Posts filed under ‘Epidemiología’

Report of mecC-carrying MRSA in domestic swine

Journal of Antimicrobial & Chemotherapy January 1, 2017 V.72 N.1 P.60-63

Ø. Angen, M. Stegger, J. Larsen, B. Lilje, H. Kaya, K. S. Pedersen, A. Jakobsen, A. Petersen, and A. R. Larsen

1Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark

2Ø-Vet, Køberupvej 33, 4700 Næstved, Denmark


We unexpectedly identified MRSA isolates carrying mecC (mecC-MRSA) from a Danish swine farm located in eastern Zealand. The objective of the present study was to investigate the origin of these isolates and their genetic relatedness to other mecC-MRSA isolates from Zealand.


WGS was used to infer the phylogenetic relationship between 19 identified mecC-MRSA isolates from the swine farm and 34 additional epidemiologically unrelated human isolates from the same geographical region of Denmark. Variations in the accessory genome were investigated by bioinformatics tools, and antibiotic susceptibility profiles were assessed by MIC determination.


mecC-MRSA was isolated from a domestic swine farm, but not from cattle reared at the same farm. Phylogenetic analysis revealed that all mecC-MRSA isolates from both farm animals and workers formed a separate cluster, whereas human isolates from the same municipality belonged to a closely related cluster. Analysis of the accessory genome supported this relationship.


To the best of our knowledge, this is the first report of mecC-MRSA isolated from domestic swine. The investigation strongly indicates that transmission of mecC-MRSA has taken place on the swine farm between the farmers and swine. The close clustering of farm isolates and isolates from the same municipality suggests a local transmission of mecC-MRSA.


August 19, 2017 at 10:35 am

Editor’s Choice: Hepatitis C Virus Postexposure Prophylaxis in the Healthcare Worker: Why Direct-Acting Antivirals Don’t Change a Thing

Clinical Infectious Diseases January 1, 2017 V.64 N.1 P.92-99

Susanna Naggie, David P. Holland, Mark S. Sulkowski, and David L. Thomas

1Duke Clinical Research Institute

2Duke University School of Medicine, Durham, North Carolina

3Emory University School of Medicine, Atlanta, Georgia

4Johns Hopkins School of Medicine, Baltimore, Maryland

Currently, 380 000–400 000 occupational exposures to blood-borne pathogens occur annually in the United States. The management for occupational HIV or hepatitis B virus exposures includes postexposure prophylaxis (PEP) when necessary; however, PEP is not recommended for hepatitis C virus (HCV) exposures.

Recent approval of HCV direct-acting antivirals (DAAs) has renewed discussions as to whether these therapies could be used to prevent infection after exposure. There are no published studies addressing this question, but the prescribing of DAAs for PEP has been reported.

We will discuss the differences in transmission of the 3 most common blood-borne pathogens, the natural history of early HCV infection, and the scientific rationale for PEP.

In particular, we will discuss how the low feasibility of conducting an adequately powered clinical trial of DAA use for PEP and the low cost-effectiveness of such an intervention is not supportive of targeting limited resources for such use.




Clinical Infectious Diseases January 1, 2017 V.64 N.1 P.100-101

Editor’s Choice: Editorial Commentary: Decision Science at Work: The Case of Hepatitis C Virus Postexposure Prophylaxis

Joshua A. Barocas and Benjamin P. Linas

1Division of Infectious Diseases, Massachusetts General Hospital

2Boston University Schools of Medicine and Public Health

3Boston Medical Center, Massachusetts

In this issue of Clinical Infectious Diseases, Naggie et al discuss clinical decision making and present the results of a decision analysis examining the cost of hepatitis C virus (HCV) postexposure prophylaxis (PEP) among healthcare workers who experience a needlestick exposure to HCV-positive body fluids.

The authors discuss that, in an era when we can cure essentially all HCV infections, there are only 3 motivations for PEP. First, it may make sense to use PEP to prevent infections if doing so would decrease HCV transmission during the period of active HCV viremia. The paper succinctly reviews the evidence and quickly makes clear that among healthcare workers in the United States with a known HCV exposure, basic universal precautions reduce the risk of forward transmission to essentially zero.

A second motivation might be cost. Given that HCV medications are expensive, a shorter course PEP may be cost saving compared with full treatment for HCV infection. To address the possible economic rationale for PEP, the authors developed a decision tree to estimate the costs of PEP for HCV in a hypothetical cohort of 100 healthcare workers who had suffered a needlestick injury. They used the model to compare the outcomes with PEP to those with a strategy of “no PEP and treat only patients who develop chronic HCV infection.”

A few notable assumptions were made—namely, that PEP was 100% effective at preventing infection, while treatment for chronic HCV was only 98% effective with the first line of therapy. In addition, individuals who failed first-line treatment for chronic HCV infection were retreated with 100% . . .


