Realising the health and wellbeing of adolescents

Adolescence is a critical stage of life characterised by rapid biological, emotional, and social development. It is during this time that every person develops the capabilities required for a productive, healthy, and satisfying life. In order to make a healthy transition into adulthood, adolescents need to have access to health education, including education on sexuality1; quality health services, including sexual and reproductive; and a supportive environment both at home and in communities and countries.The global community increasingly recognises these vital needs of adolescents, and there is an emerging consensus that investing intensively in adolescents’ health and development is not only key to improving their survival and wellbeing but critical for the success of the post-2015 development agenda.2 The suggested inclusion of adolescent health in the United Nations secretary general’s Global Strategy for Women’s and Children’s Health is an expression of this growing awareness and represents an unprecedented opportunity to place adolescents on the political map beyond 2015. Ensuring that every adolescent has the knowledge, skills, and opportunities for a healthy, productive life and enjoyment of all human rights3 is essential for achieving improved health, social justice, gender equality, and other development goals.We argue that the priority in the revised Every Women Every Child Global Strategy needs to be giving adolescents a voice, expanding their choices and control over their bodies, and enabling them to develop the capabilities required for a productive, healthy, and satisfying life. We call for a global, participatory movement to improve the health of the world’s adolescents as part of a broader agenda to improve their wellbeing and uphold their rights

Sporulating behavior influences the population dynamics of sporeformers during raw milk holding.

Thermoduric sporeformers are predominant in raw milk and form thermoduric endospores. Our previous research showed these sporeformers to cause biofouling of dairy contact surfaces and membranes, leading to cross contamination of final products. A critical factor influencing thermal inactivation is their form as vegetative cells or endospores. It would thus be of interest to understand the population dynamics of sporeformers in raw milk during storage at low temperatures. In our previous study, a low sporulating strain of Bacillus licheniformis showed an increasing trend in vegetative cell population during 72 h of storage at 10°C or higher, while maintaining spore population relatively static. In continuation, this study investigates population dynamics of a high sporulating strain of B. licheniformis (ATCC 14580). Raw milk samples were separately spiked with an average 4.0 log vegetative cells and 2.0 log spores/mL, and stored at 4°, 6°, 8°, 10°, and 12°C for 0, 24, 48, and 72 h. Standard protocols were followed for enumerating vegetative cells and spores. Three trials were conducted, in replicates of 3, and means were compared using ANOVA. Contour plots were developed using quadratic regression models to predict the population of vegetative cells and spores. In the vegetative cell spiking study, cell population remained mainly unchanged for 72 h up to 10°C, with more than 1.0 log change observed only at 12°C. As it was a sporulating strain, the spore spiking study validated a shift toward spores during storage at 4° to 8°C, with evidence of some parallel germination at 10°C or higher. The regression models helped us to develop contour plots across the holding temperature and duration. Based on the initial cell population of the spore former, such contour plots would help predict the presence of vegetative cells and spore populations in raw milk at a given time and temperature. This information will prove useful in optimizing raw milk holding conditions to keep the sporeformer population toward vegetative cells, which can subsequently be inactivated easily with thermal treatments such as pasteurization

Manufacturing low-spore-count skim milk powder by controlling raw milk holding conditions—A pilot-scale trial

