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1.
PLoS One ; 9(2): e88572, 2014.
Article in English | MEDLINE | ID: mdl-24558401

ABSTRACT

Toll-like receptors (TLRs) play an important role in mycobacterial infection, although little is known about the roles of these receptors, cytokines and nitric oxide during anti-tuberculosis treatment. Our objective was to evaluate the mRNA and cell surface expression of TLR2 and TLR4; inducible nitric oxide synthase (iNOS) expression; and cytokine Th1, Th2 and Th17 profiles in pulmonary tuberculosis patients at different time points of anti-tuberculosis treatment. Peripheral blood mononuclear cells (PBMCs) were obtained from PPD(+) healthy controls and from patients receiving anti-tuberculosis treatment. Gene expression quantification was performed by qPCR, cell surface expression was assessed using flow cytometry, and cytokine quantification was conducted using the CBA technique. The treated patients presented higher gene expression and higher numbers of receptors on the cell surface of lymphocytes and monocytes than did control individuals. IL-12 and IFN-γ levels increased after the start of treatment, whereas TNF-α levels were reduced. TGF-ß presented the highest levels during treatment. IL-10 and IL-17 expression and production tended to increase during treatment. iNOS gene expression was reduced throughout treatment in patients. Our results suggest that anti-tuberculosis treatment modulates the immune response, inducing an increase in the expression of TLRs and pro- and anti-inflammatory cytokines to combat bacteria and reduce the inflammatory process.


Subject(s)
Cytokines/metabolism , Nitric Oxide Synthase Type II/metabolism , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/metabolism , Transforming Growth Factor beta1/metabolism , Tuberculosis, Pulmonary/drug therapy , Adult , Antitubercular Agents/therapeutic use , Cell Membrane/metabolism , Female , Gene Expression Profiling , Gene Expression Regulation , Humans , Inflammation , Interferon-gamma/blood , Interleukin-10/blood , Interleukin-12/blood , Interleukin-17/blood , Leukocytes, Mononuclear/drug effects , Male , Middle Aged , Sputum , Tuberculin Test , Tuberculosis, Pulmonary/blood , Tumor Necrosis Factor-alpha/blood
2.
Tuberc Res Treat ; 2013: 285094, 2013.
Article in English | MEDLINE | ID: mdl-23634300

ABSTRACT

Cytokines play an essential role during active tuberculosis disease and cytokine genes have been described in association with altered cytokine levels. Therefore, the aim of this study was to verify if IFNG, IL12B, TNF, IL17A, IL10, and TGFB1 gene polymorphisms influence the immune response of Brazilian patients with pulmonary tuberculosis (PTB) at different time points of antituberculosis treatment (T1, T2, and T3). Our results showed the following associations: IFNG +874 T allele and IFNG +2109 A allele with higher IFN- γ levels; IL12B +1188 C allele with higher IL-12 levels; TNF -308 A allele with higher TNF- α plasma levels in controls and mRNA levels in PTB patients at T1; IL17A A allele at rs7747909 with higher IL-17 levels; IL10 -819 T allele with higher IL-10 levels; and TGFB1 +29 CC genotype higher TGF- ß plasma levels in PTB patients at T2. The present study suggests that IFNG +874T/A, IFNG +2109A/G, IL12B +1188A/C, IL10 -819C/T, and TGFB1 +21C/T are associated with differential cytokine levels in pulmonary tuberculosis patients and may play a role in the initiation and maintenance of acquired cellular immunity to tuberculosis and in the outcome of the active disease while on antituberculosis treatment.

