Bach, Susan, Ph.D.

Research Scientist


Contact Information:

4200 Highway 97
Box 5000
Summerland, British Columbia V0H 1Z0
Telephone: 250-494-6398
Fax: 250-494-0755
Email: susan.bach@agr.gc.ca

Areas of Expertise:

  • Viable but non culturable state of human pathogens
  • Safety of leafy greens (lettuce, spinach)
  • Molecular biology / microbiology
  • Effects of stress on Verotoxin-producing Escherichia coli (VTEC)
  • Horticultural products
  • Food safety
  • Human pathogens
  • Ecology of human pathogens in horticultural production systems
  • E. coli O157:H7 in cattle

Current Projects:

  • Evaluation of the viable but non culturable (VBNC) state of human pathogens in horticultural products and the environment
  • Molecular and microscopic methods for the detection of VBNC cells
  • Determination of the effects of stress on the behaviour of Verotoxin-producing E. coli (VTEC) on leafy greens, from production to consumption
  • Studies on the fate of foodborne pathogens in horticultural production systems (leafy greens)
  • Microbial comparison of organic composts based on irrigation, in row vegetation management, nitrogen availability and soil health parameters

Research Publications:

The links below lead to abstracts with access to full text.

2015

2014

2013

2012

2011

2010

2009

Other Science Related Publications:

2015

  • Bach, S.J. and Delaquis, P.J. (2015). Multistate Research Project S-294. Postharvest Quality and Safety in Fresh-cut Vegetables and Fruits. 2014-2015 Activities Report. (Report)
  • Bach, S.J., Allen, K.J., Delaquis, P.J., and Chen, J. (2015). "Improving the decontamination of fresh produce.", China International Food Safety and Quality Conference (CIFSQ), Beijing, China, November 4-5, 2015, Invited oral presentation.
  • Bach, S.J., Delaquis, P.J., and Allen, K.J. (2015). Development of validated seed disinfection strategies for the organic production of sprouted vegetables. CL02-Organic-Activity 25v1. AAFC Project ID J-000621. (Report)
  • Bach, S.J., Delaquis, P.J., and Harlton, C.E. (2015). "Effect of cold stress on biofilm formation by Shiga toxin-producing Escherichia coli (STEC).", VTEC 2015, Boston, MA, USA, September 13-16, 2015.
  • Bach, S.J., Fan, L., Forney, C.F., and Delaquis, P.J. (2015). "Quality and Safety in Fresh-cut Vegetables and Fruits. United Fresh Produce Association Food Safety and Technology Council.", United Fresh 2015, Chicago, IL, USA, June 9-11, 2015, Oral presentation and handout information on AAFC’s research activities.
  • Bach, S.J., Harlton, C.E., and Wahlgren, S. (2015). "The impact of starvation, low temperature and chlorine on the viable but non culturable (VBNC) state of Escherichia coli O157:H7.", United Fresh 2015, Chicago, IL, USA, June 9-11, 2015.
  • Bach, S.J., Kostrzynska, M., Bezanson, G.S., and Delaquis, P.J. (2015). Stress-induced behaviors of non-O157 verotoxin-producing Escherichia coli (VTEC) in leafy greens. Research Project Annual Report. AAFC Project ID J-000128. (Report)
