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Gut Pathogens Dec 2023In this study, four antimicrobial growth promoters, including virginiamycin, josamycin, flavophospholipol, poly 2-propenal 2-propenoic acid and ultraviolet light, were...
In this study, four antimicrobial growth promoters, including virginiamycin, josamycin, flavophospholipol, poly 2-propenal 2-propenoic acid and ultraviolet light, were tested for their capacity to induce stx-bacteriophages in 47 Shiga toxin-producing E. coli O157:H7 isolates. Induced bacteriophages were characterized for shiga toxin subtypes and structural genes by PCR, DNA restriction fragment length polymorphisms (RFLP) and morphological features by electron microscopy. Bacteriophages were induced from 72.3% (34/47) of the STEC O157:H7 isolates tested. Bacteriophage induction rates per induction method were as follows: ultraviolet light, 53.2% (25/47); poly 2-propenal 2-propenoic acid, 42.6% (20/47); virginiamycin, 34.0% (16/47); josamycin, 34.0% (16/47); and flavophospholipol, 29.8% (14/47). A total of 98 bacteriophages were isolated, but only 59 were digestible by NdeI, revealing 40 RFLP profiles which could be subdivided in 12 phylogenetic subgroups. Among the 98 bacteriophages, stx2a, stx2c and stx2d were present in 85.7%, 94.9% and 36.7% of bacteriophages, respectively. The Q, P, CIII, N1, N2 and IS1203 genes were found in 96.9%, 82.7%, 69.4%, 40.8%, 60.2% and 73.5% of the samples, respectively. Electron microscopy revealed four main representative morphologies which included three bacteriophages which all had long tails but different head morphologies: long hexagonal head, oval/oblong head and oval/circular head, and one bacteriophage with an icosahedral/hexagonal head with a short thick contractile tail. This study demonstrated that virginiamycin, josamycin, flavophospholipol and poly 2-propenal 2-propenoic acid induce genetically and morphologically diverse free stx-converting bacteriophages from STEC O157:H7. The possibility that these antimicrobial growth promoters may induce bacteriophages in vivo in animals and human hosts is a public health concern. Policies aimed at minimizing or banning the use of antimicrobial growth promoters should be promoted and implemented in countries where these compounds are still in use in animal agriculture.
PubMed: 38057920
DOI: 10.1186/s13099-023-00590-9 -
Translational Animal Science 2024This experiment aimed to assess the impact of virginiamycin on in vitro gas production dynamics, rumen kinetics, and nutrient digestibility in beef steers fed a...
This experiment aimed to assess the impact of virginiamycin on in vitro gas production dynamics, rumen kinetics, and nutrient digestibility in beef steers fed a grain-based diet. Nine ruminally cannulated British-crossbred steers (596 ± 49 kg) were assigned to this experiment. Animals were housed in three pens ( = 3/pen) equipped with a Calan gate feed system and water troughs. Pens were enrolled in a 3 × 3 Latin square design containing three periods of 16 d, and a 5-d washout interval between periods. Dietary treatments consisted of virginiamycin () administration at 0 (VM0), 180 (VM180), or 240 mg/d (VM240). During days 15 and 16 of each period, about 600 mL of rumen fluid and urine samples were collected before (0 h), and at 4, 8, 12, and 16 h after the morning feed (0730 hours), rumen inoculum was used to take pH and redox potential measurements immediately after collection using a portable pH and redox meter, and subsamples were taken for volatile fatty acids () and NH-N analyses, and urine samples were composited daily and analyzed for creatinine and purine derivatives () content to estimate microbial crude protein flow. During the 4-h post-morning feed rumen collection, rumen inoculum was utilized to perform in vitro gas production measurements. Fecal samples were collected on day 16 of each period to estimate nutrient digestibility using acid detergent insoluble ash as an internal marker. Animals were considered the experimental unit for the statistical analyses, and periods and squares were included as random variables. The total and rate of gas production were similar among treatments ( ≥ 0.17). The second-pool (i.e., fiber) gas production increased linearly as VM inclusion increased ( = 0.01), with VM240 being greater compared to VM180 and VM0 (7.84, 6.94, and 6.89 mL, respectively). Ruminal pH linearly increased as VM increased, with VM240 being greater than VM0 and VM180 intermediate (5.90, 5.82, and 5.86, respectively; = 0.03). The VFA concentrations did not differ ( ≥ 0.13), but the acetate-to-propionate ratio was the highest in VM240 ( = 0.005). Branched-chain VFA increased ( ≤ 0.03) while lactate concentrations decreased ( = 0.005) linearly with VM. The ruminal NH-N concentration was the lowest in the VM0 ( = 0.006). The estimated absorbed PD, purine derivative to creatinine index, and microbial N flow increased linearly with VM ( ≤ 0.07). The provision of VM influenced rumen dynamics in a dose-dependent manner.
