Caracterización molecular de carbapenemasas en el Perú durante el 2019 / Molecular characterization of carbapenemases in Peru during 2019

RESUMEN La resistencia a los carbapenémicos es un problema de salud pública. Este estudio presenta la identificación de enzimas carbapenemasas en Enterobacteriaceae, Pseudomonas spp. y Acinetobacter spp. presentes en cepas de 30 instituciones prestadoras de servicios de salud del Perú como parte del proceso de control de calidad en diagnósticos. La confirmación fenotípica e identificación enzimática se realizó utilizando la prueba de Blue CARBA y la prueba de sinergia con discos de ácido fenilborónico y ácido etilendiaminotetraacético/ácido mercaptoacético de sodio. Se identificaron 185 cepas con carbapenemasas: 78 en Enterobacteriaceae, 61 en P. aeruginosa y 46 en Acinetobacter spp. Los tipos de carbapenemasas identificadas fueron: blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-23, blaOXA-24, blaOXA-51 y la coproducción de blaVIM/IMP. Es importante reforzar la promoción del uso racional de antimicrobianos y la vigilancia epidemiológica en los nosocomios del país.

ABSTRACT Resistance to carbapenems is a public health problem. This study presents the identification of carbapenemase enzymes in Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. present in strains from 30 institutions that provide health services in Peru as part of the quality control process in diagnoses. Phenotypic confirmation and enzymatic identification were performed using the Blue CARBA test and the synergy test with phenylboronic acid and ethylenediaminetetraacetic acid/sodium mercaptoacetic acid discs. 185 strains with carbapenemases were identified: 78 in Enterobacteriaceae, 61 in P. aeruginosa and 46 in Acinetobacter spp. The types of carbapenemases identified were: blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-23, blaOXA-24, blaOXA-51 and the blaVIM/IMP co-production. It is important to strengthen the promotion of the rational use of antimicrobials and epidemiological surveillance in the country's hospitals.

Caracterización molecular de carbapenemasas en el Perú durante el 2019 / Molecular characterization of carbapenemases in Peru during 2019

RESUMEN La resistencia a los carbapenémicos es un problema de salud pública. Este estudio presenta la identificación de enzimas carbapenemasas en Enterobacteriaceae, Pseudomonas spp. y Acinetobacter spp. presentes en cepas de 30 instituciones prestadoras de servicios de salud del Perú como parte del proceso de control de calidad en diagnósticos. La confirmación fenotípica e identificación enzimática se realizó utilizando la prueba de Blue CARBA y la prueba de sinergia con discos de ácido fenilborónico y ácido etilendiaminotetraacético/ácido mercaptoacético de sodio. Se identificaron 185 cepas con carbapenemasas: 78 en Enterobacteriaceae, 61 en P. aeruginosa y 46 en Acinetobacter spp. Los tipos de carbapenemasas identificadas fueron: blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-23, blaOXA-24, blaOXA-51 y la coproducción de blaVIM/IMP. Es importante reforzar la promoción del uso racional de antimicrobianos y la vigilancia epidemiológica en los nosocomios del país.

ABSTRACT Resistance to carbapenems is a public health problem. This study presents the identification of carbapenemase enzymes in Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. present in strains from 30 institutions that provide health services in Peru as part of the quality control process in diagnoses. Phenotypic confirmation and enzymatic identification were performed using the Blue CARBA test and the synergy test with phenylboronic acid and ethylenediaminetetraacetic acid/sodium mercaptoacetic acid discs. 185 strains with carbapenemases were identified: 78 in Enterobacteriaceae, 61 in P. aeruginosa and 46 in Acinetobacter spp. The types of carbapenemases identified were: blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-23, blaOXA-24, blaOXA-51 and the blaVIM/IMP co-production. It is important to strengthen the promotion of the rational use of antimicrobials and epidemiological surveillance in the country's hospitals.

