Document Type : Review


1 School of medicine, Isfahan University of Medical Sciences, Isfahan 81744176, Iran.

2 Antimicrobial Resistance Research Center, Department of Medical Bacteriology and Virology, Qaem University Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.


The genus Raoultella is still understudied compared to other Enterobacteriaceae members. However, there are numerous published case reports on Raoultella infections. The genetic closeness of Raoultella spp. and Klebsiella spp. may lead to misidentification using conventional microbiology methods. The prevalence of this bacterium in clinical settings can vary geographically. Our knowledge of its resistome evolution contributing to Raoultella antibiotic resistance is also limited to a few characterized genes. This review summarises the current knowledge on Raoultella genetic and microbiology aspects, its identification methods, virulence factors, clinical manifestations, and so on. This combined information highlights the gaps in our understanding of Raoultella pathogenesis, resistome, and vaccine suggesting future research directions. The diversity and plasticity of the antibiotic resistance plane of Raoultella species have determined the early and precise identification of Raoultella infection is very important to improve the prognosis of the clinical infections and to control the spread of this bacterium. According to our literature review results, patients with multiple congenital abnormalities are susceptible to Raoultella infection. Tumours, immune deficiency, and invasive operations increase the risk of infection.