RESUMO
In a very remote human community of the Peruvian Amazonas with minimal antibiotic exposure, high levels of acquired resistance to the oldest antibiotics (ampicillin, tetracycline, trimethoprim/sulfamethoxazole, streptomycin and chloramphenicol) were detected in commensal Escherichia coli, with remarkable diversity of resistant clones and of resistance genes and plasmids. This pattern was similar overall to that previously observed in a very remote community of Bolivia. It was also similar to that observed in the nearest urban area, except for a lower dominance of resistant isolates and the absolute lack of quinolone resistance in the remote community. Present findings suggest that antibiotic resistance observed in remote communities with minimal antibiotic exposure is a general phenomenon contributed by complex mechanisms and provide new insights into the mechanisms involved in this phenomenon.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , DNA Bacteriano/genética , Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Peru , Plasmídeos , Polimorfismo Genético , Técnica de Amplificação ao Acaso de DNA Polimórfico , População RuralAssuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Bolívia/epidemiologia , Cefalosporinas/farmacologia , Criança , Pré-Escolar , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Feminino , Fluoroquinolonas/farmacologia , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Peru/epidemiologia , beta-Lactamases/biossíntese , beta-Lactamases/genéticaRESUMO
A survey carried out in 2005 among members of a healthy population of children living in Bolivia and Peru revealed that fecal carriage of Escherichia coli strains resistant to expanded-spectrum cephalosporins was remarkably increased compared to that observed in the same settings in 2002 (1.7% in 2005 versus 0.1% in 2002). In this work, we demonstrated that this phenomenon was mainly related to the dissemination of CTX-M-type extended-spectrum beta-lactamase (ESBL) determinants among commensal E. coli strains. Of 50 ESBL-producing isolates collected in the 2005 survey, 44 harbored a CTX-M-type and 6 an SHV-type (SHV-2 or SHV-12) ESBL. Compared to 2002 results, an increased diversity of CTX-M-type ESBLs was also observed: members of the CTX-M-1 group (CTX-M-15) emerged in Bolivia (where only CTX-M-2 was observed in 2002), while members of the CTX-M-9 group (CTX-M-14 and CTX-M-24) emerged in Peru (where only CTX-M-15 and CTX-M-2 were observed in 2002). A new CTX-M-2 variant named CTX-M-56 was also detected. Molecular characterization of the CTX-M-producing isolates and gene transfer experiments suggested that different mechanisms could be involved in the spreading of different CTX-M group determinants and revealed that additional resistance determinants for non-beta-lactam antibiotics were preferentially carried by plasmids encoding certain CTX-M variants (CTX-M-15 and variants of the CTX-M-2 group). Three CTX-M-15-encoding conjugative plasmids from Peruvian isolates carried the new fluoroquinolone resistance gene aac(6')-Ib-cr. To our best knowledge, this is the first report of the detection of aac(6')-Ib-cr in Latin America.
Assuntos
Escherichia coli/enzimologia , Transferência Genética Horizontal , Variação Genética , Pobreza , beta-Lactamases/genética , Antibacterianos/farmacologia , Bolívia/epidemiologia , Ceftriaxona/farmacologia , Resistência às Cefalosporinas , Criança , Pré-Escolar , Conjugação Genética , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Humanos , Lactente , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Peru/epidemiologia , Plasmídeos/genética , Análise de Sequência de DNA , Fatores de TempoRESUMO
In a previous study, we detected unexpectedly high levels of acquired antibiotic resistance in commensal Escherichia coli isolates from a remote Guaraní Indian (Bolivia) community with very low levels of antibiotic exposure and limited exchanges with the exterior. Here we analyzed the structure of the resistant E. coli population from that community and the resistance mechanisms. The E. coli population (113 isolates from 72 inhabitants) showed a high degree of genetic heterogeneity, as evidenced by phylogenetic grouping (77% group A, 10% group B1, 8% group D, 5% group B2) and genotyping by randomly amplified polymorphic DNA (RAPD) analysis (44 different RAPD types). The acquired resistance genes were always of the same types as those found in antibiotic-exposed settings [blaTEM, blaPSE-1, catI, cmlA6, tet(A), tet(B), dfrA1, dfrA7, dfrA8, dfrA17, sul1, sul2, aphA1, aadA1, aadA2, aadA5, aadB, and sat-1]. Class 1 and class 2 integrons were found in 12% and 4% of the isolates, respectively, and harbored arrays of gene cassettes similar to those already described. The cotransferability of multiple-resistance traits was observed from selected isolates and was found to be associated with resistance conjugative plasmids of the F, P, and N types. Overall, these data suggest that the resistance observed in this remote community is likely the consequence of the dissemination of resistant bacteria and resistance genes from antibiotic-exposed settings (rather than of an independent in situ selection) which involved both the clonal expansion of resistant strains and the horizontal transfer/recombination of mobile genetic elements harboring resistance genes.
