Sensitivity of E. Coli, PS. Aeruginosa and B. Proteus to Erythromycin in various pH Culture Media

Chemotherapy ◽  
1963 ◽  
Vol 6 (1-2) ◽  
pp. 82-89 ◽  
Author(s):  
Ž Žagar
Keyword(s):  
1992 ◽  
Vol 68 (05) ◽  
pp. 539-544 ◽  
Author(s):  
Catherine Lenich ◽  
Ralph Pannell ◽  
Jack Henkin ◽  
Victor Gurewich

SummaryWe previously found that human pro-UK expressed in Escherichia coli is more active in fibrinolysis than recombinant human pro-UK obtained from mammalian cell culture media. To determine whether this difference is related to the lack of glycosylation of the E. coli product, we compared the activity of E. coli-derived pro-UK [(-)pro-UK] with that of a glycosylated pro-UK [(+)pro-UK] and of a mutant of pro-UK missing the glycosylation site at Asn-302 [(-) (302) pro-UK]. The latter two pro-UKs were obtained by expression of the human gene in a mammalian cell. The nonglycosylated pro-UKs were activated by plasmin more efficiently (≈2-fold) and were more active in clot lysis (1.5-fold) than the (+)pro-UK. Similarly, the nonglycosylated two-chain derivatives (UKs) were more active against plasminogen and were more rapidly inactivated by plasma inhibitors than the (+)UK.These findings indicate that glycosylation at Asn-302 influences the activity of pro-UK/UK and could be the major factor responsible for the enhanced activity of E. coli-derived pro-UK.


1983 ◽  
Vol 49 (01) ◽  
pp. 024-027 ◽  
Author(s):  
David Vetterlein ◽  
Gary J Calton

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.


2020 ◽  
Vol 23 (4) ◽  
pp. 8p ◽  
Author(s):  
Prasanna T. Dahake ◽  
Sudhindra M Baliga

Background: Removal of all the pathogenic bacteria from the root canal system is of prime importance for the success of endodontic therapy. Objective: The study aimed to determine the antimicrobial efficacy of three antibiotics and their new combination against selected endodontic pathogens. Methods: In this in-vitro study, we used bacterial strains associated with the refractory endodontic condition and determined MIC and MBC of Clindamycin (C), Metronidazole (M), Doxycycline (D) as well as their combination CMD. We cultured Candida Albicans, Pseudomonas Aeruginosa, Escherichia Coli, Enterococcus Faecalis, Streptococcus Mutans, Bacillus Subtilis subsp. spizizenii, Actinomyces Actinomycetemcomitans on selective culture media. We analyzed the data using paired 't' test, one-way ANOVA, and Tuckey's HSD post hoc test. Results: Clindamycin inhibited the growth of C. Albicans (90%) and S. Mutans (90%) significantly and P. Aeruginosa, E. Coli, E. Faecalis, B. Subtilis, and A. Actinomycetemcomitans were resistant to it. Metronidazole did not inhibit any of the bacteria. Doxycycline inhibited C. Albicans (90%), P. Aeruginosa (90%), and S. Mutans (90%) significantly while E. Coli, E. Faecalis, B. Subtilis, and A. Actinomycetemcomitans were resistant to it. The combination of CMD inhibited all the microbes significantly. However, at bactericidal concentrations of CMD, E. Faecalis (p = 0.024), B. Subtilis (p = 0.021) and A. Actinomycetemcomitans (p = 0.041) were eliminated significantly, while C. Albicans (p = 0.164), P. Aeruginosa (p = 0.489), E. Coli (p = 0.106) and S. Mutans (p = 0.121) showed resistance. Conclusion: Combination CMD can be used against resistant endodontic pathogens to achieve predictable endodontic results.KEYWORDSAntimicrobial agents; Clindamycin; Doxycycline; Metronidazole; Root canal therapy.    


2017 ◽  
Vol 3 (1) ◽  
pp. 52-60
Author(s):  
Nigar Sultana ◽  
Md Atiqul Haque ◽  
Md Mostafizer Rahman ◽  
Mir Rowshan Akter ◽  
Mst Deloara Begum ◽  
...  

