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.

Restrictive measure for the commercialization of antimicrobials in Brazil: results achieved / Medida restritiva para comercialização de antimicrobianos no Brasil: resultados alcançados

ABSTRACT OBJECTIVE To assess whether the incidence of hospital infection by a resistant microorganism decreased after the implementation of the restrictive measure of the National Health Surveillance Agency for the commercialization of antimicrobials. METHODS A historical cohort study of medical records of adult patients admitted to a general and public hospital from May 2010 to July 2011. A cohort was formed with patients admitted in the period before the restrictive measure for the commercialization of antimicrobials (Phase I) and a second cohort was formed with patients admitted after the implementation of the restrictive measure (Phase II). RESULTS The instantaneous risk of hospital infection by a resistant microorganism was estimated at seven by 1,000 people-time (95%CI 0.006-0.008) in Phase I, and four by 1,000 people-time (95%CI 0.003-0.005) in Phase II of the study. The differences between the survival curves in the different phases of the study and stratified by age group were also significant (p < 0.05). CONCLUSIONS The results suggest that the implementation of the restrictive measure of the commercialization of antimicrobials by the National Health Surveillance Agency reduced the incidence of hospital infection by a resistant microorganism.

RESUMO OBJETIVO Avaliar se a incidência de infecção hospitalar por microrganismo resistente diminuiu após a implementação da medida restritiva da Agência Nacional de Vigilância Sanitária para comercialização de antimicrobianos. MÉTODOS Estudo de coorte histórica de registros de prontuários de pacientes adultos admitidos para internação em um hospital geral e público no período de maio de 2010 a julho de 2011. Foi formada uma coorte com pacientes internados em período anterior à medida restritiva para comercialização de antimicrobianos (Fase I) e uma segunda coorte com pacientes admitidos após a implantação da medida restritiva (Fase II). RESULTADOS O risco instantâneo de infecção hospitalar por microrganismo resistente foi estimado em sete por 1.000 pessoas-tempo (IC95% 0,006-0,008) na Fase I, e quatro por 1.000 pessoas-tempo (IC95% 0,003-0,005) na Fase II do estudo. As diferenças entre as curvas de sobrevida nas diferentes fases do estudo e estratificadas pela faixa etária também foram significativas (p < 0,05). CONCLUSÕES Os resultados sugerem que a implantação da medida restritiva de comercialização de antimicrobianos pela Agência Nacional de Vigilância Sanitária reduziu a incidência de infecção hospitalar por microrganismo resistente.

Evaluación de susceptibilidad y respuesta al tratamiento con piperacilina/tazobactam en pacientes con infecciones por Escherichia coli productoras de β -lactamasas de espectro extendido (BLEE) CTX-M / Evaluation of susceptibility and response to therapy with piperacillin-tazobactam in patients with infections caused by Escherichia coli with extended-spectrum β -lactamase (ESBL) CTX-M

Resumen Introducción: En las infecciones por enterobacterias productoras de β-lactamasas de espectro extendido (BLEE), los β-lactámicos preferidos para tratamiento son los carbapenémicos. Sin embargo, estudios clínicos muestran eficacia de piperacilina/tazobactam en ciertas infecciones por Escherichia coli productoras de BLEE. Objetivo: Determinar la cura clínica y microbiológica con piperacilina/tazobactam en pacientes con infecciones por E. coli productoras de BLEE, tipo CTX-M. Materiales/Métodos: Estudio descriptivo, retrospectivo, con adultos internados en un hospital universitario. Incluimos infecciones del tracto urinario (ITU), intra-abdominales (IIA) e infecciones de tejidos blandos (ITB). Resultados: Estudiamos 40 pacientes, donde 65% correspondían a ITU, 25% IIA y 10 % ITB. La cura clínica global se logró en 89,4%, con mejores resultados en las ITU (100%), seguidas de ITB (80%) e IIA (70%). El 85% de las cepas tenía concentraciones inhibitorias mínimas (CIM) ≤ 8 μg/mL y 70% con CIM ≤ 4 μg/mL. La tasa de fracaso fue mayor en las infecciones con inóculos altos intraabdominales. La BLEE del tipo CTX-M-15 se encontró en 62,5%. Conclusiones: Piperacilina/tazobactam logró cura clínica y microbiológica, en pacientes con infecciones por E. coli productoras de BLEE susceptibles, especialmente en ITU e IPB y en menor medida en IIA.

