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1.
J Environ Sci (China) ; 142: 182-192, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38527883

RESUMO

The degradation of tilmicosin (TLM), a semi-synthetic 16-membered macrolide antibiotic, has been receiving increasing attention. Conventionally, there are three tilmicosin degradation methods, and among them microbial degradation is considered the best due to its high efficiency, eco-friendliness, and low cost. Coincidently, we found a new strain, Glutamicibacter nicotianae sp. AT6, capable of degrading high-concentration TLM at 100 mg/L with a 97% removal efficiency. The role of tryptone was as well investigated, and the results revealed that the loading of tryptone had a significant influence on TLM removals. The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances. Based on the identified intermediates, the degradation of TLM by AT6 processing through two distinct pathways was then proposed.


Assuntos
Micrococcaceae , Tilosina , Tilosina/análogos & derivados , Águas Residuárias , Tilosina/toxicidade , Antibacterianos/metabolismo , Biodegradação Ambiental
2.
Int J Mol Sci ; 25(6)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38542095

RESUMO

Skin wounds and their infections by antibiotic-resistant bacteria (ARB) are very common in small animals, posing the risk of acquiring ARB by pet owners or antibiotic resistance gene (ARG) transfer to the owners' microbiota. The aim of this study was to identify the most common pathogens infecting wounds of companion animals, assess their antibiotic resistance, and determine the ARGs using culture-based, molecular, and proteomic methods. A total of 136 bacterial strains were isolated from wound swabs. Their species was identified using chromogenic media, followed by MALDI-TOF spectrometry. Antibiotic resistance was tested using disc diffusion, and twelve ARGs were detected using PCRs. The dominant species included Staphylococcus pseudintermedius (9.56%), E. coli, and E. faecalis (both n = 11, 8.09%). Enterobacterales were mostly resistant to amoxicillin/clavulanic acid (68.3% strains), all Pseudomonas were resistant to ceftazidime, piperacillin/tazobactam, imipenem, and tylosin, Acinetobacter were mostly resistant to tylosin (55.5%), all Enterococcus were resistant to imipenem, and 39.2% of Staphylococci were resistant to clindamycin. Among ARGs, strA (streptomycin resistance), sul3 (sulfonamide resistance), and blaTEM, an extended-spectrum beta-lactamase determinant, were the most frequent. The risk of ARB and ARG transfer between animals and humans causes the need to search for new antimicrobial therapies in future veterinary medicine.


Assuntos
Antibacterianos , Animais de Estimação , Humanos , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Animais de Estimação/microbiologia , Escherichia coli , Tilosina , Antagonistas de Receptores de Angiotensina , Proteômica , Inibidores da Enzima Conversora de Angiotensina , Bactérias/genética , Imipenem , Ecossistema , Testes de Sensibilidade Microbiana
3.
J Hazard Mater ; 469: 134026, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38493620

RESUMO

The purpose of the study was to evaluate the effects of using of ozonation to remove antibiotics used, among others, in veterinary medicine, from the aqueous environment. The effect of this process on the degradation, mineralisation and ecotoxicity of aqueous solutions of ampicillin, doxycycline, tylosin, and sulfathiazole was investigated. Microbiological MARA® bioassay and two in silico methods were used for the ecotoxicity assessment. Ozonation was an effective method for the degradation of the antibiotics studied and the reduction in ecotoxicity of the solutions. However, after ozonation, the solutions contained large amounts of organic products, including compounds much less susceptible to ozonation than the initial antibiotics. Structures of 14, 12, 40 and 10 degradation products for ampicillin, doxycycline, tylosin, and sulfathiazole, respectively, were proposed. It was confirmed that ozone plays a greater role than hydroxyl radicals in the degradation of these antibiotics, with the exception of TYL. The use of ozonation to obtain a high degree of mineralisation is unfavourable and it is suggested to combine ozonation with biodegradation. The pre-ozonation will cause decomposition of antibiotic pharmacophores, which significantly reduces the risk of spread of antimicrobial resistance in the active biocenosis of wastewater treatment plants.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Antibacterianos/toxicidade , Antibacterianos/química , Doxiciclina , Tilosina , Ampicilina , Sulfatiazol , Ozônio/química , Purificação da Água/métodos , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/química
4.
Parasit Vectors ; 17(1): 59, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341599

