RESUMEN
The aim of this study was to describe the microbiological characteristics and profile of genes encoding enterotoxins in 95 Staphylococcus aureus isolates obtained between April 2011 and December 2014 from foodstuffs, persons and surfaces of retail food stores. After microbiological identification and antimicrobial susceptibility testing, polymerase chain reactions (PCR) were performed, targeting sea, seb, sec, sed and see genes that code for classical enterotoxins (ET) A-E, and three additional genes: seg , seh and sei , coding for so-called "new enterotoxins" G, H and I. The isolates were characterized by Pulsed Field Gel Electrophoresis (PFGE), and five selected isolates were further analyzed through Multi Locus Sequence Typing (MLST). It is noteworthy that 54.7% of the examined isolates harbored one or more of the investigated ET gene types. Most positive isolates carried more than one ET gene up to five types; seg was the most frequent ET gene, followed by sei. Five enterotoxin-coding isolates also coded for some antimicrobial resistance genes. Two of them, and four additional non-enterotoxic isolates carried erm genes expressing inducible clindamycin resistance. PFGE-types were numerous and diverse, even among enterotoxin-coding strains, because most isolates did not belong to known foodborne outbreaks and the sampling period was long. MLST profiles were also varied, and a new ST 3840 was described within this species. ST 88 and ST 72 enterotoxin-coding isolates have been identified in other regions in association with foodborne outbreaks. This manuscript reports the first systematic investigation of enterotoxin genes in S. aureus isolates obtained from foodstuffs and infected people in Uruguay.
Asunto(s)
Toxinas Bacterianas/genética , Enterotoxinas/genética , Enfermedades Transmitidas por los Alimentos/microbiología , Staphylococcus aureus/genética , Electroforesis en Gel de Campo Pulsado , Enterotoxinas/aislamiento & purificación , Microbiología de Alimentos , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Reacción en Cadena de la Polimerasa , Staphylococcus aureus/efectos de los fármacos , UruguayRESUMEN
Considering the growing consumption of artisanal foods worldwide, we aimed to evaluate the microbial safety of Serro artisanal cheese (SAC), produced in Minas Gerais State, Brazil. This cheese is produced with raw milk using 1 of 2 natural starter cultures: "pingo" and "rala." A total of 53 SAC samples (pingo = 8; rala = 45) were obtained from different farmers and subjected to conventional and molecular assays to detect and enumerate Listeria monocytogenes, Salmonella spp., coagulase-positive staphylococci (CPS), diarrheagenic Escherichia coli, Mycobacterium tuberculosis, and Brucella abortus. The SAC samples were also subjected to an ELISA to detect classical staphylococcal enterotoxins (CSE: SEA, SEB, SEC, SED, SEE) and to PCR assays to detect staphylococcal enterotoxin-related genes (sea, seb, sec, sed, see). Coagulase-positive staphylococci isolates were obtained and tested by the same assays to detect their potential in CSE production and presence of CSE-related genes. None of the SAC samples showed any of the screened food-borne pathogens and zoonotic agents, and none showed the presence of CSE by phenotypic and genotypic approaches. Despite the absence of microbial hazards, mean counts of CPS in SAC samples were 5.2 log cfu/g (pingo starter) and 4.6 log cfu/g (rala starter), indicating poor hygiene practices during production. None of the tested CPS isolates (n = 116) produced CSE or presented CSE-related genes. Despite the relative microbial safety, hygienic conditions during SAC production must be improved to meet official guidelines established in Brazil.
Asunto(s)
Queso/microbiología , Microbiología de Alimentos , Inocuidad de los Alimentos , Animales , Brasil , Bovinos , Enterotoxinas/aislamiento & purificación , Listeria monocytogenes/aislamiento & purificación , Leche/microbiología , Reacción en Cadena de la Polimerasa , Salmonella/aislamiento & purificación , Staphylococcus/aislamiento & purificaciónRESUMEN
Introduction: Bacillus cereus is recognized as a pathogen that causes food poisoning. It is a facultative aerobic metabolism bacterium capable of forming spores, which allows it to survive pasteurization and heating even by the gamma irradiation used to reduce pathogens in food. Objective: To study the presence of Bacillus cereus and its diarrheal toxin in rice and ready-to-eat cereals, flours, and starches in school restaurants in Colombia. Materials and methods: We conducted a descriptive cross-sectional study of ready-to-eat foods distributed in school restaurants in the departments with the most and the least notification of foodborne diseases to the surveillance system. Results: A total of 479 samples were collected from eight departments, 74 municipalities, and 363 school restaurants, 63% of which were rice samples and 37%, starchy food samples; 9% of them tested positive for Bacillus cereus. In 91% of the samples that tested positive, the bacterium was isolated with the presence of the diarrheal toxin. Conclusions: In all the departments with B. cereus in the samples, the factors directly related to food-borne diseases were the handling of raw materials and the poor thermal treatment of food. Strengthening surveillance by stimulating research and reporting on outbreaks of foodborne diseases is important to improve the quality of information, to develop communication, prevention and intersectional coordination and manipulation measures, as well as to take the necessary actions to guarantee the safety of food and to eliminate the risk factors that may contribute to this problem.
