Association of recurrent furunculosis with Panton-Valentine leukocidin and the genetic background of Staphylococcus aureus.

Staphylococcus aureus is a major cause of skin and soft tissue infections, such as furuncles, carbuncles, and abscesses, but it also frequently colonizes the human skin and mucosa without causing clinical symptoms. Panton-Valentine leukocidin (PVL) is a pore-forming toxin that has been associated with soft tissue infections and necrotizing pneumonia. We have compared the genotypes, virulence gene repertoires, and phage patterns of 74 furunculosis isolates with those of 108 control strains from healthy nasal carriers. The large majority of furunculosis strains were methicillin sensitive. Clonal cluster (CC) 121 (CC121) and CC22 accounted for 70% of the furunculosis strains but for only 8% of the nasal isolates. The PVL-encoding genes luk-PV were detected in 85% of furunculosis strains, while their prevalence among colonizing S. aureus strains was below 1%. luk-PV genes were distributed over several lineages (CCs 5, 8, 22, 30, and 121 and sequence type 59). Even within the same lineages, luk-PV-positive phages characterized furunculosis strains, while their luk-PV-negative variants were frequent among nasal strains. The very tight epidemiological linkage between luk-PV and furunculosis, which could be separated from the genetic background of the S. aureus strain as well as from the gene makeup of the luk-PV-transducing phage, lends support to the notion of an important role for PVL in human furunculosis. These results make a case for the determination of luk-PV in recurrent soft tissue infections with methicillin-sensitive as well as methicillin-resistant S. aureus.

Molecular studies of an impetigo bullosa epidemic in full-term infants.

BACKGROUND: Carriers of Staphylococcus aureus strains can be the source of epidemic infection for patients. OBJECTIVES: A molecular epidemiological analysis of an impetigo bullosa outbreak in a neonatal ward was performed in order to determine a potential source of the infection and possible routes of subsequent spreading of the epidemic strain. METHODS: The genetic relatedness of S. aureus strains isolated from 6 neonates with epidermal lesions and from 21 staff members was verified by the pulsed field gel electrophoresis (PFGE) method. Additionally, detection of eta and etb genes of S. aureus strains using PCR was performed. RESULTS: None of the infected newborns' mothers was a carrier. Seven strains, 6 isolated from the newborns and 1 taken from a midwife, showed the same restriction pattern, i.e. type A. In the other 20 health care workers colonized with S. aureus, 3 genetic types could be distinguished, i.e. B (2), C (7) and D (2), as well as 9 strains with unique PFGE patterns. The eta gene detected in 7 strains belonged to the genetic type A; there was no etb gene in any of the 27 S. aureus isolates. CONCLUSIONS: The presence of the same genetic type A of S. aureus in the infected newborns is a factor which indicates that the impetigo bullosa was a hospital infection. A probable source of the infection was a midwife who was colonized with the same S. aureus type. She was present at the birth of the first infected newborn. Today, molecular methods are essential for prompt recognition of an epidemic and implementation of appropriate infection control strategies.

[Colonization (infection) of the respiratory tract in outpatients in 2000-2005 years]. / Kolonizacja (zakazenie) dróg oddechowych u chorych leczonych ambulatoryjnie w latach 2000-2005.

UNLABELLED: Infections of the respiratory tract are one of the main causes of family doctor visiting. A variety of etiological factors (mostly viruses, typical and non typical bacteria) causes that the diagnosis of these infections is rarely made in outpatient practice (usually these are nose and throat smears); additionally the carrier state of typical bacteria in the respiratory tract impedes the interpretation of microbiological results. THE AIM OF THE STUDY was to assess the incidence of potential bacterial etiological factors of respiratory tract infections in outpatients in the years 2000-2005. MATERIAL AND METHODS: The 3270 microbiological results obtained from patients at the age of between 1 month and 88 years old with chronic and acute symptoms of respiratory tract infections were analyzed. RESULTS: The positive results of bacteria culture indicating the possible bacterial etiological agent of infection were found from 1051 patients (34.4%), mostly in autumn - spring time. Most often were isolated: H. influenzae - 28.8%, S. pneumoniae - 22.1% and S. aureus - 22.1%, in less percentage M. catarrhalis - 14.1% and S. pyogenes - 13.1. Positive bacteria cultures were received most often from ear secretion- 66.8% (P. aeruginosa, S. aureus), from nose-41.2% (S. pneumoniae, H. influenzae), sputum - 34.9% (S. aureus), throat - 24.3% (H. influenzae, S. pyogenes). CONCLUSIONS: It has been confirmed that predominant participation of viruses in respiratory system infections is observed and also seasonal character of their bacterial nature occurrence (35%). Most often were isolated: H. influenzae, S. pneumoniae, S. aureus, also M. catarrhalis. On the ground of carrier state of these bacteria in nasopharynx it is a clinician's decision to recognize the bacteria as the etiological agent of infection and possible use of antibiotic treatment.