Phenotypic and molecular detection of metallo-ß-lactamase-producing Pseudomonas aeruginosa isolates from patients with burns in Tehran, Iran

Abstract INTRODUCTION: Health care-associated infections caused by metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa are a significant growing concern in patients with burns worldwide. The aims of this study were to determine the antibiotic susceptibility of and detect the presence of MBLs among P. aeruginosa isolates and assess their clonal relationship using enterobacterial repetitive intergenic consensus (ERIC)-PCR. METHODS: Non-duplicated clinical isolates (160) of P. aeruginosa were collected from patients with burns at the Motahari Hospital in Tehran, Iran. All isolates were identified using standard laboratory methods and further characterized for antimicrobial susceptibility. Any carbapenem-resistant isolates were then examined for MBL production by the E-test and MBL-encoding genes were detected by PCR. The clonal relatedness of MBL-producing isolates was assessed by ERIC-PCR. RESULTS: For multidrug-resistant isolates, the highest rates of susceptibility were observed for colistin 160 (100%), polymyxin B 160 (100%), and ceftazidime 32 (20%). In total, 69 (43.7%) isolates were identified as MBL producers. Twenty-eight (17.5%) isolates were positive for the bla VIM-1 gene followed by the bla IMP-1 (15.6%) and bla SPM-1 (5.6%) genes. ERIC-PCR revealed three separate genotypes, where type A (76.8%) was the most prevalent, followed by B (20.3%), and then C (2.9%). CONCLUSIONS: Our present study found that the bla IMP-1 and bla VIM-1 genes were present at a significant frequency and also detected the bla SPM-1 gene in P. aeruginosa isolates for the first time, highlighting the need for establishing suitable infection control measures to successfully treat patients and prevent further spread of these resistant organisms among patients with burns.

Mutation and Efflux System are Responsible for Ciprofloxacin Resistance in Klebsiella pneumoniae / Las mutaciones y el sistema de eflujo son responsables de la resistencia a la ciprofloxacina en la Klebsiella pneumoniae

ABSTRACT The main mechanism of quinolone resistance in Klebsiella (K) pneumoniae is caused by mutation of porin-related proteins and efflux pumps. This study aimed to investigate the prevalence of ciprofloxacin-resistant K pneumoniae in burns patients and to understand the role of the AcrAB multidrug efflux system on minimal inhibitory concentration (MIC) of ciprofloxacin. For this reason, 52 K pneumoniae samples were collected from burns patients and evaluated for the mechanism of ciprofloxacin resistance. The results demonstrated that 40 isolates of K pneumoniae were ciprofloxacin-resistant and 35 showed the mutation on gyrA locus. By inhibition of the efflux system, the MIC yield showed a significant decrease. Therefore, it could be concluded that the high rate of mutation on the gyrA locus in combination with quinolone resistance was responsible for ciprofloxacin resistance and by inhibition of AcrA, the resistance rate showed a significant decrease in K pneumoniae isolated from burns patients.

RESUMEN El principal mecanismo de resistencia a la quinolona en las Klebsiella (K) Pneumoniae tiene como causa la mutación de las porinas y las bombas de eflujo. Este estudio tuvo por objetivo investigar la prevalencia de las K pneumoniae resistentes a la ciprofloxacina en pacientes con quemaduras, así como entender el papel del sistema de eflujo multidroga AcrAB en la concentración inhibitoria mínima (CIM) de la ciprofloxacina. Por esta razón, se recogieron 52 muestras de K pneumoniae de pacientes con quemaduras, a fin de evaluar el mecanismo de resistencia a la ciprofloxacina. Los resultados mostraron que 40 aislados de K pneumoniae eran resistentes a la ciprofloxacina y 35 mostraron la mutación en el locus gyrA. Con la inhibición del sistema de eflujo, el rendimiento de CIM tuvo una disminución significativa. Por lo tanto, se pudo concluir que la alta tasa de mutación en el locus gyrA en combinación con la resistencia a la quinolona era responsable de la resistencia a la ciprofloxacina, y por la inhibición de AcrA, la tasa de resistencia mostró una disminución significativa en las K pneumoniae aisladas de los pacientes con quemaduras.

Infecciones en niños quemados internados en el Centro Nacional de Quemados y Cirugías Reconstructivas (CENQUER) Paraguay de Enero 2017 a Enero 2018 / Infections in burned children admitted to the National Center for Burns and Reconstructive Surgery (CENQUER) Paraguay from January 2017 to January 2018

