Related Experiment Video
Updated: May 14, 2026
Non-Invasive Model of Neuropathogenic Escherichia coli Infection in the Neonatal Rat
Published on: October 29, 2014
Preventive effects of Lactobacillus mixture on experimental E. coli urinary tract infection in infant rats
Jung Won Lee1, Jee Hyun Lee, Sun Hee Sung
1Department of Pediatrics, Kangnam Sacred Heart Hospital, Hallym University, Seoul, Korea.
Insights
Intravesical instillation of a lactobacillus mixture (LM) prevented pyelonephritis in infant rats. Oral administration of LM to mothers did not prevent infantile urinary tract infections (UTIs).
Area of Science:
- Microbiology
- Pediatrics
- Urology
Background:
- Urinary tract infections (UTIs) are common in infants.
- Lactobacilli are known to play a role in preventing UTIs.
- The efficacy of lactobacillus mixtures (LM) in preventing infantile UTIs requires further investigation.
Purpose of the Study:
- To investigate the preventive effect of LM on experimental infantile UTIs.
- To compare the efficacy of intravesical versus oral administration of LM.
Main Methods:
- A lactobacillus mixture (LM) of L. gasseri, L. rhamnosus, and L. reuteri was used.
- Mother rats received oral LM or placebo during pregnancy and lactation.
- Infant rats received intravesical LM or placebo before experimental UTI induction with E. coli.
Main Results:
- Intravesical LM significantly reduced the incidence of pyelonephritis (16.7%) compared to controls (75.0%).
- Oral LM administration to mothers did not significantly alter lactobacilli colonies or UTI incidence in offspring.
- No significant difference in cystitis incidence was observed among groups.
Conclusions:
- Intravesical administration of LM is effective in preventing experimental pyelonephritis in infant rats.
- Oral administration of LM to mothers is not an effective strategy for preventing infantile UTIs.
Purpose:
Urinary tract infection (UTI) is an ascending infection of fecal uropathogens, urogenital lactobacilli are suggested to play a role in the prevention of UTI. This study was to investigate whether lactobacillus mixture (LM) could prevent the experimental infantile UTI.
Materials And Methods:
The LM were composed of three lactobacillus strains (L. gasseri, L. rhamnosus, and L. reuteri). Mother rats were grouped as lactobacillus (LB) group I (LB I, n=22), II (LB II, n=24) and control (n=20). LB I and LB II were fed with LM (1 mL/day) and control with phosphate-buffered saline (PBS) from late pregnancy through lactation. All newborn rats were breast-fed and their urine and stool were collected at the end of the 3rd week to compare lactobacillus colony. Then, infant rats from LB II were treated with intravesical instillation of LM. Infant rats from LB I and control were instilled with PBS. Twenty-four hours later, experimental UTI was introduced by intravesical instillation of standard E. coli strain. After 72 hours later, the infant rats were sacrificed for histologic examination.
Results:
Lactobacilli colonies in urine and stool were not statistically different among the three groups. The incidence of pyelonephritis in the LB II was 16.7% (4/24), LB I 72.7% (16.22) and control 75.0% (15/20) (p=0.015). The incidence of cystitis was not significantly different among the three groups.
Conclusion:
The intravesically instilled LM significantly prevented experimental pyelonephritis in infant rats, however, LM administered orally to the pregnant and lactating mother rats did not.
