Molecular Epidemiology, Clinical Characteristics and Risk Factors for Bloodstream Infection of Multidrug-Resistant Infections in Pediatric Patients from Tianjin, China.

Purpose: The data on pediatrics with Multidrug-Resistant (MDR) infections are scarce. This study aims to investigate the molecular epidemiology of MDR , detect the mechanism of drug resistance, and determine the clinical risk factors for carbapenem-resistant (CRKP) bloodstream infections (BSIs) in a children's hospital.

Methods: A total of 62 strains were collected from Tianjin Children's Hospital. Carba NP and polymerase chain reactions (PCR) were performed to detect MDR mechanisms. Multilocus sequence typing (MLST) was used for analyzing strain homology. Clinical data were collected and logistic regression was used for BSI risk factors.

Results: ST11 was the principal ST among the CRKP isolates clinically, accounting for 56.45% (35/62); there were also 57.14% (20/35) ST11 CRKP strains co-carrying and , which were resistant to most of the tested antibiotics, being susceptible only to cotrimoxazole and tigecycline. The clinical data showed that 72.73% (40/55) of children with CRKP infection had serious underlying diseases; 20.00% (11/55) patients developed BSIs with the potential to cause multiple organ failure, shock and death. The logistic regression showed that the risk of BSIs caused by CRKP strain infections in children with hematological malignancies after chemotherapy was 7 times that of other children (95%Cl: 1.298-45.415, =0.025).

Conclusion: ST11 was the prevalent clone in our hospital. The emergence of ST11 CRKP co-carrying and should be a cause for alarm as they were resistant to most of the tested antibiotics. CRKP strain infections are mainly occurring in young immunocompromised patients and the chemotherapy for hematological malignancies is an independent risk factor for BSIs.