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P1597 Prevalence of methicillin-resistant Staphylococcus aureus carriage in Italian long-term care facilities
Epidemiology of MRSA P1597 Prevalence of methicillin-resistant Staphylococcus aureus carriage in Italian long-term care facilities P. Brugnaro, J. Mantero, R. Cazzaro, U. Fedeli, P. Mantoan, G. Pellizzer, A. Tomasini, M. Zoppelletto, P. Spolaore (Castelfranco Veneto, Vicenza, IT) Objective: Data on the prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) carriers in long term care facilities are lacking in Italy, being 11% the prevalence reported in the only available investigation conducted in a single facility. Aim of the study is to determine prevalence and risk factors for MRSA carriage in nursing home residents in Vicenza (North-Eastern Italy). Methods: Nasal swabs were obtained in late June-early July 2006 from residents of the two largest long term care facilities of the city. Laboratory screening for MRSA was performed by means of the MRSA Select Agar (Bio-Rad) and full antibiotic susceptibility was assessed in MRSA isolates. Demographic and clinical data, dependency, cognitive function, length of stay, current and previous antibiotic treatment, presence of medical devices, previous hospital admission, presence of infection according to Association for Professionals in Infection Control criteria were assessed in each subject on the same day of sample collection. The factors significantly associated to MRSA carriage at univariate analysis were introduced in a multiple logistic regression model, and the corresponding odds ratio (OR) with 95% Confidence Intervals (CI) were estimated. Results: Out of 570 residents nasal swabs were obtained in 551 subjects (96.7%). Among the latter, 73% were females; the mean age was 83 years (31% of residents being aged 90 or more). 118 residents (21%) had at least one hospital admission in the previous year. 63% of subjects received systemic antibiotic treatments in the previous 12 months: 37% were treated with fluoroquinolones, 26% with cephalosporins. Overall 43 MRSA carriers were detected (7.8%; CI: 5.7–10.4%). All MRSA isolates showed fluoroquinolones resistance. At logistic regression the risk of MRSA carriage was increased in patients with cancer (OR = 6.1; CI: 2.5–15.0), with previous hospitalisation (OR = 2.0; CI: 1.0−4.0), and raised with the number of previous antibiotic treatments, reaching an OR = 3.9 (CI: 1.6−9.1) in those with 3 or more treatments. Conclusion: To date the present study is the largest Italian survey of MRSA carriage in elderly people outside the hospital setting. The prevalence resulted higher than that reported from nursing homes in other European countries like Germany. Both comorbidities (cancer) and pattern of care (previous hospitalisation and antibiotic treatment) were associated with MRSA carriage.
P1598 Tracking the epidemiology of methicillin-resistant Staphylococcus aureus strains producing Panton-Valentine leukocidin in Greece V. Chini, A. Foka, E. Petinaki, H. Meugnier, F. Kolonitsiou, D. Garantziotou, M. Bes, J. Etienne, I. Spiliopoulou (Patras, Larissa, GR; Lyon, FR) Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is recently associated with an increasing number of community-acquired infections (CA-MRSA), including superficial, deep-seated infections and pneumonia. CA-MRSA harbours the Staphylococcal Cassette Chromosome IV or V (SCCmec) and the genes encoding the PantonValentine leukocidin (PVL). We have investigated the distribution and clonal evolution of CA-MRSA during 2005–2006 in Greece. Methods: S. aureus isolates from three hospitals in Western and Central Greece were identified by conventional tests, followed by the determination of MIC of oxacillin by the agar dilution method. PBP2a production was investigated by a Latex agglutination test (bioM´erieux). SCCmec types, agr groups and the presence of lukS and lukF genes (encoding PVL) were defined by PCRs. Clonal types were determined by MLST. CA-MRSA were isolated from patients without any predisposing risk factors and identified on the basis of their genotypes.