Contaminación ambiental por microorganismos multirresistentes y el efecto de la limpieza y desinfección en una unidad de cuidados intensivos / Environmental contamination by multi-resistant microorganisms and the effect of cleaning and disinfection in an intensive care unit / Contaminação ambiental por micro-organismos multirresistentes e o efeito de limpeza e desinfecção em unidade de terapia intensiva

Conocer el rol del medio ambiente es fundamental para evitar las infecciones intra-hospitalarias. Con ese objetivo, se planteó evaluar la prevalencia de contaminación ambiental por microorganismos multirresistentes (MMR) antes y después de la limpieza terminal de habitaciones de pacientes colonizados y establecer si la aparatología de uso común actuaba como reservorio de estos en la unidad de cuidados intensivos (UTI). Se obtuvieron muestras ambientales de las habitaciones, 48 h posteriores a la detección de colonización y luego de las limpiezas. Los resultados mostraron que luego de ambos procedimientos de limpieza se logró reducir de 28,2% a 2,6% la contaminación por Acinetobacter spp. multirresistente (AMR). También, se tomaron muestras de aparatología de uso común encontrándose entre 1,8 y 5,4% de contaminación por MMR. La limpieza y desinfección reducen significativamente la contaminación ambiental. Sin embargo, la colonización de equipos por MMR y el incumplimiento de precauciones universales representan una posibilidad de transmisión cruzada.

It is essential to understand the role of the environment in order to avoid intrahospital infections. To achieve this objective, this research proposes to assess the prevalence of the environmental contamination caused by multi-resistant microorganisms (MRM) before and after terminal disinfection in rooms with colonized patients, but also to establish whether the commonly used device acts as a reservoir of those micro-organisms in an intensive care unit (ICU). Environmental samples were obtained from the rooms, 48 hours after detecting colonization and also after the first and second final cleaning. The results showed that after both procedures, there was a reduction from 28.2% to 2.6% of contamination caused by multi-resistant Acinetobacter spp. (AMR). Samples from appliances and supplies were taken as well, in which case, between 1.8 and 5.4% of contamination levels induced by MMR were found. Cleaning and disinfecting significantly reduce environmental contamination. However, both MMR bacterial colonization and the lack of universal precautions enforcement represent a possibility of cross-transmission.

É essencial conhecer o papel do meio ambiente para evitar as infecções intra-hospitalares. Com esse objetivo, planejou-se avaliar a prevalência de contaminação ambiental por microorganismos multirresistentes (MMR) antes e depois da limpeza final dos quartos de pacientes colonizados e estabelecer se os aparelhos de uso comum atuavam como um reservatório deles na unidade de terapia intensiva (UTI). Obtiveram-se amostras ambientais dos quartos 48 horas após a detecção da colonização e logo após as limpezas finais. Os resultados mostraram que depois dos dois procedimentos de limpeza se obteve uma redução de 28,2% para 2,6% da contaminação por Acinetobacter spp. multirresistente (AMR). Foram obtidas também amostras de aparelhos de uso comum onde se encontraram entre 1,8% e 5,4% de contaminação por MMR. A limpeza e a desinfecção reduzem significativamente a contaminação ambiental. Contudo, a colonização de equipamentos por MMR e o não cumprimento de providências universais representam uma possibilidade de transmissão cruzada.

Adjustment of Modified Carbapenem Inactivation Method Conditions for Rapid Detection of Carbapenemase-Producing Acinetobacter baumannii

BACKGROUND: The existing modified carbapenem inactivation methods (mCIMs) recommended by the CLSI for detecting carbapenemase production have not been applicable for Acinetobacter baumannii. We evaluated the influence of matrices used in mCIMs and CIMTris on the stability of the disks for detecting carbapenemase producers and suggested optimal mCIM conditions for detecting carbapenemase-producing A. baumannii. METHODS: Seventy-three A. baumannii isolates characterized for antimicrobial susceptibility and carbapenemase encoding genes were tested for carbapenemase production using mCIM and CIMTris. The influence of the matrices (Tryptic soy broth [TSB] and Tris-HCl) used in these methods on the stability of the meropenem (MEM) disk was also evaluated. The mCIM conditions were adjusted to enhance screening sensitivity and specificity for detecting carbapenemase-producing A. baumannii. RESULTS: The matrices had an impact on the stability of the MEM disk after the incubation period (two or four hrs). TSB nutrient broth is an appropriate matrix for mCIM compared with Tris-HCl pH 7.6, which leads to the loss of MEM activity in CIMTris. The sensitivity and the specificity of the optimal mCIM were both 100%. CONCLUSIONS: We established optimal mCIM conditions for simple, accurate, and reproducible detection of carbapenemase-producing A. baumannii.

