In this study antibacterial activity of pomegranate peel (PPE) was evaluated against bacteria isolated from poultry meat. The bacteria were identified using 16S rRNA gene and DNA sequencing. Results of molecular characterization showed that the bacteria isolated were having 100% homology with the Pseudomonas stutzeri strain CTSP36 and further analysis showed that sample sequence clustered with the P. stutzeri strain CTSP36. Antibacterial activity of PPE was demonstrated by clear zone of inhibition in plates inoculated with extract. The diameter of inhibition zones were significantly (p<0.05) higher in PPE as compared to standard antibiotic discs used (tetracycline, vancomycin and streptomycin). Results of broth dilution assay also revealed that PPE at 1%, 5% and 10% were effective in inhibiting bacterial growth in test plates. Further, a decrease in the growth of bacterial cells and a gradual decline in protein content of bacterial cells were also observed when bacterial culture was grown with different concentration of PPE along with a control. These results showed the potential application of pomegranate peel extract as antibacterial agent against P. stutzeri.
Background: Staphylococcal spp. are recognized as one of the most frequent causes of biofilm associated infections. In routine microbiology laboratories, standard method for testing antibiotic susceptibility is Kirby-Bauer disc diffusion method and minimum inhibitory concentration (MIC) which determine the antibiotic susceptibilities in planktonic phase. However, isolates capable of producing biofilm exist in biofilm state. Thus,antibiotics prescribed based on routine methods fail to eradicate biofilms thereby causing persistent infection and possible treatment failure. Thus, this work was designed to study prevalence of biofilm producing staphylococci, its resistance profile and to perform MIC versus MBIC (Minimum biofilm inhibitory concentration) in representative biofilm positive isolates.Methods and materials: 335 clinical isolates of staphylococci included in the study were screened for biofilm formation phenotypically by Congo red agar (CRA) and Tissue culture plate method (TCPM) followed by detection of biofilm genes (icaAD,aap,atlE) by PCR. Antibiotic susceptibility testing was done for biofilm positive isolates. MIC versus MBIC testing was performed for representative biofilm positive isolates for cefoxitin and vancomycin. MIC was done by broth microdilution and MBIC testing was performed using Calgary Biofilm Device. Results were interpreted according to CLSI guidelines,2015.Results: 77/335 (30%) staphylococcal isolates were biofilm positive of which S.haemolyticus (n = 35, 45.5%) was predominant followed by S. aureus (n = 27, 35.1%) and S.epidermidis (n = 15, 19.5%). By CRA, 22 (28.6%) isolates produced black colonies after 24 hours. By TCPM, 4 (5.2%), 1 (1.3%) & 49 (63.6%) isolates showed strong, moderate and weak biofilm production respectively. Overall, 77 isolates harboured biofilm genes (47aap,15atlE,15aap+atlE,5icaAD+aap+atlE).43/77 (55.8%)isolates were methicillin resistant. Highest resistance was found towards ciprofloxacin (74%) followed by erythromycin (70.1%),cotrimoxazole (65%) and pristinamycin (65%) respectively. MIC and MBIC were compared for 25 representative biofilm positive isolates. Cefoxitin MIC and MBIC ranged between 2-1024 g/mL and 8-2048 g/mL respectively. Vancomycin MIC and MBIC ranged between 0.5-8 g/mL and 2-512 g/mL respectively. Both cefoxitin and vancomycin MBIC values were 2-64 folds higher than their respective MIC. Conclusion:The present study documents biofilm producing capability in 30% of isolates. The antibiotic sensitivities of organisms in planktonic phase tested by MIC were significantly higher than for the same organism in their biofilm state as tested by MBIC. The results of the study questions the use of vancomycin as last resort antibiotic for biofilm-associated staphylococcal infections.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.