Milk powder is one of the most traded dairy products globally, largely being used to manufacture commercially sterilized products. Skim milk powder is frequently contaminated with spores of Bacillus species and carried over from raw milk due to their ability to survive processing conditions. Our previous study proved that it is possible to use optimized raw milk holding conditions to keep their population low, which may help in making low spore count powder. This pilot scale trial was conducted to produce low spore count powder by controlling the raw milk holding conditions, to keep the spore populations low. Bacillus licheniformis being a predominant spore former in milk powders was used as an inoculant for the challenge study. Inoculated raw milk samples (batches of 1500 lbs each) were held at optimized storage conditions T1 (4°C for 24 h) and T2 (8°C for 72 h). The PMO based storage condi tions (10°C for 4 h followed by 7°C for 72 h) were kept as a control, before producing skim milk powder. Samples were drawn at different stages pre- and post-storage, pasteurization (73°C for 15 s), evaporation, and spray drying (outlet and inlet temperature of 200 and 95°C, respectively), and analyzed for sporeformers using standard culturing methods. Spore counts were done by heating the samples at 80°C for 12 min, before plating on Brain Heart Infusion agar. All samples were analyzed in the replicates of 3, and means were compared using ANOVA. Treatment T1 and T2 log spore counts (1.79 ± 0.03 and 1.82 ± 0.04, respectively), were significantly lower than control (2.59 ± 0.05), after raw milk storage step. Similarly, sporeformers log counts for T1 (3.84 ± 0.02) were significantly lower than T2 (4.07 ± 0.08) and control (4.13 ± 0.04). Skim milk powders prepared using optimized storage conditions T1 showed significantly (P \u3c 0.05) lower spore and sporeformer counts (0.58 ± 0.04 and 1.82 ± 0.05 log cfu/g), as compared with T2 (0.86 ± 0.16 and 1.90 ± 0.03) respectively, and control (1.03 ± 0.06 and 2.74 ± 0.03, respectively). This shows that skim milk powders with reduced counts can be prepared by just optimizing raw milk holding conditions

Ratiometric fluorescence spectroscopy—A novel technique for rapid detection of bacterial endospores

The current spore detection methods rely on cultural techniques, having limitations of time, efficiency, and sensitivity. Spore coat contains cal cium dipicolinic acid (CaDPA) as a major constituent, which can serve as a biomarker for bacterial endospores. We report a rapid and sensitive technique for detection of bacterial endospores by using ratiometric fluorescence-based sensors. This method is based on the detection of CaDPA that enhances luminescence of lanthanide ion, when complexed with a semiconducting polymer. A CaDPA standard curve was generated at excitation-emission wavelength of λ284-λ528 by using Synergy 2 fluorescence spectrophotometer. Intensity was recorded after chelating semiconducting fluorescent polyfluorene (PFO) dots with terbium ions, sensitized by different volumes of CaDPA (0.1 μM). All trials were conducted in the replicates of 3 and mean ± SE were calculated. The standard curve so generated showed a linear relationship (R2 = 0.98) in experimental concentration range of 2.5 to 25 nM of CaDPA, with corresponding intensity (a.u.) of 545 to 2130. Endospores of an aerobic spore former, Bacillus licheniformis ATCC 14580, were produced at 37°C for 15 d, on Brain Heart Infusion agar. The efficiency of sporulation was evaluated by spore staining and plating techniques. Total CaDPA content in spores was estimated after suspending reducing concentrations of spores (logs 9.0 through 1.0 cfu/mL, at 1-log intervals) in HPLC-grade water. For higher spore spiking levels such as 9.2 ± 0.03, 8.4 ± 0.05, 7.1 ± 0.13 and 6.3 ± 0.02 logs, the mean CaDPA content values, observed from the standard curve, were 9.4, 7.2, 6.2 and 5.3 nM, whereas, for lower levels of 4.2 ± 0.05, 3.1 ± 0.04, 2.0 ± 0.11, and 1.36 ± 0.09 logs, we observed 3.8, 3.3, 2.2 and 1.3 nM mean CaDPA content. Our results indicated a linear relationship of the CaDPA content of endospores with that of the endospore counts, and the standard curve of CaDPA concentration. This study provides a proof of concept for a potential application of this technique to rapidly detect bacterial endospores in dairy and food industry. Further studies are in progress in our laboratory to standardize this technique for dairy product matrices such as cheese, whey proteins, and powders

Manufacturing low-spore-count skim milk powders by combining optimized raw milk holding conditions and hydrodynamic cavitation

