Acetic Acid Wash Research Articles

A pilot case control study on the efficacy of acetic acid wash and chemiluminescent illumination (ViziLite™) in the visualisation of oral mucosal white lesions

Conventional screening practice for oral lesions involves visual scrutiny of the oral tissues with the naked eye under projected incandescent or halogen illumination. Visualisation is the principal strategy used to assess patients' lesions at risk for malignant transformation; hence, any procedure which highlights such lesions should aid the clinician. The aim of this pilot study was to examine the efficacy of acetic acid wash and chemiluminescent light (ViziLite) in enhancing visualisation of oral mucosal white lesions, and its ability to highlight malignant and potentially malignant lesions. Fifty five patients referred for assessment of an oral white lesion, were prospectively screened with ViziLite, and an incisional scalpel biopsy performed for a definitive diagnosis. The size, location, ease of visibility, border distinctness, and presence of satellite lesions were recorded. The ViziLite tool enhanced intra-oral visualisation of 26 white lesions. Indeed, all lesions appeared "aceto-white", regardless of the definitive diagnosis. Examination of the oral tissues with ViziLite illumination did not change the provisional diagnosis, nor alter the biopsy site. ViziLite illumination does not discriminate between keratotic, inflammatory, malignant or potentially malignant oral mucosal white lesions and thus, a high index of suspicion, expert clinical judgment, and scalpel biopsy are still essential for proper patient care.

Control of Phospholipid Synthesis by Phosphorylation of the Yeast Lipin Pah1p/Smp2p Mg2+-dependent Phosphatidate Phosphatase

Phosphorylation of the conserved lipin Pah1p/Smp2p in Saccharomyces cerevisiae was previously shown to control transcription of phospholipid biosynthetic genes and nuclear structure by regulating the amount of membrane present at the nuclear envelope (Santos-Rosa, H., Leung, J., Grimsey, N., Peak-Chew, S., and Siniossoglou, S. (2005) EMBO J. 24, 1931-1941). A recent report identified Pah1p as a Mg2+-dependent phosphatidate (PA) phosphatase that regulates de novo lipid synthesis (Han G.-S., Wu, W. I., and Carman, G. M. (2006) J. Biol. Chem. 281, 9210-9218). In this work we use a combination of mass spectrometry and systematic mutagenesis to identify seven Ser/Thr-Pro motifs within Pah1p that are phosphorylated in vivo. We show that phosphorylation on these sites is required for the efficient transcriptional derepression of key enzymes involved in phospholipid biosynthesis. The phosphorylation-deficient Pah1p exhibits higher PA phosphatase-specific activity than the wild-type Pah1p, indicating that phosphorylation of Pah1p controls PA production. Opi1p is a transcriptional repressor of phospholipid biosynthetic genes, responding to PA levels. Genetic analysis suggests that Pah1p regulates transcription of these genes through both Opi1p-dependent and -independent mechanisms. We also provide evidence that derepression of phospholipid biosynthetic genes is not sufficient to induce the nuclear membrane expansion shown in the pah1delta cells.

P‐10 TO LYSE OR NOT TO LYSE?

Introduction: A glacial acetic acid wash performed retrospectively or prospectively on visibly bloodstained cervical ThinPrep® specimens can reduce the unsatisfactory rate and increase the number of diagnostic epithelial cells. This study was undertaken to determine which specimens are most likely to benefit from a prospective glacial acetic acid wash.Methods: Bloodstained ThinPrep® specimens selected for routine lysing prior to processing were macroscopically assessed and scored based on the level of blood present (+ to +++). Both unlysed and lysed slides were prepared from each specimen and microscopically examined.Results: Fifty‐eight specimens (32 scored +, 12 ++ and 14+++) were assessed. Three unlysed slides prepared from the ++ specimens and 12 from +++ specimens were evaluated as unsatisfactory due to excessive blood and inadequate numbers of squamous cells. In contrast, only one of the unlysed slides from the 32 + specimens was considered to be unsatisfactory. Almost all the lysed slides were satisfactory and generally more cellular than the unlysed slides. Abnormal cells were found in four cases (both unlysed and lysed paired slides).Discussion: Although the acetic acid wash increases cellularity of bloodstained ThinPrep® specimens, prospectively lysing all bloodstained specimens is an unnecessary procedure. Lysing only very heavily bloodstained specimens prior to processing will reduce laboratory workload, costs and the possibility of specimen mix up. Occasionally a retrospective wash may be required but screening staff should be aware that although blood may be present on an unlysed ThinPrep® slide, a lysed slide should not be requested unless there are insufficient numbers of squamous cells present.

