Shirley Micallef

Professional Positions Held: 

Professor, Department of Plant Science and Landscape Architecture

Joint Appointment, Center for Food Safety and Security Systems (CFS3)

Affiliate, Department of Global, Environmental and Occupational Health, School of Public Health

Chair, PLSC Graduate Admissions and Examination Review Committee

Areas of Interest: 

• Food safety of fresh produce

• Rhizosphere and phyllosphere microbiomes 

• Plant microbiome-metabolome connections

• Plant exudate biology/plant surface compounds and bacterial interactions

• Agro-environmental distribution, dispersal and detection of enteric pathogens

• Irrigation water quality

• AMR in the environment

Current Research: 

My current research focuses on microbial food safety of fruit and vegetables, specifically looking at how enteric pathogens associate with specialty crops and how they interact with the environment. In our lab, we investigate microbial produce safety at all levels of biology, from the molecular responses of pathogen-commodity pairs to the ecology of enteric pathogens in the agro-environment.  We use a multidisciplinary approach and utilize a variety of methods to assess enteric pathogen populations and their ecology, as well as molecular and sequencing technologies to evaluate the plant microbiome and pathogen-plant responses.  

Research projects involve investigating Salmonella association on pre-harvest tomatoes and E. coli O157:H7 on leafy vegetables, and the influence of (i) plant genetic variation and (ii) plant responses to abiotic stresses, on plant-enteric pathogen relationships.  In controlled environments, we investigate plant traits and environmental conditions that modulate the enteric pathogen-plant association, while also assessing plant responses and resilience to abiotic stresses. 

We also study plant beneficial microbes and explore the role that plant growth promoting rhizobacteria play in improving plant resilience to abiotic stresses and in modulating enteric pathogen-plant associations.

Other areas of investigation include the impact that various cropping methods have on the persistence and dispersal of human pathogens in pre-harvest production areas, as well as the ecology of Salmonella in the environment.  We investigate irrigation water quality and the distribution of antimicrobial resistance genes (AMR) in surface and reclaimed water source.

Courses Taught: 

Publications: 

Zeng, Q., Lam, K., Salcedo, A., Tikekar, R.V., Micallef, S.A., Blaustein, R.A., 2024. Effects of Organic Soil Amendments on Antimicrobial-Resistant Bacteria in Urban Agriculture Environments. Journal of Food Protection 100344. https://doi.org/10.1016/j.jfp.2024.100344 

Gao Z, Jha A, Hudson CL, Hopper AL, Micallef SA, Tikekar RV, 2024. Development and evaluation of a modified most probable number (MPN) method for enumerating rifampicin-resistant Escherichia coli in agricultural, food and environmental samples. Journal of Food Safety, 44(3), e13127. https://doi.org/10.1111/jfs.13127

Jacob C, Micallef SA, Melotto M, 2024. Editorial: Plant and human pathogen interactions: gaining insights into the impact of environmental and crop management factors. Front. Plant Sci. 15, 1414227. https://doi.org/10.3389/fpls.2024.1414227

Ganyu Gu, Qiao Ding, Marina Redding, Yishan Yang, Regina O'Brien, Tingting Gu, Boce Zhang, Bin Zhou, Shirley A. Micallef, Yaguang Luo, Jorge Fonseca, Xiangwu Nou, 2024. Dynamics of microbial profile and quality evaluation of fresh-cut romaine lettuce under source and forward processing conditions. International Journal of Food Microbiology, Volume 416, 110665. https://doi.org/10.1016/j.ijfoodmicro.2024.110665

Adam Hopper†, Claire Hudson†, Diksha Klair, Qiao Ding, Zhujun Gao, Aprajeeta Jha, Austin Bryan, Rohan Tikekar, Timothy Coolong,  Laurel L. Dunn, Shirley A. Micallef, 2024. Rain splash-mediated dispersal of Escherichia coli from fecal deposits to field-grown lettuce in the mid- and south Atlantic U.S. region is affected by mulch type. Frontiers in Plant Science, 15:1370495 – 2024. https://doi.org/10.3389/fpls.2024.1370495

