title: Genetic variation in Pneumocystis carinii isolates from different geographic regions: implications for transmission.
abstract: To study transmission patterns of Pneumocystis carinii pneumonia (PCP) in persons with AIDS, we evaluated P. carinii isolates from patients in five U.S. cities for variation at two independent genetic loci, the mitochondrial large subunit rRNA and dihydropteroate synthase. Fourteen unique multilocus genotypes were observed in 191 isolates that were examined at both loci. Mixed infections, accounting for 17.8% of cases, were associated with primary PCP. Genotype frequency distribution patterns varied by patients' place of diagnosis but not by place of birth. Genetic variation at the two loci suggests three probable characteristics of transmission: that most cases of PCP do not result from infections acquired early in life, that infections are actively acquired from a relatively common source (humans or the environment), and that humans, while not necessarily involved in direct infection of other humans, are nevertheless important in the transmission cycle of P. carinii f. sp. hominis.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia 30341-3724, USA. cbb0@cdc.gov
authors.forename: C B
authors.initials: CB
authors.lastname: Beard
authors.forename: J L
authors.initials: JL
authors.lastname: Carter
authors.forename: S P
authors.initials: SP
authors.lastname: Keely
authors.forename: L
authors.initials: L
authors.lastname: Huang
authors.forename: N J
authors.initials: NJ
authors.lastname: Pieniazek
authors.forename: I N
authors.initials: IN
authors.lastname: Moura
authors.forename: J M
authors.initials: JM
authors.lastname: Roberts
authors.forename: A W
authors.initials: AW
authors.lastname: Hightower
authors.forename: M S
authors.initials: MS
authors.lastname: Bens
authors.forename: A R
authors.initials: AR
authors.lastname: Freeman
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: J R
authors.initials: JR
authors.lastname: Stringer
authors.forename: J S
authors.initials: JS
authors.lastname: Duchin
authors.forename: C
authors.initials: C
authors.lastname: del Rio
authors.forename: D
authors.initials: D
authors.lastname: Rimland
authors.forename: R P
authors.initials: RP
authors.lastname: Baughman
authors.forename: D A
authors.initials: DA
authors.lastname: Levy
authors.forename: V J
authors.initials: VJ
authors.lastname: Dietz
authors.forename: P
authors.initials: P
authors.lastname: Simon
authors.forename: T R
authors.initials: TR
authors.lastname: Navin
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000382:microbiology*; D017931:DNA Primers; D004094:Dihydropteroate Synthase / Q000235:genetics; D005787:Gene Frequency; D020459:Genes, rRNA; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008928:Mitochondria / Q000235:genetics; D011010:Pneumocystis / Q000235:genetics* / Q000302:isolation & purification*; D011020:Pneumonia, Pneumocystis / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission*; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D014481:United States / Q000453:epidemiology
chemical_list: D017931:DNA Primers; D012335:RNA, Ribosomal; D004094:Dihydropteroate Synthase