Biotechnology, Applied Microbiology and Biotechnology, Microbiology (medical)
191
Scopus Publications
Scopus Publications
Effect of metabolites on the survival and biofilm formation of Pantoea piersonii (Basionym: Kalamiella piersonii) in synthetic urine media Yuvarajan Subramaniyan, K. S. Megha, K. Adithyan, Rajendu R. Nair, M. Mujeeburahiman, Blessy M. Baby, Pallavi Poojarira Ganesh, Punchappady Devasya Rekha BMC Microbiology, 2026 Pantoea piersonii (Basionym: Kalamiella piersonii) is an opportunistic pathogen capable of forming strong biofilms and infecting diverse anatomical sites. In this study, we investigated the growth, biofilm forming ability and ureolytic activity of P. piersonii under different growth conditions using synthetic urine to test its adaptability under different urinary conditions. We used P. piersonii strain YU22, isolated from the urine of a patient with kidney stone disease, and cultured under different urea concentrations (10 mM − 420 mM) to evaluate urea tolerance. Glucose, creatinine, and albumin were supplemented in synthetic urine to simulate the glycosuria, creatinuria, and albuminuria. Additionally, the effect of urinary pH variation was examined by adjusting the media to pH 5, pH 7, and pH 8. To investigate the ability of P. piersonii to co-exist with other key uropathogenic bacteria, we used a uropathogenic Escherichia coli, in a co-culture experiment. Under all the tested conditions, the growth, biofilm formation, and ureolytic activity were quantified using standard methods. Expression of urea carboxylase and allophanate hydrolase, in the selected conditions was analyzed using qRT-PCR. P. piersonii was able to tolerate urea at all the tested concentrations, showing a significant increase in growth (OD600) with increasing concentrations of urea from 0.19 ± 0.01 (10 mM) to 0.59 ± 0.01 (420 mM) (p < 0.01). Biofilm formation measured by crystal violet staining method also showed significant increase with OD590 values from 10 mM (0.55 ± 0.03) to 420 mM urea (1.74 ± 0.05) (p < 0.01). Among the nutritional supplements the highest growth and biofilm formation was observed in glucose, followed by creatinine and albumin. The combination of glucose with creatinine resulted in 25% and 30% increase in growth, respectively, compared to media containing glucose or creatinine separately. pH 7 favored growth and biofilm formation in all the tested conditions, except in the presence of glucose. Growth response and ureolytic activity varied significantly with changes in the nutritional composition and pH of the media (p < 0.05). In dual-species biofilm environment, P. piersonii dominated over E. coli under the tested growth conditions, suggesting a competitive advantage in the urinary environment that may influence community structure in mixed-species biofilms. These results demonstrate that the survival mechanism and ureolytic activity of P. piersonii are complex with the ability to adapt to varying environmental conditions in response to nutrient availability to enable survival under extreme conditions. However, these preliminary findings require validation through further investigations.
Corrigendum: Enterococcus faecalis co-cultured with oral cancer cells exhibits higher virulence and promotes cancer cell survival, proliferation, and migration: an in vitro study Fida Fathima, Yuvarajan Subramaniyan, Akshatha Rai, Punchappady Devasya Rekha Journal of Medical Microbiology, 2026 Microbiology Society journals contain high-quality research papers and topical review articles. We are a not-for-profit publisher and we support and invest in the microbiology community, to the benefit of everyone. This supports our principal goal to develop, expand and strengthen the networks available to our members so that they can generate new knowledge about microbes and ensure that it is shared with other communities.
