An Advanced Understanding of Uterine Microbial Ecology Associated with Metritis in Dairy Cows

Metritis, the inflammation of the uterus caused by polymicrobial infections, is a prevalent and costly disease to the dairy industry as it decreases milk yield, survival, and the welfare of dairy cows. Although affected cows are treated with broad-spectrum antibiotics such as ceftiofur, endometrial and ovarian function are not fully recovered, which results in subfertility and infertility. According to culture-dependent studies, uterine pathogens include Escherichia coli, Trueperella pyogenes, Fusobacterium necrophorum, and Prevotella melaninogenica. Recent studies using high-throughput sequencing observed very low relative abundance of Escherichia coli, Trueperella pyogenes, and Prevotella melaninogenica in cows with metritis. Herein, we propose that metritis is associated with a dysbiosis of the uterine microbiota, which is characterized by high abundance of Bacteroides, Porphyromonas, and Fusobacterium

Genomic and Virulence Characterization of Intrauterine Pathogenic Escherichia coli With Multi-Drug Resistance Isolated From Cow Uteri With Metritis

Metritis is a major disease in dairy cows causing animal death, decrease of birth rate, milk production, and economic loss. Antibiotic treatment is generally used to treat such disease but has a high failure rate of 23–35%. The reason for the treatment failure remains unclear, although antibiotic resistance is postulated as one of factors. Our study investigated the prevalence of extended spectrum β-lactamase (ESBL) producing bacteria in uterine samples of cows with metritis and characterized the isolated intrauterine pathogenic Escherichia coli (IUPEC) strains using whole genome sequencing. We found that the cows with metritis we examined had a high percentage of ESBL producing IUPEC with multi-drug resistance including ceftiofur which is commonly used for metritis treatment. The ESBL producing IUPEC strains harbored versatile antibiotic resistance genes conferring resistance against 29 antibiotic classes, suggesting that transmission of these bacteria to other animals and humans may lead to antibiotic treatment failure. Furthermore, these strains had strong adhesion and invasion activity, along with critical virulence factors, indicating that they may cause infectious diseases in not only the uterus, but also in other organs and hosts

Effect of Chitosan Microparticles on the Uterine Microbiome of Dairy Cows with Metritis

The objective of this study was to evaluate the effect of chitosan microparticles on the uterine microbiome of cows with metritis. Dairy cows with metritis (n = 89) were assigned to 1 of 3 treatments: chitosan microparticles (n = 21), in which the cows received an intrauterine infusion of chitosan microparticles at metritis diagnosis (day 0), day 2, and day 4; ceftiofur (n = 25), in which the cows received a subcutaneous injection of ceftiofur on day 0 and day 3; and no intrauterine or subcutaneous treatment (n = 23). Nonmetritic cows (n=20) were healthy cows matched with cows with metritis by the number of days postpartum at metritis diagnosis. Uterine swab samples collected on days 0, 3, 6, 9, and 12 were used for 16S rRNA gene sequencing and 16S RNA gene copy number quantification by quantitative PCR. Principal-coordinate analysis showed that the microbiome of the ceftiofur-treated and metritic untreated groups progressed toward that of the nonmetritic group by day 3, whereas that of the chitosan microparticletreated group remained unchanged. The differences on day 3 were mainly due to a greater relative abundance of Fusobacteria, particularly Fusobacterium, in the chitosan microparticle-treated group than in the ceftiofur-treated and metritic untreated groups. Furthermore, the microbiome of the ceftiofur-treated group became similar to that of the nonmetritic group by day 9, whereas the microbiome of the chitosan microparticle-treated and metritic untreated groups became similar to that of the nonmetritic group only by day 12. The total bacterial 16S rRNA gene counts in the chitosan microparticle-treated group were greater than those in the metritic untreated controls on days 6 and 9, whereas the ceftiofur treatment group was the only group in which the total bacterial 16S rRNA gene count became similar to that in the nonmetritic group by day 12. In summary, chitosan microparticles slowed the progression of the uterine microbiome toward a healthy state, whereas ceftiofur hastened the progression toward a healthy state.Fil: Galvão, Klibs N.. University of Florida; Estados UnidosFil: de Oliveira, Eduardo B.. University of Florida; Estados UnidosFil: Cunha, Federico. University of Florida; Estados UnidosFil: Daetz, Rodolfo. University of Florida; Estados UnidosFil: Jones, Kristi. University of Florida; Estados UnidosFil: Ma, Zhengxin. University of Florida; Estados UnidosFil: Jeong, Kwangcheol C.. University of Florida; Estados UnidosFil: Bicalho, Rodrigo C.. Cornell University; Estados UnidosFil: Higgins, Catherine H.. Cornell University; Estados UnidosFil: Rodrigues, Marjory X.. Cornell University; Estados UnidosFil: Gonzalez Moreno, Candelaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Jeon, Soojin. Long Island University; Estados Unido

