13 results on '"Mdegela, Robinson"'
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2. A HPLC-MS/MS method for screening of selected antibiotic adulterants in herbal drugs
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Mwankuna, Christopher Johnson, Uwamaliya, Grâce Ange, Mariki, Eliapenda Elisante, Mabiki, Faith, Malebo, Hamisi M., Mdegela, Robinson, and Styrishave, Bjarne
- Abstract
The use of herbal products adulterated with conventional drugs increases the risk of developing microbial resistance and causes herb-to-drug interaction, leading to severe clinical consequences. The complex nature of herbal products has been a challenge for the unambiguous identification of adulterants. The improved analytical selectivity and sensitivity of hyphenated techniques such as high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) enable the confirmatory screening of adulterants in herbal products. Simultaneous screening of adulterants is necessary and efficient because it has been established that more than one chemical adulterant may be present in one herbal product. An HPLC-MS/MS method for the simultaneous detection and quantification of amoxicillin, ampicillin, metronidazole, ciprofloxacin, sulfamethoxazole, and trimethoprim in powdered herbal drugs was developed. Deuterated metronidazole-d3, trimethoprim-d3, ciprofloxacin-d8, and sulfamethoxazole-d4 were used as internal standards (ISs). For each analyte, two transitions were monitored using protonated molecules as precursor ions. The extraction of analytes from herbal products was performed using a simple methanol : water : formic acid (90 : 10 : 0.05, v/v) extraction solvent. Chromatographic separation was done in a gradient of 0.01% formic acid in methanol and 0.01% formic acid in MilliQ water. The calibration curves were linear (r2≥ 0.996) over the range of 0.005–2.5 μg mL−1for all compounds except metronidazole, whose range was 0.005–1 μg mL−1. The limit of detection (LOD) ranged from 0.012 to 0.046 μg mL−1, while the limit of quantification (LOQ) ranged from 0.066 to 0.153 μg mL−1. The accuracy, expressed as the recovery of spiked herbal products, ranged from 45% to 114%. The precision, expressed as relative standard deviation (RSD) at two concentration levels, ranged from 1.6% to 15.9%. The matrix effect expressed as the matrix factor (MF) ranged from 0.79 to 0.92. The developed method was applied to powder herbal products purchased in Tanzania. Amoxicillin, ampicillin, trimethoprim, sulfamethoxazole, and ciprofloxacin were not detected in all samples. Metronidazole was detected in eight samples with the highest concentration of 1.38 μg g−1. The developed method is suitable for the detection of all the studied antibiotic adulterants in herbal products. Quantification can be performed for all the compounds except ciprofloxacin due to its lower recovery.
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- 2022
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3. Isolation and Characterization of Flavobacteriaceae from Farmed and Wild Nile Tilapia in Tanzania.
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Mwega, Elisa, Tuntufye, Huruma, Mdegela, Robinson, Colquhoun, Duncan J., Mutoloki, Stephen, Evensen, Øystein, and Wasteson, Yngvild
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- 2019
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4. Seroprevalence and risk factors for Taenia sppinfection in pigs in Kongwa and Songwe districts, Tanzania: A cross-sectional study
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Wilson, Christina, Mdegela, Robinson Hammerthon, Nonga, Hezron Emmanuel, Makingi, George, Churi, Ayubu Jacob, Stelzle, Dominik, Mkupasi, Ernatus Martin, Schmidt, Veronika, Carabin, Hélène, Winkler, Andrea Sylvia, and Ngowi, Helena Aminiel
- Abstract
Taenia soliumporcine cysticercosis (PCC) is widespread in many low- and middle-income countries (LMICs) where free-range pig rearing is common and hygienic standards are subpar. A cross-sectional survey was conducted in 42 villages between June and September 2019 (14 in Songwe district, southwest Tanzania, and 28 in Kongwa district, central Tanzania). Using a commercial Ag-ELISA kit (apDia, Belgium), circulating antigens of Taenia sppin pig serum were identified and used to calculate the PCC seroprevalence. The study recruited 692 randomly selected households, sampling one pig per household. The relationship between each risk factor and the seroprevalence of PCC at the household and village levels was analysed using mixed logistic regression models. The findings showed that approximately 28% of the pigs were reared in free-range settings, the proportion of households with latrines across the districts was 92%. Twenty-seven percent of households with latrines had water and soap available for hand washing. Sixty-seven (9.7%) tested positive for PCC based on Ag-ELISA. The overall seroprevalence in Kongwa and Songwe districts was 7.3% and 14.0% respectively. In addition, the overall village Ag-ELISA positivity was 9.3%, with an interquartile range (IQR) of 4.6% – 14.1%. Increasing the age of the pig (OR = 3.13 95% CI = 1.48 – 6.60; p = 0.003), pig originating from outside the household (OR = 0.5 95% CI = 0.25 – 0.99; p = 0.05), and pigs kept in a household that practised deworming (OR = 2.23 95% CI = 1.08 – 4.61; p = 0.03) were important risk factors associated with PCC positivity. Therefore, the high seroprevalence of PCC, up to 14%, calls for rapid and effective control actions such as vaccination and treatment of pigs against PCC, and public health education emphasises on indoor pig rearing, hygienic practices and regular use of latrines. Our findings also point to a potential danger of Taenia. sppinfection indicating the possibility of people carrying the adult parasite Taenia soliumnot only in the rural communities of Kongwa and Songwe districts but also in the urban areas of Tanzania, where pigs from these areas are transported for consumption. To develop effective management measures, further research on taeniasis and cysticercosis in the human population is required.