Acheamfour CL, Parveen S, Gutierrez A, Handy ET, Behal S, Kim D, Kim S, East C, Xiong R, Haymaker JR, Micallef SA, Rosenberg Goldstein RE, Kniel KE, Sapkota AR, Hashem F, Sharma M, 2024. Detection of Salmonella enterica and Listeria monocytogenes in alternative irrigation water by culture and qPCR-based methods in the Mid-Atlantic U.S. Microbiol Spectr 0:e03536-23. https://doi.org/10.1128/spectrum.03536-23

Ding Q, Gu G, Nou X, Micallef SA, 2024. Cultivar was more influential than bacterial strain and other experimental factors in recovery of Escherichia coli O157:H7 populations from inoculated live Romaine lettuce plants. Microbiol Spectr 0:e03767-23. https://doi.org/10.1128/spectrum.03767-23

Ammendola S, Micallef SA, Schikora A, 2023. Editorial: Dealing with unusual hosts and unconventional habitats: versatile strategies of Salmonella enterica. Front. Microbiol. 14:1342139. https://doi.org/10.3389/fmicb.2023.1342139

Micallef SA, Callahan MT, McEgan R, Martinez L, 2023.  Soil microclimate and persistence of foodborne pathogens Escherichia coli O157:H7, Listeria monocytogenes and Salmonella enterica Newport in soil affected by mulch type. Journal of Food Protection. 2023, 100159. https://doi.org/10.1016/j.jfp.2023.100159

Kim S, Pachepsky Y, Micallef SA, Rosenberg Goldstein R, Sapkota AR, Hashem F, Parveen S, Kniel KE, Sharma M, 2023. Temporal stability of Salmonella enterica and Listeria monocytogenes in surface waters used for irrigation in the Mid-Atlantic United States. Journal of Food Protection. https://doi.org/10.1016/j.jfp.2023.100058

Redding M, Bolten S, Luo Y, Micallef SA, Millner P, Nou X, 2023. Growth and inactivation of Listeria monocytogenes in sterile extracts of fruits and vegetables: Impact of the intrinsic factors pH, sugar and organic acid content. International Journal of Food Microbiology 386: 110043. https://doi.org/10.1016/j.ijfoodmicro.2022.110043

Liu X, Li Y, Micallef SA, 2023. Natural variation and drought-induced differences in metabolite profiles of red oak-leaf and Romaine lettuce modulated the interaction with Salmonella enterica. International Journal of Food Microbiology 385: 109998. https://doi.org/10.1016/j.ijfoodmicro.2022.109998

Malayil L, Ramachandran P, Chattopadhyay S, Allard S, Bui A, Butron J, Callahan M, Craddock H, Murray R, East C, Sharma M, Kniel K, Micallef SA, Hashem F, Gerba C, Ravishankar S, Parveen S, May E, Handy E, Kulkarni P, Anderson-Coughlin B, Craighead S, Gartley S, Vanore A, Duncan R, Foust D, Haymaker J, Betancourt W, Zhu L, Mongodin E, Sapkota A, Pop M, Sapkota A, 2022. Variations in bacterial communities and antibiotic resistance genes across diverse recycled and surface water irrigation sources in the mid-Atlantic and Southwestern United States: A CONSERVE two-year field study. Environmental Science & Technology 56 (21): 15019–15033. https://doi.org/10.1021/acs.est.2c02281

 Micallef SA, Han S, Martinez L, 2022. Tomato cultivar ‘Nyagous’ fruit surface metabolite changes during ripening affect Salmonella Newport growth. Journal of Food Protection 85(11): 1604-1613. https://doi.org/10.4315/JFP-22-160

Liu X, Li Y, Micallef SA, 2022. Developmentally related and drought-induced shifts in the kale metabolome limited Salmonella enterica association, providing novel insights to enhance food safety. Food Microbiology 108: 104113. https://doi.org/10.1016/j.fm.2022.104113

Kim S, Paul M, Negahban-Azar M, Micallef SA, Rosenberg Goldstein R, Hashem F, Parveen S, Sapkota A, Kniel KE, Sapkota AR, Pachepsky Y, Sharma M, 2022. Persistent spatial patterns of Listeria monocytogenes and Salmonella enterica concentrations in surface waters: EOF analysis of data from Maryland and Delaware. Applied Sciences 12: 7526. https://doi.org/10.3390/app12157526

Solaiman S, Handy E, Brinks T, Goon K, Bollinger C, Sapkota AR, Sharma M, Micallef SA, 2022. Escherichia coli phylogroup distribution and prevalence of extended spectrum β-lactamase (ESBL) producers in U.S. mid-Atlantic surface and reclaimed water. Applied and Environmental Microbiology 88: e0083722. DOI: 10.1128/aem.00837-22

