title: Virulence factors and mechanisms of antimicrobial resistance in Shigella strains from periurban areas of Lima (Peru).
abstract: The study was aimed to describe the serotype, mechanisms of antimicrobial resistance, and virulence determinants in Shigella spp. isolated from Peruvian children. Eighty three Shigella spp. were serogrouped and serotyped being established the antibiotic susceptibility. The presence of 12 virulence factors (VF) and integrase 1 and 2, along with commonly found antibiotic resistance genes was established by PCR. S. flexneri was the most relevant serogroup (55 isolates, 66%), with serotype 2a most frequently detected (27 of 55, 49%), followed by S. boydii and S. sonnei at 12 isolates each (14%) and S. dysenteriae (four isolates, 5%). Fifty isolates (60%) were multi-drug resistant (MDR) including 100% of S. sonnei and 64% of S. flexneri. Resistance levels were high to trimethoprim-sulfamethoxazole (86%), tetracycline (74%), ampicillin (67%), and chloramphenicol (65%). Six isolates showed decreased azithromycin susceptibility. No isolate was resistant to nalidixic acid, ciprofloxacin, nitrofurantoin, or ceftriaxone. The most frequent resistance genes were sul2 (95%), tet(B) (92%), cat (80%), dfrA1 (47%), blaOXA-1like (40%), with intl1 and intl2 detected in 51 and 52% of the isolates, respectively. Thirty-one different VF profiles were observed, being the ipaH (100%), sen (77%), virA and icsA (75%) genes the most frequently found. Differences in the prevalence of VF were observed between species with S. flexneri isolates, particularly serotype 2a, possessing high numbers of VF. In conclusion, this study highlights the high heterogeneity of Shigella VF and resistance genes, and prevalence of MDR organisms within this geographic region.
authors.affiliation: Universidad Peruana Cayetano Heredia, Instituto de Medicina Tropical Alexander Von Humboldt, Lima, Peru.
authors.forename: Angela
authors.initials: A
authors.lastname: Lluque
authors.affiliation: Universidad Peruana Cayetano Heredia, Instituto de Medicina Tropical Alexander Von Humboldt, Lima, Peru.
authors.forename: Susan
authors.initials: S
authors.lastname: Mosquito
authors.affiliation: ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Gomes
authors.affiliation: Universidad Peruana Cayetano Heredia, Instituto de Medicina Tropical Alexander Von Humboldt, Lima, Peru.
authors.forename: Maribel
authors.initials: M
authors.lastname: Riveros
authors.affiliation: Universidad Peruana Cayetano Heredia, Instituto de Medicina Tropical Alexander Von Humboldt, Lima, Peru.
authors.forename: David
authors.initials: D
authors.lastname: Durand
authors.affiliation: U.S Naval Medical Research Unit No.6, Callao, Peru.
authors.forename: Drake H
authors.initials: DH
authors.lastname: Tilley
authors.affiliation: U.S Naval Medical Research Unit No.6, Callao, Peru.
authors.forename: María
authors.initials: M
authors.lastname: Bernal
authors.affiliation: Universidad Peruana Cayetano Heredia, Instituto de Medicina Tropical Alexander Von Humboldt, Lima, Peru.
authors.forename: Ana
authors.initials: A
authors.lastname: Prada
authors.affiliation: Universidad Peruana Cayetano Heredia, Instituto de Medicina Tropical Alexander Von Humboldt, Lima, Peru; Center for Infectious Disease, University of Texas School of Public Health, Houston, USA. Electronic address: Theresa.J.Ochoa@uth.tmc.edu.
authors.forename: Theresa J
authors.initials: TJ
authors.lastname: Ochoa
authors.affiliation: ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. Electronic address: joruiz@clinic.ub.es.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Ruiz
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004405:Dysentery, Bacillary / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D010568:Peru / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D065288:Serogroup; D012760:Shigella / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification / Q000472:pathogenicity*; D013383:Suburban Population; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D037521:Virulence Factors
keywords: Antimicrobial resistance; Autotransporters; Enterotoxins; Ipa; Shigella serotypes; Shigellosis