Discussion:
R. planticola is an aerobic, gram-negative rod predominantly found in
water and soil. It was previously known as Klebsiella planticola but in
2001, it was later reclassified in the new genus of Raoultella, partly
due to its histamine-producing properties. R. planticola is generally
innocuous and rarely causes infection in humans. (4) The first reported
infection was in 1986, but there has been an increasing number of
associated reports since the year 2000. (5) The incidence of R.
planticola infection might have previously been underestimated due to
the difficulty in isolating the bacterium and confusion with other
bacteria, including Klebsiella spp.
R planticola has been a cause for pneumonia, urinary tract infection,
cholangitis, conjunctivitis, peritonitis, necrotizing fasciitis,
bacteraemia, cellulitis, and soft tissue infection in both adult and
paediatric populations. Shotaro Yamamoto et al., found 34 cases of R.
planticola bacteraemia in their review of the literature in 2018.
According to their findings, 70.6% patients with R planticola infection
had a malignancy. Haematological malignancies and biliary tract
neoplasms comprised of 29.2%, pancreatic neoplasms were 16.7%, and
others were 25.0%. They opined that the immunocompromised state either
due to malignancy itself or with the associated chemotherapy appeared to
be associated with the development of R. planticola bacteraemia. (6)
R. planticola is sensitive to a wide range of antibiotics except
Ampicillin. However, a few articles have suggested that the bacteria
develop antibiotic resistance especially with the Carbapenems which have
led to severe infections. (7, 8) The mechanism of its pathogenesis
remains unclear in humans given the limited data availability.
Immunocompromised state, proton pump inhibitor use, and chemotherapy
increase the chances of infection. (9) R planticola infection can occur
when poorly cooked sea food has been consumed in a large quality and has
affected various human organs, with no inclination towards a particular
organ system. (10)