Iranian Strains Research Articles

CHARACTERIZATION OF SOME BIOFILM-FORMING BACILLUS SUBTILIS STRAINS AND EVALUATION OF THEIR BIOCONTROL POTENTIAL AGAINST FUSARIUM CULMORUM

Thirty Iranian native Bacillus sp. strains collected from the rhizosphere of various hosts in different regions of the country were studied. 16S rRNA identification and phylogenetic analysis was carried out and secondary metabolites of volatile components, protease activity, biofilm formation and antagonistic activity against Fusarium culmorum in greenhouse were investigated for a thorough characterization of the strains. Correlation between biofilm formation and biocontrol capabilities under greenhouse conditions was also studied. PCR amplification and partial sequencing of 16S rRNA showed that all Iranian strains had more than 98% similarity with Bacillus sp. strain sequences from GeneBank. Phenotypical characterization allowed their classification as Bacillus subtilis. Phylogenetic analysis revealed that the strains clustered into two different phylogenic groups. Results of laboratory and greenhouse experiments showed that volatile and protease production as well as biofilm formation by some strains had a significantly positive correlation with their antagonistic ability. Finally, based on the results from laboratory and greenhouse experiments, the most powerful antagonist strains with high biofilm production were selected for future field experiments.

Multilocus differentiation of the related dermatophytes Microsporum canis, Microsporum ferrugineum and Microsporum audouinii

Microsporum ferrugineum, an uncommon causative agent of dermatophytosis, has restricted endemicity. Iranian strains suspected to be M. ferrugineum from two patients with tinea were analysed using the rDNA internal transcribed spacer (ITS) region and the partial β-tubulin (BT2) and translation elongation factor 1-α (TEF1) genes. Strains were compared to reference strains to differentiate M. ferrugineum from its relatives Microsporum canis and Microsporum audouinii. Inter-species differences for TEF1 and BT2 were found to be higher than for the ITS region, which is the current molecular standard for species identification in dermatophytes. Intra-species variation was zero for each of the markers. In silico analysis showed that the restriction enzymes BanI and BshNI were together sufficient to differentiate the three species based on TEF1, whereas a two-step digestion was needed with BT2 or the ITS region. The prevalence of M. ferrugineum in clinical samples in Iran appeared to be higher than suspected on the basis of routine phenotypic identification.

Genotypic Diversity of Iranian strains of Ralstonia solanacearum

Normal 0 14 false false false During 2007–2009, 170 bacterial isolates were obtained from wilting potato and tomato plants from Iran. Specific polymerase chain reaction (PCR) analyses identified all the isolates as Ralstonia solanacearum . Diversity among the Iranian isolates was determined by a study based on biovar determination, pathogenicity, repetitive sequence PCR and phylotype classification. On the basis of genotypic, phenotypic and pathogenic characteristics two distinct clusters obtained. Cluster I comprised all biovar 2 isolates and cluster II comprised all biovar N2 (2T) isolates. Phylotype-specifi c multiplex PCR (pmx-PCR) indicated that all biovar 2 and N2 belong to phylotype II. This is the first report of phylotype determination of biovars of R. solanacearum with pmx-PCR in Iran.

Study of Genetic Evolution in Mycobacterium tuberculosis Isolates from Patients with Active Pulmonary Tuberculosis in the Iran and Belarus

Objective:This is the new comparative geogenetic molecular evolution research of M. tuberculosis in Iran and Belarus. Thus, we researched the genetic patterns of samples collected in the first survey of anti-tuberculosis drug-resistance by gene coding of RNA polymerase as part of the international project of on tuberculosis.Method:DNA extraction and amplification of rpoB gene was performed. All PCR products of gene were sequenced using the Amersham auto sequencer. For analysing phenogram has been demonstrated by method UPGMA and Neighbour-Joining. Clinical isolates (70/473) were analyzed by using sequencing gene rpoB and genotyped by program DNAMAN and MEGA.Results:The all data were compared with the international database of national center for biotechnology information website. Multi drug resistant of tuberculosis patient (MDR-TB) was 92% in never treated and 8% in previously treated. Mutations in rpoB gene and katG genes were showed in 95% and 84% of the MDR isolates, respectively. Two clusters were found to be identical by the four different analysis methods, presumably representing cases of recent transmission of MDR tuberculosis. The other isolates are divided in Iran into 2 groups: group A – similar to the Eastern strains (China, Taiwan) and group B – strains of another genotype. And 3 groups in Belarus: group A - Strains of the first group are more similar to the standard European and Eastern ones China and Taiwan) which diverged in the last 10 years (Genetic evolution rate), i.e. they are relatively new ones, and that is confirmed by the mutations, group B - Strains of the second group diverged earlier; they are older than the strains of the first group (16 years old- time and rate of evolution) and group C - Strains of the third group are similar to European strains and only circulate in Brest region. They are grouped separately on the phenogram and became prevalent in Iran (they are called Iranian residential strains and also is genetic analogy between group A from Iran and Belarusian isolates.Conclusion:This research gives a first result on genetic evolution of the M. tuberculosis strains distributing in the Iran and Belarus during the first survey of anti-tuberculosis drug-resistance and is homologies between groups A from Iran with group A from Belarus. It may aid in the creation of a national database that will be a valuable support for further studies.

