Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patientsinIndian

Objective: To record surveillance, antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months. Methods: Urine samples from wards and cabins were used for isolating urinary tract infection (UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests; and their antibiograms were ascertained by Kirby-Bauer’s disc diffusion method, in each 6-month interval of the study period, using 18 antibiotics of five different classes. Results: From wards and cabins, 1 245 samples were collected, from which 996 strains of bacteria belonging to 11 species were isolated, during April 2011 to September 2012. Two Gram-positive, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and nine Gram-negative bacteria, Acinetobacter baumannii, Citrobacter sp., Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were isolated. Both S. aureus and E. faecalis were vancomycin resistant, and resistant-strains of all pathogens increased in each 6-month period of study. Particularly, all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole, the most preferred antibiotics of empiric therapy for UTI. Conclusions: Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae andS. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern.

Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patients in Indian

<p><b>OBJECTIVE</b>To record surveillance, antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months.</p><p><b>METHODS</b>Urine samples from wards and cabins were used for isolating urinary tract infection (UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests; and their antibiograms were ascertained by Kirby-Bauer's disc diffusion method, in each 6-month interval of the study period, using 18 antibiotics of five different classes.</p><p><b>RESULTS</b>From wards and cabins, 1 245 samples were collected, from which 996 strains of bacteria belonging to 11 species were isolated, during April 2011 to September 2012. Two Gram-positive, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and nine Gram-negative bacteria, Acinetobacter baumannii, Citrobacter sp., Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were isolated. Both S. aureus and E. faecalis were vancomycin resistant, and resistant-strains of all pathogens increased in each 6-month period of study. Particularly, all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole, the most preferred antibiotics of empiric therapy for UTI.</p><p><b>CONCLUSIONS</b>Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and S. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern.</p>

Recomendaciones para el análisis de datos acumulados de susceptibilidad antimicrobiana en instituciones de salud / Recommendations for the analysis of cumulated data in antimicrobial susceptibility in health institutions

Due to the great variability in antimicrobial resistance patterns, local reports of cumulative antimicrobial susceptibility data are necessary in every health center. The purpose is to guide clinical decisions and the early detection of patterns that allow preventive measures to avoid dissemination of resistant strains. The main objective of this guide is to provide recommendations for the analysis of antimicrobial susceptibility data and elaboration of a local report. Recommendations provided in this guide are based on the Clinical and Laboratory Standards Institute (CLSI) document "Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data" (3). Key aspects related to information gathering and data processing, analysis and presentation are described.

Considerando la gran variabilidad en la distribución de la resistencia microbiana, es una necesidad que cada centro de salud genere reportes locales de datos acumulados de susceptibilidad, con el propósito de guiar las decisiones clínicas y detectar tendencias que permitan establecer medidas de prevención para evitar la diseminación de cepas resistentes. Esta guía tiene como objetivo entregar recomendaciones para el análisis de susceptibilidad antimicrobiana y aportar datos útiles para la elaboración del informe local. Las recomendaciones que contenidas em este documento están basadas en el documento "Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data de Clinical and Laboratory Standards Institute (CLSI) (3). Se describen aspectos claves relacionados con los requerimientos de la información, el procesamiento de los datos, el análisis y presentación de éstos.

Characterisation of Methicillin-resistant Staphylococcus aureus isolated from blood cultures in South East Asian hospitals

Methicillin-resistance Staphylococcus aureus (MRSA) are common in hospitals in many countries, including South East Asia. Nosocomial MRSA is characteristically resistant to multiple antibiotics but can be treated with vancomycin. More recently MRSA have emerged in the community (CMRSA) and these characteristically are not multiply resistant like the hospital strains. MRSA have been found to spread within and between hospitals, thus are referred to as epidermic MRSA (EMRSA). It is therefore important to characterise isolates so that pathogenic and epidemic strains of MRSA can be identified. For this study 309 MRSA isolated from blood cultures between June 1998 and December 1999 were provided by the Sentry Program Centre in Adelaide, South Australia. The isolates were from hospitals in Australia, South Africa, Singapore, China, Hong Kong, Taiwan, the Philippines and Japan. Isolates were characterised by phenotypic and molecular methods. The methods used were extended antibiograms and resistograms, bacteriophage typing, countour-clamped homogeneous electric field (CHEF) electrophoresis, plasmid profiling and analysis of the mec complex. Most of the isolates were resistant to the majority of the antimicrobials tested although all were susceptible to vancomycin. Three isolates from Hong Kong and seven from Royal Perth hospitals had resistance profiles similar to those of CMRSA. The majority of isolates were not susceptible to the International Bacteriophage Set (IBS). There was a predominant CHEF pattern amongst the South African isolates which had 88% similarity with the Australian CHEF pattern 1. However, the isolates were not related in other respects and had different plasmid profiles and mec complexes. The results indicated that the South African isolates are different from those from other hospitals and that Taiwanese and Japanese isolates are generally more diverse than those in the other countries. Hospitals in Australia, Singapore and Hong Kong appear to have many different strains but do not have predominance of a particular strain. This study has provided a basis for additional studies to further characterise isolates from various countries and to understand the epidemiology of MRSA in the hospitals.

Estudio de susceptibilidad a tigeciclina: Influencia del agar Mueller-Hinton en el método de difusión en agar y validación del método E-test® para Acinetobacter baumannii / In vitro evaluation of tygecicline: Influence of Mueller-Hinton agar in agar diffussion methods and validation of E-test® for Acinetobacter baumannii

Tigecycline is a glicylcicline with broad antimicrobial spectrum. Susceptibility testing to this drug for Acinetobacter is difficult in hospitals due to the utilization of the disk diffusion method. FDA break points have shown an unacceptable rate of errors (23 percent) for disk diffusion versus broth microdilution in American studies and overcall of resistance depending on the brand of Mueller Hinton agar used. Modifications to these FDA break points have been proposed, but there is not enough evidence yet. Data from a multicenter study from Chile allowed the evaluation of the characteristics of the agar used for susceptibility testing and the utility of E-test as an alternative MIC method for Acinetobacter. The Mueller Hinton agar brand is an important factor that affects disk diffusion method results. There is very good correlation between broth microdilution and E-test for the susceptibility category as well as for MIC determination. The intermedíate and resistant results obtained with disk diffusion method should be checked by using E-test.

Tigeciclina es una glicilciclina de amplio espectro antimicrobiano. La determinación de la susceptibilidad a este fármaco presenta dificultades en el laboratorio asistencial al utilizar la técnica de difusión por disco para Acinetobacter spp. Los puntos de corte -según la (FDA- han mostrado una tasa inaceptable de errores (23 por ciento) en comparación con el método de micro-dilución en caldo en estudios americanos, diversas evaluaciones demuestran que existe una sobreestimación de resistencia in vitro dependiendo de las características del agar Mueller Hinton utilizado. Se han propuesto modificaciones a los puntos de corte pero no se han oficializado por insuficientes evidencias. Los datos de un estudio multicéntrico realizado en Chile permitieron evaluar la influencia de las distintas marcas de medios de cultivo en el tamaño de los halos y la utilidad de la epsilometría (E-test®) como método CIM para Acinetobacter sp. La marca de agar Mueller Hinton y otros factores propios del medio dificultan la determinación de la susceptibilidad a tigeciclina utilizando difusión por disco. Existe muy buena correlación entre la micro-dilución en caldo y el E- test®, tanto para la categoría de susceptibilidad como para la CIM. Por esto, se sugiere que los resultados intermedios o resistentes obtenidos por difusión en agar para A. baumannii sean comprobados mediante el uso de E-test®.