Search Results (118)

Background/Objectives: Antimicrobial resistance (AMR) is a major global health threat that undermines treatment in humans and animals. In Zambia, where livestock production underpins food security and livelihoods, AMR challenges are aggravated by limited surveillance, weak diagnostics, and poor regulatory enforcement, facilitating the spread of resistant pathogens across the human–animal–environment interface. This study aims to analyse AMR patterns of bacterial isolates collected from Zambia’s animal health sector between 2020 and 2024, to generate evidence that informs national AMR surveillance, supports antimicrobial stewardship (AMS) interventions, and strengthens One Health strategies to mitigate the spread of resistant pathogens. Methods: We conducted a retrospective descriptive analysis of previously collected routine laboratory data from five well-established animal health AMR surveillance sentinel sites between January 2020 and December 2024. Data were analysed by year, sample type, and antimicrobial susceptibility testing (AST) profiles using WHONET. Results: A total of 1688 samples were processed, with faecal samples accounting for 87.6%. Animal environmental samples (feed, manure, litter, abattoir/meat processing floor, wall, and equipment surface swabs) (collected from abattoirs, water, and farms) increased significantly over time (p = 0.027). Overall, Escherichia coli (E. coli) (50.4%) and Enterococcus spp. (30%) were the most frequently isolated bacteria. E. coli exhibited high resistance to tetracycline (74%) and ampicillin (72%) but remained susceptible to aztreonam (98%), nitrofurantoin (95%), and imipenem (93%). Enterococcus spp. were susceptible to penicillin (84%) and ampicillin (89%) but showed borderline resistance to vancomycin (53%) and linezolid (50%). Klebsiella spp. demonstrated resistance to ciprofloxacin (52%) and gentamicin (40%), whereas Salmonella spp. remained highly susceptible. Notably, resistance to amoxicillin/clavulanic acid rose sharply from 22.2% to 81.8% (p = 0.027). Across 1416 isolates, high levels of multidrug resistance (MDR) were observed, particularly in E. coli (48.4%) and K. pneumoniae (18.6%), with notable proportions progressing toward possible Extensively Drug-Resistant (XDR) and Pan-Drug-Resistant (PDR) states. Conclusions: The findings of this study reveal rising resistance to commonly used antibiotics in the animal health sector. Despite the lack of molecular analysis, our findings underscore the urgent need for AMS programs and integrated AMR surveillance under Zambia’s One Health strategy. Full article

This study assessed the microbiological quality of free-range eggs produced in Southeastern Brazil, focusing on the effects of collection location. Eggs were collected from either nest boxes (designated laying areas containing clean substrate) or from the bedding substrate (litter-covered floor of the poultry house). Eggs from the bedding had significantly higher counts of thermotolerant coliforms, psychrotrophs, and Staphylococcus compared to nest-collected eggs. Across all evaluated microorganisms, eggshells showed greater contamination than the internal contents. Bedding substrates showed higher counts of mesophilic aerobes, psychrotrophs, Staphylococcus, and Clostridium compared to nest box substrates. Eggs from the bedding showed compromised internal microbiological quality, with coliform values exceeding 2 log10 most probable number (MPN) per mL. Further, 10% of the evaluated pools were suggestive of the presence of Salmonella spp., in the internal components of bedding eggs and on the shells of nest eggs. Therefore, it is strongly recommended that eggs be collected from nest boxes right after laying, while eggs laid on the bedding substrate should be excluded from human consumption. Full article

Forest litter plays a critical role in regulating the water balance of forest ecosystems, particularly in semi-arid regions where hydrological stability is under pressure due to climate change. This study investigates the maximum water holding capacity (MWHC) of litter layers across three ecologically distinct regions in Türkiye—Kastamonu, Kütahya, and Muğla—to evaluate how structural and physicochemical characteristics influence the maximum water holding capacity (MWHC) of litter layers. Litter samples classified into humus, fermenting debris, and needles were analyzed for MWHC, pH, electrical conductivity (EC), and total dissolved solids (TDSs). The results revealed that both the type of litter and regional ecological conditions significantly affect MWHC, with humus layers and moist environments exhibiting the highest water holding capacity. Additionally, MWHC showed moderate positive correlations with EC and TDS, highlighting the importance of chemical composition in water dynamics. The findings underscore that forest litter should be regarded as a dynamic and functional hydrological component, not merely residual biomass. This perspective is vital for sustainable watershed planning and adaptive forest management. The study supports the development of integrated management strategies aligned with the United Nations Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation), SDG 13 (Climate Action), and SDG 15 (Life on Land). Full article

