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Authors = Chika Okafor

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11 pages, 264 KiB  
Article
Residues of Tetracycline, Erythromycin, and Sulfonamides in Beef, Eggs, and Honey from Grocery Stores in Knoxville, Tennessee, USA: Failure of Cooking to Decrease Drug Concentrations
by Shamim Sarkar, Stephen A. Kania, Mohamed A. Abouelkhair, Brian Whitlock and Chika C. Okafor
Vet. Sci. 2024, 11(12), 660; https://doi.org/10.3390/vetsci11120660 - 17 Dec 2024
Viewed by 1333
Abstract
This study evaluated the concentrations of tetracycline, erythromycin, and sulfonamide in beef, eggs, and honey products sold at grocery stores and whether standard cooking to 160 °F (71 °C) reduced the concentrations of antimicrobials spiked into the evaluated food products. In June 2021, [...] Read more.
This study evaluated the concentrations of tetracycline, erythromycin, and sulfonamide in beef, eggs, and honey products sold at grocery stores and whether standard cooking to 160 °F (71 °C) reduced the concentrations of antimicrobials spiked into the evaluated food products. In June 2021, the concentrations of selected antimicrobials in 65 samples (8 beef, 48 eggs, 9 honey samples) purchased from grocery stores within Knoxville, Tennessee, were measured using enzyme-linked immunosorbent assays. The Kruskal–Wallis test was used to assess the differences in the median tetracycline concentrations across food types, while the Mann–Whitney test was used to compare the erythromycin residue concentrations between beef and honey. Linear regression was used to analyze whether standard cooking at 160 °F (71 °C) reduced antimicrobial concentrations. Detectable tetracycline concentrations were found in all beef (8/8, 100%), eggs (46/48, 96%), and honey (9/9, 100%) samples, with median concentrations of 7.73, 5.62, and 13.13 µg/kg, respectively. Honey had significantly higher tetracycline concentrations than eggs (p = 0.002). Detectable erythromycin concentrations were found in beef (5/8, 63%) and honey (9/9, 100%), with median concentrations of 0.14 µg/kg for beef and 0.48 µg/kg for honey. None of the antimicrobial concentrations found in the beef and egg products exceeded the U.S. FDA’s maximum residue limits (MRL). Sulfonamide concentrations were undetectable in the beef and egg products. The concentrations of tetracycline, erythromycin, and sulfonamide spiked into the food products did not change significantly in response to cooking to 160 °F (71 °C). The antimicrobial concentrations found in the selected commercial food products were below the MRL, and cooking appeared to not reduce the spiked antimicrobial concentrations in the evaluated food products. Full article
(This article belongs to the Section Veterinary Food Safety and Zoonosis)
23 pages, 929 KiB  
Article
Impact of Veterinary Feed Directive Rules Changes on the Prevalence of Antibiotic Resistance Bacteria Isolated from Cecal Samples of Food-Producing Animals at US Slaughterhouses
by Shamim Sarkar and Chika C. Okafor
Pathogens 2024, 13(8), 631; https://doi.org/10.3390/pathogens13080631 - 28 Jul 2024
Cited by 2 | Viewed by 1392
Abstract
This study examined the impact of the 2017 Veterinary Feed Directive (VFD) rule changes on the prevalence of tetracycline-resistant and erythromycin-resistant bacteria (Salmonella spp., Campylobacter spp., and Escherichia coli) in cecal samples of food animals (cattle, swine, chicken, and turkey) at [...] Read more.
