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1.
Arch Anim Nutr ; : 1-17, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941242

RESUMO

Dietary fibre is mainly classified according to its chemical characteristics but structure and particle size of fibre-rich feedstuff can also be decisive for digestion and performance. So far, only few studies investigated this in pigs. This experiment aimed to compare coarse and finely ground dried hemp plants and apple pomace regarding performance and ileal and total tract nutrient digestibility of growing pigs. Coarse or finely ground apple pomace or dried hemp plants were added to the diet of 56 nine weeks old growing pigs (DanBred x Duroc), housed in flat decks with each 2 animals. The growing pigs received the experimental diets for three weeks while performance was recorded. Eight pigs per group were sacrificed and digesta and organ tissue sampled. The stomach health was evaluated by visually scoring of the mucosa integrity. Apparent ileal (AID) and total tract digestibility (ATTD) were calculated using titanium dioxide as marker. Statistical analyses were performed using two-way ANOVA (p < 0.05). The highest feed intake (fibre particle size, p = 0.018) and bodyweight gain (fibre particle size, p = 0.018; fibre source x particle size interaction, p = 0.040), was observed in animals fed finely ground apple pomace, while the feed conversion ratio was 8-12% lower in pigs fed finely ground fibre sources (p = 0.012). No differences in stomach mucosa integrity were detected between the groups. The relative pancreas (p = 0.045), stomach (p < 0.001), and jejunum (p = 0.010) weights were higher in animals fed diets containing apple pomace. In contrast, the relative liver, caecum and colon weights were not affected by fibre source or particle size. The AID of protein and amino acids was not affected, while ATTD was increased by fibre source (hemp vs. apple pomace) reducing faecal nitrogen excretion. The AID of calcium was increased when diets contained apple pomace (p < 0.001), while zinc AID and ATTD were enhanced when diets contained dried hemp (p = 0.016; p = 0.016, respectively). Our results suggest that the structure as well as the chemical characteristics should be considered in a future fibre evaluation system in pigs.

2.
Animal ; 17(2): 100697, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36621110

RESUMO

Maternal dietary factors have been reported to influence Clostridioides difficile colonisation in the offspring. Twenty suckling piglets from sows fed diets supplemented with high-fermentable sugar beet pulp (SBP) or low-fermentable lignocellulose (LNC) fibres during gestation and lactation were dissected in the first week after birth. Postmortem analysis included clinical mesocolon and faecal scoring, concentration of C. difficile and respective toxins in colon digesta and faeces, immunoglobulins in serum and inflammatory markers in serum and colon tissues. Sow colostrum was assessed for nutrients, immunoglobulins and biogenic amines. Toxin-neutralising IgG antibodies were measured in colostrum and serum of the sows, and in colon digesta and serum of the piglets. Mesocolonic oedema of different severity was present in most of the piglets from both sows' feeding groups. Concentrations of C. difficile, toxins and calprotectin in colon digesta and faecal contents did not differ between the study piglets. Calprotectin correlated positively with mesocolon score (rho = 413, P = 0.07). Piglets from sows fed LNC vs SBP tended to have higher IgA (P = 0.089), IgG (P = 0.053), total Ig (P = 0.053), albumin (P = 0.075) and total protein content (P = 0.007) in serum. Colon tissues of piglets from the SFB vs LNC had upregulated expression of ZO-1 (P = 0.021), PCNA (P = 0.015) and TGF-ß (P = 0.014). Titers of anti-toxin-IgG-antibodies in serum and colostrum and in piglet colon digesta and serum did not differ between sows from both dietary groups, but they all showed strong positive correlations. In conclusion, dietary sugar beet pulp or lignocellulose fed to sows did not influence the concentrations of C. difficile and toxins titers in colon digesta and faeces of neonatal piglets.


