Antimicrobial susceptibility assessment of Campylobacter on outdoor iberian pig sows

Both Campylobacter and Salmonella are considered the most frequent bacterial causes of human enteritis in industrialized countries. The consumption of raw or undercooked poultry and pork contaminated meat products are the main sources of human infection. The prevalence of Campylobacter and Salmonella was determined in the present work for extensive production Iberian pig sows, Sus mediterraneus. Samples were collected at the maternity area of a creator from, water drinkers, feed and feed containers as well as from sows faecal matter. Of 42 samples, 31 and 23 carried Campylobacter spp. and Salmonella spp. respectively. Only Salmonella spp. was found in all 3 tested water and feed containers. Of the 58 isolated Campylobacter strains only one was identified, by multiplex-PCR, as Campylobacter jejuni, all other were C. coli. Antibiotic susceptibility was performed by disc diffusion method with Nalidixic acid, Ciprofloxacin, Erythromycin, Tetracycline, Chloramphenicol and Ampicilin. While 95% of the tested strains were susceptible to chloramphenicol, 66% and 53% were resistant to the tested fluoroquinolones, Ciprofloxacin and Nalidixic acid respectively. Erythromycin resistance was fairly low in comparison to previous publications with 14% of resistant strains. 38% were resistant to Tetracycline and 57% to Ampicilin. Seven of the 58 Campylobacter strains were entirely susceptible and none were resistant to all the antimicrobials tested. Multiple drug resistance was found in 88% of strains. Cross contamination may occur between sows inside maternity facilities and piglets may become infected in an early age by their mothers. New and better control measures are therefore necessary to minimize transmission between animals reducing the number of contaminated individuals and the potential transmission to human handlers and consumers

Interação de oxometalatos de vanádio, nióbio, tungsténio e molibdénio com a Ca2+-ATPase de retículo sarcoplasmático: um alvo de ação de fármaco

Tese de dout., Ciências Biológicas, especialidade em Bioquímica Inorgânica, Faculdade de Ciências e Tecnologia da Universidade do Algarve, 2013Os oxometalatos são compostos que têm sido descritos por apresentarem propriedades insulino-miméticas, antitumorais, antibióticas, além de serem inibidores das ATPases, nomeadamente a Ca2+-ATPase. Contudo, os efeitos da interação dos oxometalatos com a Ca2+-ATPase, não é um assunto completamente esclarecido. Este estudo teve como objetivo, esclarecer o modo de atuação de oxometalatos de vanádio, nióbio, tungsténio e molibdénio na função e estrutura da Ca2+-ATPase de RS, combinando-se estudos cinéticos com técnicas espetroscópicas. Verificou-se que os oxometalatos estudados inibem a atividade da Ca2+-ATPase, sendo o inibidor mais potente o decavanadato com um IC50 de 15 µM. Foi observado que decavanadato e decaniobato inibem a Ca2+-ATPase de modo não competitivo. Por EAA, observou-se que V10 liga-se às conformações E1, E1P, E2 e E2P, enquanto foi confirmado que V1 liga-se preferencialmente às conformações E2 e E2P. Por outro lado, o vanadato e o decavanadato induzem a oxidação de cisteínas na proteína. A presença do antioxidante quercetina previne a oxidação das cisteínas, mas não a inibição da Ca2+-ATPase por vanadato ou decavanadato. O sinal de V(IV), observado no espetro de RPE de decavanadato na presença Ca2+-ATPase de retículo sarcoplasmático e ATP, sugere uma redução de vanadato, devido à interação de V10 com a proteína. Estes resultados sugerem que a maior capacidade do V10 para inibir a Ca2+-ATPase pode estar, pelo menos em parte, relacionada com o processo de redução do vanadato associada à oxidação das cisteínas na proteína. Finalmente estes resultados contribuem para a compreensão e aplicação de oxometalatos e polioxometalatos como moduladores eficazes de muitos processos biológicos, particularmente aqueles associados com homeostasia do cálcio. De facto os oxometalatos, em especial os polioxometalatos apresentam capacidade inibitória sobre as bombas iónicas, em especial na Ca2+-ATPase, semelhante a fármacos que têm como alvo de ação terapêutica estas bombas iónicas. Sendo por isso de considerar em estudos, a inclusão deste tipo de oxometalatos em fármacos com aplicação terapêutica

