title: Susceptibility to rifaximin and other antimicrobials of bacteria isolated in patients with acute gastrointestinal infections in Southeast Mexico.
abstract: BACKGROUND
  Enteropathogenic bacteria isolated in Mexico City have shown a high rate of resistance to different antibiotics, with the exception of rifaximin (RIF). RIF is a nonabsorbable antibiotic that reaches high fecal concentrations (≈ 8,000μg/g). Susceptibility to antimicrobials can vary in different geographic regions.
  
  
  OBJECTIVE
  To study the susceptibility to rifaximin and other antimicrobials of enteropathogenic bacteria isolated in patients with acute diarrhea in the southeastern region of Mexico.
  
  
  METHODS
  A total of 614 strains of bacteria isolated from patients with acute diarrhea from 4 cities in Southeast Mexico were analyzed. An antibiogram with the following antibiotics was created: ampicillin (AMP), trimethoprim/sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), ciprofloxacin (CIP), chloramphenicol (CHL), and fosfomycin (FOS), assessed through the agar diffusion method at the standard concentrations recommended by the Clinical and Laboratory Standards Institute (CLSI) and the American Society for Microbiology (ASM), and RIF, assessed through microdilution at 4 concentrations.
  
  
  RESULTS
  The bacteria were Escherichia coli (55%), as the majority, in all its pathogenic variants, Shigella (16.8%), Salmonella (15.3%), Aeromonas (7.8%), and less than 5% Campylobacter, Yersinia, Vibrio, and Plesiomonas. The accumulated overall susceptibility to RIF was 69.1, 90.8, 98.9, and 100% at concentrations of 100, 200, 400, and 800μg/ml, respectively. Overall susceptibility to other antibiotics was FOS 82.8%, CHL 76.8%, CIP 73.9%, FUR 64%, T-S 58.7%, NEO 55.8%, and AMP 23.8%. Susceptibility to RIF at 400 and 800μg was significantly greater than with the other antimicrobials (P<.001).
  
  
  CONCLUSIONS
  The data of the present study were similar to those of a previous study carried out in Mexico City: susceptibility to RIF in > 98% of the bacterial strains and a high frequency of resistance to several common antimicrobials.
authors.affiliation: División de Microbiología Clínica, Unidad de Diagnóstico Microbiológico UDMSC, Ciudad de México, México.
authors.forename: O
authors.initials: O
authors.lastname: Novoa-Farias
authors.affiliation: Departamento de Medicina Interna, Hospital Médica Sur, Ciudad de México, México. Electronic address: AFrati@alfawassermann.com.
authors.forename: A C
authors.initials: AC
authors.lastname: Frati-Munari
authors.affiliation: Alliance for the prudent use of antibiotics (APUA), Chapter México, Ciudad de México, México.
authors.forename: M A
authors.initials: MA
authors.lastname: Peredo
authors.affiliation: Alliance for the prudent use of antibiotics (APUA), Chapter México, Ciudad de México, México.
authors.forename: S
authors.initials: S
authors.lastname: Flores-Juárez
authors.affiliation: División de Microbiología Clínica, Unidad de Diagnóstico Microbiológico UDMSC, Ciudad de México, México.
authors.forename: O
authors.initials: O
authors.lastname: Novoa-García
authors.affiliation: División de Microbiología Clínica, Unidad de Diagnóstico Microbiológico UDMSC, Ciudad de México, México.
authors.forename: J
authors.initials: J
authors.lastname: Galicia-Tapia
authors.affiliation: División de Microbiología Clínica, Unidad de Diagnóstico Microbiológico UDMSC, Ciudad de México, México.
authors.forename: C E
authors.initials: CE
authors.lastname: Romero-Carpio
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005260:Female; D005759:Gastroenteritis / Q000382:microbiology*; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008800:Mexico; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012294:Rifamycins / Q000494:pharmacology*; D000078262:Rifaximin; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D012294:Rifamycins; D000078262:Rifaximin
keywords: Acute diarrhea; Bacterial resistance; Bacterial susceptibility; Diarrea aguda; Gastroenteritis; Resistencia bacteriana; Rifaximin; Rifaximina; Southeast Mexico; Sureste mexicano; Susceptibilidad bacteriana