Translocation of Surface-Inoculated Escherichia coli O157:H7 into Beef Subprimals following Blade Tenderization†‡

2008 ◽  
Vol 71 (11) ◽  
pp. 2190-2197 ◽  
Author(s):  
J. B. LUCHANSKY ◽  
R. K. PHEBUS ◽  
H. THIPPAREDDI ◽  
J. E. CALL

In phase I, beef subprimals were inoculated on the lean side with ca. 0.5 to 3.5 log CFU/g of a rifampin-resistant (rif r ) cocktail of Escherichia coli O157:H7 and passed once, lean side up, through a mechanical blade tenderizer. Inoculated subprimals that were not tenderized served as controls. Ten core samples were removed from each subprimal and cut into six consecutive segments: segments 1 to 4 comprised the top 4 cm and segments 5 and 6 the deepest 4 cm. Levels of E. coli O157:H7 recovered from segment 1 of control subprimals when inoculated with ca. 0.5, 1.5, 2.5, or 3.5 log CFU/g were 0.6, 1.46, 2.5, and 3.19 log CFU/g, respectively. Following tenderization, pathogen levels recovered from segment 1 inoculated with 0.5 to 3.5 log CFU/g were 0.22, 1.06, 2.04, and 2.7 log CFU/g, respectively. Levels recovered in segment 2 were 7- to 34-fold lower than levels recovered from segment 1. Next, in phase II, the translocation of ca. 4 log CFU of the pathogen per g was assessed for lean-side–inoculated subprimals passed either once (LS) or twice (LD) through the tenderizer and for fat-side–inoculated subprimals passed either once (FS) or twice (FD) through the tenderizer. Levels in segment 1 for LS, LD, FS, and FD tenderized subprimals were 3.63, 3.52, 2.85, and 3.55 log CFU/g, respectively. The levels recovered in segment 2 were 14- to 50-fold lower than levels recovered in segment 1 for LS, LD, FS, and FD subprimals. Thus, blade tenderization transfers E. coli O157:H7 primarily into the topmost 1 cm, but also into the deeper tissues of beef subprimals.

2012 ◽  
Vol 75 (1) ◽  
pp. 62-70 ◽  
Author(s):  
JOHN B. LUCHANSKY ◽  
ANNA C. S. PORTO-FETT ◽  
BRADLEY A. SHOYER ◽  
JEFFREY E. CALL ◽  
WAYNE SCHLOSSER ◽  
...  

We compared the fate of cells of both Shiga toxin–producing Escherichia coli O157:H7 (ECOH) and Shiga toxin–producing non-O157:H7 E. coli (STEC) in blade-tenderized steaks after tenderization and cooking on a gas grill. In phase I, beef subprimal cuts were inoculated on the lean side with about 5.5 log CFU/g of a five-strain mixture of ECOH or STEC and then passed once through a mechanical blade tenderizer with the lean side facing up. In each of two trials, 10 core samples were removed from each of two tenderized subprimals and cut into six consecutive segments starting from the inoculated side. Ten total cores also were obtained from two nontenderized (control) subprimals, but only segment 1 (the topmost segment) was sampled. The levels of ECOH and STEC recovered from segment 1 were about 6.0 and 5.3 log CFU/g, respectively, for the control subprimals and about 5.7 and 5.0 log CFU/g, respectively, for the tenderized subprimals. However, both ECOH and STEC behaved similarly in terms of translocation, and cells of both pathogen cocktails were recovered from all six segments of the cores obtained from tenderized subprimals, albeit at lower levels in segments 2 to 6 than those found in segment 1. In phase II, steaks (2.54 and 3.81 cm thick) cut from tenderized subprimals were subsequently cooked (three steaks per treatment) on a commercial open-flame gas grill to internal temperatures of 48.9, 54.4, 60.0, 65.6, and 71.1°C. Regardless of temperature or thickness, we observed 2.0- to 4.1-log and 1.5- to 4.5-log reductions in ECOH and STEC levels, respectively. Both ECOH and STEC behaved similarly in response to heat, in that cooking eliminated significant numbers of both pathogen types; however, some survivors were recovered due, presumably, to uneven heating of the blade-tenderized steaks.


