E. OLOTON

This study examined the modulation of Escherichia coli growth by Lactobacillus rhamnosusinthe presence of polyethylene glycol (PEG), glycero-gelatin, and Theobroma. Growthkineticswere analysed using regression models of colony-forming unit counts over time. In monoculture, E. coli exhibited exponential growth (y = 6.6 + 0.21x, R² = 0.874). Co-culture with L. rhamnosussignificantly suppressed E. coli proliferation (y = 5.97 + 0.02x, R² = 0.324; p < 0.001). Theinclusion of glycero-gelatin moderately stabilized this inhibition (y = 5.93 + 0.03x, R² =0.462; p< 0.001), while PEG produced a synergistic effect, completely halting E. coli growth (y =4.46−0.003x, R² = 0.005; p < 0.001). In contrast, Theobroma reversed inhibition (y = 8.13 +0.17x, R² = 0.679; p = 0.436). These results indicate that physicochemical conditions strongly influenceprobiotic–pathogen interaction, with PEG amplifying inhibition, glycero-gelatin enhancingstability, and Theobroma antagonizing probiotic action against Escherichia coli.

The meaning of probiotics has been altered with expanding information in the field of how they work. (Thantsha, 2012) The term is gotten from the Greek language meaning 'for life. In the past, there have been many endeavors to characterize the term probiotic, one of the first being portrayed by Lilly and Stillwell in 1965 (Thantsha, 2012) . They defined probiotics as “substances secreted by one microorganism, which stimulates the growth of another”. The focal point of this definition was to recognize them and clarify that they are something contrary to antibiotics. Hence, in 1974, Parker characterized them as “organisms and substances which contribute to intestinal microbial balance” (Schrezenmier & de Vrese, 2001). In 1989, Fuller tried to improve on Parker’s definition by proposing the following definition: “live microbial feed supplement, which beneficially affects the host (animal or human) by improving its intestinal microbial balance” (Salminen et al, 1999; Vilsiljevic & Shah, 2008). Then, Havenaar & Huis In’t Veld (1992) defined probiotics acceptably as ‘a viable mono- or mixed culture of microorganisms which applies to animal or man, beneficially affects the host by improving the properties of the indigenous microflora’. Schrezenmeir & de Vrese (2001) defined the term probiotic as “a preparation of or a product containing viable, defined microorganisms in sufficient numbers, which alter the microflora by implantation or colonization, in a compartment of the host and by that, exert beneficial effects on host health”. Among these depictions and definitions, there were numerous others,

Introduction: The survival and interaction of probiotic microorganisms in pharmaceutical carriers are critical in determining their therapeutic efficacy. This study investigated the survival pattern of Lactobacillus gasseri in the presence of selected suppository bases and Escherichia coli , with the aim of identifying a suitable base that enhances probiotic viability while inhibiting pathogenic growth. Methods: Pure cultures of Lactobacillus gasseri and Escherichia coli were obtained and characterized through Gram staining and biochemical tests. Survival studies were conducted
by inoculating the organisms in media containing different suppository bases— glycerogelatin, Polyethylene Glycol (POLYETHYLENE GLYCOL), and Theobroma base—and monitoring their growth patterns over time. The regression equations for the
growth curves were determined as follows: control Lactobacillus gasseri, y = 6.81 + 0.18x; glycerogelatin, Escherichia coli , y = 4.31 − 0.06x; POLYETHYLENE GLYCOL, Escherichia coli , y = 3.27 + 0.24x; Theobroma base, Escherichia coli , y = 6.93 + 0.23x. Statistical analyses were performed to evaluate significance (p < 0.05)

Probiotic organisms coexist with a diverse range of pathogenic microbes within mucosal environments, where survival is influenced by ecological competition and surrounding physicochemical conditions. Lactobacillus reuteri is known to exert antagonistic effects against Escherichia coli, yet its viability can be altered by the medium in which it is delivered. This study evaluated the survival of L. reuteri in selected suppository bases in the presence of E. coli. L.
reuteri was incorporated into glycerogelatin, polyethylene glycol (PEG), and theobroma bases, and co-incubated with E. coli. Viable counts were monitored over time and survival was analysed using linear regression, while differences in survival relative to the control were evaluated using
paired t-test. Theobroma supported the highest survival of L. reuteri (slope = 0.26; R2 = 0.795), followed by
polyethylene glycol (slope = 0.25; R2 = 0.799), indicating that these environments better maintained microbial viability under competitive stress. In contrast, glycerogelatin significantly reduced L. reuteri survival (slope = 0.06; R2 = 0.229), with the reduction being highly significant
(P < 0.001), suggesting strong susceptibility to inhibitory effects. The result of the finding indicate that the survival of L. reuteri in the presence of E. coli is markedly influenced by the surrounding base, and theobroma base with a lipid and polymeric nature provide more favorable conditions for probiotic persistence than glycerogelatin which is a hydrophilic gelatinous systems.

Bacteria possess special features which help them attach to biotic and abiotic surfaces alike. Adhesion of bacteria to surfaces contribute to the spread of infections via contact with these surfaces, be it biotic or abiotic. On abiotic surfaces however, bacteria form biofilms, making them more difficult to eliminate. Solubilizing agents facilitate penetration of a substance into another in which it would be normally insoluble. They are used as cleaning agents, emulsifiers, vehicles, cosolvents, etc. Lactobacilli are a type of Gram-positive, nonsporulating bacteria. The aim of this study was to investigate the ability of certain solubilizing agents to detach bacteria attached to an abiotic (glass) surface, by quantifying the bacterial cells grown from a solution of the solubilizing agent. Minimum inhibitory concentrations of the solubilizing agents were first determined. A non-inhibitory concentration of the solubilizing agent was then used to detach lactobacilli attached to a glass surface and the resulting solution was diluted serially and plated out. Quantitative bacterial quantification was performed by determining colony forming units/ml. Spectrophotometric method was used to qualitatively quantify bacterial detachment. Results showed a higher cell count from the solubilizing agent than from the control, indicating that they are indeed well able to elicit bacterial detachment from abiotic surfaces.