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- 2023
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5. Levels and distribution of progesterone in receiving waters and wastewaters of a growing urban area
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Kasambala, Hildegard R., Rwiza, Mwemezi J., and Mdegela, Robinson H.
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- 2019
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6. Isolation and Characterization of Flavobacteriaceae from Farmed and Wild Nile Tilapia in Tanzania
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Mwega, Elisa, Colquhoun, Duncan J., Tuntufye, Huruma, Mdegela, Robinson, Mutoloki, Stephen, Evensen, Øystein, and Wasteson, Yngvild
- Abstract
The present study was conducted to explore the occurrence of Flavobacteriaceae in wild Nile Tilapia Oreochromis niloticus(n= 108) collected from Lake Victoria and farmed Nile Tilapia (n= 187) collected from 12 ponds in the Morogoro region of Tanzania. The size of the ponds surveyed ranged from 130 to 150 m2. Pond parameters and fish morphometric data were recorded during sampling. In total, 67 Flavobacterium‐like isolates (n= 44 from farmed fish; n= 23 from wild fish) were identified on the basis of colony morphology and biochemical tests. Sequences from the 16S ribosomal RNA(rRNA) gene revealed that all 67 isolates belonged to the genera Flavobacteriumand Chryseobacterium. Based on 16S rRNAnucleotide identity, 26 isolates showed high similarity with C. indologenes(99–100% identity), 16 showed similarity to C. joostei(98–99.9%), and 17 were similar to diverse species of Chryseobacterium(97–99%). Three isolates were similar to F. aquatileand three were similar to F. indicum, with 99–100% nucleotide identity in both cases, and two isolates were similar to F. oryzae(99–100% identity). The findings obtained in this study provide a baseline for future studies and contribute to an understanding of the threats presented by the aquatic Flavobacteriaceae reservoir toward the development of healthy fish farming in Tanzania. Such knowledge is vital for the development of a sustainable aquaculture industry in Tanzania that will contribute to increased food security.
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- 2019
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7. Genetic diversity of the giant tiger prawn Penaeus monodon in relation to trace metal pollution at the Tanzanian coast.
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Rumisha, Cyrus, Leermakers, Martine, Elskens, Marc, Mdegela, Robinson H., Gwakisa, Paul, and Kochzius, Marc
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PENAEUS monodon ,MARINE pollution ,HEAVY metal toxicology ,OCEAN - Abstract
The genetic diversity of giant tiger prawns in relation to trace metals (TMs) pollution was analysed using 159 individuals from eight sites at the Tanzanian coast. The seven microsatellites analysed showed high degree of polymorphism (4–44 alleles). The measured genetic diversity (H o = 0.592 ± 0.047) was comparable to that of populations in the Western Indian Ocean. Apart from that, correlation analysis revealed significant negative associations between genetic diversity and TMs pollution ( p < 0.05), supporting the genetic erosion hypothesis. Limited gene flow was indicated by a significant genetic differentiation (F ST = 0.059, p < 0.05). The Mantel test rejected the isolation-by-distance hypothesis, but revealed that gene flow along the Tanzanian coast is limited by TMs pollution. This suggests that TMs affect larvae settlement and it may account for the measured deficiency of heterozygosity. This calls for strengthened pollution control measures in order to conserve this commercially important species. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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8. Trace metals in the giant tiger prawn Penaeus monodon and mangrove sediments of the Tanzania coast: Is there a risk to marine fauna and public health?
