Evaluation of Staphylococcus aureus Growth Potential in Ham during a Slow-Cooking Process: Use of Predictions Derived from the U.S. Department of Agriculture Pathogen Modeling Program 6.1 Predictive Model and an Inoculation Study

2004 ◽  
Vol 67 (7) ◽  
pp. 1512-1516 ◽  
Author(s):  
STEVEN C. INGHAM ◽  
JILL A. LOSINSKI ◽  
BRENDA K. DROPP ◽  
LAURA L. VIVIO ◽  
DENNIS R. BUEGE
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Growth Potential ◽  
Department Of Agriculture ◽  
Heat Stable ◽  
Biological Hazard ◽  
Simulated Surface ◽  
C 50 ◽  
Inoculation Study ◽  
The U.S

The U.S. Department of Agriculture has cautioned against slow cooking meat such that the interior temperature increases from 10°C (50°F) to 54.4°C (130°F) in ≥6 h. During a commercial ham-smoking process, the ham cold point is typically between 10 and 54.4°C for 13 h, but the ham is subsequently exposed to heating sufficient to eliminate vegetative pathogenic bacteria. Thus, production of heat-stable staphylococcal enterotoxin is the primary biological hazard. For this study, uncooked surface and uncooked ground interior ham were inoculated with a three-strain Staphylococcus aureus mixture, exposed to simulated surface and interior slow-cook conditions, respectively, and analyzed periodically using the Baird-Parker agar and 3M Petrifilm Staph Express count plate methods. For the surface and interior conditions, S. aureus numbers increased by no more than 0.1 and 0.7 log units, respectively. Predictions derived from actual time and temperature data and S. aureus growth values from a computer-generated model (Pathogen Modeling Program 6.1, U.S. Department of Agriculture) were for 2.7 (ham surface) and 9.9 to 10.5 (ham interior) generations of S. aureus growth, indicating that use of model-derived growth values would not falsely indicate safe slow cooking of ham. The Baird-Parker method recovered significantly (P < 0.05) greater numbers of S. aureus than the Petrifilm Staph Express method. For hams pumped with brine to attain (i) 18% (wt/wt) weight gain, (ii) ≥2.3% sodium lactate, (iii) ≥0.8% sodium chloride, and (iv) 200 ppm ingoing sodium nitrite, slow-cooking critical limits of ≤4 h between 10 and 34°C, ≤5 h between 34 and 46°C, and ≤5 h between 46 and 54.4°C could be considered adequate to ensure safety.

Salmonella Prevalence in Bovine Lymph Nodes Differs among Feedyards

2012 ◽  
Vol 75 (6) ◽  
pp. 1131-1133 ◽  
Author(s):  
ASHLEY N. HANEKLAUS ◽  
KERRI B. HARRIS ◽  
DAVEY B. GRIFFIN ◽  
THOMAS S. EDRINGTON ◽  
LISA M. LUCIA ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
Performance Standards ◽  
Processing Plant ◽  
Lymphatic Tissue ◽  
Department Of Agriculture ◽  
Beef Carcasses ◽  
Beef Products ◽  
The U.S

Lymphatic tissue, specifically lymph nodes, is commonly incorporated into ground beef products as a component of lean trimmings. Salmonella and other pathogenic bacteria have been identified in bovine lymph nodes, which may impact compliance with the Salmonella performance standards for ground beef established by the U.S. Department of Agriculture. Although Salmonella prevalence has been examined among lymph nodes between animals, no data are currently available regarding feedyard origin of the cattle and Salmonella prevalence. Bovine lymph nodes (279 superficial cervical plus 28 iliofemoral = 307) were collected from beef carcasses at a commercial beef harvest and processing plant over a 3-month period and examined for the prevalence of Salmonella. Cattle processed were from seven feedyards (A through G). Salmonella prevalence was exceptionally low (0% of samples were positive ) in cattle from feedyard A and high (88.2%) in cattle from feedyard B. Prevalence in the remaining feedyards ranged widely: 40.0% in feedyard C, 4.0% in feedyard D, 24.0% in feedyard E, 42.9% in feedyard F, and 40.0% in feedyard G. These data indicate the range of differences in Salmonella prevalence among feedyards. Such information may be useful for developing interventions to reduce or eliminate Salmonella from bovine lymph nodes, which would assist in the reduction of Salmonella in ground beef.

