MFC Method Research Articles

Material flow control in make-to-stock production systems: an assessment of order generation, order release and production authorization by simulation

AbstractMaterial flow control (MFC) is a key element of production planning and control. The literature typically categorizes different MFC methods according to how MFC is realized. This distinction overlooks that MFC decisions can be subdivided into three independent tasks that are executed as orders progress through the system: (i) order generation, (ii) order release, and (iii) production authorization. MFC methods are typically designed for only one of these three tasks, which leaves a large part of the order flow uncontrolled. This study therefore not only provides a new categorization of MFC methods, but also argues for the simultaneous application (or the combining) of three different MFC methods for order generation, order release, and production authorization. To support this argument, the performance effects of an integrated MFC approach are evaluated. Findings show that each individual MFC method impacts different performance metrics, which can be explained by the presence of a hierarchy of workloads, where each workload level constrains the succeeding hierarchical level. Each MFC method has a main impact on a different workload. This has important implications for the design of MFC methods and extends recent literature on hierarchical production planning and control systems.

Measurable Residual Disease Detected by Multiparameter Flow Cytometry and Sequencing Improves Prediction of Relapse and Survival in Acute Myeloid Leukemia.

The clinically ideal time point and optimal approach for the assessment of measurable residual disease (MRD) in patients with acute myeloid leukemia (AML) are still inconclusive. We investigated the clinical value of multiparameter flow cytometry-based MRD (MFC MRD) after induction (n = 492) and two cycles of consolidation (n = 421). The latter time point was proved as a superior indicator with independent prognostic significance for both relapse-free survival (RFS, HR = 3.635, 95% CI: 2.433–5.431, P <0.001) and overall survival (OS: HR = 3.511, 95% CI: 2.191–5.626, P <0.001). Furthermore, several representative molecular MRD markers were compared with the MFC MRD. Both approaches can establish prognostic value in patients with NPM1 mutations, and FLT3, C-KIT, or N-RAS mutations involved in kinase-related signaling pathways, while the combination of both techniques further refined the risk stratification. The detection of RUNX1–RUNX1T1 fusion transcripts achieved a considerable net reclassification improvement in predicting the prognosis. Conversely, for patients with biallelic CEBPA or DNMT3A mutations, only the MFC method was recommended due to the poor prognostic discriminability in tracking mutant transcripts. In conclusion, this study demonstrated that the MFC MRD after two consolidation cycles independently predicted clinical outcomes, and the integration of MFC and molecular MRD should depend on different types of AML-related genetic lesions.

PS1352 DISSECTING THE BONE MARROW IMMUNE MICROENVIRONMENT IN THE COMPLETE SPECTRUM OF MONOCLONAL GAMMOPATHIES: POTENTIAL IMPLICATIONS IN DISEASE PATHOGENESIS

