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We investigated an outbreak of enterotoxigenic Escherichia coli (ETEC) O159:H20 associated with the consumption of a tossed-noodle dish in a high school in 2016. Thirty-three ETEC strains isolated from clinical and food samples were genetically indistinguishable. The outbreak strains were resistant to third-generation cephalosporins and harbored a blaCTX-M-15 gene on a 97-kb self-transferable IncK plasmid. This is the first outbreak caused by CTX-M-15-producing ETEC strains.
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Escherichia coli Enterotoxigênica/metabolismo , Infecções por Escherichia coli/epidemiologia , beta-Lactamases/metabolismo , Cefalosporinas/uso terapêutico , Surtos de Doenças , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Humanos , Plasmídeos/genética , República da Coreia/epidemiologiaRESUMO
A Gram-stain-positive, catalase-positive, facultatively anaerobic, non-motile, coryneform bacterium, designated strain 32T, was isolated from a closed pus sample from a patient having finger necrosis in Korea. Strain 32T was considered as representing a novel species according to its initial identification by matrix-assisted laser desorption/ionization-time-of-flight MS. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 32T belonged to the genus Dermabacter and was closely related to Dermabacter hominis DSM 7083T (=ATCC 49369T) (98.34 % similarity). Optimal growth was observed at 30-40 °C and pH 7. Growth occurred in the presence of 0-6 % (w/v) NaCl. Menaquinones MK-8, MK-7 and MK-9 were the major respiratory quinones. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, glycolipid and two unknown lipids. The major cellular fatty acids were anteiso-C17 : 0, anteiso-C15 : 0, iso-C16 : 0 and iso-C15 : 0. The DNA G+C content of strain 32T was 62.58 mol%, and the mean level of DNA-DNA relatedness between strain 32T and D. hominis ATCC 49369T was 49±1.6 %. Based on the phenotypic and genotypic characteristics, strain 32T is confirmed to represent a novel species of the genus Dermabacter, for which the name Dermabacter jinjuensis sp. nov. is proposed. The type strain is 32T (=NCCP 16133T=DSM 101003T).
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Actinomycetales/classificação , Dedos/microbiologia , Filogenia , Supuração/microbiologia , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Dedos/patologia , Humanos , Necrose , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/químicaRESUMO
Local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method (LLNA: BrdU-FCM) is a modified non-radioisotopic technique with the additional advantages of accommodating multiple endpoints with the introduction of FCM, and refinement and reduction of animal use by using a sophisticated prescreening scheme. Reliability and accuracy of the LLNA: BrdU-FCM was determined according to OECD Test Guideline (TG) No. 429 (Skin Sensitization: Local Lymph Node Assay) performance standards (PS), with the participation of four laboratories. Transferability was demonstrated through successfully producing stimulation index (SI) values for 25% hexyl cinnamic aldehyde (HCA) consistently greater than 3, a predetermined threshold, by all participating laboratories. Within- and between-laboratory reproducibility was shown using HCA and 2,4-dinitrochlorobenzene, in which EC2.7 values (the estimated concentrations eliciting an SI of 2.7, the threshold for LLNA: BrdU-FCM) fell consistently within the acceptance ranges, 0.025-0.1% and 5-20%, respectively. Predictive capacity was tested using the final protocol version 1.3 for the 18 reference chemicals listed in OECD TG 429, of which results showed 84.6% sensitivity, 100% specificity, and 88.9% accuracy compared with the original LLNA. The data presented are considered to meet the performance criteria for the PS, and its predictive capacity was also sufficiently validated.
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Acroleína/análogos & derivados , Bromodesoxiuridina , Dinitroclorobenzeno/toxicidade , Citometria de Fluxo , Ensaio de Proficiência Laboratorial , Ensaio Local de Linfonodo , Linfonodos/efeitos dos fármacos , Acroleína/toxicidade , Animais , Feminino , Citometria de Fluxo/normas , Fidelidade a Diretrizes , Guias como Assunto , Humanos , Linfonodos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , República da CoreiaRESUMO
Enterohemorrhagic Escherichia coli causes severe food-borne disease in the guts of humans and animals. Here, we report the high-quality draft genome sequence of E. coli NCCP15658 isolated from a patient in the Republic of Korea. Its genome size was determined to be 5.46 Mb, and its genomic features, including genes encoding virulence factors, were analyzed.
