The first case of Ochrobactrum intermedium bacteremia in a pediatric patient with malignant tumor

Abstract

Background Ochrobactrum spp. are non-fermenting, Gram-negative bacilli that are regarded as emerging human pathogens of low virulence that can cause infections. The first identified case of Ochrobactrum intermedium was reported in 1998 in a liver transplantation patient with liver abcess. There are no reports of infections in pediatric patients. Here, we report the first case of O. intermedium bacteremia in a pediatric patient. Case presentation A two and a half years old male was admitted with fever, chills and nausea. He had been diagnosed as pineoblastoma and underwent surgical resection and chemotherapy. O. intermedium was isolated from his blood cultures and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), however, the Vitek II automated system failed to identify the organism. Then the pathogen was confirmed by 16S rDNA sequencing and average nucleotide identity result (ANI) confirmed the precise identification of O. intermedium at genomic level. In addition, the patient recovered well after antibiotic combined therapy. Conclusions This, to our knowledge, is the first case of O. intermedium bacteremia in a pediatric patient with malignant tumor. Traditional biochemical identification methods such as API 20NE or VITEK2 system cannot differentiate O. anthropi and O. intermedium. MALDI-TOF may be a promising tool for rapid identification of microorganisms such as O. intermedium.

Ochrobactrum intermedium septicemia

“…Ochrobactrum species are resistant to all the betalactams except carbapenems due to presence of AmpC beta-lactamases. They are usually susceptible to aminoglycosides, trimethoprim-sulfamethoxazole, rifampicin, and fluoroquinolones [9,10,24]. The antibiotic sensitivity of our isolate was in concordance with the susceptibility pattern of the previously reported Ochrobactrum isolates from human infections, except that the aminoglycosides (amikacin and gentamicin) showed intermediate sensitivity [9,10,25].…”

“…They are usually susceptible to aminoglycosides, trimethoprim-sulfamethoxazole, rifampicin, and fluoroquinolones [9,10,24]. The antibiotic sensitivity of our isolate was in concordance with the susceptibility pattern of the previously reported Ochrobactrum isolates from human infections, except that the aminoglycosides (amikacin and gentamicin) showed intermediate sensitivity [9,10,25]. Ochrobactrum intermedium demonstrates resistance to a wide range of antibiotics (beta-lactams, aminoglycosides, colistin) compared to Ochrobactrum…”

“…O. anthropi and O. intermedium are most commonly associated with human infections among the Ochrobactrum species. O. intermedium has been associated with various human infections such as liver abscess, pelvic abscess, prostatic abscess, endophthalmitis, bacteremia, and infective endocarditis [9]. Ochrobactrum species are non-fastidious bacteria that produce indole and hydrolyse urea [10].…”

“…It is clinically significant to differentiate between species of Ochrobactrum as the rate of mortality and drug resistance differs among the species [10,12]. Our literature search on PubMed revealed only 6 cases of bacteremia caused by Ochrobactrum intermedium documented to date [9,[13][14][15][16]. Ochrobactrum species mainly cause indwelling device-associated nosocomial infections in the immunocompromised and are considered less virulent.…”

Pneumonia due to Ochrobactrum intermedium in an ICU patient

“…They are non-lactose-fermenting, Gram-negative environmental rods with low virulence that may act as opportunistic pathogens [ 2 ]. Reports of infections caused by O. intermedium are rare and commonly related to bacteremias in immunocompromised patients [ [3] , [4] , [5] ] whereas Ochrobactrum anthropi is more frequently encountered as an infectious agent [ 6 ]. Notably, O. intermedium is intrinsically resistant to penicillins, cefalosporins and colistin; therefore the use of colistin in our case for the treatment of Acinetobacter spp.…”