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Godínez-Oviedo A, Tamplin ML, Bowman JP, Hernández-Iturriaga M. Effects of intrinsic characteristics of Salmonella enterica strains isolated from foods and humans, and their interaction with food matrices during simulated gastric conditions. Int J Food Microbiol 2024; 413:110584. [PMID: 38295484 DOI: 10.1016/j.ijfoodmicro.2024.110584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/21/2023] [Accepted: 01/15/2024] [Indexed: 02/02/2024]
Abstract
The stomach's acidic pH is a crucial barrier against foodborne pathogens such as Salmonella enterica. This study investigated the survival of S. enterica under simulated oral and gastric conditions (SGC; pH 2 for 120 min) as a function of intrinsic pathogen characteristics and food matrix. Fifty-seven S. enterica strains isolated from food and human infections (previously characterized by serotype, virulotype, multi-drug resistance, isolation source, and isolation season) were subjected to SGC using water as a vehicle. Population reduction among the 57 isolates ranged from 2.7 to 4.7 log CFU, revealing that human isolates were inactivated less than food isolates (p = 0.0008). Among food strains, strains isolated during the cold season (food sampled from December to February) displayed the highest reduction (p = 0.00002). Six representatives of the 57 S. enterica strains were selected according to their virulotype and antimicrobial profile. They were further used to evaluate their survival under SGC in four food matrices (water, mango, tomato, and chicken), measuring S. enterica at 30 min intervals. The strains in chicken showed the lowest reduction and inactivation rate (1.42 ± 0.35 log CFU; 0.03 ± 0.005 min-1), followed by tomato (3.75 ± 0.57 log CFU; 0.15 ± 0.02 min-1), water (4.23 ± 0.27 log CFU; 0.17 ± 0.02 min-1), and mango (4.49 ± 0.39 log CFU; 0.17 ± 0.03 min-1). These data suggest that not all S. enterica strains have the same ability to survive under SGC, influencing the probability of arriving into the small intestine.
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Affiliation(s)
- A Godínez-Oviedo
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico; Food Safety and Innovation Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart 7005, Australia
| | - M L Tamplin
- Food Safety and Innovation Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart 7005, Australia
| | - J P Bowman
- Food Safety and Innovation Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart 7005, Australia
| | - M Hernández-Iturriaga
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico.
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2
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Medrano H, Lee L, Young V, Janecko N, Deckert AE, Gow SP, Reid-Smith RJ, Agunos A. Surveillance of antimicrobial resistance in Escherichia coli, Salmonella, and Campylobacter recovered from laying hens, their environment and products in Canada indicated a stable level of resistance to critically important antimicrobials, in varying time periods between 2007 and 2021. Int J Food Microbiol 2024; 412:110541. [PMID: 38199015 DOI: 10.1016/j.ijfoodmicro.2023.110541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/30/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024]
Abstract
The study objective was to determine the occurrence and antimicrobial resistance (AMR) attributes of select foodborne bacteria recovered from egg-producing (layer) chickens between 2007 and 2021 using different sample matrices (Study 1: liquid whole eggs, Study 2: spent hen cecal samples, Study 3: environmental sponge swabs and fecal samples from layer chicken barns, and Study 4: fecal samples from layer chicken barns). Samples from each study were submitted for the culture of Escherichia coli and Salmonella. In addition, samples from layer chicken barns were submitted for the culture of Campylobacter. Isolates were tested by microbroth dilution and interpreted using both clinical breakpoints and epidemiological cut-offs (ECOFFs). The ECOFFs were applied to detect non-wild type (NWT) strains. The proportion of resistant, NWT, and distribution of minimum inhibitory concentrations (MIC) were assessed. Ceftriaxone resistance was detected at a low-level in E. coli (< 2 %, all studies) and Salmonella (4.3 %, Study 2). Very low-level ciprofloxacin resistance was detected in E. coli (<1 %, Study 1) but a slightly elevated ciprofloxacin NWT E. coli (1 % to 6 %) observed. Only the farm fecal samples in Studies 2 and 3 were tested for Campylobacter as part of its study design, and moderate level ciprofloxacin resistance (<15 %) was observed. The MIC distribution patterns were similar across the organisms tested/studies and no substantial shifts in the distributions were detected. This analysis demonstrated that resistance to very important antimicrobials in bacteria from layers in Canada remains low, however, the detection of ciprofloxacin-resistant Campylobacter and the implications of this observation to the safety of egg products, and the role of laying flocks (i.e., as reservoir for resistant organisms) needs to be investigated.
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Affiliation(s)
- Hiddecel Medrano
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada.
| | - Liza Lee
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada; Department of Population Medicine, University of Guelph, Ontario, Canada
| | - Virginia Young
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada; Department of Population Medicine, University of Guelph, Ontario, Canada
| | - Nicol Janecko
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada; Department of Population Medicine, University of Guelph, Ontario, Canada
| | - Anne E Deckert
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada; Department of Population Medicine, University of Guelph, Ontario, Canada
| | - Sheryl P Gow
- Public Health Agency of Canada, Saskatoon, Saskatchewan, Canada
| | - Richard J Reid-Smith
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada; Department of Population Medicine, University of Guelph, Ontario, Canada
| | - Agnes Agunos
- Public Health Agency of Canada, Guelph (Ottawa), Ontario, Canada
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3
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Kumar Panda R, Darshana Patra S, Kumar Mohakud N, Ranjan Sahu B, Ghosh M, Misra N, Suar M. Draft genome of clinical isolate Salmonella enterica Typhimurium ms204 from Odisha, India, reveals multi drug resistance and decreased virulent gene expression. Gene 2023; 863:147248. [PMID: 36738898 DOI: 10.1016/j.gene.2023.147248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/16/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
Salmonellosis, a food-borne illnesses caused by enteropathogenic bacterium Salmonella spp., is a continuous concern in both developed and developing countries. This study was carried out to perform an in-depth examination of an MDR Salmonella strain isolated from gastroenteritis patients in Odisha, India, in order to understand the genomic architecture, distribution of pathogenic island regions, and virulence factor diversity. Fecal samples were obtained from individuals with acute gastroenteritis and further subjected to panel of biochemical tests. The IlluminaHiSeq X sequencer system was used to generate whole-genome sequencing. The draft genome was submitted to gene prediction and annotation using RAST annotation system. Pathogenicity Island database and bioinformatics pipeline were used to find Salmonella pathogenicity islands (SPI) from the built scaffold. The gene expression in SPI1 and SPI2 encoded regions was investigated using qRT-PCR. The taxonomic position of Salmonella enterica subsp. enterica serovar Typhimurium was validated by serotype analysis and 16S rRNA based phylogenetic analysis. The de-novo genome assembly showed total length of 5,034,110 bp and produced 37 contigs. There are nine prophage areas, comprising of 12 regions and scaffold 8 contained a single plasmid, IncFIB. The isolate contains six known SPI genes content which was shown to be largely conserved from SPI1 to SPI2. We identified the sit ABCD cluster regulatory cascade and acquired antibiotic resistance genes in S. enterica Typhimurium ms204. Further research may aid in the correct diagnosis and monitoring of MDR Salmonella strains with a variety of physiological activities.
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Affiliation(s)
| | | | - Nirmal Kumar Mohakud
- Kalinga Institute of Medical Sciences (KIMS), KIIT University, Bhubaneswar 751024, India
| | - Bikash Ranjan Sahu
- Department of Zoology, Centurion University of Technology and Management, India
| | - Mrinmoy Ghosh
- KIIT-Technology Business Incubator (KIIT-TBI), KIIT University, Bhubaneswar 751024, India
| | - Namrata Misra
- KIIT-Technology Business Incubator (KIIT-TBI), KIIT University, Bhubaneswar 751024, India
| | - Mrutyunjay Suar
- School of Biotechnology, KIIT University, Bhubaneswar 751024, India; KIIT-Technology Business Incubator (KIIT-TBI), KIIT University, Bhubaneswar 751024, India.
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4
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Hernández-Ledesma A, Cabrera-Díaz E, Arvizu-Medrano SM, Gómez-Baltazar A, Hernández-Iturriaga M, Godínez-Oviedo A. Virulence and antimicrobial resistance profiles of Salmonella enterica isolated from foods, humans, and the environment in Mexico. Int J Food Microbiol 2023; 391-393:110135. [PMID: 36827747 DOI: 10.1016/j.ijfoodmicro.2023.110135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/11/2023] [Accepted: 02/09/2023] [Indexed: 02/21/2023]
Abstract
Salmonella enterica genotypic and phenotypic characteristics play an important role in its pathogenesis, which could be influenced by its origin. This study evaluated the association among the antimicrobial resistance, virulence, and origin of circulating S. enterica strains in Mexico, isolated from foods, humans, and the environment. The antimicrobial susceptibility to fourteen antibiotics by the Kirby-Bauer method (n = 117), and the presence of thirteen virulence genes by multiplex PCR (n = 153) and by sequence alignments (n = 2963) were evaluated. In addition, a set of S. enterica isolates from Mexico (n = 344) previously characterized according to their genotypic and phenotypic print was included to increase the coverage of the association analysis. Strains with the presence of sopE and strains with the absence of sspH1 were significantly associated with multidrug-resistant (MDR) phenotypes (p < 0.05). The origin of the strains had significant associations with the antimicrobial profiles and some virulence genes (hilA, orgA, sifA, ssaQ, sseL, sspH1, pefA, and spvC) (p < 0.05). Animal-origin food isolates showed the highest frequency of MDR (57.2 %), followed by human isolates (30.0 %). Also, sspH1, pefA, and spvC were found in major frequency in human (32.4 %, 31.0 %, 31.7 %) and animal-origin foods (41.6 %, 10.6 %, 10.6 %) isolates. The findings highlighted that antimicrobial profiles and specific virulence genes of S. enterica strains are related to their origin. Similar genotypic and phenotypic characteristics between human and animal-origin foods isolates were found, suggesting that animal-origin foods isolates are the most responsible for human cases. The revealed associations can be used to improve risk estimation assessments in national food safety surveillance programs.
