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Indian Journal of Medical Microbiology, Vol. 30, No. 1, January-March, 2012, pp. 96-98 Case Report Pneumococcusuria: From bench to bedside S Krishna1, KV Sanjeevan2, A Sudheer1, KR Dinesh1, A Kumar1, S Karim1 1 Department of Microbiology, Amrita Institute of Medical Sciences, Cochin- 682 041, Kerala, India Correspondence Address: Date of Acceptance: 19-Oct-2011 Code Number: mb12019 PMID: 22361770 DOI: 10.4103/0255-0857.93056 Abstract The present study highlights six cases of pneumococcusuria during the time period of May 2008 to May 2010. All the patients had a co-existing predisposing factor with the isolation of Streptococcus pneumoniae in urine. Five of the six patients having signs and symptoms of urinary tract infections (UTI) were treated and cured of the same. It becomes essential to consider pneumococcal UTI in the presence of clinical signs and symptoms associated with urinary tract abnormalities like hydronephrosis and renal stones. S. pneumoniae may be regarded as an emerging pathogen in UTI. Precise microbiological diagnosis must correlate with the clinical signs and symptoms for the administration of appropriate antibiotic therapy. Keywords: Emerging pathogen, Streptococcus pneumoniae, urinary tract infections Introduction Streptococcus pneumoniae is not generally believed to cause urinary tract infections. [1],[2] The actual significance of isolation of S. pneumoniae in urine is not known and relevant data are scarce with only a few documented cases of urinary tract infections with explained and unexplained pathogenesis. [3],[4],[5] This communication looks into the implication of S. pneumoniae isolation in urine. Case Reports We reviewed all consecutive cases of pneumococcusuria treated in our University teaching hospital from May 2008 to May 2010. Centrifuged urine microscopy with pus cell count was recorded. Samples were then plated on sheep blood agar (SBA) and MacConkey agar incubated aerobically at 37°C. Growth from SBA (CO 2 incubation) after 18-24 h was confirmed as S. pneumoniae based on colony morphology, gram stain, alpha haemolysis and standard biochemical tests such as bile solubility and optochin susceptibility. Antibiotic sensitivity testing was done for penicillin, amoxicillin-clavulanic acid, cefuroxime, ceftriaxone, co-trimoxazole, nitrofurantoin and ciprofloxacin by the disk diffusion method. [6],[7] Medical records were checked for all diagnosed cases and relevant clinical details including the laboratory parameters were noted. Six cases of pneumococcusuria were reported during the study period. Case 1 An 18-month-old male child from Bahrain was admitted with bilateral hydroureteronephrosis, end-stage renal disease, renal osteodystrophy and severe anaemia. Child had a history of severe oligohydroamnios and hydronephrosis detected at the 7-month antenatal scan. Vaginal delivery was induced prematurely at 32 weeks when the baby weighed 1.96 kg. Vesicostomy was done on the sixth day of his life for posterior urethral valve causing obstructive uropathy and severely compromised renal function. Postoperatively, the child had fever of 100°C and his urine grew Streptococcus pneumoniae >10 5 cfu/ml. Fever settled with cefotaxime followed by 2 weeks of cephalexin started according to the urine culture and sensitivity pattern. Urine was sterile when studied 6 days later (Laboratory values at presentation: urinary pH 7, centrifuged urinary pus cells 25-30/HPF, Serum creatinine 2.9 mg/dl, S. urea 198.5 mg/dl, WBC count 13,900) Case 2 A 31-year-old lady presented to the outpatient clinic with increased urinary frequency and persistent significant bacteriuria with varied organisms following an abortion 6 months ago. There was no dysuria, fever or haematuria. Three urine culture studies during the preceding 6 months had grown Klebsiella spp. Acinetobacter spp. and Escherichia coli and she had been treated elsewhere with various antibiotics without significant improvement (details not available). Physical examination did not reveal any findings. Abdominal ultrasonography revealed bilateral mild hydronephrosis and thickening of bladder wall. Fresh urine culture grew S. pneumoniae >10 5 cfu/ml. She received cefuroxime for 10 days followed by 1 month of suppressive doses of nitrofurantoin. Urinary symptoms settled and follow up urine culture done in the next outpatient visit after a month revealed no growth (laboratory values: urinary pH 6, centrifuged urinary pus cells 2-3 /HPF, serum. creatinine 0.9 mg/dl). Case 3 A 69-year-old man was admitted with fever, dysuria and pain of 2 days duration while doing clean intermittent self-catheterisation for atonic bladder. He was a hypertensive, on maintenance haemodialysis for end-stage renal disease from diabetic nephropathy. There was history of transurethral resection of prostate for obstructive benign prostatic hyperplasia, and recurrent urinary tract infections from various organisms including Pseudomonas aeruginosa 4 years ago, repeated multidrug-resistant ESBL positive Escherichia coli and Klebsiella pneumoniae 3 years ago and urosepsis 2 