Oral probiotic and its delivery carriers to improve oral health: A review

In recent years, oral probiotics have been researched on their effectiveness in reducing and preventing oral diseases. Oral probiotics could be introduced into the oral cavity to keep the equilibrium of the microbiome. Hence, the delivery carrier for oral probiotics plays an important factor to ensure a high number of oral probiotics were delivered and released into the oral cavity. This review presents a brief overview of oral microbiota and the role of oral probiotics in reducing oral diseases. Moreover, important aspects of the oral probiotic product such as viability, adherence ability, health effects, safety, and delivery site were discussed. Besides that, the importance of utilizing indigenous oral probiotics was also emphasized. Oral probiotics are commonly found in the market in the form of chewing tablets, lozenges, and capsules. Hence, the oral probiotic carriers currently used in the market and research were reviewed. Furthermore, this review introduces new potential oral probiotic delivery carriers such as oral strip, bucco-adhesive gel, and mouthwash. Their effectiveness in delivering oral probiotics for oral health was also explored.

The ability of Aliarcobacter butzleri strains isolated from foods of animal origin in Costa Rica to form biofilm

Aliarcobacter butzleri is a zoonotic emerging food and waterborne pathogen widely distributed in nature. It is present in food processing environments and can easily be spread through the food industry because of its ability to form biofilm. The aim of this work was to determine the ability of strains isolated in Costa Rica from different food matrixes of animal origin to form biofilm. Thirty-eight A. butzleri strains previously isolated and identified from animal origin products were analyzed using the method described by Stepmovic et al. (2000), in three culture broths, brain heart infusion broth, Boer broth and Houf broth. Results showed that 67% of poultry origin strains, 62.5% of meat origin strains and just 8% of milk origin strains showed ability to form biofilm. The findings of this study confirm the adherence ability of A. butzleri to form biofilm, a characteristic that can promote dispersion and cross contamination along food industry processing lines.

Multidrug-resistant Staphylococcus aureus (MDRSA) properties and their adherence ability on stainless steel surfaces at different temperature and time

Staphylococcus aureus is a pathogenic bacterium that capable to adhere on the processing surfaces that could cause a cross-contamination of foods. In Malaysia, S. aureus has been reported from foods and food-handlers hand at food service environment but the multidrug -resistant S. aureus (MDRSA) and their adherence on stainless steel were limited. This study was intended 1) to isolate S. aureus from food contact surfaces and characterize the isolates for MDRSA properties, and 2) to determine the adherence ability of the MDRSA strains. A total of thirty-eight S. aureus isolated from food premises in Sri Serdang were tested for the antibiotic resistance and it was carried out using five classes of antibiotics; Penicillin (I), Cephalosporins (II), Amino-glycosides (III), Quinolones Fluoroquinolone (IV), and Sulphonamide (V) by the standard procedures of Kirby-Bauer disc diffusion method. The adherence assay was performed on stainless steel disc at 25oC and 37oC on 24, 48 and 72 hrs incubation. As a result, twenty-three S. aureus were found as multidrugresistant towards the antibiotics. All the MDRSA can adhere on stainless steel with a minimum 4.00 log CFU/mL. The adherence of MDRSA on stainless steel during 72 hrs were ranging from 4.11 to 6.55 log CFU/mL and 4.25 to 6.86 log CFU/mL at 25oC and 37oC, respectively. The highest adherence was found on 48 hrs at both temperatures. The MDRSA strains revealed high capacity to adhere on stainless steel at 37oC. As a conclusion, the MDRSA strains shows the strong adherence ability at their optimum growth temperature.

