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1.
Poult Sci ; 103(4): 103492, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38335673

RESUMO

Salmonella and Campylobacter are common bacterial hazards causing foodborne illnesses worldwide. A large proportion of Salmonella and Campylobacter illnesses are attributed to contaminated poultry products that are mishandled or under cooked. Processing interventions such as chilling and post-chill dip are critical to reducing microbial contamination of poultry. A comprehensive search of the literature published between 2000 and 2021 was conducted in the databases Web of Science, Academic Search Complete, and Academic OneFile. Studies were included if they were in English and investigated the effects of interventions against Salmonella and/or Campylobacter on whole carcasses and/or parts during the chilling or post-chill stages of poultry processing. Random-effects meta-analyses were performed using the "meta" package in the R programming language. Subgroup analyses were assessed according to outcome measure reported, microorganism tested, processing stage assessed, and chemical treatment used. The results included 41 eligible studies. Eighteen studies reported results of 28 separate interventions against Salmonella and 31 reported results of 50 separate interventions against Campylobacter. No significant difference (P> 0.05) was observed when comparing the combined mean difference of all interventions targeting Salmonella to the combined mean difference of all interventions targeting Campylobacter or when comparing chilling times within each pathogen subgroup. For analyses examining antimicrobial additives, peroxyacetic acid (PAA) had the largest reduction against Salmonella population regardless of chilling time (P< 0.05). PAA also had the largest reduction against Campylobacter population and prevalence during primary chilling (P< 0.01). Air chilling showed a lower reduction for Campylobacter than any immersion chilling intervention (P< 0.05). Chilling time and antimicrobial used during poultry processing had varying effects depending on the pathogen and outcome measure investigated (concentration or prevalence). High heterogeneity and low sample numbers in most analyses suggest that more high-quality research that is well-designed and has transparent reporting of methodology and results is needed to corroborate the results.


Assuntos
Anti-Infecciosos , Campylobacter , Animais , Aves Domésticas , Carne/microbiologia , Microbiologia de Alimentos , Galinhas/microbiologia , Manipulação de Alimentos/métodos , Salmonella , Anti-Infecciosos/farmacologia , Ácido Peracético/farmacologia
2.
J Food Prot ; 86(11): 100169, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37774838

RESUMO

Despite the continuous progress in food science and technology, the global burden of foodborne illnesses remains substantial, with pathogens in food causing millions of infections each year. Traditional microbiological culture methods are inadequate in detecting the full spectrum of these microorganisms, highlighting the need for more comprehensive detection strategies. This review paper aims to elucidate the relationship between foodborne pathogen colonization and the composition of the poultry microbiome, and how this knowledge can be used for improved food safety. Our review highlights that the relationship between pathogen colonization varies across different sections of the poultry microbiome. Further, our review suggests that the microbiome profile of poultry litter, farm soil, and farm dust may serve as potential indicators of the farm environment's food safety issues. We also agree that the microbiome of processed chicken samples may reveal potential pathogen contamination and food quality issues. In addition, utilizing predictive modeling techniques on the collected microbiome data, we suggest establishing correlations between particular taxonomic groups and the colonization of pathogens, thus providing insights into food safety, and offering a comprehensive overview of the microbial community. In conclusion, this review underscores the potential of microbiome analysis as a powerful tool in food safety, pathogen detection, and risk assessment.


Assuntos
Doenças Transmitidas por Alimentos , Microbiota , Animais , Aves Domésticas/microbiologia , Fazendas , Inocuidade dos Alimentos , Galinhas
3.
Foods ; 12(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37444297

RESUMO

Campylobacter has consistently posed a food safety issue in broiler meat. This study aimed to create a quantitative microbial risk assessment model from retail to consumption, designed to evaluate the seasonal risk of campylobacteriosis associated with broiler meat consumption in the United States. To achieve this, data was gathered to build distributions that would enable us to predict the growth of Campylobacter during various stages such as retail storage, transit, and home storage. The model also included potential fluctuations in concentration during food preparation and potential cross-contamination scenarios. A Monte Carlo simulation with 100,000 iterations was used to estimate the risk of infection per serving and the number of infections in the United States by season. In the summer, chicken meat was estimated to have a median risk of infection per serving of 9.22 × 10-7 and cause an average of about 27,058,680 infections. During the winter months, the median risk of infection per serving was estimated to be 4.06 × 10-7 and cause an average of about 12,085,638 infections. The risk assessment model provides information about the risk of broiler meat to public health by season. These results will help understand the most important steps to reduce the food safety risks from contaminated chicken products.