Solaiman S, Patterson R, Davey K, Katz Y, Payne-Sturges D, Sapkota AR, Micallef SA, 2022. Effects of season and water type on the distribution and antimicrobial resistance of Enterococcus faecalis and E. faecium from surface and reclaimed water. Journal of Applied Microbiology 133: 477-487. https://doi.org/10.1111/jam.15570

Kroft B, Gu G, Bolten S, Micallef SA, Luo Y, Millner P, Nou X, 2022. Effects of temperature abuse on the growth and survival of Listeria monocytogenes on a wide variety of whole and fresh-cut fruits and vegetables during simulated storage. Food Control 137: 108919. https://doi.org/10.1016/j.foodcont.2022.108919

Gerdes ME, Cruz-Cano R, Solaiman S, Ammons S, Allard SM, Sapkota R, Micallef SA, Rosenberg Goldstein RE, 2022. Impact of irrigation water type and sampling frequency on microbial water quality profiles required for compliance with U.S. Food Safety Modernization Act Produce Safety Rule Standards. Environmental Research 205: 112480. https://doi.org/10.1016/j.envres.2021.112480

Acheamfour CL, Parveen S, Hashem F, Sharma M, Gerdes ME, May EB, Rogers K, Haymaker J, Duncan R, Foust D, Taabodi M, Handy ET, East C, Bradshaw R, Kim S, Micallef SA, Callahan MT, Allard S, Anderson-Coughlin B, Craighead S, Gartley S, Vanore A, Kniel KE, Solaiman S, Bui A, Murray R, Craddock HA, Kulkarni P, Rosenberg Goldstein RE, Sapkota AR, 2021. Levels of Salmonella enterica and Listeria monocytogenes in alternative irrigation water vary based on water source on the Eastern Shore of Maryland. Microbiology Spectrum 9: e00669-21. https://doi.org/10.1128/Spectrum.00669-21

Anderson-Coughlin BL, Craighead S, Kelly A, Gartley S, Vanore A, Johnson G, Jiang C, Haymaker J, White C, Foust D, Duncan R, East C, Handy, ET, Bradshaw R, Murray R, Kulkarni P, Callahan MT, Solaiman S, Betancourt W, Gerba C, Allard S, Parveen S, Hashem F, Micallef SA, Sapkota A, Sapkota AR, Sharma M, Kniel KE, 2021. Enteric viruses and pepper mild mottle virus show significant correlation in select mid-Atlantic agricultural waters. Applied and Environmental Microbiology 87: e00211-21. https://doi.org/10.1128/AEM.00211-21

Solaiman S., Micallef SA, 2021. Aeromonas spp. diversity in U.S. mid-Atlantic surface and reclaimed water, seasonal dynamics, virulence gene patterns and attachment to lettuce. STOTEN Volume 779, 20 July 2021, 146472. DOI: https://doi.org/10.1016/j.scitotenv.2021.146472

Han S, Lin Sh-Sh, Ferelli AMC, Micallef SA, 2020. Stress response, amino acid biosynthesis and pathogenesis genes expressed in Salmonella enterica colonizing tomato shoot and root surfaces. Heliyon 6 (9), e04952 11 Sep 2020. DOI: https://doi.org/10.1016/j.heliyon.2020.e04952 

Solaiman S, Allard SM, Callahan MT, Jiang C, Handy ET, East C, Haymaker J, Bui A, Craddock H, Murray R, Kulkarni P, Anderson-Coughlin B, Craighead S, Gartley S, Vanore A, Duncan R, Foust D, Taabodi M, Sapkota A, May E, Hashem F, Parveen S, Kniel KE, Sharma M, Sapkota AR, Micallef SA, 2020. A longitudinal assessment of Escherichia coli, total coliforms, Enterococcus and Aeromonas spp. dynamics in alternative irrigation water sources: A CONSERVE study. Applied and Environmental Microbiology, AEM.00342-20; DOI: https://doi.org/10.1128/AEM.00342-20

Melotto M, Brandl MT, Jacob C, Jay-Russell MT, Micallef SA, Warburton ML, Van Deynze A, 2020. Breeding Crops for Enhanced Food Safety. Frontiers in Plant Science 2020, 11, 428. https://doi.org/10.3389/fpls.2020.00428

