1
|
Godijk NG, Bootsma MCJ, Bonten MJM. Transmission routes of antibiotic resistant bacteria: a systematic review. BMC Infect Dis 2022; 22:482. [PMID: 35596134 PMCID: PMC9123679 DOI: 10.1186/s12879-022-07360-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 03/28/2022] [Indexed: 11/16/2022] Open
Abstract
Background Quantification of acquisition routes of antibiotic resistant bacteria (ARB) is pivotal for understanding transmission dynamics and designing cost-effective interventions. Different methods have been used to quantify the importance of transmission routes, such as relative risks, odds ratios (OR), genomic comparisons and basic reproduction numbers. We systematically reviewed reported estimates on acquisition routes’ contributions of ARB in humans, animals, water and the environment and assessed the methods used to quantify the importance of transmission routes. Methods PubMed and EMBASE were searched, resulting in 6054 articles published up until January 1st, 2019. Full text screening was performed on 525 articles and 277 are included. Results We extracted 718 estimates with S. aureus (n = 273), E. coli (n = 157) and Enterobacteriaceae (n = 99) being studied most frequently. Most estimates were derived from statistical methods (n = 560), mainly expressed as risks (n = 246) and ORs (n = 239), followed by genetic comparisons (n = 85), modelling (n = 62) and dosage of ARB ingested (n = 17). Transmission routes analysed most frequently were occupational exposure (n = 157), travelling (n = 110) and contacts with carriers (n = 83). Studies were mostly performed in the United States (n = 142), the Netherlands (n = 87) and Germany (n = 60). Comparison of methods was not possible as studies using different methods to estimate the same route were lacking. Due to study heterogeneity not all estimates by the same method could be pooled. Conclusion Despite an abundance of published data the relative importance of transmission routes of ARB has not been accurately quantified. Links between exposure and acquisition are often present, but the frequency of exposure is missing, which disables estimation of transmission routes’ importance. To create effective policies reducing ARB, estimates of transmission should be weighed by the frequency of exposure occurrence. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07360-z.
Collapse
Affiliation(s)
- Noortje G Godijk
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
| | - Martin C J Bootsma
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Mathematics, Faculty of Sciences, Utrecht University, Utrecht, The Netherlands
| | - Marc J M Bonten
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
2
|
Kalupahana RS, Duim B, Verstappen KM, Gamage CD, Dissanayake N, Ranatunga L, Graveland H, Wagenaar JA. MRSA in Pigs and the Environment as a Risk for Employees in Pig-Dense Areas of Sri Lanka. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2019. [DOI: 10.3389/fsufs.2019.00025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
3
|
Smith TC, Thapaliya D, Bhatta S, Mackey S, Engohang-Ndong J, Carrel M. Geographic distribution of livestock-associated Staphylococcus aureus in the United States. Microbes Infect 2018; 20:323-327. [PMID: 29859252 DOI: 10.1016/j.micinf.2018.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/21/2018] [Accepted: 05/23/2018] [Indexed: 12/23/2022]
Abstract
Sampling for livestock-associated Staphylococcus aureus (LA-SA) in the United States is haphazard. The diversity of LA-S. aureus in the U.S. appears to be greater than in other countries. We review the epidemiology of LA-S. aureus in U.S. pigs, occupationally-exposed individuals, and environmental samples to assess the diversity and abundance of U.S. LA-S. aureus.
Collapse
Affiliation(s)
- Tara C Smith
- Kent State University, College of Public Health, Kent, OH, USA.
