Deciphering the role of polyphenol in defence mechanism against tea mosquito bug (Helopeltis theivora Waterhouse.) in cocoa (Theobroma cocoa L.).

Tea mosquito bug (TMB) is a serious pest of cocoa whose prevalence is high, mostly during summer and post monsoon season. Three species of tea mosquito bug have been reported on cocoa: Helopeltis antonii Signoret, H. theivora Waterhouse, and H. bradyi Waterhouse. H. theivora is the most prevalent one causing damage to young shoots, cherelles and pods. Rearing of tea mosquito bug on cocoa was found to be a failure in the present study hence Helopeltis theivora Waterhouse was maintained on the alternate host mile-a-minute (Mikania micrantha Kunth) under laboratory condition in insect rearing cages. Using freshly reared tea mosquito bugs twenty cocoa hybrids were screened for resistance and were ranked after 72 hours of screening. All the hybrids having less than three lesions per plant in seedlings and less than 33 lesions on pods were ranked as highly resistant. It was observed that hybrids classified as highly resistant had significantly higher phenol content than those classified as susceptible. The significantly low phenol content in the susceptible hybrids suggests that phenolics have a function in mediating resistance to tea mosquito bug in cocoa. From correlation and regression analysis it is confirmed that phenol content can be used as a potential marker indicating the level of resistance of cocoa hybrids against tea mosquito bug resistance.

Molecular analysis of aroma gene (BADH2) in Biriyanicheera: a tropical aromatic rice genotype from Kerala, India.

BACKGROUND: The aromatic rice cultivars sometimes show variation in aroma when they are grown in regions other than their normal traditional growing regions. An early maturing selection from a Kerala aromatic local landrace with short grains, named 'Biriyanicheera', when grown in normal tropical conditions was sufficiently fragrant. The present study focused on the analysis of aroma in 'Biriyanicheera' rice genotype through molecular methods. METHODS AND RESULTS: The seeds of two aromatic rice varieties viz., Biriyanicheera and Gandhakasala (aromatic check) along with one non-aromatic rice variety Triveni (control) were used for the study. The BADH2 gene was amplified in all the three rice varieties. Upon sequencing the amplified PCR products of genomic DNA, the mutation in BADH2 gene was detected. The sequencing results of aromatic rice varieties revealed the presence of 8 base pair mutation in exon 7 in Biriyanicheera and Gandhakasaala, whereas this mutation was absent in the non-aromatic variety Triveni. CONCLUSIONS: Aroma production in Biriyanicheera variety is observed to be due to the similar mutation in BADH2 gene as that of the popular scented rice Basmati.

In vitro bactericidal activity of levonadifloxacin (WCK 771) against methicillin- and quinolone-resistant Staphylococcus aureus biofilms.

PURPOSE: Staphylococcus aureus causes a wide range of infections, such as endocarditis, pneumonia, osteomyelitis, skin and soft tissue infections, and implant/in-dwelling device-related infections. S. aureus poses a significant challenge to clinicians because of its ability to rapidly acquire multi-drug resistance and quickly progress into a recurrent, chronic infection by biofilm formation. Levonadifloxacin (WCK 771) is a novel broad-spectrum antibacterial agent (it recently completed a phase 3 trial in India) with a differentiated mechanism of action involving high affinity to staphylococcal DNA gyrase, and is active against multi-drug-resistant (MDR) S. aureus, including those that are resistant to quinolones. The present study investigated the bactericidal activity of levonadifloxacin against biofilm-embedded S. aureus clinical isolates in comparison with other anti-S. aureus drugs. METHODOLOGY: The bactericidal activity of levonadifloxacin and comparator drugs such as vancomycin, linezolid and daptomycin was evaluated against planktonic and biofilm-encapsulated recent methicillin- and quinolone-resistant S. aureus clinical isolates using time-kill, biofilm eradication and scanning electron microscopy analysis. RESULTS: Levonadifloxacin displayed a consistent ≥90 % bacterial kill rate against biofilm-embedded organisms, while vancomycin and linezolid displayed variable activity and daptomycin did not show any activity. Scanning electron microscopy images further confirmed the efficacy of levonadifloxacin against biofilm, showing the disruption of biofilm structure and a corresponding reduction in the viable bacterial count. CONCLUSION: These results show that levonadifloxacin has an improved bactericidal effect on biofilm-embedded quinolone-resistant S. aureus and meticillin-resistant S. aureus, and that it can be a promising treatment option for such infections.

Azithromycin in Combination with Ceftriaxone Reduces Systemic Inflammation and Provides Survival Benefit in a Murine Model of Polymicrobial Sepsis.

Sepsis is a life-threatening systemic inflammatory condition triggered as a result of an excessive host immune response to infection. In the past, immunomodulators have demonstrated a protective effect in sepsis. Azithromycin (a macrolide antibiotic) has immunomodulatory activity and was therefore evaluated in combination with ceftriaxone in a clinically relevant murine model of sepsis induced by cecal ligation and puncture (CLP). First, mice underwent CLP and 3 h later were administered the vehicle or a subprotective dose of ceftriaxone (100 mg/kg of body weight subcutaneously) alone or in combination with an immunomodulatory dose of azithromycin (100 mg/kg intraperitoneally). Survival was monitored for 5 days. In order to assess the immunomodulatory activity, parameters such as plasma and lung cytokine (interleukin-6 [IL-6], IL-1ß, tumor necrosis factor alpha) concentrations, the plasma glutathione (GSH) concentration, plasma and lung myeloperoxidase (MPO) concentrations, body temperature, blood glucose concentration, and total white blood cell count, along with the bacterial load in blood, peritoneal lavage fluid, and lung homogenate, were measured 18 h after CLP challenge. Azithromycin in the presence of ceftriaxone significantly improved the survival of CLP-challenged mice. Further, the combination attenuated the elevated levels of inflammatory cytokines and MPO in plasma and lung tissue and increased the body temperature and blood glucose and GSH concentrations, which were otherwise markedly decreased in CLP-challenged mice. Ceftriaxone produced a significant reduction in the bacterial load, while coadministration of azithromycin did not produce a further reduction. Therefore, the survival benefit offered by azithromycin was due to immunomodulation and not its antibacterial action. The findings of this study indicate that azithromycin, in conjunction with appropriate antibacterial agents, could provide clinical benefits in sepsis.