RESUMO
OBJECTIVES: Disease progression, loss to follow-up, and mortality of HIV-2 compared with HIV-1 in children is not well understood. This is the first nationwide study reporting outcomes in children with the two HIV types in Guinea-Bissau. STUDY DESIGN: Nationwide retrospective follow-up study. METHODS: This is a retrospective follow-up study among HIV-infected children <15 years at nine ART centers from 2006 to 2021. Baseline parameters and disease outcomes for children with HIV-2 and HIV-1 were compared. RESULTS: The annual number of children diagnosed with HIV peaked in 2017. HIV-2 (n = 64) and HIV-1 (n = 1945) infected children were different concerning baseline median age (6.5 vs 3.1 years, P < 0.01), but had similar levels of severe immunodeficiency (P = 0.58) and severe anemia (P = 0.26). Within the first year of follow-up, 36.3% were lost, 5.9% died, 2.7% had transferred clinic, and 55.2% remained for follow-up. Mortality (HR = 1.05 95% CI: 0.53-2.08 for HIV-2) and attrition (HR = 0.86 95% CI: 0.62-1.19 for HIV-2) rates were similar for HIV types. CONCLUSIONS: The decline in children diagnosed per year since 2017 is possibly due to lower HIV prevalence, lack of HIV tests, and the SARS-CoV-2 epidemic. Children with HIV-2 were twice as old as HIV-1 infected when diagnosed, which suggests a slower disease progression. However, once they develop immunosuppression mortality is similar.
Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Criança , Humanos , Pré-Escolar , Seguimentos , Estudos Retrospectivos , Infecções por HIV/epidemiologia , HIV-2 , Guiné-Bissau/epidemiologia , Progressão da DoençaRESUMO
BACKGROUND: The relationship between increase in body temperature, heart rate, and respiratory rate has only been studied in young, healthy subjects. AIM: To show the changes in heart and respiratory rate associated with fever in acutely admitted medical patients. DESIGN: A prospective observational cohort study. METHODS: Vital parameters from 4,493 patients were retrospectively extracted. Linear and multiple variable regression analysis was used to calculate the change in heart and temperature rate for every degree rise in temperature (i.e. ΔHR/°C and ΔRR/°C) in the entire study group and in those with low (<36.1°C), normal (36.1-38°C) and high (>38°C) body temperatures. RESULTS: The ΔHR/°C and ΔRR/°C was 7.2±0.4 beats per minute (bpm) and 1.4 ±0.1 (1.2 to 1.62) breaths per minute (bpm). Adjusting for age, oxygen saturation and mean blood pressure, the results were 6.4±0.4 (5.7 to 7.1) bpm and 1.2±0.1 (1.0 to 1.4) bpm. In low, normal and high body temperature the ΔHR/°C were 2.7±1.9, 6.9±1.9 and 7.4±0.9 bpm, respectively; for ΔRR/°C the values were -0.5±0.5, 1.5±0.5 and 2.3±0.3 bpm, respectively. CONCLUSIONS: We only found a modest association between fever and changes in heart rate and respiratory rate.