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Rumisha, Cyrus, Mdegela, Robinson H., Kochzius, Marc, Leermakers, Martine, and Elskens, Marc
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PENAEUS monodon ,MARINE animals ,TRACE metals ,WASTE treatment ,PUBLIC health - Abstract
Mangroves ecosystems support livelihood and economic activities of coastal communities in the tropics and subtropics. Previous reports have documented the inefficiency of waste treatment facilities in Tanzania to contain trace metals. Therefore, the rapidly expanding coastal population and industrial sector is likely to threaten mangrove ecosystems with metal pollution. This study analysed trace metals in 60 sediment samples and 160 giant tiger prawns from the Tanzanian coast in order to document the distribution of trace metals and to establish if measured levels present a threat to mangrove fauna and are of public health importance. High levels of Cr, Co, Cu, Fe, Mn, Ni, and V was observed in mangroves of river Pangani, Wami, and Rufiji. Multivariate analysis showed that they originate mainly from weathering and erosion in the river catchments. Extreme enrichment of Cd was observed in a mangrove affected by municipal sewage. The distribution of Hg, Pb, and Zn was related with urbanisation and industrial activities along the coast. The metal pollution index was high at Pangani, Saadani, and Rufiji, suggesting that these estuarine mangroves are also affected by human activities in the catchment. Moderate to considerable ecological risks were observed in all sampled mangroves, except for Kilwa Masoko. It was revealed that As, Cd, and Hg present moderate risks to fauna. High levels of Cu, Fe and Zn were observed in prawns but the level of the non-essential Cd, Hg, and Pb did not exceed the maximum allowed levels for human consumption. However, based on the trends of fish consumption in the country, weekly intake of Hg is likely to exceed provisional tolerable weekly intake level, especially in fishing communities. This calls for measures to control Hg emissions and to strengthen sewage and waste treatment in coastal cities and urban centres in the basin of major rivers. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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9. Determination of oxytetracycline residues in cattle meat marketed in the Kilosa district, Tanzania.
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Kimera, Zuhura I., Mdegela, Robinson H., Mhaiki, Consolatha J.N., Karimuribo, Esron D., Mabiki, Faith, Nonga, Hezron E., and Mwesongo, James
- Abstract
Oxytetracycline is used to treat various diseases in cattle. However, its use may be associated with unacceptable residue levels in food. Oxytetracycline residues in tissues from indigenous cattle were determined in a cross-sectional study conducted in the Kilosa district, Tanzania, between November 2012 and April 2013. A total of 60 tissue samples, including muscle, liver and kidney, were collected from slaughterhouses and butchers and analysed for oxytetracycline using high-performance liquid chromatography. Oxytetracycline residues were found in 71.1% of the samples, of which 68.3% were above acceptable regulatory levels. The mean concentration of oxytetracycline across tissues was 3401.1 μg/kg ± 879.3 μg/kg; concentrations in muscle, liver and kidney were 2604.1 μg/kg ± 703.7 μg/kg, 3434.4 μg/kg ± 606.4 μg/kg and 3533.1 μg/kg ± 803.6 μg/kg, respectively. High levels of oxytetracycline residue in meat from indigenous cattle may pose a health threat to consumers in Kilosa. The findings possibly reflect a general lack of implementation of recommended withdrawal periods, ignorance about drug use and lack of extension services. Strict regulation of the use of antimicrobial drugs in the livestock industry and associated testing of animal-derived food sources prior to marketing are required. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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10. Human and animal Campylobacteriosis in Tanzania: A review.
