Multilocus sequence typing of Histoplasma capsulatum in formalin-fixed paraffin-embedded tissues from cats living in non-endemic regions reveals a new phylogenetic clade.
Infections caused by Histoplasma capsulatum are found most often in endemic regions of North, Central, and South America. H. capsulatum has been divided into eight geographic clades by multi-locus sequence typing (MLST). Recently, one isolate and five formalin-fixed paraffin-embedded (FFPE) tissue samples were received from six of 15 suspected cases of histoplasmosis in cats residing in areas not known to be endemic for H. capsulatum. Polymerase chain reaction (PCR) amplification and sequence analysis of the rDNA ITS-2 region confirmed the diagnosis of H. capsulatum. Since these cases were not, as noted, from the accepted endemic areas, it was of interest to understand the molecular epidemiology of these isolates. Results of molecular analysis indicated that the H. capsulatum recovered from the cats were most closely related to the North American-1 clade, but clustered separately outside this clade, suggesting that the H. capsulatum infecting the animals may represent a separate clade or phylogenetic species. This study also demonstrated the utility of obtaining valuable molecular subtype data directly from archived FFPE tissue blocks, particularly when a fungus culture was not performed or is otherwise unavailable.
Center For Global Health , Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
S
S
Arunmozhi Balajee
Steven F
SF
Hurst
Loretta S
LS
Chang
Macon
M
Miles
Emily
E
Beeler
Christa
C
Hale
Takao
T
Kasuga
Kaitlin
K
Benedict
Tom
T
Chiller
Mark D
MD
Lindsley
D000818:Animals; D001483:Base Sequence; D002371:Cat Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D002415:Cats; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005838:Genotype; D006658:Histoplasma / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D006660:Histoplasmosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing / Q000662:veterinary; D016533:Mycological Typing Techniques / Q000662:veterinary; D016612:Paraffin Embedding / Q000662:veterinary; D010802:Phylogeny; D017422:Sequence Analysis, DNA / Q000662:veterinary; D015206:Southwestern United States / Q000453:epidemiology
D017931:DNA Primers; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer