ABSTRACT
The quorum sensing inhibitory [QSI] and antimicrobial potentials of the total methanol extract [TME] and different extractives as well as the sesquiterpenes: dehydrodihydrocostus lactone [1], dehydrocostus lactone [2], arbusculin A [3], santamarine [4], reynosin [5], and specioic acid [6] isolated from Costus speciosus rhizomes were evaluated. The CHCl3:EtOAc [1:1], EtOAc, and TME fractions exhibited potent antibacterial activity toward B. cereus with inhibition zone diameter 13 mm. While the CHCl3 fraction showed strong activity towards S. aureus and B. cereus with inhibition zone diameter 11 and 19 mm, respectively. Moreover, the TME and CHCl3 fractions have strong activity towards C. albicans with inhibition zone diameter 15 and 12 mm, respectively. Compound 5 showed prominent activity towards B. cereus [MIC 385 µg/mL]. However, 6 exhibited significant activity with MIC values of 150, 400, and 550 µg/mL towards S. aureus, E. coli, and B. cereus, respectively. Moreover, it showed potent antifungal effect towards C. albicans [MIC 320 µg/mL]. Most of the tested fractions had QSI activity against C. violaceum. Only compound 6 exhibited moderate QSI effect with disappearance of violet pigment. In addition, compounds 1-6 were evaluated for their in vitro antiproliferative activity towards KB, BT-549, SK-MEL, and SKOV-3 cancer cell lines
ABSTRACT
This study was performed to assess the potential beta-lactamase inhibitory properties of nineteen crude Saudi plant extracts belonging to eight families against extended spectrum beta-lactamase [ESbetaL] strains of Klebsiella pneumoniae and other medically important pathogens. A total of 276 microbial isolates of pathogenic bacteria were used in this study; only 15 of them showed decreased sensitivity to one or several of ceftazidime, aztreonam, cefotaxime or ceftriaxone, which are deemed to be possible producers of ESbetaL. Antibacterial activities of plant extracts were carried out against ESbetaL positive isolates by the disc diffusion method. The potential ESbetaL suppressing activities of plant extracts and prepared fractions, [chloroform and methanol], with or without antibiotic were studied by disc diffusion method. Results revealed that selected plant extracts showed no antibacterial activity against tested strains; meanwhile, only Echinops viscosus, Pulicaria arabica, Tephrosia nubica, Chrozophora oblongifolia, and Clutia myricoides showed pronounced ESbetaL inhibitory activities. The extracts were quantified for phenolic compounds and their antioxidant properties. Bio-guided fractionation of the active extracts revealed that the chloroform fraction of C. myricoides possess a promising ESbetaL inhibitory activity. The separation and the structural elucidation of the active compounds from C. myricoides will offer beneficial leads for developing beta-lactamase inhibitors
ABSTRACT
Background: The emergence of drug resistant strains of Mycobacterium tuberculosis is of growing concern. Multi-drug resistance [MDR-TB] where the strain is resistant to both rifampicin [RIF] and isoniazid [INH], has been reported in all regions of the world. Early choice, and rapid determination of drug resistance can allow a customized approach to treatment early in the course of the disease and can potentially reduce morbidity, mortality and infectiousness. It would be helpful for low-resource countries to have simple and inexpensive tests which can rapidly detect resistance to RIF .The excellent performance of the BACTEC MGIT 960 for rapid detection of resistance to first- and second-line anti-TB drugs can be accomplished in days rather than weeks, although still constrained by high cost equipments and consumables. FASTPlaque-Response is a phage amplification-based test for detection of RIF resistance and has been developed for direct use on sputum specimens
Aim: The present study was undertaken to compare between BACTEC MGIT 960 method and FASTPlaque-Response method for the time, specificity and sensitivity determination of RIF susceptibility in sputum of both positive [+ve] and negative [-ve] AFB-smear of Mycobacterium tuberculosis patients
Results: In this study, a total of 60 specimens were collected and divided according to Z-N staining into two groups : group[1] which was Z.N [+ve]comprising 47 specimens ranged from+1 to +3 positivity, and group[2] which was Z.N -[-ve] comprising 13 specimens. The turnaround-time [TAT] of group[1] by BACTEC MGIT 960 ranged from 8 to 39.2 days with Mean +/- SD 13.9 +/- 3.4 days for positivity and ranged from 4 to 12.96 days with Mean +/- SD[8.02 +/- 1.98] days for susceptibility pattern, while in group[2] the TAT ranged from 8.2 to 41.75 days with Mean +/- SD[15 +/- 5.2] days for positivity and ranged from 4.04 to 13 days with Mean +/- SD [8. 