Daptomycin and vancomycin non-susceptible methicillin-resistant Staphylococcus aureus clonal lineages from bloodstream infection in a Brazilian teaching hospital

ABSTRACT Introduction: This study aimed to characterize Staphylococcus aureus isolates from bloodstream infections in patients attending a teaching hospital, between 2011 and 2015. Methods: The minimum inhibitory concentration for daptomycin, linezolid, oxacillin, teicoplanin, vancomycin, and trimethoprim/sulfamethoxazole was accessed by broth microdilution. SCCmec type and clonal profile were determined by molecular tests. Vancomycin heteroresistance was evaluated using screening tests and by population analysis profile/area under the curve. Results: Among 200 S. aureus isolates, 55 (27.5%) were MRSA, carrying SCCmec II (45.5%) or IV (54.5%). The most frequent MRSA lineages were USA100 (ST5-II) (45.5%) and USA800 (ST5-IV) (30.9%). Six isolates were confirmed as vancomycin heteroresistant, showing area under the curve ratio 1.1, 1.2 or 1.3 (four USA100, one USA800 and one USA1100 isolates). Conclusions: Daptomycin and vancomycin non-susceptible MRSA clonal lineages were found in bloodstream infections over five years, highlighting the importance of continuous surveillance of multiresistant bacteria in hospitals.

Methicillin-resistant Staphylococcus aureus in HIV patients: Risk factors associated with colonization and/or infection and methods for characterization of isolates - a systematic review

Staphylococcus aureus is an important cause of infections and HIV-infected individuals are frequently susceptible to this pathogen. The aim of this study was to perform a systematic review to identify both the risk factors associated with colonization/infection by methicillin-resistant S. aureus in HIV patients and the methods used for characterization of isolates. An electronic search of articles published between January 2001 and December 2013 was first conducted. Among 116 studies categorized as being at a quality level of A, B or C, only 9 studies were considered to have high methodological quality (level A). The majority of these studies were retrospective (4/9 studies). The risk factors associated with colonization/infection by S. aureus were use of antimicrobials (4/9 studies), previous hospitalization (4/9 studies) and low CD4+ T lymphocyte counts (<200 cells/μl) (3/9 studies). Culture in mannitol salt agar (3/9 studies) and the latex agglutination test (5/9 studies) were the main methods used for bacterial phenotypic identification. Genotypic profiles were accessed by pulsed-field gel electrophoresis (6/9 studies) and USA300 was the most prevalent lineage (5/9 studies). Most isolates were resistant to erythromycin (3/9 studies) and susceptible to vancomycin (4/9 studies). Ultimately, use of antimicrobials and previous hospitalization were the main risk factors for colonization/infection by methicillin-resistant S. aureus in HIV-infected individuals. However, the numbers of evaluated patients, the exclusion and inclusion criteria and the characterization of the S. aureus isolates were not uniform, which made it difficult to establish the characteristics associated with HIV patients who are colonized/infected by S. aureus.

Genotypic study documents divergence in the pathogenesis of bloodstream infection related central venous catheters in neonates

OBJECTIVE: To investigate the pathogenesis of bloodstream infection by Staphylococcus epidermidis, using the molecular epidemiology, in high-risk neonates. METHODS: We conducted a prospective study of a cohort of neonates with bloodstream infection using central venous catheters for more than 24 h. "National Healthcare Safety Network" surveillance was conducted. Genotyping was performed by DNA fingerprinting and mecA genes and icaAD were detected by multiplex-PCR. RESULTS: From April 2006 to April 2008, the incidence of bloodstream infection and central venous catheter-associated bloodstream infection was 15.1 and 13.0/1000 catheter days, respectively, with S. epidermidis accounting for 42.9% of episodes. Molecular analysis was used to document the similarity among six isolates of bloodstream infection by S. epidermidis from cases with positive blood and central venous catheter tip cultures. Fifty percent of neonates had bloodstream infection not identified as definite or probable central venous catheter-related bloodstream infection. Only one case was considered as definite central venous catheter-related bloodstream infection and was extraluminally acquired; the remaining were considered probable central venous catheter-related bloodstream infections, with one probable extraluminally and another probable intraluminally acquired bloodstream infection. Additionally, among mecA+ and icaAD+ samples, one clone (A) was predominant (80%). A polyclonal profile was found among sensitive samples that were not carriers of the icaAD gene. CONCLUSIONS: The majority of infections caused by S. epidermidis in neonates had an unknown origin, although 33.3% appeared to have been acquired intraluminally and extraluminally. We observed a polyclonal profile between sensitive samples and a prevalent clone (A) between resistant samples. .

