Prevalence of antibiotic resistance and virulent factors in nosocomial clinical isolates of Pseudomonas aeruginosa from Panamá

ABSTRACT Background: Pseudomonas aeruginosa is an important causative agent of nosocomial infections. As pathogen, P. aeruginosa is of increasing clinical importance due to its ability to develop high-level multidrug resistance (MDR). Methods: The aim of the present study was to better understand the intrinsic virulence of circulating strains of Pseudomonas aeruginosa, by surveying and characterizing the antibiotic resistance profiles and prevalence of virulence factors in 51 clinical isolates of P. aeruginosa obtained from children admitted to Hospital del Niño-Panamá during the period of October 2016 until March 2017. Antimicrobial susceptibilities were assessed by determining the minimum inhibitory concentration for 12 antibiotics against P. aeruginosa clinical isolates using the VITEK system (https://www.biomerieux.com). Additionally, all isolates were examined by Polymerase Chain Reaction (PCR) for the presence of components of the MexAB-OprM efflux pump system (mexABR) and pyoverdine receptor genes and betalactamases resistance genes (ESBL) using gene-specific primers. Results: A total of 51 pyoverdine producing clinical isolates were analyzed, all of which expressed resistance genes such as genes of the MexAB-OprM efflux pump system (mexABR) and pyoverdine receptor genes (fpvA). Out of 51 MDR isolates, 22 were ESBL producers. The most common ESBL gene was blaTEM expressed by 43% of the isolates. The isolates tested in this study showed increased resistance to antibiotics in the following categories: (i) penicillins (ampicillin (69%), piperacillin (22%); (ii) pyrimethamines (trimethoprim, 65%); (iii) nitrofurans (nitrofurantoin, 63%), and (iv) third-generation cephalosporin cefotaxime (53%). These results underscore a high prevalence of MDR amongst clinical isolates from Panama. Conclusions: The present study indicates that prevalence of BlaTEM-carrying strains is increasing with subsequent multidrug resistance in Panamá and as well reported worldwide. The virulent factors identified in this study provide valuable information regarding the prevalence of resistance genes and their potential impact on treatments that exploit the unique physiology of the pathogen. To prevent further spread of MDR, the proportions of resistant strains of Pseudomonas aeruginosa should be constantly evaluated on healthcare institutions of Panamá. More importantly, this information can be used to better understand the evolution and dissemination of strains hoping to prevent the development of resistance in Pseudomonas aeruginosa. Future studies quantifying the expression of these virulent genes will emphasize on the acquisition of multidrug resistance.

Molecular epidemiology of Pseudomonas aeruginosa isolated from lower respiratory tract of ICU patients / Epidemiologia molecular de Pseudomonas aeruginosa isolada em pacientes com infecções do trato respiratório inferior admitidos em UTI

Lower respiratory tract infections (LRTIs) caused by Pseudomonas aeruginosa are the most common infection among hospitalized patients, associated with increased levels of morbidity, mortality and attributable health care costs. Increased resistant Pseudomonas worldwide has been quite meaningful to patients, especially in intensive care unit (ICUs). Different species of Pseudomonas exhibit different genetic profile and varied drug resistance. The present study determines the molecular epidemiology through DNA fingerprinting method and drug resistance of P. aeruginosa isolated from patients with LTRIs admitted in ICU. A total of 79 P. aeruginosa isolated from patients with LRTIs admitted in ICU were characterized by Restriction Fragment Length Polymorphism (RFLP), Random Amplified Polymorphic DNA (RAPD) and Repetitive Extrapalindromic PCR (REP-PCR). Antibiotic resistance was determined by minimum inhibitory concentration (MIC) assay while MDR genes, viz, blaTEM, blaOXA, blaVIM, blaCTX-M-15 were detected by polymerase chain reaction (PCR). Of the 137 Pseudomonas sp isolated from ICU patients, 57.7% of the isolates were reported to be P. aeruginosa. The overall prevalence of P. aeruginosa among the all included patients was 34.5%. The RAPD analysis yielded 45 different patterns with 72 clusters with 57% to 100% similarity level. The RFLP analysis yielded 8 different patterns with 14 clusters with 76% to 100% similarity level. The REP PCR analysis yielded 37 different patterns with 65 clusters with 56% to 100% similarity level. There was no correlation among the different DNA patterns observed between the three different methods. Predominant of the isolates (46.8%) were resistant to amikacin. Of the 79 isolates, 60.8% were positive for blaTEM gene and 39.2% were positive for blaOXA gene. P. aeruginosa was predominantly isolated from patients with LRTIs admitted in ICU. The difference in the similarity level observed between the three DNA fingerprinting methods indicates that there is high inter-strain variability. The high genetic variability and resistance patterns indicates that we should continuously monitor the trend in the prevalence and antibiotic resistance of P. aeruginosa especially in patients with LRTIs admitted in ICU.