PubMed: 38406320
DOI: 10.1093/tas/txae019 -
Journal of Dairy Science Dec 2023The objective of this study was to improve understandings of the rumen microbial ecosystem during ruminal acidosis and responses to feed additives to improve prudent use...
The objective of this study was to improve understandings of the rumen microbial ecosystem during ruminal acidosis and responses to feed additives to improve prudent use strategies for ruminal acidosis control. Rumen bacterial and archaeal community composition (BCC) and its associations with rumen fermentation measures were examined in Holstein heifers fed feed additives and challenged with starch and fructose. Heifers (n = 40) were randomly allocated to 5 treatment groups: (1) control (no additives); (2) virginiamycin (VM; 200 mg/d); (3) monensin (MT; 200 mg/d) + tylosin (110 mg/d); (4) monensin (MLY; 220 mg/d) + live yeast (5.0 × 10 cfu/d); (5) sodium bicarbonate (BUF; 200 g/d) + magnesium oxide (30 g/d). Heifers were fed twice daily a 62% forage:38% concentrate total mixed ration at 1.25% of body weight (BW) dry matter (DM)/d for a 20-d adaptation period with their additive(s). Fructose (0.1% of BW/d) was added to the ration for the last 10 d of adaptation. On d 21 heifers were challenged once with a ration consisting of 1.0% of BW DM wheat and 0.2% of BW fructose plus their additive(s). A rumen sample was collected from each heifer via stomach tube weekly (d 0, 7, 14) and 5 times over a 3.6 h period at 5, 65, 115, 165, and 215 min after consumption of the challenge ration (d 21) and analyzed for pH, and ammonia, d- and l-lactate, volatile fatty acids (VFA), and histamine concentrations and total bacteria and archaea. The 16S rRNA gene spanning the V4 region was PCR amplified and sequenced. Alpha and β diversity and associations of relative abundances of taxa with rumen fermentation measures were evaluated. Rumen BCC shifted among treatment groups in the adaptation period and across the challenge sampling period, indicating the feed additives had different modes of action. The monensin-containing treatment groups, MT and MLY often had similar relative abundances of rumen bacterial phyla and families. The MLY treatment group was characterized in the challenge period by increased relative abundances of the lactate utilizing genera Anaerovibrio and Megasphaera. The MLY treatment group also had increased diversity of ruminal bacteria which may provide resilience to changes in substrates. The control and BUF treatment groups were most similar in BCC. A redundancy analysis showed the MLY treatment group differed from all other treatment groups and concentrations of histamine and valerate in the rumen were associated with the most variation in the microbiota, 5.3% and 4.8%, respectively. It was evident from the taxa common to all treatment groups that cattle have a core microbiota. Functional redundancy of rumen bacteria which was reflected in the greater sensitivity for the rumen BCC than rumen fermentation measures likely provide resilience to changes in substrate. This functional redundancy of microbes in cattle suggests that there is no single optimal ruminal microbial population and no universally superior feed additive(s). In summary, differences in modes of action suggest the potential for more targeted and improved prudent use of feed additives with no single feed additive(s) providing an optimal BCC in all heifers.
Topics: Animals; Cattle; Female; Acidosis; Animal Feed; Archaea; Bacteria; Diet; Fermentation; Fructose; Histamine; Hydrogen-Ion Concentration; Lactates; Monensin; RNA, Ribosomal, 16S; Rumen; Saccharomyces cerevisiae; Starch
PubMed: 37678787
DOI: 10.3168/jds.2023-23486 -
Scientific Reports Sep 2023This study aimed to assess the impact of a commercial blend of functional oils, specifically cashew nutshell liquid and castor oil (FO), in two physical forms (solid: P;...
