scholarly journals An improved device for sampling bacterial populations on blankets

1960 ◽  
Vol 58 (2) ◽  
pp. 157-158 ◽  
Author(s):  
A. B. McQuade ◽  
W. J. A. Sutherland
Keyword(s):  
Surface Properties ◽  
Fibrous Material ◽  
Bacterial Contamination ◽  
Agar Plate ◽  
Simple Method ◽  
Bacterial Populations ◽  
Agar Surface ◽  
Petri Dishes ◽  
Routine Sampling ◽  
Hospital Wards

One of the major difficulties in determining the cleanliness of blankets for use in hospital wards is the estimation of bacterial contamination remaining on the blanket after washing. Present procedures are either cumbersome or not readily reproducible. Procedures for measuring bacterial contamination on fabrics may be based on dispersion of the bacteria as an aqueous or as an airborne cloud. As aerial sampling has the advantages that it may be rapid and simple and can be used to sample blankets which have been washed with a bactericide the possibilities of this principle were investigated. A simple method has been developed (Blowers & Wallace, 1955) in which the blanket is scraped manually by the edge of an agar plate so that the bacterial dust is thrown on to the exposed agar surface, but this procedure is difficult to control. There are wide differences in surface properties of blankets, and consequently in the amount of fibrous material shaved off by the Petri dishes. Puck, Robertson, Wise, Loosli & Lemon (1946) worked on the principle of hitting an area of taut blanket and sampling the aerial cloud so formed, but as their apparatus was not convenient for routine sampling in wards an improved version has been developed.

Bacteriology and Storage Life of Moisture-Enhanced Pork

2003 ◽  
Vol 66 (2) ◽  
pp. 293-299 ◽  
Author(s):  
VALERIE M. BOHAYCHUK ◽  
G. GORDON GREER
Keyword(s):  
Bacterial Contamination ◽  
Lemon Juice ◽  
Storage Life ◽  
Bacterial Populations ◽  
Psychrotrophic Bacteria ◽  
Injection Process ◽  
Spoilage Bacteria ◽  
The Impact ◽  
And Storage ◽  
Brine Injection

This study was undertaken to determine the impact of the moisture enhancement process on the bacterial contamination and storage life of vacuum-packaged pork loins. Bone-in and boneless pork loins injected with brine (sodium chloride, sodium phosphate, lemon juice) were obtained from a commercial processing facility and stored for 5 weeks in vacuum packaging at 2 and 5°C. At weekly intervals, samples were excised to determine numbers of spoilage bacteria and pathogens. The loins were subjectively evaluated by a sensory panel to quantify appearance and odor acceptability. Moisture-enhanced loins were initially contaminated with a population of psychrotrophic bacteria that was approximately 2 log units higher than that for noninjected boneless loins. This difference was largely due to contamination by larger numbers of pseudomonads in the brine-injected loins. There were no significant differences in the initial numbers of lactic acid bacteria, Enterobacteriaceae, or Brochothrix thermosphacta. Similar trends in spoilage bacterial populations were observed for moisture-enhanced loins with bones, but Enterobacteriaceae counts were also found to be approximately 1 log unit higher for the injected product. Brine-injected loins generally had larger bacterial numbers at each storage time, but there were no consistent injection treatment effects on bacterial growth. Brine injection did not affect color or odor deterioration, and the storage life for vacuum-packaged loins was the same as that for noninjected controls. The incidence of Listeria monocytogenes was 21% for control loins and 27% for moisture-enhanced loins. Although the brine injection process resulted in an increase in bacterial contamination, there was no evidence that this contamination would affect the storage life of vacuum-packaged loins, and further research is necessary to determine the significance of the increased incidence of L. monocytogenes.