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Escherichia coli Êntero-Hemorrágica/genética , Genoma Bacteriano , Escherichia coli Êntero-Hemorrágica/classificação , Feminino , Gastroenteropatias/epidemiologia , Gastroenteropatias/microbiologia , Regulação Bacteriana da Expressão Gênica/fisiologia , Humanos , Dados de Sequência Molecular , República da Coreia/epidemiologiaRESUMO
Shiga toxin-producing Escherichia coli causes bloody diarrhea and hemolytic-uremic syndrome and serious outbreaks worldwide. Here, we report the draft genome sequence of E. coli NCCP15657 isolated from a patient. The genome has virulence genes, many in the locus of enterocyte effacement (LEE) island, encoding a metalloprotease, the Shiga toxin, and constituents of type III secretion.
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Genoma Bacteriano , Escherichia coli Shiga Toxigênica/genética , Colite/microbiologia , Diarreia/complicações , Diarreia/microbiologia , Surtos de Doenças , Regulação Bacteriana da Expressão Gênica/fisiologia , Alemanha/epidemiologia , Síndrome Hemolítico-Urêmica/microbiologia , Hemorragia/microbiologia , Dados de Sequência MolecularRESUMO
In August 2016, South Korea experienced a cholera outbreak that caused acute watery diarrhea in three patients. This outbreak was the first time in 15 years that an outbreak was not linked to an overseas source. To identify the cause and to study the epidemiological implications of this outbreak, we sequenced the whole genome of Vibrio cholerae isolates; three from each patient and one from a seawater sample. Herein we present comparative genomic data which reveals that the genome sequences of these four isolates are very similar. Interestingly, these isolates form a monophyletic clade with V. cholerae strains that caused an outbreak in the Philippines in 2011. The V. cholerae strains responsible for the Korean and Philippines outbreaks have almost identical genomes in which two unique genomic islands are shared, and they both lack SXT elements. Furthermore, we confirm that seawater is the likely source of this outbreak, which suggests the necessity for future routine surveillance of South Korea's seashore.
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BACKGROUND: In June 2015, a local public health laboratory was notified that students had developed gastroenteritis symptoms after attending a camp. An outbreak investigation was conducted to determine the extent and cause of the outbreak. METHOD: A retrospective cohort study was conducted to determine the correlations between the illness and specific exposures at the school camp. All attendees were interviewed with a standard questionnaire that addressed clinical symptoms, food consumption, and environmental exposures. Clinical specimens were cultured using standard microbiological methods for bacterial and viral pathogens. The genetic relationships of all isolates were determined using pulsed-field gel electrophoresis (PFGE). RESULTS: A total 188 patients with symptoms of diarrhoea, abdominal pain, and nausea were identified. The completed questionnaires suggested that the consumption of drinking water was likely to be linked to this outbreak. Using microbiological methods, enterohaemorrhagic Escherichia coli, enteropathogenic E. coli, and enteroaggregative E. coli were isolated, and the isolates from both patient stool and environmental water samples displayed indistinguishable XbaI-PFGE patterns. The water system in the camp used groundwater drawn from a private underground reservoir for cooking and drinking. The environmental investigation revealed some problems with the water supply system, such as the use of inappropriate filters in the water purifier and a defect in the pipeline between the reservoir and the chlorination device. CONCLUSIONS: This outbreak points to the importance of drinking water quality management in group facilities where underground water is used and emphasizes the need for periodic sanitation and inspection to prevent possible waterborne outbreaks.