Identification of Enterococcus faecalis by PCR in saliva of pediatric patients / Identificação do Enterococcus faecalis por PCR em saliva de pacientes pediátricos

This study aimed to identify E. faecalis in saliva of patients that were divided into two groups: 10 patients with caries lesions and 10 caries-free patients. Material and methods: Saliva samples were collected with a sterile swab and inoculated in enterococcosel media for 48 hours. The positive samples were subcultured in broth agar - blood medium for storage and subsequent PCR analysis. The data were analyzed using the SPSS (÷2). Results: From the 20 cases included in the study, 3 were positive in the Enterococcosel medium, and both tests (culture and PCR) used confirmed that three of them belonged to the species E. faecalis. No samples were positive in Enterococcosel broth in the group of caries-free patients. From the three samples that were identified as Enterococcus in broth (positive bile esculin test), an amplified for E. faecalis PCR analysis (p > 0.005). Conclusion: Through the use of PCR, it was possible to identify the genus Enterococcus and the species E. faecalis in saliva of patients with carious lesions – the pathogen that may influence the prognosis of diseases of the oral cavity...

Este estudo objetivou identificar E. faecalis em saliva de pacientes que foram divididos em dois grupos: 10 pacientes com lesões de cárie e 10 livres de cárie. Material e métodos: Amostras de saliva foram coletadas com um swab estéril e inoculadas em meios Enterococcosel por 48 horas. As amostras positivas foram repicadas em meio de caldo de agar - sangue para armazenamento e análise de PCR subsequente. Os dados foram analisados utilizando o SPSS. Resultados: Dos 20 casos incluídos no estudo, três foram positivos no médio Enterococcosel e ambos os testes (cultura e PCR) utilizados confirmaram que três deles pertenciam à espécie E. faecalis. Nenhuma amostra foi positiva em caldo Enterococcosel no grupo de pacientes livres de cáries. A partir das três amostras que foram identificadas como Enterococcus em caldo (teste positivo esculina biliar), foram amplificados por análise de PCR para o E. faecalis (p>0.005). Conclusão: Através da utilização de PCR, foi possível identificar gênero Enterococcus e a espécie de E. faecalis em saliva de pacientes com lesões de cárie – o agente patogênico que pode influenciar o prognóstico de doenças da cavidade oral...

Tetracycline and trimethoprim/sulfamethoxazole at clinical laboratory: Can they help to characterize Staphylococcus aureus carrying different SCCmec types?

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to detect at the clinical practice. METHODS: We analyzed 140 MRSA isolates from inpatients to correlate the antimicrobial susceptibility with the SCCmec types. RESULTS: Type III (n = 63) isolates were more resistant to ciprofloxacin, clindamycin, cloramphenicol, erythromycin, gentamicin, and rifampin than type IV (n = 65) ones (p < 0.05). Moreover, type IV isolates were susceptible to tetracycline (100%) and trimethoprim/sulfamethoxazole (98%), while type III isolates presented resistance to them. CONCLUSIONS: In regions where these SCCmec types are prevalent, the detection of specific resistant phenotypes could help to predict them, mainly when there are no technical conditions to SCCmec typing.

Recurrent herpes simplex infections: laser therapy as a potential tool for long-term successful treatment / Herpes simplex recorrente: laser terapia como método alternativo para tratamento a longo prazo

Herpes simplex virus types 1 and 2 are the main infectious agents associated with oral and genital ulcerations. These infections are now widely recognized as sexually transmitted diseases. Among treatment options, low-level laser therapy (LLLT) has shown promising clinical results as a longer-lasting suppression therapy. Two clinical cases are described with recurrent labial herpes for which LLLT was used. Following treatment, both patients remained symptom free during the 17-month clinical follow-up period.

Os vírus do herpes simplex tipos 1 e 2 são os principais agentes infecciosos associados às ulcerações orais e vaginais. Estas infecções são amplamente reconhecidas como doenças sexualmente transmissíveis. Entre as opções de tratamento, o laser de baixa intensidade (LBI) mostrou resultados promissores como terapia de supressão de longa duração. Descrevemos dois casos clínicos com herpes labial recorrentes nos quais o LBI foi utilizado que permaneceram assintomáticos durante 17 meses de controle clínico.