Aeromonas hydrophila in Shellfish Growing Waters: Incidence and Media Evaluation

1989 ◽  
Vol 52 (1) ◽  
pp. 7-12 ◽  
Author(s):  
CARLOS ABEYTA ◽  
STEPHEN D. WEAGANT ◽  
CHARLES A. KAYSNER ◽  
MARLEEN M. WEKELL ◽  
ROBERT F. STOTT ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Environmental Samples ◽  
Enterotoxin Production ◽  
Beef Extract ◽  
Solid Agar ◽  
Agar Media

Levels of Aeromonas hydrophila determined for the shellfish growing area of Grays Harbor, Washington, ranged from 3 to 4600/100 g in oysters and from 3 to 2400/100 ml in water. Of isolates tested, 80% produced a hemolysin, a trait reported to correlate with enterotoxin production and pathogenicity. Two enrichment broths, Tryptic Soy Broth with ampicillin (TSBA) and Modified Rimler Shotts Broth (MRSB) were compared in combination with three solid agar media: Rimler Shotts (RS), Peptone Beef Extract Glycogen (PBG), and MacConkey's (MCA) agars. TSBA was far superior to MRSB in isolating this species from the environmental samples tested.

TEM processing procedure for a bacillus organism grown on solid media

1990 ◽  
Vol 48 (3) ◽  
pp. 624-625
Author(s):  
Jane Payne ◽  
Philip Coudron
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Fume Hood ◽  
Vacuum Aspiration ◽  
Solid Media ◽  
Transmission Electron ◽  
Solid Agar ◽  
Processing Procedure ◽  
Agar Media ◽  
Rat Bone

This transmission electron microscopy (TEM) procedure was designed to examine a gram positive spore-forming bacillus in colony on various solid agar media with minimal artifact. Cellular morphology and organization of colonies embedded in Poly/Bed 812 resin (P/B) were studied. It is a modification of procedures used for undecalcified rat bone and Stomatococcus mucilaginosus.Cultures were fixed and processed at room temperature (RT) under a fume hood. Solutions were added with a Pasteur pipet and removed by gentle vacuum aspiration. Other equipment used is shown in Figure 3. Cultures were fixed for 17-18 h in 10-20 ml of RT 2% phosphate buffered glutaraldehyde (422 mosm/KgH2O) within 5 m after removal from the incubator. After 3 (30 m) changes in 0.15 M phosphate buffer (PB = 209-213 mosm/KgH2O, pH 7.39-7.41), colony cut-outs (CCO) were made with a scalpel.

Low Incidence of Aeromonas sp. in Livestock Feces

1987 ◽  
Vol 50 (1) ◽  
pp. 66-69 ◽  
Author(s):  
NORMAN J. STERN ◽  
E. S. DRAZEK ◽  
S. W. JOSEPH
Keyword(s):  
Aeromonas Hydrophila ◽  
Recovery Rate ◽  
Agricultural Research ◽  
Agar Medium ◽  
Brain Heart Infusion ◽  
Aeromonas Sobria ◽  
Aeromonas Caviae ◽  
Retail Meat ◽  
Agar Media ◽  
Low Incidence

Pig, beef, sheep and turkey fecal specimens were assayed for recovery of inoculated Aeromonas sp. by directly plating the samples on five different agar media. Of these, starch-ampicillin was optimal with respect to selectivity and ability to differentiate from other resident microflora. Generally, the numbers of inoculated Aeromonas sp. recovered on starch-ampicillin agar were similar to those recovered on brain heart infusion and blood ampicillin agar media, and were 101 to 103 greater than the recovery rate on either MacConkey-ampicillin or cefsulodinirgasan-novobiocin agars. The sensitivity for the direct recovery of Aeromonas sp. from inoculated beef feces with naturally contaminating microflora, using streaked starch-ampicillin agar medium, was between 102 and 103 cells per gram. Using starch-ampicillin agar, the incidence of Aeromonas detected from feces of beef, pig, sheep and turkey held at the Beltsville Agricultural Research Center was one of 32, none of 22, none of 24 and three of 21, respectively. Based upon current taxonomic criteria, the isolate from the beef feces had characteristics consistent with both Aeromonas sobria and Aeromonas caviae, whereas three isolates from turkey feces were identified as A. caviae or Aeromonas hydrophila. The organism was isolated from five of five packages of ground beef from retail sources. The discrepancy in the consistent presence of the organism in retail meat suggests that many of the food isolates are probably not of fecal origin.

