RESUMO
There is still considerable controversy about the relative risk of mycotoxin exposure associated with the consumption of organic and conventional cereals. Using validated protocols, we carried out a systematic literature review and meta-analyses of data on the incidence and concentrations of mycotoxins produced by Fusarium, Claviceps, Penicillium, and Aspergillus species in organic and conventional cereal grains/products. The standard weighted meta-analysis of concentration data detected a significant effect of production system (organic vs. conventional) only for the Fusarium mycotoxins deoxynivalenol, with concentrations â¼50% higher in conventional than organic cereal grains/products (p < 0.0001). Weighted meta-analyses of incidence data and unweighted meta-analyses of concentration data also detected small, but significant effects of production system on the incidence and/or concentrations of T-2/HT-2 toxins, zearalenone, enniatin, beauvericin, ochratoxin A (OTA), and aflatoxins. Multilevel meta-analyses identified climatic conditions, cereal species, study type, and analytical methods used as important confounding factors for the effects of production system. Overall, results from this study suggest that (i) Fusarium mycotoxin contamination decreased between the 1990s and 2020, (ii) contamination levels are similar in organic and conventional cereals used for human consumption, and (iii) maintaining OTA concentrations below the maximum contamination levels (3.0 µg/kg) set by the EU remains a major challenge.
Assuntos
Grão Comestível , Contaminação de Alimentos , Micotoxinas , Grão Comestível/química , Grão Comestível/microbiologia , Micotoxinas/análise , Contaminação de Alimentos/análise , Fusarium/química , Alimentos Orgânicos/análise , Alimentos Orgânicos/microbiologiaRESUMO
Antimicrobial resistance (AMR) is a recognized global public health concern. Although the link between antimicrobial usage in food animals and AMR in humans is established, the detailed interactions are unclear. Antimicrobial stewardship (AMS) in livestock was first implemented in Europe with Sweden as the pioneer in 1986. Despite this head start, AMR is still an ongoing challenge for Europe. The European Union (EU) is an established agriculture producer, the second largest pork producer globally, and one of the largest markets for organic food. China is the global leader in both production and consumption of pork. China's rise in prosperity has led to an increase in its pork demand. Chinese producers commonly use antimicrobials during production for disease treatment and prevention to meet this increased demand. China's rising prosperity together with recent publicized food safety scandals, disease outbreaks in domestic livestock products, and increased AMR awareness have resulted in an increased willingness to pay and demand for organic food by Chinese consumers. Responding to the growing concerns of AMR by consumers and the World Health Organization (WHO), the Chinese government introduced a national pilot program in 2016 to reduce unnecessary antimicrobial use. Compared with China, the EU is a different entity as it is a political union comprising diverse countries and although it may have more experience in AMS, both entities face similar issues with AMR and increasing demand for organic food. Increased interest in organic food has arisen due to concerns about AMR, food safety, outbreaks of bacterial food contamination, and animal welfare. This article aims to compare the different AMS strategies employed by each entity, China and the EU, and how the increased demand for organic produce globally also influences the effort to reduce antimicrobial use in these entities' pork industries.
Assuntos
Gestão de Antimicrobianos/métodos , Microbiologia de Alimentos/métodos , Inocuidade dos Alimentos/métodos , Agricultura Orgânica/métodos , Carne de Porco/microbiologia , Criação de Animais Domésticos/legislação & jurisprudência , Criação de Animais Domésticos/métodos , Animais , Gestão de Antimicrobianos/legislação & jurisprudência , China , Resistência Microbiana a Medicamentos , Europa (Continente) , União Europeia , Microbiologia de Alimentos/legislação & jurisprudência , Alimentos Orgânicos/microbiologia , Humanos , Gado/microbiologia , Avaliação de Programas e Projetos de Saúde , Suínos/microbiologiaRESUMO
The objective of this study was to compare the prevalence and antimicrobial resistance (AMR) rates of Campylobacter spp. isolated from conventional and organic turkey meat sold at retail in Germany. Samples of conventional (N = 527) and organic (N = 245) fresh turkey meat without skin were collected at retail markets throughout Germany and tested for Campylobacter spp.. Campylobacter isolates were tested for resistance to six antimicrobials (gentamicin, streptomycin, ciprofloxacin, nalidixic acid, erythromycin, and tetracycline) using broth microdilution. Prevalence of Campylobacter spp. was higher in organic (32.7%) than in conventional (19.4%) turkey meat. The proportion of fully susceptible isolates was lower in Campylobacter coli (6.8%) than in Campylobacter jejuni (33.9%) and higher in isolates from organic (38.4%) than from conventional production (17.4%). Overall, resistance rates were the highest to ciprofloxacin, nalidixic acid, and tetracycline. Resistance to erythromycin was only observed in C. coli and resistance to gentamicin was absent. Overall, resistance rates to tetracycline and fluoroquinolones were higher in isolates from conventional (60.9% and 78.9%) than from organic meat (32.9% and 58.9%, respectively). However, this significant difference was only observed for C. jejuni, but not for C. coli. Further studies are needed to identify the reasons for the differences in the association of production type of turkeys with AMR in the different Campylobacter spp. and the critical parameters for the reduction of AMR in Campylobacter from turkey meat.
