Sensitivity of Planktonic Cells of Staphylococcus aureus to Elevated Hydrostatic Pressure as Affected by Mild Heat, Carvacrol, Nisin, and Caprylic Acid

Jyothi George,Shahid Chowdhury,Sabrina Wadood,Md Niamul Kabir,Sadiye Aras,Aliyar Cyrus Fouladkhah

doi:10.3390/ijerph17197033

Jyothi George, Shahid Chowdhury + Show 4 more

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https://doi.org/10.3390/ijerph17197033

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Abstract

Current study investigated effects of elevated hydrostatic pressure exposure in the presence of mild heat and natural antimicrobials against Staphylococcus aureus. Hydrostatic pressure of 350 to 550 MPa with nisin (5000 IU/mL), carvacrol, or caprylic acid (0.5% v/v) were applied for the reduction in four-strain mixture of S. aureus in HEPES buffer at 4 and 40 °C for up to 7 min. Results were statistically analyzed by ANOVA and D-values were additionally calculated using best-fitted linear model. Prior to exposure to treatments at 4 °C, counts of the pathogen were 7.95 ± 0.4 log CFU/mL and were reduced (p < 0.05) to 6.44 ± 0.3 log CFU/mL after 7 min of treatment at 450 MPa. D-value associated with this treatment was 5.34 min (R2 = 0.72). At 40 °C, counts were 8.21 ± 0.7 and 5.77 ± 0.3 log CFU/mL before and after the 7-min treatments, respectively. D-value associated with 40 °C treatment was 3.30 min (R2 = 0.62). Application of the antimicrobials provided additional pathogen reduction augmentation for treatments < 5 min. The results of the current study could be incorporated for meeting regulatory requirements such as Food Code, HACCP, and Preventive Control for Human Food of Food Safety Modernization Act for assuring microbiological safety of products against this prevalent pathogen of public health concern.

Highlights

Infections caused by foodborne pathogens of public health concern are persisting challenges in healthcare settings, for the food industry, and for the consumers of raw and processed commodities.The symptoms of foodborne diseases range from mild and self-limiting manifestations such as nausea, vomiting, and diarrhea to severe complications such as kidney and liver failure, and brain and neural disorders that could result in absence from work, potential life-long health complications, and premature death [1]
Considering the public health importance of S. aureus and its prevalence in food products and food manufacturing facilities, the current study investigates the effects of elevated hydrostatic pressure for decontamination of planktonic cells of the pathogen
For samples treated at 4 °C, control counts of S. aureus was 7.95 ± 0.4 log colony-forming units (CFU)/mL (Figure 1)

Summary

Introduction

Infections caused by foodborne pathogens of public health concern are persisting challenges in healthcare settings, for the food industry, and for the consumers of raw and processed commodities.The symptoms of foodborne diseases range from mild and self-limiting manifestations such as nausea, vomiting, and diarrhea to severe complications such as kidney and liver failure, and brain and neural disorders that could result in absence from work, potential life-long health complications, and premature death [1]. Infections caused by foodborne pathogens of public health concern are persisting challenges in healthcare settings, for the food industry, and for the consumers of raw and processed commodities. Around 600 million foodborne disease episodes and 420,000 deaths are associated with foodborne diseases globally every year with 30% of deaths occurring among the children under the age of 5 [1]. These challenges are expected to be augmented in the landscape of climate change as increases in environmental temperature could augment the proliferation and persistence of an array of microbial pathogens in food and water supplies [3,4,5,6]

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