Introducción: Las infecciones juegan un rol importante en la morbilidad y mortalidad asociada a quemaduras. La experiencia en pacientes pediátricos es escasa. Objetivo: Evaluar aspectos clínicos y microbiológicos de infección intrahospitalaria en niños quemados en el Centro Nacional de Quemados y Cirugías Reconstructivas. Material y Métodos: Estudio descriptivo, observacional, retrospectivo y de corte transversal. Se incluyeron todos los niños quemados admitidos en el Servicio de Pediatría del Centro Nacional de Quemados y Cirugías Reconstructivas (CENQUER) desde enero del 2017 hasta enero del 2018. Resultados: El total de pacientes fue de 220, de los cuales fueron 161 (73%) lactantes, 24 (11%) pre escolares, 17 (8%) escolares, 13 (6%) adolescentes y 5 (2%) recién nacidos. El porcentaje de superficie corporal quemada tuvo un rango de 1 a 95% (mediana 27%). El tipo de quemadura fue A (superficial) en 78 (36%) pacientes, AB (intermedia) en 38 (17%) y B (profunda) en 104 (47%). Ciento ochenta niños (82%) tuvieron catéter venoso, 166 (75,5%) catéter arterial y 172 (78%), sonda vesical. En 150 pacientes (68%) se requirió asistencia respiratoria mecánica. Se documentaron 128 (58%) infecciones. El foco más frecuente fue la sepsis relacionada con la quemadura. Las bacterias Gram (-) Pseudomonas aeruginosa y Acinetobacter spp multirresistentes, fueron los gérmenes más frecuentemente aislados. Se fueron de alta 186(85%) pacientes y 34 (15%) fallecieron. En 28 (82%) de ellos, la causa del fallecimiento estuvo relacionada con la infección. La duración de la internación tuvo una mediana de 37 días. Conclusiones: Las infecciones en niños quemados son una importante causa de morbimortalidad y las bacterias Gram (-) multirresistentes juegan un importante rol en las mismas. La mortalidad estuvo relacionada a la infección

Introduction: Infections play an important role in the morbidity and mortality associated with burns. Experience in pediatric patients is scarce. Objective: To evaluate clinical and microbiological aspects of nosocomial infection in children burned in the National Center for Burns and Reconstructive Surgeries. Material and Methods: A descriptive, observational, retrospective and cross-sectional study. All burned children admitted to the Pediatric Service of the National Center for Burns and Reconstructive Surgery (CENQUER) from January 2017 to January 2018 were included. Results: The total number of patients was 220, of which 161 (73%) were breastfeeding, 24 (11%) pre-school, 17 (8%) schoolchildren, 13 (6%) adolescents and 5 (2%) newborns. The percentage of burned body surface area ranged from 1 to 95% (median 27%). The type of burn was A (superficial) in 78 (36%), patients, AB (intermediate) in 38 (17%) and B (deep) in 104 (47%). One hundred and eighty children (82%) had venous catheter, 166 (75.5%) arterial catheter and 172 (78%); bladder catheter in 150 patients (68%) mechanical ventilation was required. In 128(58%) patients infections were documented. The most frequent focus was sepsis related to the burn. Gramnegative bacteria Pseudomonas aeruginosa and multiresistant Acinetobacter spp were the most frequently isolated germs. 186(85%) patients were discharged and 34 (15%) died. In 28 (82%) of them, the cause of death was related to the infection. The duration of the hospitalization had a median of 37 days. Conclusions: Infections in burned children are an important cause of morbidity and mortality and multidrug resistant gram negative bacteria play an important role in them. Mortality was related to infection.

Incidencia y factores de riesgo para bacteriemia en pacientes pediátricos con quemaduras en un Centro de Atención Especializado en México / Incidence and risk factors for bacteremia on pediatric patients with burns in a specialized care center in Mexico

Background: Bacteremia events are frequent cause of mortality in burn patients and may originate from infected wounds, by bacterial translocation of endogenous microorganisms, from invasive devices or contaminated intravenous solutions. Objective: To quantify the incidence of bacteremia in pediatric patients with burns and to identify risk factors. Material and Methods: A prospective cohort study was performed in pediatric patients with burns of Hospital Civil de Guadalajara "Dr. Juan I. Menchaca". Bacteremia was diagnosed by blood cultures in patients with clinical manifestations of sepsis. Risk factors were investigated by multivariate analysis with Cox regression. Results: Were included in the cohort 260 patients, median age 3 years. The incidence of bacteremia was 9.6 events per 1,000 days patient. The most frequently isolated bacteria were Enterobacteriaceae (41.9%), Staphylococcus aureus (22.6%) and Pseudomonas aeruginosa (22.6%). Factors associated with bacteremia were: bums ≥ 20% TBSA (HR 11.06; 95% CI 4.8-25.4), deep second degree bums or higher (HR 6.9; 95% CI 2.0-23.3) and have had two or less debridement (HR 26.4; 95% CI 8.0-87.7). Conclusions: Patients with more extensive and deep burns with fewer debridement are at increased risk of bacteremia.

