Publications by authors named "Guy Loneragan"

Background: The study aimed to review the beta-lactamase resistance genes detected in Enterobacterales from humans, animals, and the environment in the United States.

Methods: We conducted a comprehensive search on PubMed, Web of Science, and Google Scholar for articles reporting beta-lactamase genes in the United States from 1981 to 22 April 2022, following the PRISMA protocol. Studies were evaluated based on predefined eligibility criteria, and both qualitative and quantitative analyses were conducted on the selected studies.

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Objectives: To characterize the genetic basis of azithromycin resistance in Escherichia coli and Salmonella collected within the EU harmonized antimicrobial resistance (AMR) surveillance programme in 2014-18 and the Danish AMR surveillance programme in 2016-19.

Methods: WGS data of 1007 E. coli [165 azithromycin resistant (MIC > 16 mg/L)] and 269 Salmonella [29 azithromycin resistant (MIC > 16 mg/L)] were screened for acquired macrolide resistance genes and mutations in rplDV, 23S rRNA and acrB genes using ResFinder v4.

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Article Synopsis
  • * Utilizing a multivariable linear regression model, researchers found that the presence of specific resistance genes significantly alters the minimum inhibitory concentrations (MICs) of various antibiotics, with increases noted for cephalosporins and carbapenems.
  • * Results revealed that in humans, certain groups heightened MICs of both cephalosporins and carbapenems, while in retail meat, specific resistance genes led to substantial increases in MIC values for antibiotics like ceftriaxone and cefoxitin over time.
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Article Synopsis
  • The study investigates the distribution of beta-lactamase-producing bacteria across three sample sources: cecal, retail meat, and human, revealing a significant global health concern.
  • A total of 115 beta-lactamase genes were identified in different bacteria, with max genes found in human isolates, indicating a complex interplay between food sources and human health.
  • The findings provide crucial insights into the molecular epidemiology of these antibiotic resistance genes, emphasizing the importance of integrated surveillance for One Health approaches.
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Article Synopsis
  • This study analyzed antimicrobial-resistant Salmonella enterica from three different sources: cecal contents, HACCP during processing, and retail meat, using data from 2014 and 2018.
  • It employed multivariable logistic regression to assess the prevalence of individual and multi-drug resistant (MDR) strains across various food animal types and sampling periods.
  • Findings revealed that turkey had a higher likelihood of harboring antimicrobial-resistant Salmonella strains, and certain serotypes, like Ceftriaxone and Sulfisoxazole-resistant, were less likely found in HACCP sources compared to cecal sources.
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Colistin is a last-resort antibiotic used to treat infections caused by multidrug-resistant Gram-negative bacteria. People with a history of travel to the Dominican Republic have become sick with pathogenic bacteria carrying the mobile colistin resistance gene, -1, during and after traveling. This investigation aimed to identify genes in Enterobacteriaceae isolated from food animal sources in the Dominican Republic.

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Extended-spectrum-β-lactamase (ESBL) and AmpC-lactamase-producing Enterobacteriaceae are serious public health threats. Due to an increasing number of reports of ESBL and AmpC producing Escherichia coli in agricultural settings, it is critical to understand the relationship between the use of two of the highest priority critically important human antibiotics (e.g.

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Extended-spectrum cephalosporins (ESC) are categorized by World Health Organization as critically important antimicrobials with limited therapeutic alternatives for the treatment of severe bacterial infections in humans. Preserving the effectiveness of ESC requires continuous monitoring of resistance and comparison of associated data across national surveillance programs in the face of globalization. In this ecological study, we compared ESC resistance in Escherichia coli and Salmonella enterica isolated from food-producing animals from 2003 to 2019 between nine countries (Canada, Denmark, Finland, Japan, Netherlands, Norway, Sweden, United Kingdom, and the United States).

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Aims: Our objective was to determine how injectable antimicrobials affected populations of Salmonella enterica, Escherichia coli and Enterococcus spp. in feedlot cattle.

Methods And Results: Two arrival date blocks of high-risk crossbred beef cattle (n = 249; mean BW = 244 kg) were randomly assigned one of four antimicrobial treatments administered on day 0: sterile saline control (CON), tulathromycin (TUL), ceftiofur (CEF) or florfenicol (FLR).

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In several developing countries, studies on antimicrobial resistance among bacteria from food animals are rare mostly because of under-resourced laboratories. The objective of this study was to develop and field-test a low cost protocol to estimate the isolate- and sample-level prevalence of resistance to critically important antibiotics among Escherichia coli and Salmonella isolated from dairy cattle feces. Using a predesigned protocol, fecal samples were collected to isolate non-type-specific E.

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This report presents the draft genome sequences of two and four unclassified isolates from Canadian agricultural surface water. Phylogenomic analysis revealed that the six isolates formed unique clades, closely related to the disease-causing species , , and .

