CLINICAL AND LABORATORY DIAGNOSES OF COMMON BACTERIAL DISEASES OF BROILER AND LAYER CHICKENS

Translating conventional wisdom on chicken comb color into automated monitoring of disease-infected chicken using chromaticity-based machine learning models

Bacteria- or virus-infected chicken is conventionally detected by manual observation and confirmed by a laboratory test, which may lead to late detection, significant economic loss, and threaten human health. This paper reports on the development of an innovative technique to detect bacteria- or virus-infected chickens based on the optical chromaticity of the chicken comb. The chromaticity of the infected and healthy chicken comb was extracted and analyzed with International Commission on Illumination (CIE) XYZ color space. Logistic Regression, Support Vector Machines (SVMs), K-Nearest Neighbors (KNN), and Decision Trees have been developed to detect infected chickens using the chromaticity data. Based on the X and Z chromaticity data from the chromaticity analysis, the color of the infected chicken's comb converged from red to green and yellow to blue. The development of the algorithms shows that Logistic Regression, SVM with Linear and Polynomial kernels performed the best with 95% accuracy, followed by SVM-RBF kernel, and KNN with 93% accuracy, Decision Tree with 90% accuracy, and lastly, SVM-Sigmoidal kernel with 83% accuracy. The iteration of the probability threshold parameter for Logistic Regression models has shown that the model can detect all infected chickens with 100% sensitivity and 95% accuracy at the probability threshold of 0.54. These works have shown that, despite using only the optical chromaticity of the chicken comb as the input data, the developed models (95% accuracy) have performed exceptionally well, compared to other reported results (99.469% accuracy) which utilize more sophisticated input data such as morphological and mobility features. This work has demonstrated a new feature for bacteria- or virus-infected chicken detection and contributes to the development of modern technology in agriculture applications.

In critique of anthropocentrism: a more-than-human ethical framework for antimicrobial resistance

Antimicrobial resistance (AMR) is often framed as a One Health issue, premised on the interdependence between human, animal and environmental health. Despite this framing, the focus across policymaking, implementation and the ethics of AMR remains anthropocentric in practice, with human health taking priority over the health of non-human animals and the environment, both of which mostly appear as secondary elements to be adjusted to minimise impact on human populations. This perpetuates cross-sectoral asymmetries whereby human health institutions have access to bigger budgets and technical support, limiting the ability of agricultural, animal health or environmental institutions to effectively implement policy initiatives. In this article, we review these asymmetries from an ethical perspective. Through a review and analysis of contemporary literature on the ethics of AMR, we demonstrate how the ethical challenges and tensions raised still emerge from an anthropocentric framing, and argue that such literature fails to address the problematic health hierarchies that underlie policies and ethics of AMR. As a consequence, they fail to provide the necessary tools to ethically evaluate the more-than-human challenges that the long list of actors involved in managing AMR face in their everyday practices. In response to such shortcomings, and to make sense of these challenges and tensions, this article develops an ethical framework based on relationality, care ethics and ambivalence that attends to the more-than-human character of AMR. We formulate this approach without overlooking everyday challenges of implementation by putting the framework in conversation with concrete situations from precarious settings in West Africa. This article concludes by arguing that a useful AMR ethics framework needs to consider and take seriously non-human others as an integral part of both health and disease in any given ecology.

Virulence attitude estimation of Pasteurella multocida isolates in embryonated chicken eggs

A total of 220 birds of age ranging from 3 to 14 weeks old were collected from several backyards and different farms in Sharkia Governorate, Egypt, and surveyed for the presence of fowl cholera. Twenty Pasteurella multocida from chickens (15/145, 10%) and ducks (5/75, 6%) were bacteriologically isolated, and it was shown that the infection was significantly related to age and breed. Capsular typing, using multiplex polymerase chain reaction (PCR), demonstrated that all strains were type A (100%). Disk diffusion assay towards ten antimicrobials revealed high susceptibilities to amikacin, doxycycline, chloramphenicol, and neomycin with varying degrees. Doxycycline was effective at the lowest concentration (MIC 0.125-1 µg/ml). Multidrug resistance was detected with a percentage of 25%. Multidrug-resistant isolates (five isolates) were subjected to study their pathogenicity in embryonated chicken eggs (ECE). The results showed a variation in indices between different dilutions of the tested strains. The resulting pathogenicity indices showed significant differences (P < 0.05) according to the origin and dilution of the isolate. From the original inoculum to 10^-4 dilutions, the mortality of inoculated embryos occurred within 1-2 days with pathological findings, including maceration and lesions on chorioallantoic membrane (CAM). From dilutions ranging from 10^-5 to 10^-9, no death occurred until 7 days post-inoculation, but a variation in the lesions on CAM was observed. In conclusion, P. multocida serogroup A could be intensely pathogenic for mature chickens thus causing considerable economic losses, and PCR provides a suitable technique for early and rapid diagnosis of fowl cholera.