4.
Front Microbiol ; 14: 1059144, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37180239

RESUMO

Introduction: The occurrence of antibiotic resistant (ABR) bacteria in foods is a growing public health challenge. We evaluated sanitizer cross-tolerance among ABR Escherichia coli (E. coli) O157:H7 and non-O157:H7 Shiga-toxin producing E. coli (STEC) serogroups. Sanitizer tolerance in STEC could be a public health concern as mitigation strategies against the pathogen might be compromised. Methods: Resistance to ampicillin and streptomycin were evolved in E. coli serogroups: O157:H7 (H1730, and ATCC 43895), O121:H19 and O26:H11. Resistance to antibiotics was evolved chromosomally through incremental exposure to ampicillin (amp C) and streptomycin (strep C). Transformation using a plasmid was performed to confer resistance to ampicillin to generate amp P strep C. Results: The minimum inhibitory concentration (MIC) of lactic acid for all strains evaluated was 0.375% v/v. Analysis of bacterial growth parameters in tryptic soy broth amended with 0.0625% v/v, 0.125% v/v, and 0.25% v/v (subMIC) lactic acid indicated that growth correlated positively with the lag phase duration, and negatively with both the maximum growth rate and change in population density for all strains evaluated except for the highly tolerant variant- O157:H7 amp P strep C. Strains O121 NR (non-ABR), O121 amp C, O121 amp P strep C, O157:H7 H1730 amp C and O157:H7 H1730 amp P strep C were not inactivated after exposure to 1% and 2.5% v/v lactic acid for 300 s. No recovery of cells was observed after the strains were exposed to 5% v/v lactic acid for 300 s. ABR strains O157:H7 H1730 amp C and O157: H7 H1730 amp P strep C demonstrated a high tolerance to lactic acid (P ≤ 0.05). Conclusion: ABR in isolate E. coli O157: H7 H1730 may improve tolerance to lactic acid. Increased tolerance may be discerned by evaluating growth parameters of bacteria in presence of sub-MIC levels of lactic acid.

5.
Sci Total Environ ; 885: 163884, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37142011

RESUMO

Preharvest agricultural water has been recognized as one of the routes of contamination for foodborne pathogens during fruit and vegetable production. Several strategies have been proposed to reduce the risk of pathogens, including preharvest water chemigation, but literature is lacking with regards to microbiological inactivation of common bacterial foodborne pathogens associated with fresh produce contamination, Salmonella enterica, Shiga-toxigenic Escherichia coli (STEC), and Listeria monocytogenes, in surface irrigation water after exposure to chlorine and peracetic acid (PAA). Surface water supplied by a local irrigation district was collected over the summer of 2019. Water was autoclaved, divided into 100 mL samples, and inoculated with a cocktail of five Salmonella, STEC, or Listeria monocytogenes strains or a single strain non-pathogenic E. coli. Samples were then treated with 3, 5, or 7 ppm of free chlorine or PAA, and surviving populations were evaluated using a time-kill assay. A first-order kinetic model was used to fit the inactivation data and obtain the D-values. A secondary model was used to explain the changes due to the type of water, treatment, and microorganism. At a concentration of 3 ppm, the observed and predicted D-values of free chlorine treatments were higher than that of PAA treatments for ground and surface water. Results indicated that PAA was more effective inactivating bacteria than sodium hypochlorite at concentrations of 3 and 5 ppm for both water sources (surface and ground). However, at 7 ppm, the effectiveness of PAA and sodium hypochlorite showed no statistically significant difference for both surface and groundwater. Findings will provide information regarding efficacy of chemical sanitizers like chlorine and PAA for inactivation of Salmonella, Listeria, and STEC in surface water from which treatments can be derived. Ultimately benefitting growers in the selection of an appropriate method for in-field treatment of irrigation water if deemed necessary.