Background: Carbapenems are the preferred β-lactamics for treatment for infections caused by enterobacteria producing extended-spectrum β-lactamases (ESBL); however, clinical studies show effectiveness of piperacillin/tazobactam in certain infections by Escherichia coli ESBL producers. Aim: To determine the clinical and micro-biological cure with piperacillin/tazobactam in patients with infections caused by E. coli ESBL producers, CTXM type. Methods: Retrospective descriptive study with adults hospitalized in a university hospital. We included urinary tract infections (UTI), intra-abdominal infections (IAI), soft tissue infections (STI) and/or bacteremia. Results: We studied 40 patients, where 65% corresponded to UTI, 25% to IAI and 10% were STI. The overall clinical cure was achieved in 89.4%, with the best results in the ITU (100%), followed by STI (80%) and 70% in IAI. The 85% of the strains had minimum inhibitory concentrations (MIC) ≤8 μg/ml and 70% with MIC ≤4 μg/mL, however the rate of failure were high in intra-abdominal infections with high inocula or not controlled; CTX-M-15 was found in the 62.5%. Conclusions: Piperacillin/tazobactam was efficient to obtain clinical and microbiological cure in patients with infections caused by ESBL producers but susceptible E. coli, especially in UTI and STI and to a lesser extent in IAI.

Clonal relationships, antimicrobial susceptibilities, and molecular characterization of extended-spectrum beta-lactamase-producing Escherichia coli isolates from urinary tract infections and fecal samples in Southeast Iran

Abstract INTRODUCTION: Multidrug-resistant (MDR) Escherichia coli, a species that is a leading cause of urinary tract infections (UTIs) and is a major global public health concern. This study was designed to detect the differences in antibiotic resistance patterns, the production and type of extended spectrum β-lactamases (ESBLs), and the clonal relationships among E. coli isolates from UTIs and fecal samples. METHODS: Antibacterial resistance was determined by the disk diffusion method. ESBL, carbapenemase, and AmpC-producing isolates were detected phenotypically. Then, the ESBL genes were sequenced to detect the type. Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) was performed on the ESBL-positive isolates. RESULTS: The most common effective antibacterial agents were colistin, imipenem, and amikacin. Among the isolates, 204 (56.6%) were MDR. Of the 163 ESBL-positive isolates, 11 (6.7%) produced AmpC, and the frequencies of beta-lactamase-positive genes were as follows: bla CTX-Mgroup1, 76%; bla TEM1, 74.8%; bla SHV12, 1.2%; and bla OXA1, 12.88%. ERIC PCR showed a diverse pattern, suggesting that clonal spread of E. coli in this area is uncommon, and that most of the infecting strains are endogenous. CONCLUSIONS: The high rates of antibacterial-resistant and MDR isolates are quite important since these strains can act as source of resistant bacteria that can be spread in the community. Controlling antibiotic use, against inappropriate use and abuse, in the community and continuous surveillance of emerging resistance traits are critical to controlling the spread of resistance.

Isolation of blaNDM-producing Enterobacteriaceae in a public hospital in Salvador, Bahia, Brazil

ABSTRACT Carbapenemases have great importance in the global epidemiological scenario since infections with carbapenemase-producing bacteria are associated with high mortality, especially in hospitalized patients in intensive care units. This study describes two microorganisms producers of the New Delhi Metallo-b-lactamase, Klebsiella pneumoniae and Citrobacter freundii, from two patients admitted to a public hospital in Salvador, Bahia. These are the first clinical cases of New Delhi Metallo-b-lactamase described in microorganisms in the north and northeast Brazil. The isolates were characterized by antimicrobial susceptibility test, with resistance to all β-lactams including carbapenems, negative Modified Hodge Test and the synergy test with Ethylenediaminetetraacetic acid, Phenylboronic Acid and Cloxacillin was positive only with Ethylenediaminetetraacetic acid (difference of >5 mm in the inhibition zone between the disk without and with the inhibitor). Analysis by multiplex PCR for blaIMP, blaVIM, blaNDM, blaKPC and blaOXA-48 enzymes confirmed the presence of blaNDM gene. This report of two different New Delhi Metallo-b-lactamase-producing microorganisms in a different region of Brazil confirms the risk of spreading resistance genes between different species and emphasizes the need for prevention and control of infections caused by these pathogens, which have limited treatment options and have been linked to high mortality rates.

