Abstract:
Background: Klebsiella pneumoniae is one of the most common nosocomial pathogens in NICUs, as it is an important part of the niche of potential sources of nosocomial NICU infections. This pathogen with its expression of extended spectrum β-lactamases and the potential spread of this pattern of resistance is forming an interesting field of research.
Objectives: Studying the expression of ESBL producing Klebsiella pneumoniae in NICUs with special emphasis on the genetic varieties of this phenomenon.
Patients and methods: The study had covered a time scale of eight months, and entailed the collection of a spectrum of samples constituting the diversity of the reservoir of Klebsiella pneumoniae strains in NICUs. This included collection of 100 samples from working environment, 44 working personnel samples, in addition to 105 different clinical samples. Of these samples, any Klebsiella pneumoniae strain was subjected to routine disk diffusion susceptibility testing, and double disk diffusion for detection of ESBL. ESBL producing Klebsiella pneumoniae isolates were further subjected to real-time multiplex PCR amplification to detect the presence of TEM and/or SHV genes using consensus gene sequences of both genes. Results were interpreted using specific melting curve peaks.
Results: Klebsiella pneumoniae was isolated from all sample categories. The isolation frequency was 11 Klebsiella pneumoniae strains of the 100 environmental samples, 7 of the 44 working personnel samples, 8 of the 45 blood culture samples, 20 of 39 lower respiratory samples, one of the 6 pyogenic samples, one of the 4 CSF samples, and two of the 11 urine samples. The overall isolation was 50 Klebsiella pneumoniae strains from 249 different samples. Of the 50 isolated Klebsiella pneumoniae strains, 33 (66%) were ESBL producers. The isolates that expressed only TEM were 6 (18.2%), and those that expressed only SHV were 13 (39.4%), and the producers of both TEM and SHV were 12 (36.4%), and the non TEM or SHV producers were 2 (6%).
Conclusion: The prevalence and transmissibility of ESBL among nosocomial Klebsiella pneumoniae are forming a great challenge in accurate diagnosis and management for clinicians and laboratory workers. The presence of TEM and SHV and occurrence of other antimicrobial resistance mechanisms together with ESBL confirm the cross resistance in nosocomial NICU Klebsiella pneumoniae and other Enterobacteriaceae as well. Multiplex PCR assay is recommended in tracing the nature and course of ESBL genotype propagation among common Gram negative bacilli in the environment and among hospital employees, especially in NICU. |
