RESUMEN
Escherichia albertii is an emerging gastrointestinal pathogen, related to Escherichia coli, which can be misidentified as enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC), due to the presence of the eae gene in E. albertii. The aim of this study was to verify our hypothesis that E. coli cytolethal distending toxin-II (Eccdt-II) gene-positive E. coli is E. albertii and to accumulate the data regarding the bacteriological characteristics of E. albertii. For these purposes, we attempted to detect E. albertii in eae gene-positive bacteria previously identified as E. coli and to examine if re-identified E. albertii contained Eccdt-II-homologous gene and remaining eae gene-positive E. coli did not. A total of 373 eae gene-positive E. coli strains were analyzed by biochemical tests, multilocus sequence analysis and an E. albertii-specific PCR. The strains re-identified as E. albertii were also examined for the presence of cdt genes by using 32P-labled DNA probes, followed by their toxin-typing. Of the 373 strains, 17 were re-identified as E. albertii by three above-mentioned methods. Furthermore, all the 17 re-identified E. albertii possessed cdt genes highly homologous to Eccdt-II and Eacdt genes. Moreover, Eccdt-I or both Eccdt-I and stx2f genes were detected in two re-identified E. albertii strains. However, the remaining 356 strains did not carry such cdt genes. These data indicate that all re-identified E. albertii isolates specifically carried cdt genes homologous to Eccdt-II and Eacdt genes. We suggest that Eccdt-II gene-positive E. coli may be identical to E. albertii.
Asunto(s)
Adhesinas Bacterianas/genética , Toxinas Bacterianas/genética , Técnicas Bacteriológicas/métodos , Proteínas de Escherichia coli/genética , Escherichia/clasificación , Animales , Técnicas de Tipificación Bacteriana , Infecciones por Enterobacteriaceae/microbiología , Infecciones por Enterobacteriaceae/veterinaria , Microbiología Ambiental , Escherichia/genética , Escherichia/aislamiento & purificación , Escherichia/fisiología , Microbiología de Alimentos , Humanos , Tipificación de Secuencias Multilocus , Reacción en Cadena de la PolimerasaRESUMEN
Multidrug-resistant (MDR) Acinetobacter spp. have been globally disseminated in association with the successful clonal lineage Acinetobacter baumannii international clone II (IC II). Because the prevalence of MDR Acinetobacter spp. in Japan remains very low, we characterized all Acinetobacter spp. (n = 866) from 76 hospitals between October 2012 and March 2013 to describe the entire molecular epidemiology of Acinetobacter spp. The most prevalent species was A. baumannii (n = 645; 74.5%), with A. baumannii IC II (n = 245) accounting for 28.3% of the total. Meropenem-resistant isolates accounted for 2.0% (n = 17) and carried ISAba1-blaOXA-23-like (n = 10), blaIMP (n = 4), or ISAba1-blaOXA-51-like (n = 3). Multilocus sequence typing of 110 representative A. baumannii isolates revealed the considerable prevalence of domestic sequence types (STs). A. baumannii IC II isolates were divided into the domestic sequence type 469 (ST469) (n = 18) and the globally disseminated STs ST208 (n = 14) and ST219 (n = 4). ST469 isolates were susceptible to more antimicrobial agents, while ST208 and ST219 overproduced the intrinsic AmpC ß-lactamase. A. baumannii IC II and some A. baumannii non-IC II STs (e.g., ST149 and ST246) were associated with fluoroquinolone resistance. This study revealed that carbapenem-susceptible A. baumannii IC II was moderately disseminated in Japan. The low prevalence of acquired carbapenemase genes and presence of domestic STs could contribute to the low prevalence of MDR A. baumannii A similar epidemiology might have appeared before the global dissemination of MDR epidemic lineages. In addition, fluoroquinolone resistance associated with A. baumannii IC II may provide insight into the significance of A. baumannii epidemic clones.
