Unveiling the Weapons of Superbug Pseudomonas: A Cross-sectional Observational Study on Virulence Factors and Antimicrobial Resistance of a Lurking Pathogen

Introduction: Pseudomonas is an opportunistic pathogen that thrives in a wide range of environments and poses a severe threat. Known for acquiring additional resistance mechanisms, it has become a formidable challenge in healthcare. Understanding its weapons and defenses is key to unveiling its strategies and identifying vulnerabilities to disarm this dangerous pathogen. Aim: To characterise clinical isolates of Pseudomonas species in terms of speciation, expression of key virulence factors, and antimicrobial resistance profiles. Materials and Methods: This cross-sectional observational study was conducted at Indira Gandhi Government Medical College and Mayo Hospital, Nagpur Maharashtra, India, from January 2020 to December 2020. A total of 500 Pseudomonas isolates were tested for speciation, virulence factors, and antibiotic susceptibility using standard laboratory tests. The biofilm detection methods were analysed using Chi-square test and Antibiotic Susceptibility Testing (AST) was done using Z test. A p-value of <0.05 was considered statistically significant. Results: Out of 500 Pseudomonas isolates, a maximum of 282 (56.4%) were from pus, while fewer than 12 (2.4%) were from other specimens. A total of 416 (83.2%) samples were pigment producers. Among these, 392 (84.12%) P. aeruginosa were identified as pigment producers. P. putida and P. fluorescens were also pigment producers, while P. stutzeri did not produce any pigment. The Tissue Culture Plate (TCP) method was more quantitative, with 244 (52.36%) being a reliable method for detecting biofilm. Out of 500 Pseudomonas isolates, 332 (66.4%) were resistant to Ceftazidime; 200 (40%) were identified as Extended-Spectrum Beta-Lactamase (ESBL) producers; 104 (20.8%) were resistant to imipenem; and 58 (11.6%) were classified as MBL. Out of 218 (43.6%) AmpC producers, 94 (18.8%) were inducible, while the remaining 124 (24.8%) were non inducible. Co-expression of beta-lactamases showing AmpC and ESBL was found in 58 (11.6%) isolates of Pseudomonas. Conclusion: Pseudomonas, armed with a wide array of virulence factors and resistance mechanisms, can evade host defenses and resist antimicrobial treatments, presenting significant challenges in healthcare settings. Efforts to curb this superbug include implementing infection prevention practices and using novel antibiotics and inhibitors targeting biofilm formation, which are vital to staying ahead of this adaptable adversary