Polymerase chain reaction ribotyping of Clostridium difficile isolates in Qatar: a hospital-based study

Background Clostridium difficile infection (CDI) is not generally reported to public health authorities in the Middle East and its true prevalence remains largely unknown. The aims of this study were to determine the prevalence of CDI and its associated ribotypes among C. difficile isolates in Qatar. Influence of age and correlation with other risk factors e.g. proton pump inhibitor use, antibiotic use, existence of chronic conditions, etc was also investigated for CDI positive patients. Methods A total of 1,532 patients with suspected CDI were recruited from two hospitals between 2011 and 2012. C. difficile was identified using glutamate dehydrogenase (GDH) lateral flow assay and toxins A and B Enzyme Immunoassay (EIA). The C. difficile positive samples were then cultured for PCR-ribotyping. Results 122 of the 1,532 (7.9%) samples from individual patients were identified as C.difficile positive; and 79 of these were viably cultured (~65%). From these, 36 different PCR ribotypes were isolated, of which strains 258 (6 [7.6%]), 01/014/046 (5 [6.3%]), and 011/053/056/107 (4 [5%]) were the most prevalent. The prevalence of PCR-ribotype 027 was 1.3% (n = 1). An age of ≥65 years and treatment with proton pump inhibitors correlated with higher frequency of CDI. Treatment with third generation cephalosporins (50 [41%]) and piperacillin/tazobactam antibiotics (55 [45.1%]) was most frequently associated with CDI. Conclusion The most common C. difficile ribotype identified in Qatar was 258, which is different from those found in North America, Europe and Asia. The prevalence of CDI was higher in Qatar than Europe; though comparable to other Middle Eastern countries. These findings underscore the importance of local surveillance to detect and control C. difficile infection

Colorimetric gold nanoparticles-based assay for direct detection of Clostridium difficile in clinical isolates from Qatar

Clostridium difficile infection (CDI) is a significant health problem worldwide. Control and prevention strategies of C. difficile horizontal transmission require assays with fast detection with high specificity and sensitivity. Conventional diagnostic methods are time consuming and costly for clinical field settings. This study aims to develop gold nanoparticles (AuNPs)-based assay for direct qualitative detection of the nucleic acid of C. difficile and its toxins. A colloidal solution of AuNPs with a diameter of 13±1 nm was prepared and characterized. The qualitative colorimetric AuNPs assay was developed for restricted genomic C. difficile DNA detection, and results were confirmed by PCR. One hundred and five positive C. difficile isolates were collected from patients with diarrheal diseases and tested using AuNPs based-assay. Ninety-six samples (91.4%) were detected positive using AuNPs based assay, as indicated by the color change from red to blue within 1 min. All ninety-six positive samples were positive for toxin B. In conclusion, nano-gold assay prototype was developed for direct and inexpensive detection of C. difficile. The developed prototypes are simple, sensitive, rapid and can substitute PCR-based detection. The developed assay may show potential in the clinical diagnosis of C. difficile, especially in developing countries as it is less costly as compared to the commercially available assays.NPRP award (NPRP 4-1215-3-317) from the Qatar National Research Fun

Human microbiome and its association with health and diseases

Human microbiota are distinct communities of microorganisms that resides at different body niches. Exploration of the human microbiome has become a reality due to the availability of powerful metagenomics and metatranscriptomic analysis technologies. Recent advances in sequencing and bioinformatics over the past decade help provide a deep insight into the nature of the host-microbial interactions and identification of potential deriver genes and pathways associated with human health, well-being, and predisposition to different diseases. In the present review, we outline recent studies devoted to elucidate the possible link between the microbiota and various type of diseases. The present review also highlights the potential utilization of microbiota as a potential therapeutic option to treat a wide array of human diseases