Fine-tuning the transcriptional regulatory model of adaptation response to phosphate stress in maize (Zea mays L.).

The post green revolution agriculture is based on generous application of fertilizers and high-yielding genotypes that are suited for such high input regimes. Cereals, like maize (Zea mays L.) are capable of utilizing less than 20% of the applied inorganic phosphate (Pi) - a non-renewable fertilizer resource. A greater understanding of the molecular mechanisms underlying the acquisition, transportation and utilization of Pi may lead to engineering genotypes with high phosphorus use efficiency. In this study, we carried out functional domain similarity analysis, promoter analysis and comparative transcriptional expression profiling of 12 selected Pi responsive genes in the Pi stress tolerant maize inbred line HKI-163 under sufficient and deficient Pi conditions. Pi starvation led to significant increase in root length; marked proliferation of root hairs and lesser number of crown roots. Eleven genes were significantly up or down regulated in Pi deficient condition. The putative acid phosphatase, ZmACP5 expression was up regulated by 162.81 and 74.40 fold in root and leaf tissues, respectively. The RNase, ZmRNS1 showed 115 fold up regulation in roots under Pi deprivation. Among the two putative high affinity Pi transporters ZmPht1;4 was found specific to root, whereas ZmPht2 was found to be up regulated in both root and leaf tissues. The genes involved in Pi homeostasis pathway (ZmSIZ1, SPX1 and Pho2) were up regulated in root and leaf. In light of the expression profiling of selected regulatory genes, an updated model of transcriptional regulation under Pi starvation in maize has been presented. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01155-x.

Insights into maize genome editing via CRISPR/Cas9.

Maize is an important crop for billions of people as food, feed, and industrial raw material. It is a prime driver of the global agricultural economy as well as the livelihoods of millions of farmers. Genetic interventions, such as breeding, hybridization and transgenesis have led to increased productivity of this crop in the last 100 years. The technique of genome editing is the latest advancement in genetics. Genome editing can be used for targeted deletions, additions, and corrections in the genome, all aimed at genetic enhancement of crops. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated protein 9 (CRISPR/Cas9) system is a recent genome editing technique that is considered simple, precise, robust and the most revolutionary. This review summarizes the current state of the art and predicts future directions in the use of the CRISPR/Cas9 tool in maize crop improvement.

Serum Zinc Levels as a Predictor of Severity of Acute Diarrhea.

OBJECTIVE: To determine relationship between serum zinc levels and severity of diarrhea as determined by hydration status, duration of diarrhea and requirement for hospitalization. Also, to compare serum zinc levels in relation to rotavirus status. METHODS: A prospective observational study which included 254 children aged 6 mo to 5 y with diarrhea was conducted. RESULTS: Serum zinc levels could be estimated in 198 children. Median (IQR) serum zinc levels of study population were 73.5 (59.11-92.86)µg/dl. Median (IQR) of serum zinc levels in children with dehydration and without dehydration were 69.64 (54.57-81.62) and 82.86 (64.1-103.48) µg/dl respectively (p < 0.001). Median (IQR) of serum zinc levels in hospitalised and non-hospitalished children were 63.28 (51.81-85.37) and 74.86 (61.75-95.78) µg/dl, respectively (p 0.013). Median (IQR) of total duration of diarrhea was 4.8 (3.5-6.0) d and it did not correlate with serum zinc levels. Median (IQR) of serum zinc levels in children, with rotavirus diarrhea was 66.8 (49.7-82.48) and non-rotavirus diarrhea was 80.0 (62.42-100.12) µg/dl (p < 0.001). CONCLUSIONS: Children with dehydration and those with rotavirus diarrhea tend to have significantly lower serum zinc levels. Hospitalized children also have lower serum zinc levels than non-hospitalized children. Duration of diarrhea does not relate with serum zinc levels.

Randomized controlled trial of topical EMLA and vapocoolant spray for reducing pain during wDPT vaccination.

