‘Filth flies’ feed and develop in excrement and decaying matter and can transmit enteric pathogens to humans and animals, leading to colonization and infection. Considering these characteristics, ...‘filth flies’ are potential vectors for the spread of antimicrobial resistance (AMR). This review defines the role of flies in the spread of AMR and identifies knowledge gaps.
The literature search (original articles, reviews indexed for PubMed) was restricted to the English language. References of identified studies were screened for additional sources.
‘Filth flies’ are colonized with antimicrobial-resistant bacteria of clinical relevance. This includes extended spectrum beta-lactamase-, carbapenemase-producing and colistin-resistant (mcr-1 positive) bacteria. Resistant bacteria in flies often share the same genotypes with bacteria from humans and animals when their habitat overlap. The risk of transmission is most likely highest for enteric bacteria as they are shed in high concentration in excrements and are easily picked up by flies. ‘Filth flies’ can ‘bio-enhance’ the transmission of AMR as bacteria multiply in the digestive tract, mouthparts and regurgitation spots.
To better understand the medical importance of AMR in flies, quantitative risk assessment models should be refined and fed with additional data (e.g. vectorial capacity, colonization dose). This requires targeted ecological, epidemiological and in vivo experimental studies.
•Majority of immature mosquitoes developed in containers located outdoors.•Pupae production significantly varies by container type and container size.•Pupae productivity is the highest in ≥50 L ...containers.•Containers with partial shade produced more pupae than containers without any shade.•Plastic-containers and flower-tubs/trays should be targeted for interventions.
The container-inhabiting Aedes mosquitoes are the major vectors transmitting dengue and several other arboviral diseases such as chikungunya and zika across the tropical world. Surveillance for immature Aedes, particularly pupae, is an effective tool for measuring dengue outbreak risk. While in Bangladesh, the greatest burden of dengue fever and dengue hemorrhagic fever cases has periodically been occurring since the first major outbreak in 2000, very limited research has yet been pursued to understand the dynamics of Aedes pupal production in this country. In this backdrop, this study was carried out to i) identify containers at household premises contributing to dengue vector productivity; ii) measure the extent of pupae productivity of household containers; and, iii) determine the effects of household ecological factors upon productivity of pupae in the city of Dhaka, Bangladesh. During the monsoon months of 2013, a total of 1,033 containers (674 wet and 363 dry) in 727 household premises in 12 wards of the city of Dhaka were inspected to measure container productivity and collect household ecological, and human behavioural data. The results reveal that the majority of immature mosquitoes (73.52% larvae and 84.91% pupae) developed in containers located outdoor that are used mostly for household chores. Plastic containers (57.55% of all immature mosquito-positive containers) used for household chores produce most of the immature mosquitos. The results of the zero-inflated negative binomial (ZINB) model reveal that pupae production significantly varies by container type (p-value = 0.0136) for the count regression group. However, when considering container size along with container type, container size is found significant for pupae production (p-value = 0.0041), showing that container size is confounded with the container type and the pupae production. Containers greater than 50 litres (L) are likely to produce 4.9 times more pupae than containers with <1L. Two household ecological factors are found to be significant (shade: p-value = 0.005 in the count regression group and type of water: p-value = 0.001 in the excess zero group) for pupae production. We found that containers with partial shade produce 4.6 times more pupae than without any shade, whereas in the excess zero group the expected number of observed zero pupae count is 86.5% lower in containers filled with rain water than those with tap water, tube-well water, ring well water and water from other sources. The most commonly used plastic-made containers (i.e., refrigerator trays, drums, buckets) and flower tubs/trays are the most abundant immature mosquito-positive containers. These findings would help the concerned authorities to formulate programs for changing human behaviour targeting the most productive containers for Aedes habitat management and vector control in the city of Dhaka, Bangladesh.
