RESUMO
The genus Prototheca, a unicellular, non-photosynthetic, yeast-like microalgae, is a pathogen of concern for the dairy industry. It causes bovine mastitis that currently cannot be cured, and hence generates significant economic losses in milk production. In this study, for the first time in Ecuador, we identify Prototheca bovis as the etiologic agent of chronic mastitis in dairy cattle. Milk samples (n = 458) of cows with chronic mastitis were cultured on Sabouraud Dextrose Agar (SDA). Microscopy and cytB gene sequencing were used to identify Prototheca, whereby Prototheca bovis was isolated from 15.1% (n = 69) of the milk samples, one of the highest infection rates that can be found in the literature in a "non-outbreak" situation. No other Prototheca species were found. We were unable to isolate the alga from environmental samples. We showed that P. bovis was relatively resistant to disinfectants used to sterilize milking equipment on the cattle farms where it was isolated. We discuss how to avoid future infection and also hypothesize that the real prevalence of Prototheca infection in bovine mastitis is probably much higher than what was detected. We recommend a protocol to increase the diagnostic yield in the bacteriology laboratory.
RESUMO
BACKGROUND AND AIMS: We evaluated the immunogenicity of the 7-valent pneumococcal conjugate vaccine (PCV7), and its impact on pneumococcal carriage in Venezuelan children at high risk for invasive pneumococcal disease (IPD). METHODS: 82 children (age 2-59 months) with sickle cell anemia (n=22), chronic heart disease (n=19), HIV infection (n=12), immune-suppressive therapy (n=11) and other IPD-predisposing conditions (n=18) were vaccinated with PCV7 according to CDC-recommended age-related immunization schedules. Blood samples were taken to determine the concentration of IgG antibody, and nasopharyngeal swabs were obtained to isolate Streptococcus pneumoniae, before the first vaccine dose and 1 month after completion of the vaccination schedule. RESULTS: Pneumococcal carriage prior to the first immunization was 27% (n=22), with the most frequently carried serotypes being vaccine serotypes 6B (22%) and 14 (13%). One month after completion of the vaccination scheme pneumococcal carriage was 22% (n=17), dominated by non-vaccine serotypes 19A (24%) and 7F (12%). Before immunization, 65% of the subjects had IgG antibody titers >0.35 µg/mL for five serotypes tested. Post-vaccination, 100% of the subjects showed titers >1.0 µg/mL for all PCV7 serotypes with geometric mean concentrations (GMC) ranging from 1.75 µg/mL (serotype 23F) to 17.16 µg/mL (serotype 14). Children previously colonized with serotype 6B had a significantly lower GMC to this serotype following immunization than children not carrying 6B prior to the first PCV dose (p<0.05). CONCLUSIONS: PCV7 is highly immunogenic in Venezuelan children at high-risk for IPD. Vaccination was associated with an immediate shift in nasopharyngeal carriage toward non-PCV7 serotypes. Finally, we observed serotype-specific hyporesponsiveness to immunization after natural carriage with the same serotype in high-risk children.
Assuntos
Portador Sadio/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico , Anticorpos Antibacterianos/sangue , Pré-Escolar , Feminino , Vacina Pneumocócica Conjugada Heptavalente , Humanos , Imunoglobulina G/sangue , Lactente , Masculino , Nasofaringe/microbiologia , Fatores de Risco , Sorogrupo , Streptococcus pneumoniae/classificação , Vacinas Conjugadas/uso terapêutico , VenezuelaRESUMO
International agencies for tuberculosis (TB) control (WHO, IUATLD, KNCV) consider the presence of acid-fast bacilli (AFB) in the sputum smear after completion of TB therapy as treatment failure. We describe a case of a pulmonary TB patient who received and correctly completed 6 months of antituberculous treatment with a positive AFB sputum smear. Treatment was continued and sputum cultures were performed for resistance determination. After 9 months, despite the persistence of AFB in the sputum smear, the treatment was suspended because none of the sputum samples yielded a positive culture, indicating no viable bacilli. In addition, the patient was asymptomatic and had recovered his body weight. An exhaustive review of medical literature allowed us to conclude that a positive sputum smear after therapy has been detected in up to 5% of cases and does not always represent a treatment failure as defined by international guidelines. For scenarios where culture methods are not available we propose a scheme to evaluate these patients. This includes compliance with the treatment, severity of the disease at the moment of diagnosis, clinical symptoms after specific therapy and rate of in vitro resistance of M. tuberculosis in the community.