Assuntos
Desinfetantes , Escherichia coli O157 , Listeria monocytogenes , Escherichia coli Shiga Toxigênica , Ácido Peracético/farmacologia , Cloro/farmacologia , Água , Desinfetantes/farmacologia , Hipoclorito de Sódio/farmacologia , Microbiologia de Alimentos , Contagem de Colônia Microbiana , Salmonella , Cloretos
6.
J Arthroplasty ; 38(6S): S109-S113, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36996948

RESUMO

BACKGROUND: Anterior knee pain (AKP) and patello-femoral crepitus (PFCr) continue to plague total knee arthroplasty patients despite advances and modifications to implant design and surgical techniques. We present our study of the femoral trochlear length measurement preimplantation and postimplantation and its association with AKP/PFCr and clinical scores. METHODS: Using computer navigation, we obtained several measurements in 263 total knee arthroplasty (posterior-stabilized) patients, which included femoral native trochlear measurement (NTM) and difference in trochlear length between implant and native trochlea. We report their association with Knee Society Score, Western Ontario McMaster University Arthritic Index, and AKP/PFCr at 1 year postoperatively. RESULTS: Mean Knee Society Score and Western Ontario McMaster University Arthritic Index scores were significantly worse in patients who had AKP (P = .005 and P = .002 respectively). Receiver operating characteristic curve showed a statistically significant association between NTM and AKP (Area under the curve = 0.609, P = .014). Lower the NTM, greater was the incidence of AKP. Analysis of the receiver operating characteristic curve identified the cutoff value of NTM to be ≤25.5 with sensitivity of 76.7(95% confidence interval - 57.7 - 90.1) and specificity of 46.9 (95% confidence interval - 41.9 - 55.1). Patients who had NTM of ≤25.5 had an odds ratio of 3.09 to have AKP. The difference in trochlear length ranged from 7.4 to 32.1 millimeters, indicating that postimplantation there was lengthwise overstuffing along the trochlea in every patient. CONCLUSION: We found that the shorter the native femoral trochlea and greater the difference between implanted and native trochlea, the higher was the occurrence of AKP. A mismatch in trochlear measurement preimplantation and postimplantation resulted in lengthwise overstuffing in the anterior knee causing AKP and PFCr.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Humanos , Artroplastia do Joelho/efeitos adversos , Artroplastia do Joelho/métodos , Prótese do Joelho/efeitos adversos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Joelho/cirurgia , Dor/cirurgia , Patela/cirurgia
7.
J Food Sci ; 88(5): 1816-1834, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36951315

RESUMO

Pecan is a major specialty crop produced in the United States. Sensory evaluation and chemical analyses of pecan nutmeats are integral components of shelf life and have been employed to investigate changes during storage, but there remains a lack of knowledge regarding storage stability. Specifically, the association between shelf life and chemical characteristics has not been investigated. We aimed to investigate the chemical changes in pecan nuts during a range of storage treatments (temperature, relative humidity, packaging material, and modified atmosphere). The results of the chemical analyses were used to build a volatile compound-based sensory prediction model. The work has utility as a rapid method to measure lipid oxidation in pecan, which is of value to the pecan industry. The research also determined a possible association between pecan nut volatile compounds and sensory attributes of pecans, and their perception by human subjects. Building a sensory-based prediction model would reduce dependency on expensive and time-consuming sensory methods.


Assuntos
Carya , Humanos , Carya/química , Temperatura , Nozes/química , Cromatografia Gasosa , Fatores de Tempo
8.
Int J Food Microbiol ; 391-393: 110144, 2023 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-36842254