Introducción: Los eventos de bacteriemia son causa frecuente de mortalidad en pacientes con quemaduras y pueden originarse en heridas infectadas, por translocación bacteriana de microorganismos endógenos, por dispositivos invasores o por soluciones intravenosas contaminadas. Objetivo: Cuantificar la incidencia de bacteriemia en pacientes pediátricos con quemaduras e identificar los factores de riesgo. Material y Métodos: Estudio de cohorte prospectivo, en población pediátrica con quemaduras del Hospital Civil de Guadalajara "Dr. Juan I. Menchaca". En pacientes con manifestaciones clínicas de sepsis se diagnosticó bacteriemia mediante cultivos de sangre. Se indagaron factores de riesgo con análisis multivariado con regresión de Cox. Resultados: Se incluyeron en la cohorte 260 pacientes, mediana de edad 3 años. La incidencia de bacteriemia fue de 9,6 eventos por 1.000 días paciente. Las bacterias más frecuentes aisladas fueron enterobacterias (41,9%), Staphylococcus aureus (22,6%) y Pseudomonas aeruginosa (22,6%). Los factores asociados a bacteriemia fueron: quemaduras ≥ 20% de superficie corporal quemada (HR 11,06; IC 95% 4,8-25,4), quemaduras de segundo grado profundo o mayores (HR 6,9; IC 95% 2,0-23,3) y haber tenido dos o menos desbridamientos (HR 26,4; IC 95% 8,0-87,7). Conclusiones: Pacientes con quemaduras más extensas y profundas, con menor número de desbridamientos presentan mayor riesgo de bacteriemia.

Determination of carbapenem resistance mechanism in clinical isolates of Pseudomonas aeruginosa isolated from burn patients, in Tehran, Iran

Carbapenems are the most important therapeutic options that effect against serious infections caused by multidrug resistant Pseudomonas aeruginosa [MDR-PA] isolates. Carbapenems resistant isolates of P. aeruginosa are increasing worldwide. The aim of this study was to determine the carbapenem resistance mechanisms in clinical P. aeruginosa isolates from burn patients, in Tehran, Iran. A total of 53 non-duplicated isolates of carbapenem-resistant P. aeruginosa were collected from burn patients. The presence of carbapenemase genes were determined by PCR. AmpC overproducer isolates were detected by phenotypic method. The mutation and transcription level of oprD were determined by PCR-sequencing and quantitative Real-time PCR [RT-PCR], respectively. Twenty-seven [50.9%] isolates were positive for carbapenemase [bla[vm] = 25 and bla[mp] = 2] and showed high-level resistance to imipenem and merope-nem. Twenty-eight isolates were AmpC overproducers. All isolates had a mutation in the oprD gene and down-regulation of oprD was found in 56.6% of MDR-PA isolates. Although the presence of carbapenemase is the common mechanism of resistant to carbapenem, but carbapenem resistance was found by oprD mutation-driven and the AmpC overproducing isolates in Tehran, Iran

The effects of low level laser therapy on Staphylococcus aureus infected third-degree burns in diabetic rats

PURPOSE: To characterize the effects of low-level laser (LLL) on third-degree burn wounds which were infected with Staphylococcus aureus (S. aureus) in diabetic rats. METHODS: Thirty streptozotocin-induced diabetic rats were divided into two groups: the control and the LLL groups. Third-degree burns were induced using a heated metal rod, and then, were contaminated with S. aureus. The wounds in the LLL group were irradiated with a LLL (685nm) daily for five consecutive days, starting three days after the induction. The wound area was measured at 3, 5, 8, 14 and 21 days after burning. At the end of trial, the skin samples were harvested. RESULTS: Reduction in wound areas in the LLL and control groups were significantly different only on the 21st day (p<0.05). The mean bacterial numbers in the LLL group were significantly lower (p<0.05) than those in the control group. The number of macrophages, new blood vessels, fibroblast, and elevated collagen deposition in the LLL group significantly increased compared to the control group (p<0.05). The mean breaking strength of scars in the control group was significantly lower (p<0.05) than that of the LLL group. CONCLUSION: The low-level laser improved the healing of S. aureus third-degree burn infections in diabetic rats.

Genotyping of multidrug-resistant strains of Pseudomonas aeruginosa isolated from burn and wound infections by ERIC-PCR

ABSTRACT PURPOSE: To determine the genetic diversity of MDR P. aeruginosa strains isolated from burn and wound infections in Ahvaz, Iran, by ERIC-PCR. METHODS: From total 99 strains of P. aeruginosa defined as MDR by using drug susceptibility testing, 66 were subjected to ERIC-PCR analysis, comprises 53 strains isolated from burn infection, and 13 randomly selected strains from wound infection with higher resistance to combinations of more numbers of drugs. RESULTS: Eight clusters (I to VIII), and 50 single clones were generated for tested MDR isolates analyzed by ERIC-PCR. The high heterogeneity was observed among the isolates from burn infections including 16 isolates which were categorized in eight clusters and 37 single clones. The isolates in clusters II, III, VI, VIII showed 100% similarity. CONCLUSIONS: The high level of genotypic heterogeneity in P. aeruginosa strains demonstrated no genetic correlation between them. Extremely high drug resistance in isolates from burn, suggests that efficient control measures and proper antibiotic policy should be observed.

