En el presente estudio, se analizaron los mecanismos de resistencia a nitrofuranos en 18 muestras cárnicas con Salmonella enterica (15 de pollo, 2 de ternera y 1 de cerdo) de mercados de Lima (Perú). Determinaron los serotipos de los aislamientos y la sensibilidad a furazolidona y nitrofurantoina (con y sin el inhibidor de bombas de expulsión Phenyl-Arginine-β-Naphthylamide [PAβN]), las mutaciones en los genes snrA y cnr por PCR y la transferabilidad de la resistencia por conjugación. Se identificaron 15 muestras con S. infantis (13 muestras de pollo), 2 con S. enteritidis y 1 con S. anatum. Todos los aislamientos, excepto S. anatum, fueron resistentes a ambos nitrofuranos (concentración mínima inhibidora [CMI] a furazolidona: 32-64 μg/mL, CMI a nitrofurantoina: 128-256 μg/mL), sin diferencias al adicionarse PAβN. Todos los aislamientos resistentes a nitrofuranos presentaron s...

The objective of the present study was to characterize Salmonella enterica serovar Infantis isolated from chicken meat determining their clonal relationships with S. Infantis isolated from children with diarrhea. Fifteen meat-recovered S. Infantis were analyzed. Susceptibility levels to 14 antibacterial agents, the presence of ESBL and that of inducible plasmid-mediated AmpC (i-pAmpC) were determined by phenotypical methods. The presence of ESBL and pAmpC was confirmed by PCR, and detected ESBL-encoding genes were sequenced and their transferability tested by conjugation. The presence of gyrA mutations as well as Class 1 integrons was determined by PCR. Clonal relationships were established by REP-PCR and RAPD. In addition, 25 clinical isolates of S. Infantis were included in clonality studies. All meat-recovered S. Infantis were MDR, showing resistance to ampicillin, nitrofurans and qui...

Revisión por pares

The objective was to develop and characterise in vitro Bartonella bacilliformis antibiotic resistant mutants. Three B. bacilliformis strains were plated 35 or 40 times with azithromycin, chloramphenicol, ciprofloxacin or rifampicin discs. Resistance-stability was assessed performing 5 serial passages without antibiotic pressure.

The objective of this study was to determine the detection limit of three PCR approaches both from blood samples as well as from filter papers. Furthermore, the specificity was also accessed. We found that the best PCR approach studied was the amplification of the 16S rRNA from blood samples with a detection limit of 5 CFU/μL, the same when using dry blood in filter paper, although the obtained bands were not so evident. Present results highlight the need to develop more sensitive techniques able to be used both in rural areas and in the detection of asymptomatic carriers. From the tested PCRs, the 16S rRNA PCR-approach is the best to be used in the direct blood detection of acute cases of Carrion’s disease.

From its introduction in 1952 onwards, the clinical use of macrolides has been steadily increasing, both in human and veterinary medicine. Although initially designed to the treatment of Gram-positive microorganisms, this antimicrobial family has also been used to treat specific Gram-negative bacteria. Some of them, as azithromycin, are considered in the armamentarium against Enterobacteriaceae infections. However, the facility that this bacterial genus has to gain or develop mechanisms of antibiotic resistance may compromise the future usefulness of these antibiotics to fight against Enterobacteriaceae infections. The present review is focused on the mechanisms of macrolide resistance, currently described in Enterobacteriaceae.

Bartonella bacilliformis is the etiological agent of Carrion’s disease, which is a neglected disease linked to people in low-socioeconomic populations in Andean valleys. An outbreak of B. bacilliformis was reported in a rural area of the Peruvian Amazon region. The aim of this study was to characterize this outbreak using molecular techniques.

From its introduction in 1952 onwards, the clinical use of macrolides has been steadily increasing, both in human and veterinary medicine. Although initially designed to the treatment of Grampositive microorganisms, this antimicrobial family has also been used to treat specific Gram-negative bacteria. Some of them, as azithromycin, are considered in the armamentarium against Enterobacteriaceae infections. However, the facility that this bacterial genus has to gain or develop mechanisms of antibiotic resistance may compromise the future usefulness of these antibiotics to fight against Enterobacteriaceae infections. The present review is focused on the mechanisms of macrolide resistance, currently described in Enterobacteriaceae.

joruiz@clinic.ub.es