The quantity, quality, and accumulation rate of plant litter play a key role in forest floor flammability and, by extension, fire regimes. The varying foliage properties of different tree species also determine litter’s decomposition and its accumulation on the forest floor. The removal of litter by soil fauna, i.e., bioturbation, depends on both the dominant tree species and the successional stage of the forest stand. This research involved laboratory mesocosm experiments aiming to determine the effects of litter quality and earthworm activity on the flammability of the forest floor material at different successional ages. The mesocosms simulated the planting of four tree species (the broadleaf species Alnus glutinosa (L.) Gaertn. (Black alder) and Quercus robur L. (English oak) and the conifers Picea omorika (Pančić) Purk. (Serbian spruce) and Pinus nigra J.F. Arnold (Austrian pine)) at a reclamation site near Sokolov (NW Czechia). The mesocosms contained litter from these different tree species, placed directly on overburden soil (immature soil) or on well-developed Oe and A layers (mature soil), inoculated or not inoculated with earthworms, and incubated for 4 months. The surface material in the mesocosms was then subjected to simulated burn events, and the fire path and soil temperature changes were recorded. Burn testing showed that litter type (tree species) and soil maturity significantly influenced flammability. Pine had longer burning times and burning paths and higher post-burn temperatures than those of the other tree species. The immature soil with earthworms had significantly shorter burning times, whereas in the mature soil, earthworms had no effect. We conclude that earthworms have a significant, immediate effect on the litter flammability of immature soils. Full article

Boreal forests have historically been regarded as some of the largest terrestrial carbon (C) sinks. However, increased soil organic matter (SOM) decomposition due to forest harvesting and post-harvest silviculture (e.g., site preparation, planting, and managing for competing vegetation) may exacerbate the effects of climate warming and shift boreal forests from being C sinks to C sources. We used an established stand-scale, fully replicated, experimental study to identify how two levels of forest management (harvesting = Harvest Only, and harvesting with post-harvest silviculture = Harvest Plus) influence SOC dynamics at three boreal forest sites varying in soil texture. Each site was surveyed for forest floor (litter and F/H horizons) and mineral soils pre-harvest (0) and 5, 14, and 20 years post-harvest. We predicted that sites harvested and left to revegetate naturally would have the lowest SOC stocks after 20 years, as sites that were planted and managed for competing vegetation would recover faster and contribute to a larger nutrient pool, and that the sand-dominated site would have the largest SOC losses following harvest due to the inherently lower ability of sand soils to chemically and/or physically protect SOC from decomposition following harvest. Over a 20-year period, both forest management treatments generally resulted in reduced total (litter, F/H, and mineral horizon) SOC stocks compared with the control: the Harvest Only treatment reduced overall SOC stocks by 15% at the silt-dominated site and 31% at the clay-dominated site but increased overall SOC stocks by 4% at the sand-dominated site, whereas the Harvest Plus treatment reduced overall SOC stocks by 32% at the sand- and silt-dominated sites and 5% at the clay-dominated site. This suggests that harvesting and leaving plots to revegetate naturally on sand-dominated sites and harvesting followed by post-harvest silviculture on clay-dominated sites may minimize total SOC losses at similar sites, though a full replicated field experiment is needed to test this hypothesis. Most treatment effects in this study were observed only in the second decade post-harvest (14 and 20 years post-harvest), highlighting the importance of long-term field experiments on the effects of forest harvesting and post-harvest silviculture. This research improves our understanding of the relationship between C dynamics, forest management, and soil texture, which is integral for developing sustainable management strategies that optimize C sequestration and contribute to the resilience of boreal forest ecosystems in the face of climate change. Full article

