Layer Poultry Research Articles

Occurrence, Multidrug Resistance, and Multilocus Sequence Typing of Extended-Spectrum Beta-Lactamase/AmpC-Producing Escherichia coli from Farmed Eggs.

The present study evaluated the occurrence, antibiogram profile, and sequence types (STs) of multidrug resistant (MDR) Escherichia coli from freshly laid eggs (n = 480), feed (n = 24), water (n = 24), poultry droppings (n = 24), and hand swab samples (n = 10) collected from 24 deep litter (DL) and caged poultry layer farms (12 per category) across Punjab, India. The overall E. coli contamination rate in DL and cage farms was 32% (95% confidence intervals [CI], 26.6-37.8%) and 16.7% (95% CI, 12.6-21.6%), respectively. The logistic regression analysis revealed that the DL system had higher odds of occurrence (odds ratio [OR]) of extended-spectrum beta-lactamase (ESBL) (2.195, 95% CI, 1.065, 4.522) and ESBL/AmpC coproducers (2.69, 95% CI, 1.122, 6.45) compared to the cage system. Additionally, isolates from the DL were 4.065 (95% CI, 1.477, 11.188) times more tetracycline resistant compared to the latter; however, resistance to amoxyclavulanate (OR, 0.437; 95% CI, 0.209, 0.912), and ampicillin (OR, 0.343; 95% CI, 0.163, 0.720) was lesser in DL system. Notably, around 97.7% and 87.2% of the isolates from the DL and cage system were MDR, with the DL system having 6.439 (95% CI, 1.246, 33.283) times more chances of harboring MDR E. coli. Additionally, among the resistance genes, the DL system demonstrated significantly high presence of blaAmpC (56%), qnrA/B/S (42.3%), and tetA/B (30.6%). Furthermore, multilocus sequence typing of 11 MDR isolates (n = 5, DL, and 6, cage) revealed the presence of 10 STs, of which ST10, ST155, and ST156 were found to be of public health importance. Therefore, the present study highlights the burden of MDR, ESBL, and AmpC-producing E. coli on poultry eggs and farm environment, which could be carried over to human handlers and consumers upon direct contact during handling and processing.

Evaluation of Compost and Manure Amendments for Suppressing Heterodera glycines.

Soybean cyst nematode (SCN) is a major pest of soybean crops, causing significant yield losses and economic impact. Current management strategies primarily rely on resistant varieties, cover crops, and seed treatments. In addition, there is a growing interest in developing sustainable, ecologically based approaches to integrate SCN risk reduction into soybean production systems. This study aimed to evaluate the efficacy of various compost and manure amendments in suppressing SCN populations and promoting soybean productivity. An in vitro egg hatching assay was conducted to screen the inhibitory effects of different compost and manure extracts on SCN egg hatching. Results indicated that poultry manure, Layer Ash Blend, and swine manure extracts significantly inhibited SCN hatching compared with other treatments across multiple time points. Greenhouse trials further validated the effectiveness of Layer Manure, poultry manure, High Carbon Dairy Doo, and Seed Starter 101 in suppressing SCN cysts, eggs, and juveniles. A field microplot trial confirmed the potential of Layer Ash Blend and poultry manure in SCN management, with significant reductions in SCN populations and increased soybean yields. The study also investigated the impact of these amendments on promoting the population of bacterivorous and frugivorous nematodes, contributing to a biological diverse soil ecosystem. Overall, the results indicate that amending SCN-infested soil with specific compost or manure formulations can effectively suppress nematode populations while improving soybean productivity. These findings contribute to the development of sustainable strategies for SCN management in soybean production systems.