RESUMO

Shiga toxin producing Escherichia coli (STEC) continues to cause foodborne outbreaks associated with beef and beef products despite consistent use of antimicrobial interventions. In this study, the influence of antibiotic resistance (ABR) in E. coli O157:H7 H1730, O157:H7 43,895, O121:H19 and O26:H11 on tolerance to peroxyacetic acid (PAA) was evaluated. Further, bactericidal concentrations of PAA in the presence of nutrient rich media (Tryptic Soy Broth, TSB and beef exudates) and nutrient deficient media (Sterile Deionized Water, SDW and Phosphate Buffered Saline, PBS) were evaluated for all bacterial strains. Antibiotic resistance to ampicillin (amp C), or ampicillin and streptomycin (amp P strep C) was generated in each bacterial strain through incremental exposure to the antibiotics or by plasmid transformation (n = 12 total strains). The mean bactericidal concentrations of PAA were higher (p ≤ 0.05) in nutrient rich media (205.55 ± 31.11 in beef exudate and 195.83 ± 25.00 ppm in TSB) than in nutrient deficient media (57.91 ± 11.97 ppm in SDW and 56.66 ± 9.56 ppm in PBS). Strain O157: H7 ampP strepC was the most tolerant to PAA (p ≤ 0.05). At 200 ppm in nutrient rich media and 60 ppm in nutrient deficient media, all bacterial strains declined in population to below the limit of detection. Analysis of the beef exudates indicated the presence of diverse amino acids that have been associated with acid tolerance. The results from this study indicate that beef exudates could contribute to acid tolerance and suggest that some STEC bacterial strains with certain ABR profiles might be more tolerant to PAA.


Assuntos
Escherichia coli O157 , Escherichia coli Shiga Toxigênica , Animais , Bovinos , Ácido Peracético , Carne/microbiologia , Microbiologia de Alimentos , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Toxinas Shiga , Ampicilina
9.
J Microbiol Methods ; 204: 106632, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36460092

RESUMO

Real-time PCR assays are the method of choice for the specific detection of DNA targets. Multiple real-time PCR chemistries are used for developing pathogen detection assays. Among them, a hydrolysis probe is a preferred choice for pathogen detection assays. Two known limitations of hydrolysis probes are high cost and limited storage life. Therefore, this study aimed to develop and validate a universal hydrolysis probe (UHP)-based approach with high-resolution melt (HRM) analysis capabilities. The approach can be used for the detection and genotyping of target DNA. The approach described in this study was validated by standardizing nine UHP assays for detecting seven Shiga toxin-producing Escherichia coli serogroups, Listeria monocytogenes, and Salmonella strains. These nine assays were validated with 141 pure culture bacterial strains. Additionally, the HRM capability of the developed approach was validated for three UHP assays targeting E. coli O26, O111, and O121 using 96 DNAs isolated from enriched food samples. The nine assays specifically detected the target bacterial strains, and the three assays showed single nucleotide polymorphism (SNP) identification capability and no cross-reactivity with non-target strains. The developed approach can be performed in singleplex or multiplex format and combined with HRM analysis. The data from this study demonstrate that the UHP real-time PCR approach is a robust method for detecting any deoxyribonucleic acid target.


Assuntos
Proteínas de Escherichia coli , Escherichia coli Shiga Toxigênica , Proteínas de Escherichia coli/genética , Microbiologia de Alimentos , Genótipo , Hidrólise , DNA
10.
Food Res Int ; 161: 111860, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36192982

RESUMO

Though most strains of E. coli are non-pathogenic components of the intestinal microbiome, certain pathogenic E. coli strains are the cause of diseases and outbreaks. Poultry is identified as a common reservoir for pathogenic E. coli. It is important to identify farm practice factors associated with E. coli in the pastured poultry environment. The objective of this study is to develop models that can predict E. coli levels and to select farm practice factors contributing to E. coli concentration in pastured poultry farms. Five kinds of samples: feces, soil, whole carcass rinse after processing (WCR-P), final product after chilling and storage (WCR-F), and ceca samples were collected for E. coli counts from 11 pastured poultry farms in the southeastern US. The regression tree (RT) and least absolute shrinkage and selection operator (LASSO) methods were applied to data from each sample type. The farm management practices and processing factors such as source of eggs, type of feed used, appearance of other animals on farm, chilling method, and storage time and temperature were all considered as possible explanatory factors in the models. Models were developed to predict the levels of E. coli and to select the most important factors used in predicting E. coli population. Model performances were compared using root mean square error (RMSE). For feces samples, average number of birds and animal source were the two most important variables affecting E. coli population by LASSO. The RT selected animal source, brood feed, day of year, flock age in days, and flock size as the most important variables in predicting E. coli concentration. The RMSE (in log10 scale) under LASSO was 0.974, while under RT it was 1.032 for feces samples. The predictive models provide practical and effective tools to predict E. coli population and to identify farm practice factors that affect E. coli levels.


