Effects of Orally Administered Bdellovibrio bacteriovorus on the Well-Being and Salmonella Colonization of Young Chicks

Abstract

Bdellovibrio bacteriovorus is a bacterium which preys upon and kills Gram-negative bacteria, including the zoonotic pathogens Escherichia coli and Salmonella. Bdellovibrio has potential as a biocontrol agent, but no reports of it being tested in living animals have been published, and no data on whether Bdellovibrio might spread between animals are available. In this study, we tried to fill this knowledge gap, using B. bacteriovorus HD100 doses in poultry with a normal gut microbiota or predosed with a colonizing Salmonella strain. In both cases, Bdellovibrio was dosed orally along with antacids. After dosing non-Salmonella-infected birds with Bdellovibrio, we measured the health and well-being of the birds and any changes in their gut pathology and culturable microbiota, finding that although a Bdellovibrio dose at 2 days of age altered the overall diversity of the natural gut microbiota in 28-day-old birds, there were no adverse effects on their growth and well-being. Drinking water and fecal matter from the pens in which the birds were housed as groups showed no contamination by Bdellovibrio after dosing. Predatory Bdellovibrio orally administered to birds that had been predosed with a gut-colonizing Salmonella enterica serovar Enteritidis phage type 4 strain (an important zoonotic pathogen) significantly reduced Salmonella numbers in bird gut cecal contents and reduced abnormal cecal morphology, indicating reduced cecal inflammation, compared to the ceca of the untreated controls or a nonpredatory ⌬pilA strain, suggesting that these effects were due to predatory action. This work is a first step to applying Bdellovibrio therapeutically for other animal, and possibly human, infections.

The dual probiotic and antibiotic nature of Bdellovibrio bacteriovorus

“…In the study mentioned earlier done by Atterbury et al (21), oral administration of BALOs to young http://bmbreports.org BMB reports chicks pre-dosed with a gut colonizing S. enterica found that these predatory strains could effectively attack Salmonella, thereby reducing its number in the cecum and significantly mitigating cecal inflammation caused by the infection. B. bacteriovorus was also found to decrease the severity of keratoconjuctivitis caused by Shigella flexneri in rabbit eyes provided that they were administrated in the first 48 hr of infection (19).…”

“…A search of the literature shows that different research groups around the world are concentrating more on this area nowadays (20)(21)(22)(23)(24)(25), with all of these studies being published within the last two years. They include research characterizing B. bacteriovorus in different animal hosts, including chicks (21) and cows, particularly their tears (22), and evaluated its effects on various pathogens, such as Helicobacter pylori (20) bacterial agent to address real environmental, industrial and medical issues and to define both the advantages and challenges that face B. bacteriovorus as both a promising probiotic and an alternative for antibiotics in the future.…”

Bdellovibrio and Like Organisms Enhanced Growth and Survival of Penaeus monodon and Altered Bacterial Community Structures in Its Rearing Water

“…They hunt other pathogenic and/or potentially pathogenic bacteria in water and biofilms (10), and the spectrum of bacteria on which they prey is very nonspecific (9,11). BALOs have also been shown to be unable to prey on eukaryotic cells and as such pose no direct risk to human or animal health (12)(13)(14)(15). These features make BALOs possible candidates as biocontrol agents (10,11,16,17).…”

Purification and Host Specificity of Predatory Halobacteriovorax Isolates from Seawater

“…Other uses involve the treatment of various infections in animals, including bovine keratoconjunctivitis caused by Moraxella bovis (5), Aeromonas hydrophila in fish (6,7), Vibrio cholerae and Proteus penneri in shrimp (8,9), and Salmonella enterica serovar Enteritidis in the chicken gut (10). They have also been applied in the treatment of human disease pathogens, including Pseudomonas aeruginosa from the lungs of cystic fibrosis patients (11), Pseudomonas aeruginosa and Serratia marcescens associated with eye infections (12), and oral pathogens that cause periodontal diseases (13,14).…”