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Prevalence of proteases and other virulence genes in APEC associated with respiratory viral infections in broilers
2019
Asmaa A. Tolba | Azza A. El-Sawah | Salama A. S. Shany
Acute upper respiratory disease in chickens is a major cause of economic losses due to high mortality rates especially in poorly managed cases. Respiratory disease in poultry is initiated by variety of viruses, bacteria and fungi. The current study aims to investigate the prevalence of avian pathogenic E. coli (APEC), their proteases and other virulence genes in respiratory viral disease outbreaks in broiler chickens. Quantitative RT-PCR (qRT-PCR) was performed on samples from 25 farms with respiratory affections, APEC was isolated and virulence determinants in E. coli were investigated phenotypically and genotypically. E. coli was isolated from different flocks (100%, n=25). They were positive to Congo red binding (100%, n=25), iss gene (100%, n=25), iutA gene (92%, n= 23), tsh gene (24%, n=6), vat gene (20%, n=5). Presence of iss gene and CR binding proves that all isolates are APEC. Although the entire 25 APEC isolates carried more than one virulence gene; either 2 genes (n=17), 3 genes (n=7) and 4 genes (n=1), no effect of the number of genes harbored on the mortality rates in different flocks was observed. The presence of two serine proteases genes (tsh and vat) was confirmed in a total of 10 isolates (40% of the isolates) with positivity to tsh gene (24%) and vat gene (20%). qRT-PCR for detection of IBV-S1, AIV-H9, AIV-H5 and velogenic NDV-F genes revealed that 96% (n=24), 44% (n=11), 12% (n=3) and 4% (n=1) of 25 farms were positive to IBV, AIV-H9, velogenic NDV and AIV-H5, respectively. The results showed that among the 25 flocks, single viral infection was observed in 12 flocks (11 IBV and 1 AIV-H9), while mixed viral infections were detected in 13 flocks; IBV/AIV-H9 (n=9), IBV/velogenic NDV (n=3) and IBV/AIV-H9/AIV-H5 (n=1).The average mortality rate was the lowest in flocks infected with IBV, higher rates of mortality were observed in flocks infected with AIV-H9, velogenic NDV and AIV-H5. Flock age seems to affect the mortality rate in flocks infected with AIV-H9 where flocks aging 16:20, 21:25 and 26:30 days suffered from 2.38%, 8.13%, 11.48% average mortality rates, respectively.
Mostrar más [+] Menos [-]Prevalence and phylogenetic analysis of Mycoplasma synoviae strains isolated from Polish chicken layer flocks
2019
Kursa, Olimpia | Tomczyk, Grzegorz | Sawicka, Anna
Introduction: Mycoplasma synoviae (MS) is a chicken pathogen of major economic importance. Material and Methods: Between 2010 and 2016, 906 commercial layer chicken flocks in Poland were examined for MS, and the phylogenetic relationship among the strains was established. Regionally dispersed samples were collected and tested with the use of real-time PCR to detect the 16S–23S intergenic spacer region. Positive samples were also tested with LAMP and conventional PCR to detect the vlhA gene. Results: MS genetic material was detected in 265 (29%) of the tested flocks by real-time PCR, in 227 by the LAMP method and in 202 (22%) by conventional PCR. The by-year percentage of positive samples began at 34% in 2010, rose to 44% in 2012, and declined to 29% in 2016. A phylogenetic analysis of Polish M. synoviae strains using a partial sequence of the vlhA gene showed nine genotypes (A–I), the most frequently occurring being F and C. Pathogenic Polish MS field isolates (n = 27) collected from chickens with clinical signs of infection were grouped for their characteristic symptoms: respiratory for genotypes C, E, F, and I (n = 13), EAA and a drop in laying for genotypes F, E, and C (n = 12), and synovitis for genotype A (n = 2). Conclusion: These data showed the country’s isolate diversity. The high prevalence suggests the need to introduce appropriate control programmes. This is the first report of molecular epidemiological data on M. synoviae infection in layer chickens in Poland.
Mostrar más [+] Menos [-]Evaluation of a polyherbal formulation for the management of wet litter in broiler chickens: Implications on performance parameters, cecal moisture level, and footpad lesions
2019
Saravanakumar Marimuthu | Brindhalakshmi Balasubramanian | Ramasamy Selvam | Prashanth DSouza
Objective: The study was carried out to develop a wet litter model with magnesium chloride to assess the effectiveness of a polyherbal formulation (PHF) on growth performance, litter and cecal moisture (LCM) level, cecal consistency (CC) score, and footpad lesions (FPLs) score in Ross 308 broiler chickens. Materials and Methods: 1,200 one-day-old chicks were assigned into five groups: normal control, negative control [NTC; treated with 1.7% magnesium chloride hexahydrate (MgCl2.6H2O)], and three treatment groups, T1, T2, and T3, where 750, 1,000, and 2,000 gm/ton of PHF, respectively, were supplemented. All the groups were fed a basal diet until day 7. However, the NTC and treat¬ment groups were fed a diet with MgCl2 from days 8 to 42. Results: The addition of MgCl2 for 35 days worsened the growth performance traits in broilers and induced wet litter problems (FPL, high LCM, and poor CC) in the NTC group. However, PHF (750, 1,000, and 2,000 gm/ton) ameliorated the negative effect of a diet with MgCl2 on growth perfor¬mance and wet litter problems, but a better response with respect to LCM and CC was observed in 2,000 gm/ton of PHF group, followed by that in 1,000 gm/ton of PHF group and 750 gm/ton of PHF group on day 42. Conclusion: The wet litter broiler model was developed through excessive feeding of MgCl2, which caused the performance parameters to worsen and the emergence of problems associated with the wet litter. Supplementation with PHF ameliorated these problems and, therefore, it can be used for the management of wet litter in poultry. [J Adv Vet Anim Res 2019; 6(4.000): 536-543]
Mostrar más [+] Menos [-]High prevalence of ciprofloxacin and ceftriaxone resistance Salmonella in the retail chicken market of Chattogram, Bangladesh
2019
Chaudhary, Preeti Kumari | Salam, S M Abdus | Reza, Ahsanur
The present study aimed to investigate the prevalence of Salmonella and their antibiotic resistance pattern against two commonly used antibiotics: ciprofloxacin and ceftriaxone in marketed live chickens in a live birds market. Materials and methods: The study was conducted on live Sonali chickens (crossbred of Fayoumi female and Rhode Island Red male). Cloacal swabs were collected from 50 randomly selected live birds from 5 retail sellers (10 samples/seller) at Jhawtola live birds’ market, Chattogram, Bangladesh. Culture and biochemical tests were used to identify Salmonella. Positives samples for Salmonella were further tested for antibiogram by disc diffusion method.Salmonella was identified from 28 (56%) of samples by culture and biochemical test. Among the positive isolates, 27 (96.42%) samples exhibited resistant to ceftriaxone, and 20 (71.42%) samples were to ciprofloxacin.The result of this study indicates there is a high prevalence of Salmonella in marketed local chicken and are resistant to ceftriaxone and ciprofloxacin which has economic importance as well as a public health concern. Awareness should be increased to prevent random use of antibiotics and provision of strict biosecurity measures.
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