Assuntos
Cuidados Críticos , Frequência Cardíaca , Taxa Respiratória , Estudos de Coortes , Humanos , Admissão do Paciente , Estudos Prospectivos , Estudos RetrospectivosRESUMO
AIM: Few real-life studies of non-severe (self-treated) hypoglycaemic events are available. This survey quantified the self-reported frequency of non-severe hypoglycaemia and its effects in adults with insulin-treated diabetes in the UK. METHODS: Adults aged > 15 years with Type 1 diabetes or insulin-treated Type 2 diabetes completed ≤ 4 weekly questionnaires (7-day recall). Respondents with Type 2 diabetes were grouped by insulin regimen: basal-only, basal-bolus and 'other'. RESULTS: Overall, 1038 respondents (466 with Type 1 diabetes, 572 with Type 2 diabetes) completed 3528 questionnaires. Mean numbers of non-severe events per week were 2.4 (Type 1 diabetes; median = 2) and 0.8 (Type 2 diabetes; median = 0); 23% and 26% of non-severe events occurred at night, respectively. Fatigue and reduced alertness were the commonest issues following events (78% and 51% of respondents, respectively). The effects of nocturnal events persisted longer than those of daytime events: Type 1 diabetes = 10.6 vs. 4.9 h (P = 0.0002); Type 2 diabetes = 15.3 vs. 5.1 h (P < 0.0001). In the week following an event, respondents' blood glucose measurements increased by 4.3 (Type 1 diabetes; 12% increment) and 4.2 (Type 2 diabetes; 21% increment) tests/week. In employed respondents, 20% of events caused work-time loss, more so following nocturnal (vs. daytime) hypoglycaemia: Type 1 diabetes = 2.7 vs. 1.1 h (P = 0.0184); Type 2 diabetes = 2.5 vs. 1.6 h (P = 0.1340). Most respondents rarely/never informed healthcare professionals about events (Type 1 diabetes = 82%, Type 2 diabetes = 69%). CONCLUSIONS: Non-severe hypoglycaemia is common in adults with insulin-treated diabetes in the UK, with consequent health-related/economic effects. Communication about non-severe hypoglycaemia is limited and the burden of hypoglycaemia may be underestimated.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Adulto , Idoso , Revelação , Feminino , Humanos , Hipoglicemia/epidemiologia , Masculino , Pessoa de Meia-Idade , Autorrelato , Inquéritos e Questionários , Reino UnidoRESUMO
Salmonella continues to be a major public health burden worldwide. Poultry are known to be one of the main reservoirs for this zoonotic pathogen. It has previously been shown that a single dose of Bacillus subtilis reduces fecal shedding of Salmonella enterica serovar Enteritidis, whereas no effect on long-term colonization of the cecum has been observed. Here we report experiments that were undertaken to test the efficacy of a conventional diet supplemented with a probiotic (B. subtilis DSM17299) on 1) Salmonella colonization in the intestinal tract of broiler chickens, and 2) fecal shedding of Salmonella under production-like conditions. The trial birds fed the B. subtilis diet showed a significant 58% reduction in Salmonella-positive drag swabs compared with control birds, which had 100% presence of Salmonella. Feeding B. subtilis significantly reduced the average Salmonella load of cecum samples of the chickens, by 3 log units. This reduction in Salmonella colonization might not only positively affect broilers on the live production side by reducing the risk of infection between birds, but could also aid on the processing side by decreasing the amount of Salmonella entering the facility and improving food safety. Furthermore, numerical, but not statistically significant, improvements in feed conversion rate and BW gain at d 42 were observed in the B. subtilis-treated group compared with control birds.
Assuntos
Bacillus subtilis/classificação , Bacillus subtilis/fisiologia , Galinhas , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella/fisiologia , Ração Animal , Animais , Ceco/microbiologia , Dieta/veterinária , Fezes/microbiologia , Microbiologia de Alimentos , Conteúdo Gastrointestinal/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Probióticos/farmacologia , Salmonelose Animal/prevenção & controleRESUMO
A series of O-acylated-ω-hydroxy fatty acids (Acyl acids) of up to 34 carbons were synthesized and characterized through DSC, FTIR and Langmuir isotherm measurements to identify potential replacements to petrolatum, a highly used occlusive technology that if unrefined, it can potentially be classified as carcinogenic. Fourier transform infrared spectroscopy studies demonstrated that long acyl acids engender orthorhombic packing; packing behavior that is predominant in the lipid matrix of healthy stratum corneum, the outmost layer of the skin. In addition, Differential Scanning Calorimetry (DSC) and Langmuir isotherm studies suggested that the length of the hydrocarbon chain and the position of the ester bond influence the molecular organization of the acyl acids. For instance, 16-(tetradecanoyloxy)hexadecanoic acid (30 carbons) displayed a higher melting point (mp=68°C) than 10-(stearoyloxy)decanoic acid (28 carbons; mp=63°C) and 10-(tetradecanoyloxy)decanoic acid (24 carbons; mp=55°C) according to DSC. Moreover, Langmuir isotherm studies showed that mixtures of acyl acid with distearoylphosphatidylcholine improved packing behavior. Finally, Water Vapor Transmission Rate (WVTR) measurements showed that the compounds in fact decrease WVTR compared to untreated control (P<0.001) which demonstrates the potential of these ingredients as occlusive technologies to combat skin barrier diseases.
