Virulence characteristics of Escherichia coli strains causing asymptomatic bacteriuria.

BACKGROUND: The objective of this study was to examine the expression of Escherichia coli virulence-associated factors among the strains isolated from a group of women with a history of recurrent urinary tract infections (UTIs), in whom asymptomatic bacteriuria (ABU) was detected at follow-up, and from a group of children without a history of previous UTI, in whom ABU was detected during the screening. Possible differences between the virulence potential of these strains were investigated. MATERIALS AND METHODS: Hemolysin production, the ability to adhere to Buffalo green monkey cell line and hemagglutination (HA) ability of the ABU-associated E. coli strains were tested. E. coli strains isolated from patients with acute recurrent UTIs served as a comparison. RESULTS: The well-known low virulence of strains isolated from patients with ABU was demonstrated. In contrast to strains isolated from recurrent uncomplicated UTIs, the ABU-associated strains were mostly nonhemolytic (75%), nonadherent (70%) and lacked HA ability (61%). HA ability was significantly more common among the strains isolated from children without a history of UTI than among the strains isolated from women with recurrent UTIs (chi2 = 9.97, p < 0.01), whereas the adherence and hemolytic abilities did not differ between the two ABU groups. CONCLUSION: A further prospective study is needed to determine whether the HA ability is the predictor of subsequent symptomatic UTI.

Immunity of the Croatian population to poliomyelitis--a serosurvey.

Eight years after the last case of poliomyelitis it was of a special interest to determine the immunity level of the Croatian population to polio and thus to evaluate the possible risk of the revival of this infection. For this purpose, 200 sera samples were collected from individuals of different age and place of residence. Neutralizing antibodies (NT) for all three polioviruses were searched for. Antibody titers of > or = 1:8 were considered positive. Results of the study showed some 75% of the study subjects to have antibodies to polio type 1 and 2, and some 83% to type 3. Only 4% of the sera tested had no NT antibodies to any of the three types. The lowest mean geometric antibody titer (GMT) was for polio type 3 (GMT3 = 19.4; reciprocal value) and somewhat higher for type 1 (GMT1 = 23.5) and type 2 (GMT2 = 22.6). When the antibody titers were related with the age of the subjects, they were found not to decline with age, which was ascribed to periodical boosters with vaccinal strains. It is stressed that, in spite of the eradication of poliomyelitis achieved in Croatia, compulsory vaccination of the children should be continued until its global eradication.

[Human viruses in the coastal environment of a Croatian harbor]. / Présence de virus humains dans l'environnement côtier d'un port croate.

The authors submit the results of a survey on the viral pollution of the costal environment in the vicinity of a Croatian harbour on the northern Adriatic sea. The presence of human viruses was established in 22% of the sea water samples, 54% of the fluffy sediments samples, 44% of the sandy sediments samples and 26% of the batches of shell-fishes. Hepatitis A virus and rotavirus antigens determined by immuno-electro-osmophoresis made up 76.3% and 15.2% of the positive results respectively, whereas the coxsackieviruses, the echoviruses and the polioviruses isolated on cell culture made up 8.5% of the remaining results together. The analysis of several specimens of different nature taken simultaneously gave a better vision of the viral pollution.

[Epidemiology of enteroviral meningitis in Croatia 1958-1988 with special emphasis on the great epidemic of 1988]. / Epidemiologija enterovirusnih meningitisa u Republici Hrvatskoj 1958-1988. s posebnim osvrtom na veliku epidemiju 1988. godine.

In 1988, there was a large outbreak of enteroviral meningitis in the Republic of Croatia and in other parts of Yugoslavia as well. A total of 4079 cases of enteroviral meningitis were registered with one fatal outcome (Mb 8.7 0/ooo). The outbreak was caused by echovirus 4. Analysis of epidemiological, virologic and ecological data for 1988, as well as for a number of previous years, showed the following: an upward morbidity trend observed from 1958 to 1979 turned to a high level stationary trend with irregular annual oscillations. A cyclic morbidity trend was noticed with peaks in 9-10 years. Seasonal peak was lower in July regularly. In 1988, age and sex distribution of the diseased persons differed from the usual picture, showing greater proportion of older age and women. The probable reason is in the long absence of echovirus 4 from the target population, resulting in low herd immunity. This caused greater proportion of older cases, among which women (mothers) had probably been more exposed to infections than men (nursing ill household members, laundry handling, etc). The epidemic years 1988 and 1979 were hot during spring and summer, at above-average level. Such climatic factors (high temperature) coupled with the sufficiently low level of herd immunity probably triggered in both examples the outbreak of enteroviral meningitis.