S449 Results: A total of 1,541 S. aureus isolates were collected from different patients from January 2005 until June 2006. Among them 697 isolates (45%) were MRSA (495 from the Department of Outpatients, OUTP) and 490 (70%) PVL-positive (443 from the OUTP). An increasing rate of the total S. aureus infections was observed with a parallel increase of PVL-positive CA-MRSA. The great majority of CA-MRSA was associated with skin and soft tissue infections, but five cases of acute osteomyelitis and one pneumonia were diagnosed. The majority of CAMRSA (432) belonged to the major European clone, which is ST80, agr 3, SCCmec IV, while the rest 11 belonged to a new emerging clone, spread also in Europe, ST377, agr 1 and SCCmec type V. Most of the PVL-positive MRSA were associated with community-acquired infections, but 47 PVL-positive MRSA of ST80 were isolated from hospital-acquired infections, mainly at the departments of Orthopaedics and Surgery. Conclusions: There is an unusual epidemiology of PVL-positive CAMRSA in Greece where, we are encountering an increasing rate of S. aureus infections, due to CA-MRSA producing PVL and causing mainly superficial but also deep-seated infections. The European CAMRSA clone seems to be spread rapidly, but a new clone is also showing up.
P1599 A CA-MRSA strain with decreased vancomycin susceptibility as a cause of serious invasive infection in an immunocompetent adolescent M. Tronci, G. Parisi, A. Pantosti, M. Monaco, P. Valentini (Rome, IT) Obiectives: CA-MRSA are primarily associated with skin and soft tissue infection although they can also cause more serious infections such as necrotising pneumonia and septicaemia. This report describes a severe invasive infection in a immunocompetent adolescent with isolation of an CA-MRSA strain with decreased susceptibility to vancomycin. Methods: Blood and CSF cultures were obtained from a 16-year old Italian boy admitted to the Paediatric Emergency room with a temperature of 40.5ºC, stiff neck, headache and vomiting. The patient was previously healthy with no recent hospitalisation story; he played football and had a purulent skin lesion in the back. An empiric therapy with a 3rd generation cefalosporin was started. The identification and susceptibility tests were performed by PHOENIX instrument. Susceptibilities were confirmed by E-test. The presence of the Panton-Valentine Leucocidin (PVL) toxin genes lukS-PV-lukF-PV was determined by PCR. The structural type of the Staphylococcal chromosomal cassette mec (SCCmec) was performed by multiplex PCR. Multi-locus sequence typing (MLST) was performed to characterise the clonal group. Results: Blood and CSF cultures grew an MRSA. In vitro susceptibility tests showed that both the isolates from blood and from CSF were resistant to oxacillin, and were sensitive to gentamycin, kanamycin, erythromycin, clindamycin, rifampicin, tetracycline, ciprofloxacin, chloramphenicol and linezolid. MIC to vancomycin was 4 mg/mL. The isolates contained SCCmec type IV and were positive for PVL. By MLST the isolates were found to belong to the European clone. The patient was transferred to another hospital where vancomycin was started. On the third day, his condition deteriorated and he was admitted to the ICU for respiratory distress and hypoxaemia. The chest X-ray revealed infiltrates and the CT scan showed severe necrotising pneumonia. The antimicrobial regimen was switched to linezolid, rifampicin and teicoplanin. His conditions improved and he was discharged after four weeks. Conclusions: To our knowledge this is the first case of an invasive infection due to a CA-MRSA strain with decreased susceptibility to vancomycin. We emphasize the importance of an early laboratory diagnosis for an appropriate and successful therapy. An epidemiological surveillance system is needed to characterise and monitor CA-MRSA infections and to understand how MRSA are transmitted in the community.
P1598 Tracking the epidemiology of methicillin-resistant Staphylococcus aureus strains producing Panton-Valentine leukocidin in Greece V. Chini, A. Foka, E. Petinaki, H. Meugnier, F. Kolonitsiou, D. Garantziotou, M. Bes, J. Etienne, I. Spiliopoulou (Patras, Larissa, GR; Lyon, FR) Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is recently associated with an increasing number of community-acquired infections (CA-MRSA), including superficial, deep-seated infections and pneumonia. CA-MRSA harbours the Staphylococcal Cassette Chromosome IV or V (SCCmec) and the genes encoding the PantonValentine leukocidin (PVL). We have investigated the distribution and clonal evolution of CA-MRSA during 2005–2006 in Greece. Methods: S. aureus isolates from three hospitals in Western and Central Greece were identified by conventional tests, followed by the determination of MIC of oxacillin by the agar dilution method. PBP2a production was investigated by a Latex agglutination test (bioM´erieux). SCCmec types, agr groups and the presence of lukS and lukF genes (encoding PVL) were defined by PCRs. Clonal types were determined by MLST. CA-MRSA were isolated from patients without any predisposing risk factors and identified on the basis of their genotypes.
