[Salmonella spp., important pathogenic agent transmitted through foodstuffs]

Ecological prevalence, genetic diversity, and multidrug resistance of Salmonella enteritidis recovered from broiler and layer chicken farms

Salmonella is a significant foodborne pathogen that has a significant impact on public health, and different strains of multidrug resistance (MDR) have been identified in this genus. This study used a combination of phenotypic and genotypic approaches to identify distinct Salmonella species collected from poultry broiler and layer farms, and antibiotic sensitivity testing was performed on these species. A total of 56 Salmonella isolates were serotyped, and phenotypic antibiotic resistance was determined for each strain. The enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) method was also used to provide a genotypic description, from which a dendrogram was constructed and the most likely phylogenetic relationships were applied. Salmonella isolates were detected in 20 (17%) out of 117 samples collected from small-scale broiler flocks. Salmonella isolates were classified as MDR strains after showing tolerance to 4 antibiotics, but no resistance to cloxacillin, streptomycin, vancomycin, or netilmicin was observed. From a genotypic perspective, these strains lack dfrD, parC, and blasfo-1 resistant genes, while harboring blactx-M, blaDHA-L, qnrA, qnrB, qnrS, gyrA, ermA, ermB, ermC, ermTR, mefA, msrA, tet A, tet B, tet L, tet M resistance genes. The genotyping results obtained with ERIC-PCR allowed isolates to be classified based on the source of recovery. It was determined that Salmonella strains displayed MDR, and many genes associated with them. Additionally, the ERIC-PCR procedure aided in the generation of clusters with biological significance. Extensive research on Salmonella serotypes is warranted, along with the implementation of long-term surveillance programs to monitor MDR Salmonella serotypes in avian-derived foods.

Recent Developments in Lateral Flow Assays for Salmonella Detection in Food Products: A Review

Salmonellosis is a disease transmitted by contaminated food and is one of the leading causes of infections worldwide, making the early detection of Salmonella of crucial importance for public health. However, current detection methods are laborious and time-consuming, thus impacting the entire food supply chain and leading to production losses and economic sanctions. To mitigate these issues, a number of different biosensors have been developed, including lateral flow assays (LFAs), which have emerged as valuable tools in pathogen detection due to their portability, ease of use, time efficiency, and cost effectiveness. The performance of LFAs has been considerably enhanced by the development of new nanomaterials over the years. In this review, we address the principles and formats of the assay and discuss future prospects and challenges with an emphasis on LFAs developed for the detection of different Salmonella serovars in food.

Microbiological evaluation of homemade mayonnaise and self-serve acai sold in Araguaína, Tocantins

Foodborne diseases are common illnesses caused by the consumption of food contaminated with microorganisms, such as viruses, fungi, bacteria, and protozoa. Every year, 600 million people become ill and 420,000 people die as a result of consuming contaminated food. Therefore, food safety is an important issue. In this study, samples of homemade spiced mayonnaise and self-serve acai sold in the city of Araguaína, Tocantins, Brazil were analyzed for microbiological contaminants. Acai was collected from 10 stores, one sample from each store, and tested for mold, yeast, and coliforms, as well as coliform identification and total and thermotolerant coliform counts. Mayonnaise was collected from 20 snack bars, one sample from each. These samples were inoculated on MacConkey and Salmonella Shigella agar plates, and the plates were analyzed for growth. Salmonella spp. were detected in some Mayonnaise samples, and coliforms were detected in all acai samples; 60% of samples had thermotolerant coliforms, and only 40% were within the limits established by ANVISA. The collected samples of mayonnaise and acai were contaminated with molds and yeasts above the established limit of 103 CFU/g. Thus, the analyzed mayonnaise and acai samples were contaminated and unfit for consumption, demonstrating the importance of hygienic-sanitary measures in food handling.