Efficacy of Zerofly® hermetic and polypropylene storage bags for conservation of maize in layer poultry farms in Ghana

Efficacy of Zerofly® hermetic and polypropylene storage bags for conservation of maize in layer poultry farms in Ghana

Whole genome sequencing of multidrug-resistant Klebsiella pneumoniae from poultry in Noakhali, Bangladesh: Assessing risk of transmission to humans in a pilot study

BackgroundMulti-drug resistant (MDR) Klebsiella pneumoniae is a public health concern due to its presence in Bangladeshi poultry products and its ability to spread resistance genes. This study genetically characterizes a distinct MDR K. pneumoniae isolate from the gut of poultry in Noakhali, Bangladesh, offering insights into its resistance mechanisms and public health impact. MethodsKlebsiella pneumoniae isolates from broiler and layer poultry were identified using biochemical and molecular analyses. Eleven isolates were tested for antibiotic sensitivity and categorized by their Multiple Antibiotic Resistance Index (MARI) profiles. The isolate with the highest MARI was selected for whole-genome sequencing using Illumina technology. The sequencing data were analyzed for genome annotation, pan-genome analysis, genome similarities, sequence type identification, and the identification of genetic determinants of resistance and virulence genes. ResultWe identified 10 MARI profiles among 11 K. pneumoniae isolates, with values ranging from 0.64 to 0.94. The highest MARI of 0.94 was found in an isolate from a layer poultry. This isolate's genome, 5401,789 base pairs long with 89.6 % coverage, showed potential inter-species dissemination, as indicated by core genome phylogenetic analysis. It possessed genes conferring resistance to fluoroquinolones, aminoglycosides, β-lactams, folate pathway antagonists, fosfomycin, macrolides, quinolones, rifamycin, tetracyclines, and polymyxins, including colistin. ConclusionPoultry serve as reservoirs for MDR K. pneumoniae, which can spread to other species and pose significant health risks. Rigorous monitoring of antibiotic use and genetic characterization of MDR bacterial isolates are essential to mitigate this threat.

Impact of Different Soil Amendments on Carbon and Nitrogen Mineralization in Ultisols

Quantifying the nutrient mineralization in soils amended with different materials is vital for understanding the nutrient availability for plant uptake. It helps to improve nutrient management by minimizing nutrient loss from the soil. The present research was conducted as a laboratory incubation to assess the nitrogen (N) and carbon (C) mineralization in Ultisols amended with cattle manure, spent poultry layer litter, Gliricidia leaves (Gliricidia sepium), leaf litter compost, urea, and Siam weed leaves (Chromolaena odorata). A Completely Randomized Design (CRD) was used with four replicates, and means were compared with Duncan’s multiple range test (DMRT) after analyzing the data with the SPSS 25 statistical package. CO2-C evolution in amended soils increased up to day 14 of incubation and became stable as incubation progressed. The highest total flux of CO2-C (171.89 g/kg) was obtained in cattle manure-amended soil. Compost-amended soil showed significantly higher (p=0.05) release of mineralized nitrogen (1530.31 mg/kg) over unamended control. The pH in all the amended soils increased over time, with the highest pH in soil amended with compost. Thus, the present study indicated rapid C and N mineralization when different amendments are integrated into the soil.

Development and use of Biocheck.UGent™ scoring system to quantify biosecurity in conventional indoor (turkey, duck, breeder) and free-range (layer and broiler) poultry farms

