Erik Senneby

Clinical and microbiological features of bacteraemia with Aerococcus urinae.

Aerococcus urinae is a Gram-positive bacterium that can cause invasive infection, including infectious endocarditis (IE), mainly in older men. A. urinae is often misclassified in routine diagnostic laboratories. Through searches in the laboratory databases we identify 16 isolates of A. urinae causing bacteraemia during a 6-year period in southern Sweden, indicating that bacteraemia with A. urinae occurs in at least three cases per million inhabitants per year. The identity of isolates was confirmed by sequencing of the 16S rRNA genes and antibiotic susceptibility testing identified two ciprofloxacin-resistant isolates. A. urinae was the only significant pathogen isolated in all cases. Fifteen of the 16 patients were male, 15/16 were more than 70 years old, and 12/16 had underlying urological conditions. Though a urinary tract focus was suspected in the majority of cases, the bacterium was rarely found in urinary samples. Nine patients fulfilled the criteria for severe sepsis and an additional four fulfilled the criteria for sepsis. Only one fatality was recorded. Patients were treated mainly with beta-lactam antibiotics but fluoroquinolones and clindamycin were also used. Three cases of IE were diagnosed and these were complicated by spondylodiscitis in one case and by septic embolization to the brain in one case. An increased awareness of A. urinae is crucial to establishing its role as an important pathogen in older men with urinary tract disease.

Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Is a Sensitive and Specific Method for Identification of Aerococci

ABSTRACT Conventional methods for the identification of human-pathogenic aerococci to the species level are not reliable. We show that matrix-assisted laser desorption ionization–time of flight mass spectrometry correctly identifies aerococci to the species level and that it can be used to identify aerococci with high specificity in the diagnostic clinical microbiology laboratory.

Epidemiology and antibiotic susceptibility of aerococci in urinary cultures

In this study, we present population-based data regarding the prevalence of aerococci in clinical urinary samples. During a 3-month period, all aerococcal isolates from urinary samples from 2 clinical microbiology laboratories were collected. We identified 64 Aerococcus urinae isolates and 40 Aerococcus sanguinicola isolates, which correlates with an incidence of 33 cases of aerococcal bacteriuria per 100,000 inhabitants per year. The median age was 83years for all patients with aerococcal bacteriuria, which was significantly higher than for patients with Escherichia coli or Enterococcus faecalis bacteriuria. Sex was almost equally distributed between men and women with aerococcal bacteriuria, whereas females dominated in E. coli bacteriuria. The aerococcal isolates displayed low MICs for ampicillin, cefalotin, mecillinam, and nitrofurantoin. Most A. sanguinicola isolates were resistant to ciprofloxacin, whereas most A. urinae isolates had low MICs. Clinical studies are needed to establish clinical breakpoints and optimal treatment.

Bacteremia with Aerococcus sanguinicola: Case Series with Characterization of Virulence Properties

We describe the clinical presentation of eleven cases with Aerococcus sanguinicola bacteremia. All patients were elderly men and a majority of them had urinary tract abnormalities. All isolates formed biofilm and a majority induced platelet aggregation – two potential virulence mechanisms.

Heart transplantation with ABO-identical versus ABO-compatible cardiac grafts: Influence on long-term survival

Abstract Objectives. To compare identical versus compatible, ABO blood group matching effects on rejection and long-term survival after heart transplantation (HT). Design. Data were collected from 196 patients who underwent HT at Lund University Hospital between 1988 and 2008. Cox proportion hazard regression analysis was used to identify factors associated with reduced long-term survival. Results. One hundred and sixty six patients (85%) had an identical ABO blood group match and 30 patients (15%) had a compatible, ABO blood group match. Four non-pharmacological variables reducing overall survival were identified: recipient blood group AB, age >55 years, ischemic time, and year of transplantation. Two pharmacological variables improved overall survival: glucocorticoids and cyclosporine. There was no significant difference in long-term survival between patients with identical blood groups compared to compatible ABO blood group matching. However, there was a trend towards graft failure as cause of death being more common in the compatible ABO group match compared identical blood group match (13% versus 5%, p=0.118). Conclusions. Six factors associated with overall survival were identified. One of these was related to blood group AB. No significant difference in survival following identical, versus compatible, ABO matching was demonstrated.

A prospective observational treatment study of aerococcal urinary tract infection

OBJECTIVES Aerococcus urinae and Aerococcus sanguinicola cause urinary tract infections (UTIs) and antibiotic treatment recommendations are solely based on in vitro findings and limited clinical experience. Our objective was to investigate the effectiveness of different treatment strategies in aerococcal UTI through a prospective observational study. METHODS Urine samples with aerococci were identified and patients were enrolled. The aerococci were subjected to Etests. Information on clinical symptoms, and the treatment given, was collected. Patients were interviewed after the conclusion of treatment to assess clinical cure and a control urine culture assessed the microbiological cure. RESULTS Of 31,629 urine samples, 144 grew aerococci and fulfilled the inclusion criteria. 91 patients gave consent and the 72 patients with UTI were assessed for treatment outcome. 53 patients had A. urinae UTI, while 19 had A. sanguinicola UTI. Nitrofurantoin was most commonly prescribed, achieving clinical and microbiological success in 71/76% of cases of A. urinae UTI, and 42/50% of cases of A. sanguinicola UTI. Pivmecillinam achieved success in patients with A. urinae cystitis and ciprofloxacin in patients with pyelonephritis. CONCLUSIONS Our results support that nitrofurantoin is a valid option for the treatment of cystitis caused by A. urinae.