Assuntos
Clostridioides difficile , Gravidez , Feminino , Animais , Suínos , Leite/metabolismo , Dieta/veterinária , Colostro/metabolismo , Suplementos Nutricionais , Lactação , Imunoglobulina G , Ração Animal/análise
3.
Antibiotics (Basel) ; 11(12)2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36551360

RESUMO

Antibiotic resistance poses a risk for human and animal health, leading to a growing demand for effective alternatives. Combining nutritional tools and parent stock vaccination could be an approach to achieve sufficient protection against bacterial infections in poultry. In an Escherichia coli O1/O18 challenge trial, we investigated the protective effects of feeding diets containing Enterococcus faecium DSM 7134 and fructooligosaccharides (FOS) combined with specific parent stock vaccination in 225 ROSS 308 broilers. Data on performance parameters, intestinal microbial composition and metabolites, and antibiotic resistance genes (sul1-3, dhfr1a, SHV-12) were obtained. E. faecium and FOS combined with parent stock vaccination led to the highest body weights, which were significantly higher than those of controls throughout the experiment and decreased the relative abundance of Proteobacteria in the crop digesta compared to that in the positive control. However, cumulative feed conversation remained unaffected by the strategies. Birds receiving the pre-/probiotic combination showed lower cecal pH levels and higher crop L-lactate concentrations than the controls, whereas copy numbers of dhfr1a (trimethoprim resistance) and SHV-12 (extended-spectrum beta-lactamase) genes were only decreased in broilers from vaccinated hens compared to those in the challenged control. In conclusion, prophylactic administration of E. faecium and FOS in combination with parent stock vaccination can have complementary effects by improving broiler weight gain and stimulating intestinal bacterial metabolism, which may be beneficial for maintaining gut health in terms of Escherichia coli infection.

4.
Arch Anim Nutr ; 76(2): 125-144, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35730596

RESUMO

Adequate levels of dietary fibre can reduce the risk of intestinal health disorders in rabbits after weaning. Therefore, it was the aim of the study to investigate the impact of different lignocellulose and cellulose addition to rabbits' diets on performance and intestinal traits in lactating does and weaned rabbits. A total of 60 rabbit does (4.41 ± 0.45 kg body weight) were fed isonitrogenous diets with lignocellulose and cellulose inclusion rates [%] of 0/8, 2/6, 4/4, 6/2 and 8/0, resulting in dietary lignin-to-cellulose ratios of 0.26, 0.30, 0.32, 0.34 and 0.40, respectively. The diets were fed from 4 d ante partum (a.p.) until day 28 post partum (p.p. weaning). After weaning, 40 young rabbits from each feeding group were fed the same diets for 12 d, when 10 rabbits per group were sacrificed. Body weight gain (BWG), feed intake and feed conversion ratio were obtained. Gastrointestinal content and gut tissue were obtained from the growing rabbits and pH, short-chain fatty acids (SCFA) concentration and gut morphology were investigated. Digestive disorders were scored, and the sanitary risk index was calculated. Does fed the highest lignocellulose addition increased their feed intake [g · kg BW-1 · d-1] in the first two weeks p.p. (p < 0.001) and increased BWG (p < 0.001) but without impact on their offsprings' performance. Weaned rabbits fed the highest lignocellulose inclusion showed a reduced feed intake and increased sanitary risk index. Additionally, a higher number of rabbits showed intestinal disorders for a short time (1-2 d, p < 0.001). In the colon content, a higher pH and a lower dry matter content were observed in this group. Caecal contents of 40-d old rabbits showed lower total SCFA, acetate and propionate and higher i-valerate and L-lactate concentrations after feeding diets with high lignocellulose contents. The diet did not influence the acetate-to-propionate ratio. No histomorphological changes were observed in the jejunum, while crypt depth and width were reduced in the caecum of weaned rabbits fed diets with lignocellulose addition. It can be concluded that different proportions of lignocellulose to cellulose addition to rabbits' diets have an impact on health and performance with differences between does and weaned rabbits. While a high lignocellulose inclusion proved beneficial for does, for weaned rabbits, a lower addition should be preferred.


