SHORT COMMUNICATION
Occurrence of Ixodes pacificus (Parasitiformes: Ixodidae) in Arizona CARL A. OLSON, EDDIE W. CUPP, SHIRLEY LUCKHART,1 JOSE M. C. RIBEIRO, AND CRAIG LEVY2 Department of Entomology, University of Arizona, Tucson, AZ 85721
J. Med. Entomol. 29(6): 1060-1062 (1992)
ABSTRACT Adults and immatures of Ixodes pacificus Cooley & Kohls were collected by flagging vegetation and from lizards during a 3-mo period in the Hualapai Mountain Park, Mohave County, AZ, in 1991. Collections were made at altitudes ^2,134 m. Two of 48 gut—salivary gland extracts of adult ticks were positive by IFA using a monoclonal antibody (H5332) specific to Borrelia burgdorferi. These are the first records of /. pacificus and of spirochetes tentatively identified as B. burgdorferi in Arizona.
Ixodes pacificus Cooley & Kohls occurs commonly throughout California and southwestern Oregon (Furman & Loomis 1984). This tick has also been collected as far north as British Columbia and eastward into Idaho, Nevada, and Utah (Arthur & Snow 1968). /. pacificus is a threehost tick with larvae and nymphs found on lizards, small mammals, and birds; the adults normally occur on medium- to large-sized mammals. Some of the more common hosts include Sceloporus occidentalis Baird & Girard (western fence lizard), Gerrhonotus spp. (alligator lizards), Lepus californicus (black-tailed jackrabbit), Odocoileus hemionus columbianus (Richardson) (Columbian black-tailed deer), Peromyscus maniculatus (Wagner) (deer mouse), and P. truei (Shufeldt) (pinyon mouse). Many avian species, especially ground-foraging birds, may also be parasitized by this tick (Manweiler et al. 1990). Because of its broad host range, /. pacificus is a suspected or confirmed vector of several pathogens, including Francisella tularensis, a rickettsia in the spotted fever group, and Borrelia burgdorferi, the causative agent of Lyme disease. /. pacificus also may cause an ascending flaccid motor paralysis ("tick paralysis") during feeding (Cupp 1991). We report here for the first time the occurrence of I. pacificus in Arizona and note several geobotanic features of the area from which this tick was collected. Based on preliminary immunolog-
1 Current address: Department of Entomology, Rutgers University, New Brunswick, NJ 08903. 2 Division of Disease Prevention, Arizona Department of Health Services, Phoenix, AZ 85012.
ical screening, we also detected putative B. burgdorferi infections in two adult ticks. Collections On 10 February 1991, two /. pacificus adults were collected by two hikers from their legs after painful bites alerted them to the presence of these ticks. The incident occurred on the Aspen Peak trail in the Hualapai Mountain County Park south of Kingman, Mohave County, AZ, at an altitude of —2,195 m. Temperatures on the date of collection were unseasonably warm (^15.5°C), and the trail and vegetation along its margin were free of snow. On 17-19 April 1991, an examination of the trail area was made, resulting in the collection of 65 adult /. pacificus from along the south-facing slopes in a scrub oak zone. The altitude in this area of the park was —2,345 m. Adult ticks were swept from the dry grass understory along the edges of the trail. The temperature during the second collection was =ss14°C. Two subsequent trips to the area in May and June also resulted in collection of both adults and immatures in other locations. In May, seven adult ticks were collected from Symphoricarpos sp. (snowberry) and Lupinus sp. (lupine) in a narrow glen located at >2,345m (Fig. 1) near Flag Mine, outside the county park. Interestingly, three adults were also found questing along a deer trail which was located on a hillside above the mine in a more open and sparsely vegetated zone. In this case, ticks were collected from the leaves oiGarrya wrightii Torr., (coffeeberry bush). In early June, immatures (n = 27) were collected from noosed fence lizards, Sceloporus undulatus and adults (n = 9) were taken
0022-2585/92/1060-1062$02.00/0 © 1992 Entomological Society of America
Downloaded from http://jme.oxfordjournals.org/ by guest on June 8, 2016
KEY WORDS Ixodes pacificus, Borrelia burgdorferi, Lyme disease
November 1992
OLSON ET AL.: OCCURRENCE OF
/. pacificus
IN ARIZONA
1061
washed with PBS for 10 min in the dark at room temperature. Coverslips were mounted on each extract with a drop of 9:1 glycerol-PBS and viewed with a fluorescent microscope. Of the 48 dissections examined, two were strongly positive by IFA, indicating a minimal adult tick infection rate of 4% along the Aspen Peak trail.