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Affiliation(s)
- A Hernández-Ledesma
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - E Cabrera-Díaz
- Departamento de Salud Pública, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Camino Ramón Padilla Sánchez 2100, Zapopan, Jalisco 45200, Mexico
| | - S M Arvizu-Medrano
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - A Gómez-Baltazar
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - M Hernández-Iturriaga
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - A Godínez-Oviedo
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico.
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5
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Goulart DB, Zhang Q, Sahin O. Growth kinetics and fitness of fluoroquinolone resistant and susceptible Campylobacter jejuni strains of cattle origin. Front Vet Sci 2023; 10:1117975. [PMID: 37143492 PMCID: PMC10151759 DOI: 10.3389/fvets.2023.1117975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/31/2023] [Indexed: 05/06/2023] Open
Abstract
Human enterocolitis is frequently caused by the Gram-negative microaerobic bacterium Campylobacter jejuni. Macrolides (e.g., erythromycin) and fluoroquinolones (FQs) (e.g., ciprofloxacin) are the preferred antibiotics for the treatment of human campylobacteriosis. Rapid emergence of FQ-resistant (FQ-R) Campylobacter during treatment with FQ antimicrobials is well known to occur in poultry. Cattle is also an important reservoir of Campylobacter for humans, and FQ-R Campylobacter from cattle has become highly prevalent in recent years. Even though the selection pressure may have contributed to the expansion of FQ-R Campylobacter, the actual impact of this factor appears to be rather low. In this study, we examined the hypothesis that the fitness of FQ-R Campylobacter may have also played a role in the rise seen in FQ-R Campylobacter isolates by employing a series of in vitro experiments in MH broth and bovine fecal extract. First, it was shown that FQ-R and FQ-susceptible (FQ-S) C. jejuni strains of cattle origin had comparable growth rates when individually cultured in both MH broth and the fecal extract with no antibiotic present. Interestingly, FQ-R strains had small but statistically significant increases over FQ-S strains in growth in competition experiments performed in mixed cultures with no antibiotic present. Lastly, it was observed that FQ-S C. jejuni strains developed resistance to ciprofloxacin more readily at high initial bacterial cell density (107 CFU/mL) and when exposed to low levels of the antibiotic (2-4 μg/mL) compared with that at a low level of initial bacterial cell density (105 CFU/mL) and exposure to a high level of ciprofloxacin (20 μg/mL) in both MH broth and the fecal extract. Altogether, these findings indicate that even though FQ-R C. jejuni of cattle origin may have a slightly higher fitness advantage over the FQ-S population, the emergence of FQ-R mutants from susceptible strains is primarily dictated by the bacterial cell density and the antibiotic concentration exposed under in vitro condition. These observation may also provide plausible explanations for the high prevalence of FQ-R C. jejuni in cattle production due to its overall fit nature in the absence of antibiotic selection pressure and for the paucity of development of FQ-R C. jejuni in the cattle intestine in response to FQ-treatment, as observed in our recent studies.
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Affiliation(s)
- Debora Brito Goulart
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States
| | - Qijing Zhang
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States
| | - Orhan Sahin
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
- *Correspondence: Orhan Sahin,
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6
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Hemez C, Clarelli F, Palmer AC, Bleis C, Abel S, Chindelevitch L, Cohen T, Abel zur Wiesch P. Mechanisms of antibiotic action shape the fitness landscapes of resistance mutations. Comput Struct Biotechnol J 2022; 20:4688-4703. [PMID: 36147681 PMCID: PMC9463365 DOI: 10.1016/j.csbj.2022.08.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 08/12/2022] [Accepted: 08/12/2022] [Indexed: 11/15/2022] Open
Abstract
Antibiotic-resistant pathogens are a major public health threat. A deeper understanding of how an antibiotic's mechanism of action influences the emergence of resistance would aid in the design of new drugs and help to preserve the effectiveness of existing ones. To this end, we developed a model that links bacterial population dynamics with antibiotic-target binding kinetics. Our approach allows us to derive mechanistic insights on drug activity from population-scale experimental data and to quantify the interplay between drug mechanism and resistance selection. We find that both bacteriostatic and bactericidal agents can be equally effective at suppressing the selection of resistant mutants, but that key determinants of resistance selection are the relationships between the number of drug-inactivated targets within a cell and the rates of cellular growth and death. We also show that heterogeneous drug-target binding within a population enables resistant bacteria to evolve fitness-improving secondary mutations even when drug doses remain above the resistant strain's minimum inhibitory concentration. Our work suggests that antibiotic doses beyond this "secondary mutation selection window" could safeguard against the emergence of high-fitness resistant strains during treatment.
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Affiliation(s)
- Colin Hemez
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Graduate Program in Biophysics, Harvard University, Boston, MA 02115, USA
- Corresponding authors at: Broad Institute, 75 Ames St, Room 3035, Cambridge, MA 02412, USA (C. Hemez). Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway (P. Abel zur Wiesch).
| | - Fabrizio Clarelli
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Adam C. Palmer
- Department of Pharmacology, Computational Medicine Program, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Christina Bleis
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Sören Abel
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
- Division of Infection Control, Norwegian Institute of Public Health, Oslo 0318, Norway
| | - Leonid Chindelevitch
- Department of Infectious Disease Epidemiology, Imperial College, London SW7 2AZ, UK
| | - Theodore Cohen
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520, USA
| | - Pia Abel zur Wiesch
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
- Division of Infection Control, Norwegian Institute of Public Health, Oslo 0318, Norway
- Corresponding authors at: Broad Institute, 75 Ames St, Room 3035, Cambridge, MA 02412, USA (C. Hemez). Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway (P. Abel zur Wiesch).
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7
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Microbial Community Structure and Bacterial Lineages Associated with Sulfonamides Resistance in Anthropogenic Impacted Larut River. WATER 2022. [DOI: 10.3390/w14071018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Anthropogenic activities often contribute to antibiotic resistance in aquatic environments. Larut River Malaysia is polluted with both organic and inorganic pollutants from domestic and industrial wastewater that are probably treated inadequately. The river is characterized by high biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia, and heavy metals. In our previous study, sulfonamides (SAs) and sulfonamide resistance genes (sul) were detected in the Larut River. Hence, in this study, we further examined the microbial community structure, diversity of sulfonamide-resistant bacteria (SARB), and their resistance genes. The study also aimed at identifying cultivable bacteria potential carriers of sul genes in the aquatic environment. Proteobacteria (22.4–66.0%), Firmicutes (0.8–41.6%), Bacteroidetes (2.0–29.4%), and Actinobacteria (5.5–27.9%) were the most dominant phyla in both the effluents and river waters. SARB isolated consisted only 4.7% of the total genera identified, with SAR Klebsiella as the most dominant (38.0–61.3%) followed by SAR Escherichia (0–22.2%) and Acinetobacter (3.2–16.0%). The majority of the SAR Klebsiella isolated from the effluents and middle downstream were positive for sul genes. Sul genes-negative SAR Escherichia and Acinetobacter were low (<20%). Canonical-correlation analysis (CCA) showed that SAs residues and inorganic nutrients exerted significant impacts on microbial community and total sul genes. Network analysis identified 11 SARB as potential sul genes bacterial carriers. These findings indicated that anthropogenic activities exerted impacts on the microbial community structure and SAs resistance in the Larut River.
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8
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Peh E, Kittler S, Seinige D, Valero A, Kehrenberg C. Adaptation of Campylobacter field isolates to propionic acid and sorbic acid is associated with fitness costs. J Appl Microbiol 2021; 131:1749-1761. [PMID: 33683781 DOI: 10.1111/jam.15057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/10/2021] [Accepted: 02/25/2021] [Indexed: 12/22/2022]
Abstract
AIMS To reduce the burden of Campylobacter at different stages of the food chain, recent studies have shown the effectiveness of organic acids as a risk mitigation strategy. However, very little is known about possible adaptation responses of Campylobacter that lead to reduced susceptibility to organic acids. Here we investigated the adaptive responses of Campylobacter field isolates to organic acids and estimated the fitness costs. METHODS AND RESULTS Exposure of two Campylobacter jejuni and one Campylobacter coli isolate to subinhibitory concentrations of propionic acid or sorbic acid resulted in twofold to fourfold increased minimal inhibitory concentration values for the adapted variants. With one exception, the decreased susceptibility was stable in at least 10 successive subcultures without selection pressure. Growth competition experiments revealed a reduced fitness of adapted variants compared to the wild-type isolates. A linear regression model allowed an estimation of the fitness cost. Growth kinetics experiments showed significantly prolonged lag phases in five of six adapted isolates while there was not a direct correlation in the maximum growth rates compared to the wild-type isolates. CONCLUSIONS The results of the study showed that a stepwise adaptation of Campylobacter to organic acids is possible, but at the detriment of changes in growth behaviour and reduced fitness. SIGNIFICANCE AND IMPACT OF THE STUDY The study contributes to the understanding of adaptive responses of Campylobacter to organic acids treatments, for example, as part of risk mitigation strategies.
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Affiliation(s)
- E Peh
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - S Kittler
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - D Seinige
- Lower Saxony State Office for Consumer Protection and Food Safety, Wardenburg, Germany
| | - A Valero
- Department of Food Science and Technology, University of Cordoba, Agrifood Campus of International, Córdoba, Spain
| | - C Kehrenberg
- Institute for Veterinary Food Science, Justus-Liebig-University Giessen, Giessen, Germany
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9
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The mutational landscape of quinolone resistance in Escherichia coli. PLoS One 2019; 14:e0224650. [PMID: 31689338 PMCID: PMC6830822 DOI: 10.1371/journal.pone.0224650] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 10/19/2019] [Indexed: 11/19/2022] Open
Abstract
The evolution of antibiotic resistance is influenced by a variety of factors, including the availability of resistance mutations, and the pleiotropic effects of such mutations. Here, we isolate and characterize chromosomal quinolone resistance mutations in E. coli, in order to gain a systematic understanding of the rate and consequences of resistance to this important class of drugs. We isolated over fifty spontaneous resistance mutants on nalidixic acid, ciprofloxacin, and levofloxacin. This set of mutants includes known resistance mutations in gyrA, gyrB, and marR, as well as two novel gyrB mutations. We find that, for most mutations, resistance tends to be higher to nalidixic acid than relative to the other two drugs. Resistance mutations had deleterious impacts on one or more growth parameters, suggesting that quinolone resistance mutations are generally costly. Our findings suggest that the prevalence of specific gyrA alleles amongst clinical isolates are driven by high levels of resistance, at no more cost than other resistance alleles.
