Lotte, L.; Durand, C.; Chevalier, A.; Gaudart, A.; Cheddadi, Y.; Ruimy, R.; Lotte, R. Acute Pyelonephritis with Bacteremia in an 89-Year-Old Woman Caused by Two Slow-Growing Bacteria: Aerococcus urinae and Actinotignum schaalii. Microorganisms2023, 11, 2908.
Lotte, L.; Durand, C.; Chevalier, A.; Gaudart, A.; Cheddadi, Y.; Ruimy, R.; Lotte, R. Acute Pyelonephritis with Bacteremia in an 89-Year-Old Woman Caused by Two Slow-Growing Bacteria: Aerococcus urinae and Actinotignum schaalii. Microorganisms 2023, 11, 2908.
Lotte, L.; Durand, C.; Chevalier, A.; Gaudart, A.; Cheddadi, Y.; Ruimy, R.; Lotte, R. Acute Pyelonephritis with Bacteremia in an 89-Year-Old Woman Caused by Two Slow-Growing Bacteria: Aerococcus urinae and Actinotignum schaalii. Microorganisms2023, 11, 2908.
Lotte, L.; Durand, C.; Chevalier, A.; Gaudart, A.; Cheddadi, Y.; Ruimy, R.; Lotte, R. Acute Pyelonephritis with Bacteremia in an 89-Year-Old Woman Caused by Two Slow-Growing Bacteria: Aerococcus urinae and Actinotignum schaalii. Microorganisms 2023, 11, 2908.
Abstract
Aerococcus urinae is an aerobic Gram-positive coccus that grows as tiny alpha-hemolytic colonies. Actinotignum schaalii is a slow-growing facultative anaerobic Gram-positive rod. These bacteria are part of the urogenital microbiota of healthy patients, but can also be involved in urinary tract infections (UTIs), particularly in elderly men and young children [1–3]. Because A. urinae and A. schaalii are fastidious and are difficult to identify with phenotypic methods, they are underestimated causes of UTIs. Their growth is slow and requires a blood-enriched medium and an incubation time of 48 hours under anaerobic or 5% CO2 atmosphere. Furthermore, accurate identification is only possible using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) or molecular-based methods. In rare cases, these bacteria can be responsible for invasive infections. We describe here the second case of bacteremic UTI caused by both A. schaalii and A. urinae in an 89-year-old woman who presented dyspnea and asymptomatic bacteriuria. This challenging clinical and microbiological diagnosis was made by our laboratory by Gram staining urine with a leucocyte count >50/μL and/or a bacterial count >14/μL, urinary culture on blood agar plate, and direct bacterial identification on positive blood culture bottles (BCBs) by MALDI-TOF MS. After 10 days of antimicrobial treatment consisting of 2g amoxicillin PO t.i.d the patient was discharged with complete clinical and biological recovery. A. schaalii and A. urinae are probably still underestimated causes of UTIs. Microbiologists should assess the presence of these two bacteria in urine using the appropriate culture and identification methods where direct examination is positive for small Gram-positive cocci or rods, and a urinary dipstick is negative for nitrites and associated with leukocyturia.
Medicine and Pharmacology, Epidemiology and Infectious Diseases
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