Background: To discriminate different outcomes among patients in CR the IMWG introduced a more stringent CR (sCR) criteria by adding to the pre-existing CR criteria the requirement of a normal free-light chain ratio (sFLCr) plus the absence of clonal plasma cells (PCs) in bone marrow (BM) by immunohistochemistry (IHC). In 2011, the low-sensitivity cytometry was included as alternative methodology to IHC to define sCR. However, the prognostic significance of the kappa/lambda ratio values is not clear. Aims: To verify the conclusion of our previous study (Blood 2015. 126:858–62) regarding the lack of influence in the prognosis of abnormal serum free light chain ratios (sFLCr) in a more extensive series of newly diagnosed multiple myeloma (NDMM) patients in CR or sCR Methods: NDMM patients aged ≤65 years enrolled in GEM2012MENOS65 (NCT01916252). Of 458 patients, 8 discontinued early and were not evaluable. The definition of CR and sCR was made according to the IMWG criteria. SFLCr (FREELITE assay) was classified as normal (0.26–1.65) or abnormal (<0.26 if the patient was λ; >1.65 if the patient was κ). MRD was assessed using next-generation flow cytometry. The median limit of detection was of 3x10–6. All the CR with normal sFLCr and absence of clonal PCs by MFC with a sensitivity of 10–2 were considered sCR. Median follow-up was 47.5 months. Results: After induction, 425 patients were evaluable for response; 201 (47%) reached ≥CR. Data from sFLCr and MRD was available in 192 and 193 patients, respectively. In the CR evaluable patients for sCR assessment (n = 184), the rate of sCR was 64% (n = 117). In a landmark from the end of induction (median follow-up 39 months), sCR didn’t show significantly differences in PFS (2 years-PFS 89% vs 87%; P = .7) (fig 1a) neither in OS (2 years-OS 94% vs 94%; P = .9). Interestingly, patients with abnormal (n = 67) vs normal (n = 125) sFLCr showed superimposable PFS (2 years-PFS 88% vs 87%; P = .9) (fig 1b) and OS (2 years-OS 96% vs 94%; P = .8).By contrast, the few patients (n = 3) in whom BM clonality was detected by the low-sensitivity IHC-adapted MFC method had significantly worse PFS (2 years-PFS 89% vs 67%; P = .03) (fig 1c) and OS (2 years-OS 95% vs 67%; P = .8) than patients in whom BM clonality was undetectable or detected at levels below the threshold proposed for IHC assessment. On using our traditional MRD method, persistent MRD (>10–4) was detectable among 39 of the 193 (20%) patients who, compared with MRD-negative cases, had significantly inferior PFS (2-years PFS 91% vs 80%; P = .01) (fig 1b) and OS (2 years-OS 96% vs 87%; P = .01).As validation, we reproduced the analysis in the ASCT end-point. Of the 395 evaluable patients; 238 (60%) reached ≥CR. Once again, in the landmark analysis, sCR didn’t show significantly differences in PFS in respect to CR (P = .3) neither in OS (P = .6). Patients with abnormal (n = 51) vs normal (n = 173) sFLCr showed superimposable PFS (P = .9) and OS (P = .6). Patients with persistent MRD (>10–4), had significantly inferior PFS (P = .003) but similar OS (P = .2).Summary/Conclusion: These results confirm our previous analysis based on GEM05menos65/ GEM10mas65 clinical trials. For MM patients in CR, the stringent CR criteria does not predict a different outcome. If this essential criterion in the definition of sCR lacks for the prognosis connotations, it is not justified to maintain a response category whose real significance depends on the combination of the traditional CR criteria with a negative MRD status based on very low (IHC) or low resolution (<104) levels, today outdated.

Loss of Plasmacytoid Dendritic Cell Differentiation Is Highly Predictive for Persistent Measurable Residual Disease and Poor Outcomes in Acute Myeloid Leukemia