RESUMO

BACKGROUND: Toxoplasma gondii is an important protozoan pathogen with medical and veterinary importance worldwide. Drugs currently used for treatment of toxoplasmosis are less effective and sometimes cause serious side effects. There is an urgent need for the development of more effective drugs with relatively low toxicity. METHODS: The effect of tylosin on the viability of host cells was measured using CCK8 assays. To assess the inhibition of tylosin on T. gondii proliferation, a real-time PCR targeting the B1 gene was developed for T. gondii detection and quantification. Total RNA was extracted from parasites treated with tylosin and then subjected to transcriptome analysis by RNA sequencing (RNA-seq). Finally, murine infection models of toxoplasmosis were used to evaluate the protective efficacy of tylosin against T. gondii virulent RH strain or avirulent ME49 strain. RESULTS: We found that tylosin displayed low host toxicity, and its 50% inhibitory concentration was 175.3 µM. Tylsoin also inhibited intracellular T. gondii tachyzoite proliferation, with a 50% effective concentration of 9.759 µM. Transcriptome analysis showed that tylosin remarkably perturbed the gene expression of T. gondii, and genes involved in "ribosome biogenesis (GO:0042254)" and "ribosome (GO:0005840)" were significantly dys-regulated. In a murine model, tylosin treatment alone (100 mg/kg, i.p.) or in combination with sulfadiazine sodium (200 mg/kg, i.g.) significantly prolonged the survival time and raised the survival rate of animals infected with T. gondii virulent RH or avirulent ME49 strain. Meanwhile, treatment with tylosin significantly decreased the parasite burdens in multiple organs and decreased the spleen index of mice with acute toxoplasmosis. CONCLUSIONS: Our findings suggest that tylosin exhibited potency against T. gondii both in vitro and in vivo, which offers promise for treatment of human toxoplasmosis.


Assuntos
Toxoplasma , Toxoplasmose , Humanos , Animais , Camundongos , Tilosina/farmacologia , Tilosina/uso terapêutico , Toxoplasmose/tratamento farmacológico , Toxoplasmose/parasitologia , Sulfadiazina/farmacologia , Sulfadiazina/uso terapêutico , Baço
5.
Poult Sci ; 103(4): 103485, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38335668

RESUMO

Chickens are the primary reservoirs of Campylobacter spp., mainly C. jejuni and C. coli, that cause human bacterial gastrointestinal infections. However, genomic characteristics and antimicrobial resistance of Campylobacter spp. in low- to middle-income countries need more comprehensive exploration. This study aimed to characterize 21 C. jejuni and 5 C. coli isolates from commercial broilers and native chickens using whole genome sequencing and compare them to 28 reference Campylobacter sequences. Among the 26 isolates, 13 sequence types (ST) were identified in C. jejuni and 5 ST in C. coli. The prominent ST was ST 2274 (5 isolates, 19.2%), followed by ST 51, 460, 2409, and 6455 (2 isolates in each ST, 7.7%), while all remaining ST (464, 536, 595, 2083, 6736, 6964, 8096, 10437, 828, 872, 900, 8237, and 13540) had 1 isolate per ST (3.8%). Six types of antimicrobial resistance genes (ant(6)-Ia, aph(3')-III, blaOXA, cat, erm(B), and tet(O)) and one point mutations in the gyrA gene (Threonine-86-Isoleucine) and another in the rpsL gene (Lysine-43-Arginine) were detected. The blaOXA resistance gene was present in all isolates, the gyrA mutations was in 95.2% of C. jejuni and 80.0% of C. coli, and the tet(O) resistance gene in 76.2% of C. jejuni and 80.0% of C. coli. Additionally, 203 virulence-associated genes linked to 16 virulence factors were identified. In terms of phenotypic resistance, the C. jejuni isolates were all resistant to ciprofloxacin, enrofloxacin, and nalidixic acid, with lower levels of resistance to tetracycline (76.2%), tylosin (52.3%), erythromycin (23.8%), azithromycin (22.2%), and gentamicin (11.1%). Most C. coli isolates were resistant to all tested antimicrobials, while 1 C. coli was pan-susceptible except for tylosin. Single-nucleotide polymorphisms concordance varied widely, with differences of up to 13,375 single-nucleotide polymorphisms compared to the reference Campylobacter isolates, highlighting genetic divergence among comparative genomes. This study contributes to a deeper understanding of the molecular epidemiology of Campylobacter spp. in Thai chicken production systems.


Assuntos
Anti-Infecciosos , Infecções por Campylobacter , Campylobacter coli , Campylobacter jejuni , Campylobacter , Animais , Humanos , Galinhas/genética , Tailândia/epidemiologia , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/veterinária , Infecções por Campylobacter/microbiologia , Tilosina , Farmacorresistência Bacteriana/genética , Campylobacter/genética , Antibacterianos/farmacologia , Sequenciamento Completo do Genoma/veterinária , Testes de Sensibilidade Microbiana/veterinária
6.
FEMS Microbiol Ecol ; 100(4)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38373802

