Isolation and characterization of raoultella ornithinolytica from clinical specimens in hilla city

Abstract EN

A total of 720 clinical samples were collected from three main hospitals in Hilla city / Babylon province.

Samples were screened for the presence of Raoultella spp., as well as studying their expression of virulence factors.

A total of 144 bacterial isolates were recovered and identified as Klebsiella-like organisms.

Out of these, 11 isolates were identified as Raoultella ornithinolytica, which represent 7.6% of all Klebsiella-like organisms found.

Many virulence factors expressed by R.

ornithinolytica were studied in vitro.

All isolates produced capsule and expressed CFA / I, and CFA / III.

Nine isolates (81.8%) were able to produce siderophores.

Four isolates (36.6%) were able to produce bacteriocin.

All R.

ornithinolytica isolates were unable to produce extracellular protease, hemolysin, and histamine.

All isolates of R.

ornithinolytica were resistant to penicillin, ampicillin, gentamicin, chloramphenicol, rifampin, cephalothin, cephotaxime, streptomycin, amoxicillin.

But they showed high sensitivity to nitrofurantoin and ciprofloxacin, and all them were completely sensitive to meropenem.

R.

ornithinolytica expressed a high degree of sensitivity to the effect of human serum when they grew in human serum at 37 oC for 3 hrs.

The present study represented the first record of occurrence of R.

ornithinolytica in human clinical samples in Iraq.