BackgroundMeasurable residual disease (MRD) is associated with inferior outcomes in patients with acute myeloid leukemia (AML). MRD monitoring enhances risk stratification and may guide therapeutic intervention. Post-induction MRD is frequently cleared with further therapy and the clearance may lead to better outcomes. In contrast, persistent MRD is associated with poor outcomes. At present it is not possible to predict which patients are likely to clear MRD with further therapy. Here we report a simple, objective, widely applicable and quantitative MFC approach using the ratio of blast/PDC to predict persistent MRD and poor outcomes in AML.Patients and MethodsA cohort of 136 adult patients with a confirmed diagnosis of AML by WHO criteria who underwent standard induction therapy at a single center between 4/2014 and 9/2017 was initially included. 69 patients achieved complete morphologic remission (36 MRD-neg. and 33 MRD-pos.). MRD status was assessed by MFC using a different from normal (DfN) approach. PDC were quantified as the percent of total WBC by flow cytometry based on low side scatter, moderate CD45, CD303, bright CD123 and HLA-DR expression.ResultsThe proportion of PDC was markedly decreased in patients with AML (≥20% blasts) (N=136) with a median of 0.016% (interquartile range IQR: 0.0019%-0.071%, Figure 1A), more than 10-fold lower than observed in normal controls (median 0.23%, IQR 0.17%-0.34%) (N=20). While there was no difference between MRD-neg. and normal control groups (median 0.31%, IQR: 0.17%-0.49%; vs. 0.28%, IQR: 0.17%-0.34%), MRD-pos. group had significantly reduced PDC proportion compared to the control (median 0.074%, IQR: 0.022%-0.33%, Wilcoxon rank sum, p=0.019). In an attempt to achieve better separation and to eliminate possible effects of hemodilution, the ratio of blast/PDC was calculated by using the proportions of blasts and PDCs out of total WBCs as quantitated by flow cytometry. A cut-off threshold of the blast/PDC ratio of 10 was chosen to separate each group (Figure 1B). Importantly, a ratio cut-off of 10 had a corresponding specificity of 97.4% for predicting MRD positivity status.MRD positivity was significantly associated with inferior overall survival (OS) and relapse-free survival (RFS) in our study cohort (OS HR 4.11 (95% CI: 1.30-13.03), p=0.016; RFS HR 4.20 (95% CI: 1.49-11.82), p=0.007, Figure 1C and D). The 2-year cumulative incidence of relapse in the MRD-neg. group compared to MRD-pos. group was 10% (95% CI: 2-24%) vs. 37% (95% CI: 18-56%, p=0.014). Importantly, blast/PDC ratio ≥10 was also strongly associated with inferior OS and RFS (OS HR 3.12 (95% CI: 1.13-8.60), p= 0.028; RFS HR 4.05 (95% CI: 1.63-10.11), p=0.003, Figure 1E and F), which is similar in magnitude to MRD positivity. Furthermore, MRD-pos. patients with blast/PDC ratio <10 had 4 times higher MRD clearance rate than MRD-pos. patients with a ratio ≥10 (6/11, 55% vs 2/17, 12%, Fisher exactp=0.02).ConclusionWe have established an objective and quantitative MFC method to risk stratify post induction AML patients by risk for relapse, MRD clearance and likelihood of survival. Loss of PDC correlates with residual leukemia, is highly specific for MRD positivity in post-induction patients, and strongly predicts poorer overall survival and higher likelihood of relapse. Loss of PDC also predicts persistent MRD in post-induction MRD-pos. patients despite further therapy, suggesting that MRD-pos. patients with normal PDC may benefit from further therapy prior to transplant, while MRD-pos. patients with loss of PDC may not. [Display omitted] DisclosuresGoldberg:AROG: Research Funding; Pfizer: Research Funding; Celgene: Consultancy. Geyer:Dava Oncology: Honoraria. Levine:Isoplexis: Equity Ownership; C4 Therapeutics: Equity Ownership; Gilead: Honoraria; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Prelude: Research Funding; Imago: Equity Ownership; Roche: Consultancy, Research Funding; Loxo: Consultancy, Equity Ownership; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Epizyme: Patents & Royalties; Janssen: Consultancy, Honoraria. Tallman:BioSight: Other: Advisory board; AROG: Research Funding; AbbVie: Research Funding; Cellerant: Research Funding; ADC Therapeutics: Research Funding; Orsenix: Other: Advisory board; Daiichi-Sankyo: Other: Advisory board.

MINIMAL RESIDUAL DISEASE ASSESMENT IN PATIENTS WITH ACUTE MYELOID LEUKEMIA BY MULTICOLOUR FLOW CYTOMETRY (LITERATURE REVIEW)

Patients with acute myeloid leukemia (AML) have a high risk of relapse. Determination of the presence of residual tumor cells during the remission of AML allows predicting the onset of relapse. Slow decrease of blast cells after induction courses is associated with a high probability of relapse. There are two most sensitive methods for determining minimal residual disease (MRD): molecular (polymerase chain reaction – PCR, droplet digital PCR, next generation sequencing – NGS) and immunophenotypic (multicolor flow cytometry – MFC). Both methods have advantages and disadvantages. The molecular diagnostic method is more sensitive, but it takes more time to get the result (from several days). Measurement of MRD by PCR is applicable in 40–50 % of AML patients, and by MFC – in 90 % of patients. The MFC method is based on the identification of antigens combination that is characteristic of tumor cells and is not found on normal hematopoietic cells. There are several drawbacks of the MFC method: the change of tumor clone immunophenotype during treatment, the inadequate difference in the antigen profiles of tumor cells and normal cells, difficulties in evaluating the MRD status in low cellularity bone marrow or blood sample. In AML patients the effect of MRD, measured by the MFC method, on long-term treatment outcomes was well-demonstrated. Evaluation of early MRD status shows tumor chemosensitivity and therapy efficacy. Despite the different approaches in MRD detection, thresholds and the combination of monoclonal antibodies, the lack of standardization, “positive” MRD values in early or later stages of therapy worsen the disease-free (DFS) and overall survival (OS) in AML patients. So far, the principles of MRD-directed therapy have not been developed, but protocols exist with the use of targeted drugs in combination with standard chemotherapy that help to reduce the MRD level. It is proved that the intensification of treatment does not affect the quantitative value of MRD and the long-term results of therapy. New prospective studies are needed to search for universal MRD markers, to create a standardized panel of monoclonal antibodies and to develop a specific therapy strategy in accordance with the MRD values.