  • Bach, S.J., Marden, C., Harlton, C.E., Wahlgren, S., and Delaquis, P.J. (2015). "The response of Shiga toxin-producing Escherichia coli (STEC) to cold stress on plants and fresh-cut Romaine lettuce.", 2015 International Association of Food Protection (IAFP), Portland, Oregon, USA, July 25-28, 2015.
  • Bach, S.J., Marden, C., Harlton, C.E., and Wahlgren, S. (2015). "Survival of cold stressed non-O157 verotoxin-producing Escherichia coli (VTEC) on fresh-cut Romaine lettuce stored at 4 C.", United Fresh 2015, Chicago, IL, USA, June 9-11, 2015.
  • Chen, J., Nadya, S., Allen, K.J., Johnson, R.P., Ziebell, K.A., Zeibell, K., Bach, S.J., Topp, E., and Delaquis, P.J. (2015). "Phenotypic and genotypic characterization of antimicrobial resistance in Shiga toxin-producing Escherichia coli isolated from surface water in the Lower Mainland of British Columbia.", VTEC 2015, Boston, MA, USA, September 13-16, 2015.
  • Delaquis, P.J. and Bach, S.J. (2015). "Fate of Salmonella enterica, Escherichia coli O157:H7 and Listeria monocytogenes in mung bean, alfalfa and radish seed stored at three levels of relative humidity.", 2015 International Association of Food Protection (IAFP), Portland, Oregon, USA, July 25-28, 2015.
  • Delaquis, P.J., Bach, S.J., Bezanson, G.S., Topp, E., McKellar, R., Blais, B., and Peréz Rodriguez, F. (2015). Phenotypic diversity in Escherichia coli O157:H7 and its influence on survival in leafy vegetables. Research Project Annual Report. AAFC Project ID J-000132. (Report)
  • Delaquis, P.J., Nadya, S., Chen, J., Allen, K.J., Johnson, R.P., Ziebell, K.A., Bach, S.J., and Topp, E. (2015). "Prevalence, phenotypic and genotypic characteristics of Shiga toxin-producing Escherichia coli isolated from irrigation waters in a Canadian urban-agricultural landscape.", VTEC 2015, Boston, MA, USA, September 13-16, 2015.
  • McAllister, T.A., Aslam, M., Bach, S.J., Alexander, T.W., Stanich, K., and McGinn, S.M. (2015). Defining the contribution of super-shedders to high event days in commercial abattoirs and contamination of the environment with Escherichia coli O157:H7. Research Project Annual Report. AAFC Project ID J-000119. (Report)
  • Mei, G.-Y., Tang, J., Bach, S.J., and Kostrzynska, M. (2015). "Biofilm formation by verotoxin-producing Escherichia coli O157:H7 and O145:NM under oxidative stress.", OMAFRA Food Safety Research Forum, Guelph, ON, Canada, May 05, 2015.
  • Tang, J., Mei, G.-Y., Bach, S.J., and Kostrzynska, M. (2015). "Comparative stress and virulence gene expression analysis in biofilms and planktonic cells of verotoxin-producing Escherichia coli (VTEC) O103:H2 in response to oxidative stress.", OMAFRA Food Safety Research Forum, Guelph, ON, Canada, May 05, 2015.
  • Tang, J., Mei, G.-Y., Bach, S.J., and Kostrzynska, M. (2015). "The complexity of stress and virulence gene expression in logarithmic and stationary phase planktonic cells and biofilms of different ages of verotoxin-producing Escherichia coli (VTEC) O103:H2 in response to hydrogen peroxide.", 12th Annual Guelph Food Safety Symposium, Guelph, ON, Canada, October 21, 2015.

