Copyright © 2014 Shivendra Dutt et al. This is an open access article distributed under the Creative Commons Attribution License , which permits
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International Journal of Health, 2 (2) (2014) 61-62
International Journal of Health
Journal home page: www.sciencepubco.com/index.php/IJH
doi: 10.14419/ijh.v2i2.3790
Case Report
Small colony variant of Escherichia coli isolated from a recurrent
urinary tract infection- a case report
Shivendra Dutt
1
*; Nagalakshmi N
2
; Shobha K. L
2
1
Department of Microbiology, Kasturba Medical College, Manipal, Karnataka 576104, India
2
Department of Microbiology, Melaka Manipal Medical College (Manipal Campus) Manipal University,
Manipal, Karnataka 576104, India
*Corresponding author E-mail: shobha.kl@manipal.edu
Abstract
Introduction: Small colony variant of Escherichia coli may cause persistent and recurrent infections in human. These slow growing
phenotypic variants are difficult to identify and mislead the diagnosis which can lead to choice of inappropriate antibiotics. In this case
report we are presenting a case of recurrent urinary tract infection which was associated with small colony variants of E. coli.
Case presentation: A two year old male child was admitted to the hospital with a complaint of passing thin stream of urine. One month
earlier the child had been previously diagnosed with bilateral grade five Vesicoureteral reflux. Child had developed recurrent urinary
tract infection caused by small colony variants of E. coli.
Conclusion: child had undergone bilateral ureter reimplantation as part of treatment to Vesicoureteral reflux. Since vesicoureteral reflex
condition is one of the risk factor to develop urinary tract infections. Repeated exposure to antibiotic might have been induced stress
condition to bacteria and emerged as slow growing sub population of E. coli.
Keywords: Escherichia coli, Small Colony Variant, Urinary Tract Infections.
1. Introduction
Urinary tract infections (UTI) are a common form of infection in
infants and children. Diagnosis of UTI in young children and
infants is very important as early detection plays a critical role for
the preservation of renal function of the growing kidney (Habib S,
2012). Microbiological investigation of urine specimen is neces-
sary for the identification of pathogens and antibiotic susceptibil-
ity (Hooton TM & Stamm WE, 1997). The most common patho-
gen associated with UTI is the uropathogenic Escherichia coli
(UPEC), however some individuals have an increased predisposi-
tion to recurrences of UTI due to the initially infecting strain
which even after elimination from urinary tract may persist in the
faecal flora. Few studies reported that Escherichia coli can invade
bladder epithelial cells and can form large bacterial inclusions
after replication intracellularly (Foxman B, 1990 & Mulvey MA et
al., 1998). Small colony variants (SCVs) are known as slow grow-
ing subpopulations that form small, non-pigmented and non-
hemolytic colonies. Deficiencies in electron transport activities
lead to auxotrophism for thymidine, menadione, or hemin causing
the typical biochemical characteristics of the variants (Proctor RA
et al., 2006 & L J Mandel et al., 1984). Studies show that 3-5 % of
persistent infections may be caused by these small colony Variant
Escherichia coli (Charlotte A. C. et al., 1946 & Roggenkamp A et
al., 1998). Clinically these small colony variants are better able to
persist in mammalian cells and are less susceptible to antibiotics
(Harald S et al., 2003 & Proctor RA et al., 1995). Due to their
unusual phenotypical and biochemical characteristics, they pose a
challenge for clinical microbiologists.This problem might lead to
diagnostic underestimation, which will cause therapeutic failures
in the clinical settings (Vaudaux P et al., 2006). Small colony
variant Escherichia coli are reported to cause persistent and recur-
rent infections with more chances of treatment failure than those
caused by wild type. However, there is limited literature regarding
this. Here, we describe the case of a recurrent UTI infections
caused by Small colony variant Escherichia coli, which occurred
after undergoing surgery for bilateral grade five vesicouteral re-
flexes.
2. Case presentation
A two year old male child was admitted to the hospital with a
complaint of passing thin stream of urine. One month earlier the
child had been previously diagnosed with bilateral grade five
Vesicoureteral reflux for which he had been surgically treated by
bilateral ureter reimplantation. Following this, a complaint of UTI
was reported and Escherichia coli was isolated. The patient on
current admission had meatal stenosis with a complaint of poor
stream of urine. The child was immunized as per the Indian prima-
ry immunization schedule. On Physical examination the child had
a pulse rate of 90 per minute and Blood pressure 110/80 mmHg.
Hematological findings showed 10% Monocyte, 1% Basophils,
51%Neutrophils, 38% Lymphocytes. Hemoglobin was 10.8 mg/dl,
Platelet count was 465 x 10 ³ per microliter and Total WBCs was
found to be 20.1 x 10 ³ per microliter. Urine specimen was col-
lected after receiving consent from parents. Specimen was sent to
laboratory for further investigations. Biochemical analysis of urine
revealed that the pH was 6.5 with the color being pale yellow and
specific gravity being <1.005. Traces of protein were present with
sugar being absent in the urine. Blood urine was +1 (25 erythro-