Nutritional security through crop biofortification in India: Status & future prospects

Malnutrition has emerged as one of the most serious health issues worldwide. The consumption of unbalanced diet poor in nutritional quality causes malnutrition which is more prevalent in the underdeveloped and developing countries. Deficiency of proteins, essential amino acids, vitamins and minerals leads to poor health and increased susceptibility to various diseases, which in turn lead to significant loss in Gross Domestic Product and affect the socio-economic structure of the country. Although various avenues such as dietary-diversification, food-fortification and medical-supplementation are available, biofortification of crop varieties is considered as the most sustainable and cost-effective approach where the nutrients reach the target people in natural form. Here, we have discussed the present status on the development of biofortified crop varieties for various nutritional and antinutritional factors. Ongoing programmes of the Indian Council of Agricultural Research on the improvement of nutritional traits in different crops have been presented. Challenges and future prospects of crop biofortification in India have also been discussed. The newly developed biofortified crop varieties besides serving as an important source for livelihood to poor people assume great significance in nutritional security.

Rapid and efficient Agrobacterium mediated transformation of early scutellum derived calli of indica rice

Rice is a staple food for humans and its demand in 2035 has been put at 852 million tons. Knowledge on genes and genome architecture helps in better understanding of growth and development mechanisms for crop improvement. Transgenic crops may offer a solution by means of higher yield and resistance to biotic and abiotic stresses. In this context, modification of Agrobacterium mediated transformation protocol for indica rice cultivar is imperative to increase transformation efficiency and reduce duration of transgenic development. Here, we developed an efficient Agrobacterium mediated transformation protocol using early scutellum derived calli of the indica rice cultivar Pusa Sugandh 2. Competency of 3, 4, 5 and 6 day old primary calli was compared with 21- day old secondary calli for Agrobacterium mediated transformation using a modified pCAMBIA 1304 harbouring GFP-GUS fusion gene driven by maize ubiquitin 1 promoter. The highest competency with stable transformation efficiency of 51% was observed for 5-6 day old primary calli. Molecular analysis confirmed stable integration of the transgene. Transgenic lines of Pusa Sugandh 2 were developed within a short period of two months using 5-6 day old primary calli.

Prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) in a Tertiary-Care Hospital in Eastern Nepal.

Nosocomial infection is a major problem in the world today. Methicillin-resistant Staphylococcus aureus (MRSA) strains, usually resistant to several antibiotics, shows a particular ability to spread in hospitals and is now present in most of the countries. The aim of the present study was to determine the prevalence of MRSA infections and their antimicrobial susceptibility pattern in our hospital located in eastern Nepal. Identification of Staphylococcus aureus was confirmed by standard methods and the antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method. Interpretation criteria were those of the national committee for clinical laboratory standards. During a period of one year, out of a total of 750 Staphylococcus aureus strains isolated from various clinical samples, 196 (26.14%) were found to be Methicillin-resistant. Seventy percent isolates of MRSA were from inpatient departments and amongst them only 10% of the isolates were from intensive care units (ICU). More than 65% of MRSA were found to be resistant to Penicillin, Cephalosporins, Ciprofloxacin, Gentamicin Erythromycin and Tetracycline, while 47.96% of them were resistant to Amikacin. Many MRSA strains were multidrug-resistant. However, no strains were resistant to Vancomycin. To reduce the prevalence of MRSA, the regular surveillance of hospital acquired infection, isolation nursing of patients who carry MRSA, monitoring of antimicrobial susceptibility pattern and formulation of a definite antibiotic policy may be helpful.

Observations on carbapenem resistance by minimum inhibitory concentration in nosocomial isolates of Acinetobacter species: an experience at a tertiary care hospital in North India.

Acinetobacter species are emerging as an important nosocomial pathogen. Multidrug-resistant Acinetobacter spp. has limited the option for effective treatment. Although carbapenems are effective for the treatment of such infections, resistance to this drug has recently been reported. This study was undertaken to assess resistance to carbapenem in clinical isolates of Acinetobacter spp. from hospitalized patients by both disc-diffusion and minimum inhibitory concentration (MIC) methods. All clinical samples from suspected cases of nosocomial infections were processed, and 265 isolates were identified as Acinetobacter species. These isolates were tested for antibiotic resistance by the disc-diffusion method with 14 antimicrobials, including meropenem and imipenem. Thereafter, all Acinetobacter species were subjected to MIC for meropenem. More than 80% resistance to second- and third-generation cephalosporins, aminoglycosides, and quinolones was recorded. Thirty percent of the strains were resistant to cefoperazone/sulbactam. Resistance to meropenem was observed in 6.4% of Acinetobacter spp. while 8.3% of the isolates showed intermediate resistance detected by MIC. All carbapenem-resistant/intermediate strains were also resistant to other (>10) antibiotics tested by the disc-diffusion method. The rising trend of resistance to carbapenem poses an alarming threat to the treatment for such infections. Regular monitoring, judicious prescription, and early detection of resistance to carbapenem are necessary to check further dissemination of drug resistance in Acinetobacter spp.

