Isolation of Bdellovibrio spp. that prey on Azospirillum brasilense in soil

1987 ◽  
Vol 33 (5) ◽  
pp. 459-461 ◽  
Author(s):  
James J. Germida
Keyword(s):  
Growth Rate ◽  
Azospirillum Brasilense ◽  
Podzolic Soil ◽  
Enterobacter Aerogenes ◽  
Broth Culture ◽  
E Coli ◽  
Podzolic Soils ◽  
Ensifer Adhaerens ◽  
Attack Phase ◽  
Curved Rods

Bdellovibrios that prey on Azospirillum brasilense were isolated from a Latosol and a Podzolic soil from Brazil which were stored air-dried for 2 years. The addition of A. brasilense strain Cd or Sp 7 cells and nutrients to these soils stimulated growth of indigenous bdellovibrios; direct assay of these soils did not yield bdellovibrios. Two other Podzolic soils from Brazil and three Chernozemic soils from Canada did not contain detectable bdellovibrios. After enrichment with strain Cd cells, the Podzolic soil yielded 1340 bdellovibrios per g of soil, whereas enrichment with strain Sp 7 cells yielded only 50. Escherichia coli and Enterobacter aerogenes cells did not stimulate growth of bdellovibrios in this soil, but did stimulate growth of bdellovibrios in the Latosol as did strains Cd and Sp 7. The morphology of an azospirilla-attacking Bdellovibrio, isolated from the Podzolic soil, was typical of the genus; attack-phase cells were curved rods, 0.2–0.4 by 1.0–1.3 μm, motile by means of a single polar flagellum. In broth culture this Bdellovibrio isolate preyed on several different gram-negative bacteria, although the apparent growth rate on prey cells was A. brasilense strain Cd > strain Sp 7 > A. lipoferum strain Sp Br 17 = E. coli = E. aerogenes > A. brasilense strain Sp 35. Pseudomonas fluorescens, Ensifer adhaerens, and 20 unidentified bacterial isolates from the Podzolic soil were not suitable prey. These results indicate that Bdellovibrio survive in some air-dry soils at undetectable levels but respond quickly to the presence of a large number of prey cells. In addition, the presence in soil of bdellovibrios that exhibit a faster growth rate on A. brasilense strain Cd than on strain Sp 7 cells and other azospirilla indicates potential problems when using strain Cd as a crop inoculant in certain soils.

scholarly journals THE B. MYCOIDES N HOST-VIRUS SYSTEM

1952 ◽  
Vol 36 (1) ◽  
pp. 127-138 ◽  
Author(s):  
B. S. Baer ◽  
A. P. Krueger
Keyword(s):  
Growth Rate ◽  
Slow Growth ◽  
Colony Count ◽  
Broth Culture ◽  
Slow Growth Rate ◽  
E Coli ◽  
Lysogenic Culture ◽  
Plaque Count ◽  
Virus System ◽  
Lines Of Evidence

Experiments were performed to determine the mechanism of release of phage from the lysogenic strain of B. mycoides N. The results suggest that qualitatively the same situation obtains as in the phage-carrying cultures of B. megatherium 899 and E. coli Li; i.e., the population consists of two kinds of cells: "lysogènes potentiels" and "producteurs." Quantitatively, however, there are more "producers" in a broth culture of the lysogenic B. mycoides N, at least curing the first 4 to 8 hours after cells have been suspended in fresh medium, suggesting that the interaction between host and parasite is one in which the balance is easily swung in favor of the virus. These conclusions are based upon the following lines of evidence: (1) the slow "growth rate" of the lysogenic culture, (2) the fact that the colony count falls far below the plaque count or the filament count (which correspond) for a well washed suspension, (3) the increase in phage output in a large number of tubes, each containing a small number of lysogenic cells, after a few hours' incubation in nutrient broth at 30°C.

scholarly journals Štúidium rastu a produkcie biogénnych amínov niektorými mikroorganizmami za modelových podmienok

1999 ◽  
Vol 17 (No. 1) ◽  
pp. 15-21 ◽  
Author(s):  
G. Greif ◽  
M. Greifova ◽  
J. Dvoran ◽  
J. Karovicova ◽  
V. Buchtova
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Klebsiella Pneumoniae ◽  
Specific Growth ◽  
Growth Curves ◽  
Enterobacter Aerogenes ◽  
Lag Phase ◽  
E Coli ◽  
The Family ◽  
Cell Densities

The study was aimed at the growth of selected strains from the family Enterobacteriaceae (Escherichia coli,  Enterobacter aerogenes and Klebsiella pneumoniae) in meat-peptone (MPB) broth and cabbage juice at different cultivation temperatures, and at the production of biogenic amines (cadaverine, putrescine, histamine). Bacterial growth was evaluated on the basis of specific growth rate (IJm) and lag phase (A.) calculated from growth curves. Cadaverine was produced as the first amine in MPB and cabbage juice by all studied st rains at the cultivation temperatures and at Jiving cell densities 10 6 KTJ/cm3. Putrescine was produced by E. coli only in both substrates at the cultivation temperatures. Histamine was produced by E. coli at 18 °C in cabbage juice and by Enterobacter aerogenes  in both substrates at the cultivation temperatures.

Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

2017 ◽  
Vol 1 (2) ◽  
pp. 48-60
Author(s):  
A.G. Salmanov ◽  
A.V. Rudenko
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Staphylococcus Epidermidis ◽  
Klebsiella Oxytoca ◽  
Enterobacter Aerogenes ◽  
Enterobacter Cloacae ◽  
Proteus Vulgaris ◽  
Providencia Rettgeri ◽  
E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

Probiotics Slow the Growth of Pathogenic Bacteria

2019 ◽  
Vol 14 (1) ◽  
pp. 28-31 ◽  
Author(s):  
Rowles H. L.
Keyword(s):  
Growth Rate ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Diarrheal Disease ◽  
Growth Curves ◽  
Mortality Rates ◽  
Controlled Delivery ◽  
E Coli ◽  
Multiple Strains ◽  
Commercial Probiotics

Probiotics are live microorganisms, which when ingested in sufficient amounts, confer health benefits to the host by improving the gut microflora balance. The purpose of this research was to determine whether commercial probiotic products containing multitude of commensal bacteria would reduce the growth rate of pathogenic bacteria, specifically Escherichia coli and Salmonella typhimurium. Growth curves were established, and the growth rates were compared for samples of E. coli, S. typhimurium, Nature’s Bounty Controlled Delivery probiotic, Sundown Naturals Probiotic Balance probiotic, and cocultures of the pathogenic bacteria mixed with the probiotics. The findings of this research were that the commercial probiotics significantly reduced the growth rate of E. coli and S. typhimurium when combined in cocultures. Probiotics containing multiple strains may be taken prophylactically to reduce the risk of bacterial infections caused by E. coli and S. typhimurium. Probiotics could be used to reduce the high global morbidity and mortality rates of diarrheal disease.

scholarly journals degS Is Necessary for Virulence and Is among Extraintestinal Escherichia coli Genes Induced in Murine Peritonitis

2003 ◽  
Vol 71 (6) ◽  
pp. 3088-3096 ◽  
Author(s):  
Peter Redford ◽  
Paula L. Roesch ◽  
Rodney A. Welch
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Luria Bertani ◽  
Broth Culture ◽  
Wild Type ◽  
E Coli ◽  
Virulence Attenuation

ABSTRACT Extraintestinal Escherichia coli strains cause meningitis, sepsis, urinary tract infection, and other infections outside the bowel. We examined here extraintestinal E. coli strain CFT073 by differential fluorescence induction. Pools of CFT073 clones carrying a CFT073 genomic fragment library in a promoterless gfp vector were inoculated intraperitoneally into mice; bacteria were recovered by lavage 6 h later and then subjected to fluorescence-activated cell sorting. Eleven promoters were found to be active in the mouse but not in Luria-Bertani (LB) broth culture. Three are linked to genes for enterobactin, aerobactin, and yersiniabactin. Three others are linked to the metabolic genes metA, gltB, and sucA, and another was linked to iha, a possible adhesin. Three lie before open reading frames of unknown function. One promoter is associated with degS, an inner membrane protease. Mutants of the in vivo-induced loci were tested in competition with the wild type in mouse peritonitis. Of the mutants tested, only CFT073 degS was found to be attenuated in peritoneal and in urinary tract infection, with virulence restored by complementation. CFT073 degS shows growth similar to that of the wild type at 37°C but is impaired at 43°C or in 3% ethanol LB broth at 37°C. Compared to the wild type, the mutant shows similar serum survival, motility, hemolysis, erythrocyte agglutination, and tolerance to oxidative stress. It also has the same lipopolysaccharide appearance on a silver-stained gel. The basis for the virulence attenuation is unclear, but because DegS is needed for σE activity, our findings implicate σE and its regulon in E. coli extraintestinal pathogenesis.

