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Veterinary Microbiology Nov 2020The prevalence and antimicrobial susceptibility of Clostridium perfringens (C. perfringens) in chickens and pigs were investigated in Beijing and Shanxi, China. In...
The prevalence and antimicrobial susceptibility of Clostridium perfringens (C. perfringens) in chickens and pigs were investigated in Beijing and Shanxi, China. In total, 322 C. perfringens (chicken n = 60 and pig n = 262) were obtained from 620 feces of chickens (n = 256) and pigs (n = 364). Multiplex PCR for toxin typing of C. perfringens revealed that all the isolates belong to type A, with 45.7 % (147/322) isolates carrying beta-2 toxin-encoding gene cpb2. Minimum inhibitory concentrations of 27 antimicrobial agents showed that 91.0 % of the tested C. perfringens isolates were resistant to gentamicin and sulfonamides (sulfisoxazole and trimethoprim-sulfamethoxazole), and little resistance was showed to amoxicillin-clavulanate, ceftiofur, doxycycline, vancomycin and linezolid. Additionally, nosiheptide, avilamycin, virginiamycin and bacitracin exhibited good activity against the tested C. perfringens with low MIC (0.06 to ≤4 μg/mL) and MIC values (0.25-8 μg/mL). Whole genome sequencing (WGS) of 48 representative isolates from each farm indicated that the C. perfringens contained diverse antimicrobial resistance genes [tetA(P), ant(6)-Ib, erm(Q), etc.] and toxin genes (cpb2, colA, cloSI, pfoA, etc.). By comparative analysis, four C. perfringens isolates from three different pig farms harboured cpb2-carrying plasmid p1 with 100 % nucleotide sequence identity, suggesting horizontal gene transfer among these microorganisms. The further phylogenomic reconstruction, based on the core-genome single nucleotide polymorphisms (SNPs) of the representatives, demonstrating that C. perfringens from the same farms and regions were closely related. These findings expanded our knowledge of C. perfringens isolated from animals in China, which provided scientific basis for efficient intervention or prevention measures of antimicrobial resistance in animal husbandry in China.
PubMed: 33316633
DOI: 10.1016/j.vetmic.2020.108932 -
Microbiology Spectrum Jun 2023Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) clonal complex 398 (CC398) isolates ( = 178) collected in the national resistance...
Genomic Diversity of Methicillin-Resistant Staphylococcus aureus CC398 Isolates Collected from Diseased Swine in the German National Resistance Monitoring Program GE-Vet from 2007 to 2019.
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) clonal complex 398 (CC398) isolates ( = 178) collected in the national resistance monitoring program GE-Vet from diseased swine in Germany from 2007 to 2019 were investigated for their genomic diversity with a focus on virulence and antimicrobial resistance (AMR) traits. Whole-genome sequencing was followed by molecular typing and sequence analysis. A minimum spanning tree based on core-genome multilocus sequence typing was constructed, and antimicrobial susceptibility testing was performed. Most isolates were assigned to nine clusters. They displayed close phylogenetic relationships but a wide molecular variety, including 13 types and 19 known and four novel types. Several toxin-encoding genes, including , , , , and , were detected. The isolates harbored a wide range of AMR properties mirroring the proportions of the classes of antimicrobial agents applied in veterinary medicine in Germany. Multiple novel or rare AMR genes were identified, including the phenicol-lincosamide-oxazolidinone-pleuromutilin-streptogramin A resistance gene , the lincosamide-pleuromutilin-streptogramin A resistance gene (C), and the novel macrolide-lincosamide-streptogramin B resistance gene (54). Many AMR genes were part of small transposons or plasmids. Clonal and geographical correlations of molecular characteristics and resistance and virulence genes were more frequently observed than temporal relations. In conclusion, this study provides insight into population dynamics of the main epidemic porcine LA-MRSA lineage in Germany over a 13-year-period. The observed comprehensive AMR and virulence properties, most likely resulting from the exchange of genetic material between bacteria, highlighted the importance of LA-MRSA surveillance to prevent further dissemination among swine husbandry facilities and entry into the human community. The LA-MRSA-CC398 lineage is known for its low host specificity and frequent multiresistance to antimicrobial agents. Colonized swine and their related surroundings represent a considerable risk of LA-MRSA-CC398 colonization or infection for occupationally exposed people through which such isolates might be further disseminated within the human community. This study provides insight into the diversity of the porcine LA-MRSA-CC398 lineage in Germany. Clonal and geographical correlations of molecular characteristics and resistance and virulence traits were detected and may be associated with the spread of specific isolates through livestock trade, human occupational exposure, or dust emission. The demonstrated genetic variability underlines the lineage's ability to horizontally acquire foreign genetic material. Thus, LA-MRSA-CC398 isolates have the potential to become even more dangerous for various host species, including humans, due to increased virulence and/or limited therapeutic options for infection control. Full-scale LA-MRSA monitoring at the farm, community, and hospital level is therefore essential.