Discussion
Downloaded from http://jme.oxfordjournals.org/ by guest on June 8, 2016
This is the first record of 7. pacificus in Arizona. Heretofore, the closest locations from which this tick had been collected included southern Utah (Allred et al. 1960; Beck et al. 1963) and eastern California (Furman & Loomis 1984). However, given the type of upland habitat seen in Hualapai Mountain Park, it is not surprising that this tick species occurs in this setting in Arizona. Further, the park has had several recent faunal surveys, and the common hosts noted earlier are currently found in the general vicinity of the tick collection sites, thus providing the necessary trophic elements for maintenance of an 7. pacificus population. Throughout its range in California, 7. pacificus has been collected at elevations ranging from sea level to =2,150 m (Furman & Loomis 1984). Thus the occurrence of this tick at ^2,345 m is not unusual. The infection rate of the single field-collected Fig. 1. Vegetation (Symphoricarpos sp., Lupinus sp.) in an emphemeral stream near Flag Mine from sample (4%) is within the range of those reported for 7. pacificus in northern California (Lane & which /. pacificus adults were collected. Pascocello 1989). However, more survey work is required before the ecology of 7. pacificus-B. along the hiking trail in the park where the orig- burgdorferi in Arizona can be validly compared inal collections had been made in February. with other locations in the western United States in which both tick and pathogen occur. Identification of B. burgdorferi was based on the use of a monoclonal antibody (H5332) that is Microbiological Findings presumably specific for this spirochete. HowFollowing the collection of adult ticks in April, ever, it has been suggested that there may be the gut and salivary gland tissues of 48 speci- variants of B. burgdorferi or closely related Bormens were examined by immunofluorescence relia species that share epitopes on the outer for B. burgdorferi using a monoclonal antibody surface (Osp A protein) that are cross-reactive in (H5332) that recognizes a 31-kDa outer surface immunofluorescent assays (Lane & Pascocello protein of this spirochete (Barbour et al. 1983). 1989). Thus, field isolations from ticks with subTicks were surface-sterilized in 3% hydrogen sequent confirmation by the polymerase chain peroxide for 3 min, rinsed in 70% ethanol and reaction (Malloy et al. 1990) would add signifi0.01M phosphate-buffered saline (PBS) (pH 7.1- cantly to these findings. 7.2), and dissected in a drop of PBS on glass The means by which this tick and pathogen slides. The gut-salivary gland preparations were have found their way to northwestern Arizona air-dried, fixed with cold acetone (4°C), and are unknown. Several possibilities exist, includstored at —20°C until examination by indirect ing transport by migrating birds or movement of tick-infested pets (particularly dogs) into the immunofluorescence. A 1:10 dilution of mouse monoclonal antibody park from endemic areas. Regardless of how in(H5332) was used, with each slide containing troduction occurred, it is obvious that the 7. pacitick extracts overlaid with 100 fi\. Slides were ficus population is resident in the park because incubated for 35 min at 37°C, then washed twice all stages were collected, and collecting sites varwith PBS at room temperature. Each slide was ied geographically and encompassed several disthen flooded with 100 fx\ of a 1:80 dilution of tinct habitats. The types of plants and hosts from fluorescein isothiocyanate antimouse sera in PBS which ticks were collected are relatively com(100 fx\), incubated at 37°C for 35 min, then mon in several mountainous areas of Arizona,
1062
JOURNAL OF MEDICAL ENTOMOLOGY
suggesting that this species may be more widespread in the state. Acknowledgments We thank M. S. Cupp and F. R. Ramberg (University of Arizona) for their assistance in preparing the tick gut-salivary gland dissections, J. C. Wright (Auburn University) for providing serological reagents, and M. Halter (University of Arizona) for supervision of the immunoflourescence assays. We also thank R. S. Lane (University of California-Berkeley) for confirming the identification of the original tick specimens and Rebecca Vandevender (University of Arizona) for identification of the plants from the Hualapai Mountains. This investigation received partial support from Hatch project ARZT-136325-H-31-018.