2009 ◽  
Vol 72 (7) ◽  
pp. 1404-1411 ◽  
Author(s):  
JOHN B. LUCHANSKY ◽  
ANNA C. S. PORTO-FETT ◽  
BRADLEY SHOYER ◽  
RANDALL K. PHEBUS ◽  
HARSHAVARDHAN THIPPAREDDI ◽  
...  

Beef subprimals were inoculated on the lean side with ca. 4.0 log CFU/g of a cocktail of rifampin-resistant (Rifr) Escherichia coli O157:H7 strains and then passed once through a mechanical blade tenderizer with the lean side facing upward. Inoculated subprimals that were not tenderized served as controls. Two core samples were removed from each of three tenderized subprimals and cut into six consecutive segments starting from the inoculated side. A total of six cores were also obtained from control subprimals, but only segment 1 (topmost) was sampled. Levels of E. coli O157:H7 recovered from segment 1 were 3.81 log CFU/g for the control subprimals and 3.36 log CFU/g for tenderized subprimals. The percentage of cells recovered in segment 2 was ca. 25-fold lower than levels recovered from segment 1, but E. coli O157:H7 was recovered from all six segments of the cores obtained from tenderized subprimals. In phase II, lean-side–inoculated (ca. 4.0 log CFU/g), single-pass tenderized subprimals were cut into steaks of various thicknesses (1.91 cm [0.75 in.], 2.54 cm [1.0 in.], and 3.18 cm [1.25 in.]) that were subsequently cooked on a commercial open-flame gas grill to internal temperatures of 48.8°C (120°F), 54.4°C (130°F), and 60°C (140°F). In general, regardless of temperature or thickness, we observed about a 2.6- to 4.2-log CFU/g reduction in pathogen levels following cooking. These data validate that cooking on a commercial gas grill is effective at eliminating relatively low levels of the pathogen that may be distributed throughout a blade-tenderized steak.


2007 ◽  
Vol 70 (5) ◽  
pp. 1174-1180 ◽  
Author(s):  
C. E. HELLER ◽  
J. A. SCANGA ◽  
J. N. SOFOS ◽  
K. E. BELK ◽  
W. WARREN-SERNA ◽  
...  

The prevalence of Escherichia coli O157:H7 on beef subprimal cuts intended for mechanical tenderization was evaluated. This evaluation was followed by the assessment of five antimicrobial interventions at minimizing the risk of transferring E. coli O157:H7 to the interior of inoculated subprimal cuts during blade tenderization (BT) or moisture enhancement (ME). Prevalence of E. coli O157:H7 on 1,014 uninoculated beef subprimals collected from six packing facilities was 0.2%. Outside round pieces inoculated with E. coli O157:H7 at 104 CFU/100 cm2 were treated with (i) no intervention, (ii) surface trimming, (iii) hot water (82°C), (iv) warm 2.5% lactic acid (55°C), (v) warm 5.0% lactic acid (55°C), or (vi) 2% activated lactoferrin followed by warm 5.0% lactic acid (55°C) and then submitted to BT or ME. Prevalence (n = 196) of internalized (BT and ME) E. coli O157:H7 was 99%. Enumeration of E. coli O157:H7 (n = 192) revealed mean surface reductions of 0.93 to 1.10 log CFU/100 cm2 for all antimicrobial interventions. E. coli O157:H7 was detected on 3 of the 76 internal BT samples and 73 of the 76 internal ME samples. Internal ME samples with no intervention had significantly higher mean E. coli O157:H7 populations than did those internal samples treated with an intervention, but there were no significant differences in E. coli O157:H7 populations among internal BT samples. Results of this study demonstrate that the incidence of E. coli O157:H7 on the surface of beef subprimal cuts is low and that interventions applied before mechanical tenderization can effectively reduce the transfer of low concentrations of E. coli O157:H7 to the interior of beef subprimal cuts.