Sustainable Production of Bioelectricity from Coovum River Using MFC Method

Sustainable Production of Bioelectricity from Coovum River Using MFC Method

An investigation on teaching performances of model-based flipping classroom for physics supported by modern teaching technologies

The core educational purposes of scientific models are to help student learning as well as develop the students' problem solving skills. This study uses three-stage method of literature review, expert Delphi method, open-ended questionnaires, and focus interviews to investigate the flipping classroom method based upon modern teaching technologies and investigate the effects of the teaching method upon the students’ learning of physics models and modeling skills. This study employed a quasi-experimental approach by comparing pre- and post-class results of students who underwent three different learning methods, namely: (1) model-based flipped classroom supported by modern teaching technology (MFC), (2) flipped classroom (FC), and (3) model-based classroom. Students who underwent the MFC method achieved significant improvements in the 5 phases of the physics modeling process and gave higher scores in the 4 dimensions of classroom teaching quality evaluation, namely (1) communication and cooperation, (2) application and learning, (3) curriculum learning, and (4) participation. The model-based flipping classroom supported by modern teaching technologies (MFC) used in this study effectively guided students through the 3 steps of new knowledge construction during the learning process, provided an empirical reference for applying modern teaching technologies and flipping classroom teaching methods in actual settings, and inspired new mindsets for applying and developing teaching theories.

Antifungal Effect of Novel 2-Bromo-2-Chloro-2-(4-Chlorophenylsulfonyl)-1-Phenylethanone against Candida Strains.

We investigated the antifungal activity of novel a 2-bromo-2-chloro-2-(4-chlorophenylsulfonyl)-1-phenylethanone (compound 4). The synthesis of compound 4 was commenced from sodium 4-chlorobenzene sulfinate and the final product was obtained by treatment of α-chloro-β-keto-sulfone with sodium hypobromite. The sensitivity of 63 clinical isolates belonging to the most relevant Candida species toward compound 4 using the method M27-A3 was evaluated. We observed among most of the clinical strains of C. albicans MIC ranging from 0.00195 to 0.0078 μg/mL. Compound 4 at 32 μg/mL exhibited fungicidal activity against nine Candida strains tested using the MFC assay. Compound 4 displayed anti-Candida activity (with clear endpoint) against 22% of clinical strains of Candida. Under compound 4, Candida susceptibility and tolerance, namely paradoxical effect (PG), was found for only two clinical isolates (C. glabrata and C. parapsilosis) and reference strain 14053 using both M27-A3 and MFC method. We found that compound 4 does not induce toxicity in vivo against larvae of Galleria mellonella (≥97% survival) and it displays reduced toxicity on mammalian cells in vitro (< CC20 at 64 μg/mL). Furthermore, XTT assay denoted clear metabolic activity of sessile cells in the presence of compound 4. Thus, the effect of compound 4 on formed C. albicans biofilms was minimal. Moreover, strain 90028 exhibited no defects in hyphal growth on Caco-2 monolayer under compound 4 influence at MIC = 16 μg/mL. The MIC values of compound 4 against C. albicans 90028, in medium with sorbitol did not suggest that compound 4 acts by inhibiting fungal cell wall synthesis. Our findings with compound 4 suggest a general strategy for antifungal agent development that might be useful in limiting the emergence of resistance in Candida strains.

Evaluation of microbiological quality of bottled water to Pseudomonas aeruginosa by membrane filter, culture and polymerase chain reaction method

Over the recent years the consumption of bottled water has increased tremendously, and this trend is expected to continue, demanding the continuous surveillance of public health service. The propose of this study was to determine the microbial quality to Pseudomonas aeruginosa by membrane filter (MFC), enrichment culture and polymerase chain reaction (PCR) method of commonly available brands of bottled water in Iran. In this cross sectional study, 52 sample from 17 bottled water of available brands of domestically produced were examined by membrane filter (MFC) culture and polymerase chain reaction (PCR) methods for detection of P. aeruginosa. Results showed that none of the 52 samples tested were positive for total coli forms and E. coli. The MFC method showed that 14 (26.9%) of all 52 water samples were positive, the culture method showed that 8 (15.3%) were positive and by PCR as gold standard 5 (10.4%) of all samples were positive for P. aeruginosa. This study showed that PCR method can be an extremely high specificity and sensitivity, safety and can be served as a gold standard for monitoring of drinking waters.

