Variability of cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant bacteria in two Brazilian intensive care units

Abstract

Objective:To compare cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant organisms in two intensive care units.Methods:A prospective cohort study was performed in adult intensive care units of two hospitals in Belo Horizonte, Brazil (April 2012 to February 2013). Clinical and demographic data were first collected by reviewing patients’ charts. Then, samples collected with nasal, groin, and perineum swabs were cultivated in selective media for 48 h at 37°C. After isolation, determination of antimicrobial susceptibility and biochemical identification were performed.Results:A total of 53 cases of colonization were observed by the following bacteria in decreasing frequencies: imipenem-resistant Acinetobacter baumannii (50.9%), vancomycin-resistant Enterococcus faecalis (43.4%), extended-spectrum beta-lactamase–producing Klebsiella pneumoniae (37.7%), imipenem-resistant Pseudomonas aeruginosa (32.1%), oxacillin-resistant Staphylococcus aureus (7.5%), and imipenem-resistant Klebsiella pneumoniae (5.7%). Among these colonization cases, 26 (49.0%) were followed by infection with bacteria phenotypically similar to those of the colonization. A relation between high population levels of colonization by most of the multidrug-resistant organisms at anatomical sites and a subsequent infection was observed. After colonization/infection, bacterial population levels decreased progressively and spontaneously until disappearance by day 45 in all the anatomical sites and for all the multidrug-resistant organisms.Conclusion:There was a correlation between high population levels of colonization by multidrug-resistant organisms at anatomical sites and a subsequent infection. Reduction in multidrug-resistant organism populations after colonization at anatomical sites could be a preventive measure to reduce evolution to infection as well as transmission of these bacteria between patients in intensive care unit.

Activity of antimicrobial peptides and conventional antibiotics against superantigen positive Staphylococcus aureus isolated from patients with atopic dermatitis

“…In the present study 17.5% of isolated strains were resistant to mupirocin, which is comparable with other report [ 37 ]. Although studies have reported resistance to the newer antimicrobial agents such as linezolid and vancomycin [ 38 ], in the present study none of the isolates were resistant to these antibiotics.…”

Fatores associados à colonização axilar por microrganismo resistente em pacientes na unidade de terapia intensiva

“…Na avaliação da microbiota de populações saudáveis, a mucosa nasal e a virilha foram identificadas entre os pontos mais consistentes em relação à composição e à estrutura da comunidade microbiana em um estudo de caracterização da variação temporal da microbiota 21 .…”

“…Os bacilos gram-negativos são amplamente descritos na literatura como um dos principais microrganismos causadores de colonização e infecção nas instituições hospitalares. Vários estudos têm relatado a presença desse microrganismo, com cepas resistentes, presentes na pele de pacientes hospitalizados em UTI, com destaque para recuperação desses microrganismos nas regiões de virilha e em poucos estudos relatando a presença na axila 20,21,23,24 .…”

“…O uso prévio de antimicrobianos tem sido identificado como um importante fator de risco para a aquisição de microrganismos resistentes. Estudos relataram que as principais características relacionadas à colonização por gram-positivo, em especial ao MRSA, foram o uso de fluoroquinolonas e glicopeptídeo de forma inapropriada e sem critério, e na colonização por VRE, destacou-se o uso de glicopeptídeo prévio 12,18,21,24 .…”

“…A permanência de um patógeno como colonizador pode implicar a possibilidade de desfecho de infecção, dependendo das condições imunológicas do paciente, e de associação com outros fatores preditivos das infecções, devido a aspectos do microrganismo, como virulência e carga microbiana, ou da resposta imune do hospedeiro 17,20,21 .…”