Infecções do trato respiratório inferior (ITRIs) são as infecções mais comuns entre pacientes internados em unidade de terapia intensiva (UTI). Pseudomonas aeruginosa é a causa mais comum de ITRIs e está associada ao aumento da mortalidade. Diferentes espécies de Pseudomonas exibem diferentes perfis genéticos e resistência variada as drogas. O presente estudo determina a epidemiologia molecular através do método de fingerprinting de DNA e resistência as drogas de P. aeruginosa isoladas de pacientes com LTRIs internados em UTI. Um total de 79 P. aeruginosa isoladas de pacientes com ITRIs internados em UTI foram caracterizados por Polimorfismo de Comprimento de Fragmentos de Restrição (RFLP), DNA Polimórfico Amplificado ao Acaso (RAPD) e PCR Extrapalindrômico Repetitivo (REP-PCR). A resistência aos antibióticos foram determinadas pelos ensaios de concentrações inibitória mínima (MIC), enquanto os genes MDR, blaTEM, blaOXA, blaVIM, blaCTX-M-15 foram detectados pela reação em cadeia da polimerase (PCR). Das 137 Pseudomonas sp isoladas de pacientes de UTI, 57,7% dos isolados foram relatados como P. aeruginosa. A prevalência geral de P. aeruginosa entre os pacientes incluídos foram de 34,5%. A análise RAPD renderam 45 padrões diferentes com 72 clusters com nível de similaridade de 57% a 100%. A análise RFLP renderam 8 padrões diferentes com 14 clusters com 76% a 100% de similaridade. A análise de PCR do REP produziram 37 padrões diferentes com 65 clusters com nível de similaridade de 56% a 100%. Não houveram correlações entre os diferentes padrões de DNA observados entre os três diferentes métodos. Predominantes dos isolados (46,8%) eram resistentes à amicacina. Dos 79 isolados, 60,8% foram positivos para o gene blaTEM e 39,2% foram positivos para o gene blaOXA. P. aeruginosa foi predominantemente isolado de pacientes com ITRIs internados em UTI. A diferença no nível de similaridade observado entre os três métodos de fingerprinting do DNA indica que há alta variabilidade inter-strain. A alta variabilidade genética e os padrões de resistência indicam que devemos monitorar continuamente a tendência na prevalência e resistência a antibióticos de P. aeruginosa, especialmente em pacientes com ITRIs internados em UTI.

Brote en simultáneo de Pseudomona aeruginosa y Klebsiella pneumoniae BLEE en una Unidad de Cuidados Intensivos Neonatal de Asunción, Paraguay / Simultaneous outbreak of Pseudomonas Aeruginosa and ESBL producing-Klebsiella Pneumoniae in a Neonatal Intensive Care Unit of Asunción, Paraguay

Las Infecciones Asociadas a las Atenciones Sanitarias (IAAS), constituyen un serio problema de salud pública. Se describe un brote de IAAS en una Unidad de Cuidados Intensivos Neonatales de Asunción y las medidas de control implementadas. Estudio descriptivo de serie de casos, entre el 26 de marzo y el 18 de abril del 2013. Fueron utilizados datos secundarios como historias clínicas, registros de enfermería, certificados de defunción, resultados de bacteriología, registros de control de IAAS. El universo estuvo constituido por 12 neonatos, en cuatro se aislaron Pseudomona aeruginosa y en tres Klebsiella pneumoniae BLEE. Predomino el sexo masculino (6/7), la media de edad de 2 días (rango:2-45 días), la mayoría prematuros (5/7). Todos con procedimientos invasivos durante la hospitalización. La tasa global de ataque fue 58% (7/12), con una tasa de ataque para P. aeruginosa de 33 % (4/12) y para K. pneumoniae BLEE de 38 % (3/12). La mortalidad global fue 29% (2/12) y la tasa de la letalidad atribuible a la infección por P. aeruginosa fue del 50% (2/4). Las medidas de control del brote fueron el aislamiento de los pacientes infectados, una enfermera por paciente, se intensifico los cuidados de bioseguridad para procedimientos invasivos y lavado de manos; suspensión de pacientes remitidos hasta que se asegurar el corte de transmisión. Se confirmó dos brotes simultáneos con agentes etiológicos diferentes, P. aeruginosa y K. pneumoniae BLEE. Es necesario reforzar las medidas de control de infecciones y lavado correcto de manos, de manera a prevenir brotes de IAAS en la UCIN(AU)

Bacteriemia por Pseudomonas aeruginosa (PAE) en niños / Pseudomonas aeruginosa-associated bacteremia en children

Introducción. La bacteriemia por Pseudomonas aeruginosa (PAE) en niños es infrecuente. Objetivo.Describir las características epidemiológicas, clínicas, microbiológicas y evolutivas en niños con bacteriemia por PAE. Métodos. Estudio de cohorte retrospectivo. Resultados. Se incluyeron 100 pacientes (p). La mediana de edad fue de 27 meses (RIC 6-88).Tenían enfermedad de base: 93 p (93%) y 36 de ellos estaban neutropénicos. Ochenta y cinco p (85%) habían recibido antibióticos en el último mes, 60 (60%) tuvieron procedimientos invasivos previos y 81 (81%) tuvieron internaciones previas. Ingresaron con shock séptico 42 p (42%), 56 p (56%) fueron admitidos en unidad de cuidados intensivos (UCI) y 49 (49%) requirieron ventilación mecánica (VM). La bacteriemia fue primaria en 17 p (17%); asociada a catéter en 15 p (15%) y secundaria en 68 p (68%). El foco más frecuente fue mucocutáneo, 21 p, seguido por el pulmonar, 20 p. El tratamiento empírico fue adecuado en 84 p (84%). La resistencia a uno o más grupos de antibióticos se dio en el 38% de los casos, 11% fueron multirresistentes y 15% fueron resistentes sólo a carbapenemes. Fallecieron 31 p (31%). Pseudomonas aeruginosa resistente a carbapenemes en forma exclusiva o combinada con otros antibióticos se relacionó en esta serie a exposición previa a antibióticos, (p≤0,03), tratamiento empírico inicial inadecuado (p≤0,006) y mayor mortalidad (p≤0,01), prolongación de la internación y del tiempo de tratamiento (p≤0,001)

