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Staphylococcus aureus: the enemy within
Abstracts
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Clinical Microbiology, University Hospitals of Leicester Child Health, University Hospitals of Leicester
STAPHYLOCOCCUS AUREUS: THE ENEMY WITHIN Dave Bella 1, Patel Mitulkumar 2, Bodasing Neena 1, Cadwgan Anthony M 1 1
Dept of Clinical Infection, University Hospital of North Staffordshire, City General Hospital, Newcastle Road, Stoke-on-Trent, Staffordshire ST4 6QG 2 Dept of Microbiology, University Hospital of North Staffordshire, City General Hospital, Newcastle Road, Stoke-on-Trent, Staffordshire ST4 6QG We report two cases of severe community acquired infections due to staphylococcus aureus. Case 1 A 51-year-old man presented with a severe necrotising and cavitating pneumonia following a trip to China and Malaysia. White cell count was 18 and sputum cultured a Methicillin Sensitive Staphylococcus Aureus (MSSA). He improved with IV antibiotics, which was changed to orals after two weeks. However, a large lung cavity persisted despite chest drain insertion. Therefore a flutter bag was inserted, he was discharged and the cavity was reducing on follow-up. Case 2 A previously well 31-year-old woman was admitted with a serious, recurrent axillary abcess and staphylococcal toxaemia. White cell count was 16.1 and she was treated with IV antibiotics and incision and drainage of the abcess. She improved with this treatment and was discharged. Material from the axillary abcess also cultured MSSA and was positive for TSST. What is the connection between the two? In both of these cases the infection was caused by a Panton-Valentine Leukocidin (PVL)-producing strain of MSSA. PVL, a pore-forming toxin that causes leukocytolysis and tissue necrosis, has been associated with severe community-acquired pneumonia in immunocompetent patients and necrotising cutaneous infections. These cases are unusual as although similar cases of pneumonia and cutaneous infections have been reported, in contrast to the literature, neither of the cases we report had an associated leucopenia. This may be a good prognostic feature in PVL cases. The current incidence of PVL positive staphylococcus aureus is reported as <2%. In our hospital we do not routinely send samples of staphylococcus aureus for PVL typing. However, the two incidents of PVL associated infections within this five-week time frame highlights the need to regularly screen patients with severe or recurrent staphylococcal infections, irrespective of leukocytosis. We also acknowledge and thank Angela Kearns for her advice.
We present a case of pupura fulminans (PF) secondary to methicillin-sensitive Stapylococcus aureus (MSSA) infection. The child was admitted in septic shock with bilateral lower limb purpura (fig. 1) complicated by multiple lung abscesses and cavitation (fig. 2). MSSA was isolated from blood, skin and pulmonary tissue and was later confirmed to be expressing the PVL genes but lacked any other toxin genes. The clinical course culminated in surgery. PF is an acute illness commonly associated with Neisseria meningitidis (and to a lesser extent streptococcal infections, malaria and chickenpox). It is characterised by disseminated intravascular coagulopathy and purpuric skin lesions due to disruption of the protein C anticoagulant pathway. PVL genes are expressed in both MSSA and MRSA. Its association with toxigenic staphylococcal infections is rare and is confined to a few reported cases globally. The true incidence of PVL-positive S. aureus (PPSA) infections is unknown as PF is not notifiable and not all S. aureus isolates are tested for PVL genes. Patients with PF are best managed in an intensive care setting with broadspectrum antimicrobials, including an anti-MRSA agent. There is some evidence for adding in linezolid or clindamycin in confirmed PPSA infections due to their antitoxin properties. The interim guidelines produced by the Health Protection Agency recommends the use of intravenous immuoglobulin (IVIG) for its antitoxin properties (2 g/kg/ day). There may also be a role for activated protein C in adults as an immunomodulator and anticoagulant. There is evidence of spread of PPSA via skin-to-skin contact and fomites. The guidelines recommend that patients and their close contacts should be screened for S. aureus carriage. Surgical masks should be worn during intubation and physiotherapy in patients with respiratory infections. In conclusion, clinicians should be aware that PF is not synonymous with meningococcaemia and this should be reflected in their empirical antimicrobial choice, especially if blistering is a presenting feature.
