Current Issue : January - March Volume : 2017 Issue Number : 1 Articles : 8 Articles
Isolation of Mycoplasma genitalium from clinical specimens remains difficult and few strains\nare available for antimicrobial susceptibility testing. We describe the antimicrobial susceptibility\nof M. genitalium strains grown in Vero cell culture with first- and second- line antibiotics,\nusing a modified cell-culture-based method. Macrolide- and -fluoroquinolone\nresistance determinants were detected by sequencing of the 23S and parC genes, respectively.\nSeven strains were examined, including three new, genetically distinct M. genitalium\nstrains isolated from endocervical and urethral swab specimens from Cuban patients\ntogether with four reference strains isolated from specimens collected from men in Denmark,\nSweden and Australia. Azithromycin was the most active drug against two of the\nCuban M. genitalium strains with MICs values of 0.008 mg/liter, however, one strain was\nmacrolide resistant with an MIC of 8 mg/liter, and the A2059G resistant genotype. Ciprofloxacin\nwas the least active antimicrobial drug and moxifloxacin was the most active fluoroquinolone\nagainst the new clinical strains, although an MIC of 1 mg/l was found for two\nstrains. However, no relevant parC mutations were detected. MICs for tetracyclines were\n0.5ââ?¬â??4 mg/liter. Although the number of Cuban strains was low, the results suggest that a\nsingle-dose azithromycin treatment could be ineffective, and that a second-line treatment\nwith moxifloxacin, should become an option in Cuba. To our knowledge, this is the first\nreport of isolation and antibiotic susceptibility testing of M. genitalium strains from the Latin-\nAmerican region, and the first detection of macrolide resistance in such strains....
Background: Accurate detection of Neisseria gonorrhoeae antimicrobial resistance is essential for appropriate\nmanagement and prevention of spread of infection in the community. In this study Calibrated Dichotomous\nSensitivity (CDS) and Clinical Laboratory Standards Institute (CLSI) disc diffusion methods were compared with\nminimum inhibitory concentration (MIC) by Etest in Neisseria gonorrhoeae isolates from Karachi, Pakistan. CDS and\nCLSI disc diffusion techniques, and Etest for ceftriaxone, penicillin G, spectinomycin and ciprofloxacin against 100\nisolates from years 2012ââ?¬â??2014 were performed. Due to lack of CLSI breakpoints for azithromycin, it was interpreted\nusing cut-offs from British Society of Antimicrobial Chemotherapy (BSAC). Due to lack of low concentration\ntetracycline discs, tetracycline was tested with CLSI disc diffusion and Etest only. Comparisons were based on the\nidentified susceptibility, intermediate susceptibility and resistance (SIR) categories using the different methods.\nComplete percent agreement was percentage agreement achieved when test and reference method had identical\nSIR-category. Essential percent agreement was percentage agreement when minor discrepancies were disregarded.\nResults: There was 100 % and 99 % overall essential agreement and 50 % versus 23 % overall complete agreement\nby CDS and CLSI methods, respectively, with MICs for all tested antibiotics. Using either method, there was 100 %\ncomplete agreement for ceftriaxone and spectinomycin. There was 90 % versus 86 % complete agreement for\nciprofloxacin, and 60 % and 75 % for penicillin using CDS and CLSI method, respectively. Essential agreement of\n99 % and complete agreement of 62 % was found for tetracycline with CLSI method. There was 100 % essential\nand complete agreement by CDS, BSAC and Etest for azithromycin.\nConclusion: No major errors with regard to identified SIR-categories were found for penicillin, ciprofloxacin,\nceftriaxone and spectinomycin using CLSI and CDS methods. All isolates were susceptible to ceftriaxone and\nspectinomycin, and 99 % to azithromycin. In low-resource settings, both the CLSI and CDS disc diffusion techniques\nmight be used for susceptibility testing of gonococcal isolates. However, these methods require considerable\nstandardization and quality controls for adequate levels of reproducibility and correct interpretation to reflect\nappropriately the MIC values of the different antimicrobials. New, emerging, or rare resistance should be confirmed\nby MIC determination....