Assuntos
Ácidos Graxos/química , Substâncias Protetoras/química , Acilação , Varredura Diferencial de Calorimetria , Ácidos Graxos/síntese química , Humanos , Modelos Moleculares , Substâncias Protetoras/síntese química , Pele/química , Pele/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Vapor/análiseRESUMO
The effects of dietary n - 3 polyunsaturated fatty acids (PUFAs) on major brain phospholipids were examined in the rat throughout four generations. Dietary fats were: a seal oil (22:6(n - 3) located mainly in the sn-1/3-position of the TG); a fish oil (22:6(n - 3) located mainly in the sn-2 position of the TG); or a vegetable oil containing 18:3(n - 3). The effect of the TG structure of the dietary fat and chain length of n - 3 PUFA on assimilation in the brain was compared with chow fed rats. The rats fed marine fats had significantly higher levels of long-chain n - 3 PUFAs in brain PE and PS, compared to the vegetable oil and chow fed rats, but no effects of TG structure of dietary fat were observed. Dietary 18:3(n - 3) raised the amount of 22:6(n - 3) compared to the control group, but not to the levels of the marine groups that received preformed 22:6(n - 3). Fish oil fed rats had higher levels of 20:5(n - 3) and 22:5(n - 3) compared with the seal oil fed rats, whereas 22:6(n - 3) were similar. Only minor changes in PI, PIP, and PIP2 were found. The fourth generation was tested for spatial learning ability in a Morris water maze. The experimental groups had similar learning abilities, which were increased compared to the control group.
Assuntos
Química Encefálica , Gorduras na Dieta/administração & dosagem , Ácidos Graxos Ômega-3/análise , Ácidos Graxos Insaturados/análise , Aprendizagem em Labirinto , Fosfolipídeos/análise , Animais , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Insaturados/administração & dosagem , Feminino , Óleos de Peixe/administração & dosagem , Fosfatidiletanolaminas/análise , Fosfatidilinositóis/análise , Fosfatidilserinas/análise , Fosfolipídeos/química , Óleos de Plantas/administração & dosagem , Ratos , Ratos WistarRESUMO
We investigated the influence of dietary fatty acid profile and triacylglycerol structure on the fatty acid profile and triacylglycerol structure of milk lipids in two generations of rats. Three groups of rats received diets containing 20% fat of which approximately 20% was n-3 fatty acids located in different positions of the triacylglycerol: a fish oil-based diet [docosahexaenoic acid (22:6n-3) predominantly in the sn-2 position], a seal oil-based diet (22:6n-3) predominantly in the sn-1/sn-3 position, or a plant oil-based diet [alpha-linolenic acid (18:3n-3) distributed evenly between the three positions]. This design allowed us to investigate (i) the effect of the triacylglycerol structure of the dietary fat; (ii) the effect of receiving the n-3 fatty acids as long-chain derivatives or as the precursor, 18:3n-3; and (ii) the long-term effects over two generations. The fatty acid profiles of the milk lipids largely reflected the diets, but in the second generation, the level of medium-chain fatty acids was higher (P < 0.05) in the milk from rats fed the fish oil diet (24%) compared with the other dietary groups (15 and 18%). This suggests an increased endogenous synthesis of fatty acids in the mammary glands of the fish oil-fed rats. The levels of long-chain n-3 fatty acids in milk were higher (P < 0.05) in rats fed marine oils (8-12%) compared with rats fed vegetable oil (1%) in both generations. The level of long-chain n-3 fatty acids was significantly higher in the milk from the fish oil-fed rats (12.3%) compared to the seal- oil fed rats (8.0%) in the first generation, but not in the second generation (8.9 vs. 9.1%). The general structure of milk triacylglycerols was maintained in the three experimental groups with 16:0 acylated in the sn-2 position and 18:1 in the sn-1/sn-3 positions. The triacylglycerol structure of mammalian milk appears to be conserved even during extreme dietary manipulation over two generations and an extensive enrichment with long-chain n-3 polyunsaturated fatty acids requires their presence in the diet.
