My lab is interested in studying the mechanisms of biofilm formation involving food-borne pathogenic and health-promoting microorganisms. Particularly, we are interested in L. monocytogenes biofilm development and the interaction of L. monocytogenes with other microorganisms in ecosystems. Our recent major findings include that conjugation can serve as an important mechanism for biofilm development in the Gram-positive bacteria Lactococcus lactis, and that commensal organisms can enhance pathogen persistence through mixed culture ecosystem development (conference reported, manuscripts in preparation). We are currently investigating the risks and benefits associated with biofilms of food-borne microorganisms. We will further explore the functionality of food ingredients on microbial ecosystem development using established screening model.

To facilitate technology transfer, we are also involved in developing rapid molecular detection systems for agricultural and food industrial applications. Our first generation of the CleanPlant detection system is based on real-time Taqman PCR technology to detect the presence of pathogenic and spoilage microorganisms within hours directly from selected foods. We are currently interested in developing the second generation of the detection system using a cutting-edge technology to expand the coverage spectrum and to incorporate new features including microbial identification.

Peer-reviewed articles, book chapters and book

1.      Wang H, Broadbent JR, Kondo JK. 1994. Analysis of the physical and functional characteristics of cell clumping in lactose positive transconjugants of Lactococcus lactis subsp. lactis ML3. J. Dairy Sci. 77:375-384. 

2.      Broadbent JR, Oberg CJ, Wang H, Wei L.  1997.  Attributes of the heat shock response in three species of dairy Lactobacillus.  System Appl. Microbiol.  20:12-19. 

3.      Wang H, Yu W, Coolbear T, O’Sullivan DJ, McKay LL.  1998.  A deficiency in aspartate biosynthesis in Lactococcus lactis subsp. lactis C2 causes slow milk coagulation.  Appl. Environ. Microbiol. 64:1673-1679. 

4.      Wang H, Baldwin K, O’Sullivan DJ, McKay LL.  2000.  Identification, gene cloning, nucleotide sequencing, and expression of pyruvate carboxylase in fast milk coagulating Lactococcus lactis subsp. lactis C2. Appl. Environ. Microbiol.  66:1223-1227. 

5.      Wang H, Baldwin K, O’Sullivan DJ, McKay LL.  2000.  Identification and characterization of a gene cluster coding for citrate synthase, aconitase, and a truncated isocitrate dehydrogenase in Lactococcus lactis subsp. lactis C2. J. Dairy Sci. 83:1912-1918. 

6.      Hsia S-CV, Wang H, Shi Y-B.  2001.  Involvement of chromatin and histone acetylation in the regulation of HIV-LTR by thyroid hormone receptor. Cell Res.11:8-16. 

7.      Marsh E, Luo L, Wang H. 2003. A three-tiered approach to differentiate Listeria monocytogenes biofilm-forming abilities. FEMS Microbiol Lett. 228:203-210. 

8.      Luo H, Yousef A, Wang HH. 2004. Rapid detection of Alicyclobacillus species in pure culture and apple juice using real-time PCR. Lett. Appl. Microbiol. 39:376-382. 

9.      Pettipher GL, Jay JM, Wang H. 2005. Microbiological Techniques. In Encyclopedia of Analytical Science, Second Edition (Worsfold PJ, Alan Townshend A, Poole CF, eds.), Elsevier Science, Oxford, UK. Vol. 6, pp. 16-24. 

10.  Connor C, Luo H, McSpadden-Gardener BB, Wang HH. 2005. Development of a second rapid detection system for Alicyclobacillus spp. using real-time PCR. Int. J. Food Microbiol. 99:229-235. 

11.  Luo H, Wan K, Wang HH. 2005. A high frequency conjugation system facilitated biofilm formation and pAMβ1 transmission in Lactococcus lactis. Appl. Environ. Microbiol. 71:2970-2978. 

12.  Hanna SE, Connor CJ, Wang HH.  2005.  Real-time polymerase chain reaction for the food microbiologist: technologies, applications, and limitations.  J Food Sci. 70:49-53. 

13.  Wan K, Yousef AE, Schwartz S, Wang HH. 2006. Rapid, specific and sensitive detection of spoilage molds in orange juice using a real-time Taqman^® PCR assay. J Food Protect. 69:385-390. 

14.  Wang HH, Manuzon MY, Lehman M, Wan K, Luo H, Wittum TE, Yousef AE, Bakaletz LO. 2006. Food commensals as a potentially important avenue in transmitting antibiotic resistance genes. FEMS Micrbiol Lett. 254: 226-231. 

15.  Lu L, Tomita A, Wang H, Buchholz DR, Shi YB. 2006. Transcriptional regulation of the Xenopus laevis stromelysin-3 gene by thyroid hormone is mediated by a DNA element in the first intron. J. Biol. Chem. (In press. E-pub: http://www.jbc.org/cgi/doi/10.1074/jbc.M603041200) 

16.  Hanna S, Wang HH. 2006. Biofilm formation by Listeria monocytogenes. In: Biofilms in the Food Environment. (Balschek H, Wang HH, Agle M, eds.). Blackwell Publishing Co. (In press) 

17.  Manuzon M, Wang HH. 2006. Mixed culture ecosystem. In: Biofilms in the Food Environment (Balschek H, Wang H, Agle M, eds.). Blackwell Publishing Co. (In press). 

