Synthetic biology has rapidly progressed over the past decade and is now positioned to impact important problems in health and energy. In the clinical arena, the field has thus far focused primarily on the use of bacteria and bacteriophages to overexpress therapeutic gene products. The next generation of multigene circuits will control the triggering, amplitude, and duration of therapeutic acti...

Bacteria of the genus Xenorhabdus are symbionts of soil entomopathogenic nematodes of the genus Steinernema. This symbiotic association constitutes an insecticidal complex active against a wide range of insect pests. Within Xenorhabdus bovienii species, the X. bovienii CS03 strain (Xb CS03) is nonvirulent when directly injected into lepidopteran insects, and displays a low virulence when associ...

Although they are ubiquitous to aquatic environments, Aeromonas species have traditionally been considered nonvirulent; however, in the past 30 years, they have emerged as important human pathogens that can cause a wide spectrum of disease. In this study, we describe a case of recurrent Aeromonas bacteremia in an immunocompetent patient, and this exposure was linked to the patient's home well w...

Combined analysis of restriction fragment length polymorphism of regions of genes coding for rRNA (ribotyping) and esterase electrophoretic typing was used to document neonatal acquisition of Escherichia coli in twins. Our study shows vertical mother-to-infant transmission of one strain of E. coli to one twin and the development of neonatal septicemia with a distinct nonvirulent carboxylesteras...

Haemophilus parasuis, the causative agent of Glässer's disease, is one of the early colonizers of the nasal mucosa of piglets. It is prevalent in swine herds, and lesions associated with disease are fibrinous polyserositis and bronchopneumonia. Antibiotics are commonly used in disease control, and resistance to several antibiotics has been described in H. parasuis. Prediction of H. parasuis vir...

We report the characterization of a bacterial-type oxygen reductase abundant in the cytoplasm of the anaerobic protozoan parasite Entamoeba histolytica. Upon host infection, E. histolytica is confronted with various oxygen tensions in the host intestine, as well as increased reactive oxygen and nitrogen species at the site of local tissue inflammation. Resistance to oxygen-derived stress thus p...

A genomic library containing DNA fragments of 0.5 to 2 kilobase pairs in length from Yersinia enterocolitica serovar O:8 was constructed in a bacteriophage lambda gt11 expression vector. Mouse antibodies specific for the iron-regulated high-molecular-weight proteins (HMWPs) were used to screen the library. Two positive clones of 1 and 0.5 kilobase pairs, designated A13 and D7, respectively, wer...

A murine model was used to study the histopathological aspects and cytokine expression levels in skeletal muscle provoked by the infection with Mexican TcI strains. BALB/c mice were inoculated with the virulent Querétaro strain and the nonvirulent Ninoa strain. Parasite numbers were counted in blood and skeletal muscle at different times post-infection, and real time-PCR expression levels of th...