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1.
PLoS Pathog ; 16(12): e1009192, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33370414

RESUMO

Asymptomatic carriage of Salmonella Typhi continues to facilitate the transmission of typhoid fever, resulting in 14 million new infections and 136,000 fatalities each year. Asymptomatic chronic carriage of S. Typhi is facilitated by the formation of biofilms on gallstones that protect the bacteria from environmental insults and immune system clearance. Here, we identified two unique small molecules capable of both inhibiting Salmonella biofilm growth and disrupting pre-formed biofilm structures without affecting bacterial viability. In a mouse model of chronic gallbladder Salmonella carriage, treatment with either compound reduced bacterial burden in the gallbladder by 1-2 logs resulting in bacterial dissemination to peripheral organs that was associated with increased mortality. Co-administration of either compound with ciprofloxacin not only enhanced compound efficacy in the gallbladder by a further 1-1.5 logs for a total of 3-4.5 log reduction, but also prevented bacterial dissemination to peripheral organs. These data suggest a dual-therapy approach targeting both biofilm and planktonic populations can be further developed as a safe and efficient treatment of biofilm-mediated chronic S. Typhi infections.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Portador Sadio/microbiologia , Vesícula Biliar/microbiologia , Salmonelose Animal , Salmonella typhi/efeitos dos fármacos , Animais , Infecções Assintomáticas , Camundongos , Febre Tifoide
2.
Am J Trop Med Hyg ; 103(3): 1032-1038, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32720632

RESUMO

Transcutaneous vaccination can induce both mucosal and systemic immune responses. However, there are few data on anti-polysaccharide responses following transcutaneous vaccination of polysaccharides, despite the role that anti-polysaccharide responses play in protecting against intestinal mucosal and respiratory pathogens. Whether transcutaneous vaccination with a conjugate polysaccharide vaccine would be able to induce memory responses is also unknown. To address this, we transcutaneously vaccinated mice with virulence antigen (Vi) polysaccharide of Salmonella enterica serovar Typhi (the cause of typhoid fever), either in unconjugated or conjugated form (the latter as a Vi-DT conjugate). We also assessed the ability of the immunoadjuvant cholera toxin to impact responses following vaccination. We found that presenting Vi in a conjugate versus nonconjugate form transcutaneously resulted in comparable serum IgG responses but higher serum and lamina propria lymphocyte IgA anti-Vi responses, as well as increased IgG memory responses. The addition of immunoadjuvant did not further increase these responses; however, it boosted fecal IgA and serum IgG anti-Vi responses. Our results suggest that transcutaneous vaccination of a conjugate vaccine can induce systemic as well as enhanced mucosal and memory B-cell anti-polysaccharide responses.


Assuntos
Anticorpos Antibacterianos/sangue , Imunidade Humoral/efeitos dos fármacos , Imunidade nas Mucosas/efeitos dos fármacos , Salmonella typhi/imunologia , Febre Tifoide/prevenção & controle , Vacinas Tíficas-Paratíficas/administração & dosagem , Vacinação/métodos , Administração Cutânea , Animais , Modelos Animais de Doenças , Feminino , Humanos , Esquemas de Imunização , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Memória Imunológica/efeitos dos fármacos , Camundongos , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/patogenicidade , Febre Tifoide/imunologia , Febre Tifoide/microbiologia , Vacinas Tíficas-Paratíficas/biossíntese , Vacinas Conjugadas
3.
An Real Acad Farm ; 86(2): 113-116, abr.-jun. 2020. tab
Artigo em Espanhol | IBECS | ID: ibc-193546

RESUMO

La resistencia a los antibióticos aumenta la búsqueda de nuevas estrategias para combatir las enfermedades que causan, y el uso de plantas medicinales representa una estrategia altamente efectiva y valiosa, como el uso de Tagetes lucida con diferentes bacterias gram positivas y gram negativas. OBJETIVO: Evaluar la actividad biológica que tiene el extracto hexanico de la planta Tagetes lucida a diferentes concentraciones sobre la inhibición del crecimiento en placa y tubo de dos enterobacterias, Shigella flexneri y Salmonella typhi MÉTODOS: En el siguiente trabajo, se evaluó un extracto de hexano de Tagetes lucida sobre la inhibición del crecimiento de dos enterobacterias, Shigella flexneri y Salmonella typhi utilizando diferentes concentraciones de vehículo para evaluar si afectaba el crecimiento bacteriano y también diferentes concentraciones de extracto para evaluar la actividad. RESULTADOS: Realizados los estudios por triplicado se logró concretar que a partir de 75mil/mig de extracto se logra una inhibición casi total del crecimiento de ambas bacterias, tanto en método de placa, como en método de tubo. Y a partir de 100 mil/mig se logra una inhibición total. CONCLUSIONES: Los resultados favorables obtenidos con 75 mil/mig, permiten confirmar que los extractos de plantas medicinales son una estrategia importante para combatir infecciones bacterianas multi-resistentes. Por otro lado permite dar paso a un estudio para evaluar los metabolitos más activos del extracto, así como, el mecanismo de acción sobre la inhibición del crecimiento de las bacterias en estudio


