Diarrhea remains a leading cause of mortality in children globally. Over the past two decades, the incidence of diarrhea has remained high, with nearly 1.7 billion cases of childhood diarrheal disease, and 500,000 children under five lose their lives due to diarrhea every year in the world [
1,
2]. In China, community-acquired diarrhea is highly prevalent among children, and the high cumulative burden of diarrhea will raise the risk of stunting [
3‐
5]. Bacteria account for 60.0–85.0% of the pathogens in diarrheal cases, and the antibiotic selection for clinical treatment depends on the severity and duration of the infection [
6]. Third-generation cephalosporins are commonly employed for treating severe diarrhea caused by Enterobacteriaceae bacteria [
7‐
9]. However, the overuse of antibiotics has accelerated the emergence of antimicrobial resistance (AMR), compromising the efficacy of antibiotics in the treatment of bacterial diarrhea [
10]. Bacteria that produce extended-spectrum β-lactamase (ESBL) could develop resistance to cephalosporins and carbapenems, which are major antibiotics in clinical practice [
11,
12].
Klebsiella pneumoniae, a human commensal and opportunistic pathogen, is one of causative agents of diarrhea infections, particularly among children with weakened immunity, causing a wide range of nosocomial and community-acquired infections worldwide [
13‐
15]. Though
K. pneumoniae is not the main cause pathogen of diarrhea, diarrhea caused by this pathogen has been reported, especially in China. From 2018 to 2021, in a certain district of Beijing, the total detection rate of
K. pneumoniae in diarrhea cases was 10.43% (115/1103), of which 66 cases were infected by
K. pneumoniae only [
16]. Over four years, 322 dirrhea infants caused by
K. pneumoniae were discovered in Zhengzhou children’s hospital [
17]. ESBL-producing
K. pneumoniae, one of the most common and severe multidrug-resistant (MDR) pathogens in hospitals, can cause nosocomial infection outbreaks [
15,
18,
19]. Carbapenem is an important antibiotic used in clinical practice, and resistance to carbapenem in
K. pneumoniae poses a major threat to public health [
20‐
24]. ESBL-positive
K. pneumoniae has been found to be widely carried in hospitals and communities across Europe, Africa, Asia, and other regions [
25‐
27]. ESBL-producing
K. pneumoniae constitutes a considerable public health challenge owing to its resistance to a broad spectrum of antibiotics, particularly beta-lactams such as penicillins and cephalosporins [
15]. This multidrug resistance (MDR) complicates treatment options, frequently leaving carbapenems as one of the few viable alternatives, although there is a rising incidence of carbapenem-resistant strains.
K. pneumoniae is a common etiological agent of healthcare-associated infections, including pneumonia, bloodstream infections, and urinary tract infections, particularly among immunocompromised individuals [
24]. The increasing prevalence of ESBL-producing strains highlights the critical need for enhanced antibiotic stewardship, robust infection control measures, and the advancement of novel therapeutic strategies to address the challenges posed by multidrug-resistant pathogens [
19,
20]. Hospitalized patients worldwide have been found to have high prevalences of hypervirulent
K. pneumoniae (hvKP), multidrug-resistant
K. pneumoniae (MDR-KP), and carbapenem-resistant
K. pneumoniae (CRKP) [
28,
29]. The high prevalence of MDR strains and the plasmid-mediated dissemination of resistance genes found in
K. pneumoniae pose significant therapeutic challenges for immunocompromised children under 5 years old [
14]. This has led to previously unheard of public health issues, including the emergence of Carbapenem-resistant hypervirulent
K. pneumoniae (CR-hvKP).