Assuntos
Campylobacter/isolamento & purificação , Farmacorresistência Bacteriana , Carne/microbiologia , Perus/microbiologia , Animais , Antibacterianos/farmacologia , Campylobacter/efeitos dos fármacos , Alimentos Orgânicos/microbiologia , Alemanha , Testes de Sensibilidade MicrobianaRESUMO
Shiga toxin-producing Escherichia coli (STECs) contamination of produce, as a result of contact with ruminant fecal material, has been associated with serious foodborne illness. Bacteriophages (phages) that infect STECs have primarily been reported to be of cattle origin. However, they likely exist in other environments or in animals that share habitats with cattle, such as goats. To explore the presence and diversity of phages specific to STEC O157 and the top six non-O157 STECs in goat-associated environments, environmental samples consisting of feces (goat and cattle) and soil samples were collected monthly for six months from an organic produce farm. A variety of phages belonging to the Myoviridae, Siphoviridae, and Podoviridae families were isolated from all goat fecal and half of the soil samples. The most commonly isolated phages belonged to Myoviridae and were lytic against STEC O103. The isolated phages had different host ranges, but collectively, showed lytic activity against O157 and the top six non-O157 STEC strains excluding O121. Two non-O157 STECs (O174: H21 and O-antigen-negative: H18) were isolated from soil and cattle feces, respectively. Although prior studies have reported that goats shed STEC into the environment, the findings of the current study suggest that goat feces may also contain lytic STEC-specific phages. The phages of goat origin have the capacity to infect STECs implicated in causing foodborne outbreaks, making them potential candidates for biocontrol pending additional characterization steps. Further work is needed to determine if the addition of goats to the farm environment could potentially reduce the presence of STECs.
Assuntos
Bacteriófagos/isolamento & purificação , Fezes/virologia , Cabras/microbiologia , Escherichia coli Shiga Toxigênica/virologia , Criação de Animais Domésticos/métodos , Animais , Bacteriófagos/genética , California , Bovinos/microbiologia , DNA Viral/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Fazendas , Alimentos Orgânicos/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Microbiologia do SoloRESUMO
INTRODUCTION: The gut microbiota plays a role in gut-brain communication and can influence psychological functioning. Diet is one of the major determinants of gut microbiota composition. The impact of unpasteurised dairy products on the microbiota is unknown. In this observational study, we investigated the effect of a dietary change involving intake of unpasteurised dairy on gut microbiome composition and psychological status in participants undertaking a residential 12-week cookery course on an organic farm. METHODS: Twenty-four participants completed the study. The majority of food consumed during their stay originated from the organic farm itself and included unpasteurised milk and dairy products. At the beginning and end of the course, participants provided faecal samples and completed self-report questionnaires on a variety of parameters including mood, anxiety and sleep. Nutrient intake was monitored with a food frequency questionnaire. Gut microbiota analysis was performed with 16S rRNA gene sequencing. Additionally, faecal short chain fatty acids (SCFAs) were measured. RESULTS: Relative abundance of the genus Lactobacillus increased significantly between pre- and post-course time points. This increase was associated with participants intake of unpasteurised milk and dairy products. An increase in the faecal SCFA, valerate, was observed along with an increase in the functional richness of the microbiome profile, as determined by measuring the predictive neuroactive potential using a gut-brain module approach. CONCLUSIONS: While concerns in relation to safety need to be considered, intake of unpasteurised milk and dairy products appear to be associated with the growth of the probiotic bacterial genus, Lactobacillus, in the human gut. More research is needed on the effect of dietary changes on gut microbiome composition, in particular in relation to the promotion of bacterial genera, such as Lactobacillus, which are recognised as being beneficial for a range of physical and mental health outcomes.
Assuntos
Dieta/métodos , Microbioma Gastrointestinal , Lactobacillus/isolamento & purificação , Transtornos Mentais/microbiologia , Leite/microbiologia , Adolescente , Adulto , Animais , Encéfalo/microbiologia , Laticínios/microbiologia , Fezes/microbiologia , Feminino , Alimentos Orgânicos/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fenômenos Fisiológicos do Sistema Nervoso , Pasteurização , RNA Ribossômico 16S/isolamento & purificação , Adulto JovemRESUMO
Poultry is one of the most consumed meats worldwide and there are many different types of poultry products available on the market for consumers. Many poultry producers provide a variety of labeled meats based on rearing system such as organic, free-range and antibiotic-free. However, these labels often can be misleading by implying organic products are better in safety and quality compared to poultry products without additional labels. In this study, the microbiological profiles of commercial poultry products were characterized via a next generation sequencing. A variety of poultry products including whole carcass, leg, breast and thigh were purchased from local markets and subdivided by labels indicating organic, non-antibiotic, free range and no-label. According to the microbiome analysis based on the 16S rRNA gene, similar level of species richness were observed in comparison by labels, however, different parts and producers exhibited significant differences. Also, microbial similarities among groups were measured and most samples showed relatively close clustering based on the poultry part and the producer. The results emphasize potential contamination routes and the importance of the control strategy during the pre-harvest step of poultry products. The results also envision potential opportunities to improve current production procedure being utilized by industries.