Assuntos
Dieta , Lignina , Ração Animal/análise , Animais , Bactérias/metabolismo , Celulose , Dieta/veterinária , Ácidos Graxos Voláteis/metabolismo , Feminino , Lactação , Propionatos , Coelhos , Desmame , Aumento de Peso
5.
Curr Microbiol ; 79(5): 154, 2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35397071

RESUMO

Dietary fiber has a potential to modulate the gut microbiota in sows. We hypothesized that a maternal diet rich in either high- or low-fermentable fiber during gestation and lactation influences Clostridioides difficile gut colonization in suckling piglets. Twenty sows were fed gestation and lactation diets enriched with either high-fermentable sugar beet pulp (SBP) or low-fermentable lignocellulose (LNC) fibers. C. difficile, toxin B (TcdB), fecal score, microbial abundance (16S-rDNA sequencing) and metabolites were measured in the feces from the sows and their piglets. C. difficile concentration was higher in piglets from the sows fed LNC than SBP along the study (P ≤ 0.05). Higher prevalence of C. difficile was noted in three-week-old piglets from sows fed LNC vs. SBP (45% vs. 0%, P = 0.001). TcdB prevalence was higher in six-day-old piglets from the sows fed LNC vs. SBP (60% vs. 17%, P = 0.009). In sows, fecal microbial metabolites were higher in SBP than LNC, while C. difficile concentration showed no difference. Higher microbial diversity Shannon index was noted in sows from SBP vs. LNC one week before parturition and at the parturition (P ≤ 0.05). Piglets from SBP vs. LNC tended to have higher microbial diversity Shannon index at two and three weeks of age. Diets enriched with high-fermentable fiber compared to low-fermentable fiber in sows reduced C. difficile colonization in their piglets. Susceptibility to colonization by C. difficile in neonatal piglets can be modulated by the sows' diet, supporting the hypothesis of the early microbial programming in the offspring and the importance of the sow-piglet couple.


Assuntos
Toxinas Bacterianas , Clostridioides difficile , Ração Animal/análise , Animais , Dieta/veterinária , Fibras na Dieta/metabolismo , Suplementos Nutricionais , Feminino , Lactação , Suínos , Verduras
6.
BMC Vet Res ; 18(1): 80, 2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35219345

RESUMO

BACKGROUND: Primary photosensitization rarely occurs in horses and can easily be misinterpreted. Descriptions of the disease in horses after ingestion of parsnip are lacking. The aim of this case series was to describe the dermatological and ocular changes due to photosensitization and to raise awareness of parsnip being a possible aetiologic agent. CASE PRESENTATION: Nine horses from three different stables in Berlin and Brandenburg, Germany, presented variable degrees of erythema, scaling, crusting and necrosis of unpigmented skin at the head and prepuce. Horses were of different breeds with a median age of 15 ± 5.9 years. A mild leukocytosis was diagnosed in 1/9 horses at admission. Analyzed liver enzymes were within the reference ranges in all horses. Ocular changes were diagnosed as follows: blepharitis (3/9), conjunctivitis (7/9), corneal edema without additional signs of keratitis and/or uveitis (2/9), corneal edema with signs of uveitis (1/9) and photophobia (4/9). One horse developed a fluorescein positive corneal erosion. Skin biopsy (1/9) revealed a moderate to severe acute, eosinophilic and lymphocytic dermatitis with dermal edema and vasculitis. All stables housing these patients fed hay from the same distributer. Analyzed hay samples showed high contents of wild parsnip (plants, seeds, roots). Wild parsnip is widespread in Europe and contains furocoumarins, a family of photodynamic pigments, which may cause primary photodermatitis, keratoconjunctivitis and uveitis. Horses were treated according to severity of clinical symptoms systemically with flunixine meglumine (1.1 mg/kg BW 1-2x/day) or prednisolone (1 mg/kg BW 1x/day). Topically, either gentamicin (3x/day), dexamethasone (2-3x/day) and/or atropine (1x/day) were used. Skin care was provided with almond oil or dexpanthenol (2x/day). All horses were kept in a dark environment or were treated with sunscreen and facemasks. Duration of treatment varied from 6-30 days (median 11.3 days). CONCLUSION: Ingestion of wild parsnip (Pastinaca sativa) can induce primary photosensitization with dermatitis and ocular injury in horses. In times of extreme weather, hay may alter in botanical composition, resulting in high amounts of uncharacteristic plants causing novel problems.


