Characterization of third generation cephalosporin-resistant Escherichia coli clinical isolates from Ushuaia, Argentina / Caracterización de aislamientos clínicos de Escherichia coli resistente a cefalosporinas de tercera generación de Ushuaia, Argentina

Abstract Escherichia coli is one of the main human pathogens causing different hospital- and community-acquired infections. During the period from January 2013 to March 2015, 1.96% (32/1632) of E. coli isolates recovered at the Hospital Regional de Ushuaia, Tierra del Fuego province, were resistant to third-generation cephalosporins (TGCs). These isolates were resistant to cefotaxime (91%) and/or ceftazidime (28%). No resistance to carbapenems was detected. Twenty-six isolates were positive for blaCTX-M gene, grouped as CTX-M-1/15 (54%); CTX-M-9/14 (25%); CTX-M-2 (17%); and CTX-M-1/15 plus CTX-M-9/14 (4%). Five TGC-resistant strains were positive for blaCMY gene, while one strain harbored TEM-19 ESBL. Twelve isolates were identified as ST131 E. coli hyperepidemic clone, and one as ST69. Genome sequence analysis of seven blaCTX-M-15 E. coli selected isolates confirm the circulation of ST131, ST617 and ST405 international high-risk clones in the city of Ushuaia.

Resumen Escherichia coli es uno de los principales patógenos humanos causantes de diferentes infecciones de inicio hospitalario y comunitario. Se determinó que el 1,96% (32/1.632) de los aislamientos de E. coli recuperados entre enero de 2013 y marzo de 2015 en el Hospital Regional de Ushuaia, provincia de Tierra del Fuego, fueron resistentes a cefalosporinas de tercera generación (CTG). Estos aislamientos fueron resistentes a cefotaxima (91%) y/o a ceftazidima (28%). No se detectó resistencia a los carbapenemes. Veintiséis aislamientos fueron positivos para el gen blaCTX-M, agrupados como CTX-M-1/15 (54%), CTX-M-9/14 (25%), CTX-M-2 (17%) y CTX-M-1/15 más CTX-M-9/14 (4%). Cinco cepas resistentes a CTG dieron positivo para el gen blaCMY, mientras que un aislamiento presentó la BLEE TEM-19. Doce aislamientos se identificaron como clon hiperepidémico E. coli ST131 y uno como ST69. El análisis de las secuencias del genoma de siete aislamientos seleccionados de E. coli blaCTX-M-15 confirmó la circulación de los clones internacionales de alto riesgo ST131, ST617 y ST405 en la ciudad de Ushuaia.

Antibiotic resistance profile in intrahospital pediatric services at third level centers in Dominican Republic / Perfil de resistencia a antibióticos en servicios pediátricos intrahospitalarios en centros de tercer nivel en República Dominicana

Objectives: The Dominican Republic lacks reliable information on antimicrobial resistance (AMR), which would allow physicians to prescribe the best treatment for common infectious diseases. This study aimed to define the antimicrobial resistance profiles of the more common pathogens from pediatric services, where data is even more important due to the vulnerability of the population. Methods: We collected data from patients admitted in the pediatric unit of three third level hospitals in the city of Santiago de los Caballeros, Dominican Republic, showing positive bacterial cultures, during a period of two years. Results: Half of the Gram negative pathogens exhibited third generation cephalosporins (3GC) resistance, 17% were resistant to carbapenems. Serratia marcescens presented an exceptionally high proportion of resistance to 3GC (95.9%). Staphylococcus aureus showed elevated resistance to methicillin (58.4%) and even to clindamycin (35.8%). Conclusion: There are elevated levels of antimicrobial resistance among the Enterobacteriaceae family and the Staphylococcus genus isolated from the pediatric population. Necessary measures should be taken to tackle AMR in the country.