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10
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Effects of antibiotic resistance (AR) and microbiota shifts on Campylobacter jejuni-mediated diseases. Anim Health Res Rev 2019; 18:99-111. [PMID: 29665882 DOI: 10.1017/s1466252318000014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Campylobacter jejuni is an important zoonotic pathogen recently designated a serious antimicrobial resistant (AR) threat. While most patients with C. jejuni experience hemorrhagic colitis, serious autoimmune conditions can follow including inflammatory bowel disease (IBD) and the acute neuropathy Guillain Barré Syndrome (GBS). This review examines inter-relationships among factors mediating C. jejuni diarrheal versus autoimmune disease especially AR C. jejuni and microbiome shifts. Because both susceptible and AR C. jejuni are acquired from animals or their products, we consider their role in harboring strains. Inter-relationships among factors mediating C. jejuni colonization, diarrheal and autoimmune disease include C. jejuni virulence factors and AR, the enteric microbiome, and host responses. Because AR C. jejuni have been suggested to affect the severity of disease, length of infections and propensity to develop GBS, it is important to understand how these interactions occur when strains are under selection by antimicrobials. More work is needed to elucidate host-pathogen interactions of AR C. jejuni compared with susceptible strains and how AR C. jejuni are maintained and evolve in animal reservoirs and the extent of transmission to humans. These knowledge gaps impair the development of effective strategies to prevent the emergence of AR C. jejuni in reservoir species and human populations.
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11
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Smith AB, Renter DG, Shi X, Cernicchiaro N, Sahin O, Nagaraja T. Campylobacter Prevalence and Quinolone Susceptibility in Feces of Preharvest Feedlot Cattle Exposed to Enrofloxacin for the Treatment of Bovine Respiratory Disease. Foodborne Pathog Dis 2018; 15:377-385. [DOI: 10.1089/fpd.2017.2398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Ashley B. Smith
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
- Bayer Healthcare, LLC, Animal Health Division, Shawnee, Kansas
| | - David G. Renter
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
- Center for Outcomes Research and Epidemiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Xiaorong Shi
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Natalia Cernicchiaro
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
- Center for Outcomes Research and Epidemiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Orhan Sahin
- Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, Iowa
| | - T.G. Nagaraja
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
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12
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Spectrum of antibacterial activity and mode of action of a novel tris-stilbene bacteriostatic compound. Sci Rep 2018; 8:6912. [PMID: 29720673 PMCID: PMC5932035 DOI: 10.1038/s41598-018-25080-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/29/2018] [Indexed: 11/22/2022] Open
Abstract
The spectrum of activity and mode of action of a novel antibacterial agent, 135C, was investigated using a range of microbiological and genomic approaches. Compound 135C was active against Gram-positive bacteria with MICs for Staphylococcus aureus ranging from 0.12–0.5 μg/ml. It was largely inactive against Gram-negative bacteria. The compound showed bacteriostatic activity in time-kill studies and did not elicit bacterial cell leakage or cell lysis. Checkerboard assays showed no synergy or antagonism when 135C was combined with a range of other antibacterials. Multi-step serial passage of four S. aureus isolates with increasing concentrations of 135C showed that resistance developed rapidly and was stable after drug-free passages. Minor differences in the fitness of 135C-resistant strains and parent wildtypes were evident by growth curves, but 135C-resistant strains did not show cross-resistance to other antibacterial agents. Genomic comparison of resistant and wildtype parent strains showed changes in genes encoding cell wall teichoic acids. 135C shows promising activity against Gram-positive bacteria but is currently limited by the rapid resistance development. Further studies are required to investigate the effects on cell wall teichoic acids and to determine whether the issue of resistance development can be overcome.
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Smith AB, Renter DG, Cernicchiaro N, Shi X, Nickell JS, Keil DJ, Nagaraja T. A Randomized Trial to Assess the Effect of Fluoroquinolone Metaphylaxis on the Fecal Prevalence and Quinolone Susceptibilities of Salmonella and Campylobacter in Feedlot Cattle. Foodborne Pathog Dis 2017; 14:600-607. [DOI: 10.1089/fpd.2017.2282] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Ashley B. Smith
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
- Bayer Animal Health, Shawnee Mission, Kansas
| | - David G. Renter
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
- Center for Outcomes Research and Epidemiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Natalia Cernicchiaro
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
- Center for Outcomes Research and Epidemiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Xiaorong Shi
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | | | | | - T.G. Nagaraja
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
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Yang Y, Ricke SC, Tellez G, Kwon YM. Quantitative Tracking of Salmonella Enteritidis Transmission Routes Using Barcode-Tagged Isogenic Strains in Chickens: Proof-of-Concept Study. Front Vet Sci 2017; 4:15. [PMID: 28261587 PMCID: PMC5306393 DOI: 10.3389/fvets.2017.00015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/30/2017] [Indexed: 11/13/2022] Open
Abstract
Salmonella is an important foodborne bacterial pathogen, however, a fundamental understanding on Salmonella transmission routes within a poultry flock remains unclear. In this study, a series of barcode-tagged strains were constructed by inserting six random nucleotides into a functionally neutral region on the chromosome of S. Enteritidis as a tool for quantitative tracking of Salmonella transmission in chickens. Six distinct barcode-tagged strains were used for infection or contamination at either low dose (103 CFUs; three strains) or high dose (105 CFUs; three strains) in three independent experiments (Experiment 1 oral gavage; Experiment 2 contaminated feed; Experiment 3 contaminated water). For all chick experiments, cecal and foot-wash samples were collected from a subset of the chickens at days 7 or/and 14, from which genomic DNA was extracted and used to amplify the barcode regions. After the resulting PCR amplicons were pooled and analyzed by MiSeq sequencing, a total of approximately 1.5 million reads containing the barcode sequences were analyzed to determine the relative frequency of every barcode-tagged strain in each sample. In Experiment 1, the high dose of oral infection was correlated with greater dominance of the strains in the ceca of the respective seeder chickens and also in the contact chickens yet at lesser degrees. When chicks were exposed to contaminated feed (Experiment 2) or water (Experiment 3), there were no clear patterns of the barcode-tagged strains in relation to the dosage, except that the strains introduced at low dose required a longer time to colonize the ceca with contaminated feed. Most foot-wash samples contained only one to three strains for the majority of the samples, suggesting potential existence of an unknown mechanism(s) for strain exclusion. These results demonstrated the proof of concept of using barcode tagged to investigate transmission dynamics of Salmonella in chickens in a quantitative manner.
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Affiliation(s)
- Yichao Yang
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Steven C. Ricke
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA
- Department of Food Science, University of Arkansas, Fayetteville, AR, USA
- Center of Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - Guillermo Tellez
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Young Min Kwon
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, USA
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA
- Center of Food Safety, University of Arkansas, Fayetteville, AR, USA
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Archundia D, Duwig C, Lehembre F, Chiron S, Morel MC, Prado B, Bourdat-Deschamps M, Vince E, Aviles GF, Martins JMF. Antibiotic pollution in the Katari subcatchment of the Titicaca Lake: Major transformation products and occurrence of resistance genes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 576:671-682. [PMID: 27810754 DOI: 10.1016/j.scitotenv.2016.10.129] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 06/06/2023]
Abstract
An increasing number of studies pointed out the ubiquitous presence of medical residues in surface and ground water as well as in soil compartments. Not only antibiotics can be found in the environment but also their transformation products about which little information is generally available. The development of bacterial resistance to antibiotics is particularly worrying as it can lead to sanitary and health problems. Studies about the dissemination of antibiotics and associated resistances in the Bolivian Altiplano are scarce. We provide baseline information on the occurrence of Sulfamethoxazole (SMX) and Trimethoprim (TMP) antibiotics as well as on the most common human SMX transformation products (TP) and on the occurrence of sulfonamide resistance genes. The studied water and soil compartments presented high levels of antibiotic pollution. This situation was shown to be mainly linked with uncontrolled discharges of treated and untreated wastewaters, resulting on the presence of antibiotics in the Titicaca Lake. SMX TPs were detected in surface waters and on soil sampled next to the wastewater treatment plant (WWTP). SMX resistance genes sulI and sulII were widely detected in the basin hydrological network, even in areas unpolluted with antibiotics. Mechanisms of co-selection of antibiotic- and metal- resistance may be involved in the prevalence of ARG's in pristine areas with no anthropogenic activity and free of antibiotic pollution.
