Enterobacter spp. infections complicating the course of HIV disease

Through a retrospective review of clinical and laboratory data of 2517 cons ecutive patients with HIV disease hospitalized since 1991, 13 patients were identified (0.52%), who suffered from a confirmed Enterobacter spp. infect ion (urinary tract disease in 7 cases, sepsis in 4 patients, and pneumonia in 2 cases). A severe immunodeficiency was recognized in all cases, as expr essed by a mean CD4+ lymphocyte count < 60 cells/muL, and frequently, a pri or diagnosis of AIDS. Bloodstream infection proved linked to a lower mean C D4+ cell count, a more frequent occurrence of leukopenia-neutropenia, and n osocomial origin of the infecting pathogen. Hospital-acquired Enterobacter sop. disease was more frequent than community-acquired, and was significant ly associated with leukopenia-neutropenia, and a diagnosis of AIDS. Antibio tic susceptibility assays showed a resistance rate to ampicillin and cephal othin involving > 90% of tested strains, and a higher (but varied) sensitiv ity to other beta -lactams, aminoglycosides, fluoroquinolones, and cotrimox azole. Adequate chemotherapy provided clinical and bacteriological success in all evaluated patients, in the absence of mortality or relapses. Only 34 episodes of HIV-associated Enterobacter spp. infection have been reported to date in 11 different literature studies. Our data point out that also En terobacter spp. organisms may have an appreciable pathogenic potential in p atients with HIV disease, especially in those with a low CD4+ lymphocyte co unt, leukopenia-neutropenia, who are hospitalized. Despite the unpredictabl e antibiotic susceptibility profile of these organisms, HIV-related Enterob acter spp. disease may be properly managed through rapid identification and timely and appropriate antimicrobial treatment.