Source attribution of salmonellosis by time and geography in New South Wales, Australia

Background Salmonella is a major cause of zoonotic illness around the world, arising from direct or indirect contact with a range of animal reservoirs. In the Australian state of New South Wales (NSW), salmonellosis is believed to be primarily foodborne, but the relative contribution of animal reservoirs is unknown. Methods The analysis included 4543 serotyped isolates from animal reservoirs and 30,073 serotyped isolates from domestically acquired human cases in NSW between January 2008 and August 2019. We used a Bayesian source attribution methodology to estimate the proportion of foodborne Salmonella infections attributable to broiler chickens, layer chickens, ruminants, pigs, and an unknown or unsampled source. Additional analyses included covariates for four time periods and five levels of rurality. Results A single serotype, S. Typhimurium, accounted for 65–75% of included cases during 2008–2014 but < 50% during 2017–2019. Attribution to layer chickens was highest during 2008–2010 (48.7%, 95% CrI 24.2–70.3%) but halved by 2017–2019 (23.1%, 95% CrI 5.7–38.9%) and was lower in the rural and remote populations than in the majority urban population. The proportion of cases attributed to the unsampled source was 11.3% (95% CrI 1.2%–22.1%) overall, but higher in rural and remote populations. The proportion of cases attributed to pork increased from approximately 20% in 2009–2016 to approximately 40% in 2017–2019, coinciding with a rise in cases due to Salmonella ser. 4,5,12:i:-. Conclusion Layer chickens were likely the primary reservoir of domestically acquired Salmonella infections in NSW circa 2010, but attribution to the source declined contemporaneously with increased vaccination of layer flocks and tighter food safety regulations for the handling of eggs.

Isolation and Molecular Detection of Mycoplasma gallisepticum in Commercial Layer Chickens in Sylhet, Bangladesh

Mycoplasma gallisepticum induced poultry diseases are associated with a huge economic crisis and have a considerable impact on the poultry industry worldwide. The aim of the current study was to isolate and perform molecular detection of MG circulating pathogenic strain in the commercial layer farms in the Sylhet district of Bangladesh. The entire study was conducted from January 2018 to January 2019 at three Upazilas of Sylhet district in Bangladesh. A total of 50 dead layer chickens (indicating signs of respiratory distress before death) were collected randomly from 15 different layer farms. The tissue samples, such as air sacs, trachea, and lungs, were taken from suspected dead chickens. Both cultural and PCR-based techniques were applied to identify Mycoplasma from tissue samples. The conventional PCR technique was implemented to amplify 185 bp DNA fragments for the MG. Out of 50 samples, 36% (18/50) and 70% (35/50) of MG were identified by cultural method and PCR, respectively. Based on the results of the study, it can be concluded that PCR is an easier, more sensitive, and less time-consuming method for the early diagnosis of MG in chickens, compared to cultural isolation and hence can lower the economic burden to poultry farmers caused by this disease.