| | | | - Sabana Bhatta
- Kent State University, College of Public Health, Kent, OH, USA
| | - Samantha Mackey
- Kent State University, College of Public Health, Kent, OH, USA
| | - Jean Engohang-Ndong
- Kent State University at Tuscarawas, Department of Biology, New Philadelphia, OH, USA
| | - Margaret Carrel
- University of Iowa, Department of Geographical & Sustainability Sciences, Department of Epidemiology, Iowa City, IA, USA
| |
Collapse
|
4
|
Thapaliya D, Forshey BM, Kadariya J, Quick MK, Farina S, O' Brien A, Nair R, Nworie A, Hanson B, Kates A, Wardyn S, Smith TC. Prevalence and molecular characterization of Staphylococcus aureus in commercially available meat over a one-year period in Iowa, USA. Food Microbiol 2017; 65:122-129. [PMID: 28399994 DOI: 10.1016/j.fm.2017.01.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 01/24/2017] [Accepted: 01/29/2017] [Indexed: 11/25/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infectious disease morbidity and mortality. Previous studies have confirmed the presence of S. aureus, including MRSA, on raw meat products. We investigated the prevalence and molecular epidemiology of S. aureus and MRSA in commercially-distributed antibiotic-free and conventional raw meat products (n = 3290) purchased in 8 Iowa retail stores weekly for a period of one year. Isolates were characterized using spa typing, and PCR was used to detect the presence of the Panton-Valentine leukocidin (PVL) and mecA genes. Quantitation of S. aureus on meat products was carried out one week per month. The prevalence of S. aureus on meat samples was 27.8% (913/3290). Compared to antibiotic-free meat samples, higher prevalence of both MRSA and methicillin-susceptible S. aureus (MSSA) were found in conventional meat samples. Among the S. aureus isolates, 18 were PVL-positive (1.9%) and 41 (4.5%) carried mecA. Phenotypic oxacillin resistance was observed for 17.1% (41/239) of the isolates tested, while 23% (55/239) were multi-drug resistant. A total of 132 spa types were detected from 913 contaminated meat samples. Overall, t002 was the most common spa type identified (137; 15.0%). The number of colony-forming units (CFU) per 10 g meat ranged from 2 to 517 (median: 8 CFU per 10 g of meat; mean: 28) with the highest bacterial load observed on turkey samples. These data reinforce the need to consider meat products as potential vehicles of S. aureus transmission from farm into human households, and the potential need for public health intervention programs pre and post-slaughter in meat processing facilities.
Collapse
Affiliation(s)
- Dipendra Thapaliya
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Brett M Forshey
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Jhalka Kadariya
- Kent State University, College of Public Health, Department of Biostatistics, Environmental Health Sciences and Epidemiology, 750Hilltop Drive, Kent, OH, 44242, United States
| | - Megan K Quick
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Sarah Farina
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Ashley O' Brien
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Rajeshwari Nair
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Amos Nworie
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Blake Hanson
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Ashley Kates
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Shylo Wardyn
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States
| | - Tara C Smith
- Department of Epidemiology, University of Iowa College of Public Health, 145N. Riverside Drive, Iowa City, IA, 52242, United States; Center for Emerging Infectious Diseases, University of Iowa College of Public Health, 2501 Crosspark Rd, Coralville, IA, 52241, United States; Kent State University, College of Public Health, Department of Biostatistics, Environmental Health Sciences and Epidemiology, 750Hilltop Drive, Kent, OH, 44242, United States.
| |
Collapse
|
5
|
Klous G, Huss A, Heederik DJ, Coutinho RA. Human-livestock contacts and their relationship to transmission of zoonotic pathogens, a systematic review of literature. One Health 2016; 2:65-76. [PMID: 28616478 PMCID: PMC5462650 DOI: 10.1016/j.onehlt.2016.03.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 02/11/2016] [Accepted: 03/14/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Micro-organisms transmitted from vertebrate animals - including livestock - to humans account for an estimated 60% of human pathogens. Micro-organisms can be transmitted through inhalation, ingestion, via conjunctiva or physical contact. Close contact with animals is crucial for transmission. The role of intensity and type of contact patterns between livestock and humans for disease transmission is poorly understood. In this systematic review we aimed to summarise current knowledge regarding patterns of human-livestock contacts and their role in micro-organism transmission. METHODS We included peer-reviewed publications published between 1996 and 2014 in our systematic review if they reported on human-livestock contacts, human cases of livestock-related zoonotic diseases or serological epidemiology of zoonotic diseases in human samples. We extracted any information pertaining the type and intensity of human-livestock contacts and associated zoonoses. RESULTS 1522 papers were identified, 75 were included: 7 reported on incidental zoonoses after brief animal-human contacts (e.g. farm visits), 10 on environmental exposures and 15 on zoonoses in developing countries where backyard livestock keeping is still customary. 43 studies reported zoonotic risks in different occupations. Occupations at risk included veterinarians, culling personnel, slaughterhouse workers and farmers. For culling personnel, more hours exposed to livestock resulted in more frequent occurrence of transmission. Slaughterhouse workers in contact with live animals were more often positive for zoonotic micro-organisms compared to co-workers only exposed to carcasses. Overall, little information was available about the actual mode of micro-organism transmission. CONCLUSIONS Little is known about the intensity and type of contact patterns between livestock and humans that result in micro-organism transmission. Studies performed in occupational settings provide some, but limited evidence of exposure response-like relationships for livestock-human contact and micro-organism transmission. Better understanding of contact patterns driving micro-organism transmission from animals to humans is needed to provide options for prevention and thus deserves more attention.