Monitoring of Antimicrobial Resistance of Salmonella Serotypes Isolated from Humans in Northwest Italy, 2012-2021

Salmonella enterica is among the most common causes of foodborne outbreaks in humans in Europe. The global emergence of resistance to antimicrobials calls for close monitoring of the spread and prevalence of resistant Salmonella strains. In this study, we investigated the occurrence of antimicrobial resistance of Salmonella serotypes isolated from humans between 2012 and 2021 in Piedmont, northwest Italy. A total of 4814 Salmonella strains (168 serotypes) were tested against six classes of antimicrobials. Many strains (83.3%) showed resistance to at least one antibiotic: tetracycline (85.1%), ampicillin (79.2%), quinolones (47.4%), and gentamicin (28.4%). Between the first (2012-2016) and the second study period (2017-2021), a decrease in antimicrobial resistance was noted for tetracycline (from 92.4% to 75.3%), ampicillin (from 85.3% to 71.3%), quinolones (from 49.4% to 44.6%), and cefotaxime (from 34.8% to 4.0%). Many multidrug resistant Salmonella strains (43.6%) belonged to S. ser. Typhimurium, S. ser. Infantis, and S. ser. Typhimurium 1,4,[5],12:i:-. Overall, multidrug resistance decreased from 60.7% to 26.4%, indicating a reduction in the antimicrobial resistance of Salmonella strains in Piedmont and in Europe and demonstrating the effectiveness of the measures that were put in place to reduce antimicrobial resistance.

Detection of invA virulence gene of multidrug-resistant Salmonella species isolated from the cloacal swab of broiler chickens in Blitar district, East Java, Indonesia

Background and Aim:

The increasing number of multidrug-resistant (MDR) Salmonella species on poultry farms in Indonesia has caused concern regarding human health. This study was conducted to determine the presence of the virulence gene invA in MDR Salmonella species isolated from the cloacal swab of broiler chickens in Blitar district, East Java Province, Indonesia.

Materials and Methods:

Cloacal swab samples were collected by purposive sampling from 15 farms in four districts. Isolation and identification of bacteria were performed using standard microbiological techniques. Confirmation of MDR isolates was done using five different classes of antibiotics, including the beta-lactam, aminoglycoside, fluoroquinolone, phenicol, and monobactam groups. An antibiotic susceptibility test was conducted using the Kirby–Bauer disk diffusion method, and a polymerase chain reaction method was used to screen for the presence of invA.

Results:

It was observed that 32.26% (50/155) of the samples were positive for Salmonella species. Of these 50 Salmonella isolates, 7 (14%) were identified as MDR strains. An important finding was the detection of invA in all the seven MDR Salmonella strains (100%) isolated from the cloacal swab of broiler chickens in Blitar district, East Java Province.

Conclusion:

Veterinarians have an extremely important role in monitoring the use of antibiotics in farm animals to mitigate the rapid spread of MDR organisms in our environment, which can otherwise cause serious economic losses and also public health issues.

Infection agents of Didelphidae (Didelphimorphia) of Brazil: an underestimated matter in zoonoses research

Zoonoses are diseases or infections naturally transmissible from vertebrate animals to humans, and can be bacterial, viral or parasitic. The growth of urbanization, industrialization and the advance of agriculture and livestock facilitate the spread of infectious and parasitic agents from wild animals to the human population and to their domestic animals. Among the various reservoirs of zoonotic agents, we find that didelphid species, due to their high capacity for adaptation in urban environments, as an important study case. We reviewed the literature data on the pathogens, including with zoonotic potential of marsupial species occurring in Brazil, accounted for infections by agents that we categorized into Bacteria, Viruses, Protozoa, and Helminths. Aiming identifies possible knowledge gaps, we also surveyed the origin of studied samples and the institutions leading the researches on host didelphids. Among the hosts, the genus Didelphis in the cycles of these agents stands out. Moreover, we found that the majority of reported cases are in the Southeastern Brazil, mean the data from other Brazilian localities and didelphid species could be underestimated. Most studies took place in graduate programs of public research institutions, emphasizing the importance of the funding public research for the Brazilian scientific development.