Assuntos
Gorduras na Dieta/administração & dosagem , Ácidos Graxos/administração & dosagem , Leite/química , Triglicerídeos/química , Animais , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/química , Ácidos Graxos Ômega-6 , Ácidos Graxos Insaturados/administração & dosagem , Ácidos Graxos Insaturados/química , Feminino , Óleos de Peixe/administração & dosagem , Óleos de Peixe/química , Óleos de Plantas/administração & dosagem , Óleos de Plantas/química , Ratos , Ratos Wistar , Focas Verdadeiras , Triglicerídeos/administração & dosagemRESUMO
Temperature-sensitive mutants of Alcaligenes faecalis that exhibited reduced growth at 42 C but grew well at 30 C were induced by N-methyl-N'-nitro-N-nitrosoguanidine. Four of the 5 mutants that were studied readily colonized the nasal mucosa of turkeys when given intranasally or in drinking water. Several mutants caused no signs of coryza or depression and produced minimal colonization of the trachea. Colonization of the nasal mucosa lasted 3 to 4 weeks and induced moderate levels of serum antibodies. When challenged with virulent isolates of A. faecalis 4 to 6 weeks after having been exposed to the mutants, unstressed turkeys were protected; turkeys subjected to water deprivation exhibited some colonization with the virulent strain and showed slight signs of coryza.
Assuntos
Alcaligenes/imunologia , Infecções Bacterianas/veterinária , Imunização/veterinária , Doenças das Aves Domésticas/prevenção & controle , Infecções Respiratórias/veterinária , Perus/microbiologia , Alcaligenes/efeitos dos fármacos , Alcaligenes/isolamento & purificação , Animais , Anticorpos Antibacterianos/análise , Infecções Bacterianas/prevenção & controle , Metilnitronitrosoguanidina/farmacologia , Mutação , Mucosa Nasal/microbiologia , Infecções Respiratórias/prevenção & controle , Traqueia/microbiologiaRESUMO
In field trials, 14 flocks of turkeys were vaccinated against coryza (rhinotracheitis) with a temperature-sensitive mutant of Alcaligenes faecalis via drinking water. Vaccine doses of 5 to 250 million bacteria per turkey were used. Turkeys ranged in age from 2.5 to 13 weeks. Doses of 5 to 7 million bacteria did not induce complete protection. Doses of 50 million bacteria or more appeared to induce substantial immunity in most flocks. Six-week-old birds receiving doses of 90 million bacteria developed a high degree of protection against challenge with virulent A. faecalis.
Assuntos
Alcaligenes/imunologia , Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/veterinária , Doenças das Aves Domésticas/prevenção & controle , Perus , Vacinação/veterinária , Administração Oral , Animais , Anticorpos Antibacterianos/análise , Vacinas Bacterianas/administração & dosagem , Mutação , TemperaturaRESUMO
During the 1980 growing season in the Sanpete Valley of Utah, about half of the 250 to 300 flocks of turkeys were vaccinated with an oral vaccine against alcaligenes rhinotracheitis (ART). The vaccine consisted of a temperature-sensitive mutant of Alcaligenes faecalis. Most vaccinated birds developed serum antibodies. No outbreaks of ART occurred in vaccinated flocks, although some outbreaks occurred in unvaccinated flocks. During 1979, when on flocks were vaccinated, over 90% of the flocks experienced outbreaks of ART during late summer.
Assuntos
Alcaligenes/imunologia , Infecções Bacterianas/veterinária , Vacinas Bacterianas , Surtos de Doenças/veterinária , Doenças das Aves Domésticas/prevenção & controle , Rinite/veterinária , Traqueíte/veterinária , Perus , Animais , Infecções Bacterianas/prevenção & controle , Surtos de Doenças/prevenção & controle , Rinite/prevenção & controle , Traqueíte/prevenção & controle , UtahRESUMO
Previous studies indicated that Staphylococcus epidermidis strain 115 might be an effective interfering agent in reducing the rate of staphylococcosis in turkeys. In the present study, strain 115 was avirulent when administered to 3-day-old chicks by oral, aerosol, or intravenous route. Strain 115 adhered specifically to tracheal, lung, air-sac, and liver cells in vitro and interfered with subsequent colonization by virulent Staphylococcus aureus. In vivo colonization of lungs and livers of young chicks occurred following exposure to aerosols of strain 115. Strain 115 interfered with the in vivo colonization of lungs and livers by virulent S. aureus.