Uropathogenic Escherichia coli is the common pathogen to cause urinary tract infections (UTIs)\nand have become multidrug-resistant (MDR) extended-spectrum -lactamase (ESBL) producers.\nThe differences in the antimicrobial susceptibility, 5 bla genes, 12 virulence genes of 87 clinical\nESBL-producing E. coli isolates and genomic variations and sequence types of 18 recurrent and\nrepeated isolates from 9 patients were investigated. The 87 MDR-ESBL isolates collected mainly\nfrom indwelling urinary catheters (IUCs) and UTIs were highly resistant to fluoroquinolones, with\nover 50% of the isolates being resistant to cefepime and piperacillin/tazobactam and a few being\nresistant to carbapenem. These isolates carried at least two of the five bla genes examined, with\nthe highest prevalence (87.4%) found for blaCTX-M (blaCTX-M3-like and blaCTX-M14-like), followed by blaCMY-\n2 (80.5%) and blaSHV (56.3%). The predominant virulence genes were the fimbriae gene fimH\nand the toxin genes cnf1 and hlyA in blood isolates and the capsule gene kpsMTII in UTI and blood\nisolates. Over 80% of the isolates carried yersiniabactin and aerobactin of siderophores. In 18 isolates, the fluoroquinolone-resistant ST131 isolate of pulsotypes I and II with blaCTX-M-15 was\nclonally disseminated in the hospital. The genomic plasticity of these ST131 occurred mainly\nthrough the conjugative plasmids with differences in replicon types A/C, I1, FIA, FIB and Y, size\nand number. In conclusion, MDR ESBL-producing E. coli isolates differed in virulence genes of\nUPEC and antibiotic resistance associated with the sources. Plasmid acquisition and chromosomal\nvariations increase the spread of fluoroquinolone-resistant UPEC ST131 worldwide....
Background: We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant Neisseria\ngonorrhoeae (GC) isolates by disk diffusion in comparison to agar dilution, and Etest�® (bioMerieux, France),\nrespectively, for three third generation extended spectrum cephalosporins (ESC): ceftriaxone (CRO), cefixime (CFX),\nand cefpodoxime (CPD).\nMethods: One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical\nLaboratory Standard Institute (CLSI) and manufacturerâ��s standards for each of the three methods. The measured\ndiameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition,\ncomparisons with the Etest�® were made. Categorical results for concordance, based on standard CLSI cutoffs,\nbetween the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics.\nReproducibility was tested for CFX across a 6-month interval by repeated disk tests.\nResults: Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting\nconcordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest�®, for CRO, CFX,\nand CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MICâ��s were -0.59, -0.\n67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest�® were -0.58, -0.\n73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%.\nConclusions: Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative\nantimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime....
Electrospinning is a simple and versatile technique for the fabrication of nonwoven fibrous materials for biomedical applications.\nIn the present study, chitosan (CS) and polyethylene oxide (PEO) nanofibrous scaffolds were successfully prepared using three\ndifferent CS/PEO mass ratios and then evaluated for their physical, chemical, and biological characteristics. Scaffold morphologies\nwere observed by scanning electron microscopy, which showed decreasing fiber diameters with increasing CS content. Higher\nCS concentrations also correlated with increased tensile strength and decreased elasticity of the scaffold. Degradation studies\ndemonstrated that PEO was solubilized from the scaffold within the first six hours, followed by CS. This profile was unaffected\nby changes in the CS/PEO ratio or the pH of the media. Only the 2 : 1 CS/PEO scaffold demonstrated superior inhibition of both\ngrowth and attachment of Staphylococcus aureus. Finally, all scaffolds exhibited little impact on the proliferation ofmurine fibroblast\nmonolayers. These data demonstrate that the 2 : 1 CS/PEO scaffold is a promising candidate for wound dressing applications due to\nits excellent antibacterial characteristics and biocompatibility....
