Accurate enumeration of Paenibacillus mucilaginosus (formerly Bacillus mucilaginosus) bacterium from environmental samples on solid medium is challenging owing to its extensive extracellular polysaccharides (EPS) excretion. In the present study, P. mucilaginosus enumeration has been facilitated by a simple modification: addition of triphenyl tetrazolium chloride (TTC) to growth medium and application of a second soft agar layer. Results show distinctively better and accurate colonies' count. This method can be applied to all bacterial species that produce excessive EPS that may interfere with direct count.
- MeSH
- Agar chemistry MeSH
- Coloring Agents chemistry metabolism MeSH
- Culture Media chemistry MeSH
- Paenibacillus growth & development MeSH
- Colony Count, Microbial methods MeSH
- Polysaccharides metabolism MeSH
- Tetrazolium Salts chemistry metabolism MeSH
- Publication type
- Journal Article MeSH
- Technical Report MeSH
An agar selective enumeration of necrotoxigenic Escherichia coli O55 (NTEC2) and probiotic E. coli Nissle 1917, using modified MacConkey agar, was developed to study bacterial interference between these E. coli strains in a gnotobiotic piglet model. Replacement of lactose with saccharose in the agar enables the direct visual enumeration of red colonies of E. coli O55 and yellow colonies of E. coli Nissle 1917 that are co-cultured in the same Petri dish. A total of 336 colonies (168 for each color) were subjected to strain-specific PCR identification with LNA probes. Sensitivity, specificity, and positive and negative predictive values were 96.43%, 95.83%, 95.86% and 96.41% respectively in E. coli O55, and 98.21%, 97.02%, 97.06% and 98.19% respectively in E. coli Nissle 1917. Color-based enumeration of both E. coli strains in colonic contents and mesenteric lymph nodes homogenates of gnotobiotic piglets demonstrated the applicability of this method for the gnotobiotic piglet model of enteric diseases.
- MeSH
- Agar chemistry MeSH
- Color MeSH
- Escherichia coli classification genetics growth & development metabolism MeSH
- Escherichia coli Infections drug therapy microbiology MeSH
- Culture Media chemistry metabolism MeSH
- Humans MeSH
- Colony Count, Microbial instrumentation methods MeSH
- Swine MeSH
- Probiotics administration & dosage chemistry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
Východisko: Stanovení signifikantní bakteriurie je důležitým kritériem pro diagnostiku močových infekcí. Rutinně se používá kvantitativní stanovení ředicí metodou na pevných půdách. Byly vyvinuty poloautomatické systémy zjišťující přítomnost a kvantitu bakterií v moči. Cílem práce bylo objektivizovat využití nefelometrického stanovení bakteriurie. Materiál a metody: Vzorky moče byly zpracovány kvantitativní ředicí metodou a zároveň nefelometricky pomocí přístroje Uro-Quick. Výsledky: Celkem bylo zpracováno 1 653 močí. Uro-Quick vyhodnotil jako pozitivní 402 (83,05 %) ze 484 pozitivních vzorků. Senzitivita metody byla 0,83, specificita 0,95, pozitivní prediktivní hodnota 0,85, negativní prediktivní hodnota 0,93 a přesnost 90,68. Prodloužením doby kultivace se statistické parametry metody zlepšily. Problémem Uro-Quicku je detekce nízkých kvantit mikroorgamzmu. Jako negativní označil 16 77 % vzorků obsahujících > 10 CFU/ml detekovaných kvantitativní ředicí metodou. Výhodou UroQuicku je rychlost, do tří hodin detekoval 73,93 % vzorků obsahujících mikroorganizmy v kvantitě > 10 CFU/ml. Závěr. Uro-Quick poskytuje rychlou detekci pozitivních vzorků moče s vysokou kvantitou bakterií, nenahrazuje plně dosavadní metody, je vhodné jej vždy doplnit klasickou kultivační metodou.
