Biofilm formation capacity of Salmonella serotypes at different temperature conditions / Capacidade de produção de biofilme por cepas de diferentes sorovares de Salmonella em quatro temperaturas de incubação

Salmonella spp. are one of the most important agents of foodborne disease in several countries, including Brazil. Poultry-derived products are the most common food products, including meat and eggs, involved in outbreaks of human salmonellosis. Salmonella has the capacity to form biofilms on both biotic and abiotic surfaces. The biofilm formation process depends on an interaction among bacterial cells, the attachment surface and environmental conditions. These structures favor bacterial survival in hostile environments, such as slaughterhouses and food processing plants. Biofilms are also a major problem for public health because breakage of these structures can cause the release of pathogenic microorganisms and, consequently, product contamination. The aim of this study was to determine the biofilm production capacity of Salmonella serotypes at four different temperatures of incubation. Salmonella strains belonging to 11 different serotypes, isolated from poultry or from food involved in salmonellosis outbreaks, were selected for this study. Biofilm formation was investigated under different temperature conditions (37°, 28°, 12° and 3°C) using a microtiter plate assay. The tested temperatures are important for the Salmonella life cycle and to the poultry-products process. A total of 92.2% of the analyzed strains were able to produce biofilm on at least one of the tested temperatures. In the testing, 71.6% of the strains produced biofilm at 37°C, 63% at 28°C, 52.3% at 12°C and 39.5% at 3°C, regardless of the serotype. The results indicate that there is a strong influence of temperature on biofilm production, especially for some serotypes, such as S. Enteritidis, S. Hadar and S. Heidelberg. The production of these structures is partially associated with serotype. There were also significant differences within strains of the same serotype, indicating that biofilm production capacity may be strain-dependent.(AU)

Salmonella spp. são um dos mais importantes agentes causadores de doenças transmitidas por alimentos em vários países, inclusive no Brasil. Produtos avícolas e ovos são os principais alimentos envolvidos na transmissão dos sorovares de Salmonella que são responsáveis por surtos de salmonelose em humanos. Salmonella possui a capacidade de formar biofilmes em diversas superfícies. O processo de formação de biofilme depende da interação entre as células bacterianas, a superfície de adesão e as condições do ambiente onde a bactéria se encontra. Estas estruturas favorecem a sobrevivência bacteriana em ambientes hostis, como em matadouros-frigoríficos e em indústrias processadoras de alimentos. Biofilmes são um grande problema em saúde pública, pois a ruptura destas estruturas pode provocar a liberação de microrganismos patogênicos e, consequentemente, a contaminação dos produtos. O objetivo deste estudo foi avaliar a capacidade de produção de biofilme por diferentes sorovares de Salmonella submetidos a quatro temperaturas de incubação. Cepas de Salmonella de 11 sorovares foram selecionadas. A produção de biofilme foi avaliada através do método de incubação em microplacas de poliestireno incubadas a 37°, 28°, 12° e 3°C. Estas temperaturas são importantes durante o ciclo de vida de Salmonella e para o processamento de produtos avícolas. Do total de cepas avaliadas, 92,2% foram capazes de produzir biofilme em pelo menos uma das quatro temperaturas testadas. Neste estudo, 71,6% das cepas produziram biofilme a 37°C, 63% a 28°C, 52,3% a 12°C e 39,5% a 3°C, independentemente do sorovar. Os resultados indicam uma forte influência da temperatura na produção de biofilme, especialmente para os sorovares S. Enteritidis, S. Hadar e S. Heidelberg. A produção de biofilme está parcialmente associada com o sorovar da cepa. Também foi observado que existe variação quanto à produção destas estruturas dentro de um mesmo sorovar, indicando que possivelmente a produção de biofilme é cepa-dependente.(AU)

Willingness and influencing factors related to "centralized slaughtering, fresh poultry listing and marketing" strategy among the household chefs in Guangzhou / 中华流行病学杂志

Objective: To study the willingness and influence factors related to "centralized slaughtering, fresh poultry listing and marketing" strategy, among the household chefs, and provide reference for government to adjust and optimize the strategy on avian influenza prevention. Methods: According to the geographical characteristics and regional functions, 6 'monitoring stations' were selected from 12 residential districts of Guangzhou, respectively. Another 21 meat markets which selling live poultry, were selected in each station and 5 household chefs of each market were invited to attend a face to face interview. Basic information, personal cognitive, willingness and influencing factors to the policy were under study. Univariate and multivariate logistic regression methods were used. Results: A total of 664 household chefs underwent the survey and results showed that the rate of support to the "centralized slaughtering, fresh poultry listing and marketing" strategy was 44.6% (296/664). Results from the multi-factor logistic regression showed that those household chefs who were males (OR=1.618, 95% CI: 1.156-2.264, P=0.005), having received higher education (OR=1.814, 95% CI: 1.296-2.539, P=0.001), or believing that the existence of live poultry stalls was related to the transmission of avian influenza (OR=1.918, 95% CI: 1.341-2.743, P<0.001) were factors at higher risk. These household chefs also intended to avoid the use of live poultry stalls (OR=1.666, 95%CI: 1.203-2.309, P=0.002) and accept the "centralized slaughtering, fresh poultry listing and marketing" strategy. Conclusion: Detailed study on this subject and, setting up pilot project in some areas as well as prioritizing the education programs for household chefs seemed helpful to the implementation of the 'freezing-fresh poultry' policy.