Assuntos
Escherichia coli , Aves Domésticas , Animais , Fazendas , Fezes , Solo
11.
Int J Food Microbiol ; 382: 109913, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36108482

RESUMO

Atmospheric cold plasma (ACP) is a promising non-thermal technology that has the potential to inactivate microorganisms in foods. In this work, the inactivation of E. coli K12, acid-adapted E. coli K12, and E. coli O157:H7 in apple cider by ACP was investigated using feed gases as simulated air (SA) (80 % N2 + 20 % O2) and a mixture of 90 % N2 + 10 % O2 with various processing times (0 to 180 s). We obtained the reduced the populations of both acid-adapted and non-adapted E. coli K12 by 5 log CFU/mL within 120 s, and E. coli O157:H7 within 90 s. Additionally, no significant changes in the °Brix, pH, temperature, or titratable acidity (TA) of apple cider were observed after exposure to ACP. However, processing times longer than 120 s resulted in significant changes in the pH values. The highest concentration of ozone and hydrogen peroxide reached to 0.22 ± 0.1 mg/L for CG in 180 s and 0.07 ± 0.01 mg/L for SA in 150 s, respectively. Both acid-adapted and non-acid adapted E. coli K12 was found to be more resistant to ACP processing than E. coli O157:H7 after the 90 s, so it could serve as a surrogate for E. coli O157:H7. When we compared the effect of the gas type on inactivation, non-selective media, the results showed no significant differences between the gas types, while selective media demonstrated significant differences. In optical absorption spectroscopy measurements of plasma species, primarily ozone peaks were observed. Furthermore, the optical absorption spectroscopy also revealed that the inactivation of the bacteria could be attributed to some plasma species with wavelengths between 190 and 308 nm. The findings provided a perspective on the use of ACP as a method for decontaminating fruit juices as a non-thermal processing.


Assuntos
Infecções por Escherichia coli , Escherichia coli O157 , Malus , Ozônio , Gases em Plasma , Ácidos/farmacologia , Bebidas/microbiologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , Malus/microbiologia , Ozônio/farmacologia , Gases em Plasma/farmacologia
12.
Food Microbiol ; 108: 104092, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36088123

RESUMO

Escherichia coli shows the potential of indicating foodborne pathogens. The purpose of this study is to investigate the association between E. coli and foodborne pathogens such as Campylobacter, Salmonella, and Listeria in pastured poultry farms, as well as in related processing facilities. Five different sample types: (i) feces, (ii) soil, (iii) whole carcass rinse during processing (WCR-P), (iv) whole carcass rinse of final product after chilling and storage (WCR-F), and (v) ceca were measured for E. coli populations. A logistic regression model for pathogen presence was developed for each sample type. The E. coli population significantly increased the predicted probability of Salmonella presence for soil and WCR-P samples (p = 0.0011 and p = 0.0157 respectively). For Campylobacter, the initial prevalence in feces and ceca were high and a decreasing trend of detecting Campylobacter was observed as E. coli concentration increased. In soil and WCR-P models, the probability of the presence of Campylobacter significantly increased as E. coli population increased. These models provide a practical and effective way of evaluating the relationship between E. coli and foodborne pathogens and enable prediction of foodborne pathogen presence based on E. coli prevalence within the pastured poultry farm-to-fork continuum.


Assuntos
Campylobacter , Aves Domésticas , Animais , Galinhas , Escherichia coli , Fazendas , Salmonella , Solo
13.
J Food Prot ; 85(11): 1614-1624, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36040230

