Background:
There has been a rapid and global dissemination of extended-spectrum-β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae in the hospital settings. The aim of the this study was molecular characterization of Escherichia coli and Klebsiella pneumoniae isolated from an outbreak in a neonatal intensive care unit (NICU), in Haíl, Saudi Arabia.
Materials/methods
An outbreak of 3rd generation cephalosporin resistant infections was reported within a neonatal intensive care ward in a maternity hospital at Haíl, Saudi Arabia. The bactria cultured were identified by routine and automated identification system. Antibiotic resistance testing was performed using VITEK 2 and Microscan. The presence of blaTEM, blaSHV and blaCTX-M antibiotic resisatnce genes was performed PCR. Isolate genotyping was performed using pulsed field gel electrophoresis.
Results
A total of 41 K. Pneumoniae isolates were cultured from neonates with the majority of isolates (95.1%) being resistant to 3rd generation cephalosporins. A total of 87.8% (36/41) K. pneumonaie were co-producers of CTX-M-15 and SHV-12. Further, 4.8% were CTX-M-2 producers and 63.4% were positive for TEM-1.
A toatl of 19 E. coli isolates were cultured from neonates, with the majority of isolates (17/19) being resistant to 3rd generation cephalosporins. A total of 21.0% were co-producers of CTX-M-15 and SHV-12. Further, 31.6% were positive for CTX-M-2 and 57.9% were TEM-1 positive.
The majority (31/41) of K. pneumoniae isolates belonged to a single genotypic lineage at the 85% similarity level, while E. coli isolates grouped into 2 genetic clusters at 80% similarity (18/19 isolates).
Conclusion
This is the first report of CTX-M-15-positive, ESBL E. coli and K. pneumoniae isolates recovered from a outbreak in a NICU in Haíl, Saudi Arabia. It is alarming to notice a high rate of outbreak isolates with simultaneous production of CTX-M-15 and SHV-12 conferring high level resistance to oxyimino-cephalosporins.