Nitrite-free implications on consumer acceptance and the behavior of pathogens in cured pork loins

Research Areas Food Science & TechnologyCured pork loins are valued products due to their particular sensory characteristics. These products are usually prepared with nitrite to guarantee adequate color and pathogen control. The use of nitrite in meat products has been criticized due to its potential contribution to carcinogenic N-nitroso-compound formation. The present work aimed to evaluate the effect of eliminating nitrite from the manufacturing of cured loins made with wine- and water-based marinades on the color evaluation of consumers and on the behavior of Clostridium sporogenes, Listeria monocytogenes, and Salmonella. The use of nitrite in processing cured loins resulted in a color considered adequate by more than 50% of the consumers. When nitrite was not used, the color was described mainly as weak. The hedonic evaluation of cured loins did not reflect the color evaluation. The samples with a weak and an adequate color had similar hedonic evaluations. The present work did not allow us to infer the potential interest in injecting S. xylosus into meat to prepare cured loins. The use of nitrite did not affect the survival of Cl. sporogenes, L. monocytogenes, or Salmonella. The reduction in the aw was the primary determinant influencing pathogen survival. The production of nitrite-free cured loins seems possible once the control of pathogens can be achieved. However, the product will have a weaker color. Consumers appreciate sensory aspects other than color, which, combined with the positive impact of the “additive-free” claim, can support the possibility of producing cured loins without nitriteinfo:eu-repo/semantics/publishedVersio

Staphylococcus saprophyticus causing infections in humans is associated with high resistance to heavy metals

Research Areas: Microbiology ; Pharmacology & PharmacyStaphylococcus saprophyticus is a common pathogen of the urinary tract, a heavy metal-rich environment, but information regarding its heavy metal resistance is unknown. We investigated 422 S. saprophyticus isolates from human infection and colonization/contamination, animals, and environmental sources for resistance to copper, zinc, arsenic, and cadmium using the agar dilution method. To identify the genes associated with metal resistance and assess possible links to pathogenicity, we accessed the wholegenome sequence of all isolates and used in silico and pangenome-wide association approaches. The MIC values for copper and zinc were uniformly high (1,600mg/liter). Genes encoding copper efflux pumps (copA, copB, copZ, mco, and csoR) and zinc transporters (zinT, czrAB, znuBC, and zur) were abundant in the population (20 to 100%). Arsenic and cadmium showed various susceptibility levels. Genes encoding the ars operon (arsRDABC), an ABC transporter and a two-component permease, were linked to resistance to arsenic (MICs$1,600mg/liter; 14or cadC and cadD-cadX or czrC) and genes encoding multidrug efflux pumps and hyperosmoregulation in acidified conditions were associated with resistance to cadmium (MICs$ 200mg/liter; 20% [85/422]; P, 0.05). These resistance genes were frequently carried by mobile genetic elements. Resistance to arsenic and cadmium were linked to human infection and a clonal lineage originating in animals (P, 0.05). Altogether, S. saprophyticus was highly resistant to heavy metals and accumulated multiple metal resistance determinants. The highest arsenic and cadmium resistance levels were associated with infection, suggesting resistance to these metals is relevant for S. saprophyticus pathogenicityinfo:eu-repo/semantics/publishedVersio

Editorial: natural compounds in food safety and preservation

Research Areas: Nutrition & Dieteticsinfo:eu-repo/semantics/publishedVersio

A Fitoterapia na profilaxia e terapêutica de infeções do trato urinário não complicadas: o caso particular da cistite