Impact of removing fixed orthodontic appliances on oral microbial dysbiosis: A longitudinal study and metagenomic sequencing analysis Nisha Fathima, Rohan Mascarenhas, Dilshad Umar, Punchappady Devasya Rekha, Sandeep Shetty, Vivek Amin Journal of Orthodontics, 2026 Objective: To investigate the impact of appliance removal on oral microbial diversity, composition, and abundance using metagenomic sequencing. It aims to identify the core microbiome and assess changes between mid-treatment and 2 weeks after debonding to understand the relationship between orthodontic therapy and oral health better. Methods: This longitudinal cohort study recruited 26 patients undergoing fixed orthodontic treatment between January 2022 and June 2023. Saliva samples were collected at two predefined time points: mid-treatment (T0, defined as before appliance removal) and 2 weeks after debonding (T1). Microbial DNA was extracted and the V1–V3 hypervariable regions of the 16S rRNA gene were sequenced using Illumina NovaSeq. Bioinformatics analysis was performed using QIIME and the SILVA database to evaluate microbial diversity and composition at T0 and T1. Beta diversity metrics and statistical tests, including PERMANOVA and Wilcoxon signed-rank tests, were applied to identify significant differences ( P < 0.05). Effect sizes with 95% confidence intervals (CIs) were reported. Results: The analysis revealed significant shifts in microbial diversity and composition between T0 and T1. A total of 189 species across 63 genera were identified, with Firmicutes, Bacteroidetes , Proteobacteria, Actinobacteria, and Fusobacteria as dominant phyla. Genera such as Fusobacterium periodonticum (↑ 12.4%, 95% CI = 10.1–14.7) and Veillonella parvula (↑ 9.8%, 95% CI = 7.6–11.3) increased after debonding, while Prevotella melaninogenica (↓ 10.2%, 95% CI = 8.1–12.0) and Rothia dentocariosa (↓ 7.9%, 95% CI = 6.3–9.2) decreased. Beta diversity analysis confirmed a statistically significant microbial community shift ( P < 0.05). Conclusion: This study demonstrated significant microbial shifts between mid-treatment and 2 weeks after debonding, including increases in potentially pathogenic genera and alterations in the core microbiome. These findings indicate microbial changes persist for at least 2 weeks after appliance removal. Further research with pre-treatment baselines and extended follow-up is required to better define the long-term trajectory of these changes.
Concurrent bacterial infections in oral cancer: risk and mitigation strategies Blessy M Baby, Yuvarajan Subramaniyan, Punchappady Devasya Rekha Future Microbiology, 2026 The oral microbiome plays a major role in health, while its dysbiosis can contribute to oral and systemic disorders. The oral cavity hosts a complex community of commensal and pathogenic microbes, and disruptions in this balance, through bacterial infections, can contribute to cancer development and progression through chronic inflammation, inhibition of cell-death, and the release of carcinogenic substances. Microbial shifts driven by prolonged inflammation resulting from chronic oral diseases can escalate dysbiosis and promote neoplastic changes. Despite growing interest, oral microbiome-cancer-axis remains an emerging field. Current research focuses on a small number of microorganisms and associated virulence factors within the tumor-microenvironment, underscoring the need for more comprehensive, systems-level analyses. In this review, we conducted a comprehensive search of PubMed and Google Scholar (2019-2025), to identify and screen studies examining the association between bacterial infections and oral cancer. This review aims to examine and summarize the existing literature to elucidate risks and potential mitigation strategies associated with concurrent bacterial infections in oral cancer. In conclusion, more comprehensive, large-scale, and interdisciplinary studies are needed to understand the microbial influence on cancer, its impact on therapeutic responses, use of probiotics to enhance chemosensitivity and targeted-antibiotic therapy to reduce pathogenic load.
