RESUMEN
OBJECTIVES: The aim of this study was to perform two cross-sectional surveys on the fecal carriage of CTX-M-producing Enterobacterales in school-aged children from rural areas of the Bolivian Chaco (2016 vs 2019). METHODS: A total of 757 fecal samples were collected from school-aged children living in nine indigenous communities (n=337, 2016; n=420, 2019). After a first passage onto MacConkey agar (MCA), samples were plated onto MCA plus cefotaxime 2 µg/mL (MCA-CTX), and a loopful of the bacterial growth was used as a template for the detection of group 1, 2, 8/25, and 9 blaCTX-M variants by multiplex reverse transcriptase polymerase chain reaction . Positive samples were tested again for detecting, identifying, and characterizing CTX-M-positive isolates. RESULTS: Growth onto MCA-CTX was obtained with 208 samples (27.5%; 62/337, 2016; 146/420, 2019), of which 201 (96.6%) were positive for blaCTX-M genes. Overall, a relevant increase of fecal carriage of CTX-M-producing Enterobacterales was observed in the study period: 17,5% (59/337) in 2016 compared with 33,8% (142/420) in 2019, p<0.01. Nonetheless, the relative group distribution of CTX-M groups remained stable, with group 1 being the prevalent, followed by group 9 and group 8/25. Group 2 was not detected. CONCLUSIONS: The present study demonstrated an alarming spread of CTX-M enzymes in rural areas of the Bolivian Chaco, where antibiotics consumption is limited. Further studies are encouraged to better understand the dissemination dynamics of such relevant resistance determinants.
Asunto(s)
Infecciones por Escherichia coli , Escherichia coli , Antibacterianos/farmacología , Bolivia/epidemiología , Niño , Estudios Transversales , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/genéticaRESUMEN
OBJECTIVE: The main objectives were to describe two blaKPC-2 plasmids recovered from Pseudomonas aeruginosa isolates belonging to the ST654 and ST235 high-risk clones, and to compare with complete sequences of blaKPC-2 harbouring plasmids available in public databases. METHODS: Antimicrobial susceptibility was determined according to CLSI (Clinical and Laboratory Standards Institute) guidelines. Genomes were sequenced using an Illumina MiSeq platform, and blaKPC-2 plasmid sequences were achieved using MinION platform. Sequences were analysed using Unicycler and RAST. In silico predictions of the isolates sequence type (ST), antimicrobial resistance genes, plasmid replicon typing and MOB relaxases were fulfilled using bioinformatics tools. RESULTS: PA_2047 and PA_HdC isolates corresponded to the high-risk clones ST654 and ST235, respectively. The carbapenem resistance was mediated by KPC-2. Both blaKPC-2 harbouring plasmids, pPA_2047 and pPA_HdC, were different among them, non-conjugative and untypable by PlasmidFinder. pPA_2047 presented high identity with a Pae-13 plasmid, and these both located blaKPC-2 in Tn4401b isoform. pPA_HdC displayed a novel architecture, and the genetic context of blaKPC-2 was original. Besides the blaKPC-2 gene, resistance genes to aminoglycosides and quinolones were detected, including the novel phosphotransferase CrpP in PA_HdC. CONCLUSION: This study expands the limited knowledge about the molecular epidemiology of blaKPC-2 in P. aeruginosa from Latin America. Two novel plasmids harbouring blaKPC-2 were described that were untypable by their incompatibility group. The plasmid recovered from P. aeruginosa PA_HdC (ST235) displayed a novel architecture and an original context for blaKPC-2. On the other hand, the genetic platform carrying blaKPC-2 in P. aeruginosa PA_2047 (ST654) seems to a be a classical one.