This study examined the impact of the 2017 Veterinary Feed Directive (VFD) rule changes on the prevalence of tetracycline-resistant and erythromycin-resistant bacteria (Salmonella spp., Campylobacter spp., and Escherichia coli) in cecal samples of food animals (cattle, swine, chicken, and turkey) at US slaughterhouses. Multivariable logistic regression was used to analyze 2013–2019 cecal samples of food-producing animals surveillance data from the National Antimicrobial Resistance Monitoring System (NARMS) in the U.S. The variables included year (used to evaluate VFD rule changes), host, and quarter of year. The analysis of surveillance data showed that the VFD rule changes have varying effects on tetracycline-resistant and erythromycin-resistant bacteria in food animals. For example, the odds of detecting tetracycline-resistant Salmonella spp. decreased in cattle but increased in chickens following the implementation of the VFD rule changes. Similarly, the odds of detecting tetracycline-resistant Escherichia coli decreased in chickens but increased in swine after the VFD rule changes. The odds of detecting erythromycin-resistant Campylobacter spp. increased in cattle but decreased in chickens after the VFD rule changes. In conclusion, the implementation of VFD rule changes has been beneficial in reducing the odds of detecting tetracycline-resistant Escherichia coli and erythromycin-resistant Campylobacter spp. in chickens, as well as tetracycline-resistant Salmonella spp. in cattle at US slaughterhouses. Full article
(This article belongs to the Section Bacterial Pathogens)
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7 pages, 1926 KiB  
Communication
Prevalence of Cardiac Lesions in Cases of Bovine Blackleg in Tennessee (USA), 2004–2018
by Chika C. Okafor, Francisco A. Uzal, Caitlin M. Culligan and Kim M. Newkirk
Vet. Sci. 2023, 10(4), 297; https://doi.org/10.3390/vetsci10040297 - 17 Apr 2023
Cited by 2 | Viewed by 4697
Abstract
Blackleg is a common cause of death in cattle, mostly caused by the bacterium Clostridium chauvoei. Cardiac lesions were traditionally considered uncommon in cases of blackleg in cattle until a 2018 study reported otherwise. This study was aimed at determining the prevalence [...] Read more.
Blackleg is a common cause of death in cattle, mostly caused by the bacterium Clostridium chauvoei. Cardiac lesions were traditionally considered uncommon in cases of blackleg in cattle until a 2018 study reported otherwise. This study was aimed at determining the prevalence of cardiac disease among cattle that died of blackleg in Tennessee, USA. The outcome of this study would reinforce the importance of assessing cardiac lesions in suspected cases of blackleg in cattle. The University of Tennessee Veterinary Medical Center database searched for cattle with a confirmed diagnosis of blackleg necropsied between 2004 and 2018. Of the 120 necropsy reports, 37 had a diagnosis of blackleg. Histology slides of skeletal muscle (26/37) and the heart (26/37) were reviewed to confirm the presence of supportive lesions. Of the 37 cases of blackleg identified, 26 animals (70.3%) had cardiac lesions, including 4 (10.8%) that had only cardiac involvement without skeletal muscle lesions. Specifically, (5.4%; 2/37) had only necrotizing myocarditis; (13.5%; 5/37) had only fibrinous or fibrinosuppurative pericarditis, epicarditis, or endocarditis; (51.4%; 19/26) had a combination of myocarditis and pericarditis, epicarditis, or endocarditis; and (29.7%; 11/37) had no lesions. Furthermore, of the 26 cases with cardiac lesions, 24 cases had gross lesions, while 2 cases were identified only by microscopic examination. This indicates that gross examination alone is insufficient to identify cardiac involvement in blackleg cases in cattle. Contrary to traditional perceptions, cardiac lesions in cases of bovine blackleg could be as high as 70% and are most often associated with skeletal muscle lesions. The prevalence of cardiac lesions in cases of blackleg in cattle may be higher when the heart is examined microscopically than if it is only evaluated grossly. Pathologists should specifically evaluate the heart for lesions in suspected cases of blackleg in cattle and utilize microscopic examination when gross lesions are absent. Full article
(This article belongs to the Section Anatomy, Histology and Pathology)
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13 pages, 957 KiB  
Article
Tetracycline, Sulfonamide, and Erythromycin Residues in Beef, Eggs, and Honey Sold as “Antibiotic-Free” Products in East Tennessee (USA) Farmers’ Markets
by Shamim Sarkar, Marcy J. Souza, Tomas Martin-Jimenez, Mohamed A. Abouelkhair, Stephen A. Kania and Chika C. Okafor
Vet. Sci. 2023, 10(4), 243; https://doi.org/10.3390/vetsci10040243 - 24 Mar 2023
Cited by 12 | Viewed by 4489
Abstract
Foods that contain antibiotic residues have potential adverse health effects on consumers and provide selective pressure for the threat of antimicrobial resistance (AMR). This study’s objective was to measure tetracycline, sulfonamide, and erythromycin residues in beef, eggs, and honey sold as “antibiotic-free” at [...] Read more.
Foods that contain antibiotic residues have potential adverse health effects on consumers and provide selective pressure for the threat of antimicrobial resistance (AMR). This study’s objective was to measure tetracycline, sulfonamide, and erythromycin residues in beef, eggs, and honey sold as “antibiotic-free” at farmers’ markets in East Tennessee (East TN) in the United States (U.S.). Between July and September 2020, 36 “antibiotic-free” food products (9 beef, 18 egg, and 9 honey products) were purchased from East TN farmers’ markets and tested for tetracycline, sulfonamide, and erythromycin residues using competitive enzyme-linked immunosorbent assays (cELISA). All beef, egg, and honey products had tetracycline residue; the median concentrations were 51.75, 30.25, and 77.86 µg/kg, respectively. Sulfonamide residue was present in every sample of beef. Of 18 eggs, 11 eggs had detectable sulfonamide residue; the median concentrations were 3.50 and 1.22 µg/kg in beef and eggs, respectively. Each sample of beef and honey contained erythromycin residue; the median concentrations were 3.67 and 0.68 µg/kg, respectively. Overall, the median concentrations of tetracycline, sulfonamide, and erythromycin residues were below the maximum residue levels (MRLs) set in the U.S. for beef and eggs. Thus, the beef and eggs sold as “antibiotic-free” in East TN farmers’ markets can be considered safe for consumption. Safety determination for honey could not be made because MRLs have not been set for honey in the U.S. Because these residues should not be expected in “antibiotic-free” food products, it is important to further investigate the potential sources of these residues in these products. Full article
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13 pages, 246 KiB  
Article
Effect of Changes in Veterinary Feed Directive Regulations on Violative Antibiotic Residues in the Tissue of Food Animals from the Inspector-Generated Sampling in the United States
by Shamim Sarkar and Chika C. Okafor
Microorganisms 2022, 10(10), 2031; https://doi.org/10.3390/microorganisms10102031 - 14 Oct 2022
Cited by 6 | Viewed by 2365
Abstract
The presence of antibiotic residues in the tissue of food animals is a growing concern due to the adverse health effects that they can cause in humans, such as antibiotic resistance bacteria. An inspector-generated sampling (IGS) dataset from the United States National Residue [...] Read more.
The presence of antibiotic residues in the tissue of food animals is a growing concern due to the adverse health effects that they can cause in humans, such as antibiotic resistance bacteria. An inspector-generated sampling (IGS) dataset from the United States National Residue Surveillance Program, collected between 2014 and 2019, was analyzed to investigate the association of changes in the veterinary feed directive (VFD) regulations on the detection of violative penicillin, tetracycline, sulfonamide, desfuroylceftiofur, tilmicosin, and florfenicol, residues in the tissue of food animals. Multivariable logistic regression models were used for analysis. While the animal production class was significantly associated with residue violations for tetracycline, having a sample collection date after the implementation of change in VFD regulations was not. However, the odds of detecting violative sulfonamide and penicillin residues in the tissue of food animals following the implementation of the change in VFD regulations were 36% and 24% lower than those collected before the implementation of the change in VFD regulations period, respectively, irrespective of animal production class. Violative desfuroylceftiofur, tilmicosin, and florfenicol residues in the tissue of food animals were not significantly associated with the implementation of changes in the VFD regulations. Further investigation of the factors that influence the presence of violative antibiotic residues in the tissue of food animals following the change in VFD regulations would lend clarity to this critical issue. Full article
(This article belongs to the Special Issue Antimicrobial Stewardship in Food-Producing Animals 2.0)
13 pages, 495 KiB  
Article
Emotive Themes from Tennessee Cattle Producers Regarding Responsible Antibiotic Use
by Chika C. Okafor, John E. Ekakoro, Marc Caldwell and Elizabeth B. Strand
Animals 2022, 12(16), 2088; https://doi.org/10.3390/ani12162088 - 16 Aug 2022
Viewed by 1714
Abstract
To improve judicious antimicrobial use (AMU) in food animals in the United States, all feed additives that were medically important antimicrobials were moved from over the counter to Veterinary Feed Directive in 2017. This action required a change in behavior of producers’ AMU [...] Read more.