Conjugation to Nedd8 Instigates Ubiquitylation and Down-regulation of Activated Receptor Tyrosine Kinases

When appended to the epidermal growth factor receptor (EGFR), ubiquitin serves as a sorting signal for lysosomal degradation. Here we demonstrate that the ubiquitin ligase of EGFR, namely c-Cbl, also mediates receptor modification with the ubiquitin-like molecule Nedd8. EGF stimulates receptor neddylation, which enhances subsequent ubiquitylation, as well as sorting of EGFR for degradation. Multiple lysine residues, located within the tyrosine kinase domain of EGFR, serve as attachment sites for Nedd8. A set of clathrin coat-associated binders of ubiquitin also bind Nedd8, but they undergo ubiquitylation, not neddylation. We discuss the emerging versatility of the concerted action of ubiquitylation and neddylation in the process that desensitizes growth factor-activated receptor tyrosine kinases.

Development of Block Co-Polymers as Self-Assembling Templates for Patterned Media

ABSTRACTBlock copolymers that self-organize are of interest as templates for patterned media, as they potentially provide a low cost fabrication route. Poly(styrene)-Poly(methylmethacrylate) block co-polymers (PS-b-PMMA) of appropriate block length and PS to PMMA ratio self-assemble into a 2-D hexagonal phase in which the PS majority phase is continuous and surrounds cylinders of the minority, PMMA phase. For application of this phase to patterned media it is necessary that the cylinders of the minority phase be oriented perpendicular to the substrate surface. This can be achieved by a number of methods, including appropriate choice of substrate and use of a random co-polymer underlayer. Appropriate substrates include H-terminated silicon, some carbon coatings and some ITO glasses. Use of an acetic acid wash causes the minority PMMA component can be induced to be rearranged, giving rise to pores perpendicular to the substrate. Electrodeposition of a metal into the pores produces a hardmask which can be used with ion-milling to transfer the block co-polymer pattern onto a magnetic thin film.

Predictive model for reduction of Escherichia coli during acetic acid decontamination of chicken skin

The response surface methodology was used to evaluate the effect of operating variables (acetic acid concentration, spraying time and temperature) on the reduction of Escherichia coli populations on poultry breast skin in a laboratory showering process, as well as to identify the best conditions that are required to develop this operation. Skin samples were inoculated with a 24-h E. coli culture and afterwards treated according to experimental design under selected acetic acid concentration, spraying time, and solution temperature. The E. coli reduction model was significantly affected by the acetic acid concentration and spraying time (P < or = 0.05 and < or =0.01), while temperature did not show a significant effect (P > 0.05). The predictive model obtained was validated through additional confirmatory experiments and showed to be adequate, and it could be used as an approach to optimize the acetic acid spray washes during poultry carcasses processing. The use of acetic acid washes in the processing of poultry does not have the capability of eliminating E. coli populations from carcasses. However, significant reductions in the initial load could be achieved.

A simple method to determine the need for glacial acetic acid treatment of bloody ThinPrep Pap tests before slide processing.

ThinPrep (TP) Papanicolaou (Pap) samples containing excessive blood often result in unsatisfactory preparations, possibly leading to undetected gynecologic disease, and added inconvenience to patients and clinicians. Reprocessing of these samples with a glacial acetic acid wash is effective at eliminating blood, providing satisfactory preparation and detection of lesions. However, it increases laboratory costs and decreases work flow efficiency. We report the use of a color standard for gauging the necessity of performing a glacial acetic acid wash before TP processing. This "preprocessing" was found to reduce the costs associated with reprocessing by 48%, while maintaining high preparation quality by improved sample adequacy.

