Distribution of microplastics in seafloor sediments and their differential assimilation in nearshore benthic molluscs along the south-west coast of India.

Spatial and temporal distribution of microplastics (MPs) in the nearshore seafloor sediments along the Southwest coast of India and their patterns of accumulation in selected infaunal and epibenthic molluscs with diverse feeding strategies were investigated. Along the 300-km coastal stretch, which is one of the most productive and biodiversity rich regions of the eastern Arabian Sea, notable levels of MP contamination in both sediment (617.7 items/kg dry weight) and molluscs (5.39 items/g) was recorded. The concentration of MPs in sediments also varied seasonally, with a higher prevalence during the post-monsoon season. Among the four molluscan groups studied, the highest MP abundance was recorded among scavenging gastropod Pseudominolia biangulosa (9.13 items/g), followed by microcarnivore scaphopod Tesseracme quadrapicalis (5.96 items/g). In comparison, the suspension feeding bivalve, Anadara hankeyana and deposit feeding clam Jitlada philippinarum had lesser accumulation of MPs (2.98 items/g and 3.50 items/g respectively). The majority of MPs in sediments and within molluscs were less than 250 µm in size (89.14%) and were predominantly fibres and fragments. Chemical characterisation of MPs revealed eleven types of polymers dominated by polyethylene (PE) and polypropylene (PP). Present study identified positive correlations between ingested MP polymers and the feeding strategies of molluscs. Higher values for the ecological risk assessment indices (PHI, PLI and PERI) in most of the stations indicated the severity of plastic pollution in the region. Molluscs being a major contributor to the benthic food web is also a connecting link to higher trophic levels. Hence understanding the specificity in the MPs accumulation pattern within this group has far reaching significance in utilizing them as potential bioindicators for pollution studies in marine ecosystems.

Spatio-temporal evaluation and risk assessment of microplastics in nearshore surface waters post-2018 Kerala deluge along the southwest coast of India.

Spatial and temporal distribution of microplastics along the nearshore surface waters of Kerala after the floods of 2018 was studied. Results indicated a seven-fold increase in its mean concentration (7.14 ± 3.03 items/m3) post deluge. The average abundance was highest during pre-monsoon (8.27 ± 3.09 items/m3). Fibres were the dominant group, with blue and black being the most prevalent colours. Polyethylene and polypropylene were the most commonly found polymers, possibly gaining entry through sewage waste or land-based plastic litter. Highest abundance of microplastic was recorded off Kochi categorising it at Hazard Level I under Pollution Load Index assessment. Similarly high levels of Pollution Hazard Index and Potential Ecological Risk Index were also reported due to the presence of hazardous polymers PVC and PU that can cause concern to marine life. The differential weathering pattern and surface morphology analysis suggested microplastics to be relatively old that had undergone substantial mechanical and oxidative weathering.

Microplastic pollution of Calicut beach - Contributing factors and possible impacts.

Annual monitoring was carried out in the shoreline sediments of the Calicut beach, from 2016 to 2019 to understand the distribution and abundance of microplastics and its environmental implications. Further, the impact of the severe fluvial floods of Kerala during the August months of 2018 and 2019, on the microplastic pollution of the Calicut beach was also determined. Microplastic concentrations ranged between 80.56 items/kg of dry sand to 467.13 items/kg of dry sand during the sampling period. Polyethylene type was consistently higher in all the samples. There was a surge in microplastics concentration during both the floods with a higher proportion of low-retention-period microplastics. Among the different oceanographic parameters, it was found that significant wave height and surface wind speed are positively correlated to the number of the microplastics in Calicut beach.

Occupational exposure to particulate matter during blackboard teaching and its deposition in the airways of human lungs.