Assuntos
Furocumarinas , Doenças dos Cavalos , Pastinaca , Transtornos de Fotossensibilidade , Animais , Ingestão de Alimentos , Doenças dos Cavalos/induzido quimicamente , Doenças dos Cavalos/tratamento farmacológico , Cavalos , Transtornos de Fotossensibilidade/induzido quimicamente , Transtornos de Fotossensibilidade/veterinária , Melhoramento Vegetal
7.
Microorganisms ; 10(1)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35056569

RESUMO

Due to the global spread of antibiotic resistance, there is a strong demand to replace antimicrobial growth promotors in livestock. To identify suitable additives that inhibit the growth of avian pathogenic Escherichia coli O1/O18 and Salmonella enterica serotype Enteritidis strains, an ex vivo screening was performed. Inulin and fructooligosaccharides (FOS) were investigated as prebiotics. Enterococcus faecium and Bacillus coagulans served as probiotic strains. Firstly, the pathogen was anaerobically incubated in caecal digesta from different broiler breeder flocks with the addition of feed additives. Secondly, subsamples of these suspensions were incubated in an antibiotic medium for selective growth of the pathogen. During this step, turbidity was recorded, and lag times were calculated for each pathogen as readout of growth inhibition. Combinations of E. faecium with inulin or FOS significantly extended the lag time for E. coli compared to control. Moreover, older age was a significant factor to enhance this inhibitory effect. In contrast, the combination of FOS and B. coagulans showed shorter lag times for S. Enteritidis. Our results indicate that the E. faecium strain with prebiotics may inhibit the pathogen proliferation in the studied poultry flocks. Furthermore, our results suggest that prophylactic treatments should be assigned by feed additive, age and animal origin.

8.
Arch Anim Nutr ; 75(4): 263-277, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34427485

RESUMO

Rye and rapeseed meal (RSM) are alternatives to wheat and soybean meal (SBM) in pig nutrition. The inclusion of rye and RSM instead of wheat and SBM may increase dietary fibre content in the feed, which may affect digestive physiology and intestinal function. However, research on the combined feeding of rye and RSM in piglets is still scarce. The aim of this study was to investigate the effects of rye and RSM containing feed on growth performance, protein and amino acid digestibility, physical characteristics of the digesta and the intestinal morphology in weaner piglets. A total of 88 piglets aged 28 d were randomly allotted to four different feeding groups at weaning: wheat/SBM, wheat/RSM, rye/SBM, rye/RSM. Cereals were included at 48%, SBM at 25% and RSM at 30%. Body weight gain and feed intake were recorded weekly. After 33 d, piglets were euthanised for assessment of digesta and intestinal morphology. Rye did not affect performance, whilst RSM resulted in reduced weight gain (p = 0.024) and feed intake (p = 0.037). Apparent ileal digestibility of crude protein and amino acids was decreased by rye and RSM (p < 0.05). Rye caused an acidification (p = 0.045) and increased viscosity (p = 0.013) of small intestinal digesta, a lower dry matter content of jejunal and colonic digesta (p < 0.05) and an increased relative weight of the colon tissue (p < 0.001). In conclusion, performance was not reduced when rye was used as an alternative to wheat in diets for weaner piglets. The inclusion of RSM instead of SBM to piglets' diet lowered animal performance under our conditions. Further investigations are warranted to characterise the quality of rapeseed meal and the optimum inclusion level in the diet for young pigs.