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Acampamento , Água Potável/microbiologia , Infecções por Escherichia coli/etiologia , Doenças Transmitidas pela Água/etiologia , Estudos de Coortes , Diarreia/epidemiologia , Diarreia/etiologia , Diarreia/microbiologia , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Gastroenterite/epidemiologia , Humanos , Estudos Retrospectivos , Instituições Acadêmicas , Doenças Transmitidas pela Água/epidemiologiaRESUMO
An enrichment semi-nested PCR procedure was developed for detection of Clostridium botulinum types A, B, E, and F. It was applied to sediment samples to examine the prevalence of C. botulinum in the Korean environment. The first pair of primers for the semi-nested PCR was designed using a region shared by the types A, B, E, and F neurotoxin gene sequences, and the second round employed four nested primers complementary to the BoNT/A, /B, /E, and /F encoding genes for simultaneous detection of the four serotypes. Positive results were obtained from the PCR analysis of five of 44 sediments (11%) collected from Yeong-am Lake in Korea; all were identified as deriving from type B neurotoxin (bontb) genes. Two of the C. botulinum type B organisms were isolated, and their bontb genes sequenced. The deduced amino acid sequences of BoNT/B showed 99.5 and 99.8% identity with the amino acid sequence of accession no. AB084152. Our data suggest that semi-nested PCR is a useful tool for detecting C. botulinum in sediments, and renders it practicable to conduct environmental surveys.
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Clostridium botulinum/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sequência de Aminoácidos , Toxinas Botulínicas/genética , Clostridium botulinum tipo A/genética , Clostridium botulinum tipo A/isolamento & purificação , Clostridium botulinum tipo B/genética , Clostridium botulinum tipo B/isolamento & purificação , Clostridium botulinum tipo E/genética , Clostridium botulinum tipo E/isolamento & purificação , Clostridium botulinum tipo F/genética , Clostridium botulinum tipo F/isolamento & purificação , Sedimentos Geológicos/microbiologia , Coreia (Geográfico) , Dados de Sequência Molecular , Alinhamento de Sequência , Microbiologia da ÁguaRESUMO
We compared 47 enterohemorrhagic Escherichia coli (EHEC) O157 isolates with 184 EHEC non-O157 isolates from Korean patients with diarrhea. In the O157 group, the strains harboring both Shiga toxin genes (stx1 and stx2) were detected with highest frequency, whereas the strains harboring only stx1 gene were most frequently detected in the non-O157 group. Eight virulence genes (eaeA, hlyA, ehx, iha, efa1, tir, toxB, and espA) were found to show a higher frequency of occurrence in the O157 group than in the non-O157 group. In addition, the symptom of bloody diarrhea was exhibited at a higher rate in the O157 group (51.1%) than in the non-O157 group (16.8%). Our findings demonstrate that EHEC O157 strains are more frequently implicated in cases of bloody diarrhea in the Korean population than EHEC non-O157 strains.
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Diarreia/microbiologia , Escherichia coli Êntero-Hemorrágica/classificação , Infecções por Escherichia coli/microbiologia , Antígenos O/análise , Toxina Shiga I/genética , Toxina Shiga II/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia/patologia , Escherichia coli Êntero-Hemorrágica/genética , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Escherichia coli Êntero-Hemorrágica/patogenicidade , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/patologia , Feminino , Humanos , Lactente , Recém-Nascido , Coreia (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Sorogrupo , Fatores de Virulência/genética , Adulto JovemRESUMO
We screened 10 CTX-M-55-producing Shigella and Salmonella isolates from a national surveillance in Korea. The blaCTX-M-55 was located on the IncI1 (n=5), IncA/C (n=4) and IncZ (n=1) plasmids, downstream of ISEcp1, IS26-ISEcp1 and ISEcp1-IS5 sequences, respectively. These results indicate that CTX-M-55 has disseminated to other bacteria by lateral plasmid transfer.
