Peritonitis in type 2 diabetes mellitus due to Ochrobactrum anthropi complicating automated peritoneal dialysis

Genomics of Ochrobactrum pseudogrignonense (newly named Brucella pseudogrignonensis) reveals a new blaOXA subgroup

Ochrobactrum pseudogrignonense (newly named Brucella pseudogrignonensis) is an emerging pathogen in immunodeficient and immunocompetent patients. Most documented cases associated with Ochrobactrum are frequently catheter-related and exhibit wide-spectrum β-lactam resistance. Misidentification of this pathogen using commercial bacterial identification kits is common. We identified a case of O. pseudogrignonense infection associated with cholelithiasis. The O. pseudogrignonense genome was sequenced and reconstructed using a Nanopore and Illumina hybrid strategy. A novel blaOXA-919 divergent from existing OXA members was identified and subsequent analysis revealed its existence in all available O. pseudogrignonense genomes, which forms a new phylogenetic subgroup distinct from other OXA clusters. Further analysis demonstrated the presence of the novel blaOXA-919 in the chromosome of several other Ochrobactrum species. Our study indicated that Ochrobactrum chromosomes may be a reservoir of blaOXA-919 β-lactamases.

The Genus Ochrobactrum as Major Opportunistic Pathogens

Ochrobactrum species are non-enteric, Gram-negative organisms that are closely related to the genus Brucella. Since the designation of the genus in 1988, several distinct species have now been characterised and implicated as opportunistic pathogens in multiple outbreaks. Here, we examine the genus, its members, diagnostic tools used for identification, data from recent Ochrobactrum whole genome sequencing and the pathogenicity associated with reported Ochrobactrum infections. This review identified 128 instances of Ochrobactrum spp. infections that have been discussed in the literature. These findings indicate that infection review programs should consider investigation of possible Ochrobactrum spp. outbreaks if these bacteria are clinically isolated in more than one patient and that Ochrobactrum spp. are more important pathogens than previously thought.

Ochrobactrum Peritonitis: Case Report and Literature Review

End-stage kidney disease (ESKD) patients, including those on peritoneal dialysis (PD), are considered immunocompromised and at risk for opportunistic pathogens. Peritonitis is a major infectious PD complication with common causative pathogens, including gram-positive organisms such as coagulase-negative Staphylococcus species, Staphylococcus aureus more often than gram negative organisms. PD peritonitis is often secondary to suboptimal technique leading to contamination of the catheter site but can also be due to bacterial translocation from the bowel lumen or transient bacteremia after procedures; this makes identification of the causative organism crucial to optimal management of PD peritonitis. Ochrobactrum are glucose-non-fermentative, non-fastidious, motile gram-negative bacilli typically isolated in aqueous environments. Reported infections primarily occur in immunocompromised hosts with environmental exposure, including nosocomial contamination of fluids or indwelling catheters. We present only the seventh reported case of Ochrobactrum peritonitis in a 67-year-old PD patient secondary to poor technique, and review the literature for all prior cases. Although there have been no previous cases leading to bacteremia, three of the seven cases required removal of PD catheter.

An opportunistic pathogen in a peritoneal dialysis patient: Ochrobactrum anthropi

The authors report a case of chronic peritoneal dialysis-related peritonitis from Ochrobactrum anthropi. O. anthropi is an emerging pathogen in immunocompromised patients. O. anthropi-related peritonitis in peritoneal dialysis patients has rarely been reported. To the authors' knowledge, no pediatric case of O. anthropi peritonitis has been reported to date in the literature.