Asunto(s)
Bacillus cereus/aislamiento & purificación , Brotes de Enfermedades , Grano Comestible/microbiología , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Oryza/microbiología , Instituciones Académicas , Colombia/epidemiología , Estudios Transversales , Diarrea/etiología , Diarrea/microbiología , Enterotoxinas/aislamiento & purificación , Manipulación de Alimentos/métodos , Manipulación de Alimentos/normas , Conservación de Alimentos/métodos , Conservación de Alimentos/normas , Enfermedades Transmitidas por los Alimentos/epidemiología , Humanos , Higiene , Abastecimiento de AguaRESUMEN
Resumen Introducción. Bacillus cereus es reconocido como un agente patógeno causante de intoxicaciones alimentarias. Se trata de una bacteria de metabolismo aerobio facultativo capaz de formar esporas, lo que le permite sobrevivir a la pasteurización y el calentamiento e, incluso, a la irradiación con los rayos gamma usados para reducir los agentes patógenos de los alimentos. Objetivo. Estudiar la presencia de B. cereus y su toxina diarreica en el arroz y en alimentos a base de cereales, harinas o féculas listos para el consumo en restaurantes escolares de algunos departamentos de Colombia. Materiales y métodos. Se hizo un estudio descriptivo y transversal con alimentos listos para el consumo distribuidos en restaurantes escolares de los departamentos que más notifican enfermedades transmitidas por alimentos al sistema de vigilancia, así como en los de menor notificación. Resultados. Se recolectaron 479 muestras en ocho departamentos, 74 municipios y 363 restaurantes escolares; el 63 % correspondió a muestras de arroz y el 37 % a alimentos como coladas. El 9 % de las muestras analizadas fueron positivas para B. cereus y, en el 91 % de estas, se detectó la toxina diarreica. Conclusiones. En todos los departamentos estudiados se encontró B. cereus. El manejo de materias primas y el inadecuado tratamiento térmico de los alimentos fueron los factores directamente relacionados con las enfermedades transmitidas por alimentos. Es importante reforzar la vigilancia e incentivar la investigación y la notificación de los brotes de enfermedades transmitidas por alimentos para mejorar la calidad de la información, llevar a cabo acciones de comunicación, prevención y coordinación intersectorial, y con los manipuladores, con el fin de adoptar las medidas necesarias que garanticen la inocuidad de los alimentos, así como la eliminación de los factores de riesgo de estas enfermedades.
Abstract Introduction: Bacillus cereus is recognized as a pathogen that causes food poisoning. It is a facultative aerobic metabolism bacterium capable of forming spores, which allows it to survive pasteurization and heating even by the gamma irradiation used to reduce pathogens in food. Objective: To study the presence of Bacillus cereus and its diarrheal toxin in rice and ready-to-eat cereals, flours, and starches in school restaurants in Colombia. Materials and methods: We conducted a descriptive cross-sectional study of ready-to-eat foods distributed in school restaurants in the departments with the most and the least notification of foodborne diseases to the surveillance system. Results: A total of 479 samples were collected from eight departments, 74 municipalities, and 363 school restaurants, 63% of which were rice samples and 37%, starchy food samples; 9% of them tested positive for Bacillus cereus. In 91% of the samples that tested positive, the bacterium was isolated with the presence of the diarrheal toxin. Conclusions: In all the departments with B. cereus in the samples, the factors directly related to food-borne diseases were the handling of raw materials and the poor thermal treatment of food. Strengthening surveillance by stimulating research and reporting on outbreaks of foodborne diseases is important to improve the quality of information, to develop communication, prevention and intersectional coordination and manipulation measures, as well as to take the necessary actions to guarantee the safety of food and to eliminate the risk factors that may contribute to this problem.
