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The Rickettsia, Wolbachia pipientis (gen. et sp.n.) and Associated Inclusions of the Mosquito, Culex pipiens

Published online by Cambridge University Press:  06 April 2009

Marshall Hertig
Affiliation:
Department of Comparative Pathology, Medical School and School of Public Health, Harvard University, Boston

Extract

The invariable presence of a rickettsia in the gonads of the mosquito, Culex pipiens, is confirmed. This rickettsia is found in the cytoplasm of every germ cell in both sexes at all stages of development from larva to adult. No other species of mosquito is known to be similarly infected.

The morphology of the organism shows the following features. In addition to “typical rickettsiae”, i.e. minute rods and coccoids which multiply by binary fission, there is a variety of other forms which are interpreted as a series of stages, usually in the following sequence: small coccoids become enlarged, and instead of dividing by binary or multiple fission, undergo a condensation of their stainable substance into points or rods which ultimately appear as various combinations of sharply curved rods and coccoids retained as in a matrix within the body of the original or “parent” coccoid. As the matrix disappears, they become the irregularly curved forms and compact aggregations of “daughter” forms characteristic of this rickettsia.

The pathological germ cells previously noted in the testis by cytologists were found to occur in both sexes at all stages, and to be apparently the result of infection with this rickettsia.

The problem of classifying the rickettsiae is discussed. The similarity of the rings and curved forms of various rickettsiae to corresponding forms, as yet little studied, in other groups of organisms is pointed out.

The name Wolbachia pipientis (gen. et sp.n.) is proposed for the rickettsia of Culex pipiens.

Large, homogeneous or granular cell inclusions with an affinity for neutral red, termed NR bodies, were found in the gonad wall of nearly every specimen of Culex pipiens, but were not found in C. territans. They resemble the inclusion bodies of certain viruses and at times closely simulate masses of rickettsiae, but are apparently distinct from the species here described. Their nature is unknown but their appearance and behaviour are consistent with their being living agents or the manifestations thereof. A degenerative process, in which NR bodies replace primary ovarian follicles in whole or in part, is described.

Inoculation and cultivation experiments resulted negatively for both rickettsiae and NR bodies.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1936

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References

REFERENCES

Aschner, M. (1931). Die Bakterienulora der Pupiparen (Diptera). Z. Morph. Ökol. Tiere, 20, 368442.CrossRefGoogle Scholar
Bedson, S. P. (1933). Observations of the developmental forms of psittacosis virus. Brit. J. exp. Path. 14, 267–77.Google Scholar
Bedson, S. P. & Bland, J. O. W. (1934). The developmental forms of psittacosis virus. Brit. J. exp. Path. 15, 243–7.Google Scholar
Cholodkovsky, N. (1905). Über den Bau des Dipterenhodens. Z. wiss. Zool. 82, 389410.Google Scholar
Coles, J. D. W. A. (1931). A rickettsia-like organism in the conjunctiva of sheep. 17th Report Dir. Vet. Serv. and An. Ind., Onderstepoort, pp. 175–86.Google Scholar
Coles, J. D. W. A. (1931 a). An unknown intracellular organism of the conjunctival epithelium of sheep. Preliminary report. Z. wiss. Zool. pp. 187–9.Google Scholar
Coles, J. D. W. A. (1935). A rickettsia-like organism and an unknown intracellular organism of the conjunctival epithelium of goats. Onderstepoort J. Vet. Sci. 4, 389–95.Google Scholar
Cowdry, E. V. (1923). The distribution of rickettsia in the tissues of insects and arachnids. J. exp. Med. 37, 431–56.CrossRefGoogle ScholarPubMed
Cowdry, E. V. (1925). Studies on the etiology of heartwater. I and II. J. exp. Med. 42, 231–52, 253–74.CrossRefGoogle Scholar
Glaser, R. W. (1930). On the isolation, cultivation and classification of the so-called intracellular “symbionts” or “rickettsia” of Periplaneta americana. J. exp. Med. 51, 5982.CrossRefGoogle ScholarPubMed
Glaser, R. W. (1930 a). Cultivation and classification of “bacteroides”, “symbionts”, or “rickett siae” of Blatella germanica. J. exp. Med. 51, 903–7.CrossRefGoogle Scholar
Heimann, H. Über den Eintritt der Geschlechtsdifferenzierung bei den Larven von Culex pipiens L. Inaug. Diss., Zool. Inst. Münster i. W. (cited by Lomen, 1914).Google Scholar
Hertig, M. & Wolbach, S. B. (1924). Studies on rickettsia-like microorganisms in insects. J. med. Res. 10, 329–74.Google Scholar
Jackson, C. (1931). The microscopic diagnosis of heartwater: A preliminary note on the value of intima smears. 17th Report Dir. Vet. Serv. and An. Ind., Onderstepoort, pp. 161–73.Google Scholar
Kligler, I. J. & Aschner, M. (1931). Cultivation of rickettsia-like micro-organisms from certain blood-sucking Pupipara. J Bact. 22, 103115.CrossRefGoogle Scholar
Lomen, F. (1914). Der Hoden von Culex pipiens L. (Spermatogenese, Hodenwandungen und Degenerationen.) Jena. Z. Naturwiss. 52, 567628.Google Scholar
Neitz, W. O., Alexander, R. A. & du Toit, P. J. (1934). Eperythrozoön ovis (sp. nov.) infection in sheep. Onderstepoort J. Vet. Sci. 3, 263–71.Google Scholar
Nicholson, A. J. (1921). The development of the ovary and ovarian egg of a mosquito, Anopheles maculipennis. Quart. J. micr. Sci. 65, 395448.Google Scholar
Pfeiffer, H. (1931). Beiträge zu der Bakteriensymbiose der Bettwanzes (Cimex lectularius) und der Schwalbenwanzes (Oeciacus hirundinis). Zbl. Bakt. i. Abt. Orig. 123, 151–71.Google Scholar
Pinkerton, H. & Hass, G. M. (1932). Intranuclear rickettsiae in spotted fever studied in tissue culture. J. exp. Med. 56, 151–6.CrossRefGoogle ScholarPubMed
da Rocha Lima, H. (1930). Rickettsien. In Kolle, Kraus und Uhienhuth, Handbuch dee pathogenen Mikroorganismen. Berlin, 3rd edition. Chapter 25, 8, 2, 1347–86.Google Scholar
Schaudinn, F. (1904). Generations- und Wirtswechsel bei Trypanosoma und Spirochäte. Arb. Gesund Amt., Berl., 20, 387.Google Scholar
Whiting, P. W. (1917). The chromosomes of the common house mosquito, Culex pipiens L. J. Morph. 28, 523–78.CrossRefGoogle Scholar