Probiotic Properties of Alcaligenes faecalis Isolated from Argyrosomus regius in Experimental Peritonitis (Rat Model)

Abstract

A strain of Alcaligenes faecalis A12C (A. faecalis A12C) isolated from Argyrosomus regius is a probiotic in fish. Previous experiments showed that A. faecalis A12C had inhibitory effects on the growth of multidrug-resistant bacteria. We aimed to confirm whether A. faecalis A12C is safe and has adequate intestinal colonization in experimental rats, and evaluate its efficacy in an animal model of peritonitis. We used 30 male rats, randomly divided into 6 groups (n = 5): three groups (HA7, HA15, HA30) received A. faecalis A12C in drinking water (6 × 108 CFU/mL) for 7 days, and three control groups received drinking water only. All groups were evaluated at 7, 15, and 30 days. Survival after A. faecalis A12C administration was 100% in all groups. Mild eosinophilia (1.5%, p < 0.01) and increased aspartate aminotransferase (86 IU/L, p < 0.05) were observed in HA7, followed by progressive normalization. No histological signs of organ injury were found. We observed significant E. coli decline in faeces, parallel to an increase in A. faecalis A12C at 7 days. E. coli had a tendency to recover initial values, while A. faecalis A12C disappeared from the intestinal microbiota at 30 days. To evaluate its efficacy against peritonitis, we studied two additional groups of animals: IA group pretreated with A. faecalis A12C before E. coli intra-abdominal inoculation, and IC group inoculated with no A. faecalis A12C. We found an increase in C-reactive protein, alanine aminotransferase, urea, and eosinophils in IC animals when compared with IA. Peritonitis was more evident in IC than in IA animals. Our findings suggest that A. faecalis A12C altered clinically relevant parameters in sepsis and was associated with a lesser spread of infection.

Long-term treatment with Alcaligenes faecalis A12C improves host resistance to pathogens in septic rats: possible contribution of curdlan-like immune-trainer

“…Recently, our research group has shown the potential probiotic effect of this strain in mammals. Administration of A. faecalis A12C in drinking water (6 × 10 8 CFU/mL) for 7 days was associated in this study with a lesser spread of infection, obtaining promising clinical, microbiological, biochemical and histopathological results in a rat model of peritonitis produced by E. coli [20]. These ndings, together with the scarcity of studies focused on the probiotic properties of this strain [56], set us the objective of evaluating whether the administration of A. faecalis A12C would generate a preventive effect against the damage caused by sepsis, as well as to identify the possible immunomodulatory mechanisms of action in an experimental model in rats.…”

“…In addition, the survival rate of healthy animals, that were administered the strain, was not affected. Regarding the clinical signs due to sepsis, and although there are authors who nd clinical signs similar to ours [20,34], but there are not papers with quantitative studies of these variables using the rat CLP model in probiotics e cacy studies.…”

“…The probiotic strain A. faecalis A12C was isolated from Argyrosomus regius gills at the Instituto de Sanidad Animal y Seguridad Alimentaria of the University of Las Palmas de Gran Canaria, Spain. Fresh cultures were made as previously described by our group [20] (details in Supplementary Material and methods).…”

“…piscicida and Vibrio anguillarum, stimulating their immune response by activating a variety of pro-in ammatory cytokines, such as interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) [4,19]. Our group reported the rst study examining the probiotic effects of A. faecalis A12C on general, biochemical, and pathological parameters in a clinically relevant rodent model of peritonitis showing that oral administration of this strain during 7 days is safe and had marked effects on the spread of infection [20].…”

Right Lower Extremity Osteomyelitis With Alcaligenes faecalis in a Patient With Poorly Controlled Type 2 Diabetes Mellitus

“…A. faecalis bacteria is usually considered non-pathogenic and has even been proposed as a potential probiotic [ 7 ]. Opportunistic infections due to A. feacalis do occur in humans [ 8 ]; however, previous cases of A. faecalis osteomyelitis have only been rarely reported. Skin and soft tissue infections of A. faecalis , including infections associated with diabetic foot ulcers, have been previously described; however, to the authors’ knowledge, only three other cases of A. faecalis osteomyelitis have been reported, all three in patients with diabetic foot ulcers [ 5 , 6 ].…”