A Novel Mismatched PCR-Restriction Fragment Length Polymorphism Assay for Rapid Detection of gyrA and parC Mutations Associated With Fluoroquinolone Resistance in Acinetobacter baumannii

BACKGROUND: Mutations in the quinolone resistance-determining regions (QRDRs) of Acinetobacter baumannii DNA gyrase (gyrA) and topoisomerase IV (parC) are linked to fluoroquinolone (FQ) resistance. We developed a mismatched PCR-restriction fragment length polymorphism (RFLP) assay to detect mutations in the gyrA and parC QRDRs associated with FQ resistance in A. baumannii. METHODS: Based on the conserved sequences of A. baumannii gyrA and parC, two primer sets were designed for mismatched PCR-RFLP to detect mutations in gyrA (codons 83 and 87) and parC (codons 80 and 84) by introducing an artificial restriction enzyme cleavage site into the PCR products. This assay was evaluated using 58 A. baumannii strains and 37 other Acinetobacter strains that have been identified by RNA polymerase β-subunit gene sequence analysis.

Evaluation of Synergistic Effect of Combined Treatment with Linalool and Colistin on Multidrug-Resistant Acinetobacter baumannii to Expand Candidate for Therapeutic Option / 대한임상미생물학회지

BACKGROUND: Acinetobacter baumannii infection is a significant health problem worldwide due to increased drug resistance. The limited antimicrobial alternatives for the treatment of severe infections by multidrug-resistant A. baumannii (MDRAB) make the search for other therapeutic options more urgent. Linalool, the major oil compound in Coriandrum sativum, was recently found to have high antibacterial activity against A. baumannii. The purpose of this study was to investigate the synergistic effect of linalool and colistin combinations against MDRAB and extensively drug-resistant A. baumannii (XDRAB).METHODS: A total of 51 strains of A. baumannii clinical isolates, consisting of 10 MDRAB and 41 XDRAB were tested. We determined the minimum inhibitory concentration (MIC) of linalool for the test strains using the broth microdilution method and searched for interactions using the time-kill assay.RESULTS: The time-kill assay showed that the linalool and colistin combination displayed a high rate of synergy (92.1%) (by synergy criteria 2), low rate of indifference (7.8%), and a high rate of bactericidal activity (74.5%) in the 51 clinical isolates of A. baumannii. The synergy rates for the linalool and colistin combination against MDRAB and XDRAB were 96% and 92.1%, respectively. No antagonism was observed for the linalool and colistin combination.CONCLUSION: The combination of linalool and colistin showed a high synergy rate, which may be beneficial for controlling MDRAB infections. Therefore, this combination is a good candidate for in vivo studies to assess its efficacy in the treatment of MDRAB infections.

Season and Temperature Effects on Bloodstream Infection Incidence in a Korean Tertiary Referral Hospital / 대한임상미생물학회지

BACKGROUND: The weather has well-documented effects on infectious disease and reports suggest that summer peaks in the incidences of gram-negative bacterial infections among hospitalized patients. We evaluated how season and temperature changes affect bloodstream infection (BSI) incidences of major pathogens to understand BSI trends with an emphasis on acquisition sites.METHODS: Incidence rates of BSIs by Staphylococcus aureus, Enterococcus spp., Escherichia coli, Klebsiella pneumoniae, Acinetobacter spp., and Pseudomonas aeruginosa were retrospectively analyzed from blood cultures during 2008–2016 at a university hospital in Seoul, Korea according to the acquisition sites. Warm months (June–September) had an average temperature of ≥20℃ and cold months (December–February) had an average temperature of ≤5℃.RESULTS: We analyzed 18,047 cases, where 43% were with community-onset BSI. E. coli (N = 5,365) was the most common pathogen, followed by Enterococcus spp. (N = 3,980), S. aureus (N = 3,075), K. pneumoniae (N = 3,043), Acinetobacter spp. (N = 1,657), and P. aeruginosa (N = 927). The incidence of hospital-acquired BSI by Enterococcus spp. was weakly correlated with temperature, and the median incidence was higher during cold months. The incidence of community-onset BSI by E. coli was higher in warm months and was weakly correlated with temperature.CONCLUSION: We found seasonal or temperature-associated variation in some species-associated BSIs. This could be a useful information for enhancing infection control and public health policies by taking season or climate into consideration.

