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Suppression of Methicillin-Resistant Staphylococcus aureus and Reduction of Other Bacteria by Black Soldier Fly Larvae Reared on Potato Substrate. Microbiol Spectr 2022; 10:e0232122. [PMID: 36197291 PMCID: PMC9602475 DOI: 10.1128/spectrum.02321-22] [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] [Indexed: 01/04/2023] Open
Abstract
Larvae of black soldier flies, Hermetia illucens, are increasingly used for biological conversion of animal and plant wastes into ingredients of animal feeds on an industrial scale. The presence of pathogenic microorganisms in harvested larvae may be a serious problem for wide-scale adoption of this technology. Fortunately, black soldier fly larvae may have some antimicrobial properties. Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium associated with various environments that can be pathogenic to humans and farmed animals. We tested whether black soldier fly larvae suppress MRSA on potato substrate. Autoclaved potatoes containing black soldier fly larvae (P+BSFL), potatoes inoculated with MRSA and containing black soldier fly larvae (P+MRSA+BSFL), and potatoes inoculated with MRSA (P+MRSA) were incubated in glass jars. Substrate samples were taken after 3 and 7 days of incubation and plated on Trypticase soy agar (TSA) and Staphylococcus medium 110 agar (SA) to quantify total bacteria and MRSA, respectively. DNA was extracted from potato substrates on both days and sequenced to assess bacterial and fungal diversity using 515F/806R and internal transcribed spacer (ITS) 1/2 primers, respectively, and QIIME 2.0 software. Both total bacterial and MRSA-specific CFU were reduced in the presence of black soldier fly larvae, with a larger reduction for the latter. Twenty-five bacterial genera and 3 fungal genera were detected. Twenty bacterial genera were shared among the treatments and the days, but their relative abundances often varied. Among the most abundant genera, only Enterococcus and Lactococcus were universally present. Our findings confirm antimicrobial properties of black soldier fly larvae. IMPORTANCE Larvae of black soldier flies, Hermetia illucens, may be used to provide an environmentally sustainable and economically viable method for biological conversion of animal and plant wastes into ingredients of animal feeds on an industrial scale. However, contamination of harvested larvae by pathogenic microorganisms inhabiting decaying substrates may be a serious problem for wide-scale adoption of this technology. Fortunately, black soldier fly larvae may have some antimicrobial properties, including suppression of several common pathogens. Our study showed that such a suppression applies to methicillin-resistant Staphylococcus aureus, which is a ubiquitous bacterium pathogenic to animals (including humans).
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Li Y, Li W, Pan Y, Liu C, Liang S, Zeng Z. The emergence and molecular study of methicillin-resistant Staphylococcus aureus ST239, ST59, ST9, and ST630 in food animals, Chongqing, China. Vet Microbiol 2022; 265:109329. [PMID: 35030381 DOI: 10.1016/j.vetmic.2021.109329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/12/2021] [Accepted: 12/29/2021] [Indexed: 11/26/2022]
Abstract
The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in animals is an increasing concern for the agriculture and public health. A four-years (2016) successional study was conducted to investigate the antimicrobial resistant profiles and molecular characterizations of the livestock-associated MRSA (LA-MRSA) from animal farms or slaughterhouses in Chongqing, China. A total of 1667 samples were collected from 2013 to 2016 in different animal farms and hog markets. LA-MRSA were isolated and subjected to antimicrobial susceptibility testing and whole genome sequencing (WGS). S. aureus was detected at a ratio of 3.7% (n = 62), in which 18 isolates were identified as MRSA. All the S. aureus isolates were multidrug-resistant (MDR) with the resistance to at least four drugs; however, none of those isolates was resistant to linezolid, vancomycin, or nitrofurantoin. The resistance was more obvious in the pig-associated S. aureus isolates than the strains associated with chickens or cows. The majority of multilocus sequence typing (MLST) types of the MRSA isolates were ST239, subsequently ST59, ST9, and ST630. Among these isolates, 18 MRSA possessed SCCmec type Ⅲ (n = 10), Ⅳa (n = 4), Ⅻ (n = 3) and Ⅴ(n = 1). Multiple spa types were also detected in the isolates, such as 899, 437, 30, 421, 969, 37, and 4549. This study indicates that MRSA could be transferred between humans and animals, and highlights the necessity of continuous surveillance of MRSA.