Topics: Animals; Humans; Swine; Methicillin-Resistant Staphylococcus aureus; Phylogeny; Streptogramin A; Staphylococcal Infections; Anti-Bacterial Agents; Genomics; Lincosamides; Livestock; Pleuromutilins
PubMed: 37154741
DOI: 10.1128/spectrum.00770-23 -
Veterinary World Mar 2022Although and are common members of human and animal gut microbiota, their resistance to different antimicrobials makes them important pathogens. Multidrug-resistant...
BACKGROUND AND AIM
Although and are common members of human and animal gut microbiota, their resistance to different antimicrobials makes them important pathogens. Multidrug-resistant enterococci often contaminate foods of animal origin at slaughterhouses. The World Health Organization and the World Organization for Animal Health recommend including animal-derived enterococci in antimicrobial resistance (AMR) monitoring programs. This study aimed to fill a literature gap by determining the current AMR prevalence of and from different food-producing animals in Russia.
MATERIALS AND METHODS
Samples of biomaterial were taken from chickens (n=187), cattle (n=155), pigs (n=49), turkeys (n=34), sheep (n=31), and ducks (n=31) raised at 28 farms in 15 regions of Russia. Isolates of (n=277) and of (n=210) (487 isolates in total; 1 isolate per sample) were tested for resistance to 12 antimicrobials from 11 classes using the broth microdilution method. Three criteria were used for the interpretation of minimum inhibitory concentration: Epidemiological cutoff values (ECOFFs) from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) clinical breakpoints. The AMR cloud online platform was used for data processing and statistical analysis.
RESULTS
A difference of >10% was found between and resistance to several antimicrobials (erythromycin, gentamycin, tetracycline, chloramphenicol, ciprofloxacin, and streptomycin). In total, resistance to most antimicrobials for enterococci isolates of both species taken from turkeys, chicken, and pigs was higher than cattle, sheep, and ducks. The highest levels were found for turkeys and the lowest for ducks. Among antimicrobials, resistance to bacitracin and virginiamycin was 88-100% in nearly all cases. High levels of clinical resistance were found for both bacteria species: Rifampicin (44-84%) from all animals, tetracycline (45-100%) from poultry and pigs, and erythromycin (60-100%), ciprofloxacin (23-100%), and trimethoprim-sulfamethoxazole (33-53%) from chickens, turkeys, and pigs. No vancomycin-resistant isolates were found. Most isolates were simultaneously resistant to one-three classes of antimicrobials, and they were rarely resistant to more than three antimicrobials or sensitive to all classes.
CONCLUSION
Differences in resistance between enterococci from different farm animals indicate that antimicrobial application is among the crucial factors determining the level of resistance. Conversely, resistance to rifampicin, erythromycin, tetracycline, and ciprofloxacin found in enterococci from farm animals in our study was notably also found in enterococci from wild animals and birds. Our results may be partly explained by the intrinsic resistance of and to some antimicrobials, such as trimethoprim/sulfamethoxazole and bacitracin.
PubMed: 35497972
DOI: 10.14202/vetworld.2022.611-621 -
PloS One 2021An experiment was conducted to evaluate the feed intake, nutrient digestibility and selected rumen parameters in feedlot bulls fed diets containing different feed...