Asunto(s)
Acinetobacter baumannii/genética , Infecciones por Acinetobacter/tratamiento farmacológico , Infecciones por Acinetobacter/microbiología , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Carbapenémicos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Japón , Pruebas de Sensibilidad Microbiana/métodos , Epidemiología Molecular/métodos , beta-Lactamasas/genéticaRESUMEN
Salmonella is a major causative agent of food borne diseases. Recently, monophasic strains of Salmonella, such as S. enterica 4: i: -, have been frequently reported. Here, we investigated the genetic background of S. enterica 4: b: - using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis. A total of 10 strains of S. enterica (I) 4: b: - were examined and compared with 34 strains including serovar Paratyphi B and Paratyphi B var Java, Schleissheim, and II b: -. All I 4: b: - strains were negative for hin which encodes an invertase that converts the H phases, and six were also negative for fljB, which encodes the second phase of the H antigen. An MLST analysis identified 12 sequence types (ST) and 6 ST complexes (STC) from the 44 strains. A clustering analysis of PFGE patterns almost corresponded to the STC. The monophasic I 4: b: - strains were assigned to 3 STCs (19, 32 and 155), corresponding to those of Paratyphi B var. Java or a monophasic strain according to the data of this and previous studies. These findings suggest that the monophasic strains examined in this study might have been derived from multiple clones of Paratyphi B var Java. This study shows the usefulness of molecular typing as complementation tools of the conventional serotyping system.
Asunto(s)
Salmonella enterica/genética , Humanos , Filogenia , Infecciones por SalmonellaRESUMEN
Enteroaggregative Escherichia coli (EAggEC) are an important cause of diarrhea. Four types of AAF have been identified; however, their prevalence and association with virulence properties remain unclear. E. coli strains carrying the aggR gene as EAggEC that were isolated in Japan and Thailand (n = 90) were examined for AAF subunit genes, two toxin genes (pet/astA), and clump formation. The most prevalent AAF gene was hdaA (28%), followed by aafA (20%), aggA (12%), and agg3A (4%), as well as a putative new AAF sequence (25.6%). Retention status of the toxin genes and intensities of clump formation appeared to vary according to the AAF type.
Asunto(s)
Adhesión Bacteriana , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/metabolismo , Escherichia coli/aislamiento & purificación , Fimbrias Bacterianas/metabolismo , Transactivadores/metabolismo , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/fisiología , Proteínas de Escherichia coli/genética , Fimbrias Bacterianas/genética , Humanos , Japón , Tailandia , Transactivadores/genética , Factores de Virulencia/genética , Factores de Virulencia/metabolismoRESUMEN
Among Shiga toxin (Stx)-producing Escherichia coli (STEC) strains of various serotypes, O157:H7 and five major non-O157 STEC (O26:H11, O111:H8, O103:H2, O121:H19 and O145:H28) can be selectively isolated by using tellurite-containing media. While human infections by O165:H25 STEC strains have been reported worldwide, their detection and isolation are not easy, as they are not resistant to tellurite. Systematic whole-genome sequencing (WGS) analyses have not yet been conducted. Here, we defined O165:H25 strains and their close relatives, including O172:H25 strains, as clonal complex 119 (CC119) and performed a global WGS analysis of the major lineage of CC119, called CC119 sensu stricto (CC119ss), by using 202 CC119ss strains, including 90 strains sequenced in this study. Detailed comparisons of 13 closed genomes, including 7 obtained in this study, and systematic analyses of Stx phage genomes in 50 strains covering the entire CC119ss lineage, were also conducted. These analyses revealed that the Stx2a phage, the locus of enterocyte effacement (LEE) encoding a type III secretion system (T3SS), many prophages encoding T3SS effectors, and the virulence plasmid were acquired by the common ancestor of CC119ss and have been stably maintained in this lineage, while unusual exchanges of Stx1a and Stx2c phages were found at a single integration site. Although the genome sequences of Stx2a phages were highly conserved, CC119ss strains exhibited notable variation in Stx2 production levels. Further analyses revealed the lack of SpLE1-like elements carrying the tellurite resistance genes in CC119ss and defects in rhamnose, sucrose, salicin and dulcitol fermentation. The genetic backgrounds underlying these defects were also clarified.