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Affiliation(s)
- Yafei Li
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Wei Li
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yu Pan
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Chang Liu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Siyu Liang
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zhenling Zeng
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
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Santos SCL, Saraiva MMS, Moreira Filho ALB, Silva NMV, De Leon CMG, Pascoal LAF, Givisiez PEN, Gebreyes WA, Oliveira CJB. Swine as reservoirs of zoonotic borderline oxacillin-resistant Staphylococcus aureus ST398. Comp Immunol Microbiol Infect Dis 2021; 79:101697. [PMID: 34530296 DOI: 10.1016/j.cimid.2021.101697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/18/2022]
Abstract
Methicillin resistance mediated by the mecA gene in Staphylococcus aureus, also known as "true MRSA", is typically associated with high oxacillin MIC values (≥8 mg/L). Because non-mecA-mediated oxacillin resistant S. aureus phenotypes can also cause hard-to-treat diseases in humans, their misidentification as methicillin-susceptible S. aureus strains (MSSA) can compromise the efficiency of the antimicrobial therapy. These strains have been refereed as Borderline Oxacillin-Resistant S. aureus (BORSA) but their characterization and role in clinical microbiology have been neglected. Considering the increasing importance of livestock-associated methicillin-resistant S. aureus ST398 (LA-MRSA) as an emerging zoonotic pathogen worldwide, this study aimed to report the genomic context of oxacillin resistance in porcine S. aureus ST398 strains. S. aureus isolates were recovered from asymptomatic pigs from three herds. Oxacillin MIC values ranged from 4 to 32 mg/L. MALDI-TOF-confirmed isolates were screened for mecA and mecC by PCR and genotyped by means of PFGE and Rep-PCR. Seven isolates were whole genome sequenced. None of the isolates harbored the mecA gene or its variants. Although all seven sequenced isolates belonged to one sequence type (ST398), two different spa types (t571 and t1471) were identified. All isolates harbored conserved blaZ gene operon and no mutations on genes encoding for penicillin-binding-proteins were detected. Genes conferring resistance against other drugs such as aminoglycosides, chloramphenicol, macrolide, lincosamide and streptogramin (MLS), tetracycline and trimethoprim were also detected. Isolates also harbored virulence genes encoding for adhesins (icaA; icaB; icaC; icaD; icaR), toxins (hlgA; hlgB; hlgC; luk-PV) and protease (aur). Pigs can serve as reservoirs of non-mecA-mediated oxacillin-resistant ST398 strains potentially pathogenic to humans. Considering that mecA has been the main target to screen methicillin-resistant staphylococci, the occurrence of BORSA phenotypes is probably underestimated in livestock.
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Affiliation(s)
- S C L Santos
- Department of Animal Science, College for Agricultural Sciences, Federal University of Paraiba (UFPB), Rod. PB079 Km12, s/n, 58397-000, Areia, PB, Brazil
| | - M M S Saraiva
- Department of Animal Science, College for Agricultural Sciences, Federal University of Paraiba (UFPB), Rod. PB079 Km12, s/n, 58397-000, Areia, PB, Brazil; Department of Veterinary Pathology, Sao Paulo State University (UNESP), Via de acesso Prof. Paulo Donato Castellane s/n, 14884-900, Jaboticabal, SP, Brazil
| | - A L B Moreira Filho
- Department of Animal Science, College for Agricultural, Social and Human Sciences, Federal University of Paraiba (UFPB), Rua João Pessoa s/n, 58220-000, Bananeiras, PB, Brazil
| | - N M V Silva
- Department of Animal Science, College for Agricultural Sciences, Federal University of Paraiba (UFPB), Rod. PB079 Km12, s/n, 58397-000, Areia, PB, Brazil
| | - C M G De Leon
- Department of Animal Science, College for Agricultural Sciences, Federal University of Paraiba (UFPB), Rod. PB079 Km12, s/n, 58397-000, Areia, PB, Brazil
| | - L A F Pascoal
- Department of Animal Science, College for Agricultural, Social and Human Sciences, Federal University of Paraiba (UFPB), Rua João Pessoa s/n, 58220-000, Bananeiras, PB, Brazil
| | - P E N Givisiez
- Department of Animal Science, College for Agricultural Sciences, Federal University of Paraiba (UFPB), Rod. PB079 Km12, s/n, 58397-000, Areia, PB, Brazil
| | - W A Gebreyes
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University (OSU), 43210, Columbus, OH, USA; Global One Health Initiative (GOHi), The Ohio State University, 43210, Columbus, OH, USA
| | - C J B Oliveira
- Department of Animal Science, College for Agricultural Sciences, Federal University of Paraiba (UFPB), Rod. PB079 Km12, s/n, 58397-000, Areia, PB, Brazil; Global One Health Initiative (GOHi), The Ohio State University, 43210, Columbus, OH, USA.
