Characterization and Fitness Cost of Tn, a Novel Integrative and Conjugative Element Conferring Multidrug Resistance in .

A multidrug-resistant (MDR) strain of , Hi-228, with phenotypic resistance toward ampicillin, cefotaxime, chloramphenicol, gentamicin, and azithromycin, was isolated in Oslo, Norway. The strain was part of a clonal outbreak (2016-2017) comprising five ST143 strains with identical resistotypes. Hi-228 carries a novel integrative and conjugative element (ICE), Tn, contributing to this remarkable and previously unreported MDR profile.

Case Report: Whole-Genome Sequencing of Serially Collected From a Patient With Common Variable Immunodeficiency Reveals Within-Host Evolution of Resistance to Trimethoprim-Sulfamethoxazole and Azithromycin After Prolonged Treatment With These Antibiotics.

We report within-host evolution of antibiotic resistance to trimethoprim-sulfamethoxazole and azithromycin in a nontypeable strain from a patient with common variable immunodeficiency (CVID), who received repeated or prolonged treatment with these antibiotics for recurrent respiratory tract infections. Whole-genome sequencing of three longitudinally collected sputum isolates during the period April 2016 to January 2018 revealed persistence of a strain of sequence type 2386. Reduced susceptibility to trimethoprim-sulfamethoxazole in the first two isolates was associated with mutations in genes encoding dihydrofolate reductase ( and its promotor region, dihydropteroate synthase (), and thymidylate synthase (), while subsequent substitution of a single amino acid in dihydropteroate synthase (G225A) rendered high-level resistance in the third isolate from 2018.

Investigating the human jejunal microbiota.

Descriptions of the small intestinal microbiota are deficient and conflicting. We aimed to get a reliable description of the jejunal bacterial microbiota by investigating samples from two separate jejunal segments collected from the luminal mucosa during surgery. Sixty patients with morbid obesity selected for elective gastric bypass surgery were included in this survey.

Multilocus sequence typing and ftsI sequencing: a powerful tool for surveillance of penicillin-binding protein 3-mediated beta-lactam resistance in nontypeable Haemophilus influenzae.

Background: Beta-lactam resistance in Haemophilus influenzae due to ftsI mutations causing altered penicillin-binding protein 3 (PBP3) is increasing worldwide. Low-level resistant isolates with the N526K substitution (group II low-rPBP3) predominate in most geographical regions, while high-level resistant isolates with the additional S385T substitution (group III high-rPBP3) are common in Japan and South Korea.Knowledge about the molecular epidemiology of rPBP3 strains is limited.

Changes in the 5'-untranslated region of the rbcL gene accelerate transcript degradation more than 50-fold in the chloroplast of Chlamydomonas reinhardtii.

Using uidA (beta-glucuronidase; GUS) reporter gene constructs, the 5'-untranslated region (UTR) of the Chlamydomonas chloroplast rbcL gene was screened by deletion and mutational analysis for the presence of a promoter element that previous studies implied to reside within the first 63 base pairs of the UTR. Deleting a large segment of the rbcL 5'UTR in a 3'-->5' direction to position +36, changing the remaining 36 base pairs at the 5' end of the UTR, and increasing by five base pairs the distance between the rbcL 5'UTR and the basic promoter element located at position -10 did not abolish transcription from the basic rbcL promoter. It is concluded that the apparent loss of transcriptional activity found in earlier studies after deletion of sequences downstream of the transcription initiation site is due to the synthesis of very unstable transcripts that escape detection by Northern analysis and in vivo transcription assays.

Structural and functional characterization of a transcription-enhancing sequence element in the rbcL gene of the Chlamydomonas chloroplast genome.

The structure and function of a transcription-enhancing sequence element in the coding region of the Chlamydomonas reinhardtii rbcL gene was analyzed in Chlamydomonas chloroplast transformants in vivo. The enhancer sequence is contained within a DNA segment extending from position +108 to position +143, relative to the start site of rbcL gene transcription. The sequence remains functional when inverted or when placed 34 bp closer to or 87 bp further downstream of the basic rbcL promoter.