Background: Significant bacteriuria is very important marker of urinary tract infection. The standard method for diagnosis of UTI is quantitative urine culture and identification of bacteria. For rapid enumeration of bacteria in urine semiautomatic systems were developed. Aim of the study was to compare the results of the conventional urine culture method with nephelometric enumeration of bacterial cells in urine. Material and method: Urine samples were evaluated simultaneously by Uro-Quick and quantitative urine culture. Results: In summary 1 653 urine samples were elaborated, 402 (83.05 %) from 484 positive samples had positive results in Uro-Quick. Sensitivity of Uro-Quick was 0.83, specificity 0.95, positive predictive value 0.85, negative predictive value 0.93 and accuracy 90.68. Culture time extension improved statistical performance characteristic of Uro-Quick. Problem of the method is the detection of the low amounts of microorganisms. Uro-Quick did not detected microbial growth in 16.77 % of samples containing > 10* CFU/ml of microorganisms. The advantage of Uro-Quick is the speed, 73.93 % of the samples with high microbial concentrations (> 10 CFU/ml) were detected in three hours. Conclusion: Uro-Quick offers rapid detection of urine samples with high microbial concentrations, but did not replace the quantitative culture of. Nephelometric detection is necessary to complete with agar plate cultivation.
- MeSH
- Bacteriuria diagnosis microbiology MeSH
- Indicator Dilution Techniques MeSH
- Urinary Tract Infections microbiology MeSH
- Culture Techniques methods MeSH
- Humans MeSH
- Nephelometry and Turbidimetry MeSH
- Predictive Value of Tests MeSH
- Reagent Kits, Diagnostic microbiology utilization MeSH
- Sensitivity and Specificity MeSH
- Check Tag
- Humans MeSH
Článek představuje výsledky studia antimikrobiálních a antimykotických vlastností derivátů 1,2,4-triazolu syntetizovanými na Katedře fyzikální a koloidní chemie Záporožské státní lékařské univerzity. Předchozí studie stanovily antimikrobiální a antimykotickou aktivitu derivátů 1,2,4-triazolu. Proto bylo účelné zkoumat mezi syntetizovanými sloučeninami vysoce účinné látky s antimikrobiálními a antimykotickými vlastnostmi. V první fázi našeho výzkumu byla provedena predikce akutní toxicity. Antimikrobiální a antimykotické vlastnosti byly provedeny metodou sériového ředění na kapalné živné půdě. Na tyto typy aktivit bylo zkoumáno 47 sloučenin různých tříd. Podle našeho výzkumu vykazovaly deriváty 3-amino-1,2,4-triazolu lepší účinnost než 3-thio-1,2,4-triazoly na Staphylococcus aureus a Candida albicans. Největší antimikrobiální a antimykotickou aktivitu vykazoval 5-(1Н-tetrazol-1-іl)methyl-4Н-1,2,4-triazol- 3-yl-1-(5-nitrofuran-2-yl)methanimin (11.6). Hlubší výzkum sloučeniny 11.6 byl proveden difuzí v agaru (jamková metoda). Studie ukázaly, že molekula 11.6 vykazovala antimikrobiální a antimykotický účinek na studované testovací kmeny v koncentraci 2 μg/ml. Proto může být tato sloučenina po zjištění její farmakologické bezpečnosti a toxicity vyvinuta jako užitečná léčivá látka.
This article presents the results of the study of the antimicrobial and antifungal properties among 1,2,4-triazole derivatives synthesized at the Department of Physical and Colloidal Chemistry of the Zaporizhzhia State Medical University. Previous studies have established the antimicrobial and antifungal activity of 1,2,4-triazole derivatives. Therefore, it was reasonable to investigate highly effective substances with antimicrobial and antifungal properties among synthesized compounds. In the first stage of our research, acute toxicity prediction was performed. The antimicrobial and antifungal properties were carried out by the method of “serial dilutions” on a liquid nutrient. Forty-seven compounds of the different classes were studied for these types of activities. According to our research, derivatives of 3-amino-1,2,4-triazole showed better performance than 3-thio-1,2.4-triazoles for Staphylococcus aureus and Candida albicans. 5-(1Н-tetrazole-1-іl)methyl-4Н- -1,2,4-triazole-3-yl-1-(5-nitrofuran-2-yl)methanimin (11.6) was showed the greatest antimicrobial and antifungal activity. Deeper research for compound 11.6 was done by diffusion in agar (method of “wells”). Studies have shown that molecule 11.6 showed antimicrobial and antifungal action to the studied test strains at a concentration of 2 μg/ml. Hence, this compound can be developed as a helpful therapeutic agent after establishing its safety pharmacology and toxicity.
