Pseudomonas aeruginosa is an adaptable bacterial pathogen that infects a variety of organs, including the respiratory tract, vascular system, urinary tract, and central nervous system, causing significant morbidity and mortality. As the primary goal of this study, we wanted to determine how pigment color production differed between clinical strains of P. aeruginosa, and whether or not that variation was associated with multidrug resistance or the ability to form biofilms. We screened in total 30.1% of yellow, 39.8% green and 30.1% of no pigment-producing P. aeruginosa strains from a total of 143 various clinical isolates. Yellow pigment-producing strains presented significant resistance to antibiotics groups, including β-lactam (91.5%), aminoglycosides (70.5%), and carbapenems (51.9%) compared to green and non-pigmented strains. Notably, 16.3% of yellow pigment-producing strains were resistant to colistin which is used as a last-resort treatment for multidrug-resistant bacteria, whereas only 2.3% of non-pigmented and 1.8% of green pigmented strains were resistant to colistin. Aside from that, yellow pigment-producing strains were frequent producers of enzymes belonging to the lactamase family, including ESBL (55.6%), MBL (55.6%), and AmpC (50%). Compared to the green groups (7.14%) and non-pigmented groups (28.5%), they had a higher frequency of efflux positive groups (64.2%). Notably, when compared to non-pigmented groups, green pigment-producing strains also displayed antibiotic susceptibility behavior similar to yellow pigment-producing strains. The majority of yellow pigment-producing strains outperformed the green and non-pigmented strains in terms of MIC levels when compared to the other two groups of strains. Despite the fact that previous studies have demonstrated a direct correlation between multidrug resistance behaviors and biofilm production, no such statistically significant association between pigment and biofilm formation was found in our investigation. Our research has demonstrated that the correlation of bacterial pigments on their susceptibility to antimicrobial agents. Yellow pigment-producing P. aeruginosa strains posed a significant problem due to the lack of alternative agents against such transformed strains, which may be associated with the development of multidrug resistance.
Keywords: Biofilm; Drug efflux; Minimal inhibitory concentration; Multidrug resistance; Pigment production; β-Lactamase.
© 2022. The Author(s).