Characterization of coagulase-negative staphylococcal isolates from blood with reduced susceptibility to glycopeptides and therapeutic options

Abstract

BackgroundCoagulase-negative staphylococci (CoNS) are a major cause of nosocomial blood stream infection, especially in critically ill and haematology patients. CoNS are usually multidrug-resistant and glycopeptide antibiotics have been to date considered the drugs of choice for treatment. The aim of this study was to characterize CoNS with reduced susceptibility to glycopeptides causing blood stream infection (BSI) in critically ill and haematology patients at the University Hospital Tor Vergata, Rome, Italy, in 2007.MethodsHospital microbiology records for transplant haematology and ICU were reviewed to identify CoNS with elevated MICs for glycopeptides, and isolates were matched to clinical records to determine whether the isolates caused a BSI. The isolates were tested for susceptibility to new drugs daptomicin and tigecycline and the genetic relationship was assessed using f-AFLP.ResultsOf a total of 17,418 blood cultures, 1,609 were positive for CoNS and of these, 87 (5.4%) displayed reduced susceptibility to glycopeptides. Clinical review revealed that in 13 cases (7 in haematology and 6 in ICU), CoNS with reduced susceptibility to glycopeptides were responsible for a BSI. Staphylococcus epidermidis was the causative organism in 11 instances and Staphylococcus haemolyticus in 2. The incidence of oxacillin resistance was high (77%), although all isolates remained susceptible to linezolid, daptomycin and tigecycline. Fingerprinting of CoNS identified one clonal relationship between two isolates.ConclusionMulti-resistant CoNS with reduced susceptibility to glycopeptides, although still relatively infrequent in our hospital, are emerging pathogens of clinical concern. Surveillance by antibiotyping with attention to multi-resistant profile, and warning to clinicians, is necessary.

Teicoplanin non-susceptible coagulase-negative staphylococci in a large Australian healthcare network: Implications for treatment with vancomycin

“…CoNS are now the second most common cause of prosthetic valve endocarditis after S. aureus and one of the most frequent pathogens isolated from deep-seated prosthetic implant infections. 4,5 CoNS have also become one of the most common causes of bacteraemia in immunosuppressed patients. 2 Treatment of CoNS infections can be challenging owing to the frequent presence of foreign materials and increasing antimicrobial resistance.…”

Vancomycin resistant coagulase-negative Staphylococcal isolates from HIV positive patients in the Limpopo Province, South Africa

“…In a study by Froggatt et al (1989), 42% of S. haemolyticus isolates were intermediately resistant (MIC 6.25 g/ml) to vancomycin. Kimberly et al (2003) in a study involving 321 coagulasenegative staphylococci, reported that a 3.9% of the CNS isolates had decreased vancomycin susceptibility while Natoli et al (2009) reported a prevalence of 5.4% of CNS with reduced susceptibility to glycopeptides. Del et al (1999) evaluated the antimicrobial susceptibility of 239 CNS isolated from blood samples and reported that all isolates were susceptible to vancomycin.…”

“…Glycopeptides have traditionally been considered as the drug of choice in the treatment of infections caused by these organisms. Since the first report of teicoplainin resistance in methicillin-resistance CNS in the USA and UK, the emergence of glycopeptides-resistant CNS in patients treated for long period with vancomycin has been increasingly documented (Aritaka et al, 1997;Smith et al, 1999;Natoli et al, 2009 (Cunnigngham, 1993;Obi et al, 2003). In Limpopo Province, Peltophorum africanum, Carissa edulis, Securidaca spp.…”

Is There Clinical Significance to Coagulase-Negative Staphylococci Isolated from Blood Cultures?

“…Vankomisin ve teikoplanin, klinisyenlerce metisiline dirençli stafilokok infeksiyonlarının tedavisinde en çok tercih edilen antibiyotiklerdir. Ancak son zamanlarda glikopeptid grubu antibiyotiklere duyarlılığı azalmış kökenler bildirilmektedir [8][9][10][11] . Asaad ve arkadaşları vankomisin, daptomisin ve teikoplanine direnç oranlarını sırasıyla %98.7, %98.7 ve %93.3 olarak bildirmişlerdir [10] .…”