BACKGROUND: Intramuscular vaccination is among the most common source of iatrogenic pain in infants. Vapocoolant sprays are rapid-acting alternative to topical anesthetics. They provide transient anesthesia via evaporation induced skin cooling, and reduce pain due to vaccine injection in children and adults. The objective was to compare the synergistic analgesic effect of eutectic mixture of local anesthetics (EMLA) with breastfeeding (EB group) and vapocoolant spay with breastfeeding (VB group) to that of only breastfeeding (BO group) during whole cell diptheria, pertussis and tetanus (wDPT) vaccination. METHODS: A double blind randomized controlled trial was done to include infants up to 3 months of age who came for their first wDPT vaccination. The primary outcome variable was the duration of cry after vaccination. Secondary outcome variables were Modified Facial Coding Score, Neonatal Infant Pain Scale and latency of onset of cry. RESULTS: Of the 201 eligible participants, 111 babies were excluded and remaining 90 babies were randomized into three groups of thirty each. The groups did not differ significantly in baseline characteristics. Median (interquartile range, IQR) of duration of cry was lesser [35.86 (21.07-107.75) seconds] in babies receiving EMLA cream with breast feeding (EB group) and in babies receiving vapocoolant spray with breast feeding (VB group) [32.58 (21.25-106.21) seconds] as compared to babies receiving only breast feeding (BO group) [67.5 (27.6-180) seconds] (P=0.147). Difference in median (IQR) of latency of cry was not statistically significant. Modified Facial Coding Score and Neonatal Infant Pain Scale at 1 minute and 3 minutes was significantly lower in the EB and VB group, as compared to the BO group (P<0.05). CONCLUSION: Addition of topical EMLA application or vapocoolant spray to breastfeeding during wDPT vaccination does not reduce duration of cry in infants up to 3 months of age. However, they are able to show reduction in pain score and further studies are warranted to assess their efficacy as pain relief measures in infants and children.

Lactobacillus GG for treatment of acute childhood diarrhoea: an open labelled, randomized controlled trial.

BACKGROUND & OBJECTIVES: Randomized controlled trials in developed countries have reported benefits of Lactobacillus GG (LGG) in the treatment of acute watery diarrhoea, but there is paucity of such data from India. The study was aimed to evaluate the efficacy and safety of Lactobacillus GG in the treatment of acute diarrhoea in children from a semi-urban city in north India. METHODS: In this open labelled, randomized controlled trial 2000 children with acute watery diarrhoea, aged between 6 months to 5 years visiting outpatient department and emergency room of a teaching hospital in north India were enrolled. The children were randomized into receiving either Lactobacillus GG in dose of 10 billion cfu/day for five days or no probiotic medication in addition to standard WHO management of diarrhoea. Primary outcomes were duration of diarrhoea and time to change in consistency of stools. RESULTS: Median (inter quartile range) duration of diarrhoea was significantly shorter in children in LGG group [60 (54-72) h vs. 78 (72-90) h; P<0.001]. Also, there was faster improvement in stool consistency in children receiving Lactobacillus GG than control group [36 (30-36) h vs. 42 (36-48) h; P<0.001]. There was significant reduction in average number of stools per day in LGG group (P<0.001) compared to the control group. These benefits were seen irrespective of rotavirus positivity in stool tests. INTERPRETATION & CONCLUSIONS: Our results showed that the use of Lactobacillus GG in children with acute diarrhoea resulted in shorter duration and faster improvement in stool consistency as compared to the control group.

Glucose & sodium chloride induced biofilm production & ica operon in clinical isolates of staphylococci.

BACKGROUND & OBJECTIVES: All colonizing and invasive staphylococcal isolates may not produce biofilm but may turn biofilm producers in certain situations due to change in environmental factors. This study was done to test the hypothesis that non biofilm producing clinical staphylococci isolates turn biofilm producers in presence of sodium chloride (isotonic) and high concentration of glucose, irrespective of presence or absence of ica operon. METHODS: Clinical isolates of 100 invasive, 50 colonizing and 50 commensal staphylococci were tested for biofilm production by microtiter plate method in different culture media (trypticase soy broth alone or supplemented with 0.9% NaCl/ 5 or 10% glucose). All isolates were tested for the presence of ica ADBC genes by PCR. RESULTS: Biofilm production significantly increased in the presence of glucose and saline, most, when both glucose and saline were used together. All the ica positive staphylococcal isolates and some ica negative isolates turned biofilm producer in at least one of the tested culture conditions. Those remained biofilm negative in different culture conditions were all ica negative. INTERPRETATION & CONCLUSIONS: The present results showed that the use of glucose or NaCl or combination of both enhanced biofilm producing capacity of staphylococcal isolates irrespective of presence or absence of ica operon.

Randomized controlled trial of topical EMLA and breastfeeding for reducing pain during wDPT vaccination.