Abstract
The trial evaluated whether the addition of garlic powder increased mineral intake and reduced fly abundance in feedlot cattle. Following a completely randomized design, one hundred and four ...(104) spring-born crossbred steers (BW 529 ± 8kg) were recruited for the feeding trial at Lakeland College, Vermilion Alberta, Canada. Each steer was assigned to one of four treatment groups (26 steers each) where each group received a commercial feedlot mineral mixed with garlic powder to give a final supplement mix that contained either 2.5% or 5% garlic powder or 0.3% garlic-oil-based premix or 0% garlic product (as control). The animals received a feedlot ration. The different treatment groups were kept within side-by-side pens, each equipped with water troughs and automatic feeding equipment to measure individual feed and mineral consumption. Feed and mineral supplements were provided ad libitum. Differences were observed for mineral intake (P = 0.003), ADG (P = 0.002) and feed conversion efficiency (P = 0.01). Compared to the control, mineral supplement consumption increased between 18 to 50% in groups that received garlic-infused supplements. Fly counts did not differ among the groups, in part, due to low overall fly abundance. While there were no differences (P = 0.21) in the length of time the steers spent consuming feed, differences existed for time spent consuming minerals (P = 0.002) and mineral bunk visits (P = 0.0003). There was no difference (P > 0.18) in DMI, final body weight or hot carcass weight among the different groups. The hematological and biochemical parameters were within normal ranges for healthy cattle, and there was no difference in carcass quality grades (P = 0.78). Even though the impact on fly-counts was inconclusive, the preliminary results show that including low-dose garlic powder could be a practical strategy of increasing mineral consumption without any associated negative health consequences.
The trial evaluated whether the addition of garlic powder increased mineral intake and reduced fly abundance in feedlot cattle. Following a completely randomized design, one hundred and four (104) ...spring-born crossbred steers (BW 529 ± 8kg) were recruited for the feeding trial at Lakeland College, Vermilion Alberta, Canada. Each steer was assigned to one of four treatment groups (26 steers each) where each group received a commercial feedlot mineral mixed with garlic powder to give a final supplement mix that contained either 2.5% or 5% garlic powder or 0.3% garlic-oil-based premix or 0% garlic product (as control). The animals received a feedlot ration. The different treatment groups were kept within side-by-side pens, each equipped with water troughs and automatic feeding equipment to measure individual feed and mineral consumption. Feed and mineral supplements were provided ad libitum. Differences were observed for mineral intake (P = 0.003), ADG (P = 0.002) and feed conversion efficiency (P = 0.01). Compared to the control, mineral supplement consumption increased between 18 to 50% in groups that received garlic-infused supplements. Fly counts did not differ among the groups, in part, due to low overall fly abundance. While there were no differences (P = 0.21) in the length of time the steers spent consuming feed, differences existed for time spent consuming minerals (P = 0.002) and mineral bunk visits (P = 0.0003). There was no difference (P > 0.18) in DMI, final body weight or hot carcass weight among the different groups. The hematological and biochemical parameters were within normal ranges for healthy cattle, and there was no difference in carcass quality grades (P = 0.78). Even though the impact on fly-counts was inconclusive, the preliminary results show that including low-dose garlic powder could be a practical strategy of increasing mineral consumption without any associated negative health consequences.
Abstract
Antimicrobial and insectifugal effects have been reported for dehydrated garlic powder. With limited knowledge of its impact on the health of beef cattle, this study investigated whether ...free-choice minerals infused with garlic powder affected cattle blood parameters and long-term stress during the summer. A total of 104 crossbred steers (26 steers per group) were randomly assigned to either 0% garlic product (Control), 0.3% garlic-oil-based premix (GOil), 2.5% garlic powder (2.5% GP) or 5% garlic powder (5% GP). Feed and mineral supplements were fed separately in individual GrowSafe® bunks to monitor each steer’s feed and mineral intake. Measures of individual steer performance collected include body weights and gains, feed intake and ultrasound body fat levels. Blood was collected from 10 steers with the greatest intake and 5 steers with the least mineral intake in each group for biochemical and hematological analyses. Hair samples were clipped from each steer (3 times) from the rump region to evaluate differences cortisol levels as a measure of long-term stress. Preliminary results showed no difference in final body weight (P =0.19) and dry matter intake (P =0.89). However, compared with the control, all garlic treatment groups had greater average daily mineral intake (P = 0.003). The group that received GOil had a greater average daily gain (P = 0.002) and more gain-to-feed ratio (P =0.01) than other groups. No difference (P >0.05) was observed in most serum biochemical parameters with the exception of 5% GP that had a significantly lower bilirubin (P = 0.0001) and albumin (P = 0.002) concentration but all biochemical and hematological measurements fell within the normal range for beef cattle. There was no difference (P = 0.29) among the groups for cortisol levels. The preliminary results show that low-dose infusion of garlic powder was not associated with any adverse health conditions in beef cattle.