RESUMO

Liver abscesses (LA) resulting from bacterial infection in cattle pose a significant global challenge to the beef and dairy industries. Economic losses from liver discounts at slaughter and reduced animal performance drive the need for effective mitigation strategies. Tylosin phosphate supplementation is widely used to reduce LA occurrence, but concerns over antimicrobial overuse emphasize the urgency to explore alternative approaches. Understanding the microbial ecology of LA is crucial to this, and we hypothesized that a reduced timeframe of tylosin delivery would alter LA microbiomes. We conducted 16S rRNA sequencing to assess severe liver abscess bacteriomes in beef cattle supplemented with in-feed tylosin. Our findings revealed that shortening tylosin supplementation did not notably alter microbial communities. Additionally, our findings highlighted the significance of sample processing methods, showing differing communities in bulk purulent material and the capsule-adhered material. Fusobacterium or Bacteroides ASVs dominated LA, alongside probable opportunistic gut pathogens and other microbes. Moreover, we suggest that liver abscess size correlates with microbial community composition. These insights contribute to our understanding of factors impacting liver abscess microbial ecology and will be valuable in identifying antibiotic alternatives. They underscore the importance of exploring varied approaches to address LA while reducing reliance on in-feed antibiotics.


Assuntos
Abscesso Hepático , Microbiota , Bovinos , Animais , Tilosina/farmacologia , RNA Ribossômico 16S/genética , Abscesso Hepático/veterinária , Abscesso Hepático/epidemiologia , Abscesso Hepático/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Suplementos Nutricionais/análise , Ração Animal/análise
7.
Vet Microbiol ; 291: 110029, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38364466

RESUMO

The antimicrobial tylosin is commonly used to control mycoplasma infections, sometimes in combination with vaccination. However, the efficacy of a live mycoplasma vaccine, when combined with subsequent antimicrobial treatment, against the effects of subsequent infection with a virulent strain is unknown. This study employed differential gene expression analysis to evaluate the effects of tylosin on the protection provided by the live attenuated Vaxsafe MG ts-304 vaccine, which has been shown to be safe and to provide long-term protective immunity against infection with Mycoplasma gallisepticum. The transcriptional profiles of the tracheal mucosa revealed significantly enhanced inflammation, immune cell proliferation and adaptive immune responses in unvaccinated, untreated birds and in unvaccinated birds treated with tylosin 2 weeks after infection with virulent M. gallisepticum. These responses, indicative of the typical immune dysregulation caused by infection with M. gallisepticum, were less severe in the unvaccinated, tylosin-treated birds than in the unvaccinated, untreated birds. This was attributable to the effect of residual levels of tylosin in the tracheal mucosa on replication of virulent M. gallisepticum. These responses were not detected in vaccinated, tylosin-treated birds or in vaccinated, untreated birds after infection. The tracheal mucosal transcriptional profiles of these birds resembled those of unvaccinated, untreated, uninfected birds, suggesting a rapid and protective secondary immune response and effective vaccination. Overall, these results show that, although tylosin treatment reduced the duration of immunity, the initial protective immunity induced by Vaxsafe MG ts-304 lasted for at least 22 weeks after vaccination, even after the administration of tylosin for 16 weeks following vaccination.


Assuntos
Anti-Infecciosos , Infecções por Mycoplasma , Mycoplasma gallisepticum , Doenças das Aves Domésticas , Animais , Tilosina/farmacologia , Vacinas Bacterianas , Galinhas , Doenças das Aves Domésticas/prevenção & controle , Infecções por Mycoplasma/prevenção & controle , Infecções por Mycoplasma/veterinária , Vacinas Atenuadas
8.
Langmuir ; 40(9): 4860-4870, 2024 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-38394629

RESUMO

Tildipirosin has no significant inhibitory effect on intracellular bacteria because of its poor membrane permeability. To this end, tildipirosin-loaded xanthan gum-gelatin composite nanogels were innovatively prepared to improve the cellular uptake efficiency. The formation of the nanogels via interactions between the positively charged gelatin and the negatively charged xanthan gum was confirmed by powder X-ray diffraction and Fourier transform infrared. The results indicate that the optimal tildipirosin composite nanogels possessed a 3D network structure and were shaped like a uniformly dispersed ellipse, and the particle size, PDI, and ζ potential were 229.4 ± 1.5 nm, 0.26 ± 0.04, and -33.2 ± 2.2 mV, respectively. Interestingly, the nanogels exhibited gelatinase-responsive characteristics, robust cellular uptake via clathrin-mediated endocytosis, and excellent sustained release. With those pharmaceutical properties provided by xanthan gum-gelatin composite nanogels, the anti-Staphylococcus aureus activity of tildipirosin was remarkably amplified. Further, tildipirosin composite nanogels demonstrated good biocompatibility and low in vivo and in vitro toxicities. Therefore, we concluded that tildipirosin-loaded xanthan gum-gelatin composite nanogels might be employed as a potentially effective gelatinase-responsive drug delivery for intracellular bacterial infection.


