RESUMO
Yersinia is an important genus comprising foodborne, zoonotic and pathogenic bacteria. On the other hand, species of the so-called group Yersinia enterocolitica-like are understudied and mostly characterized as non-pathogenic, despite of some reports of human infections. The present study aimed to provide genomic insights of Yersinia frederiksenii (YF), Yersinia intermedia (YI) and Yersinia kristensenii (YK) isolated worldwide. A total of 22 YF, 20 YI and 14 YK genomes were searched for antimicrobial resistance genes, plasmids, prophages, and virulence factors. Their phylogenomic relatedness was analyzed by Gegenees and core-genome multi-locus sequence typing. Beta-lactam resistance gene blaTEM-116 and five plasmids replicons (pYE854, ColRNAI, ColE10, Col(pHAD28) and IncN3) were detected in less than five genomes. A total of 59 prophages, 106 virulence markers of the Yersinia genus, associated to adherence, antiphagocytosis, exoenzymes, invasion, iron uptake, proteases, secretion systems and the O-antigen, and virulence factors associated to other 20 bacterial genera were detected. Phylogenomic analysis revealed high inter-species distinction and four highly diverse YF clusters. In conclusion, the results obtained through the analyses of YF, YI and YK genomes suggest the virulence potential of these strains due to the broad diversity and high frequency of prophages and virulence factors found. Phylogenetic analyses were able to correctly distinguish these closely related species and show the presence of different genetic subgroups. These data contributed for a better understanding of YF, YI and YK virulence-associated features and global genetic diversity, and reinforced the need for better characterization of these Y. enterocolitica-like species considered non-pathogenic.
Assuntos
Genoma Bacteriano , Filogenia , Fatores de Virulência , Yersinia , Yersinia/genética , Yersinia/classificação , Yersinia/patogenicidade , Yersinia/isolamento & purificação , Fatores de Virulência/genética , Brasil , Yersiniose/microbiologia , Yersiniose/veterinária , Humanos , Genômica , Prófagos/genética , Plasmídeos/genética , Tipagem de Sequências Multilocus , Virulência/genéticaRESUMO
Bat bugs (Cimex adjunctus Barber) (Hemiptera: Cimicidae) collected from big brown bats (Eptesicus fuscus Palisot de Beauvoir) in Colorado, United States were assessed for the presence of Bartonella, Brucella, and Yersinia spp. using molecular techniques. No evidence of Brucella or Yersinia infection was found in the 55 specimens collected; however, 4/55 (7.3%) of the specimens were positive for Bartonella DNA. Multi-locus characterization of Bartonella DNA shows that sequences in bat bugs are phylogenetically related to other Bartonella isolates and sequences from European bats.
Assuntos
Bartonella/isolamento & purificação , Percevejos-de-Cama/microbiologia , Brucella/isolamento & purificação , Quirópteros/parasitologia , Yersinia/isolamento & purificação , Animais , Proteínas de Bactérias/análise , Bartonella/classificação , Brucella/classificação , Colorado , DNA Bacteriano/análise , Filogenia , Yersinia/classificaçãoRESUMO
The primary goal of clinical microbiology is the accurate identification of the causative agent of the disease. Here, we describe a method for differentiation between Yersinia species using PCR-HRMA. The results revealed species-specific melting profiles. The herein developed assay can be used as an effective method to differentiate Yersinia species.
Assuntos
Técnicas de Tipagem Bacteriana/métodos , DNA Bacteriano/química , Yersiniose/microbiologia , Yersinia/isolamento & purificação , DNA Bacteriano/genética , Genótipo , Humanos , Reação em Cadeia da Polimerase/métodos , Temperatura de Transição , Yersinia/química , Yersinia/genéticaRESUMO
In this study, 15 Gram-negative isolates from Minas Frescal cheese sold in commercial establishments in Rio de Janeiro, Brazil, were able to produce antimicrobial substances (AMSs). Seven, four, two, one, and one isolates identified as Yersinia, Acinetobacter, Enterobacter, Escherichia, and Hafnia genera, respectively, were considered potentially pathogenic. All 15 AMS(+) isolates were resistant to at least 1 antibiotic; however, 7 strains presented resistance to at least 3 antibiotics from different classes, exhibiting multiresistance profiles. The strains were also subjected to plasmid profile analysis. All isolates presented different plasmid forms with most ranging in size from 1 to 10 kb. Activity against various pathogens associated with food was tested and all 15 AMS(+) showed the same activity spectrum, inhibiting all Escherichia coli and Salmonella strains that were tested. Although restricted, the action spectrum of AMS-producing strains is extremely relevant to the food industry because Gram-negative bacteria such as E. coli and Salmonella spp. are most often associated with foodborne illnesses. The findings of this study reveal that even AMS produced by pathogens can have potential applications against other foodborne pathogens.