2014

  • Bach, S.J. and Delaquis, P.J. (2014). Multistate Research Project S-294. Postharvest Quality and Safety in Fresh-cut Vegetables and Fruits. 2013-2014 Activities Report. (Report)
  • Bach, S.J., Delaquis, P.J., and Harlton, C.E. (2014). "Stress and Virulence Gene Response of Non-O157 Shiga Toxin-producing Escherichia coli (STEC) Exposed to Low Temperature.", Annual Meeting of the International Association for Food Protection (IAFP), Indianapolis, USA, August 3-6, 2014, Oral presentation. (Abstract)
  • Bach, S.J., Kostrzynska, M., Bezanson, G.S., and Delaquis, P.J. (2014). Stress-induced behaviors of non-O157 verotoxin-producing Escherichia coli (VTEC) in leafy greens. Research Project Annual Report. AAFC Project ID J-000128. (Report)
  • Bach, S.J., Marden, C., Harlton, C.E., and Wahlgren, S. (2014). "The impact of low temperature on verotoxin-producing Escherichia coli (VTEC) on fresh-cut Romaine lettuce.", United Fresh 2014, Chicago, IL, USA, June 10-14, 2014. (Abstract)
  • Bach, S.J., Ries, C., Lau, D., and Wahlgren, S. (2014). "Growth phase of non-O157 verotoxin-producing Escherichia coli affects their resistance to cold stress.", United Fresh 2014, Chicago, IL, USA, June 10-14, 2014. (Abstract)
  • Bovo, F., de Cesare, A., Manfreda, G., Bach, S.J., and Delaquis, P.J. (2014). "Fate of Salmonella enterica in a mixed ingredient salad containing lettuce, cooked chicken and cheese.", Annual Meeting of the International Association for Food Protection (IAFP), Indianapolis, USA, August 3-6, 2014, Oral presentation. (Abstract)
  • Dawson, A., Ross, K.A., and Bach, S.J. (2014). "Antimicrobial activity of phenolic and crude polysaccharide compounds isolated from apples, cherries, and North American ginseng against foodborne pathogens.", United Fresh 2014, Chicago, IL, USA, June 10-14, 2014. (Abstract)
  • Delaquis, P.J., Bach, S.J., Bezanson, G.S., Topp, E., McKellar, R., Blais, B., and Peréz Rodriguez, F. (2014). Phenotypic diversity in Escherichia coli O157:H7 and its influence on survival in leafy vegetables. Research Project Annual Report. AAFC Project ID J-000132. (Report)
  • McAllister, T.A., Aslam, M., Bach, S.J., Alexander, T.W., Stanich, K., and McGinn, S.M. (2014). Defining the contribution of super-shedders to high event days in commercial abattoirs and contamination of the environment with Escherichia coli O157:H7. Research Project Annual Report. AAFC Project ID J-000119. (Report)
  • McKellar, R.C., Peréz Rodriguez, F., Harris, L.J., Moyne, A.-L., Blais, B., Topp, E., Bezanson, G.S., Bach, S.J., and Delaquis, P.J. (2014). "Evaluation of mathematical models to describe Escherichia coli O157:H7 decay on field-grown leafy vegetables.", Annual Meeting of the International Association for Food Protection (IAFP), Indianapolis, USA, August 3-6, 2014, Oral presentation. (Abstract)
  • Nadya, S., Allen, K.J., Johnson, R.P., Ziebell, K.A., Topp, E., Delaquis, P.J., and Bach, S.J. (2014). "A comparison of the presence of total Escherichia coli and Shiga-toxigenic E. coli in irrigation waters from an intensive agricultural region.", United Fresh 2014, Chicago, IL, USA, June 10-14, 2014, Abstract. (Poster)
  • Nadya, S., Allen, K.J., Ziegler, K., Johnson, R., Bach, S.J., and Delaquis, P.J. (2014). "Prevalence of Shiga Toxin-producing Escherichia coli in Irrigation Waters and Fresh Produce in British Columbia, Canada.", Annual Meeting of the International Association for Food Protection (IAFP), Indianapolis, USA, August 3-6, 2014, Oral presentation. (Abstract)
  • Ross, K.A., Brown, D.M., Siow, Y.L., Arcand, Y., and Bach, S.J. (2014). Identification, characterization and proof of bioactivity of polysaccharide and polysaccharide conjugates in apples, cherries and North American ginseng. Research Project Final Report. AAFC RBPI #2668. (Report)
  • Tang, J., Mei, G.-Y., Bach, S.J., and Kostrzynska, M. (2014). "Biofilm formation by verotoxin-producing Escherichia coli (VTEC) O157:H7 and non-O157 strains on polypropylene and glass surfaces.", 11th Annual Guelph Food Safety Seminar (GFSS) Symposium, Guelph, ON, Canada, October 22, 2014.
  • Wang, Q., Kostrzynska, M., Gong, J., Balamurugan, S., Miller, S., Cui, S.W., and Bach, S.J. (2014). Investigation of the use of bacteriophages in combination with probiotics for the control of Salmonella infection in food-producing animals. Research Project Annual Report. AAFC Project ID J-000234. (Report)