Role of Efflux Pump Gene adeIJK to Multidrug Resistance in Acinetobacter baumannii Clinical Isolates / 대한임상미생물학회지

BACKGROUND: The emergence of multidrug-resistant Acinetobacter baumannii as a nosocomial pathogen is one of the major public health problems. The aim of this study was to evaluate the role of an efflux pump gene adeJ for the multidrug resistance of A. baumannii clinical isolates.METHODS: Two groups (MDRAB and SAB) of A. baumannii clinical isolates were studied. The SAB group consisted of strains that did not meet the criteria of MDRAB and were susceptible to more categories of antibiotics than MDRAB. Antimicrobial susceptibility results obtained by VITEKII system were used in data analysis and bacterial group allocation. We performed real-time reverse transcription PCR to determine relative expression of adeJ. We compared relative expression of adeJ in comparison groups by considering two viewpoints: i) MDRAB and SAB groups and ii) susceptible and non-susceptible groups for each antibiotic used in this study.RESULTS: The mean value of relative expression of adeJ of MDRAB and SAB groups was 1.4 and 0.92, respectively, and showed significant difference (P=0.002). The mean values of relative expression of adeJ of susceptible and non-susceptible groups to the antibiotics cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem, tigecycline, piperacillin/tazobactam, ticarcillin/clavulanic acid, trimethoprim/sulfamethoxazole, piperacillin, and gentamicin showed statistically significant differences.CONCLUSION: The overexpression of adeIJK might contribute to the multi-drug resistance in A. baumannii clinical isolates. Further, the overexpression of adeIJK might be one of the factors contributing to the resistance to numerous antibiotics.

Effects of topical azithromycin, moxifloxacin, and povidone iodine on conjunctival bacterial flora in patients undergoing intravitreal injection / Os efeitos da azitromicina tópica, moxifloxacina e iodopovidona na flora bacteriana conjuntival em injeções intravítreas

ABSTRACT Purpose: To compare effects of 5% topical povidone iodine with prophylactic topical azithromycin and moxifloxacin on bacterial flora in patients undergoing intravitreal injection. Methods: A total of 132 patients were randomly assigned to receive treatment with azithromycin or moxifloxacin, or no treatment (control group). In total, 528 specimens were obtained at the time of admission, 4 days before intravitreal injection, 4 days after intravitreal injection, and 8 days after intravitreal injection. Samples were immediately sent to the microbiology laboratory for incubation. Results: The microorganism observed most frequently was coagulasenegative Staphylococcus (23.8%). When the results of samples obtained on Day 4 before injection were assessed, growth of coagulase-negative Staphylococcus was significantly lower in the moxifloxacin group, compared with controls (p=0.049). Acinetobacter baumannii continued to grow after administration of azithromycin (p=0.033). When the results of four days after intravitreal injection were evaluated, growth of coagulase-ne gative Staphylococcus was higher in controls, compared with patients who received azithromycin or moxifloxacin (p=0.004). Eradication rate was significantly higher in the moxifloxacin group than in the control group (p=0.001). Samples obtained on Day 8 after intravitreal injection showed similar levels of bacterial growth in all groups (p=0.217). Conclusion: Moxifloxacin was more effective than 5% povidone iodine in controlling the growth of conjunctival bacterial flora. Use of moxifloxacin in combination with 5% povidone iodine resulted in a synergistic effect.

RESUMO Objetivo: Comparar os efeitos de iodopovidona tópico a 5% com azitromicina e moxifloxacina profiláticas sobre a flora bacteriana em pacientes submetidos à injeção intravítrea. Métodos: Um total de 132 pacientes foram aleatoriamente designados para receber tratamento com azitromicina ou moxifloxacina ou nenhum tratamento (grupo controle). No total, 528 amostras foram obtidas no momento na admissão, 4 dias antes da injeção intravítrea, 4 dias após a injeção intravítrea e 8 dias após a injeção intravítrea. As amostras foram imediatamente enviadas para o laboratório de microbiologia para incubação. Resultados: O microorganismo mais frequentemente observado foi o Staphylococcus coagulase-negativo (23,8%). Quando os resultados das amostras obtidas no dia 4 antes da injeção foram avaliados, o crescimento do Staphylococcus coagulase-negativo foi significativamente menor no grupo mo xifloxacina, em comparação com os controles (p=0,049). Acinetobacter baumannii continuou a crescer após a administração de azitromicina (p=0,033). Quando os resultados de 4 dias após a injeção intravítrea foram avaliados, o crescimento do Staphylococcus coagulase-negativo foi maior no controle, em comparação com pacientes que receberam azitromicina ou moxifloxacina (p=0,004). A taxa de erradicação também foi significativamente maior no grupo moxifloxacina do que no grupo controle (p=0,001). As amostras obtidas no dia 8 após injeção intravítrea mostraram níveis semelhantes de crescimento bacteriano em todos os grupos (p=0,217). Conclusão: A moxifloxacina foi mais eficaz do que 5% de iodopovidona no controle do crescimento da flora bacteriana conjuntival. O uso de moxifloxacina em combinação com 5% de iodopovidona resultou em um efeito sinérgico.