A case of human infection with highly pathogenic avian influenza A (H7N9) virus through poultry processing without protection measure / 中华流行病学杂志

Objective: To investigate the infection pattern and etiological characteristics of a case of human infection with highly pathogenic avian influenza A (H7N9) virus and provide evidence for the prevention and control of human infection with highly pathogenic avian influenza virus. Methods: Epidemiological investigation was conducted to explore the case's exposure history, infection route and disease progression. Samples collected from the patient, environments and poultry were tested by using real time reverse transcriptase-polymerase chain reaction (RT-PCR). Virus isolation, genome sequencing and phylogenetic analysis were conducted for positive samples. Results: The case had no live poultry contact history, but had a history of pulled chicken processing without taking protection measure in an unventilated kitchen before the onset. Samples collected from the patient's lower respiratory tract, the remaining frozen chicken meat and the live poultry market were all influenza A (H7N9) virus positive. The isolated viruses from these positive samples were highly homogenous. An insertion which lead to the addition of multiple basic amino acid residues (PEVPKRKRTAR/GL) was found at the HA cleavage site, suggesting that this virus might be highly pathogenic. Conclusions: Live poultry processing without protection measure is an important infection mode of "poultry to human" transmission of avian influenza viruses. Due to the limitation of protection measures in live poultry markets in Guangzhou, it is necessary to promote the standardized large scale poultry farming, the complete restriction of live poultry sales and centralized poultry slaughtering as well as ice fresh sale.

Avian Influenza A [H5N1] in Egypt

Between February and March 2016, the Ministry of Health and Populations of Egypt reported 4 new human cases of avian influenza A [H5N1] infection to WHO. These are the new human cases reported in 2016 after the surge of human cases observed in 2015 in the country. With this, a total of 350 human cases of avian influenza A [H5N1] including 117 deaths [CFR: 33.4%] were reported in Egypt since 2006

Active surveillance of avian influenza viruses in Egyptian poultry, 2015

Surveillance for avian influenza viruses in Egyptian poultry has been conducted since 2009. Up to 2011, all the detected viruses were H5N1, and the overall prevalence was 5%. In 2011, H9N2 viruses were observed to be co-circulating and co-infecting the same hosts as H5N1 viruses. Since then, the detection rate has increased to around 10%. In the 2014-2015 winter season, H5N1 was circulating heavily in poultry flocks and caused an unprecedented number of human infections. In contrast, surveillance in the last quarter of 2015 indicated a near absence of H5N1 in Egyptian poultry. Surveillance for avian influenza viruses must continue in Egypt to monitor further developments in H5N1 circulation in poultry

Monitoring and molecular characterization of group Drotavirus in brazilian poultry farms / Monitoramento e caracterização molecular de rotavírus do grupo D em criações comerciais brasileiras

Rotaviruses are etiological agents of diarrhea both in humans and in several animal species. Data on avian Group D rotaviruses (RVD) are scarce, especially in Brazil. We detected RVD in 4 pools of intestinal contents of broilers, layer and broiler breeders out of a total of 111 pools from 8 Brazilian states, representing an occurrence of 3.6%, by a specific RVD RT-PCR targeting the VP6 gene. Phylogenetic tree confirmed that the Brazilian strains belong to group D and 3 of the sequences were identical in terms of amino acid whereas one showed 99.5% identity with the others. The sequences described in this study are similar to other sequences previously detected in Brazil, confirming the conserved nature of the VP6 protein.

Rotavírus são agentes etiológicos de diarreia tanto em humanos como em várias espécies animais. Dados sobre rotavírus do grupo D (RVD) em aves são escassos, especialmente no Brasil. Nós detectamos RVD em 4 pools de conteúdo intestinal de frango de corte, poedeiras e matrizes de um total de 111 pools originários de 8 estados brasileiros, representando uma ocorrência de 3,6% a partir de uma RT-PCR específica para RVD, tendo como alvo o gene VP6. A árvore filogenética confirmou que as amostras brasileiras pertencem ao grupo D e três das sequências obtidas foram idênticas em termos de aminoácidos enquanto uma apresentou 99,5% de identidade com as demais. As sequências aqui definidas são semelhantes a outras sequências previamente definidas no Brasil, confirmando a natureza conservada da proteína VP6.