An experiment was conducted to evaluate the feed intake, nutrient digestibility and selected rumen parameters in feedlot bulls fed diets containing different feed additives. Six rumen-cannulated Nellore bulls (age = 8 ± 1.0 months; initial BW = 225 ± 13.2 kg) were distributed in a 6 × 6 Latin square design. Six experimental diets based on 30% corn silage and 70% concentrate on a dry matter (DM) basis were evaluated. Diets differed in feed additive on a DM basis, as follows: 1.4% bicarbonate and magnesium oxide in 3:1 ratio (BOX); 36 ppm lasalocid sodium (LAS); 30 ppm monensin sodium (MON); 25 ppm virginiamycin (VIR); 30 ppm monensin sodium plus 25 ppm virginiamycin (MV); and 3.15% commercial mineral supplement containing D-limonene and exogenous α-amylase (EOA). The experiment lasted 144 d, with six periods of 24 d. Each period consisted of 14 d for dietary adaptation, 3 d for feces and urine collection, and 7 d for omasal and ruminal digesta collection. Bulls fed the BOX diet showed greater (P < 0.05) intake of DM, organic matter (OM), neutral detergent fiber (apNDF), crude protein (CP), and starch compared to the other diets. Diets with LAS, MON, VIR, MV, or EOA did not influence (P > 0.05) the DM, OM, apNDF, CP, or starch intake of feedlot bulls. Bulls fed the EOA diet showed greater (trend; P = 0.09) ruminal digestibility of starch compared to the other diets. The feed additives did not affect (P > 0.05) the intestinal or total tract digestibility of starch, rumen pH, microbial efficiency, total rumen fluid, dilution rate, rate of intake, rate of degradation, or passage rate of the DM, OM, apNDF, and starch. In conclusion, LAS, MON, VIR, MV, and EOA diets reduced nutrient intake compared to BOX. Although all feed additives presented similar effects on rumen pH, temperature, and kinetics the presence of exogenous α-amylase in the EOA diet may increase ruminal starch digestibility and apparent total tract digestibility of DM and OM.
Topics: Animals; Eating; Monensin; Nutrients; Rumen; Silage
PubMed: 34727141
DOI: 10.1371/journal.pone.0259414 -
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 -
PloS One 2022This study aimed to compare the effects of different levels of cashew nutshell liquid (CNSL) and castor oil (CNSL-castor oil) with growth-promoting antibiotics...
This study aimed to compare the effects of different levels of cashew nutshell liquid (CNSL) and castor oil (CNSL-castor oil) with growth-promoting antibiotics associated with anticoccidials in broiler chickens challenged with coccidiosis. In this work, 2520 one-day-old male broiler chicks (Cobb) were randomly assigned to 84 pens, containing 30 birds each. The experimental design was completely randomized, with seven treatments: enramycin (8 ppm), virginiamycin (16.5 ppm), and tylosin (55 ppm); different doses of CNSL-castor oil (0.5, 0.75, and 1.00 kg/t); and a control diet (without additives). All treatments received semduramicin + nicarbazin (500 g/t; Aviax® Plus) from 0 to 28 d and monensin sodium (100 ppm; Elanco) from 29 to 35 days of age, when the feed was without antibiotics. The challenge was introduced at 14 days of age by inoculating broiler chickens with sporulated Eimeria tenella, Eimeria acervulina, and Eimeria maxima oocysts via oral gavage. In addition to performance parameters, intestinal contents were collected at 28 and 42 days of age for microbiota analysis by sequencing the 16s rRNA in V3 and V4 regions using the Illumina MiSeq platform. Taxonomy was assigned using the SILVA database (v. 138) with QIIME2 software (v. 2020.11). After one week of challenge, the broilers that received tylosin had a higher body weight gain (BWG) than those in the control group (p < 0.05), while the other treatments presented intermediate values. At 28 d, the BWG was lower for the control, CNSL-Castor oil 0.5 kg/t, enramycin, and virginiamycin treatments than that in the tylosin treatment. The inclusion of CNSL-Castor oil at concentrations of 0.75 and 1 kg/t acted as an intermediate treatment (p < 0.05). For alpha diversity, using the Shannon index, it was possible to observe the effect of age, with substantial diversity at 42 d. The Firmicutes phylum had the highest abundance, with values between 84.33% and 95.16% at 42 d. Tylosin showed better performance indices than other treatments. CNSL-castor oil treatments with concentrations of 0.75 and 1 kg/t showed similar results to those of enramycin and virginiamycin. Furthermore, CNSL-castor oil acted as a modulator of intestinal microbiota, reducing the abundance of pathogenic bacteria.