Asunto(s)
Humanos , Oryza/microbiología , Instituciones Académicas , Bacillus cereus/aislamiento & purificación , Grano Comestible/microbiología , Brotes de Enfermedades , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Abastecimiento de Agua , Higiene , Estudios Transversales , Colombia/epidemiología , Diarrea/etiología , Diarrea/microbiología , Enterotoxinas/aislamiento & purificación , Manipulación de Alimentos/normas , Manipulación de Alimentos/métodos , Enfermedades Transmitidas por los Alimentos/epidemiología , Conservación de Alimentos/normas , Conservación de Alimentos/métodosAsunto(s)
Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/diagnóstico , Infección Hospitalaria/microbiología , Anciano , Antibacterianos/uso terapéutico , Proteínas Bacterianas/aislamiento & purificación , Toxinas Bacterianas/aislamiento & purificación , Brasil , Enterotoxinas/aislamiento & purificación , Heces/microbiología , Hospitales Universitarios , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Proteínas Represoras/aislamiento & purificaciónRESUMEN
The major contamination sources, biofilm-forming ability and biocide resistance of Staphylococcus aureus in tilapia-processing plants were evaluated. Twenty-five processing control points were analysed twice in two factories, including whole tilapias, frozen fillets, water and food-contact surfaces. No final product was contaminated with S. aureus. However, high concentrations of S. aureus carrying enterotoxin ( se) genes were found in several processing points of both factories due to the application of inadequate hygienic and handling procedures, which generate a high risk of cross-contamination of the tilapia fillets with staphylococcal enterotoxins. Nine S. aureus strains were characterized by RAPD-PCR using primers AP-7, ERIC-2 and S. A wide diversity of se gene profiles was detected, most strains being multi- se-carriers. All S. aureus strains showed high biofilm-forming ability on stainless steel and polystyrene. Biofilm-forming ability was correlated with the presence of fliC H7 and the type of origin surface (metallic or plastic). A marked resistance of S. aureus to peracetic acid and sodium hypochlorite was also observed, required doses being higher than those recommended by manufacturers to be eradicated. Case-by-case approaches are thus recommended to determine the sources and degree of contamination present in each factory, which would allow applying precise responses that avoid, or at least reduce, the presence of bacterial pathogens and the emergence of antimicrobial resistance.
Asunto(s)
Biopelículas/crecimiento & desarrollo , Contaminación de Alimentos/prevención & control , Industria de Procesamiento de Alimentos/instrumentación , Alimentos Congelados , Alimentos Marinos , Staphylococcus aureus/fisiología , Tilapia , Animales , Acuicultura , Carga Bacteriana , Biopelículas/efectos de los fármacos , Brasil , Desinfectantes/farmacología , Farmacorresistencia Bacteriana Múltiple , Enterotoxinas/genética , Enterotoxinas/aislamiento & purificación , Enterotoxinas/metabolismo , Flagelina/genética , Flagelina/aislamiento & purificación , Flagelina/metabolismo , Alimentos Congelados/microbiología , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Ácido Peracético/farmacología , Poliestirenos , Alimentos Marinos/microbiología , Hipoclorito de Sodio/farmacología , Acero Inoxidable , Staphylococcus aureus/clasificación , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Tilapia/crecimiento & desarrollo , Tilapia/microbiología , Microbiología del AguaRESUMEN
We standardized an immunochromatographic test (IC) for heat-labile toxin I (LT-I) detection using LT-I antibodies and a specific platform containing the apparatus for application, assembly and cutting. IC detected as little as 62.5ng/mL of purified LT-I toxin and presented 91% sensitivity, 99.5% specificity and 96.0% accuracy, thereby proving to be an excellent point-of-care test for the diagnosis of enterotoxigenic E. coli infection in low-income countries.
Asunto(s)
Toxinas Bacterianas/aislamiento & purificación , Pruebas Diagnósticas de Rutina/métodos , Diarrea/diagnóstico , Escherichia coli Enterotoxigénica/aislamiento & purificación , Enterotoxinas/aislamiento & purificación , Infecciones por Escherichia coli/diagnóstico , Proteínas de Escherichia coli/aislamiento & purificación , Inmunoensayo/métodos , Anticuerpos Antibacterianos/inmunología , Toxinas Bacterianas/inmunología , Pruebas Diagnósticas de Rutina/instrumentación , Diarrea/microbiología , Escherichia coli Enterotoxigénica/metabolismo , Escherichia coli Enterotoxigénica/patogenicidad , Enterotoxinas/inmunología , Proteínas de Escherichia coli/inmunología , Calor , Humanos , Inmunoensayo/instrumentación , Sensibilidad y EspecificidadRESUMEN
Background Staphylococcus aureus produces 11 serotypes of endotoxins that may cause food poisoning. Aim To determine the prevalence of type A enterotoxigenic Staphylococcus aureus carriage among food service workers in Chillan, Chile. Material and Methods Pharyngeal swabs were obtained from 100 food service workers and were cultured in Agar plates. After identifying the presence of Staphylococcus aureus, DNA was extracted to identify type A toxin by conventional PCR. Results Thirty eight percent of samples were colonized with Staphylococcus aureus. Among these, 26% were toxin A producers. Conclusions Half of the sampled workers carried Staphylococcus aureus and a quarter of these produced type A enterotoxin.
Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Staphylococcus aureus/aislamiento & purificación , Nasofaringe/microbiología , Enterotoxinas/aislamiento & purificación , Servicios de Alimentación , Intoxicación Alimentaria Estafilocócica/microbiología , ADN Bacteriano , Chile , Reacción en Cadena de la Polimerasa , Factores de EdadRESUMEN
Background Staphylococcus aureus produces 11 serotypes of endotoxins that may cause food poisoning. Aim To determine the prevalence of type A enterotoxigenic Staphylococcus aureus carriage among food service workers in Chillan, Chile. Material and Methods Pharyngeal swabs were obtained from 100 food service workers and were cultured in Agar plates. After identifying the presence of Staphylococcus aureus, DNA was extracted to identify type A toxin by conventional PCR. Results Thirty eight percent of samples were colonized with Staphylococcus aureus. Among these, 26% were toxin A producers. Conclusions Half of the sampled workers carried Staphylococcus aureus and a quarter of these produced type A enterotoxin.
Asunto(s)
Enterotoxinas/aislamiento & purificación , Servicios de Alimentación , Nasofaringe/microbiología , Staphylococcus aureus/aislamiento & purificación , Adulto , Factores de Edad , Chile , ADN Bacteriano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Intoxicación Alimentaria Estafilocócica/microbiologíaRESUMEN
We identified and analyzed 5 new-type enterotoxin genes, including SEj, SEl, SEq, SEm, and SEr, to explore the distribution of 5 enterotoxin genes in Staphylococcus aureus of different origins as well as their correlations and differences. We examined the distribution of the S. aureus enterotoxin genes and their pathogenic mechanisms. A total of 660 specimens were collected from January 2011 to December 2014, and 217 strains of S. aureus were isolated. The template DNA of S. aureus was extracted. The Primer6.0 and Oligo7 software were used to design and synthesize polymerase chain reaction primers. Amplification results were analyzed by electrophoresis, and the amplification products were recovered and sequenced. Thirty-six bacterial strains contained the SEj gene (16.6%), including 15, 8, 8, 4, and 1 strains in fresh meat, quick-frozen food, raw milk, human purulent tissue, and living environment, respectively. Thirty-one bacterial strains contained the SEr gene (14.3%), including 16, 9, and 6 strains in fresh meat, quick-frozen food, and raw milk, respectively. Twenty-one bacterial strains contained the enterotoxin SEq gene (9.7%), including 8, 6, 6, and 1 strains in fresh meat, quick-frozen food, raw milk, and human purulent tissue, respectively. No SEm and SEl genes were detected. Different types of foods carry different types of enterotoxins, providing a basis for quick tracing for food poisoning. Three enterotoxin genes, SEj, SEr, and SEq, showed the highest carrier rate in quick-frozen food. It is imperative to improve their detection in quick-frozen food.
Asunto(s)
Enterotoxinas/genética , Microbiología de Alimentos , Genes Bacterianos , Staphylococcus aureus/metabolismo , ADN Bacteriano , Enterotoxinas/aislamiento & purificación , Análisis de los Alimentos , Humanos , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidadRESUMEN
Food handlers carrying enterotoxin-producing Staphylococcus are a potential source of food poisoning. The aim of this study was to analyze genes encoding enterotoxins in coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS) isolated from the anterior nostrils and hands of food handlers at a university restaurant in the city of Natal, Northeast Brazil. Thirty food handlers were screened for the study. The isolates were subjected to Gram staining, a bacitracin sensitivity test, mannitol fermentation, and catalase and coagulase tests. CoNS and CoPS strains were subsequently identified by a Vitek 2 System (BioMerieux, France) and various biochemical tests. Polymerase chain reaction was used to detect genes for enterotoxins A, B, C, D, E, G, H, and I (sea, seb, sec, sed, see, seg, seh, and sei) and a disc-diffusion method was used to determine susceptibility to several classes of antimicrobials. All food handlers presented staphylococci on their hands and/or noses. The study found 58 Staphylococcus spp., of which 20.7% were CoPS and 79.3% were CoNS. S. epidermidis was the most prevalent species. Twenty-nine staphylococci (50%) were positive for one or more enterotoxin genes, and the most prevalent genes were seg and sei, each with a frequency of 29.3%. Indeed, CoNS encoded a high percentage of enterotoxin genes (43.5%). However, S. aureus encoded even more enterotoxin genes (75%). Most isolates showed sensitivity to the antibiotics used for testing, except for penicillin (only 35% sensitive). The results from this study reinforce that coagulase-negative as well as coagulase-positive staphylococci isolated from food handlers are capable of genotypic enterotoxigenicity.