To improve judicious antimicrobial use (AMU) in food animals in the United States, all feed additives that were medically important antimicrobials were moved from over the counter to Veterinary Feed Directive in 2017. This action required a change in behavior of producers’ AMU practices. Because emotions are important aspects of behavior, several behavioral interventions have targeted people’s emotions as means of effecting change. Hence, understanding and incorporating the emotional experiences of producers towards current AMU practices can be a starting point to making future behavioral changes that could reduce the emergence of antimicrobial resistance challenge. Between June 2017 and March 2018, seven focus group meetings of Tennessee (TN) beef and dairy cattle producers were conducted to evaluate producers’ emotional views regarding responsible AMU in TN cattle. Sixty-two TN cattle producers participated and emotively expressed the following: (1) deep connections to animals in ways that improve animal and public health; (2) pride in their quality of products; (3) distress that consumers misconceive their AMU practices as indiscriminate; and (4) recommended that producers be more transparent about their AMU practices and the public improve their awareness for detecting marketers’ deceptive product labels that take advantage of public ignorance. Knowledge of these producers’ emotions would help educators target more successful behavioral change campaigns, improving stewardship in AMU practices among producers. Full article
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13 pages, 300 KiB  
Article
Prevalence and Outcomes Associated with Vitamin D Deficiency among Indexed Hospitalizations with Cardiovascular Disease and Cerebrovascular Disorder—A Nationwide Study
by Urvish Patel, Salma Yousuf, Komal Lakhani, Payu Raval, Nirmaljot Kaur, Toochukwu Okafor, Chail Shah, Harmandeep Singh, Mehwish Martin, Chika Nwodika, Angelina Yogarajah, Jigisha Rakholiya, Maitree Patel, Raja Chandra Chakinala and Shamik Shah
Medicines 2020, 7(11), 72; https://doi.org/10.3390/medicines7110072 - 22 Nov 2020
Cited by 5 | Viewed by 6279
Abstract
Background: According to past studies, recovery and survival following severe vascular events such as acute myocardial infarction and stroke are negatively impacted by vitamin D deficiency. However, the national estimate on disability-related burden is unclear. We intend to evaluate the prevalence and [...] Read more.
Background: According to past studies, recovery and survival following severe vascular events such as acute myocardial infarction and stroke are negatively impacted by vitamin D deficiency. However, the national estimate on disability-related burden is unclear. We intend to evaluate the prevalence and outcomes of vitamin D deficiency (VDD) among patients with cardiovascular disease (CVD) and cerebrovascular disorder (CeVD). Methods: We performed a cross-sectional study on the Nationwide Inpatient Sample data (2016–2017) of adult (≥18 years) hospitalizations. We identified patients with a secondary diagnosis of VDD and a primary diagnosis of CVD and CeVD using the 9th revision of the International Classification of Diseases, clinical modification code (ICD-10-CM) codes. A univariate and mixed-effect multivariable survey logistic regression analysis was performed to evaluate the prevalence, disability, and discharge disposition of patients with CVD and CeVD in the presence of VDD. Results: Among 58,259,589 USA hospitalizations, 3.44%, 2.15%, 0.06%, 1.28%, 11.49%, 1.71%, 0.38%, 0.23%, and 0.08% had primary admission of IHD, acute MI, angina, AFib, CHF, AIS, TIA, ICeH, and SAH, respectively and 1.82% had VDD. The prevalence of hospitalizations due to CHF (14.66% vs. 11.43%), AIS (1.87% vs. 1.71%), and TIA (0.4% vs. 0.38%) was higher among VDD patients as compared with non-VDD patients (p < 0.0001). In a regression analysis, as compare with non-VDD patients, the VDD patients were associated with higher odds of discharge to non-home facilities with an admission diagnosis of CHF (aOR 1.08, 95% CI 1.07–1.09), IHD (aOR 1.24, 95% CI 1.21–1.28), acute MI (aOR 1.23, 95% CI 1.19–1.28), AFib (aOR 1.21, 95% CI 1.16–1.27), and TIA (aOR 1.19, 95% CI 1.11–1.28). VDD was associated with higher odds of severe or extreme disability among patients hospitalized with AIS (aOR 1.1, 95% CI 1.06–1.14), ICeH (aOR 1.22, 95% CI 1.08–1.38), TIA (aOR 1.36, 95% CI 1.25–1.47), IHD (aOR 1.37, 95% CI 1.33–1.41), acute MI (aOR 1.44, 95% CI 1.38–1.49), AFib (aOR 1.10, 95% CI 1.06–1.15), and CHF (aOR 1.03, 95% CI 1.02–1.05) as compared with non-VDD. Conclusions: CVD and CeVD in the presence of VDD increase the disability and discharge to non-home facilities among USA hospitalizations. Future studies should be planned to evaluate the effect of VDD replacement for improving outcomes. Full article
(This article belongs to the Section Cardiology and Vascular Disease)
10 pages, 842 KiB  
Article
Comparison between a Conductometric Biosensor and ELISA in the Evaluation of Johne’s Disease
by Chika Okafor, Daniel Grooms, Evangelyn Alocilja and Steven Bolin
Sensors 2014, 14(10), 19128-19137; https://doi.org/10.3390/s141019128 - 15 Oct 2014
Cited by 15 | Viewed by 6254
Abstract
Johne’s disease (JD), caused by Mycobacterium avium subspecies paratuberculosis (MAP), is an important gastrointestinal disease of cattle worldwide because of the economic losses encountered in JD-affected herds. These losses include reduction in milk yield in cows, premature culling and reduced carcass weight of [...] Read more.