6 +/- 2.2] days for susceptibility pattern ,In contrast to BACTEC MGIT960, FASTPlaque-Response susceptibility pattern was completed in just 48 hours. Susceptibility pattern of RIF by BACTEC MGIT 960 and FASTPlaque-Response showed the same results in 35 out of 60 specimens [58%] which were [26,6 and 3] Sensitive, resistant, and contaminant respectively, While the other 25 specimens [42%] showed discrepant results. In group [1]: 34 out of the 47 specimens [72 %] showed the same results by FASTPlaque- Response and BACTEC MGIT 960, while discrepancy occurred in the other 13 specimens [28 %], in which 12 specimens were RIF sensitive by the BACTEC MGIT 960 and showed different results by FASTPlaque- Response [6,2 and 4 were resistant ,contaminant and no growth respectively],while the 13th specimen which was resistant by BACTEC MGIT960 became sensitive with FASTPlaque- Response .In group[2] the results by the two methods were the same in only one out of 13 specimens [8 %], whereas the discrepancy was in the other 12 specimens [92 %] in which 8 specimens were sensitive with the BACTEC MGIT 960, 7of them showed no growth and the 8th was contaminant by FASTPlaque-Response, while 3 specimens were resistant by BACTEC MGIT 960, 2 of them were contaminant and 1 showed no growth by FASTPlaqueTB- Response, whereas, the 12th specimen was contaminant by BACTEC MGIT 960,but showed no growth with FASTPlaqueTB-Response . In group[1]; 4 out 47 specimens[8.5%] were contaminants and 4 specimens[8.5%] showed no growth by FASTPlaque- Response ,while,2 specimens[4.2%] were contaminants and no specimens showed no growth by BACTEC MGIT 960. In group[2];5 specimens out of 13 [38.5%] were contaminants and 8 specimens [61.5%] showed no growth by FASTPlaque- Response ,while,2 specimens[15.3%] were contaminants and no specimens showed no growth by BACTEC MGIT 960
Recommendation: Standardization of phage method to minimize the number of contaminated or incorrect results is necessary before this diagnostic tool can be implemented widely, and improvement needed to become highly sensitive and specific in that cases to become routinely used
ABSTRACT
Rapid diagnosis of tuberculosis is essential to initiate timely and appropriate treatment to curb the spread of this potentially life threatening disease, we have evaluated the clinical utility of phage assay, using FASTPlaque TB kit, in comparison to the BACTEC MGIT 960 system with respect to Z-N stain for the recovery, time of detection and contamination rate of MBTC from sputum specimens..Our data revealed the sensitivity of the phage test with respect to AFB smear positivity -was 87.6% and specificity was WO %.The positive predictive value was 100% and negative predictive value was 86.7 %. Whereas the sensitivity and specificity of phage assay with respect to growth on BACTEC MGIT media were 82.5% and 100% respectively. While, the positive predictive value and negative predictive value were 100% and 80.6 % respectively
Conclusions: We believe that this new low cost assay may have widespread applicability, especially indeveloping countries, due to its manual format and rapid reporting of results?
ABSTRACT
The frequency of multi-drug resistance Pseudomonas aeruginosa infections are increasingly recognized worldwide. P. aeruginosa isolates resistant to all antimicrobial agents have been detected in many areas. Since IMP1 producers tend to demonstrate a wide range of resistance to various broad-spectrum beta-lactam including oxyimino cephalosporin, cephamycine and carbapenemes, early recognifion of IMP-1 producers is very important for rigorous infection control. The present study was designed to detect the incidence of P. aeruginosa infection, characterize the antimicrobial resistance profiles and screen for the IMP-1 producers strains. From 1[st]of July 2007 to 30 June 2008, A total of 4031 isolates were obtained of these 837 [20.76%] were identified as Pseudomonas, the great majority of them was P. aeruginosa [n=816; 97.5%] and the most of which was isolated from the wounds [n=256; 30.6%] , sputum [n= 242; 28.9%] , urine [n=64; 7.6%], Tracheal aspirate [n=55; 6.65] and lastly ear swab [n=3; 0.35%]. Intensive care unit accounts the most source of infection [n= 171; 20.4%] then burns unit [n=111; 13.3%] and lastly obstetric department [n=8; 0.9%]. High resistance rates were observed for all antibiotics studied. imipenem appeared to be the most active agent against the majority of isolates [ S=78%], then levofloxacin [S=75%], followed by piperacillin / tazobactam [S= 71%], amikacin [S= 67%], tobramycin [S=65%], ciprofloxacin [S= 63%], cefepime [S=60%], gentamycin [S= 59%], pipracillin and ceftazidime [S= 57% for each], while ceftriaxone and cefotaxime were the least active agents with a sensitivity [35%] only. IMP-1 Metallo-beta-lactamas were detected in 148 [41% of the 360 CAZ- resistant isolates] out of 816 P. aeruginosa iso1ates. After the results of this study we concluded that the rates of P. aeruginosa infection were high with increasing in IMP-1 Metallo-beta-lactamase producers strains. Infection control procedures for multi drug resistance need to be re-viewed urgently. There is also a pressing need for new, and hopefully novel, compounds active against pan-resistant Gram-negative bacteria a growing problem that needs to be addressed by both governments and industries