Asunto(s)
Enterotoxinas/genética , Manipulación de Alimentos , Genes Bacterianos/genética , Staphylococcus/aislamiento & purificación , Antibacterianos/farmacología , Bacitracina/farmacología , Brasil , Enterotoxinas/aislamiento & purificación , Mano/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Nariz/microbiología , Penicilinas/farmacología , Restaurantes , Staphylococcus/efectos de los fármacos , Staphylococcus/enzimología , Staphylococcus/metabolismo , UniversidadesRESUMEN
Although opportunistic pathogens, coagulase-negative staphylococci (CoNS), including Staphylococcus epidermidis and Staphylococcus haemolyticus, have long been regarded as avirulent organisms. The role of toxins in the development of infections caused by CoNS is still controversial. The objective of this study was to characterize the presence of enterotoxin and cytotoxin genes in S. epidermidis and S. haemolyticus isolates obtained from blood cultures. Cytotoxin genes were detected by PCR using novel species-specific primers. Among the 85 S. epidermidis and 84 S. haemolyticus isolates, 95.3% and 79.8%, respectively, carried at least one enterotoxin gene. The most frequent enterotoxin genes were sea (53.3%), seg (64.5%) and sei (67.5%). The seg gene was positively associated with S. epidermidis (p = 0.02), and this species was more toxigenic than S. haemolyticus. The hla/yidD gene was detected in 92.9% of S. epidermidis and the hla gene in 91.7% of S. haemolyticus isolates; hlb was detected in 92.9% of the S. epidermidis isolates and hld in 95.3%. Nosocomial Staphylococcus epidermidis and S. haemolyticus isolates exhibited a high toxigenic potential, mainly producing the non-classical enterotoxins seg and sei. The previously unreported detection of hla/yidD and hlb in S. epidermidis and S. haemolyticus using species-specific primers showed that these hemolysin genes differ between CoNS species and that they are highly frequent in blood culture isolates.
Asunto(s)
Citotoxinas/genética , ADN Bacteriano/aislamiento & purificación , Enterotoxinas/genética , Genes Bacterianos , Staphylococcus epidermidis/metabolismo , Staphylococcus haemolyticus/metabolismo , Citotoxinas/aislamiento & purificación , ADN Bacteriano/genética , Enterotoxinas/aislamiento & purificación , HumanosRESUMEN
BACKGROUND AND OBJECTIVE: Clostridium difficile NAP1/ribotype 027 is associated with severe disease and high mortality rates. Our aim was to determine the prevalence of NAP1/ribotype 027 among C. difficile isolates in a tertiary care hospital, and review the main clinical data. METHODS: We included 106 stool samples from 106 patients. Samples were tested for A&B toxins and were cultured on CCFA agar. The genes tcdA, tcdB, tcdC, cdtA, and cdtB were amplified using PCR in clinical isolates. The tcdA 3'-end deletion analysis, PCR-ribotyping, and pulsed-field gel electrophoresis (PFGE) were also performed. Stool samples that were positive for culture were tested by the GeneXpert C. difficile assay. Clinical data were collected. RESULTS: Thirty-six patients tested positive for A&B toxins; and 22 patients had positive culture for C. difficile, 14 of which tested positive for the A&B toxins and all 22 patients tested positive by the GeneXpert C. difficile assay. Risk factors included an average hospital stay of 16.1 days prior to toxin detection, average antibiotic use for 16.2 days, and a median of 3 antibiotics used. The 30-day crude mortality rate was 8.4%. Six of the 22 patients died, and 3 of those deaths were directly attributed to C. difficile infection. The majority of isolates, 90.9% (20/22), carried genes tcdB, tcdA, cdtA, and cdtB; and these strains carried the corresponding downregulator gene tcdC, with an 18-bp deletion. PFGE was performed on 17 isolates, and one main pattern was observed. Analysis of the ribotyping data showed similar results. CONCLUSION: The above findings represent the clonal spread of C. difficile in our institution, which mainly includes the NAP1/027 strain. This is the first report of C. difficile ribotype NAP1/027 in Mexico.