Assuntos
Transferência Genética Horizontal , Plasmídeos/análise , Salmonella/enzimologia , Salmonella/genética , Shigella/enzimologia , Shigella/genética , beta-Lactamases/genética , Animais , Humanos , Plasmídeos/classificação , República da Coreia , Salmonella/isolamento & purificação , Shigella/isolamento & purificaçãoRESUMO
Current human anthrax vaccines available in the United States and Europe consist of alum-precipitated supernatant material from cultures of a toxigenic, nonencapsulated strain of Bacillus anthracis. The major component of human anthrax vaccine that confers protection is protective antigen (PA). A second-generation human vaccine using the recombinant PA (rPA) is being developed. In this study, to prevent the toxicity and the degradation of the native rPA by proteases, we constructed two PA variants, delPA (163-168) and delPA (313-314), that lack trypsin (S(163)-R(164)-K(165)-K(166)-R(167)-S(168)) or chymotrypsin cleavage sequence (F(313)-F(314)), respectively. These proteins were expressed in Bacillus brevis 47-5Q. The delPAs were fractionated from the culture supernatant of B. brevis by ammonium sulfate at 70% saturation, followed by anion exchange chromatography on a Hitrap Q, Hiload 16/60 superdex 200 gel filtration column and phenyl sepharose hydrophobic interaction column. In accordance with previous reports, both delPA proteins combined with lethal factor protein did not show any cytotoxicity on J774A.1 cells. The delPA (163-168) and delPA (313-314) formulated either in Rehydragel HPA or MPL-TDM-CWS (Ribi-Trimix), elicited a comparable amount of anti-PA and neutralizing antibodies to those of native rPA in guinea pigs, and confers full protection of guinea pigs from 50xLD50 of fully virulent B. anthracis spore challenges. Ribi-Trimix was significantly more effective in inducing anti-PA and neutralizing antibodies than Rehydragel HPA. These results indicate the possibility of delPA (163-168) and delPA (313-314) proteins being developed into nontoxic, effective and stable recombinant vaccine candidates.
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Antígenos de Bactérias/genética , Bacillus anthracis/genética , Bacillus anthracis/imunologia , Toxinas Bacterianas/genética , Sequência de Aminoácidos , Animais , Vacinas contra Antraz/genética , Vacinas contra Antraz/imunologia , Vacinas contra Antraz/isolamento & purificação , Vacinas contra Antraz/toxicidade , Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/isolamento & purificação , Antígenos de Bactérias/toxicidade , Bacillus/genética , Toxinas Bacterianas/imunologia , Toxinas Bacterianas/isolamento & purificação , Toxinas Bacterianas/toxicidade , Sequência de Bases , Sítios de Ligação/genética , Linhagem Celular , Quimotripsina , DNA Bacteriano/genética , Feminino , Genes Bacterianos , Cobaias , Humanos , Camundongos , Mutação , Testes de Neutralização , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/toxicidade , Deleção de Sequência , TripsinaRESUMO
We used the Bacillus brevis-pNU212 system to develop a mass production system for the protective antigen (PA) of Bacillus anthracis. A moderately efficient expression-secretion system for PA was constructed by fusing the PA gene from B. anthracis with the B. brevis cell-wall protein signal-peptide encoding region of pNU212, and by introducing the recombinant plasmid, pNU212-mPA, into B. brevis 47-5Q. The clone producing PA secreted about 300 microg of recombinant PA (rPA) per ml of 5PY-erythromycin medium after 4 days incubation at 30 degrees C. The rPA was fractionated from the culture supernatant of B. brevis 47-5Q carrying pNU212-mPA using ammonium sulfate at 70% saturation followed by anion exchange chromatography on a Hitrap Q, a Hiload 16/60 Superdex 200 gel filtration column and a phenyl sepharose hydrophobic interaction column, yielding 70 mg rPA per liter of culture. The N-terminal sequence of the purified rPA was identical to that of native PA from B. anthracis. The purified rPA exhibited cytotoxicity towards J774A.1 cells when combined with lethal factor. The rPA formulated in either Rehydragel HPA or MPL-TDM-CWS adjuvant (Ribi-Trimix) elicited the expression of a large amount of anti-PA and neutralizing antibodies in guinea pigs and completely protected them against a 100 LD50 challenge with fully virulent B. anthracis spores.
