Intestinal microbial diversity of swines fed with different sources of lithium.

A drug that is widely used in the treatment of psychiatric disorder is lithium (Li) salts. The people who make therapeutic use of this drug develop a series of side effects. Through metataxonomic data, this study assessed the impacts of lithium, as Li carbonate or Li-enriched mushrooms, on the microbial composition of the ileum, colon, and feces of piglets. Employing Bray-Curtis metric, no differences were observed among the treatments evaluated. Nevertheless, the alpha diversity indices showed differences in the Simpson, Shannon, and Chao-1 indices in the colon and Chao-1 in the feces in the diets with Li compared with the diets without Li. The taxa with the highest relative abundance varied among the ileum, colon, and feces, with a predominance of the phyla Firmicutes, Bacteroidota, and Proteobacteria in diets with Li. Many groups of microorganisms that are important for the health of the host (e.g., Lactobacillus, Ruminococcaceae, Enterorhabdus, Muribaculaceae, and Coprococcus) had their relative abundance increased in animals that received diets with the recommended dose of lithium. Furthermore, there was an increase in the abundance of Prevotellaceae and Bacteroidales (in the diet with Li-enriched mushroom) and Clostridia, Ruminococcus, Burkholderia, and Bacteroidales (diets with Li carbonate) at the recommended dosages. This is the first study to show the effects of Li carbonate and Li-enriched mushrooms on the intestinal microbiota of piglets. Thus, the effects of lithium on the body may be related to its ability to change the composition of the intestinal microbiota. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03938-3.

Prevalence and characteristics of ESBL-producing Escherichia coli in clinically healthy pigs: implications for antibiotic resistance spread in livestock.

AIM: This study aimed to compare and characterize the resistance profile and the presence of extended-spectrum beta-lactamase (ESBL) related genes in Escherichia coli isolated from healthy finishing pigs fed with or without antibiotics in their diets. METHODS AND RESULTS: A total of 27 ceftiofur-resistant E. coli isolates were obtained from 96 healthy pigs. The antibiotic resistance profile was tested, and all 27 isolates were classified as multidrug-resistant (MDR). A high proportion of isolates were resistant to cephalosporins, ampicillin, ciprofloxacin, and tetracyclines. The ESBL production was observed in 85% of isolates by double-disc synergy test. The MDR-E. coli isolates harbored ESBL genes, such as blaTEM, blaCTX-M-1, blaCTX-M-2, and blaCTX-M-8,25. In addition, other antibiotics resistance genes (ARGs) were also detected, such as sul2, ant(3″)-I, tetA, and mcr-1. The mobilization of the blaCTX-M gene was confirmed for nine E. coli isolates by conjugation assays. The presence of blaCTX-M on mobile genetic elements in these isolates was demonstrated by Southern blot hybridization, and the resistance to cephalosporins was confirmed in the transconjugants. Our results indicate the prevalence of CTX-M-producing E. coli strains harboring mobile genetic elements in the normal microbiota of healthy pigs. CONCLUSIONS: These findings highlight the significance of ESBL genes as a global health concern in livestock and the potential spread of antimicrobial resistance to other members of the gastrointestinal tract microbiota.

Comparison of ruminal microbiota, IL-1ß gene variation, and tick incidence between Holstein × Gyr and Holstein heifers in grazing system.