Asunto(s)
Proteínas Bacterianas/aislamiento & purificación , Toxinas Bacterianas/aislamiento & purificación , Clostridioides difficile/genética , Enterocolitis Seudomembranosa/epidemiología , Enterotoxinas/aislamiento & purificación , Genes Bacterianos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Clostridioides difficile/clasificación , Clostridioides difficile/aislamiento & purificación , Clostridioides difficile/patogenicidad , Electroforesis en Gel de Campo Pulsado , Enterocolitis Seudomembranosa/tratamiento farmacológico , Enterocolitis Seudomembranosa/microbiología , Enterocolitis Seudomembranosa/mortalidad , Heces/química , Heces/microbiología , Femenino , Humanos , Tiempo de Internación , Masculino , México/epidemiología , Persona de Mediana Edad , Ribotipificación , Factores de Riesgo , Análisis de Supervivencia , Centros de Atención TerciariaRESUMEN
The non-structural protein 4 (NSP4) has different roles in rotaviral replication, morphogenesis, and enterotoxin-like activity causing secretory diarrhea. A total of 11 partial nucleotide sequences of NSP4 coding gene were defined from group A rotavirus circulating in Brazilian swine herds. On comparing the viral sequences of diarrheagenic peptide area (amino acid 114-135), there was a single point mutation at amino acid 135 presented by two strains with amino acid alanine, and valine in the others. The NSP4 gene phylogeny showed that all strains clustered into E1 genotype, and the nucleotide identity between Brazilian strains ranged from 92.4% and 100%, while the putative amino acid identity, between 95.8% and 100%. Only one site (138aa) was positively selected and at least 119 were negatively selected. As a conclusion, these data demonstrate the occurrence of a common NSP4 genotype described elsewhere in pigs and low diversity between the samples from the surveyed areas
A proteína não estrutural 4 (NSP4) desempenha diferentes funções na replicação e na morfogênese dos rotavírus, apresentando, ainda, uma atividade de enterotoxina, causando diarreia do tipo secretória. Um total de 11 sequências parciais de nucleotídeos do gene codificador da NSP4 de rotavírus suínos de criações brasileiras foram definidas como pertencentes ao grupo A. Comparando-se as sequências virais da área do peptídeo toxigênico, que compreende a porção entre os aminoácidos de 114 a 135, constatou-se uma única mutação pontual no aminoácido 135, sendo que duas amostras apresentaram alanina, e as demais, valina. A análise filogenética do gene demonstrou que todas as amostras pertencem ao genotipo E1, e que a identidade nucleotídica das amostras brasileiras variou de 92,4% a 100%, enquanto que a identidade de aminoácidos, de 95,8% a 100%. Apenas um resíduo (aa 138) sofreu seleção positiva enquanto que pelo menos outros 119 apresentam seleção negativa. Assim, esses dados mostram a ocorrência de um genotipo comum da NSP4 já descrito anteriormente em suínos, com uma baixa diversidade entre as amostras encontradas
Asunto(s)
Animales , Filogenia , Genotipo , Rotavirus/genética , Porcinos/microbiología , Enterotoxinas/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Reoviridae/genéticaRESUMEN
The non-structural protein 4 (NSP4) has different roles in rotaviral replication, morphogenesis, and enterotoxin-like activity causing secretory diarrhea. A total of 11 partial nucleotide sequences of NSP4 coding gene were defined from group A rotavirus circulating in Brazilian swine herds. On comparing the viral sequences of diarrheagenic peptide area (amino acid 114-135), there was a single point mutation at amino acid 135 presented by two strains with amino acid alanine, and valine in the others. The NSP4 gene phylogeny showed that all strains clustered into E1 genotype, and the nucleotide identity between Brazilian strains ranged from 92.4% and 100%, while the putative amino acid identity, between 95.8% and 100%. Only one site (138aa) was positively selected and at least 119 were negatively selected. As a conclusion, these data demonstrate the occurrence of a common NSP4 genotype described elsewhere in pigs and low diversity between the samples from the surveyed areas(AU)
A proteína não estrutural 4 (NSP4) desempenha diferentes funções na replicação e na morfogênese dos rotavírus, apresentando, ainda, uma atividade de enterotoxina, causando diarreia do tipo secretória. Um total de 11 sequências parciais de nucleotídeos do gene codificador da NSP4 de rotavírus suínos de criações brasileiras foram definidas como pertencentes ao grupo A. Comparando-se as sequências virais da área do peptídeo toxigênico, que compreende a porção entre os aminoácidos de 114 a 135, constatou-se uma única mutação pontual no aminoácido 135, sendo que duas amostras apresentaram alanina, e as demais, valina. A análise filogenética do gene demonstrou que todas as amostras pertencem ao genotipo E1, e que a identidade nucleotídica das amostras brasileiras variou de 92,4% a 100%, enquanto que a identidade de aminoácidos, de 95,8% a 100%. Apenas um resíduo (aa 138) sofreu seleção positiva enquanto que pelo menos outros 119 apresentam seleção negativa. Assim, esses dados mostram a ocorrência de um genotipo comum da NSP4 já descrito anteriormente em suínos, com uma baixa diversidade entre as amostras encontradas(AU)
Asunto(s)
Animales , Rotavirus/genética , Genotipo , Porcinos/microbiología , Filogenia , Reoviridae/genética , Enterotoxinas/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinariaRESUMEN
Bacillus cereus can cause diarrhea and emetic syndromes after ingestion of food contaminated with it. This ability is due to the production of enterotoxins by this microorganism, these being the hemolysin BL complex, which is involved in the diarrheal syndrome, and cereulide, which is responsible for the emetic syndrome. The detection of genes associated with the production of these toxins can predict the virulence of strains isolated from contaminated food. In this paper, we analyzed 100 samples of vegetables, 25 of each kind (broccoli, coriander, carrot, and lettuce) obtained from different markets in Mexico City and its metropolitan area. B. cereus was isolated in 32, 44, 84, and 68% of the samples of broccoli, carrot, lettuce, and coriander, respectively. The hblA gene (encoding one of the three subunits of hemolysin BL) was amplified in 100% of the B. cereus isolates, and the ces gene (encoding the cereulide) could not be amplified from any of them. This is the first report of B. cereus isolation from the vegetables analyzed in this work and, also, the first report in Mexico of the isolation from vegetables of strains with potential virulence. The results should serve as evidence of the potential risk of consuming these foods without proper treatment.