3.
s.l; s.n; 2013. 13 p. tab, graf.
Non-conventional in English | Sec. Est. Saúde SP, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1095811

ABSTRACT

Cytokines play an essential role during active tuberculosis disease and cytokine genes have been described in association with altered cytokine levels. Therefore, the aim of this study was to verify if IFNG, IL12B, TNF, IL17A, IL10, and TGFB1 gene polymorphisms influence the immune response of Brazilian patients with pulmonary tuberculosis (PTB) at different time points of antituberculosis treatment (T1, T2, and T3). Our results showed the following associations: IFNG +874 T allele and IFNG +2109 A allele with higher IFN- γ levels; IL12B +1188 C allele with higher IL-12 levels; TNF -308 A allele with higher TNF- α plasma levels in controls and mRNA levels in PTB patients at T1; IL17A A allele at rs7747909 with higher IL-17 levels; IL10 -819 T allele with higher IL-10 levels; and TGFB1 +29 CC genotype higher TGF- ß plasma levels in PTB patients at T2. The present study suggests that IFNG +874T/A, IFNG +2109A/G, IL12B +1188A/C, IL10 -819C/T, and TGFB1 +21C/T are associated with differential cytokine levels in pulmonary tuberculosis patients and may play a role in the initiation and maintenance of acquired cellular immunity to tuberculosis and in the outcome of the active disease while on antituberculosis treatment.


Subject(s)
Polymorphism, Genetic , Tuberculosis, Pulmonary/immunology , Cytokines/genetics , Tuberculosis, Pulmonary/therapy , Immunity, Cellular
4.
Botucatu; s.n; 2012. 143 p. ilus.
Thesis in Portuguese | LILACS | ID: lil-705195

ABSTRACT

It is estimated that one-third of the total world population is latently infected with M. tuberculosis and only 5-10% of the infected individuals will develop active TB disease during their life-time. The reason why some infected individuals develop active disease, while others do not is not yet entirely understood. Given the central role of TLR-2 in the incitement of inflammation, polymorphisms in its gene might be involved in both infectious and inflammatory diseases. The aim of this study was to evaluate the influence of TLR2 - 16934A/T and GT repeat polymorphisms on the immune response of PTB patients undergoing anti-TB treatment at different time points of anti-tuberculosis treatment: T1 (beginning), T2 (3 months) and T3 (end). For this we genotyped TLR2 -16934 and (GT)n repeats polymorphisms and evaluated the immune response of pulmonary tuberculosis patients during the time of anti-tuberculosis treatment. The present study suggests that TLR2 - 16934A/T and GT repeats polymorphisms can influence differential TLR-2, NF-κB and cytokine levels during anti-TB treatment. We also suggest that PTB patients with TLR2 - 16934 AA genotype may have a worst outcome of the disease, since they have a lower IFN-γ, cytokine essential to initiate the protective immunity to active TB. This association could not be made in our study due to the low number of patients evaluated. Since TLR-2 play a major role in initiating immune response against M...


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Antitubercular Agents/therapeutic use , Polymorphism, Genetic , Receptors, Cytokine , Tuberculosis, Pulmonary/immunology , Tuberculosis, Pulmonary/therapy
5.
Mem Inst Oswaldo Cruz ; 106(5): 573-83, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21894379

ABSTRACT

Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence immunity to control parasite infections. This study aimed to evaluate the mRNA expression of TLRs 2 and 4, the expression and production of the cytokines interleukin (IL)-12, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17, IL-10 and transforming growth factor (TGF)-ß and the production of nitric oxide (NO) in the spleen of mice infected with Leishmania chagasi. It also aimed to evaluate any correlations between mRNA expression TLR2 and 4 and cytokines and NO production. Infection resulted in increased TLR2-4, IL-17, TNF-α and TGF-ß mRNA expression during early infection, with decreased expression during late infection correlating with parasite load. IFN-γ and IL-12 mRNA expression decreased at the peak of parasitism. IL-10 mRNA expression increased throughout the entire time period analysed. Although TGF-ß, TNF-α and IL-17 were highly produced during the initial phase of infection, IFN-γ and IL-12 exhibited high production during the final phase of infection. IL-10 and NO showed increased production throughout the evaluated time period. In the acute phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17, NO, IL-10 and TGF-ß expression and parasite load. During the chronic phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17 and TGF-ß expression and parasite load. Our data suggest that infection by L. chagasi resulted in modulation of TLRs 2 and 4 and cytokines.