PURPOSE: This study aims to estimate the teachers' exposure to particulate matter (PM) during a chalk and talk class considering various exposure conditions and to determine the deposition pattern of PM in human airways. MATERIALS AND METHODOLOGY: The study was carried out in three steps, viz., questionnaire survey, exposure measurement, and dosage calculation. Exposure to chalk dust during teaching was measured for 40 teachers in terms of PM of different size range (PM 10, PM 2.5, and PM 1) while using different brands of chalks. Deposition in lungs was determined using Multiple Path Dosimetry model for four subject categories, viz., adult men, elderly men, adult women, and elderly women. RESULTS: The average exposure during teaching activity was 498, 85, and 30 µg/m3 of PM 10, PM 2.5, and PM 1, respectively. Chalks which are made of calcium carbonate with high density of packing emitted lesser PM 10. Results showed no significant difference in the exposure to PM by teachers while writing at different relative heights of the board. The highest total deposition of PM in lung was observed for elderly women. The deposited mass per unit area was the highest for adult women in all the three sizes of PM. CONCLUSION: This study showed that there was no significant difference in exposure to PM while using normal and dustless chalks. The exposure level suggests that there is a strong need to either shift to smart classes or to improve the technology in chalk production in such a way that it produces less dust and limit the exposure to teaching professionals.

Liability allocation in pollution involving multiple responsible parties.

World over, the instances where polluters are made to pay for the damages they have caused to the environment are on the rise. If more than one party is found responsible for pollution, our analyses of statutes of different countries, covering more than 57% of the world population and more than 45% of its land area, showed that liability is to be allocated among the involved parties on an equitable basis, often decided by the courts. Analyses of a number of court cases showed that the factors considered for allocation in such cases may be classified into two, technical and non-technical. It was also found that the legal liability of pollution was different from the technical liability in many cases due to the influence of non-technical factors that were very specific to the case. These non-technical factors often do not fall under the investigation purview of an environmental forensic expert who carries out technical investigations to find the responsible parties. Based on the analysis, it is suggested that the liability allocation be a two-stage process; the first stage being technical liability allocation done by the forensic expert and the second stage the final (legal) allocation by the court. It is also suggested that clear guidelines be prepared for technical liability allocation. There was also a felt need to quantify remediability to make the remediation liability allocation easier.

Effective reuse of waste material as an amendment in composite landfill liner: Assessment of geotechnical properties and pollutant retention capacity.

The effective reuse silica fume (S), a by-product from the silicon manufacturing industry, as an amendment in the composite landfill liner along with natural clay (C) and bentonite (B) was investigated in the present study. Experiments were conducted with various proportions of silica fume (10%-50%) to clay and bentonite to get mixtures C-B-S1 to C-B-S5. The study indicated significant improvement in the geotechnical and pollutant retention capacity by silica fume addition. The maximum dry density of the mixtures ranged from 1.568 to 1.732 g cm-3. Permeability was in the order of C-B

Analysis of benzene air quality standards, monitoring methods and concentrations in indoor and outdoor environment.

Benzene is a proven carcinogen. Its synergistic action with other pollutants can damage different components of the biosphere. Literature comparing the air quality standards of benzene, its monitoring methods and global concentrations are sparse. This study compiles the worldwide available air quality standards for benzene and highlights the importance of strict and uniform standards all over the world. It was found that out of the 193 United Nation member states, only 53 countries, including the European Union member states, have ambient air quality standard for benzene. Even where standards were available, in most cases, they were not protective of public health. An extensive literature review was conducted to compile the available monitoring and analysis methods for benzene, and found that the most preferred method, i.e, analyzing by Gas Chromatography and Mass spectroscopy is not cost effective and not suitable for real-time continuous monitoring. The study compared the concentrations of benzene in the indoor and outdoor air reported from different countries. Though the higher concentrations of benzene noticed in the survey were mostly from Asian countries, both in the case of indoor and outdoor air, the concentrations were not statistically different across the various continents. Based on the analyzed data, the average benzene level in the ambient air of Asian countries (371 µg/m3) was approximately 3.5 times higher than the indoor benzene levels (111 µg/m3). Similarly, the outdoor to the indoor ratio of benzene level in European and North American Countries were found to be 1.2 and 7.7, respectively. This compilation will help the policymakers to include/revise the standards for benzene in future air quality guideline amendments.

Cryptococcal Postinfectious Inflammatory Response Syndrome in an Immunocompetent Host.

