| 1. |
- Senneby, Erik, et al.
(författare)
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Bacteremia with Aerococcus sanguinicola: Case Series with Characterization of Virulence Properties.
- 2014
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Ingår i: Open Forum Infectious Diseases. - : Oxford University Press (OUP). - 2328-8957. ; 1:1, s. 025-025
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Tidskriftsartikel (refereegranskat)abstract
- Since Aerococcus sanguinicola was designated as a species in 2001, only a few cases of bacteremia have been reported. The aim with this study was to describe the clinical presentation of A sanguinicola bacteremia and to determine the antibiotic susceptibility and the capacity of the bacteria to form biofilm and to induce platelet aggregation.
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| 2. |
- Choi, Brian I., et al.
(författare)
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Taxonomic considerations on Aerococcus urinae with proposal of subdivision into Aerococcus urinae, Aerococcus tenax sp. nov., Aerococcus mictus sp. nov., and Aerococcus loyolae sp. nov
- 2023
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Ingår i: International Journal of Systematic and Evolutionary Microbiology. - 1466-5026. ; 73:9
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Tidskriftsartikel (refereegranskat)abstract
- Average nucleotide identity analysis, based on whole genome sequences of 115 strains previously identified as Aerococcus urinae, an emerging uropathogen, discriminates at least six unique genomic taxa. The whole genome analysis affords clearer species boundaries over 16S rRNA gene sequencing and traditional phenotypic approaches for the identification and phylogenetic organization of Aerococcus species. The newly described species can be differentiated by matrix-assisted laser desorption ionization time-of-flight analysis of protein signatures. We propose the emendation of the description of A. urinae (type strain ATCC 51268T = CCUG 34223T=NCFB 2893) and the names of Aerococcus tenax sp. nov. (ATCC TSD-302T = DSM 115700T = CCUG 76531T=NR-58630T), Aerococcus mictus sp. nov. (ATCC TSD-301T = DSM 115699T = CCUG 76532T=NR-58629T), and Aerococcus loyolae sp. nov. (ATCC TSD-300T = DSM 115698T = CCUG 76533T=NR-58628T) for three of the newly identified genomic taxa.
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| 3. |
- Oskooi, Mohammad, et al.
(författare)
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A prospective observational treatment study of aerococcal urinary tract infection
- 2018
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Ingår i: Journal of Infection. - : Elsevier BV. - 0163-4453. ; 76:4, s. 354-360
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Senneby, Erik, et al.
(författare)
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A population-based study of aerococcal bacteraemia in the MALDI-TOF MS-era.
- 2016
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer Science and Business Media LLC. - 1435-4373 .- 0934-9723. ; 35:5, s. 755-762
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to determine the incidence of aerococcal bacteraemia in the MALDI-TOF MS-era, to describe the clinical presentation and to determine the MIC values of aerococci for ten antibiotics. Aerococci in blood cultures were identified through searches in the laboratory database for the years 2012-2014. MALDI-TOF MS, sequencing of the 16S rRNA gene and a PYR test were used for species identification. Patients' medical charts were systematically reviewed. Etests were used to determine MIC values. Seventy-seven patients were identified (Aerococcus urinae n = 49, Aerococcus viridans n = 14, Aerococcus sanguinicola n = 13 and Aerococcus christensenii n = 1) corresponding to incidences of 14 cases per 1,000,000 inhabitants per year (A. urinae) and 3.5 cases per 1,000,000 inhabitants per year (A. sanguinicola and A.viridans). A. urinae was in pure culture in 61 %, A. sanguinicola in 46 % and A. viridans in 36 % of the cases. The A. urinae and A. sanguinicola patients were old and many had urinary tract disorders, and a majority had a suspected urinary tract focus of the bacteraemia. Eighty percent of the A. urinae patients were men. Five A. urinae patients were diagnosed with infective endocarditis. Six patients died within 30 days. Most isolates had low MICs to penicillins and carbapenems. MALDI-TOF MS has led to an increased identification of aerococcal bacteremia. A. urinae remains the most common Aerococcus in blood cultures and in aerococcal IE.