Litter and pruning biomass are integral to nutrient cycling in the plant–soil ecosystem, contributing significantly to organic matter formation and humus development through decomposition and nutrient mineralization, which ultimately influence soil fertility and health. However, the litterfall dynamics in mango orchards are not well understood, and its contribution to nutrient cycling has seldom been measured. This study aimed to estimate litterfall and pruning biomass in mango orchards and assess the nutrient contents of various biomass components. Litter and pruning biomass samples were collected from four commercial mango orchards planted with Kensington Pride (‘KP’) and ‘B74’ (‘Calypso^®’) cultivars in the Darwin and Katherine regions, using litter traps placed on the orchard floors. Samples were sorted (leaves, flowers, panicles, fruits, and branches) and analyzed for nutrient contents. Results showed that most biomass abscissions occurred between late June and August, spanning approximately 100 days involving floral induction phase, fruit set, and maturity. Leaves made up most of the abscised litter biomass, while branches were the primary component of pruning biomass. The overall ranking of biomass across both regions and orchards is as follows: leaves > branches > panicles > flowers > fruits. The carbon–nitrogen (C:N) ratio of litter pruning material ranged from 30 (flowers) to 139 (branches). On a hectare basis, litter and biomass inputs contained 1.2 t carbon (C), 21.2 kg nitrogen (N), 0.80 kg phosphorus (P), 4.9 kg potassium (K), 8.7 kg calcium (Ca), 2.0 kg magnesium (Mg), 1.1 kg sulfur (S), 15 g boron (B), 13.6 g copper (Cu), 99.3 g iron (Fe), 78.6 g manganese (Mn), and 28.6 g zinc (Zn). The results indicate that annual litterfall may contribute substantially to plant nutrient supply and soil health when incorporated into the soil to undergo decomposition. This study contributes to a better understanding of litter biomass, nutrient sources, and nutrient cycling in tropical mango production systems, offering insights that support accurate nutrient budgeting and help prevent over-fertilization. However, further research is needed to examine biomass accumulation under different pruning regimes, decomposition dynamics, microbial interactions, and broader ecological effects to understand litterfall’s role in promoting plant growth, enhancing soil health, and supporting sustainable mango production. Full article

This study was performed on the territory of Northern Europe in the Middle taiga subzone of Karelia. The work was conducted at two test sites (Site I, Site II) located in a pine forest in the coastal area of Lake Segozero. In these territories, areas under juniper (UCB) and under lingonberry-blueberry plant microgroups (CB) were isolated. This article presents the results of the effect of juniper on the properties of the upper soil horizon, forest litter (O), and mineral podzolic horizon (E (UCB)). The forest floor (O), and the mineral podzolic horizon (E) of soils located under the lingonberry-blueberry plant microgroup (CB) were selected as controls. The volume weight; acidity; content of total C, total N, total K, and total P had differences in different horizons (O, E) of the soils at the studied sites (Site I, Site II; CB, UCB). The results showed a tendency for C and N reserves to increase in the upper soil horizon under juniper. K and P reserves in this soil horizon tended to decrease. An increase in catalase activity was found in soils under juniper (Site I, II—UCB), which indicates a change in redox conditions. An increase in the rate of cellulose decomposition was noted in UCB sites compared with CB, which is consistent with the results of other studies. Mathematical and statistical analysis confirmed the formation of vegetative microgroups (CB and UCB) in cranberry pine (Site I, Site II) and also allowed us to identify conjugate pairs of chemical parameters (nitrogen reserves, C, catalase activity, and cellulose-destroying ability of soils) that differ in these sites. Full article