Assuntos
DNA Bacteriano/análise , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Antibacterianos/farmacologia , Bolívia , Conjugação Genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli , Transferência Genética Horizontal , Testes de Sensibilidade Microbiana , Vigilância da PopulaçãoRESUMO
Using a rapid screening method, we investigated the prevalence of fecal carriage of antimicrobial drug-resistant Escherichia coli in 3,174 healthy children from 4 urban settings in Peru and Bolivia. High resistance rates were observed for ampicillin (95%), trimethoprim-sulfamethoxazole (94%), tetracycline (93%), streptomycin (82%), and chloramphenicol (70%). Lower resistance rates were observed for nalidixic acid (35%), kanamycin (28%), gentamicin (21%), and ciprofloxacin (18%); resistance to ceftriaxone and amikacin was uncommon (<0.5%). In a random sample of 1,080 resistant E. coli isolates, 90% exhibited a multidrug-resistance (MDR) phenotype. The 2 most common MDR phenotypes (ampicillin/tetracycline/trimethoprim-sulfamethoxazole and ampicillin/tetracycline/trimethoprim-sulfamethoxazole/chloramphenicol) could be transferred en bloc in conjugation experiments. The most common acquired resistance genes were blaTEM, tet(A), tet(B), drfA8, sul1, sul2, and catI. These findings underscore the magnitude of the problem of antimicrobial drug resistance in low-resource settings and the urgent need for surveillance and control of this phenomenon.
Assuntos
Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Bolívia , Criança , Pré-Escolar , Estudos de Coortes , DNA Bacteriano/química , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Peru , Reação em Cadeia da Polimerase , Prevalência , População UrbanaRESUMO
The assessment of antimicrobial resistance among commensal bacteria is an indicator of the spread of antimicrobial resistance. Rapid screening methods for detection of antimicrobial-resistant faecal Escherichia coli directly on MacConkey plates have been successfully adopted but suffer from lack of standardisation. The purpose of this study was to evaluate a direct plating method (DPM) for detection of antimicrobial-resistant faecal E. coli and to compare it with a conventional method. Faecal samples were collected from 71 healthy children from Peru and Bolivia. In the DPM, a faecal swab was directly plated onto a MacConkey agar plate and antimicrobial disks were applied onto the seeded plate. Raw data were obtained by direct reading of the plate and were subjected to confirmatory analysis. Good concordance between the DPM and a conventional method was observed in detecting carriage of resistant E. coli, with a higher sensitivity for the DPM. Analysis of the results allowed interpretive criteria to be defined for DPM raw data. The DPM showed good sensitivity and specificity at very low cost (ten times cheaper than the conventional method) to investigate the faecal carriage of drug-resistant E. coli. It may represent a useful tool to conduct large-scale resistance surveillance studies and to monitor resistance control programmes cost effectively, particularly in low-resource countries.
