Assessment of the antifungal efficacy of whey fermentate alone or in combination with citrus extract to control Aspergillus flavus mold in semi-moist pet food for dogs

Semi-moist pet foods contain moisture levels ranging from 15 to 40%, making them ideal for mold growth and mycotoxin production. To control spoilage, synthetic mold inhibitors such as potassium sorbate have been used, but consumers prefer "natural" preservatives. Whey fermentate (WPF) is an efficient antifungal, but it requires large doses. Therefore, the objective of this study was to determine the antifungal effect of WPF alone or in combination with citrus extract oil (CEX) against Aspergillus flavus in semi-moist pet food. Nutritionally complete semi-moist pet foods were produced with WPF alone [0.25, 0.5, and 1.0% (w/w)] and in combination with CEX; 0.25% WPF+ 0.015% CEX, 0.25% WFP+ 0.15% CEX, 0.5% WPF+ 0.015% CEX, and 0.5% WFP+ 0.15% CEX (w/w). The negative control (NC) contained no antifungal additive and the positive control (PC) had potassium sorbate (0.1% w/w). The semi-moist pet food was thermally formed and was cut into 3 cm × 3 cm square pieces. Individual food pieces were inoculated with 0.1 mL of Aspergillus flavus (ATCC 204304) to achieve a final concentration of ~5.0 log CFU/piece. The inoculated pieces were individually incubated at 25°C. Fungal analysis was performed on day 3, 6, 9, 12, 15, 18, 21, 24, and 28 by surface plating on Potato Dextrose Agar (PDA) followed by incubation at 25°C for 72 h. The total log reductions were calculated by subtracting the initial inoculum from the final log counts on day 28. Higher log reductions of Aspergillus flavus (p < 0.05) were observed when WPF at 0.25 and 0.5% was combined with 0.15% CEX compared to when 0.015% CEX was used individually. All treatments were different from the NC (p < 0.05). Citrus extract at 0.15% potentiated the antifungal effect of WPF at 0.5% to give a similar log reduction (p > 0.05) to WPF at 1.0% in the food. In conclusion, CEX potentiated the antifungal efficacy and reduced the dose of WPF required to control Aspergillus flavus in semi-moist dog food.

Application of encapsulated and dry-plated food acidulants to control Salmonella enterica in raw meat-based diets for dogs

There is an increasing demand for raw meat-based diets (RMBDs) for dogs, but these foods cannot be heat-pasteurized. Thus, the objective of this study was to evaluate the antimicrobial efficacy of encapsulated and dry-plated glucono delta lactone (GDL), citric acid (CA), and lactic acid (LA) when challenged against Salmonella enterica inoculated in a model raw meat-based diet (RMBDs) for dogs. Nutritionally complete, raw diets were formulated with different levels (1.0, 2.0 and 3.0% (w/w)) of both encapsulated and dry-plated GDL, CA, and LA with both the positive (PC) and the negative controls (NC) without acidulants. The diets were formed into patties of ∼100 g and inoculated with 3-cocktail mixtures of Salmonella enterica serovars, excluding the NC to achieve a final concentration of ∼6.0 Log CFU/patty. Microbial analyses were performed on the inoculated diets and survivors of S. enterica enumerated. Both encapsulated and dry-plated CA and LA had higher log reductions compared to GDL (P < 0.05). However, encapsulated CA and LA at 1.0% (w/w) exhibited higher log reductions (P > 0.05) and preserved product quality compared to the dry-plated acidulants at 1.0%. We concluded that 1.0% (w/w) of encapsulated citric or lactic acids could be successfully applied as an antimicrobial intervention in raw diets for dogs.

108 Citrus oil Extract Potentiates the Antifungal Efficacy of Whey Protein Fermentate AgainstAspergillus Flavus in Semi-Moist pet Treats for Dogs

