Project description:Aerococcus urinae and Aerococcus sanguinicola have been increasingly recognized as causative agents of urinary tract infection (UTI) during the last decade. Nitroxoline achieves high urinary concentrations after oral administration and is recommended in uncomplicated UTI in Germany, but its activity against Aerococcus spp. is unknown. The aim of this study was to assess the in vitro susceptibility of clinical Aerococcus species isolates to standard antibiotics and to nitroxoline. Between December 2016 and June 2018, 166 A. urinae and 18 A. sanguinicola isolates were recovered from urine specimens sent to the microbiology laboratory of the University Hospital of Cologne, Germany. Susceptibility to standard antimicrobials was analyzed by disk diffusion (DD) according to EUCAST methodology, nitroxoline was tested by DD and agar dilution. Susceptibility of Aerococcus spp. to benzylpenicillin, ampicillin, meropenem, rifampicin, nitrofurantoin, and vancomycin was 100% and resistance was documented only against ciprofloxacin (20 of 184; 10.9%). MICs of nitroxoline in A. urinae isolates were low (MIC50/90 1/2 mg/L) while significantly higher MICs were observed in A. sanguinicola (MIC50/90 64/128 mg/L). If the EUCAST nitroxoline breakpoint for E. coli and uncomplicated UTI was applied (16 mg/L), 97.6% of A. urinae isolates would be interpreted as susceptible while all A. sanguinicola isolates would be considered resistant. Nitroxoline demonstrated high activity against clinical A. urinae isolates, but low activity against A. sanguinicola. Nitroxoline is an approved antimicrobial for UTI and could be an alternative oral drug to treat A. urinae urinary tract infection, yet clinical studies are needed to demonstrate this potential in vivo. IMPORTANCE A. urinae and A. sanguinicola have been increasingly recognized as causative agents in urinary tract infections. Currently, there are few data available on the activity of different antibiotics against these species and no data on nitroxoline. We demonstrate that clinical isolates in Germany are highly susceptible to ampicillin, while resistance to ciprofloxacin was common (10.9%). Additionally, we show that nitroxoline is highly active against A. urinae, but not against A. sanguinicola, which based on the presented data, should be considered intrinsically resistant. The presented data will help to improve the therapy of urinary tract infections by Aerococcus species.
Project description:The diagnosis of infective endocarditis (IE) remains a challenge. One of the rare bacterial species recently associated with biofilms and negative cultures in infective endocarditis is Aerococcus urinae. Whether the low number of reported cases might be due to lack of awareness and misidentification, mainly as streptococci, is currently being discussed. To verify the relevance and biofilm potential of Aerococcus in endocarditis, we used fluorescence in situ hybridization to visualize the microorganisms within the heart valve tissue. We designed and optimized a specific FISH probe (AURI) for in situ visualization and identification of A. urinae in sections of heart valves from two IE patients whose 16S rRNA gene sequencing had deteced A. urinae. Both patients had a history of urinary tract infections. FISH visualized impressive in vivo grown biofilms in IE, thus confirming the potential of A. urinae as a biofilm pathogen. In both cases, FISH/PCR was the only method to unequivocally identify A. urinae as the only causative pathogen for IE. The specific FISH assay for A. urinae is now available for further application in research and diagnostics. A. urinae should be considered in endocarditis patients with a history of urinary tract infections. These findings support the biofilm potential of A. urinae as a virulence factor and are meant to raise the awareness of this pathogen.
Project description:Strains belonging to the genus Aerococcus are causative agents of human and animal infections, including urogenital infections, bacteremia/septicemia, and infective endocarditis. This study reports the first fully closed and complete genome sequences of six type strains belonging to the genus Aerococcus using a combination of Illumina HiSeq and PacBio sequencing technologies.
| S-EPMC4841142 | biostudies-literature
Project description:Aerococcus urinae taxonomy study