Modified most-probable-number technique for the specific determination of Escherichia coli from environmental samples using a fluorogenic method

A salmonellosis outbreak occurred during the summer of 1995 among individuals who consumed nonpasteurized orange juice from a Florida citrus-processing facility. Clinical isolates were identified by the Centers for Disease Control as Salmonella serovars Hartford, Gaminara, and Rubislaw. At the processing facility, 70 samples (equipment swabs, fruit surface swabs, juice, and miscellaneous environmental samples) were collected before, during, and after processing runs on two different dates. Bottled juice samples from eight previous extraction dates were also collected. Total plate counts, fecal coliforms, and Escherichia coli were enumerated for each sample. Analyses for Salmonella cells were conducted on all juice samples, fruit surface swabs, environmental samples, and selected equipment swabs using direct enrichment and pre-enrichment techniques. Salmonella serovars Hartford, Rubislaw, Saintpaul, and Newport were detected from either juice, unwashed fruit surfaces, or amphibians (Hyla cinerea and Bufo terrestris) captured outside the processing building. Salmonella cells in juice were associated with population levels of fecal coliforms and E. coli above the upper most probable number (MPN) limits of detection (>110/ml).

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Microbiology of food and animal feeding stuffs. Horizontal method for the detection and enumeration of presumptive Escherichia coli. Most probable number technique

10.3403/03263836 ◽

2005 ◽

Keyword(s):

Escherichia Coli ◽

Most Probable Number ◽

Probable Number ◽

Animal Feeding

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Microbiology of food and animal feeding stuffs. Horizontal method for the determination of low numbers of presumptive Bacillus cereus. Most probable number technique and detection method

10.3403/30110930 ◽

2006 ◽

Keyword(s):

Bacillus Cereus ◽

Detection Method ◽

Most Probable Number ◽

Probable Number ◽

Animal Feeding

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Lessons from a large outbreak of Escherichia coli O157[ratio ]H7 infections: insights into the infectious dose and method of widespread contamination of hamburger patties

Epidemiology and Infection ◽

10.1017/s0950268898001976 ◽

1999 ◽

Vol 122 (2) ◽

pp. 185-192 ◽

Cited By ~ 232

Author(s):

J. TUTTLE ◽

T. GOMEZ ◽

M. P. DOYLE ◽

J. G. WELLS ◽

T. ZHAO ◽

...

Keyword(s):

Escherichia Coli ◽

Ground Beef ◽

Most Probable Number ◽

Strong Argument ◽

Probable Number ◽

Infectious Dose ◽

E Coli ◽

Beef Patties ◽

Large Outbreak ◽

Microbiological Testing

Between November 1992 and February 1993, a large outbreak of Escherichia coli O157[ratio ]H7 infections occurred in the western USA and was associated with eating ground beef patties at restaurants of one fast-food chain. Restaurants that were epidemiologically linked with cases served patties produced on two consecutive dates; cultures of recalled ground beef patties produced on those dates yielded E. coli O157[ratio ]H7 strains indistinguishable from those isolated from patients, confirming the vehicle of illness. Seventy-six ground beef patty samples were cultured quantitatively for E. coli O157[ratio ]H7. The median most probable number of organisms was 1·5 per gram (range, <0·3–15) or 67·5 organisms per patty (range, <13·5–675). Correlation of the presence of E. coli O157[ratio ]H7 with other bacterial indicators yielded a significant association between coliform count and the presence of E. coli O157[ratio ]H7 (P=0·04). A meat traceback to investigate possible sources of contamination revealed cattle were probably initially colonized with E. coli O157[ratio ]H7, and that their slaughter caused surface contamination of meat, which once combined with meat from other sources, resulted in a large number of contaminated ground beef patties. Microbiological testing of meat from lots consumed by persons who became ill was suggestive of an infectious dose for E. coli O157[ratio ]H7 of fewer than 700 organisms. These findings present a strong argument for enforcing zero tolerance for this organism in processed food and for markedly decreasing contamination of raw ground beef. Process controls that incorporate microbiological testing of meat may assist these efforts.

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Mechanically Ventilated Broiler Sheds: a Possible Source of Aerosolized Salmonella, Campylobacter, and Escherichia coli

Applied and Environmental Microbiology ◽

10.1128/aem.01380-09 ◽

2009 ◽

Vol 75 (23) ◽

pp. 7417-7425 ◽

Cited By ~ 43

Author(s):

H. N. Chinivasagam ◽

T. Tran ◽

L. Maddock ◽

A. Gale ◽

P. J. Blackall

Keyword(s):