Collapse
Affiliation(s)
- Gijs Klous
- Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, The Netherlands
- Institute for Risk Assessment Sciences, division Environmental Epidemiology, Utrecht University, The Netherlands
| | - Anke Huss
- Institute for Risk Assessment Sciences, division Environmental Epidemiology, Utrecht University, The Netherlands
| | - Dick J.J. Heederik
- Institute for Risk Assessment Sciences, division Environmental Epidemiology, Utrecht University, The Netherlands
| | - Roel A. Coutinho
- Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, The Netherlands
| |
Collapse
|
6
|
Espigares E, Moreno Roldan E, Espigares M, Abreu R, Castro B, Dib AL, Arias Á. Phenotypic Resistance to Disinfectants and Antibiotics in Methicillin-Resistant Staphylococcus aureus Strains Isolated from Pigs. Zoonoses Public Health 2016; 64:272-280. [PMID: 27762078 DOI: 10.1111/zph.12308] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Indexed: 12/20/2022]
Abstract
The aim of this research was to study the phenotypic resistances to disinfectants and antibiotics in strains of methicillin-resistant Staphylococcus aureus (MRSA) obtained from Canary black pigs. Analyses were performed on 54 strains of MRSA, isolated in Canary black pigs from the province of Tenerife (Spain); all of them carried the mecA gene. The strains were isolated by means of nasal swab samples of healthy pigs, collected under veterinarian supervision. Bactericidal activity of antiseptics and disinfectants was tested by means of the dilution-neutralization method. Susceptibility to the disinfectants glutaraldehyde, peracetic acid and silver nitrate was assessed, as well as to the antiseptics chlorhexidine, benzalkonium chloride and povidone iodine. Susceptibility to a wide array of antibiotics representing the main groups was determined by means of the disc diffusion method. All the strains demonstrated susceptibility to the disinfectants tested at the recommended concentration, and even to dilutions equal to or lesser than 1/16. The most effective antiseptic and disinfectant were, respectively, chlorhexidine and silver nitrate. With regard to the antibiotics, the strains proved to be multiresistant. All presented phenotypic resistance to the β-lactam antibiotics ampicillin, penicillin and cefoxitin, as well as to numerous aminoglycosides, tetracycline and trimethoprim-sulfamethoxazole. It was also observed that 61.1% of the strains were carriers of plasmids. Our results underline that in the strains such as MRSA, which show multiple resistances to antibiotics, the antiseptics and disinfectants show great efficacy. Moreover, as other authors also suggest, for the treatment and prevention of infections caused by MRSA, the use of β-lactam and aminoglycoside antibiotics may be less effective.