Cryptococcal-postinfectious inflammatory response syndrome (c-PIIRS) in an immunocompetent host is a rare entity. Unlike cryptococcal-immune reconstitution inflammatory syndrome, in c-PIIRS, macrophage clearance defect can be persistent, and the patient requires prolonged immunosuppressants to control inflammation. Early identification and treatment can reduce the mortality and morbidity in cryptococcal meningitis (CM). Here, we describe c-PIIRS in an apparently healthy individual who developed CM and treated with effective antifungal regimen. After initial improvement, the patient showed clinical and radiological worsening, which could be likely due to PIIRS. The patient was responded to prolonged steroids.

Photocatalytic-oxidation and photo-persulfate-oxidation of sulfadiazine in a laboratory-scale reactor: Analysis of catalyst support, oxidant dosage, removal-rate and degradation pathway.

The extent of sulfadiazine (SDZ) removal via photo-degradation (UV-C), photocatalysis with TiO2 (UV-C/TiO2) and photo-persulfate-oxidation (UV-C/PS) was investigated in a batch reactor under different UV-C power levels (i.e. 14, 28, 42 and 56 W). Moreover, effects of suspended/immobilized catalyst, i.e. TiO2 slurry/TiO2 supported on granular activated carbon (GAC-TiO2), on SDZ removal and corresponding SDZ degradation kinetics under different catalyst loading (1-6 g/L) were explored. Around 41.7% SDZ removal was observed after 120 min in UV-C system at the highest power level, i.e. 56 W. On the other hand, photocatalysis with TiO2 and GAC-TiO2 has shown better SDZ removal than photo-degradation. In UV-C/TiO2 (4 g/L and 28 W) and UV-C/GAC-TiO2 (5 g/L and 28 W) systems, SDZ removals were 91.8% after 120 min and 100% after 60 min, respectively; however, TOC analysis has revealed that 45.4% and 60.8% SDZ was mineralized in these systems, respectively. In UV-C/PS system, near complete degradation of SDZ (99.8%) was observed within 10 min under 50 mg/L of PS and 28 W UV illumination. On the other hand, complete SDZ removal was observed in PS alone system at a dosage of 1000 mg/L but the formation of SO42- was found to be a drawback. In photolysis and photocatalysis systems, SDZ removal followed pseudo-first-order kinetics whereas the kinetics followed pseudo-second-order in UV-C/PS system. The comparison of electrical energy consumed (EEO) in different systems revealed that UV-C/GAC-TiO2 and UV-C/PS system were energy efficient compared with other systems. The LC-MS analysis has confirmed the cleavage of C-N bonds in the pyrimidine ring followed by S-N bonds in the sulfonyl group, which was found to be the major degradation pathway of SDZ.

Investigation into a community outbreak of Salmonella Typhi in Bengaluru, India.

BACKGROUND & OBJECTIVES: Outbreaks of infection due to Salmonella enterica servovar Typhi (S. Typhi) are a great threat to public health. A rapid molecular typing method to characterize strains implicated in an outbreak is critical in implementing appropriate control measures. This study was done to demonstrate the power of a PCR-based method to provide rapid insights into the genetic relatedness amongst the Salmonella isolates implicated in a suspected typhoid fever outbreak. METHODS: Forty two S. Typhi isolates originating from three geographically distinct areas, with one area suspected to have a single-source outbreak were included in the study. The genetic fingerprint of all isolates was generated using enterobacterial repetitive intergenic consensus sequence based-PCR (ERIC-PCR). The antimicrobial susceptibility profiles were also evaluated. RESULTS: ERIC-PCR was found to be rapid and reproducible with a discriminatory index of 0.766. The dendrogram constructed based on ERIC-PCR fingerprinting revealed the existence of 12 distinct genotypes. The location suspected to have an outbreak displayed two genotypes amongst the 24 isolates. The other two locations (18 isolates) displayed genetic heterogeneity. The clonality of the outbreak isolates from the time-matched control isolates was established. The observed antimicrobial susceptibility profiles did not have any discriminatory power to subtype the isolates compared to the genetic fingerprints. INTERPRETATION & CONCLUSIONS: Our study demonstrated the discriminatory power and value of ERIC-PCR in the typing of S. Typhi isolates and providing valuable epidemiological insights.

Discriminatory power of three typing techniques in determining relatedness of nosocomial Klebsiella pneumoniae isolates from a tertiary hospital in India.

