The mechanism of bactericidal action of normal human serum against Salmonella rods.

Forty Salmonella strains sensitive to the bactericidal action of serum were investigated. All these strains were susceptible to complement activated by the classical pathway though in part (60%) of these strains the presence of lysozyme was necessary for killing. S. typhimurium rods were susceptible to only one mechanism of the action of bactericidal factors. On the contrary, S. enteritidis strains were sensitive to three various mechanisms of bactericidal action of serum. Next eight forms of Salmonella typhimurium LT2 differing with respect to the structure of LPS were studied. Original strain was a smooth, form S, and remaining strains were various rough (R) forms such as Ra, Rb1, Rb2, Rc, Rd1, Rd2, Re. The S form was susceptible only to the complete human serum what means that all bactericidal factors of serum were needed for killing. Ra form was susceptible to two independent bactericidal mechanisms: complement (C) activated by the alternative pathway in the presence of lysozyme and C activated simultaneously by both bactericidal C pathways without the participation of lysozyme (al, ac). The next form, Rb1, besides the mechanism mentioned above was also susceptible to C activated by the classical pathway in the presence of lysozyme (al, ac, cl). Other forms (Rb2, Rc, Rd1, Rd2, Re) were susceptible to three mechanisms (al, ac, cl) as well as to C activated by the classical pathway without lysozyme (c). The mechanism (c) was weakly efficient against forms Rb2 and Rc and somewhat more efficient against Rd1 and Rd2 and the most efficient against Re.

[Extraintestinal salmonellosis in patients with blood diseases caused by Salmonella enteritidis]. / Pozajelitowa salmoneloza u osób z chorobami krwi, wywolana przez Salmonella enteritidis.

Four cases of extraintestinal salmonellosis caused by Salmonella enteritidis were described. Underlying diseases in the three patients were haematological neoplasms (2 splenectomized and 1 with massive leukemic infiltrations of the spleen) and in the fourth haemophilia B: only that patient had a prior symptomatic intestinal infection. Blood cultures for S.ent. were positive in all patients and additionally in that suffering from Hodgkin's disease urine, lymph node and stool cultures also showed S.ent. In the haemophiliac patient culture of suppurated hematoma was positive. All patients recovered from S. sepsis but three then died of their neoplastic diseases. The haemophiliac patient is in a good condition. Various disturbances in the immunological tests were observed.

Bactericidal activity of normal human serum against Morganella, Proteus, and Providencia strains.

The susceptibility od Proteus, Providencia, and Morganella strains to bactericidal action of human serum was examined. The percentage of survival was determined after one and three hours incubation with 50% human serum. The susceptible strains were treated by serum preparations with blocked classical or alternative complement activation pathways as well as with lysozyme removed. Following mechanisms of the bactericidal action of serum were found: complement activated by the classical or alternative pathway with participation of lysozyme, complement activated simultaneously via both pathways-while the participation of lysozyme was necessary for killing some strains and superfluos for others and complement activated only via the classical pathway without lysozyme.

[Susceptibility of Proteus, Morganella and Providencia strains isolated from patients with urinary tract infections on bactericidal activity of normal human serum]. / Podatnosc szczepów Proteus, Morganella i Providencia izolowanych od chorych z zakazeniami ukladu moczowego na bakteriobójcze dzialanie normalnej surowicy ludzkiej.

Usefulness of the test determining bactericidal activity of normal human serum was investigated with 50 strains of Proteus, Morganella and Providencia isolated from patients with urinary tract infections (UTI) and with 50 strains isolated from feces. It was found that strains from UTI were more frequently resistant to the action of normal human serum (50% resistant) in comparison with strains isolated from feces (30% resistant). Strains of Proteus belonging to four species were differing greatly in their susceptibility to normal human serum. They can be ranked as followings: P. mirabilis (49% of resistant strains), P. vulgaris (62%), P. morganii (72%) and P. rettgeri (100%). In studies on interaction subinhibitory concentrations of cefotaxime and normal human serum in bactericidal reaction, a synergism was found only with some strains.

Sensitivity of Shigella strains to bactericidal activity of human serum. I. Participation of two independently active mechanisms in bactericidal action against Shigella sonnei phase II.

Normal human serum is strongly bactericidal for all studied Shigella sonnei phase II (10 strains). The studied bacteria were sensitive to two alternative mechanisms of the bactericidal activity of serum factors. The first mechanism involves the action of serum in which complement (C) is activated by the studied bacteria via the classical pathway. Lysozyme did not participate in this reaction. The second mechanism involves the combined action of two factors: C activated via the alternative pathway and lysozyme.

Sensitivity of Shigella strains to the bactericidal activity of human serum. II. Shigella flexneri 3 a is killed by complement activated via the classical pathway, with participation of lysozyme.

Normal human serum is bactericidal for all studied strains (15) of Shigella flexneri serotype 3a. The activity of the serum was similar irrespective of the invasiveness of the bacteria or its lack. The studied bacteria were susceptible to a single mechanism of bactericidal activity involving complement activated via the classical pathway, accompanied by the action of lysozyme.

Sensitivity of Shigella strains to the bactericidal activity of human serum. III. The diversity of activity variants of bactericidal serum factors against Shigella flexneri serotypes.

Normal human serum is bactericidal for all studied Shigella flexneri strains (38) belonging to nine serotypes. Six variants of bactericidal activity of serum factors for these bacteria were determined.