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Affiliation(s)
- D Archundia
- Consejo Nacional de Ciencia y Tecnologia (CONACYT), México, D.F., Mexico; ERNO, Instituto de Geologia, Hermosillo, Sonora, Mexico.
| | - C Duwig
- Université Grenoble Alpes, LTHE, F38000 Grenoble, France; IRD, LTHE, F38000 Grenoble, France
| | - F Lehembre
- Université Grenoble Alpes, LTHE, F38000 Grenoble, France
| | - S Chiron
- UMR HydroSciences 5569, Montpellier University, 15 Avenue Ch. Flahault, 34093 Montpellier cedex 5, France
| | - M-C Morel
- CNAM, Laboratoire d'analyses chimiques et bio analyses, Paris Cedex 3, France
| | - B Prado
- Instituto de Geología, Universidad Nacional Autónoma de México, México, D.F., Mexico
| | - M Bourdat-Deschamps
- INRA AgroParisTech UMR ECOSYS, Bat. EGER Thiverval-Grignon, F-78850 Paris, France
| | - E Vince
- Université Grenoble Alpes, LTHE, F38000 Grenoble, France
| | - G Flores Aviles
- MMAyA, Ministerio de Medio Ambiente y Agua (Ministry of Water and Environment of Bolivia), La Paz, Bolivia
| | - J M F Martins
- Université Grenoble Alpes, LTHE, F38000 Grenoble, France; CNRS, LTHE, F38000 Grenoble, France
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Toutain PL, Ferran AA, Bousquet-Melou A, Pelligand L, Lees P. Veterinary Medicine Needs New Green Antimicrobial Drugs. Front Microbiol 2016; 7:1196. [PMID: 27536285 PMCID: PMC4971058 DOI: 10.3389/fmicb.2016.01196] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/19/2016] [Indexed: 01/08/2023] Open
Abstract
Given that: (1) the worldwide consumption of antimicrobial drugs (AMDs) used in food-producing animals will increase over the coming decades; (2) the prudent use of AMDs will not suffice to stem the rise in human antimicrobial resistance (AMR) of animal origin; (3) alternatives to AMD use are not available or not implementable, there is an urgent need to develop novel AMDs for food-producing animals. This is not for animal health reasons, but to break the link between human and animal resistomes. In this review we establish the feasibility of developing for veterinary medicine new AMDs, termed "green antibiotics," having minimal ecological impact on the animal commensal and environmental microbiomes. We first explain why animal and human commensal microbiota comprise a "turnstile" exchange, between the human and animal resistomes. We then outline the ideal physico-chemical, pharmacokinetic, and pharmacodynamic properties of a veterinary green antibiotic and conclude that they can be developed through a rational screening of currently used AMD classes. The ideal drug will be hydrophilic, of relatively low potency, slow clearance and small volume of distribution. It should be eliminated principally by the kidney as inactive metabolite(s). For oral administration, bioavailability can be enhanced by developing lipophilic pro-drugs. For parenteral administration, slow-release formulations of existing eco-friendly AMDs with a short elimination half-life can be developed. These new eco-friendly veterinary AMDs can be developed from currently used drug classes to provide alternative agents to those currently used in veterinary medicine and mitigate animal contributions to the human AMR problem.
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Affiliation(s)
- Pierre-Louis Toutain
- Ecole Nationale Vétérinaire de Toulouse, Institut National de la Recherche Agronomique, TOXALIM, Université de ToulouseToulouse, France
| | - Aude A. Ferran
- Ecole Nationale Vétérinaire de Toulouse, Institut National de la Recherche Agronomique, TOXALIM, Université de ToulouseToulouse, France
| | - Alain Bousquet-Melou
- Ecole Nationale Vétérinaire de Toulouse, Institut National de la Recherche Agronomique, TOXALIM, Université de ToulouseToulouse, France
| | - Ludovic Pelligand
- Comparative Biomedical Sciences, The Royal Veterinary CollegeHatfield, UK
| | - Peter Lees
- Comparative Biomedical Sciences, The Royal Veterinary CollegeHatfield, UK
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The Biocide and Antibiotic Resistance in Campylobacter jejuni and Campylobacter coli. FOOD ENGINEERING SERIES 2016. [DOI: 10.1007/978-3-319-24040-4_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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Meftahi N, Namouchi A, Mhenni B, Brandis G, Hughes D, Mardassi H. Evidence for the critical role of a secondary site rpoB mutation in the compensatory evolution and successful transmission of an MDR tuberculosis outbreak strain. J Antimicrob Chemother 2015; 71:324-32. [PMID: 26538504 DOI: 10.1093/jac/dkv345] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/24/2015] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND MDR Mycobacterium tuberculosis clinical strains that cause large outbreaks, particularly among HIV-negative patients, are likely to have undergone the most successful compensatory evolution. Hence, mutations secondary to the acquisition of drug resistance are worthy of consideration in these highly transmissible strains. Here, we assessed the role of a mutation within rpoB, rpoB V615M, secondary to the rifampicin resistance-conferring mutation rpoB S531L, which is associated with a major MDR tuberculosis outbreak strain that evolved in an HIV-negative context in northern Tunisia. METHODS Using BCG as a model organism, we engineered strains harbouring either the rpoB S531L mutation alone or the double mutation rpoB S531L, V615M. Individual and competitive in vitro growth assays were performed in order to assess the relative fitness of each BCG mutant. RESULTS The rpoB V615M mutation was found to be invariably associated with rpoB S531L. Structural analysis mapped rpoB V615M to the same bridge helix region as rpoB compensatory mutations previously described in Salmonella. Compared with the rpoB single-mutant BCG, the double mutant displayed improved growth characteristics and fitness rates equivalent to WT BCG. Strikingly, the rpoB double mutation conferred high-level resistance to rifampicin. CONCLUSIONS Here, we demonstrated the fitness compensatory role of a mutation within rpoB, secondary to the rifampicin resistance mutation rpoB S531L, which is characteristic of an MDR M. tuberculosis major outbreak strain. The finding that this secondary mutation concomitantly increased the resistance level to rifampicin argues for its significant contribution to the successful transmission of the MDR-TB strain.
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Affiliation(s)
- Nedra Meftahi
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Amine Namouchi
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Besma Mhenni
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Gerrit Brandis
- Department of Medical Biochemistry and Microbiology, Box 582 Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, Box 582 Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Helmi Mardassi
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
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Larsen MH, Dalmasso M, Ingmer H, Langsrud S, Malakauskas M, Mader A, Møretrø T, Smole Možina S, Rychli K, Wagner M, John Wallace R, Zentek J, Jordan K. Persistence of foodborne pathogens and their control in primary and secondary food production chains. Food Control 2014. [DOI: 10.1016/j.foodcont.2014.03.039] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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20
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Ma L, Shen Z, Naren G, Li H, Xia X, Wu C, Shen J, Zhang Q, Wang Y. Identification of a novel G2073A mutation in 23S rRNA in amphenicol-selected mutants of Campylobacter jejuni. PLoS One 2014; 9:e94503. [PMID: 24728007 PMCID: PMC3984149 DOI: 10.1371/journal.pone.0094503] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 03/17/2014] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES This study was conducted to examine the development and molecular mechanisms of amphenicol resistance in Campylobacter jejuni by using in vitro selection with chloramphenicol and florfenicol. The impact of the resistance development on growth rates was also determined using in vitro culture. METHODS Chloramphenicol and florfenicol were used as selection agents to perform in vitro stepwise selection. Mutants resistant to the selective agents were obtained from the selection process. The mutant strains were compared with the parent strain for changes in MICs and growth rates. The 23S rRNA gene and the L4 and L22 ribosomal protein genes in the mutant strains and the parent strain were amplified and sequenced to identify potential resistance-associated mutations. RESULTS C. jejuni strains that were highly resistant to chloramphenicol and florfenicol were obtained from in vitro selection. A novel G2073A mutation in all three copies of the 23S rRNA gene was identified in all the resistant mutants examined, which showed resistance to both chloramphenicol and florfenicol. In addition, all the mutants selected by chloramphenicol also exhibited the G74D modification in ribosomal protein L4, which was previously shown to confer a low-level erythromycin resistance in Campylobacter species. The mutants selected by florfenicol did not have the G74D mutation in L4. Notably, the amphenicol-resistant mutants also exhibited reduced susceptibility to erythromycin, suggesting that the selection resulted in cross resistance to macrolides. CONCLUSIONS This study identifies a novel point mutation (G2073A) in 23S rRNA in amphenicol-selected mutants of C. jejuni. Development of amphenicol resistance in Campylobacter likely incurs a fitness cost as the mutant strains showed slower growth rates in antibiotic-free media.
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Affiliation(s)
- Licai Ma
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Zhangqi Shen
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Gaowa Naren
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Hui Li
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Xi Xia
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Congming Wu
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Jianzhong Shen
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Qijing Zhang
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
- * E-mail: (QZ); (YW)
| | - Yang Wang
- Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
- * E-mail: (QZ); (YW)
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Chen SL, Wu M, Henderson JP, Hooton TM, Hibbing ME, Hultgren SJ, Gordon JI. Genomic diversity and fitness of E. coli strains recovered from the intestinal and urinary tracts of women with recurrent urinary tract infection. Sci Transl Med 2013; 5:184ra60. [PMID: 23658245 DOI: 10.1126/scitranslmed.3005497] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Urinary tract infections (UTIs) are common in women, and recurrence is a major clinical problem. Most UTIs are caused by uropathogenic Escherichia coli (UPEC). UPEC are generally thought to migrate from the gut to the bladder to cause UTI. UPEC form specialized intracellular bacterial communities in the bladder urothelium as part of a pathogenic mechanism to establish a foothold during acute stages of infection. Evolutionarily, such a specific adaptation to the bladder environment would be predicted to result in decreased fitness in other habitats, such as the gut. To examine this prediction, we characterized 45 E. coli strains isolated from the feces and urine of four otherwise healthy women with recurrent UTI. Multilocus sequence typing and whole genome sequencing revealed that two patients maintained a clonal population in both these body habitats throughout their recurrent UTIs, whereas the other two exhibited a wholesale shift in the dominant UPEC strain colonizing both sites. In vivo competition studies in mouse models, using isolates taken from one of the patients with a wholesale population shift, revealed that the strain that dominated her last UTI episode had increased fitness in both the gut and the bladder relative to the strain that dominated in preceding episodes. Increased fitness correlated with differences in the strains' gene repertoires and carbohydrate and amino acid utilization profiles. Thus, UPEC appear capable of persisting in both the gut and urinary tract without a fitness trade-off, emphasizing the need to widen our consideration of potential reservoirs for strains causing recurrent UTI.