The presence of high numbers of Bacillus spores in skim milk powder limits its application for creating UHT products. The dairy industry has been emphasizing on developing strategies for reducing sporeformers and spores in skim milk powder. Previous studies conducted in our 10 J. Dairy Sci. Vol. 102, Suppl. 1 lab showed that it is possible to produce lower spore count skim milk powder, either by optimizing raw milk holding conditions or by using hydrodynamic cavitation as a process intervention. It was hypothesized that by combining the 2 processes it may be possible to further lower the sporeformers and spore counts in the final product. Pilot-scale challenge studies were conducted by spiking raw skim milk with approx. 4.0 log cfu/mL sporeformers and 2.0 log cfu/mL spores of Bacillus licheniformis. The inoculated raw skim milk was divided in to 3 parts and exposed to 3 treatment (T1, T2 and control) for keeping the spore and sporeformer populations low in raw milk, before manufacturing skim milk powder. Powder prepared using treatment 1 (T1) includes raw milk holding at 4°C for 24 h, treatment 2 (T2) includes holding at 4°C for 24 h combined with 2 pass hydrodynamic cavitation, whereas, control includes holding raw spiked skim milk at 10°C for 4 h and then at 7°C for up to 72 h (PMO based conditions). Spiked raw milk samples from all 3 treatments were HTST pasteurized (73°C for 15 s), evaporated, and dried (outlet and inlet temperature of 200 and 95°C) to obtain skim milk powders. Spore and sporeformer counts of samples from 3 treatments were statistically compared after initial treatments (T1, T2, and control), pasteurization, evaporation, and drying steps. Final spore and sporeformer counts from powder prepared using T1 (0.58 ± 0.04, 1.82 ± 0.05 log cfu/g), T2 (0.33 ± 0.27, 1.49 ± 0.07 log cfu/g) and control (2.74 ± 0.03 and 1.03 ± 0.06 log cfu/g) were significantly different (P \u3c 0.05) with respect to each other. Our results demonstrate that combining cavitation with optimized raw milk holding conditions (treatment T2) produces skim milk powder with least sporeformers and spore counts

Sporulation behavior of Bacillus licheniformis strains influences their population dynamics during raw milk holding

To understand the role of strain variability, population dynamics of 2 strains of Bacillus licheniformis, ATCC 6634 and ATCC 14580, were modeled as a function of temperature (4.0–12.0°C) and duration (0–72 h) using regression analysis. Based on the initial spiking of vegetative cells (approximately 4.0 log cfu/mL) and spores (approximately 2.0 log cfu/mL), regression equations, elucidating B. licheniformis growth behavior during raw milk holding at low temperature, were obtained. Contour plots were developed to determine the time-temperature combinations, keeping the population changes to less than 1.0 log. In vegetative cell spiking study of B. licheniformis ATCC 6634 (S1), cell population changes remained below 1.0 log up to 72 h at 8°C. For B. licheniformis ATCC 14580 (S2), 1.0 log shift was not observed only after 80 h at 8°C, indicating higher multiplication potential of S1 as compared with S2. As S2 was a readily sporulating strain, the vegetative spiking study showed spore formation at different storage temperatures. Evidence of some parallel germination was observed for this strain at 8°C or higher, when raw milk samples were spiked with spores. The experimental values obtained for sporeformers and spore counts were validated with contour plot-generated values. Overall, for raw milk samples predominated by the low sporulating strain, the contour plots suggested holding at 8°C or below for up to 72 h. In the case of the readily sporulating strain (S2), raw milk could be held at 8°C for 80 h, where little or no sporulation is observed. Sporulation behavior, germination and multiplication ability, strain variability, and temperature and duration of holding raw milk influenced the population dynamics of Bacillus species. However, in the presence of equivalent numbers of both types of sporulating strains in raw milk, despite strain variability, holding milk at 8°C for not more than 72 h would keep any cell population changes below 1.0 log. In addition, under these storage conditions, the population would remain as vegetative cells that are likely to be inactivated by pasteurization. The contour plots, so generated, would help predict the population shifts and define optimum holding conditions for raw milk before further processing