chetes share a common surface antigenic determinant defined by a monoclonal antibody. Inf. Immun. 41: 795-804. Beck, D. E., D. M. Allred & E. P. Brinton. 1963. Ticks of the Nevada test site. Brigham Young Univ. Sci. Bull., Biol. Ser. 4: 1-11. Cupp, E. W. 1991. Biology of ticks, pp. 1-26. In J. F. Hoskins [ed.], The veterinary clinics of North America. Small Animal Practice 21(1). Saunders, Philadelphia. Furman, D. P. & E. C. Loomis. 1984. The ticks of California (Acari: Ixodida). Bull. Calif. Insect Surv. 25: 1-239. Lane, R. S. & J. A. Pascocello. 1989. Antigenic characteristics of Borrelia burgdorferi isolates from ixodid ticks in California. J. Clin. Microbiol. 27: 2344-2349. Malloy, D. C , R. K. Nauman & H. Paxton. 1990. Detection of Borrelia burgdorferi using the polymerase chain reaction. J. Clin. Microbiol. 28: 10891093. Manweiler, S. A., R. S. Lane, W. M. Black & M. L. Morrison. 1990. Survey of birds and lizards for ixodid ticks (Acari) and spirochetal infection in northern California. J. Med. Entomol. 27: 10111015. Received for publication 30 December 1991; accepted 6 July 1992.
Downloaded from http://jme.oxfordjournals.org/ by guest on June 8, 2016
References Cited Allred, D. M., D. E. Beck & L. D. White. 1960. Ticks of the genus Ixodes in Utah. Brigham Young Univ. Sci. Bull., Biol. Ser. 1: 1-42. Arthur, D. R. & K. Snow. 1968. Ixodes pacificus Cooley and Kohls, 1943: its life history and occurrence. Parasitology 58: 893-906. Barbour, A. G., S. L. Tessier & W. J. Todd. 1983. Lyme disease spirochetes and ixodid tick spiro-
Vol. 29, no. 6
Occurrence of Ixodes pacificus (Parasitiformes: Ixodidae) in Arizona CARL A. OLSON, EDDIE W. CUPP, SHIRLEY LUCKHART,1 JOSE M. C. RIBEIRO, AND CRAIG LEVY2 Department of Entomology, University of Arizona, Tucson, AZ 85721
J. Med. Entomol. 29(6): 1060-1062 (1992)
ABSTRACT Adults and immatures of Ixodes pacificus Cooley & Kohls were collected by flagging vegetation and from lizards during a 3-mo period in the Hualapai Mountain Park, Mohave County, AZ, in 1991. Collections were made at altitudes ^2,134 m. Two of 48 gut—salivary gland extracts of adult ticks were positive by IFA using a monoclonal antibody (H5332) specific to Borrelia burgdorferi. These are the first records of /. pacificus and of spirochetes tentatively identified as B. burgdorferi in Arizona.
Ixodes pacificus Cooley & Kohls occurs commonly throughout California and southwestern Oregon (Furman & Loomis 1984). This tick has also been collected as far north as British Columbia and eastward into Idaho, Nevada, and Utah (Arthur & Snow 1968). /. pacificus is a threehost tick with larvae and nymphs found on lizards, small mammals, and birds; the adults normally occur on medium- to large-sized mammals. Some of the more common hosts include Sceloporus occidentalis Baird & Girard (western fence lizard), Gerrhonotus spp. (alligator lizards), Lepus californicus (black-tailed jackrabbit), Odocoileus hemionus columbianus (Richardson) (Columbian black-tailed deer), Peromyscus maniculatus (Wagner) (deer mouse), and P. truei (Shufeldt) (pinyon mouse). Many avian species, especially ground-foraging birds, may also be parasitized by this tick (Manweiler et al. 1990). Because of its broad host range, /. pacificus is a suspected or confirmed vector of several pathogens, including Francisella tularensis, a rickettsia in the spotted fever group, and Borrelia burgdorferi, the causative agent of Lyme disease. /. pacificus also may cause an ascending flaccid motor paralysis ("tick paralysis") during feeding (Cupp 1991). We report here for the first time the occurrence of I. pacificus in Arizona and note several geobotanic features of the area from which this tick was collected. Based on preliminary immunolog-
1 Current address: Department of Entomology, Rutgers University, New Brunswick, NJ 08903. 2 Division of Disease Prevention, Arizona Department of Health Services, Phoenix, AZ 85012.