Assuntos
Bactérias/classificação , Alimentos Orgânicos/microbiologia , Microbiota , Produtos Avícolas/microbiologia , Aves Domésticas/microbiologia , Animais , Bactérias/isolamento & purificação , Galinhas/microbiologia , Sequenciamento de Nucleotídeos em Larga Escala , RNA Ribossômico 16S/genéticaRESUMO
Dados de vigilância epidemiológica apontam uma crescente associação entre o consumo de hortaliças e surtos de origem alimentar. São inúmeras as fontes de contaminação aos quais os vegetais estão sujeitos ao longo da cadeia produtiva. Estudos sugerem que práticas agrícolas, como o uso de adubo constituído por esterco animal e água de irrigação não tratada, podem aumentar o risco de contaminação por micro-organismos patogênicos. Com as restrições ao uso de pesticidas sintéticos no sistema orgânico de produção agrícola, agentes de controle biológico, como Bacillus thuringiensis (Bt) desempenham um importante papel para a garantia da produtividade. No entanto, recentemente, a segurança do uso de Bt passou a ser questionada em função da possibilidade de produzir enterotoxinas. Este estudo teve por objetivos levantar dados sobre práticas adotadas no cultivo de hortaliças orgânicas no Estado de São Paulo, Brasil e sobre as características microbiológicas de fertilizantes, água de irrigação, água de lavagem e alfaces nas etapas pré e pós-colheita, assim como avaliar a persistência e interações entre Bt e Salmonella em hortaliças, visando contribuir para avaliações de risco microbiológico mais adequadas. Na primeira parte do estudo, dez propriedades de cultivo orgânico certificadas foram visitadas para a obtenção de dados sobre práticas adotadas e para a coleta de amostras para análise microbiológica. As amostras foram submetidas à enumeração e identificação (gênero e espécie) de Enterobacteriaceae; pesquisa de Salmonella spp. por método convencional e qPCR; e enumeração de coliformes totais e Escherichia coli nas amostras de água. Na segunda fase da pesquisa, avaliou-se a persistência e as interações entre Bt e Salmonella Montevideo no pré e pós-colheita de espinafres. Por fim, bactérias epifíticas isoladas de hortaliças foram testadas quanto a capacidade de inibir bactérias do grupo Bacillus cereus e cepas de Salmonella enterica. As contagens de Enterobacteriaceae variaram de <1 a 7,2 ± 0,1 log UFC/g nos fertilizantes, de 4,1 ± 0,3 a 5,6 ± 0,3 log UFC/g nas alfaces coletadas nos canteiros, de 2,9 ± 0,6 a 5,3 ± 0,5 log UFC/g nas alfaces lavadas, de <1 a 3,5 ± 0,1 log UFC/mL nas amostras de água de irrigação e de <1 a 3,0 ± 0,3 log UFC/mL nas amostras de água de lavagem. Salmonella não foi isolada por cultivo em placa, mas foi detectada por qPCR em uma amostra de alface orgânica lavada. Utilizando MALDI-TOF MS, 45 espécies pertencentes a 24 gêneros bacterianos foram identificadas na cadeia produtiva de hortaliças orgânicas. Bt foi capaz de persistir nas folhas de espinafre nas etapas pré e pós-colheita e afetou a persistência de Salmonella durante o cultivo, mas não durante o armazenamento pós-colheita a 12 ºC. Não foi observada tendência de germinação dos esporos de Bt após a aplicação nos espinafres, reduzindo assim a possibilidade de multiplicação e produção de enterotoxinas. A bactéria epifítica Pseudomonas chlororaphis, isolada de hortaliça, foi capaz de inibir membros do grupo Bacillus cereus, incluindo cepas patogênicas e Bt em testes in vitro, sugerindo uma barreira biológica para o controle da multiplicação destes micro-organismos. Este estudo traz importantes informações sobre a segurança microbiológica de hortaliças orgânicas e de práticas agrícolas, evidenciando a importância de boas práticas para a promoção do alimento seguro. Os resultados constituem uma importante contribuição para o desenvolvimento de modelos de avaliação de risco microbiológico e prevenção de surtos de origem alimentar
Epidemiological surveillance data indicate a growing association between vegetable consumption and food-borne outbreaks. There are numerous sources of contamination to which plants are subjected throughout the production chain. Studies suggest that agricultural practices such as the use of manure fertilizer and untreated irrigation water may increase the risk of contamination by pathogenic microorganisms. With the restrictions on the use of synthetic pesticides in the organic farming system, biological control agents such as Bacillus thuringiensis (Bt), play an important role in ensuring productivity. However, the safety of Bt has recently been questioned due to the possibility of producing enterotoxins. This study aimed to gather information about the agricultural practices employed in the organic vegetables production fields and the microbiological characteristics of fertilizer, irrigation water, wash water, and lettuces in pre and post-harvest stages, and to evaluate the persistence and interactions between Bt and Salmonella on leafy greens, aiming to contribute for more adequate microbiological risk assessments. In the first part of the study, ten certified organic farms were visited to collect data on the farming practices and for collection of samples for microbiological evaluations. The samples were submitted to Enterobacteriaceae enumeration and identification (genus and species); Salmonella spp. by conventional method and qPCR; and enumeration of total coliforms and Escherichia coli in water samples. In the second part of the study, the persistence and interaction between Bacillus thuringiensis subsp Aizawai (Bt) and Salmonella Montevideo in the pre and post-harvest of spinach were evaluated. Finally, epiphytic bacteria isolated from vegetables were tested for their ability to inhibit growth of Bacillus cereus group members and Salmonella strains. Enterobacteriaceae counts ranged from <1 to 7.2 ± 0.1 log CFU/g in fertilizers, from 4.1 ± 0.3 to 5.6 ± 0.3 log CFU/g in lettuces collected from the fields, from 