This study evaluated the effects of two types of plastic flooring—one with and one without nanotechnological antimicrobial additives—used as complete or partial replacements for wood shavings on broiler chicken performance, yield, meat quality, and litter microbiology over 42 days. A total of 1500 Ross 408^® male broiler chicks were randomly assigned to five treatment groups: wood shavings (WS), plastic flooring (PF), a 50/50 mix of plastic flooring and wood shavings (PF + WS), plastic flooring with antimicrobial additives (PFA), and a 50/50 mix of antimicrobial plastic flooring and wood shavings (PFA + WS). This study evaluated organ biometrics (liver, heart, spleen, and gizzard), the severity of Eimeria lesions, microbiological profiles, performance indices, and meat quality. The results indicated that plastic flooring, particularly when used alone, presented challenges such as increased intestinal lesions related to coccidiosis and a higher prevalence of Salmonella. Moreover, broilers raised on plastic flooring presented worse feed conversion and lower body weights and carcass yields than those raised on wood shavings. The meat quality was also negatively affected, with plastic flooring leading to less favorable fillet characteristics. Overall, the use of plastic flooring reduced the performance and health parameters of broiler chickens. Full article

This study characterized the physicochemical properties of broiler poultry litter (BPL) produced from intensively reared commercial broilers that were collected from 110 commercial poultry farms at the end of the production cycle (sixth week). A further 20 samples were collected from the end use point where BPL was utilized as a soil amendment by the farmers after a period of storage for improving poultry litter management practices, developing new litter treatment technologies, or enhancing its use as a sustainable resource. The dry matter (DM), moisture, ash, organic matter (OM), and organic carbon (OC) from the manure samples were 83.04, 16.96, 27.08, 72.92, and 42.39%, respectively. The pH, electrical conductivity (EC) (dS m⁻¹), and Kjeldahl nitrogen (N) were 8.43, 5.74, and 24.2 g kg⁻¹, respectively. The BPL from the cement floor had higher levels of P and K than the mud floor. The correlation studies revealed that the OM, C, N, and Zn had significant positive correlations; pH, moisture, and ash had positive correlations; and EC, DM, and Ca had positive correlations. The EC level of BPL negatively correlated with pH, Fe, and Mn. The N content was found to have a highly significant (p < 0.01) positive correlation with the OM, OC, Ca, and Zn content of BPL, and it was found to have a highly significant (p < 0.01) negative correlation with the ash content, pH, and K content of BPL. The P content of BPL showed a positive correlation (p < 0.01) with the K content and a negative correlation with the Zn (p < 0.05) and Fe (p < 0.01) contents of BPL. Zn was found to be negatively (p < 0.01) correlated with the ash content; the pH; and the K, Fe, and P content of BPL. According to the findings of this study, BPL as such at the end of the production cycle is rich in OM, nitrogen, macrominerals, and microminerals; however, at the point of utility (after a period of storage of 4 to 6 months), there was a loss of OM, N, and mineral concentrations, highlighting the importance of proper storage and composting. Overall, this study on the physicochemical properties of broiler poultry litter is crucial for improving agricultural practices, protecting the environment, and preserving the health and safety of human beings and livestock. Full article

Subclinical necrotic enteritis (NE) is an enteric disease that inflicts significant economic losses in the poultry industry, primarily by reducing performance in commercial flocks but without significant mortality. This study evaluated the effects of a variety of phytogenic blends on broilers’ performance and carcass composition during an induced NE challenge. In this study, 1120 day (d)-old male broilers were allocated to four treatments groups (14 replicate floor pens, 20 birds/pen): the control (CONT) group, fed a basal corn-soybean diet, and three phytogenic blend dietary additives (PHYTO1, PHYTO2, and PHYTO3) added to the basal diet at 150, 250, and 500 mg/kg feed, respectively. Subclinical NE was induced by spraying a concentrated coccidiosis vaccine onto the feed and litter 24 h post-placement. On day 8, two birds/pen were necropsied for NE lesions. On days 8, 14, 28, and 42, the average daily gain (ADG), feed intake (ADFI), and feed conversion ratio (FCR) were calculated. On day 42, two birds/pen were euthanized to assess carcass composition using dual-energy X-ray absorptiometry (DXA). Statistical analyses for all data were performed using the ANOVA procedure (JMP, Pro 16) and significance (p ≤ 0.05) between treatments was determined by the LSD test. There was no effect of treatment on NE lesions. PHYTO1, PHYTO2, and PHYTO3 significantly improved FCR from days 9 to 14, 0 to 14, and 0 to 42 and resulted in greater ADG from days 9 to 14, 29 to 42 and cumulatively on days 0 to 42. Carcass composition data revealed a numerically higher lean-to-fat ratio in the PHYTO groups compared to the CONT group. These results indicate that the dietary supplementation of phytogenic blends could alleviate the adverse effects of NE challenge on broilers’ performance and carcass composition. Full article

