Dynamics of the occurrence of influenza in relation to seasonal variation in Chennai, Tamil Nadu: A 7 -year cumulative study

Background: Influenza viruses have emerged as virulent pathogens causing considerable burden across the world. A thorough understanding of the pattern in occurrence of influenza globally is the need of hour. The present study deals with analysis of the dynamics of Influenza virus, especially the influence of seasonal change on viral circulation and causation of epidemics/pandemics in the context of subtropical region. Methods: During the 7 year (2009–2015) study, 36670 specimens were subjected to influenza analysis. Nasopharyngeal swabs collected from suspected patients from Chennai, Tamil Nadu, were tested and typed by real-time polymerase chain reaction assay. Results: During 2009 pandemic, among influenza A positives 95.16% were Apdm09, indicating that there was a predominant circulation of Apdm09. During postpandemic period, there were waves in the occurrence of Apdm09 which indicates fall in immunity with buildup in the susceptible population. Conclusion: In Chennai, Tamil Nadu, influenza positivity started with the onset of monsoon and peaks during the postmonsoon months throughout the study period. The assessment of meteorological factors compounding influenza activity can help in raising alerts to the public health officials of impending disaster which suggests that Influenza vaccination can be initiated before monsoon months in South India.

Prevalence of Dermatophytosis in patients in a tertiary care centre in and around Cuddalore district

Background: The common cause of skin infections are dermatophytes and opportunistic fungi. Aim of this study was to isolate and identify the fungal agents from clinical samples from patients with different mycoses. Superficial mycoses are among the most frequent forms of human infections, affecting more than 20–25% of the world’ population. They are predominantly caused by a group of closely related keratinophilic mycelia fungi (dermato-phytes) in the genera of Trichophyton, Microsporum, and Epidermophyton. These groups of fungi invade the stratum corneum of the skin or other keratinized tissues derived from the epidermis such as hair and nails. Aim and objectives: The present work aims at evaluation of rate of incidences of dermatophytic infections (group wise), and etiological agents with associated symptoms. In addition, we also determine to test the sensitivity of present diagnostic procedures. Materials and methods: Samples were collected from 100 patients. A portion of each sample was examined microscopically and the remaining portion of each sample was cultured onto plates of Sabouraud’s dextrose agar containing chloramphenicol with and without cycloheximide. Dermatophyte isolates were identified by studying macroscopic and microscopic characteristics of their colonies .Preliminary identification was done by conventional methods and confirmed by Polymerase Chain Reaction – Restriction Fragment length Polymorphism (PCR -RFLP) technique. Results: All over 62/100 specimens were KOH positive and 48/62 (82.7%) samples were culture positive. Of these, highest isolation rate was obtained in opportunistic mycoses such as candidiasis (29/29, 100%). Dermatophytes were isolated in 41/62 (66.3%) specimens and Trichophyton rubrum was the commonest isolate in skin samples (44/62) among the patients suffering from dermatophytosis. Phaeoannellomyces Wernicke was isolated in a patient suffering from tinea nigra. P. Gunasekaran. Prevalence of Dermatophytosis in patients in a tertiary care centre in and around Cuddalore district. IAIM, 2017; 4(8): 91-95. Page 92 The study signifies the importance of mycological examination in the diagnosis of various mycoses for their effective management. Conclusion: Dermatophytoses are distributed worldwide with increased incidence especially in a tropical country like India. Several factors such as age, sex, illiteracy, poor hygiene and social economy influence the dermatophyte infection. In the present study we have attempted to understand the epidemological status of the dermatophytes in a tertiary care centre in Cuddalore, Tamil Nadu, India. Tinea corporis was the predominant clinical site from which dermatophytes were isolated. T. Rubrum and T. Mentagrophytes have been the major etiological agents and that has been evinced by our study.

Assessment of major microorganisms involved in diabetic foot infection which delays wound healing

Background: India has the largest diabetic population of 50.8 million that could reach an epidemic proportion by 2030. Diabetic foot infection is one of the dreaded complications of diabetes. Only a few studies that focus on patterns of diabetic foot infection in our region, where diabetic foot care is inadequate. This study evaluated microbial and clinical characteristics of diabetic foot infections that will be helpful in taking appropriate measures for their management. Aim and objectives: This study was undertaken to evaluate the clinical and the microbial characteristic of diabetic foot infection in patients. The ulcers were graded and swab samples were collected under aseptic condition. Materials and methods: In this prospective study conducted during 2016-2017, Totally 100 diabetic foot patients underwent detailed history, clinical examination, and laboratory investigations including parameters of systemic infections. Microbial culture and sensitivity were performed at the time of presentation. Results: Among 100 cases, 27 (43.5%) had mono-microbial infection, 22 (35.5%) had poly-microbial infection, and 13 (21%) had sterile culture. Altogether 82 bacteria were isolated from 49 cases. Among 82 bacterial isolates, 56 (68.3%) were Gram negative while 26 (31.7%) were Gram-positive bacteria. Escherichia coli was the most common pathogen isolated followed by Staphylococcus aureus. Conclusion: Gram-negative bacteria were most prevalent in diabetic foot infection. It is not uncommon to have culture reports negative despite clinical evidence of infection. This study suggests that piperacillin/ tazobactam should be the treatment of choice on an empirical basis prior to a definitive bacteriological study and in cases with negative culture reports.