Assuntos
Queijo/microbiologia , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Salmonella/efeitos dos fármacos , Acinetobacter/isolamento & purificação , Antibacterianos/farmacologia , Brasil , Enterobacter/isolamento & purificação , Doenças Transmitidas por Alimentos/epidemiologia , Hafnia alvei/isolamento & purificação , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Yersinia/isolamento & purificaçãoRESUMO
The ability of three psychrotrophic Gram-negative bacilli isolated from Chilean Patagonian cold freshwater rivers to produce bioactive metabolites was evaluated. The strains were isolated from cold waters rivers and identified by their biochemical properties and 16S rRNA gene analysis. The metabolites fractions showing antibacterial activity were obtained by solvent extraction and partially characterized by gas-mass chromatography (GC-MS). Antibacterial activity of the fractions was evaluated by an agar-well diffusion test upon 14 bacterial strains, both Gram positive and Gram negative. Thermal and proteolytic resistances of the antibacterial metabolites fractions were also evaluated. Molecular analysis allows the identification of the three Patagonian strains as Pseudomonas sp. RG-6 (Pseudomonas brenneri 99.6 % identity), Pseudomonas sp. RG-8 (Pseudomonas trivialis 99.6 % identity) and Yersinia sp. RP-3 (Yersinia aldovae 99.5 % identity). These extracts were able to inhibit both Gram-positive and Gram-negative bacteria but not Listeria monocytogenes. The antibacterial activity of the filtrated supernatants was lost at temperatures ≥60 °C, and was not affected by proteinase K treatment. The chemical structure of the active molecule remains to be elucidated, although the GC-MS analysis of the filtrates suggests that compounds like sesquiterpenes derivatives from ß-maaliene or δ-selinene could be responsible of this antibacterial activity. Pristine cold freshwater streams showed to be interesting sources of metabolites-producing microorganisms with antibacterial activity.
Assuntos
Antibacterianos/isolamento & purificação , Água Doce/microbiologia , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Yersinia/isolamento & purificação , Yersinia/metabolismo , Antibacterianos/farmacologia , Chile , Análise por Conglomerados , Temperatura Baixa , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Cromatografia Gasosa-Espectrometria de Massas , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Filogenia , Pseudomonas/classificação , Pseudomonas/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura , Yersinia/classificação , Yersinia/genéticaRESUMO
The bacterial genus Yersinia belongs to the family Enterobacteriaceae and comprises 15 species. Species of the genus Yersinia are usually identified by their phenotypic characteristics. Thus, it is essential to establish a complete phenotypic classification for all species of the genus Yersinia. The species Yersinia massiliensis was proposed in 2008, based on 16S rRNA, gyrB, hsp60, rpoB and sodA gene sequences and some distinguishing phenotypic characteristics. In this study, four Yersinia strains classified as Y. massiliensis based on the sequencing of the loci mentioned above were subjected to a more detailed phenotypic characterization. This characterization revealed differences in the results of four tests previously reported as diagnostic for Y. massiliensis and the results of 18 additional tests provided new information about the biochemical diversity of this species. In the light of the results of the phenotypic characteristics of the four strains of Y. massiliensis, an emended description of Y. massiliensis is presented.
Assuntos
Lactuca/microbiologia , Leite/microbiologia , Microbiologia da Água , Yersinia/classificação , Yersinia/isolamento & purificação , Animais , Bovinos , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Yersinia/genética , Yersinia/metabolismoRESUMO
In the last few decades, molecular typing has become an important tool in taxonomic, phylogenetic and identification studies of numerous groups of bacteria, including the yersiniae. In this study, Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Pulsed-Field Gel Electrophoresis (PFGE), 16S rRNA gene sequencing and Multilocus Sequence Analysis (MLSA) were performed to determine the ability of these techniques to be used in taxonomy and identification of Yersinia strains. A total of 60 Yersinia strains were genotyped by ERIC-PCR and PFGE. Moreover, an in silico analysis was carried out for 16S rRNA gene sequencing and MLSA, using 68 and 49 Yersinia strains, respectively. A phylogenetic tree constructed from the ERIC-PCR, 16S rRNA gene sequencing and MLSA data grouped most of the Yersinia species into distinct species-specific clusters. In the PFGE assay these clusters were not observed. On this basis, ERIC-PCR, 16S rRNA gene sequencing and MLSA seem to be valuable techniques for use in taxonomic and identification studies of the genus Yersinia, whereas PFGE does not. Furthermore, ERIC-PCR has the advantage of being a cheaper, easier and faster assay than 16S rRNA gene sequencing or MLSA, and for these reasons can be considerate an alternative tool in taxonomic studies of yersiniae.