UNLABELLED: The primary objective was to evaluate the analgesic effect of a eutectic mixture of local anesthetics (EMLA) during whole cell DPT vaccination. The secondary objective was to evaluate if the analgesic effect of EMLA was synergistic to breastfeeding. A randomized, placebo-controlled trial was done to include infants of up to 3 months of age who came for their first DPT vaccination. The outcome variables were duration of cry, latency of onset of cry, and Modified Facial Coding Score. Thirty babies were enrolled in each of three groups. The groups did not differ significantly in baseline characteristics. Median (interquartile range) of duration of cry was least [34.6 (24.1-72.2) s] in babies receiving EMLA cream with breastfeeding (EB group), followed by 94.2 (46.1-180) s in babies receiving EMLA cream with oral distilled water (EW group), as compared to 180.0 (180-180) s in babies receiving placebo cream with oral distilled water (PCW group) (p < 0.05). Mean (SD) of latency of cry was significantly greater in EB group [2.4 (1.14) s] and EW group [1.9 (0.62) s] as compared to babies in PCW group [1.5 (0.47) s] (p < 0.05), but the difference between EB and EW groups was not significant. Modified Facial Coding Score was significantly lower in EB group as compared to the other groups (p < 0.05). CONCLUSIONS: Topical EMLA is effective in reducing pain and has a synergistic effect in analgesia when combined with breastfeeding during vaccination in infants.

Intravenous device associated blood stream staphylococcal infection in paediatric patients.

BACKGROUND & OBJECTIVES: Intravenous device (IVD) associated nosocomial blood stream infections due to staphylococci are major cause of morbidity and mortality. The present study was carried out to assess the frequency of staphylococcal IVD associated infections in a paediatric ward of a tertiary case hospital. Prevalence of resistance to commonly used antimicrobials in hospital acquired staphylococcal isolates was also tested. METHODS: Children admitted in paediatric wards with IVD for more than 48 h were enrolled. Blood, IVD tip at the time of removal, skin swab at the site of insertion of IVD and nasal swab were collected and cultured by standard protocol. All staphylococcal isolates from any source were analyzed for antimicrobial susceptibility by disk diffusion method. Genotyping matching of those staphylococcal isolates was done which were isolated from different sites of the same patient, but were phonotypically similar. Genotype of blood isolate was compared with genotype of isolate from nose/IVD/skin. RESULTS: Staphylococcus aureus was the most frequent blood isolate (8.7%) followed by Candida (2.9%), coagulase negative staphylococci (CoNS 2.6%), Pseudomonas spp. (0.4%), Klebsiella spp. (0.3%) and Escherichia coli (0.1%). Isolation of microorganisms from blood was significantly higher in patients whose skin, IVD and nose were colonized by same microorganism (P<0.001). None of the staphylococcal isolate was found to be resistant to glycopeptides (vancomycin and teicoplanin). High penicillin and oxacillin resistance was present in both S. aureus (penicillin resistance; 76.8%, oxacillin resistance; 66.7%) and CoNS (penicillin resistance; 73.3%, oxacillin resistance; 60.0%). Among CoNS biotypes, S. haemolyticus was commonest blood isolate while S. epidermidis was commonest isolate from Skin/nose. Only 33.3 per cent of S. aureus blood stream infections and most of S. epidermidis and S. haemolyticus blood infections were IVD associated. INTERPRETATION & CONCLUSIONS: Staphylococci were the major causative agent of nosocomial blood stream infections. All episodes of septicaemia due to S. epidermidis and S. haemolyticus were IVD associated while only 1/3 of S. aureus septicaemia was IVD associated.

Effect of green tea extract (catechins) in reducing oxidative stress seen in patients of pulmonary tuberculosis on DOTS Cat I regimen.

BACKGROUND AND AIM: The role played by free radicals in pathogenesis of pulmonary tuberculosis and treatment mediated toxicity is well established. Hence, the present study was undertaken to assess the effect of crude green tea catechin in reducing the oxidative stress seen in patients of AFB positive pulmonary tuberculosis. METHODS: A total of 200 newly diagnosed cases of AFB positive pulmonary tuberculosis, who received CAT I regimen were enrolled consecutively from DOTS center. Out of 200 patients, 100 randomly selected patients received catechin (500 microg) with antitubercular treatment (ATT) (cases) and 100 received starch (500 microg) with ATT (control). Oxidative stress level in blood samples of cases and controls as compared at the time of enrollment and after one and four months of treatment. Oxidative stress was measured in terms of free radicals (lipid peroxidation, nitric oxide), enzymatic antioxidant (catalase, superoxide dismutase, glutathione peroxidase) and non enzymatic antioxidant (total thiol, reduced glutathione) levels. RESULTS: The results showed significant difference in all the parameters among cases and controls. A significant decrease (p< or = 0.001) in LPO level was observed in cases as compare to controls during the follow up while the level of NO was significantly increased (p< or =0.001) in cases as compare to controls. Significant decrease (p< or =0.001) in catalase and GPx level was observed in cases as compare to controls while SOD levels significantly rose (p< or =0.001) in cases as compared to controls. Significant decrease (p< or =0.001) in SH level was observed in cases as compared to controls while the level of GSH was significantly increased (p< or =0.001) . CONCLUSION: These findings suggest that crude catechin extract can play a definite role as adjuvant therapy in management of oxidative stress seen in pulmonary tuberculosis patients. More detailed studies are needed to document use of catechin in reducing the frequency and severity of side effects of treatment.

