Molecular Evidence of Emerged Pulmonary Lophomoniasis due to Lophomonas blattarum among Hospitalized Patients in Southwestern Iran: A National Registry-Based Study

Abstract

Objectives. Lophomonas protozoan is an emerging pathogen transmitted through arthropods such as cockroaches. Lophomoniasis is still a mysterious disease with many unknown epidemiological aspects. The current study aimed to determine the prevalence of lophomoniasis among patients who were hospitalized in Hajar Hospital, Shahrekord, southwestern Iran, using a conventional PCR technique. Methods. In this retrospective study, 132 frozen bronchoalveolar lavage fluid (BALF) specimens from patients with respiratory disorders hospitalized in Hajar Hospital, Shahrekord district, southwestern Iran, were analyzed during 2020-2021. Samples are referred to the Iranian National Registry Center for Lophomoniasis (INRCL), Mazandaran Province, Northern Iran, for detecting Lophomonas spp. infection by a conventionally small subunit ribosomal RNA (SSU rRNA) PCR test. Results. A total of 132 frozen BALF specimens were examined, 36 (27.3%) tested Lophomonas spp. positive using the conventional PCR technique. Also, based on sequencing data and blast analysis, the presence of L. blattarum species was confirmed. The average age of Lophomonas spp.‐ positive patients was 67.02 ± 15.14 years. Out of the 36 positive subjects, 63.9% were male and 36.1% female. Male and Lophomonas infection had a significant correlation ( p = 0.001 ). Our findings revealed that L. blattarum infected nonsmokers more than smokers ( p = 0.001 ). The most common underlying disease was also bronchitis Conclusion. Our results showed, for the first time, that pulmonary lophomoniasis caused by L. blattarum is a common and emerging disease in the study area, southwestern Iran. Furthermore, our findings support the use of the PCR test to detect Lophomonas infection in archived frozen clinical samples.

Characterization of Lophomonas spp. Infection in a Population of Critical Care Patients

“…We also report a significantly higher number of radiological findings involving bronchi, alveoli, and pleura in chest tomography compared to other reports [1,4,16]. Unfortunately, we did not have a clear record of findings during bronchoscopy, which has also been reported to display abnormalities in the bronchial mucosa [3]. Overall, our patients appear to display a more severe lung infection related to Lophomonas, although this could be justified by a higher severity of pre-existing or ICUacquired illness at the time of the onset of a new respiratory tract infection, such as sequelae from SARS-CoV-2 infection.…”

“…Two case reports have been published showing co-infection with Lophomonas and cavitated pneumonia secondary to Mycobacterium tuberculosis [21,22]. It is likely that the presence of structural damage to normal lung anatomy may also facilitate the propagation of active protozoa and a steady clinical deterioration in these patients through a local inflammatory response, a finding that has been reported already reported by Mokhtarian et al, which reported that the commonest comorbidity on his patient sample was chronic bronchitis [3].…”

“…In recent years, Lophomonas spp. has become increasingly associated with upper and lower airway disease in humans [1][2][3][4]. Lophomonas is a flagellated protozoa primarily commensal to the gut of insects, like cockroaches and termites, although they may also be found in the environment [5].…”

True molecular phylogenetic position of the cockroach gut commensal Lophomonas blattarum (Lophomonadida, Parabasalia)

“…The sequence is 99% identical to previously published Pentatrichomonas hominis sequences. The other 17 sequences (MN243135–MN243136, MZ093069–MZ093079, OL477421–OL477423, and OL477431) were obtained by PCR from human bronchoalveolar lavage fluid or nasal secretions using primers designed to match the sequence from Thailand and L. striata (Fakhar et al, 2019, 2021; Mokhtarian et al, 2022). In our phylogenetic analyses, all of these sequences robustly branch within Trichomonadida (Figure 1F), either sister to P. hominis or with Tetratrichomonas .…”

“…However, ciliated epithelial cells, and fragments of them called ciliocytophthoria, look superficially like L. blattarum under the light microscope (Gelardi & Ciprandi, 2019), leading some authors to question the identification of Lophomonas in medical case studies (Li & Gao, 2016;Martínez-Girón & van Woerden, 2014). Recent studies claim to have confirmed the diagnosis of L. blattarum infection by molecular methods (Fakhar et al, 2019(Fakhar et al, , 2021Mokhtarian et al, 2022), but the short fragments of the 18S rRNA gene produced in these studies are highly similar to the Trichomonadida Pentatrichomonas or Tetratrichomonas, which are evolutionarily distant from Lophomonadida (Čepička et al, 2017).…”