Infecciones por Fusarium spp. en una unidad de quemados pediátrica / Fusarium spp. infections in a pediatric burn unit

Introducción: Fusarium spp. son hongos ubicuos que producen infecciones oportunistas en humanos incluyendo algunas severas en quemados. La literatura sobre infecciones por Fusarium spp. en pacientes quemados pediátricos es escasa. Objetivos: describir los hallazgos clínicos, epidemiológicos y evolutivos de infecciones por Fusarium spp. en pacientes quemados pediátricos. Pacientes y métodos: estudio retrospectivo, descriptivo de infecciones por Fusarium spp. en una unidad de cuidados intensivos pediátrica especializada entre enero de 2006 y marzo de 2015. Resultados: Quince pacientes presentaron infección por Fusarium spp. El 87% eran varones. La mediana de edad fue de 48 meses. En el 67% de los casos la quemadura fue por fuego directo. La superficie corporal quemada fue de una mediana de 45%. El 80% tuvo quemaduras profundas y el 93% presentó un índice de Garcés > 3. La infección fúngica se detectó con una mediana de 11 días desde la injuria. Todos los pacientes tuvieron catéteres centrales durante una mediana de 20 días y trece pacientes requirieron asistencia respiratoria mecánica durante una mediana de 16 días. En 14 pacientes el hongo fue aislado en la quemadura y en un paciente en el hueso. Trece pacientes tuvieron infecciones bacterianas concomitantes. Los antifúngicos de elección fueron anfotericina B y voriconazol. El tratamiento duró una mediana de 23 días. La mediana de internación fue de 55 días. Un solo paciente falleció debido a la infección fúngica. Conclusión: Fusarium spp. es un patógeno poco frecuente en pacientes quemados graves. La mortalidad fue baja (AU)

Introduction: Fusarium spp. are ubiquitous fungi recognized as opportunistic agents of human infections. They can produce severe infections in burn patients. The literature about Fusarium spp. infections in burn pediatric patients is scarce. Objectives: To describe clinical, epidemiological and outcome features of cases of Fusarium spp. infections in burn pediatric patients. Patients and Methods: Retrospective, descriptive study of Fusarium spp. infections in a specialized intensive care from January 2006 to March 2015. Results: 15 patients developed Fusarium spp infections. 87 % were male. Median age was 48 months. Direct fire injury was in ten patients. The affected burn surface was a median of 45%. Twelve patients had a full thickness burn. Fourteen patients had Garces Index>3. Fungal infection appears at a median of 11 days from injury. All patients had central lines during a median of 20 days and thirteen patients had mechanical ventilatory assistance for a median of sixteen days. Fungi vas isolated from burn wound in 14 patients and in bone in one patient. Thirteen patients had bacterial infection also. Amphotericin B was the drug of choice for treatment followed by voriconazole. Median time of complete treatment was 23 days. The median hospital stay was 55 days. One patient died of fungal infection related causes. Conclusion: Fusarium spp. is an uncommon pathogen in severely burn patients. Mortality was low (AU)

Risk factors for mortality in burn children

Studies about risk factors for mortality in burn children are scarce. We conducted this study to evaluate the risk factors for mortality in pediatric burn patients. We included 110 patients. Mean age was 31.5 months (range: 1 to 204). The burn surface was between 1% and 95%(median 27%) Type of burn was: A or superfitial in 39 patients (36%), AB or intermediate in 19 (17%), and B or full thickness in 52 (47%). Inhalatory injury was present in 52 patients (47%). Invasive procedures were: venous catheter, 90 patients (82%), arterial catheter, 83patients (75.5%), urinary catheter, 86 patients (78%), and mechanical ventilation, 75 patients (68%). In 84 patients, 128 infections were diagnosed. in 53 cases (48%). Multiresistant Pseudomonas aeruginosa and Acynetobacter baumannii were the most common organisms isolated. The median length of hospital stay was 33 days (r: 8-139 days). Seventeen patients (15%) died and 14 of them of infection-related causes. Age< <4 years, Garcés 4, full thickness burn, > 40% burn surface, presence of inhalatory syndrome, use of venous catheter, arterial catheter, urinary catheter and mechanical ventilation, positive blood cultures, colistin use in documented multiresistant infections, antifungal use and graft requirement, were identified as risks factors for mortality in the univariate analysis. By multivariate analysis: age <4 years, Garcés 4, colistin use in multiresistant infections, mechanical ventilation and graft requirement were independent variables related with mortality. CONCLUSIONS: In this series of burn children age < 4 years, Garces index score 4, colistin use in documented multiresistant infections, mechanical ventilation and graft requirement were identified as independent variables related with mortality. .

Perfil microbiológico da unidade de queimaduras da EPM/UNIFESP, São Paulo, Brasil / Microbiological surveillance of burn unit of EPM/UNIFESP in São Paulo, Brazil

Introdução: Apesar dos grandes avanços em seu tratamento, infecção de pele com queimadura continua a ser um grande desafio. O objetivo deste estudo é avaliar os aspectos microbiológicos do primeiro ano de funcionamento de uma unidade de queimadura em um Hospital Universitário. Métodos: Estudo retrospectivo. Dados microbiológicos foram coletados e analisados a partir de pacientes internados na Unidade de Queimadura (UTQ) do Hospital São Paulo, Hospital Universitário da Escola Paulista de Medicina (EPM) da Universidade Federal de São Paulo (UNIFESP), entre junho de 2009 e julho de 2010. Resultados: O tempo médio de permanência hospitalar foi de 13,8 dias, com uma taxa de mortalidade de 5,9%. A média da superfície corpórea queimada foi de 10,3%. Avaliou-se 159 culturas de 101 pacientes. Culturas de sangue foram as mais solicitadas (41%). Também foram acessadas 245 culturas de vigilância, coletadas de 75 pacientes. A análise microbiológica revelou um índice de positividade total de 34,5%. Os agentes mais prevalentes foram Staphylococcus coagulase-negativo - CoNS - (33%), Pseudomonas aeruginosa (24%), Acinetobacter spp. (22%) e Klebsiella pneumoniae (5%). Conclusão: A avaliação microbiológica do primeiro ano de funcionamento da UTQ da EPM/ UNIFESP revelou que, embora o agente mais prevalente tenha sido a CoNS, bacilos Gram negativos ainda são muito prevalentes, como a Pseudomonas aeruginosa e a Acinetobacter baumannii. Apesar de pouco tempo de operação, observou-se um grande número de microrganismos multirresistentes, que pode ser explicado por longa exposição a agentes antimicrobianos e alta taxa de transferência de outros hospitais.