PURPOSE: The purpose of this study was to evaluate the discriminatory power of two DNA-based technique and a protein-based technique for the typing of nosocomial isolates of Klebsiella pneumoniae. A second objective was to determine the antimicrobial susceptibility pattern and characterise the presence of genes encoding extended-spectrum beta-lactamases (ESBLs) and carbapenemases. MATERIALS AND METHODS: Forty-six K. pneumoniae isolates from patients with bloodstream infections at a tertiary care hospital in India between December 2014 and December 2015 were studied. All isolates were typed using enterobacterial repetitive intergenic consensus sequence-polymerase chain reaction (ERIC-PCR), randomly amplified polymorphic DNA (RAPD) analysis and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry. Antimicrobial susceptibility profiles and ESBLs were detected using the BD Phoenix system. The types of ESBL and carbapenemase genes present were detected using PCR. RESULTS: Isolates were subtyped into 31, 30 and 33 distinct genotypes by ERIC-PCR, RAPD and MALDI-TOF, respectively. Several isolates displaying identical DNA fingerprints were binned into different branches based on their proteomic fingerprint. Antimicrobial susceptibility tests revealed that 33/46 strains were multidrug resistant (MDR); a majority of the strains (83%) were sensitive to colistin. PCR-based analysis demonstrated 19 strains to harbour two or more ESBL and carbapenemase genes. CONCLUSION: ERIC-PCR was the most reproducible method for typing K. pneumoniae isolates and could not be substituted by MALDI-TOF for clonality analysis. A high degree of genetic diversity and the presence of MDR genes highlight the challenges in treating K. pneumoniae-associated infections.

A novel diterpene skeleton: identification of a highly aromatic, cytotoxic and antioxidant 5-methyl-10-demethyl-abietane-type diterpene from Premna serratifolia.

Premna serratifolia Linn. (syn: . P. corymbosa (Burm. f.) Merr., P. integrifolia L. and P. obtusifolia R. Br.) is a member of the Verbenaceae family that is extensively used in the Ayurvedic system of medicine in India. As part of our continuous pharmacological and phytochemical studies on medicinal plants, we have screened the methanolic extracts of leaves, root bark (RB) and root wood of P. serratifolia for cytotoxic activity against two cancer cell lines: SHSY-5Y neuroblastoma and B16 melanoma cells. The RB extract that showed promising activity was fractionated using solvents of increasing polarity followed by a combination of Sephadex LH-20 column and Combiflash chromatography as well as HPLC to afford the active principle. Comprehensive spectroscopic analysis including 1D and 2D NMR (COSY, HMQC, HMBC, NOESY) and MS analysis revealed the identity of the isolated compound as 11,12,16-trihydroxy-2-oxo-5-methyl-10-demethyl-abieta-1[10],6,8,11,13-pentene that appears to be a novel compound based on a new diterpene skeleton. The cytotoxic activity of the isolated compound was 21 and 23 times higher than the crude extract against the SHSY-5Y and B16 cells, respectively. The novel compound also possesses in vitro antioxidant effects as evidenced by the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging effect where an IC50 value of 20.4 ± 1.3 µM was obtained. In comparison, the positive control, caffeic acid, showed an IC50 value of 14.4 ± 1.6 µM.

The antidiabetic therapeutic potential of dietary polyphenols.

Type-2 diabetes (T2D) is a complex metabolic syndrome that is characterized by persistent hyperglycemia due to either lack of insulin secretion and/or insulin resistance. The prevalence of T2D along with its major risk factor, obesity, has been increasing with an epidemic proportion in recent years. To date, there is no drug of cure for diabetes and the existing therapeutic approaches have serious drawbacks including side effects and loss of efficacy during prolonged use. Dietary polyphenols are one group of natural products that have shown promise as potential antidiabetic agents. In this review, their molecular mechanisms of action including, antioxidant, anti-inflammatory, receptor agonist/antagonist effect and modulation of key signal transduction cascades, glucose transport, enzyme activity, receptor agonistic/antagonist effect, etc. in major insulin-sensitive cells are discussed.