Asunto(s)
Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Humanos , Escherichia coli Shiga-Toxigénica/genética , Toxina Shiga/genética , Fermentación , Proteínas de Escherichia coli/genética , Genómica , CarbohidratosRESUMEN
Shiga toxin (Stx)-producing Escherichia coli (STEC) are foodborne pathogens causing serious diseases, such as haemorrhagic colitis and haemolytic uraemic syndrome. Although O157:H7 STEC strains have been the most prevalent, incidences of STEC infections by several other serotypes have recently increased. O121:H19 STEC is one of these major non-O157 STECs, but systematic whole genome sequence (WGS) analyses have not yet been conducted on this STEC. Here, we performed a global WGS analysis of 638 O121:H19 strains, including 143 sequenced in this study, and a detailed comparison of 11 complete genomes, including four obtained in this study. By serotype-wide WGS analysis, we found that O121:H19 strains were divided into four lineages, including major and second major lineages (named L1 and L3, respectively), and that the locus of enterocyte effacement (LEE) encoding a type III secretion system (T3SS) was acquired by the common ancestor of O121:H19. Analyses of 11 complete genomes belonging to L1 or L3 revealed remarkable interlineage differences in the prophage pool and prophage-encoded T3SS effector repertoire, independent acquisition of virulence plasmids by the two lineages, and high conservation in the prophage repertoire, including that for Stx2a phages in lineage L1. Further sequence determination of complete Stx2a phage genomes of 49 strains confirmed that Stx2a phages in lineage L1 are highly conserved short-tailed phages, while those in lineage L3 are long-tailed lambda-like phages with notable genomic diversity, suggesting that an Stx2a phage was acquired by the common ancestor of L1 and has been stably maintained. Consistent with these genomic features of Stx2a phages, most lineage L1 strains produced much higher levels of Stx2a than lineage L3 strains. Altogether, this study provides a global phylogenetic overview of O121:H19 STEC and shows the interlineage genomic differences and the highly conserved genomic features of the major lineage within this serotype of STEC.
Asunto(s)
Escherichia coli Shiga-Toxigénica/clasificación , Factores de Virulencia/genética , Secuenciación Completa del Genoma/métodos , Animales , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Filogenia , Polimorfismo de Nucleótido Simple , Profagos/genética , Serotipificación , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/patogenicidad , Sistemas de Secreción Tipo III/genéticaRESUMEN
Phages and plasmids play important roles in bacterial evolution and diversification. Although many draft genomes have been generated, phage and plasmid genomes are usually fragmented, limiting our understanding of their dynamics. Here, we performed a systematic analysis of 239 draft genomes and 7 complete genomes of Shiga toxin (Stx)-producing Escherichia coli O145:H28, the major virulence factors of which are encoded by prophages (PPs) or plasmids. The results indicated that PPs are more stably maintained than plasmids. A set of ancestrally acquired PPs was well conserved, while various PPs, including Stx phages, were acquired by multiple sublineages. In contrast, gains and losses of a wide range of plasmids have frequently occurred across the O145:H28 lineage, and only the virulence plasmid was well conserved. The different dynamics of PPs and plasmids have differentially impacted the pangenome of O145:H28, with high proportions of PP- and plasmid-associated genes in the variably present and rare gene fractions, respectively. The dynamics of PPs and plasmids have also strongly impacted virulence gene repertoires, such as the highly variable distribution of stx genes and the high conservation of a set of type III secretion effectors, which probably represents the core effectors of O145:H28 and the genes on the virulence plasmid in the entire O145:H28 population. These results provide detailed insights into the dynamics of PPs and plasmids, and show the application of genomic analyses using a large set of draft genomes and appropriately selected complete genomes.