2.9 ± 0.6 to 5.3 ± 0.5 log CFU/g in washed lettuces, <1 to 3.5 ± 0.1 log CFU/mL in irrigation water and <1 to 3.0 ± 0.3 log CFU/mL in wash water. Salmonella was not isolated by plating but it was detected by qPCR in one sample of washed organic lettuce. Using MALDI-TOF MS, 45 species belonging to 24 bacterial genera were identified in the organic vegetable production chain. Bt was able to persist on pre and post-harvest of spinach and affected Salmonella persistence during cultivation, but not during the storage at 12 ºC. Bt spores showed no tendency to germinate during pre-harvest of spinach, thus reducing the probability of growth and production of enterotoxins. The epiphytic bacterium Pseudomonas chlororaphis isolated from one vegetable sample was able to inhibit members of the Bacillus cereus group, including pathogenic strains and Bt in in vitro tests, suggesting a biological barrier to control the multiplication of these microorganisms. These studies provide important information about the microbiological safety of organic vegetables and agricultural practices, highlighting the importance of good practices for the promotion of safe food. These data are fundamental for the development of microbiological risk assessment models and prevention of foodborne outbreaks
Assuntos
Verduras/efeitos adversos , Produção Agrícola , Agentes de Controle Biológico/análise , Salmonella , Bacillus thuringiensis/classificação , Enterobacteriaceae , Alimentos Orgânicos/microbiologiaRESUMO
BACKGROUND: We sought to determine if the prevalence of antibiotic-resistant Escherichia coli differed across retail poultry products and among major production categories, including organic, "raised without antibiotics", and conventional. RESULTS: We collected all available brands of retail chicken and turkey-including conventional, "raised without antibiotic", and organic products-every two weeks from January to December 2012. In total, E. coli was recovered from 91% of 546 turkey products tested and 88% of 1367 chicken products tested. The proportion of samples contaminated with E. coli was similar across all three production categories. Resistance prevalence varied by meat type and was highest among E. coli isolates from turkey for the majority of antibiotics tested. In general, production category had little effect on resistance prevalence among E. coli isolates from chicken, although resistance to gentamicin and multidrug resistance did vary. In contrast, resistance prevalence was significantly higher for 6 of the antibiotics tested-and multidrug resistance-among isolates from conventional turkey products when compared to those labelled organic or "raised without antibiotics". E. coli isolates from chicken varied strongly in resistance prevalence among different brands within each production category. CONCLUSION: The high prevalence of resistance among E. coli isolates from conventionally-raised turkey meat suggests greater antimicrobial use in conventional turkey production as compared to "raised without antibiotics" and organic systems. However, among E. coli from chicken meat, resistance prevalence was more strongly linked to brand than to production category, which could be caused by brand-level differences during production and/or processing, including variations in antimicrobial use.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Microbiologia de Alimentos , Alimentos Orgânicos/microbiologia , Aves Domésticas/microbiologia , Animais , Galinhas/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Contaminação de Alimentos , Genes Bacterianos/genética , Testes de Sensibilidade Microbiana , Perus/microbiologiaRESUMO
1. The aim of this study was to assess the incidence of pathogens and the development of spoilage microflora in organic chicken meat originating from a small poultry slaughterhouse and stored for 14 days at 2°C aerobically (control) or in one of two modified atmosphere packaging systems (MAP1: 80% O2, 20% CO2 and MAP2: 70% N2, 30% CO2). 2. Campylobacter jejuni survived well during storage; and was found on the skin in 95% of samples (262/276). 3. In general, both the skin and meat samples showed a good initial microbiological quality with total viable counts of less than 3 log cfu/g in meat and approximately 5 log cfu/g on skin. 4. No difference was found between breast and thigh samples during the experiment. 5. Shelf life was limited mainly by the development of mesophilic and psychrotrophic microflora on skin which were found at 7-day storage for the control and MAP1 and 10 days for MAP2.
Assuntos
Galinhas , Microbiologia de Alimentos , Armazenamento de Alimentos/métodos , Carne/microbiologia , Carne/normas , Matadouros , Animais , Atmosfera , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Contagem de Colônia Microbiana/veterinária , Embalagem de Alimentos , Alimentos Orgânicos/microbiologia , Alimentos Orgânicos/normas , Refrigeração , Pele/microbiologiaRESUMO
The prevalence and toxin characteristics of Bacillus thuringiensis isolated from 39 organic vegetables were investigated. B. thuringiensis was detected in 30 out of the 39 organic vegetables (76.9%) with a mean value of 2.60 log CFU/g. Twenty-five out of the 30 B. thuringiensis isolates (83.3%) showed insecticidal toxicity against Spodoptera exigua. The hblCDA, nheABC, and entFM genes were found to be the major toxin genes, but the ces gene was not detected in any of the tested B. thuringiensis isolates. The hemolysin BL enterotoxin was detected in all 30 B. thuringiensis isolates (100%). The non-hemolytic enterotoxin complex was found in 27 out of 30 B. thuringiensis isolates (90.0%). The B. thuringiensis tested in this study had similar toxin gene characteristics to B. cereus, which possessed more than one toxin gene. B. thuringiensis could have the potential risk of foodborne illness based on the toxin genes and toxin-producing ability.