Acetic acid wash and chemoluminescent illumination as an adjunct to conventional oral soft tissue examination for the detection of dysplasia: a pilot study

Acetic acid wash and chemoluminescent illumination as an adjunct to conventional oral soft tissue examination for the detection of dysplasia: a pilot study

Posters. P15 The presentation of papillary serous carcinoma of the endometrium in a cervical thinprep sample

Papillary serous carcinoma of the endometrium (PSCE) is a distinct but rare type of endometrial carcinoma. It has an aggressive nature and tumours with lympho‐vascular involvement are more likely to have extra‐uterine disease and poor prognosis.1 Post menopausal bleeding (PMB) is the most common presenting symptom. A liquid‐based cervical sample was received from a 77‐year‐old female with PMB. The sample was prepared using the ThinPrep technique. The specimen was heavily blood‐stained and the initial slide showed scattered, highly abnormal cell groups, which were difficult to assess. A glacial acetic acid wash was performed to optimize the preparation. The resultant slide showed numerous highly abnormal cell groups, with enlargement, pleomorphism and abnormal chromatin pattern and were frequently arranged in papillary clusters, many with prominent nucleoli and numerous bare nuclei with background necrosis. These characteristics are consistent with previous descriptions of the cytomorphology of PSCE in conventional cervical smears.2 The cervical biopsy and endometrial currettings showed the presence of high‐grade PSCE. Follow‐up peritoneal washings showed a few clusters of suspicious cell groups and the hysterectomy confirmed high‐grade PSCE with cervical involvement and positive left iliac lymph nodes, which is consistent with the aggressive pattern of the disease.

Safety, acceptability, and feasibility of a single-visit approach to cervical-cancer prevention in rural Thailand: a demonstration project

To increase screening and treatment coverage, innovative approaches to cervical-cancer prevention are being investigated in rural Thailand. We assessed the value of a single-visit approach combining visual inspection of the cervix with acetic acid wash (VIA) and cryotherapy. 12 trained nurses provided services in mobile (village health centre-based) and static (hospital-based) teams in four districts of Roi-et Province, Thailand. Over 7 months, 5999 women were tested by VIA. If they tested positive, after counselling about the benefits, potential risks, and probable side-effects they were offered cryotherapy. Data measuring safety, acceptability, feasibility, and effort to implement the programme were gathered. The VIA test-positive rate was 13.3% (798/5999), and 98.5% (609/618) of those eligible accepted immediate treatment. Overall, 756 women received cryotherapy, 629 (83.2%) of whom returned for their first follow-up visit. No major complications were recorded, and 33 (4.4%) of those treated returned for a perceived problem. Only 17 (2.2%) of the treated women needed clinical management other than reassurance about side-effects. Both VIA and cryotherapy were highly acceptable to the patients (over 95% expressed satisfaction with their experience). At their 1-year visit, the squamocolumnar junction was visible to the nurses, and the VIA test-negative rate was 94.3%. A single-visit approach with VIA and cryotherapy seems to be safe, acceptable, and feasible in rural Thailand, and is a potentially efficient method of cervical-cancer prevention in such settings.

Risk factors as the basis for triage in low-resource cervical cancer screening programs

Objectives: Several studies have shown impressive sensitivity and specificity of visual inspection using acetic acid wash (VIA) in detecting cervical dysplasia. This study examines how risk-factor based triage, using clinical history-taking to limit the testing to those at highest risk of disease, improves the clinical utility of VIA. Methods: The study population included 2206 woman aged 25–56 from peri-urban primary care clinics in Zimbabwe. Three risk factors variables [age, lifetime number of sexual partners and history of a sexually transmitted infection (STI)] were selected as the basis for computer-simulated patient triage. Criteria for selecting risk factors were biological relevance, programmatic feasibility, historical evidence in the scientific literature as a risk factor for cervical cancer and a significant ( P<0.05) predictor of dysplasia in this study population. Predictive values for VIA were calculated on subgroups of women with combinations of the three risk factors and then compared with the predictive value of VIA calculated on the full study population. Results: The positive predictive value (PPV) among women with all three risk factors (30.2%) was 1.6 times higher than that of all study women and 4.5 times higher than women with none of the three risk factors (4.1%). Additionally, the PPV was slightly (30%) higher than that obtained from computer-simulated serial testing using VIA as the primary test followed by HPV testing (27.4%). Conclusion: Clinical history-taking could provide the basis for patient triage to increase the clinical utility of VIA. Such an approach could also serve to prioritize who gets tested first in low-resource countries with high disease prevalence that are struggling to strengthen national cervical cancer prevention programs.