Introduction: Despite great advances in treatment, burned skin infection remains a major challenge. The aim of this study is to evaluate the microbiological aspects of the first year's operation of a Burn Unit in a University Hospital. Methods: Retrospective study. Microbiological data were collected and analyzed from patients admitted to the Burn Unit of São Paulo Hospital, a University Hospital of the Paulista Medical School (EPM) of the Federal University of São Paulo (UNIFESP) from June 2009 to July 2010. Results: The average length of stay was 13.8 days with a mortality rate of 5.9%, and median of TBSA was 10.3%. Evaluated 159 cultures from 101 patients. Blood cultures were the most requested (41%). It was also accessed 245 surveillance cultures collected from 75 patients. The microbiological analysis revealed a total positivity rate of 34,5%. The most prevalent agents were Coagulase-negative Staphylococcus - CoNS - (33%), Pseudomonas aeruginosa (24%), Acinetobacter spp. (22%) and Klebsiella pneumoniae (5%). Conclusion: The microbiological evaluation of the first year's activity of EPM/UNIFESP Burn Care Unit revealed that, although the most prevalent agent was CoNS, Gram negative bacilli are still very prevalent, such as Pseudomonas aeruginosa and Acinetobacter baumannii. Despite the short time of operation, was observed large number of multiresistant microorganisms which can be explained by long exposure to antimicrobials and high transfer rate from other hospitals.

Bacteriología en pacientes hospitalizados en la Unidad de Quemados del Hospital Nacional Daniel Alcides Carrión - Callao / Bacteriology in patients hospitalized in the Unit of Burned at the National Hospital Daniel Alcides Carrion - Callao

Formulación del Problema: ¿Cuáles serán los agentes infecciosos en los pacientes hospitalizados en la Unidad de Quemados del HNDAC?. Objetivo: Identificar los agentes infecciosos en los pacientes hospitalizados en la Unidad de Quemados del Hospital Nacional Daniel Alcides Carrión; así como identificar los patrones de sensibilidad antimicrobiana y conocer algunos aspectos de la epidemiologia de los pacientes hospitalizados. Materiales y Métodos: La investigación es un trabajo retrospectivo, descriptivo de corte transversal que se realizó en la Unidad de Quemados del Hospital Nacional Daniel Alcides Carrión, donde se revisaron 188 historias clínicas de pacientes hospitalizados en el periodo de enero del 2009 a diciembre del 2010. Se analizaron los hallazgos bacteriológicos, tipo y extensión de la lesión y algunas variables sociodemográficas. Se utilizó estadística descriptiva para la presentación de los resultados. Resultados: Los gérmenes hallados con mayor frecuencia en la colonización de las lesiones por quemadura en el HNDAC fueron Pseudomona aeruginosa con 50.8 por ciento seguido de Staphylococcus aureus con 17.9 por ciento. El germen más frecuente aislado en hemocultivos y catéteres fue Staphylococcus coagulasa negativo. En cuanto a los antibióticos que mostraron mayor resistencia están ampicilina, doxiciclina y ciprofloxacino y los antibióticos que mostraron mayor sensibilidad fueron vancomicina, meropenem e imipenem. Conclusión: P. seudomona es el principal agente bacteriano identificado en pacientes con quemadura. Los aislamientos presentan una elevada resistencia a los antimicrobianos.

[Comparative study of antibiotic resistance in bacteria isolated from the burned patients during two periods [2005-2008, 2008-2011] and in two hospitals [hospital Aziza Othmana, trauma and burn center]]