Assuntos
Bacillus thuringiensis/genética , Toxinas Bacterianas/genética , Alimentos Orgânicos/microbiologia , Verduras/microbiologia , Carga BacterianaRESUMO
Chlorhexidine (CH) and quaternary ammonium compounds (QAC), such as cetrimide (CE), are widely used as disinfectants because of their broad antimicrobial spectrum. However, their frequent use for disinfection in different settings may promote bacterial drug resistance against both biocides and clinically relevant antibiotics. This study analyzes the effects of stepwise exposure to cetrimide (CE) and chlorhexidine (CH) of bacteria from organic foods and previously classified as biocide-sensitive. Gradual exposure of these strains to biocides resulted in mainly transient decreased antimicrobial susceptibility to other antibiotics and to biocides. Biocide-adapted bacteria also exhibit alterations in physiological characteristics, mainly decreased heat tolerance, or gastric acid tolerance in CE-adapted strains, while bile resistance does not seem to be influenced by biocide adaptation. Results from this study suggest that changes in membrane fluidity may be the main mechanism responsible for the acquisition of stable tolerance to biocides.
Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Compostos de Cetrimônio/farmacologia , Clorexidina/farmacologia , Desinfetantes/farmacologia , Alimentos Orgânicos/microbiologia , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Cetrimônio , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Estresse Fisiológico/efeitos dos fármacosRESUMO
Chicken meat products are hypothesized to be vehicles for transmitting antimicrobial-resistant and extraintestinal pathogenic Escherichia coli (ExPEC) to consumers. To reassess this hypothesis in the current era of heightened concerns about antimicrobial use in food animals, we analyzed 175 chicken-source E. coli isolates from a 2013 Consumer Reports national survey. Isolates were screened by PCR for ExPEC-defining virulence genes. The 25 ExPEC isolates (12% of 175) and a 2:1 randomly selected set of 50 non-ExPEC isolates were assessed for their phylogenetic/clonal backgrounds and virulence genotypes for comparison with their resistance profiles and the claims on the retail packaging label ("organic," "no antibiotics," and "natural"). Compared with the findings for non-ExPEC isolates, the group of ExPEC isolates had a higher prevalence of phylogroup B2 isolates (44% versus 4%; P < 0.001) and a lower prevalence of phylogroup A isolates (4% versus 30%; P = 0.001), a higher prevalence of multiple individual virulence genes, higher virulence scores (median, 11 [range, 4 to 16] versus 8 [range, 1 to 14]; P = 0.001), and higher resistance scores (median, 4 [range, 0 to 8] versus 3 [range, 0 to 10]; P < 0.001). All five isolates of sequence type 131 (ST131) were ExPEC (P = 0.003), were as extensively resistant as the other isolates tested, and had higher virulence scores than the other isolates tested (median, 12 [range, 11 to 13] versus 8 [range, 1 to 16]; P = 0.005). Organic labeling predicted lower resistance scores (median, 2 [range, 0 to 3] versus 4 [range, 0 to 10]; P = 0.008) but no difference in ExPEC status or virulence scores. These findings document a persisting reservoir of extensively antimicrobial-resistant ExPEC isolates, including isolates from ST131, in retail chicken products in the United States, suggesting a potential public health threat.IMPORTANCE We found that among Escherichia coli isolates from retail chicken meat products purchased across the United States in 2013 (many of these isolates being extensively antibiotic resistant), a minority had genetic profiles suggesting an ability to cause extraintestinal infections in humans, such as urinary tract infection, implying a risk of foodborne disease. Although isolates from products labeled "organic" were less extensively antibiotic resistant than other isolates, they did not appear to be less virulent. These findings suggest that retail chicken products in the United States, even if they are labeled "organic," pose a potential health threat to consumers because they are contaminated with extensively antibiotic-resistant and, presumably, virulent E. coli isolates.