scholarly journals Fate of Staphylococcus aureus on Vacuum-Packaged Ready-to-Eat Meat Products Stored at 21°C

2005 ◽  
Vol 68 (9) ◽  
pp. 1911-1915 ◽  
Author(s):  
STEVEN C. INGHAM ◽  
REBECCA A. ENGEL ◽  
MELODY A. FANSLAU ◽  
ERICA L. SCHOELLER ◽  
GINA SEARLS ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Meat Products ◽  
Toxin Production ◽  
Water Phase ◽  
Department Of Agriculture ◽  
Wide Range ◽  
Survival And Growth ◽  
Highly Correlated ◽  
Shelf Stable ◽  
The U.S

The U.S. Department of Agriculture has established standards for the composition and shelf stability of various ready-to-eat meat products. These standards may include product pH, moisture:protein ratio, and water activity (aw) values. It is unclear how closely these standards are based on the potential for pathogen growth or toxin production. Because the vacuum packaging used on most ready-to-eat meat products inhibits mold, Staphylococcus aureus is the pathogen most likely to grow on products with reduced aw and increased percentage of water-phase salt. In this study, 34 samples of various ready-to-eat meat products were inoculated with a three-strain mixture of S. aureus, vacuum packaged, and stored at 21°C for 4 weeks. S. aureus numbers decreased by 1.1 to 5.6 log CFU on fermented products (pH ≤ 5.1) with a wide range of salt concentrations and moisture content. Similarly, S. aureus numbers decreased by 3.2 to 4.5 log CFU on dried nonacidified jerky (aw ≤ 0.82; moisture:protein ratio of ≤0.8). Products that were not fermented or dried clearly supported S. aureus growth and cannot be considered shelf stable. The product pH and moisture:protein ratio were the two compositional factors most highly correlated (R2 = 0.84) with S. aureus survival and growth for the types of products tested, but pH and aw or pH and percentage of water-phase salt also may provide useful predictive guidance (R2 = 0.81 and 0.77, respectively).

Burger Preparation: What Consumers Say and Do in the Home

2011 ◽  
Vol 74 (10) ◽  
pp. 1708-1716 ◽  
Author(s):  
HO S. PHANG ◽  
CHRISTINE M. BRUHN
Keyword(s):  
Food Safety ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
Foodborne Illness ◽  
Hand Washing ◽  
Video Observation ◽  
Cross Contamination ◽  
Internal Temperature ◽  
Department Of Agriculture ◽  
The U.S

Ground beef has been linked to outbreaks of pathogenic bacteria like Escherichia coli O157:H7 and Salmonella. Consumers may be exposed to foodborne illness through unsafe preparation of ground beef. Video footage of 199 volunteers in Northern California preparing hamburgers and salad was analyzed for compliance with U.S. Department of Agriculture recommendations and for violations of the U.S. Food and Drug Administration's Food Code 2009. A questionnaire about consumer attitudes and knowledge about food safety was administered after each filming session. The majority of volunteers, 78%, cooked their ground beef patties to the Food Code 2009 recommended internal temperature of 155°F (ca. 68°C) or above, and 70% cooked to the U.S. Department of Agriculture consumer end-point guideline of 160°F (ca. 71°C), with 22% declaring the burger done when the temperature was below 155°F. Volunteers checked burger doneness with a meat thermometer in 4% of households. Only 13% knew the recommended internal temperature for ground beef. The average hand washing time observed was 8 s; only 7% of the hand washing events met the recommended guideline of 20 s. Potential cross-contamination was common, with an average of 43 events noted per household. Hands were the most commonly observed vehicle of potential cross-contamination. Analysis of food handling behaviors indicates that consumers with and without food safety training exposed themselves to potential foodborne illness even while under video observation. Behaviors that should be targeted by food safety educators are identified.