Epidemiology of Pregnancy Losses and Practical Strategies for Prevention

Abstract Pregnancy losses from fertilization to term are extensive in lactating dairy cattle. In many cases, they are underestimated because of the inability to determine conception early after insemination. For most producers, pregnancy losses are only quantified after the initial diagnosis is performed at approximately 30 to 45 d of gestation. Recent studies that provided reliable assessments of fertilization have led to the conclusion that more than 60% of all pregnancies are lost before term in lactating dairy cows. The critical period is from fertilization until the end of the differentiation phase (embryonic period) in which approximately 85% of those losses occur. Therefore, strategies to prevent embryonic losses should result in the greatest improvement in reproductive performance. Nevertheless, although fetal losses are minor (approximately 15%) compared with embryonic losses, those are more costly than embryonic losses; therefore they cannot be overlooked. Known risk factors for pregnancy loss include prolonged periods of follicular dominance, low progesterone concentration during ovulatory follicle development, heat stress, postpartum diseases and disorders such as dystocia, metritis, endometritis, mastitis, fever, ketosis, lameness, and digestive problems, negative energy balance, excessive body weight loss, toxins found in feedstuffs such as gossypol, mycotoxins, and ergot alkaloids, and infectious agents such as Neospora caninum, Leptospira spp., Campilobacter spp., BVD virus, and IBR virus among others. Strategies that prevent or control known risk factors should help decrease pregnancy loss and improve reproductive performance

Epidemiology of Pregnancy Losses and Practical Strategies for Prevention

Abstract Pregnancy losses from fertilization to term are extensive in lactating dairy cattle. In many cases, they are underestimated because of the inability to determine conception early after insemination. For most producers, pregnancy losses are only quantified after the initial diagnosis is performed at approximately 30 to 45 d of gestation. Recent studies that provided reliable assessments of fertilization have led to the conclusion that more than 60% of all pregnancies are lost before term in lactating dairy cows. The critical period is from fertilization until the end of the differentiation phase (embryonic period) in which approximately 85% of those losses occur. Therefore, strategies to prevent embryonic losses should result in the greatest improvement in reproductive performance. Nevertheless, although fetal losses are minor (approximately 15%) compared with embryonic losses, those are more costly than embryonic losses; therefore they cannot be overlooked. Known risk factors for pregnancy loss include prolonged periods of follicular dominance, low progesterone concentration during ovulatory follicle development, heat stress, postpartum diseases and disorders such as dystocia, metritis, endometritis, mastitis, fever, ketosis, lameness, and digestive problems, negative energy balance, excessive body weight loss, toxins found in feedstuffs such as gossypol, mycotoxins, and ergot alkaloids, and infectious agents such as Neospora caninum, Leptospira spp., Campilobacter spp., BVD virus, and IBR virus among others. Strategies that prevent or control known risk factors should help decrease pregnancy loss and improve reproductive performance

Underlying mechanism of antimicrobial activity of chitosan microparticles and implications for the treatment of infectious diseases.

The emergence of antibiotic resistant microorganisms is a great public health concern and has triggered an urgent need to develop alternative antibiotics. Chitosan microparticles (CM), derived from chitosan, have been shown to reduce E. coli O157:H7 shedding in a cattle model, indicating potential use as an alternative antimicrobial agent. However, the underlying mechanism of CM on reducing the shedding of this pathogen remains unclear. To understand the mode of action, we studied molecular mechanisms of antimicrobial activity of CM using in vitro and in vivo methods. We report that CM are an effective bactericidal agent with capability to disrupt cell membranes. Binding assays and genetic studies with an ompA mutant strain demonstrated that outer membrane protein OmpA of E. coli O157:H7 is critical for CM binding, and this binding activity is coupled with a bactericidal effect of CM. This activity was also demonstrated in an animal model using cows with uterine diseases. CM treatment effectively reduced shedding of intrauterine pathogenic E. coli (IUPEC) in the uterus compared to antibiotic treatment. Since Shiga-toxins encoded in the genome of bacteriophage is often overexpressed during antibiotic treatment, antibiotic therapy is generally not recommended because of high risk of hemolytic uremic syndrome. However, CM treatment did not induce bacteriophage or Shiga-toxins in E. coli O157:H7; suggesting that CM can be a potential candidate to treat infections caused by this pathogen. This work establishes an underlying mechanism whereby CM exert antimicrobial activity in vitro and in vivo, providing significant insight for the treatment of diseases caused by a broad spectrum of pathogens including antibiotic resistant microorganisms

Effect of feeding live yeast products to calves with failure of passive transfer on performance and patterns of antibiotic resistance in fecal Escherichia coli

Fifty-two newborn Holstein calves with serum IgG concentrations less than 0.73 g.dL(-1) were randomly assigned to one of four treatments: no added live yeast (control), 0.5 g of live yeast added to the grain for 84 d (SC; Saccharomyces cerevisiae), 0.5 g of live yeast added to the milk for 42 d (SB; S. cerevisiae, spp. boulardii), and 0.5 g of live yeast added to the grain for 84 d and to the milk for 42 d (SCSB). Calves were offered 440 g of milk replacer DM for the first 42 d and grain for ad libitum intake throughout the study. Plasma was analyzed weekly for concentrations of glucose and beta-hydroxybutyrate. Escherichia coli isolated from fecal samples collected every 2 weeks were used for determination of antibiotic resistance patterns. Calves receiving SC consumed more grain DM, had increased weight gain prior to weaning, and increased plasma glucose concentrations compared to controls. Days with diarrhea were reduced by feeding live yeast to calves. Antibiotic resistance in fecal E. coli was associated with the age of calves with highest levels of resistance observed in the 3 d calves. While calves receiving SCSB had higher levels of antibiotic resistance than controls, this effect was not associated with any of the other treatments. Improvements in performance of calves with failure of passive transfer were observed when live yeast was added only to the grain