Assuntos
Antibiose , Galinhas/microbiologia , Doenças das Aves Domésticas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus epidermidis/fisiologia , Animais , Aderência Bacteriana , Masculino , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/patogenicidade , VirulênciaRESUMO
Ninety-eight Staphylococcus aureus isolates and 227 coagulase-negative staphylococcal isolates from turkeys were assayed for protein A content. The amount of protein A of each isolate was quantitated using a direct enzyme-linked immunosorbent assay. Of the S. aureus isolates, 83% possessed some protein A, whereas only 13% of the coagulase-negative staphylococci contained some protein A. No correlation was seen between protein A content and ability to adhere to turkey cells. No differences in virulence were seen between isolates of S. aureus possessing high or low levels of protein A; however, an isolate with no protein A was avirulent.
Assuntos
Doenças das Aves Domésticas/microbiologia , Infecções Estafilocócicas/veterinária , Proteína Estafilocócica A/análise , Staphylococcus aureus/análise , Perus/microbiologia , Animais , Aderência Bacteriana , Ensaio de Imunoadsorção Enzimática , Testes de Hemaglutinação/veterinária , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , VirulênciaRESUMO
Staphylococcus epidermidis strain 115 was used as an interfering agent to reduce the incidence of staphylococcosis in turkeys. In 1984, the entire Utah turkey population of about 3 million turkeys was exposed at 1 to 10 days and at 4 to 6 weeks of age to aerosols of strain 115. Some staphylococcosis was still observed in range turkeys but appeared to be at a lower rate than in previous years. At processing, about 30% of the turkeys were still colonized with strain 115. A control study was carried out in 1985 to quantitate the level of reduction of staphylococcosis in turkeys treated with strain 115. About 1 million turkeys were treated, and 2 million remained untreated. Flocks from both groups were examined periodically for existing cases of staphylococcosis. Of 174,250 treated turkeys examined, 90 had staphylococcosis on the days examined, whereas 255 of the 183,500 untreated turkeys that were examined had staphylococcosis. Turkeys housed in range sheds had five times the incidence of staphylococcosis that turkeys in enclosed coops had. The gross mortality rate of 200,636 treated turkeys was 2.7% lower (P less than 0.001) than that of 189,450 untreated control turkeys that were monitored.
Assuntos
Antibiose , Doenças das Aves Domésticas/prevenção & controle , Infecções Estafilocócicas/veterinária , Staphylococcus epidermidis/fisiologia , Perus/microbiologia , Aerossóis , Animais , Infecções Estafilocócicas/prevenção & controleRESUMO
A Staphylococcus epidermidis isolate designated strain 115, which is used as an interfering agent against staphylococcosis of turkeys, produces a bacteriocin that was partially purified and characterized in this study. This bacteriocin diffused through agar media, but it was not found in appreciable quantities in the supernatant fluid of broth cultures. Extraction of the bacterial cells with 7 M urea, 1% sodium dodecyl sulfate, or 1% Triton X-100 caused considerable amounts of the bacteriocin to go into solution. This substance was partially purified by selective chemical extraction and by gel filtration chromatography using a Sephacryl S-300 column. This bacteriocin had two active forms: an aggregate, and a small-molecular-weight form estimated by gel filtration chromatography to be less than 6500. Activity was not affected by heat, repeated freeze-thaw cycles, pH 2 and pH 10, or a variety of proteolytic enzymes, nucleases, a lipase, and lysozyme.
Assuntos
Bacteriocinas/biossíntese , Doenças das Aves Domésticas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus epidermidis/metabolismo , Perus/microbiologia , Animais , Antibiose , Bacteriocinas/isolamento & purificação , Eletroforese Descontínua , Infecções Estafilocócicas/microbiologiaRESUMO
Two Staphylococcus epidermidis isolates from turkeys were used as interfering agents to help control staphylococcosis. Both isolates adhered to tissues of the turkeys' respiratory tract, interfered with attachment of virulent S. aureus, produced bacteriocins bacteriocidal to S. aureus, and were avirulent for turkeys. About 200,000 turkeys in commercial flocks were exposed to aerosols of these interfering isolates between 1 and 6 weeks of age, and many became colonized with these bacteria. The aerosol-treated turkeys had lower levels of colonization with S. aureus and had a 3% higher gross survival rate than untreated control turkeys.