Antibiotic resistance increases the search for new strategies to combat the diseases they cause, and the use of medicinal plants represents a highly effective and valuable strategy, such as the use of Tagetes lucida with different gram positive and gram negative bacteria. OBJECTIVE: To evaluate the biological activity of the hexane extract of the Tagetes lucida plant at different concentrations on the inhibition of growth in plaque and tube of two enterobacteriaceae, Shigella flexneri and Salmonella typhi METHODS: In the following work, a hexane extract from Tagetes lucida was evaluated on the growth inhibition of two enterobacteriaceae, Shigella flexneri and Salmonella typhi using different concentrations of vehicle to evaluate if it affected bacterial growth and also different concentrations of extract to evaluate activity. RESULTS: Once the studies were carried out in triplicate, it was possible to specify that from 75mil/mig of extract, almost total inhibition of the growth of both bacteria was achieved, both in the plate method and in the tube method. And from 100 mil/mig total inhibition is achieved. CONCLUSIONS: The favorable results obtained with 75 mil/ mig, confirm that medicinal plant extracts are an important strategy to combat multi-drug resistant bacterial infections. On the other hand, it allows a study to be carried out to evaluate the most active metabolites of the extract, as well as the mechanism of action on the inhibition of the growth of the bacteria under study


Assuntos
Humanos , Tagetes/química , Extratos Vegetais/farmacologia , Shigella flexneri/efeitos dos fármacos , Salmonella typhi/efeitos dos fármacos , Testes de Sensibilidade Microbiana
4.
World J Microbiol Biotechnol ; 36(5): 72, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32363424

RESUMO

The bacteriocinogenic lactic acid bacterium Pediococcus pentosaceus LJR1 isolated from rumen liquor of goat had strong anti-bacterial activity toward Listeria monocytogenes in vitro. This antibacterial activity was lost on treatment with protease indicating that the bacteriocin is proteinaceous in nature. The bacteriocin LJR1 produced by P. pentosaceus was purified following a three step procedure consisting of ammonium sulphate precipitation, gel filtration chromatography and reverse phase-high performance liquid chromatography. The molecular weight of purified bacteriocin was determined to be 4.6 kDa using Tricine SDS-PAGE. Further, we found that the proteinaceous bacteriocin was stable at 100 °C as well as 121 °C for 30 min and 15 min respectively and also at different pH ranging from 4 to 10 when stored for 15 min at 37 °C. Its minimum inhibitory concentration for S. typhi MTCC134 and L. monocytogenes MTCC 1143 was 7.81 µg/ml and 15.63 µg/ml respectively. Scanning electron microscopy analysis of the surface of S. typhi treated with the bacteriocin showed the presence of craters; while in the case of treated L. monocytogenes blebs were observed. The addition of the bacteriocin to shrimp (white leg shrimp) has led to reduction of about 1 log units of L. monocytogenes on day 1 and maintained for 7 days on storage at 4 °C. It is clear that the purified bacteriocin has good potential as a bio preservative for application in food industry.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Conservação de Alimentos/métodos , Pediococcus pentosaceus/metabolismo , Penaeidae/microbiologia , Animais , Antibacterianos/química , Bacteriocinas/química , Bacteriocinas/genética , Microbiologia de Alimentos , Listeria monocytogenes/citologia , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Peso Molecular , Pediocinas/genética , Pediococcus pentosaceus/genética , Salmonella typhi/citologia , Salmonella typhi/efeitos dos fármacos , Alimentos Marinhos/microbiologia
5.
MMWR Morb Mortal Wkly Rep ; 69(20): 618-622, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32437343

RESUMO

Ceftriaxone-resistant Salmonella enterica serotype Typhi (Typhi), the bacterium that causes typhoid fever, is a growing public health threat. Extensively drug-resistant (XDR) Typhi is resistant to ceftriaxone and other antibiotics used for treatment, including ampicillin, chloramphenicol, ciprofloxacin, and trimethoprim-sulfamethoxazole (1). In March 2018, CDC began enhanced surveillance for ceftriaxone-resistant Typhi in response to an ongoing outbreak of XDR typhoid fever in Pakistan. CDC had previously reported the first five cases of XDR Typhi in the United States among patients who had spent time in Pakistan (2). These illnesses represented the first cases of ceftriaxone-resistant Typhi documented in the United States (3). This report provides an update on U.S. cases of XDR typhoid fever linked to Pakistan and describes a new, unrelated cluster of ceftriaxone-resistant Typhi infections linked to Iraq. Travelers to areas with endemic Typhi should receive typhoid vaccination before traveling and adhere to safe food and water precautions (4). Treatment of patients with typhoid fever should be guided by antimicrobial susceptibility testing whenever possible (5), and clinicians should consider travel history when selecting empiric therapy.