Survival of Staphylococcus aureus and Listeria monocytogenes on Vacuum-Packaged Beef Jerky and Related Products Stored at 21°C

2006 ◽  
Vol 69 (9) ◽  
pp. 2263-2267 ◽  
Author(s):  
STEVEN C. INGHAM ◽  
GINA SEARLS ◽  
SUNISH MOHANAN ◽  
DENNIS R. BUEGE
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Room Temperature ◽  
Anaerobic Growth ◽  
Department Of Agriculture ◽  
Small Individual ◽  
Beef Jerky ◽  
Maximum Water ◽  
Packaged Beef

In the manufacture of beef jerky, a thermal lethality step is followed by drying to prevent growth of pathogenic bacterial postprocessing contaminants on the finished product. Recent guidelines from the U.S. Department of Agriculture have raised the question of the maximum water activity (aw) in jerky products that will inhibit growth of pathogenic bacteria. The survival of the potential postprocessing contaminants Staphylococcus aureus and Listeria monocytogenes was evaluated on 15 vacuum-packaged beef jerky and related products with aw values ranging from 0.47 to 0.87, just below the 0.88 limit reported for anaerobic growth of S. aureus. Small individual product pieces were inoculated on the outer surface with five strains each of S. aureus and L. monocytogenes, repackaged under vacuum, and stored at room temperature (21°C) for 4 weeks. Pathogen numbers were determined before storage and after 1 and 4 weeks. None of the 15 jerky products supported growth of either pathogen. Counts of S. aureus fell by 0.2 to 1.8 log CFU after 1 week of storage and by 0.6 to 5.3 log CFU after 4 weeks of storage. Numbers of L. monocytogenes fell by 0.6 to 4.7 log CFU and by 2.3 to 5.6 log CFU after 1 and 4 weeks of storage, respectively. Although factors other than aw may have some effect on pathogen survival, the results of the present study clearly support drying beef jerky to an aw of ≤0.87 to ensure that bacterial pathogens cannot grow on vacuum-packaged product stored at room temperature.

scholarly journals Structural basis of inhibition of a transporter from Staphylococcus aureus, NorC, through a single-domain camelid antibody

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sushant Kumar ◽  
Arunabh Athreya ◽  
Ashutosh Gulati ◽  
Rahul Mony Nair ◽  
Ithayaraja Mahendran ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Major Facilitator Superfamily ◽  
Single Domain ◽  
Fluoroquinolone Resistance ◽  
Structural Basis ◽  
Antibody Complex ◽  
Complementarity Determining Regions ◽  
Major Facilitator ◽  
Alternating Access

AbstractTransporters play vital roles in acquiring antimicrobial resistance among pathogenic bacteria. In this study, we report the X-ray structure of NorC, a 14-transmembrane major facilitator superfamily member that is implicated in fluoroquinolone resistance in drug-resistant Staphylococcus aureus strains, at a resolution of 3.6 Å. The NorC structure was determined in complex with a single-domain camelid antibody that interacts at the extracellular face of the transporter and stabilizes it in an outward-open conformation. The complementarity determining regions of the antibody enter and block solvent access to the interior of the vestibule, thereby inhibiting alternating-access. NorC specifically interacts with an organic cation, tetraphenylphosphonium, although it does not demonstrate an ability to transport it. The interaction is compromised in the presence of NorC-antibody complex, consequently establishing a strategy to detect and block NorC and related transporters through the use of single-domain camelid antibodies.

scholarly journals Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO2 Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Campylobacter Jejuni ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Tio2 Nps ◽  
E Coli ◽  
Foodborne Pathogenic Bacteria ◽  
And Staphylococcus Aureus ◽  
Co Doped

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.

scholarly journals Bodipy-Loaded Micelles Based on Polylactide as Surface Coating for Photodynamic Control of Staphylococcus aureus

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Enrico Caruso ◽  
Viviana Teresa Orlandi ◽  
Miryam Chiara Malacarne ◽  
Eleonora Martegani ◽  
Chiara Scanferla ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Surface Coatings ◽  
Supramolecular System ◽  
Amphiphilic Copolymers ◽  
Oxygen Penetration ◽  
Short Period ◽  
Excellent Activity ◽  
Coating Matrix ◽  
Photodynamic Control