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Affiliation(s)
- Swaine L Chen
- Center for Genome Sciences and Systems Biology, Washington University, St. Louis, MO 63108, USA
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Park M, Sutherland JB, Kim JN, Rafii F. Effect of Fluoroquinolone Resistance Selection on the Fitness of Three Strains of Clostridium perfringens. Microb Drug Resist 2013; 19:421-7. [DOI: 10.1089/mdr.2013.0056] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Miseon Park
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas
| | - John B. Sutherland
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas
| | - Jong Nam Kim
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas
| | - Fatemeh Rafii
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas
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Antimicrobial resistance mechanisms among Campylobacter. BIOMED RESEARCH INTERNATIONAL 2013; 2013:340605. [PMID: 23865047 PMCID: PMC3707206 DOI: 10.1155/2013/340605] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/11/2013] [Indexed: 12/24/2022]
Abstract
Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world. Humans most often become infected by ingesting contaminated food, especially undercooked chicken, but also other sources of bacteria have been described. Campylobacteriosis is normally a self-limiting disease. Antimicrobial treatment is needed only in patients with more severe disease and in those who are immunologically compromised. The most common antimicrobial agents used in the treatment of Campylobacter infections are macrolides, such as erythromycin, and fluoroquinolones, such as ciprofloxacin. Tetracyclines have been suggested as an alternative choice in the treatment of clinical campylobacteriosis but in practice are not often used. However, during the past few decades an increasing number of resistant Campylobacter isolates have developed resistance to fluoroquinolones and other antimicrobials such as macrolides, aminoglycosides, and beta-lactams. Trends in antimicrobial resistance have shown a clear correlation between use of antibiotics in the veterinary medicine and animal production and resistant isolates of Campylobacter in humans. In this review, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter are discussed.
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Effects of efflux-pump inducers and genetic variation of the multidrug transporter cmeB in biocide resistance of Campylobacter jejuni and Campylobacter coli. J Med Microbiol 2013; 62:400-411. [DOI: 10.1099/jmm.0.052316-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Mavri A, Smole Možina S. Resistance to bile salts and sodium deoxycholate in macrolide- and fluoroquinolone-susceptible and resistant Campylobacter jejuni and Campylobacter coli strains. Microb Drug Resist 2013; 19:168-74. [PMID: 23289436 DOI: 10.1089/mdr.2012.0217] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Campylobacter are the most commonly reported bacterial causes of human gastroenteritis, and they are becoming increasingly resistant to antibiotics, including macrolides and fluoroquinolones, those most frequently used for the treatment of campylobacteriosis. Active efflux mechanisms are involved in resistance of Campylobacter to a broad spectrum of antimicrobials, and are also essential for Campylobacter colonization in the animal intestine, through mediation of bile resistance. Acquisition of antibiotic resistance through resistance-conferring mutations can impose a fitness cost of Campylobacter. The aim of the present study was to determine whether macrolide and fluoroquinolone resistance in Campylobacter affects their tolerance to bile salts and sodium deoxycholate through the most frequent resistance-conferring mutations. Antimicrobial efflux was studied on the basis of restored sensitivity in the presence of the efflux-pump inhibitors (EPIs) phenylalanine-arginine beta-naphthylamide (PAβN) and 1-(1-naphthylmethyl)-piperazine. In the 15 Campylobacter jejuni and 23 Campylobacter coli strains examined here, both of these EPIs partially reversed the resistance to bile salts and sodium deoxycholate. Erythromycin-sensitive C. coli strains were more resistant to bile salts and sodium deoxycholate than erythromycin-resistant strains. PAβN had greater effects on bile salt and sodium deoxycholate resistance in these erythromycin-resistant strains compared to erythromycin-sensitive strains. However, no differences were seen between the ciprofloxacin-sensitive and ciprofloxacin-resistant strains.
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Affiliation(s)
- Ana Mavri
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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Mavri A, Smole Možina S. Development of antimicrobial resistance in Campylobacter jejuni and Campylobacter coli adapted to biocides. Int J Food Microbiol 2012; 160:304-12. [PMID: 23290239 DOI: 10.1016/j.ijfoodmicro.2012.11.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 08/21/2012] [Accepted: 11/07/2012] [Indexed: 10/27/2022]
Abstract
The potential for adaptive resistance of Campylobacter jejuni and Campylobacter coli after step-wise exposure to increasing sub-inhibitory concentrations of five biocides as triclosan, benzalkonium chloride, cetylpyridinium chloride, chlorhexidine diacetate and trisodium phosphate, was investigated, to identify the mechanisms underlying resistance. The biocide resistance and cross-resistance to the antimicrobials erythromycin and ciprofloxacin, and to sodium dodecyl sulphate, were examined according to the broth microdilution method. The presence of active efflux was studied on the basis of restored sensitivity in the presence of the efflux pump inhibitors phenylalanine-arginine beta-naphthylamide, 1-(1-naphthylmethyl)-piperazine, cyanide 3-chlorophenylhydrazone, verapamil and reserpine. Changes in the outer membrane protein profiles and morphological changes in adapted strains were studied, as compared with the parent strains. Repeated exposure of C. jejuni and C. coli to biocides resulted in partial increases in tolerance to biocides itself, to other biocides and antimicrobial compounds. The developed resistance was stable for up to 10 passages in biocide-free medium. More than one type of active efflux was identified in adapted strains. These adapted strains showed different alterations to their outer membrane protein profiles, along with morphological changes. The data presented here suggest that different mechanisms are involved in adaptation to biocides and that this adaptation is unique to each strain of Campylobacter and does not result from a single species-specific mechanism.
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Affiliation(s)
- Ana Mavri
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, Ljubljana, Slovenia
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Longitudinal study comparing the dynamics of Clostridium difficile in conventional and antimicrobial free pigs at farm and slaughter. Vet Microbiol 2012; 157:172-8. [DOI: 10.1016/j.vetmic.2011.12.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 12/01/2011] [Accepted: 12/14/2011] [Indexed: 11/24/2022]
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Kunz AN, Begum AA, Wu H, D'Ambrozio JA, Robinson JM, Shafer WM, Bash MC, Jerse AE. Impact of fluoroquinolone resistance mutations on gonococcal fitness and in vivo selection for compensatory mutations. J Infect Dis 2012; 205:1821-9. [PMID: 22492860 DOI: 10.1093/infdis/jis277] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Quinolone-resistant Neisseria gonorrhoeae (QRNG) arise from mutations in gyrA (intermediate resistance) or gyrA and parC (resistance). Here we tested the consequence of commonly isolated gyrA(91/95) and parC86 mutations on gonococcal fitness. METHODS Mutant gyrA(91/95) and parC86 alleles were introduced into wild-type gonococci or an isogenic mutant that is resistant to macrolides due to an mtrR(-79) mutation. Wild-type and mutant bacteria were compared for growth in vitro and in competitive murine infection. RESULTS In vitro growth was reduced with increasing numbers of mutations. Interestingly, the gyrA(91/95) mutation conferred an in vivo fitness benefit to wild-type and mtrR(-79) mutant gonococci. The gyrA(91/95), parC86 mutant, in contrast, showed a slight fitness defect in vivo, and the gyrA(91/95), parC86, mtrR(-79) mutant was markedly less fit relative to the parent strains. A ciprofloxacin-resistant (Cip(R)) mutant was selected during infection with the gyrA(91/95), parC86, mtrR(-79) mutant in which the mtrR(-79) mutation was repaired and the gyrA(91) mutation was altered. This in vivo-selected mutant grew as well as the wild-type strain in vitro. CONCLUSIONS gyrA(91/95) mutations may contribute to the spread of QRNG. Further acquisition of a parC86 mutation abrogates this fitness advantage; however, compensatory mutations can occur that restore in vivo fitness and maintain Cip(R).
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Affiliation(s)
- Anjali N Kunz
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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Han J, Wang Y, Sahin O, Shen Z, Guo B, Shen J, Zhang Q. A fluoroquinolone resistance associated mutation in gyrA Affects DNA supercoiling in Campylobacter jejuni. Front Cell Infect Microbiol 2012; 2:21. [PMID: 22919613 PMCID: PMC3417464 DOI: 10.3389/fcimb.2012.00021] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 02/14/2012] [Indexed: 01/23/2023] Open
Abstract
The prevalence of fluoroquinolone (FQ)-resistant Campylobacter has become a concern for public health. To facilitate the control of FQ-resistant (FQR) Campylobacter, it is necessary to understand the impact of FQR on the fitness of Campylobacter in its natural hosts as understanding fitness will help to determine and predict the persistence of FQRCampylobacter. Previously it was shown that acquisition of resistance to FQ antimicrobials enhanced the in vivo fitness of FQRCampylobacter. In this study, we confirmed the role of the Thr-86-Ile mutation in GyrA in modulating Campylobacter fitness by reverting the mutation to the wild-type (WT) allele, which resulted in the loss of the fitness advantage. Additionally, we determined if the resistance-conferring GyrA mutations alter the enzymatic function of the DNA gyrase. Recombinant WT gyrase and mutant gyrases with three different types of mutations (Thr-86-Ile, Thr-86-Lys, and Asp-90-Asn), which are associated with FQR in Campylobacter, were generated in E. coli and compared for their supercoiling activities using an in vitro assay. The mutant gyrase with the Thr-86-Ile change showed a greatly reduced supercoiling activity compared with the WT gyrase, while other mutant gyrases did not show an altered supercoiling. Furthermore, we measured DNA supercoiling within Campylobacter cells using a reporter plasmid. Consistent with the results from the in vitro supercoiling assay, the FQR mutant carrying the Thr-86-Ile change in GyrA showed much less DNA supercoiling than the WT strain and the mutant strains carrying other mutations. Together, these results indicate that the Thr-86-Ile mutation, which is predominant in clinical FQRCampylobacter, modulates DNA supercoiling homeostasis in FQRCampylobacter.
