Introduction: Antibiotics are crucial drugs that hinder the synthesis of cell walls, depolarise the cell
membrane, stop the synthesis of proteins, block the synthesis of nucleic acids, and prevent the metabolic
processes of bacteria. Nevertheless, the increase in antibiotic resistance is an alarming health issue
universally, necessitating the emergence of novel medications and approaches to treat these resistant
illnesses. Drug resistance either innate or acquired presents a significant hurdle to addressing cancer.
Drug permeability pump overexpression, epigenetic alteration, and genetic mutations are some causes
of resistance.
Objectives: The study aims to identify bioactive secondary metabolites from Streptomyces rochei,
evaluate their antibacterial activity against 12 clinical isolates, and evaluate anticancer activity against
MDA-MDB-231 cell lines.
Method: Preliminary screening for antibacterial activity by the perpendicular streak method was
performed and the organisms were then narrowed down for the disc-diffusion method. In vitro,
anticancer activities were observed in triple-negative breast cancer cell lines (MDA-MB-231), and
partial sequences of the 16s rRNA gene and phylogenetic tree construction were examined.
Results: The study analyzed a total of 35isolates out of which isolate JA3 was identified as
Streptomyces rochei JA246; evinced a broad spectrum of antimicrobial activity against 12 clinical
pathogens, with a maximum zone of inhibition against 4pathogens: Enterococcus durans
(21.13±0.0577), ESBL [K.pneumonia] (24.76±0.0577), Salmonella paratyphi (24.76±0.0577), andVibrio parahaemolyticus (MTCC 451) (19.13±0.0577) at 5?g/ml. Anticancer activity against MDA-
MDB-231 cell lines which is a prominent model for studying triple-negative breast cancer is the MDA-
MB-231 cell line which is extremely aggressive and invasive with a high percentage (over 90%) of
CD44+/CD24low/- profile, which is linked to a higher risk of tumor development yielded positive dose-
dependent viable results and weak inhibitory activities against normal Vero cell lines. As the
concentration (20, 40, 60, 80, 100 ?g/ml) of the extract of isolate JA3 increases, there is a reduction in
the percentage viability of the cancerous cell line with 15.64% at 100 ?g/ml.
Conclusion: Multidrug resistance in pathogenic bacteria and cancer poses one of the biggest threats to
the public and Streptomyces rochei JA246 acts as a powerful weapon against it.
Keywords: Streptomyces rochei JA246, Actinomycetes, antibiotic resistance, antimicrobial activity, clinical isolates, anti-cancer activity
Publication date: 01/12/2025
https://ijbpas.com/pdf/2025/December/MS_IJBPAS_2025_9644.pdf
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https://doi.org/10.31032/IJBPAS/2025/14.12.9644