Ferelli AMC, Bolten S, Szczesny B, Micallef SA, 2020. Salmonella enterica elicits and is restricted by nitric oxide and reactive oxygen species on tomato.  Frontiers in Microbiology 2020, 11, 391. https://doi.org/10.3389/fmicb.2020.00391

Sharma M, Handy E, East CL, Kim S, Jiang, Callahan MT, Allard SM, Micallef SA, Craighead S, Anderson B, Gartley S, Vanore A, Kniel KE, Haymaker J, Duncan R, Foust D, White C, Taabodi M, Hashem F, Parveen S, May EB, Bui A, Craddock H, Kulkarni P, Murray RY, Sapkota A. 2020. Prevalence of Salmonella and Listeria monocytogenes in non-traditional irrigation waters in the mid-Atlantic United States is affected by water type, season, and recovery method. PLOS ONE 15(3): e0229365. https://doi.org/10.1371/journal.pone.0229365

Allard SM, Ottesen AR, Micallef SA, 2020. Rain induces temporary shifts in epiphytic bacterial communities of cucumber and tomato fruit. Scientific Reports (2020) 10:1765. https://doi.org/10.1038/s41598-020-58671-7

Todd-Searle J, Friedrich LM, Oni RA, Shenge K, LeJeune JT, Micallef SA, Danyluk MD, Schaffner D, 2020. Quantification of Salmonella enterica transfer between tomatoes, soil and plastic mulch. International Journal of Food Microbiology, 2020, 316: 108480. https://doi.org/10.1016/j.ijfoodmicro.2019.108480

Chopyk J, Daniel J Nasko DJ, Allard S, Callahan MT, Bui A, Ferelli AMC, Chattopadhyay S, Mongodin EF, Pop M, Micallef SA, Sapkota AR, 2020. Metagenomic analysis of bacterial and viral assemblages from a freshwater creek and irrigated field reveals temporal and spatial dynamics. STOTEN 706, 1 March 2020, 135395.  https://doi.org/10.1016/j.scitotenv.2019.135395 

Korir RC, Everts KL, Micallef S, 2020. Interactions between Salmonella enterica Newport, Fusarium spp. and melon cultivars. Foodborne Pathogens and Disease 2020, 17 (6), 388-395. https://doi.org/10.1089/fpd.2019.2721 

Bolten S, Gu G, Luo Y, Van Haute S, Zhou B, Millner P, Micallef SA, Nou X, 2020. Salmonella inactivation and cross-contamination on cherry and grape tomatoes under simulated wash conditions. Food Microbiology 2020, 87:103359.  https://doi.org/10.1016/j.fm.2019.103359

Callahan MT, Micallef SA, 2019. Waxing and the absence of trichomes favor Salmonella persistence on cucumber (Cucumis sativus L.) fruit – accepted to International Journal of Food Microbiology 9 Sept 2019 – in press. DOI: 10.1016/j.ijfoodmicro.2019.108359

Panthi S, Sapkota AR, Raspanti G, Allard S; Bui A, Craddock H, MurrayR, Zhu L, East C, Handy E, Callahan MT, HaymakerJ, Kulkarni P, Anderson B, Craighead S, Gartley S, Vanore A, Betancourt WQ, Duncan R, Foust D, Sharma M, Micallef SA, Gerba C, Parveen S, Hashem F, May EB, Kniel KE, Pop M, Ravishankar S, Sapkota A. Pharmaceuticals, herbicides and disinfectants in agricultural water sources. Environmental Research 2019 April 12; 174:1-8. https://doi.org/10.1016/j.envres.2019.04.011

Allard SM, Sultana S, Callahan MT, Bui A, Craddock H, Haymaker J, Foust D, Duncan R, Smyth E, Mongodin EF, Hashem F, May E, Micallef SA, Sapkota AR, 2019. Quenching by sodium thiosulfate does not influence 16S rRNA gene sequencing profiles of reclaimed water from three sites in the Mid-Atlantic United States. Environmental Research 2019 Feb 15; 172:296-300. DOI: 10.1016/j.envres.2019.02.022