Assuntos
Digestão , Grão Comestível , Ração Animal/análise , Animais , Dieta/veterinária , Íleo , Suínos
9.
BMC Microbiol ; 20(1): 133, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32450799

RESUMO

BACKGROUND: Extended spectrum beta-lactamase (ESBL)-producing enterobacteria pose a major hazard to public health. Due to the possibility of genetic transfer, ESBL genes might spread to pathogenic enterobacterial strains. Thus, information on possible genetic transfer between enterobacteria is of high interest. It was therefore the aim of this in vitro study to screen the capacity of a wide range of Enterobacteriaceae for differences in conjugation at different time points with five ESBL-producing Escherichia coli strains. RESULTS: Conjugation frequencies for five potential E. coli donor strains producing the enzymes CTX-M-1, CTX-M-15, SHV-12, TEM-1, TEM-52 and CMY-2, and six potential recipient strains commonly detected in the gastrointestinal tract of poultry (E. coli, Serratia marcescens subsp. marcescens, Enterobacter cloacae, Salmonella (S.) enterica serovar Typhimurium and Proteus mirabilis) were obtained. Different combinations of donor and recipient strains were co-incubated for between 0 and 22 h and spread on selective agar. Conjugation frequencies were calculated as transconjugants per donor. Some donor and recipient strain combinations did not perform plasmid transfer within 22 h. Hence, the recipient Proteus mirabilis did not accept plasmids from any of the given donors and the E. coli ESBL10716 donor was unable to transfer its plasmid to any recipient. Enterobacter cloacae only accepted the plasmids from the donors E. coli ESBL10708 and E. coli ESBL10716 while E. coli ESBL10708 did not transfer its plasmid to Serratia marcescens subsp. marcescens. E. coli IMT11716 on the other hand did not perform conjugation with the donor E. coli ESBL10689. The remaining mating pairs differed in conjugation frequency, ranging from 10- 5 to 10- 9 transconjugants/donor. The earliest conjugation events were detected after 4 h. However, some mating pairs turned positive only after 22 h of coincubation. CONCLUSION: A suitable mating pair for future in vivo studies to combat transfer of antibiotic resistance to pathogenic bacteria in broiler chicken was determined. The results of this study also suggest that the kinetic of conjugation differs between mating pairs and is independent of species origin. This should be considered when performing conjugation experiments.


Assuntos
Proteínas de Bactérias/genética , Enterobacteriaceae/genética , Escherichia coli/genética , beta-Lactamases/genética , Animais , Conjugação Genética , Enterobacteriaceae/classificação , Enterobacteriaceae/isolamento & purificação , Escherichia coli/classificação , Proteínas de Escherichia coli/genética , Técnicas In Vitro , Cinética , Plasmídeos/genética , Aves Domésticas/microbiologia , Especificidade da Espécie
11.
Microorganisms ; 8(3)2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32110912

RESUMO

Poultry frequently account for the highest prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in livestock. To investigate the impact of direct-fed microbials (DFM) and phytobiotic feed additives on prevalence and conjugation of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, an animal trial was conducted. Lactobacillus agilis LA73 and Lactobacillus salivarius LS1 and two commercial phytogenic feed additives (consisting of carvacrol, cinnamaldehyde, and eugenol) were used as feed additives either alone or as a combination of DFM and phytogenic feed additive. An ESBL-producing E. coli donor and a potentially pathogenic Salmonella Typhimurium recipient were inoculated at 5 × 109 cells/mL in cecal contents from 2-week-old broilers. Conjugation frequencies were determined after 4 h aerobic co-incubation at 37 °C and corrected for the impact of the sample matrix on bacterial growth of donor and recipient. Surprisingly, indigenous Enterobacteriaceae acted as recipients instead of the anticipated Salmonella recipient. The observed increase in conjugation frequency was most obvious in the groups fed the combinations of DFM and phytogenic product, but merely up to 0.6 log units. Further, cecal samples were examined for ESBL-producing Enterobacteriaceae on five consecutive days in broilers aged 27-31 days. All samples derived from animals fed the experimental diet showed lower ESBL-prevalence than the control. It is concluded that Lactobacillus spp. and essential oils may help to reduce the prevalence of ESBL-harboring plasmids in broilers, while the effect on horizontal gene transfer is less obvious.

