Abstract In recent years, several studies have described the clinical impact of bacterial infection associated with transfusion of platelet concentrates (PCs). Among the blood components, PCs are responsible for the highest rates of bacterial contamination as well as septic transfusion reactions. We assessed antimicrobial susceptibility profile, resistance to methicillin (MRCoNS), and resistance to macrolides, lincosamides and streptogramins of group B (MLSB) of 16 coagulase-negative staphylococci (CoNS) isolates from an investigation in 691 PCs bags. We then compared conventional and automated phenotypic methods, disc diffusion test (DD) and VITEK(r) 2, respectively as well as phenotypic and genotypic methods (Polymerase Chain Reaction - PCR). All CoNS were susceptible to vancomycin. The disc diffusion test characterized 18.75% as MRCoNS and 37.5% with inducible resistance to MLSB (iMLSB), and with VITEK(r) 2, 6.3% and 31.25%, respectively. The mecA gene was detected in 18.75% and the erm gene in 31.25% of the isolates. In this study, we found equal percentage values between presence of the mecA gene by PCR and resistance to methicillin using cefoxitin by DD test, evidence of the erm gene by PCR, and iMLSB resistance by automation (VITEK(r) 2). Moreover, we identified three strains with beta-lactamase overproduction, and the occurrence of a bigger mistake was verified when automation was compared with DD test. And we observed that D-test was the most reliable for the detection of iMLSB resistance in Staphylococcus sp.

ABSTRACT The enhancement of anti-leukemia therapy and the treatment of infections caused by multidrug-resistant pathogens are major challenges in healthcare. Although a large arsenal of drugs is available, many of these become ineffective, and as a result, the discovery of new active substances occurs. Notably, triazenes (TZCs) have been consolidated as a promising class of compounds, characterized by significant biological activity, especially antiproliferative and antimicrobial properties. The aim of this study is the synthesis and characterization of a new triazenide complex of gold (I), as well as the in vitro assessment of its antiproliferative activity against the K562 cell line (Chronic Myeloid Leukemia), and antibacterial activity against bacterial isolates of biofilm-producing coagulase-negative staphylococci. The combination of TZC with gold metal tends to have a synergistic effect against all biofilm-producing isolates, with Minimum Inhibitory Concentration values (MIC) between 32 and 64 µg mL-1. It has also shown activity against K562 cell line, getting an IC50=4.96 µM. Imatinib mesylate (Glivec) was used as reference, with IC50=3.86 µM. To the best of our knowledge, this study represents the first report of the activity of a TZC complexed with gold ion in the oxidation state (I) against microorganisms that produce biofilm and K562 cells.

Platelet Concentrates (PCs) are the blood components with the highest rate of bacterial contamination, and coagulase-negative staphylococci (CoNS) are the most frequently isolated contaminants. This study investigated the biofilm formation of 16 contaminated units out of 691 PCs tested by phenotypic and genotypic methods. Adhesion in Borosilicate Tube (ABT) and Congo Red Agar (CRA) tests were used to assess the presence of biofilm. The presence of icaADC genes was assessed by means of the Polymerase Chain Reaction (PCR) technique. With Vitek(r)2, Staphylococcus haemolyticus was considered the most prevalent CoNS (31.25%). The CRA characterized 43.8% as probable biofilm producers, and for the ABT test, 37.5%. The icaADC genes were identified in seven samples by the PCR. The ABT technique showed 85.7% sensitivity and 100% specificity when compared to the reference method (PCR), and presented strong agreement (k = 0.8). This study shows that species identified as PCs contaminants are considered inhabitants of the normal skin flora and they might become important pathogens. The results also lead to the recommendation of ABT use in laboratory routine for detecting biofilm in CoNS contaminants of PCs.