Caracterización molecular y patrón de susceptibilidad antimicrobiana de Escherichia coli productora de β -lactamasas de espectro extendido en infección del tracto urinario adquirida en la comunidad / Molecular characterization and antimicrobial susceptibility pattern of extended-spectrum β -lactamase-producing Escherichia coli as cause of community acquired urinary tract infection

Resumen Introducción Las infecciones del tracto urinario adquiridas en la comunidad (ITUac) causadas por cepas de Escherichia coli productoras de β-lactamasas de espectro extendido (BLEE), principalmente por cepas que contienen el gen blaCTX-M-15, es un fenómeno creciente a nivel mundial. Objetivo Determinar el patrón de susceptibilidad a antimicrobianos de cepas de E. coli productoras de BLEE causantes de ITUac y conocer su patrón molecular. Materiales y Métodos Se realizó un estudio descriptivo en Oaxaca, México, donde se incluyeron 288 cepas de E. coli aisladas de pacientes adultos con posible ITUac. Para obtener los patrones de susceptibilidad antimicrobiana se siguieron los criterios del CLSI y para obtener el análisis molecular se utilizó la técnica de RPC. Resultados Del total de cepas de E. coli aisladas, 31,3% fueron productoras de BLEE, presentando una menor susceptibilidad a antimicrobianos que las cepas no productoras de estas enzimas. El 95,6% de las cepas BLEE estudiadas fueron portadoras del gen blaCTX-M. Conclusiones Un tercio de las ITUac causadas por E. coli en nuestra población fueron causadas por cepas BLEE, mostrando un alto nivel de resistencia a los antimicrobianos comúnmente utilizados en su tratamiento y disminuyendo las opciones terapéuticas para tratamientos empíricos en esta población.

Background Community acquired urinary tract infections (CaUTI) caused by strains of extended-spectrum β-lactamases (ESBL) - producing Escherichia coli, mainly by strains carrying the blaCTX-M-15 gene, is a growing phenomenon worldwide. Aim To determine the antibiotic susceptibility pattern of ESBL-producing E. coli as cause of CaUTI and to identify their molecular pattern. Methods A descriptive study was performed in the city of Oaxaca, Mexico, from where 288 strains of CaUTI-producing strains of E. coli in adults with possible UTI were isolated. The CLSI criteria was followed to determine the antimicrobial susceptibility patterns, and their molecular characterization was performed by using PCR. Results 31.3% of E. coli strains isolated in our population were ESBL producers, which presented higher levels of antibiotic resistance than those of non-producers of these enzymes. 95.6% of the studied strains were carriers of the blaCTX-M gene. Conclusions One-third of the Ca-UTI caused by E. coli in our population are caused by ESBL-producing strains, which present high levels of resistance to the antibiotics widely used in our community. This situation considerably decreases the number of antibiotics available for an empiric treatment against these infections.

Incidencia de bacterias multi-resistentes en unidades de cuidados intensivos de hospitales chilenos / Incidence of multi-resistant bacteria in Intensive Care Units of Chilean hospitals

Resumen Introducción: La vigilancia de incidencia de bacterias multi-resistentes es un indicador que permite estimar mejor la magnitud de la resistencia bacteriana en los servicios hospitalarios. Objetivo: Evaluar la incidencia de bacterias multi-resistentes relevantes en unidades de cuidados intensivos del país y establecer las diferencias entre población adulta y pediátrica. Metodología: Se solicitó a los hospitales participantes información del número de aislados de siete bacterias multi-resistentes epidemiológicamente relevantes de unidades de cuidados intensivos (UCI) de adulto y pediátrico entre enero de 2014 y octubre de 2015, y el número de días-cama ocupados en dichas unidades en el mismo período. Con estos datos se calculó incidencia por 1.000 pacientes-día para cada unidad. Resultados: Se recibió información de 20 UCI adultos y 9 UCI pediátricas. En UCI adultos las bacterias de mayor incidencia fueron K. pneumoniae productora de BLEE [4,72 × 1.000 días cama (1,21-13,89)] y S. aureus resistente a oxacilina [3,85 (0,71-12,66)]. En pediatría la incidencia fue menor, destacando K. pneumoniae productora de BLEE [2,71 (0-7,11)] y P. aeruginosa resistente a carbapenémicos [1,61 (0,31-9,25)]. Conclusión: Se observan importantes diferencias entre los distintos hospitales en la incidencia de las bacterias estudiadas. La incidencia de bacterias multi-resistentes en UCI de adultos es significativamente mayor que en UCI pediátrica para la mayoría de las bacterias estudiadas.