Assuntos
Antituberculosos/uso terapêutico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Radiografia , Falha de Tratamento , Tuberculose Pulmonar/diagnóstico por imagemRESUMO
The levels of complement C3 and C4 components were determined in non-indigenous (creoles) and indigenous (Warao) populations, the latter with an extremely high tuberculosis (TB) rate. Serum samples from 209 adults were studied and classified in 4 groups taking into account tuberculin skin tests (TST): (1) the group of Warao patients (58 positive for the TST, WP TST+ and 9 negative for the TST, WP TST-), (2) the group of creole patients (34 positive for the TST, CP TST+ and 9 negative for the TST, CP TST-), (3) the group of healthy Warao controls (38 positive and 14 negative for TST, WC TST+ and WC TST-, respectively), (4) the creole controls (26 positive and 21 negative for the TST, CC TST+ and CC TST-, respectively). With respect to the results concerning the measurement of both complement C3 and C4 components with the exception of the WC TST and the CC groups, the WP TST+ and WP TST- as well as WC TST+ groups showed a significant frequency of individuals with decreased levels of complement C3 component (20.6, 33.3, and 26.3 percent, respectively) and also C4 component (12.0, 11.1, and 13.3 percent, respectively) in comparison to both creole patients (CP TST+, 8.82 percent and CP TST-, 0 percent and CP TST+, 5.88 percent and CP TST-, 0 percent) for C3 and C4, respectively. The study of these parameters carried out in 15 Warao subjects with active infection, before and after anti-TB chemotherapy,statisticallyconfirmedthat the effective chemotherapy did not restore normal levels of the complement C3 and C4 components among Warao patients. Aditional tests for hepatitis B or hepatitis C infection, and the profile of the hepatic proteins were not associated to the deficiency in production of the complement components.In conclusion, the results show that within the Warao population, a high percentage of subjects exhibit decreased levels of both complement C3 and C4 components independent of latent or active infection and the status of TST.
Assuntos
Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , /análise , /análise , Indígenas Sul-Americanos , Tuberculose Pulmonar/imunologia , Antituberculosos/uso terapêutico , Biomarcadores/sangue , Estudos de Casos e Controles , Prevalência , Teste Tuberculínico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/etnologia , Venezuela/epidemiologiaRESUMO
It is difficult to establish a definitive diagnosis of tuberculosis in rural areas where there is no access to a large hospital. The Warao people of the Delta Amacuro State in Venezuela, have a very high prevalence of adult TB, and we suspected that the Warao children would also have a high prevalence of the disease, almost entirely undiagnosed. We applied a simple methodology to select children suspicious for tuberculosis that is based on a rating system using clinical criteria, reactivity to tuberculin and intradomicilliary contacts. Of the 502 children under the age of 15 that were evaluated with this rating system, 27 were determined to be suspicious of TB and were further evaluated by a chest X-ray. Radiologic confirmation of TB was found in 16 (60) of the 27 suspicious children. Of these 16 patients, 13 (81) were PPD positive and 3 were PPD negative. Additionally, 7 of the 16 children with pathologic x-ray changes had one or more confirmatory findings: 3 were positive by culture or smear examination and 5 had a positive serologic B diagnostic test. In conclusion this methodology proved to be highly efficient in diagnosing childhood tuberculosis in this population, and should also be useful in other rural populations with a high prevalence of adult TB.