Continuous monitoring of the bacterial flora and antibiotic resistance of the main bacteria involved in nosocomial infections helps improve treatment and prevention strategies. To compare the bacteriological profile and antibiotic susceptibility of the main bacterial isolates within the burned patients over two periods of 3 years and in two hospitals. During two three-year periods: period 1 [P1]: 1/7/2005-30/6/2008 and period 2 [P2]: 1/7/2008-30/6/2011] and in two hospitals: Hospital Aziza Othmana [HAO] and the traumatology and burn center [CTGB], 2153 and 3719 non-repetitive strains were isolated from burn patients from different samples. The transfer of the intensive care unit was made on 01/07/2008 from the Hospital Aziza Othmana to CTGB. The study of antibiotic sensitivity was performed according to CA-SFM. During the period P1, Pseudomonas aeruginosa was the main bacteria isolated [18%] followed by Staphylococcus aureus [14%] and Acinetobacter baumannii [12%]. After the transfer of intensive care burn unit to the traumatology center, ecology bacterial varied with S. aureus [20%] in the first place followed by P. aeruginosa [15%] and Proteus mirabilis [11%]. The study of the evolution of antibiotic susceptibility showed an overall downward trend of resistance in the second half of 2008, immediately after the transfer of service in the new hospital structure. The rate of ceftazidim resistant Klebsilella pneumoniae decreased from 80.4% to 50%, Similary the resistance of P. aeruginosa to ceftazidime and imipenem decreased respectively from 61% to 39.4% and from 63.3% to 37.1%. Nevertheless, the reduction of resistance was followed by a rapid increasing during the year 2009 to reach overall rates of resistance previously observed in the hospital Aziza Othmana. Concerning S. aureus, the rate of MRSA [methicillin-resistant S. aureus] showed no significant variation throughout the study period: 60% versus 56.3% at HAO and CTGB. A. baumannii brings up the problem of mutir‚sistance: 92.7% of strains were resistant to ceftazidime and 63.9% to imipenem during P1 with an emphasis on resistance to imipenem during P2 increased to 89.3%.Resistance is a problem in the intensive care burn unit. Preventive measures have to be taken

Genetic site determination of antibiotic resistance genes in escherichiacoli isolated from different sources of human infection

This study includes isolation of Escherichia coli from different sources of human infections [urine, stool, burns, wounds, and cerebrospinal fluid]. In addition to these, a few samples were taken from sewage water. Eighty-three isolates of E. coli were obtained from 264 samples. According to the resistance to antibiotics, isolates were classified into 41 groups. The isolates varied in their resistance to tested antimicrobials. Isolate E48 was resistant to all antimicrobials under study, while isolate E37 was resistant only to three antimicrobials. All isolates showed resistance of 97.59% to Chm and less sensitivity to Amk [2.40%]. The transformation was conducted successfully by plasmid DNA of isolate E48 and failed by plasmid isolate E38. The results cleared that the genes responsible for resistance to Amk, Chm, Cln, Dox, Kan, Lin, Pac, Tet, Tob, and Tri were located on the plasmid DNA, while the genes responsible for resistance to Cef, Cph, Cip, Gen, Gul, Nal, Nit, Pip, and Rif were located on the chromosome. It appeared from the electrophoresis run DNA samples on gel that E. coli K12JM83 strain obtained two plasmids through the transformation process

[Detection of blaIMP and blaVIM metallo-beta-lactamases genes in pseudomonas aeruginosa strains isolated from wound of burnt patients in Tehran Shahid Motahari hospital during 2011, Iran]

During recent years, metallo-beta-lactamase [MBLs] producing Pseudomonas aeruginosa has been reported as an important cause of nosocomial infection. Also, infection with this bacterium has increased rate of mortality and health care costs. The aim of this study was to determine the antibiotic resistance pattern and to detect blaVIM and blaIMP Metallo-beta-lactamase genes in P. aeruginosa isolated from patients hospitalized in the burn ward. This descriptive study was conducted on P. aeruginosa strains isolated from patients hospitalized in the burn ward of Tehran Shahid Motahari Hospital between September and January 2011. For all MBL-producing strains, antibiotic resistance pattern was determined by disc diffusion method according to CLSI guidelines. CDDT method was used for detection of MBL [imipenem-imipenem+EDTA], and PCR and sequencing techniques were used to detect MBL genes, blaVIM and blaIMP. Eighty-three percent of 100 P. aeruginosa isolates were resistant to imipenem. Using combination disk diffusion test [CDDT] method, 48 isolates were detected to have MBL, of which 6 isolates were positive for blaIMP-1 gene, and all of them did not have blaVIM gene. Also, 4 [8.3%] patients with MBL-producing P. aeruginosa infection died in the hospital. The results of this study revealed that high percentage of P. aeruginosa strains are MBL-producer. Therefore, detection of MBL-producing strains is essential for better control and treatment of burnt patients

Colonización bacteriana de piel sana versus quemada de niños bajo 15 años tratados en COANIQUEM, Santiago de Chile / Bacterial colonization in areas of burnt skin and healthy children younger than 15 years, seen COANIQUEM, Santiago, Chile

Bacterial colonization in patients with burns skin without infection and outpatient management has been poorly studied. Objective: To quantify and identify the type of bacteria that colonize healthy body areas homologous location of the skin in children from 1 to 15 years, seen COANIQUEM, Santiago, Chile. Per patient, we studied 204 samples from each zone. The isolated microorganisms were S. epidermidis 35, 3%; others Staphylococcus coagulase negative, 25.8%; S. aureus, 4.4%; and S. viridans group 1.4%. In the subgroup of children who had a count between 1 and 1000 cfu, there was a higher proportion of cfu in burned skin healthy skin (p = 0.0359). The association between depth of the lesion and the bacterial count obtained p = 0.034. Conclusion: In outpatient treatment, the microorganisms are expected in healthy skin, burned skin is evident in lower counts probably associated with epithelial damage.