Assuntos
Antibiose , Doenças das Aves Domésticas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus epidermidis/fisiologia , Perus/microbiologia , Animais , Aderência Bacteriana , Bacteriocinas/biossíntese , Doenças das Aves Domésticas/prevenção & controle , Infecções Estafilocócicas/prevenção & controle , Staphylococcus epidermidis/isolamento & purificaçãoRESUMO
Escherichia coli strain 38, an isolate from turkeys, has been previously shown to produce one or more broad-spectrum bacteriocins against other related enteric bacteria. Using a collection of E. coli strains that synthesized well-characterized colicins or microcins, along with a set of colicin/microcin-insensitive mutants, we were able to classify the bacteriocins produced by strain 38. We determined that strain 38 produced a microcin (microcin C38) and a colicin (colicin V38) and that the amount of microcin C38 depended on the type of media on which it was grown. Escherichia coli strain 38 was found to have cross-immunity with the microcin C7-producing strain MC4100 and with the colicin V-producing strain 4674. OmpF mutant cells were found to be insensitive to microcin C38, whereas colicin V38 was not active on cells that had a cir mutation. Both microcin C38 and colicin V38 were inactivated by proteases. Microcin C38 was stable at extremes of pH (pH 1.5 and pH 13) and heat (10 min at 98 C) conditions, whereas colicin V38 was not. In addition, microcin C38 was found to be active against a broader spectrum of gram-negative bacteria than was colicin V38.
Assuntos
Bacteriocinas/biossíntese , Colicinas/biossíntese , Escherichia coli/fisiologia , Animais , Proteínas da Membrana Bacteriana Externa/biossíntese , Proteínas da Membrana Bacteriana Externa/genética , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Colicinas/isolamento & purificação , Colicinas/farmacologia , Meios de Cultura , Enterobacteriaceae/imunologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/imunologia , Testes de Sensibilidade Microbiana , Especificidade da Espécie , Perus/microbiologiaRESUMO
Acute respiratory signs and increased mortality due to suffocation occurred in a flock of 5-week-old male turkey poults following water administration of gentian violet. Gross lesions of laryngeal edema and occlusion of the tracheal opening with caseous plugs were present. Microscopic lesions in the tracheas consisted of vascular congestion, mucosal degeneration, and necrosis. The condition was reproduced experimentally in turkey poults by giving drinking water containing gentian violet.
Assuntos
Violeta Genciana/efeitos adversos , Edema Laríngeo/veterinária , Doenças das Aves Domésticas/induzido quimicamente , Traqueíte/veterinária , Perus , Animais , Edema Laríngeo/induzido quimicamente , Edema Laríngeo/patologia , Masculino , Microscopia Eletrônica/veterinária , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/patologia , Traqueíte/induzido quimicamente , Traqueíte/patologia , Abastecimento de ÁguaRESUMO
AN enzyme-linked immunosorbent assay (ELISA) and a microtiter agglutination (MA) test were used in a comparative study to measure the humoral antibody responses of turkeys receiving oral vaccination against fowl cholera. The ELISA was sensitive and measured antibody titers as high as 1:4,409, whereas the highest titers the MA test measured were 1:128. A close correlation was seen between ELISA antibody titers and protection against oral challenge with virulent Pasteurella multocida, whereas a poor correlation was seen between antibody titers measured by MA tests and protection. ELISA substrate reactions from a single serum dilution, measured with a spectrophotometer, could be converted directly from absorbance to antibody titers using a linear regression plot.
Assuntos
Anticorpos Antibacterianos/biossíntese , Vacinas Bacterianas/imunologia , Ensaio de Imunoadsorção Enzimática , Técnicas Imunoenzimáticas , Pasteurella/imunologia , Perus/imunologia , Testes de Aglutinação/veterinária , Animais , Infecções por Pasteurella/prevenção & controle , Infecções por Pasteurella/veterinária , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterináriaRESUMO
Staphylococcus epidermidis strain 115, used as an interfering agent to help reduce the incidence of staphylococcosis in turkeys, was converted into a penicillin- and chloramphenicol-resistant strain designated 115R. This was accomplished by introducing a plasmid carrying the beta-lactamase (penicillinase) and chloramphenicol-resistance genes into S. epidermidis 115 by electroporation. The resultant strain, 115R, was an efficient producer of beta-lactamase and had marked increased resistance to penicillin and chloramphenicol. A beta-lactamase DNA probe was used to confirm the presence of the beta-lactamase gene in strain 115R. S. epidermidis strain 115R retained the characteristics of tissue adherence, bacteriocin production, and non-virulence that were present in the original non-transformed strain 115, and in addition should theoretically remain colonized in poults following treatment with penicillin.