Novel Strains Co-Harbouring Metallo β-Lactamase and Isolated from Immunocompromised Paediatric Patients.

BACKGROUND

The rising resistance to carbapenems in Gram-negative bacteria worldwide poses a major clinical and public health risk. This study aimed to characterise carbapenem- and colistin-resistance genes, and located on IncX4 plasmid in MDR , isolated from paediatric patients undergoing chemotherapy as a result of leukaemia.

METHODS

In this study, six carbapenem-resistant strains of were isolated from two paediatric patients under chemotherapy treatment (1.8 years old female and 2.1 years male) from the Shenzhen Hospital, China, in the year 2019. Isolates were screened for conventional antibiotics such as tobramycin, cefepime, imipenem, and ciprofloxacin in additional colistin by using the broth dilution method. Furthermore, resistance determinants: and were screened using PCR and sequencing followed by multi-locus sequence typing. The horizontal gene transfer and location of and were determined by a liquid mating assay. In addition, Incompatibility type (Inc), PCR-based replicon type, and subgroup (MOB) of plasmid were studied.

RESULTS

The screening for conventional antibiotics isolates showed 100% resistance to all the tested antibiotics except tobramycin. All isolates harboured carbapenemase encoding , of which three also had located on a single IncX4 transferable plasmid. MLST typing revealed that four strains had a novel (new) STs type, while two belonged to ST1966.

CONCLUSION

This study identified for the first time colistin- and carbapenem-resistant MDR in paediatric patients with leukaemia in Shenzhen, China. It highlights the need for continuous surveillance in high-risk clones of MDR . Prudent use of antibiotics based on local antimicrobial susceptibility and clinical characteristics can help in reducing mortality in immunocompromised patients.