RESUMO

ABSTRACT: The effect of variations in temperature, UV radiation, and sunlight intensity on Escherichia coli, E. coli O157:H7, Salmonella Newport, and antibiotic resistant (ABR) variants of E. coli O157:H7 and Salmonella Newport exposed to sunlight was evaluated. Bacterial strains suspended in sterile deionized water at a concentration of 8 log CFU/mL were exposed to sunlight on three different days for 180 min; control treatments were stored in the dark. The mean temperature of 30.08 and 26.57°C on day 1 and day 3, respectively, was significantly different (P < 0.05). The UV intensity was significantly different on all 3 days, and sunlight intensity significantly differed on day 3 (P < 0.05). Bacterial population decline positively correlated with temperature, sunlight, and UV intensity. Differences in bacterial population declines differed among species, ABR profile, and day of exposure (P < 0.05). On day 1 and day 2, the populations of E. coli dropped below the limit of detection (1 log CFU/mL), whereas the percentage of live cells was 67 and 6.6%, respectively. The artificial neural network model developed to predict bacterial survival under different environmental conditions suggested that Salmonella cells were more resistant than E. coli cells. The ABR strains had significantly higher numbers of viable cells after sunlight exposure (P < 0.05). Sunlight-exposed cells resuscitated in tryptic soy broth varied in maximum population density and maximum specific growth rate based on bacterial species and presence of ABR. Morphological changes such as viable but nonculturable state transition and filament formation were detected in subpopulations of sunlight-exposed bacteria. Daily fluctuations in UV and sunlight intensity can result in significant variations in bacterial decline and recovery.


Assuntos
Escherichia coli O157 , Microbiologia de Alimentos , Animais , Contagem de Colônia Microbiana , Água , Luz Solar , Manipulação de Alimentos , Salmonella , Temperatura , Antibacterianos
14.
Food Microbiol ; 107: 104065, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35953185

RESUMO

Listeria species prevalence has been investigated at nearly all stages of the fresh produce supply chain; however, it has not been examined in transportation and distribution center (DC) related environments. Between December 2019 and March 2021, 18 DCs handling fresh produce were environmentally sampled for Listeria. Swab samples were collected from a variety of surfaces (e.g., floors, pallets, forklifts) in several areas of each DC (e.g., cold storage, shipping and receiving docks). Impaction air samples, relative humidity, and temperature data were also collected. While no Listeria spp. were isolated from air samples (n = 170), they were isolated from 49 of 982 (ca. 5%) environmental samples. The proportion of Listeria spp. positive samples varied significantly across individual DCs (P < 0.01). Several facility characteristics were significantly associated with a Listeria spp. positive sample, such as zone, sampling site dryness, and cleaning regimen. A random forest model (sensitivity: 0.786, specificity: 0.874) identified geographical location and general sampling location (e.g., cold storage rooms, shipping docks) as the two most important variables associated with Listeria spp. detection. This study identified likely harborage sites (e.g., floors, cleaning equipment) of Listeria spp. in DCs across the US and emphasized the importance of sanitation operations in Listeria-prone areas.


Assuntos
Listeria monocytogenes , Listeria , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Listeria/genética , Prevalência
15.
Foodborne Pathog Dis ; 19(9): 622-629, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35856661

RESUMO

Escherichia coli O157:H7-contaminated beef has been implicated in numerous foodborne outbreaks. Contamination occurs despite the use of antimicrobial interventions such as lactic acid (LA). In addition, resistance to antibiotics such as ampicillin and streptomycin among isolates has been frequently reported. The influence of antibiotic resistance (ABR) on growth rates and cross-tolerance of lettuce isolate E. coli O157:H7 H1730 to LA was evaluated. Antibiotic-resistant strain variants were generated by conferring resistance to either ampicillin (ampC) or streptomycin (strepC) or both ampicillin and streptomycin (ampC strepC) through incremental exposure to the antibiotics. Ampicillin resistance was also conferred by plasmid transformation to generate the ampP and ampP strepC strains. The minimum inhibitory concentration of LA on all the strains evaluated was 0.375% v/v. The lag phase duration of all strains except E. coli O157:H7 ampP strepC increased with increasing concentration of LA. The ampP strepC and ampC strains were most tolerant to 5% LA with declines in the cell population of 2.86 and 2.56 log CFU/mL, respectively (p < 0.05). The ampP strepC strain was the most tolerant when evaluated by the live/dead viability assay. The addition of the efflux pump inhibitor, carbonyl cyanide m-chlorophenylhydrazone, with 2.5% LA resulted in a significant increase in sensitivity in the no resistance (NR) wild-type and ampC strains, resulting in 6.62 and 6.65 log CFU/mL reduction, respectively, while the highly tolerant ampP strepC strain had a 2.90 log CFU/mL decrease. Tolerance to LA was significantly influenced by both the ABR profile of the strain and LA concentration. The results from this study indicate that E. coli O157:H7 strains with certain ABR profiles might be more tolerant to LA.


