthenia (n = 4). Three cases presented with obstructive symptoms and three had a history of abdominal surgery. Notably, seven had a background of tobacco use (five smokers and two ex-smokers) and one patient developed follicular lymphoma. A literature research was carried out to analyze our results and formulate a new hypothesis. In our opinion, we believe that the study of causal factors such as tobacco and its components is required due to the strong association found in this study.

Paniculitis mesentérica: experiencia en nuestro centro / Mesenteric panniculitis: experience in our center

A pesar de que se han reconocido distintos factores precipitantes en la paniculitis mesentérica, su etiología en determinados casos es incierta. Presentamos un análisis retrospectivo de 8 pacientes afectados de paniculitis mesentérica en un periodo comprendido entre mayo 2000 hasta diciembre 2006. En nuestra serie la edad media de presentación fue 63 años, siendo la mayoría de pacientes varones (proporción 3:1). Las manifestaciones clínicas más frecuentes fueron el dolor abdominal (n = 4) y la astenia (n = 4). Tres casos se presentaron como cuadro de obstrucción y tres casos presentaron antecedentes de cirugía abdominal. El antecedente más común fue el tabaquismo (5 casos eran fumadores activos y 2 exfumadores) y hubo un paciente que desarrolló un linfoma folicular en el seguimiento. Revisamos la literatura para analizar nuestros resultados y formular una hipótesis. En nuestra opinión, pensamos que debe ser analizada de forma más exhaustiva la relación entre el tabaco y sus componentes con la aparición de la enfermedad debido a la fuerte asociación encontrada en este estudio

Although several etiological factors have been associated with mesenteric panniculitis, the exact etiology in some cases remains unknown. Herein, we present a retrospective analysis of 8 patients affected with this disorder performed between May 2000 and December 2006. In our series the mean age at which patients presented was 63 years. The majority of the patients were male (with a male: female ratio of 3:1). The most common clinical manifestations were abdominal pain (n = 4) and asthenia (n = 4). Three cases presented with obstructive symptoms and three had a history of abdominal surgery. Notably, seven had a background of tobacco use (five smokers and two ex-smokers) and one patient developed follicular lymphoma. A literature research was carried out to analyze our results and formulate a new hypothesis. In our opinion, we believe that the study of causal factors such as tobacco and its components is required due to the strong association found in this study

Agenesia dental en una muestra de pacientes ortodónticos del Hospital Infantil de México / Tooth agenesis in a sample of orthodontic patients from the Pediatric Hospital of Mexico

Hipodoncia (agenesia dental) es una alteración del número de las piezas dentales, relativamente frecuente. Las piezas principalmente involucradas en agenesia dental son los terceros molares, los incisivos laterales superiores y los segundos premolares. Se tiene conocimiento de que no existen datos de la prevalencia de agenesia dental en población mexicana, constituyendo el principal objetivo del presente trabajo. Para tal fin, un estudio retrospectivo de radiografías panorámicas de pacientes del Departamento de Ortodoncia del Hospital Infantil de México, que comprendiera de 1988 a 1994, fue llevado a cabo, habiéndose incluido en este estudio 299 radiografías; 99 radiografías presentaron ausencia dental congénita (incluyendo terceros molares), representando 33 por ciento. No incluyendo terceros molares, la prevalencia fue de 4.35 por ciento. No existieron diferencias significativas entre los sexos. Las piezas más comunmente involucradas, excluyendo terceros molares, fueron los incisivos laterales superiores. Se revisan las teorías de etiología de la hipodoncia, así como su prevalencia mundial