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KOMBA, ERICK V. G., MDEGELA, ROBINSON H., MSOFFE, PETER L. M., and INGMER, HANNE
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The thermotolerant species of Campylobacter have become very important in public health, particularly as agents of infectious diarrhoea in human beings. Though the mechanism by which they cause disease is yet to be fully explained, they have been recognized as the leading cause of bacterial enteritis in both developed and developing countries. The organisms colonize different animal species without causing any symptoms of disease; and humans acquire infections through contact with or consumption of contaminated meat especially raw/undercooked poultry meat. The growing trend of antibiotic resistant Campylobacter isolates continues to pose significant public health challenges. In this review we present the available information generated in Tanzania about Campylobacter infections in humans and animals. We conducted a structured literature search of PUBMED and ScienceDirect electronic databases and identified 15 articles. Studies on humans reported Campylobacter infections in both symptomatic and asymptomatic subjects; with higher prevalence in children under the age of five years. Studies on animals found colonization of both domestic and wild species. Among isolates, some demonstrated antimicrobial resistance. The available information for both human and animal Campylobacteriosis in the country is sparse. It however provides an insight of the bacteriological and epidemiological aspects of Campylobacter infections in the country and eventually creates more awareness on the need to develop control strategies. Since the organism is zoonotic its control strategies should adopt the "One Health" approach involving collaborative efforts from veterinary and human medicine. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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11. Studies on mastitis, milk quality and health risks associated with consumption of milk from pastoral herds in Dodoma and Morogoro regions, Tanzania.
- Author
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Karimuribo, Esron D., Kusiluka, Lughano J., Mdegela, Robinson H., Kapaga, Angolwisye M., Sindato, Calvin, and Kambarage, Dominic M.
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MASTITIS ,MILK ,PASTORAL systems ,CATTLE diseases ,MYCOBACTERIUM tuberculosis - Abstract
The prevalence of mastitis, milk quality and health risks associated with milk consumption were investigated on 96 randomly selected traditional herds in Dodoma rural and Mvomero districts of Tanzania. Mastitis was investigated based on clinical signs, microbiology and California mastitis test (CMT), while milk quality was evaluated using total viable count (TVC) and total coliform count (TCC). Animals were tested for tuberculosis using a single comparative intradermal tuberculin test. The prevalence of subclinical mastitis based on CMT was low (8.3%). The major isolates were Staphylococcus aureus (35.3%), other staphylococci (20.8%), coliforms (27.7%), microcci (5.8%) and streptococci (9.8%). The average TVC of milk in Dodoma rural district (1.0 × 10
7 ± 3.4 × 107 ) was significantly higher than that in Mvomero district (8.9 × 105 ± 3.5 × 106 ) (p < 0.001) and the proportion of TCC-positive samples in Dodoma (70.7%) were significantly higher (p < 0.001) than that of Mvomero samples (20.8%). Whereas no tuberculin reactor animal was detected in the study animals, atypical mycobacteria were isolated from milk and one sample from Dodoma had Mycobacterium tuberculosis. Knowledge on health risks associated with milk consumption was low (20.8%). It is concluded that lack of awareness on health risks associated with milk consumption amongst rural communities needs to be addressed in order to safeguard their health. [ABSTRACT FROM AUTHOR]- Published
- 2005
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12. Extended Stability of Restriction Enzymes at Ambient Temperatures
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Clark, Jason, Harrison, Jennifer C., Mdegela, Robinson H., and March, John B.
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The stability of restriction enzymes as supplied by manufacturers without any modification has been examined. No reduction in activity was observed for three enzymes (HindIII, EcoRI and Tsp509I) held at ambient temperature or 4°C for the period of study (12 months), while activity was observed for up to 12 weeks after storage at 37°C, which was considerably better than following desiccation with trehalose, a recognized preservation technique. A larger trial of 23 different restriction enzymes held at room temperature for one week showed that all enzymes retained significant activity. As a practical demonstration of the usefulness of this finding, enzymes were posted to Africa by conventional mail (cost $1 US) and shown to retain activity upon arrival after three weeks in transit (compared to a cost of $1000 US by cold-chain transportation). Supplying enzymes to third-world markets should now be possible by removing the necessity for cold-chain transport. After arrival, enzymes can simply be stored in a standard domestic refrigerator.
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- 2000
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13. Virulence pattern of circulating aeromonads isolated from farmed Nile tilapia in Tanzania and novel antibiotic free attenuation of Aeromonas hydrophilastrain TZR7-2018
- Author
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Mzula, Alexanda, Wambura, Philemon N., Mdegela, Robinson H., and Shirima, Gabriel M.
- Abstract
•The aer/hly/fla combination pattern ware more frequent in the isolated aeromonads.•hydrophilastrain TZR7-2018 was attenuated through heat-shock-subculture technique.•It proved to be efficacious when given through both IP injection and immersion.
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- 2020
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