Assuntos
Gelatina , Gelatinases , Polissacarídeos Bacterianos , Tilosina/análogos & derivados , Nanogéis , Gelatina/química
9.
Sci Rep ; 14(1): 1954, 2024 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263184

RESUMO

Probiotics are widely used in agriculture including commercial beekeeping, but there is little evidence supporting their effectiveness. Antibiotic treatments can greatly distort the gut microbiome, reducing its protective abilities and facilitating the growth of antibiotic resistant pathogens. Commercial beekeepers regularly apply antibiotics to combat bacterial infections, often followed by an application of non-native probiotics advertised to ease the impact of antibiotic-induced gut dysbiosis. We tested whether probiotics affect the gut microbiome or disease prevalence, or rescue the negative effects of antibiotic induced gut dysbiosis. We found no difference in the gut microbiome or disease markers by probiotic application or antibiotic recovery associated with probiotic treatment. A colony-level application of the antibiotics oxytetracycline and tylosin produced an immediate decrease in gut microbiome size, and over the longer-term, very different and persistent dysbiotic effects on the composition and membership of the hindgut microbiome. Our results demonstrate the lack of probiotic effect or antibiotic rescue, detail the duration and character of dysbiotic states resulting from different antibiotics, and highlight the importance of the gut microbiome for honeybee health.


Assuntos
Oxitetraciclina , Probióticos , Abelhas , Animais , Disbiose , Antibacterianos , Tilosina
10.
Res Vet Sci ; 168: 105152, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38219471

RESUMO

Pleuromutilins (tiamulin and valnemulin) are often used to treat swine dysentery due to recurrent resistance to macrolides and lincosamides. Recently, reduced susceptibility of B. hyodysenteriae to pleuromutilin has been reported. 536 strains of B. hyodysenteriae were isolated from symptomatic pigs weighing 30-150 kg in northern Italy between 2005 and 2022. B. hyodysenteriae was isolated by standard methods and confirmed by PCR. The minimum inhibitory concentration (MIC) to doxycycline, lincomycin, tiamulin, tylosin, tylvalosine and valnemulin was evaluated according to CLSI procedures and MIC data were reported as MIC 50 and MIC 90. The temporal trend of the MIC values was evaluated by dividing the data into two groups (2005-2013 and 2014-2022). Comparison of the distribution in frequency classes in the two periods was performed using Pearson's chi-squared test (p < 0.01). MIC 50 was close to the highest values tested for lincomycin and tylosin, while MIC 90 was close to the highest values tested for all antibiotics. 71.7% of the strains were susceptible to tylvalosin, while 75%-80.4% had reduced susceptibility to valnemulin and tiamulin, respectively. The difference in the distribution of MIC classes was statistically significant in the two periods for doxycycline, tiamulin, tylvalosin and valnemulin, and more MIC classes above the epidemiological cut-off were observed in 2014-2022 compared with 2005-2013. The evaluation of the trends during the period considered shows a decreasing rate of wild-type strains with MIC values below the epidemiological cut-off over time and confirms the presence of resistant strains in northern Italy.


Assuntos
Brachyspira hyodysenteriae , Brachyspira , Doenças dos Suínos , Tilosina/análogos & derivados , Animais , Suínos , Brachyspira hyodysenteriae/genética , Doxiciclina , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/epidemiologia , Antibacterianos/farmacologia , Lincomicina , Testes de Sensibilidade Microbiana/veterinária , Itália , Diterpenos
11.
J Vet Diagn Invest ; 36(1): 62-69, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37968893

RESUMO

Swine dysentery, caused by Brachyspira hyodysenteriae and the newly recognized Brachyspira hampsonii in grower-finisher pigs, is a substantial economic burden in many swine-rearing countries. Antimicrobial therapy is the only commercially available measure to control and prevent Brachyspira-related colitis. However, data on antimicrobial susceptibility trends and genetic diversity of Brachyspira species from North America is limited. We evaluated the antimicrobial susceptibility profiles of U.S. Brachyspira isolates recovered between 2013 and 2022 to tiamulin, tylvalosin, lincomycin, doxycycline, bacitracin, and tylosin. In addition, we performed multilocus sequence typing (MLST) on 64 B. hyodysenteriae isolates. Overall, no distinct alterations in the susceptibility patterns over time were observed among Brachyspira species. However, resistance to the commonly used antimicrobials was seen sporadically with a higher resistance frequency to tylosin compared to other tested drugs. B. hampsonii was more susceptible to the tested drugs than B. hyodysenteriae and B. pilosicoli. MLST revealed 16 different sequence types (STs) among the 64 B. hyodysenteriae isolates tested, of which 5 STs were previously known, whereas 11 were novel. Most isolates belonged to the known STs: ST93 (n = 32) and ST107 (n = 13). Our findings indicate an overall low prevalence of resistance to clinically important antimicrobials other than tylosin and bacitracin, and high genetic diversity among the clinical Brachyspira isolates from pigs in the United States during the past decade. Further molecular, epidemiologic, and surveillance studies are needed to better understand the infection dynamics of Brachyspira on swine farms and to help develop effective control measures.