Topics: Anacardium; Animals; Anti-Bacterial Agents; Castor Oil; Chickens; Coccidiosis; Eimeria; Male; Microbiota; RNA, Ribosomal, 16S; Tylosin; Virginiamycin
PubMed: 35793288
DOI: 10.1371/journal.pone.0270350 -
MSystems Aug 2021The antibiotic growth promoters (AGPs) flavophospholipol and virginiamycin have been widely used for decades in food animal production. AGP activity is believed to be...
The antibiotic growth promoters (AGPs) flavophospholipol and virginiamycin have been widely used for decades in food animal production. AGP activity is believed to be partly modulated by gut microbial composition although exact AGP-induced changes remain unclear. In a controlled intervention study, we studied the effect of flavophospholipol and virginiamycin on the broiler chicken ileal microbiota spanning from birth to 39 days. Using 16S rRNA gene profiling and prediction of metabolic activity, we show that both AGPs result in dynamic microbial shifts that potentially increase anti-inflammatory mechanisms and bioavailability of several essential nutrients by decreasing degradation (flavophospholipol) or increasing biosynthesis (virginiamycin). Further, virginiamycin-supplemented broilers showed increased colonization with potentially pathogenic bacteria, Clostridium perfringens, Campylobacter, and Escherichia/ spp. Overall, we show that both AGPs induce microbial changes potentially beneficial for growth. However, the increase in (foodborne) pathogens shown here with virginiamycin use could impact not only broiler mortality but also human health. Antibiotic growth promoters (AGPs) are commonly used within poultry farming to increase muscle growth. Microbial composition in the gut is known to be influenced by AGP use although exact AGP-induced changes remain unclear. Utilizing 16S rRNA gene profiling, this study provides a first head-to-head comparison of the effect of the two most commonly used AGPs, flavophospholipol and virginiamycin, on the broiler chicken ileum microbiota over time. We found that supplementation with both AGPs altered ileal microbial composition, thereby increasing potential bioavailability of essential nutrients and weight gain. Flavophospholipol showed a slight benefit over virginiamycin as the latter resulted in more extensive microbial perturbations including increased colonization by enteropathogens, which could impact broiler mortality.
PubMed: 34463581
DOI: 10.1128/mSystems.00381-21 -
Molecular Biology Reports Aug 2022Streptogramins and linezolid are important in the treatment of infections caused by vancomycin-resistant enterococci.
Dissemination of Quinupristin-Dalfopristin and Linezolid resistance genes among hospital environmental and healthy volunteer fecal isolates of Enterococcus faecalis and Enterococcus faecium.
BACKGROUND
Streptogramins and linezolid are important in the treatment of infections caused by vancomycin-resistant enterococci.
PURPOSE
Then, we aimed to evaluate the resistance rates against these drugs and the prevalence of genes involved in hospital environmental and fecal normal-flora isolates of Enterococcus faecalis and Enterococcus faecium.
METHODS AND RESULTS
The strains were isolated from the stool samples and hospital environments by culturing on M-Enterococcus (ME) agar, and identified by phenotypic and genotypic microbiological tests. The disk agar diffusion method was used to identify the antimicrobial susceptibility pattern of the isolates. The genomic DNA extraction was done by the alkaline lysis method, and the PCR test was used to detect the resistance genes. A total of 145 enterococci isolates were taken, from which 84 (57.9%) isolates were detected as E. faecalis and 61 (42.06%) isolates were E. faecium. Moreover, 70 (83.33), 4 (4.76%), 1 (1.19%), and 40 (47.61%) isolates of E. faecalis and 20 (32.78%), 1 (1.63%), 4 (6.55%), and 26 (42.62%) E. faecium isolates were resistant against quinupristin-dalfopristin, linezolid, vancomycin, and erythromycin, respectively. Also, 112 (77.24%), 50 (34.48%), 39 (26.89%), 27 (18.62%), 19 (13.1%), 4 (2.75%), and 1 (0.68%) isolates were contained LsaA, vatD, vgbB, vatE, cfr, lsaE and optrA genes, respectively. None of the isolates carried the vgbA gene.
CONCLUSIONS
High-level streptogramin resistance rate and high prevalence of resistance genes in enterococci isolated from the stool of healthy persons and the hospital environment indicates the importance of possible transmission of resistance genes from these isolates to clinical ones.