Asunto(s)
Bacillus cereus/aislamiento & purificación , Contaminación de Alimentos/análisis , Verduras/microbiología , Proteínas Bacterianas/genética , ADN Bacteriano/aislamiento & purificación , Depsipéptidos/genética , Enterotoxinas/aislamiento & purificación , Microbiología de Alimentos , Proteínas Hemolisinas/genética , MéxicoRESUMEN
Clostridium difficile is the most common cause of hospital-acquired diarrhea in patients treated with antibiotics, chemotherapeutic agents, and other drugs that alter the normal equilibrium of the intestinal flora. A better understanding of the risk factors for C. difficile-associated disease (CDAD) could be used to reduce the incidence of CDAD and the costs associated with its treatment. The aim of this study was to identify the risk factors for CDAD in a cohort of Chinese patients in a Beijing hospital. Medical charts of a total of 130 inpatients (62 males and 68 females) with hospital-acquired diarrhea (45 with CDAD; 85 without CDAD) were retrospectively reviewed. C. difficile toxins A and B were detected in fecal samples using enzyme-linked fluorescence assays. The drugs used by patients with and without CDAD before the onset of diarrhea were compared. Factors that differed significantly between the two groups by univariate analysis were analyzed by multivariate analysis using a logistic regression model. Multivariate analysis showed that cephalosporin treatment was associated with a significantly higher risk of CDAD in hospitalized patients, while treatment with glycopeptides was significantly associated with a reduction in CDAD (P<0.001 for cephalosporin; P=0.013 for glycopeptides). Our data confirmed previous findings that empirical treatment with cephalosporins is positively associated with CDAD compared to individuals using other CDAD-related drugs. Additionally, we showed that treatment with glycopeptides was negatively associated with CDAD, compared to individuals using other CDAD-related drugs.
Asunto(s)
Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Antibacterianos/efectos adversos , Clostridioides difficile/patogenicidad , Infección Hospitalaria/microbiología , Diarrea/microbiología , Enterocolitis Seudomembranosa/microbiología , Proteínas Bacterianas/aislamiento & purificación , Toxinas Bacterianas/aislamiento & purificación , Cefalosporinas/efectos adversos , China/epidemiología , Infección Hospitalaria/epidemiología , Enterocolitis Seudomembranosa/epidemiología , Enterotoxinas/aislamiento & purificación , Heces/microbiología , Glicopéptidos/uso terapéutico , Incidencia , Modelos Logísticos , Análisis Multivariante , Estudios Retrospectivos , Factores de Riesgo , Estadísticas no ParamétricasRESUMEN
Clostridium difficile is the most common cause of hospital-acquired diarrhea in patients treated with antibiotics, chemotherapeutic agents, and other drugs that alter the normal equilibrium of the intestinal flora. A better understanding of the risk factors for C. difficile-associated disease (CDAD) could be used to reduce the incidence of CDAD and the costs associated with its treatment. The aim of this study was to identify the risk factors for CDAD in a cohort of Chinese patients in a Beijing hospital. Medical charts of a total of 130 inpatients (62 males and 68 females) with hospital-acquired diarrhea (45 with CDAD; 85 without CDAD) were retrospectively reviewed. C. difficile toxins A and B were detected in fecal samples using enzyme-linked fluorescence assays. The drugs used by patients with and without CDAD before the onset of diarrhea were compared. Factors that differed significantly between the two groups by univariate analysis were analyzed by multivariate analysis using a logistic regression model. Multivariate analysis showed that cephalosporin treatment was associated with a significantly higher risk of CDAD in hospitalized patients, while treatment with glycopeptides was significantly associated with a reduction in CDAD (P<0.001 for cephalosporin; P=0.013 for glycopeptides). Our data confirmed previous findings that empirical treatment with cephalosporins is positively associated with CDAD compared to individuals using other CDAD-related drugs. Additionally, we showed that treatment with glycopeptides was negatively associated with CDAD, compared to individuals using other CDAD-related drugs.
