In Vitro Antimicrobial Susceptibility Testing of Bacterial Enteropathogens Causing Traveler's Diarrhea in Four Geographic Regions

Abstract

The emergence of resistant enteropathogens has been reported worldwide. Few data are available on the contemporary in vitro activities of commonly used antimicrobial agents against enteropathogens causing traveler's diarrhea (TD). The susceptibility patterns of antimicrobial agents currently available or under evaluation against pathogens causing TD in four different areas of the world were evaluated. Pathogens were identified in stool samples from U.S., Canadian, or European adults (18 years of age or older) with TD during 1997, visiting India, Mexico, Jamaica, or Kenya. MICs of 11different antimicrobials were determined against 284 bacterial enteropathogens by the agar dilution method. Ciprofloxacin, levofloxacin, ceftriaxone, and azithromycin were highly active in vitro against the enteropathogens, while traditional antimicrobials such as ampicillin, trimethoprim, and trimethoprim/sulfamethoxazole showed high levels and high frequencies of resistance. Rifaximin, a promising and poorly absorbable drug, had an MIC at which 90% of the strains tested were inhibited of 32 g/ml, 250 times lower than the concentration of this drug in the stools. Amdinocillin, nalidixic acid, and doxycycline showed moderate activity. Fluoroquinolones are still the drugs of choice for TD in most regions of the world, although our study has a limitation due to the lack of Escherichia coli samples from Kenya and possible bias in selection of the patients for evaluation. Azithromycin and rifaximin should be considered as promising new agents. The widespread in vitro resistance of the traditional antimicrobial agents reported since the 1980s and the new finding of resistance to fluoroquinolones in Southeast Asia are the main reasons for monitoring carefully the antimicrobial susceptibility patterns worldwide and for developing and evaluating new antimicrobial agents for the treatment of TD.

Diarrheagenic Escherichia coli in sub-Saharan Africa: Status, Uncertainties and Necessities

“…The dearth of information is reflective of the lack of capacity to detect diarrheagenic E. coli for research or clinical purposes, even though they are among the most common causes of disease. Multicountry studies have rarely included an African site and when they do, diarrheagenic E. coli are often not included in the range of target organisms [243,244]. In many recent epidemiology studies that have been performed in Africa, culture has been done at the point of collection while delineation of diarrheagenic pathotypes has occurred overseas, usually in Europe or North America [67,245].…”

In-vitro antimicrobial susceptibility testing of bacteria causing diarrhea in children at Khartoum StateSudan

“…In the current study Shigella boydii, Shigella sonnei, Shigella flexneri & Shigella dysenteriae showed high-level resistance to co-trimoxazole & ampicillin (80% & 60%, 75% & 58%, 46% & 69%, 38% & 29% respectively). Resistant to SXT among enteropathogens has increased dramatically over at least 14 years [9]. It seems that the frequency of antibiotic resistance in the Sudan has increased over the last 15 years, in comparison to previous studies [8].…”

Bacteriemia por Shigellaflexneri serotipo 6 en pacientes con SIDA: Presentación de dos casos clínicos

“…Además cabe destacar que 42% de las cepas de Campylobacter spp. recuperadas en Latinoamérica fueron resistentes a ciprofloxacina 18,20 . Por último, es importante conocer los perfiles de susceptibilidad locales a los antimicrobianos de estos agentes para poder comenzar con un tratamiento empí-rico adecuado y también disponer de los resultados de PFGE para complementar los datos de la epidemiología tradicional; en este caso la PFGE permitió establecer que las cepas de ambos pacientes estaban muy relacionadas desde el punto de vista genético.…”