This study aimed to assess the impact of a commercial blend of functional oils, specifically cashew nutshell liquid and castor oil (FO), in two physical forms (solid: P; liquid: S), in comparison to a combination of virginiamycin and anticoccidials on the gut health of broilers challenged with coccidiosis. A total of 1760 1-day-old male chicks were randomly distributed in a study design with eight treatments. The treatments included: a control group (without additive), OFS_0.75_kg/t (FO spray), OFP_1.0_kg/t (FO powder), OFP_1.5_kg/t (FO liquid spray), Sal (anticoccidials), Sal_Vir (virginiamycin and anticoccidials), Sal_OFS_0.5_ kg/t (anticoccidials plus FO spray), and Sal_OFP_1.0_kg/t (anticoccidials plus FO powder). All birds were challenged with Eimeria spp. at 14 days. The physical form of FO did not affect performance and intestinal health parameters. At 42 days, broilers from the control and OFS_0.75 treatments were the lightest, while those from the Sal_Vir and Sal_OFP_1.0 treatments were the heaviest (P < 0.05). FO reduced the presence of Clostridium perfringens. The individual phytogenic additives did not prevent weight loss in birds challenged with Eimeria, but they mitigated the effects of the infection by modulating the intestinal microbiota. A synergistic effect was observed between the FO and anticoccidials, yielding satisfactory results in substituting virginiamycin.
Topics: Male; Animals; Chickens; Eimeria; Powders; Castor Oil; Virginiamycin
PubMed: 37670021
DOI: 10.1038/s41598-023-41743-9 -
Frontiers in Veterinary Science 2024Feed additives such as monensin (MON) and virginiamycin (VM) are commonly utilized in feedlot diets to enhance rumen fermentation. Nevertheless, the precise effects of...
Feed additives such as monensin (MON) and virginiamycin (VM) are commonly utilized in feedlot diets to enhance rumen fermentation. Nevertheless, the precise effects of combining MON and VM during specific feedlot periods and the advantages of this combination remain unclear. This study was designed to investigate the effects of withdrawal of MON when associated with VM during the adaptation and finishing periods on ruminal metabolism, feeding behavior, and nutrient digestibility in Nellore cattle. The experimental design was a 5 × 5 Latin square, where each period lasted 28 days. Five rumen-cannulated Nellore yearling bulls were used (414,86 ± 21,71 kg of body weight), which were assigned to five treatments: (1) MON during the entire feeding period; (2) VM during the entire feeding period; (3) MON + VM during the adaptation period and only VM during the finishing period 1 and 2; (4) MON + VM during the entire feeding period; (5) MON + VM during the adaptation and finishing period 1 and only VM during the finishing period 2. For the finishing period 1, animals fed T3 had improved potential degradability of dry matter ( = 0.02). Cattle fed T3 and T5 had the highest crude protein degradability when compared to animals receiving T2 ( = 0.01). Animals fed T2 and T3 had reduced the time ( < 0.01) and area under pH 6.2 ( = 0.02). Moreover, animals fed T4 had greater population of protozoa from the genus ( = 0.04) when compared to those from animals fed T2, T3 and T5. For the finishing period 2, animals fed T3 had greater starch degradability when compared to animals receiving T4 and T5 ( = 0.04). Animals fed T3, T4 and T5 had increased the duration of time in which pH was below 5.6 ( = 0.03). The area under the curve for ruminal pH 5.2 and pH 5.6 was higher for the animals fed T3 ( = 0.01), and the area under pH 6.2 was higher for the animals fed T3 and T5 ( < 0.01) when compared to animals receiving T2. There is no substantial improvement on the rumen fermentation parameters by the concurrent utilization of MON and VM molecules, where the higher starch and protein degradability did not improve the rumen fermentation.
PubMed: 38605925
DOI: 10.3389/fvets.2024.1325198 -
Microorganisms Jul 2023Antimicrobial growth promoters (AGP) are used in chicken production to suppress pathogens in the gut and improve performance, but such products tend to suppress...
An Immobilized Form of a Blend of Essential Oils Improves the Density of Beneficial Bacteria, in Addition to Suppressing Pathogens in the Gut and Also Improves the Performance of Chicken Breeding.
