Broiler Poultry Farms Research Articles

Molecular characterization of motile serovars of Salmonella enterica from breeder and commercial broiler poultry farms in Bangladesh.

Contaminated poultry and poultry products are a major source of motile Salmonellae for human salmonellosis worldwide. Local circulation of any motile Salmonella serovar in poultry has a wider public health impact beyond its source of origin for being dispersed elsewhere through poultry trades or human travels. To investigate the status of motile Salmonella serovars in breeder farms in Bangladesh, multiple flocks of two breeder farms were observed for a period of six months. In addition, a cross-sectional survey was carried out to determine the prevalence and serovar distribution of motile Salmonella by randomly selecting 100 commercial broiler poultry farms. Five pooled faecal samples representing an entire housed flock of breeders or broilers were screened for presence of motile Salmonella following conventional bacteriological procedures. The Salmonella isolates obtained were subsequently serotyped, and characterized by plasmid profiling and pulsed-field gel electrophoresis (PFGE). The results revealed that both the breeder farms were positive with three Salmonella serovars: S. Virchow, S. Paratyphi B var Java (S. Java) and S. Enteritidis. Eleven of the 100 broiler farms investigated were positive for motile Salmonella, giving a farm-level prevalence of 11% (95% confidence interval 5–17%). S. Virchow and S. Kentucky were the two predominant serovars isolated from the broiler farms. The PFGE genotyping demonstrated that the isolates belonging to the same serovars were closely related due to variation in only 1–4 bands. All the S. Virchow and S. Java isolates, irrespective of breeder or broiler farm origin, were plasmid-free, except for one S. Virchow isolate from a broiler farm that harboured a 9.7 kb-sized plasmid. The S. Kentucky isolates belonged to three plasmid profiles having plasmids of four different sizes, ranging from 2.7 to 109 kb. This is the first report of any motile Salmonella serovars from breeder and commercial broiler poultry farms in Bangladesh.

Genetic analysis of Newcastle disease virus from Punjab, Pakistan

The strains of Newcastle disease virus (NDV) were isolated from five suspected outbreaks of ND in broiler (n = 3) and layers (n = 2) poultry farms. The egg-isolated viruses were subjected to biological and genetic characterization. Based on the biological characterization, isolates showed haemagglutination titer ≥log 2(7), mean death time <55 h, intracerebral pathogenecity index ≤1.8, and egg lethal dose 50 from 10(-7.15) to 10(-9.31)/1 ml. Genetic characterization of the fusion (F) gene revealed that the isolates clustered with NDV strains of genotype VII (VIIf) within class II, which remained predominant genotype in the domestic poultry of Asia. The deduced amino acid sequence of the isolates confirmed virulent motif (112)RRQKRF(117) at the F protein cleavage site. A bioinformatics and pairwise comparison approach was applied to estimate the synonymous and non-synonymous substitution rates (dN/dS) and selective evolutionary pressure for the F protein. The dN/dS calculated for genotype VII indicate purifying selection, which resulted in a low evolution rate in F gene. The F protein shows a strong negative pressure throughout the length of the protein and no recombination event was determined. Collectively, the results suggest that very similar virulent strains of NDV are involved during current wave of disease outbreak throughout the country. From these results, in conjunction with our recent reports of NDV from Pakistan, it is possible to conclude that emergence of novel group may require revisiting the diagnostics and vaccine control strategies.

A survey on the prevalence of poultry salmonellosis and detection of different Salmonella serovars isolated from poultry in broiler chicken farms

Salmonellosis is an important public health problem and food of poultry origin is one of the most common sources of human salmonellosis. The aim of this study was detection of Salmonella spp and determination of the prevalence of Salmonellosis in broiler poultry farms of Ardebil province, Iran. Salmonella detection by both conventional culture and multiplex PCR methods were performed on 400 samples obtained from poultry. The samples were obtained from poultry farms of five different geographic zones (North, South, West, East and Central zone) of Ardebil province and were examined by standard microbiological tests. m-PCR technique was carried out with four and three pairs of specific primers for Salmonella typhimurium and Salmonella enteritidis respectively. Out of a total of 400 samples, 37(9.25%) were positive for Salmonella by bacteriological tests. The highest prevalence of Salmonella was recorded in Central zone (10.43%) while the lowest prevalence was in South zone of Ardebil province (8%). Based on the m-PCR results among 37 isolated Salmonella, 11 serovars were S. typhimurium and 21 serovars were identified as S. enteritidis. Also, there was no significant difference between the prevalence rate of Salmonella in five different selected areas (P>0.05). For control and prevention programs of salmonellosis, the results of this study can be used by agriculture and health organizations in Iran. Key words: m-PCR, ardebil, salmonellosis, poultry.

Prevalence and Distribution of Salmonella in Organic and Conventional Broiler Poultry Farms

The objective of this cross-sectional study was to compare the prevalence of Salmonella and antimicrobial-resistant Salmonella, as well as investigate the distribution of this pathogen in organic and conventional broiler poultry farms. Fecal (n = 420), feed (n = 140), and drinking water (n = 140) samples were collected from birds at 3 and 8 weeks of age for 2-flock cycles. One house was sampled per farm at three organic and four conventional broiler farms from the same company in North Carolina. All samples were analyzed for the presence of Salmonella using selective enrichment techniques. Further phenotypic (antimicrobial susceptibility) and genotypic (pulsed-field gel electrophoresis [PFGE]) testing were performed. Salmonella prevalences in fecal samples were 5.6% (10/180) and 38.8% (93/240) from organic and conventional farms, respectively. From feed, 5.0% (3/60) and 27.5% (22/80) of the samples were positive for Salmonella from organic and conventional farms, respectively. None of the water samples were positive for Salmonella. Seventy isolates were characterized by antimicrobial susceptibility and PFGE types. The two most common resistance phenotypes were single resistance to streptomycin (36.2% [25/58]: conventional; 25% [3/12] organic), and multidrug resistance to six antimicrobial agents: ampicillin-streptomycin-amoxicillin/clavulanic acid-cephalothin-ceftiofur-cefoxitin (AmStAxChCfFx; 39.7%: conventional only). Genotypic analysis using PFGE showed clonality among isolates within and between the two types of farms. The results of our study suggest that within this poultry company, the prevalence of fecal Salmonella was lower in certified-organic birds than in conventionally raised birds, and the prevalence of antimicrobial-resistant Salmonella was also higher in conventionally raised birds than in certified-organic birds.

