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Our objective was to assess whether the harvest processing equipment sanitation practices in beef processing plants are sufficient to mitigate pathogen transfer. Multiple regulatory agencies across the globe require that harvest equipment be sanitized using hot water at a minimum of 82°C, with a momentary dip when a time is specified. Consequently, hot water sanitizers have been widely implemented at meat processing facilities, in particular, for knife sanitation throughout the dressing process. However, there is no standard time requirement for hot water immersion and, as such, the effectiveness of hot water sanitization is uncertain. The practice for knife sanitation at a large beef processing facility was audited and the microbial reduction that simulated the audited practice was assessed along with a momentary dip at 82°C. A five-strain cocktail of Escherichia coli and 11 knives of differing degree of usage obtained from the beef plant were used in the study. An area of 50 cm² of the upper surface of each knife was spread-inoculated with the five-strain E. coli cocktail and the knife was subsequently submerged in a water bath coupled to a water circulator for immersion at 82°C. Exposures times tested were those derived from the in-plant audit for each knife type. A knife that was similarly inoculated, but was not treated with hot water, served as a positive control. E. coli surviving the treatment were enumerated by plating. In addition, two knives that had most and least reduction of E. coli were artificially contaminated with meat prior to inoculation, by passing the knife through meat multiple times. For each condition, three independent trials were conducted. Least-squares means for log counts were separated by a post-hoc Tukey test. Mean immersion times for different knives audited ranged from 1 to 9.8 s. Immersing knives in water at 82°C significantly reduced the number of E. coli (P < 0.05; Table 1), ranging from 2.3 (air knife)- 5.5 (skinning knife 2) log units. Variation among the same knife type was observed. Momentary dip at 82°C reduced E. coli on de-boning, hook, air knife and wizard knife by 1-1.2 log (P < 0.05) and < 1 log for the other six knives (P ≥ 0.05). Treatment at 82°C for the duration of average exposure time observed during the in-plant audit of knives that had been contaminated with meat debris showed lower reductions of E. coli, compared with clean knives. Those reductions (>1.5 log units) were significant (P < 0.05). In conclusion, the duration for hot water sanitation of knives at beef processing plants achieves significant reduction of E. coli if temperature is maintained at 82°C and a momentary dip at the same temperature would be less likely to be effective. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) O157:H7 and efficacy of control measures at a pork processing facility. Outbreaks of E. coli O157:H7 associated with pork, though not common globally, have been reported multiple times in recent years in Alberta. Sampling at a commercial facility processing hogs was carried out at monthly intervals for 11 mo. At the facility, the dressed carcasses are sprayed with 5% lactic acid (LA) and immediately airchilled after the LA spray. At each sampling time, 14 different types of samples were collected: dirt from the holding pen floor (n = 2), gloves of workers (n = 5), scalding water (n = 1), tonsils (n = 5), cecal material (n = 5), five swabs each from hides of animals after bleeding (HAB), and carcasses after scalding (CAS), before evisceration (CBE), after evisceration (CAE), before LA spray (BLA), after LA spray (ALA), 1h after LA spray (ALA1), 2h after LA spray (ALA2), and after chilling (ACH). All samples were enumerated for total plate count (TPC), Enterobacteriaceae, and E. coli using specific media for each. In addition, an aliquot of each sample was enriched and tested for the presence of the O-antigen gene (rfbE) for E. coli O157 and Shiga toxin-producing gene (stx1/stx2) using realtime PCR. Cultures positive for both rfbE and stx were further plated for the isolation of E. coli O157:H7. Of the 683 enrichment cultures, 12 were positive for both marker genes, from cecal material (n = 2), dirt (n = 4) and HAB (n = 6). However, none of these samples yielded STEC O157 isolates. Of these enrichment cultures, 69, 45 and 32 were positive for stx1, stx2, and both stx genes, respectively. Positive samples were mostly associated with HAB, cecal material and dirt. HAB was most and least contaminated in August/June and December, differing by 1 log unit for TPC (P < 0.05). Enterobacteriaceae and E. coli on HAB were also affected by month of sampling (P < 0.05), but this temporal trend differed from TPC (Table). The numbers for TPC, Enterobacteriaceae, and E. coli all decreased (P < 0.05) as the stage of carcass processing progressed. The overall reduction of TPC and E. coli was 7 and 5 log units, respectively. Scalding, LA spray and air chilling all reduced (P < 0.05) the numbers of indicator bacteria on carcasses. Of the 55 samples each collected from BLA, ALA, ALA1, ALA2, and ACH, 36, 13, 2, 1 and 0 were positive for E. coli, respectively. In conclusion, pork processing environments can be contaminated with STEC from hides, feces and holding pen, but levels of STEC O157 appear to be low. Scalding, LA spray and air chilling can be effective measures to reduce the risk of bacterial contamination of pork. [ABSTRACT FROM AUTHOR]