Antimicrobial growth promoters (AGP) are used in chicken production to suppress pathogens in the gut and improve performance, but such products tend to suppress beneficial bacteria while favoring the development and spread of antimicrobial resistance. A green alternative to AGP with the ability to suppress pathogens, but with an additional ability to spare beneficial gut bacteria and improve breeding performance is urgently required. We investigated the effect of supplementation of a blend of select essential oils (cinnamon oil, carvacrol, and thyme oil, henceforth referred to as EO; at two doses: 200 g/t and 400 g/t feed) exhibiting an ability to spare Lactobacillus while exhibiting strong inhibition ability under in vitro tests and immobilized in a sunflower oil and calcium alginate matrix, to broiler chickens and compared the effects with those of a probiotic yeast (Y), an AGP virginiamycin (V), and a negative control (C). qPCR analysis of metagenomic DNA from the gut content of experimental chickens indicated a significantly ( < 0.05) lower density of in the EO groups as compared to other groups. Amplicon sequence data of the gut microbiome indicated that all the additives had specific significant effects (DESeq2) on the gut microbiome, such as enrichment of uncultured Clostridia in the V and Y groups and uncultured Ruminococcaceae in the EO groups, as compared to the control. LEfSe analysis of the sequence data indicated a high abundance of beneficial bacteria Ruminococcaceae in the EO groups, Faecalibacterium in the Y group, and Blautia in the V group. Supplementation of the immobilized EO at the dose rate of 400 g/ton feed improved body weight gain (by 64 g/bird), feed efficiency (by 5 points), and cellular immunity (skin thickness response to phytoheamagglutinin lectin from by 58%) significantly ( < 0.05), whereas neither yeast nor virginiamycin showed a significant effect on performance parameters. Expression of genes associated with gut barrier and immunity function such as , , , , and were significantly higher in the EO groups. This study showed that the encapsulated EO mixture can improve the density of beneficial microbes in the gut significantly, with concomitant suppression of potential pathogens such as and improved performance and immunity, and hence, has a high potential to be used as an effective alternative to AGP in poultry.
PubMed: 37630519
DOI: 10.3390/microorganisms11081960 -
Biology Sep 2023We report on a highly virulent, multidrug-resistant strain of IRMC827A that was found colonizing a long-term male patient at a tertiary hospital in Khobar, Saudi...
We report on a highly virulent, multidrug-resistant strain of IRMC827A that was found colonizing a long-term male patient at a tertiary hospital in Khobar, Saudi Arabia. The IRMC827A strain carries several antimicrobial drug resistance genes and harbours mobile genetic elements such as Tn6009, which is an integrative conjugative element that can transfer resistance genes between bacteria and ISS1N via an insertion sequence. Whole-genome-sequencing-based antimicrobial susceptibility testing on strains from faecal samples revealed that the isolate IRMC827A is highly resistant to a variety of antibiotics, including tetracycline, doxycycline, minocycline, dalfopristin, virginiamycin, pristinamycin, chloramphenicol, streptomycin, clindamycin, lincomycin, trimethoprim, nalidixic acid and ciprofloxacin. The isolate IRMC827A carries several virulence factors that are significantly associated with adherence, biofilm formation, sortase-assembled pili, manganese uptake, antiphagocytosis, and spreading factor of multidrug resistance. The isolate also encompasses two mutations (G2576T and G2505A) in the gene associated with linezolid resistance and three more mutations ( p.S83Y, p.D759N and p.S80I) of the antimicrobial resistance phenotype. The findings through next-generation sequencing on the resistome, mobilome and virulome of the isolate in the study highlight the significance of monitoring multidrug-resistant colonization and infection in hospitalized patients. As multidrug-resistant is a serious pathogen, it is particularly difficult to treat and can cause fatal infections. It is important to have quick and accurate diagnostic tests for multidrug-resistant , to track the spread of multidrug-resistant in healthcare settings, and to improve targeted interventions to stop its spread. Further research is necessary to develop novel antibiotics and treatment strategies for multidrug-resistant infections.
PubMed: 37887006
DOI: 10.3390/biology12101296 -
Journal of Global Antimicrobial... Dec 2023The aim of this study was to characterise the whole genome sequence of multidrug-resistant Streptococcus pluranimalium strain SP21-2 of swine origin in China.
OBJECTIVES
The aim of this study was to characterise the whole genome sequence of multidrug-resistant Streptococcus pluranimalium strain SP21-2 of swine origin in China.
