TEACHING
Module coordinator of MICR311 (Advanced Bacteriology) and MICR213 (Bacteriology).
RESEARCH INTERESTS
The increasing incidence of antibiotic resistant microorganisms and the evolution of “super-bugs” has led to tremendous interest in the genetics and mechanisms of resistance evolved by bacteria in order to counteract the effect of antimicrobial agents. Many bacteria have evolved innovative means of ensuring their survival, including making a biofilm lifestyle choice and horizontal transfer of antimicrobial resistance genes. This has implications on antibiotic usage in both clinical and veterinary medicine.
One of the research focuses of this group lies in antibiotic resistance mechanisms, the horizontal gene transfer of resistance genes and the role of efflux and other resistance mechanisms in the evolution of multidrug-resistant environmental bacteria and clinical pathogens. Majority of the research projects are focused on looking at the commensal bacteria and/or pathogens of fish reared in aquaculture systems, the identification of antibiotic resistance genes, and their impact on antimicrobial use. The research is targeted to identifying integrons, containing antimicrobial resistance gene cassettes, which may be found chromosomally or on mobile genetic elements such as plasmids, and transposons, and assessing their role in the development of the resistance phenotype. Another important aspect involves trying to understand the horizontal movement of these genes (via plasmids and transposons) between bacterial species in the aquaculture environment and the impact on antimicrobial resistance in the human compartment. The impact of plasmid-mediated and efflux pump-mediated resistance determinants on fluoroquinolone resistance among potential opportunistic zoonotic pathogens from the aquaculture environment is also being investigated. Here the focus is on Aeromonas spp. isolates which show preliminary evidence of plasmid-mediated quinolone resistance.
Additionally, the use of molecular typing methods in tracing the epidemiology and understanding the population structure of fish pathogens such as Flavobacterium, Chryseobacterium, Myroides, Edwardsiella, Vibrio and Aeromonas spp. will provide useful information on the evolution of strains (acquisition and loss of genes), virulence and pathogenicity, ability to form biofilms and the development of rapid diagnostics.
The ability of these aquatic organisms to form biofilms and the structures implicated in this phenotype is being investigated to understand the outbreak and recurrence of infection. This involves using comparative proteomics and transcriotomic approaches to investigate differential protein and gene expression as these bacteria transit from a planktonic to a sessile lifestyle. The impact of antimicrobial exposure prior to and after biofilm formation is also being investigated, in order to understand the dynamic relationship between microbial resistance when part of a biofilm and antimicrobial agents targeted against them for therapy.
ACCOMPLISHMENTS
Senior Lecturer
Academic coordinator.
PUBLICATIONS (2000-2009)
H. Y. Chenia, B. Pillay, A. A. Hoosen and D. Pillay. 1997. Antibiotic susceptibility patterns and plasmid profiles of penicillinase-producing Neisseria gonorrhoeae in Durban, South Africa, 1990-1993. Sexually Transmitted Diseases 24:18-22.
M. Pillay, H. Y. Chenia, D. Pillay, A.A. Hoosen and B. Pillay. 1997. A novel b-lactamase plasmid in Neisseria gonorrhoeae. Medical Science Research 25:435-436.
H. Y. Chenia, B. Pillay, and D. Pillay. 2001. Evaluation of a polymerase chain reaction assay for the detection of Neisseria gonorrhoeae in clinical samples. South African Journal of Epidemiology and Infection 16:105-107.
Hafizah Y. Chenia, Balakrishna Pillay and Dorsamy Pillay. 2006. Mechanisms of fluoroquinolone resistance in urinary tract pathogens: Analysis of membrane composition, target gene alterations, accumulation of ciprofloxacin, and presence of the qnrA gene. Journal of Antimicrobial Chemotherapy 58: 1274-1278.
Leonard Flemming, Douglas Rawlings, Hafizah Y Chenia. 2007. Phenotypic and molecular characterisation of fish-borne Flavobacterium johnsoniae-like isolates from aquaculture systems in South Africa. Research in Microbiology 158: 18-30.
Liezl Jacobs and Hafizah Y. Chenia. 2007. Characterisation of integrons and tetracycline resistance determinants in Aeromonas spp. isolated from South African aquaculture systems. International Journal of Food Microbiology 114: 295-306.
Basson, L. A. Flemming, and H.Y. Chenia. 2008. Evaluation of adherence, hydrophobicity, aggregation characteristics and biofilm development of Flavobacterium johnsoniae-like isolates from South African aquaculture systems. Microbial Ecology 55:1-14.
Jacobs and H. Y. Chenia. Biofilm-forming capacity, surface hydrophobicity and aggregation characteristics of Myroides odoratus isolated from South African Oreochromis mossambicus fish. Journal of Applied Microbiology. DOI: 10.1111/j.1365-2672.2009.04380.x