Bacillus velezensis AP183 Inhibits Staphylococcus aureus Biofilm Formation and Proliferation in Murine and Bovine Disease Models

Abstract

The increasing frequency of S. aureus antimicrobial resistance has spurred interest in identifying alternative therapeutants. We investigated the S. aureus-inhibitory capacity of B. velezensis strains in mouse and bovine models. Among multiple B. velezensis strains that inhibited S. aureus growth in vitro, B. velezensis AP183 provided the most potent inhibition of S. aureus proliferation and bioluminescence in a mouse cutaneous wound (P = 0.02). Histology revealed abundant Gram-positive cocci in control wounds that were reduced in B. velezensis AP183-treated tissues. Experiments were then conducted to evaluate the ability of B. velezensis AP183 to prevent S. aureus biofilm formation on a tracheostomy tube substrate. B. velezensis AP183 could form a biofilm on a tracheostomy tube inner cannula substrate, and that this biofilm was antagonistic to S. aureus colonization. B. velezensis AP183 was also observed to inhibit the growth of S. aureus isolates originated from bovine mastitis cases. To evaluate the inflammatory response of mammary tissue to intramammary inoculation with B. velezensis AP183, we used high dose and low dose inocula in dairy cows. At the high dose, a significant increase in somatic cell count (SCC) and clinical mastitis was observed at all post-inoculation time points (P < 0.01), which resolved quickly compared to S. aureus-induced mastitis; in contrast, the lower dose of B. velezensis AP183 resulted in a slight increase of SCC and no clinical mastitis. In a subsequent experiment, all mammary quarters in four cows were induced to have grade 1 clinical mastitis by intramammary inoculation of a S. aureus mastitis isolate; following mastitis induction, eight quarters were treated with B. velezensis AP183 and milk samples were collected from pretreatment and post-treatment samples for 9 days. In groups treated with B. velezensis AP183, SCC and abundance of S. aureus decreased with significant reductions in S. aureus after 3 days post-inoculation with AP183 (P = 0.04). A milk microbiome analysis revealed significant reductions in S. aureus relative abundance in the AP183-treated group by 8 days post-inoculation (P = 0.02). These data indicate that B. velezensis AP183 can inhibit S. aureus biofilm formation and its proliferation in murine and bovine disease models.

Sodium hyaluronates applied in the face affects the diversity of skin microbiota in healthy people

“…Many beneficial bacteria are found on the human skin surface, which coexist with the body, expel exogenous or endogenous pathogens, and maintain the integrity of the skin barrier [66][67][68]. B. belesii can inhibit the formation and proliferation of S. aureus biofilms in vivo and in vitro [69]. Rhodococcus has been proven to have good biodegradability and can degrade a large number of organic compounds, including some toxic and persistent substances [70].…”

ESKAPEE Pathogen Biofilm Control on Surfaces with Probiotic Lactobacillaceae and Bacillus species

“…Lactobacillus agilis [122], Lactobacillus caucasicus [19], Lactobacillus gallinarum [31], Lactobacillus gastricus [90], Lactobacillus johnsonii [24], Lactobacillus kunkeei [123], Lactobacillus murinus [124], Latilactobacillus sakei [102], Lactobacillus vaginalis [106] and Lacticaseibacillus zeae [58] were each only reported once. Among Bacilli, Bacillus subtilis was the most frequently reported species (five times) [125][126][127][128][129], followed by Bacillus velezensis (two times) [130,131]. Bacillus thuringiensis [46], Bacillus amyloliquefaciens [126], Bacillus cereus [132] and Bacillus pumilus [133] were each reported once.…”

“…Six studies were based exclusively on in vivo experiments. These included three rat disease models, two of which were for wounds [53,54] and one was for surgical implants [55], two murine disease models [145], one of which also included a bovine disease model [130], one rabbit model knee implant infection [76] and one bee model [123]. Three studies were based on combined in vitro and in vivo experiments and exclusively included murine disease models, two intestinal colonization models [36,52] and one urinary tract infection model [113].…”

“…Twenty-four studies described tested probiotic bacteria as having significant anti-biofilm properties. These biofilms were of S. aureus (14 reports) [22,24,25,42,59,68,81,88,95,107,108,114,130,154], E. coli (9 reports) [24,26,60,68,70,95,101,152,154], P. aeruginosa (7 reports) [26,42,59,113,123,153,155], K. pneumoniae (2 reports) [26,146], E. faecalis (1 report) [107], Enterobacter (1 report) [26] and A. baumannii (1 report) [68] isolates. Biofilm impairment was generally by co-aggregation [24,81,108], by reducing pathogen adhesion [42,60,68,101,114], or by disrupting cell metabolism or interfering with quorum sensing [46,70].…”

Locally-isolated protease-producing Bacillus spp. from soil inhibits biofilm formation of Staphylococcus aureus

“…A separate study that evaluated S. aureus biofilm formation in vitro reported that DNA of biofilm samples from medical device substrates treated with B. velezensis AP183 prior to subsequent S. aureus colonization revealed a significant relative abundance of B. velezensis, at 96.5% against S. aureus, at 3.5% based on ribotype relative abundance data 29 . The same study showed that B. velezensis AP183 could disrupt formed biofilms of S. aureus and noted the application of beneficial bacterial biofilms, which could hinder the adhesion and biofilm formation of pathogenic bacteria such as S. aureus as a prophylactic advantage.…”