- MeSH
- Agar MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Antifungal Agents pharmacology MeSH
- Anti-Infective Agents pharmacology MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Nitrofurans chemistry pharmacology MeSH
- Tetrazoles chemistry pharmacology MeSH
- Triazoles * chemistry pharmacology MeSH
- Check Tag
- Humans MeSH
PURPOSE OF THE STUDY Infections of joint replacements represent one of the most serious problems in contemporary orthopedics. The joint infections treatment is usually multimodal and involves various combinations of drug delivery and surgical procedures. The aim of this study was to evaluate and compare the bacteriostatic and bactericidal properties of the most common antibiotic carriers used in orthopedic surgery: bone cements mixed with antibiotic and porous calcium sulfate mixed with antibiotic. MATERIAL AND METHODS Three commercial bone cements (Palacos®, Palacos® R+G, Vancogenx®) and commercial porous sulfate (Stimulan®) were prepared with a known concentration of vancomycin (a glycopeptide antibiotic). Specifically, for the purpose of our study, the testing specimens were prepared to release 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, and 512 mg of vancomycin into 1 liter of solution. The specimens with increasing amount of antibiotic were placed in a separate tubes containing 5 mL of Mueller-Hinton broth inoculated with a suspension (0.1 m, McFarland 1) of the reference strain CCM 4223 Staphylococcus aureus to evaluate their bacteriostatic properties (broth dilution method). After this initial incubation and evaluation of the broth dilution method, an inoculum from each tube was transferred onto blood agar plates. After another 24-hour incubation under the same conditions, we evaluated the bactericidal properties (agar plate method). As many as 132 of independent experiments were performed (4 specimens × 11 concentrations × 3 repetitions = 132). RESULTS The bacteriostatic properties of all investigated samples were excellent, perhaps with the exception of the first bone cement (Palacos®). The sample Palacos® started to exhibit bacteriostatic properties at concentrations ≥ 8 mg/mL, while all other samples (Palacos R+G®, Vancogenx®, and Stimulan®) were bacteriostatic in the whole concentration range starting from 1 mg/mL. The bacteriocidic properties did not show such clear trends, but correlated quite well with different properties of the investigated samples during mixing - the most homogeneous samples seemed to exhibit the best and the most reproducible results. DISCUSSION The reliable and reproducible comparison of ATB carriers is a difficult task. The situation is complicated by high numbers of local antibiotic carriers on the market, numerous antibiotics used, and differences in clinical trials at different laboratories. Simple in vitro testing of bacteriostatic and bacteriocidic properties represents a simple and efficient approach to the problem. CONCLUSIONS The study confirmed that the two most common commercial systems used in the orthopedic surgery (bone cements and porous calcium sulfate) prevent bacterial growth (bacteriostatic effect), but they may not be 100% efficient in complete elimination of bacteria (bacteriocidic effect). The scattered results in the case of bacteriocidic tests seemed to be connected with the homogeneity of ATB dispersion in the systems and with the lower reproducibility of the employed agar plate method. Key words: local release of antibiotics; bone cements; calcium sulfate; antimicrobial susceptibility.
- MeSH
- Agar MeSH
- Anti-Bacterial Agents pharmacology therapeutic use MeSH
- Bone Cements pharmacology therapeutic use MeSH
- Humans MeSH
- Orthopedic Procedures * MeSH
- Orthopedics * MeSH
- Polymethyl Methacrylate chemistry MeSH
- Reproducibility of Results MeSH
- Calcium Sulfate MeSH
- Vancomycin pharmacology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
This study provides information on the occurrence of Arcobacter in several types of water and food products of animal origin in the Czech Republic. We processed 190 samples using the modified method, and the occurrence of Arcobacter spp. was confirmed in 36.8 % of these. This total incidence consisted of Arcobacter butzleri (27.3 %), Arcobacter cryaerophilus (8.4 %) and Arcobacter skirrowii (1.1 %). We newly described the common presence of Arcobacter spp. in sewage water in the Czech Republic that is released into waterways after processing in water treatment plants (86.7 %). All the acquired isolates were subject to detailed confirmation with subsequent species classification using multiplex PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this study, we used a modification of a method using passive filtration of an enriched sample, which could be suitable for the isolation of Arcobacter, especially in combination with Campylobacter selective agar chromogenic medium. Our studies have shown this agar to be quite suited to the isolation of Arcobacter and that it can be an appropriate instrument for accelerating culture diagnostics.