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Rosen K, Ebner F, Schmidt S, Hartmann S, Merle R, Friese A, Roesler U. Influence of Immune Status on the Airborne Colonization of Piglets with Methicillin-Resistant Staphylococcus aureus (MRSA) Clonal Complex (CC) 398. Eur J Microbiol Immunol (Bp) 2020; 10:1-10. [PMID: 32363033 PMCID: PMC7182117 DOI: 10.1556/1886.2019.00024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/14/2019] [Indexed: 01/10/2023] Open
Abstract
Colonized vertebrates including humans and pigs are to date the main reservoirs of livestock-associated Methicillin-resistant Staphylococcus aureus (LA-MRSA). Currently, the mechanisms underlying colonization of pigs are not fully understood. We investigated the influence of piglet pre-immune status on airborne MRSA colonization. Three groups of MRSA-negative piglets were primed and exposed to airborne LA-MRSA (104 colony forming units (cfu)/m3) in an aerosol chamber for 24 h. One group was treated intramuscularly with dexamethasone (1 mg/kg body weight) to imitate weaning stress. The second group was exposed to bacterial endotoxin containing MRSA aerosol. Both conditions play a role in the development of multifactorial diseases and may promote MRSA colonization success. The third group served as control. The piglets' MRSA status was monitored for 21 days via swab samples. At necropsy, specific tissues and organs were analyzed. Blood was collected to examine specific immunological parameters. The duration of MRSA colonization was not extended in both treated groups compared to the control group, indicating the two immune-status influencing factors do not promote MRSA colonization. Blood sample analysis confirmed a mild dexamethasone-induced immune suppression and typical endotoxin-related changes in peripheral blood. Of note, the low-dose dexamethasone treatment showed a trend of increased MRSA clearance.
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Affiliation(s)
- Kerstin Rosen
- Institute for Animal Hygiene and Environmental Health, Centre for Infection medicine, Department for Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - Friederike Ebner
- Institute of Immunology, Centre for Infection medicine, Department for Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - Stefanie Schmidt
- Institute of Immunology, Centre for Infection medicine, Department for Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - Susanne Hartmann
- Institute of Immunology, Centre for Infection medicine, Department for Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - Roswitha Merle
- Institute for Veterinary Epidemiology and Biostatistics, Freie Universitaet Berlin, Berlin, Germany
| | - Anika Friese
- Institute for Animal Hygiene and Environmental Health, Centre for Infection medicine, Department for Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - Uwe Roesler
- Institute for Animal Hygiene and Environmental Health, Centre for Infection medicine, Department for Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
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Pauly N, Wichmann-Schauer H, Ballhausen B, Torres Reyes N, Fetsch A, Tenhagen BA. Detection and quantification of methicillin-resistant Staphylococcus aureus in fresh broiler meat at retail in Germany. Int J Food Microbiol 2018; 292:8-12. [PMID: 30553180 DOI: 10.1016/j.ijfoodmicro.2018.11.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 11/18/2018] [Accepted: 11/20/2018] [Indexed: 01/06/2023]
Abstract
The aim of this study was to detect, to quantify and to characterize MRSA in broiler meat samples with skin. Furthermore, we compared an isolation method using a second selective enrichment step (method A) with a simpler method omitting this step (method B). For quantification we used a direct plating method on selective agar plates and a "Most probable number" (MPN) technique for estimation of low numbers of MRSA. Presumptive MRSA colonies were confirmed by MALDI-TOF and by PCR. After confirmation the isolated MRSA were characterized by spa-typing and, if necessary, by multi-locus sequence typing. Method B detected more MRSA-positive samples (16.7%, n = 215) than method A (12.1%). However, method B also produced more false positive results (28.4%).The highest estimated number of MRSA in fresh broiler meat with skin was 1100 MPN/g, but in most positive samples (80.1%) the estimated numbers of MRSA were lower than 10 MPN/g. Thus, the numbers of MRSA in the samples were too low to detect using the spread plate technique. Ten different spa-types were identified. Six of these with 69% of the isolates were assigned to the clonal complex CC398 (t034; t011; t2576; t571; t5452; t1457). Spa-types t1430, t13177 and t899 can be assigned to CC9. Spa-type t304 was identified as MLST-type ST6. In conclusion, we provide quantitative data on low level contamination of fresh broiler meat with MRSA. Most isolated MRSA were from livestock associated spa-types. Omitting the second enrichment step was associated with an increase in sensitivity but lower specificity of the cultural method.
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Affiliation(s)
- N Pauly
- German Federal Institute for Risk Assessment (BfR), Department Biological Safety, Berlin, Germany
| | - H Wichmann-Schauer
- German Federal Institute for Risk Assessment (BfR), Department Biological Safety, Berlin, Germany
| | - B Ballhausen
- German Federal Institute for Risk Assessment (BfR), Department Biological Safety, Berlin, Germany; Current affiliation: The Federal Office of Consumer Protection and Food Safety, Berlin, Germany
| | - N Torres Reyes
- German Federal Institute for Risk Assessment (BfR), Department Biological Safety, Berlin, Germany
| | - A Fetsch
- German Federal Institute for Risk Assessment (BfR), Department Biological Safety, Berlin, Germany
| | - B-A Tenhagen
- German Federal Institute for Risk Assessment (BfR), Department Biological Safety, Berlin, Germany.