High rate of detection of OXA-23-producing Acinetobacter from two general hospitals in Brazil

Abstract INTRODUCTION In recent decades, the prevalence of carbapenem-resistant Acinetobacter isolates has increased, and the production of oxacillinase (OXA)-type carbapenemases is the main mechanism underlying resistance. We evaluated OXA production from 114 Acinetobacter isolates collected between March and December 2013 from different clinical specimens of patients in two hospitals (Hospital 1 [n = 61] and Hospital 2 [n = 53]) located in Niterói, Rio de Janeiro, Brazil. We also evaluated the genetic diversity of OXA-producing isolates. METHODS All the isolates were identified through the automated system Vitek II and matrix-assisted laser desorption ionization-time of flight mass spectrometry MALDI-TOF MS as belonging to the A. baumannii-A. calcoaceticuscomplex. Antimicrobial susceptibility profiles were verified through agar diffusion tests. The presence of OXA-encoding genes was confirmed by PCR. The genetic diversity of isolates positive for carbapenemase production was analyzed through pulsed-field gel electrophoresis. RESULTS There was a high rate of resistance to carbapenems in the isolates (imipenem: 96%; meropenem: 92%) from both hospitals. Moreover, a high percentage (95.6%) of OXA-23-positive isolates was observed for both hospitals, indicating that this was the main mechanism of carbapenem-resistance among the studied population. In addition, most isolates (96.5%) were positive for bla OXA-51. A high genetic diversity and a few major genotypes were found among the OXA-23-positive isolates analyzed. Only intra-hospital dissemination was observed. CONCLUSIONS The elevated dissemination of bla OXA-23-like observed among Acinetobacter isolates from both the studied hospitals highlights the need for continuous epidemiological surveillance in these institutions.

Diversity of metallo-b-lactamase-encoding genes found in distinct species of Acinetobacter isolated from the Brazilian Amazon Region

BACKGROUND The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES The present study aimed to verify the occurrence of metallo-β-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.

Earliest identification of New Delhi metallo-ß-lactamase 1 (NDM-1) in Acinetobacter pittii in Brazil

Abstract We report the occurrence in Brazil of the bla NDM-1 gene in Acinetobacter pittii, prior to the previously described first reports regarding the species Providencia rettgeri and Enterobacter hormaechei. Clinical isolates were investigated by polymerase chain reaction followed by bidirectional sequencing, and species was confirmed by 16S rDNA sequencing and matrix-assisted laser desorption-ionization time-of-flight spectrometry. A. pittii carrying bla NDM-1 was confirmed in a patient with no national or international travel history, or transfer from another hospital. The findings warn of the possibility of silent spread of bla NDM-1 to the community.

Polymicrobial Keratitis of Pseudomonas aeruginosa, Acinetobacter baumannii, and Ochrobactrum anthropi

PURPOSE: To report polymicrobial keratitis involving Pseudomonas aeruginosa, Acinetobacter baumannii, and Ochrobactrum anthropi. CASE SUMMARY: A 53-year-old female complained of pain and secretion in her right eye, which started 6 weeks before her visit. She applied steroid ointment, which was received from the dermatologist, to her eyelid 7 days prior to her visit but this treatment worsened her symptoms. At the initial visit, the visual acuity of the right eye was light perception, and purulent secretions were observed. Using a slit lamp, severe conjunctival hyperemia, hypopyon, and a ring-shaped central corneal ulcer were observed. The anterior chamber and fundus were not observed due to corneal lesions but ultrasonography showed no intraocular inflammation. Infectious keratitis was suspected and cultured by corneal scraping. During the incubation period, 0.5% moxifloxacin, 2% voriconazole, and 1% cyclopentolate were administered. A total of 400 mg of moxifloxacin and 100 mg of doxycycline were given orally. In the primary culture, Pseudomonas aeruginosa and Acinetobacter baumannii were identified so 5% ceftazidime, which was sensitive for the antibiotic susceptibility results was further instilled. Thereafter, the keratitis improved but the keratitis again worsened while maintaining the topical treatment. A secondary culture was positive for Ochrobactrum anthropi. Treatment with 1.4% gentamicin, which was sensitive for the antibiotic susceptibility test was added and the keratitis improved. A conjunctival flap was performed because of the increased risk of perforation. CONCLUSIONS: We report polymicrobial keratitis involving Pseudomonas aeruginosa, Acinetobacter baumannii, and Ochrobactrum anthropi for the first time in the Republic of Korea.

