Publications by authors named "Cassidy Klima"

Lymph nodes (LN) harboring bacteria, when being incorporated into ground beef, may impact the microbial safety and quality of such products. We tested two main foodborne pathogens Salmonella and Shiga toxin-producing Escherichia coli (STEC) and profiled the microbiota in LNs (n = 160) of cattle harvested at a Canadian abattoir, by conventional plating methods, PCR, and high throughput sequencing. LNs at two anatomical locations, subiliac and popliteal from 80 cattle were included.

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Antimicrobial use in food-producing animals has come under increasing scrutiny due to its potential association with antimicrobial resistance (AMR). Monitoring of AMR in indicator microorganisms such as spp. in meat production facilities and retail meat products can provide important information on the dynamics and prevalence of AMR in these environments.

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Multidrug-resistant (MDR; resistance to ≥3 antimicrobial classes) members of the family may compromise the efficacy of therapies used to prevent and treat bovine respiratory disease (BRD) in feedlot cattle. This study examined the prevalence of multidrug resistance in strains of and collected from BRD cattle mortalities in North America. Isolates of ( = 147) and ( = 70) spanning 69 Alberta feedlots from 2011 to 2016 and two United States feedlots from 2011 to 2012 were examined for antimicrobial resistance (AMR) in association with integrative and conjugative elements (ICEs).

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The symptoms of infectious diarrheal disease are mediated by a combination of a pathogen's virulence factors and the host immune system. is the leading bacterial cause of diarrhea worldwide due to its near-ubiquitous zoonotic association with poultry. One of the outstanding questions is to what extent the bacteria are responsible for the diarrheal symptoms via intestinal cell necrosis versus immune cell initiated tissue damage.

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Recent concerns over linkages between antimicrobial resistance in human pathogens and antimicrobial use in livestock have prompted researchers to investigate management strategies that reduce the current reliance on in-feed tylosin to control liver abscesses in feedlot cattle. A total of 7,576 crossbred yearlings were allocated to the study (~253 animals/pen, 10 replicate pens per treatment) and individually randomized to one of three treatments. Tylosin phosphate (11 ppm) was included in-feed (1) for the first 125 days on feed (DOF) (), (2) for DOF 41 to 161 (), or (3) for the entire feeding period (; day 0-161).

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Over a two-year period, (MH; = 113), (PM; = 47), (HS; = 41) and (MB; = 227) were isolated from bovine lung tissue at necropsy from cattle raised conventionally (CON, = 29 feedlots) or without antimicrobials [natural (NAT), = 2 feedlots]. Excluding MB, isolates were assayed by PCR to detect the presence of 13 antimicrobial resistance (AMR) genes and five core genes associated with integrative and conjugative elements (ICEs). Antimicrobial susceptibility phenotypes and minimum inhibitory concentrations (MICs, µg/mL) were determined for a subset of isolates (MH, = 104; PM, = 45; HS, = 23; and MB, = 61) using Sensititre analyses.

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The loss of antibiotics as a tool to improve feed efficiency in poultry production has increased the urgency to understand how the microbiota interacts with animals to impact productivity and health. Modulating and harnessing microbiota-host interactions is a promising way to promote poultry health and production efficiencies without antibiotics. In poultry, the microbiome is influenced by many host and external factors including host species, age, gut compartment, diet, and environmental exposure to microbes.

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Bovine respiratory disease (BRD) continues to be a serious health problem in beef cattle production. A multifactorial condition, BRD encompasses several types of pneumonia that are associated with multiple viral and bacterial agents. Comprehensive identification of microbes associated with BRD fatalities could enhance our understanding of the range of pathogens that contribute to the disease and identify new therapeutic targets.

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The objective of this study was to assess the prevalence of three serotypes, A1, A2, and A6 in 98 M. haemolytica isolates collected from clinical BRD cases in European cattle and assess their antimicrobial resistance profiles. Isolates were characterized by serotyping (plate agglutination and serotype specific PCR) and antimicrobial susceptibility testing.

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A novel variant of the AAD(3″) class of aminoglycoside-modifying enzymes was discovered in fatal bovine respiratory disease-associated pathogens and . The gene encodes a spectinomycin/streptomycin adenylyltransferase and was located in a variant of the integrative and conjugative element ICE, a mobile genetic element transmissible among members of the family . The gene was also detected in from a case of porcine pneumonia and in from a case of keratoconjunctivitis.

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Bovine respiratory disease (BRD) is the most important illness of feedlot cattle. Disease management targets the associated bacterial pathogens, , and . We conducted a cross-sectional study to measure the frequencies of antimicrobial-resistant BRD pathogens using a collaborative network of veterinarians, industry, government, and a diagnostic laboratory.