Escherichia Coli ◽

Most Probable Number ◽

Production Cycle ◽

Airborne Bacteria ◽

Probable Number ◽

Mechanically Ventilated ◽

The Public ◽

E Coli ◽

Poultry Farms ◽

Low Levels

ABSTRACT This study assessed the levels of two key pathogens, Salmonella and Campylobacter, along with the indicator organism Escherichia coli in aerosols within and outside poultry sheds. The study ranged over a 3-year period on four poultry farms and consisted of six trials across the boiler production cycle of around 55 days. Weekly testing of litter and aerosols was carried out through the cycle. A key point that emerged is that the levels of airborne bacteria are linked to the levels of these bacteria in litter. This hypothesis was demonstrated by E. coli. The typical levels of E. coli in litter were ∼108 CFU g−1 and, as a consequence, were in the range of 102 to 104 CFU m−3 in aerosols, both inside and outside the shed. The external levels were always lower than the internal levels. Salmonella was only present intermittently in litter and at lower levels (103 to 105 most probable number [MPN] g−1) and consequently present only intermittently and at low levels in air inside (range of 0.65 to 4.4 MPN m−3) and once outside (2.3 MPN m−3). The Salmonella serovars isolated in litter were generally also isolated from aerosols and dust, with the Salmonella serovars Chester and Sofia being the dominant serovars across these interfaces. Campylobacter was detected late in the production cycle, in litter at levels of around 107 MPN g−1. Campylobacter was detected only once inside the shed and then at low levels of 2.2 MPN m−3. Thus, the public health risk from these organisms in poultry environments via the aerosol pathway is minimal.

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l-lactate enzyme electrode obtained with immobilized respiratory chain From Escherichia coli and oxygen probe for specific determination of l-lactate in yogurt, wine and blood

Biosensors ◽

10.1016/0265-928x(87)80011-1 ◽

1987 ◽

Vol 3 (1) ◽

pp. 27-43 ◽

Cited By ~ 12

Author(s):

E. Actamowicz ◽

C. Burstein

Keyword(s):

Escherichia Coli ◽

Respiratory Chain ◽

Enzyme Electrode ◽

Oxygen Probe ◽

Specific Determination

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Microbiological counting in lamb carcasses from an abattoir in São Paulo, Brazil

Ciência Rural ◽

10.1590/s0103-84782009000600030 ◽

2009 ◽

Vol 39 (6) ◽

pp. 1836-1841 ◽

Cited By ~ 3

Author(s):

Thaís Mioto Martineli ◽

Oswaldo Durival Rossi Junior ◽

Natacha Deboni Cereser ◽

Marita Vedovelli Cardozo ◽

Cristianne Lino Fontoura ◽

...

Keyword(s):

Escherichia Coli ◽

Microbiological Quality ◽

Sao Paulo ◽

Most Probable Number ◽

São Paulo ◽

Probable Number ◽

Lamb Meat ◽

Thermotolerant Coliforms ◽

Sanitary Conditions

The consumption of lamb meat in Brazil has increased in the last years but little information about the microbiological quality of this product is available. To evaluate the hygienic-sanitary conditions of lamb carcasses, the quantification of microorganism populations indicators (mesophiles and psychrotrophs; total and thermotolerant coliforms; Escherichia coli; moulds and yeasts) and the pathogenic microorganisms indentification (Salmonella sp. and Listeria spp.) were performed. A total of 60 lamb carcasses were sampled from one abattoir in São Paulo. Swab samples were collected from three points (forequarter, back and hindquarter) on the muscle surface after carcasses final washing. Statistical analysis consisted of descriptive evaluation of the results whose counts were grouped by intervals of microorganism populations. Counts ranged from 1.0 x 10¹ to 8.0 x 10(4) colony-forming unit cm-2 (CFU cm-2) for mesophiles; 1.0 x 10(0) to 4.4 x 10(4)CFU cm-2 for psychrotrophs; < 1.0 x 10(0) to 4.4 x 10(4)CFU cm-2 for moulds and yeasts; < 0.3 to > 32.0 most probable number/cm² (MPN cm-2) for total and thermotolerant coliforms and Escherichia coli. Salmonella sp. and Listeria spp. were not found in any of the carcasses. Most carcasses presented low counts for all microorganisms. Overall results may be explained by the small size of the industry where the study was taken. Results suggest that good microbiological quality lamb meat is possible to be obtained, but improvement in hygienic-sanitary conditions is still required.

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Rapid estimation of most probable number with a hand-held calculator

Canadian Journal of Microbiology ◽

10.1139/m83-098 ◽

1983 ◽

Vol 29 (5) ◽

pp. 621-623 ◽

Cited By ~ 4

Author(s):

M. T. MacDonell

Keyword(s):

Rapid Method ◽

Environmental Samples ◽

Most Probable Number ◽

Probable Number ◽

Rapid Estimation ◽

Dilution Level

The most probable number (MPN) method of enumerating bacteria from environmental samples is widely used; however, it requires (i) that only certain numbers of tubes per dilution level be employed and (ii) a table of MPN values by which the resulting MPN codes may be evaluated. A rapid method for the estimation of MPN, regardless of the number of tubes per dilution level, applicable to unsophisticated hand-held calculators is presented.

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