title: Stenotrophomonas maltophilia in Mexico: antimicrobial resistance, biofilm formation and clonal diversity.
abstract: Stenotrophomonas maltophilia is an important multidrug-resistant nosocomial pathogen associated with high mortality. Our aim was to examine antimicrobial susceptibility, biofilm production and clonal relatedness of clinical isolates of S. maltophilia. S. maltophilia isolates were collected between 2006 and 2013 from two tertiary care hospitals in Mexico. Antimicrobial susceptibility was evaluated by the broth microdilution method. PCR was used to determine the presence of β-lactamase genes L1 and L2. Biofilm formation was assessed with crystal violet staining. Clonal relatedness was determined by PFGE. Among the 119 collected S. maltophilia isolates, 73 (61.3%) were from the respiratory tract. Resistance levels exceeded 75% for imipenem, meropenem, ampicillin, aztreonam, gentamicin and tobramycin. Resistance to trimethoprim-sulfamethoxazole was 32.8%. L1 and L2 genes were detected in 77.1% (91/118) and 66.9% (79/118) of isolates, respectively. All S. maltophilia strains were able to produce biofilms. Strains were classified as weak (47.9%, 57/119), moderate (38.7%, 46/119), or strong (13.4%, 16/119) biofilm producers. A total of 89 distinct PFGE types were identified and 21.6% (22/102) of the isolates were distributed in nine clusters. This is the first study in Mexico to reveal characteristics of clinical isolates of S. maltophilia. Clonal diversity data indicate low cross-transmission of S. maltophilia in a hospital setting. The high antibiotic resistance underscores the need for continuous surveillance of S. maltophilia in hospital settings in Mexico.
authors.affiliation: Servicio de Gastroenterología, Hospital Universitario Dr José Eleuterio González, Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. S/N y Av. Gonzalitos, Col. Mitras Centro, 64460 Monterrey, Nuevo León, Mexico.
authors.forename: Samantha
authors.initials: S
authors.lastname: Flores-Treviño
authors.affiliation: Laboratorio de Química Analítica, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, México, Pedro de Alba SN, Col. Ciudad Universitaria, 66450 San Nicolás de los Garza, Nuevo León, Mexico.
authors.forename: Jessica Lizzeth
authors.initials: JL
authors.lastname: Gutiérrez-Ferman
authors.affiliation: Hospital Civil de Guadalajara, Fray Antonio Alcalde y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Sierra Mojada 950, Col. Independencia, 44350 Guadalajara, Jalisco, Mexico.
authors.forename: Rayo
authors.initials: R
authors.lastname: Morfín-Otero
authors.affiliation: Hospital Civil de Guadalajara, Fray Antonio Alcalde y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Sierra Mojada 950, Col. Independencia, 44350 Guadalajara, Jalisco, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rodríguez-Noriega
authors.affiliation: Hospital Civil de Guadalajara, Fray Antonio Alcalde y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Sierra Mojada 950, Col. Independencia, 44350 Guadalajara, Jalisco, Mexico.
authors.forename: Diego
authors.initials: D
authors.lastname: Estrada-Rivadeneyra
authors.affiliation: Laboratorio de Química Analítica, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, México, Pedro de Alba SN, Col. Ciudad Universitaria, 66450 San Nicolás de los Garza, Nuevo León, Mexico.
authors.forename: Catalina
authors.initials: C
authors.lastname: Rivas-Morales
authors.affiliation: Departamento de Patología Clínica, Hospital Universitario Dr José Eleuterio González, Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. S/N y José E. González, Col. Mitras Centro, CP 64460 Monterrey, Nuevo León, Mexico.
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Llaca-Díaz
authors.affiliation: Servicio de Infectología, Hospital Universitario Dr José Eleuterio González, Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. S/N y José E. González, Col. Mitras Centro, CP 64460 Monterrey, Nuevo León, Mexico.
authors.forename: Adrián
authors.initials: A
authors.lastname: Camacho-Ortíz
authors.affiliation: Servicio de Gastroenterología, Hospital Universitario Dr José Eleuterio González, Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. S/N y Av. Gonzalitos, Col. Mitras Centro, 64460 Monterrey, Nuevo León, Mexico.
authors.forename: Soraya
authors.initials: S
authors.lastname: Mendoza-Olazarán
authors.affiliation: Departamento de Patología Clínica, Hospital Universitario Dr José Eleuterio González, Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. S/N y José E. González, Col. Mitras Centro, CP 64460 Monterrey, Nuevo León, Mexico.|Servicio de Gastroenterología, Hospital Universitario Dr José Eleuterio González, Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. S/N y Av. Gonzalitos, Col. Mitras Centro, 64460 Monterrey, Nuevo León, Mexico.
authors.forename: Elvira
authors.initials: E
authors.lastname: Garza-González
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D014644:Genetic Variation; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D020615:Stenotrophomonas maltophilia / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents