| 61. |
- Kibugu, James, et al.
(författare)
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Improved Sample Selection and Preparation Methods for Sampling Plans Used to Facilitate Rapid and Reliable Estimation of Aflatoxin in Chicken Feed
- 2021
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Ingår i: Toxins. - : MDPI. - 2072-6651. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Aflatoxin B1 (AFB1), a toxic fungal metabolite associated with human and animal diseases, is a natural contaminant encountered in agricultural commodities, food and feed. Heterogeneity of AFB1 makes risk estimation a challenge. To overcome this, novel sample selection, preparation and extraction steps were designed for representative sampling of chicken feed. Accuracy, precision, limits of detection and quantification, linearity, robustness and ruggedness were used as performance criteria to validate this modification and Horwitz function for evaluating precision. A modified sampling protocol that ensured representativeness is documented, including sample selection, sampling tools, random procedures, minimum size of field-collected aggregate samples (primary sampling), procedures for mass reduction to 2 kg laboratory (secondary sampling), 25 g test portion (tertiary sampling) and 1.3 g analytical samples (quaternary sampling). The improved coning and quartering procedure described herein (for secondary and tertiary sampling) has acceptable precision, with a Horwitz ratio (HorRat = 0.3) suitable for splitting of 25 g feed aliquots from laboratory samples (tertiary sampling). The water slurring innovation (quaternary sampling) increased aflatoxin extraction efficiency to 95.1% through reduction of both bias (-4.95) and variability of recovery (1.2-1.4) and improved both intra-laboratory precision (HorRat = 1.2-1.5) and within-laboratory reproducibility (HorRat = 0.9-1.3). Optimal extraction conditions are documented. The improved procedure showed satisfactory performance, good field applicability and reduced sample analysis turnaround time.
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| 62. |
- King, Carina, et al.
(författare)
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COVID-19—a very visible pandemic
- 2020
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Ingår i: The Lancet. - : Elsevier. - 0140-6736 .- 1474-547X. ; 396:10248, s. 15-15
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Tidskriftsartikel (refereegranskat)
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| 63. |
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| 64. |
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| 65. |
- Krambrich, Janina, et al.
(författare)
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Usage of FTA (R) Classic Cards for Safe Storage, Shipment, and Detection of Arboviruses
- 2022
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Ingår i: Microorganisms. - : MDPI. - 2076-2607. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Infections caused by arthropod-borne RNA viruses are overrepresented among emerging infectious diseases. Effective methods for collecting, storing, and transporting clinical or biological specimens are needed worldwide for disease surveillance. However, many tropical regions where these diseases are endemic lack analytical facilities and possibility of continuous cold chains, which presents challenges from both a biosafety and material preservation perspective. Whatman (R) FTA (R) Classic Cards may serve as an effective and safe option for transporting hazardous samples at room temperature, particularly for RNA viruses classified as biosafety level (BSL) 2 and 3 pathogens, from sampling sites to laboratories. In this study, we investigated the biosafety and perseverance of representative alpha-and flaviviruses stored on FTA (R) cards. To evaluate the virus inactivation capacity of FTA (R) cards, we used Sindbis virus (SINV), chikungunya virus (CHIKV), and Japanese encephalitis virus (JEV). We inoculated susceptible cells with dilution series of eluates from viral samples stored on the FTA (R) cards and observed for cytopathic effect to evaluate the ability of the cards to inactivate viruses. All tested viruses were inactivated after storage on FTA (R) cards. In addition, we quantified viral RNA of JEV, SINV, and tick-borne encephalitis virus (TBEV) stored on FTA (R) cards at 4 degrees C, 25 degrees C, and 37 degrees C for 30 days using two reverse transcriptase quantitative PCR assays. Viral RNA of SINV stored on FTA (R) cards was not reduced at either 4 degrees C or 25 degrees C over a 30-day period, but degraded rapidly at 37 degrees C. For JEV and TBEV, degradation was observed at all temperatures, with the most rapid degradation occurring at 37 degrees C. Therefore, the use of FTA (R) cards provides a safe and effective workflow for the collection, storage, and analysis of BSL 2- and 3-virus RNA samples, but there is a risk of false negative results if the cards are stored at higher temperatures for long periods of time. Conscious usage of the cards can be useful in disease surveillance and research, especially in tropical areas where transportation and cold chains are problematic.
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| 66. |
- Krambrich, Janina, et al.
(författare)
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Vector competence of Swedish Culex pipiens mosquitos for Japanese Encephalitis Virus
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Annan publikation (populärvet., debatt m.m.)abstract
- Japanese encephalitis virus (JEV) is an emerging mosquito-borne Orthoflavivirus that poses a significant public health concern in many temperate and tropical regions in Asia. Since the climate in some endemic countries is similar to temperate climates observed in Europe, understanding the role of specific mosquito species in the transmission of JEV is essential for predicting and effectively controlling the potential for an introduction and establishment of JEV in Europe. This study aimed to investigate the vector competence of colonized Culex pipiens biotype molestus mosquitoes for JEV. The mosquitoes were initially collected from the field in southern Sweden. The mosquitoes were offered a blood meal containing the Nakayama strain of JEV (genotype III), and infection rates (IR), dissemination rates (DR), and transmission rates (TR) were evaluated at 14, 21, and 28 days post-feeding. The study revealed that colonized Swedish Cx. pipiens are susceptible to JEV infection, with stable IR of around 10% at all time-points. However, virus was only detected in the legs of one mosquito at 21 days post feeding, and no mosquito saliva contained JEV. Overall, this research shows that Swedish Cx. pipiens can become infected with JEV, and emphasizes the importance of further understanding the thresholds and barriers for JEV dissemination in mosquitoes.
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| 67. |
- Kuboka, Maureen, et al.
(författare)
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AFM1 Secretion and Efficacy of Novasilâ„¢ Clay in Kenyan Dairy Cows
- 2022
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Ingår i: DAIRY. - : MDPI. - 2624-862X. ; 3:2, s. 220-232
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Tidskriftsartikel (refereegranskat)abstract
- The occurrence of aflatoxin M1 (AFM1) in milk has been widely reported in Kenya, with levels freqently exceeding national and international thresholds. Exposure to aflatoxin increases the risk of hepatic cancers and can also have other negative health impacts in children such as growth impairment and immunosuppression. Anti-mycotoxin agents (AMAs) included in contaminated feeds can greatly reduce the amount of AFM1 released in milk. A 45-day trial was designed to assess secretion of AFM1 in milk from individual cows fed commercial Kenyan dairy feed, as well as the efficacy of Novasil (TM) Plus in reducing the levels. A four-by-four Latin square cross-over design was used for the experiment. Four cows were fed on naturally contaminated with AFB1 feed, with levels ranging from 19 to 47 mu g/kg, and either no binder or inclusion of binder at the rate of 0.6 or 1.2%. Milk samples were collected each day and analyzed for AFM1. The results showed that AFM1 levels in the milk varied between the cows, even when fed similar levels of contaminated feed. On average, inclusion of 0.6% binder into the diet resulted in 34% decline in milk AFM1 levels, while 1.2% binder dose resulted in a decline of 45%. Significant reduction in AFM1 secretion was observed in all experimental units (p < 0.005), though only minimal reduction was recorded in one of the units (Cow 4) compared to the other three. This trial shows novel data on aflatoxin exposure and excretion in Kenyan dairy cows in a field setting where AFB1 level is uncontrolled. We demonstrate significant reduction in AFM1 secretion in milk using AMA, though AFM1 levels were still above the recommended EC standard of 50 LATIN SMALL LETTER ENGg/kg. This study suggests that AMAs alone cannot be relied on to reduce AFM1 in milk to safe levels. Training and good feeding practices are recommended in addition to use of AMAs.
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| 68. |
- Kuboka, Maureen, et al.
(författare)
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Food safety in informal public markets in Kenya : perceptions of stakeholders in the food chain
- 2024
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Ingår i: Frontiers in Sustainable Food Systems. - : Frontiers Media S.A.. - 2571-581X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Informal markets play a crucial role in providing fresh and nutritious foods for people in low and middle-income countries. However, the safety of food sold in these markets remains a major concern, contributing to a high burden of foodborne illnesses.Methods This study was designed to analyze stakeholder perceptions of food safety in selected informal public markets in Kenya. Eight focus group discussions and 15 key informant interviews were conducted. In addition, two workshops were held to validate the findings.Results and discussion We found that consumers and vendors confounded food quality, especially freshness, with safety, and paid more attention to appearance and physical qualities than food safety. Information (such as branding and expiry dates) and heuristic cues (such as the flow of buyers and the presence of flies) were used to assess food safety. Meat was perceived as the food most likely to cause disease. Chemical hazards in fresh produce and aflatoxins in maize were mentioned as priority hazards by both vendors and consumers. Stakeholders more knowledgeable about food safety considered microbial hazards as a top priority. Although diarrheal diseases were reported to be prevalent in the communities, these were often thought to be the result of agri-chemical residues in fresh produce or the consumption of high-fat foods, and not commonly linked to bacteria in food. Gaps identified during the interviews included poor infrastructure, inadequate food safety knowledge, insufficient or prohibitive policies, insufficient political will, and poor food safety-related practices. There were few mentions of lack of motivation or incentives for behavior change, or insufficient consumer demand for food safety. To fill the gaps, several opportunities were discussed, including contextualizing policies and regulations, investing in infrastructure, capacity building, and training, and promoting involvement and collaboration among various stakeholders.Conclusion This study has highlighted gaps and misperceptions that need to be addressed through proper knowledge and awareness to effectively combat foodborne disease challenges. Behavioral change approaches to improve food safety are recommended.
