Fate and Biofilm Formation of Wild-Type and Pressure-Stressed Pathogens of Public Health Concern in Surface Water and on Abiotic Surfaces

Abstract

Since the historic outbreak near Broad Street in London, which serves as cornerstone of modern epidemiology, infectious diseases spread in surface and sub-surface water has been a persisting public health challenge. The current study investigated persistence of wild-type and pressure-stressed Listeria monocytogenes, Escherichia coli O157:H7, and non-typhoidal Salmonella enterica serovars in surface water stored aerobically for up to 28 days at 5, 25, and 37 °C. Additionally, biofilm formation of wild-type and pressure-stressed non-typhoidal Salmonella serovars were monitored on surface of stainless steel and rubber coupons for 28 days at 25 and 37 °C. While L. monocytogenes exhibited a lower (p < 0.05) survival rate at 5 °C, relative to the two Gram-negative pathogens, at higher temperatures of 25 and 37 °C, all three pathogens exhibited similar (p ≥ 0.05) trends for survival in surface water. Both wild-type and pressure-stressed Salmonella serovars in the vast majority of tested times, temperatures, and surfaces exhibited comparable (p ≥ 0.05) persistence and biofilm formation capability. Our study thus indicates the occurrence of contamination could lead to prolonged survival of these microorganisms in low-nutrient environments and highlights the need for preventive measures such as those articulated under Produce Safety Rule of the U.S. Food Safety Modernization Act.

Sensitivity of wild-type and rifampicin-resistant O157 and non-O157 Shiga toxin-producing Escherichia coli to elevated hydrostatic pressure and lactic acid in ground meat and meat homogenate

“…For the experiments conducted in meat homogenate, samples were treated for 0 (untreated control), 2, 5, and 7 min at 350 MPa with or without presence of 1% lactic acid. The treatment time and intensity levels were selected based on preliminary trials and information from recently published studies to assure selected experimental conditions are in concordance with the practices in the food industry [ 11 , 14 – 16 , 22 , 23 ]. Concentration of lactic acid was selected based on previous literature and relevance for the meat industry application [ 8 , 10 ].…”

“…Utilizing the rifampicin-resistant strains of Shiga toxin-producing E . coli , researchers could differentiate between the natural microbiota of a product and the inoculated rifampicin-resistant pathogen by adding rifampicin to non-selective media and thus reporting selective (representing rifampicin-resistant inoculum) and non-selective (representing background microbiota) counts that enables examining decontamination efficacy of a treatment in presence of natural microbiota [ 8 , 11 , 34 ].…”

“…coli O157:H7 had received this regulatory status many years earlier than the non-O157 serogroups, understandably, vast majority of validation studies in microbiology literature are conducted for decontamination of O157 serogroup. Thus, validation studies comparing both O157 and non-O157 serogroups could be of great importance for stakeholders and practitioners [ 9 – 11 ]. It is noteworthy that based on active surveillance data of the U.S. Centers for Disease Control and Prevention, O157 and non-O157 Shiga toxin-producing E .…”

Inactivation of Shiga toxin‐producing Escherichia coli O157: H7 and mesophilic background microbiota of meat homogenate using elevated hydrostatic pressure, mild heat, and thymol

“…These strains (ATCC ® BAA 460 TM , 43888 TM , 43894 TM , 35150 TM , 43889 TM , and 43890 TM ) were selected based on their epidemiological significance and involvement in past human sporadic and outbreak episodes and based on previous preliminary trials on single strains (Fouladkhah et al., 2013). These strains were individually activated, cultured, subcultured, and purified and were composited on the day of the experiment to assure equal representation of the six strains as articulated in our recent studies (Aras et al., 2020; Kabir et al., 2019; Kabir, Aras, Wadood, Chowdhury, & Fouladkhah, 2020). In short, 48 hr before the experiment, 100 µL of each strain from −80 °C frozen glycerol stock was aseptically pipetted into 10 mL of Tryptic Soy Broth (Difco, Becton Dickinson, Franklin Lakes, NJ, USA) supplemented with 0.6% yeast extract (TSB + YE) and aerobically incubated for 22–24 hr at 37 °C.…”

Sensitivity of Planktonic Cells and Biofilm of Wild-Type and Pressure-Stressed Cronobacter sakazakii and Salmonella enterica Serovars to Sodium Hypochlorite

“…An emerging technology in food manufacturing and the pharmaceutical industry is the use of pressure-based pasteurization for ensuring the safety of an array of products (1)(2)(3)(4)22). Although utilization of this emerging and efficacious nonthermal technology is gaining momentum and rapid adaption in the food manufacturing and pharmaceutical industries (2,4), at the current time very limited pieces of information are available regarding the fate and proliferation of pressure-stressed pathogenic microorganisms, i.e., those that are exposed to sublethal hydrostatic pressure (23). For this reason, the purpose of this study is to compare the biofilm formation capability of wild-type and pressure-stressed Salmonella serovars and C. sakazakii at low and ambient temperatures on the surface of stainless steel.…”