Kalimuthusamy Natarajaseenivasan

Optimization and production of a biosurfactant from the sponge-associated marine fungus Aspergillus ustus MSF3

Marine endosymbiotic fungi Aspergillus ustus (MSF3) which produce high yield of biosurfactant was isolated from the marine sponge Fasciospongia cavernosa collected from the peninsular coast of India. Maximum production of biosurfactant was obtained in Sabouraud dextrose broth. The optimized bioprocess conditions for the maximum production was pH 7.0, temperature 20 degrees C, salt concentration 3%, glucose and yeast extract as carbon source and nitrogen sources respectively. The response surface methodology based analysis of carbon and nitrogen ratio revealed that the carbon source can increase the biosurfactant yield. The biosurfactant produced by MSF3 was partially characterized as glycolipoprotein based on the estimation of macromolecules and TLC analysis. The partially purified biosurfactant showed broad spectrum of antimicrobial activity. The strain MSF3 can be used for the microbially enhanced oil recovery process.

Antimicrobial activity of seaweeds extracts against multiresistant pathogens

Fourteen seaweeds collected from the intertidal zone of Southwest coast of India were tested against ten human pathogen bacteria and one human pathogen fungus using the well diffusion test in the casitone agar medium. The species used in the present study include five Chlorophyta (Bryopsis plumosa, Ulva fasciata, Acrosiphonia orientalis, Chaetomorpha antennina, Grateloupia filicina), five Rhodophyta (Hypnea pannosa, Gracilaria corticata, Centroceras clavulatum, Portieria hornemannii, Cheilosporum spectabile) and four Phaeophyta (Padina tetrastromatica, Sargassum wightii, Stocheospermum marginatum, Chnoospora bicanaliculata). Of these, seven species were determined to be highly bioactive and screened on the multiresistant pathogens. We found that drying process has eliminated the active principles in the seaweeds. In the present study, methanol:toluene (3∶1) was found to be the best solvent for extracting the antimicrobial principles from fresh algae. However, the ethanolic extract showed no antibacterial activity.Acrosiphonia orientalis showed activity against 70% of the tested organisms.Stocheospermum marginatum was the only seaweed that showed activity againstKlebsiella pneumoniae. The extract fromGracilaria corticata was highly active againstProteus mirabilis, a Gram negative pathogenic bacterium. The present findings revealed that the tested seaweeds were highly active against Gram negative bacteria than Gram positive bacteria. The antimicrobial principle from seaweed was found to be a lipophilic compound. The compound was stable over a wide range of temperature (30–60 °C). The active principles of highly active seaweedsAcrosiphonia orientalis andStocheospermum marginatum were bactericidal.

Prevalence and risk factors of HPV infection among women from various provinces of the world

ObjectiveWe set to estimate the genotype-specific prevalence of human papilloma virus (HPV) and its associated risk factors responsible among women with normal and abnormal cytology by systematic literature survey.MethodsReports on HPV prevalence published between 2000 and 2011 were retrieved. To be included, studies required information on cervical cytology, plus detailed descriptions of study populations, methods used to collect cervical samples, and assays used for HPV DNA detection and typing. Final analyses included 280 studies of which 120 were included in the final analysis. The OR, 95% CI and P value were calculated using SPSS 16.0.ResultsOverall HPV prevalence in 576,281 women was estimated to be 32.1% (95% CI 32.098, 32.102). Corresponding estimates by region showed Eastern Asia (China) with the highest prevalence of about 57.7% of the HPV infection followed by South Central Asia (Indian subcontinent). The HPV prevalence was higher in less developed countries (42.2%) than in more developed regions (22.6%). The type-specific HPV prevalence study showed HPV 16 (9.5%) and 18 (6.2%) to be the prevalent type irrespective of the region of study. First coitus at a younger (≤15) age, increased number of pregnancies, increased number of sexual partners, use of contraceptives, smoking and chewing habit and early age at marriage were recognized as the significant risk factors for HPV infection. The phylogenetic analysis of HPV-16 showed the clustering of Indian sequence with the European and American sequences suggesting a similarity between HPV types. Even though the oncogenic proteins of HPV-16 detected in more developed and less developed regions clustered, the prevalence and the severity of the diseases among the less developed regions could be well explained as the exposure of the population to the possible associated risk factors concerning to the living conditions and nature of the life style adopted by the population.

