Research Publications (Food Safety)

Publication date: January 2017
, Volume 71

Author(s): Hajime Takahashi, Yun Gao, Satoko Miya, Takashi Kuda, Bon Kimura

Brigida Rusconi, Fatemeh Sanjar, Sara S. K. Koenig, Mark K. Mammel, Phillip I. Tarr, Mark Eppinger

An outbreak of five cases of Escherichia coli O157 infection that occurred in Canada in 2012 was linked to frozen beef patties seasoned with garlic and peppercorn. Unopened retail packs of beef patties from the implicated production lot were recovered and analyzed to enumerate E. coli O157, other E. coli strains, and total coliforms. E. coli O157 was not recovered by direct enumeration on selective agar media. E.

Contamination by and persistence of pathogenic bacteria in ready-to-eat produce have emerged as significant food safety and public health concerns. Viable produceborne pathogens cope with several stresses (e.g., temperature fluctuations and low-temperature storage) during production and storage of the commodities. In this study, we investigated the impact of transient cold shock on Escherichia coli O157:H7 (EcO157) cells in a produce matrix (romaine lettuce leaf lysate).

It is well established that a high percentage of foodborne illness is caused by failure of consumers to prepare food in a hygienic manner. Indeed, a common practice in households is to use the same kitchen equipment for both raw meat and fresh produce. Such a practice may lead to cross-contamination of fruits and vegetables, which are mainly consumed without further processing, with pathogenic microorganisms originating from raw meat.

Foodborne salmonellosis is a major public health concern, with contaminated eggs identified as a significant source of infection. In Australia, the most prevalent cause of salmonellosis from eggs is Salmonella enterica subsp. enterica serovar Typhimurium. This study explored the effect of temperature after 1, 7, 14, 21, and 28 days of storage on commercially available washed free range eggs, artificially contaminated with Salmonella Typhimurium on the external surface.

A total of 44 samples of salmon, pangasius (shark catfish), shrimps, and oysters were tested for the presence of Escherichia coli, enterococci, Pseudomonas aeruginosa, and Staphylococcus aureus, which are indicator organisms commonly used in programs to monitor antibiotic resistance. The isolated bacterial strains, confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy, were tested against a panel of 29 antimicrobial agents to obtain MICs.

The exposure of farm animals to antimicrobials for treatment, prophylaxis, or growth promotion can select for resistant bacteria that can be transmitted to humans, and Salmonella as an important zoonotic pathogen can act as a potential reservoir of antimicrobial resistance determinants. We assessed the antibiogram profiles of Salmonella species isolated from pig herds in two commercial farms in South Africa.

D- and z-values for Listeria monocytogenes were obtained for two Mexican meat entrées: pork meat marinated in tomatillo (green tomato) sauce (PTS) and beef marinated in a red chili sauce (BRCS), with addition of 0, 200, and 800 ppm of grapefruit seed extract (GSE). Meat samples inoculated with L. monocytogenes were packaged in sterile bags, immersed in a water bath, and held at 55, 57.5, 60, and 62.5°C for different periods of time.

Food-producing animals carrying extended-spectrum β-lactamase–producing Escherichia coli (ESBL-EC) have posed a potential threat to human and animal health. However, information regarding ESBL-EC in the intensive broiler breeding areas of Shandong Province, People's Republic of China, is very limited. The goal of our study was to investigate the prevalence and drug resistance characteristics of ESBL-EC in healthy broilers from Shandong Province.

Investigating outbreaks of Shiga toxin–producing Escherichia coli (STEC) in England is a priority due to the potential severity of disease. However, there are often challenges in investigating outbreaks due to the small numbers of cases, poor patient recall, and low levels of bacteria that are challenging to detect in food samples using traditional laboratory culture techniques, and frequently a source is not identified.

Close contact of vegetables with soil, polluted water, and animal manure and unsanitary conditions during processing of restaurant salads led us to study the distribution of virulence factors, O-serogroups, and antibiotic resistance properties in Shiga toxigenic Escherichia coli (STEC) isolated from vegetables and salads. Samples of vegetables and salad (n =420) were collected and evaluated for the presence of E. coli using culture and a PCR assay. Total prevalence of E.

After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli–coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months.

Biting arthropods are implicated in the transdermal transmission of Salmonella to bovine peripheral lymph nodes, and such contamination can contribute to increased Salmonella prevalence in processed beef. Since horn flies can acquire Salmonella and then excrete the bacteria in their feces, on-animal fly infestations were conducted in this study to assess whether horn flies have a role in this bacterial transmission.

Salmonella serovars are responsible for foodborne diseases around the world. The ability to form biofilms allows microorganisms to survive in the environment. In this study, 73 Salmonella strains, belonging to four different subspecies, were isolated from poultry houses and foodstuffs and tested. Biofilm formation was measured at four different temperatures and two nutrient concentrations. Morphotypes and cellulose production were evaluated at three different temperatures.

Over the past decade, demand has increased for natural, minimally processed produce, including sprout-based products. Sanitization with 20,000 ppm of calcium hypochlorite is currently recommended for all sprouting seeds before germination to limit sprout-related foodborne outbreaks. A potentially promising disinfectant as an alternative to calcium hypochlorite is acidified spontaneous essential oil nanoemulsions.

Berries are normally washed before they are frozen. Washing with sanitizer and treatment with pulsed light (PL) were studied for their effectiveness to inactivate foodborne pathogens on raspberries during frozen storage, while maintaining or enhancing major quality parameters.

Isothermal inactivation studies are commonly used to quantify thermal inactivation kinetics of bacteria. Meta-analyses and comparisons utilizing results from multiple sources have revealed large variations in reported thermal resistance parameters for Salmonella, even when in similar food materials. Different laboratory or regression methodologies likely are the source of methodology-specific artifacts influencing the estimated parameters; however, such effects have not been quantified.

Sublethal heating, which can occur during slow cooking of meat products, is known to induce increased thermal resistance in Salmonella. However, very few studies have addressed the kinetics of this response. Although several recent studies have reported improved thermal inactivation models that include the effect of prior sublethal history on subsequent thermal resistance, none of these models were based on cellular-level responses to sublethal thermal stress.

Cross-contamination, improper holding temperatures, and insufficient sanitary practices are known retail practices that may lead to product contamination and growth of Listeria monocytogenes. However, the relative importance of control options to mitigate the risk of invasive listeriosis from ready-to-eat (RTE) products sliced or prepared at retail is not well understood.

Botulinum neurotoxin A (BoNT-A), derived from Clostridium botulinum, has been used clinically for several diseases or syndrome including chronic migraine, spasticity, focal dystonia and other neuropathic pain. Chronic pelvic or bladder pain is the one of the core symptoms of bladder pain syndrome/interstitial cystitis (BPS/IC). However, in the field of urology, chronic bladder or pelvic pain is often difficult to eradicate by oral medications or bladder instillation therapy.

Abstract

The ability to sense and adapt to temperature fluctuation is critical to the aquatic survival, transmission, and infectivity of Vibrio cholerae, the causative agent of the disease cholera. Little information is available on the physiological changes that occur when V. cholerae experiences temperature shifts. The genome-wide transcriptional profile of V.

Extracellular proteins play important roles in bacterial interactions with the environmental matrices. In this study, we examined the extracellular proteins from Escherichia coli O157:H7 and O104:H4 by tandem mass spectrometry. We identified 500 and 859 proteins from the growth media of E. coli O157:H7 and O104:H4, respectively, including 371 proteins common to both strains. Among proteins that were considered specific to E.