Microtitration plate most-probable-number tests for the enumeration of Escherichia coli in estuarine and marine waters

Hernandez, J.F.; Kaspar, Charles W.; Hartman, Paul A.; Colwell, Rita R.

doi:10.1016/0167-7012(93)90067-r

Cited by 7 publications

(8 citation statements)

References 22 publications

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“…In brief, all samples were streaked onto MacConkey agar (Difco) and incubated for approximately 16–18 h at 37°C. All lactose‐fermenting E. coli ‐like colonies were screened with 4‐methylumbelliferyl‐ β ‐ d ‐glucuronide (MUG) (Sigma) (Hernandez et al. 1993).…”

Section: Methodsmentioning

confidence: 99%

“…In brief, all samples were streaked onto MacConkey agar (Difco) and incubated for approximately 16-18 h at 37°C. All lactose-fermenting E. coli-like colonies were screened with 4-methylumbelliferyl-b-d-glucuronide (MUG) (Sigma) (Hernandez et al 1993). Presumptive (MUG-positive) E. coli isolates were confirmed by indole, methyl red, Voges-Proskauer and citrate (IMViC) tests.…”

Section: Isolation and Identification Of E Colimentioning

confidence: 99%

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Geographical variation in antibiotic resistance profiles of Escherichia coli isolated from swine, poultry, beef and dairy cattle farm water retention ponds in Florida1

Parveen¹,

Lukasik²,

Scott³

et al. 2006

J Appl Microbiol

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Aims: The aim of this study was to assess geographical variation in multiple antibiotic resistance (MAR) profiles of livestock Escherichia coli as well as to evaluate the ability of MAR profiles to differentiate sources of faecal pollution. Methods and Results: More than 2000 E. coli isolates were collected from water retention ponds and manure of swine, poultry, beef and dairy farms in south, central and north Florida, and analysed for MAR using nine antibiotics. There were significant differences in antibiotic resistance of E. coli by season and livestock type for more than one antibiotic, but regional differences were significant only for ampicillin. Over the three regions, discriminant analysis using MAR profiles correctly classified 27% of swine, 49% of poultry, 56% of beef and 51% of dairy isolates. Conclusions: Regional variations in MAR combined with moderate discrimination success suggest that MAR profiles of E. coli may only be marginally successful in identifying sources of faecal pollution. Significance and Impact of the Study: This study demonstrates the existence of regional and seasonal differences in MAR profiles as well as the limited ability of MAR profiles to discriminate among livestock sources.

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Section: Methodsmentioning

confidence: 99%

Section: Isolation and Identification Of E Colimentioning

confidence: 99%

Geographical variation in antibiotic resistance profiles of Escherichia coli isolated from swine, poultry, beef and dairy cattle farm water retention ponds in Florida1

Parveen¹,

Lukasik²,

Scott³

et al. 2006

J Appl Microbiol

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“…Microplates have been used by others, including Hernandez et al (1993) and Pourcher et al (1991) as an approach to miniaturize the method. Microplates have been used by others, including Hernandez et al (1993) and Pourcher et al (1991) as an approach to miniaturize the method.…”

Section: Resultsmentioning

confidence: 99%

Comparison of Different Culturing Methods for Enumeration of E. coli in Thermophilically Digested Biosolids

Aynur¹,

Weinshell²,

Riffat³

et al. 2011

proc water environ fed

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Pathogen removal in sludge treatment is an important step. Several Class A processes that utilize thermal treatment to achieve pathogen reduction have observed large increases in indicator bacteria, namely fecal coliform or E. coli, after centrifuge dewatering. In many cases, the densities before dewatering were below the detection limit. One hypothesis to explain this observation is that the bacteria were poorly enumerated after the thermophilic processes, but some were still viable and were able to be recovered after dewatering. Bacteria can be nonculturable based on type of media used and methods used for enumeration. To investigate the non-culturable hypothesis, E. coli was enumerated using EPA Method 1680 and other culturing methods using microplates for investigation of non-culturable E. coli. Effect of hydraulic retention time (HRT) on pathogen removal was investigated for two enhanced digestion processes in addition to a conventional mesophilic anaerobic digestion (MAD) process. The enhanced digestion processes were dual digestion process: Autothermal Thermophilic Aerobic Digestion (ATAD) followed by MAD and acid/gas phase digestion process: Acid Phase Digestion (APD) followed by MAD. This study suggests that EPA Method 1680 could be underestimating E. coli density and a need to develop new culturing methods that are able to enumerate injured microorganisms. ATAD is more effective in pathogen removal when compared to APD. Class A Biosolids requirements was achieved with E. coli density below 3 log 10 for only 3.5 d HRT for ATAD-MAD process, with enumeration conducted with all the culturing methods investigated for this study. The better performance of ATAD can be linked to O 2 input for this process since both APD and ATAD processes were operated at the same temperature and HRTs. Additional research is necessary for comparing the effect of O 2 input and HRT on pathogen removal for ATAD. 5697WEFTEC 2011

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“…Four methods ing of the dilutions: assuming the efficiency of the Table 4 Indirect general methods for liberation of bacteria from complex communities associated with aerial plant parts spread-plate method was constant for all experiments, the methods were significantly different (P < 0.05) from one another and were ranked from most to least efficient: stomacher blending, grinding, sonication and agitation. The mean of the population sizes enumerated ranged from 4 X lo6 cfu/cm2 to -Not yet applied for bacteria on aerial parts of plants -Particularly used for indicator bacteria * Alternative MPN tests were conducted in microtitration plates to reduce time, space and material required and to enhance precision [68] 8 X lo8 cfu/cm'.…”

Section: Isolation Methodsmentioning

confidence: 99%

A review of issues related to the quantification of bacteria from the phyllosphere

Jacques¹,

Morris²

2006

FEMS Microbiology Ecology

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Quantification of the size of epiphytic bacterial populations and characterization of their composition involves definition of a sampling strategy in time and space, the choice of methods for liberating the bacteria from the leaf surface and for recovering them for subsequent determination of the number of viable or culturable cells. This literature review focuses on some of the issues related to these choices. After briefly reviewing the different types of epiphytic colonizers we consider the biological, methodological, and statistical consequences of the choice of the sampling unit and of the spatial and temporal variability of population size and composition for epiphytic bacteria. The different methods available for the detection and enumeration of naturally occurring microorganisms in the phyllosphere are discussed. Advantages and drawbacks of each are described in this review designed as a ‘hands‐on’ guide.

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Microtitration plate most-probable-number tests for the enumeration of Escherichia coli in estuarine and marine waters

Cited by 7 publications

References 22 publications

Geographical variation in antibiotic resistance profiles of Escherichia coli isolated from swine, poultry, beef and dairy cattle farm water retention ponds in Florida1

Geographical variation in antibiotic resistance profiles of Escherichia coli isolated from swine, poultry, beef and dairy cattle farm water retention ponds in Florida1

Comparison of Different Culturing Methods for Enumeration of E. coli in Thermophilically Digested Biosolids

A review of issues related to the quantification of bacteria from the phyllosphere

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