A retrospective analysis of antimicrobial resistance in pathogenic Escherichia coli and Salmonella spp. isolates from poultry in Uganda

There are increasing reports of antimicrobial treatment failures for bacterial diseases of poultry in Uganda. The paucity of data on antimicrobial resistance (AMR) of pathogenic bacteria in Uganda is a major setback to AMR control. This study investigated the occurrence of fowl typhoid, colibacillosis, and AMR in associated pathogens from 2012 to 2018. Laboratory records from the Central Diagnostic Laboratory (CDL), a National Veterinary Diagnostic Facility located at Makerere University, were reviewed. Archived isolates of the causative bacteria for the two diseases were also evaluated for AMR. The frequencies of the two disease conditions, their clinical and necropsy presentations and the demographic data of the diagnostic samples were summarized from the records. Archived bacterial isolates were revived before antimicrobial susceptibility testing. This was done on Mueller Hinton agar using the disk diffusion method, against 16 antimicrobials of medical and veterinary importance according to the Clinical Laboratory Standards Institute guidelines. A total of 697 poultry cases were presented for bacteriological investigations in the review period. Colibacillosis and salmonellosis had prevalence rates of 39.7% (277/697) and 16.2% (113/697), respectively. A total of 63 and 92 isolates of Escherichia coli and Salmonella spp., respectively, were archived but 43 (68.3%) E. coli and 47 (51.1%) Salmonella spp. isolates were recovered and evaluated for AMR. Multidrug resistance was more frequent in E. coli (38; 88.4%) than salmonellae (25; 53.2%), (p < 0.001). The high prevalence of colibacillosis, salmonellosis and the AMR of associated pathogens warrants immediate institution of appropriate disease control measures.

Prevalence and antimicrobial susceptibility profiles of non-typhoidal Salmonella isolated from chickens in Rajshahi, Bangladesh

Salmonellosis in poultry is an important disease that seriously impedes the development of the poultry industry. The increased resistance to antimicrobials against Salmonella has been a major public health concern worldwide. We conducted a study from January to June 2016 in and around the Rajshahi district of Bangladesh on the commercial chicken to isolate, identify and characterize poultry-specific Salmonella, to assess the potential risk factors and to determine the antimicrobial resistance pattern of the isolates. The overall prevalence of Salmonella enterica was 41% (49/120) [95% CI: 31.95%-50.17%] with 41.7% in broiler chicken (25/60) [95% CI: 29.06%-55.12%] and 40% in layer chicken (24/60, 40%) [95% CI: 27.56%-53.46%]. Samples collected from Rajshahi city (OR = 1.37, 95% CI: 0.50-3.73) and Puthia Upazila (OR = 1.51, 95% CI: 0.56-4.12) were more likely to be positive for Salmonella than Charghat Upazila. Salmonella detection was 1.3 times higher in chicken, providing loose feed than those provided ready feed. All the isolates fermented dextrose, maltose and mannitol with the production of acid and gas, but did not ferment sucrose and lactose. The isolates showed catalase, MR, citrate utilization test and TSI agar test positive, but indole and V-P tests negative. Salmonella isolates were sensitive to ciprofloxacin (90%), gentamycin (80%), amoxicillin (75%), streptomycin (70%), ampicillin (45%) and sulfamethoxazole-trimethoprim (45%), whereas highly resistant to penicillin (100%) and nalidixic acid (100%) followed by sulfamethoxazole-trimethoprim (55%), ampicillin (40%) and amoxicillin (25%). Salmonella enterica is endemic in commercial chicken production in Bangladesh with high prevalence. A considerable proportion of Salmonella isolates was found to be resistant to the majority of the common antimicrobial drugs. A good biosecurity system could be effective for the reduction of Salmonella. It is necessary to obtain universal commitments to establish prudent antibiotic use policies.

