Typing of Salmonella Typhi strains isolated from Egypt by RAPD PCR

PCR-based fingerprinting using random amplified polymorphic DNA (RAPD) has been used widely for genome identification. In this study, 13 Salmonella Typhi strains were isolated from typhoid patients from Aswan, Cairo, Fayoum, and Monofya Governorates of Egypt. The isolates, along with three reference strains, i.e., O901, H901, and Ty2 were subjected to whole genome typing by RAPD PCR. Three RAPD-PCR 10-mer primers generated a total of 85 RAPD bands (81 polymorphic bands), 12 distinct PCR profiles, and proved to be useful for discriminating the isolates and strains studied. Interestingly, the B1 and C1 PCR profile were found only in Cairo and Monofya, respectively; and some PCR types appeared only in certain Governorates of Egypt. By combining the profiles obtained with the primer trio used in this study, an excellent discrimination index (D) of 0.942 was reached. Pairwise comparisons of Jaccard’s similarity coefficients calculated among the 12 PCR types identified three major clusters; i.e., O901 branch and Ty2 and H901 sub-branches. Principal component analysis adequately resolved each of these three major clusters. Three principal components accounted for about 72% of the variation, with the first two components accounting for about 62% of the total variance among the genotypes studied. Biclustering improved the display of groups of RAPD amplicons (markers) that cluster similarly across the genomes and could delineate features pertaining to genome structure. In conclusion, RAPD PCR provided a fast method with high potentials in surveillance and epidemiological investigations of Salmonella Typhi infections

Portal vein thrombosis in children and adolescents: 20 years experience of a pediatric hepatology reference center

CONTEXT: Portal vein thrombosis refers to a total or partial obstruction of the blood flow in this vein due to a thrombus formation. It is an important cause of portal hypertension in the pediatric age group with high morbidity rates due to its main complication - the upper gastrointestinal bleeding. OBJECTIVE: To describe a group of patients with portal vein thrombosis without associated hepatic disease of the Pediatric Hepatology Clinic of the Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil with emphasis on diagnosis, presentation form and clinical complications, and the treatment of portal hypertension. METHODS: This is a descriptive study of a series of children and adolescents cases assisted from January 1990 to December 2010. The portal vein thrombosis diagnosis was established by ultrasound. RESULTS: Of the 55 studied patients, 30 (54.5%) were male. In 29 patients (52.7%), none of the risk factors for portal vein thrombosis was observed. The predominant form of presentation was the upper gastrointestinal bleeding (52.7%). In 20 patients (36.4%), the initial manifestation was splenomegaly. During the whole following period of the study, 39 patients (70.9%) showed at least one episode of upper gastrointestinal bleeding. The mean age of patients in the first episode was 4.6 ± 3.4 years old. The endoscopic procedure carried out in the urgency or electively for search of esophageal varices showed its presence in 84.9% of the evaluated patients. The prophylactic endoscopic treatment was performed with endoscopic band ligation of varices in 31.3% of patients. Only one died due to refractory bleeding. CONCLUSIONS: The portal vein thrombosis is one of the most important causes of upper gastrointestinal bleeding in children. In all non febrile children with splenomegaly and/or hematemesis and without hepatomegaly and with normal hepatic function tests, it should be suspect of portal vein thrombosis. Thus, an appropriate diagnostic and treatment approach is desirable in an attempt to reduce morbidity and mortality