Assuntos
Ceftriaxona/farmacologia , Surtos de Doenças , Resistência Microbiana a Medicamentos , Salmonella typhi/efeitos dos fármacos , Doença Relacionada a Viagens , Febre Tifoide/epidemiologia , Febre Tifoide/microbiologia , Adolescente , Adulto , Idoso , Ceftriaxona/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Iraque/epidemiologia , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Febre Tifoide/tratamento farmacológico , Estados Unidos/epidemiologia , Adulto Jovem
6.
Am J Trop Med Hyg ; 102(6): 1296-1305, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32228795

RESUMO

Typhoid fever remains an important public health problem in low- and middle-income countries, with large outbreaks reported from Africa and Asia. Although the WHO recommends typhoid vaccination for control of confirmed outbreaks, there are limited data on the epidemiologic characteristics of outbreaks to inform vaccine use in outbreak settings. We conducted a literature review for typhoid outbreaks published since 1990. We found 47 publications describing 45,215 cases in outbreaks occurring in 25 countries from 1989 through 2018. Outbreak characteristics varied considerably by WHO region, with median outbreak size ranging from 12 to 1,101 cases, median duration from 23 to 140 days, and median case fatality ratio from 0% to 1%. The largest number of outbreaks occurred in WHO Southeast Asia, 13 (28%), and African regions, 12 (26%). Among 43 outbreaks reporting a mode of disease transmission, 24 (56%) were waterborne, 17 (40%) were foodborne, and two (5%) were by direct contact transmission. Among the 34 outbreaks with antimicrobial resistance data, 11 (32%) reported Typhi non-susceptible to ciprofloxacin, 16 (47%) reported multidrug-resistant (MDR) strains, and one reported extensively drug-resistant strains. Our review showed a longer median duration of outbreaks caused by MDR strains (148 days versus 34 days for susceptible strains), although this difference was not statistically significant. Control strategies focused on water, sanitation, and food safety, with vaccine use described in only six (13%) outbreaks. As typhoid conjugate vaccines become more widely used, their potential role and impact in outbreak control warrant further evaluation.


Assuntos
Febre Tifoide/prevenção & controle , Vacinas Tíficas-Paratíficas/imunologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Saúde Global , Humanos , Salmonella typhi/efeitos dos fármacos , Febre Tifoide/microbiologia , Vacinas Tíficas-Paratíficas/administração & dosagem
7.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(3): 323-326, 2020 Mar 06.
Artigo em Chinês | MEDLINE | ID: mdl-32187940

RESUMO

To conduct outbreak identification and transmission factor analysis of typhoid epidemic occurred in Xinqiao town, Jiangyin city from June to September 2016. A total of 14 strains of Salmonella typhi isolated from confirmed cases were collected, and 65 external environment samples and 13 food samples related to the outbreak were taken. Real-time PCR was used to detect specific gene of Salmonella typhi in the samples. Conventional method was used to isolate strains. The strains isolated from both the samples and patients in the epidemic were subjected to antimicrobial susceptibility testing and PFGE molecular characteristics. Salmonella typhi strain was isolated from one external sample (well water of a deli processing plant). The results of drug susceptibility showed that 15 strains were resistant to nalidixic acid. A total of 15 strains of Salmonella typhi were divided into 2 molecular patterns by pulsed field gel electrophoresis. The fingerprints of PFGE from the 13 patients and the environmental isolate were completely consistent, and there was one band difference from the other patient isolate. Combined with the epidemiological investigation and laboratory test results, it was determined that the outbreak was caused by genetic clone of the same Salmonella typhi. Food processing plant should be one of the key links.


Assuntos
DNA Bacteriano/genética , Surtos de Doenças , Epidemias , Salmonella enterica/genética , Salmonella typhi/genética , Febre Tifoide/epidemiologia , Antibacterianos/uso terapêutico , China/epidemiologia , Resistência Microbiana a Medicamentos , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase em Tempo Real , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/isolamento & purificação , Salmonella typhi/classificação , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/isolamento & purificação , Febre Tifoide/diagnóstico , Febre Tifoide/tratamento farmacológico , Febre Tifoide/microbiologia
8.
PLoS Negl Trop Dis ; 14(3): e0008040, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32155148