As infeções do trato urinário (ITUs) afetam cerca de 150 milhões de pessoas por ano, de todas as idades em todo o mundo e constituem as infeções bacterianas mais comuns a nível comunitário e hospitalar, sendo consideradas o segundo maior processo infecioso após as infeções respiratórias. Estas infeções têm um elevado impacto não só a nível económico, como também a nível pessoal, uma vez que os seus sintomas afetam consideravelmente a qualidade de vida dos doentes. São muitos os agentes etiológicos que podem causar uma ITU, no entanto considera-se que a Escherichia coli uropatogénica é o principal agente etiológico quer nas ITUs não complicadas, quer nas ITUs complicadas. As ITUs mais prevalentes na população são a cistite e a pielonefrite. Estas diferem no local de infeção, nos sintomas associados, no seu diagnóstico, bem como no seu tratamento farmacológico. De um modo geral, o tratamento de ambas as patologias, passa pelo uso de antibióticos de forma empírica, no entanto, cada vez mais os microrganismos causadores das ITUs estão a tornar-se resistentes ao uso dos antibióticos, pelo o que é necessário, para além da criação de novos antibióticos, recorrer a outras terapêuticas alternativas para contornar esta problemática. Neste sentido, a presente dissertação pretende apresentar numa primeira instância vários aspetos da patologia, nomeadamente, as diversas ITUs existentes, os fatores de risco, as vias de infeção, os principais agentes etiológicos e abordar mais detalhadamente a cistite e a pielonefrite por serem as ITUs mais comuns, clarificando as principais diferenças em termos de sintomatologia e diagnóstico. São apresentadas, também, as diversas medidas a adotar como terapêutica não farmacológica, os diversos fármacos usados na terapêutica farmacológica da cistite e pielonefrite e as diversas medidas profiláticas existentes. Na última parte da dissertação, pretende-se dar especial atenção ao papel da fitoterapia como terapêutica e profilaxia das ITUs não complicadas em alternativa à administração de antibióticos, principalmente na cistite que é a infeção urinária em que a fitoterapia poderá ter um papel importante. Por último, evidencia-se o papel do farmacêutico comunitário, bem como as preparações à base de plantas mais utilizadas nesta patologia.Urinary tract infections (UTIs) affect about 150 million people each year worldwide and are the most common bacterial infections at community and hospital level and are considered the second major infectious disease after respiratory infections. These infections have a high impact not only economically, but also on a personal level, as its symptoms significantly affect the patient’s quality of life. There are many etiologic agents that can cause UTI, however uropathogenic Escherichia coli is considered the main etiologic agent in both uncomplicated UTIs and complicated UTIs. The most prevalent UTIs in the population are cystitis and pyelonephritis. These differ in the site of infection, in the associated symptoms, in its diagnosis, as well as in its pharmacological treatment. In general, the treatment of both pathologies involves the use of antibiotics in an empirical way, however, more and more the microorganisms that cause UTIs are becoming resistant to the use of antibiotics, so it is necessary besides the creation of new antibiotics, to resort to other alternative therapies to overcome this problem. In this sense, the present dissertation intends to present in the first instance several aspects of the pathology, namely, the various existing UTIs, the risk factors, pathways of infection, main etiological agents, and to discuss cystitis and pyelonephritis in more detail because they are the most common UTIs, clarifying the main differences in symptomatology and diagnosis. The different measures to be adopted as non-pharmacological therapy, the various drugs used in the pharmacological treatment of cystitis and pyelonephritis, and the various prophylactic measures are also presented. In the last part of the dissertation, it is intended to pay special attention to the role of phytotherapy as therapeutics and prophylaxis of uncomplicated UTIs as an alternative to the administration of antibiotics, especially in cystitis which is the urinary infection in which herbal medicine may play an important role. Finally, show the role of the community pharmacist as well as the most commonly used herbal preparations in this pathology

Constraints of HACCP Application on Edible Insect for Food and Feed

In a near future there is a need to guaranty food security for approximately more than one billion people worldwide. Beyond the population increase other factors contribute to food and feed insecurity such as climate changes, rising costs of animal protein and consumer demands for protein. Edible insects are pointed out as one alternative as they have always been a part of human diets. The concern to guaranty food security cannot be dissociated from food safety and under the Codex Alimentarius principles of food hygiene, insects would be comparable to other types of foods of animal origin. The processing and storage of insects and their products should follow the same health and sanitation regulations as for any other food or feed in order to ensure their microbiological and chemical safety. Allergies induced through insects’ ingestion should also be considered. This review aims to identify potential hazards related to edible insects’ production and transformation. Preventive measures to their control will be presented considering pre-requirements in their production and transformation. An HACCP plan will be described as a study case in insects’ transformation, being discussed all constraints regarding implementation

