A Salmonella enterica Serovar Oranienburg Clone Caused a Cluster of Bacteremia Cases in Persons With No Recognizable Underlying Diseases in Japan.

Background: Salmonella enterica subspecies enterica serovar Oranienburg (SO) is a foodborne pathogen but rarely causes systemic infections such as bacteremia. Between July and September 2018, bacteremia cases caused by SO were identified in 12 persons without any underlying medical conditions in the southern Kyushu area of Japan. Methods: Randomly amplified polymorphic DNA (RAPD) analysis was performed to investigate the genetic similarity of the 12 bacteremia-related strains and other Japanese isolates. Furthermore, a series of whole-genome sequence (WGS)-based phylogenetic analyses was performed with a global SO strain set (n = 1648). Results: The resolution power of RAPD was insufficient to investigate the genetic similarity between the bacteremia-related strains and other strains. WGS-based phylogenetic analyses revealed that the bacteremia-related strains formed a tight cluster along with 2 strains isolated from asymptomatic carriers in 2018 in the same area, with a maximum within-cluster single-nucleotide polymorphism (SNP) distance of 11. While several strains isolated in the United States and the United Kingdom were found to be closely related to the bacteremia-related strains, 2 strains isolated in 2016 in the southern Kyushu area were most closely related, with SNP distances of 4-11 and 5-10, and had the same plasmids as the bacteremia-related strains. Conclusions: The 12 bacteremia cases identified were caused by a single SO clone. As none of the bacteremia patients had any underlying diseases, this clone may be prone to cause bacteremia. Although further analyses are required to understand its virulence, particular attention should be given to this clone and its close relatives in the surveillance of nontyphoidal salmonellae.

Rapidly progressive Guillain-Barré syndrome following Escherichia coli infection.

Guillain-Barré Syndrome (GBS) is a prototype of post-infectious autoimmune disease. A 76-year-old woman was treated for a renal abscess and developed muscle weakness in all four extremities, 18 days after the onset of infection. She was diagnosed with GBS on the basis of acute flaccid paralysis, hyporeflexia, nerve conduction studies (reduced amplitude of compound muscle action potentials), and high titers of IgG antibodies to GM1 and GalNAc-GD1a. GBS rarely occurs after sepsis and this case represents the first report of rapidly progressive GBS following Escherichia coli urosepsis.

[A patient of ADEM with central and peripheral conduction block improved with ultra-high-dose methylprednisolone].

A patient with exanthem and fever showed progressive disturbance of consciousness and flaccid quadriplegia predominantly in the lower extremities. Antibiotics, aciclovir, high-dose methylprednisolone (1 g/day for 3 consecutive days) and IVIG (400 mg/kg/day for 5 consecutive days) were not effective. Nerve conduction study and SEP in the lower extremities showed peripheral and central conduction block. EEG showed irregular sharp and slow waves predominantly in the left hemisphere. ABR and SEP in the upper extremities were normal. Consecutive studies of cranial and spinal MRIs showed no abnormalities. A diagnosis of acute disseminated encephalomyelitis (ADEM) was made. We started administration of ultra-high-dose methylprednisolone (5.4 mg/kg/h for 47 hours), the dose for acute spinal cord injury based on the randomized controlled trial of The Third National Acute Spinal Cord Injury Study in the USA. After this, she regained consciousness and the quadriplegia improved. The abnormalities in the electrophysiological studies also normalized. It is thought that the neuroprotective mechanism of ultra-high-dose methylprednisolone could be attributed to its inhibition of lipid peroxidation, secondary, ischemia, energy failure and so on. If the usual treatment is not effective for severe encephalomyelitis cases, we can consider the administration of ultra-high-dose methylprednisolone as one of the new treatment options.