A Rapid, Cost-Effective Pre-Clinical Method to Screen for Pro- or Antiarrhythmic Effects of Substances in an Isolated Heart Preparation.

This study describes a rapid, cost-effective pre-clinical method to screen for pro- or antiarrhythmic effects of substances in an isolated heart preparation in line with the regulatory requirements of ICHS7B. The computational method “MFC method” quantifies arrhythmic episodes from isolated perfused hearts based on measuring the variation in the maximum force of contraction. Experiments were performed on hearts isolated from male Wistar rats. Arrhythmias were induced by the addition of tefluthrin or by ligation of the left coronary artery. The “MFC method” accurately measures the maximum force of every myocardial contraction and correlates it with the magnitude of the preceding beat. Arrhythmias were quantified by determining the coefficient of variation in the maximum force of contraction. This method is a useful approach to quickly identify the pro- or antiarrhythmic effects of drugs prior to more detailed analysis; particularly where the effects are varied and not easily classified under the Lambeth Conventions. Therefore, the “MFC method” can be used as a rapid screen for the antiarrhythmic effects of novel compounds or for rapidly determining potential cardiac toxicity.

Translating Expression Profiling into a Clinically Feasible Test to Predict Neuroblastoma Outcome

To assess the feasibility of predicting neuroblastoma outcome using highly parallel quantitative real-time PCR data. We generated expression profiles of 63 neuroblastoma patients, 47 of which were analyzed by both Affymetrix U95A microarrays and highly parallel real-time PCR on microfluidic cards (MFC; Applied Biosystems). Top-ranked genes discriminating patients with event-free survival or relapse according to high-level analysis of Affymetrix chip data, as well as known neuroblastoma marker genes (MYCN and NTRK1/TrkA), were quantified simultaneously by real-time PCR. Analysis of PCR data was accomplished using high-level bioinformatics methods including prediction analysis of microarray, significance analysis of microarray, and Computerized Affected Sibling Pair Analyzer and Reporter. Internal validation of the MFC method proved it highly reproducible. Correlation of MFC and chip expression data varied markedly for some genes. Outcome prediction using prediction analysis of microarray on real-time PCR data resulted in 80% accuracy, which is comparable to results obtained using the Affymetrix platform. Real-time PCR data were useful for risk assessment of relapsing neuroblastoma (P = 0.0006, log-rank test) when Computerized Affected Sibling Pair Analyzer and Reporter analysis was applied. These data suggest that multiplex real-time PCR might be a promising approach to reduce the complexity of information obtained from whole-genome array experiments. It could provide a more convenient and less expensive tool for routine application in a clinical setting.

Using mixing ability analysis from two-way cultivar mixtures to predict the performance of cultivars in complex mixtures

Cultivar mixtures are an alternative to monoculture for crop production. Methods for predicting the performance of cultivars in mixtures would facilitate the identification of the best cultivars for mixture formation. A prediction method [Theor. Appl. Genet. 81 (1991) 265] based on the combining ability analysis proposed by Gardner and Eberhart [Biometrics 22 (1966) 439] model II was evaluated for mixtures. Mean values for percent diseased leaf area (DLA) and yield under disease (YUD) of five club wheat cultivars and all possible two-way mixtures (across three Oregon locations) were used to estimate the relative contribution of each cultivar to the mixture mean ( I i ) and the predicted mean of all possible mixtures ( Y m) according to the MFC method. Estimated I i and Y m were compared to actual mixture means. I i allowed identification of the best cultivars for mixture formation for both DLA and YUD. Actual and predicted rank correlation coefficients for DLA and YUD of complex mixtures (more than two components) were highly significant ( P<0.01) for the mean of the three environments (0.87 and 0.78, respectively) and for the mean of the two most relevant environments (0.83 and 0.93, respectively). Similar results were obtained when I i and Y m were estimated from the means of the cultivars in pure stand (instead of being estimated from the mixing ability analysis). This was due to the relatively small competitive effects ( h i ) of the cultivars compared to their additive effects ( v i ). We extended our analysis to data from a yield study of two-way mixtures of eight soybean cultivars [Crop Sci. 29 (1989) 885; Agron. J. 81 (1989) 559], where additive and competitive effects had similar magnitude. Actual and predicted mixture means could not be compared because only two-way mixtures were included in the study. In this case, the mean yield of the cultivars in pure stand was not a good predictor of the performance of cultivars in mixtures. Ra 604, the third highest yielding cultivar, had a positive additive effect ( v i=53.8 kg/ ha ), but a highly negative competitive effect ( h i=−49.7 kg/ ha ) that resulted in a negative contribution ( I i ) to yield when mixed with the other soybean cultivars. Additive ( v i ) and competitive effects ( h i ) must be considered to obtain superior mixtures, and the advantage of I i is that it takes into account both effects ( I i= 1 2 v i+(k−1/k)h i , k is the number of cultivars). The MFC method may be a useful tool to select desirable cultivars to obtain complex mixtures.

