Journal of Mazandaran University of Medical Sciences (Jun 2024)
Morphological and Molecular Identification of Acanthamoeba and Lophomonas Isolated from the Sputum of Suspected Tuberculosis Patients in Babolsar, Mazandaran Province in 2022-2023
Abstract
Background and purpose: Lophomoniasis is a relatively common emerging parasitic disease caused by a pathogenic protozoan called Lophomonas, which mostly affects the lower respiratory tract (lungs and bronchi) of humans. The parasite lives symbiotically in the digestive system of insects such as cockroaches and mites. Acanthamoeba is a free-living amoeba that has two forms of trophozoite and cyst in its life cycle. The respiratory system and airways serve as passage and deployment sites for a wide range of non-pathogenic and pathogenic microorganisms, making it a suitable place for the entry and spread of different species of Acanthamoeba amoeba and the Lophomonas pathogen in the respiratory system, which can cause clinical manifestations similar to tuberculosis. Therefore, the present study aimed to investigate the frequency of these two parasites in sputum clinical samples from suspected tuberculosis patients referred to the tuberculosis laboratory in Babolsar City to rule out the two mentioned infections. Materials and methods: This descriptive-cross-sectional study was conducted on 201 sputum samples of people suspected of tuberculosis who were referred to the tuberculosis laboratory of Babolsar Health Center in Mazandaran province in 202-2023, and all the demographic and epidemiological information of the patients was recorded. In the morphological method, Giemsa staining was used for Lophomonas and Ziehl-Neelsen staining for Acanthamoeba. To identify the presence of Acanthamoeba, sputum samples were cultured in a 1.5% non-nutrient agar culture medium for 72 to 96 hours. Approximately 50 microliters of patients' sputum were added to the NNA medium, along with 20 microliters of trypticase-yeast extract and maltose (TYM) culture medium, and 20 microliters of an autoclaved Escherichia coli bacteria mixture to enrich the culture medium. The cultured plates were then placed in an incubator at 26ºC and checked daily under a light microscope for trophozoite growth. To accurately confirm the presence of parasites, DNA extraction was performed on the patient's sputum samples using the phenol-chloroform-isoamyl alcohol method. Subsequently, conventional polymerase chain reaction (PCR) was conducted using specific primers on the extracted DNA samples. Results: In the study of 201 people suspected of tuberculosis, it was found that 80 individuals (39.8%) lived in urban areas and 121 individuals (60.2%) lived in rural areas. The age range of participants varied from 7 to 88 years old. There were 113 females (56.2%) and 88 males (43.8%) in the study, with 12 individuals from Afghanistan living in urban areas. Out of the 201 sputum samples examined, a total of 23 samples (11.4%) tested positive for the Lophomonas parasite using the PCR method. Among these positive cases, 7 individuals (30.4%) resided in urban areas (Babolsar), while 16 individuals (69.5%) lived in rural areas. However, none of the samples tested positive for Acanthamoeba in this study using staining and PCR methods. Conclusion: The present study showed that due to the similarity of the clinical manifestations of tuberculosis and lophomoniasis, there is a possibility of mistaking these two diseases clinically. Therefore, it is recommended to check fresh sputum samples of people suspected of tuberculosis, especially in endemic areas, in terms of pulmonary lophomoniasis.