Introduction. Pseudomonas aeruginosa (PAE) associated bacteremia is uncommon in children. Objective. To describe the epidemiological, clinical, and microbiological features and outcome in children with PAE-associated bacteremia. Methods. A retrospective cohort study. Results. 100 patients (p) were included. Median age was 27 months (IQR 6-88). Overall 93 p (93%) had an underlying disease, 36 of whom had neutropenia. Eighty-five p (85%) had received antibiotics over the previous month, 60 (60%) had undergone previous invasive procedures, and 81 (81%) had been previously admitted. Forty-two p (42%) were admitted because of septic shock, 56 p (56%) were admitted to the intensive care unit (ICU), and 49 (49%) required mechanical ventilation (MV). Seventeen p (17%) had primary bacteremia, 15 p (15%) had catheter-related bacteremia, and 68 p (68%) had secondary bacteremia. The most common focus was mucocutaneous (21 p), followed by pulmonary (20 p). Emperical treatment was adequate in 84 p (84%). Resistance to one or more groups of antibiotics was observed in 38% of the cases; 11% were multiresistant and 15% were only resistant to carbapenems. Thirty-one p (31%) died. In our series, Pseudomonas aeruginosa resistant to carbapenems only or combined with other antibiotics was associated with previous exposition to antibiotics (p≤0.03), inadequate initial emperical treatment (p≤0.006), and higher mortality (p≤0.01), and longer hospital stay and treatment duration (p≤0.001)

Prevalence of metallo-ß-lactamase-encoding genes among carbapenem-resistant pseudomonas aeruginosa strains isolated from burn patients in Iran

Abstract Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has been considered a major cause of infection and mortality in burn patients, especially in developing countries such as Iran. One of the most common mechanisms of carbapenem resistance is production of metallo-β-lactamases [(MBLs), including Verona Integron-encoded Metallo-beta-lactamase (VIM), imipenemase (IMP), São Paulo metalo-beta-lactamase (SPM), German imipenemase (GIM), New Delhi metallo-beta-lactamase (NDM), Dutch imipenemase (DIM), Adelaide imipenemase (AIM), Seoul imipenemase (SIM), KHM, Serratia metallo-β-lactamase (SMB), Tripoli metallo-β-lactamase (TMB), and Florence imipenemase (FIM)]. Limited information is available on the prevalence of CRPA and MBLs in Iranian burn units. We performed a systematic search by using different electronic databases, including Medline (via PubMed), Embase, Web of Science, and Iranian Database. Of 586 articles published from January 2000 to December 2016, 14 studies reporting the incidence of CRPA and MBLs as detected by molecular methods in burn patients were included in this review. The meta-analyses showed that the prevalence of CRPA, IMP, and VIM was 76.8% (95% CI 67.5-84.1), 13.1% (95% CI 4.7-31.5), and 21.4% (95% CI 14.6-30.1), respectively, in Iranian burn centers and remaining MBLs types have not yet been detected. There was a high prevalence of MBLs and CRPA in Iranian burn centers. Therefore, these measurements should be applied nationally and rigorous infection control measures and antimicrobial stewardship will be the major pillars to control multidrug resistant microorganisms, such as CRPA.

Análise da produção de biofilme por isolados clínicos de Pseudomonas aeruginosa de pacientes com pneumonia associada à ventilação mecânica / Analysis of biofilm production by clinical isolates of Pseudomonas aeruginosa from patients with ventilator-associated pneumonia

RESUMO Objetivo: Avaliar fenotipicamente a produção de biofilme por isolados clínicos de Pseudomonas aeruginosa de pacientes com pneumonia associada à ventilação mecânica. Métodos: Foram analisados 20 isolados clínicos de P. aeruginosa, sendo 19 provenientes de amostras clínicas de aspirado traqueal e uma de lavado broncoalveolar. A avaliação da capacidade de P. aeruginosa em produzir biofilme foi verificada por duas técnicas, sendo uma qualitativa e outra quantitativa. Resultados: A técnica qualitativa mostrou que apenas 15% dos isolados foram considerados produtores de biofilme, enquanto que a quantitativa demonstrou que 75% dos isolados foram produtores de biofilme. Os isolados produtores de biofilme apresentaram o seguinte perfil de suscetibilidade: 53,3% eram multidroga-resistentes e 46,7% eram multidroga-sensíveis. Conclusão: A técnica quantitativa foi mais eficaz para detecção da produção de biofilme em comparação com a qualitativa. Para a população bacteriana analisada, a produção de biofilme independeu do perfil de suscetibilidade das bactérias, demonstrando que a falha terapêutica pode estar relacionada com a produção de biofilme, por impedir a destruição das bactérias presentes nesta estrutura, ocasionando complicações da pneumonia associada à ventilação mecânica, incluindo infecções extrapulmonares, e dificultando o tratamento da infecção.

