Assemblage characterization of Giardia duodenalis in South Khorasan province, eastern Iran, using HRM real-time PCR method

BACKGROUND

Giardia duodenalis is a common parasitic protozoan causing gastrointestinal illness in humans worldwide. The genetic diversity of G. duodenalis is reflected through the identification of different assemblages. In this study, we aimed to determine the assemblages of G. duodenalis in eastern Iran using nested-PCR and high-resolution melting (HRM) real-time PCR methods.

METHODS

A total of 58 positive G. duodenalis, which were isolated from 1800 subjects, referred to medical center laboratories in South Khorasan province, eastern Iran, from April 2020 to March 2022, were included in this study. DNA was extracted and HRM real-time PCR was performed for assemblage characterization.

RESULTS

HRM real-time PCR successfully characterized all samples. Accordingly, out of 58 positive samples, 53 (91.36%) and 5 (8.62%) were identified as assemblage A and B, respectively.

CONCLUSIONS

Our findings showed that HRM real-time PCR was able to characterize the assemblages of G. duodenalis. In addition, our results suggest high prevalence of assemblage A in eastern region of Iran.

Probability of false-negative results in microscopical detection of cutaneous leishmaniasis: more accurate screening by kDNA-PCR during epidemiological survey

Leishmaniasis has an important impact on global public health, and the common form of the disease is cutaneous form as well in Iran. Different species of Leishmania parasite make variable clinical manifestations, so prompt diagnosis and recognition at the species level are important due to their impact on the treatment and outcome of the disease. We aimed to examine the potential existence of the Leishmania parasite genome in the exudate materials derived from lesions of the cutaneous leishmaniasis suspected patients referred to Varamin Health Center Laboratory, that were reported negative microscopically. Regarding the object of the study, kDNA-Nested-PCR was used. A 570 bp band equal to what expected for Leishmania major was amplified in 18 out of 29 tested samples (62%). Findings indicate the effectivness of kDNA as a high copy number gene to avoid false-negative results.

Molecular Identification of Leishmania Species in a Re-Emerged Focus of Cutaneous Leishmaniasis in Varamin District, Iran

BACKGROUND

Cutaneous leishmaniasis (CL) is one of the most important neglected tropical diseases and a major public health challenge in Iran caused by Leishmania spp and transmitted by phlebotomine sand flies. The number of CL cases has shown an increasing pattern all over the country, including the district of Varamin, southeast of Tehran, Iran. This study aimed to identify the Leishmania spp isolated from CL patients using molecular methods in Varamin during 2012-2013.

METHODS

Exudate materials collected from the swollen edge of the skin lesions of 44 parasitological positive CL patients by disposable lancet. They were referred to Varamin Health Center by physician. The samples were subjected to molecular method for Leishmania species identification.

RESULTS

The digestion pattern of restriction enzyme revealed that 37 (84.1%) CL patients were infected with L. major and 7 (15.9%) were infected with L. tropica. They were mostly male than female. More than half of the patients (58%) had multiple lesions, and they were mostly observed on extremities, 34.1% on legs and 29.5% on hands. Lesions were mostly of wet ulcerative type.

CONCLUSION

Dominancy of L. major provides more evidence that Varamin District probably could be considered as Zoonotic Cutaneous Leishmaniasis (ZCL) areas. More investigation on other epidemiological aspects of disease is needed.

Detection of Chlamydia trachomatis in Pap Smear Samples from South Khorasan Province of Iran

Background

Chlamydia trachomatis (CT), the most common bacterial sexually transmitted infection (STI), leads to pelvic inflammatory disease, infertility and chronic pelvic pain in women as well as an increased risk of vertical transmission, conjunctivitis and pneumonitis in infants. It may also be a co-factor along with human papillomavirus (HPV) in cervical cancer progression. We aimed to determine the prevalence of CT genotypes in genital specimens of women from South Khorasan, Iran and to test the association between CT and cytology statistics.

MATERIALS AND METHODS

This was a cross-sectional study on 248 Pap smear samples from women who visited a gynecologist for routine Pap smear testing in South Khorasan province. Nested polymerase chain reaction (PCR) was used to test the residual fluids of Pap smears for CT-DNA after cytological examination. Direct sequencing, alignment and phylogenic analyses were performed on eight samples to identify their genotypes.

RESULTS

The mean age of patients was 37.54 ± 5.21 years. Most samples had a normal cytology (214 cases, 86.29%). Overall, 31 samples were positive for CT infection (12.5%) of which 20 (9.34%) were normal and 11 (32.35%) were abnormal, with the frequency difference being significant (P=0.022). The co-infection of CT/HPV in total was identified in 14 cases (5.6%). The results of sequencing eight samples out of the 31 CT positive samples revealed the detection of genotypes D and E, each with four cases.

CONCLUSION

We show that a high prevalence of genital CT infection is present in women with both normal and abnormal cytology; however, the higher prevalence among women in the abnormal group may indicate its involvement in cervical neoplasia.

Noise Characterization of Polycrystalline Silicon Thin Film Transistors for X-ray Imagers Based on Active Pixel Architectures

An examination of the noise of polycrystalline silicon thin film transistors, in the context of flat panel x-ray imager development, is reported. The study was conducted in the spirit of exploring how the 1/f, shot and thermal noise components of poly-Si TFTs, determined from current noise power spectral density measurements, as well as through calculation, can be used to assist in the development of imagers incorporating pixel amplification circuits based on such transistors.