scholarly journals Unidirectional animal-to-human transmission of methicillin-resistant Staphylococcus aureus ST398 in pig farming; evidence from a surveillance study in southern Italy

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Mattia Pirolo ◽  
Daniela Visaggio ◽  
Angela Gioffrè ◽  
Irene Artuso ◽  
Monica Gherardi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Southern Italy ◽  
Animal Husbandry ◽  
Farm Workers ◽  
Swine Farm ◽  
Large Area ◽  
Methicillin Resistant ◽  
Enterotoxin Genes ◽  
Animal Contact ◽  
Animal Exposure

Abstract Background Livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) belonging to clonal complex 398 is recognized as an occupational hazard for workers employed in intensive animal husbandry, especially in the swine-breeding chain. In this study, we compared the prevalence and epidemiological type of MRSA isolates from swine and farm workers in a large area of southern Italy. Methods Between January and March 2018, 88 workers from 32 farms where we had previously performed a survey for MRSA colonization of farmed pigs, were sampled by nasal swabbing. A follow-up investigation was conducted on seven workers 1 year after primary screening. MRSA isolates were characterized by MLST, spa and SCCmec typing, and tested for susceptibility to 15 antimicrobials. Epidemiological correlations between human and swine MRSA isolates were supported by Rep-MP3 and RAPD PCR fingerprinting, and whole-genome sequencing. Results The overall colonization rate of MRSA in swine farm workers was 21.6%, being significantly higher in intensive farms and in workers with direct animal contact. All human MRSA isolates were multi-drug resistant, belonged to the ST398 livestock clade, and did not carry Panton-Valentine leukocidin and enterotoxin genes. Notably, 94.1% of human MRSA isolates belonged to the same epidemiological type as swine MRSA isolates from the corresponding farm. Persistent MRSA carriage was documented in some workers 1 year after primary sampling. Conclusions We report a high prevalence of MRSA among swine farm workers, with higher colonization rates associated with intensive breeding and animal exposure. Our findings suggest unidirectional animal-to-human transmission of LA-MRSA and denote the high zoonotic transmissibility of the ST398 livestock clade.

Occurrence and characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in buffalo bulk tank milk and the farm workers in Italy

2020 ◽  
Vol 91 ◽  
pp. 103509 ◽  
Author(s):  
Normanno Giovanni ◽  
Spinelli Elisa ◽  
Caruso Marta ◽  
Fraccalvieri Rosa ◽  
Capozzi Loredana ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Farm Workers ◽  
Bulk Tank Milk ◽  
Methicillin Resistant ◽  
Bulk Tank

scholarly journals Transmission of Methicillin-Resistant Staphylococcus aureus to Human Volunteers Visiting a Swine Farm

2017 ◽  
Vol 83 (23) ◽  
Author(s):  
Øystein Angen ◽  
Louise Feld ◽  
Jesper Larsen ◽  
Klaus Rostgaard ◽  
Robert Skov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Personal Exposure ◽  
Physical Contact ◽  
Swine Farm ◽  
Short Term ◽  
Methicillin Resistant ◽  
Content Type ◽  
Farm Work ◽  
Short Term Exposure ◽  
Human Volunteers

ABSTRACT Transmission of methicillin-resistant Staphylococcus aureus (MRSA) from animals to humans is of great concern due to the implications for human health and the health care system. The objective was to investigate the frequency and duration of MRSA carriage in human volunteers after a short-term exposure in a swine farm. The experimental study included 34 human volunteers staying 1 h in a MRSA-positive swine farm in four trials. In two of the trials, the influence of farm work involving pig contact was studied using a crossover design. The quantities of MRSA in nasal swabs, throat swabs, and air samples were measured at different time points and analyzed in relation to relevant covariates. This investigation showed that, overall, 94% of the volunteers acquired MRSA during the farm visit. Two hours after the volunteers left the stable, the nasal MRSA count had declined to unquantifiable levels in 95% of the samples. After 48 h, 94% of the volunteers were MRSA-negative. Nasal MRSA carriage was positively correlated to personal exposure to airborne MRSA and farm work involving pig contact and negatively correlated to smoking. No association was observed between MRSA carriage and face touching behavior, nasal methicillin-susceptible Staphylococcus aureus (MSSA) carriage, age, or gender. The increase in human MRSA carriage among the volunteers with pig contact seems to be dependent on the increased concentration of airborne MRSA of the surrounding air and not directly on physical contact with pigs. MRSA was not detected in any of the throat samples. IMPORTANCE The experimental approach made it possible to elucidate the contributions of airborne MRSA levels and farm work to nasal MRSA carriage in a swine farm. Short-term exposure to airborne MRSA poses a substantial risk for farm visitors to become nasal carriers, but the carriage is typically cleared within hours to a few days. The risk for short-term visitors to cause secondary transmissions of MRSA is most likely negligible due to the observed decline to unquantifiable levels in 95% of the nasal samples after only 2 h. The MRSA load in the nose was highly correlated to the amount of MRSA in the air and interventions to reduce the level of airborne MRSA or the use of face masks might consequently reduce nasal contamination.

