[The diagnosis of antileptospiral antibodies in human subjects by solid-phase immunoenzyme analysis]. / Diagnostika protivoleptospiroznykh antitel u liudei metodom tverdofaznogo immunofermentnogo analiza.

The possibility of using the enzyme-linked immunosorbent assay (ELISA) for the diagnosis of leptospirosis has been shown. This method has proved to be more simple and sensitive than the leptospiral microagglutination and lysis test. The data on obtaining genus-specific leptospiral antigens are presented. As revealed in this study, the antigens obtained by the complex treatment of microbial cells with ultrasound and detergents show the maximum activity in ELISA. The optimum parameters of the ELISA system for the diagnosis of leptospirosis have been established.

[Survival rate of Leptospira pomona in the soil at a natural leptospirosis focus]. / Vyzhivaemost' leptospir serogruppy pomona v pochve prirodnogo ochaga leptospirosa.

At the area of a natural focus of leptospirosis (caused by L. pomona) in the Mozdok region of the North Occetic ASSR leptospires were detected by the method of dark field microscopy in 22% of intact soil samples. The presence of pathogenic leptospires in this soil was not confirmed by the method of the biological assay on Syrian golden hamsters. In controlled tests lasting 1-277 days, in 30.4% of cases L. pomona retained their viability, pathogenic and antigenic properties for as long as 74 days, while staying in the soil at the focus of infection with humidity being 15.2-31.4% and pH = 6.7-7.2. 11 Leptospira cultures isolated after staying in the soil retained their pathogenic properties and the death of the animals used in the bioassay from the acute form of leptospiral infection.

[The noncorrespondence of the geographic ranges of the host and the causative agent]. / O nesootvetstvii arealov khoziaina i vozbuditela.

For the first time the experimental and field studies of Leptospira infections, carried out over the period of 6 years, have revealed that the habitat of striped field mice (Apodemus agrarius Pallas 1778) serving as a host for Leptospira pomona, serovar mozdok, is much wider than the habitat of the infective agent proper. The presence of an animal species highly sensitive to a definite leptospiral serovar and serving as its reservoir at a given locality cannot be regarded as a proof of the presence of the epizootic process without bacteriological confirmation. But, in the absence of homologous Leptospira carriage, intensive leptospiral seroconversion can be attributed to a population other than that of the host.

[The functioning of a drained natural focus of leptospirosis in a nonchernozem area]. / Funktsionirovanie osushennogo prirodnogo ochaga leptospirozov v Nechernozem'e.

The drainage of a natural focus of leptospirosis of the flood plain-swamp type, carried out over the period of 15 years, has led to changes in the species structure of small mammals and to an increase in the number of Leptospira-carrying species. Nevertheless, like before drainage, the prevalent species and the main carrier of leptospires is still the root vole (Microtus oeconomus Pallas). The intensity of the epizootic process among small mammals at the final stage of drainage has proved to be similar to that at the initial stage. At the same time the cultivated fields created on the drained territory of the natural focus abound, by the time of harvesting, with small mammals among whom the intensive epizootic process takes place.

[Populations of pathogenic Leptospira of varying virulence in nature]. / Populiatsii patogennykh leptospir razlichnoi virulentnosti v prirode.

The study of geographically remote populations of Norway rats (Rattus norvegicus) revealed that in one of these populations a highly virulent population of Leptospira copenhageni, serogroup icterohaemorrhagiae, and in another population of rats a faintly virulent population of these microorganisms circulated simultaneously. At the same time in vitro experiments with Leptospira cultures showed the absence of the constant probability of sharp changes in the level of their virulence in time.

[Effect of the viable cell count on the growth parameters of Leptospira cultures]. / Vliianie kolichestva zhiznesposobnykh kletok na parametry rosta kul'tur leptospir.

The influence of the amount of live cells on the growth characteristics of 41 Leptospira pathogenic strains belonging to 4 serogroups at different stages of growth has been studied. The study has revealed that under the conditions of batch cultivation the maximum concentration of pathogenic leptospires in the inoculum decreases the duration of the lag phase and determines the highest specific growth rate characterizing the individual features of leptospires in the serogroups under study.

[Cloning and the expression of the hemolysin gene of Leptospira pomona pomona in Escherichia coli]. / Klonirovanie i ékspressiia gena gemolizina Leptospira pomona pomona v Escherichia coli.

The library of Leptospira pomona genes was obtained on phage vector AL 47.1. From this library a recombinant phage carrying the hemolysin gene was selected. The DNA fragment (7.7 kb) of this phage containing the hemolysin gene was subcloned on plasmid pUC19. E. coli clones with hybrid plasmid pDR7 were shown to be hemolytic, but the secretion of hemolysin by E. coli into the culture medium was not observed.

[Differences in the susceptibility of field mice from the Altai Territory and Moscow Province to Leptospira of serovar mozdok and serogroup Pomona]. / Razlichiia v vospriimchivosti polevykh myshei Altaiskogo kraia i Moskovskoi oblasti k leptospiram serovara mozdok serogruppy Pomona.

Adult striped field mice (Apodemus agrarius) caught in the Altai region proved to be insusceptible to experimental infection when inoculated with Leptospira of serovar mozdok, serogroup Pomona. In pregnant females, though infected with this organism, no leptospiruria was observed. At the same time nonpubescent animals became Leptospira carriers, females becoming carriers 4.5 times more frequently than males. The formation of antibodies to Leptospira in the test rodents was poorly pronounced and did not depend on their sex, age, physiological state and the presence of renal leptospirosis. But all adult striped field mice belonging to the population of the Moscow region became Leptospira carriers in such experiments.