Characterization and biological activities of extracellular melanin produced by Schizophyllum commune (Fries).

Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment was characterized by biochemical tests and further, confirmed by UV, IR, EPR, NMR and MALDI-TOF Mass Spectra. Extracellular melanin, at 100 µg/ml, showed significant antibacterial activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas fluorescens and antifungal activity against Trichophyton simii and T. rubrum. At a concentration of 50 µg/ml, melanin showed high free radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl) indicating its antioxidant potential. It showed concentration dependent inhibition of cell proliferation of Human Epidermoid Larynx Carcinoma Cell Line (HEP-2). This study has demonstrated characterization of melanin from basidiomycetes mushroom fungus, Schizophyllum commune and its applications.

Genetic analysis of HA gene of pandemic H1N1 2009 influenza viruses circulating in India.

The H1N1 2009 influenza pandemic took the health care workers by surprise in spite of warning about influenza pandemic. Influenza A virus has the ability to overcome immunity from previous infections through the acquisition of genetic changes by shift or drift. Thus, understanding the evolution of the viruses in human is important for the surveillance and the selection of vaccine strains. A total of 23 pandemic A/H1N1 2009 viral HA gene sequences were downloaded from NCBI submitted during March and May 2010 by NIV and were analysed. Along with that the vaccine strain A/California/07/2009 was also downloaded from NCBI. All the sequences were used to analyse the evolution of the haemagglutinin (HA) by phylogenetic analysis. The HA gene could be divided into four groups with shift from 1 to lV revealing that the HA genes of the influenza A viruses evolved in a sequential way, in comparison to vaccine strain A/California/07/2009. Amino acid sequence analysis of the HA genes of the A/H1N1 2009 isolates, revealed mutations at positions 100, 220 and additional mutations in different positions 114, 171, 179, 190, 208, 219, 222, 239, 240, 247, 251, 260 and 285 .The mutations identified showed the adaptation of the new virus to the host that could lead to genetic changes inherent to the virus resulting in a reassortant which could be catastrophic, hence continuous monitoring of strains is mandatory.

A Unique Human Rotavirus (non vaccine) G9P4 Genotype Infection in a Child with Gastroenteritis.

Group A Rotaviruses with serotypes G1-G4 and G9 are the common Rotavirus types of clinical importance. This study aimed at determining the different Rotavirus genotypes in stool sample of children below 5 years. A total of 300 children with acute gastroenteritis were tested for group specific VP6 antigen of group A Rotaviruses by Enzyme Linked Immunosorbent Assay. 47 of these samples were positive for Rotavirus antigen. Out of these, 20 positive samples were subjected to Reverse Transcriptase Polymerase Chain Reaction for genotyping. The identified genotypes were G9P8, G1P8, G2P4, G9P4 (non-vaccine genotype), G1P6, and G1 (P types not identified in 5 samples).

Development of a new method for diagnosis of Group B Coxsackie genome by reverse transcription loop-mediated isothermal amplification.

Background: Coxsackie B viruses (genus, Enterovirus; family, Picornaviridae) can cause aseptic meningitis, encephalitis, pleurodynia, and fatal myocarditis, and are implicated in the pathogenesis of dilated cardiomyopathy. The differentiation of the group B Coxsackieviruses into their subtypes has potential clinical and epidemiological implications. Objective: In this study, we developed a one-step, single-tube genogroup-specific reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of group B Coxsackie genomes targeting 5′ UTR region. Materials and Methods: The amplification can be obtained in less than 1 hour by incubating all the reagents in a single tube with reverse transcriptase and Bst DNA polymerase at 63°C. Detection of gene amplification could be accomplished by agarose gel electrophoresis and the monitoring of gene amplification can also be visualised with the naked eye by using SYBR green I fluorescent dye. Results: A total of 40 samples comprising 31 positive samples and 9 negative samples were used in this study for comparative evaluation. The results were compared with those from Real-Time Polymerase Chain Reaction (RT-PCR). None of the RT-PCR-positive samples were missed by RT-LAMP, thereby indicating a higher sensitivity of the RT-LAMP assay. Conclusion: Thus, due to easy operation without a requirement of sophisticated equipment and skilled personnel, the RT-LAMP assay reported here is extremely rapid, cost-effective, highly sensitive, and specific and has potential usefulness for rapid detection of non-polio enterovirus (NPEV) not only by well-equipped laboratories but also by peripheral diagnostic laboratories with limited financial resources in developing countries.

