RESUMEN
Antibiotic-resistant bacteria have emerged due to the selective pressure of antimicrobial use in humans and animals. Water plays an important role in dissemination of these organisms among humans, animals and the environment. We studied the antibiotic resistance patterns among 493 Escherichia coli isolates from different aquatic environmental sources collected from October 2008 to May 2009 in León, Nicaragua. High levels of antibiotic resistance were found in E. coli isolates in hospital sewage water and in eight of 87 well-water samples. Among the resistant isolates from the hospital sewage, ampicillin, chloramphenicol, ciprofloxacin, nalidixic acid, trimethoprim-sulphamethoxazole was the most common multi-resistance profile. Among the resistant isolates from the wells, 19% were resistant to ampicillin, ceftazidime, ceftriaxone, cefotaxime, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid and trimethoprim-sulphamethoxazole. E. coli producing ESBL and harbouring bla(CTX-M) genes were detected in one of the hospital sewage samples and in 26% of the resistant isolates from the well-water samples. The bla(CTX-M-9) group was more prevalent in E. coli isolates from the hospital sewage samples and the bla(CTX-M-1) group was more prevalent in the well-water samples.
Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología , Proteínas Bacterianas/genética , Agua Potable/microbiología , Escherichia coli/clasificación , Escherichia coli/genética , Hospitales , Humanos , Pruebas de Sensibilidad Microbiana , Nicaragua , Técnica del ADN Polimorfo Amplificado Aleatorio , Microbiología del Agua , beta-Lactamasas/genéticaRESUMEN
BACKGROUND: PhP-S48 (Phene Plate Techniques AB), a method based on biochemical phenotypes has been developed and used successfully to typify S enteritidis strains in epidemiological studies. AIM: To identify phenotypes of S enteritidis isolated from eggs, chicken meat and infected humans in Antofagasta during the period 1997-2000. MATERIAL AND METHODS: PhP-S48 and phage typing were used to identify phenotypes of 33 S enteritidis strains, sixteen isolated from poultry and 17 from clinical sources. S enteritidis ATCC17036 was used as control strain. RESULTS: Twelve biochemical phenotypes (BTs) including 4 common (C) and 8 single (S) were identified. BTs C1 y C3 containing 16 and 5 strains, respectively, accounted for 63.6 per cent of the isolates. BT C1 was found in poultry and human sources in the period 1997-2000, and BT C3 was isolated from humans, in the period 1999-2000. Using phage typing, 5 phage types (PT) and 3 strains could be not typed (NTs). PT1 and PT21 were the dominant phage types, with 14 and 13 strains respectively. Strains of PT1 were isolated from poultry and human sources in the period 1997-2000. PT21 was found in poultry samples in the period 1997-1998 and in clinical samples, in the period 1997-1998. Combination of biochemical phenotypes and phage typing divided the strains into 5 phenotypes (BT:PT). Two phenotypes were the most frequently isolated, phenotype C1:1 with 8 isolates found in eggs and humans in 1999, and phenotype C1:21 with 5 strains isolated in 1997-1999. CONCLUSIONS: These results indicate the presence of one persistent and one recently emerged phenotype among S enteritidis in Antofagasta, Chile. PhP-S48 also provided information about a relationship among the strains.