August 19, 2017 at 10:30 am

Editor’s Choice: Coinfection With Zika and Dengue-2 Viruses in a Traveler Returning From Haiti, 2016: Clinical Presentation and Genetic Analysis

Clinical Infectious Diseases January 1, 2017 V.64 N.1 P.72-75


Nicole M. Iovine, John Lednicky, Kartikeya Cherabuddi, Hannah Crooke, Sarah K. White, Julia C. Loeb, Eleonora Cella, Massimo Ciccozzi, Marco Salemi, and J. Glenn Morris, Jr

1Division of Infectious Diseases, Department of Medicine, College of Medicine

2Emerging Pathogens Institute

3Department of Environmental and Global Health, College of Public Health and Health Professions

4Department of Epidemiology, College of Public Health and Health Professions

5Department of Pathology, Immunology and Laboratory Sciences, College of Medicine, University of Florida, Gainesville

6Department of Infectious Parasitic and Immunomediated Diseases, Reference Centre on Phylogeny, Molecular Epidemiology and Microbial Evolution/Epidemiology Unit, Istituto Superiore di Sanita, Rome, Italy

Zika virus and dengue virus serotype 2 were isolated from a patient with travel to Haiti who developed fever, rash, arthralgias, and conjunctivitis. The infecting Zika virus was related to Venezuelan and Brazilian strains but evolved along a lineage originating from strains isolated in 2014 in the same region of Haiti.


August 19, 2017 at 10:26 am

Prospective multicenter study of community-associated skin and skin structure infections due to methicillin-resistant Staphylococcus aureus in Buenos Aires, Argentina.

PLoS One. NOV. 20, 2013 V.8 N.11 P.e78303.    

López Furst MJ1, de Vedia L, Fernández S, Gardella N, Ganaha MC, Prieto S, Carbone E, Lista N, Rotryng F, Morera GI, Mollerach M, Stryjewski ME; Grupo de Estudio de Infecciones de Piel y Estructuras Relacionadas por Staphylococcus aureus meticilino-resistente de la Comunidad, Sociedad Argentina de Infectología.

Collaborators (66)

Author information

1 Unidad de Infectología, Sanatorio Municipal Dr. Julio Méndez, Ciudad Autónoma de Buenos Aires, Argentina.



Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is now the most common cause of skin and skin structure infections (SSSI) in several world regions. In Argentina prospective, multicenter clinical studies have only been conducted in pediatric populations.


PRIMARY: describe the prevalence, clinical and demographic characteristics of adult patients with community acquired SSSI due to MRSA; secondary: molecular evaluation of CA-MRSA strains. Patients with MRSA were compared to those without MRSA.


Prospective, observational, multicenter, epidemiologic study, with molecular analysis, conducted at 19 sites in Argentina (18 in Buenos Aires) between March 2010 and October 2011. Patients were included if they were ≥ 14 years, were diagnosed with SSSI, a culture was obtained, and there had no significant healthcare contact identified. A logistic regression model was used to identify factors associated with CA-MRSA. Pulse field types, SCCmec, and PVL status were also determined.


A total of 311 patients were included. CA-MRSA was isolated in 70% (218/311) of patients. Clinical variables independently associated with CA-MRSA were: presence of purulent lesion (OR 3.29; 95%CI 1.67, 6.49) and age <50 years (OR 2.39; 95%CI 1.22, 4.70). The vast majority of CA-MRSA strains causing SSSI carried PVL genes (95%) and were SCCmec type IV. The sequence type CA-MRSA ST30 spa t019 was the predominant clone.


CA-MRSA is now the most common cause of SSSI in our adult patients without healthcare contact. ST30, SCCmec IV, PVL+, spa t019 is the predominant clone in Buenos Aires, Argentina.


August 19, 2017 at 10:21 am

EDITORIAL – Oropuche virus: A virus present but ignored

Rev.MVZ Córdoba 20(3):4675-4676, 2015

Virus de Oropuche: Un virus ignorado pero presente

El virus de Oropouche deriva su nombre de la localidad de Vegas de Oropuche, la cual se encuentra en la isla de Trinidad y Tobago, en donde fue detectado en 1955 en un paciente febril y en mosquitos Coquilletidia venezuelenzis.

El virus de Oropouche es prevalente en muchas regiones de América del Sur y del Caribe.

En el ciclo silvestre, el virus tiene varios mosquitos vectores: Culicoides paraensis, Coquilletidia venezuelenzis y Aedes serratus.

Los mamíferos silvestres son picados por estos mosquitos y aumentan las viremias, como en el oso perezoso (Bradypus tridactiyus), primates (Aloutta sanguinus) y roedores entre otros.