The study was conducted aiming at the isolation and identification of pathogens from poultry feed manufactured by four different brands namely A (broiler starter), B (broiler finisher), C (layer starter) and D (layer finisher) sold in retail stores of Rangpur city of Bangladesh. All these samples were collected from four randomly chosen outlets and analyzed by culturing in different culture media such as Nutrient broth (NB), Nutrient agar (NA), Salmonella-Shigella (SS) agar, Eosin methylene blue (EMB) agar, MacConkey agar, Triple sugar iron (TSI) agar slant, Motility, Indole, Urease (MIU) and Saboraud Dextrose agar (SDA) media. The bacterial agents were isolated and examined under light microscope for their gross morphological and conventional biochemical characteristics. The bacteriological analyses were done at the Microbiology Laboratory of Hajee Mohammad Danesh Science and Technology University, Dinajpur during the period of January to June, 2014. Total bacterial colonies of all the samples were counted separately according to the American Public Health Association, using nutrient agar medium for total viable count (TVC), Eosine methylene blue (EMB) agar media for total E. coli count (TEC) and Salmonella-Shigella agar for TSC (total salmonella count). Saboraud Dextrose agar (SDA) media was used for detection of fungus. The virulence effect of the organism present in feed were observed by inoculating the organism in poultry. Recorded result showed that average TVC of feed sample A, B, C and D were 5.45x106, 3.28x105, 5.14x106 and 4.53x105 CFU/gm (colony forming unit per gram) respectively. TEC of feed sample A, B, C and D were recorded 6.25x105, 8.26x103, 5.52x105 and 5.65x104 CFU/gm respectively. TSC of feed sample A, B, C and D were recorded 3.15x104, 2.68x103, 4.46x103 and 1.19x104 CFU/gm respectively. The highest TVC, TEC and TSC were found in broiler starter (feed sample A) and lowest TVC, TEC and TSC were found in broiler finisher (feed sample B). Fungal count was 1.85x105 CFU/ gm in layer finisher (feed sample D) could be as a result of their high pathogenecity as reported by researchers elsewhere. These organisms can cause several poultry and farm animal infections specially mycotoxicosis having public health significance to both human and poultry. The presence of high numbers of E. coli and Salmonella spp. in poultry feed were indicative of poor hygienic practices during manufacture, post process contamination and unsatisfactory transportation and reservation. Therefore reinforce the need for preventive control measures, hygienic handling and processing of feeds to reduce the risk of potential human health hazards.Asian J. Med. Biol. Res. March 2017, 3(1): 52-60


Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 157 ◽  
Author(s):  
Ruby Gutiérrez ◽  
Mónica Villaquirán-Caicedo ◽  
Sandra Ramírez-Benavides ◽  
Myriam Astudillo ◽  
Daniel Mejía

Metakaolin-based geopolymer cements were produced by alkaline activation with a potassium hydroxide and potassium silicate solution. To produce the geopolymer composites, 10 wt.% titanium oxide (TiO2) and 5 wt.% copper oxide (CuO) nanoparticles were used. The geopolymer mortar was prepared using glass waste as fine aggregate. The raw materials and materials produced were characterized by X-ray diffraction, electron microscopy, and Fourier-transform infrared spectroscopy techniques. Likewise, the geopolymer samples were characterized to determine their physical properties, including their density, porosity, and absorption. The photocatalytic activity of the materials was evaluated by activating the nanoparticles in a chamber with UV–Vis light during 24 h; then, different tests were performed to determine the growth inhibition of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa bacteria in nutrient agar for times of up to 24 h. The study results showed that a geopolymer mortar containing glass waste as fine aggregate (GP-G) exhibited a water absorption 56.73% lower than that of the reference geopolymer paste without glass (GP). Likewise, glass particles allowed the material to have a smoother and more homogeneous surface. The pore volume and density of the GP-G were 37.97% lower and 40.36% higher, respectively, than those of the GP. The study with bacteria showed that, after 24 h in the culture media, the GP-G mortars exhibited a high inhibition capacity for the growth of P. aeruginosa from solutions of 10−4 mL and in solutions of 10−6 mL for E. coli and S. aureus. These results indicate the possibility of generating antibacterial surfaces by applying geopolymer composite.


2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0004
Author(s):  
Zijun Zhang ◽  
Lew Schon ◽  
Young Cho