To assess and enhance the application of biosecurity measures in poultry farming, an objective measurement tool (Biocheck.UGent™) was already available for broiler and layer. This study describes the development, validation and application of a risk-based weighted scoring tool for breeder, turkey, duck, free-range layer and free-range broiler production. In collaboration with an expert panel (n= 38), five different questionnaires were developed, following the format of the existing Biocheck.UGent scoring tools. Weights were attributed to external (7–9 subcategories) and internal (3–4 subcategories) biosecurity categories, as well as to the corresponding individual questions within each subcategory. The biosecurity measures were prioritized and weighed based on their relative importance in preventing disease transmission. Upon completion of the questionnaire, and upload of all answers to the Biocheck.UGent website, the algorithm generates a biosecurity score varying between ‘’0’’ which equals the total absence of any biosecurity measure up to ‘’100’’ which refers to full application of all biosecurity measures. The final scoring systems are available online (https://biocheckgent.com/en) for free and have been used to assess biosecurity in 70 breeders, 100 turkeys, 23 ducks, 16 free-range broilers, and 15 free-range layer farms originating from 12 countries so far. On average, the overall biosecurity score (mean ± std. dev) was 78 ± 7 % for breeders, 73 ± 11 % for turkeys, 71 ± 8 % for ducks, 73 ± 8 % for free-range layers and 70 ± 13 % for free-range broilers. There were significant differences (p < 0.05) in biosecurity (both at the overall and subcategory levels) across different poultry types. The overall farm biosecurity score for breeders was significantly higher than that for turkey (p <.001) and duck production (p = 0.001). External biosecurity levels were highest in breeders in comparison to turkeys (p < 0.001), ducks (p = 0.008) and broiler free-range (p = 0.005). There was a notable difference in internal biosecurity levels between duck and turkey (p = 0.041) production as well. The study contributed to the poultry biosecurity database which allows benchmarking of the biosecurity levels of the users’ farm results to national or international averages, indicating room for improvement and aiding to motivate stakeholders to enhance their biosecurity levels.

Effects of Liquid Whey Supplementation with Water on Egg Production and Egg Quality in Layer Chickens

Background: Liquid whey is a milk by-product and contains good quality protein and minerals. Due to lack of proper knowledge and sufficient technology it remains unutilized and thrown away as a waste. So, keeping in view of its profitable utilization, a study was planned to include liquid whey as feed supplement to layer poultry. Methods: A study was conducted by supplementation of liquid whey to layer chickens to study the effect on egg production and egg quality. A total of 120 layer birds (indicate the age) were supplemented with liquid whey ad libitum in the drinking water @ 0, 5, 10 and 15% up to 90 days. The data were collected with respect to egg production and egg quality parameters. Result: Supplementation of liquid whey in drinking water improved egg production and egg quality in laying chickens. It may be concluded that liquid whey can be supplemented with drinking water at the rate of 5% (v/v) for better egg production in layers and for production of premium quality of bigger size and weight of eggs, supplementation of whey up to 15% (v/v) can be recommended.

Accumulation of resistance genes in Salmonella Typhimurium transmitted between poultry and dairy farms increases the risk to public health.

Salmonella Typhimurium is a zoonotic pathogen that poses a major threat to public health. This generalist serotype can be found in many hosts and the environment where varying selection pressures may result in the accumulation of antimicrobial resistance determinants. However, the transmission of this serotype between food-producing hosts, specifically between poultry layer flocks and nearby dairy herds, was never demonstrated. We investigated an outbreak at a dairy in Israel to determine the role of nearby poultry houses to be sources of infection. The 2-month outbreak resulted in a 47% mortality rate among 15 calves born in that period. Routine treatment of fluid therapy, a nonsteroidal anti-inflammatory, and cefquinome was ineffective, and control was achieved by the introduction of vaccination of dry cows against Salmonella (Bovivac S, MSD Animal Health) and a strict colostrum regime. Whole genome sequencing and antimicrobial sensitivity tests were performed on S. Typhimurium strains isolated from the dairy (n = 4) and strains recovered from poultry layer farms (n = 10). We identified acquired antimicrobial-resistant genes, including the blaCTX-M-55 gene, conferring resistance to extended-spectrum cephalosporins, which was exclusive to dairy isolates. Genetic similarity with less than five single nucleotide polymorphism differences between dairy and poultry strains suggested a transmission link. This investigation highlights the severe impact of S. Typhimurium on dairy farms and the transmission risk from nearby poultry farms. The accumulation of potentially transferable genes conferring resistance to critically important antimicrobials underscores the increased public health risk associated with S. Typhimurium circulation between animal hosts.IMPORTANCESalmonella Typhimurium is one of the major causes of food-borne illness globally. Infections may result in severe invasive disease, in which antimicrobial treatment is warranted. Therefore, the emergence of multi-drug-resistant strains poses a significant challenge to successful treatment and is considered one of the major threats to global health. S. Typhimurium can be found in a variety of animal hosts and environments; however, its transmission between food-producing animals, specifically poultry layers flocks and dairy herds, was never studied. Here, we demonstrate the transmission of the pathogen from poultry to a nearby dairy farm. Alarmingly, the multi-drug-resistant strains collected during the outbreak in the dairy had acquired resistance to extended-spectrum cephalosporins, antibiotics critically important in treating Salmonellosis in humans. The findings of the study emphasize the increased risk to public health posed by zoonotic pathogens' circulation between animal hosts.