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Pseudomonas aeruginosa , beta-Lactamasas , Antibacterianos/farmacología , Células Clonales , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , Pseudomonas aeruginosa/genética , beta-Lactamasas/genéticaRESUMEN
BackgroundThe mcr-1 gene is a transferable resistance determinant against colistin, a last-resort antimicrobial for infections caused by multi-resistant Gram-negatives.AimTo study carriage of antibiotic-resistant bacteria in healthy school children as part of a helminth control and antimicrobial resistance survey in the Bolivian Chaco region.MethodsFrom September to October 2016 we collected faecal samples from healthy children in eight rural villages. Samples were screened for mcr-1- and mcr-2 genes. Antimicrobial susceptibility testing was performed, and a subset of 18 isolates representative of individuals from different villages was analysed by whole genome sequencing (WGS).ResultsWe included 337 children (mean age: 9.2 years, range: 7-11; 53% females). The proportion of mcr-1 carriers was high (38.3%) and present in all villages; only four children had previous antibiotic exposure. One or more mcr-1-positive isolates were recovered from 129 positive samples, yielding a total of 173 isolates (171 Escherichia coli, 1 Citrobacter europaeus, 1 Enterobacter hormaechei). No mcr-2 was detected. Co-resistance to other antimicrobials varied in mcr-positive E. coli. All 171 isolates were susceptible to carbapenems and tigecycline; 41 (24.0%) were extended-spectrum ß-lactamase producers and most of them (37/41) carried blaCTX-M-type genes. WGS revealed heterogeneity of clonal lineages and mcr-genetic supports.ConclusionThis high prevalence of mcr-1-like carriage, in absence of professional exposure, is unexpected. Its extent at the national level should be investigated with priority. Possible causes should be studied; they may include unrestricted use of colistin in veterinary medicine and animal breeding, and importation of mcr-1-positive bacteria via food and animals.
Asunto(s)
Portador Sano/epidemiología , Farmacorresistencia Bacteriana/genética , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Población Rural , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Bolivia/epidemiología , Carbapenémicos/farmacología , Niño , Farmacorresistencia Bacteriana Múltiple , Enterobacteriaceae/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli , Femenino , Microbioma Gastrointestinal , Humanos , Masculino , PrevalenciaAsunto(s)
Antibacterianos/farmacología , Citrobacter/efectos de los fármacos , Citrobacter/genética , Colistina/farmacología , Microbiología de Alimentos , Genes Bacterianos , Bolivia , Citrobacter/enzimología , Citrobacter/aislamiento & purificación , ADN Bacteriano/química , Farmacorresistencia Bacteriana/genética , Plásmidos , Análisis de Secuencia de ADN , Solanum tuberosum/microbiologíaAsunto(s)
Acinetobacter baumannii/aislamiento & purificación , beta-Lactamasas/genética , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Bolivia , Farmacorresistencia Bacteriana Múltiple , Humanos , Masculino , Persona de Mediana EdadAsunto(s)
Farmacorresistencia Bacteriana Múltiple , Transferencia de Gen Horizontal , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Plásmidos/análisis , Adulto , Anciano , Antibacterianos/farmacología , Bolivia , Electroforesis en Gel de Campo Pulsado , Femenino , Orden Génico , Genotipo , Humanos , Klebsiella pneumoniae/clasificación , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Bolivia is among the lowest-resourced South American countries, with very few data available on antibiotic resistance in bacterial pathogens. The phenotypic and molecular characterization of bacterial isolates responsible for urinary tract infections (UTIs) in the Bolivian Chaco are reported here. METHODS: All clinical isolates from UTIs collected in the Hospital Basico Villa Montes between June 2010 and January 2014 were analyzed (N=213). Characterization included susceptibility testing, extended-spectrum beta-lactamase (ESBL) detection, identification of relevant resistance determinants (e.g., CTX-M-type ESBLs, 16S rRNA methyltransferases, glutathione S-transferases), and genotyping of CTX-M producers. RESULTS: Very high resistance rates were observed. Overall, the lowest susceptibility was observed for trimethoprim-sulphamethoxazole, tetracycline, nalidixic acid, amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin. Of E. coli and K. pneumoniae, 11.6% were ESBL producers. Resistance to nitrofurantoin, amikacin, and fosfomycin remained low, and susceptibility to carbapenems was fully preserved. CTX-M-15 was the dominant CTX-M variant. Four E. coli ST131 (two being H30-Rx) were identified. Of note, isolates harbouring rmtB and fosA3 were detected. CONCLUSIONS: Bolivia is not an exception to the very high resistance burden affecting many South American countries. Optimization of alternative approaches to monitor local antibiotic resistance trends in resource-limited settings is strongly encouraged to support the implementation of effective empiric treatment guidelines.
