A bacterial biosensor encoding a genetically modified LuxR receptor exhibits improved detection of Pseudomonas aeruginosa's biomarker molecule 2-aminoacetophenone.

2-Aminoacetophneone (2-AA) is a volatile molecule produced in high amounts by the opportunistic pathogen Pseudomonas aeruginosa. We have previously shown that 2-AA activates the quorum sensing (QS) LuxR receptor of Aliivibrio fischeri. In the present study we were able to improve LuxR's affinity and detection limit for 2-AA by genetic modification of three amino acids within the binding pocket of the receptor. Expression of the modified LuxR receptor in a luminescent bacterial biosensor provided an efficient detection assay of 2-AA in clinical P. aeruginosa strains isolated from blood and lung infections, as well as in phlegm samples obtained from subjects suffering from lung infections.

A role for TENM1 mutations in congenital general anosmia.

Congenital general anosmia (CGA) is a neurological disorder entailing a complete innate inability to sense odors. While the mechanisms underlying vertebrate olfaction have been studied in detail, there are still gaps in our understanding of the molecular genetic basis of innate olfactory disorders. Applying whole-exome sequencing to a family multiply affected with CGA, we identified three members with a rare X-linked missense mutation in the TENM1 (teneurin 1) gene (ENST00000422452:c.C4829T). In Drosophila melanogaster, TENM1 functions in synaptic-partner-matching between axons of olfactory sensory neurons and target projection neurons and is involved in synapse organization in the olfactory system. We used CRISPR-Cas9 system to generate a Tenm1 disrupted mouse model. Tenm1(-/-) and point-mutated Tenm1(A) (/A) adult mice were shown to have an altered ability to locate a buried food pellet. Tenm1(A) (/A) mice also displayed an altered ability to sense aversive odors. Results of our study, that describes a new Tenm1 mouse, agree with the hypothesis that TENM1 has a role in olfaction. However, additional studies should be done in larger CGA cohorts, to provide statistical evidence that loss-of-function mutations in TENM1 can solely cause the disease in our and other CGA cases.

Laryngeal cancer in acquired immunodeficiency syndrome.

With improved survival, more AIDS patients, especially heavy smokers and alcohol abusers, may be confronted with laryngeal squamous cell carcinoma. Since curative treatment may require aggressive combined therapy, these patients, often suffering from immunosupression and poor general condition, present unique therapeutic challenges. The objective of the study was to describe treatment dilemmas. This case report presents a detailed description of an AIDS patient with carcinoma of the larynx. A patient with T3N0M0 laryngeal carcinoma and AIDS underwent tracheotomy and biopsy, followed by severe neck and pulmonary infection. After convalescence, radiotherapy was administered, with no evidence of a disease during a 3.5-year follow-up. During his remaining life, the patient developed severe psychoaffective disorder, his immune state deteriorated until he demised from sepsis. In conclusion, patients with HIV infection, especially having a history of tobacco or alcohol abuse, should be carefully examined for head and neck carcinoma that is likely to be more aggressive. Following surgery, AIDS patients may have worse wound healing and a greater tendency to contract infections. Radiotherapy and especially chemotherapy may cause life-threatening complications. Although early detection may increase survival, curative treatment should involve many disciplines and extra caution.