Dengue disease status in Chennai (2006-2008): A retrospective analysis.

Background & objectives: Dengue is one of the most important Arboviral diseases in man with outbreaks in Southeast Asia and India. We report a retrospective analysis of the dengue positivity in the referred samples for three years period (2006 to 2008) at the Department of Virology, King Institute of Preventive Medicine, Chennai, Tamil Nadu, India. Methods: Serum samples from 1593 suspected cases (968 male and 625 female) were obtained. Of the 1593 cases screened, 1204 (75.5%) were paediatric cases and 389 (24.4%) adults. The samples were subjected to MAC ELISA and IgG ELISA. Results: Of the 968 patients, 686 (43.0%) were positive, of which 579 (84.0%) were in the paediatric age group (<14 yr) and 107 (15.5%) were adults. The IgM positivity being 356 (36.7%) in males and 330 (52.8%) in females. Of the 686 positives, 113 (16.47%) were positive for both IgM and IgG denoting secondary infection. There was a noticeable increased occurrence during the cooler months and during the monsoon and post-monsoon months. Interpretation & conclusions: The dengue IgM seropositivity among the suspected cases indicates active dengue virus activity. Increase in the probable secondary infections especially in a country like ours where multiple serotypes are prevalent raises concern over probable increase in the incidence of the more serious DHF/DSS. Studies need to be done to identify circulating serotypes of dengue virus to design preventive strategies.

Toxicity assessment and microbial degradation of azo dyes.

Toxic effluents containing azo dyes are discharged from various industries and they adversely affect water resources, soil fertility, aquatic organisms and ecosystem integrity. They pose toxicity (lethal effect, genotoxicity, mutagenicity and carcinogenicity) to aquatic organisms (fish, algae, bacteria, etc.) as well as animals. They are not readily degradable under natural conditions and are typically not removed from waste water by conventional waste water treatment systems. Benzidine based dyes have long been recognized as a human urinary bladder carcinogen and tumorigenic in a variety of laboratory animals. Several microorganisms have been found to decolourize, transform and even to completely mineralize azo dyes. A mixed culture of two Pseudomonas strains efficiently degraded mixture of 3-chlorobenzoate (3-CBA) and phenol/cresols. Azoreductases of different microorganisms are useful for the development of biodegradation systems as they catalyze reductive cleavage of azo groups (-N=N-) under mild conditions. In this review, toxic impacts of dyeing factory effluents on plants, fishes, and environment, and plausible bioremediation strategies for removal of azo dyes have been discussed.

Improvement of xylanase production in solid state fermentation by alkali-tolerant Aspergillus fumigatus MKU1 using a fractional factorial design.

Optimization of media for the maximum production of xylanase by Aspergillus fumigatus MKUI was carried out using De Meo's fractional factorial design with seven components such as NaNO3, K2HPO4, MgSO4, FeSO4. KCl, peptone and yeast extract. A. fumigatus produced a maximum of 700 U/gds of enzyme after 48 hr of incubation (before optimization). After two steps of optimization, the medium designed favoured a 2.8 fold (1950 U/gds) increase in xylanase production by A. fumigatus. Optimized medium for Aspergillus fumigatus contained (g/l) NaNO3, 15; K2HPO4, 15; MgSO4, 5; FeSO4, 0.009; KCI, 0.5; peptone, 20; and yeast extract, 10.

Influenza activity among the paediatric age group in Chennai.