Introduction: The variation in bacterial communities among breeds has been previously reported and may be one of the reasons why Holstein × Gyr dairy heifers have better development in grazing systems in tropical conditions. This study aimed to explore the ruminal microbiota composition, the IL-1ß gene variation, tick incidence, and blood parameters of Holstein × Gyr (½ Holstein × ½ Gyr) and Holstein heifers grazing intensely managed Guinea grass (Panicum maximum Jacq. cv. Mombaça). Methods: Sixteen heifers were divided into two groups consisting of 8 Holstein × Gyr and 8 Holstein heifers. The experimental period was comprised of 3 periods of 21 days. Ruminal samples were taken via the stomach tube technique. The sequencing of the V4 hypervariable region of the 16S rRNA gene was performed using the Illumina MiSeq platform. Counting and collection of ticks were conducted each 21 days. Blood and skeletal muscle tissue biopsies were performed at the end of the experiment. Results: Firmicutes were the most abundant phyla present in both breed rumen samples and Bacteroidota showed differences in relative abundance between breed groups, with greater values for Holstein heifers (p < 0.05 with FDR correction). The 10 most abundant unique OTUs identified in each breed included several OTUs of the genus Prevotella. Holstein heifers had a greater tick count and weight (9.8 ticks/animal and 1.6 g/animal, respectively) than Holstein × Gyr (2.56 ticks/animal and 0.4 g/animal, respectively). We found nucleotide substitutions in the IL-1ß gene that might be related to adaptation and resistance phenotypes to tick infestation in Holstein × Gyr heifers. Blood concentrations of urea, albumin, insulin-like growth factor 1, triiodothyronine, and thyroxine were greater in Holstein × Gyr than in Holstein heifers. Conclusion: Adaptations in Holstein × Gyr heifers such as ruminal microbiota, tick resistance, nucleotide substitutions in IL-1ß gene, and hormone concentration suggest a better energy metabolism and thermoregulation resulting in better performance in tropical grazing systems.

Antimicrobial Resistance Profiles of Multidrug-Resistant Enterobacteria Isolated from Feces of Weaned Piglets.

Nosocomial infections caused by multidrug-resistant enterobacteria have become a major challenge in global public health. Previous studies have indicated that use of antibiotics in livestock production chains is linked to the rising threat of antibiotic resistance in humans. In this study, we aimed to evaluate the distribution of genes encoding resistance to tetracycline, ß-lactams, and colistin in multidrug-resistant enterobacteria isolated from feces of weaned pigs. Ninety-four enterobacteria isolates were submitted to antibiotic susceptibility test by minimum inhibitory concentration (MIC). In addition, we performed conjugation experiments to verify if plasmid-bearing isolates containing the mcr-1 gene could transfer their resistance determinant to a colistin-sensitive recipient strain. Our results demonstrated a positive association between the detection of antibiotic resistance genes in enterobacteria and the phenotypic resistance profiles of the bacterial isolates. At least one of the extended-spectrum ß-lactamases (ESBL) genes (blaCTX-M, blaTEM, or bla SHV) and tetA was found among most bacterial genera analyzed. In addition, results revealed that the mcr-1 gene can be transferred from E. coli UFV-627 isolate to an F- recipient (Escherichia coli K12) by conjugation. Our findings support the hypothesis that swine represents an important reservoir of antibiotic resistance genes and suggest that horizontal transfer mechanisms (e.g., conjugation) may mediate the spread of these genes in the swine gastrointestinal tract.

Bioavailability of Li-enriched mushrooms and protection against oxidative stress in pigs: First study in vivo.

Mycelia and mushrooms are able to bioaccumulate minerals. Lithium is the active principle of drugs used in the treatment of psychiatric diseases. However, a dietary source of Li can reduce the side effects of these drugs. Thus, the objective of this study was to evaluate the bioavailability of Li-enriched mushroom of Pleurotus djamor in pigs and the effects of this element on oxidative stress in the animal tissues. Pigs 28-30 days-old were fed with diets containing or not Li for five days. Levels of serum cortisol were related to the Li dosage from diet. Li-enriched mushrooms were more bioavailable source of Li to the body than Li2CO3. These mushrooms also improved the effects of oxidative enzymes and showed less oxidative damage than Li2CO3. These results demonstrate the potential to use Li-enriched P. djamor as a source of Li that is more bioavailable and present protective effects against oxidative stress.

Cooked common bean flour, but not its protein hydrolysate, has the potential to improve gut microbiota composition and function in BALB/c mice fed a high-fat diet added with 6-propyl-2-thiouracil.

