Drug resistance, Biofilm Formation and virulence gene detection in human pathogens

Document Type

News Article


1. Salmonella Typhi causative agent of enteric fever persists as a biofilm on gallstones. We studied the biofilm formation in the presence and absence of bile (280C and 370C), antibiogram, and virulence genes (invA and spvC ) of S. enterica serovars. Bile may contribute to biofilm formation and persistence of the Salmonella Typhi on gallstones, which may lead to carrier state. The presence of invA and spvC genes show the ability of invasiveness and intracellular survival.

2. Enterococcus is a commensal in the intestine and is now emerging as a drug-resistant pathogen. Enterococcus surface protein (esp) is a virulence factor that helps in the adhesion, but its role in biofilm formation is still contradictory. We studied the antimicrobial susceptibility pattern of Enterococcus spp isolated from clinical samples and correlated its drug resistance with biofilm production and esp gene. We found that biofilm formation is not always associated with the presence or absence of esp gene and or drug resistance in Enterococcus spp.

3. Biofilm formation, drug resistance, and motility contribute to virulence in P. aeruginosa. We studied the colistin resistance, biofilm formation, presence of mod A and psl A genes, and types of motilities in multi drug- resistant (MDR) and multi drug-susceptible (MDS) P. aeruginosa. Our findings showed a statistically significant association among strong biofilm formation, modA, pslA genes, and drug resistance in P. aeruginosa isolated from clinical samples. Further studies are needed to explore other genes responsible for weak and moderate biofilm formation and drug resistance.

1. Antibiogram, Virulence Genes, and Biofilm-Forming Ability of Clinical Salmonella enterica Serovars: An In Vitro Study | Microbial Drug Resistance (liebertpub.com)

2. Antibiotic Susceptibility Pattern and Biofilm Formation in Clinical Isolates of Enterococcus spp. - PMC (nih.gov)

3. Antibiogram and genetic relatedness of clinical isolates of Enterococcus spp. in Mangalore, India - PubMed (nih.gov)

Publication Date

Spring 10-1-2022