Characterization and susceptibility patterns of clinically important Enterococcus species in eastern Nepal.

Life threatening infections caused by enterococcus species with multidrug resistance has emerged as a threat to medical care in the present era. This study was conducted to characterize enterococcus species isolated from different clinical samples and to detect the pattern of susceptibility to some of the commonly used antibiotics in B.P Koirala Institute of Health Sciences (BPKIHS), a tertiary care hospital in eastern Nepal. Clinical samples submitted to the microbiology unit of Central Laboratory Service (CLS) for culture and sensitivity during March 2002 - February 2003 was analyzed. Enterococcus species were identified by colony characteristics, gram staining and relevant biochemical tests. Antibiotic susceptibility test was done by the Kirby Bauer disc diffusion technique. Of 50 Enterococcus species isolated, E. faecalis was the predominant isolate (48.0%) followed by E. faecium (32.0%) and E. avium (20.0%). Eighty-eight percent of E. faecalis showed sensitivity to cephotaxime and 87.0% to vancomycin. Multiple drug resistance was observed most commonly in E. faecium. Seventeen percent of E. faecium were resistant to vancomycin and 63.0% to ciprofloxacin and 44.0% to ampicillin. On the contrary E. avium rarely showed resistance to the antimicrobials tested including vancomycin. Enterococcal infections are common nowadays specially in hospitalized patients. Inappropriate use of antibiotics in clinical practice and poultry should be discouraged to prevent the emergence of multidrug resistant species.

Superiority of dat over elisa as a diagnostic and seroepidemiological tool for the diagnosis of Indian kala-azar.

The aim of this study was to evaluate two methods for the diagnosis of Kala-azar. The sera of 160 individuals were evaluated by ELISA using soluble antigen and direct agglutination test (DAT) for Kala-azar. These were categorized as 100 cases of clinically and parasitologically confirmed Kala-azar and 60 controls. The controls included clinically suspected but parasitologically not confirmed Kala-azar patients (10), endemic normals (15), non-endemic normals (19), typhoid fever (10) and malaria (15). The positivity rate amongst the clinically and parasitologically confirmed Kala-azar patients by ELISA and DAT were 93% and 98% respectively. Out of 10 clinically suspected Kala-azar cases three showed positive reaction in ELISA and two in DAT. Of the endemic normals, one case was found positive by both the tests whereas ELISA was found positive in one additional case. DAT did not show any cross reactivity with malaria while ELISA was found positive in one case. Both endemic normals and typhoid fever cases showed no reaction by both tests. ELISA showed a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 93%, 90%, 93% and 90% respectively while for DAT these values were 98%, 95%, 98 and 95% respectively. The diagnostic accuracy for ELISA and DAT was found to be 91.9% and 96.9%, respectively. The present study shows that DAT is a simple, sensitive, specific and cost effective test with high PPV and NPV along with approximately 97% diagnostic accuracy and is comparable to ELISA. It may be applied for the routine diagnosis as well as seroepidemiological study of Kala-azar.

Bacterial antigen detection test in meningitis.

OBJECTIVE: To evaluate the role of bacterial antigen detection test in cerebrospinal fluid (CSF) for a rapid etiological diagnosis of bacterial meningitis. METHODS: The study included 36 cases of bacterial meningitis and 14 controls. Latex particle agglutination test (LPA test) for detection of bacterial antigen was done in the CSF using slidex meningitis kit (Biomeriux, France). RESULTS: Using LPA test, an etiological diagnosis could be made in 83% cases of bacterial meningitis. In contrast, CSF Gram stain and culture showed 36% and 6% positivity, respectively. The sensitivity and specificity of LPA test were 83% and 100%, respectively. The common etiological organisms were S. pneumoniae, H. influenzae type b and N. meningitidis A. S. pneumoniae was encountered in all age groups while H. influenzae type b was found only below one year of age. CONCLUSIONS: LPA test is a rapid and superior diagnostic tool as compared to CSF Gram stain and culture. The study recommends LPA test as an adjunct laboratory test for rapid etiological diagnosis of bacterial meningitis for prompt institution of proper antibiotics.

Prevalence of methicillin resistant staphylococcus aureus in a tertiary referral hospital in eastern Uttar Pradesh.