Viral and bacterial aetiologies of epithelial ovarian cancer

We sought to analyse the presence of human papillomavirus (HPV), Chlamydia trachomatis and cytomegalovirus (CMV) infection in women with epithelial ovarian carcinomas. Polymerase chain reaction (PCR)-based detection of microbial infections was carried out. A total of 39 tissue samples were analysed with consensus and type-specific primers for HPV, primers specific for the cryptic plasmid of Chlamydia and primers for glycoprotein B of CMV. The samples analysed showed 40%, 80% and 50% positivity for HPV, Chlamydia and CMV infection, respectively, in cancerous ovarian tissues. The HPV type detected was HPV 6, with its genome integrated to the host genome in case of both invasive and borderline tumours and existed episomally in healthy controls. The patients with Chlamydia (odds ratio [OR] 32; 95% confidence interval [CI] 3.33, 307.65) and CMV infection (OR 8; 95% CI 0.888, 72.10) are at significantly higher risk of development of ovarian tumours. The present study validates the theory of chronic infections and inflammation in the pathogenesis of epithelial ovarian cancer. Further seroepidemiological studies and large fresh tissue sampling may represent the real prevalence of infections among ovarian carcinoma patients. This study is the first of its kind in detecting the bacterial and viral aetiologies in the development of ovarian carcinoma among Indian women.

Serodiagnosis of severe leptospirosis: evaluation of ELISA based on the recombinant OmpL1 or LipL41 antigens of Leptospira interrogans serovar autumnalis.

Abstract ELISA based on the recombinant OmpL1 and LipL41 antigens of Leptospira interrogans serovar autumnalis strain N2 have been developed, for the serodiagnosis of the severe pulmonary form of leptospirosis on the endemic Andaman Islands. The recombinant OmpL1 and LipL41 were produced using Escherichia coli expression systems and then purified before each was evaluated in an IgM-ELISA. The sera tested came from 224 patients who had the severe form of leptospirosis and pulmonary pneumonitis as major symptoms, 148 patients who, although clinically suspected to have severe leptospirosis, had been found seronegative for leptospirosis, 528 patients with diseases other than lepstospirosis, and 704 apparently healthy individuals, all from the Andaman Islands. Among the patients with the severe pulmonary form of leptospirosis, the ELISA based on the recombinant OmpL1 achieved a sensitivity of 91.1%, a specificity of 86.5%, a positive predictive value of 91.1%, and a negative predictive value of 86.5%. The corresponding values for the assay based on the recombinant LipL41 were 89.3%, 89.2%, 92.6%, and 84.6%, respectively. The good performance of both ELISA indicates that either may be routinely used for the diagnosis of severe pulmonary leptospirosis which, at least on the Andaman Islands, occurs soon after the patient has become leptospiraemic. The evaluated ELISA may also be useful for early case detection and for monitoring the effects of treatment.

BRCA1 and BRCA2 Mutations in the Ovarian Cancer Population across Race and Ethnicity: Special Reference to Asia

Objective: To evaluate the prevalence and spectrum of BRCA mutations among ovarian carcinoma patients of different races and ethnicity with special reference to Asia. Methods: A systematic review of the literature was undertaken to evaluate the prevalence of BRCA mutations among people belonging to different races. The electronic search strategy was developed specifically for the different databases concerned and via cross-referencing. Results: The frequency of BRCA1 and BRCA2 mutations ranged from 1.1 to 39.7 and from 0 to 13.9, respectively. BRCA1 mutations are more common among ovarian cancer cases than BRCA2 mutations, although the ratio of BRCA1 to BRCA2 varies between populations. The Swedish and Indian populations showed 12 and 7 times as many BRCA1 as BRCA2 mutations, respectively, whilst in a study from Iceland the ratio was 0.5:1. These wide-ranging estimates of the mutation prevalence suggest genetic heterogeneity between different populations. Conclusion: The ability to identify BRCA1/2 mutations was found to be successful in the clinical management of ovarian cancer. Given the implications for clinical care and for advances in cancer prevention, identifying racial difference in genetic or lifestyle factors, which may modify the cancer risk due to BRCA1/2 mutations, is a high priority for future research.