Haymaker J, Sharma M, Parveen S, Hashem F, May EB, Handy ET, White C, East C, Bradshaw R, Micallef SA, Callahan MT, Allard S, Anderson B, Craighead S, Gartley S, Vanore A, Kniel K, Solaiman S, Bui A, Murray R, Craddock HA, Kulkarni P, Foust D, Duncan R, TaabodMi , Sapkota AR, 2019. Prevalence of Shiga-toxigenic and atypical enteropathogenic Escherichia coli in untreated surface water and reclaimed water in the mid-Atlantic US. Environmental Research, 172:630-636. https://doi.org/10.1016/j.envres.2019.02.019

Allard SM†, Callahan MT†, Bui A, Ferelli AMC, Chopyk J, Chattopadhyay S, Mongodin EF, Micallef SA*, Sapkota AR*, 2019. Creek to Table: Tracking fecal indicator bacteria, bacterial pathogens and total bacterial communities from irrigation water to kale and radish crops. STOTEN 2019 May 20; 666:461-471https://doi.org/10.1016/j.scitotenv.2019.02.179

Zhu L, Torres M, Betancourt WQ; Sharma M, Micallef SA, Gerba C, Sapkota AR, Sapkota A, Parveen S, Hashem F, May E, Kniel KE, Pop M., Ravishankar S, 2019.  Incidence of fecal indicator and pathogenic bacteria in reclaimed and return flow waters in Arizona, USA. Environmental Research 2019 Mar;170: 122-127. doi: 10.1016/j.envres.2018.11.048. Epub 2018 Dec 1.

Dev Kumar Govindaraj, Macarisin D, Micallef SA, 2019. Salmonella enterica filamentation induced by pelargonic acid is a transient morphotype. Applied Environmental Microbiology 2019 Jan 9; 85(2). pii: e02191-18. doi:10.1128/AEM.02191-18

Callahan MT, Van Kessel JA, Micallef SA, 2019. Salmonella enterica recovery from river waters of the Maryland Eastern Shore reveals high serotype diversity and some multidrug resistance. Environmental Research168:7-13; online 12 Sept 2018. https://doi.org/10.1016/j.envres.2018.09.012

Allard SM, Ottesen A, Brown EW, Micallef SA, 2018. Insect exclusion limits variation in bacterial microbiomes of tomato flowers and fruit. Journal of Applied Microbiology 125:1749-1760.  doi:10.1111/jam.14087

Park E, Luo Y, Marine SC, Everts KE, Micallef SA,  Bolten S, Stommel J, 2018. Consumer Preference and physicochemical evaluation of organically grown melons. Postharvest Biology and Technology, 2018, 141:77-85. doi:10.1016/j.postharvbio.2018.03.001

Dev Kumar G, Ravi S, Micallef SA, Brown EW, Macarisin D, 2018. Aeolian contamination of fruit by enteric pathogens: An unexplored paradigm. Current Opinion in Food Science 2018, 19:138-144. doi:10.1016/j.cofs.2017.12.003

Pang H, McEgan R, Micallef SA, Pradhan AK, 2018. Evaluation of meteorological factors associated with pre-harvest contamination risk of generic Escherichia coli in a mixed produce and dairy farm. Food Control 85:135-143. doi:10.1016/j.foodcont.2017.08.003

Pang H, McEgan R, Micallef SA, Pradhan AK, 2017. Identifying and Modeling Meteorological Risk Factors Associated with Pre-harvest Contamination of Listeria Species in a Mixed Produce and Dairy Farm. Food Research International 102 (2017) 355–363.doi:10.1016/j.foodres.2017.09.029 

Hsu CK and Micallef SA, 2017. Plant-mediated restriction of Salmonella enterica on tomato and spinach leaves colonized with Pseudomonas plant growth-promoting rhizobacteria. International Journal of Food Microbiology 2017 Jul 27;259:1-6. doi: 10.1016/j.ijfoodmicro.2017.07.012. [Epub ahead of print] 

Micallef SA and Buchanan RL, 2017.  Regulatory issues associated with pre-harvest food safety - United States perspective. Microbiology Spectrum 2017, 5(4). doi:10.1128/microbiolspec. PFS-0016-2016. 