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Rosen K, Roesler U, Merle R, Friese A. Persistent and Transient Airborne MRSA Colonization of Piglets in a Newly Established Animal Model. Front Microbiol 2018; 9:1542. [PMID: 30057576 PMCID: PMC6053491 DOI: 10.3389/fmicb.2018.01542] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/20/2018] [Indexed: 12/16/2022] Open
Abstract
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) was first found in 2005 and is up to date widespread in animal husbandry reservoir – focusing on pig farming. The regular detectability of MRSA in the air of pigsties as well as in exhaust air of pig farms (mean count: 102 cfu/m3) poses the question whether an airborne spread and, therefore, a MRSA colonization of animals via the airborne route exists. To answer this question, we exposed three groups of nine MRSA-negative tested piglets each to a defined airborne MRSA concentration (102, 104, and 106 cfu/m3) in our aerosol chamber for 24 h. In the following observation period of 21 days, the MRSA status of the piglets was monitored by taking different swab samples (nasal, pharyngeal, skin, conjunctival, and rectal swab). At the end of the experiment, we euthanized the piglets and investigated different tissues and organs for the spread of MRSA. The data of our study imply the presence of an airborne MRSA colonization route: the animals exposed to 106 cfu/m3 MRSA in the air were persistent colonized. The piglets exposed to an airborne MRSA concentration of 104 cfu/m3 were transient, and the piglets exposed to an airborne MRSA concentration of 102 cfu/m3 were not colonized. Consequently, a colonization via the airborne route was proven.
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Affiliation(s)
- Kerstin Rosen
- Institute for Animal Hygiene and Environmental Health, Freie Universität Berlin, Berlin, Germany
| | - Uwe Roesler
- Institute for Animal Hygiene and Environmental Health, Freie Universität Berlin, Berlin, Germany
| | - Roswitha Merle
- Institute for Veterinary Epidemiology and Biostatistics, Freie Universität Berlin, Berlin, Germany
| | - Anika Friese
- Institute for Animal Hygiene and Environmental Health, Freie Universität Berlin, Berlin, Germany
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Antimicrobial Efficacy of a New Chlorhexidine-based Device Against Staphylococcus aureus Colonization of Venous Catheters. JOURNAL OF INFUSION NURSING 2018; 41:103-112. [PMID: 29489705 PMCID: PMC5862007 DOI: 10.1097/nan.0000000000000267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Vascular catheters are a major cause of nosocomial bloodstream infections. ChloraLock (ATTWILL Medical Solutions, Inc, West Jordan, UT, and ICU Medical, Inc, San Clemente, CA) is a novel antimicrobial device containing chlorhexidine digluconate (CHG) that is fitted onto a syringe and infuses CHG into the catheter lumen during locking. The objective of this study was to evaluate the antimicrobial efficacy of ChloraLock with in vitro tests and its ability to reduce Staphylococcus aureus contamination of catheters in the external jugular veins of Yorkshire swine. ChloraLock significantly reduced the bacterial load in the in vitro tests by up to 6 log10 colony-forming units (CFU) and by 3 to 4 log10 CFU/lumen in vivo in a swine model with 0.9% NaCl catheter locks.
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Complete Genome Sequence of the Livestock-Associated Methicillin-Resistant Strain Staphylococcus aureus subsp. aureus 08S00974 (Sequence Type 398). GENOME ANNOUNCEMENTS 2017; 5:5/19/e00294-17. [PMID: 28495772 PMCID: PMC5427207 DOI: 10.1128/genomea.00294-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We report here the complete genome sequence of the livestock-associated methicillin-resistant Staphylococcus aureus strain 08S00974 from sequence type 398 (ST398 LA-MRSA) isolated from a fatting pig at a farm in Germany.
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Individual predisposition to Staphylococcus aureus colonization in pigs on the basis of quantification, carriage dynamics, and serological profiles. Appl Environ Microbiol 2016; 81:1251-6. [PMID: 25501475 DOI: 10.1128/aem.03392-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Previous research on Staphylococcus aureus in pigs focused on livestock-associated methicillin-resistant S. aureus (MRSA) and had a qualitative cross-sectional design. This study aimed to elucidate the frequency, load, and stability of S. aureus nasal carriage in pigs over time and investigated possible associations between carriage and immune response. Nasal swabs were collected three times weekly from 480 tagged adult pigs in 20 Danish production farms. S. aureus and MRSA were quantified on selective media by the most-probable-number method. The levels of IgG against 10 S. aureus antigens in serum were quantified in selected pigs by a Luminex assay. All the farms were positive for S. aureus and 15 for MRSA, leading to overall prevalences of persistent and intermittent carriers and noncarriers of 24, 52, and 23%, respectively. Carriage frequency and nasal loads were significantly higher on MRSA-positive farms. Logistic-regression modeling revealed the presence of individual pigs characterized by high nasal loads (>10,000 CFU per swab) and stable carriage regardless of farm- and pen-associated factors. On the other hand, the humoral response was strongly influenced by these environmental factors. The existence of a minority of shedders contributing to maintenance of S. aureus within farms opens up new perspectives on the control of MRSA in pig farming.
