Medical Microbiology & Diagnosis

Introduction: Typhoid fever the common cause of morbidity and mortality especially in the developing countries where Widal test is routinely used as diagnostic tool to rule out the disease. The diagnostic ability of Widal test is debatable as the test method has a low sensitivity, specificity and positive predictive value (PPV). Therefore, reviewing articles across the world regarding the diagnostic value of Widal test is necessary.

Methods: Systematic review of published articles regarding the diagnostic value of Widal test to rule out typhoid fever was carried out. Published articles were identified from PubMed, Google scholar, HINARI and other sources. The mean, median, percentile and standard deviation of sensitivity, specificity, NPV and PPV of the reviewed articles were computed by SPSS software version 24.

Results: A total of 16 articles were included in the systematic review with the oldest publication in the year 1994 and the recent in 2015. The mean sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Widal test was 73.5%, 75.7%, 60% and 75.2%, respectively.

Conclusion: The systematic review results show that the reliability of Widal test is comparatively poor. Therefore, Widal test should not be used as a diagnostic tool to rule out typhoid fever unless supported by invasive clinical pictures and other confirmatory tests.

Introduction: Colorectal cancer is the third most common type of tumors, with more than 1.2 million new cases resulted in 600 thousand deaths annually and ranks fourth in terms of mortality worldwide. The activated leukocyte cell adhesion molecule (ALCAM) also called CD166 is a marker of colorectal cancer (CRC) stem cells. The expression of CD166 increase in colorectal cancer. Also with advancement of illness in different stages of cancer, this expression increased. So, it could be a reasonable marker for Detection and Treatment of Colorectal cancer. The purpose of this study is to produce recombinant protein CD166 for cancer therapy or early detection of colorectal cancer cells.

Methods: In this study, the sequence of CD166 was optimized for expression in E. coli using online tools and cloned into pET28a as an expression vector. The recombinant pET28a was transformed into the E. coli BL21DE3 using heat shock method and expression of recombinant CD166 was examined using SDS-PAGE.

Results: The synthetic gene of CD166 was located between NcoI/BamHI and XhoI restriction sites and cloned into pBSK (+) vector. The presence of this gene in pET28a was determined by colony and confirmed by restriction digestion. Gene of CD166 were expressed in E. coli BL21 DE3. The results of the SDS-PAGE technique confirmed the expression of recombinant 53 kDa CD166 in a bacterial expression system.

Conclusion: A portion of the CD166 gene was expressed as a recombinant in E. coli. This could be a good candidate to produce a vaccine for cancer therapy or colorectal cancer diagnostic test.

Rapid detection of infections is crucial for the prevention of infectious disease outbreaks, development of anti-microbial drugs and biodefense. When considering a diagnostic test the most important considerations are rapidity, ease of use, portability, specificity and sensitivity. Recently developed isothermal recombinase polymerase amplification (RPA) technology has been shown in many publications to be the most sensitive and effective for determining infections, require no sophisticated and expensive equipment, and is suitable for point-of-care field applications. Here we have described our viewpoints with regard to RPA technology’s suitability and usage in resource poor settings, its advantages and limitations. We have also developed a lateral flow assay to detect all serotypes of dengue virus following RPA procedure, demonstrating its suitability for field applications. We believe our suggestions may help in improving RPA procedures and may also help in transitioning to clinical applications.

Objectives: The purpose of this study was to identify serogroups and antimicrobial susceptibility of non-typhoidal Salmonellas from gastroenteritis patients among out- and in-patient population of Al Ain Hospital in Al Ain, United Arab Emirates during the period of 1st April 2007 to 30th April 2013.

.Methods: A retrospective study was carried out through review of the stool specimen record sent for bacteriological culture to Clinical Institute of Laboratory Services at Al Ain Hospital from 1st April 2007 to 30th April 2013. Culture and antimicrobial susceptibility of the isolates were carried out by using standard laboratory procedures. Serotyping was performed using commercial anti-sera.

Results: During the study period of 6 years a total of 205 laboratory confirmed non-typhoidal Salmonellas were isolated from the stool of patients with diarrhea. The majority of these strains (69%) was from patients of 0-14 years of age. Salmonella group B was the most frequent serogroup (36%) followed by serogroup D (27%) and then Salmonella spp. (26%). Salmonella serogroups A & C were 1% and 10%, respectively. The most frequently detected antibiotic resistance was to Ampicillin (25%), Co-Trimaxazole (15%) and Chloramphenicol (5%). Salmonella group B was the most resistant. The majority were, however, susceptible to other drugs with low to very low resistance rates (5% to Ciprofloxacin, and 2% to Ceftriaxone). Overall, resistant strains were more prevalent among children (30%) than adults (23%).

Conclusions: Salmonella gastroenteritis is an important clinical condition in children more than in adults In the United Arab Emirates. Salmonella serogroup B, D and Salmonella spp. are prevalent strains causing gastroenteritis. Most of the Salmonella serogroups isolated in this study showed a high resistance to Ampicillin in comparison to other antibiotics. The emergence of resistance against Ceftriaxone among non-typhoidal Salmonella spp. is an alarming sign.

Background: The present study was conducted in the clinical lab of Microbiology department, College of Medical Sciences. The samples that were sent for culture and sensitivity from patients developing signs and symptoms collected from patients developing symptoms of SSIs in different wards as well as ICUs of this hospital were included in this study. A total of 206 pus samples were processed and result was interpreted on the basis of different tests. Isolation and identification of the organism was done by gram stains and culture growth. Antibiotic susceptibility test was performed by Kirby Bauer disc diffusion method and result was interpreted as per Clinical and Laboratory Standards Institute (CLSI) guidelines.

Result: Out of 206 clinically suspected cases 106 (51.4%) were culture negative and 100 (48.6%) were culture positive. The growths were found to be higher in male patients than in female patients. The most commonly isolated pathogens were Staphylococcus aureus 24 (21.8%) and Escherichia coli 24 (21.8%), followed by Pseudomonas aeruginosa 17 (15.4%). Amikacin (86.4%) was the most sensitive drug. 14 isolates of Methicillin resistant S. aureus (MRSA) were found.

Conclusion: The study helped in the assessment of the current anti-microbial resistance patterns of bacterial isolates in post-operative wound infections and helps in formulation of the strategy to reduce the infection rate in College of Medical Sciences-Teaching Hospital, Bharatpur.