Culture on Selective Media and Amplicon-Based Sequencing of 16S rRNA from Spontaneous Brain Abscess-the View from the Diagnostic Laboratory.

Forty-one stored samples from cases of spontaneous brain abscess were investigated to gain insight into the natural history, causative agents, and relevant laboratory diagnostics of a rare infection. Samples from a larger collection were selected based on retrospective analysis of patient records. All samples were subjected to amplicon sequencing of 16S rRNA gene fragments.

Prevalence of hypermutator isolates of Achromobacter spp. from cystic fibrosis patients.

Bacteria colonising the lungs of cystic fibrosis (CF) patients encounter high selective pressures. Hypermutation facilitates adaptation to fluctuating environments, and hypermutator strains are frequently isolated from CF patients. We investigated the prevalence of hypermutator isolates of Achromobacter spp.

Genetic Adaptation of Achromobacter sp. during Persistence in the Lungs of Cystic Fibrosis Patients.

Achromobacter species are increasingly isolated from the respiratory tract of cystic fibrosis patients and often a chronic infection is established. How Achromobacter sp. adapts to the human host remains uncharacterised.

Lack of evidence of increased risk of bacterial transmission during cystic fibrosis educational programmes.

Background: Educational and rehabilitation programmes increase the quality-of-life of patients with cystic fibrosis, but patients are discouraged to participate because of the risk of cross-infections.

Methods: Isolates of Pseudomonas aeruginosa, Staphylococcus aureus and Haemophilus influenzae cultured one year before to one year after attendance were investigated by pulsed field gel electrophoresis, multilocus sequence typing and/or spa-typing.

Results: We typed 984 bacterial isolates cultured from 46 patients aged 5-18 years attending educational programmes at Aarhus University Hospital during 2009-2011.

Complete genome sequence of the cystic fibrosis pathogen Achromobacter xylosoxidans NH44784-1996 complies with important pathogenic phenotypes.

Achromobacter xylosoxidans is an environmental opportunistic pathogen, which infects an increasing number of immunocompromised patients. In this study we combined genomic analysis of a clinical isolated A. xylosoxidans strain with phenotypic investigations of its important pathogenic features.

Low occurrence of 'non-haemolytic Haemophilus haemolyticus' misidentified as Haemophilus influenzae in cystic fibrosis respiratory specimens, and frequent recurrence of persistent H. influenzae clones despite antimicrobial treatment.

Non-influenzae commensal Haemophilus species of low pathogenicity may be difficult to discriminate from Haemophilus influenzae. We investigated the level of misidentifications in respiratory specimens from cystic fibrosis patients and evaluated the colonisation dynamics of genuine H. influenzae isolates.

Multilocus sequence analysis of isolates of Achromobacter from patients with cystic fibrosis reveals infecting species other than Achromobacter xylosoxidans.

A multilocus sequence analysis (MLSA) scheme was developed for characterization of strains and species from the genus Achromobacter, which are increasingly recovered from patients with cystic fibrosis (CF). Five conserved housekeeping genes were selected for the MLSA, which was applied to a diverse collection of 77 strains originating from Europe, Asia, and South America and including type strains of the seven recognized Achromobacter species, six environmental strains, eight non-CF clinical strains, and 56 CF clinical strains. The discriminatory power of MLSA, based on 2,098 nucleotides (nt), was much superior to a 16S rRNA gene comparison based on 1,309 nt.

Marked increase in incidence of Achromobacter xylosoxidans infections caused by sporadic acquisition from the environment.

Background: An increased incidence of Achromobacter xylosoxidans infections has been observed at the Cystic Fibrosis Centre at Aarhus University Hospital, as the proportion of patients colonised with A. xylosoxidans increased from 6 to 10% from 2005 to 2009.

Methods: Pulsed field gel electrophoresis (PFGE) was used to type isolates of A.

Evaluation of disk diffusion methods to detect low-level β-lactamase-negative ampicillin-resistant Haemophilus influenzae.

We evaluated the efficacy of disk diffusion methods for detection of low-level β-lactamase-negative ampicillin-resistant (low-BLNAR) Haemophilus influenzae. Four hundred and seventy unselected, recent clinical isolates were tested with ampicillin (10 μg), cefaclor (30 μg) and cefuroxime (30 μg) on iso-Sensitest agar enriched with nicotinamide adenine dinucleotide (NAD) and horse blood [ST agar; Swedish Reference Group for Antibiotics (SRGA) guidelines], and on chocolate agar (in-house guidelines). Selected isolates (n = 147) were subjected to partial sequencing of the ftsI gene.

Polymicrobial subdural empyema: involvement of Streptococcus pneumoniae revealed by lytA PCR and antigen detection.

The authors report a case of a subdural empyema (SDE) caused by a coinfection with Streptococcus intermedius and Streptococcus pneumoniae, initially considered a S. intermedius infection only. An otherwise healthy 11-year-old female was admitted to the hospital after 5 days of illness.