ABSTRACT Objective: To phenotypically evaluate biofilm production by Pseudomonas aeruginosa clinically isolated from patients with ventilator-associated pneumonia. Methods: Twenty clinical isolates of P. aeruginosa were analyzed, 19 of which were from clinical samples of tracheal aspirate, and one was from a bronchoalveolar lavage sample. The evaluation of the capacity of P. aeruginosa to produce biofilm was verified using two techniques, one qualitative and the other quantitative. Results: The qualitative technique showed that only 15% of the isolates were considered biofilm producers, while the quantitative technique showed that 75% of the isolates were biofilm producers. The biofilm isolates presented the following susceptibility profile: 53.3% were multidrug-resistant, and 46.7% were multidrug-sensitive. Conclusion: The quantitative technique was more effective than the qualitative technique for the detection of biofilm production. For the bacterial population analyzed, biofilm production was independent of the susceptibility profile of the bacteria, demonstrating that the therapeutic failure could be related to biofilm production, as it prevented the destruction of the bacteria present in this structure, causing complications of pneumonia associated with mechanical ventilation, including extrapulmonary infections, and making it difficult to treat the infection.

Carbapenem-resistant Pseudomonas aeruginosa: association with virulence genes and biofilm formation

Abstract Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virulence genes in metallo-β-lactamases producers and to evaluate their ability to produce biofilm. We conducted a case–control study in the Uberlândia Federal University – Hospital Clinic, Brazil. Polymerase Chain Reaction was performed for metallo-β-lactamases and virulence genes. Adhesion and biofilm assays were done by quantitative tests. Among the 157 strains analyzed, 73.9% were multidrug-resistant, 43.9% were resistant to carbapenems, 16.1% were phenotypically positive for metallo-β-lactamases, and of these, 10.7% were positive for blaSPM gene and 5.3% positive for blaVIM. The multivariable analysis showed that mechanical ventilation, enteral/nasogastric tubes, primary bacteremia with unknown focus, and inappropriate therapy were independent risk factors associated with bacteremia. All tested strains were characterized as strongly biofilm producers. A higher mortality was found among patients with bacteremia by carbapenem-resistant P. aeruginosa strains, associated independently with extrinsic risk factors, however it was not evident the association with the presence of virulence and metallo-β-lactamases genes.

The role of gyrA and parC mutations in fluoroquinolones-resistant Pseudomonas aeruginosa isolates from Iran

Abstract The aim of this study was to examine mutations in the quinolone-resistance-determining region (QRDR) of gyrA and parC genes in Pseudomonas aeruginosa isolates. A total of 100 clinical P. aeruginosa isolates were collected from different university-affiliated hospitals in Tabriz, Iran. Minimum inhibitory concentrations (MICs) of ciprofloxacin and levofloxacin were evaluated by agar dilution assay. DNA sequences of the QRDR of gyrA and parC were determined by the dideoxy chain termination method. Of the total 100 isolates, 64 were resistant to ciprofloxacin. No amino acid alterations were detected in gyrA or parC genes of the ciprofloxacin susceptible or ciprofloxacin intermediate isolates. Thr-83 → Ile substitution in gyrA was found in all 64 ciprofloxacin resistant isolates. Forty-four (68.75%) of them had additional substitution in parC. A correlation was found between the number of the amino acid alterations in the QRDR of gyrA and parC and the level of ciprofloxacin and levofloxacin resistance of the P. aeruginosa isolates. Ala-88 → Pro alteration in parC was generally found in high level ciprofloxacin resistant isolates, which were suggested to be responsible for fluoroquinolone resistance. These findings showed that in P. aeruginosa, gyrA was the primary target for fluoroquinolone and additional mutation in parC led to highly resistant isolates.

Prevalence of resistance to aminoglycosides and fluoroquinolones among Pseudomonas aeruginosa strains in a University Hospital in Northeastern Poland

The present study was conducted to investigate the prevalence of genes encoding resistance to aminoglycosides and fluoroquinolones among twenty-five Pseudomonas aeruginosa isolated between 2002 and 2009. In PCR, following genes were detected: ant(2")-Ia in 9 (36.0%), aac(6')-Ib in 7 (28.0%), qnrB in 5 (20.0%), aph(3")-Ib in 2 (8.0%) of isolates.

