Lethal necrotizing pneumonia caused by an ST398 staphylococcus aureus strain.
Article Type: Letter to the editor
Subject: Bacterial pneumonia (Causes of)
Bacterial pneumonia (Diagnosis)
Bacterial pneumonia (Care and treatment)
Bacterial pneumonia (Genetic aspects)
Bacterial pneumonia (Research)
Pneumonia (Causes of)
Pneumonia (Diagnosis)
Pneumonia (Care and treatment)
Pneumonia (Genetic aspects)
Pneumonia (Research)
Polymerase chain reaction (Usage)
Staphylococcus aureus (Health aspects)
Staphylococcus aureus (Research)
Authors: Rasigade, Jean-Philippe
Laurent, Frederic
Hubert, Philippe
Vandenesch, Francois
Etienne, Jerome
Pub Date: 08/01/2010
Publication: Name: Emerging Infectious Diseases Publisher: U.S. National Center for Infectious Diseases Audience: Academic; Professional Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 U.S. National Center for Infectious Diseases ISSN: 1080-6040
Issue: Date: August, 2010 Source Volume: 16 Source Issue: 8
Topic: Event Code: 310 Science & research
Geographic: Geographic Scope: Canada Geographic Code: 1CANA Canada
Accession Number: 237533377
Full Text: To the Editor: Several recent studies have shown massive colonization of livestock (especially pigs) and livestock workers by methicillin-resistant Staphylococcus aureus (MRSA) in western Europe, Canada, and the United States (1,2). Livestock MRSA isolates belong almost exclusively to a single sequence type, ST398. Evidence of zoonotic and interhuman transmission of methicillin-resistant and methicillin-susceptible variants of this hitherto unusual sequence type was recently reported (1,3). S. aureus ST398 infections in humans with or without a history of contact with livestock include bacteremia, endocarditis, ventilator-associated pneumonia, and wound infections, none of which involve the expression of specific toxins. Indeed, ST398 isolates are negative for all major virulence factors, with the exception of some rare isolates that harbor the genes that encode the Panton-Valentine leukocidin (PVL) (1), a toxin that is usually associated with community-acquired MRSA (4). We report a case of lethal necrotizing pneumonia caused by a PVL-positive methicillin-susceptible ST398 S. aureus isolate.

A previously healthy 14-year-old girl came to the emergency room with influenza-like illness, cough, fever, and a 2-day history of severe abdominal pain. She was given intravenous antibacterial chemotherapy with cefotaxime and amikacin. An exploratory laparotomy showed no signs of abdominal disease. Immediately after surgery, acute respiratory distress syndrome with hemodynamic instability developed in the patient; mechanical ventilation and inotropic support were required. A chest radiograph showed bilateral pulmonary infiltrates and pleural effusion. S. aureus was isolated by bronchoalveolar lavage fluid and blood culture, and staphylococcal necrotizing pneumonia was diagnosed. Clinical features, including the preceding influenza-like illness, were highly consistent with those previously reported (5). However, viral cultures and immunofluorescence assays were negative for all common respiratory viruses, and, although the patient had positive serologic test results for influenza B virus, antibody titers were too low to affirm influenza B infection. Severity factors were present (5), including leukopenia, airway bleeding, and multiorgan failure. She died 6 days after symptom onset, with refractory shock and respiratory failure caused by bilateral pneumothorax. The S. aureus strain, which was susceptible to all tested antimicrobial agents except macrolides, was agr1/ST398, spa-type t571 and nontypeable by SmaI pulsed-field gel electrophoresis, which showed its relatedness to live-stock-associated strains. The origin of the infection could not be determined. The presence of the genes encoding PVL was confirmed by PCR.

Thus, the spread of S. aureus ST398 among livestock is a matter of increasing concern because strains of this sequence type were able to acquire PVL genes and cause necrotizing pneumonia in a young immunocompetent patient. Transmission control and surveillance efforts are urgently needed to prevent further spread of such strains.

References

(1.) Wulf M, Voss A. MRSA in livestock animals --an epidemic waiting to happen? Clin Microbiol Infect. 2008;14:519-21. DOI: 10.1111/j.1469-0691.2008.01970.x

(2.) Smith TC, Male MJ, Harper AL, Kroeger JS, Tinkler GP, Moritz ED, et al. Methicillin-resistant Staphylococcus aureus (MRSA) strain ST398 is present in mid-western U.S. swine and swine workers. PLoS One. 2009;4:e4258. DOI: 10.1371/journal.pone.0004258

(3.) Fanoy E, Helmhout LC, van der Vaart WL, Weijdema K, van Santen-Verheuvel MG, Thijsen SF, et al. An outbreak of non-type-able MRSA within a residential care facility. Euro Surveill. 2009;14(1):pii=19080.

(4.) Chambers HF. Community-associated MRSA-resistance and virulence converge. N Engl J Med. 2005;352:1485-7. DOI: 10.1056/NEJMe058023

(5.) Gillet Y, Vanhems P, Lina G, Bes M, Vandenesch F, Floret D, et al. Factors predicting mortality in necrotizing communityacquired pneumonia caused by Staphylococcus aureus containing PantonValentine leukocidin. Clin Infect Dis. 2007;45:315-21. DOI: 10.1086/519263

Jean-Philippe Rasigade, Frederic Laurent, Philippe Hubert, Francois Vandenesch, and Jerome Etienne

Author affiliations: Hospices Civils de Lyon, Lyon, France (J.P. Rasigade, F. Laurent, J. Etienne, F. Vandenesch); and Assistance Publique-Hopitaux de Paris, Paris, France (P. Hubert)

Address for correspondence: Jean-Philippe Rasigade, Centre de Reference des Staphylocoques, Centre de Biologie Est, Groupement Hospitalier Est, 59 boulevard Pinel, Bron, 69677 France; email: jean-philippe.rasigade@chu-lyon.fr

DOI: 10.3201/eid1608.100317

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