DETERMINING AMMONIUM OXALATE-EXTRACTABLE Si IN SOILS

1986 ◽  
Vol 66 (4) ◽  
pp. 751-755 ◽  
Author(s):  
C. WANG ◽  
P. A. SCHUPPLI
Keyword(s):  
Atomic Absorption ◽  
Key Words ◽  
Podzolic Soil ◽  
Ammonium Oxalate ◽  
Podzolic Soils ◽  
Significant Difference ◽  
Key Words Oxalate

Determination of oxalate-extractable Si and Al is useful in assessing the degree of accumulation of allophane-like materials in Podzolic soils. Three procedures were tested for determining Si: manual spectrophotometry, automated spectrophotometry and atomic absorption. For concentrations of oxalate-extractable Si above 0.5 g kg−1, there was no significant difference among results by the three procedures. For lower concentrations of Si, results by atomic absorption were higher than those by the spectrophotometric procedures. Determination by Si by autoanalyzer is the preferred procedure as it is convenient, sensitive and reliable. Key words: Oxalate Si, Podzolic soil, autoanalyzer

Fate of Escherichia coli O157:H7 and Other Coliforms in Commercial Mayonnaise and Refrigerated Salad Dressing

1995 ◽  
Vol 58 (1) ◽  
pp. 13-18 ◽  
Author(s):  
ERROL V. RAGHUBEER ◽  
JIM S. KE ◽  
MICHAEL L. CAMPBELL ◽  
RICHARD S. MEYER
Keyword(s):  
Escherichia Coli ◽  
Storage Temperature ◽  
Enterobacter Aerogenes ◽  
Antimicrobial Effect ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Salad Dressing ◽  
E Coli ◽  
Survival Pattern ◽  
High Level

Commercial mayonnaise and refrigerated ranch salad dressing were inoculated at two levels with two strains of Escherichia coli O157:H7, a non-pathogenic E. coli, and the non-fecal coliform Enterobacter aerogenes. Results showed that at the high inoculation level (>106 colony forming units [CFU]/g) in mayonnaise stored at room temperature (ca. 22°C) both strains of O157:H7 were undetected at 96 h. At the high inoculation level, all strains of coliform bacteria tested survived longer in salad dressing stored at 4°C than in mayonnaise stored at 22°C. The O157:H7 strains were still present at low levels after 17 days. The survival time in the low-level inoculum (104CFU/g) study decreased, but the survival pattern in the two products was similar to that observed in the high-level inoculum study. Slight differences in survival among strains were observed. The greater antimicrobial effect of mayonnaise may be attributable to differences in pH, water activity (aw), nutrients, storage temperature, and the presence of lysozyme in the whole eggs used in the production of commercial mayonnaise. Coliform bacteria survived longer in refrigerated salad dressing than in mayonnaise particularly at the high-level inoculum. Both mayonnaise (pH 3.91) and salad dressing (pH 4.51) did not support the growth of any of the microorganisms even though survival was observed.

scholarly journals IN VITRO MICROBIAL TIME-KILLING CURVE FOR NEWLY SYNTHESIZED AMINOACETYLENIC-2-MERCAPTOBENZOTHIAZOLE COMPOUND

2017 ◽  
Vol 9 (10) ◽  
pp. 125
Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Hiba Al-malliti
Keyword(s):  
Minimum Bactericidal Concentration ◽  
Viable Count ◽  
Broth Culture ◽  
Dilution Method ◽  
Time Intervals ◽  
Minimum Fungicidal Concentration ◽  
E Coli ◽  
Different Types ◽  
Broth Dilution

Objective: To determine the time needed for killing different types of microorganisms by a newly synthesized 2-mercapto-1,3-benzothiazole derivative in comparison to ciprofloxacin and fluconazole.Methods: The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) for 2-{[4-(2,6-dimethylPiperidin-1-yl)but-2-yn-1-yl]Sulfanyl}-1,3-benzothiazole(AZ3) compound were determined, using the broth dilution method. The MBC and MFC dilutions were prepared. Broth cultures of Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) were incubated at 37 °C for 24 h, and Candida albicans (C. albicans) was incubated at 25 °C for 48 h. 0.1 ml of each broth culture represent 1.5 x 106 CFU/ml was challenged with 9.9 ml broth containing the MBC or MFC concentrations of the AZ3 compound. From each sample at different time intervals, 1 ml was taken and added to 9 ml of sterile distilled water, in order to neutralize the effect of AZ3. Serial dilution was done and a viable count was determined from the appropriate dilutions.Results: The viability of the P. aeruginosa, E. coli, S. aureus, B. subtilis and C. albicans were killed within 3.5 h, 5 h, 24 h, 3 h and 5 h respectively. The time killing curves showed that AZ3 needed longer time for killing S. aureus than the time needed to kill B. subtilis. On the other hand, AZ3 needed a shorter time to kill P. aeruginosa, than the time needed to kill E. coli. In comparison with ciprofloxacin, AZ3 needed a shorter time to kill P. aeruginosa and E. coli, and the same time to kill B. subtilis, while it needed longer time than ciprofloxacin to kill S. aureus. In comparison with fluconazole, AZ3 with lower MFC than fluconazole needed longer time to kill C. albicans.Conclusion: AZ3 showed promising antimicrobial killing activities, in compared with ciprofloxacin and fluconazole, which promoted our interest to investigate the time of killing needed for other 2-mercaptobenzothiazole derivatives against different types of microorganisms.

