Characteristics of Pseudomonas aeruginosa strains isolated from urinary tract infections.

Thirty-three uropathogenic strains of Pseudomonas aeruginosa were investigated for hemolytic activity in both bacterial broth culture filtrates and isolate lyzates, resistance to bactericidal activity of fresh human serum, resistance to six antibiotics and plasmid DNA profile. Twenty-four of the 33 (73%) bacterial filtrates showed lysis of rabbit erythrocytes, as did the three after guinea-pig erythrocyte treatment. Twelve of 33 isolate lysates showed in parallel lysis of both types of erythrocytes used. Serum resistance was found in 17 (52%) isolates, intermediate resistance in 15 (45 %) isolates and only one isolate showed serum sensitivity. Resistance to antibiotics was detected as follows (in %): tetracycline 94, kanamycin 79, chloramphenicol 76, septrin 73, ampicillin 64, streptomycin 45, gentamicin 18. None of the isolates investigated showed resistance to colistine. With the exception of one isolate, plasmid DNA was detected in all P. aeruginosa strains.

[Sorbitol-negative E. coli 016 in a 10-year-old child diagnosed with hemolytic-uremic syndrome and in his asymptomatic father]. / Sorbitol-negatívne E. coli 016 u desat'rocného diet'at'a s diagnózou hemolyticko-uremický syndróm a u jeho asymptomatického otca.

In Escherichia coli strains isolated from faeces and smears from the rectum in haemolytic-uraemic syndrome of a child and healthy relatives the authors assessed the biochemical activity, antigenic characteristic, sensitivity to twelve antimicrobial substances and factors of virulence. Sorbitol negative strains were isolated from the ill child and his father. The strains belonged into serogroup 016. The remaining strains were sorbitol positive. They belonged into serogroups 02, 012 and 019. Nineteen sorbitol negative strains of E. coli from the sick child caused mannose sensitive agglutination of chicken and guinea pig erythrocytes, they produced colicin V and aerobactin. Except for one strain they were serum resistant. Fourteen strains induced the oedema on the foot of mice and eleven produced a lethal effect in mice. Except for three ampicillin resistant strains the remaining were sensitive to the examined antibacterial substances. Two sorbitol negative strains of E. coli isolated from the asymptomatic father produced aerobactin and one strain was serum resistant.

[Virulence factors in strains of Escherichia coli isolated in urinary tract infections]. / Faktory virulencie u kmenov Escherichia coli izolovaných pri mocových infekciách.

In 21 strains of E. coli isolated from patients with cystitis and asymptomatic bacteriuria the authors assessed the group, mannososensitive and mannoresistant agglutination of human, bovine, chick, guinea pig, sheep and pig erythrocytes, the production of haemolysis, colicins, aerobactin, the capacity of strains to induce oedema on mouse paws, the lethal effect in mice, the resistance to tetracycline, streptomycin, chloramphenicol, kanamycin, ampicillin and sulfamethoxidine, the transmission of resistance and sensitivity of strains to the action of fresh human serum. In ten strains the authors recorded also the production of haemolysin and the lethality for mice, in four strains the production of colicin V. production of aerobactin and serum resistance. In three strains the aerobactin production was recorded concurrently with the haemolysin production. In none of the samples P. fimbriae were found.

Killing of alpha-haemolytic and non-haemolytic Escherichia coli strains in human serum and polymorphonuclear leucocytes.

The role of alpha-haemolysin (AH) in the resistance of Escherichia coli strains, isolated from patients with extra-intestinal diseases or diarrhoea, to the bactericidal activity of human serum and intracellular killing in polymorphonuclear leucocytes (PMNL) was investigated in vitro. Sets of alpha-haemolytic and non-haemolytic E. coli strains and sets of isogenic E. coli strains, which included wild-type alpha-haemolytic strains and derived strains with a reduced production of AH, were used. Compared with non-haemolytic strains, alpha-haemolytic strains were significantly more resistant to the bactericidal activity of 10% and 100% human serum and to intracellular killing in PMNL. Higher resistance to serum killing and to intracellular killing in PMNL was also found in wild-type alpha-haemolytic E. coli than in isogenic bacteria with reduced production of AH. These results provide evidence that production of AH in E. coli strains counteracts both the bactericidal activity of serum and intracellular killing in PMNL.

[Characteristics of E. coli strains isolated in infantile diarrhea]. / Vlastnosti kmenov E. coli izolovaných pri hnackách dojciat.

In a group of 50 strains of E. coli isolated from infants hospitalized on account of diarrhoea the authors investigated, based on the phenotypic manifestation and in a selected number of strains also genotypic factors of virulence: fimbrial adhesins, aerobactin, haemolysins, colicins, toxic and lethal action in mice, seroresistence and resistance against tetracycline, streptomycin, chloramphenicol, kanamycin, ampicillin and sulfamethoxidine. All strains had one to eight factors of virulence. The presence of plasmid DNA was confirmed in 14 of 16 tested strains. From this the authors conclude that the investigated virulence factors were in the majority coded plasmids.

[Personal experience in testing for E. coli enterotoxigenicity]. / Nase skúsenosti z testovania enterotoxinogenity u kmenov E. coli.

When testing the production of the thermolabile enterotoxin by strains of E. coli, using six different methods, the highest positivity (100%) was recorded when using the modified test of oedema on mouse paws and the lowest one (5%) when using the Biken test. The strains were isolated from diarrhoeal infections in young children.

[Escherichia coli in diarrheal disease in young children]. / Escherichia coli pri hnackových ochoreniach malých detí.

The authors describe a lower incidence of enteropathogenetic serogroups of Escherichia coli (EPEC) in 1981-1987. Of 85 EPEC strains tested for the presence of factors of virulence (fimbrim, enterotoxins, haemolysins, colicins) and factors of virulence against six antimicrobial substances (tetracycline, streptomycin, chloramphenicol, kanamycin, ampicillin, sulfamethoxidine) only three strains did not possess any of the mentioned factors. The authors draw attention to other pathogenetically important groups of E. coli in the aetiology of diarrhoea in young children.