Assuntos
Galinhas/microbiologia , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Doenças Transmitidas por Alimentos/epidemiologia , Produtos da Carne/microbiologia , Carne/microbiologia , Animais , Antibacterianos/farmacologia , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Microbiologia de Alimentos , Inocuidade dos Alimentos/métodos , Alimentos Orgânicos/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Estados Unidos/epidemiologiaRESUMO
In the present study, a collection of 76 biocide-sensitive bacterial strains isolated from organically produced food were adapted by repeated exposure to increasing concentrations of the quaternary ammonium compounds (QACs) benzalkonium chloride (BC) and hexadecylpyridinium chloride (HDP). The sensitivity of both wildtype strains and their corresponding QAC-adapted strains to other biocides and to antibiotics was studied. QAC tolerance increased in 88.2% of strains for BC and in 30.3% of strains for HDP, with increases in minimum inhibitory concentrations between 2 and over 100 fold. Adaptive resistance was stable after 20 subcultures in biocide-free medium for 7 and 5 of the BC- and HDP-adapted strains, respectively. Adaptation to BC and HDP also reduced the susceptibility to other biocides, mainly hexachlorophene (CF), didecyldimethylammonium bromide (AB), triclosan (TC) and chlorhexidine (CH). BC-adapted strains showed increased antibiotic resistance to ampicillin (AM) followed by sulfamethoxazol (SXT) and cefotaxime (CTX), and some showed increased sensitivity to ceftazidime (CAZ), CTX, AM and STX. Changes in antibiotic resistance in HDP-adapted strains were more heterogeneous and strain-dependent. Main efflux pump genes detected in QAC-adapted strains were acrB, sugE, norC, qacE and qacH, as well as antibiotic resistance genes aac(6_)-Ie-aph(2_)-Ia, aph(2_)-Ic, ant(4_)-Ia, lsa, mrsA/B, ereA, ermB and cat. Membrane anisotropy experiments revealed that QAC adaptation induced an increase in membrane rigidity in the case of BC, while response to HDP was more heterogeneous and strain-dependent. Growth capacity was significantly higher in some QAC-adapted strains and strain-dependent changes in heat tolerance were also detected in QAC-adapted strains. Gastric acid or bile resistances do not seem to be influenced by QAC adaptation.
Assuntos
Bactérias/efeitos dos fármacos , Desinfetantes/farmacologia , Alimentos Orgânicos/microbiologia , Compostos de Amônio Quaternário/farmacologia , Estresse Fisiológico , Bactérias/química , Bactérias/genética , Bactérias/isolamento & purificação , Compostos de Benzalcônio/farmacologia , Desinfetantes/química , Resistência Microbiana a Medicamentos/genética , Microbiologia de Alimentos , Fluidez de Membrana/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Estresse Fisiológico/efeitos dos fármacosRESUMO
Organic foods have risen in popularity recently. However, the increased risk of bacterial contamination of organic foods has not been fully evaluated. In this study, 100 samples each of organic and conventional fresh vegetables (55 lettuce samples and 45 sprout samples) sold in South Korea were analyzed for aerobic bacteria, coliforms, Escherichia coli, and Bacillus cereus. Although the aerobic bacteria and coliform counts were not significantly different between the two farming types (p > 0.05), the occurrence rate of B. cereus was higher in organically cultivated vegetables compared with those grown conventionally (70% vs. 30%, respectively). The mean contamination level of B. cereus-positive organic samples was also significantly higher (1.86 log colony-forming unit [CFU]/g vs. 0.69 log CFU/g, respectively) (p < 0.05). In addition, six samples of organic vegetables were found to be contaminated with B. cereus at over 4 log CFU/g categorized as unsatisfactory according to Health Protection Agency guideline. The relatively higher occurrence rate of B. cereus in organic vegetables emphasizes the importance of implementing control measures in organic vegetable production and postharvest processing to reduce the risk of food poisoning.
Assuntos
Bacillus cereus/isolamento & purificação , Contaminação de Alimentos , Qualidade dos Alimentos , Alimentos Orgânicos/microbiologia , Verduras/microbiologia , Bacillus cereus/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Enterobacteriaceae/crescimento & desenvolvimento , Enterobacteriaceae/isolamento & purificação , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Inspeção de Alimentos , Conservação de Alimentos , Alimentos Orgânicos/efeitos adversos , Alimentos Orgânicos/economia , Alimentos Orgânicos/normas , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/etiologia , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Bactérias Aeróbias Gram-Negativas/crescimento & desenvolvimento , Bactérias Aeróbias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/crescimento & desenvolvimento , Bactérias Gram-Positivas/isolamento & purificação , Guias como Assunto , Humanos , Lactuca/economia , Lactuca/crescimento & desenvolvimento , Lactuca/microbiologia , Lactuca/normas , Folhas de Planta/efeitos adversos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Prática de Saúde Pública , Controle de Qualidade , República da Coreia/epidemiologia , Risco , Plântula/efeitos adversos , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Verduras/economia , Verduras/crescimento & desenvolvimento , Verduras/normasRESUMO
Natural sourdoughs are commonly used in bread-making processes, especially for organic bread. Despite its role in bread flavor and dough rise, the stability of the sourdough microbial community during and between bread-making processes is debated. We investigated the dynamics of lactic acid bacteria (LAB) and yeast communities in traditional organic sourdoughs of five French bakeries during the bread-making process and several months apart using classical and molecular microbiology techniques. Sourdoughs were sampled at four steps of the bread-making process with repetition. The analysis of microbial density over 68 sourdough/dough samples revealed that both LAB and yeast counts changed along the bread-making process and between bread-making runs. The species composition was less variable. A total of six LAB and nine yeast species was identified from 520 and 1675 isolates, respectively. The dominant LAB species was Lactobacillus sanfranciscensis, found for all bakeries and each bread-making run. The dominant yeast species changed only once between bread-making processes but differed between bakeries. They mostly belonged to the Kazachstania clade. Overall, this study highlights the change of population density within the bread-making process and between bread-making runs and the relative stability of the sourdough species community during bread-making process.
