Enterococcal UTIs May Signal Underlying Urinary Problems in Children
Community-acquired urinary tract infections (UTIs) in children caused by enterococcal bacteria are associated with a high rate of underlying urinary abnormalities, a study found. As a result, renal imaging of pediatric patients with these types of UTIs is recommended, according to researchers.
In addition, in a five-year prospective study of 355 children at the Schneider Children's Medical Center of Israel in Tikva, investigators there found that enterococcal infections were not susceptible to antibiotics commonly used empirically to treat UTIs.
Of the 355 children hospitalized for cultured proven UTIs, 22 (6.2%) had enterococcal bacteria as the causative pathogen, investigators reported in Pediatric Nephrology (2012;27:109-114). Underlying urinary abnormalities were identified in 70% of patients with enterococcal UTIs compared with 43.7% of those with Gram negative UTIs. Renal abnormalities in the enterococcal UTI group included vesicoureteral reflux (53% of patients), hydronephrosis, and extrarenal pelvis.
All of the enterococcal isolates were uniformly resistant to cephalosporins, whereas Gram negative isolates had a 24%, 7%, and less than 5% rate of resistance for first- second-, and third generation cephalosporins, respectively.
Additionally, compared with Gram negative bacteria, enterococcal isolates were significantly less commonly resistant to ampicillin (10% vs. 69%) and more common resistant to ofloxacin (20% vs. 6%). All Gram negative isolates were uniformly resistant to vancomycin but all enterococcal isolates were susceptible to the drug.
Inappropriate empiric antibiotic treatment was given about four times more frequently to patients with enterococcal than Gram negative infections (22% vs. 5.6%). Cefuroxime and ceftriaxone were the inappropriate antibiotics given empirically to treat enterococcal UTIs. After obtaining culture results, appropriate antibiotics were administered to patients with enterococcal UTIs based on the known susceptibility results, the researchers stated.
In light of the high rates of renal abnormalities in children with enterococcal UTI, “we recommend routine imaging in such cases, at least with the non-invasive and safe technique of ultrasonography,” the investigators noted.
Since Enterococcus species are almost the only species causing Gram positive UTIs in young children, “they can be detected early by using Gram stain of the urine, which we recommend performing, especially in such circumstances as the presence of underlying urinary abnormalities or ineffectiveness of previous cephalosporin or other antibiotic treatment.”
They also observed, “Timely and appropriate administration of antimicrobial therapy is essential for eliminating symptoms, eradicating infection, reducing the likelihood of renal damage, and preventing complications,” the authors wrote.
The investigators, led by Gilat Livni, MD, observed that most pediatric UTIs are caused by Gram negative bacteria, particularly Escherichia coli. Among the Gram positive organisms, Enterococcus is the most common genus. Research on enterococcal UTIs in children is quite limited, the authors noted, with most studies dealing with nosocomial infections.