Study of a lytic bacteriophage as a tool for the control of Salmonella Gallinarum in layer poultry

One of the leading diseases affecting laying poultry in Argentina is fowl typhoid, caused by the pathogen Salmonella enterica serovar Gallinarum (S. Gallinarum). Although this disease was eradicated from industrial hatcheries in several developed countries, it is still present in commercial farms in Latin America, causing substantial economic losses due to high mortality rates, limited production of quality eggs, high veterinary costs, and the need to renovate infected facilities. To develop a new S. Gallinarum biocontrol method, in the present study, we characterized a bacteriophage in terms of host specificity, growth kinetics, and stability under different environmental conditions. The phage could infect an ample range of bacterial hosts and had no lytic activity against the vaccine strain 9R. Moreover, the phage was stable at pH 3, chloroform presence did not significantly reduce its titer, and its activity wasnot affected by antibiotics or various chemical agents often used in aviculture. Application of a phage suspension on S. Gallinarum-contaminated surfaces resulted in a significant reduction of bacterial load (p &lt; 0.05). These results show that lytic bacteriophages such as the one studied here are innovative alternatives with potential applications to control S. Gallinarum in laying poultry farms.

Level of aflatoxins in dairy feeds, poultry feeds, and feed ingredients produced by feed factories in Addis Ababa, Ethiopia.

Aflatoxins are one of the major factors that affect the quality and safety of feeds. They can be transferred into livestock through contaminated feed and then onto humans via animal sources of food such as milk, meat, and eggs. The objective of this study was to detect and quantify the level of aflatoxins (B1, B2, G1, G2, and total aflatoxin) in dairy feeds, poultry (layer and broiler) feeds, and feed ingredients produced in Addis Ababa. A total of 42 feeds and feed ingredients consisting of dairy feeds (n = 5), poultry broiler feeds (n = 6), layer feeds (n = 6), and feed ingredients (n = 25) were collected from feed factories in the city and analyzed in fresh weigh basis. The aflatoxins were analyzed using high-performance liquid chromatography after clean-up with immunoaffinity columns. Aflatoxin B1 levels in feeds ranged from 51.66 to 370.51µg/kg in dairy cattle feed, from 1.45 to 139.51µg/kg in poultry layer feed, and from 16.49 to 148.86µg/kg in broiler feed. Aflatoxin B1 levels in maize ranged from 2.64 to 46.74µg/kg and in Niger seed cake from 110.93 to 438.86µg/kg. Aflatoxin B1 levels in wheat bran, wheat middling, and soybean were below 5µg/kg. 100% of dairy feeds, 67% of poultry layer, 67% of broiler feeds, and 24% of ingredients contained aflatoxin in levels higher than the maximum tolerable limit set by the US Food and Drug Administration and Ethiopian Standard Agency. This shows the need for strong regulatory monitoring and better feed management practices to prevent consumers of animal-source foods from significant health impacts associated with aflatoxins.

