Polymerase chain reaction targeting insertion sequence for the diagnosis of extrapulmonary tuberculosis.

BACKGROUND & OBJECTIVES Diagnosis of extrapulmonary tuberculosis (EPTB) is difficult using conventional diagnostic methods. This study was conducted to evaluate the use of polymerase chain reaction (PCR) in diagnosis of definitive and probable extrapulmonary tuberculosis patients, and to assess the performance of insertion sequence (IS) 6110 based PCR assay as compared to conventional culture by Lowenstein-Jensen (LJ) method for the diagnosis of EPTB. METHODS A total of 178 non repeated clinical specimens were collected from clinically suspected extrapulmonary tuberculosis patients. The specimens included 59 ascitic fluid, 54 pleural fluid, 25 cerebrospinal fluid (CSF), 12 fine needle aspiration (FNA), 8 urine, 7 pus, 6 synovial fluid, 2 skin tissue, one pericardial fluid, one liver abscess, one pancreatic cyst fluid, one omental biopsy and one semen sample. All these clinical samples were subjected to Ziehl-Neelsen staining (ZN) for acid fast bacilli (AFB) and culture on LJ medium. PCR was performed by targeting 123bp fragment of insertion sequence IS6110 of Mycobacterium tuberculosis (MTB). RESULTS Of the 178 specimens, 10 (5.61%) were ZN smear positive for AFB, six (3.37%) were L-J culture positive from 10 AFB smear positive cases and 48 (26.96%) were PCR IS 6110 positive for M. tuberculosis. INTERPRETATION & CONCLUSIONS PCR using IS6110 primer was able to pick up more EPTB patients compared to conventional L-J culture method for detection of M. tuberculosis. False positive PCR IS6110 in three CSF samples may be due to latent TB infection which was limitation in this study

CRISPR/Cas9: an advanced platform for root and tuber crops improvement

Root and tuber crops (RTCs), which include cassava, potato, sweet potato, and yams, principally function as staple crops for a considerable fraction of the world population, in addition to their diverse applications in nutrition, industry, and bioenergy sectors. Even then, RTCs are an underutilized group considering their potential as industrial raw material. Complexities in conventional RTC improvement programs curb the extensive exploitation of the potentials of this group of crop species for food, energy production, value addition, and sustainable development. Now, with the advent of whole-genome sequencing, sufficient sequence data are available for cassava, sweet potato, and potato. These genomic resources provide enormous scope for the improvement of tuber crops, to make them better suited for agronomic and industrial applications. There has been remarkable progress in RTC improvement through the deployment of new strategies like gene editing over the last decade. This review brings out the major areas where CRISPR/Cas technology has improved tuber crops. Strategies for genetic transformation of RTCs with CRISPR/Cas9 constructs and regeneration of edited lines and the bottlenecks encountered in their establishment are also discussed. Certain attributes of tuber crops requiring focus in future research along with putative editing targets are also indicated. Altogether, this review provides a comprehensive account of developments achieved, future lines of research, bottlenecks, and major experimental concerns regarding the establishment of CRISPR/Cas9-based gene editing in RTCs

Cassava mosaic disease in South and Southeast Asia: current status and prospects

Cassava is one of the most important food and industrial crops in Asia, Africa, and South America. Cassava mosaic disease (CMD), caused by cassava mosaic geminivirus, is one of the major constraints to cassava cultivation. In Asia, the disease is caused by the Indian cassava mosaic virus and Sri Lankan cassava mosaic virus. Phytosanitation, vector control, breeding, and genetic engineering strategies have been widely adopted to manage the disease. This study provides a comprehensive review of the disease spread, the development of diagnostic methods, and various approaches employed for the management of CMD in South and Southeast Asia

Operational Challenges in Conducting a Subnational TB Prevalence Survey in India: Lessons Learned for Resource-Limited, High-Burden Settings

Estimating the burden of TB at the subnational level is critical to planning and prioritizing resources for TB control activities according to the local epidemiological situation. We report the experiences and operational challenges of implementing a TB prevalence survey at the subnational level in India. Information was collected from research reports that gathered data from periodic meetings, informal discussions with study teams, letters of communication, and various site visit reports. During the implementation of the survey, several challenges were encountered, including frequent turnover in human resources, lack of survey participation and community engagement, breakdown of X-ray machines, laboratory issues that delayed sputum sample testing, delays in X-ray reading, and network and Internet connectivity issues that impeded data management. To help ensure the survey was implemented in a timely manner, we developed several solutions, including planning ahead to anticipate challenges, ensuring timely communication, having a high commitment from all stakeholders, having strong team motivation, providing repetitive hands-on training, and involving local leaders to increase community engagement. This experience may help future states and countries that plan to conduct TB prevalence surveys to address these anticipated challenges and develop alternative strategies well in advance

Optimization of in vitro regeneration and microcorm induction in elephant foot yam (Amorphophallus paeoniifolius)

Elephant foot yam (Amorphophallus paeoniifolius) is a vegetatively propagated stem tuber crop. In this investigation we describe a highly competent and reproducible in vitro propagation of the plant from corm bud, petiole and young leaf explants. Friable callus was initiated from all the explants on modified MS medium (half the concentration of NH4NO3 and KNO3) supplemented with 0.5 mg l-1 each of benzyl amino purine (BAP), α-naphthalene acetic acid (NAA) and 2,4-dichloro phenoxy acetic acid (2,4-D). Shoot regeneration from calli was optimal on modified MS medium supplemented with 5.0 mg l-1 BAP and 1.0 mg l-1 NAA. Microcorms, capable of producing micro shoots all over the surface, were induced from the callus at a frequency of 90% on shoot regeneration medium supplemented with 5% sucrose. Rooting was 100% on modified liquid MS medium augmented with 5.0 mg l-1 Indole 3- butyric acid (IBA). A 100% survival rate of plantlets on transplantation to soil: sand: coir pith mixture was recorded.Keywords: Callus, elephant foot yam, in vitro, microcorms, regeneration, somatic embryoAfrican Journal of Biotechnology, Vol 13(49) 4508-451

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Effect of zirconium and niobium on the microstructure and mechanical properties of high-strength low-alloy cast steels

The aim of this work is to study the effect of zirconium and niobium on the refinement of grain size and mechanical properties of micro-alloyed cast steels in heat treated conditions. Five micro-alloyed cast steels with different compositions, as steel without microalloying elements and micro-alloyed steel with (i) 0.05% Zirconium (Zr), (ii) 0.05% Zirconium (Zr) and 0.05% Niobium (Nb), (iii) 0.10% Zirconium (Zr), and (iv) 0.10% Zirconium (Zr) and 0.10% Niobium (Nb) were investigated. The heat treated samples are normalized at 1000 °C followed by air cooling and were characterized to study the characteristics of carbide precipitates by SEM and TEM and mechanical properties were evaluated by tensile test as per ASTM A370. Among these five cast steels, steel containing 0.10% Zr and 0.10% Nb showed a higher tensile strength of 1184 MPa and yield strength of 740 MPa with reasonable impact energy of 42 J compared to other steels under the same heat treated conditions. Due to the combined addition of Zr and Nb elements in the micro-alloyed steel, a remarkable improvement of mechanical properties particularly strength and impact energy was observed. As evident from microstructure investigation, these improved mechanical properties in the present steel could be attributed due to the effective refinement of ferritic grain size in the normalized condition