ABSTRACT
Objective@#The study examined the efficacy of various generations of cephalosporins against biofilms developed by pathogenic S. aureus and E. coli. @*Methods@#The development of biofilms by both bacteria was assessed using petri-plate and microplate methods. Biofilm hydrolysis and inhibition were tested using first to fourth generations of cephalosporins, and the effects were analyzed by crystal violet staining and phase contrast microscopy. @*Results@#Both bacterial strains exhibited well-developed biofilms in petri-plate and microplate assays. Cefradine (first generation) showed 76.78% hydrolysis of S. aureus biofilm, while significant hydrolysis (59.86%) of E. coli biofilm was observed by cefipime (fourth generation). Similarly, cefuroxime, cefadroxil, cefepime, and cefradine caused 78.8%, 71.63%, 70.63%, and 70.51% inhibition of the S. aureus biofilms, respectively. In the case of E. coli, maximum biofilm inhibition (66.47%) was again shown by cefepime. All generations of cephalosporins were more effective against S. aureus than E. coli, which was confirmed by phase contrast microscopy. @*Conclusions@#and Relevance: Cephalosporins exhibit dual capabilities of hydrolyzing and inhibiting S. aureus and E. coli biofilms. First-generation cephalosporins exhibited the highest inhibitory activity against S. aureus, while the third and fourth generations significantly inhibited E. coli biofilms. This study highlights the importance of tailored antibiotic strategies based on the biofilm characteristics of specific bacterial strains.
ABSTRACT
In current study we investigated the efficacy of organic extracts of Azadirachta indica leaves against Methicillin Resistant Staphylococcus aureus [MRSA] clinical isolates. For this purpose fresh leaves were used to prepare ethanol, methanol and chloroform extract. Secondly, a cross sectional study was conducted to isolate MRSA in clinical samples from patients having surgical/ non-surgical wounds from Allied Hospital and District Head Quarter Hospital, Faisalabad. The S. aureus isolates were initially identified by biochemical characterization, followed by identification of MRSA using cefoxitin disc diffusion test that was finally confirmed by genomic amplification of mecA gene, responsible for resistance. All MRSA isolates were tested to find vancomycin resistant S. aureus [VRSA] using E-strips [M.I.C. EvaluatorTM, Oxide, UK]. The data showed an overall 37% prevalence of S. aureus including 56.75% clinical MRSA isolates while none of the isolated S. aureus showed resistance to vancomycin. The antimicrobial activity was measured as mean zone of inhibition for each extract against all MRSA isolates and it was found as 15.38+/-2.26, 16.09+/-3.09 and 17.42+/-2.48 for methanol, ethanol and chloroform extracts respectively. Chloroform extract showed significantly high antimicrobial activity against MRSA isolates. Altogether, the current study exposed the high prevalence of MRSA isolates from tertiary care hospitals. However, all MRSA isolates were found susceptible to organic extracts of A. indica leaves