Collapse
Affiliation(s)
- E Espigares
- Department of Preventive Medicine and Public Health, University of Granada, Granada, Spain
| | - E Moreno Roldan
- Department of Preventive Medicine and Public Health, University of Granada, Granada, Spain
| | - M Espigares
- Department of Preventive Medicine and Public Health, University of Granada, Granada, Spain
| | - R Abreu
- Department of Preventive Medicine and Public Health, University of La Laguna, Canary Islands, Spain
| | - B Castro
- University Hospital of Canary Islands, Tenerife Canary Islands, Spain
| | - A L Dib
- Laboratoire de Gestion de la Santé et Productions Animales-Institut des Sciences Vétérinaire El Khroub, Université des Frères Mentouri, Constantine, Algeria
| | - Á Arias
- Department of Preventive Medicine and Public Health, University of La Laguna, Canary Islands, Spain
| |
Collapse
|
7
|
|
8
|
Rossi G, Cerquetella M, Attili AR. Amphixenosic Aspects of Staphylococcus aureus Infection in Man and Animals. Curr Top Microbiol Immunol 2016; 409:297-323. [PMID: 27023699 DOI: 10.1007/82_2016_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
According to the mode of transmission, Staphylococcus aureus infection between hosts is classified as "direct zoonoses," or infection that is transmitted from an infected vertebrate host to a susceptible host (man) by direct contact, by contact with a fomite or by a mechanical vector. The agent itself undergoes little or no propagative or developmental changes during transmission. According to the reservoir host, staphylococcosis is most precisely defined as "zooanthroponoses" or infections transmitted from man to lower vertebrate animals (e.g., streptococci, diphtheria, Enterobacteriaceae, human tuberculosis in cattle and parrots), but also "anthropozoonoses" or infections transmitted to man from lower vertebrate animals. In particular, actually, the correct definition of S. aureus infections between humans and animals is "amphixenoses" or infections maintained in both man and lower vertebrate animals and transmitted in either direction. S. aureus exhibits tropisms to many distinct animal hosts. While spillover events can occur wherever there is an interface between host species, changes in host tropism only occur with the establishment of sustained transmission in the new host species, leading to clonal expansion. Although the genomic variation underpinning adaptation in S. aureus genotypes infecting bovids and poultry has been well characterized, the frequency of switches from one host to another remains obscure. In this review, we sought to identify the sustained switches in host tropism in the S. aureus population, both anthroponotic and zoonotic, and their distribution over the species phylogeny. S. aureus is an organism with the capacity to switch into and adapt to novel hosts, even after long periods of isolation in a single host species. Based on this evidence, animal-adapted S. aureus lineages exhibiting resistance to antibiotics must be considered a major threat to public health, as they can adapt to the human population.
Collapse
Affiliation(s)
- Giacomo Rossi
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Circonvallazione 93/95, 62024, Matelica, MC, Italy.
| | - Matteo Cerquetella
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Circonvallazione 93/95, 62024, Matelica, MC, Italy
| | - Anna Rita Attili
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Circonvallazione 93/95, 62024, Matelica, MC, Italy
| |
Collapse
|
9
|
Sun J, Yang M, Sreevatsan S, Davies PR. Prevalence and Characterization of Staphylococcus aureus in Growing Pigs in the USA. PLoS One 2015; 10:e0143670. [PMID: 26599635 PMCID: PMC4658009 DOI: 10.1371/journal.pone.0143670] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/06/2015] [Indexed: 01/02/2023] Open
Abstract
A decade of research of methicillin-resistant S. aureus (MRSA) in pigs shows that the prevalence and predominant genotypes (i.e., ST398, ST9, ST5) of MRSA vary widely geographically, yet knowledge of the epidemiology of S. aureus generally in swine remains rudimentary. To characterize S. aureus, including MRSA, in the US swine industry, we sampled 38 swine herds in 11 states in major swine producing regions. The herds sampled included pigs sourced from 9 different breeding stock companies, and the sample was likely biased towards larger herds that use regular veterinary services. Twenty nasal swabs were collected from 36 groups of growing pigs by 36 swine veterinarians, 2 more herds were sampled opportunistically, and a historically MRSA-positive herd was included as a positive control. S. aureus was detected on 37 of the 38 herds, and in 77% of pigs sampled. Other than the positive control herd, no MRSA were detected in the study sample, yielding a 95% upper confidence limit of 9.3% for MRSA herd prevalence. All but two (ST1-t127; ST2007-t8314) of 1200 isolates belonged to three MLST lineages (ST9, ST398, and ST5) that have been prominent in studies of MRSA in pigs globally. A total of 35 spa types were detected, with the most prevalent being t337 (ST9), t034 (ST398), and t002 (ST5). A purposively diverse subset of 128 isolates was uniformly negative on PCR testing for major enterotoxin genes. The findings support previous studies suggesting a relatively low herd prevalence of MRSA in the US swine industry, but confirm that methicillin susceptible variants of the most common MRSA genotypes found in swine globally are endemic in the US. The absence of enterotoxin genes suggests that the source of toxigenic S. aureus capable of causing foodborne enterotoxicosis from pork products is most likely post-harvest contamination.
