International Journal of Medical Laboratory

272-277

Authors: Archana Garg 1 M.D., Lakshmi Agarwal 2 M.D., Mamta Gupta 3 M.D., Manmohan Agarwal 4* M.D.

Background and Aims: Emerging antimicrobial resistance is one of the major public health threats worldwide. It can result in increased morbidity and mortality rates along with increased treatment costs and hospitalization stays. Methicillin-resistant Staphylococcus aureus (MRSA) has become a global challenge. It is a major cause of nosocomial and community-acquired infections. Its prevalence varies with country and within hospitals within a country. The current study estimates the prevalence of MRSA. Materials and Methods: A total of 162 Staphylococcus aureus strains were isolated from various clinical specimens, and antibiotic susceptibility tests and identification by cefoxitin disc (30 μg) were performed as per Clinical and Laboratory Standards Institute guidelines. Results: Among 162 Staphylococcus aureus 92 isolates were found to be MRSA. The highest rate of resistance was detected for penicillin (100), followed by erythromycin (97%), clindamycin (57%), tetracycline (13%), sulfamethoxazole-trimethoprim (SXT) (55%), ciprofloxacin (23%), and gentamicin (2%). All of the isolates were susceptible to linezolid and vancomycin. Conclusions: Treatment of multi-drug resistant MRSA is still problematic because of the limited choice of antibiotic. This analysis will assist clinicians to choose an appropriate course of action for MRSA infections.

286-294

Authors: Esmaeil Sarani 1 M.Sc., Maryam Hataminejad 2 Ph.D., Hakim Azizi 3* Ph.D.

Background and Aims: Toxocariasis is a zoonotic parasitic disease with worldwide distribution caused by the larval stage of ascaridoid nematodes of dogs (Toxocara canis) and cats (Toxocara cati). The study was accomplished to determine the sequence variation in ITS2 and COX1 genes within isolates of Toxocara canis. Materials and Methods: Two hundred Stool samples were collected randomly from dogs in public parks and streets from different regions of Zabol. Thirty samples containing eggs were isolated from the feces using Formalin ether 10% and centrifugal flotation. Genomic DNA was extracted, and COX1 and ITS2 were amplified by PCR-RFLP and sequenced. Sequence data were aligned using the BioEdit software and BLAST program and compared with published sequences in GenBank. The phylogenetic relationship between isolates of T. canis from Zabol city with other regions based on sequences obtained from COX1 and ITS2 genes and using MEGA7.0 software was investigated. Results: For all samples, amplicons of about 388 and 422 base pairs were produced by PCR for ITS2 and COX1, respectively. Drawing the phylogenic tree of ITS2 and COX1 sequences of isolates of T. canis showed that the identified genotypes are not only different from each other but also from other parts of the world. Conclusions: Our result showed that genetic variation among isolates of T. canis from Zabol is very low. For a deeper understanding of genetic diversity among populations of Toxocara, it is recommended to analyze more isolates from various geographical areas and variable genetic markers.

304-310

Authors: Seyed Ali Salari 1 M.Sc., Seyed Mohsen Miresmaeili 1* Ph.D., Mahta Mazaheri Naeini 2 Ph.D.

Background and Aims: One of the most important genes involved in Alzheimer's disease (AD) is the presenilin2 (PSEN2) gene, which is one of the main constituents of the gamma-secretase complex. Mutations in this gene promote the formation of amyloid plaques resulting in AD. The study aimed to evaluate the mutation variant in exon 6 of the PSEN2 gene in patients with Late-Onset Alzheimer's disease (LOAD). Due to the important role of the PSEN2 gene in the formation of beta-amyloid aggregates and the investigation involves an association between PSEN2 mutations and their pathogenicity in LOAD progression, we presented this exon as a more efficient alternative. Materials and Methods: The thirty patients with LOAD and 16 healthy subjects as a control group were involved in this experimental study. DNA was extracted from blood samples and purified. The desired gene fragment was propagated using polymerase chain reaction and the products were electrophoresed and the results were analyzed. Result: A novel mutation was found in PSEN2 IVS6 + 30 G → C at the intron region of exon 6 in 20 cases of patients suffering from LOAD and 12 subjects in control cohort. In this mutation a guanine base was substituted by cytosine base which this position was 30 nucleotides separated from coding region. Conclusions: The novel mutation was identified in both studied groups. These findings reveal no relationship between PSEN2 mutation and pathogenicity of LOAD disease. However, further studies are required to find the role of PSEN2 mutation in LOAD progression.