Mammad Manafi

• PHD
• Lecturer at University of Vienna

Enzymatic substrates are widely used in microbiology to study metabolic pathways, to monitor metabolism and to detect, enumerate and identify microorganisms. In general, fluorogenic and chromogenic enzyme substrates have proved to be a powerful tool, utilizing specific enzymatic activities of certain microorganisms. By incorporation of these substr...

The European Directive on drinking water quality has included mCP agar as the reference method for recovering C. perfringens from drinking waters. mCP agar is difficult to handle, the reaction is reversible and the cells are killed by the ammonia evaporation. In the presented study, three media (mCP, TSCF and CP ChromoSelect Agar) were evaluated fo...

Medios de cultivo fluorogénicos y cromogénicos y su evaluación en aguas de consumo y costeras RESUMEN El monitoreo de la calidad sanitaria del agua es de notable importancia para la salud humana debido a la posibilidad de transmisión de microorganismos patógenos causantes de enfermedades por vía hídrica. El objetivo del presente trabajo fue incorpo...

Time-kill curve experiments were performed with linezolid, doripenem, tigecycline, moxifloxacin, and daptomycin against Staphylococcus aureus and with colistin, moxifloxacin, and doripenem against Pseudomonas aeruginosa to evaluate the effect of porcine pulmonary surfactant on antimicrobial activity. Pulmonary surfactant significantly impaired the...

The European Directive on drinking water quality has included mCP agar as the reference method for recovering Clostridium perfringens from drinking waters. In the present study, three media (mCP, TSCF and CP Chromo Select Agar) were evaluated for recovery of C. perfringens in different surface water samples. Out of 139 water samples, using a membra...

Linezolid is considered for treatment of central nervous system (CNS) infections caused by multidrug-resistant Gram-positive bacteria. Therefore, the influence of cerebrospinal fluid (CSF) on the antimicrobial activity of linezolid was evaluated in vitro. Time-kill curves were conducted in CSF and Mueller-Hinton broth (MHB) using Staphylococcus aur...

Statins possess a variety of pleiotropic effects. Direct antimicrobial effect of simvastatin and, to a smaller degree, fluvastatin, has been reported for Gram-positive bacteria. The present study investigated antimicrobial activity of all statins available on the European market on Gram-positive and -negative organisms, with particular attention on...

Acidification of urine is widely recommended for prevention and treatment of urinary tract infections. We set out to describe the effect of modification of pH on bacterial growth of relevant bacteria as well as on activity of modern fluoroquinolones in urine in vitro. Bacterial growth of Escherichia coli ATCC 25922 and Klebsiella oxytoca ATCC 70032...

ABSTRACT: although plasma protein binding (PPB) is accepted to be an essential factor in reducing antimicrobial activity, little is known about the underlying mechanisms. One possibility includes impaired penetration of an antimicrobial into bacterial cells in the presence of PPB. As a prerequisite for testing this hypothesis an optimized medium di...

although plasma protein binding (PPB) is accepted to be an essential factor in reducing antimicrobial activity, little is known about the underlying mechanisms. One possibility includes impaired penetration of an antimicrobial into bacterial cells in the presence of PPB. As a prerequisite for testing this hypothesis an optimized medium displaying h...

Activities of glycosidases (n= 8), esterases (n= 10), arylamidases (n= 63), acid phosphatase, alkaline phosphatase and phosphoamidase were tested in 47 Borrelia strains. Forty-four were B. burgdorferi strains; 22 of which were isolated from human specimens (skin 13, cerebrospinal fluid six, and one each from blood, heart muscle and synovia), 13 wer...

Introduction Bacillus cereus is a gram-positive spore forming microorganism that can grow over a wide range of temperature, pH and water activity. This review gives an overview of the characteristics, the occurrence and the significance of Bac. cereus in milk and milk products, and discusses the impact on food legislation in particular. Literature...

This study compares the performance of a 3-h dipstick trehalose test with GLABRATA RTT, a new commercially available 20-min test for the rapid identification of Candida glabrata. With the exception of blood agar, GLABRATA RTT gave reliable results with all media tested and was always superior to the dipstick test.

Recent developments in enrichment and selective media for the isolation and enumeration of ‘total’ Enterobacteriaceae, coliforms, faecal coliforms and E. coli from water and foods are described and effects of time and temperature of incubation discussed. Factors to be considered in the selection of media for this group of organisms are noted based...

Zymogram analysis of nine strains of Toxoplasma gondii all highly virulent for mice was performed with the API enzyme research kits(R). The parasite strains had been maintained by continuous intraperitoneal infection in mice for many years separately in different laboratories in Europe and were retraced to five isolates (RH, BK, 928, KB, Alt). The...

Enterococci are used as indicators of faecal contamination of water and food and are commonly detected using kanamycin-aesculin-azide media. Aesculin can be enzymatically hydrolysed at the beta-glucose linkage to yield two products: aesculetin and glucose. Aesculetin produces a brown-black coloured compound with ferric ions. Enterococci give a posi...

The enzymatic activities of thirteen strains of Plesiomonas shigelloides were studied using the API enzyme research kit. This system uses chromogenic substrates to detect the presence or absence of 97 enzymes. Enzyme classes assayed include aminopeptidases, glycosidases, esterases, lipases, phosphatases and phosphoamidase. These strains were positi...

150 clinical isolates of Candida species, Trichosporon species and Pichia anomala as well as 32 yeasts isolated from dairy products were tested in order to evaluate the utilization of a specific fluorogenic substrate in direct detection of Candida albicans. Detection of (NAGase) was performed with fluoroplate candida agar (Merck, Darmstadt, FRG), w...

Methods based on the application of chromogenic and fluorogenic substrates enable specific and rapid detection of a variety of bacterial enzymatic activities. By using these techniques, enzymatic reactions can be examined simultaneously or individually, either directly on the isolation plate or in cell suspensions. For this purpose, various testing...

The detection and enumeration of enterococci is of primary importance for monitoring sanitation and microbiological quality of water. Chromocult enterococci agar (Merck) is a new medium for the detection of enterococci using a chromogenic mix in a selective agar. Enterococci cleave chromogenic substrates in this medium. This produces red colonies a...