Date of Award


Document Type

Master Thesis

Degree Name

Masters of Science (Research)


Biological Sciences

First Advisor

Dr. Jim O'Mahony


Despite the medical advances of recent years, pneumonia is still a common disease in Ireland, accounting for approximately 7% of deaths in this country'. While national databases such as those run by CIDR and SARI ensure that incidences of systemic and notifiable infections such as tuberculosis are recorded, there are currently no available statistics on commonplace respiratory isolates within Ireland. This study analysed the available data on bacterial pathogens isolated from respiratory samples at a 355 bed Irish hospital over a one year period. Seasonal variations and resistance patterns were noted. The most frequently isolated pathogens were Staphylococcus aureus (27%), Haemophilus influenzae (17%), Streptococcus pneumoniae (9%) and mixed coliforms (24%). An average of 14% of the Gram-negative bacilli isolated showed resistance to third generation cephalosporins, while 31% Streptococcus pneumoniae isolates showed non-susceptibility to penicillin. Results indicated that sensitivity patterns of invasive isolates currently recorded in Ireland and across Europe may not accurately reflect those of other clinical isolates.

The first antimicrobials were derived from natural sources, and interest in these sources has once again increased in recent years. In the second part of this study, extracts were prepared from a selection of plants which were known to have been used as traditional respiratory remedies in the past. These were then tested for antibacterial activity against a range of pathogens which had been found to cause respiratory infection within the southern Ireland hospital. The results were promising. Ethanolic extracts of Solidago virgaurea showed activity against Enterocoeeus faecium and S.aureus comparable to 1 mg/ml gentamicin. This plant, along with extracts of Mentha pulegium and Tussilago farfara, also exhibited activity against the more classical respiratory pathogens S.pneumoniae, H.influenzae, and species of mycobacteria. Extracts from plants not native to Ireland were also examined, giving a total of 16 plants screened.

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