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Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Escherichia coli/aislamiento & purificación , Klebsiella pneumoniae/aislamiento & purificación , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Infecciones Urinarias/microbiología , Bolivia/epidemiología , Farmacorresistencia Bacteriana/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/efectos de los fármacos , Proteínas de Escherichia coli/genética , Fosfomicina/uso terapéutico , Genotipo , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Metiltransferasas/efectos de los fármacos , Metiltransferasas/genética , ARN Ribosómico 16S/efectos de los fármacos , ARN Ribosómico 16S/genética , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/epidemiología , beta-Lactamasas/efectos de los fármacos , beta-Lactamasas/genéticaRESUMEN
During the last decade, a significant diffusion of CTX-M-type extended-spectrum ß-lactamases (ESBLs) was observed in commensal Escherichia coli from healthy children in the Bolivian Chaco region, with initial dissemination of CTX-M-2, which was then replaced by CTX-M-15 and CTX-M-65. In this work, we demonstrate that the widespread dissemination of CTX-M-65 observed in this context was related to the polyclonal spreading of an IncI1 sequence type 71 (ST71) epidemic plasmid lineage. The structure of the epidemic plasmid population was characterized by complete sequencing of four representatives and PCR mapping of the remainder (n = 16). Sequence analysis showed identical plasmid backbones (similar to that of the reference IncI1 plasmid, R64) and a multiresistance region (MRR), which underwent local microevolution. The MRR harbored genes responsible for resistance to ß-lactams, aminoglycosides, florfenicol, and fosfomycin (with microevolution mainly consisting of deletion events of resistance modules). The bla CTX-M-65 module harbored by the IncI1 ST71 epidemic plasmid was apparently derived from IncN-type plasmids, likely via IS26-mediated mobilization. The plasmid could be transferred by conjugation to several different enterobacterial species (Escherichia coli, Cronobacter sakazakii, Enterobacter cloacae, Klebsiella oxytoca, Klebsiella pneumoniae, and Salmonella enterica) and was stably maintained without selective pressure in these species, with the exception of K. oxytoca and S. enterica. Fitness assays performed in E. coli recipients demonstrated that the presence of the epidemic plasmid was apparently not associated with a significant biological cost.
Asunto(s)
Plásmidos/genética , beta-Lactamasas/genética , beta-Lactamas/farmacología , Antibacterianos/farmacología , Enterobacter cloacae/efectos de los fármacos , Enterobacter cloacae/enzimología , Enterobacter cloacae/genética , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/enzimología , Enterobacteriaceae/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/genética , Fosfomicina/farmacología , Klebsiella oxytoca/efectos de los fármacos , Klebsiella oxytoca/enzimología , Klebsiella oxytoca/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , Salmonella enterica/efectos de los fármacos , Salmonella enterica/enzimología , Salmonella enterica/genética , beta-Lactamasas/metabolismoRESUMEN
OBJECTIVES: Information is lacking on the methicillin-resistant Staphylococcus aureus (MRSA) clonal lineages circulating in Bolivia. We investigated the prevalence and molecular epidemiology of S. aureus colonization in hospitalized patients from the Bolivian Chaco, and compared their features with those of the few clinical isolates available from that setting. METHODS: S. aureus nasal/inguinal colonization was investigated in 280 inpatients from eight hospitals in two point prevalence surveys (2012, n=90; 2013, n=190). Molecular characterization included genotyping (spa typing, multilocus sequence typing, and pulsed-field gel electrophoresis), detection of virulence genes, and SCCmec typing. RESULTS: Forty-one inpatients (14.6%) were S. aureus nasal/inguinal carriers, of whom five were colonized by MRSA (1.8%). MRSA isolates mostly belonged to spa-type t701, harboured SCCmec IVc, and were negative for Panton-Valentine leukocidin (PVL) genes. However, a USA300-related isolate was also detected, which showed the characteristics of the USA300 Latin American variant (USA300-LV; i.e., ST8, spa-type t008, SCCmec IVc, presence of PVL genes, absence of arcA). Notably, all the available MRSA clinical isolates (n=5, collected during 2011-2013) were also identified as USA300-LV. CONCLUSIONS: Overall, MRSA colonization in inpatients from the Bolivian Chaco was low. However, USA300-LV-related isolates were detected in colonization and infections, emphasizing the importance of implementing control measures to limit their further dissemination in this resource-limited area.