Category: Basic Sciences/Biologics Introduction/Purpose: Diabetic foot infection (DFI), including skin infection and osteomyelitis, is a severe complication of late- stage diabetes. Mesenchymal stem cells (MSCs) facilitate bacterial clearance. In bacterial infection, MSCs, via paracrine mediators, regulate the host cell metabolism and inflammatory response. Particularly, MSCs augment the antibacterial function of neutrophils. It is generally believed that hyperglycemia in diabetes is toxic to MSCs/progenitors and detrimental to their regenerative function. It is unknown, however, whether the antibacterial function of MSCs is compromised in diabetes. Methods: Bone marrow samples from 6 diabetic and 4 non-diabetic patients (approved by IRB) were used for MSC isolation. 1. MSCs from both diabetic and non-diabetic patients were treated with lipopolysaccharides (LPS), a bacterial wall component, for 6 hours. The tissue culture media were collected as conditioned medium. E. coli from a single colony were cultured with addition of the conditioned medium generated by either diabetic or non-diabetic MSCs and inoculated on LB-agar plates overnight. Bacterial colonies were counted. 2. Human macrophages were isolated from umbilical cord blood and co-cultured with either diabetic or non-diabetic MSCs, in a trans-well system, for 24 hours. The macrophages were then cultured with heat-inactivated E. coli for one hour. After extensive washing, macrophage and bacteria were stained with Pappenheim method. Bacterial phagocytosis of macrophages, after co- cultured with diabetic or non-diabetic MSCs, was assessed under a microscope. Results: There was no statistical difference in the number of E. coli colonies when regular medium produced by diabetic and non- diabetic MSCs was added into the bacterial culture. When the diabetic and non-diabetic MSCs were treated with LPS and the conditioned medium was collected and added into bacterial cultures, E. coli colonies increased in the diabetic group, about 3 fold, as compared with the non-diabetic group (p < 0.05). Macrophages were counted in defined areas of the Petri dishes and designated as infected or uninfected, according to the presentation of bacterial bodies or not. While the infection rate of macrophages co-cultured with non-diabetic MSCs was 85% (±5.5%), it was 70% (±6.6%) when macrophages were co-cultured with diabetic MSCs (p = 0.006). Conclusion: MSCs-produced paracrine factors suppressed the growth of E. coli but diabetic and non-diabetic MSCs had no difference in such a function. Activation with LPS did not augment the non-diabetic MSCs but weakened diabetic MSCs in suppression of bacterial growth. MSCs regulate macrophages in bacterial phagocytosis. Diabetic MSCs, however, had a limited role in regulation of macrophages. This study demonstrated that MSCs in diabetic patients are compromised in anti-bacterial infection. The results not only deepen the understanding of bacterial infection in diabetes but also open up new strategy to control bacterial infection in diabetic patients.


2010 ◽  
Vol 61 (1) ◽  
pp. 67-76 ◽  
Author(s):  
A. Mavridou ◽  
E. Smeti ◽  
G. Mandilara ◽  
P. Boufa ◽  
M. Vagiona-Arvanitidou ◽  
...  

In this study ten laboratories in Greece compared the performance of reference method TTC Tergitol 7 Agar (with the additional test of β-glucuronidase production) with five alternative methods, to detect E. coli in water, in line with European Water Directive recommendations. The samples were prepared by spiking drinking water with sewage effluent following a standard protocol. Chlorinated and non-chlorinated samples were used. The statistical analysis was based on the mean relative difference of confirmed counts and was performed in line with ISO 17994. The results showed that in total, three of the alternative methods (Chromocult Coliform agar, Membrane Lauryl Sulfate agar and Trypton Bilex-glucuronidase medium) were not different from TTC Tergitol 7 agar (TTC Tergitol 7 agar vs Chromocult Coliform agar, 294 samples, mean RD% 5.55; vs MLSA, 302 samples, mean RD% 1; vs TBX, 297 samples, mean RD% −2.78). The other two alternative methods (Membrane Faecal coliform medium and Colilert 18/ Quantitray) gave significantly higher counts than TTC Tergitol 7 agar (TTC Tergitol 7 agar vs MFc, 303 samples, mean RD% 8.81; vs Colilert-18/Quantitray, 76 samples, mean RD% 18.91). In other words, the alternative methods generated performance that was as reliable as, or even better than, the reference method. This study will help laboratories in Greece overcome culture and counting problems deriving from the EU reference method for E. coli counts in water samples.


2011 ◽  
Vol 74 (2) ◽  
pp. 254-260 ◽  
Author(s):  
HAMZAH M. AL-QADIRI ◽  
XIAONAN LU ◽  
NIVIN I. AL-ALAMI ◽  
BARBARA A. RASCO

Survival of Escherichia coli O157:H7 and Campylobacter jejuni that were separately inoculated into bottled purified drinking water was investigated during storage at 22, 4, and −18°C for 5, 7, and 2 days, respectively. Two inoculation levels were used, 1 and 10 CFU/ml (102 and 103 CFU/100 ml). In samples inoculated with 102 CFU/100 ml, C. jejuni was not detectable (&gt;2-log reduction) after storage under the conditions specified above. E. coli O157:H7 was detected on nonselective and selective media at log reductions of 1.08 to 1.25 after storage at 22°C, 1.19 to 1.56 after storage at 4°C, and 1.54 to 1.98 after storage at −18°C. When the higher inoculation level of 103 CFU/100 ml was used, C. jejuni was able to survive at 22 and 4°C, with 2.25- and 2.17-log reductions, respectively, observed on nonselective media. At these higher inoculation levels, E. coli O157:H7 was detectable at 22, 4, and −18°C, with log reductions of 0.76, 0.97, and 1.21, respectively, achieved on nonselective media. Additionally, E. coli O157:H7 showed significant differences in culturability (P &lt; 0.05) on the nonselective and selective culture media under the different storage conditions, with storage at −18°C for 2 days being the treatment most inhibiting. The percentage of sublethal injury of E. coli O157:H7 ranged from ~33 to 75%, indicating that microbial examination of bottled water must be done carefully, otherwise false-negative results or underestimation of bacterial numbers could pose a health risk when low levels of pathogens are present.


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