ABSTRACT
Trichomonas species usually reside in the mouth and occasionally in the respiratory tract. These species can be found in the lungs of humans. Although the pathogenicity of the parasite in the respiratory system has not been proven, it is more prevalent in people who lack good oral health or suffer from asthma or chronic pulmonary diseases. In the present descriptive study, we have identified Trichomonas by direct microscopic observation of stained smears and by PCR on the lung sputum of patients with asthma and chronic lung diseases that include lung cancer, bronchiectasis, COPD, and malignant pulmonary disease who were admitted to Masih Daneshvari Hospital, Tehran, Iran. For direct examination of 133 sputum samples, we stained the smears with giemsa. In addition a total of 60 samples were used for DNA extraction by an extraction kit [Cinnagen]. Nested-PCR was used for amplifying the ITS1 target gene of the parasite. Finally the DNA sequence of the gene was determined. According to the results, in direct examination of the sputum smears there were only 4 positive cases identified, whereas 22 [36.66%] of the samples were identified as Trichomonasby nested PCR. According to gender, 33.33% of the female samples and 38.46% of the male samples were found to be positive. Considering the high prevalence of this parasite in the study group, chronic pulmonary disease and asthmatic patients may be more susceptible to Trichomonas