RESUMO
Shigella flexneri has been a major public health problem in developing countries. This work analyzed the frequency of 16 virulence genes, the genotypic diversity, and the antimicrobial resistance profiles of 130 S. flexneri strains isolated in Brazil. The ipaH gene was found in all the 130 strains. The frequencies of the other genes were variable ial (88.5%), sigA (82.3%), iuc (74.6%), virA (73%), pic (72.3%), virF (57.7%), sat (48.5%), ipaBCD (37%), sen (36%), set1A (35.4%), sepA (30%), set1B (30%), virB (14%), icsA (10%), and ipgD (5.4%). A total of 57 (43.8%) strains were multidrug-resistant. ERIC-PCR grouped 96 of the strains into a single cluster with ≥ 70.4% of similarity, 75 of these strains presented a similarity ≥ 80.9%. PFGE grouped 120 of the strains into a single cluster with 57.4% of similarity and 82 of these strains presented a similarity ≥ 70.6%. In conclusion, the high frequency of some virulence genes reinforces the pathogenic potential of the strains studied. The high rates of MDR strains are alarming once it may lead to failure when antimicrobial treatment is necessary. Genotype techniques reveled a major cluster with high genetic similarity including S. flexneri strains from the different Brazilian states and distinct years of isolation, showing that they probably emerged from a common ancestor.
Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Disenteria Bacilar/microbiologia , Shigella flexneri , Fatores de Virulência/genética , Brasil/epidemiologia , Variação Genética , Humanos , Shigella flexneri/classificação , Shigella flexneri/isolamento & purificação , Shigella flexneri/patogenicidadeRESUMO
Fish is the most indispensable source of proteins for individuals and have high nutritional value. On the other hand, the fish culturing raised issues of fish health due to close contact between the aquatic environment and the fish pathogens. So, the aim of the current study was to identify the bacterial pathogens and screen the injured Rainbow trout rearing in different trout hatcheries run under fisheries department of the government of Azad Jammu and Kashmir, Pakistan. Seven bacterial pathogens such as Shigella flexneri, Enterobacter amnigenus, Salmonella Typhimurium, Serratia odorifera, Pseudomonas aeruginosa, Streptococcus pyogenes, and Bacillus cereus were isolated and identified. Results revealed that the injury of fish specimens was due to overcrowding. Instead of rainbow coloration, specimens have darker black in color. The water of ponds was not clean and clear and such conditions was because of the greater quantity of feed thrown in the water. It was concluded that poor hygienic water condition and overloading allowed the opportunistic bacterial contaminations to succeed which cause a serious threat to hatcheries.(AU)
O peixe é a fonte mais indispensável de proteínas para os indivíduos e tem alto valor nutricional. Por outro lado, a cultura dos peixes levantou questões sobre a saúde dos peixes devido ao próximo contato entre o ambiente aquático e os agentes patogênicos desses peixes. Assim, o objetivo do presente estudo foi identificar os patógenos bacterianos e rastrear a criação da truta arco-íris que apresentou lesões em diferentes incubadoras de trutas, com supervisão do departamento de pesca do governo de Azad Jammu e Caxemira, Paquistão. Sete patógenos bacterianos foram isolados e identificados, tais como: Shigella flexneri, Enterobacter amnigenus, Salmonella typhimurium, Serratia odorifera, Pseudomonas aeruginosa, Streptococcus pyogenes e Bacillus cereus. Os resultados revelaram que a lesão de espécimes de peixes foi devido à superlotação. Em vez da coloração do arco-íris, os espécimes tiveram uma coloração preta mais escura. A água das lagoas não era limpa e nem clara, e tais condições ocorreram devido a maior quantidade de alimento lançada na água. Concluiu-se que a precária condição higiênica da água e também a sobrecarga permitiram que as contaminações bacterianas oportunistas fossem bem-sucedidas, causando séria ameaça às incubadoras.(AU)
Assuntos
Animais , Peixes/microbiologia , Incubadoras , Shigella flexneri/patogenicidade , Enterobacter/patogenicidade , Salmonella typhimurium/patogenicidade , Serratia/patogenicidade , Pseudomonas aeruginosa/patogenicidade , Noxas/análiseRESUMO
Molecular characterization of virulence and antimicrobial resistance profiles were determined for Shigella species isolated from children with diarrhea in Fortaleza, Brazil. Fecal specimens were collected along with socioeconomic and clinical data from children with moderate to severe diarrhea requiring emergency care. Shigella spp. were isolated by standard microbiological techniques, and we developed 4 multiplex polymerase chain reaction assays to detect 16 virulence-related genes (VRGs). Antimicrobial susceptibility tests were performed using disk diffusion assays. S. flexneri and S. sonnei were the predominant serogroups. S. flexneri was associated with low monthly incomes; more severe disease; higher number of VRGs; and presence of pic, set, and sepA genes. The SepA gene was associated with more intense abdominal pain. S. flexneri was correlated with resistance to ampicillin and chloramphenicol, whereas S. sonnei was associated with resistance to azithromycin. Strains harboring higher numbers of VRGs were associated with resistance to more antimicrobials. We highlight the correlation between presence of S. flexneri and sepA, and increased virulence and suggest a link to socioeconomic change in northeastern Brazil. Additionally, antimicrobial resistance was associated with serogroup specificity in Shigella spp. and increased bacterial VRGs.