Semi-moist pet treats contain moisture content ranging from 20-30% making them ideal for mold growth and mycotoxin production. To control spoilage, synthetic mold inhibitors, such as potassium sorbate, have been used. Unfortunately, consumers would prefer “natural” preservatives. Whey protein fermentate (WPF) is an efficient antifungal, albeit in large doses. Therefore, the objective of this study was to determine the effect of citrus extract (CX) to potentiate WPF against Aspergillus flavus in semi-moist pet treats. Nioutritionally complete semi-moist dog treats were produced with WPF alone [0.25%, 0.5% and 1.0% (w/w)] or in combination with CX [0.25% WPF+ 0.015% CX, 0.25% WFP+ 0.15% CX, 0.5% WPF+ 0.015% CX, 0.5% WFP+ 0.15% CX (w/w)]. The negative control (NC) contained no antifungal additive and the positive control had potassium sorbate (0.1% w/w). Treats were baked into 3cm x 3cm squares. Individual squares were inoculated with 0.1 mL of Aspergillus flavus (ATCC 204304) to achieve a final concentration of ~ 5.0 Log CFU/square. The inoculated squares were individually incubated at 250 C. Fungal analysis was performed at day 3, 6, 9, 12, 15, 18, 21, 24 and 28 by surface plating on Potato Dextrose Agar (PDA) followed by incubation at 250 C for 72h. The total log reductions were calculated by subtracting the initial inoculum with the colony counts on day 28. Log reductions of Aspergillus flavus (P&lt; 0.05) were observed when WPF at 0.25% and 0.5% were added with 0.15% CX compared with when 0.015% CX was applied. All treatments were different from the NC (P&lt; 0.05). Citrus extract at 0.15% potentiated the antifungal potency of WPF at 0.5% to give a similar log reduction (P &gt;0.05) to WPF at 1.0% the treats. In conclusion, CX reduced the dose of WPF required to control Aspergillus flavus in semi-moist dog treats.

Routine HIV clinic visit adherence in the African Cohort Study

Background

Retention in clinical care is important for people living with HIV (PLWH). Evidence suggests that missed clinic visits are associated with interruptions in antiretroviral therapy (ART), lower CD4 counts, virologic failure, and overlooked coinfections. We identified factors associated with missed routine clinic visits in the African Cohort Study (AFRICOS).

Methods

In 2013, AFRICOS began enrolling people with and without HIV in Uganda, Kenya, Tanzania, and Nigeria. At enrollment and every 6 months thereafter, sociodemographic questionnaires are administered and clinical outcomes assessed. Missed clinic visits were measured as the self-reported number of clinic visits missed in the past 6 months and dichotomized into none or one or more visits missed. Logistic regression with generalized estimating equations was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between risk factors and missed visits.

Results

Between January 2013 and March 2020, 2937 PLWH were enrolled, of whom 2807 (95.6%) had initiated ART and 2771 had complete data available for analyses. Compared to PLWH 50+, missed clinic visits were more common among those 18–29 years (aOR 2.33, 95% CI 1.65–3.29), 30–39 years (aOR 1.59, 95% CI 1.19–2.13), and 40–49 years (aOR 1.42, 95% CI 1.07–1.89). As compared to PLWH on ART for < 2 years, those on ART for 4+ years were less likely to have missed clinic visits (aOR 0.72, 95% CI 0.55–0.95). Missed clinic visits were associated with alcohol use (aOR 1.34, 95% CI 1.05–1.70), a history of incarceration (aOR 1.42, 95% CI 1.07–1.88), depression (aOR 1.47, 95% CI 1.13–1.91), and viral non-suppression (aOR 2.50, 95% CI 2.00–3.12). As compared to PLWH who did not miss any ART in the past month, missed clinic visits were more common among those who missed 1–2 days (aOR 2.09, 95% CI 1.65–2.64) and 3+ days of ART (aOR 7.06, 95% CI 5.43–9.19).

Conclusions

Inconsistent clinic attendance is associated with worsened HIV-related outcomes. Strategies to improve visit adherence are especially needed for young PLWH and those with depression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00425-0.

PSX-A-4 Late-Breaking: Assessing the antifungal efficacy of EverWildTM D01 against Aspergillus flavus in semi-moist pet treats

Semi-moist pet treats contain moisture levels ranging from 20–30% making them ideal for mold growth and mycotoxin production. To control mold, synthetic mold inhibitors such as potassium sorbate or calcium propionate are used. Synthetic additives are effective, but there is a shift in the pet owner preferences for ‘natural’ products. Fermented and (or) cultured whey has been shown to contain antifungal metabolites and has been used to control fungal growth in bread. EverWildTM D01 is a commercially available cultured whey product. The objective of this study was to assess the efficacy of EverWildTM D01 against Aspergillus flavus in a semi-moist pet treat. A model semi-moist pet treat fortified to be nutritionally complete was produced with three levels of powdered whey fermentate, [1.0%, 3.0% and 5% (w/w)], a negative control with no antifungal and a “positive control” which contained potassium sorbate as a standard industrial mold inhibitor. Treats were produced by baking in 3cm x 3cm squares. Individual squares were inoculated with 0.1 mL of Aspergillus flavus (ATCC 204304) to achieve a final concentration of ~ 5.0 Log CFU/square. The inoculated squares were individually incubated at 250 C. Fungal analysis was performed at day 3, 6, 9, 12, 15, 18, 21, 24 and 28 by surface plating on Potato Dextrose Agar (PDA) followed by incubation at 250 C for 72h. The total log reductions were calculated by subtracting the initial inoculum with the colony counts on day 28. EverWildTM D01 at 1.0%, 3.0%, and 5% (w/w) had a 1.90, 3.89 and 4.58 Log CFU/square log reduction, respectively. The positive control had a 1.19 Log CFU/square log reduction. All treatments differed from the negative control (P &lt; 0.05). In conclusion, EverWildTM D01 may be effective as a natural alternative to synthetic mold inhibitors in semi-moist pet treats.