Pathogenic, diagnostic and vaccine potential of leptospiral outer membrane proteins (OMPs)

Abstract Pathogenic Leptospira species are important human and animal pathogen that causes leptospirosis, with more than half a million cases reported annually but little is known regarding the true incidence of leptospirosis due to the limitations in diagnosis. Proteins embedded in the outer membrane are found to be prime drug targets due to its key role as receptors for cellular communication and gatekeepers for iron and substrate transport across cell membranes. The major key issues to be addressed to overcome the disease burden of leptospirosis are: need to identify the genes that turn on in vivo; development of rapid diagnostic methods to facilitate the early diagnosis and to develop a universal vaccine. Recent whole genome sequencing of Leptospira species and development of in silico analysis tools have led to the identification of a large number of leptospiral virulence genes, metabolic pathways and surface protein secretion systems that represent potential new targets for the development of anti-leptospiral drug, vaccine and diagnostic strategies. This review surveys the different types of outer membrane proteins (OMPs) of Leptospira and combines all the novel features of OMPs reported till date and put forth some views for future research.

Antimicrobial potential of a marine seaweedAsparagopsis taxiformis againstLeptospira javanica isolates of rodent reservoirs

In this present investigation pharmacologically active compounds were isolated from red algae (Asparagopsis taxiformis) and their efficacy was evaluated against theLeptospira javanica isolates of rodent carriers. The GC-MS analysis of the purified compound revealed the presence of 4,5-dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester (56.012%), fattyacids, 14-methyl-pentadecanoic acid methyl ester (26.6%), octadecanoic acid methyl ester (8.46%), octadec-9-enoic acid 2,3-dihydroxy-propyl ester (4.11%), 9-octadecanoic acid, methyl ester (4.535%) and trace amount of chlorobenzene (0.09%). MICs and MBCs of the purified compound against pathogenic leptospiral strains belonging to 14 serovars and 11 isolates belonging to serovarjavanica ofLeptospira borgpetersenii were determined in a range of 100–1600 μg/ml. The antibiotics penicillin and doxycycline were used as the standards for the efficiency determination of the seaweed extract against the leptospiral reference serovars and isolates. The minimal inhibitory concentration of penicillin and doxycyline were in the range of 25–200 μg/ml. The seaweed active fraction exhibited comparable MIC and MBC values with that of the standard antibiotic doxycycline. In the present study the seaweed compound has been developed to apply for the 2nd nodal point of transmission cycle, the environment. Thus the present study draws the development of a novel drug to treat leptospires particularly in environments augmented with rodent carriers.

Prevalence of high-risk HPV and associated risk factors in cases of cervical carcinoma in Tamil Nadu, India

To assess the prevalence of HPV infection among women with cervical cancer in Tiruchirapalli, Tamil Nadu, India.

Detection of LipL32-specific IgM by ELISA in sera of patients with a clinical diagnosis of leptospirosis.

Abstract Successful treatment of leptospirosis is heavily dependent on early diagnosis and prompt initiation of antibiotic therapy. An ELISA test to detect specific IgM antibodies against LipL32 for early diagnosis of leptospirosis is described and evaluated here. One thousand one hundred and eighty sera from clinically suspected leptospirosis cases were enrolled together with 109 healthy volunteers selected from an endemic area between October 2007 and January 2010. Patients were categorized based on their clinical signs and symptoms. Sera were screened for leptospiral antibodies by the microscopic agglutination test (MAT) using a panel of locally circulating serovars followed by enzyme-linked immunosorbent assay (ELISA) based on recombinant LipL32 from Leptospira interrogans serovar Autumnalis strain N2. The sensitivity and specificity of the ELISA test were determined to establish its diagnostic efficiency. The cut-off value was determined to be 0·205. Overall sensitivity and specificity compared to the MAT were found to be 96·4 and 90·4%, respectively. The LipL32-specific IgM ELISA had good sensitivity and acceptable specificity and may be a candidate for the early serodiagnosis of human leptospirosis.