Assessment of the Cervix After Acetic Acid Wash

In Brief OBJECTIVE To estimate the inter-rater agreement on the assessment of cervical photographs after acetic acid wash, using visual inspection with acetic acid categories. METHODS Three raters individually assessed 144 photographs as negative, positive, or suspicious for cancer. The inter-rater agreement was analyzed using the unweighted and weighted κ coefficient. To explore the reasons for concordancy and discordancy, photographs were compared on histologic evidence of cervical intraepithelial neoplasia and on testing for oncogenic types of human papillomavirus. RESULTS Overall raw agreement among the three raters was 66.7% (96 of 144) with a κ of 0.57 (95% confidence interval 0.48, 0.66). Pair-wise agreement using unweighted and weighted κ was moderate to substantial: 0.54–0.60 and 0.56–0.63, respectively. There was concordance on negative in 25.7% (37 of 144) and on positive or suspicious for cancer in 41.0% (59 of 144). Cervical intraepithelial neoplasia II or III was not present on biopsy if photographs were concordant-negative, and the human papillomavirus test was less likely to be positive (relative risk 0.3; 95% confidence interval 0.2, 0.6) in concordant-negatives compared with concordant-positives, including suspicious for cancer. Cervical intraepithelial neoplasia II or III was more common in photographs that were concordant-positive, including suspicious for cancer, compared with discordants (relative risk 3.4, 95% confidence interval 1.5, 7.6). CONCLUSION Based on photographs of the cervix taken after acetic acid wash, the level of agreement among raters using visual inspection with acetic acid categories was moderate to substantial, consistent with other commonly used tests. Inter-rater agreement on the assessment of cervical photographs after acetic acid wash, using visual inspection with acetic acid categories, was moderate to substantial, consistent with other commonly used tests.

Assessment of the cervix after acetic acid wash: inter-rater agreement using photographs

OBJECTIVE: To estimate the inter-rater agreement on the assessment of cervical photographs after acetic acid wash, using visual inspection with acetic acid categories. METHODS: Three raters individually assessed 144 photographs as negative, positive, or suspicious for cancer. The inter-rater agreement was analyzed using the unweighted and weighted κ coefficient. To explore the reasons for concordancy and discordancy, photographs were compared on histologic evidence of cervical intraepithelial neoplasia and on testing for oncogenic types of human papillomavirus. RESULTS: Overall raw agreement among the three raters was 66.7% (96 of 144) with a κ of 0.57 (95% confidence interval 0.48, 0.66). Pair-wise agreement using unweighted and weighted κ was moderate to substantial: 0.54–0.60 and 0.56–0.63, respectively. There was concordance on negative in 25.7% (37 of 144) and on positive or suspicious for cancer in 41.0% (59 of 144). Cervical intraepithelial neoplasia II or III was not present on biopsy if photographs were concordant-negative, and the human papillomavirus test was less likely to be positive (relative risk 0.3; 95% confidence interval 0.2, 0.6) in concordant-negatives compared with concordant-positives, including suspicious for cancer. Cervical intraepithelial neoplasia II or III was more common in photographs that were concordant-positive, including suspicious for cancer, compared with discordants (relative risk 3.4, 95% confidence interval 1.5, 7.6). CONCLUSION: Based on photographs of the cervix taken after acetic acid wash, the level of agreement among raters using visual inspection with acetic acid categories was moderate to substantial, consistent with other commonly used tests.

The unsatisfactory ThinPrep Pap Test: missed opportunity for disease detection?

Cervical cytology specimens classified as "unsatisfactory for interpretation" represent a potential source of undetected disease. This prospective study analyzed the potential benefits of a laboratory procedure to reprocess unsatisfactory ThinPrep Pap Tests (Cytyc, Boxborough, MA). All unsatisfactory ThinPrep samples were reprocessed using a glacial acetic acid wash. The study period unsatisfactory rate was compared with that for the previous 12 months. The initial unsatisfactory rate was 1.3% (197/15,154). Of the unsatisfactory ThinPrep samples, 55.8% (110/197) had residual material for reprocessing. After reprocessing, 67.3% (74/110) were reclassified as "satisfactory" or "satisfactory but limited by," and the final unsatisfactory rate was 0.8% (123/15,154), a 62% decrease. Compared with the previous 12-month rate of 0.9% (209/23,730), this was a 12% reduction. Seven (6.4%) of 110 initially classified as unsatisfactory contained an epithelial abnormality (atypical squamous cells of undetermined significance, 3; atypical glandular cells of undetermined significance, 2; low-grade squamous intraepithelial lesion, 1; squamous cell carcinoma, 1) on the reprocessed slide. Reprocessing of unsatisfactory ThinPrep slides yielded additional cellular abnormalities that otherwise would have been undetected. The present study confirms that reprocessing of unsatisfactory ThinPrep slides is a beneficial laboratory procedure.