Yeast-rich mannan fractions in duck cultivation: prospects of using

Introduction. Due to the trend of avoiding antibiotics and acquiring eco-friendly products, the use of environmentally safe preparations is becoming increasingly relevant in poultry farming. Study objects and methods. We used Salmonella enteritidis and Campylobacter jejuni isolated from poultry carcasses. At the first in vitro stage, we studied the ability of mannan oligosaccharides, isolated from the cell walls of Saccharomyces cerevisiae yeast, to adsorb bacterial pathogens. At the second stage, we studied the influence of fraction on the activity, colonization and microflora composition of ducklings’ intestines. At the third stage, we determined the antagonistic activity of Bifidobacterium spp. (Bifidobacterium lactis, Bifidobacterium longum, Bifidobacterium bifidum) and Lactobacillus spp. (Lactobacillus fermentun, Lactobacillus salivarius, Lactobacillus acidophilus) against Salmonella enteritidis and Campylobacter jejuni isolates. The experiment was conducted on the ducklings of Star 53 H.Y. cross. Their diet was supplemented with probiotics, prebiotics, and their combination. Results and discussion. In vitro studies showed the ability of mannan oligosaccharides isolated from the cell walls of Saccharomyces cerevisiae yeast to adsorb Salmonella enteritidis and Campylobacter jejun. In vivo experiment showed the ability of mannan oligosaccharides to prevent colonization of poultry intestines by bacterial pathogens with type I fimbriae. Conclusion. The reisolation rate of ducks infected with Salmonella enteritidis was 53.6% lower, and those infected with Campylobacter jejuni, 66.2% lower than the control. Mannan oligosaccharides added to the diet did not affect the concentration of lactobacilli, enterococci, and anaerobic bacteria in the ducks’ intestines. A combined use of Bifidobacterium spp. and mannan oligosaccharides improved the preservation of poultry stock by 8.7%, which made it an effective way to prevent poultry salmonellosis.

Assessing the prevalence and economic significance of coccidiosis individually and in combination with concurrent infections in Pakistani commercial poultry farms

Coccidiosis is one of the most economically important diseases of the poultry, around the globe. In order to assess seasonal and age-wise prevalence of coccidiosis individually and with concurrent infections, this study was conducted on commercial poultry farms in and around Multan division, province of Punjab, Pakistan. A total of 28,126 boilers, 4,052 layers and 7,699 golden bird samples, provided by regional farmers and consultants, were examined by microscopy for the diagnosis of coccidiosis. Based on postmortem lesions, several infections including coccidiosis, viral, and miscellaneous diseases were catalogued, whereas samples were cultured to identify concurrent bacterial diseases. Cumulative analysis of this large set of samples revealed a prevalence of 14.16, 11.01, and 19.57% in broiler, layer and golden birds, respectively. Ascaridia galli (A. galli) showed a higher prevalence in layer (2.47%) compared to golden (0.21%) birds (P < 0.01). Amongst all concurrent infections investigated, bacterial infections were identified in highest percentage of samples (59.24%; P < 0.05). The age-wise and season-wise prevalence of coccidiosis and A. galli was found to be significant (P < 0.05). During the study period, an estimated of 10.69 (coccidiosis) and 0.29 (A. galli) million poultry birds were treated or provided prophylaxis and supportive therapy at Pakistani commercial poultry farms. Depending upon the prevailing market conditions, the total economic losses (treatment, prophylaxis, and supportive therapy) from coccidiosis and A. galli were estimated to be US $45,405.00 and 2,638.50, respectively, while production (weight and eggs) losses for broiler (US$ 2,750,779.00), layer and golden, young (US$ 13,974.98 and 50,228.76) and adult (US$ 104.74 and 203.77) were estimated. Unit loss of coccidiosis with concurrent diseases and intestinal worm was estimated to be US$ 0.005 and 0.01, respectively. These results highlight the potential impact of coccidiosis individually and with concurrent infections on the poultry productivity and will inform farmers, policy makers, and other governmental and non-governmental stakeholders on the use of control and management measures in containing these infections.