Aerobacterias en las unidades de cuidado intensivo del Hospital Universitario Fernando Troconis, Colombia / Air bacteria existing in the intensive care units of Fernando Troconis university hospital in Colombia

Introducción: las infecciones nosocomiales se consideran un importante problema de salud. Los agentes patógenos frecuentemente responsables de estas infecciones son Pseudomonas spp. y Staphylococcus spp., patógenos que pueden estar presente en los bioaerosoles en hospitales. Objetivo: valorar la presencia de aerobacterias en las unidades de cuidado intensivo del Hospital Universitario Fernando Troconis, Colombia. Métodos: se recolectaron muestras de aire por triplicado en las dos estaciones de monitoreo ubicadas en las unidades de cuidados intensivos para adultos, pediátrica y neonatal, respectivamente. Se empleó para ello un impactador de cascada provisto con agar manitol salado para la recolección de aerobacterias Staphylococcus spp. y agar pseudomona para Pseudomonas spp. Las muestras recolectadas se incubaron a 37 °C durante 48 horas. Se aplicó análisis de varianza jerarquizado para determinar la influencia del género, estación y unidad sobre la concentración de aerobacterias. Resultados: la máxima concentración obtenida fue 979,9 ± 31,3 UFC/m³ y el máximo valor promedio 277 ± 59,2 UFC/m³. La concentración de Staphylococcus spp. sobrepasó a la de Pseudomonas spp. La unidad con mayor concentración de aerobacterias fue la de adulto, seguida por la neonatal y pediátrica. Los aerosoles respirables representaron el 65 por ciento en relación con los aerosoles sedimentables y se registraron mayores concentraciones de aerobacterias respirables Staphylococcus spp. (71,5 por ciento) comparadas con Pseudomonas spp. (64,6 por ciento). Conclusiones: la concentración de aerobacterias en las unidades de cuidados intensivos es alta, con un alto porcentaje de aerosoles respirables, lo que incrementa la probabilidad de que los pacientes asistidos contraigan infecciones nosocomiales por aerobacterias(AU)

Introduction: nosocomial infections are considered to be significant health problems. The most frequent pathogenic agents responsible for this are Pseudomonas spp. and Staphylococcus spp which can be present in bioaerosols in hospitals. Objective: to assess the presence of airborne bacteria in intensive care unit of Fernando Troconis university hospital in Colombia. Methods: samples were collected in triplicate at the two monitoring stations located in each of the three intensive care units of the hospital (adult, pediatric and neonatal), using cascade impactor with selective agars: mannitol salt for Staphylococcus spp. and pseudomona agar for Pseudomonas spp. The collected samples were incubated at 37 °C for 48 hours. A hierarchical variance analysis was applied to determine the influence of factors such as gender, monitoring station and unit on the concentration of airborne bacteria concentration. Results: the highest concentration was 979.9 ± 31.3 CFU/m3 and the maximum average value was 277 ± 59.2 CFU/m3. Staphylococcus spp. concentration exceeded that of Pseudomonas spp. The intensive care unit with the highest concentration was the adult one, followed by the neonatal and the pediatric ones. Breathable aerosols accounted for 65 percent compared with settleable aerosols, and higher concentration of breathable Staphylococcus spp. airborne bacteria (71.5 percent) compared with Pseudomonas spp. (64.6 percent). Conclusions: airborne bacteria concentration in the intensive care units was high, with significant percentage of breathable aerosols. All this increases the probabilities for the assisted patients to catch nosocomial infections caused by airborne bacteria(AU)

Un brote epidémico de endocarditis por Pseudomonas aeruginosa secundario a angiografía coronaria / An outbreak of Pseudomonas aeruginosa infective endocarditis subsequent to coronary angiography

Objectives: To describe an endocarditis outbreak affecting three patients due to Pseudomonas aeruginosa infection post coronary angiography performed in the Cardiovascular Surgery and Cardiology Medical Center of a private hospital. Methods: After recognition of an infection cluster within a onemonth period, the outbreak was reported to Antalya Department of Health and a broad investigation was initiated in order to determine the most probable cause and/or source of nosocomial pseudomonal endocarditis. Patient data were obtained by medical record review as well as interviews with patients or their next of kin. Thirty-six surveillance samples for P. aeruginosa were collected from various locations within the coronary angiography unit. The outbreak research team reviewed the private hospital's Cardiovascular Surgery and Cardiology Medical Center's infection control procedures. The epidemiology of P. aeruginosa was studied through analysis of phenotypic markers, including antimicrobial sensitivity profiles. Results: The infection control audit revealed multiple breaches of infection control procedures. Only 1/36 environmental samples yielded, which was isolated from a radio-opaque solution within an angiography injector pump. P. aeruginosa from the radio-opaque solution had an identical antimicrobial susceptibility pattern to the strain isolated from patients. Both samples were susceptible to all antipseudomonal agents. This outbreak could have been successfully controlled by instituting combined infection control measures. Conclusions: This outbreak emphasizes the important of adherence to infection control standards and practices for cardiac catheterization, as well as the need for closer collaboration between the Infection Control Committee and coronary angiography personnel.