An Overview of the Antimicrobial Activity of Polymeric Nanoparticles Against Enterobacteriaceae

Bacterial resistance is considered one of the most important public health problems of the century, due to the ability of bacteria to rapidly develop resistance mechanisms, which makes it difficult to treat infections, leading to a high rate of morbidity and mortality. Based on this, several options are being sought as an alternative to currently available treatments, with a particular focus on nanotechnology. Nanomaterials have important potential for use in medical interventions aimed at preventing, diagnosing and treating numerous diseases by directing the delivery of drugs. This review presents data on the use of polymeric nanoparticles having in vitro and in vivo activity against bacteria belonging to the Enterobacteriaceae family.

Formação de biofilmes e resistência a antimicrobianos de isolados de Salmonella spp

Resumo O presente estudo avaliou a presença de Salmonella spp. em 89 amostras de produtos cárneos comercializados na região sul do Rio Grande do Sul e, a partir dos isolados obtidos, foi verificada a capacidade de resistência a agentes antimicrobianos e de formação de biofilme em superfícies de poliestireno. Foi constatada a presença de Salmonella spp. em 19,1% das amostras avaliadas e, dos isolados obtidos, 40% mostraram resistência a pelo menos um dos agentes antimicrobianos testados e 33,3% manifestaram-se multirresistentes. Apenas o antimicrobiano amicacina (30 µg) foi eficaz na inibição de todos os isolados testados. Nenhum isolado mostrou-se capaz de formar biofilmes em superfícies de poliestireno.

Worldwide Epidemiology of Salmonella Serovars in Animal-Based Foods: a Meta-analysis

Salmonella spp. are among the most important foodborne pathogens and the third leading cause of human death among diarrheal diseases worldwide. Animals are the primary source of this pathogen, and animal-based foods are the main transmission route to humans. Thus, understanding the global epidemiology of Salmonella serovars is key to controlling and monitoring this bacterium. In this context, this study aimed to evaluate the prevalence and diversity of Salmonella enterica serovars in animal-based foods (beef, pork, poultry, and seafood) throughout the five continents (Africa, the Americas [North and Latin America], Asia, Europe, and Oceania). The meta-analysis consisted of a chemometric assessment (hierarchical cluster analysis and principal component analysis) to identify the main epidemiological findings, including the prevalence and diversity of the Salmonella serovars in each matrix. Regarding the serovar distribution, S Typhimurium presented a cosmopolitan distribution, reported in all four assessed matrices and continents; poultry continues to play a central role in the dissemination of the Enteritidis serovar to humans, and Anatum and Weltevreden were the most frequently found in beef and seafood, respectively. Additionally, we recommended careful monitoring of certain serovars, such as Derby, Agona, Infantis, and Kentucky. Finally, given the scientific data regarding the most frequently reported serovars and which matrices constitute the main vehicles for the transmission of this pathogen, control programs may be improved, and specific interventions may be implemented in an attempt to reduce the risk of this pathogen reaching humans.IMPORTANCE Salmonellosis is caused by Salmonella spp. and is the third leading cause of death among food-transmitted diseases. This pathogen is commonly disseminated in domestic and wild animals, and the infection's symptoms are characterized by acute fever, nausea, abdominal pain, and diarrhea. The animals are the primary source of salmonellae, and animal-based foods are the main transmission route to humans. Therefore, data collected from these sources could contribute to future global interventions for effective control and surveillance of Salmonella along the food chain. In light of this, the importance of our research is in identifying the prevalence of Salmonella serovars in four animal-based food matrices (pork, poultry, beef, and seafood) and to evaluate the importance that each matrix has as the primary source of this pathogen to humans.

