title: Microbiological and clinical significance of a new property of defective lysis in clinical strains of pneumococci.
abstract: A pneumococcal isolate that caused relapsing meningitis in a patient infected with human immunodeficiency virus (HIV) was found to display an unusual response to penicillin--rapid death but a striking lack of cellular lysis. This lytic defect was also detected in all four pneumococcal isolates from three additional HIV-infected patients and in more than half of the clinical isolates from patients with bacteremia. In a rabbit model of meningitis, the lysis-defective strain remained cryptic, with a delay of 5 h in the onset of leukocytosis in cerebrospinal fluid. A marked burst of leukocytosis was associated with ampicillin-induced lysis of a lysis-sensitive strain but not of a lysis-defective strain. Pneumococcal clinical isolates have different lytic responses to penicillin; defective lysis may adversely affect the course of meningitis, an observation suggesting that autolysins play a role in modulating infectious diseases.
authors.affiliation: Rockefeller University, New York, New York 10021.
authors.forename: E
authors.initials: E
authors.lastname: Tuomanen
authors.forename: H
authors.initials: H
authors.lastname: Pollack
authors.forename: A
authors.initials: A
authors.lastname: Parkinson
authors.forename: M
authors.initials: M
authors.lastname: Davidson
authors.forename: R
authors.initials: R
authors.lastname: Facklam
authors.forename: R
authors.initials: R
authors.lastname: Rich
authors.forename: O
authors.initials: O
authors.lastname: Zak
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications; D000328:Adult; D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D001433:Bacteriolysis / Q000187:drug effects*; D006801:Humans; D008586:Meningitis, Pneumococcal / Q000134:cerebrospinal fluid / Q000150:complications / Q000382:microbiology*; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D011817:Rabbits; D018805:Sepsis / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D010406:Penicillins; D000667:Ampicillin