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Antígenos de Bactérias/genética , Bacillus anthracis/genética , Bacillus anthracis/imunologia , Bacillus/genética , Bacillus/imunologia , Toxinas Bacterianas/genética , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/biossíntese , Antígenos de Bactérias/isolamento & purificação , Antígenos de Bactérias/toxicidade , Infecções por Bacillaceae/imunologia , Infecções por Bacillaceae/prevenção & controle , Toxinas Bacterianas/biossíntese , Toxinas Bacterianas/isolamento & purificação , Toxinas Bacterianas/toxicidade , Sequência de Bases , Linhagem Celular , Clonagem Molecular , DNA Bacteriano/genética , Feminino , Expressão Gênica , Genes Bacterianos , Cobaias , Técnicas In Vitro , Camundongos , Testes de Neutralização , Plasmídeos/genética , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/toxicidade , Esporos Bacterianos/genética , Esporos Bacterianos/imunologia , VirulênciaRESUMO
OBJECTIVES: The aim of this study was to characterize the pathogens responsible for causing diarrhea according to season, region of isolation, patient age, and sex as well as to provide useful data for the prevention of diarrheal disease. METHODS: Stool specimens from 14,886 patients with diarrhea were collected to identify pathogenic bacteria from January 2014 to December 2014 in Korea. A total of 3,526 pathogenic bacteria were isolated and analyzed according to season, region of isolation, and the age and sex of the patient. RESULTS: The breakdown of the isolated pathogenic bacteria were as follows: Salmonella spp. 476 (13.5%), pathogenic Escherichia coli 777 (22.0%), Vibrio parahaemolyticus 26 (0.74%), Shigella spp. 13 (0.37%), Campylobacter spp. 215 (6.10%), Clostridium perfringens 508 (14.4%), Staphylococcus aureus 1,144 (32.4%), Bacillus cereus 356 (10.1%), Listeria monocytogenes 1 (0.03%), and Yersinia enterocolitica 10 (0.3%). The isolation rate trend showed the highest ratio in the summer season from June to September for most of the pathogenic bacteria except the Gram-positive bacteria. The isolation rate of most of the pathogenic bacteria by patient age showed highest ratio in the 0-19 year age range. For isolation rate by region, 56.2% were isolated from cities and 43.8% were isolated from provinces. CONCLUSION: Hygiene education should be addressed for diarrheal disease-susceptible groups, such as those younger than 10 years, aged 10-19 years, and older than 70 years, and monitoring for the pathogens is still required. In addition, an efficient laboratory surveillance system for infection control should be continued.
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Sibutramine is an anorectic that has been banned since 2010 due to cardiovascular safety issues. However, counterfeit drugs or slimming products that include sibutramine are still available in the market. It has been reported that illegal sibutramine-contained pharmaceutical products induce cardiovascular crisis. However, the mechanism underlying sibutramine-induced cardiovascular adverse effect has not been fully evaluated yet. In this study, we performed cardiovascular safety pharmacology studies of sibutramine systemically using by hERG channel inhibition, action potential duration, and telemetry assays. Sibutramine inhibited hERG channel current of HEK293 cells with an IC50 of 3.92 µM in patch clamp assay and increased the heart rate and blood pressure (76 Δbpm in heart rate and 51 ΔmmHg in blood pressure) in beagle dogs at a dose of 30 mg/kg (per oral), while it shortened action potential duration (at 10 µM and 30 µM, resulted in 15% and 29% decreases in APD50, and 9% and 17% decreases in APD90, respectively) in the Purkinje fibers of rabbits and had no effects on the QTc interval in beagle dogs. These results suggest that sibutramine has a considerable adverse effect on the cardiovascular system and may contribute to accurate drug safety regulation.