RESUMO

Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever; a systemic disease affecting ~20 million people per year globally. There are little data regarding the contemporary epidemiology of typhoid in Latin America. Consequently, we aimed to describe some recent epidemiological aspects of typhoid in Colombia using cases reported to the National Public Health Surveillance System (Sivigila) between 2012 and 2015. Over the four-year reporting period there were 836 culture confirmed cases of typhoid in Colombia, with the majority (676/836; 80.1%) of reported cases originated from only seven departments. We further characterized 402 S. Typhi isolates with available corresponding data recovered from various departments of Colombia through antimicrobial susceptibility testing and molecular subtyping. The majority (235/402; 58.5%) of these typhoid cases occurred in males and were most commonly reported in those aged between 10 and 29 years (218/402; 54.2%); there were three (0.74%) reported fatalities. The overwhelming preponderance (339/402; 84.3%) of S. Typhi were susceptible to all tested antimicrobials. The most common antimicrobial to which the organisms exhibited non-susceptibility was ampicillin (30/402;7.5%), followed by nalidixic acid (23/402, 5.7%). Molecular subtyping identified substantial genetic diversity, which was well distributed across the country. Despite the diffuse pattern of S. Typhi genotypes, we identified various geographical hotspots of disease associated with local dominant genotypes. Notably, we found limited overlap of Colombian genotypes with organisms reported in other Latin American countries. Our work highlights a substantial burden of typhoid in Colombia, characterized by sustained transmission in some regions and limited epidemics in other departments. The disease is widely distributed across the country and associated with multiple antimicrobial susceptible genotypes that appear to be restricted to Colombia. This study provides a current perspective for typhoid in Latin America and highlights the importance of pathogen-specific surveillance to add insight into the limited epidemiology of typhoid in this region.


Assuntos
Salmonella typhi/isolamento & purificação , Febre Tifoide/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Colômbia/epidemiologia , Farmacorresistência Bacteriana , Monitoramento Epidemiológico , Feminino , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem Molecular , Estudos Retrospectivos , Salmonella typhi/classificação , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/genética , Distribuição por Sexo , Adulto Jovem
9.
Z Gastroenterol ; 58(2): 160-170, 2020 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-32050286

RESUMO

Typhoid fever and paratyphoid fever are systemic infectious diseases of global significance caused by Salmonella enterica subspecies enterica Serovar Typhi (short name: Salmonella Typhi) or Serovar Paratyphi (short name: Salmonella Paratyphi). The course of these fecal-orally transmitted diseases is mainly characterized by a high fever. Left untreated, the course of typhoid fever can be severe and lethal. The infection is almost always acquired outside of Europe (mainly in India) and is notifiable in Germany, Austria and Switzerland. Paratyphoid is an attenuated disease of typhoid fever caused by Salmonella Paratyphi. Available vaccines only protect against Salmonella Typhi. Antibiotic resistance reflects the situation in endemic countries and shows a worrying increase of multi-drug resistant isolates. Currently, third-generation cephalosporins such as ceftriaxone are recommended as first-line therapy; if sensitive to quinolones, fluoroquinolones such as ciprofloxacin may continue to be administered. Crucial preventive measures for travelers to endemic regions include consistent water and food hygiene as well as vaccination, whereby only protection rates of 50-70 % are achieved by currently available vaccines. In the light of increasing multi-drug resistance, a more effective conjugate vaccine against Salmonella Typhi with cross-reactivity against Salmonella Paratyphi is needed more than ever.


Assuntos
Antibacterianos/farmacologia , Febre Paratifoide/tratamento farmacológico , Febre Paratifoide/prevenção & controle , Salmonella paratyphi A/efeitos dos fármacos , Salmonella typhi/efeitos dos fármacos , Febre Tifoide/tratamento farmacológico , Febre Tifoide/prevenção & controle , Vacinas Conjugadas/administração & dosagem , Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Fluoroquinolonas/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Febre Paratifoide/diagnóstico , Febre Paratifoide/microbiologia , Quinolonas/uso terapêutico , Salmonella enterica , Salmonella paratyphi A/isolamento & purificação , Salmonella typhi/isolamento & purificação , Febre Tifoide/diagnóstico , Febre Tifoide/microbiologia
11.
PLoS Negl Trop Dis ; 14(2): e0008036, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32106221