We report the prevalence of methicillin resistant Staphylococcus aureus (MRSA) infections and their antibiotic susceptibility pattern in our hospital located in eastern Uttar Pradesh. Out of total 549 strains of Staphylococcus aureus isolated from different clinical specimens 301 (54.85%) were found to be methicillin resistant. More than 80% of MRSA were found to be resistant to penicillin, cotrimoxazole, ciprofloxacin, gentamicin, erythromycin, tetracycline, 60.5% to amikacin and 47.5% to netilmicin. However, no strains were resistant to vancomycin. Many MRSA strains (32.0%) were multi-drug resistant. To reduce the prevalence of MRSA, the regular surveillance of hospital associated infection, monitoring of antibiotic sensitivity pattern and formulation of definite antibiotic policy may be helpful.

Partial molecular characterization of some kiwi fruit cultivars by RAPD markers.

Molecular variability among seven cultivars of A. deliciosa var. deliciosa was investigated through RAPD markers. Thirty four decamer primers were screened generating polymorphic patterns of amplified DNA for these cultivars. Twenty one selected primers gave clear and reporducible patterns. A total of 430 bands were produced and 29.37% of them were polymorphic. The patterns distinguished between the cultivars and their analysis established an approach to classification within A. deliciosa var. deliciosa based on RAPD markers. The dendrogram clearly differentiated male from female cultivars. While abbot and allison female cultivars were closely related, bruno and abbot female cultivars showed maximum dissimilarity.

Influence of dietary protein on DDT-induced immune responsiveness in rats.

The influence of protein deficiency was evaluated on immune responsiveness after subchronic DDT exposure in albino rats. Rats were given 20%, 12% and 3% protein diets and exposed to DDT (20, 50 or 100 ppm) for 4 weeks. DDT (50 and 100 ppm) induced humoral and cellular immune suppression only in rats fed on 3% protein diet. There was (a) an increase in the albumin/globulin ratio, (b) suppression in IgM and IgG levels, and (c) attenuation in the tetanus toxoid-induced antibody responses. Further, in rats immunized with tetanus toxoid, the leucocyte and macrophage migration inhibition were also attenuated. Moreover, these animals maintained on 3% protein diet showed depression in humoral and cellular immune responses to antigen in a dose-dependent pattern after exposure to DDT at dose levels which were not immunosuppressive for rats on 12% or 20% protein diet. These results suggest that dietary protein content may predispose to the immunotoxic effects of DDT exposure, and also be a crucial determinant in DDT detoxification.

DNA polymorphism in Cab locus of tomato induced by tissue culture.

Plants were regenerated from callus induced from leaf disc explants of a tomato F1 hybrid heterozygous for three marker loci anthocyaninless (a), without anthocyanin (aw), and hairless (hl). Regenerants were studied for somaclonal variation at the phenotypic level by scoring for variation in the marker loci, and at the DNA level by probing geomic DNA blots with a chlorophyll a/b binding protein (Cab-3C) cDNA sequence. While no variation was observed at the phenotypic level in over 950 somaclones studied, DNA polymorphism for the Cab locus could be detected in two out of 17 somaclones tested. Tissue culture induced variation at the phenotypic level for specific loci is very low (less than 0.001 for a, aw or hl) but DNA sequence changes are induced at much greater frequency (approximately 0.1 for a multicopy gene family such as Cab).

Agrobacterium mediated genetic transformation of chickpea, Cicer arietinum L.

In leaf and stem explants of chickpea, wild type strains of Agrobacteria were able to induce tumors. These tumors were capable of phytohormone independent growth. A supervirulent strain A281 was found to be most effective. Thus, using an agrobacterium R1601, which carries genes conferring supervirulent phenotype along with a plant selectable marker gene (npt II), transformed calli of chickpea were selected in the presence of 100 micrograms/ml level of kanamycin. Molecular analyses of genomic DNA from transformed calli confirmed the integration of the marker gene into chickpea genome.

Circulating immune complexes and complement in bancroftian filariasis.

Sixty filarial cases, 30 endemic normal individuals and 10 non endemic subjects were investigated for the presence of Circulating Immune Complexes (CICs) and Complement Component C3. Using Polyethylene Glycol precipitation and Polyethylene Glycol precipitation-Complement Consumption methods, it was observed that CICs were raised significantly in chronic lymphatic filariasis and Tropical Pulmonary Eosinophilia (TPE) groups. The results observed by both the techniques for detection of CICs were comparable. Low levels of C3 were detected in chronic lymphatic filariasis cases by single radial immunodiffusion method, suggesting the utilization of complement by immune complexes.