La colonización bacteriana de la piel de pacientes quemados, sin infección y de manejo ambulatorio, ha sido escasamente estudiada. Objetivo: Cuantificar e identificar el tipo de bacterias que colonizan las zonas cruentas y las zonas sanas de localización homóloga de la piel, en niños entre uno y 15 años de edad que son tratados de forma ambulatoria en la Corporación de Ayuda al Niño Quemado (COANIQUEM) en Santiago de Chile. Pacientes y Métodos: Se estudiaron 204 pacientes quemados en los que se tomó una muestra para cultivo desde la zona de la quemadura y otra desde el sitio homólogo sin quemadura. Resultados: Las especies bacterianas aisladas desde ambos tipos de muestra fueron similares: Staphylococcus epidermidis; otras especies de Staphylococcus coagulasa negativa; Staphylococcus aureus, y Streptococcus grupo viridans. El recuento bacteriano de uno a 999 ufc/ 10,5 cm² fue significativamente superior en las muestras de piel sana (p = 0,0359). La asociación entre mayor profundidad de la lesión y el menor recuento bacteriano obtuvo un p = 0,034. Conclusión: En niños quemados de entre uno y 15 años, de manejo ambulatorio, los microorganismos que colonizan la zona quemada fueron los mismos que colonizan la piel sana, pero en recuento inferior.

Incidência de infecções bacterianas em pacientes queimados sob tratamento em hospital universitário de Curitiba / Incidence of bacterial infections in burn patients undergoing treatment at university hospital in Curitiba

Objetivo: Avaliar a incidência de infecções bacterianas em pacientes queimados hospitalizados e a frequência dos agentes etiológicos responsáveis porestas infecções. Método: Os dados para esse estudo foram coletados no sistema de informação do laboratório de um hospital universitário, a partir da análise de resultados de culturas icrobiológicas de feridas de pacientes queimados que tenham realizado ao menos uma vez este exame durante sua permanência no hospital, no período de janeiro a dezembro de 2009. Resultados: Aproximadamente 60% das culturas microbiológicas realizadas no ano de 2009 foram positivas para algum tipo de bactéria, sendo que os agentes etiológicos de maior incidência foram Pseudomonas aeruginosa, Acinetobacter baumannii e Staphylococcus aureus. Os meses de janeiro, fevereiro, maio e junho apresentaram taxas de infecção elevadas acima da média, em que foram identificadas as três bactérias anteriormente citadas, e ainda Enterobacter gergoviae, Morganella morganii e Xanthomonas maltophilia.Conclusão: Em 56,7% das culturas microbiológicas de amostras de feridas de pacientes queimados realizadas em 2009, o resultado foi positivo. Os agentes etiológicos de maior incidência nas infecções em queimados foram: Pseudomonas aeruginosa (38,7%); Acinetobacter baumannii (24,4%);Staphylococcus aureus (19,3%). Esses patógenos foram responsáveis por82,4% das infecções em pacientes queimados no ano de 2009.

Objective: To evaluate the incidence of bacterial infections in hospitalizedburn patients and the frequency of the etiologic agents responsible for these infections. Methods: Data for this study were collected in the information system of the laboratory of an university hospital, from the analysis of results of microbiological cultures of wounds of burn patients who have performed at least once this exam during their stay in hospital during the period January to December 2009. Results: Approximately60% of microbiological cultures performed in 2009 were positive for some type of bacteria, and the highest incidence of etiologic agents were Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus.The months of January, February, May and June showed high infection ratesabove the average, which were identified in the three bacteria mentionedabove, and still Enterobacter gergoviae, Morganella morganii and Xanthomonasmaltophilia. Conclusion: In 56.7% of microbiological cultures of samples from the wounds of burn patients performed in 2009, the result was positive. The etiologic agents of greatest incidence of infections in burned were: Pseudomonas aeruginosa (38.7%), Acinetobacter baumannii (24.4%), Staphylococcus aureus (19.3%). These pathogens were responsible for 82.4% of infections in burn patients in 2009.

[Molecular detection and identification of virulence factors of Pseudomonas aeruginosa isolated from wound and burn infections]

In recent decades, Pseudomonas aeruginosa has emerged as one of the most important nosocomial pathogens. Due to the clinical importance this bacterium, various methods have been developed to rapidly and accurately identify it. The aim of this research was to detect P. aeruginosa isolated from wound and burn infections on the basis of the amplification of the oprl, oprL and toxA genes, and to determine the prevalence of nanl and exoS genes among them. A total of 150 P. aeruginosa isolates was collected from patients with burn and wound infections of Imam-Khomaini, Tohid and Motahari hospitals in Tehran. The isolates were identified as P. aeruginosa using specific biochemical tests. Chromosomal DNA of the isolates was extracted with phenol chloroform method and used for PCR of oprl, oprL, toxA, exoS and nanl genes by specific primers. Among 150 P. aeruginosa isolates all carried the oprl and oprL genes; 98 [65.3%] 142 [94.7%] and 19 [12.66%] of the isolates were positive for exoS, toxA and nanl genes respectively. The presence of nanl gene in wound isolates [30%] was significantly higher [p<0.05] than in burn isolates [4%].Our results indicated that simultaneous use of oprl, oprL and toxA genes provide sufficient sensitivity to detect P. aeruginosa in clinical samples. The high prevalence of exoS in isolates suggests invasive phenotype of wound and burn isolates. The high prevalence of nanl in wound isolates suggests a possible role of this gene in those infections