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In Rwanda, information on antibiotic resistance in food animals is scarce. This study was conducted to detect and phenotypically characterize antibiotic-resistant and in feces of cattle, goats, pigs, and poultry in the East province of Rwanda. We isolated non-type-specific (NTS) and using plain culture media.

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Salmonella enterica is a major foodborne pathogen, and contaminated beef products have been identified as one of the primary sources of -related outbreaks. Pathogenicity and antibiotic resistance of are highly serotype and subpopulation specific, which makes it essential to understand high-resolution population dynamics in cattle. Time of year, source of cattle, pen, and sample type (i.

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can exist in food animals as multiserovar populations, and different serovars can harbor diverse antimicrobial resistance (AMR) profiles. Conventional isolation assesses AMR only in the most abundant members of a multiserovar population, which typically reflects their relative abundance in the initial sample. Therefore, AMR in underlying serovars is an undetected reservoir that can readily be expanded upon antimicrobial use.

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One objective of this study was to determine overall prevalence of in ground pork from U.S. retail stores over three seasons including both case-ready and store-ground packages.

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Background: is a common inhabitant of the ruminant gastrointestinal tract, where it often resides asymptomatically and may be shed into the feces. More recently it was discovered that may be contained within the peripheral, non-mesenteric lymph nodes, where it is impervious to in-plant pathogen control interventions and may serve as a source of -contamination of ground beef. Over the past 10 years considerable research effort has been expended at understanding how this pathogen gets to these lymph nodes, the duration of infection, and, most importantly, screening and developing potential intervention strategies that may be employed on farm prior to the animal being presented for slaughter.

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Listeriosis is a clinically severe foodborne disease caused by (Lm). However, approximately 45% of Lm isolates in food carry a virulence-attenuating single-nucleotide polymorphism in , which normally facilitates crossing the intestinal barrier during the initial stages of infection. We hypothesized that (i) natural exposure to virulence-attenuated (vA) Lm strains through food can confer protective immunity against listeriosis attributable to fully virulent (fV) strains and (ii) current food safety measures to minimize exposure to both Lm strains may have adverse population-level outcomes.

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Antibiotic use in beef cattle is a risk factor for the expansion of antimicrobial-resistant Salmonella populations. However, actual changes in the quantity of Salmonella in cattle feces following antibiotic use have not been investigated. Previously, we observed an overall reduction in Salmonella prevalence in cattle feces associated with both ceftiofur crystalline-free acid (CCFA) and chlortetracycline (CTC) use; however, during the same time frame the prevalence of multidrug-resistant Salmonella increased.

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Article Synopsis
  • - The study investigated the long-term impact of administering ceftiofur or tulathromycin antibiotics in cattle on antimicrobial resistance and population characteristics in feces, lymph nodes, and hides.
  • - A total of 134 beef cattle were monitored, with results showing no significant permanent effects of the antibiotics on resistance prevalence, but a notable increase in fecal prevalence was observed from spring to midsummer.
  • - Key serotypes of Salmonella were frequently found, indicating strong clustering effects by pen and cattle source, raising concerns about the potential for these antibiotics to promote resistant bacteria that can impact human health.
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A total of 44 lactic acid bacteria (LAB) strains originally isolated from cattle feces and different food sources were screened for their potential probiotic features. The antimicrobial activity of all isolates was tested by well-diffusion assay and competitive exclusion on broth against Montevideo, O157:H7 and strain N1-002. Thirty-eight LAB strains showed antagonistic effect against at least one of the pathogens tested in this study.

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Vineyards and grape musts harbor complex locally specific microbial communities, among which yeast species can be responsible of spontaneous alcoholic fermentation. Although relying on indigenous yeast can be a risk for winemaking, local yeast diversity is associated with complexity and stronger identity of the wine produced, compared to inoculated alcoholic fermentation with commercial yeast strains. In this context, the main yeast species present on grapes, leaves and soils of Tempranillo and Cabernet Sauvignon vineyards in the hot semi-arid climate of the Texas High Plains area were investigated, as well as the presence and dynamics of yeast species during spontaneous fermentations of Tempranillo grapes from the same vineyards.

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Salmonella enterica serotype Lubbock emerged most likely from a Salmonella enterica serotype Mbandaka ancestor that acquired by recombination the operon from Salmonella enterica serotype Montevideo. Here, we report the complete genome sequence of two Lubbock, one Montevideo, and one Mbandaka strain isolated from bovine lymph nodes.

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Salmonella enterica serovar Fresno is an infrequently isolated serovar whose ecology and genomic characteristics have not yet been described. To further understand the genomic characteristics of this serovar, we sequenced the complete genome of a single isolate recovered from a bovine lymph node at harvest.

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