Introduction: Incidence of multi-resistant bacteria is an indicator that permits better estimation of the magnitude of bacterial resistance in hospitals. Aim: To evaluate the incidence of relevant multi-drug resistant bacteria in intensive care units (ICUs) of Chile. Methods: Participating hospitals submitted information about the number of isolates from infected or colonized patients with 7 epidemiologically relevant multi-resistant bacteria in adult and pediatric ICUs between January 1, 2014 and October 31, 2015 and the number of bed days occupied in these units in the same period was requested. With these data incidence was calculated per 1,000 patient days for each unit. Results: Information from 20 adults and 9 pediatric ICUs was reviewed. In adult ICUs the bacteria with the highest incidence were K. pneumoniae ESBL [4.72 × 1,000 patient day (1.21-13.89)] and oxacillin -resistant S. aureus [3.85 (0.71-12.66)]. In the pediatric units the incidence was lower, highlighting K. pneumoniae ESBL [2.71 (0-7.11)] and carbapenem -resistant P. aeruginosa [1.61 (0.31-9.25)]. Conclusion: Important differences between hospitals in the incidence of these bacteria were observed. Incidence of multi-resistant bacteria in adult ICU was significantly higher than in pediatric ICU for most of the studied bacterias.

Detection of multidrug-resistant Pseudomonas aeruginosa harboring bla GES-1 and bla GES-11 in Recife, Brazil

Abstract INTRODUCTION: Pseudomonas aeruginosa, an important pathogen globally, presents several resistance mechanisms. This study aimed to investigate the presence of bla GES in clinical isolates of Pseudomonas aeruginosa obtained from various clinical specimens from patients admitted to three different hospitals in Recife, Brazil. The Guiana extended spectrum beta-lactamase (GES) enzymes are responsible for conferring broad spectrum resistance to beta-lactam drugs, including the carbapenems. METHODS: A total of 100 carbapenem-resistant P. aeruginosa isolates underwent polymerase chain reaction (PCR) testing to identify bla GES, bla KPC, bla SPM-1, bla IMP, and bla VIM. Additionally, PCR products positive for bla GES were sequenced. The clonal profiles of these same isolates were then determined by means of enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis. RESULTS: PCR analysis revealed that four isolates harbored bla GES; DNA sequencing showed that two harbored bla GES-1 and two bla GES-11. Beta-lactamase genes bla SPM-1, bla IMP, bla VIM, and bla KPC were investigated; none of these genes was detected. Automated susceptibility testing methods (Vitek®2, bioMérieux) showed that the bla GES-1-positive isolates were only susceptible to polymyxin B. The patterns obtained with ERIC-PCR methods showed clonal relationship between the two isolates that harbored bla GES-11, whereas different clonal profiles were found in the isolates harboring bla GES-1. CONCLUSIONS: We detected the presence of bacterial isolates positive for two different variants of the enzyme GES in three different hospitals from Recife, Brazil. These enzymes have a great capacity for dissemination among Gram-negative bacteria and confer broad-spectrum resistance to beta-lactam antibiotics and to the carbapenems.

Primer relevamiento de marcadores de resistencia a antibióticos en Enterobacteriaceae en Cochabamba, Bolivia / First survey on antibiotic resistance markers in Enterobacteriaceae in Cochabamba, Bolivia

A molecular survey was conducted in Cochabamba, Bolivia, to characterize the mechanism involved in the resistance to clinically relevant antibiotics. Extended Spectrum β-lactamase encoding genes and plasmid-mediated quinolone resistance (PMQR) markers were investigated in a total of 101 oxyimino-cephalosporin-resistant enterobacteria recovered from different health centers during four months (2012-2013). CTX-M enzymes were detected in all isolates, being the CTX-M-1 group the most prevalent (88.1%). The presence of blaOXA-1 was detected in 76.4% of these isolates. A high quinolone resistance rate was observed among the included isolates. The aac(6′)-Ib-cr gene was the most frequent PMQR identified (83.0%). Furthermore, 6 isolates harbored the qnrB gene. Interestingly, qepA1 (6) and oqxAB (1), were detected in 7 Escherichia coli, being the latter the first to be reported in Bolivia. This study constitutes the first molecular survey on resistance markers in clinical enterobacterial isolates in Cochabamba, Bolivia, contributing to the regional knowledge of the epidemiological situation. The molecular epidemiology observed herein resembles the scene reported in South America.