The Poultry Red Mite, Dermanyssus gallinae, travels far but not frequently, and takes up permanent residence on farms

Management of Dermanyssus gallinae, a cosmopolitan hematophagous mite responsible for damage in layer poultry farming, is hampered by a lack of knowledge of its spatio-temporal population dynamics. Previous studies have shown that the circulation of this pest between farms is of strictly anthropogenic origin, that a mitochondrial haplogroup has been expanding on European farms since the beginning of the 21st century and that its local population growth may be particularly rapid. To refine our understanding of how D. gallinae spreads within and among farms, we characterized the genetic structure of mite populations at different spatial scales and sought to identify the main factors interrupting gene flow between poultry houses and between mitochondrial haplogroups. To this end, we selected and validated the first set of nuclear microsatellite markers for D. gallinae and sequenced a region of the CO1-encoding mitochondrial gene in a subsample of microsatellite-genotyped mites. We also tested certain conditions required for effective contamination of a poultry house through field experimentation, and conducted a survey of practices during poultry transfers. Our results confirm the role of poultry transport in the dissemination of mite populations, but the frequency of effective contamination after the introduction of contaminated material into poultry houses seems lower than expected. The high persistence of mites on farms, even during periods when poultry houses are empty and cleaned, and the very large number of nodes in the logistic network (large number of companies supplying pullets or transporting animals) undoubtedly explain the very high prevalence on farms. Substantial genetic diversity was measured in farm populations, probably as a result of the mite's known haplodiploid mode of sexual reproduction, coupled with the dense logistic network. The possibility of the occasional occurrence of asexual reproduction in this sexually reproducing mite was also revealed in our analyses, which could explain the extreme aggressiveness of its demographic dynamics under certain conditions.

Descriptive epidemiology of smothering in Australian commercial free-range layer hen farms

Since the early 2000s the practice of free-range egg production has increased in developed countries, partly driven by consumer perception that free-range housing is better for hen welfare. While poultry in free-range systems have more behavioural opportunities compared with poultry in caged systems, free-range systems are associated with greater frequencies of infectious disease, predation and ‘smothering’, a condition where birds pile on top of one another with death occurring due to suffocation. Although the frequency of smothering deaths in Australian free-range layer poultry is anecdotally high, there is a lack of empirical evidence quantifying smothering cause-specific mortality rates and identifying factors that place birds at higher risk of death from smothering.This was a prospective cohort study of poultry flocks managed by three commercial free-range layer organisations in Eastern Australia. Flocks were enrolled into the study from 1 January 2019 to 29 March 2021 and were followed until the end of lay or until the end of the study on 31 March 2022, whichever occurred first. Throughout the follow-up period flock managers provided production details for each flock and details of smothering events using custom-designed logbooks.A total of 84 flocks were enrolled in the study: 32 from Organisation 1, 35 from Organisation 2 and 17 from Organisation 3. The number of birds per flock ranged from 16,000 to 45,000. The total mortality rate was 1131 deaths per 10,000 bird-years. Smothering mortality rate across the three organisations was 183 (minimum 133, maximum 223) deaths per 10,000 bird-years at risk. Smothering accounted for around 16% (minimum 9%, maximum 22%) of all deaths.We identified no distinctive temporal pattern in daily smothering risk as a function of either the number of days since placement or calendar date. The locations of smothering events in sheds and in the outdoor range were not consistent, with relatively large numbers of smothering events occurring in specific locations for some sheds but not others. To the best of our knowledge, this study is the largest prospective study of smothering mortality in commercial free-range layer flocks conducted to date. Estimates of smothering incidence rate and how that varies within and between flocks and organisations over time provides a critically important benchmark for further investigations into this substantial area of productivity loss.