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Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/microbiología , Bolivia , Hospitalización , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/clasificación , Prevalencia , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificaciónRESUMEN
High quinolone resistance rates were observed among oxyiminocephalosporin-resistant enterobacteria. In the present study, we searched for the prevalence of plasmid-mediated quinolone resistance (PMQR) genes within the 55 oxyiminocephalosporin-resistant enterobacteria collected in a previous survey. The main PMQR determinants were aac(6')-Ib-cr and qnrB, which had prevalence rates of 42.4% and 33.3%, respectively. The aac(6')-Ib-cr gene was more frequently found in CTX-M-15-producing isolates, while qnrB was homogeneously distributed among all CTX-M producers.
Asunto(s)
Antibacterianos/farmacología , Resistencia a las Cefalosporinas , Enterobacteriaceae/efectos de los fármacos , Quinolonas/farmacología , Argentina , Enterobacteriaceae/clasificación , Proteínas de Escherichia coli/genética , Humanos , Pruebas de Sensibilidad Microbiana , PrevalenciaRESUMEN
OBJECTIVE: To investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in rural and urban community settings of Bolivia and Peru. METHODS: MRSA nasal carriage was investigated in 585 individuals living in rural and urban areas of Bolivia and Peru (one urban area, one small rural village, and two native communities, one of which was highly isolated). MRSA isolates were subjected to molecular analysis for the detection of virulence genes, characterization of the staphylococcal cassette chromosome mec (SCCmec), and genotyping (multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE)). RESULTS: An overall very low prevalence of MRSA nasal carriage was observed (0.5%), with MRSA carriers being detected only in a small rural village of the Bolivian Chaco. The three MRSA isolates showed the characteristics of community-associated MRSA (being susceptible to all non-beta-lactam antibiotics and harboring the SCCmec type IV), were clonally related, and belonged to ST1649. CONCLUSIONS: This study provides an insight into the epidemiology of MRSA in community settings of Bolivia and Peru. Reliable, time-saving, and low-cost methods should be implemented to encourage continued surveillance of MRSA dissemination in resource-limited countries.
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Portador Sano/epidemiología , Staphylococcus aureus Resistente a Meticilina/genética , Nariz/microbiología , Antibacterianos/farmacología , Bolivia/epidemiología , Niño , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Perú/epidemiología , Prevalencia , Población Rural , Población UrbanaRESUMEN
BACKGROUND: Quinolones are potent broad-spectrum bactericidal agents increasingly employed also in resource-limited countries. Resistance to quinolones is an increasing problem, known to be strongly associated with quinolone exposure. We report on the emergence of quinolone resistance in a very remote community in the Amazon forest, where quinolones have never been used and quinolone resistance was absent in 2002. METHODS: The community exhibited a considerable level of geographical isolation, limited contact with the exterior and minimal antibiotic use (not including quinolones). In December 2009, fecal carriage of antibiotic resistant Escherichia coli was investigated in 120 of the 140 inhabitants, and in 48 animals reared in the community. All fluoroquinolone-resistant isolates were genotyped and characterized for the mechanisms of plasmid- and chromosomal-mediated quinolone resistance. PRINCIPAL FINDINGS: Despite the characteristics of the community remained substantially unchanged during the period 2002-2009, carriage of quinolone-resistant E. coli was found to be common in 2009 both in humans (45% nalidixic acid, 14% ciprofloxacin) and animals (54% nalidixic acid, 23% ciprofloxacin). Ciprofloxacin-resistant isolates of human and animal origin showed multidrug resistance phenotypes, a high level of genetic heterogeneity, and a combination of GyrA (Ser83Leu and Asp87Asn) and ParC (Ser80Ile) substitutions commonly observed in fluoroquinolone-resistant clinical isolates of E. coli. CONCLUSIONS: Remoteness and absence of antibiotic selective pressure did not protect the community from the remarkable emergence of quinolone resistance in E. coli. Introduction of the resistant strains from antibiotic-exposed settings is the most likely source, while persistence and dissemination in the absence of quinolone exposure is likely mostly related with poor sanitation. Interventions aimed at reducing the spreading of resistant isolates (by improving sanitation and water/food safety) are urgently needed to preserve the efficacy of quinolones in resource-limited countries, as control strategies based only on antibiotic restriction policies are unlikely to succeed in those settings.