Early Intravenous Colistin Therapy as a Favorable Prognostic Factor for 28-day Mortality in Patients with CRAB Bacteremia: a Multicenter Propensity Score-Matching Analysis

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) infection is associated with high mortality. One of the strategies to reduce the mortality in patients with CRAB infections is to use intravenous colistin early but the effect of this strategy has not been proven. Therefore, we investigated the association of early colistin therapy with 28-day mortality in patients with CRAB bacteremia. METHODS: This retrospective multicenter propensity score-matching analysis was conducted in the Korea by reviewing the medical records of adult patients with CRAB bacteremia between January 2012 and March 2015. Early colistin therapy was defined as intravenous colistin administration for > 48 hours within five days after the blood culture collection. To identify the risk factors associated with the 28-day mortality in CRAB bacteremia, the clinical variables of the surviving patients were compared to those of the deceased patients. RESULTS: Of 303 enrolled patients, seventy-six (25.1%) patients received early colistin therapy. The 28-day mortality was 61.4% (186/303). Fatal or rapidly-fatal McCabe classifications, intensive care unit admission, Sequential Organ Failure Assessment scores ≥ 8, vasopressor use, and acute kidney injury were statistically independent poor prognostic factors. Catheter-related infection and early colistin therapy (adjusted odds ratio [aOR], 0.45; 95% confidence interval [CI], 0.21–0.94) were independent favorable prognostic factors associated with 28-day mortality in patients with CRAB bacteremia. Early colistin therapy was still significantly associated with lower 28-day mortality in the propensity score-matching analysis (aOR, 0.31; 95% CI, 0.11–0.88). CONCLUSION: This study suggests that early colistin therapy might help reduce the mortality of patients with CRAB bacteremia.

Colistin, Hot Potato for the Therapy of Carbapenem-resistant Acinetobacter baumannii infections

No abstract available.

RND efflux pump systems in Acinetobacter, with special emphasis on their role in quorum sensing

Acinetobacter is an important opportunistic, multidrug resistant pathogen causing majority of nosocomial infections worldwide. The multidrug resistance is attributed by a plethora of efflux pumps and the overexpression of the same mediates export of antimicrobial agents. Quorum sensing (QS) is the cell-to-cell communication system in which bacteria produces specific signaling molecules which are transported out to the surrounding environment to communicate with other bacterial cells. It has been noticed that multidrug efflux pumps like resistance-nodulation-cell division (RND) efflux pumps play an important role in QS by exporting these signaling molecules. This review discusses various RND efflux pumps and the current understanding of the interrelationship of RND efflux pumps and QS in Acinetobacter spp. Studies demonstrate that RND efflux pumps could be considered as potential targets to block QS thereby reducing pathogenesis and antibiotic resistance. The known RND efflux pump-mediated quorum quenching strategies for Acinetobacter and other bacterial strains are discussed in detail. Finally, the prospective quorum quenching strategies targeting the transcriptional regulators of RND efflux pumps to inhibit multidrug efflux pumps are addressed.

Distribution of adeG, adeB, adeE, adeY, abeM, and adeJ Efflux Pump Genes in Clinical Isolates of Acinetobacter Species from Korea

BACKGROUND: The aim of the present study was to determine the frequency of six efflux pump genes in Acinetobacter clinical isolates collected from South Korean hospitals. METHODS: In this study, we used a total of 339 Acinetobacter strains, comprising 279 Acinetobacter calcoaceticus–Acinetobacter baumannii (ACB) complex and 60 non-ACB complex strains. We performed specific PCR assays to detect adeG, adeB, adeE, adeY, abeM, and adeJ, transporter genes of the multidrug efflux pumps AdeFGH, AdeABC, AdeDE, AdeXYZ, AbeM, and AdeIJK, respectively. RESULTS: Frequencies of six efflux pump genes varied according to the species of Acinetobacter. Frequencies of adeE, abeM, and adeJ between A. baumannii group and A. nosocomialis group were found to be significantly different. Significant differences were found in the frequencies of adeB, adeE, adeY, and adeJ among the susceptible A. baumannii (SAB), multidrug-resistant A. baumannii (MDRAB), and extensively drug-resistant A. baumannii (XDRAB) groups within the 154 strains of A. baumannii. The frequencies of efflux pump genes in imipenem-susceptible and imipenem-nonsusceptible groups were significantly different for adeB, adeY, and adeJ. The frequencies of efflux pump genes in ciprofloxacin-susceptible and ciprofloxacin-nonsusceptible groups were significantly different for adeB and adeY. No significant difference was found in the frequency of efflux pump genes among groups sampled from different regions of Korea, across 86 strains of A. baumannii collected in 2012. CONCLUSIONS: The frequencies of six efflux pump genes obtained in this study demonstrate the fundamental epidemiological feature of efflux pump genes in Korean Acinetobacter clinical isolates.