Se llevó a cabo un relevamiento molecular de la resistencia a antibióticos de importancia clínica en aislamientos recuperados en Cochabamba, Bolivia. Se estudiaron los genes codificantes de β-lactamasas de espectro extendido y de resistencia a quinolonas de localización plasmídica (PMQR) en un total de 101 aislamientos de enterobacterias resistentes a oximinocefalosporinas recuperados en distintos centros de salud, durante 4 meses (2012-2013). En todos ellos se detectó la presencia de cefotaximasas, las CTX-M grupo 1 fueron las más prevalentes (88,1%). La presencia de blaOXA-1 se detectó en el 76,4% de estos aislamientos. Se observó una elevada proporción de aislamientos resistentes a quinolonas. El gen aac(6′)-Ib-cr fue el determinante PMQR más frecuentemente identificado (83%). Además, 6 aislamientos resultaron ser portadores de qnrB. Por otro lado, cabe remarcar que 7 Escherichia coli presentaron qepA1 (6) y oqxAB (1); se documenta así por primera vez la presencia de oqxAB en Bolivia. Este estudio constituye el primer relevamiento de marcadores de resistencia en aislamientos clínicos de enterobacterias en Cochabamba, Bolivia; de este modo se contribuye al conocimiento regional de la situación epidemiológica, la cual presenta un escenario similar al observado en el resto de Latinoamérica.

Antimicrobial resistance profiles and oxacillinase genes in carbapenem-resistant Acinetobacter baumannii isolated from hospitalized patients in Santa Catarina, Brazil

Abstract: INTRODUCTION: Carbapenems are the therapy of choice for treating severe infections caused by the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. We aimed to assess the prevalence and antimicrobial susceptibility profiles of producers of distinct oxacillinases among nosocomial isolates of the A. calcoaceticus-A. baumannii complex in a 249-bed general hospital located in Joinville, Southern Brazil. METHODS: Of the 139 A. baumannii clinical isolates with reduced susceptibility to carbapenems between 2010 and 2013, 118 isolates from varying anatomical sites and hospital sectors were selected for genotypic analysis. Five families of genes encoding oxacillinases, namely blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, blaOXA-58-like, and blaOXA-143-like, wereinvestigated by multiplex polymerase chain reaction (PCR). RESULTS: Most (87.3%) isolates simultaneously carried the blaOXA-23-likeand blaOXA-51-likegenes, whereas three (2.5%) isolates harbored only blaOXA-51-likeones. The circulation of carbapenem-resistant isolates increased during the study period: from none in 2010, to 22 in 2011, 64 in 2012, and 53 in 2013. CONCLUSIONS: Isolates carrying the blaOXA-23-likeand blaOXA-51-likegenes were widely distributed in the hospital investigated. Because of the worsening scenario, the implementation of preventive measures and effective barriers is needed.

In vitro activity of fosfomycin tromethamine against extended spectrum beta-lactamase producing urinary tract bacteria

To determine the in vitro activity of Fosfomycin tromethamine against extended spectrum beta-lactamase producing uropathogens. Experimental study. Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from October 2011 to October 2012. A total of 381 culture positive ESBL producing isolates from 2400 urine samples submitted over a period of one year were included in this study. Identification of isolates was done by standard biochemical profile of the organisms. The antimicrobial susceptibility of culture positive isolates was performed by disk diffusion method as recommended by Clinical Laboratory Standard Institute guidelines [CLSI]. The antimicrobial activity of Fosfomycin to various isolates revealed that 93% of E. coli, 64% Klebsiella spp. 50% Proteus spp. 75% Enterobacter cloacae, 100% Citrobacter freundii, 100% Burkholderia spp. 100% Serratia spp. and 50% Stenotrophomonas maltophilia were susceptible to this chemical compound. Fosfomycin showed excellent effectiveness to most of the common ESBL producing bacteria such as E. coli, Klebsiella and Proteus spp

Detection of FUS-1 (OXA-85), a Class D Betalactamase from Fusobacterium nucleatum Subspecies Polymorphum in Nigeria.

Aims: Beta-lactamase production and subsequent resistance to β-lactam drugs has been a global concern in the treatment of Gram negative anaerobes. The aim of this study was to identify F. nucleatum strains producing Class D β-lactamase through the detection of FUS-1 (OXA-85) resistance gene. Place and Duration of Study: Department of Preventive Dentistry, Lagos University Teaching Hospital, Idi-Araba, between February 2010 and November 2010. Methodology: Twenty two oral clinical samples were obtained from patients with chronic periodontitis who admitted to previous use of amoxicillin. Antibacterial susceptibility of the bacterial isolates was determined by E-test on Brucella Blood agar. Amplification of the bacterial DNA was carried out by PCR using F. nucleatum species-specific primer, FUS-1 specific for blaFUS-1 and strain-specific primers for subspecies nucleatum,, fusiforme, polymorphum and vincentii. Results: From the 19 samples collected, F. nucleatum was isolated, and the identity of the isolates was confirmed by PCR. Four of the isolates produced similar bands with the control strain, 3 (15.7%) strains were able to produce amplication with FUS-1 primer specific for blaFUS-1 gene found in β-lactamase producing F. nucleatum subsp. polymorphum. Conclusion: This study shows the presence of class D β-lactamase producing F. nucleatum species in Nigeria.