Assuntos
Antibacterianos/farmacologia , Disenteria Bacilar/microbiologia , Shigella flexneri/genética , Shigella flexneri/patogenicidade , Shigella sonnei/genética , Shigella sonnei/patogenicidade , Ampicilina/farmacologia , Azitromicina/farmacologia , Proteínas de Bactérias/genética , Brasil , Cloranfenicol/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana , Disenteria Bacilar/tratamento farmacológico , Humanos , Reação em Cadeia da Polimerase Multiplex/métodos , Serina Proteases/genética , Shigella flexneri/efeitos dos fármacos , Shigella flexneri/isolamento & purificação , Shigella sonnei/efeitos dos fármacos , Shigella sonnei/isolamento & purificação , Virulência/genéticaRESUMO
Shiga toxins (Stx) are cytotoxins involved in severe human intestinal disease. These toxins are commonly found in Shigella dysenteriae serotype 1 and Shiga-toxin-producing Escherichia coli; however, the toxin genes have been found in other Shigella species. We identified 26 Shigella flexneri serotype 2 strains isolated by public health laboratories in the United States during 2001-2013, which encode the Shiga toxin 1a gene (stx1a). These strains produced and released Stx1a as measured by cytotoxicity and neutralization assays using anti-Stx/Stx1a antiserum. The release of Stx1a into culture supernatants increased ≈100-fold after treatment with mitomycin C, suggesting that stx1a is carried by a bacteriophage. Infectious phage were found in culture supernatants and increased ≈1,000-fold with mitomycin C. Whole-genome sequencing of several isolates and PCR analyses of all strains confirmed that stx1a was carried by a lambdoid bacteriophage. Furthermore, all patients who reported foreign travel had recently been to Hispañiola, suggesting that emergence of these novel strains is associated with that region.
Assuntos
Disenteria Bacilar/epidemiologia , Disenteria Bacilar/microbiologia , Regulação Bacteriana da Expressão Gênica/fisiologia , Toxina Shiga I/metabolismo , Shigella flexneri/metabolismo , Animais , Chlorocebus aethiops , República Dominicana/epidemiologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Haiti/epidemiologia , Humanos , Lisogenia , Mitomicina/farmacologia , Mutação , Prófagos , Sorogrupo , Toxina Shiga I/classificação , Toxina Shiga I/genética , Shigella flexneri/classificação , Shigella flexneri/genética , Shigella flexneri/patogenicidade , Siphoviridae/genética , Siphoviridae/fisiologia , Células Vero , VirulênciaRESUMO
Shigella flexneri causes bacillary dysentery in humans. Essential to the establishment of the disease is the invasion of the colonic epithelial cells. Here we investigated the role of the lipopolysaccharide (LPS) O antigen in the ability of S. flexneri to adhere to and invade polarized Caco-2 cells. The S. flexneri 2a O antigen has two preferred chain lengths: a short O antigen (S-OAg) regulated by the WzzB protein and a very long O antigen (VL-OAg) regulated by Wzz pHS2. Mutants with defined deletions of the genes required for O-antigen assembly and polymerization were constructed and assayed for their abilities to adhere to and enter cultured epithelial cells. The results show that both VL- and S-OAg are required for invasion through the basolateral cell membrane. In contrast, the absence of O antigen does not impair adhesion. Purified LPS does not act as a competitor for the invasion of Caco-2 cells by the wild-type strain, suggesting that LPS is not directly involved in the internalization process by epithelial cells.