Subject(s)
Cytokines/biosynthesis , Leishmania infantum/immunology , Leishmaniasis, Visceral/metabolism , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/metabolism , Animals , DNA Primers , Female , Leishmania infantum/genetics , Leishmaniasis, Visceral/parasitology , Mice , Mice, Inbred C57BL , Parasite Load , Polymerase Chain Reaction , RNA, Messenger , Toll-Like Receptor 2/genetics , Toll-Like Receptor 4/genetics
6.
Mem. Inst. Oswaldo Cruz ; 106(5): 573-583, Aug. 2011. graf, tab
Article in English | LILACS | ID: lil-597718

ABSTRACT

Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence immunity to control parasite infections. This study aimed to evaluate the mRNA expression of TLRs 2 and 4, the expression and production of the cytokines interleukin (IL)-12, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17, IL-10 and transforming growth factor (TGF)-β and the production of nitric oxide (NO) in the spleen of mice infected with Leishmania chagasi. It also aimed to evaluate any correlations between mRNA expression TLR2 and 4 and cytokines and NO production. Infection resulted in increased TLR2-4, IL-17, TNF-α and TGF-β mRNA expression during early infection, with decreased expression during late infection correlating with parasite load. IFN-γ and IL-12 mRNA expression decreased at the peak of parasitism. IL-10 mRNA expression increased throughout the entire time period analysed. Although TGF-β, TNF-α and IL-17 were highly produced during the initial phase of infection, IFN-γ and IL-12 exhibited high production during the final phase of infection. IL-10 and NO showed increased production throughout the evaluated time period. In the acute phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17, NO, IL-10 and TGF-β expression and parasite load. During the chronic phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17 and TGF-β expression and parasite load. Our data suggest that infection by L. chagasi resulted in modulation of TLRs 2 and 4 and cytokines.


Subject(s)
Animals , Female , Mice , Cytokines/biosynthesis , Leishmania infantum/immunology , Leishmaniasis, Visceral , DNA Primers , Leishmania infantum , Leishmaniasis, Visceral , Parasite Load , Polymerase Chain Reaction , RNA, Messenger
7.
Mutat Res ; 723(2): 177-81, 2011 Aug 16.
Article in English | MEDLINE | ID: mdl-21570479

ABSTRACT

Leishmania chagasi, which causes visceral leishmaniasis in South America, is an obligate intracellular protozoan. Production of nitric oxide by macrophages during the inflammatory response is one of the main microbicidal mechanisms against this parasite. The goal of this study was to evaluate whether L. chagasi infection causes DNA damage in peripheral blood and spleen cells of Balb/c mice and whether such damage may be related to NO production. Balb/c mice were either infected with L. chagasi or maintained as controls. The single-cell gel electrophoresis (comet) assay was used to measure DNA damage in peripheral blood and spleen cells, and the Griess reaction was used to measure NO production in the spleen. L. chagasi infection induced DNA damage in peripheral blood and spleen cells of infected mice. Macrophages from the control group, challenged with L. chagasi, showed significantly (p<0.05) greater NO production, compared to non-challenged cells. Treatment of spleen cells with N(G)-monomethyl-l-arginine (LNMMA) caused a significant reduction of NO production and DNA damage (p<0.05). Our results indicate that L. chagasi induces DNA damage in the peripheral blood and spleen cells and that NO not only causes killing of the parasite but also induces DNA damage in adjacent cells.