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Preliminary evaluation of good sampling locations on a pig carcass for livestock-associated MRSA isolation. INTERNATIONAL JOURNAL OF FOOD CONTAMINATION 2015. [DOI: 10.1186/s40550-015-0013-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Tulinski P, Duim B, Wittink FR, Jonker MJ, Breit TM, van Putten JP, Wagenaar JA, Fluit AC. Staphylococcus aureus ST398 gene expression profiling during ex vivo colonization of porcine nasal epithelium. BMC Genomics 2014; 15:915. [PMID: 25331735 PMCID: PMC4210494 DOI: 10.1186/1471-2164-15-915] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/13/2014] [Indexed: 11/10/2022] Open
Abstract
Background Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Results We report the analysis of changes in the transcription of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes may represent metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of the main virulence associated genes or known human colonization factors. Here, we documented regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vWbp, encoded on SaPIbov5). Colonization with isogenic-deletion strains (Δvwbp and ΔscpA) did not alter the ex vivo nasal S. aureus colonization compared to wild type. Conclusions Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-915) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Birgitta Duim
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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Verstappen KM, Duim B, van Nes A, Snijders S, van Wamel WJB, Wagenaar JA. Experimental nasal colonization of piglets with methicillin-susceptible and methicillin-resistant Staphylococcus aureus. Vet Microbiol 2014; 174:483-488. [PMID: 25448448 DOI: 10.1016/j.vetmic.2014.09.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 09/10/2014] [Accepted: 09/24/2014] [Indexed: 11/18/2022]
Abstract
Methicillin-resistant Staphylococcus aureus sequence type (ST)398 is widely spread among livestock. People in contact with livestock have a higher risk of testing positive for MRSA. Several experimental settings have been described to study in vivo colonization of MRSA in pigs, each having its own limitations. The aim of this study was to develop a nose-colonization model in pigs to quantitatively study the colonization of MRSA and the co-colonization of MSSA and MRSA. Two experiments were performed: in the first experiment piglets received an intranasal inoculation with MRSA ST398, spa-type t011, and in the second experiment piglets received an intranasal inoculation with two MSSA strains (ST398, spa-type t011 and t034) and two MRSA strains (also ST398, spa-type t011 and t034) to investigate co-colonization. Colonization was quantitatively monitored for 2 weeks in both experiments. Nasal colonization was successfully established in all piglets with stable numbers of S. aureus between 10(4) and 10(6) CFU. MSSA and MRSA were able to co-colonize.
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Affiliation(s)
- Koen M Verstappen
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.165, 3508 TD Utrecht, The Netherlands
| | - Birgitta Duim
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.165, 3508 TD Utrecht, The Netherlands
| | - Arie van Nes
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, The Netherlands
| | - Susan Snijders
- Department for Medical Microbiology, Erasmus Medical Centre, P.O. box 2040, 3000 CA Rotterdam, The Netherlands
| | - Willem J B van Wamel
- Department for Medical Microbiology, Erasmus Medical Centre, P.O. box 2040, 3000 CA Rotterdam, The Netherlands
| | - Jaap A Wagenaar
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.165, 3508 TD Utrecht, The Netherlands; Central Veterinary Institute of Wageningen UR, Edelhertweg 15, 8219 PH Lelystad, The Netherlands.
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Lassok B, Tenhagen BA. From pig to pork: methicillin-resistant Staphylococcus aureus in the pork production chain. J Food Prot 2013; 76:1095-108. [PMID: 23726208 DOI: 10.4315/0362-028x.jfp-12-341] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a major global public health concern and could be a food safety issue. Recurrent reports have documented that pig herds are an important reservoir for MRSA, specifically the livestock-associated sequence type 398. The high prevalence of MRSA in pig primary production facilities and the frequent detection of MRSA of the same types in pork and pig meat products raise the question of underlying mechanisms behind the introduction and transmission of MRSA along the pork production chain. A comprehensive review of current literature on the worldwide presence of livestock-associated MRSA in various steps of the pork production chain revealed that the slaughter process plays a decisive role in MRSA transmission from farm to fork. Superficial heat treatments such as scalding and flaming during the slaughter process can significantly reduce the burden of MRSA on the carcasses. However, recontamination with MRSA might occur via surface treating machinery, as a result of fecal contamination at evisceration, or via increased human handling during meat processing. By optimizing processes for carcass decontamination and avoiding recontamination by effective cleaning and personal hygiene management, transmission of MRSA from pig to pork can be minimized.
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Affiliation(s)
- Birgit Lassok
- Federal Institute for Risk Assessment, Max-Dohrn-Strasse 8-10, D-10589 Berlin, Germany
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Abstract
Food-borne intoxication, caused by heat-stable enterotoxins produced by Staphylococcus aureus, causes over 240,000 cases of food-borne illness in the United States annually. Other staphylococci commonly associated with animals may also produce these enterotoxins. Foods may be contaminated by infected food handlers during slaughter and processing of livestock or by cross-contamination during food preparation. S. aureus also causes a variety of mild to severe skin and soft tissue infections in humans and other animals. Antibiotic resistance is common in staphylococci. Hospital-associated (HA) S. aureus are resistant to numerous antibiotics, with methicillin-resistant S. aureus (MRSA) presenting significant challenges in health care facilities for over 40 years. During the mid-1990s new human MRSA strains developed outside of hospitals and were termed community-associated (CA). A few years later, MRSA was isolated from horses and methicillin resistance was detected in Staphylococcus intermedius/pseudintermedius from dogs and cats. In 2003, a livestock-associated (LA) MRSA strain was first detected in swine. These methicillin-resistant staphylococci pose additional food safety and occupational health concerns. MRSA has been detected in a small percentage of retail meat and raw milk samples indicating a potential risk for food-borne transmission of MRSA. Persons working with animals or handling meat products may be at increased risk for antibiotic-resistant infections. This review discusses the scope of the problem of methicillin-resistant staphylococci and some strategies for control of these bacteria and prevention of illness.