Objetivos: Describir un brote de endocarditis por Pseudomonas aeruginosa que afectó a tres pacientes tras habérseles efectuado una coronariografía en el Centro Médico de Cardiología y de Cirugía Cardiovascular (CMC-CCV) de un hospital privado. Métodos: Después de reconocer la aparición de un brote en un periodo de un mes, este hecho fue comunicado al Departamento de Salud de Antalya, iniciándose una exhaustiva investigación para precisar la más probable causa y/o fuente de las endocarditis nosocomiales. Se extrajo de los registros médicos los datos clínicos de los pacientes y se efectuaron entrevistas a los pacientes o sus familiares. Se extrajo 36 muestras medioambientales de vigilancia en busca de P. aeruginosa de diversos sitios dentro de la unidad de coronariografía. Un team que investigó el brote revisó los procedimientos en uso para la prevención de infecciones en el CMC-CCV. Se estudió la epidemiología de la P. aeruginosa mediante análisis de su fenotipos, incluyendo el perfil de susceptibilidad in vitro a antimicrobianos. Resultados: La auditoria comprobó el quiebre de diversas normas de control de infecciones. Sólo 1/36 de las muestras ambientales arrojó el cultivo de P. aeruginosa, a partir de una solución de medio radio-opaco dentro de una bomba inyectora empleada en las angiografías. Los aislados de P. aeruginosa desde la solución del medio radio-opaco tenían idéntico patrón de susceptibilidad antimicrobiana que las cepas recuperadas de los pacientes. Ambos tipos de muestras eran susceptibles a todos los antimicrobianos con actividad anti-pseudomonas. El brote pudo evitarse si se hubieran instaurado una serie de medidas de control de infecciones. Conclusiones: Este brote enfatiza la importancia de adherir a los estándares y prácticas de control de infecciones para la cateterización cardiaca, así como la necesidad de una estrecha colaboración entre el Comité de Control de Infecciones y el personal involucrado en el procedimiento de coronariografía.

Colonization pressure as a risk factor for colonization by multiresistant Acinetobacter spp and carbapenem-resistant Pseudomonas aeruginosa in an intensive care unit

OBJECTIVE: To determine factors associated with colonization by carbapenem-resistant Pseudomonas aeruginosa and multiresistant Acinetobacter spp. METHODS: Surveillance cultures were collected from patients admitted to the intensive care unit at admission, on the third day after admission and weekly until discharge. The outcome was colonization by these pathogens. Two interventions were implemented: education and the introduction of alcohol rubs. Compliance with hand hygiene, colonization pressure, colonization at admission and risk factors for colonization were evaluated. RESULTS: The probability of becoming colonized increased during the study. The incidence density of colonization by carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. and colonization pressure were different between periods, increasing gradually throughout the study. The increase in colonization pressure was due to patients already colonized at admission. The APACHE II score, colonization pressure in the week before the outcome and male gender were independent risk factors for colonization. Every 1% increase in colonization pressure led to a 2% increase in the risk of being colonized. CONCLUSION: Colonization pressure is a risk factor for carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. colonization. When this pressure reaches critical levels, efforts primarily aimed at hand hygiene may not be sufficient to prevent transmission. .

An outbreak of forty five cases of Pseudomonas aeruginosa acute endophthalmitis after phacoemulsification / Surto de quarenta e cinco casos de endoftalmite aguda por Pseudomonas aeruginosa após facoemulsificação

PURPOSE: To describe an outbreak of Pseudomonas aeruginosa endophthalmitis post cataract surgery. Clinical findings, treatment and outcome are discussed. METHODS: Clinical charts review of forty-five patients treated for endophthalmitis in a two-day period. The patients underwent primary vitrectomy, anterior chamber irrigation and intravitreous antibiotic injection. Cultures from vitreous and anterior chamber samples were performed in all patients. RESULTS: Forty-five patients (twenty-three men and twenty-two women) were identified. The average age was 71.2 years (range, 56-83 years). The right eye (62%) was affected more often than the left eye (38%). The median interval between surgery and endophthalmitis onset was 5.5 days (range, 5-6 days). The visual acuity at the diagnosis was better than 20/40 in one patient (2%), from 20/40 to 20/200 in one patient (2%), from 20/400 to counting fingers in two patients (4%), hand movements in eleven patients (24%), and light perception in thirty patients (68%). Pseudomonas aeruginosa was the isolated agent in twenty-six vitreous samples and in three anterior chamber samples. Overall, one patient (2%) achieved a final visual acuity better than 20/40; eight patients (18%) achieved a final visual acuity from 20/40 to 20/200; six patients (13%) achieved a final visual acuity from 20/400 to counting fingers; eleven patients (25%) achieved a final acuity of hand movements; thirteen patients (29%) achieved a final acuity of light perception and six (13%) patients had no light perception at the last examination. None of these eyes underwent evisceration or enucleation in a three-month follow-up period. CONCLUSION: Even with all the safety that cataract surgery has achieved, today, endophthalmitis remains a risk and a fearful complication of this procedure. In the present study, it was impossible to identify the source of the outbreak.