ical screening, we also detected putative B. burgdorferi infections in two adult ticks. Collections On 10 February 1991, two /. pacificus adults were collected by two hikers from their legs after painful bites alerted them to the presence of these ticks. The incident occurred on the Aspen Peak trail in the Hualapai Mountain County Park south of Kingman, Mohave County, AZ, at an altitude of —2,195 m. Temperatures on the date of collection were unseasonably warm (^15.5°C), and the trail and vegetation along its margin were free of snow. On 17-19 April 1991, an examination of the trail area was made, resulting in the collection of 65 adult /. pacificus from along the south-facing slopes in a scrub oak zone. The altitude in this area of the park was —2,345 m. Adult ticks were swept from the dry grass understory along the edges of the trail. The temperature during the second collection was =ss14°C. Two subsequent trips to the area in May and June also resulted in collection of both adults and immatures in other locations. In May, seven adult ticks were collected from Symphoricarpos sp. (snowberry) and Lupinus sp. (lupine) in a narrow glen located at >2,345m (Fig. 1) near Flag Mine, outside the county park. Interestingly, three adults were also found questing along a deer trail which was located on a hillside above the mine in a more open and sparsely vegetated zone. In this case, ticks were collected from the leaves oiGarrya wrightii Torr., (coffeeberry bush). In early June, immatures (n = 27) were collected from noosed fence lizards, Sceloporus undulatus and adults (n = 9) were taken
0022-2585/92/1060-1062$02.00/0 © 1992 Entomological Society of America
Downloaded from http://jme.oxfordjournals.org/ by guest on June 8, 2016
KEY WORDS Ixodes pacificus, Borrelia burgdorferi, Lyme disease
November 1992
OLSON ET AL.: OCCURRENCE OF
/. pacificus
IN ARIZONA
1061
washed with PBS for 10 min in the dark at room temperature. Coverslips were mounted on each extract with a drop of 9:1 glycerol-PBS and viewed with a fluorescent microscope. Of the 48 dissections examined, two were strongly positive by IFA, indicating a minimal adult tick infection rate of 4% along the Aspen Peak trail.
Discussion
Downloaded from http://jme.oxfordjournals.org/ by guest on June 8, 2016
This is the first record of 7. pacificus in Arizona. Heretofore, the closest locations from which this tick had been collected included southern Utah (Allred et al. 1960; Beck et al. 1963) and eastern California (Furman & Loomis 1984). However, given the type of upland habitat seen in Hualapai Mountain Park, it is not surprising that this tick species occurs in this setting in Arizona. Further, the park has had several recent faunal surveys, and the common hosts noted earlier are currently found in the general vicinity of the tick collection sites, thus providing the necessary trophic elements for maintenance of an 7. pacificus population. Throughout its range in California, 7. pacificus has been collected at elevations ranging from sea level to =2,150 m (Furman & Loomis 1984). Thus the occurrence of this tick at ^2,345 m is not unusual. The infection rate of the single field-collected Fig. 1. Vegetation (Symphoricarpos sp., Lupinus sp.) in an emphemeral stream near Flag Mine from sample (4%) is within the range of those reported for 7. pacificus in northern California (Lane & which /. pacificus adults were collected. Pascocello 1989). However, more survey work is required before the ecology of 7. pacificus-B. along the hiking trail in the park where the orig- burgdorferi in Arizona can be validly compared inal collections had been made in February. with other locations in the western United States in which both tick and pathogen occur. Identification of B. burgdorferi was based on the use of a monoclonal antibody (H5332) that is Microbiological Findings presumably specific for this spirochete. HowFollowing the collection of adult ticks in April, ever, it has been suggested that there may be the gut and salivary gland tissues of 48 speci- variants of B. burgdorferi or closely related Bormens were examined by immunofluorescence relia species that share epitopes on the outer for B. burgdorferi using a monoclonal antibody surface (Osp A protein) that are cross-reactive in (H5332) that recognizes a 31-kDa outer surface immunofluorescent assays (Lane & Pascocello protein of this spirochete (Barbour et al. 1983). 