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| 5. |
- Senneby, Erik
(författare)
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Aerococcal infections - from bedside to bench and back
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The genus Aerococcus comprises eight species of Gram-positive cocci. The incidence and the clinical importance of aerococcal infections have been underestimated in the past, due to species identification difficulties. In our first study, we evaluated the usefulness of MALDI-TOF MS as a species identification method for aerococci and found that it had a high sensitivity and specificity. Two population-based studies on aerococcal bacteriuria were performed after MALDI-TOF MS was implemented in the clinical microbiology laboratory. A. urinae and A. sanguinicola were more common than previously thought and grew in almost 1 % of all urine samples. The patients were of old age and gender was almost equally distributed between men and women. Almost 80 % of the patients had symptoms of a urinary tract infection in one of the studies. Several antibiotics, including nitrofurantoin and amoxicillin, could serve as treatment options. Resistance against ciprofloxacin was recorded, especially in A. sanguinicola isolates. In a retrospective population-based study on aerococcal bacteremia, 77 cases were identified during a three-year period (A. urinae n=49, A. sanguinicola n=13, A. viridans n=14 and A. christensenii n=1). The A. urinae and A. sanguinicola patients were old (median age >80 years), predominately of male gender and underlying urological diseases were common. A majority of the A. urinae and A. sanguinicola patients had severe sepsis. Five patients with A. urinae bacteremia were diagnosed with infective endocarditis. A. viridans seemed to be a contaminant in most cases. The aerococcal isolates were sensitive to betalactam antibiotics and vancomycin. Two studies were conducted regarding virulence mechanisms. We demonstrated that A. sanguinicola isolates produced biofilms and induced platelet aggregation, two potentially important virulence mechanisms. A. urinae isolates were subjected to masspectrometry-based proteomics and whole genome sequencing. Two cell wall-anchored proteins with LPXTG-motifs (denoted Asp proteins) quantitatively dominated the surface and genes encoding these proteins were localized in a conserved locus on the aerococcal chromosome. It is of interest to determine the function of the Asp proteins to create a better understanding of how A. urinae cause infection.
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| 6. |
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| 7. |
- Senneby, Erik, et al.
(författare)
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Epidemiology and antibiotic susceptibility of aerococci in urinary cultures.
- 2015
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Ingår i: Diagnostic Microbiology and Infectious Disease. - : Elsevier BV. - 1879-0070 .- 0732-8893. ; 81:2, s. 149-151
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Senneby, Erik, et al.
(författare)
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Genetic relatedness of Streptococcus dysgalactiae isolates causing recurrent bacteraemia
- 2021
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Ingår i: Journal of Medical Microbiology. - : Microbiology Society. - 0022-2615 .- 1473-5644. ; 70:3
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Tidskriftsartikel (refereegranskat)abstract
- Introduction.Streptococcus dysgalactiae subspecies equisimilis (SDSE) is becoming increasingly recognized as an important human pathogen. Recurrent bacteremia with SDSE has been described previously.Aim. The aims of the study were to establish the genetic relatedness of SDSE isolates with emm-type stG643 that had caused recurrent bacteraemia in three patients and to search for signs of horizontal gene transfer of the emm gene in a collection of SDSE stG643 genomes.Hypothesis. Recurring SDSE bacteremia is caused by the same clone in one patient.Methodology. Whole genome sequencing of 22 clinical SDSE stG643 isolates was performed, including three paired blood culture isolates and sixteen isolates from various sites. All assemblies were aligned to a reference assembly and SNPs were extracted. A total of 53 SDSE genomes were downloaded from GenBank. Two phylogenetic trees, including all 75 SDSE isolates, were created. One tree was based on the emm gene only and one tree was based on all variable positions in the genomes.Results. The genomes from the three pairs of SDSE isolates showed high sequence similarity (1-17 SNPs difference between the pairs), whereas the median SNP difference between the 22 isolates in our collection was 1694 (range 1-11257). The paired isolates were retrieved with 7-53 months between episodes. The 22 SDSE isolates from our collection formed a cluster in the phylogenetic tree based on the emm gene, while they were more scattered in the tree based on all variable positions.Conclusions. Our results show that the paired isolates were of the same clonal origin, which in turn supports carriage between bacteraemia episodes. The phylogenetic analysis indicates that horizontal gene transfer of the emm-gene between some of the SDSE isolates has occurred.
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| 9. |
- Senneby, Erik, et al.
(författare)
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Identification of two abundant Aerococcus urinae cell wall-anchored proteins
- 2019
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Ingår i: International Journal of Medical Microbiology. - : Elsevier BV. - 1618-0607 .- 1438-4221. ; 309:7
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Tidskriftsartikel (refereegranskat)abstract
- Aerococcus urinae is an emerging pathogen that causes urinary tract infections, bacteremia and infective endocarditis. The mechanisms through which A. urinae cause infection are largely unknown. The aims of this study were to describe the surface proteome of A. urinae and to analyse A. urinae genomes in search for genes encoding surface proteins. Two proteins, denoted Aerococcal surface protein (Asp) 1 and 2, were through the use of mass spectrometry based proteomics found to quantitatively dominate the aerococcal surface. The presence of these proteins on the surface was also shown using ELISA with serum from rabbits immunized with the recombinant Asp. These proteins had a signal sequence in the amino-terminal end and a cell wall-sorting region in the carboxy-terminal end, which contained an LPATG-motif, a hydrophobic domain and a positively charged tail. Twenty-three additional A. urinae genomes were sequenced using Illumina HiSeq technology. Six different variants of asp genes were found (denoted asp1-6). All isolates had either one or two of these asp-genes located in a conserved locus, designated Locus encoding Aerococcal Surface Proteins (LASP). The 25 genomes had in median 13 genes encoding LPXTG-proteins (range 6-24). For other Gram-positive bacteria, cell wall-anchored surface proteins with an LPXTG-motif play a key role for virulence. Thus, it will be of great interest to explore the function of the Asp proteins of A. urinae to establish a better understanding of the molecular mechanisms by which A. urinae cause disease.
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| 10. |
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