Collapse
Affiliation(s)
- Jisun Sun
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - My Yang
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Srinand Sreevatsan
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Peter R. Davies
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
- * E-mail:
| |
Collapse
|
10
|
|
11
|
Haarstad AC, Eisenschenk MC, Heinrich NA, Weese JS, McKeever PJ. Isolation of bacterial skin flora of healthy sheep, with comparison between frequent and minimal human handling. Vet Dermatol 2014; 25:215-e56. [DOI: 10.1111/vde.12126] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Amy C. Haarstad
- McKeever Dermatology Clinics; 7723 Flying Cloud Drive Eden Prairie MN 55344 USA
| | | | - Nicole A. Heinrich
- McKeever Dermatology Clinics; 7723 Flying Cloud Drive Eden Prairie MN 55344 USA
| | - J. Scott Weese
- Department of Pathobiology; Ontario Veterinary College; University of Guelph; Guelph ON Canada N1G 2W1
| | - Patrick J. McKeever
- McKeever Dermatology Clinics; 7723 Flying Cloud Drive Eden Prairie MN 55344 USA
| |
Collapse
|
12
|
Isolation and characterization of methicillin-resistant Staphylococcus aureus from pork farms and visiting veterinary students. PLoS One 2013; 8:e53738. [PMID: 23301102 PMCID: PMC3536740 DOI: 10.1371/journal.pone.0053738] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/03/2012] [Indexed: 01/21/2023] Open
Abstract
In the last decade livestock-associated methicillin-resistant S. aureus (LA-MRSA) has become a public health concern in many parts of the world. Sequence type 398 (ST398) has been the most commonly reported type of LA-MRSA. While many studies have focused on long-term exposure experienced by swine workers, this study focuses on short-term exposures experienced by veterinary students conducting diagnostic investigations. The objectives were to assess the rate of MRSA acquisition and longevity of carriage in students exposed to pork farms and characterize the recovered MRSA isolates. Student nasal swabs were collected immediately before and after farm visits. Pig nasal swabs and environmental sponge samples were also collected. MRSA isolates were identified biochemically and molecularly including spa typing and antimicrobial susceptibility testing. Thirty (30) veterinary students were enrolled and 40 pork farms were visited. MRSA was detected in 30% of the pork farms and in 22% of the students following an exposure to a MRSA-positive pork farm. All students found to be MRSA-positive initially following farm visit were negative for MRSA within 24 hours post visit. Most common spa types recovered were t002 (79%), t034 (16%) and t548 (4%). Spa types found in pork farms closely matched those recovered from students with few exceptions. Resistance levels to antimicrobials varied, but resistance was most commonly seen for spectinomycin, tetracyclines and neomycin. Non-ST398 MRSA isolates were more likely to be resistant to florfenicol and neomycin as well as more likely to be multidrug resistant compared to ST398 MRSA isolates. These findings indicate that MRSA can be recovered from persons visiting contaminated farms. However, the duration of carriage was very brief and most likely represents contamination of nasal passages rather than biological colonization. The most common spa types found in this study were associated with ST5 and expands the range of livestock-associated MRSA types.