- MeSH
- Arcobacter genetics growth & development isolation & purification metabolism MeSH
- Culture Media metabolism MeSH
- Sewage microbiology MeSH
- Colony Count, Microbial instrumentation methods MeSH
- Food Microbiology * MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
The aim of this study was to assess the diagnostic properties of the two selective plating media and a chromogenic medium for identification of Bacillus cereus. The 324 isolates were B. cereus (37%), Bacillus weihenstephanensis (45%) or Bacillus thuringiensis (18%), as identified by a new combination of techniques. All isolates were growing on mannitol-egg yolk-polymyxin agar (MYP), and they did not form acid from mannitol. However, a significant lower number of B. thuringiensis isolates did not show lecithinase activity. All isolates were also growing on polymyxin-egg yolk-mannitol-bromothymol blue agar (PEMBA); however, 11% isolates indicated that they did produce acid from mannitol, and 15% isolates did not show any lecithinase activity. Five of the isolates did not grow at all on the chromogenic agar, and 14 of the growing isolates were β-glucosidase negative. It is concluded that the two recommended selective plating media MYP and PEMBA for detection of B. cereus group bacteria both have their limitations for identification of some B. cereus, B. weihenstephanensis or B. thuringiensis. However, MYP is preferable compared to PEMBA. The chromogenic medium has its own advantages and limitations, and some of the limitations seem to be solved by incubation at 30°C instead of the recommended 37°C.
- MeSH
- Bacillus cereus classification growth & development isolation & purification metabolism MeSH
- Bacillus thuringiensis classification growth & development isolation & purification metabolism MeSH
- Bacillus classification growth & development isolation & purification metabolism MeSH
- Arthropods microbiology MeSH
- Gram-Positive Bacterial Infections microbiology MeSH
- Culture Media metabolism MeSH
- Humans MeSH
- Colony Count, Microbial methods MeSH
- Food Microbiology MeSH
- Soil Microbiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
Lactococcus lactis subsp. lactis has been isolated from the intestines of marine fish and is a candidate probiotic for aquaculture. In order to use the bacterium as a probiotic, properties such as bile tolerance need to be assessed. Here, we compared bile tolerance in L. lactis strains derived from different sources. Three L. lactis subsp. lactis strains from marine fish (MFL), freshwater fish (FFL), and cheese starter (CSL) were used along with an Lactococcus lactis subsp. cremoris strain from cheese starter (CSC). The four strains were grown under various culture conditions: deMan-Rogosa-Sharpe (MRS) broth containing bile salts/acids, MRS agar containing oxgall, and phosphate-buffered saline (PBS) containing fish bile. Survival/growth of the strains in the presence of sodium cholate and sodium deoxycholate varied in the order MFL, CSL > CSC > FFL; in the presence of sodium taurocholate, the order was MFL > CSL > CSC > FFL. In liquid media containing various concentrations of oxgall, survival of the strains was observed in the order MFL > CSL > FFL and CSC. The survival of MFL was not affected by bile collected from the goldfish (Carassius auratus subsp. auratus) or the puffer fish (Takifugu niphobles), although the other strains showed significant inhibition of growth. It is a novel and beneficial finding that MFL has the highest resistance to bile acid.
- MeSH
- Lactococcus lactis metabolism MeSH
- Colony Count, Microbial MeSH
- Probiotics metabolism therapeutic use MeSH
- Fishes microbiology MeSH
- Aquaculture MeSH
- Bile Acids and Salts pharmacology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