Qualitative and Quantitative Coating Tests: A Comparison in Magnesia–Spinel Refractory Bricks

In cement processing, which involves the production of clinker in rotary kilns, the main refractories used in the transition and burning zones are magnesia–spinel bricks. These bricks present suitable chemical and thermomechanical properties, not to mention that they can be easily landfilled. Among the main wear mechanisms of these bricks in the kiln, the infiltration of alkaline salts is noteworthy and occurs through the open pores of the refractory. In this way, the coating—a clinker layer adhered to the brick surface—appears as a protection mechanism of the lining against infiltration. Thus, the objective of this investigation is to run a qualitative coating test based on the contact method, and quantitative coating test based on the sandwich method to check the suitability of the methodologies and to evaluate the coating adherence on two different magnesia–spinel bricks. It was possible to distinguish the superior adherence ability of brick B in both coatings due to the higher porosity and the presence of nonreacted ZrO2. Despite the similarity between the test results, the quantitative sandwich-coating test is preferable because it does not depend on subjective analysis.

Enterotoxins production, biofilm formation and antimicrobial resistance of Staphylococcus aureus strains isolated from refrigerated raw cow milk

This study aimed to isolate Staphylococcus aureus in refrigerated raw cow milk, and identify the presence of enterotoxin-expression genes, enterotoxin production and adherence ability, and antimicrobial resistance potential of the isolated strains. Fifty raw milk samples obtained in different dairy farms were analyzed for S. aureus and evaluated in the isolates the presence of genes associated with the production of major staphylococcal enterotoxins and biofilm formation. In vitro assays were also performed to evaluate the production of enterotoxins and adherence ability, and the antimicrobial resistance. One half (25/50) of raw milk samples presented coagulase-positive staphylococci and 95.2% of the isolates were confirmed to be S. aureus. Among them, 42.4% were carrying genes for enterotoxins production; however, only one isolate was able to produce enterotoxins. All S. aureus isolates were carrying at least two genes associated with biofilm formation and 95.2% isolates was able to adhere upon the in vitro assay. All isolates demonstrated antimicrobial resistance potential to one or more of the tested antibiotics.

Isolation and Characterization of Lactobacillus spp. from Kefir Samples in Malaysia

Kefir is a homemade, natural fermented product comprised of a probiotic bacteria and yeast complex. Kefir consumption has been associated with many advantageous properties to general health, including as an antioxidative, anti-obesity, anti-inflammatory, anti-microbial, and anti-tumor moiety. This beverage is commonly found and consumed by people in the United States of America, China, France, Brazil, and Japan. Recently, the consumption of kefir has been popularized in other countries including Malaysia. The microflora in kefir from different countries differs due to variations in culture conditions and the starter media. Thus, this study was aimed at isolating and characterizing the lactic acid bacteria that are predominant in Malaysian kefir grains via macroscopic examination and 16S ribosomal RNA gene sequencing. The results revealed that the Malaysian kefir grains are dominated by three different strains of Lactobacillus strains, which are Lactobacillus harbinensis, Lactobacillusparacasei, and Lactobacillus plantarum. The probiotic properties of these strains, such as acid and bile salt tolerances, adherence ability to the intestinal mucosa, antibiotic resistance, and hemolytic test, were subsequently conducted and extensively studied. The isolated Lactobacillus spp. from kefir H maintained its survival rate within 3 h of incubation at pH 3 and pH 4 at 98.0 ± 3.3% and 96.1 ± 1.7% of bacteria growth and exhibited the highest survival at bile salt condition at 0.3% and 0.5%. The same isolate also showed high adherence ability to intestinal cells at 96.3 ± 0.01%, has antibiotic resistance towards ampicillin, penicillin, and tetracycline, and showed no hemolytic activity. In addition, the results of antioxidant activity tests demonstrated that isolated Lactobacillus spp. from kefir G possessed high antioxidant activities for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing ability of plasma (FRAP), and 1,1-diphenyl-2-picryl-hydrazine (DPPH) assay compared to other isolates. From these data, all Lactobacillus spp. isolated from Malaysian kefir serve as promising candidates for probiotics foods and beverage since they exhibit potential probiotic properties and antioxidant activities.