Asunto(s)
Genoma Bacteriano , Plásmidos , Profagos , Escherichia coli Shiga-Toxigénica/genética , Siphoviridae , Factores de Virulencia/genética , Filogenia , Polimorfismo de Nucleótido SimpleRESUMEN
We extracted lipopolysaccharides from 58 O-serogroup strains of Escherichia coli with phenol-water for use as antigens for an Ec-LPS array. The Ec-LPS array was made by dot-blotting of E. coli LPS on PVDF membrane. Commercial anti-E. coli O-serogroup antisera reacted with homologous O-serogroup LPS in Ec-LPS arrays. Convalescent sera of 6 patients with hemolytic uremic syndrome reacted strongly with O157 LPS when IgM and IgA antibodies in patient sera analyzed by Ec-LPS arrays. When IgG antibody was analyzed in this array, it was difficult to diagnose the O-serogroup because of the reactivity of patient sera against many O-serogroup LPS. These results match those by ELISA and western blotting. Compared to these serological techniques, Ec-LPS array appears superior to ELISA and western blotting in cost performance, time performance, and technical complexity.
Asunto(s)
Infecciones por Escherichia coli/diagnóstico , Escherichia coli/inmunología , Síndrome Hemolítico-Urémico/diagnóstico , Antígenos O/inmunología , Adolescente , Niño , Preescolar , Escherichia coli O157/inmunología , Síndrome Hemolítico-Urémico/microbiología , Humanos , Polisacáridos Bacterianos/inmunología , Pruebas SerológicasRESUMEN
For infection control in pediatric hospitals, we investigated the risk of pertussis and diphtheria infections among pediatric healthcare workers. Forty-nine Japanese pediatric healthcare workers in 12 general hospitals were screened for antibodies of pertussis toxin (PT), filamentous hemagglutinin (FHA), and diphtheria toxin (DT). The seropositive rates of anti-PT IgG (protective level, > 10 U/mL), anti-FHA IgG (> 10 U/ mL), and anti-DT (> 0.11 U/mL) were 50, 82, and 59%, respectively. During this survey period (Oct. 2003-Feb. 2004), 16 (33%) of the healthcare workers were in contact with pertussis-infant (s). However, all culture and PCR tests for Bordetella pertussis were negative. One of the 16 exposed healthcare workers, a male pediatrician, had serological evidence of a pertussis infection, but no disease symptomatic of pertussis. Our observations indicate that i) 50 and 41% of Japanese pediatric healthcare workers were seronegative for pertussis (anti-PT IgG) and diphtheria antibodies, respectively, and ii) although the healthcare workers had a high rate of contact with pertussis-infant (s), the infection rate was low. For pertussis and diphtheria infection control in pediatric hospitals, it is important for healthcare workers to be aware of their own protection levels against these diseases.
Asunto(s)
Difteria/transmisión , Transmisión de Enfermedad Infecciosa de Profesional a Paciente , Enfermería Pediátrica , Pediatría , Tos Ferina/transmisión , Adhesinas Bacterianas/sangre , Anticuerpos Antibacterianos/sangre , Niño , Toxina Diftérica/inmunología , Humanos , Japón , Masculino , Toxina del Pertussis/inmunología , Factores de Virulencia de Bordetella/sangreRESUMEN
This study was performed to determine the prevalence, antimicrobial susceptibility, and genetic relatedness of Salmonella enterica subsp. enterica and Campylobacter spp. in poultry meat, and to analyze the association of genetic types of these bacteria with their geographical distribution and antimicrobial resistance profiles. Salmonella and Campylobacter isolates have been detected, respectively, in 54 and 71 samples out of 100 samples tested. Nine Salmonella serotypes were found, including S. enterica subsp. enterica serovar Infantis (33%), Schwarzengrund (12%), Manhattan (9%), and others. Campylobacter jejuni and C. coli were detected in 64 (64%) and 14 (14%) samples, respectively. S. enterica subsp. enterica isolates were very frequently resistant to tetracycline (78.3%) and streptomycin (68.3%). Many C. jejuni and C. coli isolates were resistant to sulfamethoxazole/trimethoprim (90.5%), nalidixic acid (47.3%), ampicillin (45.9%), and ciprofloxacin (40.5%). Cluster analysis was performed for the Salmonella isolates using pulsed-field gel electrophoresis (PFGE) data. For Campylobacter isolates, the cluster analysis was based on both PFGE and comparative genomic fingerprinting. The molecular typing results were compared with the information about antimicrobial resistance and geographical locations in which the poultry meat was produced. This analysis revealed that C. jejuni strains with a particular genotype and antimicrobial resistance profile are spreading in specific areas of Japan.