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Portador Sano/microbiología , Portador Sano/veterinaria , Farmacorresistencia Bacteriana Múltiple , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/efectos de los fármacos , Quinolonas/farmacología , Adolescente , Adulto , Anciano , Animales , Antibacterianos/farmacología , Niño , Preescolar , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Heces/microbiología , Femenino , Variación Genética , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Plásmidos/análisis , Población Rural , América del Sur , Árboles , Adulto JovenAsunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Plásmidos , Quinolonas/farmacología , Infecciones por Salmonella/microbiología , Salmonella enterica/efectos de los fármacos , Adolescente , Animales , Niño , Preescolar , Electroforesis en Gel de Campo Pulsado , Femenino , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Salmonella enterica/clasificación , Salmonella enterica/genética , Salmonella enterica/aislamiento & purificación , VenezuelaAsunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Proteínas de Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Plásmidos/genética , Quinolonas/farmacología , Diarrea/epidemiología , Diarrea/microbiología , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Genotipo , Humanos , Lactante , Pruebas de Sensibilidad Microbiana , Perú/epidemiología , Filogenia , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
We have previously observed high rates of acquired antibiotic resistance in commensal Escherichia coli from healthy children living in urban areas of Bolivia and Peru, including resistance to tetracycline and quinolones, which are not routinely used in childhood. In this work we investigated acquired resistance in commensal E. coli from healthy children and home-raised chickens in 12 households from one of the previously surveyed urban area in Bolivia, to ascertain the possibility of human-animal exchange of resistant strains in similar settings. The resistance rates to ampicillin, tetracycline, chloramphenicol, streptomycin, and trimethoprim-sulphametoxazole were overall high (≥50%) and comparable between children and chickens, whereas those to quinolones were significantly higher in chickens (81% vs. 29% for nalidixic acid; 43% vs. 10% for ciprofloxacin). Molecular characterization of tetracycline- and quinolone-resistant isolates (n = 66) from children and chickens of three selected households revealed a remarkable clonal diversity and, in some cases, the presence of the same resistant strains among children or among chickens living in the same household, but not between children and chickens. Several resistance plasmids were characterized, but inter-clonal plasmid dissemination was not detected. Overall, the results from the present study suggested that cross-transmission between children and home-raised chickens could not represent a major spreading mechanism for resistant E. coli in households of resource-limited settings with high human-animal promiscuity.
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Antibacterianos/administración & dosificación , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/genética , Quinolonas/administración & dosificación , Tetraciclina/administración & dosificación , Animales , Bolivia/epidemiología , Portador Sano , Pollos , Niño , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/transmisión , Heces/microbiología , Variación Genética , Humanos , Pruebas de Sensibilidad Microbiana , PlásmidosAsunto(s)
Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana , Escherichia/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Plásmidos/análisis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Niño , Preescolar , Escherichia/genética , Escherichia/aislamiento & purificación , Proteínas de Escherichia coli/genética , Femenino , Humanos , Lactante , Recién Nacido , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Perú , Población Rural , Adulto JovenRESUMEN
A remarkable prevalence of qnrB (54%) and, at a lower level, of qnrS (14%) was discovered in pools of commensal enterobacteria from 310 healthy children living in Peru and Bolivia, using a metagenomic approach. Analysis of randomly selected enterobacterial pools revealed that qnrB was mainly carried by Escherichia coli and qnrS by Klebsiella pneumoniae. Investigation of 11 qnrB-positive isolates and 9 qnrS-positive isolates revealed the presence of plasmid-borne qnrB19 (n = 8), qnrB2 (n = 2), qnrB10 (n = 1), and qnrS1 (n = 9) genes.
Asunto(s)
Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana/genética , Proteínas de Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Quinolonas/farmacología , Secuencia de Bases , Bolivia , Niño , Preescolar , Escherichia coli/genética , Humanos , Lactante , Klebsiella pneumoniae/genética , Datos de Secuencia Molecular , Perú , Plásmidos , Reacción en Cadena de la PolimerasaRESUMEN
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.
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Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Técnicas de Tipificación Bacteriana , Dermatoglifia del ADN , ADN Bacteriano/genética , Escherichia coli/clasificación , Escherichia coli/aislamiento & purificación , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Perú , Plásmidos , Polimorfismo Genético , Técnica del ADN Polimorfo Amplificado Aleatorio , Población RuralAsunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Bolivia/epidemiología , Cefalosporinas/farmacología , Niño , Preescolar , Escherichia coli/enzimología , Escherichia coli/aislamiento & purificación , Heces/microbiología , Femenino , Fluoroquinolonas/farmacología , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Perú/epidemiología , beta-Lactamasas/biosíntesis , beta-Lactamasas/genéticaRESUMEN
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.