12.
Microorganisms ; 7(12)2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31835884

RESUMO

Probiotics and phytobiotics have been studied as in-feed antibiotic alternatives for decades, yet there are no studies on their possible symbiotic effects. In the present study, newly hatched chickens were fed with feeds supplemented either with host-specific Lactobacillus strains (L. agilis and L. salivarius), commercial phytobiotics, or combinations of both. After 13 days of life, crops and caecums were analyzed for bacterial composition (16S rDNA sequencing, qPCR) and activity (bacterial metabolites). Crop and caecum samples were also used to study the ex vivo survival of a broiler-derived extended-spectrum beta-lactamase (ESBL) producing Escherichia coli strain. In the crop, combinations of probiotics and phytobiotics, but not their single application, increased the dominance of lactobacilli. The single application of phytobiotics reduced the metabolite concentrations in the crop, but certain combinations synergistically upregulated the metabolites. Changes in the qualitative and quantitative composition of the caecal microbiota were less pronounced than in the crop. Acetate concentrations were significantly lower for phytobiotics or the L. agilis probiotic strain compared to the control group, but the L. salivarius probiotic showed significantly higher acetate concentrations alone or in combination with one phytobiotic. The synergistic effects on the reduction of the ex vivo survival of an ESBL producing E. coli strain in crop or caecum contents were also observed for most combinations. This study shows the beneficial synergistic effects of probiotics and phytobiotics on the intestinal bacterial composition and their metabolic activity in young broilers. The reduced survival of potentially problematic bacteria, such as ESBL-producing E. coli further indicates that combinations of probiotics and phytobiotics may lead to a more enhanced functionality than their individual supplementation.

13.
Front Microbiol ; 10: 2705, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824469

RESUMO

A novel three-step combination of in vitro and ex vivo screening was established to massively screen host derived lactic acid bacteria (LAB) from the broiler chicken intestine with inhibitory activity against Escherichia coli. In a first step, a massive sample pool consisting of 7102 broiler-derived colonies from intestinal contents were established and sub-cultured. Supernatants thereof were incubated with an E. coli model strain to screen suitable isolates with inhibitory activity. A total of 76 isolates of interest were subsequently further studied based on either pH dependent or -independent activity in the second step of the assay. Here, in-depth growth inhibition of the E. coli model strain and the potential of isolates for lactic acid production as inhibitory substance were indexed for all isolates. Resulting scatter plots of both parameters revealed five isolates with exceptional inhibitory activity that were further studied under ex vivo condition in the third step of the assay. These isolates were taxonomically classified as strains of the species Lactobacillus agilis, Lactobacillus salivarius, and Pediococcus acidilactici. Samples from the broiler chicken intestine were inoculated with the Lactobacillus isolates and the E. coli model strain. After 8 and 24 h incubation, respectively, growth of the E. coli model strain was monitored by cultivation of the E. coli strain in antibiotic supplemented medium. By their superior inhibitory activity against the E. coli model strain, one L. agilis and one L. salivarius strain were selected and characterized for further application as probiotics in broiler chicken. Additionally, their antibiotic resistance patterns and resilience under gastric stress of isolates were also characterized. The results of this study demonstrate that the novel isolation procedure was able to efficiently and rapidly isolate and identify bacterial strains from a massive sample pool with inhibitory potential against specific types of bacteria (here E. coli). The introduction of the final ex vivo selection step additionally confirmed the inhibitory activity of the strains under conditions simulating the intestinal tract of the host. Furthermore, this method revealed a general potential for the isolation of antagonistic strains that active against other pathogenic bacteria with specific biomarker.