Asunto(s)
Antibacterianos/efectos adversos , Clostridioides difficile/patogenicidad , Infección Hospitalaria/microbiología , Diarrea/microbiología , Enterocolitis Seudomembranosa/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/aislamiento & purificación , Toxinas Bacterianas/aislamiento & purificación , Cefalosporinas/efectos adversos , China/epidemiología , Infección Hospitalaria/epidemiología , Enterocolitis Seudomembranosa/epidemiología , Enterotoxinas/aislamiento & purificación , Heces/microbiología , Femenino , Glicopéptidos/uso terapéutico , Humanos , Incidencia , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Factores de Riesgo , Estadísticas no ParamétricasRESUMEN
La leche en polvo es un producto de alto consumo humano que no precisa de ser conservado en frío, no obstante, diversos microorganismos pueden deteriorarlo. En la población costarricense, también se observa este alto consumo, por la facilidad del alimento para transporte, preparación y su costo competitivo. Bacillus cereus es una bacteria potencialmente patógena asociada a este tipo de producto, capaz de desarrollar toxinas dependiendo de la presencia o ausencia de los respectivos genes codificantes. En este estudio se determinó la presencia de los genes toxigénicos nheA, nheB y nheC en cepas de B. cereus aisladas de leche deshidratada vendida en el mercado nacional costarricense.Se examinaron cinco lotes diferentes, de diez marcas comerciales de leche en polvo distribuidos en el área metropolitana de San José Costa Rica. Se procedió a cuantificar B. cereus en las muestras de leche en polvo mediante la técnica de Número Más Probable (NMP) e identificar los aislamientos utilizando el equipo automatizado Vitek®. Adicionalmente, se determinó la presencia de los genes nheA, nheB y nheC mediante la técnica de PCR. La frecuencia de aislamiento de Bacillus cereus en las muestras de leche en polvo analizadas alcanzó un 50%, con cantidades que oscilaron entre 3 y >100 NMP/g. Se recuperaron 19 cepas de B. cereus aisladas, cinco fueron positivas para los tres genes toxigénicos, lo cual revela la presencia de B. cereus potencialmente toxigénico en leches deshidratadas del mercado nacional, lo que representa un riesgo para la salud pública.
Powdered milk is a frequently consumed product that does not need to be kept under cold conditions. Nevertheless, different microorganisms may contaminate it. Powdered milk is a highly consumed product by Costa Rican population, and Bacillus cereus is a potentially pathogenic bacteria associated to it, with the ability to develop toxins depending on the presence of the respective codifying genes. The aim of this study was to determine the presence of the toxigenic genes nheA, nheB and nheC from B. cereus strains, found in powdered milk sold at the Costa Rican national market. Five different lots of ten brands of powdered milk, distributed in the metropolitan area of San José, Costa Rica were analyzed. B cereus load was quantified using the Most Probable Number technique and identified using the Vitek® system. The presence of the toxigenic genes was determined using the PCR technique. The isolation frequency of this bacteria in the powdered milk samples analyzed reached 50%, with populations ranging from 3 to >100 MPN/g. Five out from nineteen strains were found positive for the three toxigenic genes, indicating contamination with potentially toxigenic B. cereus in powdered milk distributed in the national market, and an important risk for public health.
Asunto(s)
Animales , Bacillus cereus/aislamiento & purificación , Enterotoxinas/genética , Microbiología de Alimentos , Leche/microbiología , Bacillus cereus/genética , Recuento de Colonia Microbiana , Costa Rica , ADN Bacteriano/genética , Enterotoxinas/aislamiento & purificación , Reacción en Cadena de la PolimerasaRESUMEN
The isolation of heat-stable enterotoxin (STa) from Escherichia coli and cholera toxin from Vibrio cholerae has increased our knowledge of specific mechanisms of action that could be used as pharmacological tools to understand the guanylyl cyclase-C and the adenylyl cyclase enzymatic systems. These discoveries have also been instrumental in increasing our understanding of the basic mechanisms that control the electrolyte and water balance in the gut, kidney, and urinary tracts under normal conditions and in disease. Herein, we review the evolution of genes of the guanylin family and STa genes from bacteria to fish and mammals. We also describe new developments and perspectives regarding these novel bacterial compounds and peptide hormones that act in electrolyte and water balance. The available data point toward new therapeutic perspectives for pathological features such as functional gastrointestinal disorders associated with constipation, colorectal cancer, cystic fibrosis, asthma, hypertension, gastrointestinal barrier function damage associated with enteropathy, enteric infection, malnutrition, satiety, food preferences, obesity, metabolic syndrome, and effects on behavior and brain disorders such as attention deficit, hyperactivity disorder, and schizophrenia.