Validation of Cefazolin as Initial Antibiotic for First Upper Urinary Tract Infection in Children

Simple determination of urine cefazolin concentration in pediatric patients with urinary tract infections using high-performance liquid chromatography

Recently, global health concerns regarding increasing multidrug resistance have arisen. This study aimed to develop a simple, inexpensive, and rapid high-performance liquid chromatography-ultraviolet (HPLC-UV) method for determining urinary concentrations of a 1st generation cephem antibiotic in pediatric patients with urinary tract infections (UTIs). HPLC-UV was used to analyze urinary cefazolin concentrations at a detection wavelength of 254 nm. The assay used contained 10-fold diluted urine with an internal standard (cephapirin). The standard calibration curve for cefazolin was linear in the concentration range of 31.25-500 μg/mL (r² >0.999). The retention times of cefazolin and the internal standard were 4.2 and 4.9 min, respectively. The within-day and between-day coefficients of variation were at these concentrations ranged 1.2-15.2 and 5.5-19.2 %, respectively. The urinary cefazolin concentration of a pediatric patient with a UTI was 1,476.6 μg/mL, which was over 700-fold higher than the minimum inhibitory concentration (MIC) of cefazolin (≤ 2 μg/mL). The developed method is applicable to the confirmation of appropriate use for UTIs treatment as a therapeutic drug monitoring of cefazolin. Therefore, the findings of this study may contribute to the appropriate use of antibiotics to prevent antimicrobial resistance (AMR) in pediatric patients with UTIs.

Risk factors for cefazolin-resistant febrile urinary tract infection in children

BACKGROUND

Febrile urinary tract infection (fUTI) is a common bacterial infection among children. This study investigated the risk factors for fUTI caused by cefazolin-resistant bacteria in children.

METHODS

The medical records of patients with fUTI hospitalized between April 2014 and March 2020 were retrospectively analyzed. The patients were divided into two groups based on the cefazolin susceptibility of the infection-causing bacteria: cefazolin-resistant and cefazolin-susceptible groups.

RESULTS

The records of 80 patients were evaluated. The median age was 5.0 months (range 0.5-119.4 months). Cefazolin-susceptible bacteria were detected in 60 patients (75.0%). Significant differences were noted between the cefazolin-resistant and cefazolin-susceptible groups regarding UTI-related antimicrobial prophylaxis and recurrence of UTI within 3 months (P = 0.0318 and P = 0.00876, respectively). However, no significant differences were observed between these two groups regarding renal anomalies, or UTI history. Logistic regression analysis revealed that the recurrence of UTI within 3 months was an independent, significant risk factor for cefazolin-resistant fUTI (odds ratio 3.81, 95% confidence interval: 1.07-13.5, P = 0.0388). Six patients who were empirically treated with antibiotics ineffective against the infection-causing bacteria recovered from fever before these antibiotics were switched to those effective against the infection-causing bacteria.

CONCLUSIONS

In children, a recurrence of UTI within 3 months is a risk factor for fUTI caused by cefazolin-resistant bacteria. Recognizing these risk factors before initiating fUTI treatment in children may support treatment with narrower-spectrum antibiotics, such as first-generation cephalosporins (e.g., cefazolin).

β-Lactams and β-Lactamase Inhibitors: An Overview

β-Lactams are the most widely used class of antibiotics. Since the discovery of benzylpenicillin in the 1920s, thousands of new penicillin derivatives and related β-lactam classes of cephalosporins, cephamycins, monobactams, and carbapenems have been discovered. Each new class of β-lactam has been developed either to increase the spectrum of activity to include additional bacterial species or to address specific resistance mechanisms that have arisen in the targeted bacterial population. Resistance to β-lactams is primarily because of bacterially produced β-lactamase enzymes that hydrolyze the β-lactam ring, thereby inactivating the drug. The newest effort to circumvent resistance is the development of novel broad-spectrum β-lactamase inhibitors that work against many problematic β-lactamases, including cephalosporinases and serine-based carbapenemases, which severely limit therapeutic options. This work provides a comprehensive overview of β-lactam antibiotics that are currently in use, as well as a look ahead to several new compounds that are in the development pipeline.