Assuntos
Técnicas Bacteriológicas/normas , Farmacorresistência Bacteriana , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Técnicas Bacteriológicas/métodos , Bolívia , Criança , Pré-Escolar , Escherichia coli/efeitos dos fármacos , Humanos , Lactente , Peru , Sensibilidade e EspecificidadeRESUMO
PURPOSE: To evaluate the frequency of neurocysticercosis (NCC) in a well-defined prevalent cohort of epilepsy patients in the rural area of the Cordillera province. METHODS: We carried out a two-phase door-to-door neuroepidemiologic survey in a sample of 10,124 subjects in a rural area of the Cordillera Province, Bolivia, to detect the prevalence of the most common neurologic disorders including epilepsy. A team of health workers administered a standard screening instrument for neurologic diseases; subjects found positive at the screening phase underwent a complete neurologic examination. Epilepsy patients were diagnosed according to the definition proposed by the International League Against Epilepsy (ILAE, 1993). Epilepsy patients identified this way underwent electroencephalographic recording, computed tomography (CT) scan, and serologic evaluation to detect antibodies against Taenia solium by enzyme-linked immunoelectrotransfer blot. RESULTS: At the end of the survey, we detected 124 defined prevalent epilepsy patients. On the basis of the classification proposed by the ILAE in 1981, partial seizures were the most common type diagnosed (66 patients, 53.3%). Of the 124 patients, 105 underwent CT scan, and a serum sample was taken to detect antibodies against T. solium in 112 patients; for 97 patients, both neuroradiologic and serologic data were available. Considering radiologic, serologic, and clinical features, of these 124 patients, 34 (27.4%) fulfilled the diagnostic criteria for definitive or probable NCC proposed in 2001. Of these 34 patients 24 (70.6%) had partial seizures. CONCLUSIONS: Our data confirm a high frequency of NCC among a well-defined prevalent cohort of epilepsy patients.
Assuntos
Epilepsia/epidemiologia , População Rural/estatística & dados numéricos , Bolívia/epidemiologia , Estudos de Coortes , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/epidemiologia , Epilepsia/diagnóstico , Humanos , Programas de Rastreamento/estatística & dados numéricos , Neurocisticercose/diagnóstico , Neurocisticercose/epidemiologia , PrevalênciaRESUMO
A survey was carried out from August to November 2002 to evaluate the antimicrobial susceptibilities of fecal Escherichia coli isolates from 3,208 healthy children from four different urban areas of Latin America, two in Bolivia (Camiri and Villa Montes) and two in Peru (Yurimaguas and Moyobamba). Ceftriaxone-resistant E. coli isolates were detected in four children, one from each of the areas sampled. The isolates exhibited a multidrug-resistant phenotype, including resistance to oxyimino-cephalosporins and aztreonam, and the MICs of ceftazidime for the isolates were lower than those of cefotaxime. By PCR and sequencing, the bla(CTX-M-2) determinant was detected in three isolates and the bla(CTX-M-15) determinant was detected in one isolate (from Peru). The CTX-M-2-producing isolates belonged to three different phylogenetic groups (groups A, B2, and D), while the CTX-M-15-producing isolate belonged to phylogenetic group D. The bla(CTX-M-2) determinants were transferable to E. coli by conjugation, while conjugative transfer of the bla(CTX-M-15) determinant was not detectable. Plasmids harboring the bla(CTX-M-2) determinant exhibited similar restriction profiles, and in all of them the gene was located on a 2.2-kb PstI fragment, suggesting a genetic environment similar to that present in In35 and InS21. The findings of the present study confirm the widespread distribution of CTX-M-type beta-lactamases and underscore the role that commensal E. coli isolates could play as a potential reservoir of these clinically relevant resistance determinants. This is the first report of CTX-M-type enzymes in Bolivia and Peru and also the first report of the detection of CTX-M-15 in Latin America.