CONTEXTO: A síndrome da pele escaldada estafilocócica é uma doença esfoliativa de pele. São raros os relatos desta síndrome causada por Staphylococcus aureusresistente à meticilina em neonatos, mas, quando presentes, exigem diagnóstico e tratamento rápidos para diminuir a morbidade e mortalidade. RELATO DE CASO: Uma menina recém-nascida prematura, pesando 1.520 g ao nascimento, com idade gestacional de 29 semanas e 4 dias, desenvolveu síndrome da pele escaldada estafilocócica no quinto dia de vida. As culturas de sangue coletadas no primeiro e quarto dias foram negativas, mas houve desenvolvimento de Pseudomonas aeruginosa e Enterococcus sp. (vancomicina sensível) na hemocultura realizada no dia do óbito (sétimo dia) e Pseudomonas aeruginosa e Serratia marcescens foram identificadas nas culturas de secreção da nasofaringe, nádega e da secreção abdominal. Na cultura do coto umbilical (sétimo dia), além desses dois bacilos Gram-negativos, foi isolado o Staphylococcus aureus resistente à meticilina. O diagnóstico da síndrome da pele escaldada estafilocócica foi baseado em critério clínico.

CONTEXT: Staphylococcal scalded skin syndrome is an exfoliative skin disease. Reports of this syndrome in newborns caused by methicillin-resistant Staphylococcus aureus are rare but, when present, rapid diagnosis and treatment is required in order to decrease morbidity and mortality. CASE REPORT: A premature newly born girl weighing 1,520 g, born with a gestational age of 29 weeks and 4 days, developed staphylococcal scalded skin syndrome on the fifth day of life. Cultures on blood samples collected on the first and fourth days were negative, but Pseudomonas aeruginosa and Enterococcus sp. (vancomycin-sensitive) developed in blood cultures performed on the day of death (seventh day), and Pseudomonas aeruginosa and Serratia marcescens were identified in cultures on nasopharyngeal, buttock and abdominal secretions. In addition to these two Gram-negative bacilli, methicillin-resistant Staphylococcus aureus was isolated in a culture on the umbilical stump (seventh day). The diagnosis of staphylococcal scalded skin syndrome was based on clinical criteria.

INTRODUÇÃO: Metalo-β-lactamases (MBL) têm sido reportadas em todo o mundo. MÉTODOS: Avaliamos o efeito inibitório do ácido mercaptopropiônico (AMP) sobre o crescimento bacteriano mediante a comparação entre a difusão em disco e a metodologia de diluição em caldo com a determinação da concentração inibitória mínima (CIM) entre cepas multirresistentes de Acinetobacter baumanni. RESULTADOS: O AMP inibiu o crescimento das cepas do presente estudo de maneira significativa. CONCLUSÕES: O uso do AMP pode afetar os resultados dos métodos de detecção fenotípica de MBL.

INTRODUCTION: Metallo-β-lactamase (MBL) has been reported all over the world. METHODS: The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. RESULTS: MPA significantly inhibited growth of the strains. CONCLUSIONS: The use of MPA can affect the results in phenotypic methods of MBL detection.

INTRODUÇÃO: Neste estudo, objetivou-se caracterizar a prevalência e o perfil de suscetibilidade de cepas de Staphylococcus coagulase negatives resistentes à oxacilina isoladas de culturas de sangue, em um hospital escola, localizado na Cidade de Santa Maria. Além disso, buscou-se comparar ao teste genotípico de referência, diferentes metodologias fenotípicas para a caracterização da resistência mediada pelo gene mecA. MÉTODOS: Após identificação (MicroScan® - Siemens), os isolados foram submetidos a testes de sensibilidade antimicrobiana a partir da difusão do disco e automação (MicroScan® - Siemens). A presença do gene mecA foi evidenciada através da técnica molecular de reação em cadeia da polimerase. RESULTADOS: A espécie prevalente foi Staphylococcus epidermidis (67%). O gene mecA foi detectado em 90% das cepas e conforme análise dos perfis de sensibilidade, observou-se um índice elevado de resistência a várias classes de antimicrobianos. Contudo, todos os isolados mostraram-se uniformemente sensíveis à vancomicina e tigeciclina. O disco de cefoxitina foi a metodologia fenotípica que melhor correlacionou-se com o padrão ouro. CONCLUSÕES: A análise da significância clínica de SCN isolados de hemoculturas e a detecção precisa da resistência à oxacilina representam fatores decisivos para a instituição correta da antibioticoterapia. Apesar da vancomicina constituir o tratamento usual na maioria dos hospitais brasileiros, tem a redução de seu emprego recomendada.