ISOLATION METHODS FOR MOLECULAR DETECTION AND ANTIBIOTIC RESISTANCE PATTERN OF CAMPYLOBACTER SPP IN LAYER CHICKENS

This study was conducted to compare two culture methods for the isolation of Campylobacter spp from commercial layer chickens and subsequently confirmed by Polymerase Chain Reaction assays (PCR). Furthermore, the antimicrobial resistance profiles of PCR positive Campylobacter isolates were determined.Cloacal swab samples (550) from chickens randomly selected from five poultry farms in the four geographical zones in Ogun State were cultured for Campylobacter using modified charcoal Cefoperazone deoxycholate agar (MCCDA) and an improved culture method involving Preston broth pre-enrichment and subsequent subculture on Mueller Hinton agar with Campylobacter growth supplements. Putative isolates were later confirmed by PCR assay and sequencing analysis.Other isolates that grew on MCCDA and confirmed by sequencing analysis are Enterococcus faecalis, Escherichis coli, Comamonas kerstli and Pseudomonas aeroginusa . The antibiotic resistant profile of all the isolates were evaluated genotypically for resistance genes to tetracyclines (tetO), multiclasses (cmeB), aminoglycosides (aphA-3-1) and β-lactams (Blaoxa-61) using multiplex PCR (mPCR), and phenotypically for chlortetracycline, tylosin, streptomycin, ciprofloxacin and erythromycin resistance by microbroth dilution method which correspond to the antibiotic resistance genes. The apparent prevalence of Campylobacter was 16.8% by MCCDA while none of the isolates was positive to PCR. Meanwhile, prevalence rate of 26% was obtained using Preston broth pre-enrichment and Mueller Hinton agar with Campylobacter growth supplements, of which 11/50 (22%) of the isolates was confirmed positive by PCR. Genotypic characterization of PCR positive isolates showed 10/11(90%) were C. coli, 1/11(10%) other Campylobacter species and 0% C. jejuni. All the isolates carried both tetO and cmeB resistant genes. The results of minimum inhibitory concentration presented all PCR positive isolates had resistance of 10/10(100%), 9/10(90%), 6/10(60%), 9/10(90%), and 8/10(80%) to tetracycline, ciprofloxacin, erythromycin, spectinomycin and tylosin respectively. In addition, all isolates carried multiple resistance to most antibiotics tested which are commonly used in poultry practice in Nigeria. Campylobacter spp in the study areas showed diverse genotypic characteristics, and gene mediated multidrug resistance.

Prevalence and molecular detection of infectious laryngotracheitis virus in chickens in selected areas of Bangladesh

Infectious laryngotracheitis (ILT) is a viral disease of poultry species caused by infectious laryngotracheitis virus (ILTV) that shows high morbidity and mortality. The present study was under taken for ILTV prevalence in broiler and layer chickens from four different geographical areas including Bogura, Gazipur, Chattogram and Dhaka districts during 2017 to 2018. Total 350 tracheal swabs were collected and were evaluated by real time RT-PCR (rRT-PCR). The overall 5.14% (18/350) ILTV prevalence was found that included 6.5% (13/200) in layer and 3.33% (5/150) in broiler chickens. The prevalence of ILTV was highest (10%) in layer chickens under age below 20 weeks and broiler chicks showed ILTV (1. 42%) infection when they were 7-14 days old. Winter season showed highest 6.6% prevalence whereas 5% and 3% prevalence were noticed at summer and rainy seasons, respectively. Bang. J. Livs. Res. Vol. 27 (1&2), 2020: P. 113-117

A novel whole yeast-based subunit oral vaccine against Eimeria tenella in chickens

Cheap, easy-to-produce oral vaccines are needed for control of coccidiosis in chickens to reduce the impact of this disease on welfare and economic performance. Saccharomyces cerevisiae yeast expressing three Eimeria tenella antigens were developed and delivered as heat-killed, freeze-dried whole yeast oral vaccines to chickens in four separate studies. After vaccination, E. tenella replication was reduced following low dose challenge (250 oocysts) in Hy-Line Brown layer chickens (p<0.01). Similarly, caecal lesion score was reduced in Hy-Line Brown layer chickens vaccinated using a mixture of S. cerevisiae expressing EtAMA1, EtIMP1 and EtMIC3 following pathogenic-level challenge (4,000 E. tenella oocysts; p<0.01). Mean body weight gain post-challenge with 15,000 E. tenella oocysts was significantly increased in vaccinated Cobb500 broiler chickens compared to mock-vaccinated controls (p<0.01). Thus, inactivated recombinant yeast vaccines offer cost-effective and scalable opportunities for control of coccidiosis, with relevance to broiler production and chickens reared in low-and middle-income countries (LMICs).