Johne’s disease (JD), caused by Mycobacterium avium subspecies paratuberculosis (MAP), is an important gastrointestinal disease of cattle worldwide because of the economic losses encountered in JD-affected herds. These losses include reduction in milk yield in cows, premature culling and reduced carcass weight of culled diseased animals. In the U.S. dairy industry, economic losses from reduced productivity associated with JD are estimated to cost between $200 and $250 million annually. The development of non-laboratory-based assays would support more frequent testing of animals for JD and could improve its control. Conductometric biosensors combine immunomigration technology with electronic signal detection and have been adapted for the detection of IgG antibody against MAP. In the present study, a capture membrane with limited variability in the immunomigration channel and an optimal concentration of the secondary anti-bovine antibody used in a previously developed conductometric biosensor were compared with a commercially available antibody detection ELISA in their evaluation of JD, using samples of serum from cattle whose JD status where unknown. There was a moderate strength of agreement (kappa = 0.41) between the two assays. Findings from this preliminary study support the continued development of conductometric biosensors for use in the diagnosis of JD. Full article
(This article belongs to the Special Issue Biosensors for Pathogen Detection)
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11 pages, 89 KiB  
Article
Fabrication of a Novel Conductometric Biosensor for Detecting Mycobacterium avium subsp. paratuberculosis Antibodies
by Chika Okafor, Daniel Grooms, Evangelyn Alocilja and Steven Bolin
Sensors 2008, 8(9), 6015-6025; https://doi.org/10.3390/s8096015 - 26 Sep 2008
Cited by 22 | Viewed by 11791
Abstract
Johne’s disease (JD) is one of the most costly bacterial diseases in cattle. In the U.S., economic losses from the disease have been estimated to exceed $1,500,000,000 per year, mainly from the effects of reduced milk production. Current diagnostic tests for JD are [...] Read more.
Johne’s disease (JD) is one of the most costly bacterial diseases in cattle. In the U.S., economic losses from the disease have been estimated to exceed $1,500,000,000 per year, mainly from the effects of reduced milk production. Current diagnostic tests for JD are laboratory based and many of those tests require specialized equipment and training. Development of rapid and inexpensive diagnostic assays, which are adapted for point-ofcare applications, would aid in the control of JD. In this study, a polyaniline (Pani)-based conductometric biosensor, in an immunomigration format, was fabricated for the detection of serum antibody (IgG) against the causal organism of JD, Mycobacterium avium subsp. paratuberculosis (MAP). Immobilized Mycobacterium avium purified proteins in the capture membrane were used to detect MAP IgG, previously bound with Pani/anti-bovine IgG* conjugate in the conjugate membrane. After detection, the Pani in the sandwiched captured complex bridges an electrical circuit between the silver electrodes, flanking the capture membrane. The electrical conductance, caused by Pani, was measured as drop in electrical resistance. Testing of the biosensor with known JD positive and negative serum samples demonstrated a significant difference in the mean resistance observed between the groups. This proof-of-concept study demonstrated that a conductometric biosensor could detect MAP IgG in 2 minutes. The biosensor’s speed of detection and the equipment involved would, among other things, support its application towards the various point-ofcare opportunities aimed at JD management and control. Full article
(This article belongs to the Special Issue Biosensors for Point-of-Care Applications)
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