INTRODUCTION: This study aimed to characterize the prevalence and susceptibility profile to oxacillin-resistant Coagulase-negative Staphylococci strains isolated from blood cultures in a teaching hospital, located in Santa Maria, RS. In addition, different methodologies for phenotypic characterization of mecA-mediated oxacillin resistance were compared with genotypic reference testing. METHODS: After identification (MicroScan® - Siemens), the isolates were tested for antimicrobial sensitivity using disk diffusion and automation (MicroScan® - Siemens). The presence of mecA gene was identified by the polymerase chain reaction molecular technique. RESULTS: The most common species was Staphylococcus epidermidis (n=40, 67%). The mecA gene was detected in 54 (90%) strains, while analysis of the sensitivity profiles revealed a high rate of resistance to multiple classes of antimicrobial drugs. However, all isolates were uniformly sensitive to vancomycin and tigecycline. The cefoxitin disk was the phenotypic method that best correlated with the gold standard. CONCLUSIONS: Analysis of the clinical significance of CoNS isolated from hemocultures and the precise detection of oxacillin resistance represent decisive factors for the correct choice of antibiotic therapy. Although vancomycin constitutes the normal treatment in most Brazilian hospitals, reduction in its use is recommended.

INTRODUÇÃO: Devido à sepse bacteriana associada à transfusão de concentrados plaquetários (CPs) ter sérias consequências clínicas para os pacientes, alguns procedimentos têm sido incorporados na preparação e no controle de qualidade dos componentes sanguíneos para reduzir o risco da contaminação bacteriana. Este artigo descreve a prevalência da contaminação bacteriana dos CPs que foram transfundidos, o espectro bacteriano detectado com seu perfil de sensibilidade aos antimicrobianos e as reações transfusionais nos receptores. MÉTODOS: Um total de 292 CPs (278 randômicos e 14 por aférese), proveniente do Hemocentro do Estado do Rio Grande do Sul (HEMORGS) de Santa Maria foi testado. As quantidades de 100μL e 200μL foram coletadas da porção tubular da bolsa de plaquetas e semeadas utilizando dois tipos de metodologias. RESULTADOS: Em cinco unidades(1,7%; 5/292) foram isoladas bactérias pela metodologia qualitativa e apenas uma pela quantitativa. Staphylococcus epidermidis foi o microrganismo identificado em todas as amostras. Dois pacientes apresentaram sepse associada à transfusão com desfecho fatal. CONCLUSÕES: A contaminação bacteriana pelas transfusões de CPs constitui-se num importante problema de saúde pública devido a sua associação com altas taxas de morbidade e mortalidade. Neste estudo, somente microrganismos gram-positivos foram isolados sendo que nenhuma amostra obtida por aférese apresentou contaminação.

INTRODUCTION: Bacterial sepsis associated with the transfusion of platelet concentrates (PCs) results in serious clinical implications for patients. Given these implications, certain procedures have been integrated into the preparation and quality control of blood components to reduce the risk of bacterial contamination. This article describes the prevalence of bacterial contamination on transfused PCs, the bacterial spectrum detected and their antimicrobial susceptibility profile and transfusion reactions in receptors. METHODS: A total of 292 PCs (278 random and 14 per apheresis) from the Blood Center of the State of Rio Grande do Sul (HEMORGS), located in the city of Santa Maria, were tested. Quantities of 100μL and 200μL were collected from platelet bag tubing and seeded using two methodologies. RESULTS: Using the qualitative methodology, bacteria were isolated in five units (1.7%; 5/292), while only one was isolated using the quantitative methodology. Staphylococcus epidermidis was the microorganism identified in all samples. Two patients died of transfusion-related sepsis. CONCLUSIONS: Bacterial contamination due to PC transfusion is considered a major public health problem due to its association with high rates of morbidity and mortality. In this study only gram-positive microorganisms were isolated and none of the samples obtained by apheresis presented contamination.