Asunto(s)
Campylobacter jejuni/aislamiento & purificación , Contaminación de Alimentos , Carne/microbiología , Aves de Corral/microbiología , Salmonella/aislamiento & purificación , Animales , Antibacterianos/farmacología , Campylobacter jejuni/clasificación , Campylobacter jejuni/efectos de los fármacos , Campylobacter jejuni/genética , Análisis por Conglomerados , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Japón , Tipificación Molecular , Filogeografía , Prevalencia , Salmonella/clasificación , Salmonella/efectos de los fármacos , Salmonella/genéticaRESUMEN
Serratia marcescens is a Gram-negative bacterium that is often associated with nosocomial infections. Here we analyzed the resistance mechanism of the ceftazidime-resistant S. marcescens nosocomial strains. The five S. marcescens urinary tract infection-associated isolates were positive for chromosomal ampC and bla(TEM-1). Four of the five strains, ES11, ES31, ES42, and ES46, were single clone and ceftazidime resistant. The fifth strain, ES71, was susceptible to ceftazidime. Analysis of the deduced amino acid sequence revealed a Glu-235-Lys substitution in the third amino acid of the third motif of AmpC from both ES46 and ES71, and a site-directed mutagenesis experiment confirmed that this substitution is involved in the ceftazidime resistance phenotype. However, the resistance phenotypes of strains ES46 and ES71 to ceftazidime were quite different from one another, indicating that another mechanism, in addition to the AmpC mutation, is also involved in the determination of the resistance phenotype of these strains. Basal AmpC activity was more than two times higher in strain ES46 than in ES71, which could result in the differing resistance phenotypes of these two strains. The clinical significance and prevalence of extended-spectrum cephalosporin-resistant S. marcescens strains harboring the mutated chromosomal ampC gene are unclear in Japan and remain to be elucidated.
Asunto(s)
Proteínas Bacterianas/genética , Ceftazidima/farmacología , Resistencia a las Cefalosporinas/genética , Infección Hospitalaria/microbiología , Infecciones por Serratia/microbiología , Serratia marcescens/genética , beta-Lactamasas/genética , Secuencia de Aminoácidos , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/metabolismo , Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado/métodos , Escherichia coli/genética , Humanos , Japón/epidemiología , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida/métodos , Infecciones por Serratia/epidemiología , Serratia marcescens/efectos de los fármacos , Serratia marcescens/enzimología , Serratia marcescens/aislamiento & purificación , Transformación Bacteriana , Inhibidores de beta-Lactamasas , beta-Lactamasas/biosíntesis , beta-Lactamasas/metabolismoRESUMEN
To determine the significance of poultry and bovine as infectious sources of Campylobacter jejuni in Japan, the serotype distribution and pulsed-field gel electrophoresis (PFGE) patterns of poultry and bovine isolates were compared with those of isolates from patients with diarrhea in Akita (Japan). Serotypes O:2 and O:4-complex were common in human, poultry, and bovine isolates, and serotype O:23,36,53 was common in human and bovine isolates. SmaI PFGE patterns of isolates belonging to these serotypes were generated. Eight PFGE patterns were shared by poultry and human isolates and three patterns were shared by human and bovine isolates. Further analysis of the isolates having the same SmaI PFGE pattern by KpnI PFGE confirmed that four patterns and two patterns were still shared by poultry and human isolates, and bovine and human isolates, respectively. Thus, serotypic and genotypic data indicated a possible link between sporadic human campylobacteriosis and C. jejuni from retail poultry and bovine bile and feces, suggesting that bovine serves as an infectious source of C. jejuni in Japan, as is observed in other countries.