Colony formation by Bact. lactis aerogenes on solid media containing antibacterial agents

1952 ◽  
Vol 215 (1123) ◽  
pp. 565-565
Keyword(s):  
Inoculum Size ◽  
Survival Times ◽  
Fluctuation Test ◽  
Solid Media ◽  
Statistical Variation ◽  
Toxic Concentration ◽  
Solid Agar ◽  
Agar Media ◽  
Different Cultures ◽  
The Given

A study has been made of the formation of colonies of Bact. lactis aerogenes on solid agar media containing antibacterial substances (brilliant green, 1-phenyl semicarbazide, phenyl mercuric nitrate, phenol, thymol and chloramphenicol) at such concentrations that a small fraction only of the inoculated cells develop. The pattern of behaviour varies from drug to drug and sometimes from culture to culture with a given drug. As the toxic concentration increases, colonies diminish in number, in size or in both. Anomalous dependence in some cases upon inoculum size, and the appearance in others of satellites to the main colonies, indicate the operation of co-operative effects probably depending upon diffusion of metabolites or antagonists. The statistical variation in the number of developing colonies is greater for different cultures than for samples of a given culture (as in the well-known fluctuation test for mutations), but the behaviour of a culture may depend upon the aeration, and upon the precise conditions of the test. The variances show no apparent relation to the ease of production of resistance to the given drug. Nor does the scatter of the survival times in liquid media containing phenol (no resistance developable) differ much from that in chloramphenicol (resistant forms readily produced). Consideration of the factors determining the successful formation of a colony on a drug plate suggests that the fluctuation test for the demonstration of mutations must be applied with great reserve.

scholarly journals A comparative study of the virulence factors of Klebsiella spp. Isolated from different environments: دراسة مقارنة لعوامل الضراوة الخاصة ببكتيريا الكليبسيلا Klebsiella spp. المعزولة من بيئات مختلفة

2016 ◽  
Vol 2 (8) ◽  
Author(s):  
Laith Mosleh Naguib , Nagham Mued Hamdy
Keyword(s):  
Comparative Study ◽  
Virulence Factors ◽  
Environmental Samples ◽  
Bacterial Infections ◽  
Bacterial Culture ◽  
Antibiotic Sensitivity ◽  
Bacterial Isolates ◽  
Agar Media ◽  
Different Sources ◽  
Klebsiella Spp

The Current study conducted to investigate of different virulence factors for bacterial isolates resistant to antibiotics and isolated from different environments. where it was collected 247 clinical and environmental samples from different sources isolated on Nutrient agar media.    The results of bacterial culture have shown that 46 isolation dating back to the bacterium Klebsiella spp , isolates  also showed mixed results towards  antibiotics . and antibiotic sensitivity results were selected 18 bacterial isolates resistant to antibiotics to study some of the virulence factors ant to investigate the genes responsible for the kinship between the isolates using (PCR), and the results showed the overall rate of similarity of isolates sick and environmental by 64%, which shows that source of bacterial infections maybe caused by contact with water or soil.

