Prevalence of goitre and iodine deficiency among school children (6-12 years) in rural areas of North Karnataka, India: A cross-sectional survey, 2016-19.

Introduction: Iodine deficiency disorders (IDD) have remained an unresolved public health problem in India. In this survey, we have estimated the prevalence of IDD among 6-12 years of school children in rural areas of north Karnataka, India and estimated the prevalence of low iodine content (<15 ppm) in salt at the household level and urine iodine excretion in this population. Material and Methods: In this cross-sectional survey, we recruited 16,827 children between 6 and 12 years of age through multistage sampling from six districts. Goitre was examined clinically for all children. Household-level salt iodine estimation and urinary iodine estimation were carried out among a subset of the participants. Results: Overall prevalence of goitre was 17.1% (95% CI: 16.5, 17.7). Out of this, 76.7% (n = 2116) had Grade-1 goitre, and 23.7% (n = 656) had Grade-2 goitre. The prevalence of goitre was higher among females (17.9%, vs. male 16.4%, P < 0.05). The prevalence of low iodine content (<15 ppm) in salt was 48.5% (95%CI: 46.7, 50.3). The overall median iodine excretion in urine was 85 µg/L (IQR: 60-150 µg/L). In total, 37.2% (n = 601) had mild iodine deficiency, 5.2% (n = 84) had moderate deficiency, and 10.1% (n = 163) had severe deficiency. All parameters showed high inter- and intradistrict variations. Conclusion: North Karnataka has a high goitre prevalence. Low use of iodized salt can be a major reason for the high prevalence of the condition. Ensuring the availability of iodized salt in this region and periodic surveillance to measure the impact of the programme should be the priority in this region.

Undernutrition among rural school-age children: a major public health challenge for an aspirational district in Karnataka, India.

Background: For school-age children, a healthy transition from childhood to adolescence and adulthood depends on proper nutrition. Globally, most nutritional surveys focus on preschool and adolescents, neglecting school-age children. Recent studies have shown the prevalence of thinness among adolescents to be 26.5% in Karnataka. Similarly, among children aged < 5 years in the Raichur district, the prevalence of stunting, wasting, and being underweight was 39.8, 23.2, and 40.7%, respectively. The present study aimed to bridge the data gap between < 5 years of children and adolescents through a nutritional survey of school-going children in Raichur, one of the aspirational districts of India. Materials and methods: A cross-sectional survey was conducted from January to March 2020 among rural school-age children (n = 2700) in 30 villages of the Raichur district of Karnataka, India. The school children were selected through a multi-stage cluster sampling technique. The WHO Anthro-plus software was used for calculating the age and sex-specific Z-scores for weight-for-age (WAZ), height-for-age (HAZ), and BMI-for-age (BAZ). Results: Of the 2,700 school-age children surveyed, the mean weight and height were 22.2 kg (+5.8) and 124.9 cm (+11.6), respectively. The prevalence of children having weight-for-age Z-scores < -2 SD (Underweight) was 45.3% (95% CI: 42.7%-47.8%). The magnitude of stunting and severe stunting was 19.5% (95% CI: 18.0%-21.0%) and 7.6% (95% CI: 6.6%-8.6%), respectively. The proportion of children with BMI for age Z-scores < -2SD (thinness) was 43% (95% CI: 41.1%-44.9%), with sub-district Sindhanur having a dual burden of malnutrition. Conclusion: Despite many flagship programs, the prevalence of undernutrition in school-age children remains a considerable public health problem in the aspirational district of Raichur, India. Furthermore, exploratory studies are recommended to identify the factors associated with undernutrition among school-age children and strategize evidence-based intervention.

A community-based study of dental fluorosis in rural children (6-12 years) from an aspirational district in Karnataka, India.

Objectives: The present study was planned to estimate the prevalence of dental fluorosis in 6-12 years of children and its association with various drinking water sources, water, and urine fluoride levels among the subset of children under the umbrella of a larger study to address iodine deficiency disorders and iron deficiency anemia in 17 villages of Manvi and Devadurga talukas of Raichur district of Karnataka. Methods: Analysis of subset of data and urine samples of children under the umbrella of a larger cross-sectional community-based study was conducted in 17 villages of Manvi and Devadurga taluks of Raichur district. House to house survey was carried out to collect data using a semi-structured questionnaire in ODK software. Demographic details, source of drinking water, clinical assessment of dental fluorosis, and height and weight measurements were performed by trained staff. Urine and water samples were collected for fluoride level estimation. The overall prevalence of dental fluorosis and its severity-wise prevalence were estimated. Association between dental fluorosis and age, gender, type of diet, source of drinking water, height for age, BMI for age, water fluoride level, and urine fluoride level were carried out using logistic regression analysis. Results: The prevalence of dental fluorosis was 46.0%. Mild, moderate, and severe dental fluorosis was found in 37.9, 7.8, and 0.3% of children. With the increasing age of participants, the odds of dental fluorosis were found to increase by 2-4 folds. The odds of having dental fluorosis were significantly increased with increasing water fluoride levels of 3 to 5 ppm [AOR = 3.147 (1.585-6.248); P = 0.001] in comparison with water fluoride levels of < 1 ppm. The similar trend was found with urine fluoride level > 4 ppm [AOR = 3.607 (1.861-6.990); P < 0.001]. As compared to river water, other sources of drinking water were significantly associated with higher odds of dental fluorosis. Conclusions: Prevalence of dental fluorosis was high in 6 to 12 years due to overexposure of fluoride from drinking water. High water and urine fluoride levels in children indicate the chronic exposure to fluoride and suggest that the population is at high risk of developing chronic fluorosis.