Assuntos
Técnicas Bacteriológicas/métodos , Impressões Digitais de DNA/métodos , Yersinia/classificação , Yersinia/genética , Animais , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Eletroforese em Gel de Campo Pulsado , Microbiologia Ambiental , Microbiologia de Alimentos , Genótipo , Humanos , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sensibilidade e Especificidade , Análise de Sequência de DNA , Yersinia/isolamento & purificação , Yersiniose/diagnóstico , Yersiniose/veterináriaRESUMO
Data on the occurrence of Yersinia species. other than Y. pestis in Brazil are presented. Over the past 40 years, 767 Yersinia strains have been identified and typed by the National Reference Center on Yersinia spp. other than Y. pestis, using the classical biochemical tests for species characterization. The strains were further classified into biotypes, serotypes and phagetypes when pertinent. These tests led to the identification of Yersinia cultures belonging to the species Y. enterocolitica, Y.pseudotuberculosis, Y. intermedia, Y. frederiksenii and Y. kristensenii. Six isolates could not be classified in any of the known Yersinia species and for this reason were defined as Non-typable (NT). The bio-sero-phagetypes of these strains were diverse. The following species of Yersinia were not identified among the Brazilian strains by the classical phenotypic or biochemical tests: Y. aldovae, Y. rhodei, Y. mollaretti, Y. bercovieri and Y.ruckeri. The Yersinia strains were isolated from clinical material taken from sick and/or healthy humans and animals, from various types of food and from the environment, by investigators of various Institutions localized in different cities and regions of Brazil.
Assuntos
Humanos , Animais , Yersinia enterocolitica , Yersinia pseudotuberculosis , Yersinia/classificação , Yersinia/isolamento & purificação , Yersiniose/epidemiologiaRESUMO
OBJECTIVE: To determine the prevalence and characteristics of selected enteric pathogens in diarrheic children in six counties of the island of Trinidad. METHODS: This cross-sectional study was conducted from April 1998 through March 2000. Fecal or rectal swab specimens from children (<12 years) were collected and then processed, using standard methods, to detect Salmonella spp., Shigella spp., enteropathogenic Escherichia coli (EPEC), Campylobacter spp., Yersinia spp., Cryptosporidium parvum, and parasite ova. The antibiograms of the enteropathogens were determined using the disk diffusion method. RESULTS: A total of 236 samples were processed; 86 samples originated directly from 17 heath centers in two counties (St. George East and St. George West), while 150 samples were obtained from the Trinidad Public Health Laboratory, having been submitted by private practitioners and personnel from six counties in Trinidad. Of the 236 samples, 33 (14.0%) were positive for Shigella, 4 (1.7%) for Salmonella, and 1 (0.4%) for EPEC. Two of the samples (0.8%) were positive for Campylobacter jejuni, while 1 sample (0.4%) was positive for hookworm ova. All the samples were negative for Cryptosporidium parvum and Yersinia spp. With the 86 samples collected directly from the health centers, in St. George East County the frequency of Shigella was 20.0% (12 of 60), compared with 26.9% (7 of 26) for samples from St. George West County, but the difference was not statistically significant (P>0.05 with the chi-square test). For the 150 samples from the six counties that had been submitted directly to the Trinidad Public Health Laboratory, 14 of them (9.3%) were positive for Shigella, a figure statistically significantly lower than that found with the samples sampled directly from the health centers (P<0.05 with the chi-square test). Sh. sonnei was the predominant serotype detected, accounting for 28 of the 33 Shigella isolates (84.8%) recovered from the 236 samples. Overall, the frequency of detection of enteropathogens had no seasonal pattern nor relationship to the county of origin. Of the 37 isolates of Salmonella and Shigella tested for antimicrobial sensitivity, all of them were sensitive to ciprofloxacin, gentamicin, and cefotaxime. In terms of resistance, 3 of the 37 isolates (8.1%) exhibited resistance to ampicillin, 1 (2.7%) to chloramphenicol, and 1 (2.7%) to sulfamethoxazole/ trimethoprim. CONCLUSION: Of the enteropathogens for which assays were done, Shigella sonnei was the most prevalent, and it has the highest probability of being an important etiological agent of childhood diarrhea in Trinidad.