scholarly journals Staphylococcus aureus and Methicillin Resistant S. aureus in Nepalese Primates: Resistance to Antimicrobials, Virulence, and Genetic Lineages

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 689
Author(s):  
Marilyn C. Roberts ◽  
Prabhu Raj Joshi ◽  
Stefan Monecke ◽  
Ralf Ehricht ◽  
Elke Müller ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Microarrays ◽  
Rhesus Macaques ◽  
Antibiotic Resistance Genes ◽  
Methicillin Resistant ◽  
Genetic Lineages ◽  
Exfoliative Toxin ◽  
Human Contact ◽  
Enterotoxin Genes ◽  
Panton Valentine Leukocidin

Staphylococcus aureus is a ubiquitous pathogen and colonizer in humans and animals. There are few studies on the molecular epidemiology of S. aureus in wild monkeys and apes. S. aureus carriage in rhesus macaques (Macaca mulatta) and Assam macaques (Macaca assamensis) is a species that has not previously been sampled and lives in remote environments with limited human contact. Forty Staphylococcus aureus isolates including 33 methicillin-susceptible S. aureus (MSSA) and seven methicillin-resistant S. aureus (MRSA) were characterized. Thirty-four isolates were from rhesus macaques and six isolates (five MSSA, one MRSA) were from Assam macaques. Isolates were characterized using StaphyType DNA microarrays. Five of the MRSA including one from Assam macaque were CC22 MRSA-IV (PVL+/tst+), which is a strain previously identified in Nepalese rhesus. One MRSA each were CC6 MRSA-IV and CC772 MRSA-V (PVL+). One MSSA each belonged to CC15, CC96, and CC2990. Six MRSA isolates carried the blaZ, while ten known CC isolates (seven MRSA, three MSSA) carried a variety of genes including aacA-aphD, aphA3, erm(C), mph(C), dfrA, msrA, and/or sat genes. The other 30 MSSA isolates belonged to 17 novel clonal complexes, carried no antibiotic resistance genes, lacked Panton–Valentine Leukocidin (PVL), and most examined exotoxin genes. Four clonal complexes carried egc enterotoxin genes, and four harbored edinB, which is an exfoliative toxin homologue.

scholarly journals Identification of a Highly Transmissible Animal-Independent Staphylococcus aureus ST398 Clone with Distinct Genomic and Cell Adhesion Properties

mBio ◽  
2012 ◽  
Vol 3 (2) ◽  
Author(s):  
Anne-Catrin Uhlemann ◽  
Stephen F. Porcella ◽  
Sheetal Trivedi ◽  
Sean B. Sullivan ◽  
Cory Hafer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Human Skin ◽  
Mobile Genetic Elements ◽  
Urban Setting ◽  
Adhesion Properties ◽  
Methicillin Resistant ◽  
Content Type ◽  
Genetic Elements ◽  
Skin Keratinocytes ◽  
Animal Contact