Prescribed burning is a cost-effective method for reducing hazardous fuels in pine- and oak-dominated forests, but smoke emissions contribute to atmospheric pollutant loads, and the potential exists for exceeding federal air quality standards designed to protect human health. Fire behavior during prescribed burns influences above-canopy sensible heat flux and turbulent kinetic energy (TKE) in buoyant plumes, affecting the lofting and dispersion of smoke. A more comprehensive understanding of how enhanced energy fluxes and turbulence are related during the passage of flame fronts could improve efforts to mitigate the impacts of smoke emissions. Pre- and post-fire fuel loading measurements taken during 48 operational prescribed burns were used to estimate the combustion completeness factors (CC) and emissions of fine particulates (PM_2.5), carbon dioxide (CO₂), and carbon monoxide (CO) in pine- and oak-dominated stands in the Pinelands National Reserve of southern New Jersey. During 11 of the prescribed burns, sensible heat flux and turbulence statistics were measured by tower networks above the forest canopy. Fire behavior when fire fronts passed the towers ranged from low-intensity backing fires to high-intensity head fires with some crown torching. Consumption of forest-floor and understory vegetation was a near-linear function of pre-burn loading, and combustion of fine litter on the forest floor was the predominant source of emissions, even during head fires with some crowning activity. Tower measurements indicated that above-canopy sensible heat flux and TKE calculated at 1 min intervals during the passage of fire fronts were strongly influenced by fire behavior. Low-intensity backing fires, regardless of forest type, had weaker enhancement of above-canopy air temperature, vertical and horizontal wind velocities, sensible heat fluxes, and TKE compared to higher-intensity head and flanking fires. Sensible heat flux and TKE in buoyant plumes were unrelated during low-intensity burns but more tightly coupled during higher-intensity burns. The weak coupling during low-intensity backing fires resulted in reduced rates of smoke transport and dispersion, and likely in more prolonged periods of elevated surface concentrations. This research facilitates more accurate estimates of PM_2.5, CO, and CO₂ emissions from prescribed burns in the Pinelands, and it provides a better understanding of the relationships among fire behavior, sensible heat fluxes and turbulence, and smoke dispersion in pine- and oak-dominated forests. Full article

Bacterial chondronecrosis with osteomyelitis (BCO) lameness is a major welfare issue for broiler production worldwide affecting approximately 1.5% of broilers over 42 days old. Excessive body weight gain causes mechanical stress on long bones, leading to micro-fractures. This condition induces a bacterial infection of fractures, resulting in bone necrosis and eventual BCO lameness. Increasing gut integrity and supporting Calcium metabolism contribute to the optimal bone structure and subsequently reduce BCO lameness. Probiotics thus provide an excellent strategy for alleviating BCO due to the improvement of intestinal integrity and barrier function. Accordingly, the present study investigated the lameness reduction through the feed supplementation of a selected probiotic. Broiler chickens were assigned to three treatments, including a control litter group (FL), a PoultryStar^®Bro probiotic fed group (BRO), and a control wire-flooring group (CW) designed to induce BCO lameness. The probiotic significantly decreased lameness by 46% compared to the control group (p < 0.05). The most predominant bacteria identified from the BCO lesions were Staphylococcus cohnii and Staphylococcus lentus. Moreover, significant increments of tight junction gene expression in jejunum and ileum, plus numerical improvements of body weight gain (BW; +360 g) and feed conversion ratio (FCR; −12 pts) were observed in BRO-supplemented birds. Full article