Incidence of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in patients with urinary tract infection / Incidência de Klebsiella pneumoniae produtoras de beta-lactamases de espectro estendido em pacientes com infecção do trato urinário

CONTEXT AND OBJECTIVES: Resistant bacteria are emerging worldwide as a threat to favorable outcomes from treating common infections in community and hospital settings. The present investigation was carried out to study the incidence of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in patients with urinary tract infection in different seasons of the year, in order to determine the prevalence of the genes blaTEM, blaSHV and blaCTX-M, which are responsible for ESBL production among ESBL-producing K. pneumoniae, in three cities in Iran, and to investigate the antimicrobial susceptibility pattern of K. pneumoniae in different seasons. DESIGN AND SETTING: Retrospective study carried out among patients with urinary tract infections in five hospitals in Iran. METHOD: Two hundred and eighty-eight clinical isolates of K. pneumoniae were collected between March 2007 and April 2008 from five hospitals in three cities in Iran. ESBLs were identified by phenotypic and genotypic methods. ESBL-producing Klebsiella pneumoniae were evaluated against non-beta-lactam antibiotics. Genes coding for ESBLs (blaSHV, TEM and CTX-M) were screened. RESULTS: Among the 288 clinical isolates of K. pneumoniae, 37.7 percent, 46.7 percent and 15.6 percent were obtained from hospitals in Ilam, Tehran and Tabriz, respectively, of which 39.4 percent, 50.7 percent and 45.8 percent were ESBL-producing K. pneumoniae in Ilam, Milad and Emam Reza hospitals, respectively. CONCLUSION: According to the results from this study, resistance to third-generation cephalosporins is higher during the cold months than during the warm months.

CONTEXTO E OBJETIVOS: As bactérias resistentes estão surgindo em todo o mundo como uma ameaça ao resultado favorável no tratamento de infecções comuns em ambientes comunitários e hospitalares. O presente estudo foi realizado com o objetivo de avaliar a incidência de Klebsiella pneumoniae produtoras de beta-lactamases de espectro estendido (BLEEs) em pacientes com infecção do trato urinário em diferentes estações do ano, para verificar a prevalência dos genes blaTEM, blaSHV e blaCTX-M responsáveis para a produção de BLEEs em K. pneumoniae productoras de BLEEs, em três cidades do Irã, e investigar o perfil de sensibilidade antimicrobiana de K. pneumoniae em diferentes estações. DESENHO E LOCAL: Estudo retrospectivo realizado em pacientes com infecções do trato urinário em cinco hospitais no Irã. MÉTODO: Duzentos e oitenta e oito isolados clínicos de K. penumoniae foram coletados entre março de 2007 e abril de 2008 em cinco hospitais de três cidades no Irã. BLEEs foram identificados por métodos fenotípicos e genotípicos. K. pneumoniae produtoras de BLEEs foram avaliadas contra antibióticos não beta-lactâmicos. Os genes codificadores de BLEEs (blaSHV, TEM e CTX-M) foram investigados. RESULTADOS: Entre os 288 isolados clínicos de K. pneumoniae, 37,7 por cento, 46,7 por cento e 15,6 por cento eram provenientes dos hospitais em Ilam, Tehran e Tabriz, respectivamente, dos quais 39,4 por cento, 50,7 por cento e 45,8 por cento eram K. pneumoniae produtoras de BLEEs nos hospitais em Ilam, Milad e Eman Reza, respectivamente. CONCLUSÃO: De acordo com os resultados deste estudo, a resistência às cefalosporinas de terceira geração é maior nos meses frios do que nos meses quentes.

Antimicrobial susceptibility testing and ESBLdetection from the bacteria in haemodialysis patients

To find out the antimicrobial sensitivity and extended spectrum beta-lactamase producing organisms among clinical isolates recovered from patients on haemodialysis. Extended spectrum beta-lactamase are enzymes produced from some strains of gram negative bacilli that mediate resistance to extended spectrum cephalosporin and aztreonam. They are most common in E.coli and Klebsiella species but are present in variety of enterobacteriacea. Experimental and observational study. This study was carried out in Microbiology Department of BMSI, JPMC, Karachi. This study was carried out from June 2005 to June 2006. A total of 250 cases irrespective of age and gender were included in this study. A total of 15 gram positive cocci [7.5%] and 175 [87.5%] gram negative organisms were recovered. In this study 66.66% E.coli and 33.33% Klebsiella species were ESBL producing. Antimicrobial sensitivity pattern in this study show that most of the organisms were sensitive to 2[nd] and 3[rd] generation cephalosporins and fluroquinolones i.e. ciprofloxacin. Table 1 shows isolation of ESBL producing organisms from 200 positive cases. Out of these 175 cases were from Enterobacteriaceae, among these 06 [3.42%] cases have been found to be ESBL producing organisms. The results of this study support the use of initial antimicrobial therapy to reduce the spread of infection and other complications. Currently ciprofloxacin is regarded as the drug of choice for the treatment of infection caused by both gram negative and gram positive bacteria in patients on hemodialysis

