Buscar en
Enfermedades Infecciosas y Microbiología Clínica (English Edition)
Toda la web
Inicio Enfermedades Infecciosas y Microbiología Clínica (English Edition) Genitourinary tract infection in children due to Aerococcus other than Aerococcu...
Journal Information
Vol. 39. Issue 3.
Pages 156-158 (March 2021)
Vol. 39. Issue 3.
Pages 156-158 (March 2021)
Scientific letter
Full text access
Genitourinary tract infection in children due to Aerococcus other than Aerococcus viridans. Literature review and 3 case reports
Infección del tracto genitourinario en el niño por Aerococcus no viridans. Revisión bibliográfica y descripción de 3 casos
José Gutiérrez-Fernándeza,b, Antonio Gámiz-Gámizc,
Corresponding author

Corresponding author.
, José María Navarro-María, Juan Luis Santos-Pérezc
a Laboratorio de Microbiología, Hospital Virgen de las Nieves-IBS, Granada, Spain
b Departamento de Microbiología, Facultad de Medicina, Universidad de Granada-IBS, Granada, Spain
c Unidad de Gestión Clínica de Pediatría y Cirugía Pediátrica, Hospital Virgen de las Nieves-IBS, Granada, Spain
This item has received
Article information
Full Text
Download PDF
Tables (1)
Table 1. Infections caused by non-viridans Aerococcus in paediatric patients published in PubMed up to 7/2/2020 and 3 cases reported in our article.
Full Text

The genus Aerococcus spp. was described for the first time in 1953. It comprises eight different species, among which Aerococcus urinae and Aerococcus sanguinicola are the primary human pathogens, being associated with underlying disease in adults.1 However, they have been reported as rare causes of infection in the paediatric population. We report clinical and microbiological characteristics corresponding to three cases.

Case 1

A 10-year-old boy visited the emergency department owing to a fever of 40 °C lasting 24 h associated with abdominal pain. Notably, he was found to have pain on palpation of his right flank, with painful fist percussion.

He had a history of admission when he was 25 days old due to a suspected febrile urinary tract infection (UTI), not confirmed microbiologically. A renal ultrasound revealed bilateral pyelocaliceal dilation. At 7 years of age, he was diagnosed with acute appendicitis. In the postoperative period, he was readmitted owing to fever and elevated acute-phase reactants, with normal urinalysis results. He was treated with piperacillin/tazobactam and responded favourably.

A urinalysis showed leukocyturia. A urine culture and blood testing revealed 14,259 leukocytes/mm3 and C-reactive protein (CRP) 22.6 mg/l. The boy was diagnosed with pyelonephritis and a decision was made to treat him with cefixime for 7 days. A renal ultrasound showed pyelocaliceal dilatation, distally tortuous right ureter and urinary retention.

Case 2

A 5-year-old boy had erythema of the urinary meatus and whitish urethral discharge, with the rest of the examination being normal. A sample of the discharge was taken for culture and treatment was started with a topical corticosteroid. He was seen by his paediatrician 21 days later due to persistent urethral discharge, with no fever. He was prescribed topical mupirocin for a week, and his symptoms remitted.

Case 3

An 8-year-old boy had colicky abdominal pain for 2 days and diarrhoeic stools. A urinalysis revealed microhaematuria, and a mid-stream urine culture was performed. He was prescribed fosfomycin tromethamine for 2 days, and his signs and symptoms disappeared. A subsequent renal ultrasound was normal.

Microbiology study

Using previously described procedures,1,2 the urine cultures performed showed >100,000 colony-forming units (CFUs)/mL and >10,000 CFUs/mL of A. urinae for case 1 and A. sanguinicola for case 3. Abundant colonies of A. urinae alone grew in the urethral discharge culture. For the urine cultures, sensitivity to cefotaxime, ciprofloxacin, nitrofurantoin, penicillin and vancomycin was studied. For the urethral discharge culture, sensitivity to ampicillin, levofloxacin, linezolid, meropenem, rifampicin, tetracycline and vancomycin was studied. The micro-organisms were sensitive to all the antibiotics assessed.