Assuntos
Pão/microbiologia , Microbiologia de Alimentos , Lactobacillus/metabolismo , Consórcios Microbianos/fisiologia , Leveduras/metabolismo , Contagem de Colônia Microbiana , Fermentação , Alimentos Orgânicos/microbiologia , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/isolamento & purificação , RNA Ribossômico 16S/genética , Triticum/microbiologia , Leveduras/classificação , Leveduras/genética , Leveduras/isolamento & purificaçãoRESUMO
The need to minimise consumer risk, especially for food that can be consumed uncooked, is a continuing public health concern, particularly in places where safe sanitation and hygienic practices are absent. The use of wastewater in agriculture has been associated with disease risks, though its relative significance in disease transmission remains unclear. This study aimed at identifying key risk factors for produce contamination at different entry points of the food chain. Over 500 produce and ready-to-eat salad samples were collected from fields, markets, and kitchens during the dry and wet seasons in Accra, Ghana, and over 300 soil and irrigation water samples were collected. All samples were analysed for E. coli, human adenovirus and norovirus using standard microbiological procedures, and real time RT-PCR. Finally, critical exposures associated with microbial quality of produce were assessed through observations and interviews. The study found that over 80% of produce samples were contaminated with E. coli, with median concentrations ranging from 0.64 to 3.84 Log E. coli/g produce. Prepared salad from street food vendors was found to be the most contaminated (4.23 Log E. coli/g), and that consumption of salad exceeded acceptable health limits. Key risk factors identified for produce contamination were irrigation water and soil at the farm level. Storage duration and temperature of produce had a significant influence on the quality of produce sold at markets, while observations revealed that the washed water used to rinse produce before sale was dirty. The source of produce and operating with a hygiene permit were found to influence salad microbial quality at kitchens. This study argues for a need to manage produce risk factors at all domains along the food chain, though it would be more effective to prioritise at markets and kitchens due to cost, ease of implementation and public health significance.
Assuntos
Agricultura/economia , Contaminação de Alimentos , Águas Residuárias/microbiologia , Escherichia coli/fisiologia , Alimentos Orgânicos/microbiologia , Gana , Humanos , Infecções/economia , Infecções/microbiologia , Medição de Risco , Fatores de Risco , Microbiologia do Solo , Águas Residuárias/economiaRESUMO
Consumption of locally, organically grown produce is increasing in popularity. Organic farms typically produce on a small scale, have limited resources, and adopt low technology harvest and postharvest handling practices. Data on the food safety risk associated with hand harvesting, field packing, and packing-house handling with minimal treatment, at this production scale, are lacking. We followed produce from small organic farms from the field through postharvest handling and packing. Pre- and postharvest produce (177 samples) and water (29 samples) were collected and analyzed quantitatively for Escherichia coli, total coliforms (TC), aerobic bacteria (APC), yeasts, molds (M), and enteric pathogens. No pathogens were recovered. E. coli was detected in 3 (3.6%) of 83 preharvest produce samples, 2 (6.3%) of 32 unwashed and 0 of 42 washed postharvest produce samples, and 10 (34.5%) of 29 water samples. No correlation was found between bacterial levels in irrigation water and those on produce. Postharvest handling without washing was a factor for APC and M counts on tomatoes, with lower frequencies postharvest. Postharvest handling with washing was a factor for leafy greens for TC counts, with higher frequencies postharvest. APC (P = 0.03) and yeast (P = 0.05) counts were higher in preharvest than in unwashed postharvest tomatoes. Washed postharvest leafy greens had higher M counts (P = 0.03) and other washed produce had higher TC counts (P = 0.01) than did their preharvest counterparts. Barriers were found to the use of sanitizer in wash water for leafy greens among small farms using organic practices. Hand harvesting and dry handling did not appear to be associated with a significant food safety risk, but washed leafy greens carried higher levels of some microbial indicators, possibly because of the lack of sanitizer in the wash water. The development of resources and materials customized for this sector of growers could enhance dissemination of information on best practices for handling of leafy greens.
Assuntos
Produtos Agrícolas/microbiologia , Microbiologia de Alimentos , Alimentos Orgânicos/microbiologia , Agricultura Orgânica , Escherichia coli/crescimento & desenvolvimento , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Solanum lycopersicum , Folhas de Planta/microbiologia , Verduras/microbiologiaRESUMO
Antibiotic-resistant bacteria existing in agricultural environments may be transferred to humans through food consumption or more multifaceted environmental paths of exposure. Notably, enterococcal infections are becoming more challenging to treat as their resistance to antibiotics intensifies. In this study, the prevalence and antibiotic resistance profiles of enterococci in organic and conventional chicken from retail stores were analyzed. Of the total 343 retail chicken samples evaluated, 282 (82.2%) were contaminated with Enterococcus spp. The prevalence was higher in organic chicken (62.5%) than conventional chicken (37.5%). Enterococcus isolates were submitted to susceptibility tests against 12 antimicrobial agents. Among the isolates tested, streptomycin had the highest frequencies of resistance (69.1 and 100%) followed by erythromycin (38.5 and 80.0%), penicillin (14.1 and 88.5%), and kanamycin (11.3 and 76.9%) for organic and conventional isolates, respectively. Chloramphenicol had the lowest frequency (0.0 and 6.6%, respectively). The predominant species in raw chicken was E. faecium (27.3%), followed by E. gallinarum (6.0%), E. casseliflavus (2.1%), and E. durans (1.4%). These species were also found to be resistant to three or more antibiotics. The data indicated that antibiotic-resistant enterococci isolates were found in chicken whether it was organic or conventional. However, enterococci isolates that were resistant to antibiotics were less common in organic chicken (31.0%) when compared with those isolated from conventional chicken (43.6%). The results of this study suggest that raw retail organic and conventional chickens could be a source of antibiotic-resistant enterococci.