OBJETIVO: Descrever surto de endoftalmite por Pseudomonas aeruginosa após facectomia. Os achados clínicos, o tratamento e o resultado são discutidos. MÉTODOS: Revisão dos prontuários de quarenta e cinco pacientes tratados para endoftalmite em um período de dois dias. Todos os pacientes foram tratados por vitrectomia primária, irrigação da câmara anterior e injeção vítrea de antibióticos. Culturas do vítreo e de amostras de câmara anterior foram realizadas em todos os pacientes. RESULTADOS: Quarenta e cinco pacientes (23 homens e 22 mulheres) foram identificados. A idade média foi 71,2 anos (variação, 56-83 anos). O olho direito (62%) foi mais afetado do que o esquerdo (38%). O intervalo médio entre a cirurgia e a apresentação da endoftalmite foi de 5,5 dias (intervalo de 5-6 dias). A acuidade visual no momento do diagnóstico foi melhor que 20/40 em um paciente (2%), de 20/40 a 20/200 em um paciente (2%), de 20/400 para contar dedos em dois pacientes (4%), movimento de mão em onze pacientes (24%), percepção de luz em trinta pacientes (68%). Pseudomonas aeruginosa foi o agente isolado em 26 amostras de vítreo e em três amostras da câmara anterior. No geral, um paciente (2%) obteve acuidade visual final melhor que 20/40, oito pacientes (18%) obtiveram acuidade visual final de 20/40 a 20/200, seis pacientes (13%) obtiveram acuidade visual final de 20/400 para contar os dedos; onze pacientes (25%) obtiveram acuidade visual final de movimento de mão; treze pacientes (29%) obtiveram acuidade visual final de percepção de luz e seis (13%) pacientes não havia percepção luminosa no último exame. Nenhum olho foi submetido à evisceração ou enucleação em três meses de acompanhamento. CONCLUSÃO: Mesmo com toda a segurança da cirurgia de catarata nos dias atuais, endoftalmite permanece um risco e uma complicação temível deste procedimento. No presente estudo não foi possível identificar a fonte do surto.

Epidemiological and microbiological profile of infective keratitis in Ahmedabad.

Context: Study of patients attending tertiary care ophthalmology institute at Ahmedabad. Aims: To study the microbiological etiology and epidemiological factors associated with suppurative keratitis. Settings and Design: A total of 150 corneal scrapings were evaluated from patients presenting with corneal ulcers at a tertiary ophthalmology center, Ahmedabad from July 2007 to June 2008. Materials and Methods: Scrapings were subjected to Gram stain, potassium hydroxide preparation and culture for bacterial and fungal pathogens. Socio-demographic data and risk factors were recorded. Results: Ninety percent (135/150) people with corneal ulcers had trauma as predisposing factor for keratitis. Trauma due to wooden objects was the leading cause (46/135) followed by vegetable matter and stone injury (23/135). Microbial etiology was established in 59.3% (89/150) of scrapings. Out of 89 positive isolates, 65.1% (58/89) were bacterial while 34.9% (31/89) were fungal. Among the bacterial isolates, 60.3% (35/58) were Gram-positive cocci while 39.7% (23/58) were Gram-negative bacilli. The most common bacterial isolate was Staphylococus aureus (32.7%, 19/58) followed by coagulase-negative Staphylococci (25.8%, 15/58) and Pseudomonas (18.9%, 11/58). Among the 31 fungal pathogens, Aspergillus species was the most common (35.4%11/31), followed by Fusarium species (22.5%, 7/31). Conclusion: Trauma with wooden material is the most common predisposing factor for suppurative keratitis. Males were more affected than females. Bacterial ulcers were more common than fungal in areas in and around Ahmedabad. Staphylococcus aureus and Aspergillus were the commonest bacterial and fungal isolates respectively. Geographical variation persists in microbial etiology of suppurative keratitis.

Ceftriaxone and ciprofloxacin restriction in an intensive care unit: less incidence of Acinetobacter spp. and improved susceptibility of Pseudomonas aeruginosa / Restricción del uso de ceftriaxona y ciprofloxacino en una unidad de cuidados intensivos: menor incidencia de Acinetobacter spp. y mayor sensibilidad de Pseudomonas aeruginosa

Objective. To determine whether restricting the use of ceftriaxone and ciprofloxacin could significantly reduce colonization and infection with resistant Gram-negative bacilli (r-GNB). Methods. A two-phase prospective study (before/after design) was conducted in an intensive care unit in two time periods (2004–2006). During phase 1, there was no antibiotic restriction. During phase 2, use of ceftriaxone or ciprofloxacin was restricted. Results. A total of 200 patients were prospectively evaluated. In phase 2, the use of ceftriaxone was reduced by 93.6% (P = 0.0001) and that of ciprofloxacin by 65.1% (P = 0.041), accompanied by a 113.8% increase in use of ampicillin-sulbactam (P = 0.002). During phase 1, 48 GNB were isolated [37 r-GNB (77.1%) and 11 non-r-GNB (22.9%)], compared with a total of 64 during phase 2 [27 r-GNB (42.2%) and 37 non-r-GNB (57.8%)] (P = 0.0002). Acinetobacter spp. was isolated 13 times during phase 1 and 3 times in phase 2 (P = 0.0018). The susceptibility of Pseudomonas aeruginosa to ciprofloxacin increased from 40.0% in phase 1 to 100.0% in phase 2 (P = 0.0108). Conclusions. Restriction of ceftriaxone and ciprofloxacin reduced colonization byAcinetobacter spp. and improved the susceptibility profile of P. aeruginosa.

