After reading the paragraphs below, answer the questions that follow.
A negative impact of biofilms in the human body is that biofilms can cause head and neck diseases. A study was completed that compared three groups of medical patients for presence or absence of biofilms. Group 1 were patients with chronic otitis media (COM), a disease where the eardrum continually drains and can often become clogged, that also displayed ear discharge. Group 2 were COM patients without ear discharge. Group 3 were patients undergoing surgery for cochlear implantation, a procedure where a small electronic instrument is placed in the ear to carry out normal functions of the inner ear. Two microscopy methods were used to detect presence of biofilms in all patients of both groups: direct microscopy (DM) and transmission electron microscopy (TEM).
The table below shows the results of presence or absence of biofilms in all study participants.
Table 1. Number of study participants detected with biofilms
| Group | Group Size | Biofilm on DM | Biofilm on TEM |
| 1 COM, discharge | 10 | 10 | 10 |
| 2 COM no discharge | 9 | 2 | 2 |
| 3 cochlear implant | 10 | 0 | 0 |
| Total | 29 | 12 | 12 |
Source: Adapted from Akyıldız, I., Take, G., Uygur, K., Kızıl, Y., & Aydil, U. (2013). Bacterial biofilm formation in the middle-ear mucosa of chronic otitis media patients.
Indian J Otolaryngol Head Neck Surg, 557-561. doi:10.1007/s12070-012-0513-x
How can you interpret results of the study?
◦ All patients with a history of ear discharge and two without ear discharge were found by DM and TEM to have presence of biofilms.
◦ Half of the patients with ear discharge were found to be free of biofilms.
◦ All cochlear transplant patients were found by DM to have presence of biofilms.
◦ Cochlear transplant patients were found to have more occurrences of biofilms than all other study patients.
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