Contribution of Company Affiliation and Social Contacts to Risk Estimates of Between-Farm Transmission of Avian Influenza

BackgroundModels of between-farm transmission of pathogens have identified service vehicles and social groups as risk factors mediating the spread of infection. Because of high levels of economic organization in much of the poultry industry, we examined the importance of company affiliation, as distinct from social contacts, in a model of the potential spread of avian influenza among broiler poultry farms in a poultry-dense region in the United States. The contribution of company affiliation to risk of between-farm disease transmission has not been previously studied.Methodology/Principal FindingsWe obtained data on the nature and frequency of business and social contacts through a national survey of broiler poultry growers in the United States. Daily rates of contact were estimated using Monte Carlo analysis. Stochastic modeling techniques were used to estimate the exposure risk posed by a single infectious farm to other farms in the region and relative risk of exposure for farms under different scenarios. The mean daily rate of vehicular contact was 0.82 vehicles/day. The magnitude of exposure risk ranged from <1% to 25% under varying parameters. Risk of between-farm transmission was largely driven by company affiliation, with farms in the same company group as the index farm facing as much as a 5-fold increase in risk compared to farms contracted with different companies. Employment of part-time workers contributed to significant increases in risk in most scenarios, notably for farms who hired day-laborers. Social visits were significantly less important in determining risk.Conclusions/SignificanceBiosecurity interventions should be based on information on industry structure and company affiliation, and include part-time workers as potentially unrecognized sources of viral transmission. Modeling efforts to understand pathogen transmission in the context of industrial food animal production should consider company affiliation in addition to geospatial factors and pathogen characteristics. Restriction of social contacts among farmers may be less useful in reducing between-farm transmission.

Experimental assessment of rodent control on two poultry farms of central Argentina

SUMMARY We experimentally assessed the effect of controlling vegetation height along farm perimeters on the abundance of rodents in 2 broiler poultry farms in central Argentina. We carried out an experimental design based on the before-after–control-impact method. After vegetation treatments, there was a significant decrease in rodent abundance at the perimeter of the farm with control of vegetation height because of the reduction of the Pampean grassland mouse Akodon azarae. In poultry houses, there was a significant decrease in rodent abundance on nonaffected farms because of the reduction of the commensal house mouse Mus musculus domesticus, possibly because of a major collocation of rodenticide. Our results indicate that both the control of vegetation growth at the perimeters and the appropriate timing of rodenticide applications are effective measures for rodent control on broiler poultry farms when both control measures are applied simultaneously. We achieved effective rodent control through an understanding of the habitat use and population dynamics of the species involved and the characteristics of the area where the control program would be applied.

Characterization of Vancomycin-Resistant Enterococcus faecium Isolates from Broiler Poultry and Pig Farms in England and Wales

This study aimed to investigate the occurrence and molecular epidemiology of vancomycin-resistant Enterococcus faecium (VREF) isolates on poultry and pig farms in England and Wales. A total of 217 VREF isolates were obtained from fresh feces and environmental swabs collected from conventional and organic farms. A predominant pulsed-field gel electrophoresis (PFGE) profile was found for each VREF-positive farm, together with less frequent types. All isolates presented the vanA genotype and were esp negative. Seventy-six percent of the VREF isolates were additionally resistant to nine or more antimicrobials, presenting a diverse range of resistance phenotypes. The multiresistance traits did not appear to be specific to individual farms or sample types (i.e., environmental or fecal), nor did they correlate with any specific PFGE type. Ninety-three percent of the isolates were resistant to penicillin, 89% were resistant to tetracycline, 87.5% were resistant to erythromycin, and 50% were resistant to quinupristin-dalfospristin (Synercid). The lack of clonality among these populations may suggest the horizontal transfer of resistance genes and/or a dynamic replacement of clonal lines rather than persistence.

An adenovirus infection of poultry in Pakistan.

Summary: A previously unknown disease which has spread among broiler poultry farms in Pakistan, attacks well-growing chicks at 3-5 weeks of age, with 30 to 60% mortality. At necropsy, the most prominent lesion is hydropericardium. Lungs are congested and oedematous, and liver and kidneys are pale and swollen. Histologically, there was necrosis and severe vascular changes in the heart as well as congestion, oedema and inflammatory cell infiltration in the lungs. Focal necrosis and mononuclear cell infiltration were present in the liver and many hepatocytes contained large, basophilic, intranuclear inclusions. The disease was reproduced in 15-day-old broiler chicks by subcutaneous inoculation of liver homogenate. The liver homogenate also caused stunted growth and haemorrhages when inoculated into embryonating eggs. Virus particles with icosahedral symmetry were seen by electron microscopy in purified liver extract. The disease is believed to be caused by a hitherto unreported adenovirus. However, the role of some other potentiating factor cannot be ruled out at this stage.