Use of the direct epifluorescent filter technique for the enumeration of bacterial spores

Kelly, Alison F.; Kroll, R.G.

doi:10.1111/j.1365-2672.1987.tb02725.x

Cited by 7 publications

(2 citation statements)

References 8 publications

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“…Kelly and Kroll (18) reported a mean bacterial spore count of log 4.5 for enumeration of bacterial spores in food, which was markedly higher than the one obtained in our sample.…”

Section: Discussioncontrasting

confidence: 80%

Microbial load, prevalence and antibiograms of Salmonella and Shigella in lettuce and green peppers

Guchi¹,

Ashenafi²

2011

Ethiop J Health Sci

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BackgroundHuman food borne infections traditionally are acquired through the ingestion of foods of animal origin. Fresh fruits and vegetables are major vehicles for the transmission of the food-borne infections. In Ethiopia, there is a tradition of consuming raw vegetables, particularly lettuce and green pepper, without adequate treatment. The objective of this study was to investigate the microbial load of fresh lettuce and green pepper, used as salad vegetables, and to assess the prevalence and antibiotic resistance of Salmonella and Shigella spp. isolated from lettuce and green pepper.MethodsA total of eighty samples of lettuce and green peppers were purchased from different outlets in Addis Ababa and analyzed for their load of various microbial groups and flora analysis was conducted following standard microbiological methods. The presence of Salmonella and Shigella and their antibiotic resistance was also determined.ResultsOver 90% of the vegetable samples had aerobic mesophilic counts of ≥ log 6 cfu/g. Ninety seven percent of the lettuce and 58% of the green pepper samples had enterobacteraceae counts of ≥ log 5 cfu/g. Coliforms were encountered at counts ≥ log 4 cfu/g in 48% and 35% of lettuce and green pepper samples, respectively. Over 80% of vegetable samples harbored staphylococci with counts ranging from log 4 to log 6 cfu/g. More than 88% of lettuce and 18% of green pepper samples had yeast and mold counts ≥ log 4 cfu/g. The aerobic mesophilic flora of the vegetable samples was dominated by Bacillus and Micrococcus spp. Salmonella and Shigella were isolated from eight (10%) and 24 (30%) samples, respectively. All of the Salmonella and 97% of Shigella isolates showed resistance to penicillin. Ampicillin resistance was observed in 42% of Salmonella and 79% of Shigella isolates. Multiple drug resistance was seen in 8 and 24 isolates of Salmonella and Shigella isolates, respectively.ConclusionThe majority of lettuce and green pepper samples had high microbial load and multiple drug resistant pathogens were also isolated from some samples. As lettuce and green pepper, when used as salad vegetables, do not get any further heat treatment, thorough washing and considerably longer exposure of the vegetables to food grade chemicals is recommended to kill pathogens and significantly reduce the microbial load.

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“…Kelly and Kroll (18) reported a mean bacterial spore count of log 4.5 for enumeration of bacterial spores in food, which was markedly higher than the one obtained in our sample.…”

Section: Discussioncontrasting

confidence: 80%

Microbial load, prevalence and antibiograms of Salmonella and Shigella in lettuce and green peppers

Guchi¹,

Ashenafi²

2011

Ethiop J Health Sci

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“…Detection and enumeration of fluorescently labeled bacteria, bacterial spores, yeasts, and fungi is emerging as a powerful, rapid, sensitive, and accurate approach having many applications, e.g., for water, foods, and pharmaceuticals (5,6,(10)(11)(12)(16)(17)(18)(19)(20)(21)(22)(23). Many different fluorochromes have been used, but to date, acridine orange has been the most widely applied because of the differential staining that can occur, so that in DEFT "active" bacteria fluoresce orange and "inactive" bacteria fluoresce green (16)(17)(18).…”

Section: Discussionmentioning

confidence: 99%

Microcolony epifluorescence microscopy for selective enumeration of injured bacteria in frozen and heat-treated foods

Rodrigues

Kroll

1989

Appl Environ Microbiol

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A rapid (<6 h) method for selectively enumerating coliforms, pseudomonads, and staphylococci has been developed which involves counting microcolonies grown on the surface of polycarbonate membranes under selective conditions. The method was not directly applicable to foods containing injured bacteria due to the poor formation of or an inability to form microcolonies under selective conditions. However, the introduction of a 3to 5-h resuscitation step in tryptone soya broth allowed the method to give reliable estimates of these organisms in a variety of frozen and heat-processed foods. Under nonselective conditions, i.e., for total counts, the microcolony method enabled a rapid count to be made of viable bacteria in heat-treated foods, but these results were also made more consistent by the introduction of a resuscitation step. This method makes results from these foods available far faster than conventional enumeration methods.

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Evaluation of a direct epifluorescent filter technique (DEFT) for the enumeration of bacterial spores in raw milk

Moran¹,

Rowe²,

Gilmour³

1991

International Dairy Journal

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Use of the direct epifluorescent filter technique for the enumeration of bacterial spores

Cited by 7 publications

References 8 publications

Microbial load, prevalence and antibiograms of <i>Salmonella</i> and <i>Shigella</i> in lettuce and green peppers

Microbial load, prevalence and antibiograms of <i>Salmonella</i> and <i>Shigella</i> in lettuce and green peppers

Microcolony epifluorescence microscopy for selective enumeration of injured bacteria in frozen and heat-treated foods

Evaluation of a direct epifluorescent filter technique (DEFT) for the enumeration of bacterial spores in raw milk

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