Collapse
|
13
|
McCarthy AJ, Lindsay JA, Loeffler A. Are all meticillin-resistant Staphylococcus aureus (MRSA) equal in all hosts? Epidemiological and genetic comparison between animal and human MRSA. Vet Dermatol 2012; 23:267-75, e53-4. [PMID: 22823579 DOI: 10.1111/j.1365-3164.2012.01072.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Meticillin-resistant Staphylococcus aureus (MRSA) continues to pose a major threat to human health. In animals, MRSA has become established as a veterinary pathogen in pets and horses; in livestock, it presents a concern for public health as a reservoir that can infect humans and as a source of transferrable resistance genes. Genetic analyses have revealed that the epidemiology of MRSA is different in different animal hosts. While human hospital-associated MRSA lineages are most commonly involved in pet infection and carriage, horse-specific MRSA most often represent 'traditional' equine S. aureus lineages. A recent development in the epidemiology of animal MRSA is the emergence of pig-adapted strains, such as CC398 and CC9, which appear to have arisen independently in the pig population. Recent insight into the genome structure and the evolution of S. aureus has helped to explain key aspects of these three distinct epidemiological scenarios. This nonsystematic literature review summarizes the structure and variations of the S. aureus genome and gives an overview of the current distribution of MRSA lineages in various animal species. It also discusses present knowledge about the emergence and evolution of MRSA in animals, adaptation to different host species and response to selective pressure from animal-specific environments. An improved understanding of the genetics and selective pressure that underpin the adaptive behaviour of S. aureus may be used in the future to predict new developments in staphylococcal diseases and to investigate novel control strategies required at a time of increasing resistance to antimicrobial agents.
Collapse
Affiliation(s)
- Alex J McCarthy
- Centre for Infection, Division of Clinical Sciences, St George's University of London, London SW17 0RE, UK
| | | | | |
Collapse
|
14
|
Epidemiology and genotypic characteristics of methicillin-resistant Staphylococcus aureus strains of porcine origin. J Clin Microbiol 2012; 50:3687-93. [PMID: 22972820 DOI: 10.1128/jcm.01971-12] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The main goal of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), particularly livestock-associated MRSA (LA-MRSA) in pigs and pork. The genotypic relatedness of isolates on the farm, at slaughter, and at the retail level was assessed. Paired nasal and perianal swab samples were collected from 10 cohorts of market-age pigs (24 pigs per cohort) and carcasses at slaughterhouse, and pork samples were collected at retail. Staphylococci were isolated using selective enrichment method. Isolates were tested for antimicrobial resistance by broth microdilution. Duplex PCR was used to confirm MRSA using species-specific (nuc) and methicillin resistance (mecA) genes. The clonal relatedness of isolates was determined using pulsed-field gel electrophoresis (PFGE), Staphylococcus protein A (spa) typing, multilocus sequence typing (MLST), and staphylococcal cassette chromosome mec element (SCCmec) typing. MRSA was detected in 5 of the 10 cohorts (50%), with the prevalence ranging from 0% to 12.5% per cohort. Of all the pigs sampled on the farm before they went to market, 3% (7/240) were MRSA positive. A higher prevalence of MRSA was detected at holding pens at the slaughterhouse (11% [27/240]). MRSA was also detected in 2% (4/235) of the carcasses and 4% (5/135) of the retail pork. While the isolates appear predominantly to be highly clonal, PFGE had a relatively higher discriminatory power (discriminatory index [DI] = 0.624). Four genotypic clusters were identified by PFGE; of the four clusters, clonal type B was predominant across the farm-to-retail continuum. MLST findings revealed that sequence type 5 (ST5) was the most predominant subtype (32/50). The livestock-associated MRSA (clonal complex 398 [CC398] or sequence type 398 [ST398]) was the second common type (12/50) and was detected at all stages from farm to retail. Nine of the 50 (18%) MRSA isolates belonged to spa type 539/t034 that were of ST398 based on MLST. The results of this study confirm that MRSA, including LA-MRSA, is common in herds of swine in Ohio and hereby shown to persist in the farm to processing and retail continuum.
Collapse
|
15
|
Petinaki E, Spiliopoulou I. Methicillin-resistant Staphylococcus aureus among companion and food-chain animals: impact of human contacts. Clin Microbiol Infect 2012; 18:626-34. [DOI: 10.1111/j.1469-0691.2012.03881.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|