Antimicrobial Susceptibility of Microorganisms Isolated from Patients with Intraabdominal Infection in Korea: a Multicenter Study

Avaliação da contaminação por Acinetobacter spp. em uma unidade de terapia intensiva / Evaluation of contamination by Acinetobacter spp. in an intensive care unit / Evaluación de la contaminación por Acinetobacter spp. en una unidad de cuidados intensivos

Justificativa e Objetivos: A relevância clínica das Infecções Relacionadas à Assistência à Saúde (Iras) ocasionadas pelo Acinetobacter spp. e a confirmação da existência de cepas com multirresistência no meio hospitalar mostram a necessidade de se conhecer melhor a epidemiologia dessas infecções, a fim de auxiliar a implantação de medidas mais efetivas de prevenção e controle deste patógeno. Objetivou-se avaliar a diversidade fenotípica e o perfil de sensibilidade de Acinetobacter spp. isolados de pacientes internados, de mãos de profissionais e de superfícies inanimadas em uma Unidade de Terapia Intensiva de um hospital público da região sudeste do estado do Pará. Métodos: As coletas das superfícies e das mãos dos profissionais foram realizadas utilizando swabs umedecidos em soro fisiológico estéril e friccionados por meio de rolamento. Para análise dos dados, foram utilizadas técnicas de estatística descritiva por meio de distribuições absolutas e percentuais. Resultados: Das 163 amostras coletadas, 87 (53,4%) foram das superfícies, 47 (28,8%) dos pacientes e 29 (17,8%) das mãos dos profissionais. Em 28% observou-se o crescimento de bactérias Gram-negativas, sendo o Acinetobacter baumannii a cepa mais prevalente, estando presente nos isolados clínicos de pacientes e nas superfícies após o processo de limpeza. O A. baumannii apresentou-se resistente a todos os antimicrobianos testados. Conclusão: O A. baumannii foi a única espécie do gênero Acinetobacter a ser encontrada, sendo tais cepas resistentes a todos os antibióticos testados.(AU)

Background and Objectives: The clinical relevance of Healthcare Associated Infections caused by Acinetobacter spp. and the confirmation of the existence of strains with multi-resistance in the hospital environment show the need to know better the epidemiology of these infections, in order to help the implantation of more effective measures of prevention and control of this pathogen. The objective of this study was to evaluate the phenotypic diversity and the sensitivity profile of Acinetobacter spp. isolated from inpatients, hands of professionals and inanimate surfaces in an Intensive Care Unit of a public hospital in the southeast region of the state of Pará. Methods: The professionals' hands and surfaces were collected using swabs moistened in sterile saline and rubbed by rolling. Data analysis was performed using descriptive statistics techniques using absolute and percentage distributions. Results: Of the 163 samples collected, 87 (53.4%) came from the surfaces, 47 (28.8%) from the patients and 29 (17.8%) from the hands of professionals. Growth of Gram-negative bacteria was observed in 28%, being Acinetobacter baumannii the most prevalent strain, present in the clinical isolates of patients and on the surfaces after the cleaning process. A. baumannii was resistant to all antimicrobials tested. Conclusion: A. baumannii was the only species of the genus Acinetobacter to be found, being such strains resistant to all antibiotics tested.(AU)