Objetivo. Determinar si la restricción del uso de ceftriaxona y ciprofloxacino reduce significativamente la colonización y la infección por bacilos gramnegativos resistentes. Métodos. Se efectuó un estudio prospectivo de dos fases (diseño antes/después de la intervención) en una unidad de cuidados intensivos en dos períodos sucesivos entre los años 2004 y 2006. Durante la fase 1, no hubo ninguna restricción de antibióticos. Durante la fase 2, se restringió el uso de ceftriaxona y ciprofloxacino. Resultados. Se evaluó prospectivamente a 200 pacientes en total. En la fase 2, el uso de ceftriaxona se redujo en 93,6% (P = 0,0001) y el de ciprofloxacino en 65,1% (P = 0,041), lo que se acompañó de un aumento de 113,8% en el uso de ampicilina/sulbactam (P = 0,002). Durante la fase 1, se aislaron 48 bacilos gramnegativos (37 resistentes [77,1%] y 11 no resistentes [22,9%]), en comparación con un total de 64 durante la fase 2 (27 resistentes [42,2%] y 37 no resistentes [57,8%]) (P = 0,0002). Se aisló Acinetobacter spp. 13 veces durante la fase 1 y 3 veces en la fase 2 (P = 0,0018). La sensibilidad de Pseudomonas aeruginosa al ciprofloxacino aumentó de 40,0% en la fase 1 a 100,0% en la fase 2 (P = 0,0108). Conclusiones. La restricción del uso de ceftriaxona y ciprofloxacino redujo la colonización por Acinetobacter spp. y mejoró el perfil de sensibilidad de P. aeruginosa.

Prevalence and clinical outcomes of episodes of ventilator-associated pneumonia caused by SPM-1-producing and non-producing imipenem-resistant Pseudomonas aeruginosa / Prevalência e evolução clínica de episódios de pneumonia associada à ventilação mecânica causada por Pseudomonas aeruginosa resistente a imipenem produtoras e não-produtoras de SPM-1

INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-β-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-β-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2 percent) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40 percent and 54.2 percent for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.

INTRODUÇÃO: Pseudomonas aeruginosa é uma importante causa de pneumonia associada à ventilação mecânica (PAV) e exibe altas taxas de resistência a vários antimicrobianos. Os carbapenens são usualmente as drogas de escolha para esse microorganismo. Contudo, a resistência a carbapenens tem crescido entre essas amostras em todo o mundo. A presença de metalo- β-lactamase (MBL) tem sido apontado como um importante mecanismo de resistência nessas cepas. Nenhum estudo prévio avaliou desfechos clínicos de infecções respiratórias causadas por essas amostras MÉTODOS: Nosso grupo analisou a epidemiologia e evolução clínica de episódios de PAV causada por P. aeruginosa resistente a imipenem. Um total de vinte e nove isolados clínicos de Pseudomonas aeruginosa resistente a carbapenem foram avaliados quanto à presença de genes para metalo-β-lactamase (MBL). RESULTADOS: Variáveis clínicas e demográficas foram similares entre o grupo produtor de SPM-1 e o não-produtor. Cinco (17,2 por cento) isolados foram positivos para blaSPM-1. Nenhum outro gene para MBL foi encontrado. Todos os pacientes foram tratados com polimixina B. A mortalidade relacionada à infecção foi de 40 por cento e 50 por cento respectivamente para os isolados produtores de SPM-1 e não-produtores de SPM-1. CONCLUSÕES: Nao houve diferença entre os dados epidemiológicos e a evolução clínica entre os dois grupos.

Detección del gen codificante de la metalo-ß-lactamasa VIM-2 en un integrón de clase 1 asociado con el gen blaCTX-M-2 en un aislamiento clínico de Pseudomonas aeruginosa en el Uruguay: primera comunicación

Con el fin de analizar la presencia de metalo-ß-lactamasas en nuestro medio, se incluyeron en este estudio aislamientos de Pseudomonas aeruginosa causantes de infecciones nosocomiales en un centro hospitalario del Uruguay, en el período comprendido entre abril y setiembre de 2008. En un aislamiento se detectó la presencia del gen codificante de la metalo-ß-lactamasa VIM-2 asociado a un integrón de clase 1 y del gen codificante de una ß-lactamasa de espectro extendido CTX-M-2. Esta es la primera comunicación de la presencia de los genes blaCTX-M-2 y blaVIM-2 en un mismo aislamiento de P. aeruginosa. A pesar de que las carbapenemasas ya han sido ampliamente documentadas en varias partes del mundo, esta es la primera comunicación de una metalo-ß-lactamasa adquirida con actividad carbapenemasa en bacterias patógenas encontradas en el Uruguay.

VIM-2 metallo-ß-lactamase gen detection in a class 1 integron associated to blaCTX-M-2 in a Pseudomonas aeruginosa clinical isolate in Uruguay: first communication. In order to analyze the presence of metallo-ß-lactamase in our country, we included in this study Pseudomonas aeruginosa isolates causing nosocomial infections in a hospital from Uruguay. The presence of a metallo-ß-lactamase VIM-2 in a class 1 integron and of an extended spectrum -lactamase CTX-M-2 was detected in one isolate. This is the first report of both genes, blaCTX-M-2 and blaVIM-2,in the same P. aeruginosa isolate. Although carbapenemases have been extensively documented in the world, this is the first report of an acquired metallo-ß-lactamase with carbapenemase activity in pathogenic bacteria in Uruguay.