Assuntos
Diarreia/microbiologia , Diarreia/parasitologia , Fezes/microbiologia , Fezes/parasitologia , Reto/microbiologia , Reto/parasitologia , Animais , Campylobacter/isolamento & purificação , Criança , Coccídios/isolamento & purificação , Estudos Transversais , Cryptosporidium/isolamento & purificação , Diarreia/epidemiologia , Escherichia coli/isolamento & purificação , Humanos , Prevalência , Salmonella/isolamento & purificação , Shigella/isolamento & purificação , Trinidad e Tobago , Yersinia/isolamento & purificaçãoRESUMO
AIMS: To determine the species, bio-sero-phagetypes, antimicrobial drug resistance and also the pathogenic potential of 144 strains of Yersinia spp. isolated from water sources and sewage in Brazil. METHODS AND RESULTS: The 144 Yersinia strains were characterized biochemically, serologically and had their antibiotic resistance and phenotypic virulence markers determined by microbiological and serological standard techniques. The Y. enterocolitica strains related to human diseases were also tested for the presence of virulence genes, by the PCR technique. The isolates were classified as Y. enterocolitica, Y. intermedia, Y. frederiksenii, Y. kristensenii and Yersinia biochemically atypical. The 144 isolates belonged to various bio-serogroups. Half of the strains showed resistance to three or more drugs. The Y. enterocolitica strains related to human diseases exhibited phenotypic virulence characteristics and virulence genes. CONCLUSIONS: Water from various sources and sewage are contaminated with Yersinia spp. in Brasil. Among these bacteria, virulent strains of Y. enterocolitica were found, with biotypes and serogroups related to human diseases. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first documented description of the occurrence of pathogenic Y. enterocolitica in water sources and sewage in Brazil. The occurrence of virulence strains of Y. enterocolitica shows that the environment is a potential source of human infection by this species in this country.
Assuntos
Esgotos/microbiologia , Microbiologia da Água , Yersinia/patogenicidade , Brasil , Farmacorresistência Bacteriana , Água Doce/microbiologia , Genes Bacterianos , Humanos , Água do Mar/microbiologia , Virulência/genética , Yersinia/classificação , Yersinia/isolamento & purificação , Yersinia enterocolitica/isolamento & purificação , Yersinia enterocolitica/patogenicidadeRESUMO
AIMS: To investigate the presence of Staphylococcus aureus, enteropathogenic Escherichia coli (EPEC), Aeromonas spp. and Yersinia spp. in soft cheese commercialized in Rio de Janeiro, Brazil. METHODS AND RESULTS: A total of 45 samples of cheese from three different brands marketed in Rio de Janeiro city were analysed for faecal coliform levels using the Most Probable Number (MPN) technique. The samples were also analysed using conventional methodology for the investigation of food-borne pathogens. High levels of faecal contamination were detected in 95.5% of cheese samples. Staphylococcus aureus was isolated from 20% of samples, of which 17.7% were above the limits allowed by Brazilian legislation. Aeromonas hydrophila and Aer. caviae were detected in 17.7% of the samples. Yersinia spp. were not found in this study. EPEC was isolated from 21.1% of the samples and the most frequently found serogroups were O127, followed by O55 and O26. CONCLUSIONS: Our results showed that 95.5% of cheese samples had high levels of faecal coliforms. The isolation of Staph. aureus, serogroups of EPEC and Aeromonas spp. suggested that the soft cheese commercialized in the city of Rio de Janeiro may represent a health risk for the consumers. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest that soft cheese may act as an important vehicle of transmission for well-established pathogens.
Assuntos
Queijo/microbiologia , Escherichia coli/isolamento & purificação , Contaminação de Alimentos/estatística & dados numéricos , Staphylococcus aureus/isolamento & purificação , Aeromonas/isolamento & purificação , Brasil , Saneamento , Saúde da População Urbana , Yersinia/isolamento & purificaçãoRESUMO
A total of 160 meat product samples were collected from commercial outlets in Mexico City to investigate the presence of different species of Yersinia by the 4 degrees C enrichment method after 1, 3, 5, and 7 days of incubation using alkaline treatment and isolating in cefsulodin-Irgasan-novobiocin and MacConkey agars with Tween 80. Overall, Yersinia spp. were isolated from 27% of the samples analyzed, whereas 40% of the raw and only 13% of the precooked samples were contaminated. Although 2,970 colonies showed Yersinia characteristics, only 706 (24%) actually corresponded to this genus: 49% were Yersinia enterocolitica, 25% Yersinia kristensenii, 15% Yersinia intermedia, 9% Yersinia frederiksenii, and 2% Yersinia aldovae; 10% corresponded to biotype 2, 2% to biotype 3, and 4% to biotype 4. The presence of Yersinia in raw and cooked meat products represents a health risk for consumers in Mexico, where further clinical studies are needed to assess the epidemiological importance of this pathogen.