Chemical and biological evaluation of essential oils from cardamom species Emira Noumi, Mejdi Snoussi, Mousa M. Alreshidi, Punchappady-Devasya Rekha, Kanekar Saptami, Lucia Caputo, Laura De Martino, Lucéia Fatima Souza, Kamel Msaada, Emilia Mancini, Guido Flamini, Abdulbasit Al-sieni, Vincenzo De Feo Molecules, 2018
Diabetic wound management Punchappady-Devasya Rekha, Sneha S Rao, Talanjeri Gopalakrishna Sahana, Ashwini Prabhu British Journal of Community Nursing, 2018
Interaction of carbon nanotubes reinforced hydroxyapatite composite with Bacillus subtilis, P. aeruginosa and C. albicans Indian Journal of Science and Technology, 2014
Comparison of medicine quality of the generic formulation of amoxicillin provided by the government of Karnataka with marketed brands - a public health perspective International Journal of Pharmaceutical Sciences Review and Research, 2013
Virgibacillus soli sp. nov., isolated from mountain soil P. Kämpfer, A. B. Arun, H.-J. Busse, S. Langer, C.-C. Young, W.-M. Chen, A. A. Syed, P. D. Rekha International Journal of Systematic and Evolutionary Microbiology, 2011
Novosphingobium soli sp. nov., isolated from soil Peter Kämpfer, Chiu-Chung Young, Hans-Jürgen Busse, Shi-Yao Lin, P. D. Rekha, A. B. Arun, Wen-Ming Chen, Fo-Ting Shen, Y.-H. Wu International Journal of Systematic and Evolutionary Microbiology, 2011
Gordonia humi sp. nov., isolated from soil P. Kämpfer, Chiu-Chung Young, Jiunn-Nan Chu, A. Frischmann, H.-J. Busse, A. B. Arun, Fo-Ting Shen, P. D. Rekha International Journal of Systematic and Evolutionary Microbiology, 2011
Microlunatus soli sp. nov., isolated from soil P. Kämpfer, Chiu-Chung Young, H.-J. Busse, Jiunn-Nan Chu, P. Schumann, A. B. Arun, Fo-Ting Shen, P. D. Rekha International Journal of Systematic and Evolutionary Microbiology, 2010
Algoriphagus olei sp. nov., isolated from oil-contaminated soil C.-C. Young, S.-Y. Lin, A. B. Arun, F.-T. Shen, W.-M. Chen, P. D. Rekha, S. Langer, H.-J. Busse, Y.-H. Wu, P. Kampfer International Journal of Systematic and Evolutionary Microbiology, 2009
Azospirillum picis sp. nov., isolated from discarded tar S.-Y. Lin, C. C. Young, H. Hupfer, C. Siering, A. B. Arun, W.-M. Chen, W.-A. Lai, F.-T. Shen, P. D. Rekha, A. F. Yassin International Journal of Systematic and Evolutionary Microbiology, 2009
Erratum: Sphingobium rhizovicinum sp. nov., isolated from rhizosphere soil of Fortunella hindsii (Champ. ex Benth.) Swingle (International Journal of Systematic and Evolutionary Microbiology (2008) vol. 58 (1801-1806)) International Journal of Systematic and Evolutionary Microbiology, 2008
Azospirillum rugosum sp. nov., isolated from oil-contaminated soil C. C. Young, H. Hupfer, C. Siering, M.-J. Ho, A. B. Arun, W.-A. Lai, P. D. Rekha, F.-T. Shen, M.-H. Hung, W.-M. Chen, A. F. Yassin International Journal of Systematic and Evolutionary Microbiology, 2008
Lysobacter defluvii sp. nov., isolated from municipal solid waste A. F. Yassin, Wen-Ming Chen, H. Hupfer, C. Siering, R. M. Kroppenstedt, A. B. Arun, Wei-An Lai, Fo-Ting Shen, P. D. Rekha, Chiu Chung Young International Journal of Systematic and Evolutionary Microbiology, 2007
Gordonia soli sp. nov., a novel actinomycete isolated from soil Fo-Ting Shen, Michael Goodfellow, Amanda L. Jones, Ye-Pei Chen, A. B. Arun, Wei-An Lai, P. D. Rekha, Chiu-Chung Young International Journal of Systematic and Evolutionary Microbiology, 2006
Millennium development goals and biodiversity Current Science, 2005
Distribution and occurrence of diatom community along three estuaries of Dakshina Kannada, west coast of India. Indian Journal of Environmental Health, 2002