ABSTRACT A methicillin-resistant Staphylococcus aureus (MRSA) clone known as ST398 has emerged as a major cause of acute infections in individuals who have close contact with livestock. More recently, the emergence of an animal-independent ST398 methicillin-sensitive S. aureus (MSSA) clone has been documented in several countries. However, the limited surveillance of MSSA has precluded an accurate assessment of the global spread of ST398 and its clinical relevance. Here we provide evidence that ST398 is a frequent source of MSSA infections in northern Manhattan and is readily transmitted between individuals in households. This contrasts with the limited transmissibility of livestock-associated ST398 (LA-ST398) MRSA strains between humans. Our whole-genome sequence analysis revealed that the chromosome of the human-associated ST398 MSSA clone is smaller than that of the LA-ST398 MRSA reference strain S0385, due mainly to fewer mobile genetic elements (MGEs). In contrast, human ST398 MSSA isolates harbored the prophage φ3 and the human-specific immune evasion cluster (IEC) genes chp and scn. While most of the core genome was conserved between the human ST398 MSSA clone and S0385, these strains differed substantially in their repertoire and composition of intact adhesion genes. These genetic changes were associated with significantly enhanced adhesion of human ST398 MSSA isolates to human skin keratinocytes and keratin. We propose that the human ST398 MSSA clone can spread independent of animal contact using an optimized repertoire of MGEs and adhesion molecules adapted to transmission among humans. IMPORTANCE Staphylococcus aureus strains have generally been considered to be species specific. However, cross-species transfers of S. aureus clones, such as ST398 methicillin-resistant S. aureus (MRSA), from swine to humans have been reported. Recently, we observed the emergence of ST398 methicillin-susceptible S. aureus (MSSA) as a colonizing strain of humans in northern Manhattan. Here we report that ST398 is a frequent cause of MSSA infections in this urban setting. The ST398 MSSA clone was readily transmitted within households, independent of animal contact. We discovered that human ST398 MSSA genomes were smaller than that of the LA-ST398 strain S0385 due to fewer mobile genetic elements. Human and LA-ST398 strains also differed in their composition of adhesion genes and their ability to bind to human skin keratinocytes, providing a potential mechanism of S. aureus host adaptation. Our findings illustrate the importance of implementing molecular surveillance of MSSA given the evidence for the rapid and clinically undetected spread of ST398 MSSA.

scholarly journals Prevalence and Genomic Structure of Bacteriophage phi3 in Human-Derived Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates from 2000 to 2015

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Sarah van Alen ◽  
Britta Ballhausen ◽  
Ursula Kaspar ◽  
Robin Köck ◽  
Karsten Becker
Keyword(s):  
Staphylococcus Aureus ◽  
Clonal Complex ◽  
Genomic Structure ◽  
Animal Husbandry ◽  
Bacterial Attachment ◽  
University Hospital ◽  
Dense Area ◽  
Methicillin Resistant ◽  
Content Type ◽  
Human Host

ABSTRACT Whereas the emergence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) clonal complex 398 (CC398) in animal husbandry and its transmission to humans are well documented, less is known about factors driving the epidemic spread of this zoonotic lineage within the human population. One factor could be the bacteriophage phi3, which is rarely detected in S. aureus isolates from animals but commonly found among isolates from humans, including those of the human-adapted methicillin-susceptible S. aureus (MSSA) CC398 clade. The proportion of phi3-carrying MRSA spa-CC011 isolates, which constitute presumptively LA-MRSA within the multilocus sequence type (MLST) clonal complex 398, was systematically assessed for a period of 16 years to investigate the role of phi3 in the adaptation process of LA-MRSA to the human host. For this purpose, 632 MRSA spa-CC011 isolates from patients of a university hospital located in a pig farming-dense area in Germany were analyzed. Livestock-associated acquisition of MRSA spa-CC011 was previously reported as having increased from 1.8% in 2000 to 29.4% in 2014 in MRSA-positive patients admitted to this hospital. However, in this study, the proportion of phi3-carrying isolates rose only from 1.1% (2000 to 2006) to 3.9% (2007 to 2015). Characterization of the phi3 genomes revealed 12 different phage types ranging in size from 40,712 kb up to 44,003 kb, with four hitherto unknown integration sites (genes or intergenic regions) and several modified bacterial attachment (attB) sites. In contrast to the MSSA CC398 clade, phi3 acquisition seems to be no major driver for the readaptation of MRSA spa-CC011 to the human host.

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