Multilocus microsatellite typing shows three different genetic clusters of Leishmania major in Iran

Ten polymorphic microsatellite markers were used to analyse 25 strains of Leishmania major collected from cutaneous leishmaniasis cases in different endemic areas in Iran. Nine of the markers were polymorphic, revealing 21 different genotypes. The data displayed significant microsatellite polymorphism with rare allelic heterozygosity. Bayesian statistic and distance based analyses identified three genetic clusters among the 25 strains analysed. Cluster I represented mainly strains isolated in the west and south-west of Iran, with the exception of four strains originating from central Iran. Cluster II comprised strains from the central part of Iran, and cluster III included only strains from north Iran. The geographical distribution of L. major in Iran was supported by comparing the microsatellite profiles of the 25 Iranian strains to those of 105 strains collected in 19 Asian and African countries. The Iranian clusters I and II were separated from three previously described populations comprising strains from Africa, the Middle East and Central Asia whereas cluster III grouped together with the Central Asian population. The considerable genetic variability of L. major might be related to the existence of different populations of Phlebotomus papatasi and/or to differences in reservoir host abundance in different parts of Iran.

Full genome characterization of hepatitis B virus strains from blood donors in Iran

Iran is a low to medium endemic country for hepatitis B virus (HBV), depending on the region, where genotype D is dominant. Samples from 170 asymptomatic HBsAg-positive blood donors were quantified and the median viral load was 6.7 × 10(2) IU/ml with 10.6% samples unquantifiable. Fifty complete genome sequences of these strains were characterized. Phylogenetic analysis identified 98% strains as subgenotype D1 and 2% as D2. Deduced serotypes were ayw2 (94%), ayw1 (4%), and adw (2%). The nucleotide diversity of the complete genome subgenotype D1 Iranian strains was limited (2.8%) and comparison with D1 strains from Egypt and Tunisia revealed little variation between strains from these three countries (range 1.9-2.8%). The molecular analysis of the individual genes revealed that the G1896A mutation was present in 86.2% of the strains and in 26 strains (29.9%) this mutation was accompanied by the G1899A mutation. The double mutations A1762T/G1764A and G1764T/C1766G were found in 20.7% and 24.1% of the strains, respectively. The pre-C initiation codon was mutated in five strains (5.8%). One strain had a 2-amino acid (aa) insertion at position s111 and another sP120Q substitution suggesting a vaccine escape mutant.

Genetic diversity of the common bacterial blight pathogen of bean, Xanthomonas axonopodis pv. phaseoli, in Iran revealed by rep-PCR and PCR–RFLP analyses

Xanthomonad-like bacteria that are associated with common bacterial blight of bean in Iran were identified on the basis of their colonial morphology, biochemical and serological properties, presence of a specific DNA fragment using PCR primers and pathogenicity on bean. Xanthomonas axonopodis pv. phaseoli (Xap) strains were further characterized using rep-PCR and restriction fragment length polymorphism (RFLP). RFLP profiles generated by the restriction endonucleases RsaI, TaqI, HaeIII and Sau96I and rep-PCR analysis revealed that Iranian strains were relatively genetically homogenous. The similarity coefficients among the strains ranged from 0.87 to 1. The genetic diversity coefficients among strains from three infected provinces, Isfahan, Markazi and Lorestan, were 0.019, 0.072 and 0.033, respectively. The low overall level of polymorphism within Xap isolates collected from the three Iranian infected regions could suggest that few initial inoculum introductions might have distributed among these different bean-growing areas in Iran.

