Recurrent joint infection caused by a multidrug-resistant capnophilic Escherichia coli ST131 O25H4 strain.

We report a case of a native knee septic arthritis and subsequent osteomyelitis due to a CO2-dependent (capnophilic) multidrug-resistant E. coli ST131 O25:H4 strain. Capnophilic phenotype made microbiology investigation challenging; susceptibility testing could not be performed and the organism did not grow in the urine culture using standard method. The combination of unique virotype and capnophilia may have contributed to the aggressiveness of this organism and the initial unsuccessful carbapenem course, leading to recurrent infection.

Escherichia coli Meningitis in a 72-year-old Woman.

Spontaneous community-acquired meningitis caused by E. coli is rare in the adult population. It is associated with a high risk of morbidity and mortality. We describe a case of a 72-year-old woman who presented with altered mental status and neck stiffness and was found to have E. coli meningitis. Urine cultures grew E. coli, representing a likely source. The E. coli strain was identified as sequence type 73 (E. coli ST73). Her symptoms and laboratory values improved following antibiotic initiation, and she was discharged from the hospital to a rehabilitation facility.