Alexandra Davis wins research award
Alexandra Davis, PhD candidate in the lab of Dr. Michael Allen, won second place in
the graduate poster presentation category at the Fall meeting of the Texas Branch
of the American Society for Microbiology.
Here’s a summary of her research:
Antibiotic-resistant infections cause nearly 5 million deaths annually, and Staphylococcus
aureus alone accounts for more global deaths than malaria, breast cancer, or HIV/AIDS.
Its rapid acquisition of antibiotic resistance has created an urgent need for alternative
treatments such as bacteriophage therapy. Because phages are highly strain-specific,
effective phage cocktails must include viruses capable of infecting a broad range
of S. aureus isolates.
This study evaluated phages isolated from diverse environments against 32 S. aureus
clinical strains using two host-range methods: agar plate assays and liquid culture
assays. Infection was detected in 51.6% of phage–bacteria combinations on plates and
42.9% in liquid culture. A two-proportion z-test showed no significant difference
between methods, indicating that both are equally valid. Agar plates provide higher
apparent titers and are ideal for isolating mutants, while liquid cultures offer real-time
monitoring of bacterial resistance. Together, these findings support selecting broad-host-range
phages and using both methods strategically to develop more effective therapeutic
phage cocktails.