2015 ◽  
Vol 78 (6) ◽  
pp. 1090-1097 ◽  
Author(s):  
KYUNG YUK KO ◽  
IFIGENIA GEORNARAS ◽  
HYUN-DONG PAIK ◽  
KEE-TAE KIM ◽  
JOHN N. SOFOS

The antimicrobial effects of thyme oil (TO), grapefruit seed extract (GSE), and basil essential oil, alone or in combination with cetylpyridinium chloride (CPC), sodium diacetate, or lactic acid, were evaluated against Escherichia coli O157:H7 in a moisture-enhanced beef model system. The model system was composed of a nonsterile beef homogenate to which NaCl (0.5%) and sodium tripolyphosphate (0.25%) were added, together with the tested antimicrobial ingredients. Beef homogenate treatments were inoculated (ca. 3 log CFU/ml) with rifampin-resistant E. coli O157:H7 (eight-strain mixture) and incubated at 15°C (48 h). The most effective individual treatments were TO (0.25 or 0.5%) and GSE (0.5 or 1.0%), which immediately reduced (P < 0.05) pathogen levels by ≥3.4 log CFU/ml. Additionally, CPC (0.04%) reduced initial E. coli O157:H7 counts by 2.7 log CFU/ml. Most combinations of the tested plant-derived extracts with CPC (0.02 or 0.04%) and sodium diacetate (0.25%) had an additive effect with respect to antibacterial activity. In a second study, antimicrobial interventions were evaluated for their efficacy in reducing surface contamination of E. coli O157:H7 on beef cuts and to determine the effect of these surface treatments on subsequent internalization of the pathogen during blade tenderization. Beef cuts (10 by 8 by 3.5 cm) were inoculated (ca. 4 log CFU/g) on one side with the rifampin-resistant E. coli O157:H7 strain mixture and were then spray treated (20 lb/in2, 10 s) with water, GSE (5 and 10%), lactic acid (5%), or CPC (5%). Untreated (control) and spray-treated surfaces were then subjected to double-pass blade tenderization. Surface contamination (4.4 log CFU/g) of E. coli O157:H7 was reduced (P < 0.05) to 3.4 (5% CPC) to 4.1 (water or 5% GSE) log CFU/g following spray treatment. The highest and lowest transfer rates of pathogen cells from the surface to deeper tissues of blade-tenderized sections were obtained in the untreated control and CPC-treated samples, respectively.


Author(s):  
Peter Muriana ◽  
Jackie Eager ◽  
Brent Wellings ◽  
Brad Morgan ◽  
Jacob Nelson ◽  
...  

The USDA-FSIS considers mechanically-tenderized beef as ‘non-intact’ and a food safety concern because of the potential for translocation of surface E. coli O157:H7 into the interior of the meat that may be cooked ‘rare or medium-rare’ and consumed. We evaluated 14 potential spray interventions on E. coli O157:H7-inoculated lean beef wafers (~106 CFU/cm2 , n=80) passing through a spray system (18 sec dwell time, ~40 PSI) integrated into the front end of a Ross TC-700MC tenderizer. Inoculated and processed beef wafers were stomached with D/E neutralizing broth and plated immediately, or were held in refrigerated storage for 1-, 7-, or 14 days prior to microbial plating. Seven antimicrobials that showed better performance in preliminary screening on beef wafers were selected for further testing on beef subprimals in conjunction with blade tenderization. Boneless top sirloin beef subprimals were inoculated at ~2 x 104 CFU/cm2 with a four-strain cocktail of Escherichia coli O157:H7 and passed once, lean side up, through an integrated spray system and blade tenderizer. Core samples obtained from each subprimal were examined for the presence/absence of E. coli O157:H7. Absence of E coli O157:H7 translocated into core samples correlated with the ability of the antimicrobials to reduce bacterial levels on the surface of beef prior to blade tenderization.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ziyan Yan ◽  
Wenfeng Deng ◽  
Yuchen Wang ◽  
Yanna Liu ◽  
Hengbiao Sun ◽  
...  