Assuntos
Anti-Infecciosos , Brachyspira hyodysenteriae , Brachyspira , Infecções por Bactérias Gram-Negativas , Doenças dos Suínos , Humanos , Suínos , Estados Unidos/epidemiologia , Animais , Tilosina/farmacologia , Antibacterianos/farmacologia , Tipagem de Sequências Multilocus/veterinária , Bacitracina/farmacologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/veterinária , Doenças dos Suínos/epidemiologia , Farmacorresistência Bacteriana , Brachyspira/genética , Brachyspira hyodysenteriae/genética , Anti-Infecciosos/farmacologia , Variação Genética
12.
Ecotoxicol Environ Saf ; 270: 115861, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38154153

RESUMO

As agents in an emerging technology, Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae) larvae, black soldier fly, have shown exciting potential for degrading antibiotics in organic solid waste, a process for which gut microorganisms play an important role. This study investigated the characteristics of larval gut bacterial communities effected by typical antibiotics. Initially, antibiotics significantly reduced the diversity of gut bacterial species. After 8 days, diversity recovered to similar to that of the control group in the chlortetracycline, tylosin, and sulfamethoxazole groups. Proteobacteria, Firmicutes, and Actinobacteriota were the dominant phyla at the initial BSFL gut. However, after 4 days treatment, the proportion of Actinobacteriota significantly decreased, but Bacteroidota notably increased. During the conversion process, 18, 18, 17, 21, and 19 core genera were present in the chlortetracycline, sulfamethoxazole, tylosin, norfloxacin, and gentamicin groups, respectively. Pseudomonas, Actinomyces, Morganella, Providencia and Klebsiella might be the important genera with extraordinary resistance and degradation to antibiotics. Statistical analyses of COGs showed that antibiotics changed the microbial community functions of BSFL gut. Compared with the control group, (i) the chlortetracycline, sulfamethoxazole, and tylosin groups showed significant increase in the classification functions of transcription, RNA processing and modification,and so on, (ii) the norfloxacin and gentamicin groups showed significant increase in defense mechanisms and other functions. Note that we categorized the response mechanisms of these classification functions to antibiotics into resistance and degradation. This provides a new perspective to deeply understand the joint biodegradation behavior of antibiotics in environments, and serves as an important reference for further development and utilization of microorganisms-assisted larvae for efficient degradation of antibiotics.


Assuntos
Clortetraciclina , Dípteros , Microbioma Gastrointestinal , Animais , Dípteros/fisiologia , Larva , Antibacterianos/farmacologia , Norfloxacino , Tilosina , Bactérias , Sulfametoxazol , Gentamicinas
13.
J Anim Sci ; 1012023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38069626

RESUMO

The effects of a novel direct-fed microbial (DFM) on feedlot performance, carcass characteristics, digestibility, ruminal morphology, and volatile fatty acid (VFA) profile of finishing steers were evaluated. Single-source Angus-crossbred yearling steers (n = 144; initial body weight (BW) = 371 ±â€…19 kg) were used in a randomized complete block design. Steers were blocked by initial BW and randomly assigned to treatments (12 pens/treatment; 4 steers/pen). Treatments included (A) CONTROL (no DFM, tylosin, or monensin, (B) MONTY (monensin sodium [330 mg/animal-daily] and tylosin phosphate [90 mg/animal-daily]), and (C) MONPRO (monensin sodium [same as previous] and Lactobacillus salivarius L28 [1 × 106 CFU/animal-daily]). Treatments were included in a steam-flaked corn-based finisher diet offered once daily using a clean-bunk management for ~149 d. The digestibility assessment was performed from days 70 to 74. Ruminal fluid and rumen tissue samples were collected at the slaughter for VFA profile and papillae morphology analyses, respectively. Data were analyzed using the GLIMMIX procedure of SAS with pen serving as the experimental unit, treatment as fixed effect, and BW block as random effect. Steers offered MONPRO had on average 5.3% less (P < 0.01) dry matter intake (9.56 kg/d) compared with either CONTROL (10.16 kg/d) or MONTY (9.96 kg/d). The carcass-adjusted final BW (613 kg; P = 0.23), overall average daily gain (1.64 kg/d; P = 0.23), and gain-efficiency (0.165; P = 0.61) were not affected by treatments. Steers offered CONTROL had greater (P < 0.01) marbling score and tended (P = 0.06) to have less carcasses grading Select and tended (P = 0.10) to have more carcasses grading Upper-Choice, while other carcass characteristics and liver-abscesses were not affected (P ≥ 0.23) by treatments. The digestibility of nutrients (P ≥ 0.13) and the ruminal VFA profile (P ≥ 0.12) were not affected by treatments. Steers offered MONPRO tended (P = 0.09) to have 16% greater average papillae number compared to other treatments. Yearlings offered finishing diets containing L. salivarius L28 plus monensin did not affect growth performance, digestibility, or ruminal VFA, but reduced feed intake. Carcass quality was negatively affected by treatments, while animals consuming L. salivarius L28 and monensin tended to improve ruminal morphology. Current findings in ruminal morphology and feed intake may warrant further assessment of diets containing L. salivarius L28 on beef cattle food safety aspects.