METHODS
Illumina Miseq (200X coverage) and Nanopore PromethION platform (100X coverage) were used for genome sequencing. Rapid Annotation using Subsystem Technology (RAST) was used to annotate the genome of SP21-2. The antimicrobial resistance genes (ARGs) were identified using ResFinder-4.1.
RESULTS
The assembled circular genome of S. pluranimalium SP21-2 was 1,987,058 bp in length with a GC content of 39.54%, and no plasmid sequence was detected. A total of 2086 coding sequences were predicted by RAST. Oxazolidinone-phenicol resistance gene, optrA, and pleuromutilin-lincosamide-streptogramin A resistance gene, lsa(E), are both located on chromosomes, associated with IS1216 and ISS1S, respectively. In addition, SP21-2 harbours lnu(B) (lincosamide), ant (6)-Ia and aac(6')-aph(2") (aminoglycoside), erm(B) (macrolide), and tet(O) (tetracycline).
CONCLUSION
We firstly report the oxazolidinone-phenicol gene, optrA, and pleuromutilin-lincosamide-streptogramin A resistance gene, lsa(E), in S. pluranimalium. In this strain, we firstly identified ISS1S and IS1216 carrying ARGs in S. pluranimalium, which will provide a valuable reference to understanding potential transfer mechanisms of ARGs in S. pluranimalium.
Topics: Animals; Swine; Streptogramin A; Anti-Bacterial Agents; Lincosamides; Anti-Infective Agents; Oxazolidinones; Chromosomes; Pleuromutilins
PubMed: 37709136
DOI: 10.1016/j.jgar.2023.09.007 -
Journal of Dairy Science May 2024Heifers (n = 40) were randomly allocated to 5 treatment groups: (1) control (no additives); (2) virginiamycin (VM; 200 mg/d); (3) monensin (MT; 200 mg/d) + tylosin (110...
Heifers (n = 40) were randomly allocated to 5 treatment groups: (1) control (no additives); (2) virginiamycin (VM; 200 mg/d); (3) monensin (MT; 200 mg/d) + tylosin (110 mg/d); (4) monensin (MLY; 220 mg/d) + live yeast (5.0 × 10 cfu/d); (5) sodium bicarbonate (BUF; 200 g/d) + magnesium oxide (30 g/d).
PubMed: 38637063
DOI: 10.3168/jds.2024-107-5-3336 -
Heliyon Feb 2024The seaweeds are in focus for their immunity and gut health-stimulating potentials in humans and farm animals, but their potential as a gut health-promoting agent and...
The seaweeds are in focus for their immunity and gut health-stimulating potentials in humans and farm animals, but their potential as a gut health-promoting agent and performance booster to replace antibiotic growth promoters (AGP) in broiler chicken-feed remains to be evaluated. feeding experiments were conducted on commercial broiler chickens (1-42 days post-hatch) to evaluate dried aqueous exact of red seaweed (referred to as PBD 5). Each of the three test diets (basal diet with three dosing regimens of PBD5, 0.25 g kg for 0-6 weeks, 0.25 g kg for 0-4 weeks or 1.0 g kg for 0-2 weeks), along with an AGP supplemented diet (Virginiamycin (V), 20 ppm in basal diet), and a control diet was fed to 13 pen replicates of five chicks in each. PBD5 at 1.0 g kg diet for 0-2 weeks improved (P < 0.05) cumulative feed efficiency (4.65 % improvement at 28 d, and 3.74 % at 35 d) than the control and comparable to the V group and the trend in improvement persisted up to 42 d. The group fed with PBD5 @ 1.0 g kg for 0-2 weeks had significantly (P < 0.05) higher serum IgG level, glutathione peroxidase levels, fat digestibility, and expression of occludin and avian beta-defensin 4 gene in the gut and a trend of increased expression of growth hormone receptor gene in the liver as compared to the control with no significant effect on body weight, phytohemagglutinin response or haemagglutination inhibition titer. At d 25 of age, fecal count was significantly (P < 0.01) lower in the seaweed extract groups and the V group as compared to the control. It can be concluded that dried aqueous extract of at 1 g kg diet for 0-2 weeks can be used as an alternative to antibiotic growth promoter in broiler chickens to improve feed efficiency and reduce gut pathogen load, and the improved performance was associated with increased expression of gut immunity and growth hormone receptor genes.
PubMed: 38333794
DOI: 10.1016/j.heliyon.2024.e25219