Antimicrobial and insectifugal effects have been reported for dehydrated garlic powder. With limited knowledge of its impact on the health of beef cattle, this study investigated whether free-choice ...minerals infused with garlic powder affected cattle blood parameters and long-term stress during the summer. A total of 104 crossbred steers (26 steers per group) were randomly assigned to either 0% garlic product (Control), 0.3% garlic-oil-based premix (GOil), 2.5% garlic powder (2.5% GP) or 5% garlic powder (5% GP). Feed and mineral supplements were fed separately in individual GrowSafe® bunks to monitor each steer's feed and mineral intake. Measures of individual steer performance collected include body weights and gains, feed intake and ultrasound body fat levels. Blood was collected from 10 steers with the greatest intake and 5 steers with the least mineral intake in each group for biochemical and hematological analyses. Hair samples were clipped from each steer (3 times) from the rump region to evaluate differences cortisol levels as a measure of long-term stress. Preliminary results showed no difference in final body weight (P =0.19) and dry matter intake (P =0.89). However, compared with the control, all garlic treatment groups had greater average daily mineral intake (P = 0.003). The group that received GOil had a greater average daily gain (P = 0.002) and more gain-to-feed ratio (P =0.01) than other groups. No difference (P >0.05) was observed in most serum biochemical parameters with the exception of 5% GP that had a significantly lower bilirubin (P = 0.0001) and albumin (P = 0.002) concentration but all biochemical and hematological measurements fell within the normal range for beef cattle. There was no difference (P = 0.29) among the groups for cortisol levels. The preliminary results show that low-dose infusion of garlic powder was not associated with any adverse health conditions in beef cattle.
Abstract
Garlic products have been reported to have antimicrobial effects and may trigger anemia in horses, but their direct impact on feedlot cattle has not been detailed. With increased free-choice ...feeding of garlic-infused mineral supplements to beef cattle, it is important to evaluate this strategy’s impact on the animals’ health and the potential impact on carcass qualities. This 2-yr study recruited 208 crossbred feedlot steers in a supplementation trial using a completely randomized design. Each year, 104 steers were assigned to 1 of 4 groups that received either non-garlic mineral supplement (MS), MS + 0.3% garlic-oil-based premix (GOil), MS + 2.5% garlic powder (LGP), MS + 5% garlic powder (HGP). Feed and supplements were provided on an ad-lib basis and were measured for each steer with automatic feeding units. The study evaluated health indicators such as blood parameters and internal parasites. At harvest, carcass characteristics (including the incidence of liver abscesses) were assessed for all steers. The groups consumed between 156 and 208 g/d of the supplement over the two years, with the MS group having a lower overall supplement intake than other groups. The average daily consumption of garlic products in GOil, LGP, and HGP were approximately 0.6g/d, 5.2g/d, and 10.1g/d, respectively. There was no difference in total fecal egg counts (P = 0.45) among the groups. There was no association between the treatment groups and incidences of liver abscess scores (P = 0.10) nor carcass grade outcomes (P = 0.84). Further, there were no differences in hot carcass weight (P = 0.90), rib eye area (P = 0.34) and carcass backfat thickness (P = 0.99). All blood parameters evaluated were within normal ranges for all groups. The results suggest that infusing commercial garlic products into mineral supplements is not associated with undesirable effects on cattle health or carcass characteristics.