BACKGROUND & OBJECTIVE: Respiratory viral infections have a major impact on public health. Acute respiratory infections largely caused by viruses, are the most common illnesses experienced by otherwise healthy adults and children. Among the respiratory viruses, influenza viruses are known to cause outbreaks globally. Information on the activity of influenza virus in our country is limited and none from Chennai. The present study was carried out to isolate and identify the influenza virus serotypes causing acute respiratory infection in children attending a tertiary care centre at Chennai. METHODS: During January to December 2002, 240 children with acute respiratory infection attending the out patient clinic of Institute of Child Health were included by convenient sampling. Throat swabs were collected from 4 to 5 cases every week. Isolation of influenza virus was attempted by inoculating the sample in Madin Darby Canine Kidney (MDCK) cell line. The isolates were typed by haemagglutination inhibition test and confirmed by immunoflourescence assay. RESULTS: Virus isolation was positive in 30 (12.5%) of the 240 samples. Influenza A/H3N2/Panama/ 2000/99 was the predominant serotype isolated accounting for 24 (80%) of the 30 isolates. Influenza B/Sichuan/379/99 was isolated in 4 (13.33%) and a combination of Influenza A/H3N2 and B/Sichuan in 2 (6.6%) of the isolates. INTERPRETATION & CONCLUSION: Isolation of influenza A and B viruses indicated a significant activity of these viruses in Chennai. Peak activity was observed during and after the first spell of rain. The predominance of A/H3N2/ Panama is an indication that the Indian scenario is similar to the global picture of influenza activity.

Biodiversity of rice (Oryza sativa L.) and sugarcane (Saccharum officinarum L.) rhizosphere pseudomonads.

Fluorescent pseudomonads were isolated from the rhizosphere of rice and sugarcane and examined for their biodiversity. All fifty strains of the fluorescent pseudomonads produced indole acetic acid. Among these pseudomonads, halves of sugarcane rhizosphere isolates and one isolate from the rice rhizosphere exhibited phosphate solubilization activity. On the contrary, majority of the rice rhizosphere pseudomonads, and one isolate from sugarcane rhizosphere exhibited antifungal activity. These fluorescent pseudomonads were further classified based on their growth and biochemical characteristics. Those isolates that had same biochemical characteristics were distinguished by random amplification of polymorphic DNA (RAPD). These biochemical and molecular biological methods clearly differentiated fluorescent Pseudomonads of rice and sugarcane rhizosphere.

Microbes in heavy metal remediation.

Heavy metal contamination due to natural and anthropogenic sources is a global environmental concern. Release of heavy metal without proper treatment poses a significant threat to public health because of its persistence, biomagnification and accumulation in food chain. Non-biodegradability and sludge production are the two major constraints of metal treatment. Microbial metal bioremediation is an efficient strategy due to its low cost, high efficiency and ecofriendly nature. Recent advances have been made in understanding metal--microbe interaction and their application for metal accumulation/detoxification. This article summarizes the potentials of microbes in metal remediation.

Biodegradation of benzidine based azodyes Direct red and Direct blue by the immobilized cells of Pseudomonas fluorescens D41.

Benzidine based azodyes are proven carcinogens, mutagens and have been linked to bladder cancer of human beings and laboratory animals. The textile and dyestuff manufacturing industry are the two major sources that released azodyes in their effluents. The dye, Direct blue contains two carcinogenic compounds namely benzidine (BZ), 4-amino biphenyl (4-ABP), while the dye Direct red has benzidine (BZ). Among 40 isolates of Pseudomonas fluorescens screened, one isolate designated as D41 was found to be capable of extensively degrading the dyes Direct blue and Direct red. Immobilized cells of P. fluorescens D41 efficiently degraded Direct red (82%) and Direct blue (71%) in the presence of glucose.

Induction and accumulation of phytoalexins in cowpea roots infected with a mycorrhizal fungus Glomus fasciculatum and their resistance to Fusarium wilt disease.

The interaction of a vesicular-arbuscular mycorrhizal fungus Glomus fasciculatum with a wilt-causing soil borne pathogen, Fusarium oxysporum, was studied in cowpea (Vigna unguiculata). It was found that pre-establishment by vesicular-arbuscular mycorrhizal fungus reduced the colonization of the pathogen and the severity of the disease, as determined by reduction in vascular discolouration index. In mycorrhizal plants, the production of phytoalexin compounds was always higher than in the nonmycorrhizal plants. There appeared to be a direct correlation between the concentration of the phytoalexins and the degree of mycorrhizal association. Three different compounds with Rf values of 0·23 (I), 0·17 (II) and 0·11 (III) were obtained from mycorrhizal plants. Similar compounds were also found to be induced by an abiotic elicitor CuSO4. The first compound was identified as an isoflavonoid, daidzein and the other two remain to be identified. These compounds were checked for their antifungal activity in vitro. The germination of conidial spores of Fusarium oxysporum was strongly inhibited by the compound III than the other two. It is argued that the production of phytoalexin compounds in mycorrhizal plant could be one of the mechanisms imparting tolerance of the plants to wilt disease.

Mechanism of action of carboxin and the development of resistance in yeast.

Carboxin prevents the growth of yeast by inhibiting protein synthesis; the resumption of growth in the presence of this chemical appears to be primarily due to a cellular alteration affecting carboxin entry into the cells.