Objetivos: La República Dominicana carece de información confiable sobre las resistencias antimicrobianas en el país, lo que permitiría al personal médico prescribir los mejores tratamientos para infecciones comunes. El objetivo de este estudio es definir los perfiles de resistencia antimicrobiana de los patógenos más comunes en servicios pediátricos, donde esta información es esencial, debido a la vulnerabilidad de la población. Métodos: Se tomaron los datos de reportes microbiológicos con cultivo bacteriano positivo procedentes de pacientes admitidos en la unidad pediátrica de tres hospitales de tercer nivel en la ciudad de Santiago de los Caballeros, República Dominicana, durante un periodo de dos años. Resultados: La mitad de los patógenos Gram negativos mostraron resistencia a cefalosporinas de tercera generación (3GC), 17% eran resistentes a carbapenémicos. Serratia marcescens presentó una resistencia excepcionalmente elevada a 3GC (95.9%). Staphylococcus aureus mostró alta resistencia a meticilina (58.4%) e incluso a clindamicina (35.8%). Conclusión: Existen elevados niveles de resistencia antimicrobiana entre las enterobacterias y los estafilococos en la población pediátrica dominicana. Es necesario tomar medidas para abordar este problema en el país.

Antimicrobial Profile of Clinical Isolates in Intensive Car e Unit at a Tertiary Care Hospital

Introduction: Intensive Care Units (ICU’s) provides a suitable environment for the proliferation and persistence of multidrug organisms. The burden of nosocomial infections among critically ill patients is much higher in developing countries. Aims and Objectives: The present study was conducted to know the prevalence of bacterial pathogens from various ICU’s of a tertiary care hospital and to determine their resistance profile. Materials and methods: A retrospective study was done on 188 isolates collected over a period of 10 months from January 2018 to October 2018. The isolates were identified by the conventional biochemical method and antimicrobial susceptibility testing was performed by Kirby bauer disc diffusion method. Results: The most common gram negative isolate obtained in this study was Klebsiella spp. About 90/188 (47.87%), followed by Pseudomonas aeruginosa 22/188 (11.70%), Acinetobacter spp. 21/188 (11.17%), and E. coli 20/188 (10.64%). The predominant gram positive cocci isolated were Enterococcus spp. 9/188 (4.79%). All gram negative bacilli were sensitive to Imipenem. About 23.33% of Klebsiella isolates were resistant to Piperacillin tazobactam and 18.89% to Cefoperazone sulbactam. The most effective drugs against gram negative bacilli were Imipenem, Piperacillin tazobactam, and Cefoperazone sulbactam. Conclusion: This study showed the prevalence of multidrug resistant Klebsiella spp. from various ICU’s. These isolates were resistant to third generation cephalosporins, quinolones, and aminoglycosides and were sensitive to carbapenems. Among the non-fermenting gram negative bacilli, the resistant rates were higher for Acinetobacter isolates compared to Pseudomonas aeruginosa.

The Trends of the Species and Antimicrobial Susceptibility of Bacteria and Fungi Isolated from Blood Cultures (1986-1996) / 대한임상병리학회지

BACKGROUND: Analysis of the species and antimicrobial susceptibility trend of bacterial and fungal isolate from blood can provide the clinicians with important informations for the treatment of the patients. METHODS: We analyzed the species and antimicrobial susceptibility trends of microorganisms isolated from blood cultures from 1986 to 1996 at Kyunghee Medical Center. Identification of organism was based on conventional methods or commercial kit systems. Antimicrobial susceptibility test was done by the NCCLS disk diffusion method. RESULTS: The positive blood culture was obtained from 3,559 patients. Among the patients 95.6% showed aerobic and facultative anaerobic bacteria, 0.9% anaerobes, and 3.6% fungi. Escherichia coli was isolated most frequently, followed by Coagulase-negative staphylococcus, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus, alpha- hemolytic Streptococcus and Serratia. The proportion of patients with E. coli decreased from 34.5% in 1986 to 22.1% in 1996, while that of S. aureus increased from 9.7% to 13.9%. Proportion of methicillin-resistant S. aureus and the third generation cephalosporin-resistant K. pneumoniae increased during the study period. CONCLUSIONS: We conclude that E. coli is the most common cause of bacteremia at Kyunghee Medical Center. The third generation cephalosporin-resistant K. pneumoniae and methicillin- resistant S. aureus are increasing in proportion.