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Entamoeba moshkovskii and Entamoeba dispar are impossible to differentiate microscopically from the pathogenic species Entamoeba histolytica. There are limited data on the prevalence of these commensal parasites in Iran. We utilized a single-round PCR assay to determine the prevalence of E. moshkovskii, E. dispar, and E. histolytica in stool samples from Iranian patients infected with gastrointestinal disorders. After culturing of microscopy-positive isolates and extraction of DNA, PCR was carried out to differentiate the Entamoeba isolates. Out of 3,825 stool samples examined by microscopy, 58 specimens (1.52%) were infected with E. histolytica, E. dispar, or E. moshkovskii. By PCR, 2 E. histolytica (3.45%), 53 E. dispar (91.37%), 2 E. moshkovskii (3.45%), and one mixed E. dispar/E. moshkovskii infection (1.73%) were detected. In view of the reporting of E. moshkovskii in this study in Iran and the difficulty in discriminating this ameba from two similar Entamoeba spp. by microscopy, we recommend the single-round PCR assay as an alternative tool in routine diagnosis and in epidemiological studies of amebiasis.

Persistent infection of arteries with organisms such as Chlamydia pneumoniae was previously found to contribute to the development of atherosclerosis. We investigate the presence of C. pneumoniae in atherosclerotic plaque by polymerase chain reaction and direct immunofluorescence assay, and we examine the correlation between clinical status and the presence of this bacterium in Iran. The study group consisted of 33 atherosclerotic plaque specimens from the arteries (26 coronary and 7 abdominal aorta) of patients who had undergone coronary artery bypass grafting surgery (CABG). The control group consisted of 31 specimens: 12 from biopsies of macroscopically healthy regions of the ascending aorta in patients who had undergone CABG and 19 autopsy specimens of normal coronary arteries. C. pneumoniae DNA and antigen were found in 6 (18%) and 7 (21%) of 33 endarterectomy specimens, respectively. C. pneumoniae was not detected in the control group by either method. The presence of C. pneumoniae in atherosclerotic plaques and its absence in healthy vessels supports the idea that C. pneumoniae may have a role in the development of atherosclerosis, especially in countries where infection is prevalent and where conventional risk factors fail to explain the exact reason for the high prevalence of atherosclerotic vascular disease.

Mosaicism in vacA alleles with two distinct families of vacA signal sequences (s1 and s2) and two distinct families of middle region alleles (m1 and m2) has been reported. Research suggests that the vacA s1 genotype is closely associated with duodenal ulcer disease and with high cytotoxin production. The aims of this study were to evaluate the role of vacA genotyping with respect to gastric inflammation and injury, and clinical presentation in Iranian populations. Genomic DNA of biopsy specimens from patients with gastritis, peptic ulcer disease (PUD), or gastric cancer (GC) were characterized based on ureC (glmM), cagA, and vacA genotyping by using polymerase chain reaction. Of 167 patients including 33 with PUDs, 129 with non-ulcer dyspepsia (NUD), and 5 with GC, 96 (57.5%) cases were infected by Helicobacter pylori. Among these patients, H. pylori were isolated from 19 (57.7%) PUD patients, 74 (68.7%) NUD patients, and 3 (60%) GC patients. The cagA was detected in 76% of H. pylori-positive cases. The vacA s1-m2 genotype was the most prevalent in 7/19 PUD (37%) and 30/74 NUD (40.5%) patients with H. pylori infection. The prevalence of vacA s2-m1 (8%) was high in Iranian isolates. A significant association was not found between H. pylori genotypes and clinical outcomes. The vacA genotypes and cagA status were not useful markers for gastroduodenal diseases in Tehran, Iran.