Effect of Abamectin on Fungal Growth and its Efficacy as a Miticide in the Laboratory

2020 ◽  
Author(s):  
Dana Sebestyen ◽  
Gabriel Perez-Gonzalez ◽  
Mrinalini Ghoshal ◽  
Barry Goodell
Keyword(s):  
Fungal Growth ◽  
Recommended Dose ◽  
Effective Control ◽  
Phaeomoniella Chlamydospora ◽  
Trunk Disease ◽  
Solid Agar ◽  
The Media ◽  
Agar Media ◽  
The Common ◽  
Mold Mite

Abamectin was tested for use with solid agar media in the laboratory to eliminate or kill the common mold mite Tyrophagus spp. in fungal cultures of Phaeomoniella chlamydospora (Pch) and Phaeoacremonium minimum (Pmin), two important grape pathogens involved in grapevine trunk disease. Abamectin concentrations tested were at or below the recommended dose for abamectin in greenhouse spray applications (≦625ug/mL) to control mites and determine if: a) fungal growth would be inhibited, and b) mites would be killed or their activity suppressed. Abamectin was added either to the media before autoclaving, or filter-sterilized and added after autoclaving, to test the effects of autoclaving on abamectin efficacy. Streptomycin (100µg/mL) was also added to a set of treatments to determine if this commonly-used antibiotic would impact abamectin efficacy against mites, or have an effect on fungal growth when in combination with abamectin. Filter-sterilized abamectin in the range of 62.5 - 312ug/mL, delivered to the media after it had been autoclaved, provided the most effective control of mites while also showing limited inhibition of fungal growth on solid agar media in the absence of streptomycin. The addition of filter-sterilized streptomycin had no significant effect on fungal growth for Pch, while for Pmin a small but significant reduction in growth with streptomycin occurred at abamectin concentrations above 62.5 ug/ml.

scholarly journals Effects of inositol starvation on the levels of inositol phosphates and inositol lipids in Neurospora crassa

1993 ◽  
Vol 292 (3) ◽  
pp. 805-811 ◽  
Author(s):  
P L Lakin-Thomas
Keyword(s):  
Neurospora Crassa ◽  
Phytic Acid ◽  
Inositol Phosphates ◽  
Acid Synthesis ◽  
Extracellular Medium ◽  
Absolute Requirement ◽  
Solid Agar ◽  
Inositol Lipids ◽  
Agar Media ◽  
High Concentrations

An inositol-requiring strain of Neurospora crassa was labelled during growth in liquid medium with [3H]inositol, and the levels of inositol phosphates and phosphoinositides were determined under inositol-sufficient and inositol-starved conditions. Because the mutant has an absolute requirement for inositol, the total mass of inositol-containing compounds could be determined. Inositol-containing lipids were identified by deacylation and co-migration with standards on h.p.l.c.; PtdIns3P, PtdIns4P, and PtdIns(4,5)P2 were found in approximately equal amounts, in addition to large amounts of PtdIns. Inositol starvation decreased the level of PtdIns to 10% of the sufficient level, and decreased the levels of the other phosphoinositides to about 25%. A number of inositol phosphates were found, including several InsP3s, InsP4s and InsP5s and phytic acid. Ins(1,4,5)P3 was identified by co-migration with standards on h.p.l.c. and by digestion with inositol phosphomonoesterase. High concentrations of all inositol phosphates were found in the extracellular medium in inositol-starved cultures. Inositol starvation on both liquid and solid agar media decreased the intracellular levels of some inositol phosphates, but increased the levels of phytic acid and several other inositol phosphates which may be its precursors and/or breakdown products. These results may indicate that inositol starvation induces phytic acid synthesis as a protection against the free-radical production and lipid peroxidation characteristic of inositol-less death.

scholarly journals A Hidden Pitfall in the Preparation of Agar Media Undermines Microorganism Cultivability

2014 ◽  
Vol 80 (24) ◽  
pp. 7659-7666 ◽  
Author(s):  
Tomohiro Tanaka ◽  
Kosei Kawasaki ◽  
Serina Daimon ◽  
Wataru Kitagawa ◽  
Kyosuke Yamamoto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Environmental Samples ◽  
Agar Medium ◽  
Total Cell ◽  
Plate Count ◽  
Growth Media ◽  
Content Type ◽  
Cell Counts ◽  
Soil Sediment ◽  
Agar Media