Subject(s)
DNA Damage , Leishmaniasis, Visceral/genetics , Leishmaniasis, Visceral/metabolism , Nitric Oxide/biosynthesis , Animals , Female , Leishmaniasis, Visceral/blood , Macrophages/metabolism , Macrophages/parasitology , Mice , Mice, Inbred BALB C , Spleen/metabolism , Spleen/parasitology , omega-N-Methylarginine/pharmacology
8.
J Bras Pneumol ; 34(11): 942-9, 2008 Nov.
Article in English, Portuguese | MEDLINE | ID: mdl-19099101

ABSTRACT

OBJECTIVE: To evaluate the pattern of pro-inflammatory cytokines, anti-inflammatory cytokines and the acute phase response (APR) as markers of the response to treatment of pulmonary tuberculosis. METHODS: Twenty-eight patients with pulmonary tuberculosis were evaluated at three time points: pretreatment (T0), treatment month 3 (T3) and treatment month 6 (T6). Levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukine-10 (IL-10) and transforming growth factor-beta (TGF-beta) were determined using ELISA in the supernatant of peripheral blood mononuclear cell and monocyte culture. Levels of total protein, albumin, globulins, C-reactive protein (CRP), alpha-1-acid glycoprotein (AAG) and erythrocyte sedimentation rate (ESR) were also determined. All of these parameters were also evaluated, only once, in a group of healthy controls. RESULTS: In relation to controls, patients presented cytokine levels and APR that were higher at T0, lower at T3 and either lower (TNF-alpha, IL-10, TGF-beta, AAG and ESR) or normal (IFN-gamma and CRP) at T6. CONCLUSIONS: For individuals with negative smear sputum microscopy, CRP, AAG and ESR are potential markers of pulmonary tuberculosis and of the need for treatment; CRP (T0 > T3 > T6 = reference) can also be a marker of treatment response. In the patients, the Th0 profile (IFN-gamma, IL-10, TNF-alpha and TGF-beta), inducer of and protector against inflammation, predominated at T0, whereas the Th2 profile (IL-10, TNF-alpha and TGF-beta), protecting against the harmful pro-inflammatory effect of the remaining TNF-alpha, predominated at T6. The behavior of IFN-gamma (T0 > T3 > T6 = controls) suggests its use as a marker of treatment response.


Subject(s)
C-Reactive Protein/analysis , Interferon-gamma/blood , Interleukin-10/blood , Transforming Growth Factor beta/blood , Tuberculosis, Pulmonary/blood , Tumor Necrosis Factor-alpha/blood , Adult , Aged , Biomarkers/blood , Blood Sedimentation/drug effects , Cell Culture Techniques , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Time Factors , Tuberculosis, Pulmonary/drug therapy , Young Adult
9.
J. bras. pneumol ; J. bras. pneumol;34(11): 942-949, nov. 2008. ilus, tab
Article in Portuguese | LILACS, Sec. Est. Saúde SP, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: lil-623383

ABSTRACT

OBJETIVO: Analisar o padrão de citocinas pró- e antiinflamatórias e da resposta de fase aguda (RFA) como marcadores de resposta ao tratamento da tuberculose pulmonar. MÉTODOS: Determinação dos níveis de interferon-gama (IFN-γ), tumor necrosis factor-alpha (TNF-α, fator de necrose tumoral-alfa), interleucina-10 (IL-10) e transforming growth factor-beta (TGF-β, fator transformador de crescimento-beta), pelo método ELISA, em sobrenadante de cultura de células mononucleares do sangue periférico e monócitos, assim como dos níveis de proteínas totais, albumina, globulinas, alfa-1-glicoproteína ácida (AGA), proteína C reativa (PCR) e velocidade de hemossedimentação (VHS) em 28 doentes com tuberculose pulmonar, em três tempos: antes (T0), aos três meses (T3) e aos seis meses (T6) de tratamento, em relação aos controles saudáveis, em um único tempo. RESULTADOS: Os pacientes apresentaram valores maiores de citocinas e RFA que os controles em T0, com diminuição em T3 e diminuição (TNF-α, IL-10, TGF-β, AGA e VHS) ou normalização (IFN-γ e PCR) em T6. CONCLUSÕES: PCR, AGA e VHS são possíveis marcadores para auxiliar no diagnóstico de tuberculose pulmonar e na indicação de tratamento de indivíduos com baciloscopia negativa; PCR (T0 > T3 > T6 = referência) pode também ser marcador de resposta ao tratamento. Antes do tratamento, o perfil Th0 (IFN-γ, IL-10, TNF-α e TGF-β), indutor de e protetor contra inflamação, prevaleceu nos pacientes; em T6, prevaleceu o perfil Th2 (IL-10, TNF-α e TGF-β), protetor contra efeito nocivo pró-inflamatório do TNF-α ainda presente. O comportamento do IFN-γ (T0 > T3 > T6 = controle) sugere sua utilização como marcador de resposta ao tratamento.