Sustainability and Pet Food: Is There a Role for Veterinarians?

Sustainability has become a watchword for a wide array of resource-intensive goods and services. This is promulgated by an increasing global population and concerns that natural resources and a hospitable climate will not be preserved for future generations. Life-cycle analysis is a tool that provides a framework to determine the magnitude products contribute to carbon emissions and depletion of natural resources. In this review, published research has been summarized to provide an overview of the impacts that pet food production and pet ownership have on the environment and the prospective role of veterinary practitioners in advocating for sustainability.

Thyme Oil Enhances the Inactivation of Salmonella enterica on Raw Chicken Breast Meat During Marination in Lemon Juice With Added Yucca schidigera Extract

Enteric pathogens such as Salmonella enterica can survive in low pH conditions and pose a food safety threat during marinating of raw poultry meat. A study was conducted to investigate the effectiveness of thyme oil for killing S. enterica on raw chicken during marination in lemon juice containing yucca extract. Samples of raw chicken breast were inoculated with a five-serovar mixture of S. enterica (~10⁸ CFU/mL) and immersed for 2, 4, 6, and 8 h in four lemon-based marinades at 22°C: lemon juice alone (L), L with added 0.5% yucca extract (L + Y), L + Y and 0.5% thyme oil (L + Y + 0.5% TO) and L + Y + 1.0% TO. The L and L + Y served as controls. Survivors were determined by surface plating chicken homogenates on xylose-lysine tergitol-4 (XLT4) agar and XLT4 agar overlaid with non-selective agar (TAL) and counting bacterial colonies after 48 h of incubation (35°C). Marinades containing Y and TO significantly reduced initial viable populations of S. enterica compared to control (L and L + Y) solutions (P < 0.05). Based on S. enterica survivors on TAL medium, the L and L + Y reduced initial populations by 1.12 and 1.42 Log CFU/sample, respectively, after 8 h whereas, Log reductions caused by L + Y + 0.5% TO and L + Y + 1.0% TO, respectively, were 2.62 and 3.91 (P < 0.05). Numbers of survivors were higher on TAL compared to XLT4 agar (P < 0.05); however, the extent of sub-lethal injury caused by the marinades was not statistically significant (P > 0.05). The death rate of S. enterica increased significantly (P < 0.05) in the marinades containing TO (0.5 or 1.0%) compared to control (L + Y). Based on these results, thyme oil has good potential to increase the antimicrobial efficacy of lemon juice marinade against Salmonella on raw chicken breast and enhance the microbial safety of this popular poultry product.

Predictors and Barriers to Condom Use in the African Cohort Study

Consistent condom use is an inexpensive and efficacious HIV prevention strategy. Understanding factors associated with condom use and barriers to use can inform strategies to increase condom uptake. The ongoing African Cohort Study prospectively enrolls adults at 12 clinical sites in Uganda, Kenya, Tanzania, and Nigeria. At enrollment, participants are asked about condom use at last sex with a regular partner. Robust Poisson regression models were used to evaluate predictors of self-reported condom use. Participants who reported not using condoms were asked to provide reasons. From January 2013 to September 2019, 2482 participants reported having at least one regular sexual partner in the preceding 6 months. Of those, 1577 (63.5%) reported using a condom at last sex. Condom use was more common among older participants, males, HIV-infected participants, and those with an HIV-infected partner. Married participants, those with a partner of unknown HIV status, and those reporting alcohol use were less likely to report condom use at last sex. Condom use at last sex also varied significantly by clinical site. Partner disapproval or refusal to use a condom was a consistent driver of disparities in condom use among participants who were HIV infected, female, and aged 18-24 years. Effective HIV prevention programs should integrate condom education with the tools necessary to negotiate condom use with regular partners.