The evaluation and importance of Newcastle disease’s economic loss in commercial layer poultry

Velogenic Newcastle disease virus (VNDV) causes a highly contagious and devastating disease in poultry and causes up to 100 percent mortality in susceptible populations during devastating outbreaks. Newcastle disease causes heavy economic losses to the global poultry industry by decreasing the growth rate, decreasing egg production, and increasing morbidity and mortality. The households face substantial economic losses throughout the year due to Newcastle disease. It is ranked first among other poultry diseases in village chickens. The economic losses caused by this disease in the poultry industry have given awareness about the importance of Newcastle disease and made it easier to justify the operations against this disease. So, estimating the economic losses caused by Newcastle disease is very important. Regarding the Newcastle disease's huge impact on production and causing a lack of eggs, we will have to compensate for this reduction by importing eggs from other countries. Hence, a tremendous amount of money will be needed to compensate for the shortage of eggs, which will result in a huge economic loss. Finally, these will directly affect the poultry industry and its financial resources, which clarifies the importance of correct and on-time vaccination and caring for Newcastle disease in poultry flocks to prevent enormous economic losses. In this study, the economic impact of Newcastle Disease on egg-laying farms was quantitatively assessed. Data were collected on the total number of egg-laying poultry monthly and annually. Subsequently, the economic loss for each period was calculated based on the total production period. The minimal damage caused by this disease is about 116,591 Tons. Summing all these periods' production decreases, the total loss will be 10538 Tons. To estimate the losses of the disease, it is necessary to estimate the losses in breeding herds and broiler herds so that the loss resulting from the endemic Newcastle disease of the country can be measured.

The Profit Potential of Layer Poultry Farms: A Case Study of the Largest Egg Producing Indian State

In this investigation, an attempt was made to analyse the economic viability of poultry layer farms in the East Godavari district of Andhra Pradesh. The investigation was based on primary data collected from 90 poultry farmers from two randomly selected mandals of East Godavari district by interviewing the respondents during 2018-19. The result revealed that the investment made per bird was `138.15 for the overall category, while for small, medium and large farms, it was found to be `165.81, 162.22, and 130.91, respectively. Per 100 eggs, the production cost was `340 for the whole sample and `368.11, 356.39 and 336.18 for different size groups of farms under investigation. Gross and net returns per 100 eggs were `423.07 and 3.06, respectively, for the sample as a whole. Average gross and net returns per layer were worked out to be `1308.37 and 256.89, respectively. Benefit-Cost (B: C) ratios were 1.21 and 1.19 for the sample as a whole at discount rates of 12 and 18 per cent, respectively. All farm size groups obtained positive Net Present Value (NPV). Internal Rate of Returns (IRR) was 30.79 in overall farms, whereas IRR was estimated to be 28.66, 29.60 and 31.03 in small, medium and large farms. Hence, layer farms were found to be financially viable and profitable for all groups of layer farms. Keywords: B-C ratio, costs and returns, establishment costs, internal rate of return, net present value. JEL Codes: D24, D25, D57, D61.

Profit Analysis of Small-Scale Poultry Layers in Iwo Agricultural Development Programme (ADP) Zone of Osun State

This study focused on the profit analysis of small-scale poultry layers in Iwo ADP Zone of Osun State. Data were collected from the poultry farmers using a well-structured questionnaire and multi-stage sampling procedure. A total sample size of one hundred and five (105) poultry farmers was selected. Data were analyzed using descriptive statistics budgetary analysis and inferential statistical tools (OLS). Results of the study revealed that majority (80%) of the farmers were below 50 years and the farmers’ mean age was 49.5±7.7 years. The majority (95%) of the farmers had primary education and above. The mean year of experience was 11.0±3.4 years. The mean birds reared and profit was 405 birds and N84, 849.54 respectively. Return on investment during the period was N1.04 establishing positive returns. Household size, years of poultry farming experience and stock size were the factors significantly influencing the profit positively. Therefore, it is suggested that poultry farmers in the study area should try to increase their pen size, explore the use of family labour and endeavour to learn new methods of poultry management from farmers with more years of poultry-keeping experience to increase their level of profit.