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Hawken P, Weese JS, Friendship R, Warriner K. Longitudinal study of Clostridium difficile and Methicillin-resistant Staphylococcus aureus associated with pigs from weaning through to the end of processing. J Food Prot 2013; 76:624-30. [PMID: 23575124 DOI: 10.4315/0362-028x.jfp-12-330] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
There has been a recent increase in community-associated infections linked to methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. It is established that both pathogens can be recovered from retail pork, although it is unclear to what degree contamination is acquired at the farm in comparison to that acquired during processing. To address this gap, the following study reports on the carriage of MRSA and C. difficile on pigs from birth through to the end of processing. C. difficile was isolated from 28 (93%) of 30 pigs at 1 day of age, but prevalence declined sharply to 1 of 26 by market age (188 days). MRSA prevalence peaked at 74 days of age, with 19 (68%) of 28 pigs testing positive, but declined to 3 of 26 at 150 days of age, with no pig being detected as positive at market age. At the processing facility, C. difficile was isolated from the holding area, with a single carcass testing positive for the pathogen at preevisceration. MRSA was primarily isolated from nasal swabs with 8 (31%) carcasses testing positive at postbleed, which increased to 14 (54%) positive at postscald tanks. Only one carcass (sampled at postbleed) tested positive for MRSA, with no recovery of the pathogen from environmental samples taken. C. difficile ribotype 078 predominated in the longitudinal portion of the study, accounting for all of the 68 isolates recovered from pigs. Only three C. difficile isolates, which were identified as ribotype 078, were recovered at the slaughterhouse. MRSA spa type 539 (t034) predominated in pigs on the farm and samples taken at the slaughterhouse, accounting for 80% of all isolates recovered. The study demonstrated that both C. difficile and MRSA acquired on the farm can be transferred through to processing, although no evidence for significant cross-contamination between carcasses or the slaughterhouse environment was evident.
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Affiliation(s)
- Philip Hawken
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
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16
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Crombé F, Argudín MA, Vanderhaeghen W, Hermans K, Haesebrouck F, Butaye P. Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs. Front Microbiol 2013; 4:57. [PMID: 23518663 PMCID: PMC3602589 DOI: 10.3389/fmicb.2013.00057] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Accepted: 02/28/2013] [Indexed: 12/14/2022] Open
Abstract
From the mid-2000s on, numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA), renowned as human pathogen, has a reservoir in pigs and other livestock. In Europe and North America, clonal complex (CC) 398 appears to be the predominant lineage involved. Especially worrisome is its capacity to contaminate humans in close contact with affected animals. Indeed, the typical multi-resistant phenotype of MRSA CC398 and its observed ability of easily acquiring genetic material suggests that MRSA CC398 strains with an increased virulence potential may emerge, for which few therapeutic options would remain. This questions the need to implement interventions to control the presence and spread of MRSA CC398 among pigs. MRSA CC398 shows a high but not fully understood transmission potential in the pig population and is able to persist within that population. Although direct contact is probably the main route for MRSA transmission between pigs, also environmental contamination, the presence of other livestock, the herd size, and farm management are factors that may be involved in the dissemination of MRSA CC398. The current review aims at summarizing the research that has so far been done on the transmission dynamics and risk factors for introduction and persistence of MRSA CC398 in farms.