A prospective study of ceftriaxone treatment in acute pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria.

BACKGROUND: Much controversy exists as to whether cephalosporin treatment is appropriate for infections caused by ESBL-producing organisms because no randomized controlled studies have been performed. OBJECTIVE: Evaluate the therapeutic outcomes of ceftriaxone treatment in acute pyelonephritis caused by ESBL-producing Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis. MATERIAL AND METHOD: The authors performed a prospective study in female patients hospitalized with acute pyelonephritis caused by ESBL-producing or ESBL-nonproducing E. coli, K. pneumoniae, or P. mirabilis in four hospitals in Thailand from 2004 to 2006. The clinical and microbiological outcomes were evaluated at 72 hours after empirical ceftriaxone treatment. RESULTS: One hundred eleven patients with the mean age of 65.29 years participated in this study. There were no differences in demographic and clinical characteristics and laboratory data between the ESBL-producing and ESBL-nonproducing groups except the higher rates of previous antibiotic use and urinary tract infection; and the lower frequency of costovertebral angle tenderness in the ESBL-producing group. Both clinical (65% and 93%) and microbiological (67.5% and 100%) responses at 72 hours after ceftriaxone treatment were poorer in the ESBL-producing group than in the ESBL-nonproducing group (p < 0.0002). CONCLUSION: To the authors' knowledge, this is the first prospective study to evaluate the outcomes of ceftriaxone treatment in acute pyelonephritis caused by ESBL-producing Enterobacteriaceae. The present study confirms that acute pyelonephritis in the female patients caused by ESBL-producing strains could not be treated with ceftriaxone.

In vitro study to compare sensitivity of amoxicillin+clavulanic acid and cefpodoxime+clavulanic acid among beta-lactamase positive clinical isolates of gram-positive and gram-negative pathogens.

The present study was carried out to compare the in vitro sensitivity of cefpodoxime + clavulanic acid and amoxicillin + clavulanic acid against 55 Gram-positive and 123 Gram-negative beta-lactamase positive clinical isolates. Micro-organisms isolated from different clinical specimens were tested for beta-lactamase/ESBL by using nitrocefin disc test and for metallo beta-lactamase by using double disc synergy test. A total of 299 (93 Gram-positive and 206 Gram-negative) clinical isolates were tested for beta-lactamase. Among 93 Gram-positive clinical isolates 25 (78.12%) out of 32 coagulase positive S. aureus, 23 (60.52%) out of 38 coagulase negative S aureus, 7 (63.63%) out of 11 enterococci and 0 (0%) out of 12 Strept pneumoniae were positive for beta-lactamase /ESBL. Notably Strept pneumoniae was found to be beta-lactamase/ESBL negative. Among 206 Gram-negative clinical isolates, 25 (69.44%) out of 36 acinetobacter spp, 20 (41.66%) out of 48 Branhamella catarrhalis, 24 (64.86%) out of 37 E. coli, 7 (46.66%) out of 15 H influenzae and 22 (62.85%) out of 35 proteus were positive for beta-lactamase/ ESBL/metallo beta-lactamase. Positive strains were tested for comparative sensitivity to amoxicillin+ clavulanic acid and cefpodoxime+clavulanic acid by Kirby Bauer disc diffusion method. As regards comparative sensitivity among beta-lactamase/ESBL positive Gram-positive strains, 84% and 92% strains of coagulase positive S aureus, 65.21% and 86.95% strains of coagulase negative S. aureus, 83.33% and 100% strains of Strept pneumoniae and 71.42% and 100% strains of enterococci were found sensitive to amoxicillin +clavulanic acid and cefpodoxime + clavulanic acid respectively. Sensitivity to amoxicillin+ clavulanic acid and cefpodoxime +clavulanic acid among beta lactamase/ESBL positive Gram-negative strains of acinetobacter spp, Branhamella catarrhalis, E. coli, H. influenzae and proteus spp were found to be 20% and 28%, 100% and 100%, 50% and 75%, 71.42% and 100%, 50% and 68.18% respectively. This study demonstrated that cefpodoxime +clavulanic acid combination has more potent in vitro activity in comparison to amoxicillin+ clavulanic acid combination against beta-lactamase producing strains of Gram-positive and Gram-negative bacteria. Given this broad spectrum of activity, cefpodoxime+clavulanic acid appears well suited for use in the treatment of a variety of healthcare-associated infections.