Bacterial meningitis (BM) is a life-threatening condition which affects the central nervous system\n(CNS). Its incidence rate is estimated between 0.22 - 2.66 and 0.81 - 6.1 cases/1000 lives worldwide\nand in Africa respectively. The objective of this study was to determine the frequency of bacterial\norganisms isolated from CSF of children less than five years old in Windhoek. A retrospective\nanalysis was performed on 784 results of CSF submitted to the Namibia Institute of Pathology\n(NIP) from January 2010 to August 2014. The results showed that out of the suspected meningitis\ncases, 18 (28.6%) were due to Streptococcus pneumoniae, making it the frequently isolated organism,\nfollowed by Staphylococcus aureus 7 (11.1%), Escherichia coli 5 (7.9%) and Haemophilus influenzae\n4 (6.3%). Streptococcus pneumoniae showed high resistance to penicillin 17 (70.5%) &\ncotrimoxazole 16 (93.7%) and 100% susceptibility to ciprofloxacin (5), vancomycin (13) & ceftriaxone\n(8). Haemophilus influenzae showed moderate resistance to cotrimoxazole 3 (66%) & tetracycline\n2 (50%). It showed 100% sensitivity to chloramphenicol (4), cefuroxime (2) & ceftriaxone\n(3). Neisseria meningitidis showed high resistance to cotrimoxazole by 100% (n = 2) and\nhigh sensitivity to chloramphenicol (n = 2), ceftriaxone & penicillin by 100% (n = 2). Streptococcus\nagalactiae was resistant to tetracycline and sensitive to penicillin & erythromycin by 100% (n =\n1). Streptococcus pneumoniae was isolated the most in this current study and it had high resistance\nto penicillin & cotrimoxazole. There was a significant difference between results CSF culture and PCR, Gram stain, CSF cell count, protein & glucose, as all comparisons yielded in P values less than\n0.05, indicating a significant statistical association...
Dothideomycetes sp. Css035 was used for the production of chitosanase with specific activity 3.41 U/mg that have\nbeen increased by 2.45 fold by the use of 30-70% ethanol concentration as a precipitating agent. The optimal conditions for\nenzymatic hydrolysis of chitosan was found to be, the addition of chitosanase with enzyme/ substrate ratio 0.05 U/mg to 2 ml of\n2% soluble chitosan in a shaking water bath at 55�°C for 4 h with 87% reducing sugar released. The produced\nchitooligosaccharides was analyzed by thin layer chromatography and HPLC and the thin layer chromatography clearly\nvisualized the specificity of the used chitosanase for the production of chitooligosaccharides. The produced\nchitooligosaccharides had more than 90% fibrinolytic activity....
Probiotic curd (PC) is an identical food product that supplies live bacterial strains and additive fibers to the human\nbody to maintain normal gut function and digestion. One objective of this study was to determine various nutritive value\nparameters such as protein content, total carbohydrates, reducing sugar, organic acids, ascorbic acid/Vitamin-C, anti-oxidant\nactivity, total phenolic content and proteolytic activity of PC. Fortification of PC with probiotic strain of bacteria can enhance the\nnutritive value of PC. In this study we have fortified PC using Lactobacillus plantarum (L. plantarum) pure lyophilized strain and\nnutritive value parameters before and after fortification were compared. The results showed higher nutritional value and\nsuperiority of L. plantarum fortified probiotic curd (LPC) compared to that of the PC. This study also involves investigating the\neffects of antibiotics on nutritive parameters of PC and LPC. For this study, cephalosporin and fluoroquinolone categories of\nantibiotics were added to LPC and PC. Results showed the suppression of nutritive values of probiotic as well as bacteria\nfortified PC. However, degree of suppression of nutritive value parameters in LPC was less when compared with PC. L.\nplantarum was found to help in maintaining normal nutritional value of probiotic curd even in presence of antibiotics.\nCephalosporin showed higher degree of suppression of nutritive values than the fluoroquinolone. Conclusively, L. plantarum has\nproven its effectiveness as a probiotic strain by improving the nutritional value of probiotic curd. Presence of antibiotics is\nresponsible for reduction in the nutritive value parameters of probiotics....
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