Assuntos
Microbiologia de Alimentos , Produtos da Carne/microbiologia , Yersinia/isolamento & purificação , Animais , Galinhas , Microbiologia de Alimentos/normas , Produtos da Carne/normas , México , SuínosRESUMO
The 16S rRNA sequences and selected phenotypic characteristics were determined for six recently isolated bacteria that can tolerate high levels of hydrolyzable and condensed tannins. Bacteria were isolated from the ruminal contents of animals in different geographic locations, including Sardinian sheep (Ovis aries), Honduran and Colombian goats (Capra hircus), white-tail deer (Odocoileus virginianus) from upstate New York, and Rocky Mountain elk (Cervus elaphus nelsoni) from Oregon. Nearly complete sequences of the small-subunit rRNA genes, which were obtained by PCR amplification, cloning, and sequencing, were used for phylogenetic characterization. Comparisons of the 16S rRNA of the six isolates showed that four of the isolates were members of the genus Streptococcus and were most closely related to ruminal strains of Streptococcus bovis and the recently described organism Streptococcus gallolyticus. One of the other isolates, a gram-positive rod, clustered with the clostridia in the low-G+C-content group of gram-positive bacteria. The sixth isolate, a gram-negative rod, was a member of the family Enterobacteriaceae in the gamma subdivision of the class Proteobacteria. None of the 16S rRNA sequences of the tannin-tolerant bacteria examined was identical to the sequence of any previously described microorganism or to the sequence of any of the other organisms examined in this study. Three phylogenetically distinct groups of ruminal bacteria were isolated from four species of ruminants in Europe, North America, and South America. The presence of tannin-tolerant bacteria is not restricted by climate, geography, or host animal, although attempts to isolate tannin-tolerant bacteria from cows on low-tannin diets failed.
Assuntos
Clostridium/classificação , Escherichia coli/classificação , Taninos Hidrolisáveis/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Rúmen/microbiologia , Streptococcus/classificação , Yersinia/classificação , Animais , Clostridium/genética , Clostridium/isolamento & purificação , Colômbia , DNA Ribossômico/genética , Cervos , Erwinia/classificação , Erwinia/genética , Erwinia/isolamento & purificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Eubacterium/classificação , Eubacterium/genética , Eubacterium/isolamento & purificação , Cabras , Honduras , Taninos Hidrolisáveis/farmacologia , New York , Oregon , Peptostreptococcus/classificação , Peptostreptococcus/genética , Peptostreptococcus/isolamento & purificação , Fenótipo , Ovinos , Streptococcus/genética , Streptococcus/isolamento & purificação , Yersinia/genética , Yersinia/isolamento & purificaçãoAssuntos
Yersinia enterocolitica/isolamento & purificação , Yersinia/isolamento & purificação , Animais , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana , Bovinos , Reservatórios de Doenças , Enterocolite/epidemiologia , Enterocolite/microbiologia , Microbiologia de Alimentos , Cabras/microbiologia , Humanos , Suínos/microbiologia , Virulência/genética , Microbiologia da Água , Yersinia/classificação , Yersinia/patogenicidade , Yersiniose/epidemiologia , Yersiniose/microbiologia , Yersinia enterocolitica/classificação , Yersinia enterocolitica/patogenicidadeAssuntos
Testes de Aglutinação , Yersinia/classificação , Yersinia/imunologia , Animais , Técnicas de Tipagem Bacteriana , Técnicas Bacteriológicas , Tipagem de Bacteriófagos , Humanos , Lectinas , Sorotipagem , Especificidade da Espécie , Yersinia/isolamento & purificação , Yersinia enterocolitica/classificação , Yersinia enterocolitica/imunologiaRESUMO
This study examined the occurrence of Y. enterocolitica and other Yersinia species in Brazilian food products. Samples included raw vegetables (lettuce, spinach, watercress and chicory), raw and pasteurized milk as well as meat and meat products. Raw milk samples were obtained in a dairy plant and the other food samples were purchased at the retail level in Sao Paulo city. Yersinia spp. was isolated from raw milk (45.2%), pasteurized milk (14.3%), raw vegetables samples (13.3%) and meat and meat products (40.0%). Most of the strains isolated were Y. enterocolitica followed by Y. intermedia. This high incidence in raw milk and meat and meat products implies that these products are a likely sources of contamination with Yersinia spp.
