ABSTRACT
Present study was designed to evaluate the biosurfactant production potential by native strains of Bacillus cereus as well as determine their antimicrobial and antioxidant activities. The strains isolated from garden soil were characterized as B. cereus MMIC 1, MMIC 2 and MMIC 3. Biosurfactants were extracted as grey white precipitates. Optimum conditions for biosurfactant production were 37°C, the 7[th] day of incubation, 0.5% NaCl, pH 7.0. Moreover, corn steep liquor was the best carbon source. Biuret test, Thin Layer Chromatography [TLC], agar double diffusion and Fourier Transform Infrared Spectroscopy [FTIR] characterized the biosurfactants as cationic lipopeptides. Biosurfactants exhibited significant antibacterial and antifungal activity against S. aureus, E. coli, P. aeruginosa, K. pneumoniae, A. niger and C. albicans at 30 mg/ml. Moreover, they also possessed antiviral activity against NDV at 10 mg/ml. Cytotoxicity assay in BHK-21 cell lines revealed 63% cell survival at 10 mg/ml of biosurfactants and thus considered as safe. They also showed very good antioxidant activity by ferric-reducing activity and DPPH scavenging activity at 2 mg/ml. Consequently, the study offers an insight for the exploration of new bioactive molecules from the soil. It was concluded that lipopeptide biosurfactants produced from native strains of B. cereus may be recommended as safe antimicrobial, emulsifier and antioxidant agent
ABSTRACT
The oral cavity has its own significant micro-flora but under unhygienic conditions can cause infections or diseases like gingivitis, caries, plaque and gum bleeding. Out of more than 700 oral microbial species, some opportunistic pathogens such as Staphylococcus aureus, Streptococcus spp. and Candida albicans are more prevalent. In this study, the antimicrobial activities of various toothpastes [dilutions ranging from 1:1-1:128] against above mentioned pathogens were assessed. The pathogens were isolated from clinical samples using various differential and selective media and identified through microscopic examination, cultural characteristics and biochemical tests using both conventional and API kit system [Biomerieux, France]. Antimicrobial activities of selected dentifrice formulations against identified microbes were determined using agar well diffusion and Minimum Inhibitory Concentration assays. Statistical analysis of the data on different variables has been performed by Analysis of Variance and Mean +/-SD using SPSS software. From the collected samples Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius, Streptococcus intermedius and Candida albicans were isolated and identified. All the selected toothpastes showed significant [p<0.01] antimicrobial activity against the bacterial and fungal isolates. Variable results [inhibitory zone diameters ranging from 35.10+/-8.00 to 2.40+/-5.37] were found when mean of different dilutions were compared. Conventional dentifrices exhibited more inhibition as compared to herbal products
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
ABSTRACT
The aim of this study is to explore the presence of antimicrobial bioactive agents in the foot muscle extracts of snails belonging to genus Physa and Ceciloides. Antibacterial activity of foot extracts belonging to species named as P. fontinalis, P. gyrina, P. acuta, C. acicula, C. eulima, C. petitiana, was checked and compared against three bacterial strains i.e. E.coli, P. auroginosa, S. aureus by using disc diffusion method. The results were highly significant with maximum zone of inhibition of 20.10 mm in the P. fontinalis acetone extract and the least was 12.97 mm of C. eulima diethyl ether extract. The microdilution method was employed to observe MIC to evaluate antimicrobial resistance pattern of snails foot muscle extract against three mentioned strains. MIC of foot extracts was ranging from 0.03ug/ml-5 ug/ml for six species. TLC was carried out for profiling of extracts with positive results. Foot extracts from species of both genera eluted in different fractions of compounds with a good resolution in 100% n-hexane and ethyl acetate each. The plates developed in solvent system showed purple and yellow spots indicating the presence proteins and organic compounds showing it a promising canditadate for the therapeutic purposes
ABSTRACT