The risk of salt reduction in dry-cured sausage assessed by the influence on water activity and the survival of salmonella

Research Areas: Food Science & TechnologyWater activity (aw) is the main hurdle for microbial control in dry-cured sausages. The aw can be influenced by drying or adding electrolytes or humectants. Dry-cured meat products are partially dried, which, together with added salt, results in safe aw values. Currently, there is a trend to reduce salt in meat products, which can compromise the preservation process. The present work aims to evaluate the influences of added salt levels (1% or 3%) and the use or omission of phosphates and wine on the aw of a dry-cured sausage, and to evaluate the possibility of estimating the aw from the moisture loss and the behavior of Salmonella during dry-cured sausage (chouriço) processing. There was a strong relationship between moisture and aw, regardless of the salt level and the presence of phosphates or wine. Predicting aw from moisture loss is possible using the Boltzmann sigmoid function. The salt level strongly influences Salmonella behavior, mainly through aw reduction. An increase in aw by 0.01 units reduced the odds of achieving a 5-log reduction in Salmonella counts to half. Increasing added salt from 1% to 3% increased the odds of achieving a 5-log Salmonella reduction 7.5-fold. The current trend to reduce salt in foods must be carefully approached if applied to cured meat products, as it has substantial consequences on aw evolution and Salmonella survivalinfo:eu-repo/semantics/publishedVersio

Physico-chemical and sensorial characteristics evolution of vacum packaged Iberian dry-cured ham stored at refrigerated temperature

Two groups of five dry-cured hams from Alentejano pig breed submitted to a post-salting cure of 12 months were studied. One of the groups was processed through craft methods at Barrancos (small city of south-east Alentejo region, Portugal) and the other one in a Portuguese meat plant. Equal groups of slices and unitary portions weighing about 250 g were vacuum packed and stored at 7 °C. Physico-chemical analysis (pH, aw, chlorides, total volatile basic nitrogen, thiobarbituric acid index and colour-L*, a*, b*) and sensorial evaluation (colour, off colour, aroma, off aroma, tenderness, succulence, taste, off taste, salt intensity and global evaluation) were carried out before packaging (time 0) and after 2, 5 and 8 months of storage. Statistical analysis consisted in analysis of variance considering the factors “process” (artisanal and industrial), “sample presentation” (portions and slices) and “storage time” (0, 2, 5 and 8 months). Physico-chemical analysis exhibit differences, mainly for “process” factor and sensorial evaluation for “storage time” factor. However, results evidence desirable evolution of the samples during storage time. These study allow to conclude that under refrigeration (7 °C) is possible to store vacuum packaged high quality dry-cured ham during, at least, 8 months

The Ca2+-ATPase inhibition potential of gold (I, III) compounds

The therapeutic applications of gold are well-known for many centuries. The most used gold compounds contain Au(I). Herein, we report, for the first time, the ability of four Au(I) and Au(III) complexes, namely dichloro (2-pyridinecarboxylate) Au(III) (abbreviated as1), chlorotrimethylphosphine Au(I) (2), 1,3-bis(2,6-diisopropylphenyl) imidazole-2-ylidene Au(I) chloride (3), and chlorotriphenylphosphine Au(I) (4), to affect the sarcoplasmic reticulum (SR) Ca2+-ATPase activity. The tested gold compounds strongly inhibit the Ca2+-ATPase activity with different effects, being Au(I) compounds2and4the strongest, with half maximal inhibitory concentration (IC50) values of 0.8 and 0.9 mu M, respectively. For Au(III) compound1and Au(I) compound3, higher IC(50)values are found (4.5 mu M and 16.3 mu M, respectively). The type of enzymatic inhibition is also different, with gold compounds1and2showing a non-competitive inhibition regarding the native substrate MgATP, whereas for Au compounds3and4, a mixed type of inhibition is observed. Our data reveal, for the first time, Au(I) compounds with powerful inhibitory capacity towards SR Ca(2+)ATPase function. These results also show, unprecedently, that Au (III) and Au(I) compounds can act as P-type ATPase inhibitors, unveiling a potential application of these complexes.FCT: UIDB/04326/2020/ UIDB/50006/2020info:eu-repo/semantics/publishedVersio