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Molecular Characterization and Epidemiology of Carbapenem-Resistant Enterobacteriaceae Isolated from Pediatric
Fei Gao1, Zhile Xiong1, Bingshao Liang1
1Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong 510623, China.
Insights
Carbapenem-resistant Enterobacteriaceae (CRE) infections in children are a growing concern. This study found the NDM carbapenemase gene to be most prevalent in Guangzhou, highlighting the need for enhanced infection control measures.
Area of Science:
- Microbiology
- Infectious Diseases
- Public Health
Background:
- Carbapenem-resistant Enterobacteriaceae (CRE) pose a significant global health threat.
- Limited data exists on CRE infections in pediatric populations in Guangzhou, China.
- This study addresses the knowledge gap regarding CRE epidemiology and resistance in Southern China's children.
Purpose of the Study:
- To investigate the epidemiology of CRE strains causing infections in children in Guangzhou.
- To analyze the antimicrobial resistance patterns and mechanisms of these CRE isolates.
- To identify the predominant resistance genes and molecular types of CRE in pediatric patients.
Main Methods:
- Collected 54 non-repetitive CRE strains from pediatric patients (2016-2018).
- Performed antimicrobial susceptibility testing, modified Hodge test (MHT), and modified carbapenem inactivation method (mCIM).
- Utilized PCR for detecting resistance genes and MLST for Klebsiella pneumoniae epidemiology.
Main Results:
- Klebsiella pneumoniae (63.0%) was the most common CRE species, primarily isolated from blood and sputum.
- All CRE isolates exhibited high resistance to cephalosporins, carbapenems, and beta-lactam/beta-lactamase inhibitor combinations.
- The NDM carbapenemase gene was most prevalent (48.6%), followed by OXA-232 (37.1%) and OXA-48 (11.4%).
Conclusions:
- NDM carbapenemase genes are dominant in pediatric CRE infections in Guangzhou.
- Urgent implementation of infection control strategies is crucial for preventing and managing CRE infections in children.
- Continued surveillance and research are necessary to combat the spread of antimicrobial resistance.
Background:
Carbapenem-resistant Enterobacteriaceae (CRE) are spreading worldwide, posing a serious public health concern. However, the data on CRE strains that cause infections in children in Guangzhou remain limited. Therefore, this study aimed to investigate the epidemiology of CRE, drug resistance, and resistance mechanisms in children in Guangzhou, Southern China.
Methods:
In total, 54 nonrepetitive CRE strains were collected in pediatric patients at three centers in Guangzhou, Southern China, from January 2016 to August 2018. CRE isolates were used for further studies on antimicrobial susceptibility, the modified Hodge test (MHT), the modified carbapenem inactivation method (mCIM), and drug resistance genes. Multilocus sequence typing (MLST) was used to elucidate the molecular epidemiology of K. pneumoniae.
Results:
The isolated CRE strains include 34 K. pneumoniae (63.0%), 10 E. coli (18.5%), 4 Enterobacter cloacae (7.4%), and 6 Proteus mirabilis (11.1%) strains. The strains were isolated mainly from the blood (31.5%, n = 17), sputum (31.5%, n = 17), and urine (16.7%, n = 9). All CRE isolates were highly resistant to the third- or fourth-generation cephalosporins, carbapenems, and β-lactam + β-lactamase inhibitors (94.4%-96.3%). In addition, the resistance rates to amikacin, ciprofloxacin, levofloxacin, tigecycline, and colistin were 5.6%, 14.8%, 16.7%, 9.3%, and 0%, respectively. Carbapenemase was detected in 35 (64.8%) of the CRE isolates. The most dominant carbapenemase gene was bla (n = 17, 48.6%), followed by bla (n = 13, 37.1%) and bla (n = 4, 11.4%). Other carbapenemase genes (bla KPC, bla sim, bla Aim, bla GES, bla Gim, bla , and bla ) and the mcr-1 gene were not detected. MLST analysis showed high diversity among the K. pneumoniae, and ST45 (11.7%, 4/34) was the dominant sequence type.
Conclusion:
This study revealed bla NDM was the most dominant carbapenemase gene in children in Guangzhou. Infection control measures need to be taken for the prevention and treatment of CRE infections.