Disinfection of selected Aspergillus spp. using ultraviolet germicidal irradiation

2004 ◽  
Vol 50 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Christopher F Green ◽  
Pasquale V Scarpino ◽  
Paul Jensen ◽  
Nancy J Jensen ◽  
Shawn G Gibbs
Keyword(s):  
Aspergillus Fumigatus ◽  
Aspergillus Flavus ◽  
Fungal Spores ◽  
Petri Dish ◽  
Testing Unit ◽  
Ultraviolet Germicidal Irradiation ◽  
Airborne Fungal Spores ◽  
Agar Surface ◽  
Petri Dishes ◽  
Higher Doses

Aims: The efficacy of ultraviolet germicidal irradiation (UVGI) and the UVGI dose necessary to inactivate fungal spores on an agar surface for cultures of Aspergillus flavus and Aspergillus fumigatus were determined. Methods and results: A four-chambered UVGI testing unit with a 9-W, Phillips, low pressure, mercury UVGI lamp in each chamber was used in this study. An aperture was adjusted to provide 50, 100, 150, and 200 µW/cm2 of uniform flux to the surfaces of the Petri dish, resulting in a total UVGI dose to the surface of the Petri dishes ranging from 12 to 96 mJ/cm2. The UVGI dose necessary to inactivate 90% of the A. flavus and A. fumigatus was 35 and 54 mJ/cm2, respectively. Conclusions: UVGI can be used to inactivate culturable fungal spores. Aspergillus flavus was more susceptible than A. fumigatus to UVGI. Significance and impact of the study: These results may not be directly correlated to the effect of UVGI on airborne fungal spores, but they indicate that current technology may not be efficacious as a supplement to ventilation unless it can provide higher doses of UVGI to kill spores traveling through the irradiated zone.Key words: Aspergillus, ultraviolet germicidal irradiation, fungi.

A bilayer plate technique to detect broad-spectrum antagonism in microorganisms and its application to wood-inhabiting fungi

1973 ◽  
Vol 19 (11) ◽  
pp. 1455-1458 ◽  
Author(s):  
D. E. Etheridge ◽  
H. M. Craig
Keyword(s):  
Broad Spectrum ◽  
Mycelial Growth ◽  
Growth Response ◽  
Agar Plate ◽  
Antagonistic Activity ◽  
Simple Method ◽  
Decay Fungi ◽  
Quantitative Estimates ◽  
Wide Range ◽  
Single Agar

A simple method is described for measuring antagonistic activity in microorganisms based on the mycelial growth response of up to 10 isolates of the bioassay fungus in a single agar plate. The technique overcomes disadvantages of existing methods by providing quantitative estimates of interstrain variability in the bioassay fungus as well as the antagonist. Application of the method to a wide range of isolates of Ascocoryne sarcoides (Jacq. ex Gray) Groves and Wilson against three species of decay fungi has permitted the rapid detection of broad-spectrum strains of this fungus which would not have been practical by conventional bioassays.

scholarly journals A Simple Method for Anaërobic Cultivation in Petri Dishes

1922 ◽  
Vol 12 (2) ◽  
pp. 119-121 ◽  
Author(s):  
Sterne Morse ◽  
Nicholas Kopeloff
Keyword(s):  
Simple Method ◽  
Petri Dishes

scholarly journals A simple method for characterizing the surface properties of polymers

2003 ◽  
Vol 22 (7) ◽  
pp. 727-731 ◽  
Author(s):  
D. Hosseinpour ◽  
N. Mohammadi ◽  
S. Moradian
Keyword(s):  
Surface Properties ◽  
Simple Method

GROUP A STREPTOCOCCAL INFECTIONS IN A CHILDREN'S HOME

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 5-10
Author(s):  
Hugh L. Moffet ◽  
Henry G. Cramblett ◽  
Joyce P. Black
Keyword(s):  
Agar Plate ◽  
Streptococcal Pharyngitis ◽  
School Age Children ◽  
Blood Agar Plate ◽  
Normal Children ◽  
Simple Method ◽  
Sheep Blood Agar Plate ◽  
Children's Home ◽  
Group A ◽  
Refrigerator Temperature