Assuntos
Aderência Bacteriana/fisiologia , Proteínas de Bactérias/análise , Disenteria Bacilar/microbiologia , Antígenos O/química , Shigella flexneri/patogenicidade , Células CACO-2 , Disenteria Bacilar/imunologia , Humanos , Antígenos O/metabolismo , Polimerização , Shigella flexneri/imunologiaRESUMO
Shigella flexneri causes bacillary dysentery in humans. Essential to the establishment of the disease is the invasion of the colonic epithelial cells. Here we investigated the role of the lipopolysaccharide (LPS) O antigen in the ability of S. flexneri to adhere to and invade polarized Caco-2 cells. The S. flexneri 2a O antigen has two preferred chain lengths: a short O antigen (S-OAg) regulated by the WzzB protein and a very long O antigen (VL-OAg) regulated by Wzz pHS2. Mutants with defined deletions of the genes required for O-antigen assembly and polymerization were constructed and assayed for their abilities to adhere to and enter cultured epithelial cells. The results show that both VL- and S-OAg are required for invasion through the basolateral cell membrane. In contrast, the absence of O antigen does not impair adhesion. Purified LPS does not act as a competitor for the invasion of Caco-2 cells by the wild-type strain, suggesting that LPS is not directly involved in the internalization process by epithelial cells.
Assuntos
Humanos , Aderência Bacteriana/fisiologia , Proteínas de Bactérias/análise , Disenteria Bacilar/microbiologia , Antígenos O/química , Shigella flexneri/patogenicidade , Disenteria Bacilar/imunologia , Antígenos O/metabolismo , Polimerização , Shigella flexneri/imunologiaRESUMO
We have previously described a protein termed Shigella enterotoxin 2 (ShET-2), which induces rises in short-circuit current in rabbit ileum mounted in the Ussing chamber. Published reports have postulated that ShET-2 may be secreted by the Shigella type III secretion system (T3SS). In this study, we show that ShET-2 secretion into the extracellular space requires the T3SS in Shigella flexneri 2a strain 2457T and a ShET-2-TEM fusion was translocated into epithelial cells in a T3SS-dependent manner. The ShET-2 gene, sen, is encoded downstream of the ospC1 gene of S. flexneri, and we show that sen is cotranscribed with this T3SS-secreted product. Considering that T3SS effectors have diverse roles in Shigella infection and that vaccine constructs lacking ShET-2 are attenuated in volunteers, we asked whether ShET-2 has a function other than its enterotoxic activity. We constructed a ShET-2 mutant in 2457T and tested its effect on epithelial cell invasion, plaque formation, guinea pig keratoconjunctivitis and interleukin 8 (IL-8) secretion from infected monolayers. Although other phenotypes were not different compared with the wild-type parent, we found that HEp-2 and T84 cells infected with the ShET-2 mutant exhibited significantly reduced IL-8 secretion into the basolateral compartment, suggesting that ShET-2 might participate in the Shigella-induced inflammation of epithelial cells.
Assuntos
Enterotoxinas/metabolismo , Enterotoxinas/toxicidade , Células Epiteliais/microbiologia , Interleucina-8/imunologia , Interleucina-8/metabolismo , Shigella flexneri/imunologia , Shigella flexneri/patogenicidade , Animais , Linhagem Celular , Células Epiteliais/imunologia , Humanos , Transporte ProteicoRESUMO
Enteroinvasive Escherichia coli (EIEC) and Shigella spp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. Although EIEC and Shigella share many genetic and biochemical similarities, the illness caused by Shigella is more severe. Thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on Shigella rather than EIEC. Here we comparatively studied the interactions of EIEC and of Shigella flexneri with cultured J774 macrophage-like cells. We evaluated several phenotypes: (i) bacterial escape from macrophages after phagocytosis, (ii) macrophage death induced by EIEC and S. flexneri, (iii) macrophage cytokine expression in response to infection and (iv) expression of plasmidial (pINV) virulence genes. The results showed that S. flexneri caused macrophage killing earlier and more intensely than EIEC. Both pathogens induced significant macrophage production of TNF, IL-1 and IL-10 after 7 h of infection. Transcription levels of the gene invasion plasmid antigen-C were lower in EIEC than in S. flexneri throughout the course of the infection; this could explain the diminished virulence of EIEC compared to S. flexneri.
