Changes in the conjunctival bacterial flora of patients hospitalized in an intensive care unit / Mudanças na flora bacteriana conjuntival de pacientes internados em unidade de terapia intensiva

ABSTRACT Purpose: To identify the changes in aerobic conjunctival bacterial flora and to correlate culture results with physical health and the duration of patients' hospitalization in an intensive care unit (ICU). Methods: Patients hospitalized in the ICU were included in this study. Conjunctival cultures from all patients were obtained using a standard technique on days 1, 3, 7, and 14. Swabs were plated on nonselective (blood agar) and enriched (chocolate agar) media within one hour. Visible colonies were isolated, and standard microbiological techniques were used to identify the bacteria. The frequency, identity, and correlation of culture results with patients' physical findings and the duration of hospitalization were determined. Results: We obtained 478 cultures (day 1, 270; day 3, 156; day 7, 36; and day 14, 16) from 135 patients; 288 (60.2%) cultures were positive, and 331 microorganisms were isolated. The most frequently isolated microorganism from the cultures was coagulase-negative Staphylococcus species (n=210/331, 63.5%), and the others were Corynebacterium diphtheriae (n=52/331, 15.7%), S. aureus (n=26/331, 7.9%), gram-negative bacilli other than Pseudomonas (n=14/331, 4.2%), Neisseria species (n=8/331, 2.4%), Pseudomonas aeruginosa (n=6/331, 1.8%), Haemophilus influenzae (n=7/331, 2.1%), Acinetobacter species (n=6/331, 1.8%), and Streptococcus species (n=2/331, 0.6%). The frequency of positive cultures significantly increased (p<0.03) with time. Conclusions: Prolonged hospitalization significantly predisposes to bacterial colonization. The colonization rate of S. aureus and Neisseria spp. increased significantly after one week.

RESUMO Objetivo: Identificar as mudanças na flora bacteriana aeróbia da conjuntiva e correlacionar os resultados da cultura com o estado de saúde física e a duração da hospitalização em pacientes em uma unidade de terapia intensiva (UTI). Método: Pacientes que estavam na UTI foram incluídos neste estudo. Culturas conjuntivais foram obtidas nos dias 1, 3, 7 e 14 de todos os pacientes com uma técnica normalizada. Zaragatoas foram semeadas em placas não seletivas (ágar sangue) e enriquecidas (ágar chocolate) dentro de uma hora. Colônias visíveis foram separadas, isoladas, e identificadas utilizando técnicas microbiológicas convencionais. A frequência, identificação e correlação da cultura resulta com achados físicos e a duração da hospitalização foram determinados. Resultados: Um total de 478 culturas (no primeiro dia 270, terceiro dia 156, sétimo dia 36 e dia catorze 16 culturas) foram obtidas de 135 pacientes hospitalizados durante o estudo. Duzentos e oitenta e oito (60,2% de todas as culturas obtidas) culturas foram positivas. Trezentos e trinta e um microrganismos foram isolados a partir dessas culturas. Em todos os grupos, o microrganismo mais frequentemente isolado foi o Staphylococcus species coagulase negativo (n=210/331, 63,5% de todos os microrganismos isolados). Outras bactérias isoladas foram Corynebacterium diphteriae (n=52/331, 15,7%), Staphylococcus aureus (n=26/331, 7,9%), bacilos Gram-negativos que não sejam Pseudomonas (n=14/331, 4,2%), Neisseria species (n=8/331, 2,4%), Pseudomonas aeruginosa (n=6/331, 1,8%), Haemophilus influenzae (n=7/331, 2,1%), Acinetobacter species (n=6/331, 1,8%), e Streptococcus species (n=2/331, 0,6%). Como o tempo de hospitalização prolongada, a positividade em culturas aumentou significativamente (p<0,03). Conclusões: hospitalização prolongada predispõe significativamente a frequência de colonização bacteriana. A taxa de colonização de S. aureus e Neisseria spp. aumentou significativamente depois de uma semana.

The Evaluation of the Combination of Caspofungin with Voriconazole and Amphotericin B against Clinical Candida krusei Isolates by Etest and Disk Diffusion Methods.

Background: C. krusei is an opportunistic fungal pathogen that known of its intrinsic fluconazole resistance and its frequency is increasing especially among hematology patients. The increase in the frequency of high mortality fungal infections have accelerated the efforts of new drug development with broad spectrum, low toxicity and the studies including their combination. However, there is no standardized method to evaluate the activity of drug combinations. Aims: To evaluate the activity of caspofungin (CAS) with voriconazole (VOR) and amphotericin B (AMB) alone and in combination and the utility of Etest and disk diffusion methods for antifungal combinations. Methodology: The minimum inhibitory concentrations of VOR, CAS and AMB against 30 clinical C. krusei isolates were determined by using Etest, disk diffusion and reference broth microdilution methods. Combinations of CAS with VOR and CAS with AMB were evaluated using disk diffusion (three different ways) and Etest (two different ways) methods. Results: All isolates tested were susceptible to VOR and CAS in vitro by all three methods. Categorical agreements of Etest and disk diffusion methods with reference microdilutiontest were 100% for CAS and VOR (for each method), 86.7% and 50% for AMB, respectively. In the all ways of both combination methods, we did not observe distinctly antagonistic or synergic interaction. Conclusion: Etest and disk diffusion could be easy, convenient, and nontime-consuming alternative methods to evaluate the antifungal combinations. The combinations of CAS with VOR and AMB exhibited promising results because of an apparent antagonistic interaction was not detected in this study.