Genetic Diversity and Pathogenicity of Xanthomonas axonopodis Strains Inducing Citrus Canker Disease in Iran and South Korea

For the first time in 1989 citrus bacterial canker disease has seen on Citrusaurantiifolia in southern Iran. A total of 43 strains from affected citrus trees, ten strains from South Korea and representative from all known five pathotypes of Xanthomonas axonopodis pathogenic on citrus trees were used in this study. Isolated strains from Iran were indistinguishable by phenotypic, FAMEs, and SDS-PAGE analyses but showed different host range. First group were pathogenic on all tested citrus seedlings including C. aurantiifolia, C. limettioides, C. limon, C. jambhiri, Poncirus trifoliata X C. paradisi, C. aurantium, C. paradise, C. medica, P. trifoliate, C. grandis, C. sinensis, C. reticulate and C. sinensis X P. trifoliate. Pathogenicity of the second group were limited to C. aurantiifolia, C. limettioides, C. limon, C. jambhiri, P. trifoliata X C. paradis, and C. aurantium. Among the strains studied by AFLP fingerprinting six clusters were found. These clusters were: (1) strains of pathotype C; (2) strains of pathotypes B and D; (3) strains of pathotype A together with the main group of the Iranian strains; (4) strains isolated from Korea; (5) strains of pathotype E; and (6) seven strains from Iran which made a completely separate cluster. Strains from pathotypes B and D could not be differentiated by AFLP. The tested Iranian strains belongs to the two different groups and strains from Korea grouped as a subcluster from main cluster of Iranian strains belong to the pathotype A.

ITS rDNA phylogeny of Iranian strains of Cytospora and associated teleomorphs

Cytospora spp. and associated teleomorphic species (Ascomycota, Diaporthales, Valsaceae) are among the most common and widespread canker- and dieback-causing fungi on trees, shrubs and herbaceous plants worldwide. From specimens collected all over Iran a total of 114 isolates were morphologically identified, representing 20 Cytospora, one Leucostoma and five Valsa species from 38 plant species. Nine of the identified taxa were new records for Iran, and many new hosts were identified. The phylogenetic relationships of the Iranian strains, along with sequences of 13 reference strains from GenBank, were inferred from ITS1-5.8S-ITS2 nuclear rDNA sequences. Parsimony analysis established five distinct major clades and 12 subclades, which represented accepted species and genera. Some of these subclades corresponded to morphologically based taxonomic concepts of single Cytospora species, while others contained more than one morphospecies. Teleomorphic states were present in six subclades, and most clustered with the corresponding anamorphs. This suggests that morphological and phylogenetic species concepts overlap and that in most cases they are meaningful for correct species identification.

Detection and characterisation of group A rotavirus in asymptomatic piglets in southern Ireland

Porcine group A rotaviruses (GARV) are causative agents of enteritis in piglets and are a large reservoir of genetic material for the diversification of human GARVs. Accumulation of information on the genetic heterogeneity of porcine viruses is pivotal for readily characterising unusual human strains. Screening of 292 fecal samples, collected from 4-5- to 8-9-week-old asymptomatic pigs from four herds in Ireland between 2005 and 2007 resulted in 19 (6.5%) samples testing positive by reverse-transcription PCR (RT-PCR) for GARV. The strains were molecularly characterized to collate data on the VP7 and partial VP4 outer capsid genes. By sequence analysis of the VP7 gene, the Irish strains were identified as G2, G4, G5, G9 and G11 viruses. The G11 strains were closely related to other human and porcine G11 strains, while the G2 strains resembled porcine G2 viruses detected recently in Europe and southern Asia. The G4 strains were distantly related to other G4 human and animal strains, constituting a separate G4 VP7 lineage. Analysis of the G5 strains revealed that they were similar to a selection of G5 human and porcine strains, while the G9 strains resembled other porcine G9 viruses. By sequence analysis of the VP8* fragment of the VP4, the Irish viruses were characterised as P[6], P[7], P[13], P[13]/[22], P[26] and P[32].

Ethnic and Geographic Differentiation of Helicobacter pylori within Iran

The bacterium Helicobacter pylori colonizes the human stomach, with individual infections persisting for decades. The spread of the bacterium has been shown to reflect both ancient and recent human migrations. We have sequenced housekeeping genes from H. pylori isolated from 147 Iranians with well-characterized geographical and ethnic origins sampled throughout Iran and compared them with sequences from strains from other locations. H. pylori from Iran are similar to others isolated from Western Eurasia and can be placed in the previously described HpEurope population. Despite the location of Iran at the crossroads of Eurasia, we found no evidence that the region been a major source of ancestry for strains across the continent. On a smaller scale, we found genetic affinities between the H. pylori isolated from particular Iranian populations and strains from Turks, Uzbeks, Palestinians and Israelis, reflecting documented historical contacts over the past two thousand years.