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Affiliation(s)
- Jing Han
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University Ames, IA, USA
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Habing GG, Lo YJ, Kaneene JB. Changes in the antimicrobial resistance profiles of Salmonella isolated from the same Michigan dairy farms in 2000 and 2009. Food Res Int 2012. [DOI: 10.1016/j.foodres.2011.02.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Maher MC, Alemayehu W, Lakew T, Gaynor BD, Haug S, Cevallos V, Keenan JD, Lietman TM, Porco TC. The fitness cost of antibiotic resistance in Streptococcus pneumoniae: insight from the field. PLoS One 2012; 7:e29407. [PMID: 22272234 PMCID: PMC3260144 DOI: 10.1371/journal.pone.0029407] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 11/28/2011] [Indexed: 11/24/2022] Open
Abstract
Background Laboratory studies have suggested that antibiotic resistance may result in decreased fitness in the bacteria that harbor it. Observational studies have supported this, but due to ethical and practical considerations, it is rare to have experimental control over antibiotic prescription rates. Methods and Findings We analyze data from a 54-month longitudinal trial that monitored pneumococcal drug resistance during and after biannual mass distribution of azithromycin for the elimination of the blinding eye disease, trachoma. Prescription of azithromycin and antibiotics that can create cross-resistance to it is rare in this part of the world. As a result, we were able to follow trends in resistance with minimal influence from unmeasured antibiotic use. Using these data, we fit a probabilistic disease transmission model that included two resistant strains, corresponding to the two dominant modes of resistance to macrolide antibiotics. We estimated the relative fitness of these two strains to be 0.86 (95% CI 0.80 to 0.90), and 0.88 (95% CI 0.82 to 0.93), relative to antibiotic-sensitive strains. We then used these estimates to predict that, within 5 years of the last antibiotic treatment, there would be a 95% chance of elimination of macrolide resistance by intra-species competition alone. Conclusions Although it is quite possible that the fitness cost of macrolide resistance is sufficient to ensure its eventual elimination in the absence of antibiotic selection, this process takes time, and prevention is likely the best policy in the fight against resistance.
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Affiliation(s)
- M. Cyrus Maher
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, United States of America
| | - Wondu Alemayehu
- ORBIS International, New York, New York, United States of America
| | - Takele Lakew
- ORBIS International, New York, New York, United States of America
| | - Bruce D. Gaynor
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Sara Haug
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Vicky Cevallos
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Jeremy D. Keenan
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Thomas M. Lietman
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, United States of America
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Institute for Global Health, University of California San Francisco, San Francisco, California, United States of America
| | - Travis C. Porco
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, United States of America
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Institute for Global Health, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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Garbeva P, Tyc O, Remus-Emsermann MNP, van der Wal A, Vos M, Silby M, de Boer W. No apparent costs for facultative antibiotic production by the soil bacterium Pseudomonas fluorescens Pf0-1. PLoS One 2011; 6:e27266. [PMID: 22110622 PMCID: PMC3217935 DOI: 10.1371/journal.pone.0027266] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 10/13/2011] [Indexed: 11/18/2022] Open
Abstract
Background Many soil-inhabiting bacteria are known to produce secondary metabolites that can suppress microorganisms competing for the same resources. The production of antimicrobial compounds is expected to incur fitness costs for the producing bacteria. Such costs form the basis for models on the co-existence of antibiotic-producing and non-antibiotic producing strains. However, so far studies quantifying the costs of antibiotic production by bacteria are scarce. The current study reports on possible costs, for antibiotic production by Pseudomonas fluorescens Pf0-1, a soil bacterium that is induced to produce a broad-spectrum antibiotic when it is confronted with non-related bacterial competitors or supernatants of their cultures. Methodology and Principal Findings We measured the possible cost of antibiotic production for Pseudomonas fluorescens Pf0-1 by monitoring changes in growth rate with and without induction of antibiotic production by supernatant of a bacterial competitor, namely Pedobacter sp.. Experiments were performed in liquid as well as on semi-solid media under nutrient-limited conditions that are expected to most clearly reveal fitness costs. Our results did not reveal any significant costs for production of antibiotics by Pseudomonas fluorescens Pf0-1. Comparison of growth rates of the antibiotic-producing wild-type cells with those of non-antibiotic producing mutants did not reveal costs of antibiotic production either. Significance Based on our findings we propose that the facultative production of antibiotics might not be selected to mitigate metabolic costs, but instead might be advantageous because it limits the risk of competitors evolving resistance, or even the risk of competitors feeding on the compounds produced.
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Affiliation(s)
- Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
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Mild RM, Joens LA, Friedman M, Olsen CW, McHugh TH, Law B, Ravishankar S. Antimicrobial edible apple films inactivate antibiotic resistant and susceptible Campylobacter jejuni strains on chicken breast. J Food Sci 2011; 76:M163-8. [PMID: 21535839 DOI: 10.1111/j.1750-3841.2011.02065.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
UNLABELLED Campylobacter jejuni is the leading cause of bacterial diarrheal illness worldwide. Many strains are now becoming multidrug resistant. Apple-based edible films containing carvacrol and cinnamaldehyde were evaluated for bactericidal activity against antibiotic resistant and susceptible C. jejuni strains on chicken. Retail chicken breast samples inoculated with D28a and H2a (resistant strains) and A24a (a sensitive strain) were wrapped in apple films containing cinnamaldehyde or carvacrol at 0.5%, 1.5%, and 3% concentrations, and then incubated at 4 or 23 °C for 72 h. Immediately after wrapping and at 72 h, samples were plated for enumeration of viable C. jejuni. The antimicrobial films exhibited dose- and temperature-dependent bactericidal activity against all strains. Films with ≥1.5% cinnamaldehyde reduced populations of all strains to below detection at 23 °C at 72 h. At 4 °C with cinnamaldehyde, reductions were variable for all strains, ranging from 0.2 to 2.5 logs and 1.8 to 6.0 logs at 1.5% and 3.0%, respectively. Films with 3% carvacrol reduced populations of A24a and H2a to below detection, and D28a by 2.4 logs at 23 °C and 72 h. A 0.5-log reduction was observed for both A24a and D28a, and 0.9 logs for H2a at 4 °C at 3% carvacrol. Reductions ranged from 1.1 to 1.9 logs and 0.4 to 1.2 logs with 1.5% and 0.5% carvacrol at 23 °C, respectively. The films with cinnamaldehyde were more effective than carvacrol films. Reductions at 23 °C were greater than those at 4 °C. Our results showed that antimicrobial apple films have the potential to reduce C. jejuni on chicken and therefore, the risk of campylobacteriosis. Possible mechanisms of antimicrobial effects are discussed. PRACTICAL APPLICATION Apple antimicrobial films could potentially be used in retail food packaging to reduce C. jejuni commonly present on food.
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Affiliation(s)
- Rita M Mild
- Department of Veterinary Science and Microbiology, University of Arizona, 1117 E Lowell St., Tucson, AZ 85721, USA
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Zeitouni S, Kempf I. Fitness cost of fluoroquinolone resistance in Campylobacter coli and Campylobacter jejuni. Microb Drug Resist 2011; 17:171-9. [PMID: 21388301 DOI: 10.1089/mdr.2010.0139] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, the fitness cost of fluoroquinolone resistance was evaluated in vitro, on food matrices, and in vivo, using Campylobacter coli and Campylobacter jejuni in vitro selected mutants. In vitro, the growth rate of the susceptible (wild type) and resistant (mutant) strains did not differ when cultured separately. However, by conducting sequential passages of mixed cultures, the ratio of the resistant mutant to the susceptible strain decreased for C. coli but not for C. jejuni. When the wild type and the mutant were co-inoculated on food matrices, mutants were no longer detectable 3 to 5 days after artificial contamination, but the wild-type strains remained detectable for over 13 days. In mono-inoculated animals, no difference was observed between wild-type and mutant fecal titers. When co-inoculated into chickens, the susceptible strain outcompeted the resistant mutant for C. coli and for C. jejuni. However, for C. coli, if the resistant strain was already present in animals, it could persist at high titers in the digestive tract even in the presence of the wild-type strain. Together, these findings suggest that, depending on strain and study conditions, fluoroquinolone resistance can impose a fitness cost on Campylobacter.
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Affiliation(s)
- Salman Zeitouni
- Mycoplasmology and Bacteriology Unit, French Agency for Food, Environmental and Occupational Health Safety, Ploufragan, France
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Frye JG, Lindsey RL, Meinersmann RJ, Berrang ME, Jackson CR, Englen MD, Turpin JB, Fedorka-Cray PJ. Related antimicrobial resistance genes detected in different bacterial species co-isolated from swine fecal samples. Foodborne Pathog Dis 2011; 8:663-79. [PMID: 21385089 DOI: 10.1089/fpd.2010.0695] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
A potential factor leading to the spread of antimicrobial resistance (AR) in bacteria is the horizontal transfer of resistance genes between bacteria in animals or their environment. To investigate this, swine fecal samples were collected on-farm and cultured for Escherichia coli, Salmonella enterica, Campylobacter spp., and Enterococcus spp. which are all commonly found in swine. Forty-nine of the samples from which all four bacteria were recovered were selected yielding a total of 196 isolates for analysis. Isolates were tested for antimicrobial susceptibility followed by hybridization to a DNA microarray designed to detect 775 AR-related genes. E. coli and Salmonella isolated from the same fecal sample had the most AR genes in common among the four bacteria. Genes detected encoded resistance to aminoglycosides (aac(3), aadA1, aadB, and strAB), β-lactams (ampC, ampR, and bla(TEM)), chloramphenicols (cat and floR), sulfanillic acid (sul1/sulI), tetracyclines (tet(A), tet(D), tet(C), tet(G), and tet(R)), and trimethoprim (dfrA1 and dfh). Campylobacter coli and Enterococcus isolated from the same sample frequently had tet(O) and aphA-3 genes detected in common. Almost half (47%) of E. coli and Salmonella isolated from the same fecal sample shared resistance genes at a significant level (χ², p < 0.0000001). These data suggest that there may have been horizontal exchange of AR genes between these bacteria or there may be a common source of AR genes in the swine environment for E. coli and Salmonella.
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Affiliation(s)
- Jonathan G Frye
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, Richard B. Russell Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia 30605, USA.