Antimicrobial resistance is a growing concern to public health and medically important antibiotics have been listed in the Veterinary Feed Directive. Nutritional technologies, such as direct-fed microbials, are being increasingly studied for the development of an effective use on beef cattle production systems. The newly isolated strain of Lactobacillus salivarius L28 has demonstrated pathogenic inhibition of Escherichia coli, Salmonella, and Listeria monocytogenes on in vitro assessments. The potential benefits have warranted the exploration of L. salivarius L28 in a feedlot setting. Single-source Angus-crossbred yearling steers were offered steam-flaked corn-based finishing diets containing no feed additive, or either a combination of tylosin plus monensin or L. salivarius L28 plus monensin. Steers offered L. salivarius L28 plus monensin consumed 5.3% less feed compared with other treatments, while other growth performance variables and the digestibility of nutrients were not affected. Carcasses from cattle supplemented with monensin had slightly lower carcass quality grades than those not supplemented with monensin. Lactobacillus salivarius L28 plus monensin tended to improve steers ruminal morphology. Current findings may warrant further food safety assessments when cattle are offered diets containing L. salivarius L28.


Assuntos
Monensin , Tilosina , Bovinos , Animais , Monensin/farmacologia , Tilosina/farmacologia , Dieta/veterinária , Ingestão de Alimentos , Peso Corporal , Nutrientes , Ração Animal/análise , Digestão
14.
Mikrochim Acta ; 191(1): 42, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38114730

RESUMO

To avoid false negative results due to the low cross-reactivity rate (CR) in rapid immunoassay, a group-specific antibody with homogeneous CR toward target compounds is needed for accuracy. In this study, tylosin (TYL) and tilmicosin (TM) were selected as model molecules. Firstly, two-dimensional similarity, electrostatic potential energy, spatial conformation and charge distribution of the haptens TYL-CMO, TYL-6-ACA, TYL-4-APA, TYL-CHO and DES-CMO and target compounds of TYL and TM were obtained using Gaussian 09W and Discovery Studio. The optimal hapten was DES-CMO because it is the most similar to TYL and TM. Subsequently, the mAb 14D5 cell line was obtained with IC50 values of 1.59 and 1.72 ng/mL for TYL and TM, respectively, and a CR of 92.44%. Finally, amorphous carbon nanoparticles (ACNPs) were conjugated with mAb 14D5 to develop an accurate lateral flow immunoassay (LFA) for detection of TYL and TM by the reflectance value under natural light. The recoveries of TYL and TM ranged from 77.18 to 112.04% with coefficient of variation < 13.43%. The cut-off value in milk samples was 8 ng/mL, and the limits of detection were 11.44, 15.96, 22.29 and 25.53 µg/kg for chicken muscle, bovine muscle, porcine muscle and porcine liver samples, respectively, and the results being consistent with HPLC-UV. The results suggest that the developed LFA is accurate and potentially useful for on-site screening of TYL and TM in milk and animal tissue samples.


Assuntos
Anticorpos Monoclonais , Tilosina , Animais , Bovinos , Suínos , Ensaio de Imunoadsorção Enzimática/métodos , Imunoensaio , Haptenos
15.
Environ Monit Assess ; 195(12): 1423, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37934331

RESUMO

Industrial wastewater from drug production is one of the contributors to water pollution. For drug wastewater treatment, photodegradation-based chemical technology has gained more attention because of the drug's microbicidal nature and stability. A zinc-chromium-nickel trimetallic-layered double hydroxide compounding with graphene oxide catalyst (ZnCrNi/GO) was synthesized and exhibited a clustered crumb sheet morphology. The prepared catalyst was characterized by a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared (FTIR) spectra, and X-ray photoelectron spectroscopy (XPS). The results of material analysis established the crystallographic structures of catalysts and evidenced the successful synthesis. The ZnCrNi/GO nanohybrid revealed a higher activity of approximately 90% degradation of tolysin under high-pressure mercury lamp irradiation. The optimized condition of the catalyst dosage of 500 mg/L and the natural pH of the solution at 7.0 under the tylosin concentration of 10 mg/L with high photocatalytic efficiency was explored. In addition, the main reactive species involved in this photocatalysis degradation were explored as the active cavity h+ and ·O2- to a certain extent by the radical trapping experiments. Reuse experiments have shown that as-prepared catalysts possessed the properties of high efficiency and long-lasting catalytic performance, which could meet pharmaceutical wastewater treatment. A three-metal-layered double hydroxide composed by the metal of Ni, Zn, and Cr was synthesized and attached onto graphene oxide. The catalytic materials obtained in this way have a significant catalysis efficiency to tylosin with the likely degradation mechanism of the active cavity h+ and the oxidative capacity of hydroxyl radials.


