Protective effect of Lactobacillus casei on Pseudomonas aeruginosa infection in mice

Abstract

The protective effect of heat-killed Lactobacillus casei YIT9018 (LC 9018) against Pseudomonas aeruginosa infection in mice was compared with that of Corynebacterium parvum. Survival of mice after intraperitoneal (i.p.) infection with P. aeruginosa was augmented in mice that had been pretreated i.p. with LC 9018 5 days previously. Similar treatment of mice with C. parvum, however, was not effective at all. Moreover, mice became more susceptible to infection with P. aeruginosa after such treatment. Growth of P. aeruginosa in the peritoneal cavity and spleen was markedly inhibited in LC 9018-pretreated mice, whereas such inhibition of bacterial growth was not observed in C. parvum-treated mice. The protective effect of LC 9018 was observed in mice subjected to 800 rads of whole body irradiation but was abrogated when mice were treated with carrageenan. These results suggest that augmentation of the resistance of mice to P. aeruginosa was caused by the induction of activated macrophages. The number of macrophages detectable in the peritoneal cavity was almost the same in LC 9018-and C. parvum-treated mice. Growth of Listeria monocytogenes was inhibited by pretreatment with LC 9018. Inhibition of L. monocytogenes was also observed after the same pretreatment with C. parvum. It was suggested that macrophages activated with LC 9018 were involved in the protective immunity to P. aeruginosa.

Lactobacillus casei strain Shirota suppresses serum immunoglobulin E and immunoglobulin G1 responses and systemic anaphylaxis in a food allergy model

“…Lactobacillus casei strain Shirota (LcS) was originally isolated from the faeces of healthy humans and is widely used as a starter for fermented milk products. It has been well established that LcS can activate cellular immunity of the host, and LcS has been studied intensively with regard to its anti‐tumour and anti‐infectious activities [4–6]. Our recent paper [7] showed a novel ability of LcS to suppress IgE secretion from antigen‐stimulated splenocytes, and suggested a possible use of LcS in preventing IgE‐mediated allergy.…”

Protective Effect of Administration of Skim Milk on Exogenous and Endogenous Infection in Mice

“…We ascertained preliminarily that the facultative anaerobes detected in the feces of the mice were mainly E. coli. E. coli was thought to be the main translocating bacteria in mice after X-ray irradiation (7), and Lactobacilli were reported to be the potent immune stimulants (11,15). In our previous study, the administration of immune milk resulted in a decrease in the number of E. coli in the feces at all points before and after irradiation and an increase in the number of Lactobacilli after irradiation (8).…”

Probiotic use of lactobacilli in the human female urogenital tract

“…Pretreatment of mice with L. casei increased the survival of mice inoculated with Pseudomonas aeruginosa intraperitoneally [95] and into thermal injury wounds [96]. The authors suggested that the protective effect of the lactobacilli was afforded by activated macrophages, interferon production and accumulation of phagocytes which cleared the infecting bacteria [94,95,[97][98][99]. Studies initiated by Bogdanov et al [100] into the antitumour substance of Lactobacillus bulgaricus, blastolysin, have shown that the active component of the antitumour drug is a tetrasaccharide-containing muramylpeptide [101] which stimulates production of cytokines such as tumour necrosis factor and interferon [102,103].…”

“…Subcutaneous [93] and intraperitoneal [94] injection of L. casei and L. acidophilus respectively stimulated the listericidal activity of mouse peritoneal 258 macrophages. Pretreatment of mice with L. casei increased the survival of mice inoculated with Pseudomonas aeruginosa intraperitoneally [95] and into thermal injury wounds [96]. The authors suggested that the protective effect of the lactobacilli was afforded by activated macrophages, interferon production and accumulation of phagocytes which cleared the infecting bacteria [94,95,[97][98][99].…”