Perfil microbiológico da colonização do sítio de inserção do cateter venoso central considerando dois curativos transparentes / Microbiological assessment of the colonization of a central venous catheter insertion site considering two transparent dressings

RESUMO: Modelo do Estudo: estudo transversal da fase prospectiva de um ensaio clínico. Objetivo: identificar os microrganismos e a sensibilidade antimicrobiana no sítio de inserção do cateter venoso central coberto pelo curativo gel de clorexidina ou pelo filme transparente de poliuretano. Metodologia: estudo transversal, descritivo, realizado com adultos críticos no período de abril a dezembro de 2014 em um hospital universitário no interior do estado de São Paulo. Imediatamente após a retirada do curativo, foi coletada amostra de swab da pele do sítio de inserção do cateter, semeado em placas de Agar sangue e Agar MacConkey e incubadas em estufas bacteriológicas a 35 °C. Nas amostras que apresen-taram crescimento bacteriano após 24 horas de incubação, foram realizados testes de sensibilidade aos antimicrobianos utilizando o equipamento automatizado Vitek II (Biomerieux®). Resultados: 45 pacientes fizeram uso do curativo gel de clorexidina e 47 utilizaram o filme transparente de poliuretano. No grupo com o curativo gel de clorexidina houve crescimento dos microrganismos Acinetobacter baumannii, Pseudomonas aeruginosa, Morganella morganii, Enterobacter cloacae, Staphylococcus aureus e Staphylococcus epidermidis em 13 amostras de swabs. O Staphylococcus aureusapresentou resistência a oxacilina. No grupo do filme transparente de poliuretano seis amostras foram positivas com o crescimento de Serratia marcescens, Acinetobacter baumannii, Staphylococcus epidermidis, Staphylococcus haemolyticus e Klebsiella pneumoniae, esta resistente a amicacina (Klebsiella pneumoniae carbapenemase - KPC). Conclusão: os resultados demonstram maior crescimento bacteriano no sítio de inserção do cateter venoso central coberto pelo curativo gel de clorexidina quando comparado ao filme transparente de poliuretano. (AU)

ABSTRACT: Study design: a prospective, cross-sectional study. Objectives: identify microbiological growth at the insertion site of the central venous catheter covered by a chlorhexidine impregnated dressing or a transparent polyurethane dressing, and identify antimicrobial sensitivity. Methods: immediately after dressing removal, a skin swab was collected from the catheter insertion site and seeded in blood agar plates and MacConkey agar, then incubated in bacteriological incubators at 35 °C. After 24 hours, the plates were analyzed to verify the presence of microbial growth. In the samples that displayed microbial growth, the identification and the sensitivity test were performed using the automated equipment Vitek II (Biomerieux®). Results: A total of 45 patients were treated with chlorhexidine impregnated dressing and 47 with transparent polyurethane dressing. In the chlorhexidine dressing group, 13 swabs samples presented with microbial growth of the following bacterial populations: Acinetobacter baumannii, Pseudomonas aeruginosa, Morganella morganii, Enterobacter cloacae, Staphylococcus aureus, and Staphylococcus epidermidis. Staphylococcus aureus presented resistance to oxacillin. In the transparent polyurethane dressing group, six samples were positive for the growth of Serratia marcescens, Acinetobacter baumannii, Staphylococcus epidermidis, Staphylococcus haemolyticus, and amikacin resistant Klebsiella pneumoniae (Klebsiella pneumoniaecarbapenemase - KPC). Conclusion: The results demonstrate higher bacterial growth in the chlorhexidine impregnated dressing compared to the transparent polyurethane dressing. (AU)

Is community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) an emerging pathogen among children in Brazil?

ABSTRACT Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is spreading worldwide, but little is known about the epidemiology of this pathogen in Brazil. Objective: To evaluate clinical and microbiological features of children with S. aureus infections admitted to a university hospital. Methods: This was a cross-sectional study evaluating the potential risk factors for CA-MRSA, and a retrospective cohort evaluating in-hospital clinical outcomes. To include patients with both community and hospital-associated infections, we screened the results of the microbiological laboratory tests from January 1, 2012, to December 31, 2016. According to the phenotype, we classified the isolates in Methicillin-Susceptible S. aureus (MSSA), Hospital-Associated Methicillin-Resistant S. aureus (HA-MRSA), and CA-MRSA. Clinical data were collected from the patients' medical records. Results: We identified 279 cases of S. aureus infections (MSSA = 163, CA-MRSA = 69, HA-MRSA = 41). Overall, the incidence density of CA-MRSA and MSSA infections increased while the HA-MRSA incidence density decreased over the study period. CA-MRSA infected patients were more likely to present with skin and soft tissue infections (OR: 2.83, 95%CI: 1.54-5.33, p < 0.001) and osteomyelitis (OR: 4.76; 95%CI: 1.16-22.71, p = 0.014) when compared to MSSA and HA-MRSA infections. Unadjusted case fatality rates were similar between MSSA-infected patients (3.14%, 5/159) and CA-MRSA infected patients (3.80%, 3/79, p = 0.792), while HA-MRSA infected patients were more likely to die in the hospital (12.20%, 5/41, p = 0.013). Conclusions: CA-MRSA is an emergent pediatric pathogen in Brazil. Our results highlight the relevance of choosing an appropriate initial antimicrobial drug for treating children with severe S. aureus infections.

In vitro activity of antimicrobial combinations against multidrug-resistant Pseudomonas aeruginosa

Introduction Pseudomonas aeruginosa isolates related to nosocomial infections are often resistant to multiple antibacterial agents. In this study, antimicrobial combinations were evaluated to detect in vitro synergy against clinical isolates of P. aeruginosa. Methods Four clinical P. aeruginosa isolates were selected at random among other isolates from inpatients treated at the public University hospital in Ribeirão Preto, SP, Brazil. Two isolates were susceptible to imipenem (IPM-S) and several other antimicrobials, while the other two isolates were imipenem and multidrug resistant (IPM-R). The checkerboard method was used to assess the interactions between antimicrobials. Results Combinations of imipenem or other anti-Pseudomonas drugs with complementary antibiotics, such as aminoglycosides, fosfomycin and rifampin, reached synergy rates of 20.8%, 50%, 62.5% and 50% for the two IPM-S and two IPM-R Pseudomonas isolates, respectively. Imipenem, piperacillin-tazobactam and ceftazidime yielded a greater synergy rate than cefepime or ciprofloxacin. Synergist combinations were more commonly observed when the complementary drug was tobramycin (65%) or fosfomycin (57%). Conclusions Some antibacterial combinations led to significant reductions of the minimum inhibitory concentrations of both drugs, suggesting that they could be clinically applied to control infections caused by multidrug-resistant P. aeruginosa. .