18.  Blaschek H, Wang HH, Agle M. (eds.) 2006. Biofilms in the Food Environment. Blackwell Publishing Co. (In press). 

Conference presentations and Abstracts 

19.  Broadbent JR, Wang H, Oberg C.  1994.  Evidence for heat- and acid adaptation responses in Lactobacillus helveticus LH212.  ASM 93^rd General Meeting, paper #K54. p.80. 

20.  Broadbent JR, Gillies K, Wang H, Kondo JK, Sandine WE. Evidence for pAMb1-mediated conjugal retrotransfer in lactococcus lactis subsp. lactis.  1994. ASM 4^th international conference on Streptococcal genetics. p.18. 

21.  Wang H, Yu W, Coolbear T, McKay LL.  1996.  A deficiency in aspartate biosynthesis in Lactococcus lactis ssp. lactis C2 causes slow milk coagulation.  ADSA annual meeting. J. Dairy Sci. 79(Suppl. 1):26. 

22.  Wang H, O’Sullivan DJ, McKay LL.  1998.  Identification, gene cloning, sequencing and expression of pyruvate carboxylase in fast milk coagulating Lactococcus lactis subsp. lactis C2.  ADSA annual meeting. J. Dairy Sci. 81(Suppl. 1):8. 

23.  Luo H, Yousef AE, Wang H. 2002. Developing a rapid detection system for Listeria monocytogenes using real-time PCR. Institute of Food Technologists (IFT) annual meeting. Abstract #100A-28, p.246. 

24.  Wang H. 2002. Applying biotechnology to impact food safety and quality. Proceedings of OCAPA Symposium 2002. p. 46. 

25.  Kim M, Luo H, Wang H. 2003. Detecting Listeria monocytoegenes in artificially contaminated meat using a real-time PCR system. IFT annual meeting. Abstract # 76E-1, p.194-195. 

26.  Luo H, Yousef A, Wang H. 2003. Rapid detection of Alicyclobacillus species in pure culture and apple juice using real-time PCR. IFT annual meeting. Abstract #104A-15, p.256.  

27.  Marsh E, Luo H, Wang H. 2003. Biofilm development in Listeria monocytogenes. IFT annual meeting. Abstract #76E-10, p.196. 

28.  Connor C, Luo H, McSpadden-Gardener BB, Wang H. 2003. Development of a second rapid detection system for Alicyclobacillus spp. using real-time PCR. IFT annual meeting. Abstract #104A-2, p.254. 

29.  Wan K, Luo H, Yousef A, Wang H. 2004. Rapid and specific detection of spoilage fungi using a real-time Taqman^â PCR-based system. ASM-Ohio annual meeting. The Ohio J. Sci. 104 (1): A-11. 

30.  Wan K, Wang H. 2004. Rapid and specific detection of spoilage molds in juice products using a real-time Taqman PCR-based system. IFT annual meeting. Abstract #99A-29, p.253. 

31.   Luo H, Wang H.  2004. Mixed culture ecosystem: a possible surviving mechanism for non-biofilm formers? IFT annual meeting. Abstract #99D-30, p.268. 

32.  Wang H, Yousef A, Schwartz S. 2004. Molecular approaches to improve food safety and quality: development and application of the OSU CleanPlant detection system. IFT annual meeting (symposium speaker). Abstract #20-2, p.52. 

33.  Wang H. 2004. Biofilm development by Listeria monocytogenes and the potential risks. IFT annual meeting (symposium speaker). Abstract #51-3, p.143. 

34.  Wang HH. 2005. Biofilm formation and gene transfer by foodborne microorganisms: a major challenge to human health. ASM conference: Beneficial Bacteria. p. 54. 

35.  Wan K, Wang HH. 2005. Horizontal transfer of the broad host range drug-resistance plasmid pAMβ1 from Lactococcus lactis to foodborne pathogen Listeria monocytogenes. ASM annual meeting. Abstract#P-004, p. 438.  

36.  Hanna S, Wang HH. 2005. Upregulated expression of Listeria monocytogenes virulence factor inlA in acidic environment. ASM annual meeting. Abstract#P-048, p. 447.

 37.  Hanna S, Wang HH. 2005. Influence of environment conditions on Listeria monocytogenes virulence factor expression. IFT annual meeting. Abstract#36B-12. 

38.  Luo H, Wan K, Wang HH. 2005. Bacterial intrinsic mechanism facilitated horizontal gene transfer –an illustration by Lactococcus lactis. 3^rd Conference on functional genomics of Gram-positive microorganisms. Abstract#P86. 

39.  Manuzon M, Hanna S, Luo H, Wang HH. 2006. Development of a real-time PCR method to quantify antibiotic resistance gene pool in retail dairy products. ASM annual meeting.  

40.  Lehman M, Wang HH. 2006. Prevalence of antibiotic resistant bacteria in ready-to-eat salad. IFT annual meeting.  

41.  Wang HH, McKay LL. 2006. Horizontal gene transfer as an important mechanism facilitating biofilm ecosystem development by Lactococcus lactis. ASM streptococcus genetics meeting.