Identification of clinical specimens isolated from neonates
Elida Zairina, Junaidi Khotib, Chrismawan Ardianto, Syed Azhar Syed Sulaiman, Charles D. Sands, Timothy E. Welty in Unity in Diversity and the Standardisation of Clinical Pharmacy Services, 2017
Antimicrobials susceptible to S. epidermidis in this study are clindamycin and rifampicin. The suspected sepsis should be treated with a broad-spectrum antibiotic until culture and sensitivity results are obtained and discontinued after 48 h with negative cultures. The empirical antibiotic regimen chosen must cover Gram-positive organisms (CoNS). Gentamicin is the only aminoglycoside that is more potent than amikacin or netilmicin to act against Gram-positive microorganisms, but some microorganisms have been shown to have increased resistance to this antibiotic. The avoidance of vancomycin has been studied to prove that use of empirical antibiotics to treat sepsis due to coagulase-negative staphylococcus significantly reduces the existence of vancomycin-resistant bacteria. Nevertheless, vancomycin should not be used for prophylaxis in order to avoid excessive exposure to microorganisms; therefore, vancomycin resistance can be treated by teicoplanin (Tripathi et al. 2011). S. aureus (coagulase-positive staphylococci) is a normal flora that can be found in the skin, but in various sides of isolate (Table 3). Methicillin-resistant Staphylococcus aureus (MRSA) strains are usually resistant to oxacillin and other antibiotics. MRSA commonly precipitates infections similar to those caused by sensitive strains of S. aureus. Spread of MRSA may transfer from health facilities and environment in the NICU. Staff or health facilities are involved in MRSA spreading as carriers. This is the reason why MRSA will be a difficult problem to resolve, even though the hand-washing technique had been implemented (Gili et al. 2005). Figure 3 shows the antibiotic resistance of staphylococci to aminoglycoside, cephalosporins, penicillin, penicillinase-resistant penicillin, and macrolide. The gene responsible for intrinsic methicillin resistance is mecA, which encodes penicillin-binding protein PBP2a. This has been reported in worldwide studies and was identified in the earliest strains. As shown in Figure 3, methicillin-resistant Staphylococcus aureus or MRSA was found to be only 57.7% in 2003 (Figure 4). S. aureus has a significant pathogen causing morbidity and mortality in patients. MRSA is the same as those of antibiotic-sensitive S. aureus.
Complications of Open Arterial Vascular Surgery
Stephen M. Cohn, Matthew O. Dolich in Complications in Surgery and Trauma, 2014
The incidence of aortic graft infection is less than 5% [25]. It is higher in emergency cases or those where the graft extends to the groins [26]. Symptoms can range from sepsis to anastomotic pseudoaneurysms to non-specific complaints such as malaise and weight loss. For late presentation, a CT scan is helpful in the diagnosis, whereas in early infections, CT scan is not as helpful. The most common organism is Staphylococcus spp. Staphylococcus epidermidis causes more indolent late appearing infections. Staphylococcus aureus can cause acute or more chronic infections. Preventive measures include careful sterile technique, prophylactic antibiotics, and extensions to the groins only when necessary. A variety of treatment options have been devised for aortic graft infection [27], ranging from total graft excision with axillobifemoral bypass, replacement of the graft with homograft or superficial femoral vein grafts, to a combination of serial debridements, antibiotic beads placements, and eventual muscle flaps for infections localized to the groins. Mortality and morbidity in terms of limb loss remain very high. Choice of treatment depends on time of presentation, systemic manifestations, degree of ischemia, and the microbiology of the infection.