Summary: Microbes naturally build nanoscale structures, including structures assembled from inorganic materials. Here, we combine the natural capabilities of microbes with engineered genetic control circuits to demonstrate the ability to control biological synthesis of chalcogenide nanomaterials in a heterologous host. We transferred reductase genes from both Shewanella sp. ANA‐3 and Salmonella enterica serovar Typhimurium into a heterologous host (Escherichia coli) and examined the mechanisms that regulate the properties of biogenic nanomaterials. Expression of arsenate reductase genes and thiosulfate reductase genes in E. coli resulted in the synthesis of arsenic sulfide nanomaterials. In addition to processing the starting materials via redox enzymes, cellular components also nucleated the formation of arsenic sulfide nanomaterials. The shape of the nanomaterial was influenced by the bacterial culture, with the synthetic E. coli strain producing nanospheres and conditioned media or cultures of wild‐type Shewanella sp. producing nanofibres. The diameter of these nanofibres also depended on the biological context of synthesis. These results demonstrate the potential for biogenic synthesis of nanomaterials with controlled properties by combining the natural capabilities of wild microbes with the tools from synthetic biology. Escherichia coli produce arsenic sulfide nanomaterials through heterologous expression of arsenic and thiosulfate reductase genes. In addition to processing starting materials, E. coli regulates the nanomaterial shape and provides sites for nanomaterial nucleation. [ABSTRACT FROM AUTHOR]

To investigate the microbiological effects of a hide-on carcass decontaminating treatment recently implemented at a beef packing plant, carcasses undergoing routine processing at the plant were sampled during successive periods in January/February, April/May, and September/October. During each period, samples were collected from carcasses before and after the decontamination of hide-on carcasses, after skinning, before decontamination of the skinned carcasses, and at the end of the carcass dressing process. At each stage of processing during each period, samples were obtained by swabbing an area of 1.000 cm² on each of 25 carcasses. Aerobes, coliforms, and Escherichia coli were enumerated. In most samples, coliforms were predominantly E. coli. In all three periods, the log mean numbers of aerobes and E. coli recovered from hides before decontamination were between 6.6 and 6.8 and between 5.3 and 5.9 log CFU/1,000 cm², respectively. The log mean numbers of aerobes recovered from decontaminated hides were 6.6 log CFU/1,000 cm² in January/February and April/May but 5.4 log CFU/ 1.000 cm² in September/October. The log total numbers of E. coli recovered from decontaminated hides in January /February and April/May were 2.4 and 3.8 log CFU/25,000 cm², respectively, but no E. coli was recovered from such carcasses in September/ October. Log total numbers of aerobes and E. coli recovered from skinned or dressed carcasses were mostly > 4 and between 1 and 2 log CFU/25,000 cm², respectively. Typing of 480 E. coli isolates by multiple-locus variable-number tandem repeat analysis (MLVA) identified 218 MLVA types. Most isolates recovered from carcasses in different periods or at different stages of processing were of different MLVA types. However, small numbers of MLVA types were recovered in more than one period or from both hides before and after decontamination and skinned or dressed carcasses. The findings show that the hide-decontaminating treatment disrupted the usual transfer of E. coli from hides to meat surfaces during carcass skinning. [ABSTRACT FROM AUTHOR]

FNR is a well-studied global regulator of anaerobiosis, which is widely conserved across bacteria. Despite the importance of FNR and anaerobiosis in microbial lifestyles, the factors that influence its function on a genome-wide scale are poorly understood. Here, we report a functional genomic analysis of FNR action. We find that FNR occupancy at many target sites is strongly influenced by nucleoid-associated proteins (NAPs) that restrict access to many FNR binding sites. At a genome-wide level, only a subset of predicted FNR binding sites were bound under anaerobic fermentative conditions and many appeared to be masked by the NAPs H-NS, IHF and Fis. Similar assays in cells lacking H-NS and its paralog StpA showed increased FNR occupancy at sites bound by H-NS in WT strains, indicating that large regions of the genome are not readily accessible for FNR binding. Genome accessibility may also explain our finding that genome-wide FNR occupancy did not correlate with the match to consensus at binding sites, suggesting that significant variation in ChIP signal was attributable to cross-linking or immunoprecipitation efficiency rather than differences in binding affinities for FNR sites. Correlation of FNR ChIP-seq peaks with transcriptomic data showed that less than half of the FNR-regulated operons could be attributed to direct FNR binding. Conversely, FNR bound some promoters without regulating expression presumably requiring changes in activity of condition-specific transcription factors. Such combinatorial regulation may allow Escherichia coli to respond rapidly to environmental changes and confer an ecological advantage in the anaerobic but nutrient-fluctuating environment of the mammalian gut. [ABSTRACT FROM AUTHOR]