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Affiliation(s)
- Florence Crombé
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - M. Angeles Argudín
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
| | - Wannes Vanderhaeghen
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - Katleen Hermans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - Patrick Butaye
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
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17
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Moodley A, Espinosa-Gongora C, Nielsen SS, McCarthy AJ, Lindsay JA, Guardabassi L. Comparative host specificity of human- and pig- associated Staphylococcus aureus clonal lineages. PLoS One 2012; 7:e49344. [PMID: 23166643 PMCID: PMC3498157 DOI: 10.1371/journal.pone.0049344] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/10/2012] [Indexed: 01/27/2023] Open
Abstract
Bacterial adhesion is a crucial step in colonization of the skin. In this study, we investigated the differential adherence to human and pig corneocytes of six Staphylococcus aureus strains belonging to three human-associated [ST8 (CC8), ST22 (CC22) and ST36(CC30)] and two pig-associated [ST398 (CC398) and ST433(CC30)] clonal lineages, and their colonization potential in the pig host was assessed by in vivo competition experiments. Corneocytes were collected from 11 humans and 21 pigs using D-squame® adhesive discs, and bacterial adherence to corneocytes was quantified by a standardized light microscopy assay. A previously described porcine colonization model was used to assess the potential of the six strains to colonize the pig host. Three pregnant, S. aureus-free sows were inoculated intravaginally shortly before farrowing with different strain mixes [mix 1) human and porcine ST398; mix 2) human ST36 and porcine ST433; and mix 3) human ST8, ST22, ST36 and porcine ST398] and the ability of individual strains to colonize the nasal cavity of newborn piglets was evaluated for 28 days after birth by strain-specific antibiotic selective culture. In the corneocyte assay, the pig-associated ST433 strain and the human-associated ST22 and ST36 strains showed significantly greater adhesion to porcine and human corneocytes, respectively (p<0.0001). In contrast, ST8 and ST398 did not display preferential host binding patterns. In the in vivo competition experiment, ST8 was a better colonizer compared to ST22, ST36, and ST433 prevailed over ST36 in colonizing the newborn piglets. These results are partly in agreement with previous genetic and epidemiological studies indicating the host specificity of ST22, ST36 and ST433 and the broad-host range of ST398. However, our in vitro and in vivo experiments revealed an unexpected ability of ST8 to adhere to porcine corneocytes and persist in the nasal cavity of pigs.
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Affiliation(s)
- Arshnee Moodley
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
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18
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Gibbons JF, Markey BK, Jahns H, Boland F, Abbott Y, Burns A, Egan J, Fanning S, Gutierrez M, Leonard FC. Investigation of the persistence and transmission of MRSA CC 5 in pigs following intra-nasal inoculation. Vet Microbiol 2012; 162:771-778. [PMID: 23116587 DOI: 10.1016/j.vetmic.2012.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/29/2012] [Accepted: 10/01/2012] [Indexed: 12/15/2022]
Abstract
MRSA CC5 spa type t002 appears to have a broad host range, has been isolated from animals and in-contact humans in Ireland and could potentially become established in pigs in Ireland. The aims of this study were to determine if MRSA CC5 spa type t002 could persist in the tissues of the porcine upper respiratory tract following intra-nasal inoculation; to determine the relative importance of environmental and animal sources of the bacterium in the transmission cycle and to determine the importance of the pharynx as a carriage site of Staphylococcus aureus and MRSA. Twelve pigs were inoculated intra-nasally with MRSA CC5 t002. After 1 or 6 days, the inoculated pigs were removed from the contaminated environment, were washed in an antiseptic solution and placed in a clean house with a group of naive pigs (in-contact group). Another group of naive pigs was placed in the contaminated environment to assess transmission from the environment (environmental group). Nasal swabs, environmental swabs and tissue samples from the upper respiratory tract were taken for MRSA culture. Infection rates were calculated for each group of exposed pigs. MRSA persisted in the pharyngeal tissues of 6 inoculated pigs for at least 30 days and higher counts of S. aureus were found in pharyngeal tissues than in other sites. In this study we were able to demonstrate the establishment of colonisation by MRSA CC5 spa type t002 in commercially sourced pigs already colonised by S. aureus; however, colonisation was sporadic despite the inoculation of large doses. Onward transmission via pig-to-pig contact or environmental contamination was possible and a significant difference was found between the proportion of pigs infected in the environmental group and the proportion infected in the in-contact group during the first 5 days. However, no significant difference was detected in overall infection rates between the 2 groups. The tissues of the pharynx were found to carry greater numbers of S. aureus than other tissues of the upper respiratory tract; therefore, pharyngeal carriage of MRSA and S. aureus in pigs may be more significant than previously thought.