Seroprevalence and associated risk factors of mycoplasmosis in layer chickens at southern region of Bangladesh

Mycoplasma gallisepticum (MG) is the most important pathogenic Mycoplasma spp. causing avian mycoplasmosis and brought about huge economic losses to poultry industry in Bangladesh. The present study was undertaken to know the seroprevalence of MG in layer birds in three different geographical areas of southern Barishal division, Bangladesh. Total 310 sera samples were collected from wing vein of 30 farms for this study. Sera samples were tested with Rapid Serum Agglutination (RSA) for MG using commercial Antigen Kit (manufactured by Lillidale Diagnostic) to detect the presence of antibodies against MG. The overall seroprevalence of MG by RSA was 36.13%. Seroprevalence of MG infection was dominant in winter season (45.54%) and significantly highest occurrence was recorded in age groups from 20-40 weeks of layer chickens (51.79%). Serological investigation in three different upazila of Barishal division showed the highest infection rate (45.26%) in medium scale flocks (1000-3000) in comparison to (21.43%) small (<1000) flocks. The seroprevalence of MG was highest in Swarupkathi (44.38%) than in Barishal Sadar (26%) and Banaripara upazila (28%). Biosecurity and managemental failure is the overall risk factor in all types of farm due to lack of proper knowledge among farmer. This study reveals the current scenario of mycoplasmosis in layer birds of three different areas of Barishal division. Asian J. Med. Biol. Res. 2021, 7 (3), 292-297

Source Attribution of Salmonellosis by Time and Geography in New South Wales, Australia

BackgroundSalmonella is major cause of zoonotic illness around the world, arising from direct or indirect contact with a range of animal reservoirs. In the Australian state of New South Wales (NSW), salmonellosis is believed to be primarily foodborne, but the relative contribution of animal reservoirs is unknown.MethodsThe analysis included 4,543 serotyped isolates from animal reservoirs and 30,073 serotyped isolates from domestically acquired human cases in NSW between January 2008 and August 2019. We used a Bayesian source attribution methodology to estimate the proportion of foodborne Salmonella infections attributable to broiler chickens, layer chickens, ruminants, pigs, and an unknown or unsampled source. Additional analyses included covariates for four time periods and five levels of rurality.ResultsA single serotype, S. Typhimurium, accounted for 65-75% of included cases during 2008-2014 but <50% during 2017-2019. Attribution to layer chickens was highest during 2008-2010 (48.7%, 95%CrI: 24.2-70.3%) but halved by 2017-2019 (23.1%, 95%CrI: 5.7-38.9%) and was lower in the rural and remote populations than in the majority urban population. The proportion of cases attributed to the unsampled source was 11.3% (95%CrI: 1.2%–22.1%) overall, but higher in rural and remote populations. The proportion of cases attributed to pork increased from approximately 20% in 2009-2016 to approximately 40% in 2017-2019 coinciding with a rise in cases due to S. ser 4,5,12:i:-.Conclusion Layer chickens were likely the primary reservoir of domestically acquired Salmonella infections in NSW circa 2010, but attribution to the source declined contemporaneously with increased vaccination of layer flocks and tighter food safety regulations for the handling of eggs.

The Impact of Effective Microorganisms (EM) on Egg Quality and Laying Performance of Chickens

Chickens kept under modern production system are very small and contribute less than 2% of eggs and meat production in Ethiopia. In some parts of the country, effective microorganism (EM) has been used as a means of improving egg and meat production. However, there is information gap on the use and effect of EM on egg quality and laying performance of chickens in the local context. This study was conducted in Aksum University’s poultry farm located at the main campus in Axum, to evaluate egg laying performance and quality of eggs in layer chickens treated with effective microorganisms in feed and water. In this experiment, 180 pullets of ISA Brown chickens with uniform age and weight were used and managed in a cage system. Chickens were subjected to 4 treatments with 3 replications, and each replication consisted of 15 chickens. Data collection was started at the first egg lay. Data including feed intake, conversion ratio, and age at first laying, laying percentage, and egg quality parameters were collected. Statistical analysis was carried out using JMP. Chickens fed with EM in feed and drinking water had higher egg production percentage. There was a significant difference in egg laying percentage between the treated and control groups ( P < 0.001 ). Eggs from chickens given EM in feed and water were 6% heavier in weight than those from control birds. Lower feed daily intake (115.5 gram) and feed conversion rate (2.05) were achieved in chickens treated with EM in feed and water. Significant improvement on egg quality was revealed in chickens that received EM in feed and water. From this experiment, it can be concluded that the use of EM in feed and water improves egg production in layer chickens and therefore recommended for medium-scale poultry farms in Northern Ethiopia.