[Pathogenicity indices of Newcastle disease viruses isolated from Iranian poultry flocks in Iran]

Newcastle disease [ND] is caused by serotype I of avian paramyxoviruses. The ND virus [NDV] strains are conveniently grouped as velogenic, mesogenic, lentogenic, and nonpathogenic-intestinal pathotypes. The purpose of this study was to determine the pathogenicity indices of the isolated NDVs from poultry flocks in Iran. Samples were provided from poultry flocks in different provinces of Iran and prepared for NDV isolation. From many isolated NDVs, 12 isolates belonged to 10 provinces with highly populated poultry farms which were selected for this study. A clone for each of these virus isolates was generated using limiting dilution procedure. Then, the mean death time [MDT], intracerebral pathogenicity index [ICPD, and intravenous pathogenicity index [IVPI] were determined for each virus clone and compared with those of standard virulent strains such as Hertz 33.56 and Texas GB. The results showed that the pathogenicity indices of the NDVs in the present study ranged from 41.6 - 60 hr for MDT, 1.76 - 1.91 for ICPI, and 2.68- 2.88 for IVpI indicate which the velogenic type of our viruses. The findings of this study suggested that the very virulent NDVs currently circulating in Iranian poultry flocks are close to and even more virulent than standard virulent NDVs. Isolation, identification, pathotype determination, and molecular characterization of Iranian NDVs may help authorities to make right decisions to reduce the risks posing the Iranian poultry industry

Antibodies specific to infectious bronchitis in broilers in Ceará state, Brazil

The experiment was carried out to determine the antibody levels to infectious bronchitis virus (IBV) in 1120 broilers of two broiler flocks, both from the same parental flock and free from previous vaccination. Forty chicks of each line were alloted to the control group and the sera were tested by indirect ELISA. The vaccination program consisted on the administration of commercial vaccines against IBV at 10 and 25 days of age. Chicks with low levels of maternal antibodies (Mab) did not show significant titers to the first vaccinal stimulus. They presented a vaccinal response to the second vaccinal stimulus reaching the top around GMT 1100 at 45 days. Chicks with high Mab titers did not show significant titers to the primary and secondary vaccinal stimuli, reaching peak levels of GMT 500 at 45 days. No antibody response was detected after the primary vaccination at day 10. A delayed antibody response was detected after the secondary vaccination on day 25, indicating no previous priming. The maternal antibody titers can interfere on the response to the first and second vaccinal stimulus promoting the neutralization of the first vaccination and a different response to the second one, according to high or low maternal antibodies.

Utilizaram-se 1120 pintos de um dia de idade, de duas linhagens, não vacinados, para determinar os níveis de anticorpos para o vírus da bronquite infecciosa (VBI) em frangos de corte no estado do Ceará. Quarenta aves de cada linhagem, colocadas em boxes isolados e não vacinadas, foram usadas como controle. As aves vacinadas contra VBI aos 15 e 25 dias foram submetidas a coletas de sangue periódicas para avaliação, pelo ELISA indireto, dos títulos de anticorpos para VBI. As aves com baixos títulos de anticorpos maternos (AcM) não apresentaram títulos significativos ao primeiro estímulo vacinal; para o segundo estímulo, o pico de resposta de GMT 1100 ocorreu aos 45 dias. As com elevado título de AcM não responderam significativamente à primeira vacinação e o pico de resposta ao segundo estímulo de GMT 500 ocorreu aos 45 dias. Não se verificou resposta de anticorpos para o primeiro estímulo vacinal, observando-se resposta tardia somente para o segundo. Os AcM podem ter interferido tanto no primeiro quanto no segundo estímulo, promovendo neutralização da primeira vacinação e resposta diferenciada para a segunda de acordo com o nível, elevado ou baixo, de AcM.

On the need to assess cancer risk in populations environmentally and occupationally exposed to virus and chemical agents in developing countries

Existe evidência de que exposiçäo a vírus oncogênicos de aves possa produzir elevada mortalidade de câncer em populaçöes humanas, havendo particularmente excesso de câncer de pulmäo e dos sistemas linfáticos e hemopoiéticos. Até o momento, esse risco potencial é desconhecido em populaçöes dos países em desenvolvimento. Sugere a necessidade de avaliar o risco de câncer em populaçöes dos países em desenvolvimento com sabida exposiçäo a produtos avícolas e ovos; a necessidade de avaliar o risco de câncer em populaçöes que foram inoculadas com vacinas desenvolvidas em embriöes de aves contaminadas e a necessidade de avaliar o risco de câncer em populaçöes de trabalhadores com grande exposiçäo a vírus oncogênico de aves, e com potencial exposiçäo simultânea a agentes químicos que säo reconhecidos ou suspeitos carcinógenos.