Pang H, McEgan R, Micallef SA, Pradhan AK, 2017. Evaluation of Meteorological Factors Associated with Pre-harvest Contamination Risk of Generic Escherichia coli in a Mixed Produce and Dairy Farm. Food Control – in press. https://doi.org/10.1016/j.foodcont.2017.08.003

Dev Kumar G and Micallef SA, 2017. Susceptibility of Salmonella enterica isolates from tomato farm environments to fatty acids naturally found on tomato fruit.  2017, 14(5):293-301. doi: 10.1089/fpd.2016.2239. PMID: 28398868

Goldstein RR, Kleinfelter L, He X, Micallef SA, George A, Gibbs SG, Sapkota AR, 2017.  Higher prevalence of coagulase-negative staphylococci carriage among reclaimed water spray irrigators.  Sci Total Environ. 2017 Apr 1;595:35-40. doi: 10.1016/j.scitotenv.2017.03.174. [Epub ahead of print]. PMID: 28376426
 

Sharma M, Dashiell G, Handy ET, East C, Reynnells R, White C, Nyarko E, Micallef SA, Hashem F, and  Millner PD, 2017.  Survival of Salmonella Newport on whole and fresh-cut cucumbers treated with lytic bacteriophages. Journal of Food Protection (2017) 80(4): 668-673. doi:10.4315/0362-028X.JFP-16-449

 Allard SM, Walsh CS, Wallis AE, Ottesen AR, Brown EW, Micallef SA, 2016.  Solanum lycopersicum (tomato) hosts robust phyllosphere and rhizosphere bacterial communities when grown in soil amended with various organic and synthetic fertilizers. Science of the Total Environment (2016) 573:555-563. doi: 10.1016/j.scitotenv.2016.08.157.  PMID: 27580466

Micallef SA, Callahan MT and Pagadala S, 2016.  Occurrence and dispersal of indicator bacteria on cucumber grown horizontally or vertically on various mulch types.  Journal of Food Protection (2016) 79(10): 1663-1672. doi.org/10.4315/0362-028X.JFP-16-106.

Callahan MT, Micallef SA, Sharma M, Millner PD, Buchanan RL, 2016.  Investigating Metrics Proposed to Prevent the Harvest of Leafy Green Crops Exposed to Floodwater Contaminated with Escherichia coli. Appl Environ Microbiol. 2016 Apr 15. pii: AEM.00052-16. [Epub ahead of print] PMID: 27084022

Han S and Micallef SA, 2016. Environmental metabolomics of the plant surface provides insights on Salmonella enterica colonization of tomato. Applied and Environmental Microbiology, 82:10 3131-3142; Accepted manuscript posted online 18 March 2016, doi: 10.1128/AEM.00435-16. PMID: 26994076 

Callahan MT, Marine SC, Everts KL and Micallef SA, 2016. Drip line flushing with chlorine may not be effective in reducing bacterial loads in irrigation water distribution systems. Journal of Food Protection (2016) – accepted 23 February 2016, in press.  doi:10.4315/0362-028X.JFP-16-011

Xu A, Buchanan RL, Micallef SA, 2016.  Impact of mulches and growing season on indicator bacteria survival during lettuce cultivation.  International Journal of Food Microbiology 224:28-39. doi: 10.1016/j.ijfoodmicro.2016.02.013 [Epub ahead of print]. PMID: 26938806.

Reed-Jones N, Marine SC, Everts K and Micallef SA, 2016. Effect of cover crop species and season on population dynamics of Escherichia coli and Listeria innocua in soil. Applied and Environmental Microbiology – posted online 4 January 2016, doi: 10.1128/AEM.03712-15. PMID: 26729724

Rainfall intensity effects on removal of fecal indicator bacteria from solid dairy manure applied over grass-covered soil.  Science of the Total Environment 539:583-591. doi: 10.1016/j.scitotenv.2015.07.108. Epub 2015 Sep 18. PMID: 26386449

Xu. A., Pahl, D.M., Buchanan R. and Micallef S.A. Comparing the microbiological status of pre- and post-harvest produce from small organic production. Journal of Food Protection 78(6):1072-80. doi: 10.4315/0362-028X.JFP-14-548. PMID: 26038895 

Marine S.C.†, Pagadala S.†, Wang F.†, Pahl D.M., Melendez M.V., Kline W. L., Oni R.A., Walsh C.S., Everts K.L., Buchanan R.L. and Micallef S.A. Growing season, but not farming system, a food safety risk determinant for leafy greens in the mid-Atlantic region, Applied and Environmental Microbiology (2015) 81(7):2395-407 - online 23 January 2015, doi: 10.1128/AEM.00051-15. PMID: 25616798.   