14.
Biomolecules ; 9(8)2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370208

RESUMO

The transfer of extended spectrum ß-lactamase (ESBL)-genes occurs frequently between different bacteria species. The aim of this study was to investigate the impact of nutrition related stress factors on this transfer. Thus, an Escherichia coli donor and a Salmonella Typhimurium recipient were co-incubated for 4 h in media containing different levels of the stress factors' pH, osmolality, copper, zinc and acetic, propionic, lactic, and n-butyric acid, as well as subtherapeutic levels of cefotaxime, sulfamethoxazole/trimethoprim, and nitrofurantoin. Conjugation frequencies were calculated as transconjugants per donor, recipient, and total bacterial count. A correction factor for the stress impact on bacterial growth was used. Acetic, lactic, and n-butyric, acid, as well as pH, showed no significant impact. In contrast, increasing concentrations of propionate, zinc, copper, and nitrofurantoin, as well as increased osmolality reduced conjugation frequencies. Sulfamethoxazole/trimethoprim and cefotaxime showed increased transconjugants per donor, which decreased after correction for stress. This study showed, for the model mating pair, that conjugation frequencies decreased under different physiological stress conditions, and, thus, the hypothesis that stress factors may enhance conjugation should be viewed with caution. Furthermore, for studies on in vitro gene transfer, it is vital to consider the impact of studied stressors on bacterial growth.


Assuntos
Escherichia coli/genética , Transferência Genética Horizontal , Nutrientes/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Estresse Fisiológico , Resistência beta-Lactâmica/genética , Animais , Antibacterianos/farmacologia , Cobre/farmacologia , Ácidos Graxos Voláteis/farmacologia , Genes Bacterianos/genética , Concentração de Íons de Hidrogênio , Concentração Osmolar , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/fisiologia , Zinco/farmacologia
15.
Anim Health Res Rev ; 18(1): 46-57, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28641596

RESUMO

For several billion years, bacteria have developed mechanisms to resist antibacterial substances. In modern time, antibiotics are frequently used in veterinary and human medicine for prevention and treatment of diseases, globally still also for their growth promoting effects as feed additives. This complex situation has evolved in accelerating development and prevalence of multi-drug resistant bacteria in livestock and people. Extended-spectrum beta-lactamase (ESBL) producing bacteria are resistant to a wide range of ß-lactam antibiotics. They are currently considered as one of the main threats for the treatment of infections in humans and animals. In livestock and animal products, poultry and poultry products show the highest prevalence of ESBL-producers with CTX-M-1, TEM-52 and SHV-12 being the most common ESBL-types in poultry. Escherichia coli and Salmonella spp. are the bacteria in poultry, which carry ESBL-genes most frequently. ESBL-producing bacteria are present at every level of the poultry production pyramid and can be detected even in the meconium of newly hatched chicks. The environment close to poultry barns shows high prevalence rates of these bacteria and contributes to an ongoing infection pressure with further ESBL-types. Probiotics have been shown to successfully reduce ESBL-producers in chicken, as well as ESBL-gene transfer. Other feed additives, such as zinc and copper, increase the prevalence of ESBL-producing bacteria when fed to animals. To our best knowledge, this is the first publication presenting a comparative overview of the prevalence of ESBL-types using data from different countries. To reduce the hazard for public health from poultry carrying high numbers of ESBL-producers, preventive measurements must include the surrounding environment and avoidance of antibiotic usage at all levels of the production pyramid. The first results, of the research on the impact of feed additives on the spread of ESBL-genes, indicate the diet as a further, possible magnitude of influence.


Assuntos
Antibacterianos/farmacologia , Enterobacteriaceae/enzimologia , Aves Domésticas/microbiologia , beta-Lactamases/metabolismo , Animais , Antibacterianos/administração & dosagem , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/efeitos dos fármacos
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