S449 Results: A total of 1,541 S. aureus isolates were collected from different patients from January 2005 until June 2006. Among them 697 isolates (45%) were MRSA (495 from the Department of Outpatients, OUTP) and 490 (70%) PVL-positive (443 from the OUTP). An increasing rate of the total S. aureus infections was observed with a parallel increase of PVL-positive CA-MRSA. The great majority of CA-MRSA was associated with skin and soft tissue infections, but five cases of acute osteomyelitis and one pneumonia were diagnosed. The majority of CAMRSA (432) belonged to the major European clone, which is ST80, agr 3, SCCmec IV, while the rest 11 belonged to a new emerging clone, spread also in Europe, ST377, agr 1 and SCCmec type V. Most of the PVL-positive MRSA were associated with community-acquired infections, but 47 PVL-positive MRSA of ST80 were isolated from hospital-acquired infections, mainly at the departments of Orthopaedics and Surgery. Conclusions: There is an unusual epidemiology of PVL-positive CAMRSA in Greece where, we are encountering an increasing rate of S. aureus infections, due to CA-MRSA producing PVL and causing mainly superficial but also deep-seated infections. The European CAMRSA clone seems to be spread rapidly, but a new clone is also showing up.
P1599 A CA-MRSA strain with decreased vancomycin susceptibility as a cause of serious invasive infection in an immunocompetent adolescent M. Tronci, G. Parisi, A. Pantosti, M. Monaco, P. Valentini (Rome, IT) Obiectives: CA-MRSA are primarily associated with skin and soft tissue infection although they can also cause more serious infections such as necrotising pneumonia and septicaemia. This report describes a severe invasive infection in a immunocompetent adolescent with isolation of an CA-MRSA strain with decreased susceptibility to vancomycin. Methods: Blood and CSF cultures were obtained from a 16-year old Italian boy admitted to the Paediatric Emergency room with a temperature of 40.5ºC, stiff neck, headache and vomiting. The patient was previously healthy with no recent hospitalisation story; he played football and had a purulent skin lesion in the back. An empiric therapy with a 3rd generation cefalosporin was started. The identification and susceptibility tests were performed by PHOENIX instrument. Susceptibilities were confirmed by E-test. The presence of the Panton-Valentine Leucocidin (PVL) toxin genes lukS-PV-lukF-PV was determined by PCR. The structural type of the Staphylococcal chromosomal cassette mec (SCCmec) was performed by multiplex PCR. Multi-locus sequence typing (MLST) was performed to characterise the clonal group. Results: Blood and CSF cultures grew an MRSA. In vitro susceptibility tests showed that both the isolates from blood and from CSF were resistant to oxacillin, and were sensitive to gentamycin, kanamycin, erythromycin, clindamycin, rifampicin, tetracycline, ciprofloxacin, chloramphenicol and linezolid. MIC to vancomycin was 4 mg/mL. The isolates contained SCCmec type IV and were positive for PVL. By MLST the isolates were found to belong to the European clone. The patient was transferred to another hospital where vancomycin was started. On the third day, his condition deteriorated and he was admitted to the ICU for respiratory distress and hypoxaemia. The chest X-ray revealed infiltrates and the CT scan showed severe necrotising pneumonia. The antimicrobial regimen was switched to linezolid, rifampicin and teicoplanin. His conditions improved and he was discharged after four weeks. Conclusions: To our knowledge this is the first case of an invasive infection due to a CA-MRSA strain with decreased susceptibility to vancomycin. We emphasize the importance of an early laboratory diagnosis for an appropriate and successful therapy. An epidemiological surveillance system is needed to characterise and monitor CA-MRSA infections and to understand how MRSA are transmitted in the community.