Proteases of Acanthamoeba.

The members of genus Acanthamoeba are the etiological agent of uncommon but severe or even fatal opportunistic infections in human beings. The presence of different classes of intracellular and extracellular proteases including serine proteases, cysteine proteases, and metalloproteases has been well documented in environmental and clinical isolates of Acanthamoeba spp. However, the role of the proteolytic enzymes in physiological, biological, and pathological mechanisms of the amoeba remains partially investigated. Some attempts have been conducted using various methods to determine the profile of proteases (number, class, optimal conditions, and activity of the enzymes), and possible pathogenicity mechanism of the proteolytic enzymes (various protein substrate degradation, cytopathic effect on different cell lines). In some cases, it was attempted to correlate intracellular and extracellular protease profile with pathogenicity potential of strains. This review revealed that the protease profile of different strains of Acanthamoeba was extremely complex, therefore, further comprehensive studies with application of a combination of various methods may help to elucidate the role of the enzymes.

Frequency of Smear-Negative Tuberculosis in Northwest Iran.

BACKGROUND: Microscopic smear examination is the most common test in tuberculosis (TB) detection. It is, however, not strong enough to identify TB in the majority of afflicted individuals; thus, a significant number of TB patients are smear negative and capable of transmitting the infection. The aim of this study was to evaluate the rate of smear-negative TB in northwest Iran. METHODS: In this cross-sectional study, 329 TB-confirmed patients were evaluated through culture up to March 1, 2015, in northwest Iran. The demographic and clinical features of the smear-negative and smear-positive TB patients were compared. The χ2 test was used to compare the frequency of the variables. All the statistical analyses were conducted using SPSS, version 16 (Chicago, IL, USA). RESULTS: Seventy-five cases were smear negative and 254 were smear positive. Smokers, asthmatics, and extra-pulmonary TB patients were primarily among the smear-negative cases. The rate of mortality was also relatively higher among the smear-negative TB patients. CONCLUSION: Totally, 22.8% of the TB cases in northwest Iran were smear negative, with a relatively higher rate of mortality than those with positive smears. A delay in these patients' return to TB diagnosis and treatment centers increases the chance of transmission to others. This is a very sensitive issue in centers where there is no equipment for TB cultivation. Thus, it is essential to equip centers without TB cultivation facilities and to use appropriate diagnostic techniques in centers with those facilities to help rapidly detect smear-negative cases.

Characterization of extracellular proteases of Acanthamoeba genotype T4 isolated from different sources in Iran.

The members of the genus Acanthamoeba are ubiquitous, free-living amoebae found in various environments. The amoebae can cause severe complications in both, immunocompetent and immunocompromised individuals. The aim of this study was to characterize extracellular proteases of Acanthamoeba isolates from different sources belonging to genotype T4 as well as the determination of the pathogenicity potential to correlate pathogenicity with protease activity and protease banding pattern. A total of 19 isolates (11 clinical and 8 environmental) were cultured axenically, then the pathogenicity of the isolates was assessed by osmo- and thermo- tolerance tests. An applied colorimetric method using azocasein as a substrate was used for the extracellular protease activity assay. Protease characterization was carried out by zymography analysis with and without protease inhibitors. Assessment of the pathogenicity potential using physical parameters revealed that 2 (25%), 2 (25%), and 4 (50%) of the environmental isolates were potential pathogens, weak potential pathogens, and non-pathogens, respectively. According to our results, this protease activity assay can be a powerful tool for differentiating pathogenic and non-pathogenic strains of Acanthamoeba.

Host Risk Factors for Tuberculosis.

Tuberculosis (TB) spreads through droplets that contain Mycobacterium tuberculosis (Mtb) and can infect susceptible people. Due to different risk factors, people have different susceptibility ranges towards TB. The risk factors are classified into three main groups, includ-ing bacterial, environmental, and host factors. Literature review reveals that the most important host risk factors are aging, male gender, genetics, epigenetics, having an impaired immune system, diabetes, malignancy, malnutrition, anemia, and pregnancy. The risk factors contribute to the increase in TB cases through inflammation, increased contact with TB patients, disrup-tion of immune genes, changes in gene expression, increased activity of Mtb, damage to cellu-lar immunity, reactivation of Latent TB Infection (LTBI), increased susceptibility to TB, com-promised immunity, and changes in the proportion of T cell subgroups, respectively. Therefore, identification of the infection source and high-risk people and timely treatment of the patients can reduce TB mortality and help control the disease.

Interleukin-10 Promoter and the CCR5 Polymorphisms in Iranian Azari Population with Multiple Sclerosis.

BACKGROUND: Changes in the expression of cytokines as the result of the single nucleotide polymorphisms (SNPs), can affect the incidence of multiple sclerosis (MS). OBJECTIVE: To investigate the relationship between the frequencies of interleukin-10 (IL-10)-1082 A/G (rs1800896) and CCR5-delta32 genotypes and susceptibility to MS in the Iranian Azari population. METHODS: IL-10-1082 A/G SNP and the CCR5-delta32 were genotyped in 152 patients suffering from MS and 242 healthy non-relatives by allele specific-PCR and simple PCR methods, respectively. RESULTS: The frequencies of AA (37.6%) and AG (55.9%) genotypes of IL-10-1082 were significantly high in the control (p = 0.021) and MS patients (p = 0.015), respectively, with no statistical difference between these groups. There was no significant difference in the CCR5 gene based on the possession of wild/wild and wild/del32 genotypes between MS patients and the control group. The del32/del32 genotype was not seen in any of the investigated groups. Tobacco (cigarettes and hookahs) consumption was higher among the MS patients (p=0.004), and this has the potential to raise the risk of MS in both the individuals and their family. However, it had no significant relation with the frequency of different genotypes of the IL-10-1082 and the CCR5. CONCLUSION: Our finding conclude on possible role of AA genotype of IL-10 -1082 as a protective factor in MS.

Identification of bovine leukemia virus in raw milk samples in North-West of Iran.

Bovine leukemia virus (BLV) is one of the most important carcinogenic viruses genetically related to the human T-cell lymphotropic viruses (HTLV-1 and HTLV-2). The virus infects type B lymphocytes and creates lymph glands tumors. Recently, the association between the presence of this virus and breast cancer has been addressed in humans. Here, we studied the prevalence of BLV in the samples of raw milk of native Iranian and Iranian-foreign cows in traditional, semi-industrial and industrial dairy farms in rural and urban areas of Zanjan province. Raw milk samples of cows were collected manually in sterile tubes. The samples were tested by nested-PCR method. Forty samples (9.93%) out of 403 samples showed BLV contamination. In this study, nested-PCR was successfully applied to determine the level of contamination in raw milk samples from cows infected with BLV. Furthermore, a relatively high rate of BLV infection was found in dairy cows in Zanjan province, northwestern of Iran.

Role of Immigration in Tuberculosis Transmission to Iran: A Systematic Review.

BACKGROUND: Today, because of increasing immigration and the prevalence of drug-resistant tuberculosis in Iran, identifying intra-community cases is necessary in the country. It will be possible through the use of molecular epidemiologic methods. In this inquiry, in order to determine the role of immigrants in the transmission of specific strains to Iran, the studies have been examined which had been conducted based on molecular epidemiologic methods among Iranians and non-Iranians people. METHODS: All studies from 1997 to the end of March 2017 were examined in three databases of PubMed, Scopus, and Google Scholar and finally, 16 studies were selected. RESULTS: The common clustering rate between Iranians and non-Iranians was determined to be 19.8, and the intra-community recent transmission rate was from 0% to 49% with average of 18.1%. The rate of multidrug-resistant tuberculosis (MDR-TB) was 12.5%, which was higher among immigrants, especially Afghans, and a significant number of the strains were Beijing. CONCLUSIONS: The studies have shown that migrants, especially Afghans, are more effective in transmitting specific strains of tuberculosis to migratory areas. To control tuberculosis, it is necessary to register of immigrant's health information, while enter to the country, so that, by doing appropriate diagnostic tests, the curing the patients, the transmission of tuberculosis to the country would be prevented.

Risk Factors for COVID-19.

SARS-CoV-2 in bats was transmitted to humans at a live and wet animal market in China through the intermediate host, creating COVID-19. Viral, environmental and host factors play roles in virus infection and disease. The virus has high transmissibility and is rapidly transmitted to people through close contact and droplets from coughing, sneezing and talking loudly, as well as through contact with contaminated objects. As crowding is an environmental risk factor for contamination, its transmission is high among patients and staff in hospital and also in elderly-care centers. It is more common in the elderly, in men, and subjects with diabetes mellitus, hypertension, cardiovascular disease, and malignancy.

Role of Molecular Epidemiology on Tuberculosis Control in the Middle East Countries: a Systematic Review and Meta-Analysis.

BACKGROUND: Tuberculosis (TB) is a public health problem in developing countries and yet the numbers of people with the disease are abundant. Early detection of transmission sources and effective treatment of the cases is essential to control the disease which will be possible by application of molecular epidemiology approaches. Studies conducted based on Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) method in Muslim Middle East countries were evaluated to determine their role in TB control. MATERIALS AND METHODS: All studies from January 2005 to April 2016 were systematically reviewed in four electronic databases and finally 16 articles were found eligible to be included in this study. The mean clustering rate was determined as 44% and the recent transmission rate was 12.3 to 78.8% with average of 33%. RESULTS: The results showed that both reactivation and recent transmission were important in developing new cases of TB in Middle East countries; but, reactivation plays a more critical role. CONCLUSION: Regarding to ongoing war and immigration in the region along with the increasing of drug-resistant TB, in the case of improper supervision in the future, the disease, especially drug- resistant TB, will be problematic.

Cytotoxic effect of rosemary extract on gastric adenocarcinoma (AGS) and esophageal squamous cell carcinoma (KYSE30) cell lines.

AIM: The present study was conducted to survey the potential cytotoxic influence of freeze-dried aqueous extract of its fruits on gastrointestinal cell lines, namely AGS (human gastric carcinoma) and KYSE30 (human esophageal squamous cell carcinoma. BACKGROUND: Rosemary (Rosmarinus officinalis) is a wild medicinal plant shown to have anticancer activity. Carnosic and rosmarinic acids are compounds, obtained from it through several extraction methods. METHODS: The aqueous extract of the fruits of R.officinalis was freeze-dried, and KYSE30 and AGS cancer cell lines were treated with crude extract. Cytotoxic effect of the extracts on the cell lines was examined using 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutral red assay. Apoptotic cells were detected with ethidium bromide/acridine orange (EB/AO). Cell-cycle distributions were evaluated by flow cytometry. RESULTS: IC50 values were 4.1, 1.8 and 1.3 mg/mL for AGS cell lines after 24, 48 and 72 hours by MTT assay, respectively, and 4.4, 2.1 and 1.1 mg/mL by neutral red assay, respectively. IC50 values for KYSE30 cell lines were 600, 180 and 150 mg/mL after 24, 48 and 72 hours by MTT assay, and 860, 270 and 230 mg/mL by neutral red. EB/AO staining increased in apoptotic cells. After 24 h of treatment at different concentrations, significant increases and decreases in population were shown at G2/M and G1 phases, respectively. CONCLUSION: The aqueous extract of the fruits of R.officinalis was freeze-dried, and KYSE30 and AGS cancer cell lines were treated with crude extract. Cytotoxic effect of the extracts on the cell lines was examined using 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutral red assay. Apoptotic cells were detected with ethidium bromide/acridine orange (EB/AO). Cell-cycle distributions were evaluated by flow cytometry.

Tuberculosis Control and Role of Molecular Epidemiology Studies in Iran: A Systematic Review.

BACKGROUND: Today because of immigration, HIV pandemic and spread of drug resistant tuberculosis, mortality caused by tuberculosis (TB) has increased. To control the disease it is essential to identify the sources of the infection and patterns of transmission. This becomes possible through using molecular epidemiology methods. MATERIALS AND METHODS: This research reviewed studies based on IS6110-restriction fragment length polymorphism (IS6110-RFLP) as a primary method to recognize the role of molecular epidemiology researches in managing TB in Iran. Within 1995-2015 all human population based studies which had use IS6110-RFLP as the primary method systematically reviewed. RESULTS: At the end, 11 articles were selected. The mean clustering rate obtained was 28.1%. The rate of recent transmission was variable from 2% to 49% and the mean value was determined 17%. CONCLUSION: The studies revealed that in Iran both reactivation and recent transmission were significant in developing new cases of TB. Yet, reactivation plays greater role. If the matter is supervised insufficiently and carelessly, because of increasing rate of drug resistant TB, immigration of HIV infected individuals, TB especially drug resistant TB will be problematic in the near future.

Molecular Diversity of Mycobacterium tuberculosis Strains in Northwestern Iran.

BACKGROUND: Years after the development of antituberculosis (TB) drugs, many people continue to suffer from this disease. To control the spread of TB, strains of the Mycobacterium tuberculosis complex need to be determined, and sources of infection must be identified. Such steps should help to prevent transmission of the infection. OBJECTIVES: The aim of this study was to perform molecular genotyping of isolates of the M. tuberculosis complex obtained from patients in northwestern Iran. METHODS: One hundred ninety-four culture-positive M. tuberculosis isolates obtained from patients in northwestern Iran were analyzed using the mycobacterial interspersed repetitive unit-exact tandem repeats (MIRU-ETR) method. RESULTS: The MIRU-ETR method distinguished 162 different patterns in the 194 isolates, comprising 23 clusters and 139 unique patterns. Its discriminatory power according to the Hunter-Gaston discriminatory index (HGDI) was 0.9978. The largest cluster contained six isolates. CONCLUSIONS: This research indicated that various strains of M. tuberculosis were responsible for TB and that the majority of cases were due to reactivation.

Association of Promoter Polymorphisms of Interleukin-10 and Interferon-Gamma Genes with Tuberculosis in Azeri Population of Iran.

Promoter polymorphism of cytokine genes may lead to inter-individual differences in cytokine levels, therefore, polymorphisms may associate with susceptibility to infectious diseases. In this study, we investigated a possible association between interleukin-10 (IL-10) -1082A/G (rs1800896) and interferon (IFN)-gamma +874T/A (rs2430561) promoter polymorphisms and tuberculosis (TB) in the Azeri population of Iran. IL-10 -1082G/A and IFN-gamma +874T/A single nucleotide polymorphisms (SNPs) were genotyped by amplification refractory mutation system (ARMS)-PCR in 200 healthy controls and 124 tuberculosis patients. IL-10 -1082 A allele was more frequent in the control group than in the patient group (p=0.001, odds ratio [OR]=2.183). On the other hand, the AA genotype was significantly more frequent in the control group (p=0.0001). The frequency of IFN-gamma +874 T allele was significantly higher in the controls (p=0.013, OR=1.56). There was no significant association between IFN-gamma +874 T/A genotypes and susceptibility to tuberculosis (p=0.078), but TT genotype was more frequent in the control group. Our findings suggest that interleukin-10 -1082G/A polymorphism may play an important role in susceptibility to tuberculosis in our population. On the other hand, the +874T allele, which has been suggested to be associated with high IFN-gamma levels, was significantly higher in the controls and TT genotype was also more frequent in the control group. Thus, +874 T allele may be associated with resistance to tuberculosis in this Azeri population of Iran.

Molecular Characterization of Cryptosporidium Species in Children with Diarrhea in North West of Iran.

Cryptosporidium is one of the most common causes of childhood diarrhea in developing countries. The aim of this randomized pilot study was to detect and characterize infective species and determine the genotypes of Cryptosporidium parasites in pediatric patients suffering from diarrhea in North West of Iran. A total of 113 fecal samples were collected from diarrheic children hospitalized in Tabriz Pediatric Hospital. The amplification of small subunit ribosomal RNA gene was performed using a nested polymerase chain reaction protocol and its products were digested using two restriction enzymes for Cryptosporidium species and genotype differentiation. Cryptosporidium oocysts were found in 2 (1.76%) children with diarrhea and restriction pattern revealed the presence of C.parvum bovine genotype in both positive fecal samples. The findings indicate that Cryptosporidium parvum is responsible for cryptosporidiosis in children in the study region and probably zoonotic transmission is the predominant route of parasite transmission.