Utility of the ceftazidime-imipenem antagonism test (CIAT) to detect and confirm the presence of inducible AmpC beta-lactamases among enterobacteriaceae

Detection of AmpC beta-lactamase production by enterobacteria has been problematic. Contrary to ESBLs, no specific guidelines are available for detection and confirmation of AmpC production by clinical relevant microorganisms. Moreover, some bacterial species may produce inducible AmpC beta-lactamases that can be easily overlooked by routine susceptibility tests. We reported here a new test based on the strong inducible effect of imipenem on AmpC genes and the consequent antagonism with ceftazidime. This test is very simple and proved to be helpful in detecting AmpC-inducible enzymes among several species of clinical isolates.

Alta correlación entre el consumo de ciprofloxacina y la prevalencia de Klebsiella pneumoniae productora de ß-lactamasas de espectro extendido / High relationship between ciprofloxacin use and prevalence of ESBL Klebsiella pneumoniae

Background: To assess the relationship between ciprofloxacin use and the prevalence of extended spectrum betalactamases (ESBL) Klebsiella pneumoniae. Patients and Methods: Semestral mean values regarding use of antibiotic and prevalence of ESBL Kp were compared during 9 semesters using linear regression and coefficient of correlation. Results: The only statistically significant correlation was ciprofloxacin use and ESBL(+) K. pneumoniae prevalence, with a coefficient of correlation of 0.86 and p = 0.0027 using linear regression. Conclusions: Ciprofloxacin use must be taking into account when considering infection control programs due to high prevalence rates of ESBL(+) K. pneumoniae in the hospital setting.

Fundamento: Evaluar la correlación entre el consumo de cefalosporinas de tercera generación y ciprofloxacina con la prevalencia de cepas de Klebsiella pneumoniae productoras de ß-lactamasas de espectro extendido (BLEE). Pacientes y Métodos: Los valores promedios semestrales, correspondientes a consumo y prevalencia se compararon durante 9 semestres, usando coeficiente de correlación y regresión lineal. Resultados: La única asociación que resultó estadísticamente significativa, fue la correspondiente al consumo de ciprofloxacina y K. pneumoniae BLEE (+), con un coeficiente de correlación de 0,86 y una p de 0,0027, en el análisis de regresión lineal. Conclusiones: El consumo de ciprofloxacina debe ser tenido en cuenta al momento de establecer programas de control de infecciones frente a elevadas tasas de prevalencia de K. pneumoniae productoras de BLEE en un hospital.

Fatores de risco para amigdalite aguda de repetiçäo em crianças / Risk factors for recurrent acute tonsillitis in children

Objetivo: Avaliar os fatores de risco envolvidos na gênese de quadros de amigdalite aguda de repetiçao. Método: Quarenta crianças com idades entre dois e doze anos, portadoras de amigdalite de repetiçao e outras quarenta, aparentemente saudáveis e sem qualquer doença de mesma faixa etária foram submetidos a questionário que investiga sobre presença dos seguintes fatores de risco: tempo de aleitamento materno, condiçoes de habitaçao (número de cômodos, número de pessoas dormindo no mesmo cômodo, grau de insolaçao), presença de animais na moradia, hábito de chupar dedo ou chupeta, permanência em creche ou escola, presença de contactantes, apetite e presença de fumantes na moradia. Os dados foram submetidos a análise estatística empregando-se as teses de Qui-quadrado e exato de Fisher com nível de significância de 5 por cento. Resultados: Na amostra analisada, piores condiçoes de hábitaçao, com moradias pequenas, com maior número de pessoas e presença de animais na mesma, a exposiçao passiva ao fumo e a reduçao do apetite foram estatisticamente mais freqüentes entre os com amigdalite aguda de repetiçao. Já, o tempo de aleitamento materno, a freqüência à creche ou escola, o hábito de chupar o dedo ou a chupeta, a insolaçao da residência e a presença de contactantes nao o foram. Conclusao: Piores condiçoes de habitaçao, presença de animal doméstico na residência, exposiçao ao fumo e apetite diminuído foram possíveis fatores de risco para amigdalite aguda de repetiçao.