RESUMO

BACKGROUND: Multi-drug resistant typhoid fever remains an enormous public health threat in low and middle-income countries. However, we still lack a detailed understanding of the epidemiology and genomics of S. Typhi in many regions. Here we have undertaken a detailed genomic analysis of typhoid in urban Dhaka, Bangladesh to unravel the population structure and antimicrobial resistance patterns in S. Typhi isolated between 2004-2016. PRINCIPAL FINDINGS: Whole genome sequencing of 202 S. Typhi isolates obtained from three study locations in urban Dhaka revealed a diverse range of S. Typhi genotypes and AMR profiles. The bacterial population within Dhaka were relatively homogenous with little stratification between different healthcare facilities or age groups. We also observed evidence of exchange of Bangladeshi genotypes with neighboring South Asian countries (India, Pakistan and Nepal) suggesting these are circulating throughout the region. This analysis revealed a decline in H58 (genotype 4.3.1) isolates from 2011 onwards, coinciding with a rise in a diverse range of non-H58 genotypes and a simultaneous rise in isolates with reduced susceptibility to fluoroquinolones, potentially reflecting a change in treatment practices. We identified a novel S. Typhi genotype, subclade 3.3.2 (previously defined only to clade level, 3.3), which formed two localized clusters (3.3.2.Bd1 and 3.3.2.Bd2) associated with different mutations in the Quinolone Resistance Determining Region (QRDR) of gene gyrA. SIGNIFICANCE: Our analysis of S. Typhi isolates from urban Dhaka, Bangladesh isolated over a twelve year period identified a diverse range of AMR profiles and genotypes. The observed increase in non-H58 genotypes associated with reduced fluoroquinolone susceptibility may reflect a change in treatment practice in this region and highlights the importance of continued molecular surveillance to monitor the ongoing evolution of AMR in Dhaka. We have defined new genotypes and lineages of Bangladeshi S. Typhi which will facilitate the identification of these emerging AMR clones in future surveillance efforts.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella typhi/efeitos dos fármacos , Bangladesh/epidemiologia , DNA Bacteriano/genética , Genoma Bacteriano , Genótipo , Humanos , Internacionalidade , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Infecções por Salmonella/transmissão , Salmonella typhi/genética , Salmonella typhi/isolamento & purificação , Fatores de Tempo , Viagem , População Urbana
12.
J Pak Med Assoc ; 70(1): 96-99, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31954032

RESUMO

OBJECTIVE: To determine the use of pefloxacin as a surrogate marker to detect fluoroquinolone (ciprofloxacin) susceptibility against Salmonella enterica serotypes Typhi and Paratyphi A. METHODS: The prospective, descriptive cross-sectional study was conducted at the Aga Khan University Hospital, Karachi, from September 2016 to March 2018, and comprised Salmonella Typhi and Paratyphi A isolates of blood cultures. Disk susceptibility tests and broth microdilution to test minimum inhibitory concentration were performed as per standard guidelines. Data was analysed using SPSS 21. RESULTS: Of the 138 isolates, 91(66%) were intermediate resistant to ciprofloxacin but were resistant to pefloxacin, 42(30%) were resistant to both ciprofloxacin and pefloxacin, and 5(4%) were susceptible to both ciprofloxacin and pefloxacin. Of the isolates that were intermediate resistant to ciprofloxacin, 85(93%) had minimum inhibitory concentration range0.12-0.5mg\L, while 6(7%) had MIC>1mg\L (p<0.0001). CONCLUSIONS: Pefloxacin disk diffusion test was found to be reliable in detecting fluoroquinolone resistance among enteric fever causing Salmonella.


Assuntos
Ciprofloxacino/farmacologia , Testes de Sensibilidade Microbiana , Pefloxacina/farmacologia , Salmonella paratyphi A/efeitos dos fármacos , Salmonella typhi/efeitos dos fármacos , Antibacterianos/farmacologia , Estudos Transversais , Humanos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Estudos Prospectivos , Infecções por Salmonella/microbiologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-31963643

RESUMO

Enteric fever is a foodborne infectious disease caused by Salmonella enterica serotypes Typhi and Paratyphi A, B and C. The high incidence in low income countries can increase the risk of disease in travelers coming from high income countries. Pre-travel health advice on hygiene and sanitation practices and vaccines can significantly reduce the risk of acquiring infections. Although the majority of the cases are self-limiting, life-threatening complications can occur. Delayed diagnosis and cases of infections caused by multi-drug resistant strains can complicate the clinical management and affect the prognosis. More international efforts are needed to reduce the burden of disease in low income countries, indirectly reducing the risk of travelers in endemic settings. Surveillance activities can help monitor the epidemiology of cases caused by drug-susceptible and resistant strains.


Assuntos
Farmacorresistência Bacteriana Múltipla , Salmonella paratyphi A/fisiologia , Salmonella typhi/fisiologia , Doença Relacionada a Viagens , Febre Tifoide , Antibacterianos/farmacologia , Humanos , Incidência , Prognóstico , Salmonella paratyphi A/efeitos dos fármacos , Salmonella typhi/efeitos dos fármacos , Febre Tifoide/complicações , Febre Tifoide/diagnóstico , Febre Tifoide/epidemiologia
14.
BMC Med ; 18(1): 1, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31898501