1989). Thus, field isolations from ticks with subTicks were surface-sterilized in 3% hydrogen sequent confirmation by the polymerase chain peroxide for 3 min, rinsed in 70% ethanol and reaction (Malloy et al. 1990) would add signifi0.01M phosphate-buffered saline (PBS) (pH 7.1- cantly to these findings. 7.2), and dissected in a drop of PBS on glass The means by which this tick and pathogen slides. The gut-salivary gland preparations were have found their way to northwestern Arizona air-dried, fixed with cold acetone (4°C), and are unknown. Several possibilities exist, includstored at —20°C until examination by indirect ing transport by migrating birds or movement of tick-infested pets (particularly dogs) into the immunofluorescence. A 1:10 dilution of mouse monoclonal antibody park from endemic areas. Regardless of how in(H5332) was used, with each slide containing troduction occurred, it is obvious that the 7. pacitick extracts overlaid with 100 fi\. Slides were ficus population is resident in the park because incubated for 35 min at 37°C, then washed twice all stages were collected, and collecting sites varwith PBS at room temperature. Each slide was ied geographically and encompassed several disthen flooded with 100 fx\ of a 1:80 dilution of tinct habitats. The types of plants and hosts from fluorescein isothiocyanate antimouse sera in PBS which ticks were collected are relatively com(100 fx\), incubated at 37°C for 35 min, then mon in several mountainous areas of Arizona,
1062
JOURNAL OF MEDICAL ENTOMOLOGY
suggesting that this species may be more widespread in the state. Acknowledgments We thank M. S. Cupp and F. R. Ramberg (University of Arizona) for their assistance in preparing the tick gut-salivary gland dissections, J. C. Wright (Auburn University) for providing serological reagents, and M. Halter (University of Arizona) for supervision of the immunoflourescence assays. We also thank R. S. Lane (University of California-Berkeley) for confirming the identification of the original tick specimens and Rebecca Vandevender (University of Arizona) for identification of the plants from the Hualapai Mountains. This investigation received partial support from Hatch project ARZT-136325-H-31-018.
chetes share a common surface antigenic determinant defined by a monoclonal antibody. Inf. Immun. 41: 795-804. Beck, D. E., D. M. Allred & E. P. Brinton. 1963. Ticks of the Nevada test site. Brigham Young Univ. Sci. Bull., Biol. Ser. 4: 1-11. Cupp, E. W. 1991. Biology of ticks, pp. 1-26. In J. F. Hoskins [ed.], The veterinary clinics of North America. Small Animal Practice 21(1). Saunders, Philadelphia. Furman, D. P. & E. C. Loomis. 1984. The ticks of California (Acari: Ixodida). Bull. Calif. Insect Surv. 25: 1-239. Lane, R. S. & J. A. Pascocello. 1989. Antigenic characteristics of Borrelia burgdorferi isolates from ixodid ticks in California. J. Clin. Microbiol. 27: 2344-2349. Malloy, D. C , R. K. Nauman & H. Paxton. 1990. Detection of Borrelia burgdorferi using the polymerase chain reaction. J. Clin. Microbiol. 28: 10891093. Manweiler, S. A., R. S. Lane, W. M. Black & M. L. Morrison. 1990. Survey of birds and lizards for ixodid ticks (Acari) and spirochetal infection in northern California. J. Med. Entomol. 27: 10111015. Received for publication 30 December 1991; accepted 6 July 1992.
Downloaded from http://jme.oxfordjournals.org/ by guest on June 8, 2016
References Cited Allred, D. M., D. E. Beck & L. D. White. 1960. Ticks of the genus Ixodes in Utah. Brigham Young Univ. Sci. Bull., Biol. Ser. 1: 1-42. Arthur, D. R. & K. Snow. 1968. Ixodes pacificus Cooley and Kohls, 1943: its life history and occurrence. Parasitology 58: 893-906. Barbour, A. G., S. L. Tessier & W. J. Todd. 1983. Lyme disease spirochetes and ixodid tick spiro-
Vol. 29, no. 6