Assuntos
Microbiologia de Alimentos , Yersinia/isolamento & purificação , Animais , Tipagem de Bacteriófagos , Brasil , Carne/microbiologia , Produtos da Carne/microbiologia , Leite/microbiologia , Sorotipagem , Esterilização , Verduras/microbiologia , Yersinia/classificação , Yersinia enterocolitica/classificação , Yersinia enterocolitica/isolamento & purificaçãoRESUMO
Yersinia spp. was examined in three rivers and two lakes located in the Province of San Luis, Argentina, over a 1-year period. Water samples were concentrated either by Moore's gauze technique or by filtering through diatomaceous earth. Five enrichment media: yeast extract--Bengal rose broth (YER) with bile-oxalate-sorbose broth (BOS); 67 mmol/L phosphate-buffered saline (pH 7.6; PBS); PBS enriched with a 1% mannitol and 1% peptone (PBSMP); PBS with lyzed 0.5% sheep blood (PBSB); Wauters broth (W); and five plating media: Mac Conkey agar (MC); Salmonella--Shigella agar (SS); 5% sheep blood agar (BA); lactose-sucrose-urea agar (LSU) and irgasan-novobiocin agar (IN) were used. The following strains were isolated: Y. intermedia B1 O:4,32-4,33 Lis Xz (four strains), Y. intermedia B1 O:57 Lis Xo (one strain), Y. intermedia B2 O:57 Lis Xo (one strain), Y. enterocolitica B1 O:10-34 Lis Xz (one strain), and Y. frederiksenii undetermined biovar, O:16-16,29 Lis Xz (two strains). The incidence of isolation of Yersinia spp. was 7.14%. YER-BOS proved to be the best enrichment method since it allowed the highest recovering Yersinia spp. strains. Among plating media, the best results were obtained with MC. Apparently, the isolation of Yersinia spp. can be related to environmental variables such as temperature differences between cold and warm seasons. Negative results obtained during virulence assays suggest that isolated strains lack the pathogenic potential against man.
Assuntos
Microbiologia da Água , Yersinia/isolamento & purificação , Argentina , Meios de Cultura , Água Doce , Yersinia enterocolitica/isolamento & purificaçãoRESUMO
Mediante medios selectivos se aislaron 105 cepas bacterianas desde quesos de cabra, adquiridos en mercados locales de la ciudad de Valparaiso (Chile). Todas las cepas bacterianas junto a 4 de referencia, fueron examinadas para para 54 características fenotípicas, incluyendo pruebas morfológicas, fisiológicas y bioquímicas. Los resultados obtenidos fueron sometidos a un análisis numérico, utilizando el coeficiente de apareamiento simple Ssm. y la técnica de agrupación UPGMA. A nivel de semejanza de un 80 por ciento las cepas se agruparon en 8 fenómenos, representando a miembros de la familia enterobacteriaceae (7) y uno al género streptococcus
Assuntos
Queijo/microbiologia , Enterobacteriaceae/isolamento & purificação , Citrobacter/isolamento & purificação , Escherichia coli/isolamento & purificação , Microbiologia de Alimentos/normas , Gastroenterite/microbiologia , Salmonella typhi/isolamento & purificação , Serratia/isolamento & purificação , Shigella/isolamento & purificação , Yersinia/isolamento & purificaçãoRESUMO
Over the past 9 years, 468 bacterial strains isolated from raw and pasteurized milk, beef and pork, bovine and chicken liver, chicken heart, gizzards and lung sausage, hamburger, cheese and lettuce in different regions of the State of São Paulo and in the city of Rio de Janeiro were received by the Reference Laboratory for Yersinia in Brazil. All were confirmed to be Yersinia spp. The 468 Yersinia isolates were grouped as 184 strains because some of the bacteria isolated from the same food sample belonged to the same species, and were considered to be a single strain. The Yersinia food strains were classified as Y. enterocolitica (46), Y. intermedia (67), Y. frederiksenii (20), Y. kristensenii (8) and 43 of them were biochemically atypical. Pathogenic types were not detected.