RESUMO

BACKGROUND: Antimicrobial resistance (AMR) is an increasing threat to global health. There are > 14 million cases of enteric fever every year and > 135,000 deaths. The disease is primarily controlled by antimicrobial treatment, but this is becoming increasingly difficult due to AMR. Our objectives were to assess the prevalence and geographic distribution of AMR in Salmonella enterica serovars Typhi and Paratyphi A infections globally, to evaluate the extent of the problem, and to facilitate the creation of geospatial maps of AMR prevalence to help targeted public health intervention. METHODS: We performed a systematic review of the literature by searching seven databases for studies published between 1990 and 2018. We recategorised isolates to allow the analysis of fluoroquinolone resistance trends over the study period. The prevalence of multidrug resistance (MDR) and fluoroquinolone non-susceptibility (FQNS) in individual studies was illustrated by forest plots, and a random effects meta-analysis was performed, stratified by Global Burden of Disease (GBD) region and 5-year time period. Heterogeneity was assessed using the I2 statistics. We present a descriptive analysis of ceftriaxone and azithromycin resistance. FINDINGS: We identified 4557 articles, of which 384, comprising 124,347 isolates (94,616 S. Typhi and 29,731 S. Paratyphi A) met the pre-specified inclusion criteria. The majority (276/384; 72%) of studies were from South Asia; 40 (10%) articles were identified from Sub-Saharan Africa. With the exception of MDR S. Typhi in South Asia, which declined between 1990 and 2018, and MDR S. Paratyphi A, which remained at low levels, resistance trends worsened for all antimicrobials in all regions. We identified several data gaps in Africa and the Middle East. Incomplete reporting of antimicrobial susceptibility testing (AST) and lack of quality assurance were identified. INTERPRETATION: Drug-resistant enteric fever is widespread in low- and middle-income countries, and the situation is worsening. It is essential that public health and clinical measures, which include improvements in water quality and sanitation, the deployment of S. Typhi vaccination, and an informed choice of treatment are implemented. However, there is no licenced vaccine for S. Paratyphi A. The standardised reporting of AST data and rollout of external quality control assessment are urgently needed to facilitate evidence-based policy and practice. TRIAL REGISTRATION: PROSPERO CRD42018029432.


Assuntos
Salmonella paratyphi A , Salmonella typhi , Febre Tifoide/epidemiologia , Antibacterianos/farmacologia , Azitromicina/farmacologia , Farmacorresistência Bacteriana , Saúde Global , Humanos , Febre Paratifoide/epidemiologia , Prevalência , Salmonella paratyphi A/classificação , Salmonella paratyphi A/efeitos dos fármacos , Salmonella paratyphi A/isolamento & purificação , Salmonella typhi/classificação , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/isolamento & purificação , Febre Tifoide/tratamento farmacológico
15.
Microsc Res Tech ; 83(1): 72-80, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31617656

RESUMO

Nanoparticles as biomedicine has made a crucial role in health biotechnology. Different transition metals in various forms playing role in nanotechnological advances and biological applications. Silver as one of the nontoxic, safe inorganic antibacterial agents and can serve as replacement of antibiotics. Present research is based on biogenic synthesis of silver nanoparticles (Ag-NPs) as potential antibiotics from fungal metabolites of Penicillium oxalicum. We used different analytical techniques X-ray diffraction (XRD) and scanning electron microscopy (SEM) for characterization of biosynthesized silver nanoparticles. Furthermore, the antibacterial activity of biosynthesized silver nanoparticles was checked against Staphylococcus aureus, S. dysenteriae, and Salmonella typhi by using well diffusion method and UV visible spectrophotometer. Maximum zone of inhibition recorded against S. aureus, Shigella dysenteriae was 17.5 ± 0.5 mm (mm) for both species and 18.3 ± 0.60 mm for Salmonella typhi. The biosynthesized silver nanoparticles of P. oxalicum showed excellent antibacterial activity. It was concluded from our results that biosynthesized silver nanoparticles have significant potential and might be useful for a wide range of biological applications such as bactericidal agent against resistant bacteria, preventing infections, healing wounds, and anti-inflammation.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Nanopartículas Metálicas/toxicidade , Penicillium/metabolismo , Prata/metabolismo , Prata/farmacologia , Antibacterianos/química , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Salmonella typhi/efeitos dos fármacos , Prata/química , Staphylococcus aureus/efeitos dos fármacos
16.
Microb Pathog ; 138: 103813, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31654777

RESUMO

Salmonella enterica Typhi and Paratyphi A are food borne pathogens causing typhoid, which is one of the most important food borne disease in the developing world. S. Typhi and S. Paratyphi A are of much concern as multi drug resistance has been on the rise. The current study is aimed to screen phytochemicals for anti quorum sensing (QS) activity against S. Typhi and S. Paratyphi A. Upon screening with swarming assay, tannic acid (TA) showed highest anti-QS activity with minimal concentration of 400µg/ml. The anti-QS activity of TA was confirmed with C. violaceum ATCC 12,472. TA showed 38-43% and 35-50% of inhibition in cell surface hydrophobicity and EPS production respectively. Through FTIR analysis, it has been observed that EPS of treated cells has a considerable change in protein and peptide. TA has also exhibited drastic reduction in the surfactant production as high as 85-90%. Blood sensitivity and antibiotic sensitivity assay revealed that TA significantly sensitizes the S. Typhi and S. Paratyphi A cells to immune components in human blood and antibiotics. It has reduced the resistance of S. Typhi and S. Paratyphi A cells against amikacin, ampicillin, ciprofloxacin, azithromycin, chloramphenicol and gentamycin, thus revitalized the usage of these antibiotics against drug resistant S. Typhi and S. Paratyphi A infections. The consistency of anti-QS potential of TA was further evaluated and established with another eight clinical isolates of S. Typhi and S. Paratyphi A. Thus TA has been proved as a promising anti QS agent that can be developed as a therapeutic combination against S. Typhi and S. Paratyphi A.