ABSTRACTMicrobiologists have been using agar growth medium for over 120 years. It revolutionized microbiology in the 1890s when microbiologists were seeking effective methods to isolate microorganisms, which led to the successful cultivation of microorganisms as single clones. But there has been a disparity between total cell counts and cultivable cell counts on plates, often referred to as the “great plate count anomaly,” that has long been a phenomenon that still remains unsolved. Here, we report that a common practice microbiologists have employed to prepare agar medium has a hidden pitfall: when phosphate was autoclaved together with agar to prepare solid growth media (PT medium), total colony counts were remarkably lower than those grown on agar plates in which phosphate and agar were separately autoclaved and mixed right before solidification (PS medium). We used a pure culture ofGemmatimonas aurantiacaT-27Tand three representative sources of environmental samples, soil, sediment, and water, as inocula and compared colony counts between PT and PS agar plates. There were higher numbers of CFU on PS medium than on PT medium usingG. aurantiacaor any of the environmental samples. Chemical analysis of PT agar plates suggested that hydrogen peroxide was contributing to growth inhibition. Comparison of 454 pyrosequences of the environmental samples to the isolates revealed that taxa grown on PS medium were more reflective of the original community structure than those grown on PT medium. Moreover, more hitherto-uncultivated microbes grew on PS than on PT medium.

scholarly journals The influence of media on the recovery of bacteria from the normal mouse caecum

1982 ◽  
Vol 16 (4) ◽  
pp. 364-368
Author(s):  
J. P. Koopman ◽  
H. M. Kennis
Keyword(s):  
Normal Mouse ◽  
Viable Count ◽  
Potassium Salts ◽  
Lower Yield ◽  
Solid Agar ◽  
The Media ◽  
Agar Media ◽  
Microscopic Count ◽  
Quantitative Recovery

3 diluting fluids and 6 agar media were compared for the culture of caecal micro flora of mice. The efficiency of the media in the growth of caecal bacteria was determined by comparing the quantitative recovery (expressed as percentage of the total microscopic count) from the specimens. Of the diluting fluids saline resulted in a low yield (11·47%). Addition of potassium salts increased the yield (23·25%). A broth medium resulted in the highest recovery (44·44%). The influence of storing the caecal micro flora in 3 different diluting fluids on the yield was studied. In all diluents the viable count of caecal bacteria decreased with time, but did so least in broth medium. 6 solid agar media were tested. When saline was used as the diluting fluid, no significant differences in yields were found with all 6 media. When broth medium was used as diluting fluid and yields up to 60% were obtained, no significant differences were shown between the results with 5 media but one medium resulted in a lower yield (32·59%).

scholarly journals Differentiation and Anaerobiosis in Standing Liquid Cultures of Streptomyces coelicolor

2003 ◽  
Vol 185 (4) ◽  
pp. 1455-1458 ◽  
Author(s):  
Geertje van Keulen ◽  
Henk M. Jonkers ◽  
Dennis Claessen ◽  
Lubbert Dijkhuizen ◽  
Han A. B. Wösten
Keyword(s):  
Metabolic Pathways ◽  
Minimal Medium ◽  
Streptomyces Coelicolor ◽  
Anaerobic Growth ◽  
Liquid Cultures ◽  
Air Interface ◽  
Solid Agar ◽  
Aerial Hyphae ◽  
Agar Media ◽  
Surface Liquid

ABSTRACT Streptomyces coelicolor differentiates on solid agar media by forming aerial hyphae that septate into spores. We here show that differentiation also occurs in standing liquid minimal media. After a period of submerged growth, hyphae migrate to the air interface, where they become fixed by a rigid reflecting film. Colonies that result from these hyphae form sporulating aerial hyphae. In addition, submerged hyphae in the liquid minimal medium may attach to the surface. Liquid standing cultures easily become anoxic only 1 to 2 mm below the surface. Yet, biomass increases, implying the existence of metabolic pathways supporting anaerobic growth.

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