Aberrant Forms of Bacteria and Fungi Found in Blood or Cerebrospinal Fluid

Five patients with presumptive bacteremia or meningitis whose routine cultures were negative were found to harbor aberrant forms of bacteria or fungi. In each instance, organisms grew initially from blood, tissue, or spinal fluid specimens only in hypertonic salt or sucrose media. Upon reversion to the parent organism, two were found to beCorynebacteriumstrains; two, α-hemolytic streptococci; and one,Cryptococcus neoformans. In one instance, a coagulasenegativeStaphylococcus albuswas recovered in addition to αhemolytic streptococcus. In four of the five patients, serologic studies supported the bacteriologic findings. In two of the five, no antibiotic had been administered prior to isolation of the aberrant forms. Therapy directed against the aberrant form was beneficial in one patient, and the condition of two others improved following treatment directed against the parent strain or against both the parent and the transitional forms.