Asunto(s)
Infecciones por Campylobacter/microbiología , Campylobacter jejuni/aislamiento & purificación , Bovinos/microbiología , Diarrea/microbiología , Microbiología de Alimentos , Aves de Corral/microbiología , Animales , Bilis/microbiología , Campylobacter jejuni/clasificación , Campylobacter jejuni/genética , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Electroforesis en Gel de Campo Pulsado , Heces/microbiología , Genotipo , Humanos , Japón , SerotipificaciónRESUMEN
In order to evaluate reliability of pulsed-field gel electrophoresis (PFGE) analysis performed at different prefectural public health institutes (PHIs) for use in the PulseNet Japan surveillance system to detect enterohemorrhagic Escherichia coli O157, we compared the results of PFGE-typing of 14 selected strains of O157 performed at 8 selected PHIs to evaluate the reliability of different experimental protocols used in these PHIs. PFGE was performed for 14 strains for which there were 14 PFGE types in 3 PHIs, and 13 PFGE types in 5 PHIs by using their own protocols and/or those of the National Institute of Infectious Diseases (NIID). PFGE fingerprints from 5 out of the 8 PHIs were successfully genotyped for all of the 14 strains. A PFGE fingerprint from one PHI was successfully genotyped when the NIID pulsing protocol was used, but was not genotyped when the PHI's own protocols were used. PFGE fingerprints from 2 PHIs failed to be genotyped for one each of the strains. The cause of this genotyping failure was considered to be inappropriate PFGE pulsing protocols or inadequate digestion of chromosomal DNA. These results suggest that PFGE protocols should be standardized for the establishment of PulseNet Japan.
Asunto(s)
Electroforesis en Gel de Campo Pulsado/normas , Escherichia coli O157/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Humanos , Japón/epidemiología , Vigilancia de la Población , Salud PúblicaRESUMEN
To quantify the number of Vibrio vulnificus in shellfish, we compared the most probable number (MPN) combined with a culture (MPN-culture) or polymerase-chain reaction (PCR) assay (MPN-PCR) to a quantitative PCR assay. Enrichment in alkaline peptone water by MPN was conducted at 25 and 35 degrees C. Enrichment at 35 degrees C was superior or similar to enrichment at 25 degrees C in over 65% of samples by MPNculture and in more than 75% of samples by MPN-PCR assay. V. vulnificus was more easily isolated on chromogenic agar medium during culture, MPN-PCR assay was superior or similar to MPNculture in over 90% of samples by enrichment at 25 degrees C and to over 88% of samples by enrichment at 35 degrees C. The number of V. vulnificus by quantitative PCR assay was similar to that of MPN-PCR assay in 6 of 8 samples but not from MPNculture. V. vulnificus contamination was frequently detected in samples from Kyushu Island.
Asunto(s)
Vibrio vulnificus/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Recuento de Colonia Microbiana/métodos , Medios de Cultivo Condicionados , Japón , Reacción en Cadena de la Polimerasa/métodos , Alimentos Marinos/microbiología , TemperaturaRESUMEN
Extended-spectrum ß-lactamase (ESBL)-producing Salmonella are one of the most important public health problems in developed countries. ESBL-producing Salmonella strains have been isolated from humans in Asian countries neighboring Japan, along with strains harboring the plasmid-mediated extended-spectrum cephalosporin (ESC)-resistance gene, ampC (pAmpC). However, only a few studies have investigated the prevalence of ESC-resistant Salmonella in chicken products in Japan, which are the main vehicle of Salmonella transmission. The aim of this study was to investigate the prevalence of ESBL-producing, pAmpC-harboring, or carbapenem-resistant Salmonella in chicken products in Japan. In total, 355 out of 779 (45.6%) chicken product samples collected from 1996-2010 contained Salmonella, resulting in 378 distinct isolates. Of these isolates, 373 were tested for resistance to ESCs, cephamycins, or carbapenems. Isolates that showed resistance to one or more of these antimicrobials were then examined by PCR and DNA sequence analysis for the presence of the bla(CMY), bla(CTX-M), bla(TEM), and bla(SHV) resistance genes. Thirty-five resistant isolates were detected, including 26 isolates that contained pAmpC (bla(CMY-2)), and nine ESBL-producing isolates harboring bla(CTX-M) (n = 4, consisting of two bla(CTX-M-2) and two bla(CTX-M-15 genes)), bla(TEM) (n = 4, consisting of one bla(TEM-20) and three bla(TEM-52) genes), and bla(SHV) (n = 1, bla(SHV-12)). All pAmpC-harboring and ESBL-producing Salmonella isolates were obtained from samples collected after 2005, and the percentage of resistant isolates increased significantly from 0% in 2004 to 27.9% in 2010 (P for trend = 0.006). This increase was caused in part by an increase in the number of Salmonella enterica subsp. enterica serovar Infantis strains harboring an approximately 280-kb plasmid containing bla(CMY-2) in proximity to ISEcp1. The dissemination of ESC-resistant Salmonella containing plasmid-mediated bla(CMY-2) in chicken products indicates the need for the development of continuous monitoring strategies in the interests of public health.