[Sensitivity of different morphological variants of Leptospira to the leptospirocidal activity of normal animal sera]. / Chuvstvitel'nost' razlichnykh morfologicheskikh variantov Leptospira k leptospirotsidnoi aktivnosti normal'nykh syvorotok zhivotnykh.

The leptospirocidal activity of normal animal sera with respect to 23 Leptospira strains was experimentally studied in vitro. 91.3% of the strains under study proved to be sensitive to the lytic action of cattle serum and 86.9%, to sheep serum. The uncinate variants of the pathogenic strains showed resistance to the action of the above sera, and their nonuncinate analogs were subject to agglutination with subsequent lysis, similarly to saprophytes.

[Natural focus of leptospirosis in the rice paddies of Krasmodar Territory and the means for its eradication]. / Prirodnyi ochag leptospiroza na risovykh poliakh Krasnodarskogo kraia i puti ego ozdorovleniia.

OFFthe rice fields of the Krasnodar Territory the intensive epizootic of leptospirosis icterohemorrhagica can be observed in the population of Norway rats (995 animals have been examined and 102 cultures obtained) the whole year round. The highest intensity of the epizootic process is known to fall on the end of summer and the beginning of autumn (45-50% of Leptospira carriers). The natural focus of leptospirosis on the rice-growing complex is epidemiologically dangerous. The epizootic process can be suppressed by reducing the population of rats by means of poisoned baits. The alternate use of different poisons ( rotindan , brodifacum ) given in the form of paraffined briquettes has proved to be most expedient.

[Bactericidal activity of normal sera from various animal species against pathogenic and saprophytic leptospires]. / Bacteritsidnaia aktivnost' normal'nykh syvorotok zhivotnykh nekotorykh vidov v otnoshenii patogennykh i saprofitnykh leptospir.

The leptospirocidal activity of 5 animal species against L. interrogans, L. biflexa and L. kazachstanica I and II, belonging to different serogroups and serovars, was studied. Cattle and sheep sera had no lytic effect on 36.9-40.1% of pathogenic Leptospira strains, but other pathogenic strains, as well as saprophytes, were lyzed by these sera. L. pomona and L. grippotyphosa exhibited high resistance to cattle serum, the latter being also resistant to sheep serum.

[Etiological structure of icterohemorrhagic leptospirosis in gray rats (Rattus norvegicus)]. / Etiologicheskaia struktura leptospiroza Icterohaemorrhagiae serykh krys (Rattus norvegicus).

In 93 Leptospira strains isolated from Norwegian rats serovar determination was made. As a result, leptospires circulating among Norwegian rats were found to belong mainly to serovar copenhageni, group Icterohaemorrhagiae, while leptospires of serovar icterohaemorrhagiae, even if occurring, were found only in the animals inhabiting pigsties. Leptospirosis epizooty among rats, caused by L. icterohaemorrhagiae, took its course independently of leptospirosis epizooty among mice, caused by L. hebdomadis, and simultaneously with it.

[Classification of Leptospira isolated in Peru]. / K klassifikatsii leptospir, vydelennykh v Peru.

Antigenic properties of 23 leptospira cultures isolated in Peru were studied by immunological absorption. Two new individual leptospira serovars were classified as huanuco with a reference strain M-4, representing a new Huanuco serological group, and san-martini with a reference strain CT-63 belonging to the Hebdomadis serological group. Besides for the first time in the American part of the world serovar budapest belonging to Icterohaemorrhagiae serological group was recorded; also the first finding of serovar pyrogenes of the pyrogenes serological group was certified.

[Formation of group and intergroup antibodies in humans with leptospirosis infections]. / Obrazovanie gruppovykh i mezhgruppovykh antitel pri leptospiroznoi infektsii u cheloveka.

The authors studied regularities attending the biosynthesis of group (homologous) and intergroup (heterologous) antibodies in man during the whole cycle of leptospirosis infection, and for three months after it. Leptospira of the serological groups Pomona, Grippotyphosa, Icterohaemorrhagiae, Hebdomadis, the most prominent in the morbidity structure at present, served as etiological causative agents of the disease. Biosynthesis of both homologous and heterologous antibodies had its specific features for each serological group of the disease, and was characterized by the quadripol dynamics of 19S-macro and 7S-microglobulin antibodies production in leptospiroses of serological groups Pomona and Gryppotyphosa, whereas in leptospiroses of serological groups Icterohaemorrhagiae and Hebdomadis a graphically dipolic synthesis dynamics of 19S-macroglobulin antibodies alone was noted.

[Comparative study of the immunoglobulin content in persons from leptospirosis foci in different geographical zones of the RSFSR]. / Sranvitel'noe izuchenie soderzhaniia immunoglobulinov u liudei iz ochagov leptospiroza razlichnykh geograficheskikh zon RSFSR.

The authors carried out a comparative study of the content of serum immunoglobulins in persons from the leptospirosis foci of various geographical zones of the RSFSR: European part--the Centre (Moscow and Ryazan regions), the South (Checheno-Ingush ASSR and Krasnodar Territory), and Western Siberia (Altai territory), Leptospira of serological group Pomona, Grippotyphosa, and Hbedomadis served as the causative agents of the diseases. It appeared that the annual course of the climatic factors acted equally (inhibitory action) on the immuno-globulin metabolism in the residents of temperate and southern zones of the RSFSR at the warm period of the year (May-September), and in the Western Siberia- in winter. However, irrespective of the time of the year, the level of immunoglobulins G and A was greater in the residents of Western Siberia than in the native population of the European part. There proved to be no correlation between the levels of leptospirosis seropositivity in the foci of infection under study and the serum immunoglobulins in local residents of various geographical zones.