School-age children living in a children's home had pharyngeal cultures made on 485 consecutive infirmary admissions during a period of 14 months by inoculating the throat swab on the surface of a sheep blood agar plate. ASO titers were determined for the acute and convalescent phases of 95% of the 321 untreated illnesses associated with negative cultures. A rise in ASO titer occurred in 3.6% of these illnesses. ASO titers were also determined on pairs of sera for 51 of 53 untreated febrile illnesses associated with negative streptococcal cultures in 1962 and a rise in ASO titer occurred for only one of these illnesses (2%). This simple method for pharyngeal cultures is adequate and accurate as a laboratory aid to the practicing physician for the diagnosis of streptococcal pharyngitis in normal children. Bacitracin sensitivity showed an excellent correlation with Group A streptococci. Studies of duplicate swabs indicated that overnight storage of a dry swab at room or refrigerator temperature was associated with the recovery of more than 10 colonies of hemolytic streptococci from 80% to 88% of the swabs whose duplicates had more than 50 colonies.

scholarly journals Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

2016 ◽  
Vol 30 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Guodong Zha ◽  
Bochu Wang ◽  
Junyu Liu ◽  
Jie Yan ◽  
Liqing Zhu ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Lateral Root ◽  
Plant Root ◽  
Primary Root ◽  
Agar Plate ◽  
Touch Response ◽  
Agar Surface ◽  
Root Growth And Development ◽  
Touch Stimulus

Abstract The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

Degradation of antifouling booster biocides in water

2005 ◽  
Vol 85 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Hiroya Harino ◽  
Masaaki Kitano ◽  
Yoshiaki Mori ◽  
Kazuhiko Mochida ◽  
Akira Kakuno ◽  
...  
Keyword(s):  
Detection Limit ◽  
Water Samples ◽  
Uv Light ◽  
Agar Plate ◽  
Estuarine Water ◽  
Bacterial Populations ◽  
Sunlight Irradiation ◽  
Irgarol 1051 ◽  
Colony Forming Units ◽  
Copper Pyrithione

The concentrations of booster compounds were surveyed in the port of Osaka, Japan. The concentrations of Sea-Nine 211, Diuron and Irgarol 1051 in water samples from the port of Osaka were in the ranges <0·30–0·55 ng l−1, 13–350 ng l−1, 1·3–77 ng l−1, respectively. Pyrithiones were not detected in water samples. The levels of Diuron and Irgarol 1051 in the port of Osaka were high in the mooring area for small and medium-hull vessels with poor flushing.Susceptibility of bacterial populations in estuarine water to antifouling biocides was studied. Sea-Nine 211, Diuron, Irgarol 1051 and Copper pyrithione dissolved in dimethyl sulfoxide (DMSO) were added to estuarine water and number of colony forming units (CFU) of bacteria in estuarine water was counted using R2A agar plate. The CFU was not decreased at the concentration less than 1·0 mg/l of Diuron, Irgarol 1051 and Copper pyrithione. However, CFU was decreased at 0·1 mg/l of Sea-Nine 211. Degradation of Sea-Nine 211, Diuron, Irgarol 1051 and Copper pyrithione by bacteria in estuarine water was studied using a die-away method. At an initial concentrations of 0·1 mg/l, observed half-lives of Sea-Nine 211 and Copper pyrithione were 10 and 20 days, respectively. In contrast, Diuron and Irgarol 1051 were degraded scarcely during 60 days of culture.Photodegradation of these booster biocides by sunlight and UV light were studied. Under UV, all biocides were below detection limit after one day of irradiation. Under sunlight, Copper pyrithiones were also below detection limits after one day. Drastic decrease of Sea-Nine 211 concentration was observed after one day. Diuron and Irgarol 1051 scarcely decreased during 17 days of sunlight irradiation.

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