Asunto(s)
Antibacterianos/farmacología , Cefalosporinas/farmacología , Pollos/microbiología , Salmonella/efectos de los fármacos , Salmonella/genética , Resistencia betalactámica/genética , Animales , Proteínas Bacterianas/genética , Japón , Carne/microbiología , Datos de Secuencia Molecular , Fenotipo , Reacción en Cadena de la Polimerasa , Salmonella/enzimología , beta-Lactamasas/genéticaRESUMEN
We compared Campylobacter jejuni strains isolated from the patient stools associated with two food-borne diarrheal outbreak cases by the serotypic methods (Lior and Penner systems) and the genotypic methods (restriction fragment length polymorphism (RFLP) of flaA gene and pulsed-field gel electrophoresis (PFGE)). Fla-RFLP was based on the digestion of 410 bp DNA fragment by MboI restriction enzyme amplified from a 5' portion of C. jejuni flaA gene. Six distinctive fla-RFLP patterns were identified by examining 29 serotype reference strains and 58 strains isolated from the patients infected with C. jejuni independently. In the first outbreak case, 4 isolates were shown to be the same patterns each other by the fla-RFLP and PFGE, and by the Lior serotyping, except the Penner system that serotyped into 2 distinct types. On the other hand, in the second case, out of 10 isolates, 5 isolates were identical by the both genotypic and the both serotypic methods, and 4 isolates were not differentiated by the fla-RFLP and Penner system, but were separated into 4 types by PFGE in a little difference. The rest isolate was completely different from the other isolates by the all of methods used now. The findings suggest that the second case occurred by the infection of at least 3 different strains of C. jejuni.
Asunto(s)
Infecciones por Campylobacter/microbiología , Campylobacter jejuni/clasificación , Serotipificación/métodos , Adolescente , Secuencia de Bases , Infecciones por Campylobacter/epidemiología , Campylobacter jejuni/genética , Campylobacter jejuni/aislamiento & purificación , Brotes de Enfermedades , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Japón/epidemiología , Datos de Secuencia Molecular , Fenotipo , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
A 4-year-old girl who was positive for adenovirus according to a rapid immunochromatographic test conducted at a hospital, progressed to hemorrhagic diarrhea and hemolytic uremic syndrome (HUS). The presence of adenovirus serotype 41 (AdV-41) was confirmed by TaqMan real-time PCR and sequence analysis. However, most enteric viral infections cause mild to moderate diarrhea. In the present case, enterohemorrhagic Escherichia coli (EHEC) O165:HNM was isolated concomitantly with AdV-41. In addition, O165 antibody was specifically detected in patient sera. The EHEC isolate was positive for the virulence genes stx1, stx2a, eae type ε, ehxA, and norV. Therefore, we concluded that EHEC O165:HNM was the precise pathogen leading to HUS in this patient.