OBJECTIVE: To evaluate the pattern of pro-inflammatory cytokines, anti-inflammatory cytokines and the acute phase response (APR) as markers of the response to treatment of pulmonary tuberculosis. METHODS: Twenty-eight patients with pulmonary tuberculosis were evaluated at three time points: pretreatment (T0), treatment month 3 (T3) and treatment month 6 (T6). Levels of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukine-10 (IL-10) and transforming growth factor-beta (TGF-β) were determined using ELISA in the supernatant of peripheral blood mononuclear cell and monocyte culture. Levels of total protein, albumin, globulins, C-reactive protein (CRP), alpha-1-acid glycoprotein (AAG) and erythrocyte sedimentation rate (ESR) were also determined. All of these parameters were also evaluated, only once, in a group of healthy controls. RESULTS: In relation to controls, patients presented cytokine levels and APR that were higher at T0, lower at T3 and either lower (TNF-α, IL-10, TGF-β, AAG and ESR) or normal (IFN-γ and CRP) at T6. CONCLUSIONS: For individuals with negative smear sputum microscopy, CRP, AAG and ESR are potential markers of pulmonary tuberculosis and of the need for treatment; CRP (T0 > T3 > T6 = reference) can also be a marker of treatment response. In the patients, the Th0 profile (IFN-γ, IL-10, TNF-α and TGF-β), inducer of and protector against inflammation, predominated at T0, whereas the Th2 profile (IL-10, TNF-α and TGF-β), protecting against the harmful pro-inflammatory effect of the remaining TNF-α, predominated at T6. The behavior of IFN-γ (T0 > T3 > T6 = controls) suggests its use as a marker of treatment response.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Young Adult , C-Reactive Protein/analysis , Interferon-gamma/blood , /blood , Transforming Growth Factor beta/blood , Tuberculosis, Pulmonary/blood , Tumor Necrosis Factor-alpha/blood , Biomarkers/blood , Blood Sedimentation/drug effects , Cell Culture Techniques , Enzyme-Linked Immunosorbent Assay , Time Factors , Tuberculosis, Pulmonary/drug therapy
10.
Braz J Infect Dis ; 11(2): 226-33, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17625767

ABSTRACT

Despite the existence of highly sensitive tests, inconclusive serological results are frequent in chronic chagasic infection. This study aimed to define a diagnostic conduct for 30 individuals with inconclusive serology (G3) for chagasic infection assisted at the Outpatient Unit for Infectious and Parasitic Diseases of the Botucatu School of Medicine. Twenty-one individuals with negative serology (G1) and 33 with positive serology (G2) were also studied. Serological methods ELISA, HAI, IFI and immunoblotting TESA-cruzi were used for G1, G2 and G3, and parasitological methods xenodiagnosis, hemoculture and PCR-LIT were used for G2 and G3 individuals. ELISA, HAI and IFI were performed in 5 different blood samples in G2 and G3. TESA-cruzi was carried out only once in G1, G2 and G3 and, since it is the most sensitive, it was utilized as standard. In G3, positivity for ELISA reached 86% in the fifth blood sample; the ELISA+HAI+IFI combination showed a maximum of 44.8% in the second sample; and TESA-cruzi, 76% in one single sample. Xenodiagnosis positivity was 9.4%; hemoculture showed 15.2%; and PCR-LIT exhibited 22% positivity in G2. Nevertheless, in G3, positivity percentage was 3.4% for xenodiagnosis, 6.7% for PCR-LIT, and no positive result was found for hemoculture. In G3, PCR-LIT resolved one case which was still inconclusive according to serology tests. In order to define inconclusive diagnoses, the results suggest the combined use of ELISA+HAI+IFI in 2 blood samples, decreasing the occurrence of false positive/negative results. If results remain inconclusive, the performance of TESA-cruzi and PCR-LIT, if necessary, is recommended.


