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1.  The distribution of Blastocystis subtypes in isolates from Qatar 
Parasites & Vectors  2015;8:465.
Blastocystis is a common single-celled intestinal parasite of humans and other animals comprising at least 17 genetically distinct small subunit ribosomal RNA lineages (subtypes (STs)), nine of which have been found in humans. The geographic distribution of Blastocystis subtypes is variable, but the subtypes present in Qatar are at present unknown.
Stool samples were collected from randomly selected, apparently healthy subjects arriving in Qatar for the first time. Blastocystis subtypes were determined by sequencing of the small subunit rRNA gene (SSU rDNA) PCR products. Phylogenetic analyses were done using Maximum Composite Likelihood method.
71.1 % of samples were positive for Blastocystis infection based on PCR-detection methodology compared to only 6.9 % by microscopy. Prevalence of Blastocystis did not differ between the sexes nor between age classes. However, there was a regional difference in prevalence with subjects arriving from Africa showing the highest (87.6 %), those from Western Asia intermediate (68.6 %) and from Eastern Asia the lowest prevalence (67.6 %). Genetic analysis detected only three STs. ST3 was the most common (69.3 %) and ST2 was the rarest (3.5 %), while ST1 had a prevalence of 27.2 %. ST2 showed a regional variation, being absent from the 64 Western Asian Blastocystis-positive subjects. Both ST1 and ST3 showed significant differences in prevalence between the sexes.
This is the first report exploring the distribution of Blastocystis subtypes in our region. We recommend that stool screening via microscopy for the presence of Blastocystis should be abandoned since it is extremely insensitive. In future, the prevalence of Blastocystis infections should be based on PCR methodology and we predict that in the years ahead diagnostic PCR will become the tool of choice. More work is needed to identify the full range of Blastocystis subtypes that circulate in our region.
PMCID: PMC4573284  PMID: 26384209
Blastocystis; Real time-PCR; Subtype; Small subunit ribosomal DNA; Prevalence; Genotyping; Phylogenetic analysis; Qatar
2.  Unusual rotavirus genotypes among children with acute diarrhea in Saudi Arabia 
BMC Infectious Diseases  2015;15:192.
Human rotavirus A (human RV-A) is the most common cause of viral gastroenteritis in infants. The objective of the study was to characterize the G and P genotypes among clinical rotavirus isolates from children with acute diarrhea admitted to a tertiary care hospital in Riyadh, Saudi Arabia.
From 2011 to 2012, 541 pediatric patients with acute diarrhea were tested for rotavirus infection. RNA extractions from the fecal specimens were done by commercial kit. RT-PCR and sequencing techniques were used to detect the prevalent genotypes. Phylogenetic analysis by Maximum Likelihood method was used to study the clustering of the circulating genotypes.
The data showed that 171/541 (31.6%) faecal samples were positive for human RVA and majority were children aged below 2 years. From the G and P [types] detected it was seen that (a) 171 minus 43 ie. 128 rotavirus positives were G typed successfully (b) 171 minus 20 ie. 151 rotavirus positives were P typed successfully; (c) overall G [P] nature was determined for 113 rotavirus positives out of 171. VP4 genotyping showed that majority of the positives 146/151 (96.7%) were P [8]; 4/151 (2.6%) were P [4]; 1/151 (0.66%) was P [6]. The dominant strains included G1P [8] 70/113 (61.9%); G9P [8] 19/113 (16.8%); G12P [8] 7/113 (6.2%) and G3P [8] 5/113 (4.4%) while the uncommon strains detected from Saudi Arabia during the study were G1P [4] 1/113 (0.88%) and G12P [6] 1/113 (0.88%). Phylogenetic tree, based on VP4/VP7 sequence analysis, revealed that G1P [8] was distinctly related to homologous strains included in human RV-A vaccine strains. Nevertheless, the uncommon genotypes G1P [4] and G12P [6] were clustered with isolates from other countries such as Bangladesh, China, Japan, Thailand and Philippines.
More studies will be required to further focus on newly emerging genotypes in our region together with the seasonality of rotavirus infection in the region, especially after January 2013 when the rotavirus vaccination has become part of routine childhood immunizations.
PMCID: PMC4407833  PMID: 25884670
Rotavirus; Gastroenteritis; Diarrhea; Epidemiology; VP4; VP7; KSA
3.  The prevalence of antimicrobial resistance in clinical isolates from Gulf Corporation Council countries 
The burden of antimicrobial resistance worldwide is substantial and is likely to grow. Many factors play a role in the emergence of resistance. These resistance mechanisms may be encoded on transferable genes, which facilitate the spread of resistance between bacterial strains of the same and/or different species. Other resistance mechanisms may be due to alterations in the chromosomal DNA which enables the bacteria to withstand the environment and multiply. Many, if not most, of the Gulf Corporation Council (GCC) countries do not have clear guidelines for antimicrobial use, and lack policies for restricting and auditing antimicrobial prescriptions.
The aim of this study is to review the prevalence of antibiotic resistance in GCC countries and explore the reasons for antibiotic resistance in the region.
The PubMed database was searched using the following key words: antimicrobial resistance, antibiotic stewardship, prevalence, epidemiology, mechanism of resistance, and GCC country (Saudi Arabia, Qatar, Bahrain, Kuwait, Oman, and United Arab Emirates).
From January1990 through April 2011, there were 45 articles published reviewing antibiotic resistance in the GCC countries. Among all the GCC countries, 37,295 bacterial isolates were studied for antimicrobial resistance. The most prevalent microorganism was Escherichia coli (10,073/44%), followed by Klebsiella pneumoniae (4,709/20%), Pseudomonas aeruginosa (4,287/18.7%), MRSA (1,216/5.4%), Acinetobacter (1,061/5%), with C. difficile and Enterococcus representing less than 1%.
In the last 2 decades, E. coli followed by Klebsiella pneumoniae were the most prevalent reported microorganisms by GCC countries with resistance data.
PMCID: PMC3436690  PMID: 22958584
Antibiotics/antimicrobials; Resistance; GCC; (Saudi Arabia, Qatar, Bahrain, Kuwait, Oman, and United Arab Emirates) Gram negative; Gram positive; Anaerobes; Pathogens; Infection; Resistance mechanisms; Molecular typing
4.  First Evidence of Genotypes Ad3a16 and Ad3a18 in North America, Obtained by Genetic Analysis of Infectious Human Adenovirus from Wastewaters of Two Urban Communities in Canada▿  
Applied and Environmental Microbiology  2011;77(12):4256-4259.
A 1-year study found seven infectious human adenovirus serotypes, including Ad3, Ad31, Ad46, Ad27, Ad22, Ad51, and clinical clone PB3, in wastewaters of two major cities in Canada. Comparative genomic analysis revealed the existence of the reportedly highly contagious Ad3a16/18 genotypes. This is the first report of Ad3a16/18 genotypes in North America.
PMCID: PMC3131634  PMID: 21515731

Results 1-4 (4)