Assuntos
Farmacorresistência Bacteriana Múltipla , Alimentos Orgânicos/microbiologia , Carne/microbiologia , Animais , Antibacterianos/farmacologia , Galinhas/microbiologia , Enterococcus/efeitos dos fármacos , Enterococcus/isolamento & purificação , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: The aim of the study was to evaluate the potential of acid whey and set milk as a marinade in the traditional production of fermented eye round. METHODS: Studies involved assaying pH value, water activity (aw), oxidation-reduction potential and TBARS value, colour parameters in CIE system (L*, a*, b*), assaying the number of lactic acid bacteria and certain pathogenic bacteria after ripening process and after 60-day storing in cold storage. Sensory analysis and analysis of the fatty acids profile were performed after completion of the ripening process. RESULTS: Analysis of pH value in the products revealed that application of acid whey to marinate beef resulted in increased acidity of ripening eye round (5.14). The highest value of the colour parameter a* after ripening process and during storage was observed in sample AW (12.76 and 10.07 respectively), the lowest on the other hand was observed in sample SM (10.06 and 7.88 respectively). The content of polyunsaturated fatty acids (PUFA) was higher in eye round marinated in acid whey by approx. 4% in comparison to other samples. CONCLUSIONS: Application of acid whey to marinade beef resulted in increased share of red colour in general colour tone as well as increased oxidative stability of the product during storage. It also increased the content of polyunsaturated fatty acids (PUFA) in the product. All model products had high content of lactic acid bacteria and there were no pathogenic bacteria such as: L. monocytogenes, Y. enterocolitica, S. aureus, Clostridium sp.
Assuntos
Condimentos/microbiologia , Produtos Fermentados do Leite/microbiologia , Ácidos Graxos Ômega-6/análise , Conservação de Alimentos , Qualidade dos Alimentos , Carne/análise , Soro do Leite/química , Animais , Animais Endogâmicos , Bovinos , Condimentos/efeitos adversos , Condimentos/análise , Qualidade de Produtos para o Consumidor , Produtos Fermentados do Leite/efeitos adversos , Produtos Fermentados do Leite/análise , Gorduras Insaturadas na Dieta/análise , Ácidos Graxos Ômega-6/biossíntese , Fermentação , Armazenamento de Alimentos , Alimentos Orgânicos/efeitos adversos , Alimentos Orgânicos/análise , Alimentos Orgânicos/microbiologia , Concentração de Íons de Hidrogênio , Lactobacillales/crescimento & desenvolvimento , Lactobacillales/isolamento & purificação , Lactobacillales/metabolismo , Carne/efeitos adversos , Carne/microbiologia , Pigmentos Biológicos/análise , Polônia , Refrigeração , Sensação , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Soro do Leite/efeitos adversosRESUMO
We investigated the implied health benefits of retail chicken breast labeled as "organic" or "antibiotic-free" when compared to conventional products based on frequency of contamination by Salmonella spp., Campylobacter spp., and coliform bacteria resistant to fluoroquinolones, extended-spectrum cephalosporins, or carbapenems. We purchased 231 prepackaged chicken breasts from 99 grocery stores representing 17 retail chains in Ohio, Michigan, and Pennsylvania from June to September 2012. Ninety-six (41.5%) packages were labeled "antibiotic free" and 40 (17.3%) were labeled "organic," with the remaining 95 (41.1%) making neither label claim. Salmonella were recovered from 56 (24.2%) packages, and the recovery rate was not different between product types. Five percent of packages contained Salmonella carrying the extended-spectrum cephalosporin resistance gene bla(CMY-2), representing 21.4% of Salmonella isolates. Campylobacter spp. were recovered from 10.8% of packages, with observed recovery rates similar for the three product types. Using selective media, we recovered Escherichia coli harboring bla(CMY-2) from over half (53.7%) of packages, with similar recovery rates for all product types. In addition, we recovered E. coli carrying bla(CTX-M) from 6.9% of packages, and E. coli with QRDR mutations from 8.2% of packages. Fluoroquinolone-resistant E. coli recovered using selective media were more common (p<0.05) in conventional (18.9%) compared to organic (0) and antibiotic-free (2.1%) packages. Our results indicate that, regardless of product type, fresh retail chicken breast is commonly contaminated with enteric pathogens associated with foodborne illness and commensal bacteria harboring genes conferring resistance to critically important antimicrobial drugs.