Mycobacterium tuberculosis genotypes in an ethnically diverse area with millions of pilgrims and thousands of immigrants.

BACKGROUND: Immigration is considered as a risk factor of tuberculosis (TB). Qom province receives millions of pilgrims and significant numbers of immigrants each year. Most of the immigrants to Qom, arrive from neighboring TB-endemic countries. This study aimed to identify the current circulating Mycobacterium tuberculosis genotypes in Qom province using 24-locus MIRU-VNTR genotyping. METHODS: Eighty six M. tuberculosis isolates were collected during 2018-2022 from patients referring to Qom TB reference laboratory. The DNA of isolates was extracted and followed by 24 loci MIRU-VNTR genotyping which performed using the web tools available on MIRU-VNTRplus. RESULTS: Of 86 isolates, 39 (45.3%) were of Delhi/CAS genotype, 24 (27.9%) of NEW-1, 6 (7%) of LAM, 6 (7%) of Beijing, 2 (2.3%) of UgandaII, 2 (2.3%) of EAI, 1 of S (1.2%) and 6 (7%) did not match with profiles present in MIRUVNTRplus database. CONCLUSIONS: About half of the isolates belong to Afghan immigrants; which warns health policy makers about the future situation of TB in Qom. Also, the similarity of Afghan and Iranian genotypes provides evidence that immigrants partake in the circulation of M. tuberculosis. This study underpin the studies about the circulating M. tuberculosis genotypes, their geographical distribution, the association of TB risk factors with these genotypes and the impact of immigration on the situation of TB in Qom province.

In vitro evaluation of albendazole nanocrystals against Echinococcus granulosus protoscolices.

Echinococcus granulosus is a zoonotic parasite causing hydatidosis in humans and animals. This study has been done in order to investigate the effect of albendazole nanocrystals on the viability of E. granulosus protoscolices. The average size and hydrodynamic diameter of albendazole nanocrystals were 976±218 and 1334±502 nm, respectively. Fertile hydatid cysts were isolated from the liver of slaughtered sheep. The isolated cysts were further identified using morphological and molecular techniques. The nucleotide sequence analysis indicated that the genotype of the protoscolices was E. granulosus sensu stricto with 100% similarity. The parasites were examined precisely for susceptibility to albendazole nanocrystals. The results revealed that albendazole nanocrystals are effective in removing protoscolices. It was observed that 1 µg/ml albendazole nanocrystals and albendazole completely inhibited the viability of the protoscolices within 17 and 23 days, respectively. The results suggested that albendazole nanocrystals can be used as an alternative effective treatment for E. granulosus infection.

Helicobacter pylori FliD protein is a highly sensitive and specific marker for serologic diagnosis of H. pylori infection.

Screening for H. pylori in large populations continues to be a challenging task, since available tests have limited sensitivity and specificity, which, in population-based approaches, leads to significant numbers of false positive and false negative results. Various H. pylori proteins associated with virulence are highly immunogenic and therefore candidates to detect the infection. There are currently no defined markers that are recognized in all H. pylori infected patients and that do not show cross-reactivity with other bacterial proteins. We identified the H. pylori "hook-associated protein 2 homologue", FliD (UniProtKB/Swiss-Prot: P96786.4) as a novel marker of infection for serological analysis. The H. pylori FliD protein is an essential element in the assembly of the functional flagella. However, this virulence factor has not yet been tested as a diagnostic marker in serology. For this purpose FliD was recombinantly expressed in E. coli, purified by affinity chromatography and gel filtration and used to coat ELISA plates or immobilized on nitrocellulose stripes. To evaluate its antigenicity we screened a defined panel of patient sera. The recombinant H. pylori FliD protein reacted with a high percentage of human sera. Among 318 samples reported positive by histology, 310 (97.4%) were tested positive by FliD Line assay, and 165 out of 170 samples were tested positive by ELISA (97%). We could also reconfirm 297 out of 300 (99%) negative sera by Line assay and 73 from 76 (96%) by ELISA. Taken together, application of FliD in serological diagnosis of H. pylori infection presents a high specificity of up to 99% and a sensitivity of up to 97%. This makes especially the FliD ELISA a simple, cost effective and highly efficient tool to detect H. pylori infection in developing countries where prevalence is high and other screening methods are either not available or are unaffordable.

Frequency of sabA Gene in Helicobacter pylori Strains Isolated From Patients in Tehran, Iran.

BACKGROUND: The importance of sialic acid binding adhesin (sabA) as a new outer membrane protein in gastroduodenal diseases has been recognized. The prevalence rate of sabA gene varies in different geographic areas. OBJECTIVES: The aim of this study was to determine the frequency of sabA gene in Helicobacter pylori (H. pylori) strains isolated from different clinical outcomes in Tehran, Iran. PATIENTS AND METHODS: The study included 120 patients with dyspeptic symptoms admitted to the endoscopy suite of gastroenterology section of Firouzgar University Hospital, Tehran, Iran from March to August 2011. Gastric biopsy specimens were evaluated for the presence of H. pylori using standard microbiological method and polymerase chain reaction (PCR) assay. The sabA genopositive was determined by PCR in H. pylori strains. RESULTS: H. pylori isolates were recovered from 82 patients with duodenal ulcer (DU; n = 17), gastric ulcer (GU; n = 15), gastric cancer (GC; n = 13), and gastritis (G; n = 37). The frequency of sabA gene in H. pylori strains was 100% in gastric cancer, 86.7% in gastric ulcer, and 83.3% in both gastritis and duodenal ulcer. CONCLUSIONS: This is a report on the prevalence of sabA gene in H. pylori isolated from different gastric patients in Iran. The results showed a high prevalence of sabA in our clinical H. pylori isolates.