The glass ionomer cement: the sources of soluble fluoride

This study aimed to investigate certain processes of fluoride production which enable glass ionomer cements to leach fluoride. Two fluoroaluminosilicate glasses, G338 and LG26 were used. The free and total fluoride which could be dissolved from the glasses was measured, before and after acetic acid washing. Both glasses contained appreciable amounts of soluble fluoride prior to any acid treatment. The latter process reduced the amount to some 75% of the original levels. Replacing the customary polymeric acid with propionic acid produced a cement which disintegrated in water allowing the amount of fluoride generated by the cement forming process to be measured. Cement production increased soluble fluoride by a further 3%. Both glasses behaved similarly when undergoing the various processes. G338 produced significantly greater quantities of fluoride, of the order of 10, compared with LG26 although containing only three times the amount of fluoride in the glass formula. A substantial proportion, over half, of the total fluoride was complexed especially after contact with cement and when G338 was used. During the period of the experiment, 21 days, total fluoride release did not seem to depend on the square root of time.

Cervical cancer screening in developing countries

In developing countries, cervical cancer remains a clinical problem of public health proportions. Eighty percent of the approximately 400,000 new cases of cervical cancer each year occur in such settings. Primarily as a result of the introduction and success of screening programs, cervical cancer rates in developed countries have dropped remarkably. However, in most developing countries, screening programs are virtually nonexistent. Reasons for this relate primarily to lack of public awareness and the fact that screening via cytology is an untenable proposition for mass screening in such low-resource settings. Matching the resources available to provide cervical cancer screening in such settings requires alternative means of providing testing and treatment. Recent evidence indicates that, depending on local conditions and locally-made decisions, visual inspection of the cervix with acetic acid wash, coupled with a benign form of therapy, such as cryotherapy, could hold promise as a means of testing and treatment. By adapting resource-appropriate technologies and building local consensus regarding clinically driven public health approaches that are safe and feasible, the challenge of reducing the mortality from cervical cancer in developing countries can yet be met.

Radiocarbon dating of bone apatite by step heating

Summary and Analysis The choice of pretreatment methods is critical to the success of the step heatingmethod as dating results varied widely depending upon the pretreatment used. Theuse of an acetic acid wash followed by a NaOCl/acetic acid wash gave the bestresults. Performing solution transfers under a nitrogen atmosphere may have im-proved dates as well, but more likely the success of Dent series 4 is due to the useof tooth enamel. The success of the dates from Murray Springs supports this con-tention as solution transfers were not performed under nitrogen. All of the seriesgenerally showed a trend of increasing age with increased extraction temperature.The lowest temperature fraction consistently produced the youngest dates and inthree series (e.g., Dent series 2 and 4, Murray Springs) were significantly offsetfrom the general trend of the other samples. This suggests that perhaps CO 2 re-leased at very low temperatures ( 500 C) is derived in part from a highly ex-changeable fraction of carbonate, perhaps that absorbed to crystal surfaces aspostulated by Hedges et al. (1995:289).The general patterning seen in the Dent data suggests a system composed of aseries of carbonate fractions that vary in their susceptibility to exchange, with noparticular temperature fraction being totally immune. A simple model shows howtemperature-age spectra may evolve with increased contamination (Figure 3). Themodel shows five temperature fractions, each being less susceptible to exchangethan the previous lower temperature fraction. As a bone becomes increasinglycontaminated, the slope of temperature-age spectra becomes increasingly steep.This occurs because low temperature fractions, being more susceptible to ex-change, are contaminated at a greater rate than high temperature fractions. If sucha model is accurate, it provides a convenient means of estimating the amount ofcontamination affecting a sample based on shape of the temperature-age spectrumproduced. Spectra with a steep slope tend to produce

Combination Spray Washes of Saponin with Water or Acetic Acid to Reduce Aerobic and Pathogenic Bacteria on Lean Beef Surfaces