Background: Colonization of Cryptococcus rarely occurs in a graft. This study reports a case of malacoplakia and cryptococcoma caused by E. coli and Cryptococcus albidus in a transplanted kidney, with detailed pathology and metagenome sequencing analysis.Case Presentation: We presented a case of cryptococcoma and malacoplakia in the genitourinary system including the transplant kidney, bladder, prostate, and seminal vesicles caused by Cryptococcus albidus and Escherichia coli in a renal-transplant recipient. Metagenome sequencing was conducted on a series of samples obtained from the patient at three different time points, which we termed Phase I (at the diagnosis of cryptococcoma), Phase II (during perioperative period of graftectomy, 3 months after the diagnosis), and Phase III (2 months after graftectomy). Sequencing study in the Phase I detected two and four sequences of C. albidus respectively in cerebrospinal fluid (CSF) and feces, with resistant Escherichia coli 09-02E presented in urine and renal mass. A 3-month antibiotic treatment yielded a smaller bladder lesion but an enlarged allograft lesion, leading to a nephrectomy. In the Phase II, two sequences of C. albidus were detected in CSF, while the E. coli 09-02E continued as before. In the Phase III, the lesions were generally reduced, with one C. albidus sequence in feces only.Conclusions: The existence and clearance of Cryptococcus sequences in CSF without central nervous system symptoms may be related to the distribution of infection foci in vivo, the microbial load, and the body's immunity. Overall, this study highlights the need for enhanced vigilance against uncommon types of Cryptococcus infections in immunocompromised populations and increased concern about the potential correlation between E. coli and Cryptococcus infections.


1998 ◽  
Vol 61 (2) ◽  
pp. 162-165 ◽  
Author(s):  
WARREN J. DORSA ◽  
GREGORY R. SIRAGUSA

The purge from beef combos (a boxed collection of beef trimmings) was tested as a means of representatively sampling the microbial content of this raw product. In the first experiment, purge was sampled from model beef combos that had been inoculated with bovine feces. Data from this experiment indicated a strong correlation (r = 0.94) between the total aerobic bacteria counts derived from the purge samples of a model beef combo and the total aerobic bacteria present in a rinse sample of the entire model beef combo. In a second experiment, two 500-g meat pieces were inoculated with an antibiotic-resistant Escherichia coli O157:H7 and placed at various levels within a 75-cm meat column. The marked bacteria were retrievable from the purge of the meat column after 24 h, showing that bacteria are carried downward into the purge. During the third part of the study, 90 beef combos (~900 kg beef/combo) were randomly selected at the receiving dock of a commercial grinding facility and sampled using both purge and concurrently used 11-g core samples. Purge samples from these combos recovered significantly greater numbers of mesophilic and psychrotrophic aerobic bacteria, coliforms, and E. coli than core samples from the same combos. Additionally, coliforms and E. coli were recoverable from 100% and 80%, respectively, of the purge samples taken, whereas core samples were only able to recover 60% and 40%, respectively, from the same combos. These findings indicate that a purge sample from a beef combo is a more efficacious sampling method for determining the general bacterial profile and identifying the presence of coliforms and E. coli than randomly taken core samples.


2013 ◽  
Vol 76 (10) ◽  
pp. 1778-1783 ◽  
Author(s):  
C. C. CHANCEY ◽  
J. C. BROOKS ◽  
J. N. MARTIN ◽  
A. ECHEVERRY ◽  
S. P. JACKSON ◽  
...  

Mechanical tenderization improves the palatability of beef; however, it increases the risk of translocating pathogenic bacteria to the interior of beef cuts. This study investigated the efficacies of lactic acid spray (LA; 5%), storage, and cooking on the survivability of Escherichia coli O157:H7 in mechanically tenderized beef steaks managed under simulated industry conditions. Beef subprimals inoculated with either high (105 CFU/ml) or low (103 CFU/ml) levels of E. coli O157:H7 were treated (LA or control) and stored for 21 days prior to mechanical tenderization, steak portioning (2.54 cm), and additional storage for 7 days. Steaks were then cooked to an internal temperature of 55, 60, 65, 70, or 75°C. Samples were enumerated and analyzed using DNA-based methods. Treatment with LA immediately reduced E. coli O157:H7 on the lean and fat surfaces of high- and low-inoculum–treated subprimals by more than 1.0 log CFU/cm2 (P < 0.05). Storage for 21 days reduced surface populations of E. coli O157:H7 regardless of the inoculation level; however, the populations on LA- and control-treated lean surfaces of high- and low-inoculum–treated subprimals were not different after 21 days (P > 0.05). E. coli O157:H7 was detected in core samples from high-inoculum–treated steaks cooked to 55, 60, or 70°C. Conversely, E. coli O157:H7 was not detected in core samples from low-inoculum–treated steaks, regardless of the internal cooking temperature. These data suggest that LA- and storage-mediated reduction of pathogens on subprimals exposed to typical industry contamination levels (101 CFU/cm2) reduces the risk of pathogen translocation and subsequent survival after cooking.


