Culture-based and culture-independent approach for the study of the methanogens and obligate anaerobes from different landfill sites.

The landfill is a cheap way of solid waste management in developing countries. The majority of landfills are non-sanitary and work as open garbage dumping sites and pose threats to public and environmental health. Therefore, an in-depth understanding of the chemistry and microbiology of landfills is imperative to develop the right policies for landfill management. In the current study, we investigated the chemistry and microbiology of three Indian landfill sites using culture-based and culture-independent molecular approaches. Our data indicate that the nature of landfills varies from site to site in terms of chemistry, pollutants, and pathogens. We also enriched and cultivated three methanogens using an optimized medium and constructed two high-quality draft genomes from enriched microbiomes using metagenome-assembled genome approaches. The phylogenomic study of one draft genome showed the highest 93% sequence similarity with members of Methanomassiliicoccaceae and was always enriched with Acholoplasma and Anaerohalosphaera lusitana. Despite all the efforts, we did not isolate it in pure culture and hypothesized that for the cultivation of some not-yet-cultured methanogen, the presence of other organisms plays an important role, and their syntrophic interaction must be discerned for its successful cultivation in the future. Co-cultivation of amino acid-degrading organisms indicates that their co-culture can assist in boosting the growth of methanogens. In addition, our data indicated that landfill leachate contains a heavy load of pollutants and treatment is a must before discharge in nature or use in irrigation or biofertilizer.

Tumour necrosis factor (TNF) inhibitor-induced isolated pleural granulomas: a rare adverse effect.

A 53-year-old man with a history of Crohn's disease on infliximab, presented with several weeks of cough and dyspnoea. He had a right-sided pleural effusion, found to be exudative with lymphocytic predominance. He underwent right-sided video-assisted thoracic surgery (VATS) with biopsies and pleurodesis. Histopathology showed pleural-based non-caseating granulomas with unremarkable lung parenchyma. Cultures were only positive for Propionibacterium acnes 8 months later, he was found to have a left-sided exudative, lymphocytic predominant pleural effusion. Left-sided VATS and biopsies again showed pleural-based non-caseating granulomas with normal lung parenchyma. Having ruled out an active infection and malignant lesions, we diagnosed infliximab-induced pleural granulomas. Infliximab was stopped. The patient continues to do well at 6 years of follow-up. We believe this is the first report of tumour necrosis factor (TNF) inhibitor-induced isolated pleural granulomas. P. acnes and cytokine imbalance might be responsible for the pathogenesis of TNF inhibitor-induced granulomas.