Evaluation of Two Techniques: mFC AND mTEC for Determining Distributions of Fecal Pollution in Small, North Carolina Tidal Creeks

Most tidal creeks in North Carolina are closed or partially closed to shellfishing. These creeks often remain closed due to the inability to determine sources of fecal pollution. This study was designed for intensive fecal coliform monitoring of Futch Creek, N.C., to try and determine sources(s) of fecal pollution. Futch Creek is a mildly polluted tidal creek, with marginal levels of fecal coliforms and could potentially be reopened. Problems in interpreting levels of fecal coliforms and pollution risks are two fold and were extremely pronounced in this study. First, several environmental factors have been shown to influence levels of fecal coliforms. Therefore, effects of temperature, salinity, tidal cycles, and rain events on fecal coliform counts were examined. There were higher fecal coliform levels in the warmer temperatures. There was a strong inverse relationship with salinity, with highest fecal coliform counts in the 10–14 g L-1 range for both the mFC and mTEC counts with no apparent source of pollution. This trend was also observed in three other tidal creeks. Tidal cycles did affect fecal coliform counts with substantially higher counts during low tide and appeared to be more important than rain events. It is apparent that when evaluating several stations in a creek, samples must be taken during the same tidal cycle stage in order to have comparative data. Counts obtained using the mTEC method were consistently higher than mFC counts in all salinity ranges. Basic taxonomic tests were performed on fecal coliforms isolated from three salinity regimes: 0 g L-1, 10–14 g L-1, and 23–26 g L-1. The mFC method in the 10–14 g L-1 (45%) and 23–26 g L-1 (70%) salinity range had the highest incidence of false-positive counts (non E. coli). The mTEC method also had the highest incidence of false-positive counts in the 23–26 g L-1 (27%) and 10–14 g L-1 (24%), none as high as the mFC method. Therefore, the mTEC method appears to be the better of the two but is still not an ideal approach.

Enumeration of faecal coliforms andescherichia coliin new Zealand receiving waters and effluents

Abstract A membrane filter method, mTEC, was evaluated under New Zealand conditions.This method can enumerate both faecal coliforms and Escherichia coli. The mTEC method was compared to MPN methods for faecal coliforms (the New Zealand standard reference method) and for E. coli (a British standard method). It was also compared to the mFC membrane filter method for faecal coliforms, recommended by the American Public Health Association. The mTEC method was found to be a satisfactory alternative to the MPN methods and the mFC method. Samples tested included freshwater, sewage and meat processing plant effluent

Evaluating the Membrane Fecal Coliform Test by Using Escherichia coli as the Indicator Organism

The fecal coliform membrane filter method (MFC) currently used in water pollution analysis was evaluated by using two strains of Escherichia coli, a known fecal coliform, as the indicator organism. A large relative error in the results obtained with this method was found to be dependent upon the brand of membrane filter employed, the medium, and the temperature of incubation. MFC densities varied between 10 and 60% of the densities determined by means of total bacteria counts and total coliform counts performed at 35 C. Due to the large relative error encountered, the MFC method cannot be recommended as an analytical tool for the laboratory enumeration of E. coli. The results do show that the MFC method can be used at 35 C for enumeration of E. coli and for differential counts of E. coli and Enterobacter aerogenes.