Structure of Uncertain Nature

Anaplasma, Theiler, 1910
(Text-figure 1, Figs. 18–26)

Theiler (1910) established the genus Anaplasma for intraerythrocytic bodies which he considered to be the causal organisms of gall-sickness in African cattle. Anaplasma may occur either free in the plasma or within red cells. The bodies are of irregularly circular shape and range up to 2μ in diameter. With Giemsa they stain deeply and uniformly red and appear quite devoid of internal structure. Intraerythrocytic anaplasmata are usually marked off from the host cell cytoplasm by a lightly staining halo. Theiler considered Anaplasma to be a protozoon consisting entirely of chromatin, but its protozoan or even parasitic nature has yet to be demonstrated. A few years after the publication of Theiler's account of Anaplasma, similar bodies had been recorded from all the great vertebrate groups (Porter, 1915). It is difficult to differentiate between Anaplasma and Jolly bodies, if, indeed, there is any actual distinction between these structures. Jolly bodies are spherical, stain deep red with Giemsa, and have a similar size range to that of Anaplasma. They occur in the blood of young and anaemic animals, and, according to Wenyon (1926), are generally supposed to represent the remains of the nuclei of immature red cells. Wenyon suggested that Anaplasma may have the same origin as Jolly bodies, becoming associated with disease conditions in cattle as a secondary result of infection with some as yet unknown virus.

Gilruth (1909) recorded structures free in the plasma and within the red cells of pigs in New Zealand. He subsequently (Gilruth et al., 1911) recognized these as Anaplasma. During the present survey Anaplasma-like bodies were seen in smears from a majority of the species of all classes of vertebrates examined. Bodies of this kind from grey opossums and cattle are described below.

Heart-blood smears of 71 specimens of the Australian grey opossum Trichosurus vulpecula, trapped in the Orongorongo ranges during April and May, 1947, were page 11 searched for haematozoa. No such parasites were found, but in every smear at least a few erythrocytes were found to contain Anaplasma-like bodies (Text-fig. 1, Fogs. 19 and 20). The bodies occur within the erythrocytes both singly and in diplococcus-like pairs, and are also found free in the plasma. They stain deeply and uniformly red with Giemsa, are often surrounded by a distinct halo, and range in diameter from 0.9μ to 1.8μ Most of the bodies occur at or near the margin of the host cell, thus resembling Anaplasma marginale Theiler, 1910, also the similar bodies described from Trichosurus vulpecula in Australia by Gilruth et al. (1911).

Bodies similar to the above in every respect were seen in the blood of 36 cows examined at the Wellington City Corporation Abattoirs during October, 1947 (Text-fig. 1, Figs. 25 and 26). In most cases only a few cells of each smear contain Anaplasma-like bodies, although in one preparation a considerable proportion of the erythrocytes are involved. Numerous cells of the latter smear show pronounced basophilic granulation (Text-fig. 1, Figs. 22–24) like that described by Johnston and Cleland (1909) from the blood of two cows suffering from endemic haematuria of vesicle origin. From 30 to 45 purplish staining granules of varying size (Plehn's bodies) occur in each corpuscle, the cells concerned being larger than normal erythrocytes and polychromatophilic like those studied by Johnston and Cleland.

These granules bear a marked resemblance to the bodies described as Grahamella by Brumpt (1911), from which, however, they differ in being of rounded shape, Grahamella usually appearing as short straight or curved rods. Red cells containing basophilic granules occur commonly in bone marrow, and those under discussion in all probability owe their appearance in the peripheral blood to an anaemic condition.

Table 1
A list of the mammals examined from which no haematozoa were recorded (an asterisk * denotes a non-indigenous species).

Systematic position	Common name	No. examined	Locality	Month and year
Phalangeridae *Trichosurus vulpecula (Kerr)	Grey opossum	71	Orongorongo	4–5/47
Macropodidae *Wallabia ualabatus (Lesson & Garnier)	Black-tailed wallaby	50	Waimate	7/47
Erinaceidae *Erinaceus europaeus Linnaeus	Hedgehog	6	Wellington	11/48
Leporidae *Oryctolagus cuniculus (Linnaeus)	Rabbit	48	Various North Island localities	47–49
Mustelidae *Putorius putorius (Linnaeus)	Polecat	1	Canterbury	7/47
*Mustela erminea Linnaeus Felidae	Stoat	1	Fiordland	2/49
*Felis domestica Brisson Otariidae	Cat	9	Wellington	6/48
Arctocephalus forsteri (Lesson)	Fur seal	2	Kapiti Island	8/47
			Wellington	5/48
Balaenopteridae Megaptera nodosa (Bonaterre) Cervidae	Humpback whale	15	Cook Strait	7–8/48–49
*Cervus elephas Linnaeus Bovidae	Red deer	8	Tararua Mtns	4/47
*Bos taurus Linnaeus	Cattle	36	Wellington	10/47
*Capra aegagrus Erxleben	Goat	7	Wellington	5/48
*Ovis aries Linnaeus	Sheep	137	Wellington	10/47