Assuntos
Monitoramento Ambiental , Tilosina , Hidróxidos
16.
J Environ Qual ; 52(6): 1193-1205, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37739441

RESUMO

The practice of using therapeutic and prophylactic veterinary antibiotics in livestock farming is a worldwide phenomenon. Over the last decade, there has been a growing concern of antibiotic residues entering the environment via animal manure. Similar studies have focused on the occurrence and biological effects of antibiotics in land-applied animal feedlots; however, limited research has been conducted on the occurrence and persistence of antibiotics in animal feedlots. Therefore, the objective of this study was to evaluate antibiotic persistence, fate, and transport in surface water runoff and feedlot sediment in feedlot pens with livestock either receiving or not receiving antibiotic treatments through injection and feed. The two antibiotics (tylosin and monensin) added to animal feed were observed to persist in the soil environment for more than 30 days along with injected florfenicol. Monensin (5.6× higher) and tylosin (20× higher) were significantly higher in livestock pens receiving antibiotics compared to livestock pens not receiving the antibiotics. Further, rainfall was observed to significantly impact soil surface concentrations of florfenicol. Other antibiotics administrated by injection were not observed to statistically increase in concentrations in runoff or feedlot sediment. Our findings emphasize antibiotics administered in feedlots have the potential to persist and remain in feedlot sediment and runoff, particularly in instances of regular administration in feed.


Assuntos
Antibacterianos , Tilosina , Bovinos , Animais , Monensin , Solo , Esterco
17.
J Vet Diagn Invest ; 35(6): 645-654, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37705301

RESUMO

American foulbrood (AFB) is an infectious disease of honey bee brood caused by the endospore-forming bacterium Paenibacillus larvae. P. larvae spores are resilient in the environment, thus colonies with clinical signs of AFB are often destroyed by burning to eradicate the causative agent. To prevent outbreaks of AFB, oxytetracycline metaphylaxis is widely used in North America, resulting in sustained selective pressure for oxytetracycline resistance in P. larvae. To determine if antimicrobial resistance (AMR) is present among P. larvae isolates from commercial beekeeping operations in Saskatchewan, Canada, we performed antimicrobial susceptibility testing of 718 P. larvae samples cultured from pooled, extracted honey collected from 52 beekeepers over a 2-y period, 2019 and 2020. We found that 65 of 718 (9%) P. larvae samples collected from 8 beekeepers were resistant to oxytetracycline with minimum inhibitory concentration (MIC) values of 64-256 µg/mL. Eight of 718 (1%) samples from 4 beekeepers had intermediate resistance to oxytetracycline (MIC: 4-8 µg/mL). Susceptibility testing for tylosin and lincomycin indicated that P. larvae in Saskatchewan continue to be susceptible to these antimicrobials (tylosin MIC: <1 µg/mL, lincomycin MIC: ≤2 µg/mL). Most oxytetracycline-resistant P. larvae samples were identified in northeastern Saskatchewan. Whole-genome sequence analysis identified the P. larvae-specific plasmid pMA67 with tetracycline-resistance gene tet(L) in 9 of 11 oxytetracycline-resistant P. larvae isolates sequenced. Our results highlight the advantage of using pooled, extracted honey as a surveillance tool for monitoring AMR in P. larvae.


Assuntos
Oxitetraciclina , Paenibacillus larvae , Abelhas , Estados Unidos , Animais , Oxitetraciclina/farmacologia , Paenibacillus larvae/genética , Tilosina/farmacologia , Saskatchewan/epidemiologia , Criação de Abelhas , Antibacterianos/farmacologia , Larva/microbiologia , Lincomicina
18.
Huan Jing Ke Xue ; 44(9): 5017-5024, 2023 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-37699819

