Effect of Esomeprazole and Its Combined Action with Vancomycin on Staphylococcus aureus Biofilm Formation

Abstract

Bacteria exist, in most environments, as complex organised communities of sessile cells embedded within a matrix of self-produced, hydrated extracellular polymeric substances known as biofilms. Bacterial biofilms contribute to more than 80% of hospital acquired and community acquired infections. S. aureus is an important example of the pathogens able to form biofilms. The capability to form biofilm by bacteria can be considered as a virulence factor. Infections caused by biofilm forming pathogens typically exhibit tolerance to antimicrobial and immunological challenges. This renders them difficult, sometimes impossible, to treat using conventional chemo-therapeutic agents. Effective alternative approaches for prevention and eradication of biofilm associated infections are therefore urgently required. This study aimed to examine the effect of esomeprazole and its combined action with vancomycin on S. aureus biofilm formation. This study was conducted during the period from January 2015 till March 2016 on 69 S. aureus isolates obtained from laboratories of Ain Shams University hospitals including Outpatient departments 21(30.43%), medical Departments 14(20.29%), surgical Departments 18(27.54%) and ICUs 16(21.74%). Samples from which isolates were obtained were 27(39.13%) body fluids, 28(40.58%) swabs and 14(20.29%) access devices. All isolates were identified according to Collee et al., (1996). The differentiation between S. areus and other species of Staphylococci was done by slide coagulase test, tube coagulase test, culturing on mannitol salt agar and dry spot STAPHYTECT PLUS test. Staphylococcus areus isolates were tested for their ability to form biofilm using MTP based system. Then the effect of esomeprazole and its combined action with vancomycin was tested on the isolates detected to be biofilm forming. It was found that: • Biofilm was formed in 30 (43.48%) out of 69 isolates. • Among 30 biofilm forming isolates 11(36.7%) were strong, 13(43.3%) were moderate and 6(20%) were weak biofilm producers. • Among different types of samples, swabs have the highest rate of biofilm formation 18 (60%). • In weak biofilm forming isolates, there was statistically significant difference between the OD readings with and without the presence of esomeprazole at 72 hrs of incubation (P value : 0.02) and after challenging isolates with vancomycin (P value : 0.001). • In moderate biofilm forming isolates, there was statistically significant difference between the OD readings with and without the presence of esomeprazole at 24hrs (P value : 0.013), 48hrs (P value : 0.001) and 72 hrs of incubation (P value : < 0.001) and after challenging isolates with vancomycin (P value : < 0.001). • In strong biofilm forming isolates, there was statistically significant difference between the OD readings with and without the presence of esomeprazole at 48hrs (P value: 0.001) and 72 hrs of incubation (P value : 0.001) and after challenging isolates with vancomycin (P value : < 0.001).