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Affiliation(s)
- J F Gibbons
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
| | - B K Markey
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - H Jahns
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - F Boland
- School of Mathematical Sciences, University College Dublin, Belfield, Dublin 4, Ireland
| | - Y Abbott
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - A Burns
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - J Egan
- National Reference Laboratory for Antimicrobial Resistance (Food, Feed and Animal Health), Department of Agriculture, Food and Forestry, Backweston Laboratories, Celbridge, Co. Kildare, Ireland
| | - S Fanning
- Centres for Food Safety & Food-borne Zoonomics, University College Dublin, Belfield, Dublin 4, Ireland
| | - M Gutierrez
- National Reference Laboratory for Antimicrobial Resistance (Food, Feed and Animal Health), Department of Agriculture, Food and Forestry, Backweston Laboratories, Celbridge, Co. Kildare, Ireland
| | - F C Leonard
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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Verhegghe M, Pletinckx LJ, Crombé F, Vandersmissen T, Haesebrouck F, Butaye P, Heyndrickx M, Rasschaert G. Methicillin-resistant Staphylococcus aureus (MRSA) ST398 in pig farms and multispecies farms. Zoonoses Public Health 2012; 60:366-74. [PMID: 22925210 DOI: 10.1111/zph.12007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
During the last few years, methicillin-resistant Staphylococcus aureus (MRSA) ST398 has been isolated frequently from livestock, especially from pigs and to a lesser extent from cattle and poultry. To gain insight into the distribution of this bacterium in pig farms versus multispecies farms, 30 Belgian farms (10 pig, 10 pig/poultry and 10 pig/cattle farms) were screened for the presence of MRSA. On each farm, 10 nasal swabs were taken from pigs. When present, cattle (n=10) were sampled in the nares and poultry (n=10) in the nares, earlobes and cloaca. A selection of the obtained isolates were further characterized using multilocus sequence typing (MLST), spa typing, SCCmec typing, pulsed field gel electrophoresis (PFGE), multiple-locus variable-number tandem repeat analysis (MLVA) and antimicrobial susceptibility testing. On 26 of 30 farms, MRSA was isolated from pigs. Furthermore, MRSA was also isolated from poultry and cattle on one pig/poultry and five pig/cattle farms, respectively. All tested MRSA isolates belonged to ST398. Eight spa types (t011, t034, t567, t571, t1451, t2974, t3423 and t5943) were detected, among which t011 predominated. SCCmec cassettes type IVa and V were present in 20% and 72% of the isolates, respectively. When combining the results of the two remaining typing methods, PFGE and MLVA, eighteen genotypes were obtained of which one genotype predominated (56% of the positive farms). All MRSA isolates were resistant to tetracycline. Resistance to trimethoprim, aminoglycosides, macrolides, lincosamides, fluoroquinolones and chloramphenicol was also observed. In conclusion, there was no effect of the farm type on the MRSA status of the pigs. A statistically significant difference was observed when comparing the pig/poultry or the pig/cattle MRSA status on the multispecies farms. Additionally, a wide variety of MRSA ST398 strains was found within certain farms when combining different typing methods.
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Affiliation(s)
- M Verhegghe
- Food Safety Research Group, Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Melle, Belgium
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Jouy E, Le Roux A, Kéranflec'h A, Granier SA, Laurent F, Kempf I, Brisabois A, Cariolet R, Chauvin C. Methicillin-resistant Staphylococcus aureus ST398 contamination and transmission in pigs after a low dose inoculation. Lett Appl Microbiol 2012; 54:518-23. [PMID: 22404325 DOI: 10.1111/j.1472-765x.2012.03239.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Methicillin-resistant Staphylococcus aureus (MRSA) ST398 has recently been described as a zoonotic agent. Its transmission between animals seems to be a pivotal factor in its emergence and dissemination. This experimental trial was performed to describe MRSA ST398 contamination and transmission in pigs after a low dose inoculation. METHODS AND RESULTS Twelve specific pathogen-free (SPF) pigs were randomly divided between two separate pens. Three pigs in each pen received a nasal inoculation of 2 × 10(4) colony-forming units per animal, and three naïve pigs were left in contact with them. Every 2 days and at necropsy, different samples were screened for MRSA. It was detected in nasal swabs from five inoculated and three naïve contact pigs, as early as 1 day after inoculation. MRSA was also found in environmental wipes but never in faecal samples. At necropsy, MRSA was detected in the lymph nodes of two contact pigs and in the tonsils and lymph nodes of three inoculated pigs. Twelve other SPF pigs were included as negative control in a separate room. CONCLUSION This experiment showed that inoculation of a low dose of MRSA ST398 could lead to the horizontal transmission of the bacterium between pigs, the contamination of mandibular lymph nodes and the contamination of the environment without faecal carriage. SIGNIFICANCE AND IMPACT OF THE STUDY The minimal inoculated dose via nasal route to observe transmission of MRSA ST398 between pigs is equal or lower to 2 × 10(4) colony-forming units per animal, and faecal excretion seems not to be a necessary condition for horizontal transmission.
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Affiliation(s)
- E Jouy
- Anses, Ploufragan-Plouzané Laboratory, Ploufragan, France.
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21
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Occurrence of MRSA in air and housing environment of pig barns. Vet Microbiol 2012; 158:129-35. [PMID: 22386671 DOI: 10.1016/j.vetmic.2012.01.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 01/17/2012] [Accepted: 01/19/2012] [Indexed: 01/26/2023]
Abstract
A high prevalence of MRSA among farm animals, especially pigs, has been observed for some time. However, knowledge on transmission routes of MRSA in livestock production is still scarce. Therefore, the aim of this study was to determine the occurrence of MRSA in pig house air as well as in samples from pigs and their housing environment in 27 MRSA positive pig barns of different sizes and production types. In 85.2% of all barns MRSA was detected in the animal house air. Impingement turned out to be a more sensitive sampling technique than filtration. Other environmental samples such as boot swabs or faeces showed prevalences of MRSA from 55.6% to 85.2% at sample level. The level of MRSA was 88.3% for pooled and 82.1% for single nasal swabs, in skin swabs the one was 87.7%, the others was 78.7%. Spa typing of isolates from air and nasal swabs showed predominantly spa types t011 and t034. MRSA prevalences in pigs as well as in various environmental samples were significantly higher in fattening farms than in breeding farms. This study provides good reference that there could be an airborne transmission of MRSA within pig herds indicating a potential contamination of the environment of barns.
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