Justificación y Objetivos: La relevancia clínica de las infecciones relacionadas con el cuidado de la salud ocasionadas por el Acinetobacter spp. y la confirmación de la existencia de cepas con multirresistencia en el medio hospitalario implican la necesidad de conocer mejor la epidemiología de esas infecciones, a fin de auxiliar en la implantación de medidas más efectivas de prevención y control de este patógeno. El objetivo de este estudio fue evaluar la diversidad fenotípica y el perfil de sensibilidad de Acinetobacter spp. aislados de pacientes hospitalizados, de las manos de profesionales y de superficies inanimadas en una Unidad de Cuidados Intensivos de un hospital público en la región sureste del estado de Pará. Métodos: Las colectas de las superficies y de las manos de los profesionales se realizaron utilizando hisopos humedecidos en suero fisiológico estéril y frotados por medio de rodamiento. El análisis de los datos se realizó mediante técnicas de estadística descriptiva utilizando distribuciones absolutas y porcentuales. Resultados: De las 163 muestras recogidas, 87 (53,4%) fueron de las superficies, 47 (28,8%) de los pacientes y 29 (17,8%) de las manos de los profesionales. El crecimiento de bacterias Gram-negativas se observó en el 28,0%, siendo Acinetobacter baumannii la cepa más prevalente en los aislados clínicos de los pacientes y en las superficies después del proceso de limpieza. A. baumannii fue resistente a todos los antimicrobianos probados. Conclusiones: El A. baumannii fue la única especie del género Acinetobacter encontrada, siendo tales cepas resistentes a todos los antibióticos probados.(AU)

The antimicrobial activity of ephedrine and admixture of ephedrine and propofol: an in vitro study / A atividade antimicrobiana de efedrina e da combinação de efedrina e propofol: um estudo in vitro

Abstract Introduction Propofol and Ephedrine are commonly used during anesthesia maintenance, the former as a hypnotic agent and the later as a vasopressor. The addition of propofol to ephedrine or administration of ephedrine before propofol injection is useful for decreasing or preventing propofol related hemodynamic changes and vascular pain. This in vitro study evaluated the antibacterial effect on common hospital-acquired infection pathogens of ephedrine alone or combined with propofol. Material and method The study was performed in two stages. In the first, the Minimum Inhibitory Concentration of propofol and ephedrine alone and combined was calculated for Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Pseudomonas aeruginosa, and a clinical isolate of Acinetobacter spp. at 0, 6, 12 and 24 h, using the microdilution method. In the second stage, the same drugs and combination were used to determine their effect on bacterial growth. Bacterial solutions were prepared at 0.5 MacFarland in sterile 0.9% physiological saline and diluted at 1/100 concentration. Colony numbers were measured as colony forming units.mL-1 at 0, 2, 4, 6, 8, 10 and 12th hours. Results Ephedrine either alone or combined with propofol did not have an antimicrobial effect on Escherichia coli, Enterococcus faecium, or Pseudomonas aeruginosa and this was similar to propofol. However, ephedrine alone and combined with propofol was found to have an antimicrobial effect on Staphylococcus aureus and Acinetobacter species at 512 mcg.mL-1 concentration and significantly decreased bacterial growth rate. Conclusion Ephedrine has an antimicrobial activity on Staphylococcus aureus and Acinetobacter species which were frequently encountered pathogens as a cause of nosocomial infections.

Resumo Introdução Propofol e efedrina são fármacos comumente usados durante a manutenção da anestesia, o primeiro como agente hipnótico e o segundo como vasopressor. A adição de propofol à efedrina ou a administração de efedrina antes da injeção de propofol é útil para diminuir ou prevenir alterações hemodinâmicas e dor vascular relacionadas ao propofol. Este estudo in vitro avaliou o efeito antibacteriano de efedrina, isolada ou em combinação com propofol, em patógenos comuns implicados em infecção hospitalar. Material e método O estudo foi feito em duas etapas. Na primeira, a concentração inibitória mínima (CIM) de propofol e de efedrina isolada e em combinação foi calculada para Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Pseudomonas aeruginosa e um isolado clínico de Acinetobacter spp às 0, 6, 12 e 24 horas, com o método de microdiluição. Na segunda etapa, o mesmo fármaco e sua combinação foram usados para determinar seus efeitos no crescimento bacteriano. As soluções bacterianas foram preparadas em soro fisiológico a 0,9% em 0,5 McFarland e diluídas a uma concentração de 1/100. Os números das colônias foram medidos como ufc.mL-1 às 0, 2, 4, 6, 8, 10 e 12 horas. Resultados Efedrina isolada ou em combinação com propofol não apresentou efeito antimicrobiano sobre E. coli, E. faecium ou P. aeruginosa, um resultado semelhante ao de propofol. Porém, efedrina isolada e em combinação com propofol apresentou efeito antimicrobiano sobre Staphylococcus aureus e Acinetobacter spp, em concentração de 512 mcg.mL-1, e redução significativa da taxa de crescimento bacteriano. Conclusão Efedrina tem atividade antimicrobiana em S. aureus e Acinetobacter spp, patógenos frequentemente identificados como causa de infecções nosocomiais.