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This study examined the use of comparative genomic analysis for vaccine design against Mannheimia haemolytica, a respiratory pathogen of ruminants. A total of 2,341genes were identified in at least half of the 23 genomes. Of these, a total of 240 were identified to code for N-terminal signal peptides with diverse sub-cellular localizations (78 periplasmic, 52 outer membrane, 15 extracellular, 13 cytoplasmic membrane and 82 unknown) and were examined in an ELISA assay using a coupled-cell free transcription/translation system for protein expressionwith antisera from cattle challenged with serovars 1, 2 or 6 of M.

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Bovine respiratory disease (BRD) is a significant and costly illness in feedlot cattle. Metagenomic analysis was performed on bronchoalveolar lavage samples obtained from 18 feedlot cattle that died of BRD.

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Article Synopsis
  • Mannheimia haemolytica is a significant respiratory disease-causing bacteria in cattle, primarily with serotypes 1 and 6 causing illness, while serotype 2 is mostly harmless.
  • Researchers analyzed 24 M. haemolytica genomes to find unique genes for capsular polysaccharide synthesis, which were then used to develop a multiplex PCR assay to distinguish between serotypes 1, 2, and 6.
  • The new PCR method is simpler and cheaper than traditional agglutination tests, allowing for easier identification of the most common serotypes in cattle without relying on animal testing or costly serum production.
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Bovine respiratory disease is a common health problem in beef production. The primary bacterial agent involved, Mannheimia haemolytica, is a target for antimicrobial therapy and at risk for associated antimicrobial resistance development. The role of M.

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Background: Mannheimia haemolytica is a commensal bacterium that resides in the upper respiratory tract of cattle that can play a role in bovine respiratory disease. Prophages are common in the M. haemolytica genome and contribute significantly to host diversity.

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The production of recombinant vaccines in plants may help to reduce the burden of veterinary diseases, which cause major economic losses and in some cases can affect human health. While there is abundant research in this area, a knowledge gap exists between the ability to create and evaluate plant-based products in the laboratory, and the ability to take these products on a path to commercialization. The current report, arising from a workshop sponsored by an Organisation for Economic Co-operation and Development (OECD) Co-operative Research Programme, addresses this gap by providing guidance in planning for the commercialization of plant-made vaccines for animal use.

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Advancements in high-throughput "omics" technologies have revolutionized the way vaccine candidates are identified. Now every surface expressed protein that an organism produces can be identified in silico and possibly made available for the rapid development of recombinant/subunit vaccines. However, evaluating the antigenicity of a large number of candidate proteins is an immense challenge, typically requiring cloning of several hundred candidates followed by immunogenicity screening.

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In this study, we determined the prevalence of bovine respiratory disease (BRD)-associated viral and bacterial pathogens in cattle and characterized the genetic profiles, antimicrobial susceptibilities, and nature of antimicrobial resistance determinants in collected bacteria. Nasopharyngeal swab and lung tissue samples from 68 BRD mortalities in Alberta, Canada (n = 42), Texas (n = 6), and Nebraska (n = 20) were screened using PCR for bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus, bovine herpesvirus 1, parainfluenza type 3 virus, Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni. Excepting bovine herpesvirus 1, all agents were detected.

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Mannheimia haemolytica is the principal bacterial pathogen associated with bovine respiratory disease (BRD). As an opportunistic pathogen, M. haemolytica is also frequently isolated from the respiratory tract of healthy cattle.

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Mannheimia haemolytica isolated from feedlot cattle were tested for tulathromycin resistance. Cattle were sampled over a 3-year period, starting 12 months after approval of tulathromycin for prevention and treatment of bovine respiratory disease. Nasopharyngeal samples from approximately 5,814 cattle were collected when cattle entered feedlots (N = 4) and again from the same cattle after ≥60 days on feed.

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Macrolides are the first-line treatment against bovine respiratory disease (BRD), and are also used to treat infections in humans. The macrolide, tylosin phosphate, is often included in the diet of cattle as a preventative for liver abscesses in many regions of the world outside of Europe. This study investigated the effects of administering macrolides to beef cattle either systemically through a single subcutaneous injection (therapeutic) or continuously in-feed (subtherapeutic), on the prevalence and antimicrobial resistance of Mannheimia haemolytica and Enterococcus spp.

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The draft genome of a Mannheimia haemolytica serotype 6 isolate obtained from the nasopharynx of a feedlot calf with bovine respiratory disease is described.

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