Assuntos
Escherichia coli/enzimologia , Escherichia coli/genética , Fezes/microbiologia , beta-Lactamases/genética , Bolívia/epidemiologia , Ceftriaxona/farmacologia , Cefalosporinas/farmacologia , Conjugação Genética , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Transferência Genética Horizontal , Testes de Sensibilidade Microbiana , Peru/epidemiologia , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In a very remote rural Bolivian community where the use of antimicrobials has been minimal and where exchanges with the exterior are very limited, 67% of subjects were found to be carriers of fecal Escherichia coli with acquired resistance to >/=1 antimicrobial agent(s); the highest rates were observed for tetracycline (64%), ampicillin (58%), trimethoprim-sulfamethoxazole (50%), and chloramphenicol (41%). The most relevant implication of these findings is that, in certain settings, the spread and maintenance of antimicrobial resistance can occur, regardless of whether selective pressure generated by the use of antimicrobials is present.
Assuntos
Farmacorresistência Bacteriana Múltipla/fisiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Adolescente , Adulto , Idoso , Bolívia/epidemiologia , Criança , Pré-Escolar , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Fezes/microbiologia , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , População RuralRESUMO
OBJECTIVE: To determine the seroprevalence of antibodies against varicella zoster virus (VZV) and rubella virus among the population of two rural areas, Camiri and Villa Montes, Chaco region, south-eastern Bolivia. METHODS: In a cross-sectional study, serum samples from randomly selected subjects were screened for VZV- and rubella antibodies using enzyme-linked immunosorbent assay (ELISA). RESULTS: The prevalence of VZV antibodies was 80% (391 of 489). No significant differences were observed between genders and study areas. The prevalence increased with age with a seropositivity rate of 21.2% in the 1-4-year-old children, 56.9% in the 5-9 age group and 83.7% in the 10-14 age group, and reached 98.2% in over 45-year olds. The prevalence of rubella virus antibodies was 76.9% (377 of 490), without significant differences between genders and study areas. Similar to the trend observed for VZV antibodies, the seroprevalence increased with age with a seropositivity rate of 18.1% in the 1-4-year-old children, 53.9% in the 5-9 age group and 78.4% in the 10-14 age group, and reached 94.7% in over 45-year-old subjects. Among the 95 women of childbearing age (15-44 years) the susceptibility rate was 11.6%. CONCLUSIONS: A common seroimmunological profile was evidenced for the two infections. The age-specific profile of VZV seropositivity differs from that reported for other tropical countries where higher median age of seroconversion and lower seroprevalence among adults are observed. Data concerning the prevalence of immunity to rubella may be useful to evaluate the impact of the recently introduced rubella immunization programme.
Assuntos
Anticorpos Antivirais/sangue , Varicela/imunologia , População Rural , Adolescente , Adulto , Distribuição por Idade , Bolívia , Criança , Pré-Escolar , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Distribuição por SexoRESUMO
Se realizó un estudio seroepidemiológico para determinar la prevalencia de anticuerpos contra Trichinella spiralis en el área rural de la provincia Cordillera del Departamento de Santa Cruz en Bolivia. Se examinaron 234 muestras de suero mediante el ensayo de inmunoabsorción enzimática (ELISA) y se detectaron los anticuerpos en siete muestras (3 por cien). Los resultados documentan por primera vez la presencia de infestación humana por Trichinella en Bolivia y sugieren la necesidad de fortalecer la vigilancia sanitaria de la triquinosis en los mataderos municipales, impedir la faena clandestina de animales y, sobre todo, lograr que los productores y pobladores tomen conciencia de los peligros de esta zoonosis
A seroepidemiological study was conducted to determine the prevalence of antibodies to Trichinella spiralis among rural residents of Cordillera province, Santa Cruz Department, Bolivia. Using the enzyme-linked immunosorbent assay (ELISA), 234 serum samples were examined, and antibodies were detected in seven of the samples (3%). The results document for the first time the presence of human infestation with Trichinella in Bolivia and suggest the need to strengthen trichinelosis surveillance in the municipal slaughterhouses, to prevent the clandestine slaughter of animals, and particularly to ensure that residents and meat producers in the area become aware of the dangers of this zoonosis