Irradiation of reduced-sodium uncooked lamb sausage: antimicrobial efficacy and physicochemical impact

Excess sodium in food is associated with an increased risk of noncommunicable diseases. Faced with this reality, consumers are becoming aware of the importance of eating foods with reduced sodium content. This work assesses the effects of partial replacement of NaCl by KCl on the microbiological and physicochemical characteristics of uncooked lamb sausage treated with different doses of gamma radiation. Analyses of thermotolerant coliforms, sulfite-reducing Clostridium, Salmonella sp., protein, moisture, ash, lipids, pH, water activity, and color were performed. The results showed that the formulations with reduced sodium content did not differ significantly concerning microbial growth and met the identity and quality standards considering its physicochemical characteristics. Also, irradiation is efficient as a microbiological control method, and the ± 3-kGy dose was the most effective to eliminate pathogenic bacteria present in the sausage formulation prepared with reduced sodium content, inducing less intense changes in physicochemical parameters.

QUALIDADE MICROBIOLÓGICA DE PRODUTOS DE ORIGEM ANIMAL ENCAMINHADOS PARA ALIMENTAÇÃO ESCOLAR

Resumo Doenças Transmitidas por Alimentos (DTA) estão associadas ao consumo de alimentos e água contaminados por microrganismos patogênicos, sendo alguns desses grupos utilizados como indicadores dos cuidados higiênico-sanitários e empregados nos produtos de origem animal (POA). O objetivo foi avaliar a qualidade higiênico-sanitária dos POA encaminhados para alimentação escolar no município de Pelotas, Rio Grande do Sul, Brasil. As coletas foram realizadas no posto de distribuição da Secretaria de Educação. Foram coletadas cinco amostras de todos os lotes de leite UHT, bebida láctea e filés de frango que deram entrada no período de onze meses, totalizando cinquenta e cinco amostras. Os produtos foram avaliados quanto aos padrões microbiológicos da Agência Nacional de Vigilância Sanitária (ANVISA). Além dessas análises foram realizadas pesquisa da presença de Campylobacter e de Salmonella nos produtos de frango. Foi aplicada uma lista de verificação das boas práticas de armazenamento. Todas as amostras estavam dentro dos padrões microbiológicos admitidos pela ANVISA, entretanto Salmonella foi detectada em quatro amostras de filés de frango. Campylobacter não foi isolado de nenhuma amostra. As condições de armazenamento foram consideradas ruins, apresentando 72,4% de não conformidades, especialmente nos quesitos temperatura e condições de armazenamento. A presença de Salmonella pode oferecer risco à saúde das crianças que venham a consumir filé de frango.

Investigation of resistance of Salmonella spp. isolated from products and raw material of animal origin (swine and poultry)to antibiotics and disinfectants

ABSTRACT The genus Salmonella spp. Has worldwide geographical distribution, and represents a potential risk both to animal and human health. Inadequate use as well as continuous exposure to antibiotics and disinfectants might lead to the appearance of resistance of these microorganisms to antimicrobial compounds. The aims of this study were to investigate the occurrence of resistance in Salmonella spp., isolated from products and raw material of animal origin (swine and poultry), to antibiotics and disinfectants, and check whether the phenomenon of simultaneous resistance to disinfectants occurs among the antibiotic-resistant isolates. The test of susceptibility to antimicrobials (TSA) applied in 134 isolates indicated that 51 (38%) were resistant to at least one of the eight antibiotics used, and 28 (55%) of resistant isolates were multi-resistant. Resistant isolates were submitted to the test of quantitative suspension against four concentrations of disinfectants in three contact times, and the result was compared with that of the reference strain (Salmonella Choleraesuis ATCC 10.708). While the reference strain was sensitive considering the highest concentration (200 ppm) and the lowest contact time (5 min) as indicators, 12 (24%) isolates were resistant to cetyltrimethylammonium chloride (ammonia quaternary); the reference strain was resistant to chlorhexidine, which also occurred with 22 (43%) of the isolates; similar to the reference strain, all isolates were sensitive/inactivated by sodium hypochlorite and iodophore. There were no significant relations of simultaneous resistance between the antibiotics and the disinfectants tested.