FATE OF COLIFORMS IN YOGURT, BUTTERMILK, SOUR CREAM, AND COTTAGE CHEESE DURING REFRIGERATED STORAGE1

1971 ◽  
Vol 34 (1) ◽  
pp. 54-58 ◽  
Author(s):  
M. C. Goel ◽  
D. C. Kulshrestha ◽  
E. H. Marth ◽  
D. W. Francis ◽  
J. G. Bradshaw ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Enterobacter Aerogenes ◽  
Cottage Cheese ◽  
Rapid Decline ◽  
Initial Value ◽  
E Coli ◽  
Ph Values ◽  
Test Culture ◽  
Marked Decline ◽  
Sour Cream

Aerobacter (Enterobacter) aerogenes and Escherichia coli were inoculated separately into commercially produced samples of yogurt, buttermilk, sour cream, and cottage cheese. Inoculated products were stored at 7.2 C and were tested daily for up to 10 days to determine changes in numbers of coliforms and in pH values. The number of viable coliforms in yogurt declined dramatically and was markedly different from the initial value after only 24 hr of storage. Usually, survival of coliforms in yogurt did not exceed 3 days of holding. In buttermilk, most often a marked decline in numbers of coliforms was evident after 24 hr of storage. A substantial reduction in numbers (>50% of organisms present initially) of A. aerogenes B199 occurred in sour cream during the first 24 hr of storage, but a similar decline in numbers of E. coli and A. aerogenes FD was not evident until after 3 days of storage. Changes in numbers of E. coli and A. aerogenes in cottage cheese generally were not as rapid as in other products during the first days of storage. A few cottage cheese samples, however, did support rapid increases in test culture numbers. Because of the rapid decline in numbers of coliforms in yogurt, buttermilk, and sour cream, the provision in Standard Methods for the Examination of Dairy Products that permits examination of some of these products for up to 48 hr after manufacture seems inadvisable.

scholarly journals PREVALENCE OF EXTENDED-SPECTRUM BETA-LACTAMASE PRODUCING ENTEROBACTERIACEAE MEMBERS ISOLATED FROM CLINICALLY SUSPECTED PATIENTS

2018 ◽  
Vol 11 (5) ◽  
pp. 364 ◽  
Author(s):  
Moorthy Kannaiyan ◽  
Gedif Meseret Abebe ◽  
Chinnasamy Kanimozhi ◽  
Punitha Thambidurai ◽  
Saranya Ashokapuram Selvam ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antibiotic Sensitivity ◽  
Enterobacter Aerogenes ◽  
Clinical Problem ◽  
Clinical Samples ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Extended Spectrum ◽  
Genotypic Identification ◽  
Esbl Producers

 Objective: Emergence of extended-spectrum beta-lactamases (ESBLs) production poses another clinical problem with Gram-negative bacterial infections. The present study was aimed to evaluate the ESBL producers among various clinical samples of clinically suspected patients.Methods: A total of 1279 samples (urine [918], pus [207] and stool [154]) were collected and 465 isolates (Escherichia coli [320], Enterobacter aerogenes [119] and Klebsiella pneumoniae [26]) were isolated and screened for the presence of ESBL producers using combination disc method and double disc synergy test.Results: Of the 465 culture positive isolates, 130 (E. coli 93 [29.06%], E. aerogenes 35 [29.41%] and K. pneumoniae 2 [7.69%]) were identified as ESBL producers. Among the three Enterobacteriaceae members, E. coli 93 (29.06%) was found to be predominant ESBL producer next in order E. aerogenes 35 (29.41%) and K. pneumoniae 2 (7.69%). Maximum number of ESBL producers were recovered from urine (n=111) followed by pus (n=14) and stool (n=5). All the ESBL-producing isolates were subjected to antibiotic sensitivity test using 10 different antibiotics. ESBL producers were chiefly resistance to ceftriaxone followed by ceftazidime and cefotaxime. Of 130 ESBL producers, 15 (E. coli (8), E. aerogenes (6) and K. pneumoniae (1)] strains were selected for genotypic identification. Among, only two strains of E. aerogenes were positive isolates for CTX-M type ESBL in polymerase chain reaction.Conclusion: This study concluded that among Enterobacteriaceae members, E. coli was the predominant ESBL producers and urine was noted as the prime source for the ESBL positive isolates when compared to other source. Genotypic identification was the best method to differentiate ESBL types which were essential to provide proper treatment.

Sign in / Sign up

Export Citation Format

Share Document