| 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 .- 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 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 .- 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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| 68. |
- 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. - 0066-4774 .- 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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| 69. |
- Kumar Dey, Tushar, et al.
(författare)
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Characterization of Lactic Acid Bacteria and Pathogens Isolated from Traditionally Fermented Foods, In Relation to Food Safety and Antimicrobial Resistance in Tribal Hill Areas of Northeast India
- 2023
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Ingår i: Journal of Food Quality. - : WILEY-HINDAWI. - 0146-9428 .- 1745-4557. ; 2023
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Tidskriftsartikel (refereegranskat)abstract
- Traditional fermented food products are often connected to various indigenous tribes and thus vary due to ethnicity, geography, and natural resource availability. The indigenous tribes from India greatly rely on fermentation processes for food preservation, flavor, and nutrition. Fermented foods can provide health benefits but also pose risks from harmful microbes and contaminants that grow in the food due to poor hygiene. In this study, we identified lactic acid bacteria (LAB) in fermented food collected from Northeast India, assessed their beneficial properties, and highlighted the risk from food pathogens that have antimicrobial resistance traits. A total of 113 different samples of fermented food products were collected from the local markets of five Northeastern Indian states (Nagaland, Manipur, Meghalaya, Arunachal Pradesh, and Sikkim). Standard laboratory methods were used to isolate LAB and determine their probiotic properties, conduct coliform counts, and isolate presumptive staphylococci from the fermented food samples. Antimicrobial susceptibility was determined by using the BD-Phoenix 100 automated system. We isolated 30 LAB with probiotic potential. The average aerobic colony count in different fermented food was 4.4-7.7 log center dot cfu/g, while coliforms were present in 43% (49/113, 95% (CI 34-53)) of the food samples, indicating low-hygiene levels. Additionally, some food samples contained staphylococci with phenotypic antibiotic-resistance markers (MRS, HLMUP, BLACT, and STAMLS). This study indicates that probiotic bacteria could be present in traditional fermented food products of Northeast India, but contamination with staphylococci and other bacterial pathogens with antibiotic resistance traits could put the health of consumers at risk.
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| 70. |
- Kumar Dey, Tushar, et al.
(författare)
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Molecular Characterization of Methicillin-Resistant Staphylococci from the Dairy Value Chain in Two Indian States
- 2023
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Ingår i: Pathogens. - : MDPI. - 2076-0817. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Bovine milk and milk products may contain pathogens, antimicrobial resistant bacteria, and antibiotic residues that could harm consumers. We analyzed 282 gram-positive isolates from milk samples from dairy farmers and vendors in Haryana and Assam, India, to assess the prevalence of methicillin-resistant staphylococci using microbiological tests, antibiotic susceptibility testing, and genotyping by PCR. The prevalence of genotypic methicillin resistance in isolates from raw milk samples was 5% [95% confidence interval, CI (3-8)], with 7% [CI (3-10)] in Haryana, in contrast to 2% [CI (0.2-6)] in Assam. The prevalence was the same in isolates from milk samples collected from farmers [5% (n = 6), CI (2-11)] and vendors [5% (n = 7), CI (2-10)]. Methicillin resistance was also observed in 15% of the isolates from pasteurized milk [(n = 3), CI (3-38)]. Two staphylococci harboring a novel mecC gene were identified for the first time in Indian dairy products. The only SCCmec type identified was Type V. The staphylococci with the mecA (n = 11) gene in raw milk were commonly resistant to oxacillin [92%, CI (59-100)] and cefoxitin [74%, CI (39-94)], while the isolates with mecC (n = 2) were resistant to oxacillin (100%) only. All the staphylococci with the mecA (n = 3) gene in pasteurized milk were resistant to both oxacillin and cefoxitin. Our results provided evidence that methicillin-resistant staphylococci occur in dairy products in India with potential public health implications. The state with more intensive dairy systems (Haryana) had higher levels of methicillin-resistant bacteria in milk.
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