Subject(s)
Chagas Disease/diagnosis , Trypanosoma cruzi/genetics , Trypanosoma cruzi/immunology , Animals , Case-Control Studies , Chronic Disease , Female , Humans , Male , Polymerase Chain Reaction , Sensitivity and Specificity , Serologic Tests , Xenodiagnosis
11.
Braz. j. infect. dis ; Braz. j. infect. dis;11(2): 226-233, Apr. 2007. graf, ilus, tab
Article in English | LILACS | ID: lil-454724

ABSTRACT

Despite the existence of highly sensitive tests, inconclusive serological results are frequent in chronic chagasic infection. This study aimed to define a diagnostic conduct for 30 individuals with inconclusive serology (G3) for chagasic infection assisted at the Outpatient Unit for Infectious and Parasitic Diseases of the Botucatu School of Medicine. Twenty-one individuals with negative serology (G1) and 33 with positive serology (G2) were also studied. Serological methods ELISA, HAI, IFI and immunoblotting TESA-cruzi were used for G1, G2 and G3, and parasitological methods xenodiagnosis, hemoculture and PCR-LIT were used for G2 and G3 individuals. ELISA, HAI and IFI were performed in 5 different blood samples in G2 and G3. TESA-cruzi was carried out only once in G1, G2 and G3 and, since it is the most sensitive, it was utilized as standard. In G3, positivity for ELISA reached 86 percent in the fifth blood sample; the ELISA+HAI+IFI combination showed a maximum of 44.8 percent in the second sample; and TESA-cruzi, 76 percent in one single sample. Xenodiagnosis positivity was 9.4 percent; hemoculture showed 15.2 percent; and PCR-LIT exhibited 22 percent positivity in G2. Nevertheless, in G3, positivity percentage was 3.4 percent for xenodiagnosis, 6.7 percent for PCR-LIT, and no positive result was found for hemoculture. In G3, PCR-LIT resolved one case which was still inconclusive according to serology tests. In order to define inconclusive diagnoses, the results suggest the combined use of ELISA+HAI+IFI in 2 blood samples, decreasing the occurrence of false positive/negative results. If results remain inconclusive, the performance of TESA-cruzi and PCR-LIT, if necessary, is recommended.


Subject(s)
Animals , Female , Humans , Male , Chagas Disease/diagnosis , Trypanosoma cruzi/genetics , Trypanosoma cruzi/immunology , Case-Control Studies , Chronic Disease , Polymerase Chain Reaction , Sensitivity and Specificity , Serologic Tests , Xenodiagnosis
12.
Braz. j. microbiol ; Braz. j. microbiol;37(1): 70-74, Jan.-Mar. 2006. tab
Article in English | LILACS | ID: lil-430984

