No abstract

The aim of this work was to assess the viability of some commercial probiotics after exposure to gastric acid and the possibility of modifying these formulations for delivery into the distal parts of the intestines. Gastrointestinal tolerance testing was conducted for three commercial probiotics and an in-house freeze-dried Lactobacillus acidophilus strain. The contents of the commercial products and the in-house freeze-dried strain were then loaded into capsules for site-specific delivery into the colon using the Phloral coating technology; the viability upon release was then ascertained. An assessment of the potential of these products to adhere to intestinal cells was also conducted. The results showed that all the commercial products contained the minimum number of probiotic strains as indicated on their respective packages. When gastric acid tolerance tests were performed on these products, all the commercial probiotics and the prepared freeze-dried strain demonstrated over 10 CFU reductions within 5min. When these were encapsulated for site-specific delivery into the distal parts of the gut, viabilities of approximately 90% were obtained after these capsules had been initially deposited in gastric acid for 2h. An evaluation of the ability of the probiotic formulations to adhere to intestinal cells demonstrated adhesion in the range 64-76% for the products evaluated. The need to target the delivery of probiotics into the intestines has been demonstrated here as this offers a greater potential for colonisation of the intestines once the harshness of the stomach has been overcome.

Background: Candida is the leading cause of vaginitis, and 75% of women have at least one episode of infection in their lives, with pregnancy being a predisposing factor. If left untreated, vulvovaginal candidiasis (VVC) can lead to chorioamnionitis with subsequent abortion, prematurity and congenital infection of the neonate. We aimed to determine the prevalence of VVC, identify the recent and most frequently occurring species of Candida in pregnant women, and determine the most effective antifungal drug of choice for treatment. Method: A prospective cross-sectional study in which 176 high vaginal swab samples of consented pregnant women visiting the antenatal clinic from February 2018 to April 2018 were subjected to direct gram smear and culture for Candida isolation. Candida isolates were identified using a germ tube test and HiCrome Candida differential agar. Candida isolates were then subjected to a disk diffusion method using fluconazole (25 μg), nystatin (100 units), and voriconazole (1 μg) on Mueller-Hinton agar supplemented with 2% (w/v) glucose and 0.5 μg/ml methylene blue dye to determine the susceptibility pattern as per the guidelines of the Clinical Laboratory Standard Institute (CLSI). Chi-square analysis was used to ascertain the significant association of participants' sociodemographics and clinical presentations to VVC. A univariate logistic regression model was used to identify potential risk factors of VVC.

Antimicrobial resistance (AMR) remains an important global public health issue with antimicrobial misuse and overuse being one of the main drivers. The Global Point Prevalence Survey (G-PPS) of Antimicrobial Consumption and Resistance assesses the prevalence and the quality of antimicrobial prescriptions across hospitals globally. G-PPS was carried out at 17 hospitals across Ghana, Uganda, Zambia and Tanzania. The overall prevalence of antimicrobial use was 50% (30–57%), with most antibiotics prescribed belonging to the WHO ‘Access’ and ‘Watch’ categories. No ‘Reserve’ category of antibiotics was prescribed across the study sites while antimicrobials belonging to the ‘Not Recommended’ group were prescribed infrequently. Antimicrobials were most often prescribed for prophylaxis for obstetric or gynaecological surgery, making up between 12 and 18% of total prescriptions across all countries. The most prescribed therapeutic subgroup of antimicrobials was ‘Antibacterials for systemic use’. As a result of the programme, PPS data are now readily available for the first time in the hospitals, strengthening the global commitment to improved antimicrobial surveillance. Antimicrobial stewardship interventions developed included the formation of AMS committees, the provision of training and the preparation of new AMS guidelines. Other common interventions included the presentation of findings to clinicians for increased awareness, and the promotion of a multi-disciplinary approach to successful AMS programmes. Repeat PPS would be necessary to continually monitor the impact of interventions implemented. Broader participation is also encouraged to strengthen the evidence base.

No abstract

Warfarin is a widely used anticoagulant that is critical in reducing patient morbidity and mortality associated with thromboembolic disorders. However, its narrow therapeutic index and large inter-individual variability can lead to complex dosage regimes. Formulating warfarin as an orodispersible film (ODF) using thermal ink-jet (TIJ) printing could enable personalisation of therapy to simplify administration. Commercial TIJ printers are currently unsuitable for printing the milligram dosages, typically required for warfarin therapy. As such, this study aimed to modify a commercial TIJ printing system to formulate personalised warfarin ODFs containing therapeutic dosages. A TIJ printer was modified successfully with the printer functionality intact; the substrate (paper) rolling mechanism of the printer was replaced by printing onto a stationary stage. Free film substrates were composed of hydroxypropyl methylcellulose (20%w/w) and glycerol (3%w/w). The resulting ODFs were characterised for morphology, disintegration, solid-state properties and drug content. Printed film stability was assessed at 40 °C/75% relative humidity for 30 days. Therapeutic warfarin doses (1.25 and 2.5 mg) were successfully printed onto the film substrates. Excellent linearity was observed between the theoretical and measured dose by changing the warfarin feed concentration (R = 0.9999) and length of the print objective, i.e. the Y-value, (R = 0.9998). Rapid disintegration of the ODFs was achieved. As such, this study successfully formulated personalised warfarin ODFs using a modified TIJ printer, widening the range of applications for TIJ printing to formulate narrow therapeutic index drugs.

An isothermal microcalorimetric assay was used to quantify the efficacy of a silver-containing wound dressing against two common wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. The growth patterns of the two species were unique and varied depending on the environment in which the organisms were grown. Addition of non-silver-containing dressing altered the growth kinetics while addition of silver (contained either in a dressing or as AgNO3 solution) was seen to elicit inhibition and/or kill depending on concentration. Tests were conducted in nutrient broth and simulated wound fluid. It was found that minimum inhibitory and minimum bactericidal concentration values were higher in simulated wound fluid and under anaerobic conditions. Bioavailability of silver from the wound dressing was 35% against S. aureus in nutrient broth and 68% against both species in simulated wound fluid. The data highlight the importance of developing and conducting in vitro assays in biorelevant media.

Oral infections like dental caries are major public health issues globally. Management of these conditions include methods like brushing, tongue cleaning and dental flossing with or without the use of antibiotics. A major challenge with these management approaches is the difficulty to obtain complete eradication of the disease-causing organisms. An alternative approach is the use of probiotics, which can be administered in oro-dispersible films (ODFs), and which have prolonged activity in the mouth. ODFs made of xylitol and containing Streptococcus salivarius were formulated using inkjet printing and tested against Streptococcus mutansa causative organism of dental caries. The testing of the prepared ODFs involved co-incubating ink-jetted formulation of S. salivarius and xylitol with S. mutans and monitoring the microbial growth kinetics in real-time using isothermal microcalorimetry and colony plate counts. Cell-free supernatants (CFS) of S. salivarius were also tested against S. mutans. Prior to the formulation the phosphate solubilisation potential of S. salivarius was determined and found to be negative, a sign that the species will not deplete phosphate from teeth. From the tests, it was observed that the formulation reduced S. mutans population from 7.9 to 5.04-Log CFU/mL post-calorimetry (approximately 3-Log reduction) which was comparable to the 99.9% reduction expected during antimicrobial activity testing. A gradual decrease in S. mutans population was also observed with increasing of S. salivarius CFS volumes indicative of pathogen suppression. This study demonstrates that S. salivarius can be useful in managing dental caries and ODFs of S. salivarius can be formulated easily using ink-jetting for such management.