Molecular and genetic characteristics of hemagglutinin and neuraminidase in Iranian 2009 pandemic influenza A(H1N1) viruses

Influenza virus infections cause severe illness worldwide. Vaccination reduces the morbidity and mortality of influenza. The efficacy of vaccines varies due to antigenic differences between the circulating influenza strains and the vaccine. Neuraminidase inhibitors are effective for prophylaxis and treatment of influenza infections, and the emergence of drug resistant mutants is an important challenge. Full-length nucleotide and deduced amino acid sequences of the hemagglutinin and neuraminidase genes of three 2009 pandemic influenza A/H1N1 isolates were compared with the vaccine strain and some strains from different countries. Phylogenetic analysis for hemagglutinin and neuraminidase showed they were related to their vaccine strain, with an average of 99.56 and 99.53% sequence identity, respectively. No genetic indication of resistance to neuraminidase inhibitors was found. Although genomic analysis of hemagglutinin and neuraminidase genes of Iranian strains in comparison to the corresponding vaccine strain revealed some mutations, none of these were identified in functionally important receptor-binding sites.

Analysis of 3′‐end variable region of the cagA gene in Helicobacter pylori isolated from Iranian population

The 3' region of the cagA gene, the most well-known virulence factor of Helicobacter pylori, contains Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs. Four segments flanking the EPIYA motifs, EPIYA-A, -B, -C, or -D, were reported to play important roles in H. pylori-related gastroduodenal pathogenesis. The aim was to determine the roles of EPIYA segments in gastroduodenal pathogenesis in an Iranian population. A total of 92 cagA-positive Iranian strains isolated from dyspepsia patients with non-ulcer dyspepsia (n = 77), peptic ulcer (n = 11) and gastric cancer (n = 4) were studied. The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing. A total of 86 (93.5%) strains had three copies of EPIYA (ABC type), three (3.3%) had four copies (ABCC type) and three (3.3%) had two copies (AB type). The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences (EPIYATIDFDEANQAG) in Iranian strains. When the prevalence of strains with multiple EPIYA-C segments in Iran was compared with previously published data, it was much lower than that in Colombia and Italy, but was higher than that of Iraq, and the patterns were parallel to the incidence of gastric cancer in these countries. The structure of the 3' region of the cagA gene in Iranian strains was Western type. Although we could not find differences between EPIYA types and clinical outcomes, low prevalence of strains with multiple EPIYA-C segments might be reasons for low incidence of gastric cancer in Iran.

Potential use of Iranian rhizobial strains as plant growth-promoting rhizobacteria (PGPR) and effects of selected strains on growth characteristics of wheat, corn and alfalfa.

Many agricultural researches have been performed to improve soil productivity. Nitrogen (N) and Phosphorus (P) are essential elements which are utilized by the plants in large amounts. Phosphorus can be provided by applying chemical fertilizers. Microorganisms convert insoluble phosphate to the soluble form and some bacteria such as rhizobacteria play an important role in this process. This research was designed to determine the plant growth promoting (PGP) abilities, especially phosphate solubilization, of different isolates of indigenous rhizobia and their effect on growth characteristics of wheat, corn and alfalfa. 446 isolates belonging to different species of rhizobia were examined regarding inorganic and organic P solubilization, siderophore, auxin (IAA and homologes), 1aminocyclopropane-1-carboxylate (ACC) - deaminase and hydrogen cyanide (HCN) production. It was found that 7% of the strains could produce HCN, 86% siderophores and 74% IAA and 44% were able to solubilize phosphorus. 8 rhizobial isolates were found as superior plant growth promoting rhizobacterial (PGPR) strains. Green house experiments using these strains evaluated the promoting effects of different strains on legume (alfalfa) and nonlegume (wheat and corn) plants. Total biomass to the above mentioned plants was determined and the amount of N, P and iron (Fe) in shoots were also measured. The results were analyzed by the RCBD contrast method using SAS software V6.12. In conclusion, the green house experiment showed that P1B2 and a mixture of 4 plant growth stimulating rhizobacterial strains are the best suited as growth promoting inoculants.