Assuntos
Antibacterianos/farmacologia , Percepção de Quorum/efeitos dos fármacos , Salmonella enterica/efeitos dos fármacos , Salmonella typhi/efeitos dos fármacos , Taninos/farmacologia , Virulência/efeitos dos fármacos , Antibacterianos/química , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Análise Espectral , Taninos/química
17.
Indian Pediatr ; 56(12): 1033-1036, 2019 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-31884434

RESUMO

OBJECTIVE: To describe the demographic, clinical, laboratory and bacteriological profile of children with diagnosis of typhoid fever over a six-year period. METHODS: Case record analysis of hospitalized children (≤5 y) with culture positive typhoid fever. RESULTS: Blood culture was positive in 100 (61%) of 166 suspected cases, with 78 isolates of Salmonella Typhi and 22 Salmonella Paratyphi A. Only 12 children were aged below two years. Hepatomegaly (32), splenomegaly (44), eosinopenia (42), positive widal (15, 21.1%) and positive Typhidot IgM (18, 28.1%) were not consistently observed. High susceptibility to Ampicillin, Chloramphenicol, Cotrimoxazole (87, 89, and 94, isolates, respectively), 100% susceptibility to third generation cephalosporins and Azithromycin, and high resistance to Nalidixic Acid [(S. Typhi 48 (61.5%)], S. Paratyphi A 16 (72.7%)) were observed. CONCLUSIONS: We observed a high isolation rate of salmonella in blood culture, despite prior use of antibiotics. Most salmonella isolates were susceptible in vitro to standard drugs, except nalidixic acid.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Salmonella typhi/efeitos dos fármacos , Febre Tifoide/microbiologia , Adolescente , Criança , Pré-Escolar , Feminino , Hospitais Privados , Humanos , Índia , Masculino , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Febre Tifoide/diagnóstico
18.
Malawi Med J ; 31(3): 184-192, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31839887

RESUMO

Background: Over-dependence on clinical presentation and/or the Widal agglutination test for the diagnosis of typhoid fever in developing countries can lead to antibiotic abuse. In Nigeria, the antibiotic resistance of typhoid organisms is poorly characterized. In this study, we determined the prevalence of culture positivity among patients suspected of having typhoid fever, evaluated the diagnostic value of the Widal test and the burden created by the multi-drug resistance of typhoid organisms in South-East Nigeria. Methodology: This was a prospective and case-controlled study carried out between 2013 and 2016. We acquired samples of blood/stool/urine cultures, and data relating to the Widal agglutination test and malaria parasites from 810 febrile patients (suspected of having typhoid) and 288 apparently healthy controls. Individuals with a history of antibiotic use within the previous 14 days were excluded. We then carried out antibiotic susceptibility tests on all isolates. Multi-drug resistance was defined as a resistance to ≥3 of the antibiotics tested. We determined the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Widal test for typhoid laboratory diagnosis compared to bacterial culture which is the gold standard. A P-value <0.05 was considered to be statistically significant. Results: The mean age of typhoid suspects was 33.1±6.5 years and 50.7% were women. Of the 810 typhoid suspects tested, 114 (14.1%) had positive cultures for the typhoid organisms Salmonella enterica serovar paratyphi (72) and S. enterica serovar Typhi (42). Sample-specific rates of culture positivity were as follows: stool (72; 8.9%), blood (21; 2.6%) and urine (21; 2.6%), P<0.001. None of the controls had typhoid isolates. The sensitivity, specificity, PPV and NPV of the Widal test were 49.1%, 90.7%, 46.2% and 91.6%, respectively. Malaria parasitaemia was detected in 180 (22.2%) febrile patients, out of whom 115 (63.9%) had a positive Widal test for O/H antigens vs. 1% (6/630) in those with negative malaria parasite test results (P<0.001). The rate of false-positive Widal titres was 48%. Antibiotic multi-drug resistance was detected in 52.6% of patients. The antibiotics with the highest susceptibility were ciprofloxacin, levofloxacin and meropenem (all 100% susceptibility) and ceftriaxone (95.6% susceptibility). Conclusion: Our data showed that while typhoid fever is common in Nigeria, malaria is more prevalent. Our analysis showed that the Widal test performed poorly as a diagnostic test and that the burden created by multi-drug resistance was high. Our data indicate that periodic surveillance of antibiotic susceptibility is critical for optimal typhoid therapy.