Combined effects of oregano essential oil and salt on the growth of Escherichia coli in salad dressing

There is a broad research interest in the search for alternatives to chemical additives for use as natural food preservatives. Although many natural compounds have biological in vitro properties evidenced, in situ studies are still scarce. This study evaluated the effect of oregano essential oil (OEO) and salt (NaCl) concentrations against Escherichia coli (ATCC 8739), in salad dressing, using the response surface methodology. The experiment included a 2² central composite rotatable design (CCRD) in a total of 11 formulations of salad dressings. Oregano essential oil was characterized by gas chromatography and salad dressings by ash, lipids, proteins and moisture. OEO was composed mainly by carvacrol (65.1%) and p-cymene (12.0%). Salad dressings showed similar chemical profiles. A mathematical model for the prediction of the antibacterial activity in salad dressing was obtained. The results revealed that the interaction between OEO and salt showed effect on the bacterial count. However, the effect of salt was negative suggesting that the highest NaCl concentrations decreases the bacterial count. Therefore, within the parameters studied, the use of OEO to control E. coli in salad dressing can be considered promising and allows reduction in the levels of salt to be incorporated in food.

Age influence on quality of shell and penetration in bacterial laying lightweight eggs

ABSTRACT This study evaluated the influence of the bird’s age on the quality of the shell and percentage of bacterial penetration in commercial eggs. White-shelled commercial eggs were used, laid by light laying hens in their first laying cycle at 21, 39, 51, and 62 weeks of age. Shell quality evaluations comprised: egg weight, specific gravity, percentage and thickness of shell, number and size of pores. For evaluations regarding bacterial penetration, strains of several enterobacterias and one salmonella were used, all of which resistant to Nalidixic acid (100µg/ml). The method employed for evaluation of bacterial penetration was filling the eggs with growth medium. The data were subjected to variance analysis with 5% of probability using SAS (Education Analytical Software, 2013). Eveb though increase in the laying hen's age caused reduction of the quality of eggshells, it failed to affect the percentage of penetration of the bacterial samples evaluated.

Segurança dos alimentos: contaminação por Salmonella sp. no abate de suínos

Resumo Este estudo teve o objetivo de avaliar a contaminação de carcaças suínas por Salmonella sp. em oito pontos específicos, no processo de abate de suínos, identificando a ocorrência e o motivo dessas contaminações. A pesquisa foi realizada em um frigorífico do Estado do Rio Grande do Sul, no período de abril a agosto de 2014. As amostras foram coletadas a partir de esfregaços, utilizando a técnica da esponja abrasiva em quatro regiões anatômicas na superfície da carcaça. A análise estatística foi realizada através do teste Qui-Quadrado. Trinta e três carcaças foram submetidas à coleta amostral, totalizando 258 amostras coletadas em todos os pontos. A partir da análise microbiológica, obteve-se uma frequência total de isolamento de Salmonella sp. igual a 7,75% do total de amostras. De acordo com os resultados das análises estatísticas, não há diferença significativa entre os pontos amostrados, uma vez que as diferenças dos valores encontrados para o número de carcaças contaminadas por Salmonella sp. são baixas, mesmo comparando os pontos de maior contaminação com os de menor contaminação. O maior percentual de isolamento microbiano foi encontrado após a escaldagem e a depilação (ponto A), com 17,85%. Os pontos B (após o toalete externo), C (seguido da abertura do abdômen) e E (imediatamente após a serragem das carcaças) apresentaram 10% de contaminantes cada. Os pontos F (antes da lavagem final das carcaças) e H (após 24 horas de resfriamento) tiveram valores de 6,89%, seguidos pelo ponto G (imediatamente após a lavagem final das carcaças, antes do resfriamento), com 3,33%. O menor valor de contaminação foi encontrado no ponto D (após a liberação do rabo), com 3,1%. Assim, de acordo com os pontos amostrados, o frigorífico avaliado possui condições higienicossanitárias satisfatórias, de acordo com padrões estabelecidos internacionalmente e programas de controle, que favorecem as boas práticas de fabricação e avaliação dos pontos críticos de controle.