2011 ◽  
Vol 74 (8) ◽  
pp. 1334-1337 ◽  
Author(s):  
DANIEL F. JOHNS ◽  
CHRISTY L. BRATCHER ◽  
CHRIS R. KERTH ◽  
THOMAS McCASKEY

Translocation of Escherichia coli among beef loins processed with a mechanical tenderizer was evaluated. Two beef striploins were inoculated on the lean side with 6.4 to 7.2 ml of a nalidixic acid–resistant E. coli at 8.2 to 10.1 log CFU/ml. Total E. coli inoculated onto striploins ranged from 1.12 × 109 to 9.10 × 1010 CFU. Striploins were passed once (lean side up, anterior end first) through a mechanical blade tenderizer. After the inoculated striploins had been tenderized, uninoculated beef striploins (n = 5) were passed once (lean side up, anterior end first) through the same mechanical tenderizer. This procedure was repeated twice for a total of 12 striploins. Six core samples were taken from each striploin starting with the anterior end. Each core was cut into six sections; sections 1 through 4 represented the top 4 cm of the core sample, and sections 5 and 6 represented the remaining part of the core split in half. After tenderization, E. coli levels were highest (P < 0.05) in loin 1. Loin 2 had higher levels (P < 0.05) than did loins 4, 5, and 6. No differences in E. coli levels (P > 0.05) were found among loins 3, 4, 5, and 6, for which levels were below the limit of detection. Levels of E. coli from section 1 were higher than those for all other sections. Section 2 had higher levels (P < 0.05) than did sections 3, 4, 5, and 6. E. coli recovery from section 6 was higher (P < 0.05) than that from sections 3, 4, and 5. No differences in E. coli recovery (P > 0.05) were found among sections 3, 4, and 5. Data indicate that even after inoculation of E. coli a high initial levels, contamination from one loin to another is quickly reduced to <10 CFU/g.


2020 ◽  
Vol 16 (3) ◽  
pp. 373-380
Author(s):  
Mohammad B. Zendeh ◽  
Vadood Razavilar ◽  
Hamid Mirzaei ◽  
Khosrow Mohammadi

Background: Escherichia coli O157:H7 is one of the most common causes of contamination in Lighvan cheese processing. Using from natural antimicrobial essential oils is applied method to decrease the rate of microbial contamination of dairy products. The present investigation was done to study the antimicrobial effects of Z. multiflora and O. basilicum essential oils on survival of E. coli O157:H7 during ripening of traditional Lighvan cheese. Methods: Leaves of the Z. multiflora and O. basilicum plants were subjected to the Clevenger apparatus. Concentrations of 0, 100 and 200 ppm of the Z. multiflora and 0, 50 and 100 ppm of O. basilicum essential oils and also 103 and 105 cfu/ml numbers of E. coli O157:H7 were used. The numbers of the E. coli O157:H7 bacteria were analyzed during the days 0, 30, 60 and 90 of the ripening period. Results: Z. multiflora and O. basilicum essential oils had considerable antimicrobial effects against E. coli O157:H7. Using the essential oils caused decrease in the numbers of E. coli O157:H7 bacteria in 90th days of ripening (P <0.05). Using from Z. multiflora at concentration of 200 ppm can reduce the survival of E. coli O157:H7 in Lighvan cheese. Conclusion: Using Z. multiflora and O. basilicum essential oils as good antimicrobial agents can reduce the risk of foodborne bacteria and especially E. coli O157:H7 in food products.


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