Topics: Agar; Anti-Bacterial Agents; Drug Resistance, Bacterial; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Healthy Volunteers; Hospitals; Humans; Linezolid; Microbial Sensitivity Tests; Virginiamycin
PubMed: 35716285
DOI: 10.1007/s11033-022-07627-3 -
Accounts of Chemical Research Apr 2021Continued, rapid development of antimicrobial resistance has become worldwide health crisis and a burden on the global economy. Decisive and comprehensive action is...
Continued, rapid development of antimicrobial resistance has become worldwide health crisis and a burden on the global economy. Decisive and comprehensive action is required to slow down the spread of antibiotic resistance, including increased investment in antibiotic discovery, sustainable policies that provide returns on investment for newly launched antibiotics, and public education to reduce the overusage of antibiotics, especially in livestock and agriculture. Without significant changes in the current antibiotic pipeline, we are in danger of entering a post-antibiotic era.In this Account, we summarize our recent efforts to develop next-generation streptogramin and lankacidin antibiotics that overcome bacterial resistance by means of modular chemical synthesis. First, we describe our highly modular, scalable route to four natural group A streptogramins antibiotics in 6-8 steps from seven simple chemical building blocks. We next describe the application of this route to the synthesis of a novel library of streptogramin antibiotics informed by in vitro and in vivo biological evaluation and high-resolution cryo-electron microscopy. One lead compound showed excellent inhibitory activity in vitro and in vivo against a longstanding streptogramin-resistance mechanism, virginiamycin acetyltransferase. Our results demonstrate that the combination of rational design and modular chemical synthesis can revitalize classes of antibiotics that are limited by naturally arising resistance mechanisms.Second, we recount our modular approaches toward lankacidin antibiotics. Lankacidins are a group of polyketide natural products with activity against several strains of Gram-positive bacteria but have not been deployed as therapeutics due to their chemical instability. We describe a route to several diastereomers of 2,18--lankacidinol B in a linear sequence of ≤8 steps from simple building blocks, resulting in a revision of the C4 stereochemistry. We next detail our modular synthesis of several diastereoisomers of -lankacidinol that resulted in the structural reassignment of this natural product. These structural revisions raise interesting questions about the biosynthetic origin of lankacidins, all of which possessed uniform stereochemistry prior to these findings. Finally, we summarize the ability of several - and -lankacidins to inhibit the growth of bacteria and to inhibit translation in vitro, providing important insights into structure-function relationships for the class.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Gram-Negative Bacteria; Gram-Positive Bacteria; Macrolides; Microbial Sensitivity Tests; Molecular Conformation; Molecular Dynamics Simulation; Ribosomes; Streptogramins; Virginiamycin
PubMed: 33792282
DOI: 10.1021/acs.accounts.0c00894 -
Microorganisms Sep 2021Mature and stable intestinal microbiota in chickens is essential for health and production. Slow development of microbiota in young chickens prolongs the precarious...
Mature and stable intestinal microbiota in chickens is essential for health and production. Slow development of microbiota in young chickens prolongs the precarious period before reaching mature configuration. Whether probiotics can play a role in the early maturation of intestinal microbiota is unknown. To address this, day-old chicks were assigned into six groups: NC (basal diet), PC (virginiamycin), low (BPL) and high-dose (BPH) of and low (BSL) and high-dose (BSH) of . Cecal contents at days 7, 14, 28 and 42 were used to analyze the treatment and time effects on the diversity and composition of microbiota. Overall, the alpha diversity was significantly decreased in the NC group between days 7 and 14, while this decline was prevented in the probiotic (BSL and BSH) and even reversed in the BPH group. The beta-diversity showed significant responses of microbial communities to probiotics in first two weeks of life. Analyses of the abundance of microbiota reflected that members of the family Ruminococcaceae (, , , and ), which were dominant in mature microbiota, were significantly higher in abundance at day 14 in the probiotic groups. Conversely, the abundance of genera within the family Lachnospiraceae (, and ) was dominant in early dynamic microbiota but was significantly lower in the probiotic groups at day 14. The and abundance was higher, while the Enterobacteriaceae abundance was lower in the probiotic groups. In summary, the probiotics efficiently helped the cecal microbiota reach mature configuration earlier in life. These results could be used for the future manipulation of microbiota from the perspective of improving poultry performance.
PubMed: 34576794
DOI: 10.3390/microorganisms9091899