Revista Argentina de Microbiología ISSN: 0325-7541 [email protected] Asociación Argentina de Microbiología Argentina

Leite, A.; Vinhas-Da-Silva, A.; Felício, L.; Vilarinho, A. C.; Ferreira, G. urinary tract infection in a pediatric patient with secondary pseudohypoaldosteronism Revista Argentina de Microbiología, vol. 42, núm. 4, octubre-diciembre, 2010, pp. 269-270 Asociación Argentina de Microbiología Buenos Aires, Argentina

Available in: http://www.redalyc.org/articulo.oa?id=213016779005

How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Aerococcus viridans urinary tract infection ISSN 0325-7541269 INFORME BREVE Revista Argentina de Microbiología (2010) 42: 269-270

Aerococcus viridans urinary tract infection in a pediatric patient with secondary pseudohypoaldosteronism

A. LEITE*1, A. VINHAS-DA-SILVA1, L. FELÍCIO2, A. C. VILARINHO1, G. FERREIRA1

1Department of Pediatrics, Centro Hospitalar Gaia/Espinho, EPE (CHVNG); 2Department of , CHVNG/E. ��Ru�����a Dr. Francisco Sá Carneiro 4400-129, Vila Nova de Gaia, Portugal *Correspondence. E-mail: [email protected]

Abstract Aerococcus viridans is a catalase-negative gram-positive bacterium rarely found as human pathogen. Some cases of urinary tract infection (UTI) have been described in immunocompromised adults. In this article we describe a UTI case caused by this agent in a child with severe obstructive uropathy, clinically presented with secondary pseudohypoaldos- teronism (SPHA). Although A. viridans is rarely associated with child infection, it can be responsible for life threatening conditions/ situations. To our knowledge, A. viridans UTI has never been reported in pediatric patients. Key words: Aerococcus viridans, pediatric, urinary tract infection, secondary pseudohypoaldosteronism.

Resumen Infección del tracto urinario por Aerococcus viridans en un paciente pediátrico con pseudohipoaldosteronismo secundario. ��������Aerococcu�s���������� viridans es una catalasa-negativa rara vez encontrada como patógeno humano. Algunos casos de infección del tracto urinario (ITU) han sido descritos en adultos inmunodeprimidos. En este trabajo se describe un caso de ITU en un niño con uropatía obstructiva grave, que se manifestó como pseudohipoaldoste- ronismo secundario (PHAS). En forma infrecuente esta bacteria es responsable de casos de infección en la infancia, pero puede provocar situaciones amenazadoras para la vida. Hasta la fecha no se han descrito casos de ITU por A. viridans en la edad pediátrica. Palabras clave: Aerococcus viridans, pediátrico, infección del tracto urinario, pseudohipoaldosteronismo secundario