Genitourinary tract sample culture enables identification of unusual micro-organisms that may present in patients with risk factors. Two of these micro-organisms, which were recently described, are A. urinae and A. sanguinicola. Infection with these micro-organisms has been widely reported as a cause of potentially serious diseases (pyelonephritis, bacteraemia, endocarditis, peritonitis, etc.) in elderly patients with urinary tract infections, immune disease or systemic disease.1 In a review conducted in PubMed (7/2/2020), we found just 8 cases in patients 0–18 years of age (Table 1).3–10 Among them, 6 cases featured the notable finding of extremely foul-smelling urine and two presented endocarditis. Another corresponded to a case of pyelonephritis in a patient with vesicoureteral reflux who presented abdominal pain and fever.8 A case of bacteraemia in a 14-year-old patient with leukaemia was also reported.9 Patients were mostly adolescent or pre-adolescent males and generally received a late diagnosis. Case 2 in our series is notable for being the first reported case of balanitis caused by A. urinae.

Table 1.

Infections caused by non-viridans Aerococcus in paediatric patients published in PubMed up to 7/2/2020 and 3 cases reported in our article.

Case  Age  Sex  Clinical presentation  Personal history  Urine testing  Blood testing  Diagnosis  Sample  Concomitant microbiota  Treatment  References 
11 years  Male  Prolonged fever  Interventricular communication  Normal  Leukocytes 14,800/mm3, CRP 156 mg/l  Endocarditis  Blood    Ceftriaxone plus vancomycin  Sous et al.3 
      Foul-smelling urine  Imperforate anus      Mycotic pulmonary aneurysm      Pulmonary lobectomy   
                    Penicillin G for 6 weeks   
17 years  Male  Fever, headache, tiredness, foul-smelling urine  Obesity  LE traces  Leukocytes 9900/mm3, CRP 125 mg/l  Bacterial endocarditis  Urine    Nitrofurantoin for 7 days  Qureshi and Patel4 
        Bicuspid aortic valve  N negative          Ampicillin plus gentamicin for 3 days   
          E 2+          Penicillin plus gentamicin for 3 weeks   
          Leukocytes 11−22          Penicillin for 3 weeks   
5 years  Male  Foul-smelling urine  Bladder diverticulum  50-70 leukocytes/field    Cystitis  Urine    Amoxicillin/clavulanic acid for 10 days  Skalidis et al.5 
12 years  Male  Foul-smelling urine    187−275 leukocytes    Cystitis  Urine  Corynebacterium, Actinomices neuii, Veillonella, Bacteroides fragilis  Amoxicillin/clavulanic acid for 10 days  Lenherr et al.6 
11 years  Male  Foul-smelling urine      Normal  Cystitis  Urine    Penicillin  Gibb and Sivaraman7 
7 years  Male  Foul-smelling urine    LE and N negative    Cystitis  Urine    Trimethoprim/sulfamethoxazole  De Vries and Brandenburg8 
12 years  Male  Fever (39.5 °C), pain in RF, vomiting and diarrhoea  Bilateral JGO  LE 4+  Leukocytes 15,300/mm3  Pyelonephritis  Urine    Ampicillin/sulbactam for 2 days  Murray et al.9 
        Grade 4 left VUR  N negative  Erythrocyte sedimentation rate (ESR) 34 mm/h        Cefazolin for 5 days   
        Pyeloplasty  E 4+          Cefalexin for 7 days   
14 years  Male  Fever 38.1 °C  Acute myeloid leukaemia    Leukocytes 800/mm3  Bacteraemia  Blood    Ceftriaxone  Colakoglu et al.10 
        Leukopenia    CRP 96 mg/l           
10 years  Male  Fever 40 °C, pain in RF  Recurrent UTI  LE 2+  Leukocytes 14,590/mm3  Pyelonephritis  Urine    Cefixime for 7 days  Our case 
          N negative  CRP 22.6 mg/l           
10  5 years  Male  Erythema and urinary meatus discharge        Balanitis  Urethral discharge    Topical mupirocin for 7 days  Our case 
11  8 years  Male  Abdominal pain, dysuria, diarrhoea    E 2+    Cystitis  Urine    Fosfomycin tromethamine  Our case 

CRP: C-reactive protein; E: erythrocytes; JGO: juxtaglomerular obstruction; LE: leukocyte esterase; N: nitrites; RF: right flank; VUR: vesicoureteral reflux.