Iranian Non-Responding Contact Method German Cockroach Permethrin Resistance Strains Resulting from Field Pressure Pyrethroid Spraying

The present study investigated the probable responsible reasons for non-response the B. germanica to permethrin only in World Health Organization glass jar method after insecticide spraying control failure with pyrethroid insecticide groups in Islamic Republic of Iran. Eleven German cockroach strains were collected from field populations of nine infested kitchen student dormitories and two infested hospitals after insecticide spraying control failure with pyrethroid insecticide groups in Iran. The current study, in World Health Organization glass jar and knock down methods conducted on newly emerged adult males. All feral strains, with various levels of resistance to pyrethroids, in World Health Organization glass jar method at 400 min (6 h) time exposures, was not observed mortality, while the susceptible strain was observed 100% mortality in 25 min time exposures. Susceptible strain at LT50 after assessing on mortality data from the replicates by probit analysis in World Health Organization glass jar method was 15.3 min. In this study, all feral strains in World Health Organization glass jar method after 400 min (6 h) time exposures, was not observed mortality, that showed these strains very high-level resistance to permethrin. In the knock down method, the resistance ratios were 3.6 to 26.1-folds compare with the susceptible reference strain. In a comparison, among this study and previous studies resistance ratios of 8.6 to 17.7-folds for permethrin in topical application, indicated that German cockroach have had under pressure spraying. German cockroach have had in vicinity to pyrethroid insecticides especially permethrin in these locations in long period for non-responding to permethrin insecticide only in World Health Organization glass jar method, and the field evident confirm this subject.

Determination of Helicobacter pylori virulence by analysis of the cag pathogenicity island isolated from Iranian patients

The cag pathogenicity island (PAI), which can be divided into two parts, cagI and cagII, is the most well-known virulence factor of Helicobacter pylori. We investigated the association between genetic variations within the cag PAI (cagA and cagE in the cagI and cagT in the cagII) and clinical outcomes in Iranian patients. A total of 231 patients including 182 patients with gastritis, 41 with peptic ulcer and 8 with gastric cancer. The presence of the cagA, cagE and cagT genes were measured by polymerase chain reaction and the results were compared with clinical outcomes and gastric histology. The cagA, cagE and cagT genes were found in 154 (66.7%), 90 (39.0%) and 70 (30.3%) of clinical isolates. At least 144 (62.3%) strains possessed partially deleted cag PAI (e.g., 69 [29.9%] strains were cagA-positive, but cagE and cagT-negative). The single genes as well as the combination of genes in the cag PAI appeared not to be useful markers to predict H. pylori-related diseases in Iranian patients. The genomic sequences of the cag PAI in Iranian strains might be considerably different from those in other geographic locations.

Hepatitis B virus subgenotypes D1 and D3 are prevalent in Pakistan

BackgroundAs the hepatitis B genotyping is important for assessing its clinical implications and geographical distribution, the sub-genotypes have been found useful for determination of specific genomic markers related to hepatocarcinogenesis. In Pakistan, there is no reported data on molecular evolutionary analysis of HBV. A study was, therefore, much needed to evaluate the spectra of mutations present in the strains prevalent here.Findingsto confirm specificity of PCR typing, phylogenetic analysis of the pre-S1 region and the divergence was studied through 13 sequences of 362 bp (accession number EF432765 – EF432777). A total of 315 serum samples, selected from HBsAg positive patients representing the major ethnic groups, residing in Karachi, Sindh were tested for genotyping. Genotype D (219/315) was found to be the most prevalent (70%) amongst our patients. The rest of the genotypes A and a mixture of A and D (AD) were distributed as 20%, and 10% respectively. Phylogenetic tree demonstrated clustering of 11 samples with subgenotype D1 sequences and the remaining two strains on a branch within D3 samples. All samples intermixed with strains from other countries and were found to be closely related to Indian, Iranian and Egyptian HBV strains with 98.7 – 99.0% homology.ConclusionThis study confirms the predominance of genotype D in southeastern Asia and presence of subgenotypes DI and D3 in the Pakistani infected patients. More studies are required to investigate the reason for fewer inclusions of D3 compared to the D1 in Pakistani HBV strains.