Detection of pathotype of Marek's Disease in layer chicken in Iraq

Marek's Disease is a viral disease that affects poultry, particularly chickens. It is caused by the Marek's Disease Virus (MDV), which belongs to the herpesvirus family. The disease is characterized by the formation of tumors in various organs, including the nerves, skin, and internal organs such as the liver, spleen, and kidneys. A layer poultry farm of one day old, vaccinated with Marek's disease virus vaccine. The flock was infected with a virulent Marek's disease virus with a mortality rate of up to 60%. Histopathological examination of affected tissues is an important tool for the diagnosis of the disease. The histopathological finding of tissue sections from chickens with MDV shows extensive proliferation of lymphocytes of various sizes. The confirmation was done by PCR and standardized targeting a 132 bp tandem repeat region specific for serotype-1 MD viruses Meq gene was carried out by PCR and nucleotide sequencing, The sequence analysis of Meq gene of different clinical cases from Iraq homology with very virulent strain and Phylogenetic analysis of oncogenes was carried out with other available sequences in the GenBank we conclude that MDV strains obtained in the present outbreaks in Iraq could be designated as very virulent pathotypes based on nucleotide and phylogenetic analysis of the viruses.

Glimpse into the biosecurity, antimicrobial usage, and antimicrobial resistance of fecal &lt;em&gt;Escherichia coli&lt;/em&gt; associated with commercial chicken layer farms in a poultry dense area in Sri Lanka

Industrial food animal production plays an essential role in the global food supply chain. In parallel with the growth of the Sri Lankan poultry sector, antimicrobial usage has also been increased with the aim of reducing disease incidents. The development of antimicrobial resistance due to the irrational use of antimicrobials is a global problem. Commensals like Escherichia coli (E. coli) can easily acquire and transfer resistance to pathogenic and zoonotic bacteria which cause treatment failures in both humans and animals. The present study was conducted in 50 poultry layer (commercial chicken layers) farms in Kurunegala district of Sri Lanka during the period from November 2016 to January 2017. A questionnaire-based survey was conducted to collect information mainly on the management, biosecurity, and antimicrobial usage of selected farms. Further, E. coli were isolated from the fecal samples collected from 26 farms among those 50 farms, and their antimicrobial-resistant profiles (AMR) were investigated. Results revealed that 98% of the farms had poor biosecurity management practices while using at least one antimicrobial drug (98%). The most commonly used antimicrobial drug was enrofloxacin (79.6%) followed by amoxicillin (61.2%), both sulfamethoxazole and trimethoprim (49%), tetracycline (26.5%), neomycin (22.4%), and tylosin (4.1%). AMR profile of fecal E. coli revealed that the highest resistance is for tetracycline(81.8%) followed by nalidixic acid (54.5%), trimethoprim-sulfamethoxazole (40.9%), ampicillin (45.5%) and ciprofloxacin (31.8%). Lower levels of resistance, 13.6%, 9.1%, and 4.5% were observed for streptomycin, ceftazidime, and imipenem respectively. All the isolates were susceptible to amikacin and gentamycin; while 68.18% of isolated E. coli were multidrug-resistant (MDR). AMR and MDR findings of this study highlight the need of implementing strategies to regulate the usage of antimicrobial drugs in poultry farms in Sri Lanka, to prevent and control the emergence of antimicrobial-resistant pathogens and diseases from a ‘one health’ perspective.

Drivers of antimicrobial resistance in layer poultry farming: Evidence from high prevalence of multidrug-resistant Escherichia coli and enterococci in Zambia.

