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Published on: February 17, 2023
Causative organisms and antimicrobial susceptibility in jaundiced infants with significant bacteriuria
Lih-Ju Chen1,2,3, Ping-Ju Chen4,2,3, Shun-Fa Yang2
1Division of Neonatology, Changhua Christian Children's Hospital, Changhua City, Taiwan, ROC.
Insights
Jaundice in infants can signal urinary tract infections (UTIs). This study found E. coli is common, with rising resistance to ampicillin, suggesting amikacin may be a better antibiotic choice.
Area of Science:
- Neonatal Medicine
- Infectious Diseases
- Microbiology
Background:
- Jaundice is an early indicator of urinary tract infection (UTI) in infants.
- Escherichia coli is the most frequent pathogen identified in neonatal UTIs.
- Increasing resistance to ampicillin and gentamicin in E. coli necessitates re-evaluation of treatment protocols.
Purpose of the Study:
- To identify causative microorganisms in jaundiced infants with significant bacteriuria (SB).
- To assess the antimicrobial susceptibility patterns of isolated pathogens.
- To inform updated empiric antibiotic therapy recommendations for neonatal UTIs.
Main Methods:
- Evaluation of 615 asymptomatic, jaundiced infants (<1-month old) with hyperbilirubinemia requiring phototherapy.
- Urine analysis and culture performed on all enrolled infants.
- Significant bacteriuria defined by pathogen isolation: >10^5 CFU/ml (collection bag) or >10^4 CFU/ml (catheterization).
Main Results:
- 88 infants (14.3%) had positive urine cultures.
- E. coli was the predominant pathogen (45.5%), followed by Enterococcus faecalis (19.3%).
- Ampicillin sensitivity was low (22.5%) for E. coli, while gentamicin sensitivity remained high (84.2%).
Conclusions:
- E. coli is the primary cause of SB in jaundiced infants.
- Current empiric antibiotic regimens for neonatal Gram-negative infections should be reconsidered.
- Amikacin is proposed as a potential alternative to gentamicin for treating neonatal bacterial infections.
Background:
Jaundice may be one of the first signs of urinary tract infection (UTI) in infants. The most common pathogen is Escherichia coli. Currently recommended antibiotic treatment for neonatal UTI is ampicillin and an aminoglycoside. Recently, increasing ampicillin and gentamicin resistance in strains of E. coli has been isolated. The aim of this study was to determine causative organisms and antimicrobial susceptibility in jaundiced infants with significant bacteriuria (SB).
Methods:
We evaluated admitted afebrile, asymptomatic infants younger than 1-month old with hyperbilirubinemia (total bilirubin >15 mg/dl) requiring phototherapy between January 2011 and December 2015. A total of 615 asymptomatic jaundiced infants were enrolled. Urinalysis and urine cultures were performed on all jaundiced infants. A urine culture was defined as SB if a single pathogen with more than 105-colony forming units per milliliter (CFU/ml) by sterile urinary collection bag or 104 CFU/ml by catheterization was isolated.
Results:
A total of 88 (14.3%) of 615 asymptomatic jaundiced infants had positive urinary culture. E coli was the most common cultured bacteria (40 cases, [45.5%]). Enterococcus faecalis was the second most common bacteria (17 cases, [19.3%]). Seven cases (8.0%) of Streptococcus agalactiae and six cases (6.8%) of Klebsiella pneumoniae were also identified. Ampicillin sensitivity was found in 22.5% of E. coli infections, gentamicin sensitivity was found in 84.2%, and extended-spectrum β-lactamases were found in 7.5%.
Conclusion:
E. coli was the most common causative organism for infants with SB. We suggest modifying current empiric antibiotics by changing gentamicin to amikacin for neonatal Gram-negative bacterial infections.
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