Analysis Interconnection Evolution by rpoB Genome in Multidrug Resistant of Mycobacterium tuberculosis in Iranian Isolates

Background: This is the first genetic biodiversity study of M. tuberculosis in Iran. Thus, we investigated the genetic patterns of strains isolated in the first survey of antituberculosis drug-resistance by rpoB gene as part of the Global Project of Anti-tuberculosis Drug Resistance Surveillance (IPI, Iran). Material and Method: A 411-bp fragment of the rpoB gene, containing the sequence of the 81-bp rpoB fragment, was amplified by PCR and the rpoB gene fragments of tuberculosis strains were sequenced using the Amersham auto sequencer. For analysing tree evolution used method UPGMA and Neighbour-Joining. Clinical isolates (34/163) were analyzed by using sequencing gene rpoB and genotyped by program MEGA. Results: The results were compared with the international database. MDR was 14% in never treated patients and 8% in previously treated patients. Mutations in rpoB gene and katG genes were detected in 95% and 84% of the MDR strains, respectively. Two clusters were found to be identical by the four different analysis methods, presumably representing cases of recent transmission of MDR tuberculosis. The other strains are divided into 2 groups: group A similar to the standard and Eastern strains (China, Taiwan) and group B strains of another genotype. They are grouped separately on the dendrogram and became prevalent in Iran (they are called Iranian residential strains). Conclusion: This study gives a first overview of the M. tuberculosis strains circulating in Iran during the first survey of anti-tuberculosis drug-resistance. It may aid in the creation of a national database that will be a valuable support for further studies.

Investigation of cagI and cagII in H. pylori Isolated from Dyspepsia Patients in Iran

Background: The major virulence factor of H. pylori is the cag pathogenicity island divided into two parts: the upstream cagII region and the downstream cagI region. The downstream region includes cagA, cagE, and themost important gene introduced in cagII is cagT. The aim of this study was to investigate the important markers of cagI and cagII regions in Helicobacter pylori isolated from Iranian peptic ulcer and non ulcer disease patients. Methods and materials: 80 clinical isolates of H. pyloriwere collected from 120 patients with gastric disorders. The genomic DNA was extracted from biopsy samples by the QIAgen kit. The PCR was performed for detection of cagA, cagE and cagT in cagPAI. Results: Among 80 H. pylori strains, 20 (25%) and 60 (75%) were isolated from PUD and NUD patients respectively. In PUD patients with rate of 14 (70%), all of isolates were cagA positive and distribution of cagE was 7 (35%) and cagT was 5 (25%). Also the prevalence of cagA, cagE and cagT in NUD patients was 48 (80%), 21 (35%) and 22 (36%) respectively. Discussion: Our results indicated that presence of cag PAI is very common in Iranian strains of H. pylori. The structural variety of the cag PAI might be related to the virulence of H. pylori. Present study showed that the prevalence of cagT, a marker for cagII, in PUD patients is less than NUD patients. In cagI region the presence of cagA in PUD patient is higher than cagE, so it may have an important role in peptic ulcer disease. According to our results it seems that it is not absolutely necessary to coexist of cagII and cagI in peptic ulcer patients.

Molecular epidemiology of hepatitis B virus in Iran

Hepatitis B virus (HBV) infection is a major cause of liver disease worldwide. Eight genotypes and 24 subgenotypes of HBV have been identified. The aim of this study was to determine the distribution of HBV genotypes, subgenotypes and subtypes, and to understand HBV genetic variability in the HBV genome circulating in Iranian provinces. Two hundred and forty-nine sera from HBV-infected patients living in 25 provinces of Iran were collected (2004-2007). A part of the HBV S/pol and whole BCP/C genes were amplified, sequenced and then subjected to phylogenetic, recombination and genetic variability analysis. Results revealed genotype D of HBV in all samples and subgenotypes D1 (98.52%), D2 (0.74%) and D3 (0.74%) among Iranian patients living in different provinces of Iran. Subtypes ayw2 (94.4%), ayw1 (2.8%), ayw3 (2%) and ayw4 (0.4%) were deduced, on the basis of HBV small surface antigen (HBsAg) amino acid sequences. The mean percentage intra-genotypic distance of S plus core regions was 2.8%; the mean percentage inter-genotypic distance of this region between Iranian strains and genotype D isolates was 3.1%; and this rate for other genotypes was 5.2-11.4%. Various rates of point mutations have been found within different HBV genes, e.g. HBsAg (17.2%), precore-G1896A (59.5%) and Basal core promoter (BCP) double mutations (49.2%), whereas no recombination was found. In conclusion, these results indicate that the only genotype circulating in the provinces of Iran is genotype D. There exist high genetic variabilities in the S/pol and BCP/C regions among the Iranian HBV isolates.