Abstract
Conflicting anecdotal accounts from producers about their cattle performance and fly-repellence outcomes while receiving garlic-infused supplements have limited feeding decisions. This study ...evaluated differences in animal performance and insectifugal outcomes among four groups (26 steers per group) over two years (total = 208 steers). The steers either received non-garlic mineral supplement (MS), MS+0.3% garlic oil-based premix (GOil), MS+2.5% garlic powder (LGP), or MS+5% garlic powder (HGP). A completely randomized design was implemented where each steer was assigned to each treatment group while balancing for bodyweight and breed composition. Steers received a feedlot ration and free-choice mineral supplement for 86 and 108 d in the first and second year, respectively. Individual feed and supplement consumption were measured with automatic feeding units. Fly abundance on each animal was determined using digital images collected during weekly fly surveys. The ADG, feed efficiency, ultrasound body composition, and intake-related activities were also evaluated during the study. Data were analyzed using linear- or generalized linear mixed models in SAS. A significant year and Group×year interactions were observed for daily supplement intake (P < 0.02). Similar interactions (P < 0.04) were observed for feeding behaviors associated with supplement intake. Fly abundance during the peak months was below the economic threshold and was not different among the groups (P = 0.25), but the year and Group×year interactions were significant (P < 0.02). There were no differences among the groups for DMI (P = 0.81), ADG (P = 0.54) and gain to feed ratio (P = 0.34). The Group×year interactions were present for the change in ultrasound rib-fat-thickness. The reasons behind the differences in supplement intake are not clear but may be related to the garlic products’ phytochemical profiles. These results suggest that further studies are required to identify the specific bioactive compounds in garlic that affect supplement intake.
The geographic distribution of the Rocky Mountain wood tick, Dermacentor andersoni Stiles, was determined in Alberta, Canada, by drag sampling at 86 and 89 sites during 2011 and 2012, respectively. ...Tick density and prevalence varied between years, averaging (range) 1.0 (0–26.2) and 5.9 (0–110) ticks/1,000 m2 in 2011 and 2012, respectively. Ticks were detected at 24.4% and 42.7% of the sites sampled in each respective year. Tick density and presence declined in a northerly direction to 51.6°N and in a westerly direction to ca. 113°W, except for a small area of high density at the edge of the Rocky Mountains in the southeastern portion of the province. Ticks were most abundant in the Dry Mixedgrass and Montane natural subregions and in areas with Brown Chernozemic, Regosol, and Solodized Solonetzic great soil groups. A logistic regression model indicated that tick presence was increased in the Dry Mixedgrass natural subregion and in regions with greater temperatures during the previous summer and normal winter precipitation but was reduced in areas with Dark Brown Chernozemic soils. The model will be useful for predicting tick presence and the associated risk of tick-borne diseases in the province.
Passive and active surveillance for the blacklegged tick, Ixodes scapularis Say, in the Canadian province of Saskatchewan was conducted over a 9-yr period (2009–2017). More than 26,000 ixodid ticks, ...representing 10 species, were submitted through passive surveillance. Most (97%) of these were the American dog tick, Dermacentor variabilis (Say). Of the 65 I. scapularis adults submitted, 75% were collected from dogs. Infection rates of Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti in I. scapularis were 12%, 8%, and 0%, respectively. Although the I. scapularis submitted by passive surveillance were collected from five of seven ecoregions in central and southern Saskatchewan, they were most frequent in the Moist Mixed Grassland and Aspen Parklands. In contrast, no I. scapularis were collected from the extensive field sampling conducted at multiple sites in different ecoregions across the province. Hence, there is no evidence of I. scapularis having established a breeding population in Saskatchewan. Nonetheless, continued surveillance for blacklegged ticks is warranted given their important role as a vector of medically and veterinary important pathogens, and because they have recently become established across much of the southern portions of the neighboring province of Manitoba.
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