En el ciclo urbano los vectores son mosquitos Culicoides paraensis y Culex quinquefasciatus, ambos muy comunes en los ambientes tropicales de Colombia …


August 16, 2017 at 2:02 pm

Whole-Genome Sequencing of Human Clinical Klebsiella pneumoniae Isolates Reveals Misidentification and Misunderstandings of Klebsiella pneumoniae, Klebsiella variicola, and Klebsiella quasipneumoniae

mSphere August 2017 V.2 N.4

Wesley Long, Sarah E. Linson, Matthew Ojeda Saavedra, Concepcion Cantu, James J. Davis, Thomas Brettin, Randall J. Olsen

Sarah E. F. D’Orazio, Editor

Klebsiella pneumoniae is a major threat to public health, causing significant morbidity and mortality worldwide. The emergence of highly drug-resistant strains is particularly concerning.

There has been a recognition and division of Klebsiella pneumoniae into three distinct phylogenetic groups: Klebsiella pneumoniae, Klebsiella variicola, and Klebsiella quasipneumoniae.

K. variicola and K. quasipneumoniae have often been described as opportunistic pathogens that have less virulence in humans than K. pneumoniae does.

We recently sequenced the genomes of 1,777 extended-spectrum-beta-lactamase (ESBL)-producing K. pneumoniae isolates recovered from human infections and discovered that 28 strains were phylogenetically related to K. variicola and K. quasipneumoniae.

Whole-genome sequencing of 95 additional non-ESBL-producing K. pneumoniae isolates recovered from patients found 12 K. quasipneumoniae strains. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) analysis initially identified all patient isolates as K. pneumoniae, suggesting a potential pitfall in conventional clinical microbiology laboratory identification methods.

Whole-genome sequence analysis revealed extensive sharing of core gene content and plasmid replicons among the Klebsiella species.

For the first time, strains of both K. variicola and K. quasipneumoniae were found to carry the Klebsiella pneumoniae carbapenemase (KPC) gene, while another K. variicola strain was found to carry the New Delhi metallo-beta-lactamase 1 (NDM-1) gene. K. variicola and K. quasipneumoniae infections were not less virulent than K. pneumoniae infections, as assessed by in-hospital mortality and infection type.

We also discovered evidence of homologous recombination in one K. variicola strain, as well as one strain from a novel Klebsiella species, which challenge the current understanding of interrelationships between clades of Klebsiella….



August 16, 2017 at 8:29 am

Activity of ceftolozane/tazobactam against surveillance and ‘problem’ Enterobacteriaceae, Pseudomonas aeruginosa and non-fermenters from the British Isles

Journal of Antimicrobial Chemotherapy August 2017 V.72 N.8 P.2278–2289

David M. Livermore; Shazad Mushtaq; Daniele Meunier; Katie L. Hopkins; Robert Hill …


We assessed the activity of ceftolozane/tazobactam against consecutive isolates collected in the BSAC Bacteraemia Surveillance from 2011 to 2015 and against ‘problem’ isolates sent to the UK national reference laboratory from July 2015, when routine testing began.


Susceptibility testing was by BSAC agar dilution with resistance mechanisms identified by PCR and interpretive reading.


Data were reviewed for 6080 BSAC surveillance isolates and 5473 referred organisms. Ceftolozane/tazobactam had good activity against unselected ESBL producers in the BSAC series, but activity was reduced against ertapenem-resistant ESBL producers, which were numerous among reference submissions. AmpC-derepressed Enterobacter spp. were widely resistant, but Escherichia coli with raised chromosomal AmpC frequently remained susceptible, as did Klebsiella pneumoniae with acquired DHA-1-type AmpC. Carbapenemase-producing Enterobacteriaceae were mostly resistant, except for ceftazidime-susceptible isolates with OXA-48-like enzymes. Ceftolozane/tazobactam was active against 99.8% of the BSAC Pseudomonas aeruginosa isolates; against referred P. aeruginosa it was active against 99.7% with moderately raised efflux, 94.7% with strongly raised efflux and 96.6% with derepressed AmpC. Resistance in P. aeruginosa was largely confined to isolates with metallo-β-lactamases (MBLs) or ESBLs. MICs for referred Burkholderia spp. and Stenotrophomonas maltophilia were 2–4-fold lower than those of ceftazidime.


Ceftolozane/tazobactam is active against ESBL-producing Enterobacteriaceae; gains against other problem Enterobacteriaceae groups were limited. Against P. aeruginosa it overcame the two most prevalent mechanisms (up-regulated efflux and derepressed AmpC) and was active against 51.9% of isolates non-susceptible to all other β-lactams, rising to 80.9% if ESBL and MBL producers were excluded.


August 11, 2017 at 9:20 am

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