Prosthetic Device Infections in the Elderly
Thomas T. Yoshikawa, Shobita Rajagopalan in Antibiotic Therapy for Geriatric Patients, 2005
Key Points:• The pathogenesis of prosthetic device infection, an increasing problem due to the expanding use of implanted devices in the elderly, involves microbial virulence factors as well as impairment in host defenses. • Central nervous system shunt infections usually require removal of the device, reimplantation (often after a period of external drainage), and prolonged antibiotic administration. • The diagnosis of prosthetic joint infection is suggested by clinical, radiographic, and laboratory features; standard treatment (two-stage exchange arthroplasty) may be modified to debridement and long-term antibiotic therapy in selected elderly patients. • Prosthetic valve endocarditis can be difficult to diagnose in the elderly. Curative treatment always requires prolonged antibiotic therapy and often replacement of the prosthetic valve; transesophageal echocardiography provides improved diagnostic accuracy in selected patients. • Infected vascular grafts, pacemakers, and defibrillators may involve either endovascular or extravascular aspect of the device and provide unique challenges in diagnosis and treatment. While each type of prosthetic device has its own pattern of pathogens, staphylococci are particularly important. A balance between bacterial virulence factors and host resistance accounts for the frequency of these infections. Virulence factors include tissue and microbial adherence molecules and foreign body surface biofilm formation. Staphylococcus aureus has been well studied in this regard. It produces several adhesins which attach to fibrinogen (important in endovascular infections) and fibronectin (important in tissue infections). The specific gene cluster for adhesin production has been described and is shared by several strains (1). Biofilm is a mixture of microbial products (mostly carbohydrates) and host proteins and is largely responsible for the failure of antimicrobials and host defenses to clear organisms from the infected device. Host response to device infection is abnormal in that neutrophil and monocyte function are inhibited by contact with the device surface. Endothelialization of endovascular devices (a process which usually takes 1-3 months) appears to decrease the likelihood of infection. T-cell function and platelet adherence may be abnormal when exposed to grafts or devices. Whether or not the waning of host immunity with aging increases the likelihood and virulence of device infections in the elderly is unknown. It is possible that the frequency of such infections in the elderly is simply a reflection of the increasing use of devices for degenerative diseases. All of these factors emphasize the importance of optimal antibiotic therapy for prosthetic device infections in the elderly. The clinical aspects of these device infections, including their diagnosis, treatment, and prevention, are described.
Staphylococcus aureus bacteraemia in children: a formidable foe
Published in Southern African Journal of Anaesthesia and Analgesia, 2015
T Pretorius, B Brennan, J Thomas
Staphylococcus aureus remains one of the most common causes of bacteraemia in children. In order to evade and overcome the immune responses of its host and any antimicrobial therapies aimed at destroying it, this organism, through various mechanisms, continues to evolve. Staphylococcus aureus bacteraemia is a systemic disease; and, multiple organ involvement should be assessed and appropriately managed. This is especially important for the anaesthetist who will be administering general anaesthesia to children presenting for surgical source control.
Staphylococcal alpha-toxin tilts the balance between malignant and non-malignant CD4
Published in OncoImmunology, 2019
Edda Blümel, Andreas Willerslev-Olsen, Maria Gluud, Lise M. Lindahl, Simon Fredholm, Claudia Nastasi, Thorbjørn Krejsgaard, Bas G. J. Surewaard, Sergei B. Koralov, Tengpeng Hu, Jenny L. Persson, Charlotte Menné Bonefeld, Carsten Geisler, Lars Iversen, Jürgen C. Becker, Mads Hald Andersen, Anders Woetmann, Terkild Brink Buus, Niels Ødum
Staphylococcus aureus is implicated in disease progression in cutaneous T-cell lymphoma (CTCL). Here, we demonstrate that malignant T cell lines derived from CTCL patients as well as primary malignant CD4+ T cells from Sézary syndrome patients are considerably more resistant to alpha-toxin-induced cell death than their non-malignant counterparts. Thus, in a subset of Sézary syndrome patients the ratio between malignant and non-malignant CD4+ T cells increases significantly following exposure to alpha-toxin. Whereas toxin-induced cell death is ADAM10 dependent in healthy CD4+ T cells, resistance to alpha-toxin in malignant T cells involves both downregulation of ADAM10 as well as other resistance mechanisms. In conclusion, we provide first evidence that Staphylococcus aureus derived alpha-toxin can tilt the balance between malignant and non-malignant CD4+ T cells in CTCL patients. Consequently, alpha-toxin may promote disease progression through positive selection of malignant CD4+ T cells, identifying alpha-toxin as a putative drug target in CTCL.
The newly filed patent applications for vaccines against staphylococcus aureus
Published in Human Vaccines & Immunotherapeutics, 2017
Staphylococcus aureus (S. aureus) frequently causes life threatening disease. To release the threat, vaccine has been proposed as a preventive intervention against the cause. However, the development of the vaccines is still in early stages. Thus, highlighting the related newly filed patent applications would stimulate further developments.
Related Knowledge Centers
- Methicillin
- Penicillin Binding Proteins
- Vancomycin Resistance
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- Glycopeptide
- Staphylococcus
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