We sequenced and assembled genomes for 17 isolates of Staphylococcus cohnii isolated from osteomyelitis lesions in young broilers from two separate experiments where we induced lameness using a hybrid wire-litter flooring system. Whole genome comparisons using three different methods support a close relationship of genomes from both S. cohnii and Staphylococcus urealyticus. The data support three different lineages, which we designated as Lineage 1, Lineage 2, and Lineage 3, uniting these two species within an evolving complex. We present evidence for horizontal transfer between lineages of genomic regions from 50–440 kbp. The transfer of a 186 kbp region from Lineage 1 to Lineage 2 appears to have generated Lineage 3. Human-associated isolates appear to be limited to Lineages 2 and 3 but Lineage 2 appears to contain a higher number of human pathogenic isolates. The chicken isolates from our lameness trials included genomically diverse isolates from both Lineage 1 and 2, and isolates from both lineages were obtained from osteomyelitis lesions of individual birds. Our results expand the diversity of Staphylococci associated with osteomyelitis in poultry and suggest a high diversity in the microbiome of day-old chicks. Our data also support a reevaluation and unification of the taxonomic classifications of S. cohnii and S. urealyticus. Full article

Invasive plants are capable of homogenizing both aboveground and belowground biota and, along with climate change, are recognized as one of the biggest threats to global biodiversity. Soil nematode communities reflect the surroundings they inhabit and are therefore frequently employed as biological indicators of soil condition. In this study, soil properties and nematode communities in Carpathian beech forest floor covered by dense vegetation of invasive Impatiens parviflora (small balsam) were investigated over two vegetation seasons. We assumed that the spread of invasive I. parviflora could influence soil fauna through litter accumulation when established and could also change several soil properties, consequently altering soil nematode communities. A total of 52 nematode species were found in the soil samples. The mean number of species varied from 18 to 31, but did not significantly differ between invaded and uninvaded plots across all sampling dates. However, redundancy analysis indicated that the nematode community in plots with small balsam differed significantly from that in uninvaded plots, reflecting different proportions of genera in the two communities. Invasion by small balsam significantly enhanced the relative abundance of bacterivores, whereas it decreased the abundance of plant parasites and root-fungal feeders, mainly in the spring and summer season. Ordination of nematode species along the structure index and enrichment index trajectories revealed a maturing food web, low to moderately disturbed in the I. parviflora invaded soils as well as in uninvaded forest plots. Decomposition channels of soil food webs in both plots were balanced and fungal–bacterial mediated, although low values of the channel index suggested prevailing bacterial decomposition. Our study reveals that the expansion of I. parviflora moderately influenced the composition of nematode communities and the soil food web, increased soil nitrogen, carbon and C/N ratio, but did not modify soil acidity. Full article

The research was aimed at studying the taxonomic diversity, habitat specialization, and trophic characteristics of mycobiota, including Basidiomycota, in the northern ecosystems of the Krasnoyarsk Krai (Central Siberia) near Norilsk. Larch forests and woodlands in the Siberian permafrost zone are distinctive and Basidiomycota, as a component of these ecosystems, plays an essential role in their functioning. Currently, there is a paucity of information about this group in Arctic ecosystems, both in terms of floristic and ecological aspects. Seventy species of macromycetes belonging to different trophic groups were discovered and identified. Only 15% of species occur regularly, while most species are found rarely or only once. The identified species belong to 44 genera, 25 families, and 8 orders, which are included in the class Agaricomycetes. The leading families in terms of the number of species are Russulaceae, Polyporaceae, Tricholomataceae, Suillaceae, Strophariaceae, and Cortinariaceae. Mycorrhizal fungi and wood decay fungi dominate the structure of mycobiota of the study area (the total share is 71%). The rest of the species (29%) are fungal decomposers inhabiting plant litter, the forest floor, and humus. The largest number of species occur in forest ecosystems, which are dominated by mycorrhizal and wood decay fungi (up to 70%), which are trophically associated with woody plants and debris. The fungal decomposers inhabiting plant litter, the forest floor, and humus dominate (about 80%) in the species composition of tundra, where, in the absence of woody substrate, wood decay fungi have not been found at all. The species richness of tree and shrub Arctic ecosystems is low, yet the taxonomical and ecological structure of Basidiomycota is similar to that observed in taiga and temperate forests. These data permit a more comprehensive description of the biodiversity of the Arctic and may prove useful in studying biological processes in these ecosystems. Full article