Evaluation of rapid low-cost colorimetric methods for diagnosis of multidrug-resistant tuberculosis in limited-resource settings

One third of the world\u27s population is currently infected with tuberculosis (TB), a consuming airborne disease whose main causative agent is Mycobacterium tuberculosis. The majority of these patients are found in the world\u27s poorest areas. Treatment of TB is a lengthy and demanding process utilizing a cocktail of powerful drugs; however, multidrug resistant TB (MDR-TB) strains, defined by resistance to both isoniazid (INH) and rifampicin (RIF), are now emerging worldwide and threatening disease control efforts. The major problem facing efforts to combat MDR-TB spread is its early detection. Conventional fairly affordable methods for drug resistance detection are based on solid culture and are highly time consuming (3-6 weeks in addition to initial pathogen culturing). On the other hand, the more rapid liquid culture-based automated systems are costly to set up and maintain while the very rapid molecular assays (hours to few days) are simply too complex and unaffordable and non-sustainable in limited resource settings. The objective of this work was to evaluate the performance of two liquid culture-based colorimetric assays for detection of drug resistance; nitrate reducate assay (NRA) and colorimetric redox indicator (CRI) methods for detection of MDR-TB. The assays were tested on mycobacterial isolates from Egyptian patients and their performance was compared with microscopic observation drug susceptibility assay (MODS) and the commercial automated culture system MGIT 960. Concordance was 96.7% for CRI and 93.3%, at almost one-tenth of the MGIT cost, and close to that of MODS without the need for an inverted microscope. The NRA format used in this study is more convenient and higher in throughput than the initially developed format. Additionally, DNA was extracted from the mycobacterial isolates and16S rDNA was amplified and sequenced to gain insight on the molecular diversity of Egyptian strains. Moreover, the molecular basis of strain resistance was investigated by DNA sequencing of the genes most commonly containing resistance conferring mutations. Analysis of the 16S rDNA sequencing results confirmed the identity of the samples as mycobacterium tuberculosis and suggested possible presence of two different strains. On the other hand, the analysis of the resistance related genes found common resistance conferring mutations in the MDR samples

Pneumonia due to a Rare Pathogen: Achromobacter xylosoxidans, Subspecies denitrificans

Achromobacter xylosoxidans, subspecies denitrificans, is a gram-negative rod recently implicated as an emerging cause of infection in both immunosuppressed and immunocompetent populations. Few cases are reported in literature involvingmultiple body systems. Diagnosis depends on cultures of appropriate specimens, and management usually is by administration of appropriate antibiotics(usually agents with antipseudomonal activity).We report a rare case of pneumonia due to infection with this organism, in a patient with preexisting bronchiectasis secondary to chronic aspiration

STR-990: SUSTAINABLE GROUTED HELICAL PILES: MATERIALS AND PERFORMANCE

Cementitious materials are widely used as a construction material all over the world. However, cement industry has high environmental impact such as the release of CO2 and the consumption of natural resources for its manufacturing energy. Therefore, reducing cement consumption is vital to achieve sustainable green construction practices. In this study, the effects of using treated oil sand waste (TOSW) as a partial replacement of cement in grouted helical pile applications were investigated. Fresh and hardened properties of the green grout incorporating different percentages of TOSW were evaluated. In addition, a model scale grouted helical pile with the green grout was tested to characterize its performance. The experimental results show that the properties of TOSW grout mixes were comparable to conventional grout and satisfy the strength and construction requirements of grouted piles. Moreover, tested grouted helical pile using the developed mixture exhibited similar geotechnical performance as those installed using conventional grout mix. Hence, TOSW can be implemented in grouted helical pile applications, which would assist in achieving sustainable construction

Complete Esophageal Obstruction after Endoscopic Variceal Band Ligation in a Patient with a Sliding Hiatal Hernia

Complete esophageal obstruction is a rare complication of endoscopic variceal banding, with only 6 cases in the English literature since the introduction of endoscopic variceal banding in 1986. We report a case of complete esophageal obstruction following esophageal banding due to entrapment of part of a sliding hiatal hernia. To our knowledge, our case is one of few with esophageal obstruction post-banding, and the first associated with a hiatal hernia. We recommend caution when performing esophageal banding on patients with a hiatal hernia