Aerococcus viridans is a catalase-negative gram-posi- At 3 months old, he was readmitted in Pediatric Ne- tive , belonging to the family. �����It is phrology for vomiting and poor weight gain. Laboratory generally considered a saprophytic microorganism which studies showed mild hyponatraemia (Na+ 125.9 mEq/l), can be found as an indigenous inhabitant on the upper hyperkalaemia (K+ 6.43 mEq/l), metabolic acidosis and airways and skin of healthy individuals (9). Since 1967, slightly azotemia (BUN 45 mg/dl). its importance as a potential human pathogen has been Urine obtained by suprapubic bladder aspiration revea- increasing among adults and children (8). led turbid urine. Urinalysis showed pH 6.5, density 1007, The authors present a case of urinary tract infection pyuria, nitrites, proteins and slight hematuria. Prompt (UTI) caused by A. viridans in a child with obstructive plating of the urine sample was done. uropathy, presented as secondary pseudohypoaldos- Plasma aldosterone (281.2 ng/dl) and renin (1679.0 teronism. pg/ml) were once again markedly elevated (normal ranges: aldosterone 5-90 ng/dl and renin 40-220 pg/ml). Case Report Considering the possibility of another episode of SPHA A 28 day- old boy, with congenital bilateral vesico-ure- triggered by UTI, fluid and antibiotic therapy (cefuroxime theral reflux grade V, was admitted to hospital presenting plus gentamicin I.V., according to our institutional guide- failure to thrive, vomiting and dehydration. He manifested line) was administered, with clinical improvement. severe hyponatraemia, hyperkalaemia and metabolic aci- Meanwhile, the urine culture was worked up by a dosis. Plasma aldosterone and renin concentration were streaking technique on two plates with artificial media markedly elevated featuring secondary pseudohypoaldos- C����������������olumbia colistin�-�������������������������������nalidixic acid agar (Columbia C��NA����, at �35 teronism (SPHA) syndrome. Later, Enterococcus faecalis °C with 5% CO2) and�������� cystine�-�����������������������������lactose electrolyte deficient was isolated from the urine culture. Clinical and laboratory (CLED, at 35 °C) and a stained smear of a drop of urine features were normalized with antibiotics. After this episode, was used for microscopy observation. After 24-48 hours he received daily trimethoprim for prophylaxis and under- of incubation, we obtained a heavy monomicrobial growth went vesicostomy to relieve the obstructive uropathy. (that extends to the fourth quadrant) of small b-hemolytic 270 Revista Argentina de Microbiología (2010) 42: 279-270 colonies on Columbia CNA agar with negative catalase been infrequently associated with human infections and reaction. The microscopic observation of the is usually susceptible to penicillin. However, susceptibility smear showed leukocytes and pairs and tetrads of gram- patterns have been changing from general susceptibility positive cocci. The bacterial identification conducted by the to the most commonly used antibiotic to recognize resist- automatic method: GPI-Vitek 2 (bioMérieux SA, France) ance not only to penicillin but also to chloramphenicol and and PosID-Walkaway (Dade-Behring, Germany) identi- quinolones (5). Augustine et al. reported a case of endo- fied A. viridans. carditis caused by multidrug-resistant A. viridans (penicil- On the 3rd day of treatment, the urine culture collected lin, ampicillin, cefotaxime, gentamicin, and intermediate by pubic sterile aspiration was repeated. Unfortunately, no resistant to ciprofloxacin) (1). Its susceptibility to second antimicrobial susceptibility test was done, but considering generation cephalosporin remains uncertain. the clinical and analytic improvement with cefuroxime and In our case, the fact of having sterile urine after three gentamicin association, a ten day course of antibiotics days of treatment with cefuroxime and gentamicin, shows was completed. good control of the infection; although the actual knowl- Later, on day 9, the internal aldosterone and renin edge defends that with clinical improvement there is no levels showed lower values (190.9 ng/dl and 115.0 pg/ml, benefit in doing a second urine culture (4). Unfortunately, respectively) in spite of the positive response to the treatment, the SPHA is a rare syndrome occurring in early infancy, lack of a susceptibility test did not allow us to determine mainly characterized by very elevated concentrations of whether it was due to the use of cephalosporin, aminogly- aldosterone and renin. It is transient and commonly as- coside or both. sociated with obstructive uropathy, urinary tract infection In conclusion, even though A. viridans is rarely as- (UTI) or both (6). sociated with child infection, it can be responsible for life UTI is a common infection in infancy, being Es- threatening conditions, such as SPHA. If this agent is cherichia coli the most common responsible agent in isolated in a culture, especially in immunocompromised all age groups. Immunocompromised hosts are at risk or infant patients with obstructive uropathy, we must con- of infection with less typical agents like Enterococcus, sider it a real pathogen and antibiotics should be promptly Pseudomonas aeruginosa and Candida albicans (2). administered. In our report, the first episode of SPHA was triggered by an E. faecalis UTI. In the second SPHA episode, A. viridans was isolated from the urine culture. Aerococci References are generally saprophytic and frequently considered con- 1. Augustine T, Thirunavukkarasu, Bhat BV, Bhatia BD. Ae- taminants in clinical cultures. However, there are some rococcus viridans endocarditis. Case report. Indian Pediatr reports of human infection caused by this agent, such 1994; 31: 599-601. as bacteremia, septic arthritis, endocarditis, meningitis, 2. Azzarone G, Liewehr S, O’Connor K. Cystitis. Pediatr Rev osteomyelitis, empyema and urinary tract infection (7). 2007; 28: 474-6. 3. Çetin M, Ocak S, Ertunç D. An unusual case of urinary tract In the literature, there are some reports of UTI caused infection. ��������������������������ANKEM Derg 2007; 21: 65-7. by this agent in adults, but we could not find any reports 4. Cunha O, Garrido A, Gonçalves M, Ferreira G, Marques E, in children (3, 5). Aerococci appear to have low virulence, Vilarinho A. Utilidade da urocultura de controlo na infecção only becoming pathogenic in patients with vulnerable urinária. Acta Pediatr Port 2010; 41: 51-3. 5. Gopalachar A, Akins RL, Davis WR, Siddiqui AA. Urinary������� conditions, such as immunosupression, chronic disease, tract infection caused by Aerococcus viridans, a case report. malnutrition, prolonged hospitalization, invasive proce- Med Sci Monit 2004; 10:CS73-5. dures, urinary tract pathology and antibiotic treatment 6. Leite AL, Silva V, Vilarinho A, Ferreira G. Secondary pseudo- (8). A. viridans has indolent growth so its contribution to hypoaldosteronism in an infant with malformative uropathy. Port J Nephrol Hypert 2010; 24: 63-6. infectious states may be misdiagnosed (7). 7. Martín V, Vela AI, Gilbert M, Cebolla J, Goyache J, Domín- Our patient, besides his early age, also presented a guez, L et al. Characterization of Aerococcus viridans iso- severe urinary tract malformation, a vesicostomy and had lates from swine clinical specimens. J���������������������� Clin Microbiol �����2007; been exposed to a long course of antibiotic therapy (for 45: 3053-7. 8. Popescu GA, Benea E, Mitache E, Piper C, Horstkotte D. An prophylaxis), all potential risk factors for UTI caused by unusual bacterium, Aerococcus viridans, and four cases of atypical agents. infective endocarditis. J Heart Valve Dis 2005; 14: 317-9. There is limited data in the literature on the antimicrobial 9. Williams RE, Hirch A, Cowan ST. Aerococcus, a new bacte- susceptibility of A. viridans because this organism has rial genus. J Gen Microbiol 1953; 8: 475-80.

Recibido: 18/05/2010 – Aceptado: 17/08/2010