Effect of Clinical X-rays on Methicillin-resistant Staphylococcus aureus and Other Bacterial Isolates from Radiology Equipment

Aim: Methicillin-resistant Staphylococcus aureus (MRSA) and other nosocomial pathogens are frequently isolated from the Radiology Department of hospitals. These pathogens are repeatedly exposed to refracted electromagnetic radiations during diagnostic clinical X-ray imaging sessions. This study thus investigated the effect of these refracted radiations on the nosocomial bacteria found within Radiology units and their possible survival mechanism.

Methodology: Swab samples were collected from three (3) Radiology units; plain radiography machine, ultrasound machine and mammography machine. The samples were cultured and identified following standard microbiology procedures. The identified bacterial isolates were exposed to X-rays at different KVp and MAs factors, cell counts and catalase activities of the isolates were determined using standard procedures.

Results: The bacterial isolates identified were Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli and Enterococcus faecalis where Staphylococcus aureus had the highest prevalence (29.41%) and Enterococcus faecalis (11.76%) was least. The highest survival level to KVp and MAs exposure was S. aureus with values 11.16 ± 0.86 x103 and 19.50 ± 0.16 x103 cfu/ml respectively while Enterococcus faecalis was least with negative value. There was a positive correlation between catalase activity and cell survival with R-value of 0.2512 and 0.6925 for KVp and MAs exposure factors respectively.

Conclusion: The study revealed that clinical X-ray does not completely eliminate nosocomial pathogens within Radiology Department and MRSA is a formidable bacterium in the units.