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Almofti YA, Dai M, Sun Y, Haihong H, Yuan Z. Impact of erythromycin resistance on the virulence properties and fitness of Campylobacter jejuni. Microb Pathog 2011; 50:336-42. [PMID: 21377522 DOI: 10.1016/j.micpath.2011.02.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 02/23/2011] [Accepted: 02/25/2011] [Indexed: 12/30/2022]
Abstract
Epidemiological studies of macrolide resistance in Campylobacter jejuni demonstrated that infections with macrolide-resistant C. jejuni could be associated with an increased risk of adverse events, development of invasive illness or death compared to macrolide-susceptible isolates. In this study, an in vitro induction experiment was conducted using susceptible C. jejuni strain and erythromycin as a selecting agent to obtain Ery-resistant mutant with 23S rRNA gene mutation (A2074C). Changes in the virulence characteristics and fitness between the susceptible parent strain and Ery-resistant mutant were examined. Ery-resistant mutant demonstrated slightly more resistance to bile in the bile tolerance assay compared to the susceptible strain but with no statistical significant difference. However Ery-resistant mutant apparently demonstrated reduced adhesion and invasion characteristics to intestinal epithelial cells, murine macrophage and short time intracellular survivability within macrophage compared to the susceptible strain. Co-inoculation of the two strains in the mice resulted in low colonization level of the resistant strain compared to the susceptible strain. Competition experiments resulted in mutant that grew significantly slower than the susceptible parent strain and the mutation imposed a fitness cost in Ery-resistant mutant. Taken together these findings demonstrated the increment of the virulence characteristics of Ery-susceptible strain rather than Ery-resistant strain. The adverse events previously observed in the epidemiological studies for macrolide-resistant strains infection, we suggested this maybe attributed to the resistivity of the resistant strains to the treatment and consequently prolonged the symptoms and compromised the disease in patients.
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Affiliation(s)
- Yassir A Almofti
- MOA Key Laboratory of Food Safety Evaluation, National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
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Lanzas C, Lu Z, Gröhn YT. Mathematical modeling of the transmission and control of foodborne pathogens and antimicrobial resistance at preharvest. Foodborne Pathog Dis 2010; 8:1-10. [PMID: 21043837 DOI: 10.1089/fpd.2010.0643] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Foodborne diseases are a significant health-care and economic burden. Most foodborne pathogens are enteric pathogens harbored in the gastrointestinal tract of farm animals. Understanding the transmission of foodborne pathogens and the dissemination of antimicrobial resistance at the farm level is necessary to design effective control strategies at preharvest. Mathematical models improve our understanding of pathogen dynamics by providing a theoretical framework in which factors affecting transmission and control of the pathogens can be explicitly considered. In this review, we aim to present the principles underlying the mathematical modeling of foodborne pathogens and antimicrobial resistance at the farm level to a broader audience.
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Affiliation(s)
- Cristina Lanzas
- Department of Population Medicine and Diagnostic Sciences, Cornell University , Ithaca, New York, USA.
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Ferrari R, Magnani M, Souza RB, Tognim MCB, Oliveira TCRM. Mutant prevention concentration (MPC) of ciprofloxacin against Salmonella enterica of epidemic and poultry origin. Curr Microbiol 2010; 62:628-32. [PMID: 20872005 DOI: 10.1007/s00284-010-9754-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 09/03/2010] [Indexed: 11/25/2022]
Abstract
Salmonella isolates resistant or with reduced susceptibility to quinolones increased in recent years. The mutant prevention concentration (MPC) is a new alternative that can prevent the selection and multiplication of resistant Salmonella spp. strains. The MPC of ciprofloxacin (CipMPC) was evaluated for 312 Salmonella enterica strains of epidemic and poultry origin susceptible and resistant to nalidixic acid (NAL). The CipMPC for NAL-susceptible strains were in the range from 0.002 to 4 μg/ml and for NAL-resistant strains, it ranged from 0.004 to 16 μg/ml. The average MPC/MIC ratio for NAL-resistant strains was higher than NAL susceptible. S. Enteritidis showed the highest CipMPC and the highest MPC/MIC ratio also for NAL-resistant strains and with mutations in gyrA. Serovar Corvallis, a NAL-resistant strain without mutations, and of poultry origin showed the highest CipMPC value. The lowest value was observed for epidemic NAL-susceptible strains serovars Typhimurium and London. The average MPC/MIC ratio for strains with mutations in Aspartate 87 was higher than that mutated in Serine 83. The results show the importance of MPC in determining the correct dosage of Cip for treatment of Salmonella spp.
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Affiliation(s)
- Rafaela Ferrari
- Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, Londrina, Brazil
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Stapleton K, Cawthraw SA, Cooles SW, Coldham NG, La Ragione RM, Newell DG, Ridley AM. Selecting for development of fluoroquinolone resistance in a Campylobacter jejuni strain 81116 in chickens using various enrofloxacin treatment protocols. J Appl Microbiol 2010; 109:1132-8. [PMID: 20408918 DOI: 10.1111/j.1365-2672.2010.04734.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS To determine the effect of various enrofloxacin dose regimes on the colonization and selection of resistance in Campylobacter jejuni strain 81116P in experimentally colonized chickens. METHODS AND RESULTS Two experiments were undertaken, in which 14-day-old chickens were colonized with 1 × 10(7) -1 × 10(9 ) CFU g(-1) Camp. jejuni strain 81116P and then treated with enrofloxacin at 12-500 ppm in drinking water for various times. Caecal colonization levels were determined at various time-points after start-of-treatment, and the susceptibility of recovered isolates to ciprofloxacin was monitored. Resistance was indicated by growth on agar containing 4 μg ml(-1) ciprofloxacin, MICs of 16 μg ml(-1) and the Thr86Ile mutation in gyrA. Enrofloxacin at doses of 12-250 ppm reduced Camp. jejuni colonization over the first 48-72 h after start-of-treatment. The degree of reduction in colonization was dose, but not treatment time, dependent. In all cases, maximal colonization was re-established within 4-6 days. Fluoroquinolone-resistant organisms were recoverable within 48 h of start-of-treatment; after a further 24 h all recovered isolates were resistant. In contrast, a dose of 500 ppm enrofloxacin reduced colonization to undetectable levels within 48 h, and the treated birds remained Campylobacter negative throughout the remaining experimental period. By high pressure liquid chromatography, for all doses, the maximum concentrations of enrofloxacin and ciprofloxacin in the caecal contents were detected at the point of treatment completion. Thereafter, levels declined to undetectable by 7 days post-treatment withdrawal. CONCLUSIONS In a model using chickens maximally colonized with Camp. jejuni 81116P, treatment with enrofloxacin, at doses of 12-250 ppm in drinking water, enables the selection, and clonal expansion, of fluoroquinolone-resistant organisms. However, this is preventable by treatment with 500 ppm of enrofloxacin. SIGNIFICANCE AND IMPACT OF THE STUDY Treatment of chickens with enrofloxacin selects for resistance in Camp. jejuni in highly pre-colonized birds. However, a dose of 500 ppm enrofloxacin prevented the selection of resistant campylobacters.
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Affiliation(s)
- K Stapleton
- Veterinary Laboratories Agency Weybridge, Surrey, UK
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Vågsholm I, Höjgård S. Antimicrobial sensitivity—A natural resource to be protected by a Pigouvian tax? Prev Vet Med 2010; 96:9-18. [DOI: 10.1016/j.prevetmed.2010.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 04/13/2010] [Accepted: 05/01/2010] [Indexed: 11/25/2022]
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Abstract
Campylobacter is a commensal in poultry, and therefore, poultry and poultry products are major sources of Campylobacter infections in humans. Fluoroquinolones inhibit the growth of Campylobacter and other microorganisms by binding to bacterial DNA gyrase and DNA topoisomerase IV. These enzymes are associated with bacterial transcription, replication, and chromosome condensation and segregation. Selection pressure in the presence of fluoroquinolones rapidly leads to resistance in Campylobacter, due to the selection for mutations in DNA gyrase. Fluoroquinolone-resistant campylobacters have been found in poultry feces and carcasses, and in retail poultry meat products in most areas of the world. In addition, other food animals and the meat products from those animals have been shown contaminated with fluoroquinolone-resistant campylobacters. Even the removal of fluoroquinolones from use in treating animal diseases has not entirely eliminated the presence of resistant Campylobacter jejuni and Campylobacter coli from animals and animal products. Human exposure to Campylobacter infection could be reduced by using strategies that decrease colonization of chickens by the pathogen.
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Affiliation(s)
- James L Smith
- Microbial Food Safety Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038-8598, USA.
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Compensation of fitness costs and reversibility of antibiotic resistance mutations. Antimicrob Agents Chemother 2010; 54:2085-95. [PMID: 20176903 DOI: 10.1128/aac.01460-09] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Strains of bacterial pathogens that have acquired mutations conferring antibiotic resistance often have a lower growth rate and are less invasive or transmissible initially than their susceptible counterparts. However, fitness costs of resistance mutations can be ameliorated by secondary site mutations. These so-called compensatory mutations may restore fitness in the absence and/or presence of antimicrobials. We review literature data and show that the fitness gains in the absence and presence of antibiotic treatment need not be correlated. The aim of this study is to gain a better conceptual grasp of how compensatory mutations with different fitness gains affect evolutionary trajectories, in particular reversibility. To this end, we developed a theoretical model with which we consider both a resistance and a compensation locus. We propose an intuitively understandable parameterization for the fitness values of the four resulting genotypes (wild type, resistance mutation only, compensatory mutation only, and both mutations) in the absence and presence of treatment. The differential fitness gains, together with the turnover rate and the mutation rate, strongly affected the success of antibacterial treatment, reversibility, and long-term abundance of resistant strains. We therefore propose that experimental studies of compensatory mutations should include fitness measurements of all possible genotypes in both the absence and presence of an antibiotic.