Effects of 5-hydroxytryptophan and m-hydroxybenzylhydrazine associated to Lactobacillus spp. on the humoral response of broilers challenged with Salmonella Enteritidis

This study investigates the effects of different doses of serotonin, its precursor 5-hydroxytry-ptophan (5HTP), and m-hydroxybenzylhydrazine inhibitor (NSD1015), administered via intraperitoneal for 5 consecutive days, on behavior and average body weight of broilers. We also measured the humoral immune response and quantification of Salmonella Enteritidis in broilers chickens that received the drugs evaluated and a Lactobacillus pool. The study was divided into 3 experiments: Experiment 1--administration of pharmaceuticals with choice of dosage; Experiment 2--administration of pharmaceuticals and a Lactobacillus pool in birds that were not challenged with S. Enteritidis, and Experiment 3--administration of pharmaceuticals and a Lactobacillus pool in birds challenged with S. Enteritidis. The ELISA was used to scan dosages of intestinal IgA and serum IgY. We used colony-forming units to quantify S. Enteritidis. The concentrations of IgA and IgY did not show significant differences (P>0.05) in Experiment 2. In Experiment 3, NSD1015 associated with Lactobacillus determined higher IgA concentrations, promoting greater stimulus to the immune system than 5HTP. Regarding quantification of S. Enteritidis in the cecal content of birds, 5HTP associated to Lactobacillus determined the smallest number of bacteria, showing possible interaction of 5-hydroxytryptophan and Lactobacillus spp. with the immune system of broiler chickens.

SALMONELLA TYPHIMURIUM EM LINFONODOS MESENTÉRICOS DE OVINOS AO ABATE

RESUMO O rebanho de ovinos no Brasil está estimado em mais de 16 milhões de cabeças. Embora o consumo da carne desta espécie ainda seja pequeno, comparado ao de outros países, o consumo de carne, inclusive ovina, tem sido associado às doenças transmitidas por alimentos, em especial a salmonelose. No presente estudo, investigou-se a ocorrência de salmonelas em linfonodos mesentéricos e conteúdo intestinal de 175 ovinos ao abate. “Pools” constituído por cinco amostras de contéudo fecal ou 5 amostras de linfonodos de 25 g foram pre-enriquecidos em 250 mL de água peptonada tamponada e incubados a 37° C por 18-24 horas. Uma alíquota de 0,1 mL do pré-enriquecimento foi transferida para 9,9 mL de caldo de enriquecimento Rappaport-Vassiliadis e 1,0 mL do pré-enriquecimento foi transferido para 10 mL de caldo tetrationato Muller-Kaufmann, incubados a 42° C for 24h. 10 μL do caldo de enriquecimento foi semeado superfície de placas de ágar BPLS e ágar XLT4 incubadas a 37º C for 24-48h. Colônias suspeitas de salmonela foram testadas por provas bioquímicas e serologicas. Os testes bioquímicos utilizados para identificação de Salmonella foram TSI (triple sugar iron àgar), LIA (lysine iron àgar) e ágar ureia. Sorotipagem foi realizada no Laboratório de Enterobactérias do Instituto Osvaldo Cruz. Isolou-se Salmonella Tiphymurium de um pool de linfonodos mesentéricos, provenientes de cinco animais. O fato de se observar a ocorrência de salmonela em ovino portador sadio alerta para necessidade de monitorar este micro-organismo também nesta espécie, especialmente quando destinada ao abate, com vistas à produção de alimentos seguros.