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| 69. |
- Kuboka, Maureen M, et al.
(författare)
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Occurrence of aflatoxin M1 in raw milk traded in peri-urban Nairobi, and the effect of boiling and fermentation.
- 2019
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dairy production in Kenya is important and dominated by small-holder farmers who market their produce through small-scale traders in the informal sector. Method: This study aimed to determine the prevalence of aflatoxin (AFM1) in informally marketed milk in peri-urban Nairobi, Kenya, and to assess knowledge of milk traders on aflatoxins using questionnaires. A total of 96 samples were analyzed for AFM1 using enzyme-linked immunosorbent assay. In addition, boiling and fermentation experiments were carried out in the laboratory. Results: All samples had AFM1 above the limit of detection (5 ng/kg) (mean of 290.3 ± 663.4 ng/kg). Two-thirds of the samples had AFM1 levels above 50 ng/kg and 7.5% of the samples exceeded 500 ng/kg. Most of the traders had low (69.8%) or medium (30.2%) knowledge. Educated (p = 0.01) and female traders (p= 0.04) were more knowledgeable. Experimentally, fermenting milk to lala (a traditional fermented drink) and yogurt significantly reduced AFM1 levels (p< 0.01) (71.8% reduction in lala after incubation at room temperature for 15 h, and 73.6% reduction in yogurt after incubation at 45ºC for 4h). Boiling had no effect. Conclusion: The study concluded that the prevalence of raw milk with AFM1 was high, while knowledge was low. Fermentation reduced the AFM1 levels.
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| 70. |
- Kumar Dey, Tushar, et al.
(författare)
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Analyses of Extended-Spectrum-β-Lactamase, Metallo-β-Lactamase, and AmpC-β-Lactamase Producing Enterobacteriaceae from the Dairy Value Chain in India
- 2023
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Ingår i: Antibiotics. - : MDPI. - 2079-6382. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- The consumption of milk contaminated with antibiotic-resistant bacteria poses a significant health threat to humans. This study aimed to investigate the prevalence of Enterobacteriaceae producing β-lactamases (ESBL, MBL, and AmpC) in cow and buffalo milk samples from two Indian states, Haryana and Assam. A total of 401 milk samples were collected from dairy farmers and vendors in the specified districts. Microbiological assays, antibiotic susceptibility testing, and PCR-based genotyping were employed to analyze 421 Gram-negative bacterial isolates. The overall prevalence of β-lactamase genes was 10% (confidence interval (CI) (7–13)), with higher rates in Haryana (13%, CI (9–19)) compared to Assam (7%, CI (4–11)). The identified β-lactamase genes in isolates were blaCMY, blaMOX, blaFOX, blaEBC, and blaDHA, associated with AmpC production. Additionally, blaCTX-M1, blaSHV, and blaTEM were detected as ESBL producers, while blaVIM, blaIMP, blaSPM, blaSIM, and blaGIM were identified as MBL producers. Notably, Shigella spp. were the dominant β-lactamase producers among identified Enterobacteriaceae. This study highlights the presence of various prevalent β-lactamase genes in milk isolates, indicating the potential risk of antimicrobial-resistant bacteria in dairy products. The presence of β-lactam resistance raises concern as this could restrict antibiotic options for treatment. The discordance between genotypic and phenotypic methods emphasizes the necessity for comprehensive approaches that integrate both techniques to accurately assess antibiotic resistance. Urgent collaborative action incorporating rational and regulated use of antibiotics across the dairy value chain is required to address the global challenge of β-lactam resistance.
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