Medical significance and management of staphylococcal biofilm.

Biofilm is one of the important virulence factors of staphylococci that plays a role in many device-related infections such as native valve endocarditis, otitis media, urinary tract infections, cystic fibrosis, acute septic arthritis, etc. Biofilm is a microbially derived sessile community of microorganisms, developed either from single or multiple microorganisms. Formation of biofilm is a two-step process: adherence of cells to a surface and accumulation of cells to form multilayered cell clusters. A trademark of biofilm formation in staphylococci is the production of polysaccharide intercellular adhesin. In the formation and regulation of biofilm, some biosynthetic genes (icaADBC) and some regulatory genes (icaR, sar, agr, rbf, sigma(B)) are involved. In this article, we reviewed the structure and formation of staphylococcal biofilm and its role in medical infections.

Biofilm production, a marker of pathogenic potential of colonizing and commensal staphylococci.

Biofilm is one of the known virulence factors of staphylococci, a human and animal pathogen and commensal. Some of the strains become invasive under favorable conditions while others do not cause disease. Early detection and management of potentially pathogenic staphylococci is the essential step to prevent device-associated infections. There is also a need to evaluate one simple method for the detection of potential pathogens. Hence this study was planned to study the difference in potential of commensal, colonizing and invasive strains of staphylococci to produce biofilm. We used one qualitative (Congo red agar) and one quantitative (microtiter plate) method for detection of biofilm production and evaluated the sensitivity and specificity of Congo red agar method by using microtiter plate method as a gold standard. We consecutively enrolled staphylococcal strains isolated from peripheral intravenous device (IVD), venous blood, site of IVD insertion and nasal mucosa of patients admitted to pediatric ward with peripheral intravenous devices in place for more than 48 h. Total 100 invasive, 50 colonizing and 50 commensal isolates were studied. Of 100 invasive isolates 74% (74/100) were biofilm positive while only 68% (34/50) colonizing and 32% (16/50) commensal isolates were biofilm positive. The difference in biofilm production by commensal, colonizing and invasive strains was statistically significant (p<0.0001). Sensitivity and specificity of Congo red agar test for detection of biofilm producers were 90.63% and 90.79% for Staphylococcus aureus and 75.86% and 96.88% respectively for coagulase negative staphylococci. CRA is a method that could be used to determine whether an isolate has the potential for biofilm production or not.

Cefoxitin disc diffusion test for detection of meticillin-resistant staphylococci.

Staphylococci are the main causative agents of nosocomial diseases. Over the last few years, the increase in the number of meticillin-resistant (MR) staphylococci has become a major clinical problem. Accuracy and promptness in the detection of meticillin resistance are of key importance in ensuring the correct antibiotic treatment in infected patients and control of MR staphylococci in the hospital environment. This study evaluated the accuracy of a cefoxitin disc diffusion (DD) test for the detection of meticillin resistance in staphylococci. A total of 144 clinical isolates [97 Staphylococcus aureus and 47 coagulase-negative staphylococci (CoNS)] were tested using a mecA gene PCR, a DD test (oxacillin, 1 mug disc; cefoxitin, 30 mug disc), determination of oxacillin MIC by agar dilution (AD), and an oxacillin screen agar test at oxacillin concentrations of 4 and 6 mug ml(-1). Of the 97 S. aureus and 47 CoNS isolates, 73 (75.26 %) and 30 (63.83 %), respectively, were mecA-positive. The sensitivity and specificity of the cefoxitin DD test were 94.44 and 95.83 %, respectively, for S. aureus and 80 and 100 %, respectively, for CoNS. The oxacillin DD method was 100 % sensitive and 58.33 % specific for S. aureus, and 86.67 % sensitive and 70.59 % specific for CoNS. The AD test was highly sensitive (98.63 %) and specific (98.53 %) for S. aureus and CoNS (83.33 % sensitive and 94.12 % specific). The cefoxitin DD test for meticillin-resistance detection was more specific but less sensitive than the oxacillin DD test. Use of DD tests for both cefoxitin and oxacillin can help in more accurate prediction of meticillin resistance. Centres that are not equipped to carry out PCR can use AD methods for confirmation of meticillin resistance, especially in oxacillin-resistant and cefoxitin-sensitive cases.