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Drug metabolism mostly occurs in the liver. Cytochrome P450 (CYP) is a drug-metabolizing enzyme that is responsible for many important drug metabolism reactions. Recently, the US FDA and EU EMA have suggested that CYP enzyme induction can be measured by both enzymatic activity and mRNA expression. However, these experiments are time-consuming and their inter-assay variability can lead to misinterpretations of the results. To resolve these problems and establish a more powerful method to measure CYP induction, we determined CYP induction by using luminescent assay. Luminescent CYP assays link CYP enzyme activity to firefly luciferase luminescence technology. In this study, we measured the induction of CYP isozymes (1A2, 2B6, 2C9, and 3A4) in cryopreserved human hepatocytes (HMC424, 478, and 493) using a luminometer. We then examined the potential induction abilities (unknown so far) of mesalazine, a drug for colitis, and mosapride citrate, which is used as an antispasmodic drug. The results showed that mesalazine promotes CYP2B6 and 3A4 activities, while mosapride citrate promotes CYP1A2, 2B6, and 3A4 activities. Luminescent CYP assays offer rapid and safe advantages over LC-MS/MS and qRT-PCR methods. Furthermore, luminescent CYP assays decrease the interference between the optical properties of the test compound and the CYP substrates. Therefore, luminescent CYP assays are less labor intensive, rapid, and can be used as robust tools for high-throughput CYP screening during early drug discovery.
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Tramadol is an opioid analgesic agent that has been the subject of a series of case reports suggesting potential for misuse or abuse. However, it is not a controlled substance and is not generally considered addictive in Korea. In this study, we examined the dependence potential and abuse liability of tramadol as well as its effect on the dopaminergic and serotonergic systems in rodents. In animal behavioral tests, tramadol did not show any positive effects on the experimental animals in climbing, jumping, and head twitch tests. However, in the conditioned place preference and self-administration tests, the experimental animals showed significant positive responses. Taken together, tramadol affected the neurological systems related to abuse liability and has the potential to lead psychological dependence.
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Synthetic cannabinoids (CBs) such as the JWH series have caused social problems concerning their abuse liability. Because the JWH series produces euphoric and hallucinogenic effects, they have been distributed illegally under street names such as "Spice" and "Smoke". Many countries including Korea have started to schedule some of the JWH series compounds as controlled substances, but there are a number of JWH series chemicals that remain uncontrolled by law. In this study, three synthetic CBs with different binding affinities to the CB1 receptor (JWH-073, 081, and 210) and Δ(9)-tetrahydrocannabinol (Δ(9)-THC) were evaluated for their potential for psychological dependence. The conditioned place preference test (unbiased method) and self-administration test (fixed ratio of 1) using rodents were conducted. Ki values of the three synthetic cannabinoids were calculated as supplementary data using a receptor binding assay and overexpressed CB1 protein membranes to compare dependence potential with CB1 receptor binding affinity. All mice administered JWH-073, 081, or 210 showed significantly increased time spent at unpreferred space in a dose-dependence manner in the conditioned place preference test. In contrast, all tested substances except Δ(9)-THC showed aversion phenomenon at high doses in the conditioned place preference test. The order of affinity to the CB1 receptor in the receptor binding assay was JWH-210 > JWH-081 >> JWH-073, which was in agreement with the results from the conditioned place preference test. However, no change in self-administration was observed. These findings suggest the possibility to predict dependence potential of synthetic CBs through a receptor binding assay at the screening level.
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OBJECTIVE: Recombinant protective antigen (rPA) is the active pharmaceutical ingredient of a second generation anthrax vaccine undergoing clinical trials both in Korea and the USA. By using the rPA produced from Bacillus brevis pNU212 expression system, correlations of serological immune response to anthrax protection efficacy were analyzed in a guinea pig model. METHODS: Serological responses of rPA anthrax vaccine were investigated in guinea pigs that were given single or two injections (interval of 4 weeks) of various amounts of rPA combined with aluminumhydroxide adjuvant. Guinea pigs were subsequently challenged by the intramuscular injection with 30 half-lethal doses (30LD50) of virulent Bacillus anthracis spores. Serumantibody titerswere determined by anti-PA IgGELISA and the ability of antibodies to neutralize the cytotoxicity of lethal toxin on J774A.1 cell was measured through the toxin neutralizing antibody (TNA) assay. RESULTS: To examine correlations between survival rate and antibody titers, correlation between neutralizing antibody titers and the extent of protection was determined. Toxin neutralization titers of at least 1176 were sufficient to confer protection against a dose of 30LD50 of virulent anthrax spores of the H9401 strain. Such consistency in the correlation was not observed from those antibody titers determined by ELISA. CONCLUSION: Neutralizing-antibody titers can be used as a surrogate marker.