P 064 CLINICAL AND MICROBIOLOGICAL CHARACTERISTICS OF STAPHYLOCOCCAL TOXIC SHOCK SYNDROME PRESENTING TO A PAEDIATRIC INTENSIVE CARE UNIT O’Dell E 1, Davies F 2, Kearns AM 3, Festa M 1, Klein JL 2 1
BLISTERING PURPURA
Paediatric Intensive Care Unit, Health Protection Agency (HPA), London 2 Dept of Infection, Health Protection Agency (HPA), London 3 Guy’s and St. Thomas’ NHS Foundation Trust, London and Centre for Infections, Health Protection Agency (HPA), London
Hussain A 1, Robinson G 2, Malkin J 1, Duthie M 2, Perera N 1
Background: Staphylococcal toxic shock syndrome (STSS) is a toxin-mediated disease which presents with
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P 062
e73 1 2
Clinical Microbiology, University Hospitals of Leicester Child Health, University Hospitals of Leicester
STAPHYLOCOCCUS AUREUS: THE ENEMY WITHIN Dave Bella 1, Patel Mitulkumar 2, Bodasing Neena 1, Cadwgan Anthony M 1 1
Dept of Clinical Infection, University Hospital of North Staffordshire, City General Hospital, Newcastle Road, Stoke-on-Trent, Staffordshire ST4 6QG 2 Dept of Microbiology, University Hospital of North Staffordshire, City General Hospital, Newcastle Road, Stoke-on-Trent, Staffordshire ST4 6QG We report two cases of severe community acquired infections due to staphylococcus aureus. Case 1 A 51-year-old man presented with a severe necrotising and cavitating pneumonia following a trip to China and Malaysia. White cell count was 18 and sputum cultured a Methicillin Sensitive Staphylococcus Aureus (MSSA). He improved with IV antibiotics, which was changed to orals after two weeks. However, a large lung cavity persisted despite chest drain insertion. Therefore a flutter bag was inserted, he was discharged and the cavity was reducing on follow-up. Case 2 A previously well 31-year-old woman was admitted with a serious, recurrent axillary abcess and staphylococcal toxaemia. White cell count was 16.1 and she was treated with IV antibiotics and incision and drainage of the abcess. She improved with this treatment and was discharged. Material from the axillary abcess also cultured MSSA and was positive for TSST. What is the connection between the two? In both of these cases the infection was caused by a Panton-Valentine Leukocidin (PVL)-producing strain of MSSA. PVL, a pore-forming toxin that causes leukocytolysis and tissue necrosis, has been associated with severe community-acquired pneumonia in immunocompetent patients and necrotising cutaneous infections. These cases are unusual as although similar cases of pneumonia and cutaneous infections have been reported, in contrast to the literature, neither of the cases we report had an associated leucopenia. This may be a good prognostic feature in PVL cases. The current incidence of PVL positive staphylococcus aureus is reported as <2%. In our hospital we do not routinely send samples of staphylococcus aureus for PVL typing. However, the two incidents of PVL associated infections within this five-week time frame highlights the need to regularly screen patients with severe or recurrent staphylococcal infections, irrespective of leukocytosis. We also acknowledge and thank Angela Kearns for her advice.
We present a case of pupura fulminans (PF) secondary to methicillin-sensitive Stapylococcus aureus (MSSA) infection. The child was admitted in septic shock with bilateral lower limb purpura (fig. 1) complicated by multiple lung abscesses and cavitation (fig. 2). MSSA was isolated from blood, skin and pulmonary tissue and was later confirmed to be expressing the PVL genes but lacked any other toxin genes. The clinical course culminated in surgery. PF is an acute illness commonly associated with Neisseria meningitidis (and to a lesser extent streptococcal infections, malaria and chickenpox). It is characterised by disseminated intravascular coagulopathy and purpuric skin lesions due to disruption of the protein C anticoagulant pathway. PVL genes are expressed in both MSSA and MRSA. Its association with toxigenic staphylococcal infections is rare and is confined to a few reported cases globally. The true incidence of PVL-positive S. aureus (PPSA) infections is unknown as PF is not notifiable and not all S. aureus isolates are tested for PVL genes. Patients with PF are best managed in an intensive care setting with broadspectrum antimicrobials, including an anti-MRSA agent. There is some evidence for adding in linezolid or clindamycin in confirmed PPSA infections due to their antitoxin properties. The interim guidelines produced by the Health Protection Agency recommends the use of intravenous immuoglobulin (IVIG) for its antitoxin properties (2 g/kg/ day). There may also be a role for activated protein C in adults as an immunomodulator and anticoagulant. There is evidence of spread of PPSA via skin-to-skin contact and fomites. The guidelines recommend that patients and their close contacts should be screened for S. aureus carriage. Surgical masks should be worn during intubation and physiotherapy in patients with respiratory infections. In conclusion, clinicians should be aware that PF is not synonymous with meningococcaemia and this should be reflected in their empirical antimicrobial choice, especially if blistering is a presenting feature.
P 064 CLINICAL AND MICROBIOLOGICAL CHARACTERISTICS OF STAPHYLOCOCCAL TOXIC SHOCK SYNDROME PRESENTING TO A PAEDIATRIC INTENSIVE CARE UNIT O’Dell E 1, Davies F 2, Kearns AM 3, Festa M 1, Klein JL 2 1
BLISTERING PURPURA
Paediatric Intensive Care Unit, Health Protection Agency (HPA), London 2 Dept of Infection, Health Protection Agency (HPA), London 3 Guy’s and St. Thomas’ NHS Foundation Trust, London and Centre for Infections, Health Protection Agency (HPA), London
Hussain A 1, Robinson G 2, Malkin J 1, Duthie M 2, Perera N 1
Background: Staphylococcal toxic shock syndrome (STSS) is a toxin-mediated disease which presents with
P 063