Volume 25, Number 5—May 2019
Rickettsiales in Ticks Removed from Outdoor Workers, Southwest Georgia and Northwest Florida, USA
|Tick species and stage||Months submitted||No. positive ticks/no. tested (%)
|E. chaffeensis||PME||Rickettsia spp.|
|Amblyomma americanum, adults||Feb–Sep||0/11 (0)||0/11 (0)||4/11 (36.4)||2 R. amblyommatis|
|A. americanum nymphs‡||Mar–Sep||0/43 (0)||0/43 (0)||12/43 (27.9)||9 R. amblyommatis|
|A. americanum larvae‡||Apr and Oct||0/5 (0)||0/5 (0)||1/5 (20.0)||1 R.amblyommatis|
|Amblyomma sp. nymphs||Jun and Oct||0/3 (0)||0/3 (0)||1/3 (33.3)||1 R. amblyommatis§|
|Amblyomma sp. larvae||Oct||0/5 (0)||0/5 (0)||0/5 (0)|
|A. maculatum adults||May–Oct||1/83 (1.2)||2/83 (2.4)¶||18/83 (21.7)||5 R. amblyommatis,§ 4 R. parkeri,§ 1 Rickettsia sp. TR-39/TX125, 2 Candidatus R. andeanae|
|A. tuberculatum nymphs‡||Apr||0/5 (0)||0/5 (0)||1/5 (5.0)||1 novel SFG Rickettsia sp.|
|A. tuberculatum larvae‡||Feb#||0/182 (0)||0/182 (0)||10/182 (5.5)**||10 novel SFG Rickettsia sp.**|
|Dermacentor variabilis adults||Jun–Aug||0/10 (0)||1/10 (10.0)||2/10 (20.0)||1 R. amblyommatis§|
|Ixodes scapularis adults||Oct–Mar||NT||0/15 (0)||7/15 (46.7)||4 Rickettsia sp. TR-39, 3 R. buchneri|
*All Rickettsia spp. were identified by sequencing unless otherwise noted. NT, not tested; PME, Panola Mountain Ehrlichia sp., SFG, spotted fever group.
†Rickettsia spp. for whom amplicons did not provide high-quality bidirectional sequences were categorized as unknown Rickettsia spp.
‡Minimum infection prevalence is no. positive tick pools/no. ticks tested.
§The following R. amblyommatis samples were identified by restriction fragment length polymorphism analysis: for 1 D. variabilis adult, 5 A. maculatum adults, and 1 Amblyomma sp. nymph; for A. americanum, 1 adult, 2 nymphs, and 1 larva. Three A. maculatum adults were also identified as containing R. parkeri positive by restriction fragment length polymorphism analysis.
¶Data included in Loftis et al. (5).
#Date was known only for 1 submission of 20 larvae. Dates for others were not provided when submitted.
**Data included in Zemtsova et al. (6).
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1Current affiliation: Hollins University, Roanoke, Virginia, USA.