Study Design: Systematic review., Objective: To characterize the effects of postoperative physical therapy (PT) after surgery for cervical spondylosis on patient-reported outcomes and impairments. Secondarily, to identify associated complications, adverse effects, and health care costs with postoperative PT, and to describe the content, timing, and duration of the PT., Summary of Background Data: Cervical spine surgery is common; however, it is unclear if the addition of postoperative PT leads to improved patient outcomes and decreased health care costs., Materials and Methods: PubMed, Embase, Cochrane Central Register of Controlled Trials, Physiotherapy Evidence Database, and Web of Science were searched until July 2019. All peer-reviewed articles involving cervical spine surgery with postoperative PT for cervical spondylosis were considered for inclusion. Risk of bias was assessed using the Revised Cochrane risk-of-bias tool for randomized trials. Findings were described narratively, and GRADE approach was used to define the quality of evidence., Results: A total of 10,743 studies were screened. Six studies met inclusion criteria; 2 randomized controlled trials and 4 subsequent follow-up studies containing study arms that included postoperative PT after cervical spine surgery. Meta-analysis was not performed due to study heterogeneity and no study compared PT+surgery to surgery alone. PT treatment included exercise therapy, cognitive behavioral therapy, and optional vestibular rehabilitation. Included studies indicated PT appeared to have positive effects on patient outcomes, however, there were no treatment control groups and the quality of evidence was very low to low. Timing, duration, and content of PT programs varied. No studies reported complications, adverse effects, or cost-effectiveness relating to PT after surgery., Conclusions: Current literature prevents a definitive conclusion regarding the impact of postoperative PT, given the lack of treatment control groups. PT treatment was limited to exercise therapy, cognitive behavioral therapy, and optional vestibular rehabilitation in the included studies. PT treatment varied, limiting consistent recommendations for content, timing, and treatment duration. Controlled trials are needed to determine the effectiveness of the addition of postoperative PT following cervical spine surgery for cervical spondylosis., Level of Evidence: Level II., Competing Interests: Z.B.: Consulting: AOSpine (B, $10,000, past), Xenco Medical (B, $1001–$10,000, past); Research Support (Investigator Salary, Research Support—Staff and/or Materials): SeaSpine (F, Paid directly to institution/employer); Research Support (Investigator Salary, Research Support—Staff and/or Materials): Next Science (F, Paid directly to institution/employer); Trips/Travel: AO Spine (Travel Expense Reimbursement, travel reimbursements for AO Spine Knowledge forum meetings and congresses); NASS (Travel Expense Reimbursement, travel reimbursements for meetings). J.C.W.: Board of Directors: AOFoundation (20,000 honorariums for board position, plus travel for board meetings), Cervical Spine Research Society (nonfinancial, reimbursement for travel for board meetings), North American Spine Society (nonfinancial, reimbursement for travel for board meetings, courses, etc.); Royalties: Amedica (B, $1001–$10,000), Biomet (F, $100,001–$500,000), Depuy Synthes (C, $10,001–$25,000), Seaspine (C, $10,001–$25,000); Fellowship Support: AO Foundation (E, spine fellowship funding paid to institution, Paid directly to institution/employer); Private Investments: Bone Biologics (51,255 Shares, 1.00%, 51,255 options, <1% of entity), Electrocore (1 Shares, 1.00%, $25,000 investment, <1% of entity, unknown amount of shares), Pearldiver (25,000 Shares, 1.00%, 25,000 options, <1% of entity), Surgitech (1 Shares, 1.00%, $20,000 investment, <1% of entity, unknown amount of shares). R.J.H.: Consulting: Nuvasive ($32,000); Trips/Travel: NASS ($2000). L.A.M.: Board of Directors: Academy of Orthopedic Physical Therapy ($6000), Scientific Advisory Board: Associate Editor—Journal of Orthopaedic and Sports Physical Therapy ($2500), Grants: Optimization of Spinal Manipulation for Patient with Shoulder Pain—Bauer Foundation ($100,000). J.M.L.: Consulting: SI-Bone Inc. The remaining authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Microbes naturally build nanoscale structures, including structures assembled from inorganic materials. Here, we combine the natural capabilities of microbes with engineered genetic control circuits to demonstrate the ability to control biological synthesis of chalcogenide nanomaterials in a heterologous host. We transferred reductase genes from both Shewanella sp. ANA-3 and Salmonella enterica serovar Typhimurium into a heterologous host (Escherichia coli) and examined the mechanisms that regulate the properties of biogenic nanomaterials. Expression of arsenate reductase genes and thiosulfate reductase genes in E. coli resulted in the synthesis of arsenic sulfide nanomaterials. In addition to processing the starting materials via redox enzymes, cellular components also nucleated the formation of arsenic sulfide nanomaterials. The shape of the nanomaterial was influenced by the bacterial culture, with the synthetic E. coli strain producing nanospheres and conditioned media or cultures of wild-type Shewanella sp. producing nanofibres. The diameter of these nanofibres also depended on the biological context of synthesis. These results demonstrate the potential for biogenic synthesis of nanomaterials with controlled properties by combining the natural capabilities of wild microbes with the tools from synthetic biology., (© 2018 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.)