2013

  • Bach, S.J. (2013). SAES-422 Multistate Research Activity Accomplishments Report 2013. S294 Quality and Safety of Fresh-cut Vegetables and Fruits. (Report)
  • Bach, S.J., Bezanson, G.S., Delaquis, P.J., and Kostrzynska, M. (2013). The influence of stress on survival and infectivity of Verotoxin-producing Escherichia coli (VTEC) in ready-to-eat foods. Research Project FINAL Report AAFC RBPI #1848. (Report)
  • Bach, S.J., Delaquis, P.J., Toivonen, P.M.A., and Lu, C. (2013). "Impact of hydrogen peroxide on Escherichia coli O157:H7 in vitro and in vivo on fresh-cut lettuce.", United Fresh 2013, San Diego Convention Center, San Diego, CA, USA, May 14-16, 2013, Abstract. (Poster)
  • Bach, S.J., Delaquis, P.J., Toivonen, P.M.A., and Lu, C. (2013). "The effect of hypoxic treatment of Romaine lettuce on the survival of Escherichia coli O157:H7.", United Fresh 2013, San Diego Convention Center, San Diego, CA, USA, May 14-16, 2013, Abstract. (Poster)
  • Bach, S.J., Guévremont, É., Bezanson, G.S., Brassard, H., Delaquis, P.J., Ells, T.C., Hodges, D.M., Toivonen, P.M.A., and Kostrzynska, M. (2013). Enhancing mitigation strategies for microbiological risks in fresh horticultural products. Research Project FINAL Report AAFC RBPI #1489. (Report)
  • Bach, S.J., Lu, C., Delaquis, P.J., and Toivonen, P.M.A. (2013). "Impact of wound induced hydrogen peroxide production on Escherichia coli O157:H7 in fresh-cut lettuce.", 5th Congress of European Microbiologists (FEMS 2013), Leipzig, Germany, July 21-25, 2013, Presentation. (Poster)
  • Bach, S.J., Toivonen, P.M.A., Lu, C., and Delaquis, P.J. (2013). Multistate Research Project S-294. Postharvest Quality and Safety in Fresh-cut Vegetables and Fruits. 2012-2013 Activities Report. (Report)
  • Delaquis, P.J., Bach, S.J., Lu, C., and Toivonen, P.M.A. (2013). "Effect of environmental factors (field versus controlled environment chamber) on the survival of Escherichia coli O157:H7 on Romaine lettuce.", United Fresh 2013, San Diego Convention Center, San Diego, CA, USA, May 14-16, 2013, Abstract. (Poster)
  • Delaquis, P.J., Bach, S.J., McKellar, R., Bezanson, G.S., and Topp, E. (2013). "Survival of six Shiga-toxigenic Escherichia coli serotypes in field lettuce.", 58th Annual Meeting of the International Association of Food Protection (IAFP 2013), Charlotte Convention Center, Charlotte, NC, USA, July 28-31, 2013. (Poster)
  • Fung, S., Rempel, H., Block, G.S., Chen, W., Janzen, T., Lewis, C.T., Zhang, N., El-Kayssi, N., Bilkhu, S., Hambleton, S., Amoako, K.K., Lévesque, C.A., Bach, S.J., Delaquis, P.J., and Diarra, M.S. (2013). "Bacillus species across Canada's agriculture environment: an ecological perspective.", International conference on Bacillus antracis, B. cereus, and B. thurengiensis, Victoria, BC, Canada, September 1-5, 2013, Abstract. (Poster)
  • Mei, G.-Y., Tang, J., Bach, S.J., and Kostrzynska, M. (2013). "Viability and gene expression of verotoxin-producing Escherichia coli (VTEC) O111:NM abd O26:H11 under oxidative stress on Romaine lettuce.", 10th Annual GFSS Symposium, Food Safety: Compliance to Commitment, Guelph, ON, Canada, October 23, 2013.
  • Mei, G.-Y., Tang, J., Carey, C.M., Bach, S.J., and Kostrzynska, M. (2013). "Behaviour of verotoxin-producing Escherichia coli on lettuce treated with H2O2.", Food Safety Research Forum, Guelph, ON, Canada, May 9, 2013.
  • Ross, K.A., Brown, D.M., Siow, Y.L., Arcand, Y., and Bach, S.J. (2013). Identification, characterization and proof of bioactivity of polysaccharide and polysaccharide conjugates in apples, cherries and North American ginseng. Research Project Annual Report. AAFC RBPI #2668. (Report)
  • Toivonen, P.M.A., Lu, C., Bach, S.J., and Delaquis, P.J. (2013). "Hypoxic atmospheres can induce subsequent increases in cutting‐induced hydrogen peroxide production by fresh‐cut Romaine lettuce.", 11th International Controlled and Modified Atmosphere Research Conference, Trani, Italy, June 3-7, 2013. (Poster)
  • Toivonen, P.M.A., Lu, C., Bach, S.J., and Delaquis, P.J. (2013). "Hypoxic treatment can enhance cut-edge hydrogen peroxide production in Romaine lettuce.", United Fresh 2013, San Diego Convention Center, San Diego, CA, USA, May 14-16, 2013, Abstract. (Poster)
  • Topp, E., Lanthier, M., Diarra, M.S., Delaquis, P.J., Bach, S.J., McAllister, T.A., Sharma, R., Inglis, G.D., Masse, D., Bezanson, G.S., Bittman, S., Talbot, G., Masse, L., Brassard, J., Houde, A., Jones, T.H., Lapen, D.R., van Bochove, É., Gannon, V.P.J., Pintar, K.D.M., Masson, L., Neumann, N.F., and Koning, W. (2013). Assessment and management of on-farm fate of microbial and chemical contaminants carried in human and animal wastes used as organic fertilizers. Final Report SAGES #1462. (Report)
  • Yang, X., Gill, C.O., and Bach, S.J. (2013). Detection and enumeration by real-time PCR of food borne pathogens Salmonella, Verotoxigenic Escherichia coli and Listeria monocytogenes that survive decontaminating treatments. Research Project Final Report. AAFC RBPI #2509. (Report)
  • Yang, X.Q., Bach, S.J., and Gill, C.O. (2013). Detection and enumeration by real-time PCR of food borne pathogens Salmonella, Verotoxigenic Escherichia coli and Listeria monocytogenes that survive decontaminating treatments. Research Project Annual Report. AAFC RBPI #2509. (Report)