These micro-organisms are difficult to identify by conventional methods since they are easily mistaken for Enterococcus or Streptococcus viridans, Abiotrophia defectiva, Lactococcus, Leuconostoc, or Pediococcus. Furthermore, urine cultures often yield false negatives since these are slow-growing, nutritionally demanding, facultative anaerobic bacteria that usually grow with CO2. Proper identification requires an experienced microbiologist.1,2 At present, MALDI-TOF mass spectrometry is being used to help identify these pathogens.

In conclusion, A. urinae and A. sanguinicola are uncommon, difficult-to-identify micro-organisms that cause genitourinary infections in paediatric patients and are probably underdiagnosed. Studying their epidemiology, signs and association with underlying disease in the paediatric population will enable the relationship to the prognosis to be established and suitable treatments to be selected.

G. Jiménez-Guerra, A. Lara-Oya, I. Martínez-Egea, J. Navarro-Marí, J. Gutiérrez-Fernández.
Urinary tract infection by Aerococcus sanguinicola. An emerging opportunistic pathogen.
Rev Clin Esp, 218 (2018), pp. 351-355
J.M. Goméz-Luque, C. Foronda-García-Hidalgo, J. Gutiérrez-Fernández.
Balanopostitis por Facklamia hominis en Pediatría.
Rev Esp Quimioter, 32 (2019), pp. 278-280
N. Sous, J. Piwoz, A. Baer, S. Bhavsar.
Subacute Aerococcus urinae infective endocarditis with mycotic aneurysms in a pediatric patient: case report and literature review.
J Ped Infect Dis, 8 (2019), pp. 492-494
N. Qureshi, E. Patel.
Aerococcus urinae as the causative agent in infective endocarditis of the aortic valve in a pediatric patient.
Ped Infect Dis J, 37 (2018), pp. 1065-1066
T. Skalidis, J. Papaparaskevas, D. Konstantinou, E. Kapolou, M. Falagas, N. Legakis.
Aerococcus urinae, a cause of cystitis with malodorous urine in a child: clinical and microbiological challenges.
N. Lenherr, A. Berndt, N. Ritz, C. Rudin.
Aerococcus urinae: a possible reason for malodorous urine in otherwise healthy children.
Eur J Ped, 173 (2014), pp. 1115-1117
A. Gibb, B. Sivaraman.
A second case of foul smelling urine in a boy caused by Aerococcus urinae.
Ped Infect Dis J, 32 (2013), pp. 1300-1301
T. De Vries, A. Brandenburg.
Foul smelling urine in a 7-year-old boy caused by Aerococcus urinae.
Ped Infect Dis J, 31 (2012), pp. 1316-1317
T. Murray, K. Muldrew, R. Finkelstein, L. Hampton, S. Edberg, M. Cappello.
Acute pyelonephritis caused by Aerococcus urinae in a 12-year-old boy.
Ped Infect Dis J, 27 (2008), pp. 760-762
S. Colakoglu, T. Turunc, M. Taskoparan, H. Aliskan, E. Kizilkilic, Y. Demiroglu, et al.
Three cases of serious infection caused by Aerococcus urinae: a patient with spontaneous bacterial peritonitis and two patients with bacteremia.
Infection, 36 (2008), pp. 288-290

Please cite this article as: Gutiérrez-Fernández J, Gámiz-Gámiz A, Navarro-Marí JM, Santos-Pérez JL. Infección del tracto genitourinario en el niño por Aerococcus no viridans. Revisión bibliográfica y descripción de 3 casos. Enferm Infecc Microbiol Clin. 2021;39:156–158.

Copyright © 2020. Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica
Article options
es en pt

¿Es usted profesional sanitario apto para prescribir o dispensar medicamentos?

Are you a health professional able to prescribe or dispense drugs?

Você é um profissional de saúde habilitado a prescrever ou dispensar medicamentos