Decontaminating coating systems (DCSs) represent a challenge against pathogenic bacteria that may colonize hospital surfaces, causing several important infections. In this respect, surface coatings comprising photosensitizers (PSs) are promising but still controversial for several limitations. PSs act through a mechanism of antimicrobial photodynamic inactivation (aPDI) due to formation of reactive oxygen species (ROS) after light irradiation. However, ROS are partially deactivated during their diffusion through a coating matrix; moreover, coatings should allow oxygen penetration that in contact with the activated PS would generate 1O2, an active specie against bacteria. In the attempt to circumvent such constraints, we report a spray DCS made of micelles loaded with a PS belonging to the BODIPY family (2,6-diiodo-1,3,5,7-tetramethyl-8-(2,6-dichlorophenyl)-4,4′-difluoroboradiazaindacene) that is released in a controlled manner and then activated outside the coating. For this aim, we synthesized several amphiphilic copolymers (mPEG–(PLA)n), which form micelles, and established the most stable supramolecular system in terms of critical micelle concentration (CMC) and ∆Gf values. We found that micelles obtained from mPEG–(PLLA)2 were the most thermodynamically stable and able to release BODIPY in a relatively short period of time (about 80% in 6 h). Interestingly, the BODIPY released showed excellent activity against Staphylococcus aureus even at micromolar concentrations.

scholarly journals Staphylococcus aureus Serves as an Iron Source for Pseudomonas aeruginosa during In Vivo Coculture

2005 ◽  
Vol 187 (2) ◽  
pp. 554-566 ◽  
Author(s):  
Lauren M. Mashburn ◽  
Amy M. Jett ◽  
Darrin R. Akins ◽  
Marvin Whiteley
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Iron Acquisition ◽  
Low Oxygen ◽  
Dialysis Membrane ◽  
Opportunistic Human Pathogen ◽  
The Impact

ABSTRACT Pseudomonas aeruginosa is a gram-negative opportunistic human pathogen often infecting the lungs of individuals with the heritable disease cystic fibrosis and the peritoneum of individuals undergoing continuous ambulatory peritoneal dialysis. Often these infections are not caused by colonization with P. aeruginosa alone but instead by a consortium of pathogenic bacteria. Little is known about growth and persistence of P. aeruginosa in vivo, and less is known about the impact of coinfecting bacteria on P. aeruginosa pathogenesis and physiology. In this study, a rat dialysis membrane peritoneal model was used to evaluate the in vivo transcriptome of P. aeruginosa in monoculture and in coculture with Staphylococcus aureus. Monoculture results indicate that approximately 5% of all P. aeruginosa genes are differentially regulated during growth in vivo compared to in vitro controls. Included in this analysis are genes important for iron acquisition and growth in low-oxygen environments. The presence of S. aureus caused decreased transcription of P. aeruginosa iron-regulated genes during in vivo coculture, indicating that the presence of S. aureus increases usable iron for P. aeruginosa in this environment. We propose a model where P. aeruginosa lyses S. aureus and uses released iron for growth in low-iron environments.

scholarly journals Estimating a global demand model for soybean traffic through the Panama Canal

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Javier Ho ◽  
Paul Bernal
Keyword(s):  
Pacific Northwest ◽  
Least Square ◽  
Panama Canal ◽  
Demand Model ◽  
Department Of Agriculture ◽  
Explanatory Variables ◽  
Ordinary Least Square ◽  
Global Demand ◽  
Alternative Routes ◽  
The U.S

AbstractThis study attempts to fit a global demand model for soybean traffic through the Panama Canal using Ordinary Least Square. Most of the soybean cargo through the interoceanic waterway is loaded on the U.S. Gulf and East Coast ports -mainly destined to East Asia, especially China-, and represented about 34% of total Panama Canal grain traffic between fiscal years 2010–19. To estimate the global demand model for soybean traffic, we are considering explanatory variables such as effective toll rates through the Panama Canal, U.S. Gulf- Asia and U.S. Pacific Northwest- Asia freight rates, Baltic Dry Index, bunker costs, soybean export inspections from the U.S. Gulf and Pacific Northwest, U.S. Gulf soybean basis levels, Brazil’s soybean exports and average U.S. dollar index. As part of the research, we are pursuing the estimation of the toll rate elasticity of vessels transporting soybeans via the Panama Canal. Data come mostly from several U.S. Department of Agriculture sources, Brazil’s Secretariat of Foreign Trade (SECEX) and from Panama Canal transit information. Finally, after estimation of the global demand model for soybean traffic, we will discuss the implications for future soybean traffic through the waterway, evaluating alternative routes and sources for this trade.

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