An unusual presentation of pulmonary cryptococcosis with co-existing disseminated tuberculosis in an AIDS patient.

Although cryptococcosis with lung involvement is not rare in patients with HIV, it is rarely considered in the differential diagnosis of an abnormal chest roentgenogram. Pulmonary cryptococcosis with concomitant opportunistic infections is frequently seen among AIDS and its association with tuberculosis (TB) has been previously reported. Untreated pulmonary cryptococcosis in immunocompromised hosts usually becomes disseminated and results in considerable mortality despite antifungal therapy. We report a case of cryptococcosis with pulmonary involvement in a patient with coexisting disseminated TB in HIV infection.

Secondary syphilis mimicking cutaneous lymphoma.

Atypical features of secondary syphilis are more common in patients with human immunodeficiency virus infection. We report this case in which the clinical features, serology and response to therapy were clearly suggestive of secondary syphilis but histopathology raised concerns about cutaneous lymphoma. A 30-year-old male presented with history of fever and cough of one month duration. He was seropositive for human immunodeficiency virus infection one year back. He had discrete multiple papular and papulonodular patches all over the body. VDRL and TPHA tests were positive. HIV infection was confirmed by two ELISA tests. Skin biopsy report raised the possibility of lymphomatous infiltration. He was treated with penicillin and responded favourably. He was also instituted antiretroviral therapy later.

Role of PCR for diagnosing Pneumocystis jirovecii pneumonia in HIV-infected individuals in a tertiary care hospital in India.

OBJECTIVES: In developing countries like India, the diagnosis of Pneumocystis jirovecii infection is often made either by conventional staining or clinically. This study was planned to know the utility of polymerase chain reaction (PCR) in diagnosing Pneumocystis jirovecii pneumonia (PJP) in human immunodeficiency virus (HIV)-infected patients, to compare the PCR results with that of staining techniques and also to correlate the results with clinical condition of patients. MATERIALS AND METHODS: A prospective study included 50 HIV-infected adult in-patients with symptoms of lower respiratory tract infection. Induced sputum, bronchoalveolar lavage or tracheal aspirate were proceeded for both staining and PCR for mitochondrial large subunit rRNA gene of P. jirovecii. RESULTS: In our study PCR results correlated with staining findings in 14% (7/50) of cases. Another 20% (10/50) cases could be diagnosed only with PCR, where staining was negative for the presence of P. jirovecii. When compared with clinical evidence of disease, PCR showed 93.7% sensitivity and 94.1% specificity. Presence of dyspnea and CD 4 count showed statistical significance (P<0.05) in PCP-diagnosed patients. CONCLUSIONS: PCR can be used for early and accurate diagnosis of PCP in HIV-infected patients.

Bacterial organisms and antimicrobial resistance patterns.

Gram negative bacilli are the commonest cause of infections at all sites in the Indian setting. There is a considerable degree of resistance to both first line and second line gram negative agents. Resistance to gram positive cocci is less of a problem than that of gram negative bacilli. MRSA prevalence though is not insignificant.

Pulmonary nocardiosis presenting with cardiac tamponade and bilateral pleural effusion in a HIV patient.

Nocardiosis induces a high mortality rate in those infected with HIV. It is now being increasingly described in patients with AIDS. Nocardia infection usually involves the lungs. In immunocompromised individuals it tends to disseminate. It mimics pulmonary TB both clinically and radiologically and many a time is wrongly treated with anti-tubercular drugs. Involvement of the pericardium is uncommon, having only been reported infrequently in the past. We describe a patient who presented with a cardiac tamponade and was confirmed as having pulmonary parenchymal and pleural disease.

Melioidosis--a case series from south India.

Melioidosis is sporadically reported from various parts of India. We present a case series from south India, highlighting the varied manifestations of the disease. Seven cases of culture-proven melioidosis are presented in whom Burkholderia pseudomallei were isolated from aspirate or blood. Melioidosis had a varied presentation involving multiple abscesses in the soft tissues, liver, spleen, mediastinum and the subdural space. It presented as either acute fulminant sepsis or followed a chronic indolent course, mimicking tuberculosis. Most cases had predisposing risk factors such as diabetes and chronic alcoholism.