INFECTION AND IMMUNITY, June 1990, p. 2021-2023 0019-9567/90/062021-03$02.00/0 Copyright C) 1990, American Society for Microbiology

Vol. 58, No. 6

Variation in Virulence among Oculogenital Serovars of Chlamydia trachomatis in Experimental Genital Tract Infection JAMES

ITO, JR.,* JOSEPH M. LYONS, AND LUCY P. AIRO-BROWN Department of Infectious Diseases, City of Hope National Medical Center, Duarte, California 91010 I.

Received 18 December 1989/Accepted 27 March 1990

Seven different oculogenital serovars (D, E, F, G, H, I, and K) of Chlamydia trachomatis were inoculated intravaginally into CF-1 mice, and subsequent infection was monitored. The duration of infection was longest with serovars D and E. This may help to explain clinical surveys which demonstrate a high (50%) prevalence of these serovars. Furthermore, a comparison of the invasiveness of strains D and H demonstrated a much higher frequency of uterine horn infection with serovar D.

There are 15 known serotypes (serovars) of Chlamydia trachomatis. While types A, B, Ba, and C are primarily associated with ocular disease (endemic trachoma) and types L1, L2, and L3 are isolated predominantly from patients with lymphogranuloma venereum, types D, E, F, G, H, I, J, and K (oculogenital serovars) are primarily isolated from genital and neonatal infections (8). Although lymphogranuloma venereum serovars are generally considered more invasive than other serovars because of their propensity to cause lymphoproliferative and systemic disease, there is little evidence to suggest differences in virulence among the oculogenital serovars. However, surveys of genital isolates from around the world have demonstrated that certain serovars occur more frequently than others (1, 4, 6, 7, 11). Specifically, in large surveys in the United States and Europe, immunotypes D and E account for approximately

immunotypes were obtained from the Centers for Disease Control (R. C. Barnes) and were serotyped as D, E, F, G, I, and K. These latter strains were originally obtained from the University of Washington, Seattle, collection and have been passaged in the laboratory an unrecorded number of times. The organisms were propagated, titrated, and isolated in cyclohexamide-treated McCoy cell monolayers by standard techniques. Isolates collected during the late stages of infection were retyped, and in all cases the type was identical to that of the original infecting strain. With minor exceptions, the methods and procedures used to produce and monitor chlamydial infection of the female genital tract have been published (5). In addition, progesterone, in the form of medroxyprogesterone acetate (Depo-Provera; The Upjohn Co.) was given subcutaneously in 2.5-mg doses 10 and 3 days prior to infection to enhance the initial infection rate (10).

TABLE 1. Lower genital tract infection caused by various oculogenital serovars of C. trachomatis 2

4

6

8

10

13

17

20

24

28

31

34

38

41

45

48

52

55

62

66

69

72

Median duration (days)

12 12 10 11 8 12 12

11 12 9 9 6 10 12

12 12 8 7 5 9 11

12 12 7 6 3 10 12

10 10 10 5 5 4 11

8 3 10 5 2 6 11

6 5 7 6 3 3 8

5 8 4 6 0 3 4

8 8 2 0 0 2 6

5 6 2 1 0 0 5

3 4 3 3 1 0 4

4 3 2 1 0 0 2

4 4 2 0 0 1 2

2 1 0 0 0 0 1

2 1 2 0 0 0 0

2 0 0 0 0 0 1

2 1 1 0 0 0 0

1 0 0 0 0 0 0

1 1 0 0 0 0 0

0 0 0 0 0 0 0

0 0 0 0 0 0 0

0 0 0 0 0 0 0

38 36 17 20 7 10.5 29.5

No. of animals culture positive at day postinoculation

Serovar

D E F G H I K

pa

Variation in virulence among oculogenital serovars of Chlamydia trachomatis in experimental genital tract infection.

Seven different oculogenital serovars (D, E, F, G, H, I, and K) of Chlamydia trachomatis were inoculated intravaginally into CF-1 mice, and subsequent...
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