Assuntos
Escherichia coli O157 , Ampicilina , Animais , Antibacterianos/farmacologia , Bovinos , Contagem de Colônia Microbiana , Resistência Microbiana a Medicamentos , Microbiologia de Alimentos , Ácido Láctico/farmacologia , Estreptomicina/farmacologia
16.
Lung India ; 39(3): 247-253, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35488682

RESUMO

Background: Hypoxia in patients with COVID-19 is one of the strongest predictors of mortality. Silent hypoxia is characterised by the presence of hypoxia without dyspnoea. Silent hypoxia has been shown to affect the outcome in previous studies. Methods: This was a retrospective study of a cohort of patients with SARS-CoV-2 infection who were hypoxic at presentation. Clinical, laboratory and treatment parameters in patients with silent hypoxia and dyspnoeic hypoxia were compared. Multivariate logistic regression models were fitted to identify the factors predicting mortality. Results: Among 2080 patients with COVID-19 admitted to our hospital, 811 patients were hypoxic with SpO2 <94% at the time of presentation. Among them, 174 (21.45%) did not have dyspnoea since the onset of COVID-19 symptoms. Further, 5.2% of patients were completely asymptomatic for COVID-19 and were found to be hypoxic only on pulse oximetry. The case fatality rate in patients with silent hypoxia was 45.4% as compared to 40.03% in dyspnoeic hypoxic patients (P = 0.202). The odds ratio of death was 1.1 (95% CI: 0.41-2.97) in the patients with silent hypoxia after adjusting for baseline characteristics, laboratory parameters, treatment and in-hospital complications, which did not reach statistical significance (P = 0.851). Conclusion: Silent hypoxia may be the only presenting feature of COVID-19. As the case fatality rate is comparable between silent and dyspnoeic hypoxia, it should be recognised early and treated as aggressively. Because home isolation is recommended in patients with COVID-19, it is essential to use pulse oximetry in the home setting to identify these patients.

17.
Sensors (Basel) ; 22(5)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35271073

RESUMO

In the last decade, the proactive diagnosis of diseases with artificial intelligence and its aligned technologies has been an exciting and fruitful area. One of the areas in medical care where constant monitoring is required is cardiovascular diseases. Arrhythmia, one of the cardiovascular diseases, is generally diagnosed by doctors using Electrocardiography (ECG), which records the heart's rhythm and electrical activity. The use of neural networks has been extensively adopted to identify abnormalities in the last few years. It is found that the probability of detecting arrhythmia increases if the denoised signal is used rather than the raw input signal. This paper compares six filters implemented on ECG signals to improve classification accuracy. Custom convolutional neural networks (CCNNs) are designed to filter ECG data. Extensive experiments are drawn by considering the six ECG filters and the proposed custom CCNN models. Comparative analysis reveals that the proposed models outperform the competitive models in various performance metrics.


Assuntos
Análise de Dados , Processamento de Sinais Assistido por Computador , Inteligência Artificial , Eletrocardiografia , Redes Neurais de Computação
18.
J Arthroplasty ; 37(6S): S155-S158, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35202759