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BACKGROUND: The workers in an animal laboratory are exposed to laboratory animal allergens (LAAs). OBJECTIVES: To evaluate the difference of sensitization to LAAs and the symptoms according to the exposure levels and to investigate the risk factors for sensitization to LAAs. METHODS: The subjects were divided into 3 groups according to the presence or absence of exposure: 74 subjects were in the direct exposure group, 33 subjects were in the indirect exposure group, and 30 subjects were in the control group. Each group answered the questionnaire and underwent skin prick tests that included 10 common allergens and 10 LAAs. The levels of total IgE and specific IgE to mouse and rat urine allergen were measured by enzyme-linked immunosorbent assay in 2 exposure groups. Allergic symptoms, skin sensitization, and serum IgE level were compared between the study groups. RESULTS: Twenty-five (34%) of the 74 subjects in the direct exposure group experienced allergic symptoms since their exposure to laboratory animals. The subjects in the direct and indirect exposure groups had more sensitization to LAAs than did the control subjects. The direct exposure group had more positive results for total IgE than did the indirect exposure group. The subjects in the direct exposure group with atopy had more severe allergic symptoms than the subjects in the indirect exposure group with atopy. Atopy and total IgE level were risk factors for the sensitization to LAAs for the direct exposure group (odds ratios, 7.47 and 7.33, respectively). CONCLUSIONS: Indirect exposure may be as risky for sensitization to LAAs as direct exposure. More careful protection is needed for laboratory animal workers with atopy.
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Experimentação Animal , Pessoal de Laboratório Médico , Doenças Profissionais/etiologia , Doenças Profissionais/imunologia , Rinite Alérgica Perene/etiologia , Rinite Alérgica Perene/imunologia , Adulto , Alérgenos/imunologia , Animais , Feminino , Cobaias , Humanos , Hipersensibilidade Imediata/diagnóstico , Hipersensibilidade Imediata/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Camundongos , Coelhos , Ratos , Fatores de Risco , Testes Cutâneos , Inquéritos e QuestionáriosRESUMO
Bacillus anthracis is a gram-positive bacterial organism responsible for anthrax. This organism has two pathogenic plasmids: pX01 and pX02. The genetic function of pX01, which comprises about 198 kb, is not known, except for a region called the pathogenic island, which contains three genes-pag, lef, and cya-that code for three toxic proteins. A 2-D difference gel electrophoresis (2-D DIGE) system was used to verify the existence of proteins controlled by the pX01 plasmid, and protein regulation data were obtained using DeCyder software. A total of 1728 proteins were identified in the wild-type strain of this organism and 1684 in the pX01 plasmid. Twenty-seven of these proteins disappeared and eight appeared when the pX01 plasmid was removed. An additional 52 proteins were downregulated and 15 were upregulated when this plasmid was removed. A total of 102 proteins have been identified using the MALDI-TOF method of analysis, including 49 whose functions are unknown. Among these, 31 participate in metabolic processes, two in cellular processes, 15 in the processing of genetic information, and five in the processing of extracellular information. Another seven proteins participate in bacterial virulence and pathogenesis. We investigated the functions of these proteins in other bacteria, particularly the B. anthracis derivative H9041. Bacterial growth differed between pX01+/pX02+ B. anthracis and its pX01-/pX02+ derivative as did the cytotoxicity of macrophages infected by pX01+/pX02+ B. anthracis and the pX01-pX02+ derivative. We also found that S100B protein levels increased in the host infected with pX01+/pX02+ B. anthracis or its pX01-/pX02+ derivative. These data suggest that the pX01 plasmid plays a key role in the regulation of protein functions in B. anthracis.