RESUMO

Antibiotic contamination in drinking water has attracted widespread attention. The pollution condition of six macrolide antibiotics (erythromycin-H2[KG-*2/5]O, clarithromycin, oleandomycin, roxithromycin, leucomycin, and tylosin) in two drinking water treatment plants was monitored, and the reaction mechanism of tylosin, a typical macrolide antibiotic, during chlorination disinfection treatment was investigated. The results showed that the six macrolide antibiotics can be widely detected in the drinking water treatment processes; however, their concentrations were generally very low. The concentrations of macrolide antibiotics in the influents and effluents ranged from 0.18 ng·L-1 to 3.97 ng·L-1 and 0.02 ng·L-1 to 1.91 ng·L-1, respectively. The removal rates of the six macrolides in the drinking water treatment were different, ranging from 18% (oleandomycin) to 100% (erythromycin- H2[KG-*2/5]O). The degradation of the six macrolides during chlorination was slow and greatly affected by water quality parameters. The chlorination degradation of tylosin followed the second-order reaction kinetic mode, with the kinetic rate constant of 0.77 L·(mol·s)-1 at pH 7.0. Nine chlorination degradation products of tylosin were detected, and the reaction pathways primarily included tertiary amine hydroxylation, aromatic oxidation, and epoxy addition.


Assuntos
Água Potável , Tilosina , Halogenação , Antibacterianos , Macrolídeos , Eritromicina , Oleandomicina
19.
Chemosphere ; 341: 139854, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37619745

RESUMO

The aim of the work was primarily to determine the relationship between the doses of Fenton's reagents and the effectiveness of the ecotoxicity removal of aqueous solutions containing selected antibiotics. The degradation process of ampicillin, doxycycline, and tylosin in an acidic environment in the presence of H2O2 and FeSO4 was studied. The effect of reagent doses on the degree of degradation and identification of antibiotic transformation products was measured by the UPLC qTOF method. The degree of mineralisation was determined based on changes in the concentration of total organic carbon. The ecotoxicity of products was determined with commercial MARA® and MICROTOX® bioassays, as well as against unselected microorganisms from polluted rivers and wastewater treatment plant effluent. It was found that the complete degradation of antibiotics and the simultaneous elimination of the toxicity of the Fenton process products required the use of a precisely defined amount of reagents. When an insufficient dose of reactants was used, the post-reaction solutions contained antibiotic derivatives showing antimicrobial activity. On the other hand, the toxicity of the post-reaction solution against to microbiocenoses was observed when too high doses of H2O2 were used in the process. This effect resulted from the presence of unreacted reagent or other unidentified peroxides.


Assuntos
Antibacterianos , Poluentes Químicos da Água , Antibacterianos/toxicidade , Peróxido de Hidrogênio , Doxiciclina , Ampicilina , Tilosina , Oxirredução , Poluentes Químicos da Água/toxicidade
20.
J Food Prot ; 86(10): 100144, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37597606

RESUMO

The impact of in-feed use of tylosin in feedlot cattle on Gram-negative foodborne bacteria is unknown. We evaluated the effect of continuous in-feed tylosin use on the concentration and prevalence of tetracycline-resistant (TETr)-, third-generation cephalosporin-resistant (3GCr)-, and extended-spectrum ß-lactamase-producing (ESBLs) E. coli in feedlot cattle. A cohort of weaned calves (10 animals/group) were randomized to receive a feed ration with or without tylosin. Fecal samples, regularly collected over the entire feeding period, and pen surface and feed samples, collected at the end of the feeding period, were cultured on selective media. Enumeration and binary outcomes were analyzed by mixed effects linear regression or logistic regression, respectively, using treatment and days on feed as fixed factors, and animal ID as a random variable. Tylosin supplementation did not affect the fecal concentrations of TETrE. coli or fecal prevalence of 3GCrE. coli. However, cattle in the tylosin group were 1.5 times more likely (Odds ratio = 1.5: 95% confidence interval: 1.1-2.0) to harbor ESBLs E. coli than the control cattle. Regardless of tylosin treatment, fecal concentrations of TETrE. coli and the prevalence of 3GCr- and ESBLs-E. coli increased over time. Tylosin-supplemented feed did not affect the prevalence of TETrE. coli; 3GCr and ESBLs-E. coli were not detected from the feed samples. Most of the 3GCr- and ESBLs-E. coli isolates carried the blaCTX-M-15 gene, widely detected among ESBLs-E. coli human isolates. In summary, although in-feed tylosin use in feedlot cattle did not select for TETr- and 3GCr-E. coli, it increased the likelihood of detecting ESBL-producing E. coli. Furthermore, the study indicated that the feedlot production setting gradually increases the levels of E. coli resistant to the critically and/or important antibiotics for public health, indicating an increased risk of their dissemination beyond the feedlot environment.


Assuntos
Infecções por Escherichia coli , Tilosina , Animais , Bovinos , Humanos , Antibacterianos/farmacologia , beta-Lactamases , Cefalosporinas/farmacologia , Escherichia coli , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Tetraciclina/farmacologia , Tilosina/farmacologia
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