Saponins are naturally occurring compounds known as triterpenoid glycosides found in a variety of plant species. Saponins are approved for use in the food industry as foaming agents. When combined with water or organic acid in spray treatments, saponins' foaming property may improve carcass decontamination. In the first experiment of this study, lean beef carcass surfaces were experimentally inoculated with a fecal slurry containing antibiotic-resistant Escherichia coli O157:H7 and Salmonella Typhimurium. Spray-washing treatments with 1% saponin followed by a water wash, or 1% saponin followed by 2% acetic acid, were more effective for reducing aerobic bacteria than saponin, water, or 2% acetic acid washes alone. However, 1% saponin followed by a either a water or 2% acetic acid wash was no more effective than a 2% acetic acid wash for reducing populations of E. coli O157:H7 or Salmonella Typhimurium. In the second experiment, experimentally inoculated beef surfaces were subjected to spray treatments with water followed by another water wash, water followed by a 2% acetic acid wash, 1% saponin followed by a water wash, or 1% saponin followed by a 2% acetic acid wash. When examined for effectiveness against all bacterial populations, 1% saponin followed by a water wash and 1% saponin followed by a 2% acetic acid wash were as effective as two water washes or a water wash followed by 2% acetic acid for reducing aerobic bacteria, E. coli O157:H7, and Salmonella Typhimurium from beef surfaces. Under the conditions described, reductions associated with combination spray washes may be attributed to the physical removal of bacteria during the spraying process, not to any specific action of saponin.

Visual inspection with acetic acid for cervical-cancer screening: test qualities in a primary-care setting

<h2>Summary</h2><h3>Background</h3> Naked-eye visual inspection of the cervix with acetic-acid wash (VIA), or cervicoscopy, is an alternative to cytology in screening for cervical cancer in poorly resourced locations. We tested the sensitivity, specificity, and predictive value of VIA done by nursemidwives in a less-developed country. <h3>Methods</h3> Women were screened by six trained nursemidwives in a two-phase, cross-sectional study at 15 primary-care clinics in Zimbabwe. VIA and Pap smears were done concurrently, and their sensitivity and specificity compared. Colposcopy, with biopsy as indicated, was used as the reference test to allow a direct comparison of the test unaffected by verification bias. <h3>Findings</h3> 10 934 women were screened. In phase II, 2148 (97·5%) of the 2203 participants for whom there was a screening result also had a reference test result. Also in phase II, VIA was more sensitive but less specific than cytology. Sensitivity (95% CI) was 76·7% (70·3–82·3) for VIA and 44·3% (37·3–51·4) for cytology. Specificity was 64·1% (61·9–66·2) for VIA and 90·6% (89·2–91·9) for cytology. <h3>Interpretation</h3> The high sensitivity of VIA shows that the test could be valuable in detection of precancerous lesions of the cervix. However, there are costs to the patient and system costs associated with high numbers of false-positive results, so attention should be given to improving the specificity of VIA.

Long-Term Bacterial Profile of Refrigerated Ground Beef Made from Carcass Tissue, Experimentally Contaminated with Pathogens and Spoilage Bacteria after Hot Water, Alkaline, or Organic Acid Washes

The effects of 2% (vol/vol) lactic acid (LA), 2% (vol/vol) acetic acid (AA), 12% (wt/vol) trisodium phosphate (TSP), 72°C water (HW), and 32°C water (W) washes on bacterial populations which were introduced onto beef carcass surfaces after wash treatments were determined up to 21 days of storage at 4°C of packaged ground beef prepared from the treated and inoculated carcasses. Beef carcass necks were collected from cattle immediately after harvest and subjected to the above treatments or left untreated (control). Neck meat was then inoculated with low levels (ca. <2 log10) of Listeria innocua, Salmonella typhimurium, Escherichia coli O157:H7, and Clostridium sporogenes contained in a bovine fecal cocktail. In general, growth of these four bacteria, aerobic bacteria, lactic acid bacteria, and pseudomonads was suppressed or not observed in the ground beef when LA, AA, or TSP treatments were used as compared to the untreated control. HW or W washes offered little suppression of growth of pathogens during subsequent storage of ground beef when these bacteria were introduced onto beef tissue posttreatment. Of the treatments used, a final LA or AA wash during the processing of beef carcasses offers the best residual efficacy for suppression of pathogen proliferation in ground beef during long-term refrigerated storage or short-term abusive temperature storage if these bacteria contaminate the carcass immediately after carcass processing.