Characterization of Pseudomonas aeruginosa strains isolated from burned patients hospitalized in a major burn center in Tehran, Iran

Pseudomonas aeruginosa is an important life-threatening nosocomial pathogen and plays a prominent role in serious infections in burned patients. The current study was undertaken to characterize P. aeruginosa strains isolated from burned patients in Tehran, Iran. The study was conducted in a major burn center in Tehran, Iran in 2007. A total of seventy specimens obtained from different clinical origin with positive culture results for P. aeruginosa were included in the study. Antimicrobial susceptibility test was performed according to the standard CLSI guideline. The relationship between the strains was also determined using antimicrobial drug resistance pattern analysis and plasmid profiling. All strains were multi drug resistant. The percentage of resistance to tested antibiotics was: imipenem 97.5%, amikacin 90%, piperacillin 87.5%, ceftizoxime 72.7%, gentamicin 67.5%, ciprofloxacin 65%, ceftriaxone 60%, and ceftazidime 57.5%. Thirteen resistant phenotypes were recognized, R3 [TET, IPM, AMK, CIP, PIP, GM, CAZ, CRO, CT] was the predominant resistance pattern seen in 27.5% of isolates. Results obtained from Etest showed that 100% of P. aeruginosa strains were resistant to cefoxitin, 97% to cefotetan, 93% to ticarcillin, 89% to ticarcillin/clav, 76% to gentamicin and imipenem, 63% to piperacillin, 49% to tetracycline, and 20% to meropenem. Nine different plasmid profiles were observed among the strains. The current study showed an increase rate of resistance for some antibiotics tested among P. aeruginosa strains isolated from burned patients in Tehran. A combination of antibiotic susceptibility testing and profile plasmid analysis, which are relatively cheap and available methods, showed to be useful to characterize the clinical strains of P. aeruginosa isolated from burned patients in Iran

Infecciones por acinetobacter multirresistente en la unidad de quemados / Multiresistant acinetobacter infections in the burn unit

Acinetobacter spp ha emergido como un importante germen en unidades de cuidados intensivos y en pacientes críticos como los quemados. Objetivos: Evaluar las características epidemiológicas, clínicas y de evolución en pacientes admitidos en la unidad de quemados con infecciones por Acinetobacter spp multiresistente. Población y Métodos: Se realizó un estudio de todos los pacientes que entre enero de 2005 y diciembre de 2006 tuvieron aislamiento de Acinetobacter spp multitresistente en la unidad de quemados del Hospital J P Garrahan. Resultados: Se incluyeron 26 pacientes. La edad media fue de 66.5 meses (rango: 2 a 168 m), 17 pacientes (65%) fueron del sexo masculino. La superficie quemada fue entre 10% y 87% (mediana 42.5%). Diez pacientes (39%) tenían quemadura profunda o "full thickness". El foco más frecuente fue sepsis asociada a la quemadura en 10 pacientes (39%). En 8 pacientes (30%), la infección de la quemadura no se asoció con sepsis. Fue diagnosticada Bacteriemia asociada a catéter en 3 pacientes (11%), y bacteriemia no asociada en 1 paciente (4%). Dos pacientes tuvieron neumonía asociada a respirador (8%), y 2 (8%) infección urinaria asociada a sonda. Todos los pacientes recibieron colistín de acuerdo a test de susceptibilidad. El tiempo de tratamiento con colistín fue entre 10 y 71 días (mediana 21días). Ninguno de los pacientes presentó alteraciones renales o neurológicas relacionadas con el colistín. La evolución fue favorable en todos los pacientes (AU)

Acinetobacter spp has emerged as an important germ in intensive care units and in critical patients, such as those with burn wounds. Objectives: To assess epidemiological and clinical features and evolution of patients admitted to the burn unit with multiresistent Acinetobacter spp infections. Patients and Methods: All patients admitted to the burn unit of the J P Garrahan Hospital between January 2005 and December 2006 in whom multiresistent Acinetobacter spp was isolated were studied. Results: 26 patients were included in the study. Mean age was 66.5 months (range: 2 to 168 m), 17 patients (65%) were male. The burn surface was between 10% and 87% (median 42.5%). Ten patients (39%) had a deep or "full thickness" burn. The most frequent focus was burn-wound-associated sepsis in 10 patients (39%). In 8 patients (30%), infection of the burn wound was not associated with sepsis. Catheter-related bacteriemia was diagnosed in three patients (11%) and non-catheter-related bacteriemia in one patient (4%). Two patients developed respirator-associated pneumonia (8%) and two (8%) catheterassociated urinary infection. After susceptibility testing, all patients received colistin. Duration of colistin treatment was between 10 and 71 days (median: 21days). None of the patients developed colestin-related renal or neurological impairment. Evolution was favorable in all patients (AU)