[The effect of adherence on virulence of uropathogenic strains of Escherichia coli]. / Utjecaj atherencije na virulenciju uropatogenih sojeva Eserihije koli.

Bacterial adherence is an extremely important process in the initiation of many infections. After the successful colonization other factors of bacterial virulence produce inflammation and damage of the tissue. A close contact between bacterial and host cells, which is mediated by adherence, makes bacterial antigens better presented. In this paper correlation between the adhesin type of uropathogenic strains of Escherichia coli (UPEC), serogroup and production of hemolysin was investigated. A total of 160 Escherichia coli strains isolated from urine with significant bacteriuria (i.e. 10(5) or more organisms per ml) were analyzed. Bacterial adhesins were determined by hemagglutination and hemagglutination-inhibition tests. Serogroups were determined by standardized method, and production of hemolysin was estimated semiquantitatively using original method. P-fimbriated strains produced high amount of hemolysin, in contrast, to often nonhemolytic strains in which some other adhesins were identified (chi 2 = 50.33; p < 0.01). P-fimbriae were present mostly on strains of serogroups 06 and 02. Production of hemolysin is an important factor of UPEC virulence. Lower concentrations cause release of inflammatory mediators, and higher concentrations are cytotoxic. It also seems that lipid A, an integral part of the cell wall lipopolysaccharide, influences on induction of inflammation and aggregation of leukocytes.

Production of pyrogenic exotoxins in group A streptococci isolated from patients in Zagreb, Croatia.

The pyrogenic exotoxin profiles were determined of group A streptococci isolated from patients in Zagreb, Croatia in the period 1989-1990. A total of 12 strains were studied, five from patients with serious infections and seven from patients with uncomplicated infections. Serotypes M1 and M3 were found in seven (58%) patients. Seven strains produced exotoxin A and ten strains exotoxin B. The proportion of exotoxin A and B producing strains in patients with severe infections (3 patients respectively) was similar to that found in patients with uncomplicated infections (4 and 7 patients respectively).

[Bacteremia caused by beta-hemolytic group A streptococci]. / Bakteriemije uzrokovane betahemolitickim streptokokom grupe A.

The epidemiological, clinical and laboratory characteristic of group A beta-hemolytic streptococcal (GABHS) bacteremia in patients treated at the University Hospital of Infectious Diseases in Zagreb were analyzed. Of 51 cases of bacteremia due to GABHS seen over the past 15 years, 15 (29%) have been registered since 1987. The mean age of our patients was 25 years (range, 5 months to 87 years); and 29 (57%) were under 18. Ten (19%) patients died, 6 being less than 18 years of age. Forty-seven (92%) cases were community-acquired and 16 (32%) had underlying disease. Primary foci of infection, defined as a sites of inflammation that precedes bacteremia, included pharyngitis in 15 and erysipelas/cellulitis in 16 patients. Six patients had no focus of infection. Shock was recorded in 4 patients, all of whom died. Seven patients had a rash, in 5 the rash was typical of scarlet fever. Of the 6 children who died 4 were previously healthy and they all died within 24 hours following admission, and were sick at least 48 hours before admission to our hospital. Our experience suggests that serious GABHS infections may appear in children, that it requires prompt recognition and treatment and that a worldwide change in the virulence of GABHS may have occurred.

Ciprofloxacin in the treatment of gram-negative bacillary meningitis.

Gram-negative bacillary meningitis (typically caused by E. coli, K. pneumoniae, P. aeruginosa, A. calcoaceticus, and others) has been associated with head trauma, neurosurgical operations, pathologic anastomosis with nasal cavity, and CSF rhinorrhea, as well as with impaired host defenses. Intravenous ciprofloxacin was given to 20 patients with gram-negative bacillary meningitis. The dose of ciprofloxacin was 200 mg by intravenous infusion, over 30 minutes, every 12 hours for 10 days. Two patients also received intravenous cefotaxime and penicillin G. All patients were monitored daily. Of 20 patients, 18 had cure and therapy failed in two. Because relatively low concentrations of ciprofloxacin are achieved in the CSF, the drug should be used in the treatment of gram-negative bacillary meningitis only if the MICs of the causative pathogen and the ciprofloxacin concentration in CSF can be followed. A randomized, controlled study is needed to compare the efficacy of intravenous ciprofloxacin with standard antibiotic therapy in the treatment of this disease.