Author: Miladin Kostovic

# icterohaemorrhagiae

- `Genus:............ Leptospira`
- `Species:.......... interrogans`
- `Serogroup:........ Icterohaemorrhagiae`
- `Serovar:.......... icterohaemorrhagiae`
- `Strain:........... Ictero No. 1`
- `Year:............. 1915`
- `Origin:........... Human`
- `Country:.......... Japan`

### History of serovar:

The serovar* name icterohaemorrhagiae was first used by the Japanese workers Inada and Ido (1915, a and b), when they reported the isolation of the first leptospire from man in February, 1915. They called it Spirochaeta icterohaemorrhagiae (japanica).

Since it was published earlier it takes priority over the name icterogenes that was used in the original publication of Uhlenhuth and Fromme (1916) in their description of the organism that they had isolated and believed to be aetiological agent of Weil's disease, which they called Spirochaeta icterogenes.

A Japanese and the German isolate were later designated Ictero No. 1 and RGA respectively. Both strains could have been attached to this serovar as reference strain. Because of doubt, on the authenticity of strain Ictero No. 1, strian RGA was designated many years as reference strain (TSC 1966 and 1986), not withstanding the fact that the latter was published a year later.

Only after the recent detailed publication on the histoy of strain Ictero No. 1 (Yamamoto and Yanagawa, 1990) it was decided at the TSC meeting (Osaka 1990) to recognize the authenticity of this strain. Because Ictero No. 1 was isolated earlier than RGA the TSC agreed at the same meeting to replace RGA by Ictero No. 1 as reference strain of serovar icterohaemorrhagiae and as neotype strain of the species L. interrogans. A historical description of both strains will now be given.

*The word serovar was a that time desgnated as "serotype".

icterohaemorrhagiae (Ictero No.1)

Naming:

In the original Japanese publications (Inada and Ido, 191, a and b, and Inada et al. 1917) no mention is made of the strain name Ictero No. 1. The authors only recorded the isolation of four strains, Nichimura, Yamasaki, Matsumoto and Sakamoto, throught serial guinea-pig passages.

In an other publication of 1915 (in Japanese) Inado and Ido use the notation "No. 1" in combination with the Yamasaki strain. However, they do so in one table only without any further explanation in the text.

The first publication with a more explicit reference to the name Ictero No. 1 is from Kitaoka (1937), who describes the strain as "Icteroh. Nr. 1" (in combination with "Menschlicher Stamm Nr 1"). He claims this strain to be the original decent of the Yamasaki strain. Much later (1968) Babudieri and Smith made the same reference to this strain but under the name "Ictero No 1".

Also in correspondence between Yamamoto and Bor-Petersen, dated May 3, 1968, the strain name is mentioned. In this correspondence and in the publication of Babudieri et al. (1968) it is stated that according to Yamamoto, strain Ictero No. 1 corresponds to the original Yamasaki strain that was recorded by Inada et al. (1915, a and b, and 1917).

History:

In the original Japanese publications (see above) it is stated that the Yamasaki strain was isolated from a guinea-pig inoculated on November 23, 1914, with blood from a sick 59 years old rice-handler, who was suffering from weil's disease and admitted to the Kyushu University Hospital in Fukuoka. The strain was maintained by many serial guinea-pig passages (Inada et al., 1917). On May 13, 191, after 24 passages through guinea-pigs, the straain was cultured in Noguchi's medium (Inada et al., 1916).

On the further history of the strain, different papers (correspondence between Borg-Petersen and Yamamoto, 1968, Bududieri et al., 1968, TSC report to ICNB, 1971 and Yamamoto et al., 1990) provide identical information, all basedon the same source (Prof. Yamamoto). The papers indicate that Inada maintained the strain in the laboratory of Kuishu University until 1918. Then he moved to the Faculty of Medicin, Tokyo University, where the strain was maintained by him and by his successor Professor Sakaguchi. In 1940, Dr. Kubo, who worked in the same laboratory, sent a culture of the strain to Profesor Yamamoto at the Tokyio Institute of Veterinary Pathology. He refered to it as Ictero No. 1 and stated that it corresponds to the strain Yamasaki, which Inada and Ido isolated from a patient of that name (Inada at al., 1917).

In 194, this culture of strain Ictero No. 1 was found to be contaminated by fungi. Yamamoto purified the culture by intraperitioneal inoculation of splenectomized mice and by culturing their heart blood ten minutes later. Unfortunately, the mice were not examined on a concurrent leptospiral infection before the decontamination procedure was started. Nevertheless both before and after mouse passage the strain was found to be antigenically identical with another Japanese stain of human origin. Akasawa, isolated in 1933 by Numata in Ibarki. "It seems therefore unlikely that the purified strain was other than the oriinal strain Ictero No. 1" Badudieri and Smith, 1968).

After World War II, no information was obtained on the existence of strain Incero No. 1. According to the Report (1962-1966) of the TSC, Kitaoka informed the Subcommittee that he "understood that the original strain of Inada and Ido (Strain No. 1) had been lost". The same report mentions that as a result of a following circular letter "Yammamoto claimed to have a culture of strain No. 1" and subsequently he gives its history as from 1940 as mentioned above.

In the 2Statements and Recommendations" of the TSC meeting - Moscow, 1966, it is reported that "Strain RGA was unanimously accepted as authentic and well documented. It was preferred to the Japanese strain because the authenticity of the strain is now doubfull".

This view continued until the recent review on the strain's history by Yamamoto and Yanagawa (1990).

The TSC then decided during its emeeting in Osaka (1990) to recognize the authenticity of strain Ictero No. 1. As Ictero No. 1 is earlier isolated and published than strain RGA the TSC decided at the same meeting to replace RGA by Ictero No. 1 as reference strain of serovar icterohaemorrhagiae and as neotype strain of the species interrogans, notwithstanding its serological difference from strain RGA.

No comparative typing studies had been carried out on strains RGA and Ictero No. 1 until those of Babudieri and Smith (1968), which revealed serological differences. Lately this was confirmed y Yamamoto (1990). Borg-Peterson (1971) and Kmety (1972) considered these differences to be due to the presence in Ictero No. 1 of a thermolabile anigen, designated as Vi, which was not present in strain RGA. Kmety suggested subvividing serovar icterohaemorrhagiae into two varieties, Vi+ and Vi-, with Ictero No. 1 being the reference strain of Vi+ variety and RGA the reference strain of Vi- variety. However, over the years the stability of the Vi antigen became questionable.

Back to Lepto homepage