Pagadala S.†, Marine S.C.†, Micallef S.A., Wang F., Pahl D.M., Melendez M.V., Kline W. L., Oni R.A., Walsh C.S., Everts K.L. and Buchanan R.L. "Assessment of region, farming system, irrigation source and sampling time as food safety risk factors for tomatoes and their production areas on small- and medium-sized farms in Maryland, Delaware and New Jersey" Int J Food Microbiol. 2015 Mar 2;196:98-108. doi: 10.1016/j.ijfoodmicro.2014.12.005. Epub 2014 Dec 13. PMID:25540859

Han S. and Micallef S.A., 2014. Salmonella Newport and Typhimurium Colonization of Fruit Differs from Leaves in Various Tomato Cultivars –Journal of Food Protection 77(11):1844-50. doi: 10.4315/0362-028X.JFP-13-562.

Rachel E. Rosenberg Goldstein, Shirley A. Micallef, Shawn G. Gibbs, Xin He, Ashish George, Amir Sapkota, Sam W. Joseph, Amy R. Sapkota.  Occupational exposure to Staphylococcus aureus and Enterococcus spp. among spray irrigation workers using reclaimed water. International Journal of Environmental Research and Public Health (2014) 11(4), 4340-4355.

Rosenberg Goldstein R.E., Micallef S.A., Gibbs S.G., George A., Claye E., Sapkota A., Joseph S.W., Sapkota A.R. Detection of Vancomycin-Resistant Enterococci (VRE) at Four U.S. Wastewater Treatment Plants that Provide Effluent for Reuse. Science of the Total Environment (2014) 1;466-467:404-11. PMID:23933428.

Micallef, S.A. and Colón-Carmona, A. (2013) Genetic and Developmental Control of Rhizosphere Bacterial Communities, in Molecular Microbial Ecology of the Rhizosphere: Volume 1 & 2 (ed F.J. de Bruijn), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118297674.ch24

Micallef S.A., Rosenberg Goldstein R.E., George A., Ewing L., Tall B.D., Boyer, M.S., Joseph S.W., Sapkota A.R. Diversity , Distribution abd Antibiotic Resistance of Enterococcus spp. Recovered from Tomatoes, Leaves, Water and Soil on Mid-Atlantic Farms. Food Microbiology (2013) 36(2):465-74. PMID:24010630

Rosenberg Goldstein R.E., Micallef S.A., Gibbs S.G., Davis J.A., He X., George A., Kleinfelter L.M., Schreiber N.A., Mukherjee S., Sapkota A., Joseph S.W., Sapkota A.R. Methicillin-Resistant Staphylococcus aureus (MRSA) Detected at Four U.S. Wastewater Treatment Plants. Environmental Health Perspectives(2012) 120(11):1551-1558. PMID: 23124279

Jean-Gilles Beaubrun, J., Cheng, C.-M., Chen, K.-S., Ewing, L., Wang, H., Agpaoa, M.C., Huang, M.- C.J., Dickey, E., Du, J.M., Williams-Hill, D.M., Hamilton B., Micallef S.A., Rosenberg Goldstein R.E., George A., Joseph, S.W., Sapkota, A.R., Jacobson, A.P., Tall, B.D., Kothary, M.H., Dudley, K., Hanes, D.E. The evaluation of a PCR-based method for identification of Salmonella entericaserotypes from environmental samples and various food matrices. Food Microbiology (2012) 31(2):199-209. PMID: 22608224

Micallef S.A., Rosenberg Goldstein R.E., George A., Kleinfelter L., Boyer M.S., McLaughlin C.R., Estrin A., Ewing L., Jean-Gilles Beaubrun J., Hanes D.E., Kothary M.H., Tall B.D., Razeq J.H., Joseph S.W., Sapkota A.R. Occurrence and Antibiotic Resistance of Multiple Salmonella Serotypes Recovered from Water, Sediment and Soil on Mid-Atlantic Tomato Farms. Environmental Research(2012) 114: 31-39. PMID: 22406288

Micallef S.A., Channer S., Shiaris M.P. and Colón-Carmona A.  Plant age and genotype impact the progression of bacterial community succession in the Arabidopsis rhizosphere.  Plant Signaling and Behavior (2009) 4(8): 777-780.

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