Assuntos
Citocinas/análise , Escherichia coli/patogenicidade , Regulação Bacteriana da Expressão Gênica/imunologia , Macrófagos/microbiologia , Shigella flexneri/patogenicidade , Fatores de Virulência/biossíntese , Morte Celular , ELISPOT , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/genética , Genes Bacterianos , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Shigella flexneri/genética , Fatores de Virulência/genéticaRESUMO
Se describe un caso de prolapso rectal secundario a diarrea por Shigella en un neonato de 10 días de vida, alimentado con pecho exclusivo. Su hermano de 2 años había tenido diarrea por el mismo patógeno hasta 2 semanas antes. El coprocultivo fue positivo para Shigella flexneri II, resistente a amoxicilina; los hemocultivos y el cultivo de líquido cefalorraquídeo fueron negativos. El tratamiento con ceftriaxone por vía parenteral revirtió el prolapso en 48 h. Conclusión. El prolapso rectal es una complicación poco común de la diarrea por Shigella en la infancia. Se ha descripto en edades mayores, pero nunca antes en un neonato.
Assuntos
Humanos , Masculino , Recém-Nascido , Ceftriaxona/uso terapêutico , Diarreia/terapia , Prolapso Retal/fisiopatologia , Prolapso Retal/terapia , Shigella flexneri/patogenicidadeRESUMO
Se describe un caso de prolapso rectal secundario a diarrea por Shigella en un neonato de 10 días de vida, alimentado con pecho exclusivo. Su hermano de 2 años había tenido diarrea por el mismo patógeno hasta 2 semanas antes. El coprocultivo fue positivo para Shigella flexneri II, resistente a amoxicilina; los hemocultivos y el cultivo de líquido cefalorraquídeo fueron negativos. El tratamiento con ceftriaxone por vía parenteral revirtió el prolapso en 48 h. Conclusión. El prolapso rectal es una complicación poco común de la diarrea por Shigella en la infancia. Se ha descripto en edades mayores, pero nunca antes en un neonato.(AU)
Assuntos
Humanos , Masculino , Recém-Nascido , Prolapso Retal/terapia , Prolapso Retal/fisiopatologia , Diarreia/terapia , Ceftriaxona/uso terapêutico , Shigella flexneri/patogenicidadeRESUMO
Important features of the enteroinvasive Escherichia coli (EIEC) phenotype and gene expression likely to confer EIEC with a lower ability to cause disease than Shigella flexneri were described here for the first time. To confirm the lower pathogenicity of EIEC, we have analyzed the keratoconjunctivitis developed in guinea-pigs with EIEC or S. flexneri. Shigella flexneri induced a more pronounced proinflammatory response, whereas EIEC induced a mild form of the disease. EIEC showed a significantly less efficient cell-to-cell Caco-2 dissemination when compared with S. flexneri. Plaques formed by EIEC during intercellular spreading were four times smaller than those formed by S. flexneri. At the molecular level, the lower expression of virulence genes by EIEC during infection of Caco-2 cells highlighted the importance of effective gene transcription for bacterial pathogenicity.
Assuntos
Proteínas de Bactérias/biossíntese , Escherichia coli/patogenicidade , Expressão Gênica , Shigella flexneri/patogenicidade , Fatores de Virulência/biossíntese , Animais , Proteínas de Bactérias/genética , Células CACO-2 , Contagem de Colônia Microbiana , Túnica Conjuntiva/microbiologia , Túnica Conjuntiva/patologia , Modelos Animais de Doenças , Células Epiteliais/microbiologia , Perfilação da Expressão Gênica , Cobaias , Humanos , Ceratoconjuntivite/microbiologia , Virulência , Fatores de Virulência/genéticaRESUMO
BACKGROUND: Shigella is the etiological agent of shigellosis, a disease responsible for more than 500,000 deaths of children per year, in developing countries. These pathogens colonize the intestinal colon, invade, spreading to the other enterocytes. Breastfeeding plays a very important role in protecting infants from intestinal infections. Amongst milk compounds, glycosylated proteins prevent the adhesion of many enteropathogens in vitro. The aim of this work was to determine the effect of human milk proteins on the colonization potential of Shigella dysenteriae, S. flexneri and S. sonnei. To fulfill this purpose, pooled milk samples from five donors, were fractionated by gel filtration and affinity chromatography. Using tissue culture, the milk fractions obtained were tested in Shigella adhesion and invasion assays. RESULTS: Our revealed showed that both adhesion and invasion of Shigella species were inhibited by low concentration of secretory immunoglobulin A, lactoferrin and free secretory component. This work also showed that, these proteins bind to superficial and whole-cell Shigella proteins. CONCLUSIONS: Our findings suggest that human milk may act inhibiting adhesion and, consequently, invasion of Shigella, thereafter preventing shigellosis in infants.