ABSTRACT

A intoxicação alimentar estafilocócica ocorre devido à ingestão de alimentos contaminados com enterotoxinas. Essa contaminação tem sido oriunda, principalmente, da manipulação humana, ou de matérias-primas procedentes de animais portadores. Embora Staphylococcus aureus coagulase positiva, seja o principal agente de intoxicação alimentar, alguns pesquisadores enfatizam que os estafilococos coagulase-negativa (ECN) podem produzir as enterotoxinas estafilocócicas, podendo contribuir para a intoxicação alimentar. Este estudo teve como objetivos isolar os ECN de alimentos e verificar a capacidade enterotoxigênica dessas linhagens. Foram estudadas 88 amostras de alimentos, sendo que 22,7 por cento foram positivas para ECN com crescimento entre 102 e 106 UFC/g or mL. A espécie predominante dentre as linhagens isoladas foi S. epidermidis (40 por cento), seguido por S. warneri (20 por cento), S. xylosus (20 por cento), S. saccharolyticus (15 por cento) e S. hominis (5 por cento). Entre as linhagens isoladas, quatro apresentaram genes para produção de enterotoxinas pelo método de Reação da Polimerase em Cadeia (PCR), com predominância do gene sea. Não se detectou a produção de enterotoxina pelo método de aglutinação em látex (RPLA). Através dos resultados obtidos, observou-se que os ECN isolados de alimentos não devem ser ignorados quanto à sua capacidade toxigênica, necessitando de maior estudo e atenção para melhor caracterização desse grupo de microrganismos em alimentos.


Subject(s)
Wastewater , Bioaccumulation , Bivalvia , In Vitro Techniques , Ostreidae , Poliovirus , Tissue Extracts , Methods , Reverse Transcriptase Polymerase Chain Reaction
13.
Article in English | VETINDEX | ID: vti-443947

ABSTRACT

Staphylococcal food poisoning is caused by ingestion of enterotoxins preformed in the food contaminated essentially through human manipulation or raw material obtained from animals. Although coagulase-positive Staphylococcus aureus is the main agent responsible for food intoxication, some researches emphasise that coagulase-negative staphylococci (CNS) are able to produce staphylococcal enterotoxins and may be a potential cause of food poisoning. In the present study CNS were isolated from foods and the toxigenic capacity of the strains determined. A total of 88 food samples were analysed and 22.7% were positive for CNS strains. Staphylococcal counts ranged from 3.0 x 10² to 1.4 x 10(6) CFU/g or mL of food examined. S. epidermidis predominated among the isolates (40%). Further isolates included S. xylosus (20%), S. warneri (20%), S. saccharolyticus (15%), and S. hominis (5%). Four isolates were positive for enterotoxin genes, as detected by polymerase chain reaction, with sea being the predominant gene. Although no enterotoxin production was detected by the reverse passive latex agglutination method, the data showed that the toxigenic capacity of CNS should not be ignored, requiring investigation of this group of microorganisms in food.


A intoxicação alimentar estafilocócica ocorre devido à ingestão de alimentos contaminados com enterotoxinas. Essa contaminação tem sido oriunda, principalmente, da manipulação humana, ou de matérias-primas procedentes de animais portadores. Embora Staphylococcus aureus coagulase positiva, seja o principal agente de intoxicação alimentar, alguns pesquisadores enfatizam que os estafilococos coagulase-negativa (ECN) podem produzir as enterotoxinas estafilocócicas, podendo contribuir para a intoxicação alimentar. Este estudo teve como objetivos isolar os ECN de alimentos e verificar a capacidade enterotoxigênica dessas linhagens. Foram estudadas 88 amostras de alimentos, sendo que 22,7% foram positivas para ECN com crescimento entre 10² e 10(6) UFC/g or mL. A espécie predominante dentre as linhagens isoladas foi S. epidermidis (40%), seguido por S. warneri (20%), S. xylosus (20%), S. saccharolyticus (15%) e S. hominis (5%). Entre as linhagens isoladas, quatro apresentaram genes para produção de enterotoxinas pelo método de Reação da Polimerase em Cadeia (PCR), com predominância do gene sea. Não se detectou a produção de enterotoxina pelo método de aglutinação em látex (RPLA). Através dos resultados obtidos, observou-se que os ECN isolados de alimentos não devem ser ignorados quanto à sua capacidade toxigênica, necessitando de maior estudo e atenção para melhor caracterização desse grupo de microrganismos em alimentos.

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