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Rollo SN, Norby B, Bartlett PC, Scott HM, Wilson DL, Fajt VR, Linz JE, Bunner CE, Kaneene JB, Huber JC. Prevalence and patterns of antimicrobial resistance in Campylobacter spp isolated from pigs reared under antimicrobial-free and conventional production methods in eight states in the Midwestern United States. J Am Vet Med Assoc 2010; 236:201-10. [PMID: 20074013 DOI: 10.2460/javma.236.2.201] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare apparent prevalence and patterns of antimicrobial resistance in Campylobacter spp in feces collected from pigs reared with antimicrobial-free versus conventional production methods in 8 states in the Midwestern United States. DESIGN Cross-sectional study. SAMPLE POPULATION 95 swine farms that used antimicrobial-free (n = 35) or conventional (60) production methods. PROCEDURES Fecal samples from 15 pigs/farm were collected. Biochemical and multiplex-PCR analyses were used to identify Campylobacter spp. The minimal inhibitory concentrations of erythromycin, azithromycin, ciprofloxacin, nalidixic acid, gentamicin, and tetracycline for these organisms were determined by use of a commercially available antimicrobial gradient strip. The data were analyzed by use of population-averaged statistical models. RESULTS Campylobacter spp were isolated from 512 of 1,422 pigs. A subset (n = 464) of the 512 isolates was available for antimicrobial susceptibility testing. The apparent prevalence of Campylobacter spp isolates from pigs on conventional farms (35.8%) and antimicrobial-free farms (36.4%) did not differ significantly. Resistances to azithromycin, erythromycin, and tetracycline were significantly higher on conventional farms (70.0%, 68.3%, and 74.5%, respectively) than antimicrobial-free farms (20.1%, 21.3%, and 48.8%, respectively). Resistances to azithromycin, erythromycin, and tetracycline declined as the number of years that a farm was antimicrobial-free increased. CONCLUSIONS AND CLINICAL RELEVANCE Production method did not affect the apparent prevalence of Campylobacter spp on swine farms. However, antimicrobial-free farms had a significantly lower prevalence of antimicrobial resistance. Although cessation of antimicrobial drug use will lower resistance over time, investigation of other interventions designed to reduce resistance levels is warranted.
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Affiliation(s)
- Susan N Rollo
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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Fitness costs and stability of a high-level ciprofloxacin resistance phenotype in Salmonella enterica serotype enteritidis: reduced infectivity associated with decreased expression of Salmonella pathogenicity island 1 genes. Antimicrob Agents Chemother 2009; 54:367-74. [PMID: 19917752 DOI: 10.1128/aac.00801-09] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The fitness costs associated with high-level fluoroquinolone resistance were examined for phenotypically and genotypically characterized ciprofloxacin-resistant Salmonella enterica serotype Enteritidis mutants (104-cip and 5408-cip; MIC, >32 microg/ml). The stability of the fluoroquinolone resistance phenotype in both mutants was investigated to assess whether clones with better fitness could emerge in the absence of antibiotic selective pressure. Mutants 104-cip and 5408-cip displayed altered morphology on agar and by electron microscopy, reduced growth rates, motility and invasiveness in Caco-2 cells, and increased sensitivity to environmental stresses. Microarray data revealed decreased expression of virulence and motility genes in both mutants. Two clones, 104-revert and 1A-revertC2, with ciprofloxacin MICs of 3 and 2 microg/ml, respectively, were recovered from separate lineages of 104-cip after 20 and 70 passages, respectively, on antibiotic-free agar. All fitness costs, except motility, were reversed in 104-revert. Potential mechanisms associated with reversal of the resistance phenotype were examined. Compared to 104-cip, both 104-revert and 1A-revertC2 showed decreased expression of acrB and soxS but still overexpressed marA. Both acquired additional mutations in SoxR and ParC, and 1A-revertC2 acquired two mutations in MarA. The altered porin and lipopolysaccharide (LPS) profiles observed in 104-cip were reversed. In contrast, 5408-cip showed no reversal in fitness costs and maintained its high-level ciprofloxacin resistance for 200 passages on antibiotic-free agar. In conclusion, high-level ciprofloxacin resistance in S. Enteritidis is associated with fitness costs. In the absence of antibiotic selection pressure, isolates may acquire mutations enabling reversion to an intermediate-level ciprofloxacin resistance phenotype associated with less significant fitness costs.
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Zou W, Frye J, Chang CW, Liu J, Cerniglia C, Nayak R. Microarray analysis of antimicrobial resistance genes inSalmonella entericafrom preharvest poultry environment. J Appl Microbiol 2009; 107:906-14. [DOI: 10.1111/j.1365-2672.2009.04270.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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El-Shibiny A, Connerton P, Connerton I. Survival at refrigeration and freezing temperatures of Campylobacter coli and Campylobacter jejuni on chicken skin applied as axenic and mixed inoculums. Int J Food Microbiol 2009; 131:197-202. [PMID: 19324444 DOI: 10.1016/j.ijfoodmicro.2009.02.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 02/25/2009] [Accepted: 02/26/2009] [Indexed: 11/26/2022]
Abstract
Campylobacter is considered to be the most common cause of bacterial diarrhoeal illness in the developed world. Many cases are thought to be acquired from consumption of undercooked poultry. The aim of this study was to compare the effect of the rate of cooling on the survival, at 4 degrees C and -20 degrees C, of Campylobacter coli and Campylobacter jejuni strains, inoculated on chicken skin from axenic culture or as mixed inoculums. Strains chilled in a domestic refrigerator varied in their tolerance to storage at 4 degrees C. Statistically significant differences between strains applied as axenic or mixed inoculums were observed for specific strain combinations using two-way ANOVA, including the enhanced survival of antibiotic resistant C. coli 99/367 at 4 degrees C. The use of rapid cooling (at -20 degrees C/min) enhanced the survival of all the Campylobacter strains chilled to 4 degrees C compared to standard refrigeration. Freezing to -20 degrees C reduced viable counts by 2.2-2.6 log10 CFU/cm(2) in 24 h. Rapid cooling to -20 degrees C (at -30 degrees C/min) enhanced the survival of C. coli 99/367 compared to freezing in a domestic freezer. Statistically significant interaction terms between specific strains were observed in mixed inoculums chilled to -20 degrees C by freezing in a domestic freezer and by rapid chilling to -20 degrees C. Rapid chilling of poultry, particularly for 4 degrees C storage may enhance survival of Campylobacter and although this is an issue that affects meat quality, it should be considered by poultry processors.
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Affiliation(s)
- Ayman El-Shibiny
- Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE125RD, United Kingdom
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Development, stability, and molecular mechanisms of macrolide resistance in Campylobacter jejuni. Antimicrob Agents Chemother 2008; 52:3947-54. [PMID: 18779354 DOI: 10.1128/aac.00450-08] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies of macrolide resistance in Campylobacter were primarily focused on strains from various origins or used in vitro systems. In this study, we conducted both in vitro and in vivo experiments to examine the development, stability, and genetic basis of macrolide resistance in Campylobacter jejuni using erythromycin-resistant (Ery(r)) mutants derived from the same parent strain. Chickens inoculated with low-level Ery(r) mutants (MIC = 32 or 64 microg/ml) at 15 days old did not shed highly Ery(r) mutants (MIC > 512 microg/ml) after prolonged exposure to a low dose of tylosin. The low-level Ery resistance was not stable in vitro or in vivo in the absence of macrolide selection pressure. However, high-level Ery resistance displayed remarkable stability in vitro and in vivo. Ribosomal sequence analysis of 69 selected Ery(r) mutants showed that specific point mutations (A2074G or A2074C) occurred in all highly Ery(r) mutants. No mutations in ribosomal protein L4 were observed in any of the in vitro-selected Ery(r) mutants. However, three specific mutations in L4, G74D, G57D, and G57V, were widely found among in vivo-selected Ery(r) mutants. Insertion of three amino acids, TSH, at position 98 in ribosomal protein L22 was observed only in mutants selected in vitro. Inactivation of the CmeABC efflux pump dramatically reduced Ery MICs in Ery(r) mutants. Together, these findings suggest that multiple factors contribute to the emergence of highly Ery(r) Campylobacter in chicken, reveal resistance level-dependent stability of macrolide resistance in C. jejuni, and indicate that C. jejuni utilizes complex and different mechanisms to develop Ery resistance in vitro and in vivo.
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Silbergeld EK, Graham J, Price LB. Industrial food animal production, antimicrobial resistance, and human health. Annu Rev Public Health 2008; 29:151-69. [PMID: 18348709 DOI: 10.1146/annurev.publhealth.29.020907.090904] [Citation(s) in RCA: 337] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Antimicrobial resistance is a major public health crisis, eroding the discovery of antimicrobials and their application to clinical medicine. There is a general lack of knowledge of the importance of agricultural antimicrobial use as a factor in antimicrobial resistance even among experts in medicine and public health. This review focuses on agricultural antimicrobial drug use as a major driver of antimicrobial resistance worldwide for four reasons: It is the largest use of antimicrobials worldwide; much of the use of antimicrobials in agriculture results in subtherapeutic exposures of bacteria; drugs of every important clinical class are utilized in agriculture; and human populations are exposed to antimicrobial-resistant pathogens via consumption of animal products as well as through widespread release into the environment.
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Affiliation(s)
- Ellen K Silbergeld
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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Han J, Sahin O, Barton YW, Zhang Q. Key role of Mfd in the development of fluoroquinolone resistance in Campylobacter jejuni. PLoS Pathog 2008; 4:e1000083. [PMID: 18535657 PMCID: PMC2390758 DOI: 10.1371/journal.ppat.1000083] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Accepted: 05/07/2008] [Indexed: 12/11/2022] Open
Abstract
Campylobacter jejuni is a major food-borne pathogen and a common causative agent of human enterocolitis. Fluoroquinolones are a key class of antibiotics prescribed for clinical treatment of enteric infections including campylobacteriosis, but fluoroquinolone-resistant Campylobacter readily emerges under the antibiotic selection pressure. To understand the mechanisms involved in the development of fluoroquinolone-resistant Campylobacter, we compared the gene expression profiles of C. jejuni in the presence and absence of ciprofloxacin using DNA microarray. Our analysis revealed that multiple genes showed significant changes in expression in the presence of a suprainhibitory concentration of ciprofloxacin. Most importantly, ciprofloxacin induced the expression of mfd, which encodes a transcription-repair coupling factor involved in strand-specific DNA repair. Mutation of the mfd gene resulted in an approximately 100-fold reduction in the rate of spontaneous mutation to ciprofloxacin resistance, while overexpression of mfd elevated the mutation frequency. In addition, loss of mfd in C. jejuni significantly reduced the development of fluoroquinolone-resistant Campylobacter in culture media or chickens treated with fluoroquinolones. These findings indicate that Mfd is important for the development of fluoroquinolone resistance in Campylobacter, reveal a previously unrecognized function of Mfd in promoting mutation frequencies, and identify a potential molecular target for reducing the emergence of fluoroquinolone-resistant Campylobacter.
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Affiliation(s)
- Jing Han
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Orhan Sahin
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Yi-Wen Barton
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Qijing Zhang
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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