Assuntos
Aderência Bacteriana/efeitos dos fármacos , Proteínas do Leite/farmacologia , Shigella dysenteriae/patogenicidade , Shigella flexneri/patogenicidade , Shigella sonnei/patogenicidade , Anticorpos Antibacterianos/farmacologia , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Criança , Células HeLa , Humanos , Imunoglobulina A Secretora/imunologia , Lactoferrina/metabolismo , Ácido Periódico/farmacologia , Shigella dysenteriae/efeitos dos fármacos , Shigella dysenteriae/isolamento & purificação , Shigella flexneri/efeitos dos fármacos , Shigella flexneri/isolamento & purificação , Shigella sonnei/efeitos dos fármacos , Shigella sonnei/isolamento & purificaçãoRESUMO
The principal aim of this work was to detect the bacteriocinogenic capacity of S. flexneri strains on members of the human intestinal flora. A total of 49 bacteriocinogenic S. flexneri strains were isolated from individuals of both sexes and different ages. The bacteriocins were detected by means of the drop method using E. coli and B. fragilis as target strains. The serotypes of the S. flexneri were determined. The producer capacity of bacteriocins was analysed in 10 different colonies of the same cellular clone and also the arbitrary units were determined. The highest number of bacteriocinogenic S. flexneri strains were obtained from diarrhoeal individuals from 0-10 years old and the S. flexneri serotype 2a was the most abundant. It was demonstrated that E. coli and B. fragilis isolated from the normal intestinal flora of healthy individuals were susceptible to the bacteriocinogenic S. flexneri strains. By means of the determination of arbitrary units per ml of the bacteriocin, it was demonstrated that colonies from a single colony isolate of a same clone of bacteriocinogenic S. flexneri produce different quantities of bacteriocin.
Assuntos
Bacillus/efeitos dos fármacos , Bacteriocinas/metabolismo , Escherichia coli/efeitos dos fármacos , Intestinos/microbiologia , Shigella flexneri/fisiologia , Adolescente , Adulto , Bacteriocinas/classificação , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Criança , Pré-Escolar , Disenteria Bacilar/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Sorotipagem , Shigella flexneri/classificação , Shigella flexneri/isolamento & purificação , Shigella flexneri/patogenicidadeRESUMO
Shigella flexneri infections are one of the main causes of acute diarrhoea in Cuba. Twenty strains isolated from sporadic cases in nine different Cuban provinces were characterized. Serotyping, antibiotic-resistance typing, plasmid-typing and AFLP-typing were used to determine their suitability for use in epidemiological studies of S. flexneri. The predominant serotypes were serotype 6 (35%) and serotype 2 (35%). Eleven different plasmid profiles were detected (Diversity Index = 0.92). AFLP-typing discriminated 12 different patterns (DI = 0.95), these patterns were not coincident with plasmid-typing patterns. Both techniques combined distinguished 14 patterns among the 20 studied strains (DI = 0.99). There was no consistent relationship between plasmid-typing and AFLP-typing patterns or antibiotic-resistance typing patterns. Ninety-five percent of S. flexneri strains were multiresistant.
Assuntos
Polimorfismo Genético , Shigella flexneri/classificação , Shigella flexneri/genética , Cuba , Primers do DNA , Diarreia/etiologia , Disenteria Bacilar , Humanos , Fenótipo , Plasmídeos/classificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Sorotipagem , Shigella flexneri/patogenicidadeRESUMO
The peptide containing the catalytic serine of beta-lactamase from Shigella flexneri was determined as V-D-E-R-F-P-M-M-S*-T-F-K. It is a local pathogenic strain which produces intestinal problems, especially in children. The highly purified enzyme was prepared by affinity chromatography in phenylboronic acid-agarose gels. The peptide was obtained by tryptic hydrolysis, with further purification by Bio-Gel P-4, Sephadex QAE-25 and Sephadex SP-25. The relevance of the serine, lysine and arginine residues was mainly shown by the loss of enzymatic activity after specific chemical modifications. Finally, this enzyme was classified as A, according to the similarity of this peptide with that of class A beta-lactamases such as R-TEM 1 and 2.
Assuntos
Shigella flexneri/enzimologia , beta-Lactamases/química , Sequência de Aminoácidos , Sítios de Ligação/genética , Criança , Humanos , Modelos Moleculares , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Conformação Proteica , Shigella flexneri/genética , Shigella flexneri/patogenicidade , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
Comenta-se nesta breve revisao a participacao e o significado de Shigella em processos de infeccao alimentar. Sao tambem abordados as caracteristicas do microrganismo, seus fatores de virulencia e determinancia genetica.Aspectos epidemiologicos da infeccao, bem como, condicoes de crescimento e metodos de deteccao em alimentos, sao tambem abordados
Assuntos
Humanos , Disenteria Bacilar/diagnóstico , Disenteria Bacilar/epidemiologia , Disenteria Bacilar/patologia , Disenteria Bacilar/prevenção & controle , Manipulação de Alimentos/métodos , Shigella boydii/crescimento & desenvolvimento , Shigella boydii/patogenicidade , Shigella dysenteriae/crescimento & desenvolvimento , Shigella dysenteriae/patogenicidade , Shigella flexneri/crescimento & desenvolvimento , Shigella flexneri/patogenicidade , Shigella sonnei/crescimento & desenvolvimento , Shigella sonnei/patogenicidade , Virulência , Contaminação de Alimentos/prevenção & controle , Higiene dos Alimentos , Indústria de Processamento de Alimentos/métodos , Indústria de Processamento de Alimentos , Infecções Bacterianas/transmissão , Intestinos/patologiaRESUMO
We conducted a prospective, community-based study of healthy breast-fed Mexican infants to determine the protective effects of anti-Shigella secretory IgA antibodies in milk. Milk samples were collected monthly, and stool culture specimens were obtained weekly and at the time of episodes of diarrhea. Nineteen breast-fed infants were found to have Shigella flexneri, Shigella boydii, or Shigella sonnei in stool samples. Ages of the 10 infants with symptomatic infection and the nine with asymptomatic infection did not differ significantly. Milk samples collected up to 12 weeks before infection were evaluated by enzyme-linked immunosorbent assay for secretory IgA antibodies against lipopolysaccharides of S. flexneri, S. boydii serotype 2, S. sonnei, and virulence plasmid-associated antigens. The geometric mean titers of anti-Shigella antibodies to virulence plasmid-associated antigens in milk received before infection were eightfold higher in infants who remained well than in those in whom diarrhea developed. The significance of milk secretory IgA directed against lipopolysaccharide was less clear. We conclude that human milk protects infants against symptomatic shigella infection when it contains high concentrations of secretory IgA against virulence plasmid-associated antigens.
Assuntos
Antígenos de Bactérias/imunologia , Aleitamento Materno , Disenteria Bacilar/imunologia , Imunoglobulina A Secretora/análise , Leite Humano/imunologia , Plasmídeos/imunologia , Shigella boydii/imunologia , Shigella flexneri/imunologia , Shigella sonnei/imunologia , Disenteria Bacilar/epidemiologia , Disenteria Bacilar/microbiologia , Ensaio de Imunoadsorção Enzimática , Fezes/microbiologia , Humanos , Lactente , Recém-Nascido , México/epidemiologia , Prognóstico , Estudos Prospectivos , Estudos Soroepidemiológicos , Shigella boydii/isolamento & purificação , Shigella boydii/patogenicidade , Shigella flexneri/isolamento & purificação , Shigella flexneri/patogenicidade , Shigella sonnei/isolamento & purificação , Shigella sonnei/patogenicidade , População Urbana/estatística & dados numéricos , Virulência/imunologiaRESUMO
The study of susceptibility to 11 antimicrobial by agar difusion method of 561 Shigella strains at the Enteric Reference Laboratory of I.S.P., is informed. We found 18.7 percent of resistance, a lower value than the described in the literature of other countries
Assuntos
Humanos , Disenteria Bacilar/tratamento farmacológico , Shigella flexneri/patogenicidade , Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Resistência Microbiana a Medicamentos/imunologia , Testes de Sensibilidade Microbiana , Microbiologia , Shigella/efeitos dos fármacos , Shigella/isolamento & purificaçãoRESUMO
In a study of the findings on bacteriological investigation of infantile diarrhoea in British Guiana during a period of 14 months in 1858-1959, the agents were as follows: Shigella sonnei 38 percent, Shigella flexneri types 16 percent, Salmonella coeln 16 percent, Escherichia coli types 24 percent of 76 positive results. Death from diarrhoea represent some 22 percent of all deaths in infants aged one year and under (Summary)