Cloning, Expression and Characterization of NAD Kinase from Staphylococcus aureus Involved in the Formation of NADP (H): A Key Molecule in the Maintaining of Redox Status and Biofilm Formation.

BACKGROUND: Staphylococcus aureus has the ability to form biofilms on any niches, a key pathogenic factor of this organism and this phenomenon is directly related to the concentration of NADPH. The formation of NADP is catalyzed by NAD kinase (NADK) and this gene of S. aureus ATCC 12600 was cloned, sequenced, expressed and characterized. MATERIALS AND METHODS: The NADK gene was polymerase chain reaction amplified from the chromosomal DNA of S. aureus ATCC 12600 and cloned in pQE 30 vector, sequenced and expressed in Escherichia coli DH5α. The pure protein was obtained by passing through nickel metal chelate agarose column. The enzyme kinetics of the enzyme and biofilm assay of the S. aureus was carried out in both aerobic and anaerobic conditions. The kinetics was further confirmed by the ability of the substrates to dock to the NADK structure. RESULTS: The recombinant NADK exhibited single band with a molecular weight of 31kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the gene sequence (GenBank: JN645814) revealed presence of only one kind of NADK in all S. aureus strains. The enzyme exhibited very high affinity for NAD compared to adenosine triphosphate concurring with the docking results. A root-mean-square deviation value 14.039Å observed when NADK structure was superimposed with its human counterpart suggesting very low homology. In anaerobic conditions, higher biofilm units were found with decreased NADK activity. CONCLUSION: The results of this study suggest increased NADPH concentration in S. aureus plays a vital role in the biofilm formation and survival of this pathogen in any environmental conditions.

Phosphorylation controls the functioning of Staphylococcus aureus isocitrate dehydrogenase--favours biofilm formation.

Isocitrate dehydrogenase (IDH) gene from Staphylococcus aureus ATCC12600 was cloned, sequenced and characterized (HM067707). PknB site was observed in the active site of IDH; thus, it was predicted as IDH may be regulated by phosphorylation. Therefore, in this study, PknB, alkaline phosphatase III (SAOV 2675) and IDH genes (JN695616, JN645811 and HM067707) of S. aureus ATCC12600 were over expressed from clones PV 1, UVPALP-3 and UVIDH 1. On passing the cytosloic fractions through nickel metal chelate column, pure enzymes were obtained. Phosphorylation of pure IDH by PknB resulted in the complete loss of activity and was restored upon dephosphorylation with SAOV 2675 which indicated that phosphorylation and dephosphorylation regulate IDH activity in S. aureus. Further, when S. aureus ATCC12600 was grown in BHI broth, decreased IDH activity and increased biofilm units were observed; therefore, this regulation of IDH alters redox status in this pathogen favouring biofilm formation.

In Staphylococcus aureus the regulation of pyruvate kinase activity by serine/threonine protein kinase favors biofilm formation.

Staphylococcus aureus, a natural inhabitant of nasopharyngeal tract, survives mainly as biofilms. Previously we have observed that S. aureus ATCC 12600 grown under anaerobic conditions exhibited high rate of biofilm formation and L-lactate dehydrogenase activity. Thus, the concentration of pyruvate plays a critical role in S. aureus, which is primarily catalyzed by pyruvate kinase (PK). Analyses of the PK gene sequence (JN645815) revealed presence of PknB site in PK gene indicating that phosphorylation may be influencing the functioning of PK. To establish this hypothesis the pure enzymes of S. aureus ATCC 12600 were obtained by expressing these genes in PK 1 and PV 1 (JN695616) clones and passing the cytosolic fractions through nickel metal chelate column. The molecular weights of pure recombinant PK and PknB are 63 and 73 kDa, respectively. The enzyme kinetics of pure PK showed K M of 0.69 ± 0.02 µM, while the K M of PknB for stpks (stpks = NLCNIPCSALLSSDITASVNCAK) substrate was 0.720 ± 0.08 mM and 0.380 ± 0.07 mM for autophosphorylation. The phosphorylated PK exhibited 40 % reduced activity (PK = 0.2 ± 0.015 µM NADH/min/ml to P-PK = 0.12 ± 0.01 µM NADH/min/ml). Elevated synthesis of pyruvate kinase was observed in S. aureus ATCC 12600 grown in anaerobic conditions suggesting that the formed pyruvate is more utilized in the synthesis phase, supporting increased rate of biofilm formation.

Cloning, expression and characterization of NADP-dependent isocitrate dehydrogenase from Staphylococcus aureus.

The Krebs cycle dictates oxidative and reductive conditions in Staphylococcus aureus and is mainly regulated by isocitrate dehydrogenase (IDH) which plays pivotal role in the growth and pathogenesis of the bacteria. In the present study, IDH gene from S. aureus ATCC12600 was cloned in the Sma I site of pQE 30 vector; the resultant clone was named as UVIDH1. The insert in the clone was sequenced (accession number HM067707), and the sequence showed complete homology with IDH sequence of other S. aureus strains reported in the database indicating presence of single enzyme in S. aureus, and considerable sequence homology with other bacteria was observed; however, only 24% homology was found with NADP-dependent human IDH. Phylogenetically, the S. aureus IDH showed close identity with Bacillus subtilis and high degree of variability with other bacteria and human IDH. The expression of IDH in the clone UVIDH1 was induced with 1 mM IPTG, and the recombinant IDH was purified by passing through nickel metal chelate column; the purified recombinant IDH showed a single band in SDS-PAGE with a molecular weight of 40 kDa; K(m) and V(max) for isocitrate are 8.2 ± 0.28 and 525 ± 25 µM NADPH/mg/min, respectively, and for cofactor NADP 67.5 ± 2.82 µM and V(max) 50.5 ± 2.12 µM NADPH/mg/min.