Asunto(s)
Infecciones por Adenoviridae/complicaciones , Adenovirus Humanos/aislamiento & purificación , Escherichia coli Enterohemorrágica/aislamiento & purificación , Infecciones por Escherichia coli/complicaciones , Síndrome Hemolítico-Urémico/complicaciones , Infecciones por Adenoviridae/virología , Adenovirus Humanos/clasificación , Anticuerpos Antibacterianos/sangre , Preescolar , ADN Bacteriano/genética , ADN Viral/genética , Escherichia coli Enterohemorrágica/clasificación , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Femenino , Síndrome Hemolítico-Urémico/microbiología , Humanos , Reacción en Cadena de la Polimerasa , Serotipificación , Factores de Virulencia/genéticaRESUMEN
Between 2007 and 2009, a total of 2168 Escherichia coli strains derived from diarrheal patients, defined as putative diarrheagenic E. coli (DEC), were collected from medical institutions in Akita prefecture, Japan. Thirty five of the strains lacked typical pathogenic determinants of DEC other than astA, which encodes enteroaggregative E. coli (EAggEC) heat-stable enterotoxin 1 (EAST1). These E. coli strains are referred to as EAST1EC. Several studies have suggested a role of EAST1 in diarrhea; however, the correlation between diarrhea and the presence of astA remains inconclusive. To investigate whether EAST1EC strains derived from diarrheal patients shared pathogenic factors other than EAST1, virulence gene profiling of 12 virulence genes - iha, lpfA, ldaG, pilS, pic, pet, irp2, daa, aah, aid, cdtB and hlyA - was carried out. PCR analysis revealed that four of the 35 EAST1EC strains harbored only astA, 24 harbored genes associated with adhesins and intestinal colonization, three strains harbored the gene for α-hemolysin, and 24 strains harbored the gene for a siderophore. These results indicated that some EAST1EC strains harbor various virulence genes associated with distinct E. coli pathotypes, primarily enterohemorrhagic E. coli and EAggEC, which may represent additional pathogenic determinants of EAST1EC.
Asunto(s)
Toxinas Bacterianas/genética , Diarrea/microbiología , Enterotoxinas/genética , Infecciones por Escherichia coli/microbiología , Escherichia coli/genética , Escherichia coli/patogenicidad , Factores de Virulencia/genética , Adhesinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Enterotoxinas/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Genes Bacterianos , Humanos , Virulencia/genéticaRESUMEN
A microbial strain harboring the eae gene, which is known as the virulence gene of enteropathogenic Escherichia coli (EPEC) and most enterohemorrhagic E. coli, was isolated from a patient in a gastroenteritis outbreak that occurred in 22 patients in Akita Prefecture, Japan, in November 2011. The biochemical characteristics of the isolate were more similar to those of a novel Escherichia sp., E. albertii than E. coli. Partial 16S rRNA gene sequences of the isolate were identical to those of a certain E. albertii strain, but also showed a high degree of similarity to those of E. coli strains. Finally, we identified this isolate as E. albertii by performing PCR analysis that targeted the uidA, lysP, mdh, and cdtB genes in addition to stx and eae genes to differentiate between the EPEC and E. albertii strains.
Asunto(s)
Brotes de Enfermedades , Escherichia/clasificación , Escherichia/aislamiento & purificación , Gastroenteritis/epidemiología , Gastroenteritis/microbiología , Técnicas de Tipificación Bacteriana , ADN Bacteriano/análisis , ADN Bacteriano/genética , Escherichia/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Humanos , Japón/epidemiología , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
A total of 18 strains of EHEC O157:H7 were isolated from distinct cases in Akita Prefecture, Japan from July to September 2007. The genetic relatedness of these isolates was investigated by performing a multilocus variable number of tandem repeats analysis (MLVA) and a pulsed-field gel electrophoresis (PFGE) analysis using XbaI. The PFGE analyses allowed us to group these 18 isolates into three major clusters. The MLVA results correlated closely with those obtained by PFGE, although some variants were found within the clusters obtained by PFGE, thus highlighting the utility of this technique for determining a precise classification when it is difficult to differentiate between isolates with indistinguishable or very similar PFGE patterns. In addition, MLVA is a much easier and more rapid method than PFGE for analysis of the genetic relatedness of strains. Thus, as a second molecular epidemiological subtyping method, MLVA is useful for the regional outbreak surveillance of EHEC O157:H7 infections.