2012

  • Delaquis, P.J. and Bach, S.J. (2012). "Resistance and sub-lethal damage.", in Gómez-López, V.M. (ed.) - Decontamination of Fresh and Minimally Processed Produce, Wiley - Blackwell, Chapter 4, pp. 77-86.
  • Diarra, M.S., Rempel, H., Bach, S.J., Harlton, C.E., Delaquis, P.J., Pritchard, J., Aslam, M.N., Leslie, M., and Topp, E. (2012). "Distribution of antibiotic resistance phenotypes and genotypes among Salmonella spp. Isolated from broiler chickens in British Columbia.", 101st Annual Meeting of the International Association of Food Protection (IAFP 2012), Rhode Island Convention Center, Providence, RI, USA, July 22-25, 2012, Poster ID# 2398. (Poster)

2011

  • Bach, S.J., Lu, C., Delaquis, P.J., and Toivonen, P.M.A. (2011). "Cutting Romaine lettuce while submerged in sanitizer improves efficacy of sodium hypochlorite.", The Grower, 61(5), pp. 20.
  • Toivonen, P.M.A., Lu, C., Delaquis, P.J., and Bach, S.J. (2011). "Timing of sanitizer application reduces microbial counts on fresh-cut Romaine lettuce.", 2nd ISHS International Conference on Quality Management of Fresh Cut Produce: Convenience Food for a Tasteful Life, Università degli Studi di Torino, Torino, Italy, July 17-21, 2011.

2010

  • Bach, S.J., Leblanc, D., and Lin, P. (2010). "The influence of chlorine and low temperature on the induction of the viable but non-culturable state in Escherichia coli 0157:H7.", 2010 Canadian Institute of Food Science & Technology (CIFST) and AAFC Conference, Fairmont Winnipeg Hotel, Winnipeg, MB, Canada, May 30-June 1, 2010, # 02-2. (Abstract)
  • Toivonen, P.M.A., Lu, C., Delaquis, P.J., and Bach, S.J. (2010). "Evaluation of timing for application of sanitizing washes to reduce microbial counts on Romaine lettuce.", 14th Annual Federal Food Safety and Nutrition Research Meeting (FFSNRM), Ottawa, ON, Canada, November 3-4, 2010, pp. 28.

2009

  • Bach, S.J. (2009). "On-farm Food Safety and Water Quality: Just What Does a Test Result Mean?", 51st Annual Horticulture Growers' Short Course, Tradex, Abbotsford Airport, Abbotsford, BC, Canada, February 14-16, 2009.
  • Bach, S.J. and Delaquis, P.J. (2009). "The origin and spread of human pathogens in fruit production systems.", in Fan, X, Miemira, B., Doona, C., Feeherry, F., and Gravani, B. (eds.) - Microbial Safety of Fresh Produce: Challenges, Perspectives and Strategies, Wiley - Blackwell, Chapter 2, pp. 43-54.
  • Delaquis, P.J., Bach, S.J., LeBlanc, D.I., Brassard, J., Houde, A., Villeneuve, S., Bezanson, G.S., Diarra, M.S., Topp, E., Blais, B., Gajadhar, A., Bisaillon, J.-R., Fazil, A.M., Gilmour, M., Mattison, K., and Bidawid, S. (2009). "A systems-based approach for the assessment of microbiological threats to the food supply.", 13th Annual Federal Food Safety and Nutrition Research Meeting (FFSNRM), Ottawa, ON, Canada, November 4-5, 2009. (Presentation)
Date modified: