Seroprevalence of Toxoplasma gondii among HIV Patients in Jahrom, Southern Iran

Toxoplasma gondii is an important opportunistic agent especially in immunocompromised hosts and can cause significant morbidity and mortality. Hence, detection and monitoring of anti-Toxoplasma antibodies are of a great interest in HIV-infected patients. A study on the prevalence of toxoplasmosis and associated risk factors was carried out among HIV-infected patients in Jahrom, southern Iran. The prevalence of anti-Toxoplasma IgG antibodies was 21.1% in HIV-infected patients by ELISA. PCR was performed on all of the samples, and 1 of the blood samples was positively detected. Among the HIV patients, anti-Toxoplasma IgG antibodies were significantly higher in age group of 30–39 years old (P=0.05). The seroprevalence of toxoplasmosis in patients with CD4+<100 cells/μl was 33.3% that was significantly higher than the other groups (P=0.042) with or without IgG antibodies. The CD4+ count mean of seropositive patients was lower than that of seronegative patients. The seroprevalence of toxoplasmosis in patients with highly active antiretroviral therapy was significantly less than patients without therapy (P=0.02). In conclusion, this study showed low seroprevalence of latent toxoplasmosis among HIV-infected patients in the region and confirmed the need for intensifying prevention efforts among this high-risk population and also the risk of toxoplasmosis reactivation which could be important among this population.

Epidemiology of rotavirus-norovirus co-infection and determination of norovirus genogrouping among children with acute gastroenteritis in Tehran, Iran

Background: Enteric viruses, particularly human rotavirus and norovirus, have been shown to replace bacteria and parasites, as the most common pathogens responsible for acute diarrhea. However, there are still few epidemiological data on the simultaneous occurrence of these viruses in Iran. In this regard, the aim of this study was to assess the useful epidemiological data on the gastroenteritis associated with rotavirus-norovirus mixed infection and to examine the prevalence of norovirus genogrouping among children aged less than five years old in Iran

Methods: A total of 170 stool samples were collected from children under five years of age with the clinical signs and symptoms of acute gastroenteritis, from May 2013 to May 2014. For the detection of both rotavirus and norovirus, total RNA was extracted from all samples, followed by reverse transcription polymerase chain reaction [RT-PCR]. For both detected rotaviruses and noroviruses, genogrouping was performed

Results: Of 170 samples, 49 [28.8%] and 15 [8.8%] samples were found to be positive for rotavirus and norovirus infections by RT-PCR. Interestingly, 6 [3.5%] patients were positive for both infections. Among the 15 norovirus-positive patients, 13 [86.6%] and 2 [13.3%] belonged to genogroups GII and GI

Conclusions: The norovirus genogroup GII and rotavirus lead to the serious infections in children with acute gastroenteritis. However, more well-designed studies are needed to further elucidate the role of other enteric viruses in acute gastroenteritis

Distribution of IL-28B genotypes in patients with hepatitis C and healthy individuals in Jahrom city

The purpose of this study was to compare the distribution of interleukin [IL]-28B genotypes between Iranian healthy individuals and patients with chronic hepatitis C based on the genotype. Polymorphisms in the region of IL-28B gene have been identified as the strongest genetic pretreatment predictor of sustained virological response [SVR] in hepatitis C infection. In this study, 147 patients with chronic hepatitis C and 80 healthy individuals were included. The IL-28B rs12979860 and rs8099917 polymorphisms were genotyped by PCR-RFLP method and the frequency of IL-28B polymorphisms with respect to HCV genotypes was also determined. The frequencies of rs12979860 TT, CC and CT genotypes in the chronic hepatitis C patients and healthy individuals were as follows: 10.8% vs. 11.3%, 38.7% vs. 46.2% and 50.3% vs. 42.5%. Also, the frequencies of rs8099917 TT, GG and GT genotypes in the chronic hepatitis C patients was 61.9%, 6.1% and 32% and in controls was 47.5%, 11.2% and 41.3%. The differences in the distribution of rs12979860 genotypes and alleles between HCV genotype 1 and HCV genotype 3a infected patients were statistically significant. The rs12979860 C allele is the favorable allele for the spontaneous clearance of HCV. It seems that the impact of IL-28B polymorphism on the spontaneous clearance of HCV genotype 3 is more prominent than HCV genotype 1, which results in the observation of higher rs12979860 C allele frequency in chronic hepatitis C patients with HCV genotype 3 than HCV genotype 1

Construction of an eGFP expression plasmid under control of T7 promoter and IRES sequence for assay of T7 RNA polymerase activity in mammalian cell lines

Recently, the use of T7 RNA polymerase instead of other viral and cellular promoters is increasing due to high efficacy of transcription in the cell cytoplasm by this polymerase. In order to translate the transcripts produced by T7 RNA polymerase in mammalian cell lines, it is necessary to include Internal Ribosome Entry Site [IRES] sequences. In addition, if sequence of poly A signal would be included after interested gene, the rate of expression could be increased in the cells. For expression of eGFP in HEK-293 and T7-BHK cells by T7 RNA polymerase, the sequence of eGFP as well as IRES sequences upstream of eGFP gene and poly A signal were inserted into a pUC57 plasmid. On the other hand, gene of T7 RNA polymerase was cloned into modified pIRES2-EGFP plasmid. Then, the constructed plasmids were transfected into HEK-293 cells. T7-BHK cell was used for control of T7 RNA polymerase activity. Our results showed that using T7 RNA polymerase for expression of foreign genes in mammalian cell lines is highly efficient. Highly efficient eGFP expression in HEK-293 cells showed that T7 RNA polymerase could be used for cytoplasmic RNA transcription such as production of anti-cancer proteins and oncolytic viral genomic RNA by reverse genetics

Construction of a minigenome rescue system for measles virus, AIK-c strain

In the recent decade, the reverse genetics method has been broadly used for rescue of negative-stranded RNA viruses from cDNA or viral minigenomes. This technique has been applied to study different steps in virus replication and virus-host interactions. Reverse genetics could also be implemented for design of new vaccines. The T7 RNA polymerase activity as well as virus [nucleocapsid protein] N, [phosphoprotein] P and [Large] L proteins are necessary to rescue the virus or viral minigenome. Measles virus is a negative-stranded non-segmented RNA virus. There are useful vaccine strains to prevent measles disease. Here, we describe the construction of a new helper cell line for rescue of measles virus minigenome. The helper cell line stably expresses T7 RNA polymerase as well as measles virus N and P proteins by tricistronic mRNA. Materials and Methods: For rescue of measles virus minigenome a stable helper cell line by using tricistronic expression vector was developed which expressed T7 RNA polymerase as well as measles virus N and P proteins. To construct the tricistronic expression vector, T7 RNA polymerase gene was cloned after cytomegalovirus [CMV] promoter and measles virus N and P proteins were under control of IRES [internal ribosome entry site] sequences. Our results indicated that measles virus minigenome could be rescued in this constructed helper cell line. Through this system, the measles virus minigenome was rescued. Further studies are necessary to improve the rescue efficiency. This may be possible by replacing the CMV promoter with the T7 promoter