years ago. Two consecutive catheterised samples of urine grew S. pneumoniae >10 5 cfu/ml over a period of 2 months, 2 years ago. Two week′s course of amoxicillin-clavulanic acid and moxifloxacin sterilised his urine, relieved him of his symptoms (Laboratory values: urinary pH 6, centrifuged urinary pus cells 8-10/HPF, Serum creatinine 6.83 mg/dl, blood urea 80.9 mg/dl, WBC count 10,100). Case 4 A 28-year-old man presented to the outpatient clinic with urinary urgency and frequency of 1 year duration. He was a diabetic on oral hypoglycaemic agents and was diagnosed to have small renal stones and overactive bladder and was commenced on conservative management. The patient had a history of one episode of UTI 2 months back (details not available) for which he had received antibiotics. Ultrasound revealed 4.5-mm bilateral renal calculi and a normal bladder. Urine culture grew S. pneumoniae >10 5 cfu/ml and the patient was started on cefuroxime. He was lost to follow up (laboratory values: urinary pH 6, centrifuged urinary pus cells 2-3/HPF, serum creatinine 1.1 mg/dl, blood urea 17.5 mg/dl, WBC count- 12,600). Case 5 A 33-year-old lady, teacher at Riyadh, under treatment for hyperthyroidism, presented with complaints of severe dysmenorrhoea and suprapubic discomfort. She had history of treatment for chronic pelvic inflammatory disease from E. coli 3 years ago. There was one episode of UTI with haematuria and Trichomoniasis on cervical Papanicolaou smear the year before, which had promptly responded to treatment. There was no history of urinary stones or lower urinary tract symptoms. USG abdomen showed a simple cortical cyst in lower kidney. She was treated as a case of urinary tract infection when the urine cultures had grown S. pneumoniae >10 4 cfu/ml with amoxicillin-clavulanic acid (laboratory values: urinary pH 6, centrifuged urinary pus cells 8-10/HPF, serum creatinine 0.7 mg/dl, blood urea 16 mg/dl, WBC count 7,800). Case 6 A 61-year-old man, a known case of mild obstructive lower urinary tract symptoms, hypertension, dyslipidaemia and chronic obstructive pulmonary disease on treatment, presented to the urology outpatient clinic for two episodes of hematospermia over a period of 6 weeks. Digital rectal examination showed Grade I tender benign prostate. Semen analysis revealed plenty of RBCs. Urine culture grew S. pneumoniae >10 4 cfu/ml. No antibiotics were administered; the patient did not report back ( laboratory values: serum creatinine 1.0 mg/dl, blood urea 17 mg/dl). Discussion Isolation of common organisms but from unusual sites presents a reporting dilemma to the clinical microbiologists. In majority of cases, urine microscopy showing pus cells prompts a microbiologist to arrive at the diagnosis of UTI, and culture on the next day confirms it. S. pneumoniae is known to be labile in the normal urinary pH. However, all our six strains grew well on the ordinary sheep blood agar with CO 2 supplementation. Sheep blood agar is an essential primary isolation media. Many laboratories especially in multi-specialty hospitals use Cysteine lactose electrolyte deficient Agar for the urine cultures in which case Pneumococci can be completely missed out. All the cases strikingly had a renal or urogenital structural or other abnormality as an accompanying factor (hydronephrosis, renal stones, renal cyst, diabetic cystopathy, benign prostatic hypertrophy, etc.). [8] All had pure growth with four of them having significant bacteriuria, and all were uniformly sensitive to the antibiotics tested (amoxicillin-clavulanic acid, cefuroxime, ceftriaxone, ciprofloxacin, nitrofurantoin and cotrimoxazole). The last patient in this series was presumed to be only shedding bacteria or probably showed asymptomatic bacteriuria as there was no clinical evidence of UTI. Perineal carriage has been reported as a result of autoinoculation with nasal secretions by transmission through unhygienic hands. [9] Some authors have also considered it as periurethral contaminant as well. [3] As there was no suggestive Pneumococcal bacteremia in any of the cases, disease was presumed to be localised. Due to its potential invasive nature of the disease outside the genitourinary tract, it may be worth an attempt to look for the source of Pneumococci if isolated in urine. Equally important is to serotype the strains causing UTI, to assess the role of potential vaccination coverage for prevention, more so in children. Reporting of more such cases would reveal the steps of pathogenesis and route of acquisition. S. pneumoniae may cause urinary tract infections. Direct microscopy with findings of leucocyturia plays an important role in dispatching microbiological reports of such uncommon isolations in a symptomatic patient. Urinary tract abnormalities like hydronephrosis and renal stones may predispose S. pneumoniae UTI. S. pneumoniae may not be an important cause of UTI, but it is important to be aware of the possibility of this unlisted emerging pathogen for antibiotic therapy. References
Copyright 2012 - Indian Journal of Medical Microbiology |
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