Antibiotic resistant Klebsiella pneumoniae, is associated with various nosocomial infections that are difficult to treat. This study is designed to find out the patterns of resistance against commonly used antibiotics in K. pneumoniae clinical isolates with special attention to fluoroquinolones. A total number of 200 K. pneumoniae clinical isolates collected from various tertiary care hospitals of Punjab, Pakistan for a span of 1 year were investigated. Isolates were identified biochemically and genetically using VITEKR system and species-specific PCR, respectively. Antibiogram of isolates was studied by using disc diffusion and broth micro-dilution assays. Highest infection of K. pneumoniae detected in urinary tract [43%] followed by respiratory tract [25.5%]. Most of the isolates displayed strong resistance against ampicillin, cefotetan, tazobactam, cefuroxime, cefixime, ceftriaxone, ampicillin-sulbactam imipenem, meropenem, ciprofloxacin and moxifloxacin, while sensetive to cefotaxime. Chromosoaml mutation was deteted in gyrA gene, gyrA harbors a strong mutation which provides resistance against ciprofloxacin by substituting Ser83 -> Ile. However, no mutation was detected in gyrB gene. Moreover, qnrB1 plasmid born resistant gene was only detected among qnrA, qnrB and qnrS. The story depicts an alarming situation of antibiotic resistance among K. pneumoniae associated with various nosocomial infections
ABSTRACT
In the present study we investigated the pro-inflammatory and anti-inflammatory effect of Lactobacillus casei following infection with multi-drug resistant enteropathogenic Escherichia coli infection in experimental rabbits. For this purpose, 40 adult rabbits were divided into different groups and were infected with multi-drug resistant E. coli AZ1 strain except the control groups. The rabbits were orally administered with L. casei SABA6 strain in two different ways i.e. pre-treatment and post-treatment and both were continued for 7 days. The rabbits were sacrificed sequentially at 0, 4, 7 and 10 days post infection [dpi]. Serum and intestinal tissue samples were collected from each rabbit. Intestinal tissue samples were subjected to histopathological examination that showed microscopic lesions at 4 and 7 dpi among infected group. The serum samples were processed for determination of Interleukin-6 [IL-6, pro-inflammatory] and Interleukin-10 [IL-10, anti-inflammatory] using ELISA. It was found that oral administration of L. casei SABA6 reduces the eruption of intestinal epithelial cells and reduces the incidence of diarrhea. Further, L. casei SABA6 also resulted in immuno modulation by significant increase in concentration of IL-6 and IL-10 particularly at 4 and 7 dpi and protects against E. coli AZ1 infection. Altogether, it was concluded that increased IL-6 and IL-10 levels were responsible for protection against EPEC infections. The sequential sacrifice of experimental animals could be adopted for future studies to find out pathogenesis and virulence mechanism of EPEC infections along with protective efficacy of different probiotics
ABSTRACT
Metallo-beta-lactamases [MBLs] producing Pseudomonas aeruginosa are major threat for public health. They produce resistance against various antibiotics and remain low or no therapeutic options. A total of 200 clinical isolates of P. aeruginosa were collected from tertiary care hospital, Faisalabad. Isolates were sub-cultured on basic and selective media and confirmed by API 20NE. Phenotypic detection of carbapenamase, MBLs, antibiogram and MIC were determined as per CLSI guidelines. Molecular detection of blaVIM was performed using specific primers by PCR. Among 200 P. aeruginosa, majority [n=82] were isolated from pus samples followed by 28 from tracheal aspirates and 27 from sputum. Out of 110 [55%] MDR P. aeruginosa, 12 [11%] were positive for MHT and MBLs and blaVIM was identified in MBL positive isolates. Antibiogram revealed that all the isolates were resistant to beta-lactam drugs including carbapenems followed by 95% to levofloxacin, 67% to doxycycline and more effective drugs were tigecycline and colistin. MIC value for imipenem drug was 16micro g/mL and 8micro g/mL against 6 and 5 isolates respectively while MIC value for meropenem against 6 and 3 isolates were 8micro g/mL and 16micro g/mL respectively. Our study concluded the high prevalence of blaVIM producing P. aeruginosa in our clinical settings