Assuntos
Testes de Aglutinação/métodos , Antibacterianos/farmacologia , Anticorpos Antibacterianos/sangue , Febre/etiologia , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/isolamento & purificação , Febre Tifoide/diagnóstico , Febre Tifoide/epidemiologia , Adulto , Antibacterianos/uso terapêutico , Estudos de Casos e Controles , Farmacorresistência Bacteriana , Feminino , Humanos , Testes de Sensibilidade Microbiana , Nigéria/epidemiologia , Prevalência , Estudos Prospectivos , Sensibilidade e Especificidade , Febre Tifoide/tratamento farmacológico , Febre Tifoide/microbiologia
19.
Sci Rep ; 9(1): 18404, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804525

RESUMO

Typhoid fever caused by Salmonella enterica serovar Typhi (S.Typhi) continues to be a major problem, especially in developing countries. Due to the rapid emergence of multi-drug-resistant (MDR) strains, which limits the efficacy of conventional antibiotics as well as problems associated with the existing vaccines, efforts are being made to develop effective prophylactic agents. CdtB subunit of typhoid toxin was selected for assessing its vaccine potential due to its high conservation throughout the Typhi strains. In-vitro assessment of DNase activity of cloned and purified CdtB protein showed a significant decrease in the band intensity of DNA. The measure of metabolic activity and morphological alterations assessed using different cell lines in the presence of CdtB protein showed no significant signs of toxicity. These observations were further strengthened by cell cycle analysis, assessed by flow cytometry. Keeping these observations in mind, the immunoprotective potential of CdtB was assessed using S.Typhi induced mouse peritonitis model. A significant titer of IgG antibodies (>128000) against CdtB protein was recorded in the immunized mice by enzyme-linked immunosorbent assay (ELISA), which was also validated by immunoblotting. Active immunization with the protein protected 75% mice against a lethal dose of S.Typhi Ty2. The data indicated a significant (up to 5 log) reduction in the bacterial load in the spleen and liver of immunized-infected mice compared to control (unimmunized-infected) mice which might have resulted in the modulation of histoarchitecture of spleen and liver and the levels of cytokines (IL-6, TNF-α and IL-10) production; thereby indicating the effectiveness of the subunit. The observations deduced from the study give the proof of concept of immunogenic potential of protein. However, further studies involving the immunoreactivity of CdtB with the statistically significant number of sera samples obtained from the human patients would be helpful in establishing the relevance of CdtB protein in humans and for making the strategies to develop it as an effective vaccine candidate.


Assuntos
Anticorpos Antibacterianos/biossíntese , Toxinas Bacterianas/administração & dosagem , Imunoglobulina G/biossíntese , Peritonite/prevenção & controle , Salmonella typhi/efeitos dos fármacos , Febre Tifoide/prevenção & controle , Vacinas Tíficas-Paratíficas/administração & dosagem , Animais , Toxinas Bacterianas/imunologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Expressão Gênica , Humanos , Imunização/métodos , Imunogenicidade da Vacina , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/microbiologia , Camundongos , Peritonite/imunologia , Peritonite/microbiologia , Peritonite/mortalidade , Salmonella typhi/imunologia , Salmonella typhi/patogenicidade , Baço/efeitos dos fármacos , Baço/imunologia , Baço/microbiologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Febre Tifoide/imunologia , Febre Tifoide/microbiologia , Febre Tifoide/mortalidade , Vacinas Tíficas-Paratíficas/imunologia
20.
Int J Med Mushrooms ; 21(7): 713-724, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679305

RESUMO

Antibiotic resistance has become a global concern and threatens the clinical efficacy of many drugs, leading to increased screening of several sources of potential antimicrobial substances. Mushrooms have long been recognized as a valuable source of nutritive and pharmacologically active compounds. Our previous studies showed that the acetone, ethanol, methanol, and cold water crude extracts of various mushrooms-Amanita and Cantharellus species, Ganoderma lucidum, and Lactarius kabansus-exhibited high antibacterial activity against Salmonella typhi. The objective of this study was to isolate, characterize, and identify antibacterial compounds from these crude mushroom extracts. The crude extracts were separated by preparative thin-layer chromatography. Fractions (n = 99) were obtained and screened for antimicrobial activity against S. typhi by using the MTT assay. Of the isolated components, 13 exhibited high inhibitory activity against the growth of S. typhi, with half-maximal inhibitory concentrations ranging from 206 to 619 µg/mL. Some of the highly potent antibacterial compounds were identified by using liquid chromatography-mass spectrometry. Terpenoids (lucidenic acid M and cavipetin D), a phospholipid (C16 sphinganine), and fatty acid amines (stearamide and palmitic amide) were some of the compounds found to be responsible for the antibacterial activity observed. The importance of local mushrooms as sources of antibacterial compounds was revealed. The high inhibitory activity of some mushroom extracts strongly suggests that the mushrooms contain compounds that have great potential for use in developing therapeutic agents against infections caused by S. typhi.


Assuntos
Agaricales/química , Antibacterianos/farmacologia , Misturas Complexas/farmacologia , Antibacterianos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Salmonella typhi/efeitos dos fármacos , Zimbábue
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