Karp
Karp. (ATCC VR-150) Rickettsiae were isolated from the blood of a wounded American soldier (surname Karp), who had been evacuated to the 42nd U.S. Hospital, Brisbane, Australia from the Buna-Guna region of New Guinea where he had been presumptively infected. The patient recovered and survived. Blood collected from the soldier was submitted to the Laboratory of Microbiology and Pathology, Queensland Health Dept. on 15 January 1943. The clot was inoculated intraperitoneally into a guinea pig (Plotz, 1946). At 10 days post inoculation the febrile guinea pig was sacrificed and liver-spleen-kidney emulsions were multiply passed. Rickettsiae appeared to become more virulent, killing about 50% of inoculated guinea pigs. The material also proved virulent in mice, killing them in 6 to 10 days and showing organisms upon staining of peritoneal fluid. The isolate was sent to Dr F.M. Burnet at the Walter and Eliza Hall Memorial Institute for Medical Research, Melbourne, Australia, passed again in guinea pigs, and tissues provided to CDR I.L.V.Norman, MC, U.S. Navy by Dr. Burnet for transport on dry ice to the U.S. On the second attempt frozen samples were received at the Naval Medical Research Institute, Bethesda MD U.S.A. on 17 August 1943 where the isolate was used in scrub typhus vaccine and immunological studies (Blake, 1945; Plotz, 1946; Derrick , 1949). Although it did not kill the soldier who was the index case, the Karp strain of Rickettsia tsutsugamushi (now Orientia tsutsugamushi) was implicated in the infection or death of several laboratory workers, including one at the Hall Institute (Lancet, 1943).
Note: As stated above, O. tsutsugamushi is very infectious but is highly temperature labile making it difficult to both transport and work with.
Bengston, IA, Apparent Serological Heterogeneity among Strains of Tsutsugamushi Disease (Scrub Typhus). Public Health Reports 1945; 60: 1483-1488.
Derrick EH, Brown HE. Isolation of the Karp strain of Rickettsia tsutsugamushi. Lancet. 1949; 257: 150-151.
Obituary for Dora Lush. The Lancet, 1973; 241 (Issue 6249): 726; 5 June 1943.
Plotz HH. (1946). “Preparation of an inactivated tissue culture scrub typhus vaccine. Proceedings of the Society for Experimental Biology and Medicine. 1946;61; 313.
Rights FL, Smadel JE, Jackson EB. Studies on scrub typhus (tsutsugamushi disease) III. Heterogeneity of strains of R. tsutsugamushi as demonstrated by cross-vaccination studies. J. Exp. Med. 1948;87: 339-351.