Common bean has the potential to improve gut microbiota function due to its chemical composition and content of dietary fiber. This study evaluated the effect of cooked common bean (CCB) flour and its protein hydrolysate as part of a high-fat diet (HFD) added with 6-propyl-2-thiouracil (10 mg/kg/d), an inhibitor of thyroid hormone synthesis, on gut health of BALB/c mice. Forty-eight adult mice were divided into four groups: normal control; HFD; HFD plus CCB flour (346.6 g/kg of diet) (HFBF group) and HFD plus CCB protein hydrolysate (700 mg/Kg/d) (HFPH group). HFBF, but not HFPH, increased cecum weight, and the moisture, and lipids in the excreted feces, compared to control groups. Sequencing of the 16S rRNA gene of the cecal microbiota indicated changes in the beta-diversity between the HFBF and HFPH groups, compared to the normal control. The abundance of Bacteroidetes increased and the Firmicutes/Bacteroidetes ratio decreased in the HFBF compared to control groups. However, HFPH was not able to prevent the damage caused by a HFD to the gut bacterial communities. The OTUs enriched by HFBF were mainly assigned to members of the Muribaculaceae family, which shows potential to improve gut health. The intake of CCB flour improved intestinal health and modulated the composition and function of the cecal microbiota, attenuating the effects of the HFD, added wit 6-propyl-2-thiouracil, when fed to BALB/c mice.

A Genetically Modified Anti-Plasmodium Bacterium Is Harmless to the Foragers of the Stingless Bee Partamona helleri.

Paratransgenesis consists of genetically engineering an insect symbiont to control vector-borne diseases. Biosafety assessments are a prerequisite for the use of genetically modified organisms (GMOs). Assessments rely on the measurement of the possible impacts of GMOs on different organisms, including beneficial organisms, such as pollinators. The bacterium Serratia AS1 has been genetically modified to express anti-Plasmodium effector proteins and does not impose a fitness cost on mosquitoes that carry it. In the present study, we assessed the impact of this bacterium on the native bee Partamona helleri (Meliponini), an ecologically important species in Brazil. Serratia eGFP AS1 (recombinant strain) or a wild strain of Serratia marcescens were suspended in a sucrose solution and fed to foragers, followed by measurements of survival, feeding rate, and behavior (walking and flying). These bacteria did not change any of the variables measured at 24, 72, and 144 h after the onset of the experiment. Recombinant and wild bacteria were detected in the homogenates of digestive tract during the 144 h period analyzed, but their numbers decreased with time. The recombinant strain was detected in the midgut at 24 h and in the hindgut at 72 h and 144 h after the onset of the experiment under the fluorescent microscope. As reported for mosquitoes, Serratia eGFP AS1 did not compromise the foragers of P. helleri, an ecologically relevant bee.

Effect of the ingestion of vegetable oils associated with energy-restricted normofat diet on intestinal microbiota and permeability in overweight women.

Previous studies suggest that the type of dietary fatty acid may modulate the intestinal bacterial ecosystem. However, this effect is still inconclusive. Thus, the aim of this study was to investigate the effect of the intake of vegetable oils rich in different types of fatty acids, associated with energy-restricted normofat diets, on the composition of intestinal microbiota and permeability, on LPS concentrations, and fecal short chain fatty acids and pH. This was a 9 consecutive weeks (±5 days), randomized, parallel, double-blind clinical trial. Overweight women received daily breakfast containing 25 mL of one of the test oils: soybean oil (n = 17), extra virgin olive oil (n = 19) or coconut oil (n = 16). Blood, fecal and urine samples were collected on the first and last day of the experiment for the analysis of the variables of interest. The consumption of the three oils did not affect the diversity and relative abundance of intestinal bacteria. We observed an increase in bacterial richness estimated by the Chao 1 index, and a reduction in the concentration of isovaleric fatty acid in the group that ingested soybean oil. Paracellular and transcellular permeability increased after the ingestion of extra virgin olive oil and coconut oil. However, LPS concentrations remained unchanged. The intake of different types of fatty acids associated with the energy-restricted normofat diet modestly affected the intestinal microbiota and permeability, without resulting in metabolic endotoxemia in overweight women.