Cryptosporidium rubeyi, Li & Pereira & Larsen & Xiao & Phillips & Striby & McCowan & Atwill, 2015

Li, Xunde, Pereira, Maria das Graças Cabral, Larsen, Royce, Xiao, Chengling, Phillips, Ralph, Striby, Karl, McCowan, Brenda & Atwill, Edward R., 2015, Cryptosporidium rubeyi n. sp. (Apicomplexa: Cryptosporidiidae) in multiple Spermophilus ground squirrel species, International Journal for Parasitology: Parasites and Wildlife 4 (3), pp. 343-350 : 349

Family: Cryptosporidiidae .

Species: C. rubeyi n. sp.

Diagnosis: Oocysts are shed in feces fully sporulated. Oocysts measure 4.4 ‾ 5.0 M m (mean = 4.67) × 4.0 ‾ 5.0 M m (mean = 4.34) with a mean length/width index of 1.08 (n = 220). Prepatent period, patent period and endogenous stages are unknown.

Type host: California ground squirrel ( S. beecheyi )

Other hosts: Belding's ground squirrel ( S. beldingi ), Golden Mantled ground squirrel ( S. lateralis )

Type locality: California .

Materials deposited: Pending.

Etymology: This species name is derived from the nickname Rube which was given to the late father of Dr. Edward R. Atwill, School of Veterinary Medicine, University of California, Davis.

Earlier work has documented Cryptosporidium infections in a gray squirrel ( Sundberg and Ryan, 1982), fox squirrels ( Current, 1989), flying squirrels ( Current, 1989), and a 13-lined ground squirrel ( Current, 1989). Using “ Cryptosporidium ” and “squirrel” as key words during a recent literature search in PubMed conducted on January 13, 2015 resulted in only a few publications. C. parvum was reported in Eurasian red squirrels ( Sciurus vulgaris ) in Italy ( Bertolino et al., 2003); C. parvum was also reported in Siberian chipmunks ( Tamias sibiricus ) originated from China and found infectious to SCID mice and ICR mice ( Matsui et al., 2000); Cryptosporidium muris was reported in Siberian chipmunks ( Eutamias sibiricus ) imported from Southeast Asia to Czech Republic and found infectious to BALB/c mice (H̊urkováet al., 2003); Cryptosporidium ferret genotype and chipmunk genotype were reported in red squirrels ( Sciurus vulgaris L) in Italy and no detectable infection was found in CD1 mice and BALB/c mice after inoculation 1000

oocysts (Kv́ac et al., 2008). All these squirrel species belong to different genus other than Spermophilus . The only documentation of Cryptosporidium in Spermophilus genus besides ours was a report of C. parvum in spotted souslik ( Spermophilus suslicus ) in Poland ( Kloch and Bajer, 2012). S. suslicus is a different species with distinct geographic distributions compared to Spermophilus ground squirrels in California, USA. In contrast to these sporadic detections of Cryptosporidium in different species of squirrels, we have consistently detected the Cryptosporidium sp. c-genotype in Spermophilus ground squirrels from throughout California over the past decade ( Atwill et al., 2001, 2004; Pereira et al., 2010 present work).

Describing a novel species of Cryptosporidium requires four attributes to be satisfied: 1) genetic characterization; 2) morphometric studies of oocysts; 3) demonstration of natural and at least some experimental host specificity; and 4) compliance with International Commission on Zoological Nomenclature (ICZN) (Xiao et al., 2004; Fayer, 2010). Combining our current work and previous works ( Atwill et al., 2004; Pereira et al., 2010), we have satisfied the requirements of genetic and morphometric characteristics as well as host specificity studies similar in scope to other researchers who have established Cryptosporidium scrofarum (Kva ́̆c et al., 2013), Cryptosporidium viatorum ( Elwin et al., 2012) , Cryptosporidium xiaoi ( Fayer and Santín, 2009) , Cryptosporidium ryanae ( Fayer et al., 2008) , Cryptosporidium fayeri ( Ryan et al., 2008) , and Cryptosporidium bovis ( Fayer et al., 2005) . To comply with ICZN, we provide morphological description of c-genotype oocysts (see above) and present DIC photos of Sbey11c oocysts from S. beecheyi collected in 2011 ( Fig. 1 ).

Figures

Fig. 1. Cryptosporidium sp. Sbey11c oocysts from California ground squirrels (S. beecheyi). Differential interference contrast (DIC) microscopy (1000×), bar = 10 Mm.