Inappropriate use of antimicrobials exacerbates antimicrobial resistance (AMR) in the poultry sector. Information on factors driving AMR in the layer poultry sector is scarce in Zambia. This study examined the drivers of AMR in the layer poultry sector in the Lusaka and Copperbelt Provinces of Zambia. This cross-sectional study employed a structured questionnaire in 77 layer poultry farms in the provinces of Lusaka and Copperbelt, Zambia, from September 2020 to April 2021. Data analysis was conducted using Stata version 16.1. Antimicrobial resistance was defined as the presence of multidrug resistance (MDR) isolates. Multivariable regression analysis was used to identify drivers of AMR. In total, 365 samples were collected, from which 339 (92.9%) Escherichia coli and 308 (84.4%) Enterococcus spp. were isolated. Multidrug resistance was identified in 39% of the E. coli and 86% of the Enterococcus spp. The overall prevalence of AMR in layer poultry farms was 51.7% (95% confidence interval [CI]: 40.3%-63.5%). Large-scale farmers (Adjusted odds ratio [AOR] = 0.20, 95% CI: 0.04%-0.99%) than small-scale and farmers who were aware of AMR than those who were unaware (AOR = 0.26, 95% CI: 0.08%-0.86%) were less likely to experience AMR problems. This study found a high prevalence of AMR in layer poultry farming linked to the type of farm management practices and lack of AMR awareness. Evidence of high MDR in our study is of public health concern and requires urgent attention. Educational interventions must increase AMR awareness, especially among small- and medium-scale poultry farmers.

Susceptibility of the adult house fly (Diptera: Muscidae) and 3 of its principal parasitoids (Hymenoptera: Pteromalidae) to the GHA strain of Beauveria bassiana and 4 isolates from field-collected muscid flies.

House fly (Musca domestica L.) (Diptera: Muscidae) populations can negatively impact poultry layer facilities, posing a risk to human and animal health and egg food safety. House flies quickly develop resistance to traditional chemical control methods; therefore, improved biological control may provide opportunities for improved integrated pest management (IPM) programs. Biological control methods currently used include augmentative releases of pteromalid pupal parasitoids and application of the fungal entomopathogen Beauveria bassiana (Balsamo) Vuillemin. This study used bioassays to compare the impact of different B. bassiana strains on survival of house flies and of 3 species of filth fly parasitoids. The B. bassiana that were compared were 3 new field-collected isolates, an older field-collected isolate (L90), and a common commercially available strain (GHA). Flies and parasitoids were exposed to filter paper treated with 1.5 × 109 spores of each strain and a control. All field-isolated strains induced lower mean survival times in house flies than GHA did. The results for all species of parasitoids demonstrated less difference among the treatment groups and the control than in-house flies. Although there was some effect of B. bassiana exposure on parasitoid mortality, the expected spatial separation of parasitoids from areas of application may offer some protection. Using the most effective tested strains of B. bassiana and filth fly parasitoids jointly could be a biological component of an IPM plan for fly control in poultry facilities.

Antimicrobial resistance profiles of Escherichia coli isolated from laying hens in Zambia: implications and significance on one health.

Antimicrobial resistance (AMR) has been deepening in the layer poultry sector in Zambia partly due to the inappropriate use of antimicrobials. Escherichia coli (E. coli), a commensal and zoonotic bacterium, can potentially be a source of AMR. This study assessed the phenotypic AMR profiles of E. coli isolated from the apparent health-laying hens in Lusaka and Copperbelt provinces of Zambia. A cross-sectional study was conducted between September 2020 and April 2021 in which 365 cloacal swabs were collected from 77-layer farms based in Lusaka and Copperbelt provinces of Zambia. E. coli isolation and identification were done using cultural and biochemical properties and confirmed using the 16S rRNA gene sequencing. Antimicrobial susceptibility testing (AST) was done using the Kirby-Bauer disc-diffusion method. Data analysis was done using WHONET 2020 and Stata v.16.1. Of the 365 samples, E. coli was isolated from 92.9% (n = 339). The AMR was detected in 96.5% (n = 327) of the isolates, of which 64.6% (n = 219) were multidrug-resistant (MDR). E. coli was highly resistant to tetracycline (54.6%) and ampicillin (54%) but showed low resistance to meropenem (0.9%), ceftazidime (6.2%) and chloramphenicol (8.8%). This study found a high prevalence of E. coli resistant to some commonly used antibiotics in poultry, which is a public health concern because of the potential contamination of eggs and layers of chicken meat that enter the food chain. Urgent attention is needed, including strengthening antimicrobial stewardship and surveillance programmes in layer poultry production in Zambia.