RESUMO

BACKGROUND: Timely and effective iron supplementation may help reduce the incidence of postoperative anemia and its associated problems. In this study, we aim to assess the efficacy of intravenous ferric carboxy maltose (FCM) on improving hemoglobin(Hb) level posttotal knee arthroplasty (TKA). METHODS: We retrospectively reviewed 263 patients who had undergone unilateral TKA with 157 patients in the study group (year 2019) and 106 in the control group (year 2016). Patients in the study group received FCM (500 mg IV) on postoperative day 1, whereas patients in the control group did not receive FCM or any other iron supplementation postoperatively. Hb levels were recorded preoperatively (Pr-Hb), postoperatively on day 3 (Day3-Hb) and postoperatively at 5(+1) weeks (Week5-Hb). Statistical analysis was performed using student's paired and unpaired t-tests. RESULTS: Pr-Hb and Day3-Hb levels were comparable in the control and study group, while Week5-Hb levels were significantly higher (P < .001) in the study group. The drop in Hb at Day3 from preoperative values was comparable between the two groups (P = 1.0). The rise in Hb from Day3 to 5 weeks was significantly higher in the study group as compared to the control group (P < .001). The difference between Pr-Hb and Week5-Hb was significantly lower (P < .001) in the study group compared to the control group. However, Week5-Hb in both groups remained lower than Pr-Hb (P < .001) in all patients. CONCLUSION: Intravenous FCM (500 mg) was found to be a safe method of iron supplementation to improve hemoglobin levels rapidly and consistently, post-TKA. We need to further study the additive effect of higher dose FCM (1000 mg) on hemoglobin recovery.


Assuntos
Anemia Ferropriva , Artroplastia do Joelho , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/etiologia , Artroplastia do Joelho/efeitos adversos , Compostos Férricos/uso terapêutico , Hemoglobinas/análise , Humanos , Ferro , Maltose/análogos & derivados , Maltose/uso terapêutico , Estudos Retrospectivos
19.
Indian J Orthop ; 56(2): 256-262, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35140856

RESUMO

BACKGROUND: High-flex posterior stabilised rotating platform (PSRP) implant was introduced to provide for deep knee flexion. Few short-term results have been reported, but there are no long-term outcomes reported. METHODS: We prospectively followed 48 patients (53 knees) implanted with one such design. Inclusion criteria for implantation were patients with good pre-operative flexion and wishing to perform activities requiring deep knee flexion post-operatively, with femorotibial varus angle < 15° and having good flexion stability at trialling stage. Previously, we reported their outcomes at 2-6 years (FU-1). We now report their functional and radiological results at a minimum follow-up of 10 years (FU-2) in 39 patients (43 knees); 5 patients having died and 4 lost to follow-up. RESULTS: The mean pre-operative flexion of 124° improved to 130° at FU-1 and to 134° at FU-2. Flexion of 130° or more was seen in 59.6% knees at FU-1 and 74.42% knees at FU-2. At FU-2 mean Knee score was 90.5 and Function score was 67.8. Incidence of patellofemoral symptoms increased from 7.7% at FU-1 to 11.36% at FU-2. There were no cases of bearing spin out, osteolysis or revision surgeries. CONCLUSION: At a minimum 10-year follow-up, high-flexion PSRP design in selected patients yielded 100% survival. We recorded good knee flexion and knee society scores, with no case of spin out, implant loosening, osteolysis or revision surgery. Although deep knee flexion improved at longer follow-up, its use in ADL had reduced due to other age-related factors. There was increased incidence of patellofemoral symptoms.

20.
Neural Comput Appl ; : 1-15, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-35002086

RESUMO

With the advances in technology, assistive medical systems are emerging with rapid growth and helping healthcare professionals. The proactive diagnosis of diseases with artificial intelligence (AI) and its aligned technologies has been an exciting research area in the last decade. Doctors usually detect tuberculosis (TB) by checking the lungs' X-rays. Classification using deep learning algorithms is successfully able to achieve accuracy almost similar to a doctor in detecting TB. It is found that the probability of detecting TB increases if classification algorithms are implemented on segmented lungs instead of the whole X-ray. The paper's novelty lies in detailed analysis and discussion of U-Net + + results and implementation of U-Net + + in lung segmentation using X-ray. A thorough comparison of U-Net + + with three other benchmark segmentation architectures and segmentation in diagnosing TB or other pulmonary lung diseases is also made in this paper. To the best of our knowledge, no prior research tried to implement U-Net + + for lung segmentation. Most of the papers did not even use segmentation before classification, which causes data leakage. Very few used segmentations before classification, but they only used U-Net, which U-Net + + can easily replace because accuracy and mean_iou of U-Net + + are greater than U-Net accuracy and mean_iou , discussed in results, which can minimize data leakage. The authors achieved more than 98% lung segmentation accuracy and mean_iou 0.95 using U-Net + + , and the efficacy of such comparative analysis is validated.

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